Physics Essays

Theoretical Review of Optical Materials used in Concentrating Photovoltaic (CPV) Technology. Solar cells produce electrical current in direct proportion to the amount of solar radiation falling on them. By increasing the intensity of solar radiation, it is possible to significantly increase the efficiency of electricity production by these cells.

EPI is a fast, flexible imaging method, with good contrast and resolution, and with many potential applications in clinical imaging, such as functional MRI and rapid entire brain imaging. Though, EPI can be very unforgiving and requires careful parameter selection. EPI is fast because it uses single excitation of a slice followed by the continuous readout.

Therefore, this chapter details previous studies on the optical and thermal analysis of optical materials. The basics of ray tracing, optical features and thermal analysis are described first, followed by a discussion on previous investigations on optical, thermal and physical properties of glasses and polymeric materials such as polymethyl methacrylate (PMMA).

The existing boundaries between fat and compact bone are normally affected by the transverse magnetic field de-phasing and signal distortion. The consequence of the above is that frequency positions in the wrong location in the phase direction. Different results have been found from different body areas which have varying magnetic field strengths.

In the second law of thermodynamics, when complex systems undergo a certain change, then the system will either maintain their current order or decrease their order. This means that a change in a system cannot increase the order of the system. This principle can be well applied in our day to day life.

The magnetic geophysical method is a scientific approach that is used to measure variations or anomalies that are localized and small in the magnetic field of the earth. Materials found on the surface of the earth such as the basic igneous rocks, and the ore magnetic bodies are helpful when it comes to the identification of the magnetic variations because they have the magnetic properties.

If the positive side of the ohmmeter is connected to the P-material and the negative side to the N-material the diode will be forward biased and due to this the voltmeter will at an appropriate scale will indicate some resistance. When the two ohmmeter leads are reversed the diode will be reverse biased and this indicates whether a diode is good or bad.

The crucial elements of the physical aspects of the earthquakes are the energy that is dissipated, which also have far-reaching consequences on the life of human beings. In this regard, it is agreeable that the studies that are oriented toward studying the impacts of the amounts of energy that are produced by the seismic events are also pertinent.

Evidence for (or against) water on Mars. The issue of presence of water on mars has been a challenging question for many astronomers since 1877. “In the 1800s, human imaginations ran wild as astronomers glimpsed what they took to be canals on the Martian surface.

When a low energy positron collides with a low energy electron, there is an emittance of two gamma rays in the opposite direction. This phenomenon, also called positron annihilation, results in two gamma rays at 180° and with 0.511 MeV of energy moving in opposite directions.

Diffusion on the molecular level is said to be the result of natural Brownian movement, where molecules randomly move through the diffusion medium, because of the agitation caused by thermal characteristics of the medium. In all the displacement of the molecules comes up to zero by mean figures but over time, there are positive probabilities.

The extinction event that is most familiar today is the one which killed off the dinosaurs, and allowed mammals to take their current place as the dominant species type (York 2006). One of the most well-known theories for the cause of this extinction event is an asteroid hit, but there are several others, including global climate change, volcanic eruptions, communicable disease, and sex determination.

This essay analyzes the two main specific types of current: alternative current and direct current. The direction of the current flow is altered or reversed in the case of alternative current. Direct current is a little different from alternative current because it flows in the same direction all the time and no alteration is done with it like in the case of alternative current.

(Liboff, 1990) The addition of energy especially heat energy triggers particles to move faster while the removal of heat energy slows the particles down. Hence, if the state of heat energy of a system is known then the speed of its particles can be ascertained to a reasonable extent.

Some say that cell phones are linked to higher occurrences of cancer and other ailments, while other studies report that cell-phone users have no higher rate of cancer than the population as a whole. No study to date has provided conclusive evidence that cell phones can cause any of these illnesses.

Passive strategies for drag reduction in air and underwater vehicles, such as airplanes and submarines, are increasingly being investigated as they reduce the cost of operation of the vehicle by increasing its speed and efficiency. This essay discusses riblets and tripwires, and their use in drag reduction technology.

The origin of moon has always been an unresolved enigma for investigators of science. Though four different theories have been proposed, none were able to explain completely the circumstances in which moon was born and became paired in a crucial way with the earth.

