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Magnetostatics

As we move from from electrostatics to magnetostatics we leave behind two of Maxwell’s equations and begin using the remaining two equations r B D 0 r H D J; where as a quick review B is the megnetic flux density, H is the magnetic filed intensity, and of course J is the current density Also recall that B D H, but in magnetics it is not always a lin ...

Magnetism and Relativity

A reference frame is a coordinate system that you set up around yourself in order to make measurements, e.g. up/down, north/south, east/west, and your wristwatch for measuring time. x • If you are moving at a constant velocity, then you are in an inertial reference frame. You can only measure things with respect to your own frame. People in other referen ...

Visible Light Communication: a System Perspective—Overview and Challenges

EDs) have fueled the idea of replacing the solid-state lighting for illumination purpose. It was until 1996 when the first white LED was commercially introduced in the market for sale [1]. LED lights are highly powered efficient, low carbon emissions, free from mercury, durable and produce good quality illumination. LED lights have 75% less power consump ...

An Overview of Some Fundamentals of Electroacoustics

The acoustic radiation pattern, or beam pattern, is the relative sensitivity of a transducer as a function of spatial angle. This pattern is determined by factors such as the frequency of operation and the size, shape and acoustic phase characteristics of the vibrating surface. The beam patterns of transducers are reciprocal, which means that the beam wi ...

Pneumatics Manual

Fluid power technology encompasses both hydraulics and pneumatics. Hydraulic applications use pressurized fluids, mostly oil, while pneumatic applications use pressurized gases, mostly air. Mobile construction equipment uses a hydraulic pump mounted on the engine. The outlet of the pump is plumbed to a set of valves. Each valve is then plumbed to a cylin ...

Introduction to Fluid Dynamics

gas, the latter being distinguished by its great relative compressibility. Fluids are treated as continuous media, and their motion and state can be specified in terms of the velocity u, pressure p, density ρ, etc evaluated at every point in space x and time t. To define the density at a point, for example, suppose the point to be surrounded by a very sm ...

Continuum Mechanics

The subject of all studies in continuum mechanics, and the domain of all physical quantities, is the material body. A material body B = {X } is a compact measurable set of an infinite number of material elements X , called the material particles or material points, that can be placed in a one-to-one correspondence with triplets of real numbers. Such trip ...

Science and Reactor Fundamentals -- Fluid Mechanics

Basic Definitions • Define the following terms and state their units of measurement: pressure, density, and viscosity. 1.2 Pressure • Convert a given value of pressure expressed on the absolute, gauge or vacuum scale to the appropriate values on either of the other two scales. • Given a pressure differential acting on a given area, calculate the force pr ...

Acoustics in Practice

The economics of French instrument making consists almost entirely of very small handicraft enterprises. Faced with strong international competition, they are positioned on the top-end and concert musical instruments market, while learning instruments are rather manufactured on an industrial basis. This observation may certainly be applied more generally ...

Solid Mechanics

The application of the principles of mechanics to bulk matter is conventionally divided into the mechanics of fluids and the mechanics of solids. The entire subject is often called continuum mechanics, particularly when we adopt the useful model of matter as being continuously divisible, making no reference to its discrete structure at microscopic length ...

STEPHEN HAWKING a Life in Science

When Stephen Hawking was involved in a minor road accident in Cambridge city center early in 1991, within twelve hours American TV networks were on the phone to his publisher, Bantam, for a lowdown on the story. The fact that he suffered only minor injuries and was back at his desk within days was irrelevant. But then anything about Stephen Hawking is ne ...

Platonism As a Philosophical Method

According to the dictionary and popular opinion, Platonism is the school and doctrine of Plato, which defends the existence of immutable entities. These are the basis of all beings and of our knowledge. Obviously, it cannot be denied that this is one of the most important aspects of his thought, also related to his epistemology, political and ethical phi ...

A L B E R T E I N S T E I N 1879—1955

ALBERT EINSTEIN was born in Ulm, Germany on March -**- 14, 1879. After education in Germany, Italy, and Switzerland, and professorships in Bern, Zurich, and Prague, he was appointed Director of Kaiser Wilhelm Institute for Physics in Berlin in 1914. He became a professor in the School of Mathematics at the Institute for Advanced Study in Princeton beginn ...

A Brief History of Astronomy and Telescopes

The Thirty Meter Telescope (TMT) will take us on an exciting journey of discovery. The TMT will explore the origin of galaxies, reveal the birth and death of stars, probe the turbulent regions surrounding supermassive black holes, and uncover previously hidden details about planets orbiting distant stars, including the possibility of life on these alien ...

John Buridan and the Theory of Impetus

BOOK VIII, QUESTION 12. It is sought whether a projectile after leaving the hand of the projector is moved by the air, or by what it is moved. It is argued that it is not moved by the air, because the air seems rather to resist, since it is necessary that it be divided. Furthermore, if you say that the projector in the beginning moved the projectile and ...

FOUR CENTURIES of ATOMIC THEORY an Overview

It might seem oddly perverse to give a lecture entitled “Four Centuries of Atomic Theory” at a symposium entitled “200 Years of Atoms in Chemistry.” No one questions, of course, that the 19th- and 20thcenturies were the heyday of chemical atomism and historians of chemistry have long agreed that Dalton’s work was the starting point for our current quanti ...

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