Awe-inspiring skyscrapers, futuristic IT zones, mushrooming businesses and impossibly clean roads, sprawled over 740 sq. kms. housing 8 million ambitious but friendly people, together comprise Bengaluru city. The various attributes of the city led to Bengaluru being dubbed as Garden City, India’s Silicon Valley, Pub Capital Of India, Fashion Capital Of India, Floriculture Capital and Science Capital Of The Country.
Bengaluru owes its name to a kind old lady who rescued a Hoysala king from the pangs of hunger by serving him some cooked pulses. As a token of appreciation for this deed, the king named his region Benda Kaaluru (city of boiled beans). The city’s history has been constructed by a number of note worthy kings belonging to the Hoysala dynasty and the Vijayanagar empire, and British governors. A number of monuments and palaces glorify various events that took place over the ages.
Bengaluru has metamorphosed from the peaceful abode of quiet retired souls to the headquarters of loud, fast-paced, tech-savvy professionals. The Bengaluru City seems to have a knack for adopting cutting-edge technologies that inevitably boost its developmental pace – its streets were the foremost to be illuminated by electricity in India, and the foundations of the country’s first aircraft manufacturers, Hindustan Aeronautics Ltd. (HAL), were laid here.
Bengaluru is India’s premier IT hub, housing the highest number of software companies in India. That the city attracts IT professionals like bees buzzing about a flower has been proved by a survey conducted by Aspiring minds Research Cell, where in Bengaluru is stated to be the preferred workplace of 72% of fresh IT graduates. The city’s IT sector records exponential growth that is unparalleled by any other Indian state.
Sound educational systems are a pre-requisite for development, and Bengaluru is home to hundreds of schools and colleges boasting commendable infrastructural facilities. From elementary schools to PG colleges, one is guaranteed to find an educational institution that caters to all their needs. The superior educational system of Bengaluru is the reason that the city is credited with cultivating most of India’s Nobel Prize nominees.
Bengaluru is enlivened by the zealous, mall-hopping, club-crashing youth of the city, who zip by the streets as though they were a part of a Grand Prix. The city is home to the most effervescent clubs, whose dance-floors are set on fire by the state’s best DJs, live musicians and bands. There is no dearth of entertainment for the people of Bengaluru, thanks to the 90-odd cinema halls and multiplexes peppered over the city. The multi-lingual state celebrates all festivals with great gusto, and numerous cultural organizations strive to regenerate the ebbing interest in the Indian tradition by conducting various entertainment programmes aimed at different audiences.
Over 230 hotels in Bengaluru (both budget and 5-star) cater to the needs of business and leisure travelers. Arranging sight-seeing trips has been made easier than ever as most of the accommodation facilities consist of a travel desk. Bengaluru is a city that features on the itinerary of all those visiting India, for its cultural diversity, rich heritage and wondrous modernity.
This article details the process of how solar electric cells are mixed with specific impurities to enhance their electric efficiencies. The silicon that is doped enhances the transfer of free electrons between the silicon wafers. It all relates to chemistry and physics in many ways.
In some detail, we will also describe how a solar PV cells use photons created and distributed by the sun to create solar generated electricity. For home solar power, this is the physical process, called the photoelectric effect, makes it possible to create passive solar energy simply from sunlight.
Doping Silicon Cells to Create Home Solar Arrays
Introducing impurities, called dopants, into the silicon making up the solar cell creates the one-way flow of electrons necessary to produce electricity more efficient. Two differently doped silicon wafers are layered together to create this flow. The next section details out the dopants that are often mixed with solar grade silicon to improve efficiencies.
Boron (p-type): Boron is an element containing three electrons within it’s atomic structure, unlike silicon, which has four outer electrons. So wherever boron is introduced into the lattice, a hole is created due to the absence of an electron. This hole creates a net positive charge and is filled by a neighboring electron vibrating in to fill the hole there, and leaving a new hole. These positively charged holes move about. Boron doped silicon is also called p-type, because the freely moving charge is positive.
Phosphorus (n-type): Phosphorus atoms contain five electrons rotating around their nucleus. This is one more than silicon. Wherever a phosphorus atom is introduced into the lattice, it has a complete set of 4 electrons to share with its 4 silicon neighbors and a 5th electron with no bond to fill. The fifth external electron rotating around the core of the atom bumps free of the atom and moves throughout the silicon wafers or lattice structure. So the introduction of phosphorus provides an electron that moves within the crystal lattice. This type of doped silicon is called n-type because the freely moving charge is negative.
