...Running head: PHOTOSYNTHESIS VS. SEMICONDUCTOR BASED SOLAR CELL Photosynthesis Vs. Semiconductor Based Solar Cell Biology – SCI 115 23 January 2012 Abstract This paper discusses photosynthesis and how it is used by plants to harness solar energy. It also discusses semiconductor-based solar cells and how they are able to harness solar energy and convert it to electricity. This paper also compares the two types of solar energy systems and provides an overview of how the two systems are alike and how they are different. In closing, this paper will briefly explain how the laws of thermodynamics apply to each of the two energy systems. Photosynthesis Photosynthesis is a process that transfers solar energy, or energy from the sun, into a chemical energy that provides nutrients to plants and animals all over the world. Without these important nutrients, plants, animals and humans would not be able to survive on earth. “Animals and plants get energy by metabolizing nutrient molecules made by photosynthesizers.” (Mader, 2010) Semiconductor-Based Solar Cell Before discussing what a semiconductor-based solar cell is, I would first like to define a semiconductor and then explain how it is used in a solar cell type environment. A semiconductor is, “a class of materials, such as silicon and germanium, whose electrical properties lie between those of conductors (such as copper and aluminum) and insulators (such as glass and rubber)...
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...Running head: PHOTOSYNTHESIS AND SEMICONDUCTOR-BASED SOLAR CELL 1 Photosynthesis and Semiconductor-based Solar Cell Jorge Tavarez Strayer University PHOTOSYNTHESIS AND SEMICONDUCTOR-BASED SOLAR CELL 2 Abstract Energy is the capacity to do work and make things happen (Mader, 2009, p. 72). Human or other living things would not be on Earth without the source of energy. In photosynthesis, plant cells harness the sun’s solar energy with carbon dioxide to transform water molecules into oxygen, hydrogen and electrons and a semiconductor-based solar cell harnesses solar energy to convert it to electricity required by humans. In this paper, I will discuss the comparison and contrast of the two systems. I will also describe ways in which the plant cell and the solar cell are similar and different to each other. In addition, I will discuss how the laws of thermodynamics apply to each system. PHOTOSYNTHESIS AND SEMICONDUCTOR-BASED SOLAR CELL 3 Photosynthesis and Semiconductor-Based Solar Cell Two ways in which energy is created for the various life forms on earth are photosynthesis and the process that a semiconductor-based solar cell goes through to make energy. Photosynthesis is a process used by plants and other organisms to convert the light energy captured from the sun into chemical energy that can be used to fuel the organism's activities. Semiconductor-based solar cells utilize photovoltaic...
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...2012 There are many similarities and also many differences when comparing photosynthesis and semiconductor based solar cells this paper will outline those these as well as give a description of the two cycles. I will also be defining the law of thermodynamics and explaining how it applies to photosynthesis and also semiconductor based solar cells harnessing solar energy. Photosynthesis is the process of converting solar energy into chemical energy in the form of carbohydrates. For photosynthesis to occur a few factors must be present such as water, carbon dioxide, chlorophyll, and light energy. Photosynthesis consists of two sets of reactions the first being the photo portion or light reaction which is the reaction that captures solar energy the second being the synthesis reaction or Calvin cycle reactions which converts that solar energy into carbohydrates (Mader, 2010). For light reactions to occur first light energy enters the cells and is absorbed by the chlorophyll. That Light energy raises the energy level chlorophyll enabling electrons to be freed form the chlorophyll molecules. This makes the chlorophyll molecules positively charged the electrons from hydrogen atoms are attracted to the positively chlorophyll causing water molecules to break apart into oxygen atoms. The elections freed from the chlorophyll and the protons freed from water take part in the chemical reactions in the cell. The reactions result in the production of adenosine triphosphate (ATP) and nicotinamide...
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...Anthocyanin from Basella alba (Alugbati) stems as light-accumulators for making of dye-sensitized solar cells ________________________ An Investigatory Project Presented to Association of Science Educators of the Philippines (ASEP) in cooperation with Department of Education (DepEd) ________________________ As an Entry to the 2014 REGIONAL SCIENCE QUEST (Regional Level – Physical Science Team – Private Schools Category) ________________________ Proponents Dan Carlos C. Calubaquib Lisa Marielle S. Tagasa Rea Melissa P. Espiritu EFREN PAZ Research Adviser ________________________ Roosevelt College Science High School Sumulong Highway Cainta, Rizal November 2014 ACKNOWLEGDEMENT We would like to thank our parents for their nonstop support during our research project. Thank you for Mr. and Mrs. Tagasa for letting us stay at their house to do our experiments in the middle of the night. Thanks you for Mrs. Espiritu for helping us to find Indium Tin Oxide, which is essential to our study. And last but not the least, thank you for Ms. Corpuz for helping us to find the chemicals we needed. To our friends that encouraged us to continue. Thank you for Austin Kinn Rubin for giving us a piece of advice on what would be the best thing to do for our research. And to the entire Batch 10, we thank you for the support you gave. To our teachers that taught us how to think and not what to think. To Ms. Luzita Alcid, our principal, who helped us defend our study better. To our research...
