Coherent Silicon

Physics Question (10 Points)?

a) In a diode laser, electrons dropping from the conduction band, across the gap, and into the valence band produce the photons that add to the coherent light. The ZnTe laser has a band gap of 2.25 eV. Determine the wavelength of the light emitted.

b) The energy gap for Si at 300 K is 1.14 eV.
i) Find the lowest-frequency photon that will promote an electron from the valence band to the conduction band of silicon.

ii) What is the wavelength of this photon?

c) Near room temperature, an increase of I K decreases the conductivity of copper by only 0.4%. For another semiconductor, it increases the conductivity by 4.8%. Estimate the semiconductor’s band gap.

answers for b and c are
b i) 2.75 X 1014 Hz ii) 1.09 X 10-6 m c) EGAP = 0.68 eV
but I dont know how to get there

a) The relation between photon wavelength and energy is E = hc/lambda, where h = Planck's constant, c = speed of light, lambda = wavelength

Just plug in the numbers. Since E is in eV, you can use h in eV units, which is 4.14 x 10^-15 eV-s

If c is in m/sec, the wavelength will be in meters.

b) i) Instead of E = hc/lambda, use E = hf. Just plug in the values of E and h.

ii) Now you can use f = c/lambda to solve for lambda

c) I would guess there is a formula in your notes that says "relationship between conductivity temperature" that is the key to this problem.

Coherent Duality $58.94 High Quality Content by WIKIPEDIA articles Coherent duality in mathematics refers to a number of generalisations of Serre duality, applying to coherent sheaves, in algebraic geometry and complex manifold theory, as well as some aspects of commutative algebra that are part of the local theory. The historical roots of the theory lie in the idea of the adjoint linear system of a linear system of divisors in classical algebraic geometry. This was reexpressed, with the advent of sheaf theory, in a way that made an analogy with Poincare duality more apparent. Then according to a general principle, Grothendiecks relative point of view, the theory of JeanPierre Serre was extended to a proper morphism; Serre duality was recovered as the case of the morphism of a nonsingular projective variety (or complete variety) to a point. The resulting theory is now sometimes called SerreGrothendieckVerdier duality, and is a basic tool in algebraic geometry. A treatment of this theory, Residues and Duality (1966) by Robin Hartshorne, became an accessible reference. One concrete spinoff was the Grothendieck residue. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 74 Publication Date: 2010/08/15 Language: English Dimensions: 6.00 x 9.02 x 0.18 inches

Coherent (Operating System) $73.28 High Quality Content by WIKIPEDIA articles The Coherent operating system was a Version 7 Unix clone by the nowdefunct Mark Williams Company, originally produced for the PDP11 in 1980. A port was introduced in 1983 as the first Unixlike system for IBM PC compatible computers. Coherent was able to run on most Intelbased PCs with Intel 8088, 286, 386, and 486 processors. Coherent version 3 for Intelbased PCs required at least a 286, Coherent version 4 for Intelbased PCs required at least a 386. Like a true Unix, Coherent was able to multitask and support multiple users. From version 4 on Coherent also had support for X11 and MGR windowing systems. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 96 Publication Date: 2010/11/17 Language: English Dimensions: 6.00 x 9.02 x 0.23 inches

Coherent Fog $24.33 No Synopsis Available

Coherent Systems $171.6 No Synopsis Available

Silicon $116.03 No Synopsis Available

Coherent LightWave Communication Systems $141.12 This book covers the history and implementation of coherent lightwave communication systems. Packed with information on narrow linewidth lasers, it also provides you with detailed discussion on circuit design techniques for receivers, methods of overcoming polarization fluctuation, multigigabit systems, and the construction of longdistance optical links. Author: Ryu, Shiro Binding Type: Hardcover Number of Pages: 302 Publication Date: 1994/12/31 Language: English Dimensions: 9.33 x 6.25 x 0.82 inches

