Micro and Nano Mechanics Group - User contributions [en]

Chris Weinberger

2013-10-09T00:44:43Z

Cweinber:

Christopher R. Weinberger <cweinberger@coe.drexel.edu>

is now an Assistant Professor at Drexel University in the Mechanical Engineering and Mechanics department [mem.drexel.edu]. His group's webpage is at: [http://multiscalemodeling.mem.drexel.edu Multiscale Materials Modeling and Mechanics]

Chris Weinberger

2013-10-09T00:43:03Z

Cweinber:

Chris Weinberger

2013-09-21T00:33:09Z

Cweinber:

Christopher R. Weinberger <cweinberger@coe.drexel.edu>

is now an Assistant Professor at Drexel University in the Mechanical Engineering and Mechanics department [mem.drexel.edu].

Chris Weinberger

2009-02-02T22:37:57Z

Cweinber:

Christopher R. Weinberger <cweinber@stanford.edu>

Research Meeting Schedule

2009-01-02T18:11:50Z

Cweinber: /* Winter 2009 */

===Winter 2009===

Prof. Wei Cai's weekly schedule.

{| class="wikitable" style="text-align:center;"
!width="150pt" | Time
!width="200pt" | Monday
!width="200pt" | Tuesday
!width="200pt" | Wednesday
!width="200pt" | Thursday
!width="200pt" | Friday
|-
|9:00-10:00|| bi-weekly Eunseok, Hark, Prof. Prinz
| rowspan="3" | ''work''
| ''work''
| rowspan="3" | ''work''
| ''work''
|-
|10:00-10:45|| lecture prep. || lecture prep. || lecture prep.
|-
|11:00-12:15||'''ME346A'''||'''ME346A'''||'''ME346A''' (make-up lecture)
|-
|12:30-1:15 || colspan="5" align="center" bgcolor="lightgrey" | lunch break
|-
|1:30-2:05 ||research meeting ||Keonwook ||research meeting ||research meeting
| rowspan="5" align="center" | ''work''
|-
|2:10-2:45 ||research meeting ||research meeting ||Chris ||research meeting
|-
|2:50-3:25 ||research meeting || research meeting ||Jie ||research meeting
|-
|3:30-4:00 || colspan="3" align="center" bgcolor="lightgrey" | coffee break
| ''work''
|-
|4:00-6:00 || ''work'' || ''work'' || ''work'' || '''MC seminar'''
|}

Meetings to sign-up

{| class="wikitable" style="text-align:center;"
|-
| width="120pt" | Eunseok
| width="120pt" |
| width="120pt" |
| width="120pt" | Billy
| width="120pt" |
| width="120pt" | Seunghwa
|-
| width="120pt" | Sylvie
| width="120pt" | Alfredo
| width="120pt" | Seokwoo
| width="120pt" | Hark
| width="120pt" | Haneesh
| width="120pt" |
|-
| colspan="2" | '''Group lunch'''
| colspan="2" | '''ME346A Office hour'''
| colspan="2" | Seminar speaker
|}

Research Meeting Schedule

2009-01-02T18:11:03Z

Cweinber: /* Winter 2009 */

===Winter 2009===

Prof. Wei Cai's weekly schedule.

{| class="wikitable" style="text-align:center;"
!width="150pt" | Time
!width="200pt" | Monday
!width="200pt" | Tuesday
!width="200pt" | Wednesday
!width="200pt" | Thursday
!width="200pt" | Friday
|-
|9:00-10:00|| bi-weekly Eunseok, Hark, Prof. Prinz
| rowspan="3" | ''work''
| ''work''
| rowspan="3" | ''work''
| ''work''
|-
|10:00-10:45|| lecture prep. || lecture prep. || lecture prep.
|-
|11:00-12:15||'''ME346A'''||'''ME346A'''||'''ME346A''' (make-up lecture)
|-
|12:30-1:15 || colspan="5" align="center" bgcolor="lightgrey" | lunch break
|-
|1:30-2:05 ||research meeting ||Keonwook ||research meeting ||research meeting
| rowspan="5" align="center" | ''work''
|-
|2:10-2:45 ||research meeting ||research meeting ||research meeting ||research meeting
|-
|2:50-3:25 ||research meeting ||Chris ||Jie ||research meeting
|-
|3:30-4:00 || colspan="3" align="center" bgcolor="lightgrey" | coffee break
| ''work''
|-
|4:00-6:00 || ''work'' || ''work'' || ''work'' || '''MC seminar'''
|}

Meetings to sign-up

{| class="wikitable" style="text-align:center;"
|-
| width="120pt" | Eunseok
| width="120pt" |
| width="120pt" |
| width="120pt" | Billy
| width="120pt" | Chris
| width="120pt" | Seunghwa
|-
| width="120pt" | Sylvie
| width="120pt" | Alfredo
| width="120pt" | Seokwoo
| width="120pt" | Hark
| width="120pt" | Haneesh
| width="120pt" |
|-
| colspan="2" | '''Group lunch'''
| colspan="2" | '''ME346A Office hour'''
| colspan="2" | Seminar speaker
|}

Group Presentation Schedule

2008-10-30T17:04:23Z

Cweinber:

Please contact '''Jie Yin''' to sign up for your presentation at the group meeting.

