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Efficiency of photovoltaic cells

This year's Nobel Prize has been awarded to an American physicist and chemist whose work paved the way to built efficient and low-cost polymer photovoltaic cells. Professor A. J. Heeger of University of California at Santa Barbara, US received the prestigious Nobel Prize for his research on polymer photovoltaic solar cells...

Organic semiconductors

General Observation of n-type Field effect Behaviour in Organic Semiconductors Organic semiconductors have been the main subject of active research in the recent years which is active for over a decade now with many new and advanced applications emerging in light emitting displays and printable electronic circuits. One main characteristic feature...

Physically aware of hot and cold

A BRIEF HISTORY OF TEMPERATURE MEASUREMENT Ancient people were physically aware of hot and cold and probably related temperature by the size of the fire needed, and how close to sit, to keep warm. An Australian tribe, still primitive, uses dogs instead of blankets to keep warm, thus, they can relate temperature by the...

The universe is very vast

The Scale of the Universe The Universe is very vast. Many unanswered questions of life lay hidden beneath this place so unfamiliar to our society. This mysterious dark sky that we are floating in is supposedly constantly expanding to no end. Is there an edge? Well apparently there is no center...

Determination of coefficient of expansion of air

INTRODUCTION This experiment is based on investigating the coefficient of expansion of air using a simple laboratory set up; the stopper flask method, where pressure is constant throughout the experiment. The increase in volume of a gas is directly proportional its temperature increase and is expressed as a fractional changed in...

DSS measuring system

EXPERIMENTAL METHODS DSS MEASURING SYSTEM A computer controlled dielectric Spectroscopy (DSS) measuring system has been used to obtain the dielectric measurements. The system is based on dual phase lock-in amplifier SR530 and a precision Hewlett Packard function generator; HP116A and an interface unit to select current or voltage mode of the lock-in...

Uniformity of gamma camera images

Introduction In 1958, Hal Anger developed the first ?- camera and forever changed the area of nuclear medical imaging. Anger's camera (also known as scintillation camera or gamma camera) used a 6 mm thick scintillation crystal (NaI) coupled to seven photomultiplier tubes (PMTs), each 3.5 cm diameter, arranged in a hexagonal...

Refracting And Refractig Type Telescope Physics Essay

The idea that curved mirrors behave like lenses dates back at least to Alhazen's 11th century treatise on optics, works that had been widely disseminated in Latin translations in early modernHYPERLINK "http://en.wikipedia.org/wiki/Early_modern_Europe" HYPERLINK "http://en.wikipedia.org/wiki/Early_modern_Europe"Europe. Soon after the invention of the refractingHYPERLINK "http://en.wikipedia.org/wiki/Refracting_telescope" HYPERLINK "http://en.wikipedia.org/wiki/Refracting_telescope"telescope, Galileo, GiovanniHYPERLINK "http://en.wikipedia.org/wiki/Giovanni_Francesco_Sagredo" HYPERLINK "http://en.wikipedia.org/wiki/Giovanni_Francesco_Sagredo"FrancescoHYPERLINK "http://en.wikipedia.org/wiki/Giovanni_Francesco_Sagredo"...

Polymer photovoltaic cells

To produce cheap photovoltaic devices there is a need to develop a device which uses the low cost renewable energy sources like sunlight, heat air, etc. First the research is made on in-organic semiconductors like silicon & amorphous form of silicon they found the manufacturing price was quite high, hence...

Bubble in stagnant Newtonian fluids

Introduction:          Viscosity is an important property of a fluid which governs the many phenomena that appear when work is done on them. Fluids of different viscosities behave very differently and therefore their applications can vary. For example, with lubricants, high viscosity lubricants are used in the slow moving parts reducing friction...

Presentatie ANW Artikel 50

Presentatie ANW Artikel 50: Zon en Aarde Wij houden onze presentatie over Artikel 50: Zon en Aarde. Dit artikel gaat over het verschil in warmte op aarde, het ontstaan van de seizoenen, en over Eratosthenes die de omtrek van de aarde berekende. Over deze onderwerpen gaan we jullie wat vertellen ...

Einstein's theory of lasers

INTRODUCTION The name LASER is an acronym for Light Amplification by the Stimulated Emission of Radiation. Light is really an electromagnetic wave. Each wave has brightness and color, and vibrates at a certain angle, so-called polarization. This is also true for laser light but it is more parallel than any other light...

Van Allen Belt

INTRODUCTION The Van Allen radiation belt is atorus of energetic charged particles (plasma) around Earth, which is held in place by Earth's magnetic field. This field is not uniformly distributed around the Earth. On the sunward side, it is compressed because of thesolar wind, while on the other side it is...

My clinical work

I manage and provide clinical supervision for 6 clinical psychologists, and as budgetholder, oversee an annual expenditure budget of £320K. My clinical work consists of a mixture of direct work with children, parent support and staff liaison and consultation. In addition, for the more complex inpatient cases, I regularly adopt...

Universe and its history

The problem of the origin of the universe is one of the most profound and fascinating issues in the scientific world. There are certain theories which are trying to explain how the universe came into existence. However, only the Big Bang theory remains the most accurate explanation of the origin...

Light is an extremely valuable source to all plants

Light is an extremely valuable source to all plants, without it, it is hard for them to photosynthesize, compete and reproduce Givnish 1988).  Light availability often affects which plants will succeed and the life-history strategies (they choose to adopt (Valladares et al 97). Plants do not all receive the same...

Vacuum pump

What is Vacuum Pump ? A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The vacuum pump was invented in 1650 by Otto von Guericke. History of the vacuum pump The predecessor to the vacuum pump was the suction...