Solar Cells, Electricity and the P-N Junction: What?
The magical flow direction needed to provide current of positive charge in one direction and negative charge in the opposite is created where these two differently doped silicon wafers are “mashed together” as a diode. The surface where the where n-type silicon meets p-type silicon is called the p/n junction.
An interesting aspect to define, the two materials each containing an opposite charge when placed side-by-side create an electric field where electrons pass back and forth. This simple structure is called a diode; an important and necessary processing step as silicon atoms are manufactured into silicon grade solar cells often used in the creation of residential solar panel arrays.
At the p-n junction, the extra phosphorus electron breaks free and wanders until it falls into a hole near a boron atom. Since the phosphorus site was electrically neutral before it lost its negative electron, the net charge around it now becomes positive. Similarly, the boron site, which was electrically neutral, now has one more electron, which makes the net charge at the site negative.
This process continues all along the region between n-type and p-type silicon, with extra phosphorus electrons crossing over to fill boron holes. Creating two areas with opposite atomic charges, this process creates two charges within the silicon PV cell. The result is a flow of electrons from one side to the other and the production of an electric current. The electric field is produced within the silicon wafers at the p-n junction of the diode.
Understanding How Solar Energy Fits into the Mix
We are at the dawn of a solar revolution in the United States. Every aspect of the solar industry is experiencing explosive growth. Currently, there is huge demand and great expansion across the solar PV cell manufacturing industry. Specifically, the production of solar grade silicon. There is added demand for solar sales personal as well as huge demand for solar installation crews with appropriate certification. Opportunities abound everywhere.
The renting of a solar energy system for your home is a new, attractive twist to the idea of switching to renewable energy. With the adoption of a leasing or rental model for residential solar electric systems, an average homeowner can now go green at home as well as build a part-time, solar energy business.
More Evidence That Army’s Reliance on, and Testing of, Body Armor Ceramic Plates is Fatally Flawed
As we study Friday’s release of the Government Accountability Office (GAO) report on body armor (asked for by Senators Jim Webb and Hillary Rodham Clinton in May of 2007 and by other congressional offices), it’s worth reviewing some important, related news.
First, here’s some text copied from the web site for the Ceramics and Composites Material Center at Rutgers University. (CCMC is a multi-university research center, but hosted at Rutgers.)
“Structural Ceramics/Ceramic Armor
Determination of the Root Cause of the Poor Ballistic Performance of Boron Carbide — Manish Chhowalla and Dale Niesz
Non-Destructive Evaluation of Ceramic Armor — Richard Haber and Dale Niesz
Property Measurements as Estimators of Ballistic Performance — Roger Cannon
Effect of Gas Phase Composition in Pores During Densification — M. John Matthewson and Dale Niesz
Defining Microstructural Tolerance Limits of Defects for SiC [Silicon Carbide] Armor — Richard Haber”
Note the subject of the first-listed research project. The topic focused on “Root Cause of the Poor Ballistic Performance of Boron Carbide.”
Boron carbide is one of the two most commonly used materials in the manufacture of the ceramic ballistic-protective plates used today by America’s frontline troops. Here is proof that among the real experts, university professors whose life is researching ceramic and (composite materials), there is open acknowledgment that Boron Carbide ballistic performance is “poor.”
Their research is not into how well the Boron Carbide performs. They already have the answer to that question, and under most grading systems were they to issue a grade for Boron Carbide’s ballistic performance, “poor” would generally merit a “D,” at best.
The other most commonly used material for use in today’s Army and Marine Corps ceramic ballistic-protective plates is, silicon carbide, or as it is abbreviated in the fifth item in the above list, “SiC.”
Three Rutgers University professors who participate in the premier multi-university cooperative research center in the nation dealing with ceramics, list two principal research topics having to do with the performance of the two most commonly used ceramic ballistic protective materials, and both topics raise serious, fundamental questions about: (1) of how well the ceramic material performs in the case of Boron Carbide, and (2) the key structural integrity, i.e., performance, of the second ceramic material, Silicon Carbide.