{| border="1"
|+ '''2008-2009 Autumn Quarter (9/23-12/12) Weekly Presentation Schedule'''
|-
| Name || Date || Topic
|-
|Enseok Lee || 9/25 || ESC Meeting Practice, Topic TBD
|-
| || 10/2 ||
|-
| || 10/9 ||
|-
| Chris Weinberger || 10/16 || Dislocation 2008 Conference Talk Practice
|-
| Seunghwa Ryu || 10/30 || Nucleation in 2-D and 3-D Ising Systems I
|-
| Seunghwa Ryu || 11/6 || Nucleation in 2-D and 3-D Ising Systems II
|-
| || 11/13 ||
|-
| || 11/20 ||
|-
| || 11/27||
|-
| || 12/4 ||
|-
| || 12/11 ||
|}

{| border="1"
|+ '''Tentative topics'''
|-
| Name || Date || Topic
|-
| Jie Yin || TBD || Qual practice talk
|-
| Jie Yin || TBD || Anisotropic Elasticity
|-
| Keonwook Kang || TBD || Brittle and Ductile Failures of Silicon Nanowires under Tension Simulation
|-
| Chris Weinberger || TBD || Torsion and Bending Simulations of Metallic Nanowires
|}

Past Group meetings

{| border="1"
|+ '''2007-2008 Summer Quarter (6/24-9/14) Weekly Presentation Schedule'''
|-
| Name || Date || Topic
|-
|Alfredo Correa || 7/3 || An introduction to Quantum Mechanics I
|-
| Alfredo Correa || 7/31 || An introduction to Quantum Mechanics II
|-
| Alfredo Correa || 8/14 || An introduction to Quantum Mechanics III
|-
| Chris Weinberger || 8/28 || Basic Differential Geometry I
|-
| Chris Weinberger || 9/4|| Basic Differential Geometry II
|-
| Seokwoo Lee || 9/11 || Uniaxial Compression Tests of FCC Au Nanopillars I
|-
| Seokwoo Lee || 9/18 || Uniaxial Compression Tests of FCC Au Nanopillars II
|}

{| border="1"
|+ '''2007-2008 Spring Quarter (4/2-6/14)Weekly Presentation Schedule'''
|-
| Name || Date || Topic
|-
|Alfredo Correa || 4/14 || Quantum Corral Wave-function engineering
|-
| Seunghwa Ryu || 4/22 || Binary Phase Diagram from Atomistic Simulation I (Related Physics Review)
|-
| Seunghwa Ryu || 4/29 || Binary Phase Diagram from Atomistic Simulation II (Realization via Simulation)
|-
| Seunghwa Ryu || 5/6 ||Fast Quantum Entanglement Minimization Algorithm (Pure mathematical approach)
|}

{| border="1"
|+ '''2007-2008 Winter Quarter(1/8-3/16) Weekly Presentation Schedule'''
|-
| Name || Date || Topic
|-
| Yongxing Shen || 1/17 || Modeling electrostatic force microscopy and related technique (PhD thesis defense practice)
|-
| Sylvie Aubry || 1/23 || Calculation of Si thermal boundary resistance
|-
| Seokwoo Lee || 1/30 || Dislocation Dynamics in thin films
|-
| Jie Yin || 2/6 || Anisotropic elasticity I
|-
| Hark Lee || 2/13 || TBD
|-
| Billy Cash || 2/20 || Fatigue in metals
|-
| Steven Fitzgerald || 2/27 || An extended Frenkel-Kontorova model for crowdions
|-
| Yongxing Shen || 3/5 || Euler-Bernoulli beam theory applied to AFM
|}

PARADISCYL:How-To-Get-Nodal-Force

2008-10-27T17:04:13Z

Cweinber:

<H1 ALIGN="CENTER">Manual 04 for ParaDiS Cylinder Codes
 
How to get nodal force</H1>
<DIV>

This document describes the extension of the ParaDiS program that implements the cylindrical free surface boundary condition. This extension is based on Weinberger and Cai, J. Mech. Phys. Solids, 55, 2027 (2007)([http://micro.stanford.edu/~caiwei/papers/Weinberger07jmps-image.pdf PDF]). The code is written by Chris Weinberger and Wei Cai and is not included in the standard distribution of ParaDiS. Keonwook Kang wrote the first draft of this document, which was later revised by Chris Weinberger and Wei Cai. Questions on this document should be addressed to [[Chris Weinberger]]. Please read the manual of ParaDiS before reading this document.

== Motivation ==

In ParaDiS, a dislocation line is represented by piecewise straight segments connecting a set of discrete nodal points. For diagnostic purposes, we may want to find out the driving force on every node. Here we explain how to extract this information from the ParaDiS Cylinder code.

== Computing nodal force ==

Modify '''makefile''' in ParaDiS/cylinder directory so that the following line is active.
DEFS += -D_WRITENODEFORCE
Then compile ParaDiS cylinder codes again.

Next, run the executable with the input file, such as that in [[PARADISCYL:Test-Run |M02 Test Run]],

$ bin/paradiscyl runs/concentric_loop_test.ctrl.

Note that, even if the total simulation step is set as 100 in the control file, the ParaDiS simulation does one time force evaluation and will quit immediately afterwards.

The force data is dumped out as '''force.out''' in the '''outputs/concentric_loop_test/''' directory. Each line of this file has 6 values for nodal point coordinate (''x'', ''y'', ''z'') and nodal force components (''f''x, ''f''y, ''f''z), respectively.

Because the default stress unit is Pa and length unit is '''burgMag''', the unit of nodal forces is Pa.burgMag^2. Of course, this is the case for cylinder radius R = 1. If we want to interprete the results for the case of R not equal to one, then the force will have to be scaled according to [[PARADISCYL:Scale-Rule |M03 How units are scaled]].
----