Fiber optics and its applications

INTRODUCTION Nothing in the world gives us more power and confidence than having information. The ability to communicate information is essential to achieve the successful advancement of humankind. Transmission of information is imperative to the expansion of our horizons. What does this all have to do with fiber optics? This research paper...

Fibre optics

ACKNOWLEDGEMENT: History of all great works in to witness that no great work was ever done without either active or passive support of a person 'surrounding and one's close quarters. Thus is it not hard to conclude how active assistance from senior could positively impact the execution of a project...

International gamma-ray astrophysics laboratory satellite

Introduction Gamma-ray has become the newest source to reveal the deepest mysteries of the Universe, to capture gamma-ray emitting from the gamma-ray burst, black holes, supernova explosions, interstellar medium, cosmic-ray interactions and sources, neutron stars, active galactic nuclei and the cosmic gamma-ray background. Bulk of these explosions often emits at gamma-ray...

Micro Electro Mechanical Systems (MEMS)

Chapter No.1 INTRODUCTION On the basis of atomic theory presented by Democritus around 450 B.C. many branches of science originated. According to his hypothesis everything to be composed of atoms called "atomos", were indivisible, and indestructible. The discoveries of the 19th century further specified the existing science into electrical engineering. The important...

Piezo-resistive pressure sensor

Introduction: Sensor is defined to be a device that can be responded to any type of signal and can receive those signals. The physical property of sensor is that it can convert any input into electrical signals with in electronic circuits. A sensor does not function itself because it is such...

Complex musical signal

From the theory and the outcomes of the informal experiment, by presenting a complex musical signal in a harmonically decomposed and spatially distributed manner, it was expected that as the spatial spread of harmonics was increased, the perceived degree of spatial impression would also increase. The increase in spatial impression was expected to break down...

The comparison of contrast sensitivity

Introduction: The aim of the experiment was to determine if comparable contrast sensitivity measurements could be taken using different psychophysical methods. Contrast Sensitivity is defined as "the ability of the eye to detect luminance contrast". (Millodot, M, 2009) It is important as it makes objects stand out from one another. Contrast Sensitivity...

Time dilation and length contraction

INTRODUCTION: Time dilation is a phenomenon (or two phenomena, as mentioned below) described by the theory of relativity. It can be illustrated by supposing that two observers are in motion relative to each other, and/or differently situated with regard to nearby gravitational masses. Length contraction, according to Hendrik Lorentz, is the physical...

Minimizing stress concentration in a member

Introduction A stress concentration (often called stress raisers or stress risers) is a location in an object where stress is concentrated. An object is strongest when force is evenly distributed over its area, so a reduction in area, e.g. caused by a crack, results in a localized increase in stress. A...

Interfacial Thermocapillary Pressure of an Accelerated Droplet in Microchannels

Abstract Fluid flow and thermocapillary heat transfer near a droplet/air interface in microchannels is studied analytically and numerically in this set of two companion papers. Thermocapillary forces generate a pressure difference across the droplet, which drives two symmetric re-circulation cells in the upper and lower half-portions of the droplet. The numerical...

Fiber optics

ABSTRACT This paper looks at fiber optics as a technology that has been developing and improving the way the world communicates for more than two centuries. It examines its origins from 1790, when a French engineer Claude Chappe invented a system for sending messages using a series of semaphores mounted on...

Fabrication of Rhizophora spp

Abstract The aim of this study is to fabricate Rhizophora spp. Particleboard humanoid breast phantom and compare it with perspex phantom, and water phantom in therapy range by using TLD and other detectors to determine the dose in phantom at different depth in different type of phantom using photon and electron...

How to move an SPM tip

Introduction: In 1980's Scanning probe microscopy (SPM) dazed the world with its real images of the surface of silicon and these are used in variety of disciplines of fundamental surface science and in three dimensional imaging. SPM is an imaging tool used for vast dynamic range in optical and electron microscopies.Generally...

The Discovery Of The Electron

Two very basic and important equipments to investigation about the electron. 1. Vacuum Tube : Vacuum tube is a glasses tube surrounding vacuum which have anode and cathode. Simply, it is a different type of bulbs (Invented in 19thcentury). 2. Crookes Tube : Crookes tube is a glass cone with one anode and...

Dielectric

CHAPTER-4 RESULTS AND DISCUSSION EXPERIMENTAL RESULTS This chapter represents the results and discussion of the dielectric response of the four different sets of the samples without and with fillers. The dynamic response of these samples has been studied with thickness as a parameter with zero dc bias at room temperature. DIELECTRIC RESPONSE OF SAMPLES...

What are solar cells in physics

What are Solar Cells? Solar cells are devices that work on the principle of Photovoltaic Effect. These tiny compact devices convert solar light energy directly into electricity. In Greek, Photo-means light whereas voltaic means electrical current or electricity (light-electricity). Since, a solar cell...

Interengaging shearing blades

EFFECT OF SHEAR FORCE 0N SCISSORS TYPE STEEL Abstract: A plurality of pairs of interengaging shearing blades on upper and lower jaws are maintained at distances and tilt angles from a reference line which separates the shearing into discretely acting zones. The distances and tilt angles produce vertical steps between ends...

Frequency modulation the amplitude

INTRODUCTION In frequency modulation the amplitude is kept constant and the frequency is modulated by the amplitude of the modulating signal. The modulation index for fm is m = maximum frequency deviation/modulating frequency. FM signal can be represented as:- v = ac sin(wct + m sin wmt ) ABSTRACT Frequency modulation is a type...