Grizzly Bear. The grizzly bear (see Figure 1), whose scientific name is Ursus arctos horribilis, is called grizzly due to the light-colored fur on the back and shoulders, which may be brown, or blonde, or black. However, the fur of all grizzlies are white-tipped, making the fur looked grizzled.

In other words, ozone is more important than oxygen as far as the sustainment of life forms on earth is concerned. The Ozone layer at the top of the atmosphere prevents harmful ultraviolet radiations produced by sun and other stars from reaching earth. However, manmade activities are causing huge problems to the ozone layer at the top of the atmosphere and the depletion of this layer is currently taking place.

Black Hole. Black holes are very condensed space objects that were formerly the huge stars, which crumpled inward as a result of the power of their own gravity. Consequently, black holes are extremely thick. A black hole is a section of space-time from which “nothing, not even light, can escape” (Susskind & Lindesay, p.

The paper briefs about the initial problems after the 2009 floods and explains the reasons behind this installation. Furthermore, the paper contains a detailed but simplified explanation of the working of solar cells including the structure of solar cells, the P-N junction and the mobile electron-hole pairs, along with the number of cells which will be needed for the required purpose.

To have an in-depth analysis of the situation, various stakeholders such as philosophers, physicists, and astronauts have been working together. Despite this, disagreements have been evident due to differences in educational background. The main difference between cosmology and astronomy is that cosmology covers a wider scope while astronomy is narrower and limited to celestial bodies and their interaction.

A quantum computer is an instrument with the ability to accommodate a certain amount of data. This data in the quantum computer is accommodated within a system of quantum mechanical double-level networks for example as spin-half particles or atoms of two levels. The opportunity of incorporation of an advantageous new feature into data synthesis.

Erosion occurs when wind or water blow/wash away the topmost fertile layer of soil. As fertile land loses its fertility due to soil erosion, it is difficult to grow crops on eroded lands. Apart from affecting crops, erosion also weakens land, causing buildings to collapse.

Space and everything it holds are unimaginable boundaries. For a long, man has been in pursuance of finding out what the space beyond the Earth’s skies is actually composed of. Time and again man invented various instruments that assisted in the finding out of what resided in the skies that were apparently unseen to man.

The Lewis Spacecraft Mission Failure Investigation Board Report. The Lewis Spacecraft Mission failure of 1997 brings to the fore the risks inherent in engineering project management in the area of space exploration. NASA hoped to use the project to demonstrate the viability of using smaller satellites for space applications (NRC & NASA 54).

One of the most amazing part of creation would be the solar system. Today, the solar system is still a mystery to some people while those that understand what it really is are awed by its vastness. First of all, the solar system is made up of the star which we call the Sun; many planets namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto; and numerous comets, asteroids, and meteoroids.

For each configuration, we suspended a number of masses on the spring system and measured the displacement of the setup from its original position. We’d then find out the effective spring constants graphically by plotting the graph between the force applied and displacement of the system.

The main reason of the climate change is the green house gases that are the result of burning of fuel and other resources of the earth to attain power. The increases in the emission of the green house gases given rise to the temperature of the earth, which became one of the biggest threats to the habitat of the earth like the many species of the coral reefs, are vanishing due to the rise in temperature.

He has accomplished numerous achievements and this paper will name and exemplify these attainments and successful discoveries. In addition to his great contribution to theoretical physics, applied mathematics, and physical cosmology, this research paper will also take a look at his different awards, both national and international.

Here the original constellation is expanded so that it can accommodate all possible combinations of different components of signal points in the original constellation. In order to cooperate effectively in the relay phase, it is necessary for the relay to extract all the information required.

Securing a good employment position is not easy especially with the current observed scenarios of employment, unemployment and laying off of workers to account for certain economic situations. Doing what one really wants to do is the beginning of success for any one person who seeks for employment.

The United States should embrace the advancement in technology and introduce the usage of electric cars which uses batteries and are chargeable with the help of solar energy since this will reduce the reliance on petroleum to drive the engine of cars. The use of electric cars will also reduce the depletion of the ozone due to gaseous emissions causing global warming.

He said that the continents seemed to fit together at the edge of their continental shelves. He based his argument from the observation that the rocks and fossils at the southern hemisphere exhibited a similar pattern. This pattern referred to as the "Gondwana sequence".