== Plotting nodal force ==

<gallery widths="200px" heights="200px" perrow="3">
Image:Nodalforce1_v2.jpg |Nodal force with all image stress considered
Image:Nodalforce2.jpg |Nodal force with no BEM image stress
Image:Nodalforce3.jpg |Nodal force with no Yoffe stress
</gallery>

matlab script
<pre>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% plot node force
%
% outdir : directory where nodal force data file is dumped out.
% nodalforcefilename : file name of nodal force data

outdir = '~/Codes/ParaDiS/outputs/concentric_loop_test/';
nodalforcefilename = 'force.out';

fullname_nodalforcefile = sprintf('%s%s',outdir,nodalforcefilename);

data = load(fullname_nodalforcefile);

node_position = data(:,1:3);
nodal_force = data(:,4:6);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% cylinder geometry
r = 1;
theta = linspace(0,2*pi,100);
z = 0;
[x,y,z] = pol2cart(theta,r,z);

figure(1), set(gca,'fontsize',20), hold on
plot(x,y,'-k') % plot cylinder
plot3([node_position(:,1);node_position(1,1)],... % plot dislocation loop
[node_position(:,2);node_position(1,2)],...
[node_position(:,3);node_position(1,3)],'.-')
quiver3(node_position(:,1),node_position(:,2),node_position(:,3),...
nodal_force(:,1),nodal_force(:,2),nodal_force(:,3),1,'r')
text('position',[0 .07 0],'string','b','fontsize',20,'fontweight','bold')
annotation('arrow', [0.48 0.60],[0.53 0.53],...
'LineWidth',3,'HeadStyle','plain','HeadWidth',12,'HeadLength',12);
xlabel('x'), ylabel('y')
view(2), axis equal, axis([-1 1 -1 1])
hold off
</pre>
----

== Notes ==

<references/>

PARADISCYL:Scale-Rule

2008-10-27T17:03:23Z

Cweinber:

<H1 ALIGN="CENTER">Manual 03 for ParaDiS Cylinder Codes
 
How Units Are Scaled</H1>
<DIV>

This document describes the extension of the ParaDiS program that implements the cylindrical free surface boundary condition. This extension is based on Weinberger and Cai, J. Mech. Phys. Solids, 55, 2027 (2007)([http://micro.stanford.edu/~caiwei/papers/Weinberger07jmps-image.pdf PDF]). The code is written by Chris Weinberger and Wei Cai and is not included in the standard distribution of ParaDiS. Keonwook Kang wrote the first draft of this document, which was later revised by Chris Weinberger and Wei Cai. Questions on this document should be addressed to [[Chris Weinberger]]. Please read the manual of ParaDiS before reading this document.

== Motivation ==

For simplicity, the ParaDiS Cylinder program requires the radius of the cylinder to be 1. Because elasticity model does not have an intrinsic length scale, we can model a cylinder with arbitrary radius by appropriately scaling all lengths in the problem. Accordingly, other parameters, such as stress may also change. In this manual, we will describe how all quantities scale with the cylinder radius ''R''.

== Rule of Scale ==
In our test case '''concentric_loop_test.ctrl''' in [[Test-Run#Examples|M02 Test Run]], we can find the following lines.

<pre>
burgMag = 1.0e0

#Elastic constants
shearModulus = 1.0e+0
pois = 3.050000e-01

#Core cut-off radius
rc = 1.0e-3

#Applied stress in Pa (xx,yy,zz,yz,zx,xy)
appliedStress = [ 0 0 0 0 0 0 ]
</pre>

Let's find out what each line means in real physical units, if we want to model to represent a cylinder with a radius ''R'' that is not 1.

Non-dimensional quantity will be notified with the asterisk (*). For example, the dimensionless radius is expressed as <math> R^* = R/R_c </math> and is fixed to be 1 in ParaDiS Cylinder codes, which means all the length units are scaled by the cylinder radius (''R'') since <math> R_c = R </math>. The cut-off radius '''rc''' in the script is the scaled cut-off radius (''r''c*) and is .375 nm in real unit if the cylinder radius is given as 375 nm, because

{|border="0" align="center"
|<math> r_c = r_c^* \times R_c = r_c^* \times R. </math>
|}

In addition, according to the script ('''burgMag = 1.0e0''' and '''shearModulus = 1.0e+0'''), both shear modulus and Bergers vector magnitude are scaled to be 1 or ''μ''* = 1 and ''b''* = 1. In other words,

{|border="0" align="center"
| ''μ''c = ''μ'' and ''b''c = ''b''.
|}

In the table below, listed are four key physical quantities which will be used to scale other physical quantity.

{|border="0" align="center"
|
{| class="wikitable"
|-
! Scaling Parameters
! ''e.g.''
|-
| Shear Modulus, ''μ''
| 23e9 (Pa)
|-
| Burgers vector magnitude, ''b''
| 3e-10 (meter)
|-
| Cylinder radius, ''R''
| .375e-6 (meter)
|-
| Mobility, ''m''
| 1 /(Pa*sec)
|}
|}

You might think that shear modulus could be a good scaler for stress because they share same unit. However, the reference stress is, in fact, μb/R or

{|border="0" align="center"
|<math> \sigma_c = \frac{\mu_c b_c}{ R_c} = \frac{\mu b}{ R} </math>
|}

and hence nondimensional stress (''σ''*) is

{|border="0" align="center"
|<math>\sigma^* = \sigma/\sigma_c = \sigma \times (\mu b/R)^{-1}</math>
|}

You would understand the choice of reference stress considering that the stress due to a dislocation is proportional to

{|border="0" align="center"
|<math> \sigma \sim \frac{\mu b}{ L },</math>
|}

where ''L'' is in the unit of distance, according to the elasticity solution. Thus, one of the stress components -3 in the script, though commented out, becomes 55.2 (MPa) in compression in real unit if you multiply ''μb/R'' (=18.4 MPa when μ = 23e9Pa, b = 3Å and R = 375 nm )

Energy stored per unit length ''E''' in the elastic media due to a dislocation is proportional to μb2, which is natural reference choice for energy per unit length. (or effectively force.)

The next table lists multiplcation factors to convert the scaled quantity to the real one.

