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davidar
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davidar's Bookmarks 

Main Page - Proteopedia    13/08/2008 04:37:18 PM
The collaborative, 3D encyclopedia of proteins and other molecules.
biology, database, free - saved by: davidar - more details ...
Unicode Character Database    13/08/2008 04:37:18 PM
The Unicode Character Database (UCD) consists of a number of data files listing character properties and related data along with a documentation file that explains the organization of the database and the format and meaning of the data in the files.
database, download, free - saved by: davidar - more details ...
Huygens’ clocks    13/08/2008 04:37:18 PM
The 336-year-old synchronization observations of Christiaan Huygens are reexam- ined in modern experiments. A simple model of synchronization is proposed. Keywords: synchronization, nonlinear dynamics
physics, synchronisation - saved by: davidar - more details ...
Huygens' Clocks    13/08/2008 04:37:18 PM
In 1657, Christiaan Huygens revolutionized the measurement of time by creating the first working pendulum clock. In early 1665, Huygens discovered ``..an odd kind of sympathy perceived by him in these watches [two pendulum clocks] suspended by the side of each other.'' The pendulum clocks swung with exactly the same frequency and 180 degrees out of phase; when the pendulums were disturbed, the antiphase state was restored within a half-hour and persisted indefinitely. Huygens deduced that the crucial interaction for this effect came from ``imperceptible movements'' of the common frame supporting the two clocks. He thought this synchronization could be used to provide the exquisite timing necessary to solve the famous ``longitude problem'' in maritime navigation and spent many years developing and testing designs for pendulum clocks that function at sea.
physics, synchronisation - saved by: davidar - more details ...
Synchronization of Metronomes    13/08/2008 04:37:18 PM
A version of Huygens original system provides an elegant classroom demonstration of how systems synchronize. The system consists of two pendulum metronomes resting on a light wooden board which sits on two empty soda cans, see picture above. The metronomes used are Wittner's Super-Mini-Taktell (Series 880), and were chosen because they were inexpensive and had a light base. The base supports were empty beverage containers (Mountain Dew, 12 fl. oz).
physics, synchronisation - saved by: davidar - more details ...
Physics Tutoring: Electric Flux    13/08/2008 04:37:18 PM
electricity, physics - saved by: davidar - more details ...
Resistance and Resistivity    13/08/2008 04:37:18 PM
electricity, physics - saved by: davidar - more details ...
How Fast Does a Charge Decay?    13/08/2008 04:37:18 PM
There's a phrase that has been bothering me for years: "How do you remove static electricity?" At one level the question makes sense. Everybody involved in electrostatics understands what the inquirer is trying to ask. But at a physics level, as well as a linguistic one, the phrasing is more dubious. A better expression of the question would be "How do you neutralize the field from static charges?"
electricity, physics - saved by: davidar - more details ...
HyperPhysics Concepts    13/08/2008 04:37:18 PM
physics - saved by: davidar - more details ...
Python inside LaTeX    13/08/2008 04:37:18 PM
"With this style file for LaTeX it is possible to write Python code inside a LaTeX document. It can be extremely useful for generating figures and similar things." And in fact, Martin was really right! I started to play with his python.sty package, the results where somewhat promising, even if I had hard times figuring out how to work with accented chars [I found a trick, but I don't like it very much]. My first sample was writing squares of integers ranging from 0 to 9. After some tries, I was wondering if I could play with python.sty together with SymPy. Why ? Because I'm working as a maths teacher and have sometimes the need to build exercises with responses quickly.
code, download, latex, maths, opensource, python - saved by: davidar - more details ...
An introduction to Sketch 3D for PGF and TikZ users | fauskes.net    13/08/2008 04:37:18 PM
In this notebook entry I will give a brief introduction to this great tool. Note that you have to read the Sketch manual to actually learn Sketch. I will only cover aspects specific to PGF and TikZ.
code, graphics, latex, tutorials - saved by: davidar - more details ...