Synchronization in Coherent MPsk Receivers $167.53 MPSK (Mary Phase Shift Keying) modulation is used in a wide variety of communications systems. Use of MPSK is widespread in wireless networking standards, telephony links, cellular telephony, digital television standards, fiberoptic communications, mobile communications, and military communications. Systems which use MPSK can be found worldwide in terrestrial, satellite, and deepspace applications. Despite the ubiquitous use of MPSK, some coherent MPSK receiver structures have evolved very little since the Costas loop was invented in the 1950s. In this groundbreaking book, new structures for use within coherent MPSK receivers are presented. These include carrier lock detectors, carrier phase detectors, and SNR (Signal to Noise Ratio) estimators. The aforementioned structures are thoroughly analyzed and compared to previously available structures and it is shown that they have significant performance advantages and have immediate applications for use in MPSK systems. Therefore, this book is indispensable to any scientist or engineer who is tasked with the research or development of MPSK communications systems. Author: Linn, Yair Binding Type: Paperback Number of Pages: 292 Publication Date: 2008/09/01 Language: English Dimensions: 9.00 x 6.00 x 0.61 inches

Coherent Stress Testing (Hardcover) $116.68 In Coherent Stress Testing: A Bayesian Approach, industry expert Riccardo Rebonato presents a groundbreaking new approach to this important but often undervalued part of the risk management toolkit. Based on the author`s extensive work, research and presentations in the area, the book fills a gap in quantitative risk management by introducing a new and very intuitively appealing approach to stress testing based on expert judgement and Bayesian networks. It constitutes a radical departure from the traditional statistical methodologies based on Economic Capital or Extreme-Value-Theory approaches. The book is split into four parts. Part I looks at stress testing and at its role in modern risk management. It discusses the distinctions between risk and uncertainty, the different types of probability that are used in risk management today and for which tasks they are best used. Stress testing is positioned as a bridge between the statistical areas where VaR can be effective and the domain of total Keynesian uncertainty. Part II lays down the quantitative foundations for the concepts described in the rest of the book. Part III takes readers through the application of the tools discussed in part II, and introduces two different systematic approaches to obtaining a coherent stress testing output that can satisfy the needs of industry users and regulators. In part IV the author addresses more practical questions such as embedding the suggestions of the book into a viable governance structure.

Coherent Radar Performance Estimation $207.12 This book provides you with a complete understanding of error effects in coherent systems. Covering performance issues never before addressed in one source, it places special emphasis on phase noise effects and detection of targets in clutter. Supported by 196 illustrations, 260 equations, and 150 references. Author: Scheer, James A./ Kurtz, James L./ Kurtz, James L. Series Title: Artech House Radar Library (Hardcover) Binding Type: Hardcover Number of Pages: 464 Publication Date: 1993/12/01 Language: English Dimensions: 9.48 x 6.26 x 1.33 inches

Scalable Coherent Interface $68.51 High Quality Content by WIKIPEDIA articles SCI, for Scalable Coherent Interface, is a highspeed computer bus that supports a variety of topologies, speeds and connection systems. It is used primarily in the highperformance computing market, where it is used to build NUMA computer clusters and other parallel architectures. In this role most systems use high speed networking devices, typically Gigabit Ethernet, but SCI is much lighter in terms of the protocol overhead, and can offer considerably higher performance regardless of the actual link speed. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 76 Publication Date: 2010/08/23 Language: English Dimensions: 6.00 x 9.02 x 0.18 inches

Learn the Ability of Coherent Consciousness $17.9 Empower Your Mind by learning to become a Positive, Productive, and Motivated Individual through Positive Motivating Solutions in any level of community challenges. Coherent Consciousness, simply meansbeing able to place together a positive thought process. By renewing our minds into positive thinking, and surrounding ourselves with positive people, places, and/or things, we can begin repairing, restoring, rejuvenating, and renewing into a better future, and/or lifestyle. Remember the old saying, Dont let people rent space in your head. This book contains: 9 Golden Rules to Successful Living, Memory Charts, Key Words, sidebars, and Blueprints as Guidelines. Golden Rule No.4 I will learn to be in control of my destiny, and that means avoiding the time robbers,the controllers, and negative people. Author: Hill Sr, Steven Lawrence Binding Type: Paperback Number of Pages: 144 Publication Date: 2007/05/06 Language: English Dimensions: 5.98 x 9.01 x 0.33 inches

Coherent Dynamics of Complex Quantum Systems $194.7 Coherent Dynamics of Complex Quantum Systems is aimed at seniorlevel undergraduate students in the areas of atomic, molecular, and laser physics, physical chemistry, quantum optics and quantum informatics. It should help them put particular problems in these fields into a broader scientific context and thereby take advantage of the wellelaborated technique of the adjacent fields. Author: Akulin, Vladimir M. Series Title: Theoretical and Mathematical Physics Binding Type: Paperback Number of Pages: 471 Publication Date: 2010/11/23 Language: English Dimensions: 9.21 x 6.14 x 0.97 inches