{| class="wikitable"
|-
! Physical quantity
! Multiplication factor
! ''e.g.''
|-
| Length, ''L''
| R
| .375e-6 (meter)
|-
| Stress, σ
| μb/R
| 18.4e6 (Pa)
|-
| Energy per length, ''E''' (effectively, force)
| μb2
| 2.07e-9 (Newton or Pa<math>\cdot</math>meter2)
|-
| Force per length, ''F'''
| μb2/R
| 5.52e-3 (Newton/meter or Pa<math>\cdot</math>meter)
|-
| Velocity, ''v''
| μb2m/R
| 5.52e-3 (meter/sec)
|-
| Strain rate, <math>\dot\epsilon</math>
| μb2m/R2
| 1.472e+4 (1/sec)
|-
| Time, ''t''
| (μb2m/R2)-1
| 6.7935e-5 (sec)
|}

The Poisson number '''pois''' is already dimensionless and it doesn't need to be scaled additionaly.

PARADISCYL:Test-Run

2008-10-27T17:02:42Z

Cweinber:

<H1 ALIGN="CENTER">Manual 02 for ParaDiS Cylinder Codes
 
How to run test simulations</H1>
<DIV>

This document describes the extension of the ParaDiS program that implements the cylindrical free surface boundary condition. This extension is based on Weinberger and Cai, J. Mech. Phys. Solids, 55, 2027 (2007)([http://micro.stanford.edu/~caiwei/papers/Weinberger07jmps-image.pdf PDF]). The code is written by Chris Weinberger and Wei Cai and is not included in the standard distribution of ParaDiS. Keonwook Kang wrote the first draft of this document, which was later revised by Chris Weinberger and Wei Cai. Questions on this document should be addressed to [[Chris Weinberger]]. Please read the manual of ParaDiS before reading this document.

== Run a Test Case ==

The command line to run the ParaDiS Cylinder code is the same as that of the original ParaDiS code. See [[Overview of ParaDiS 2.2#Executing ParaDiS|ParaDiS manual]] for details. The command line format is:

paradiscyl [-r <numCycles>] [-d dataFile] <controlFile>

where:

<TABLE CELLPADDING=3 >
<TR valign="top">
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT"><ctrlFile></TD>
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT">Specifies the name of the ParaDiS control parameter file
</TD>
</TR>
<TR valign="top">
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT">-d <dataFile></TD>
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT">Specifies the base name of the file(s) containing the nodal data for the run. If this file name is not supplied, the code looks for a data file named the same as the control file with the file name suffix (if any) replaced with ".data"
</TD>
</TR>
<TR valign="top">
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT">-r  <numCycles></TD>
<TD ALIGN="LEFT">     </TD>
<TD ALIGN="LEFT">Causes the code to execute a series of <numCycles> cycles during which no force calculations or dislocation movement will occur. These cycles will be used strictly for load-balancing purposes and will be done before the normal cycles. This can be useful when a simulation is started with a uniform domain decomposition and needs time to converge on an optimal decomposition as would occur when restarting a simulation on a different number of cpus
</TD>
</TR>
</TABLE>

Run the following control file, which simulates a dislocation loop inside a cylinder. You will need two input files: one is control file ('''concentric_loop_test.ctrl''') and the other is data file ('''concentric_loop_test.data'''). Both files are shown below. See [[Overview of ParaDiS 2.2#Inputs|here]] for details about input files.

$ bin/paradiscyl runs/concentric_loop_test.ctrl

This run requires the following two input files.

[[media:concentric_loop_test.ctrl.txt‎ | concentric_loop_test.ctrl]]
[[media:concentric_loop_test.data‎.txt | concentric_loop_test.data]]

If your run is successful, you should see a pop-up window as shown below.

<gallery widths="300px" heights="300px" perrow="1">
Image:Paradis-cyl-testrun.jpg |Fig.1 ParaDiS Cylinder Codes Test Run. A dislocation loop in a cylinder
</gallery>

--------

== X Window Control ==

Default X Window '''control parameters''' are given in the file '''inputs/paradis.xdefaults'''.
You can change window size, line width, rotation of angles, ''etc'' by modifying this file.

The '''3D View''' in the X Window can be manipulated by both mouse and keyboard. For example, press r (default) and then move mouse to rotate the object, press s and then move mouse to scale the object. A complete list of hot keys are given below.

<pre>
YWindow: yview:
Mouse drag to rotate
Hot Keys:
F1 : display this message
Up : rotate up
Down : rotate down
Left : rotate left
Right : rotate right
PgUp : rotate counterclockwise
PgDn : rotate clockwise
Home : back to initial viewpoint
Space : stop rotate
p : toggle pause
t : translation
s : scaling
d : move projection infinity point
r : rotation
f : toggle pbc enableness
m : toggle drawframe
g : pbc glide
x : pbc shift in x
y : pbc shift in y
z : pbc shift in z
w : print window specification
F9 : output gif
F10 : output postscript
</pre>
----

== Tcl script to generate input data ==

The input data file '''concentric_loop_test.data''' is generated by the tcl script[[media:create_loop_data.tcl.txt | create_loop_data.tcl]] in the ParaDiS/tools directory, which can run by typing

$ tools/create_loop_data.tcl

You can easily modify this tcl script to change the resulting input dislocation structure, such as the radius of the dislocation loop.

----

== Problems and solutions ==

=== Cannot open shared library libgsl ===

Sometimes the code may compile successfully but throws the following error message when you try to run it.
./bin/paradiscyl: error while loading shared libraries: libgsl.so.0: cannot open
shared object file: No such file or directory
This means you need to specify the path to the GSL libraries, which are dynamically linked to the executable. For example, if your GSL library files are located in /usr/local/lib, then you can add the following line in your '''~/.bash_profile''' file

LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/

and then type

source ~/.bash_profile

=== Error in opening input file ===

When ParaDiS can not locate input files, it shows the following error message.
Fatal: ReadControlFile: Error 2 opening file XXXX
Check whether you gave the correct path for your input file.



=== Underflow error ===

In the old version of Cylinder code, you may get an underflow error message. This can be avoided by downloading the latest version or by inserting the following line into '''cylinder/gridstress.c'''

gsl_set_error_handler_off();

You also need to include the following header file at the beginning of '''gridstress.c'''.