Physics ToolKit (World-in-Motion)    13/08/2008 04:37:18 PM
Physics ToolKit, previously named World-in-Motion, is a useful educational tool for lecture, lab, and student assignments. Features include: * Video analysis software with videos covering common topics in mechanics, sound and electromagnetic fields and waves. * Video capture software with support for VFW, WDM and DX capture devices. * Documents, problem sets and demonstration videos covering common topics in the first year of algebra or calculus based physics courses.
download, free, physics, tools, video - saved by: davidar - more details ...
Avoid eqnarray!    13/08/2008 04:37:18 PM
Whenever the eqnarray environment appears in a question or an example of a problem on comp.text.tex or the TEXhax mailing list there is a large chance that someone will tell the poster not to use eqnarray. This article will provide some examples of why many of us consider eqnarray to be harmful and why it should not be used.
latex, maths - saved by: davidar - more details ...
Moment of Inertia of a Rotating Cam    13/08/2008 04:37:18 PM
physics - saved by: davidar - more details ...
List of moments of inertia - Wikipedia, the free encyclopedia    13/08/2008 04:37:18 PM
formulae for moments of inertia of various objects
formulae, list, physics - saved by: davidar - more details ...
Rotational Inertia    13/08/2008 04:37:18 PM
how to prove / derivate moments of inertia for simple objects (e.g. a disc)
maths, physics - saved by: davidar - more details ...
Moment of Inertia    13/08/2008 04:37:18 PM
physics - saved by: davidar - more details ...
Precession of Top    13/08/2008 04:37:18 PM
This process involves a considerable number of physical and mathematical concepts. The angular momentum of the spinning top is given by its moment of inertia times its spin speed but this exercise requires an understanding of it's vector nature. A torque is exerted about an axis through the top's supporting point by the weight of the top acting on its center of mass with a lever arm with respect to that support point. Since torque is equal to the rate of change of angular momentum, this gives a way to relate the torque to the precession process. From the definition of the angle of precession, the rate of change of the precession angle q can be expressed in terms of the rate of change of angular momentum and hence in terms of the torque.
maths, physics - saved by: davidar - more details ...
Precession - Wikipedia, the free encyclopedia    13/08/2008 04:37:18 PM
Torque-induced precession (gyroscopic precession) is the phenomenon in which the axis of a spinning object (e.g. a part of a gyroscope) "wobbles" when a torque is applied to it. The phenomenon is commonly seen in a spinning toy top, but all rotating objects can undergo precession.
physics - saved by: davidar - more details ...
Rubik's Cube Solver    13/08/2008 04:37:17 PM
online, tools - saved by: davidar - more details ...
Online X-Face Converter    13/08/2008 04:37:17 PM
conversion, graphics, online, tools - saved by: davidar - more details ...
PHP MIDI CLASS    13/08/2008 04:37:17 PM
download, library, midi, php - saved by: davidar - more details ...
How-To: Internet Explorer Warning Infobar | Hisham's Blog    13/08/2008 04:37:17 PM
I have received a few emails asking how to implement the Internet Explorer infobar warning on their own site. If you don't know what I'm taking about, when
code, css, howto, javascript, webdesign - saved by: davidar - more details ...
ChemSpider - Database of Chemical Structures and Property Predictions    13/08/2008 04:37:17 PM
ChemSpider is a chemistry search engine built with the intention of aggregating and indexing chemical structures and their associated information into a single searchable repository and making it available to everybody, at no charge. ChemSpider is a value-added offering since many properties have been added to each of the chemical structures within the database – structure identifiers such as SMILES, InChI, IUPAC and Index Names as well as many physicochemical properties.
chemistry, database, search - saved by: davidar - more details ...
Core JavaScript Guide 1.5: 6 Functions    13/08/2008 04:37:17 PM
The Sun-Netscape Alliance, a strategic alliance formed by America Online and Sun Microsystems, Inc., is delivering iPlanet e-commerce software and enterprise solutions that enable companies to compete successfully in the Net Economy
javascript, reference - saved by: davidar - more details ...
LaTeX document in landscape mode    13/08/2008 04:37:17 PM
latex landscape mode with two column layout and central dividing line
code, example, howto, latex - saved by: davidar - more details ...