Silicon Tubes: Silicon Tube/1M D6*3 $2 Silicon Tubes: Silicon Tube/1M D6*3

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Coherent Behavior in Neuronal Networks $207.34 No Synopsis Available

Highly Coherent Semiconductor Lasers $143.39 THis book shows you the principles of operation, device structure, noise properties, and a wide range of possible application systems of semiconductor lasers, and describes methods for improving their coherence. Supported by 300 equations and 169 illustrations. Author: Ohtsu, Motoichi/ Ohtsu, Motoichi Series Title: Artech House Optoelectronics Library Binding Type: Hardcover Number of Pages: 356 Publication Date: 1991/10/01 Language: English Dimensions: 9.35 x 6.42 x 1.07 inches

Coherent Structures and Simple Games $364.83 Author: Ramamurthy, K. G. Series Title: Cancer Treatment and Research Series Number: 6 Binding Type: Hardcover Number of Pages: 180 Publication Date: 1990/09/30 Language: English Dimensions: 9.21 x 6.14 x 0.50 inches

Probabilistic Logic in a Coherent Setting $301.11 The approach to probability theory followed in this book (which differs radically from the usual one, based on a measuretheoretic framework) characterizes probability as a linear operator rather than as a measure, and is based on the concept of coherence, which can be framed in the most general view of conditional probability. It is a flexible and unifying tool suited for handling, e.g., partial probability assessments (not requiring that the set of all possible outcomes be endowed with a previously given algebraic structure, such as a Boolean algebra), and conditional independence, in a way that avoids all the inconsistencies related to logical dependence (so that a theory referring to graphical models more general than those usually considered in bayesian networks can be derived). Moreover, it is possible to encompass other approaches to uncertain reasoning, such as fuzziness, possibility functions, and default reasoning. The book is kept selfcontained, provided the reader is familiar with the elementary aspects of propositional calculus, linear algebra, and analysis. Author: Coletti, Giulianella/ Coletti, G./ Scozzafava, R. Series Title: Trends in Logic Series Number: 15 Binding Type: Hardcover Number of Pages: 296 Publication Date: 2002/10/31 Language: English Dimensions: 9.72 x 6.40 x 0.84 inches

Generalized Coherent States and Their Applications $301.11 Author: Perelomov, Askold Series Title: Texts and Monographs in Physics Binding Type: Hardcover Number of Pages: 332 Publication Date: 1986/08/27 Language: English Dimensions: 9.21 x 6.14 x 0.88 inches

Coherent Evolution in Noisy Environments $173.65 In the last two decades extraordinary progress in the experimental handling of single quantum objects has spurred theoretical research into investigating the coupling between quantum systems and their environment. Decoherence, the gradual deterioration of entanglement due to dissipation and noise fed to the system by the environment, has emerged as a central concept. The present set of lectures is intended as a highlevel, but selfcontained, introduction into the fields of quantum noise and dissipation.In particular their influence on decoherence and applications pertaining to quantum information and quantum communication are studied, leading the nonspecialist researchers and the advanced students gradually to the forefront of research. Author: Buchleitner, A./ Buchleitner, Andreas/ Hornberger, Klaus Series Title: Lecture Notes in Physics, Series Number: 611 Binding Type: Hardcover Number of Pages: 308 Publication Date: 2003/02/12 Language: English Dimensions: 9.42 x 6.26 x 0.65 inches

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Silicon Valley Stories, Part 1

What about acupuncture needles?

The fundamental question: how to do acupuncture? needs a complicated answer, but in a pragmatic way one should always start with: using a needle. This is a straightforward statement but which leads nowhere but rather opens a can of interrogations.

Being the "king" of instruments in Chinese acupuncture, it is the object of many discussions. Each of the paragraphs below could be lengthened and detailed considerably. Let us say that a combination of history, technical evolution, practicality and adjustments, have made the basic instrument of chinese and non chinese acupuncture more civilized and less feared by western patients.

How to hold the needle, how to insert it, how deep, at what angle, and mostly, should it be manipulated to induce a bigger stimulation? Arguments are still flowing because it used to be a theoretical stronghold of traditional acupuncturists. Moreover the variety of movements of the needle that one can produce is too impressive to be realistic. What they show is most of the time not what they do.