#include <gsl/gsl_errno.h>

== Notes ==

<references/>

PARADISCYL:How-To-Install

2008-10-25T18:02:52Z

Cweinber: Chris Edited a few things including removing all references to "BEM"

<H1 ALIGN="CENTER">Manual 01 for ParaDiS Cylinder Codes
 
How to install</H1>
<DIV>

This document describes the extension of the [http://paradis.stanford.edu ParaDiS] program that implements the cylindrical free surface boundary condition. This extension is based on Weinberger and Cai, J. Mech. Phys. Solids, 55, 2027 (2007)([http://micro.stanford.edu/~caiwei/papers/Weinberger07jmps-image.pdf PDF]). The code is written by Chris Weinberger and Wei Cai and is not included in the standard distribution of ParaDiS. Keonwook Kang wrote the first draft of this document, which was later revised by Chris Weinberger and Wei Cai. Questions on this document should be addressed to [[Chris Weinberger]]. Please read the [[Overview of ParaDiS 2.2 | manual of ParaDiS]] before reading this document.

----

== Library Requirements ==

Even though the standard ParaDiS distribution can be compiled and run on parallel computers, the cylinder extension currently can run only in serial. To compile the code, you need GNU scientific libraries ('''libgsl''' and '''libgslcblas''') and DFT library ('''libfftw3'''). The code should compile on Linux workstations. Preferably we should use the intel compiler '''icc''' but you may also try to compile it with '''gcc'''. Free evaluation verion of intel compilers can be downloaded from the [http://www.intel.com/cd/software/products/asmo-na/eng/compilers/284132.htm Intel Software Network Site].

'''libgsl and libgslcblas'''

The GNU Scientific library can be downloaded at http://www.gnu.org/software/gsl/. It can be installed by the following commands.

# mv ./gsl-1.9.tar.gz /usr/local/src/
# cd /usr/local/src
# tar -zxvf gsl-1.9.tar.gz
# cd gsl-1.9
# ./configure
# make
# make install

This will intall the gsl libraries will be installed at /usr/local/lib/.

'''libfftw3'''

The image stress calculation requires the use of discrete Fourier transform (DFT). In particular, we will use the Fastest Fourier Transform in the West (FFTW), the standard in DFT programs, provided by the [http://www.fftw.org/ FFTW] library, which can be installed by the following commands.

# mv ./fftw-3.1.2.tar.gz /usr/local/src/
# cd /usr/local/src
# tar -zxvf fftw-3.1.2.tar.gz
# cd fftw-3.1.2
# ./configure
# make
# make install

This will install library files libfftw3.a and libfftw3.la in /usr/local/lib/.
----

== Compile ==

First, you need to download the standard ParaDiS distribution from http://paradis.stanford.edu . The cylinder code, however, is in the cylinder/ subdirectory that is not included in the standard ParaDiS distribution. If you have the cylinder code, go to the cylinder/ subdirectory.

$ cd ParaDiS/cylinder

This directory contains a '''makefile''', which also make references to the standard makefiles '''../makefile.sys''' and '''../makefile.setup''' in the parent directory.

'''makefile.sys''' defines system-dependent compilers and compiling options for different systems such as ''linux'', ''aix'', etc. The pre-defined system types and their descriptions are listed at the beginning of the '''makefile.sys''' file.

In '''makefile.setup''', you can select various 'make' settings, some of which are explained below.

::;SYS : select system type. you can use '''SYS = linux'''
::;MODE : set serial or parallel mode. you need to use '''MODE = SERIAL'''
::;XLIB_MODE : enable or disable xwindow plotting capability. you can use '''XLIB_MODE = ON'''
::;OPT : define optimization level. you can use '''OPT = -O3'''

In '''makefile''', there is an important macro '''DEFS'''. The cylinder codes behave differently depending on how '''DEFS''' is defined.

::;DEFS += -D_CYL : Needs to be included to activate cylinder specific functions.
::;DEFS += -D_NOBEMSTRESS : Disables the calculation of the general image stress by our spectral methods. This is a misnomer, there is no boundary element method (BEM) involved
::;DEFS += -D_NOYOFFESTRESS : Disables the Yoffe Image Stress. See Modelling Simul. Mater. Sci. Eng. 14, 1139 (2006) ([http://micro.stanford.edu/~caiwei/papers/Tang06msmse-hybrid.pdf PDF])
::;DEFS += -D_NULLCYLSTRESS : Ignore all image stress calculations (including BEM, Yoffe, Virtual segment contributions).
::;DEFS += -D_NOVIRTUALSEG : No force contribution from virtual segments. Do not use this flag unless you are absolutely sure you know what you are doing!
::;DEFS += -D_CYLMETHOD1 : If defined, analytic expressions using Bessel functions are used for image stress calculation. If not, the Greens function method is used to compute image stress. . <ref>For details of each method, refer C. R. Weinberger and Wei Cai, '''Computing Image Stress in an Elastic Cylinder''', ''Journal of the Mechanics and Physics of Solids'','''55''' (2007) 2027--2054 ([http://micro.stanford.edu/~caiwei/papers/Weinberger07jmps-image.pdf PDF]) </ref>
::;DEFS += -D_WRITENODEFORCE : If defined, code will write nodal force data in '''force.out''' file after the first nodal force evaluation and immediately exit. Each line of the file contains nodal position ''x'', ''y'', ''z'' and nodal force ''f''x, ''f''y and ''f''z.
::;DEFS += -D_PRINTCYLSTRESS : If defined, code will write nodal force data in '''force.out''' and stress field in '''stress.out''' files. Each line of '''stress.out''' contains grid position ''r'', ''θ'', ''z'' and stress components ''σ''11, ''σ''22, ''σ''33, ''σ''23, ''σ''31, ''σ''12.