Substances are dispersed from ground planes into the air to act as ice nuclei or cloud condensers. Their function is to change the microphysical process within the mass of the cloud. This technology is gaining widespread application globally and its practical uses are fog removal, lighting suppression, causing precipitation in form of rainfall.

Challenge to the determination of the density of an irregular solid is poised to its non-conformity to the any three-dimensional object that are used in the functional determination of the volume of natural and synthetic three dimensional objects. An irregular object falls outside the circular, ellipse, triangular, square, and rectangular or sphere basic units used in the mathematical computation of object.

Turbojets with converging-diverging nozzle (Sherwin, Keith & Michael, Horsley, 1996) There is an upstream rotating compressor that is coupled to a downstream turbine, and a combustion chamber in-between, and the accelerated gases moving through the engine nozzle is used to provide thrust, which drives the aircraft.

Transducers act as both a transmitter and a receiver of ultrasound and are capable of producing beams that are in turn directed in a variety of ways of improving the quality of the images that are seen on the screen. The main component of the transducer is made from a special piezoelectric material, which implies that they are capable of converting one form of energy to another; for instance, electrical energy can be converted to mechanical energy and vice-versa.

The research paper commences on the comprehension of components that work up several and easy equations that can be used to determine weight transfer in any car. The weight transfer will also be determined using information only obtained from the wheelbase, CH height, distribution of the static weight of the car and driver, and the design of the racetrack, or simple space amid the wheels across the car (Beckman, 2002, p.

The article by Bidisha Mukherjee, “The Relationship Between Magnetism and Electricity”, discusses the link between electric and magnetic fields, and the way one can be produced and effected by the other. It states that a changing electric field, or electric field in motion, called electricity, produces a magnetic field.

This lies in the number and atoms’ type, which constitute their individual molecules. For instance, diatomic molecules like N2 & O2 have similar atoms contradictory H2O, CH4, and CO2 whose atoms plus bonds differ radically. This influences their rate of IR absorption.

At the edges of these plates are what is known as volcanoes, openings in the surface of the earth that can at times spew hot ash, steam, lava, and molten magma that will obliterate anything and everything in their paths. They are aptly and appropriately named, given their designation long ago by the ancient Romans, who witnessed many eruptions on the island of Vulcano, and thus gave the name to the spitting mountains of molten lava in tribute to Vulcan, their god of fire and maker of weapons (Decker and Decker 7).

The paper operates mainly based on research questions which can be stated as follows: Technical log: required information, purpose, who can certify? How is data recorded, kept where? Maintenance schedule: who creates it? who approves it? types of maintenance check, flight hours and cycles, work pack, job cards maintenance records?

“The universe is reflected in the sides of a grain of sand” stated William Blake and this stands absolutely true for the region defining the South Florida Everglades (as cited in Dugger, n.d). It is a living example of how much destruction a hundred years of forced oppression can impose upon a region.

In the past few years, scientists have been indulged in such kind of imaginations which are a sight of both excitement and fear. This mind is exploring the possibility of extra-terrestrial life on earth or in the universe. Recent studies have convinced them, at least, that even bacteria are classified under this kind of life.

It is a fact that the average atmospheric temperature has increased more than 1 degree Fahrenheit since 1900. Moreover, climate changes, unexpected floods, storms, earthquakes, tsunami, etc are taking place quite frequently in recent times. Sea level is also rising because of the melting of huge ice blocs in the Polar Regions.

The first of these and one which is really worth mentioning is the Gulf Stream. The Gulf Stream is responsible for the “relatively mild climates of northeastern North America and Europe” (Murck et al., 2010). The Gulf Stream is a warm water current that begins in the Gulf of Mexico and goes out into the Atlantic through the Florida strait.

The loss of crew members is one of the highlights and turning points of the history of NASA. Important mechanical, leadership, and ethical issues can be observed in the loss of Shuttle Columbia. The recommendations balance deontological and utilitarian ethics; thus, NASA would achieve better outcomes in space exploration.

COVER STORY During the heat of the space race in the 1960s, NASA decided it needed a ballpoint pen to write in the zero gravity confines of its space capsules. After considerable research and development, the Astronaut Pen was developed at a cost of approximately $1 million US dollars.

The durability of any material in its production has been a crucial aspect; a factor that calls for eventual upgrading of the raw materials. The enhancement of glass and PMC has been effected by altering their physical properties through the optical and thermal properties enhancement (Brydson, 1999).