This is one of the biggest problems one encounters when teaching acupuncture (much less in herbal medicine): there are many ritual topics that must be covered in order to enhance the value of the practitioners gesture or give apparently more meaning to his diagnosis or treatment decisions.

The needles we use these days are packed in sterilized blisters and are disposable, which means that they should be thrown away after one use. They bear the acronym ISO or CE showing that they have been approved by international or European official agencies. However in some parts of the world, for financial reasons, needles are still reused after having been properly sterilized.

Where can you find needles? In congresses, seminars, big classes of acupuncture. You can also surf on the web and find the names and addresses of many companies who sell them and will send them to you through the post.

The needles that are used at the present time are quite thin. The gauge seldom exceeds 0.32 mm; the thinnest can have a diameter of only 0.16 mm. There are even needles that are short and as thin as a hair, with a gauge of 0.10 mm, sometimes coated in gold (you can imagine the thickness of that coating!) used for facial or cosmetic acupuncture. The shaft is always made of stainless steel and often covered with a layer of silicone so that they slide better when inserted in the skin and flesh. The hardness, solidity and flexibility of the shaft or body of the needle must be balanced, so as not to break and not to bend too easily. But it is on the tip that the manufacturers have concentrated all their efforts: depending on its shape and sharpness it must glide into the skin effortlessly, and inflict as little pain as possible, if none at all. So there are many kinds of needles, and the manufacturers come from China, Japan, Korea, Germany, and I suppose other countries (I don't pretend to be an encyclopedia)

One can speculate as to the nature of the material used in the beginning for making an acupuncture needle. Bamboo, jade, bronze, copper, gold, silver, other kinds of metals. Already in the Neijing the emperor Huangdi (the Yellow Emperor) declared that he wants the stone needles to be replaced by metal ones.

During the seventies there was, in some circles, the belief that the metal in itself had a specific role to play in the action of the needles. This idea came from the acupuncturist who introduced the technique in a practical way in Europe, Georges Soulie de Morant. This self-taught sinologist, diplomat, prolific writer, published a little book called: "Precis de la Vraie acupuncture chinoise". It came out for the first time in 1934. He had decided that gold and silver needles where the best for strengthening or dispersing, needles made of nickel having a balancing and neutral effect. A few researchers experimented later with all kinds of materials, from zinc to platinum, from manganese to cobalt, from copper to cadmium or molybdenum. The results were not convincing.

Before the use of stainless steel, for centuries simple steel was the favorite metal for manufacturing needles. But iron and copper, bronze, tin, all these metals or alloys had the inconvenience of deteriorating when in contact with oxygen. Only since 1913, when stainless steel, a mixture of iron, chrome and nickel, was invented, were most acupuncture needles made of that very practical combination.

The acupuncture manuals, since the very beginning, describe "the Nine Needles of Acupuncture". Actually they reflect more the kit of a medical practitioner as some of the needles are obviously used as lancets or as bleeding or massage instruments. Modern replicas of these kits have been manufactured, I hope for decoration purposes, as the length and diameter of even the thinnest of the needles are impressive.

In the first book on acupuncture of which we have a copy (printed nearly one thousand years after the original), called the Neijing, the Classic of the Interior, when the authors recommend needling a point, they usually mention only one or two of them, no more. The reason lies probably in the fact that the needles made in those days were certainly much thicker, and the point not so sharp, making the insertion quite painful.

When Chinese archeologists unearth a needle, or several of them, or simply a fairly thin and pointed instrument in a site they are prospecting, they often declare that they have found an acupuncture instrument, usually because they were put together with other medical instruments or medicines. The sites often go back to the Neolithic period, making the assumption rather dubious because it is unlikely that acupuncture existed already as a coherent and sophisticated technique.

Often the question comes up as to what is acupuncture. All civilizations have been using pointed and sharpened instruments for rudimentary medical purposes like piercing an abscess. But only in China, and much later than Neolithic times, have needles been associated with a complex technique supposed to manage the flows of energy in the body.

So many questions rise around the main instrument of Chinese acupuncture: material, sizes, numbers, qualities, manufacturing, hygiene, techniques of insertion, intrinsic properties, adaptation to times and countries. If one searches for all the texts where the topic is mentioned in a not too repetitive way it would be possible to write hundreds of pages, and I feel frustrated not to be able to give here everything I know, including anecdotes and stories, of which I have many. On the other hand many claims and statements are questionable. It is necessary to keep our feet on the ground and be as pragmatic as possible.

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