To compile, type

$ make

and executable file '''paradiscyl''' should appear in the directory ../bin/.

----

== Notes ==

<references/>

Computing Clusters

2008-02-06T23:36:12Z

Cweinber: /* Semaphores */

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with 8 processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to frequently clean up your Semaphores.

'''How do I clean up Semahpores, you ask?''' Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing
$ ./cleanipcs
This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use
$ cluster-fork ./cleanipcs.

'''How do I know if I have a Semaphore problem?''' Ok, thats easy too. Just run the command
$/usr/bin/ipcs -s
This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

'''Finally, how do I know if this is crashing my parallel job?''' Well, likely your job will crash with the following error:
$ p4_error: semget failed for setnum:0
If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores.

Computing Clusters

2008-02-06T23:35:39Z

Cweinber: /* Semaphores */

Computing Clusters

2008-02-06T23:35:00Z

Cweinber: /* Semaphores */

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with 8 processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to frequently clean up your Semaphores.

How do I clean up Semahpores, you ask? Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing
$ ./cleanipcs
This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use
$ cluster-fork ./cleanipcs.

How do I know if I have a Semaphore problem? Ok, thats easy too. Just run the command
$/usr/bin/ipcs -s
This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

Finally, how do I know if this is crashing my parallel job? Well, likely your job will crash with the following error:
$ p4_error: semget failed for setnum:0
If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores. For this reason, cleaning up your Semaphores is good manners because it can affect all users.

Computing Clusters

2008-02-06T23:34:02Z

Cweinber: /* Semaphores */

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with 8 processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to frequently clean up your Semaphores.

How do I clean up Semahpores, you ask? Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing ./cleanipcs. This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use

$ cluster-fork ./cleanipcs.

How do I know if I have a Semaphore problem? Ok, thats easy too. Just run the command /usr/bin/ipcs -s. This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

Finally, how do I know if this is crashing my parallel job? Well, likely your job will crash with the following error: p4_error: semget failed for setnum:0. If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores. For this reason, cleaning up your Semaphores is good manners because it can affect all users.

Computing Clusters

2008-02-06T23:32:00Z

Cweinber: /* Computing Clusters */

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with 8 processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to frequently clean up your Semaphores.

How do I clean up Semahpores, you ask? Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing ./cleanipcs. This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use cluster-fork ./cleanipcs.

How do I know if I have a Semaphore problem? Ok, thats easy too. Just run the command /usr/bin/ipcs -s. This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

Finally, how do I know if this is crashing my parallel job? Well, likely your job will crash with the following error: p4_error: semget failed for setnum:0. If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores. For this reason, cleaning up your Semaphores is good manners because it can affect all users.

Computing Clusters

2008-02-06T23:30:57Z

Cweinber: /* Semaphores */

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with eight processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to frequently clean up your Semaphores.

How do I clean up Semahpores, you ask? Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing ./cleanipcs. This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use cluster-fork ./cleanipcs.

How do I know if I have a Semaphore problem? Ok, thats easy too. Just run the command /usr/bin/ipcs -s. This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

Finally, how do I know if this is crashing my parallel job? Well, likely your job will crash with the following error: p4_error: semget failed for setnum:0. If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores. For this reason, cleaning up your Semaphores is good manners because it can affect all users.

Computing Clusters

2008-02-06T23:30:19Z

Cweinber: Initial page

==Computing Clusters==
The Micro and Nano Mechanics Group primarily uses two clusters here at Stanford. They are MC-CC and WCR (or Glacial). MC-CC is a cluster supported by the Mechanics and Computation Group in the Mechanical Engineering Department and whose name means "Mechancs and Computation Computing Cluster". WCR, or alternatively Glacial, is a computer cluster hosted the the Mechanical Engineering Department and is the initials of the late William Renolds (Not the Reynolds number Reynolds, but a Professor at Stanford who did research in thermodynamics). To use either cluster, you must be working with a faculty affiliated with the cluster. MC-CC has 45 nodes, each with 2 processors and WCR has 221 nodes with eight processors per node.

==Hints For working with the clusters==
Below you will find information regarding nuances of working with these computing clusters. This is not meant to be a exhaustive list nor a tutorial, but a collection of advice and tools. They may not follow and order and we will update them as we remember.

===Semaphores===
A semaphore is a type of shared resource on the clusters that can lead to communication problems in paralle runs. If any job you run terminates abnormally, you may leave Semaphore Arrays on the computer. If you run the job on the head node, then the Semaphore Array is left with the head node, otherwise it will be associated with the compute node you were working on. This can lead to problems with future parallel jobs run by you or other users. Therefore, it is good manners to make frequently clean up your Semaphores.

How do I clean up Semahpores, you ask? Easy! You need to run the cleanipcs script to clean semphores from your the computer. To do this, first you must find cleanipcs in the cluster using the locate command. Then, copy it over to you home directory and chmod it so that you have execute privaleges. Now, you can run the program by typing ./cleanipcs. This will clean all of your Semaphores from the computer. However, if you are on a cluster, then this will only clean the Semaphores from the head node. Generally, the problem usually lies with Sempahores on the compute nodes, which can be cleaned using the cluster-fork command. To clean the compute nodes, use cluster-fork ./cleanipcs.

How do I know if I have a Semaphore problem? Ok, thats easy too. Just run the command /usr/bin/ipcs -s. This will list all of the Semaphore Arrays used on the head node. For the compute nodes, just use the cluster-fork prefix.

Finally, how do I know if this is crashing my parallel job? Well, likely your job will crash with the following error: p4_error: semget failed for setnum:0. If you see this error in your parallel job, you may have a problem with Semaphore Arrays. Run the ipcs command to see which nodes have Semaphore Arrays and clean up yours. You cannot clean up Sempahores owned by other users, so you may have to contact them to free all Semaphores. For this reason, cleaning up your Semaphores is good manners because it can affect all users.