An Inequality: 1/2*3/4*5/6* ... 99/100 < 1/10    13/08/2008 04:37:17 PM
maths, proof - saved by: davidar - more details ...
Wallis product - Wikipedia, the free encyclopedia    13/08/2008 04:37:17 PM
pi expressed as a product
formulae, maths, proof - saved by: davidar - more details ...
CSS Font and Text Style Wizard    13/08/2008 04:37:17 PM
css, tools, webdesign - saved by: snig178 - more details ...
How to Create a Frames Layout with CSS - WebReference.com    13/08/2008 04:37:17 PM
How to Create a Frames Layout with CSS
code, css, example, howto, webdesign - saved by: davidar - more details ...
Mandarin Design: CSS Opacity and Transparency    13/08/2008 04:37:17 PM
Opacity and Transparency served copy and paste style. Blog tips, Web site tips, tricks, and help. Located in Sacramento, California
code, css, example, webdesign - saved by: davidar - more details ...
History of Matrices and determinants    13/08/2008 04:37:17 PM
history, maths - saved by: davidar - more details ...
BibTeX Style Examples    13/08/2008 04:37:17 PM
example, latex, list - saved by: davidar - more details ...
jsMath    13/08/2008 04:37:17 PM
render TeX-style maths in html documents
javascript, latex, library, maths, opensource, webdesign - saved by: davidar - more details ...
NASA pictures    13/08/2008 04:37:17 PM
image - saved by: davidar - more details ...
REMF Image Index    13/08/2008 04:37:17 PM
Dartmouth Electron Microscope Facility - Dartmouth College - A variety of images from the scanning and transmission electron microscopes
image, index, physics - saved by: davidar - more details ...
How the SEM Works    13/08/2008 04:37:17 PM
diagram of scanning electron microscope (SEM)
physics, quantum - saved by: davidar - more details ...
Roulette -- from Wolfram MathWorld    13/08/2008 04:37:17 PM
A particularly interesting case of a roulette is a regular n-gon rolling on a "road" composed of a sequence of truncated catenaries, as illustrated above. This motion is smooth in the sense that the geometric centroid follows a straight line, although in the case of the rolling equilateral triangle, a physical model would be impossible to construct because the vertices of the triangles would get "stuck" in the ruts (Wagon 1991). For the rolling square, the shape of the road is the catenary y=-coshx truncated at x=+/-sinh^(-1)1 (Wagon 1991).
interest, maths - saved by: davidar - more details ...
Passing argument list and keyword list [python] [args] [kw]    13/08/2008 04:37:17 PM
def func(*args, **kw):
code, python - saved by: davidar - more details ...
Submitting Forms by Detecting Carriage Return / Enter Key Presses    13/08/2008 04:37:17 PM
detect press of enter / return key in textfield with javascript
code, howto, javascript, webdesign - saved by: davidar - more details ...
The Fruits of my Labour » Blog Archive » My htmlspecialchars() functions for Javascript    13/08/2008 04:37:17 PM
javascript equivalent of php htmlspecialchars function
code, javascript - saved by: davidar - more details ...
Abramowitz and Stegun: Handbook of Mathematical Functions    13/08/2008 04:37:17 PM
Scanned version of "Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables" by Milton Abramowitz and Irene A. Stegun. As a work of the US government, it is in the public domain.
download, free, maths - saved by: davidar - more details ...
Lightbox 2    13/08/2008 04:37:17 PM
Lightbox 2 is a simple, unobtrusive script used to overlay images on the current page. It's a snap to setup and works on all modern browsers.
javascript, library, opensource - saved by: davidar - more details ...
ImageMagick Tutorial    13/08/2008 04:37:17 PM
command-line, graphics, howto - saved by: davidar - more details ...
UIUC Airfoil Coordinates Database    13/08/2008 04:37:17 PM
database, download - saved by: davidar - more details ...
Neural Network Tutorial    13/08/2008 04:37:17 PM
neural network tutorial in plain english
code, tutorials - saved by: davidar - more details ...

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