(The two authors cited for the Boron Carbide study did not respond to a phone call and emails asking for an opportunity to discuss their project. The author of the Silicon Carbide study did respond in a series of back-and-forth emails, saying, “I am not sure I am at liberty to share my results.”)
DOD’s View: there’s never been a failure of a single ceramic plate, ever…
Yet Defense Department representatives from three-star generals to public affairs civilian flacks continue to claim that there has never been one failure of a DOD-issued ceramic plate. Not a single one. Never, ever.
Which leads us to the next “paradox” in the body armor debate.
Why is the Army installing multi-million dollar x-ray devices in combat theaters to do non-destructive testing on ceramic ballistic protective plates?
Does this installation contradict the Army and Marine Corps claims of zero failures?
Or, does it reinforce the views of the above cited ceramic materials professors who are doing research on the poor performance of Boron Carbide plates, and others researching defect “limits” in the microstructure of Silicon Carbide?
Army officials contribute chapter in “Advances in Ceramic Armor IV”
The following is an abstract posted in an on-line advertisement for the above cited book. Several civilians in key roles of the Army corrupt body armor program, including Karl Masters and James Zhang, boast of their achievements in fielding the Non-Destructive Evaluation Automated Inspection System (NDE-AIS).
Abstract To properly protect personnel, the ceramic plate component in body armor must be free of cracks. Studies by the U.S. Army and Britain(2) have shown that while cracked plates can still defeat a threat, their ballistic performance is degraded. The Non-Destructive Automated Inspection System (NDE-AIS) is a deployable, high speed, automated digital radiographic inspection system that evaluates ceramic plate serviceability in the filed… results demonstrated that the NDE-AIS is 99.8% effective in keeping defective body armor plates from being reissued to Soldiers. Ceramic plates are inspected at an average rated of about 240 plates per hour in a process that automatically identifies and withdraws defective plates from service…
Let’s stop right here to take a closer look at this amazing admission from the Army’s own body armor experts. They claim a 99.85 success rate in keeping defective body armor plates from being reissued.
Note that the Army authors of this chapter are admitting that there are defective plates that have been worn by our frontline, combat troops because if there were no defective plates, there would be no need for NDE-AIS.
The Army response will be that every single plate ever issued to any Soldier was perfect, hence the perfect historical record of no failures, ever. (Yep, while the Army will admit that defective plates have been worn, they will adamantly claim no defective plate has been shot in combat, ever!! More about this incredulous claim below.)
Thus, according to the Army, the “defective” plates discovered and rejected as unfit for reissue have become so after having been subjected to the environment of tactical operations.
Let’s examine that claim, keeping in mind that the Army says that no plate has ever failed to stop a single round at the threat level for which that plate was certified.
The Army is therefore claiming that in eight years of combat in Afghanistan and in six and one-half years of combat in Iraq, all the ceramic plates that became defective due to the bumps and grinds and other environmental factors of tactical operations became defective only in that period following the plates morphing from pristine-perfect to defective. And, during this period no Soldier was ever shot while wearing a morphed, defective plate!!
That’s right. For the Army’s blatantly specious claim to be valid, we must accept that some sort of battlefield miracles have routinely occurred wherein every frontline trooper that was shot, with the round impacting in their ceramic plate, was wearing a plate that had not yet morphed from pristine-perfect (as issued) into a defective plate.
BTW — to accept the Army’s claim of no ceramic plates failures every, you must first accept the Army’s implied claim that every single plate produced in the past eight years has been perfect. Given DOD IG investigations and reports over the past two years documenting serious flaws in the First Article Testing by the Army that qualifies vendors for producing ceramic plates, only the most diehard “Kool-aide drinker” in PEO-Soldier would accept such a preposterous contention.
[NB: The Associated Press broke the story on the GAO report late morning on Friday, Oct. 16. Here's the first graph:
Investigators find flaws in Army body armor tests
By RICHARD LARDNER (AP)
WASHINGTON - The Army made critical mistakes in tests of a new body armor design, according to congressional investigators who recommend an independent review of the trials before the gear is issued to troops in Iraq and Afghanistan.]
DefenseWatch will be studying the GAO report and will report its findings as soon as completing its examination of GAO’s latest confirmation of serious flaws in the Army’s testing of this life-or-death item of personal protective equipment.