Tutorials

2008-02-06T23:05:45Z

Cweinber: added computing clusters

==Tutorials==

[[Dislocations]]

[[Atomistic Calculations]]

[[Unix Basics]]

[[Computer Setup]]

[[MD++ Manuals]]

[[DDLab Manuals]]

[[ParaDiS Manuals]]

[[ParaDiS Workshop Notes]]

[[Computing Clusters]]

File:Cufoiles set.txt

2008-01-30T23:08:06Z

Cweinber:

MD Potential Files

2008-01-30T23:07:45Z

Cweinber: foiles copper

==Potential Problems With Potentials==

These are some potential files we used in our simulations of molecular structures. Please note that since we use a variety of codes, the potential files will be in a variety of foremats. The most common codes used by our group are LAMMPS ( and ParaDyne) and MD++. These codes use different file formats for EAM potentials, so all files should specify which file format. We will also try to provide a reference describing the potential.

==Potentials==

===MD++ Files===

[[media:eamdata_aufoiles.txt‎ | EAM Foiles potential for Gold.]]
Ref: Park, H. S., Zimmerman J. A., Modeling inelasticity and failure in gold nanowires. Phys. Rev. B 72, 054106 (2005).

[[media:eamdata_cufoiles.txt‎ | EAM Foiles potential for Copper.]]
Ref: Aubry, S. and Hughes, D. A., Reductions in stacking fault widths in fcc crystals: Semiempirical calculations. Phys. Rev. B 73, 224116 (2006).

===LAMMPS SET Files ===

[[media:cufoiles_set.txt‎ | EAM Foiles potential for Copper.]]
Ref: Aubry, S. and Hughes, D. A., Reductions in stacking fault widths in fcc crystals: Semiempirical calculations. Phys. Rev. B 73, 224116 (2006).

===LAMMPS FUNC Files===

File:Eamdata cufoiles.txt

2008-01-30T23:05:59Z

Cweinber:

MD Potential Files

2008-01-30T23:05:27Z

Cweinber: added copper foiles

MD Potential Files

2008-01-30T20:29:35Z

Cweinber: new sub categories

MD Potential Files

2008-01-29T22:35:06Z

Cweinber: /* Potentials */

MD Potential Files

2008-01-29T22:34:51Z

Cweinber: /* Potentials */

MD Potential Files

2008-01-29T22:34:38Z

Cweinber: /* Potentials */

MD Potential Files

2008-01-29T22:34:18Z

Cweinber: /* Potentials */

File:Eamdata aufoiles.txt

2008-01-29T22:33:37Z

Cweinber:

MD Potential Files

2008-01-29T22:30:06Z

Cweinber: added au_foiles for MD++

MD Potential Files

2008-01-29T22:22:18Z

Cweinber: New page: ==Potential Problems With Potentials== These are some potential files we used in our simulations of molecular structures. Please note that since we use a variety of codes, the potential ...

Research Projects

2008-01-29T22:17:59Z

Cweinber: added Tools and potential files

==Research Projects==

[[Nanowire Mechanics]]

[[Dislocation Core]]

==Tools==

[[MD Potential Files]]

Recommended Books

2008-01-22T22:50:06Z

Cweinber: added weertman and weertman

==Dislocations==

* J. P. Hirth and J. Lothe, ''Theory of Dislocations'', (Wiley, New York, 1982). This is the "Bible" for research in dislocations. It may be somewhat difficult to read if you do not have background in dislocations.

* D. H. Hull and D. J. Bacon, ''Introduction to Dislocations'', 4th ed. paperback. This book provides a good entry-level introduction to dislocations. It is recommended as a first read if you do not have previous background in dislocations.

* J. Weertman and J. R. Weertman, ''Elementary Dislocation Theory'',(Oxford University Press, 1992, paperback). Another reasonable introductory text to dislocations. Chris and Keonwook both started learning dislocation theory from this book. This book costs less than $40!

* V. V. Bulatov and W. Cai, [http://micro.stanford.edu ''Computer Simulations of Dislocations''] (Oxford University Press, 2006). This book provides numerical models and algorithms useful for modeling dislocations at atomistic and continuum level.

==Materials Science==

* Y.-M. Chiang, W. D. Kingery, D. P. Birnie, ''Physical Ceramics''. This book provides the basic materials science background in ceramics. It is important if your research is in solid oxide fuel cells.

* S. Suresh, ''Fatigue of Metals'', 2nd ed. (Cambridge University Press, 1998). A must read if your research is related to metal fatigue.

==Computer Simulations==

* M. P. Allen and D. J. Tildesley, ''Computer Simulation of Liquids'', (Oxford University Press, 1989). This is the classic text on molecular simulations. But since it is about 20 years old, several important methods are not discussed in this book.

* D. Frenkel and B. Smit, ''Understanding Molecular Simulation: From Algorithms to Applications'', 2nd ed. Academic Press, San Diego, CA, 2002. This book provides an update to Allen and Tildesley's book with discussions on more advanced algorithms. It is a good reference but may be too advanced if you did not have any background in molecular simulations.

==Statistical Mechanics==

* J. P. Sethna, ''Statistical Mechanics: Entropy, Order Parameters and Complexity'', (Oxford University Press, 2006). [http://pages.physics.cornell.edu/sethna/StatMech/ PDF available]

* D. Chandler, ''Introduction to Modern Statistical Mechanics'', (Oxford University Press). Somewhat advanced, but very interesting to read. This is the book that Spider man uses when studying nanotechnology.

Recommended Courses

2008-01-22T22:37:32Z

Cweinber:

'''ENG 202W''' Professional Writing (everybody must take it!)

'''MATSCI 206''' Imperfections in Crystalline Solids, Prof. Nix

Courses taught by Prof. Wei Cai

* '''ME 334''' Introduction to Statistical Mechanics
* '''ME 346''' Introduction to Molecular Simulation
* '''ME 340''' Elasticity
* '''ME 340B''' Micromechanics
* '''ME 80''' Strength of Materials (undergraduate)

Chris would recommend

* '''MATSCI 208''' Mechanical Properties of Materials (for those witout a strong mechanical background)
* '''MATSCI 358''' Fracture and Fatigue of Materials and Thin Film Structures
* thinking...

Recommended Courses

2008-01-22T22:37:11Z

Cweinber:

'''ENG 202W''' Professional Writing (everybody must take it!)

'''MATSCI 206''' Imperfections in Crystalline Solids, Prof. Nix

Courses taught by Prof. Wei Cai

* '''ME 334''' Introduction to Statistical Mechanics
* '''ME 346''' Introduction to Molecular Simulation
* '''ME 340''' Elasticity
* '''ME 340B''' Micromechanics
* '''ME 80''' Strength of Materials (undergraduate)

Chris would recommend

* '''MATSCI 208''' Mechanical Properties of Materials (for those witout a strong mechanical background)
* '''MATSCI 348''' Fracture and Fatigue of Materials and Thin Film Structures
* thinking...

Watch out for snakes

2008-01-22T22:31:39Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Watch out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is never injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px| Rattlesnake]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

[[Image:gophersnake.jpg|right|thumb|250px|Gophersnake]]

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:30:44Z

Cweinber: /* Snakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Watch out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px| Rattlesnake]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

[[Image:gophersnake.jpg|right|thumb|250px|Gophersnake]]

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:30:11Z

Cweinber: /* Snakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatch out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px| Rattlesnake]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

[[Image:gophersnake.jpg|right|thumb|250px|Gophersnake]]

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

File:Gophersnake.jpg

2008-01-22T22:29:09Z

Cweinber:

Watch out for snakes

2008-01-22T22:28:55Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px| Rattlesnake]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

[[Image:gophersnake.jpg|right|thumb|250px|Gophersnake]]

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:25:24Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px| Rattlesnake]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:25:07Z

Cweinber: /* Other Snakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px|Mountain Kingsnake]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

File:Kingsnake.jpg

2008-01-22T22:24:39Z

Cweinber:

Watch out for snakes

2008-01-22T22:19:51Z

Cweinber: /* Other Snakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

[[Image:kingsnake.jpg|right|thumb|250px]]

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:17:04Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg|right|thumb|250px]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

File:Rattler1.jpg

2008-01-22T22:16:22Z

Cweinber:

Watch out for snakes

2008-01-22T22:16:03Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.
[[Image:rattler1.jpg]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:13:30Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.

[[Image:rattler1.jpg]]

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:07:05Z

Cweinber: /* Other Snakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

===Other Snakes===

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!

Watch out for snakes

2008-01-22T22:06:55Z

Cweinber: /* Rattlesnakes */

==Snakes==

This site was put up to accompany the driving suggestions as part of a series of warnings for those of you new to California. So, we may begin by saying that "Whatching out for snakes" may be a bit dramatic. Snakes are really not a danger here in California, since the state has only two types of venemous snakes.

===Seasnakes===

The first is a venemous sea snake in Southern California. This snake is so rarely encountered that sometimes Southern California is not listed as part of its habitat. The combination of low toxicity of its venom and rarity in the state makes this not worth worrying about.

===Rattlesnakes===

The only other type of venemous snake is the rattlesnake. These are very common throughout California and are frequently seen. However, snake bites are rare and usually involve handling the snakes and, of course, alcohol.

Rattlesnakes only bite when attacking prey or if they are in imminent danger. Rattlesnakes do not have to inject their venom either, so many human snake bites do not end up being life threatening because not venom is ever injected through the bite wounds. Rattlesnakes do not want to bite people and do not want to inject their venom. However, young rattle snakes cannot control their venom and are much more of a danger to people than the adult. Rattlesnakes, in general, would much rather use their fangs and venom to hunt rodents and therefore are generally not considered a large risk to people.

Rattlesnakes will generally warn people by both rattling their tales, making a distinct rattling noise, and by hissing. They will coil into a defensive position, but are able to strike and will if provoked. It is suggested that should you encounter a rattlesnake, leave it alone and it wil leave you alone. Also, it is important to identify rattle snakes by their rattle. It is very common for other snakes, such as gopher snakes, to drage their tales back and forth along dry leaves to mimic rattling noises. This is a tactic to scare you away, but if you know the visual differences and sound differences, it should be easy to distinguish between rattlers and gopher snakes. Again, though, rattlesnakes can loose their rattles so be carfeful!

Rattlesnakes are typically camoflaged. They have colorations that are gray, black and brown to blend in with the surrounding rock and dirt. Rattlesnakes are not colorful. Colorful snakes in California are not venemous!

Finally, Rattlesnakes have lived in California for much longer than we have. They help control rodent populations and provide food for birds and other snakes. Thus, they are an important part of our ecosystem. Please respect these beautiful animals and leave them where they are. Remember, they are more scared of you than you are of them!

==Other Snakes==

All other snakes in California are non-venemous and are also important part of the California ecosystems. Most feed on rodents, and so provide a necessary service by keeping rodent populations in control.

Many Califoria snakes are quite beautiful. The more common colorful snakes in California are Kingsnakes. One variety of Kingsnakes can be found here in the Santa Clara foothills, and can be described by a alternating pattern of black and white bands. The California Mountain Kingsnake is also very colorul, showing alternating bands of red, black and white.

Garter snakes are small snakes usually found near water such as streams and ponds. They feed on much smaller animals such as small fish. Gopher snakes are found in the low lands and feed on rodents.

You are most likely to encounter rattlesnakes, kingsnakes, gophersnakes and garter snakes. Just remember, snakes are more afraid of you than you are of them! Admire them from a distance and let them be!