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...1 1 Fundamentals of Semiconductor Electrochemistry and Photoelectrochemistry Krishnan Rajeshwar The University of Texas at Arlington, Arlington, Texas 1.1 1.2 1.3 1.3.1 1.3.2 1.3.3 1.3.4 1.4 1.4.1 1.4.2 1.4.3 1.5 1.5.1 1.5.2 1.5.3 1.5.4 1.5.5 1.6 1.7 1.7.1 1.7.2 1.7.3 1.7.4 1.7.5 Introduction and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electron Energy Levels in Semiconductors and Energy Band Model . The Semiconductor–Electrolyte Interface at Equilibrium . . . . . . . . The Equilibration Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Depletion Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mapping of the Semiconductor Band-edge Positions Relative to Solution Redox Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Surface States and Other Complications . . . . . . . . . . . . . . . . . . . Charge Transfer Processes in the Dark . . . . . . . . . . . . . . . . . . . . Current-potential Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dark Processes Mediated by Surface States or by Space Charge Layer Recombination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rate-limiting Steps in Charge Transfer Processes in the Dark . . . . . Light Absorption by the Semiconductor Electrode and Carrier Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Light Absorption...
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...An electromagnetic wave of a frequency used for long distant communication. 4. Explain the difference between a transverse wave and a longitudinal wave, and give examples of each. In a longitudinal wave, the vibration travels in the same direction that wave travels. Examples of longitudinal waves include: Sound, p-waves (earthquakes) In a transverse wave, the vibration direction is perpendicular to direction that wave travels. Examples include: Light/electromagnetic, (radio, microwave, xray, etc.), water waves, swaves (earthquakes). The major difference between longitudinal and transverse waves is their direction. Longitudinal waves move left to right while transverse waves move up and down. 5. Compare and contrast: light waves vs. sound waves Light waves are transverse and sound waves are longitudinal. Light waves can travel through a vacuum but sound waves cannot. Speed of light is nearly 300 million m/s while sound has a speed of about 340 m/s. 6. What changes the pitch of sound? The frequency of vibration. Faster vibration would cause a higher pitch while slower vibration would cause a lower pitch. 7. Explain how different factors affect the speed of sound? Speed of sound depends on factors such as altitude, humidity, and temperature because sound waves need molecules to collide in...
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...Chapter 01 1.1 Introduction: A storage device may be used to store energy from renewable energy source in DC form which can be converted to AC power by using power inverter. Pulse Width Modulated (PWM) technique may be used to control output rms voltage of the inverter. As the load is variable, the power consumed by the load (PL) may be smaller than the power generated from the renewable energy source (PR). Therefore a Flexible AC Transmission System (FACTS) Controller may be used to supply the additional power (PR – PL) from the renewable energy source to the grid. On the other hand if the power consumed by the load (PL) is greater than the power generated from the renewable energy source (PR) therefore the same FACTS controller may be used to absorb the additional power (PR – PL) from the grid to the load. In this case the FACTS controller must allow bi-directional power flow. If all the active houses are connected to the grid in the same way (proposed way), the active houses that generate more power than the load can be supplied to the active houses that generate less power than the load. Therefore a suitable FACTS controller should be designed in such a way that it can control the power flow in both directions. The idea is illustrated in the following figure. 1.2 Objectives: • Study on different FACTS controllers • Study on different renewable energy sources • Study on different...
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...McKinsey Global Institute May 2013 Disruptive technologies: Advances that will transform life, business, and the global economy The McKinsey Global Institute The McKinsey Global Institute (MGI), the business and economics research arm of McKinsey & Company, was established in 1990 to develop a deeper understanding of the evolving global economy. Our goal is to provide leaders in the commercial, public, and social sectors with the facts and insights on which to base management and policy decisions. MGI research combines the disciplines of economics and management, employing the analytical tools of economics with the insights of business leaders. Our “micro-to-macro” methodology examines microeconomic industry trends to better understand the broad macroeconomic forces affecting business strategy and public policy. MGI’s in-depth reports have covered more than 20 countries and 30 industries. Current research focuses on four themes: productivity and growth, the evolution of global financial markets, the economic impact of technology and innovation, and urbanization. Recent reports have assessed job creation, resource productivity, cities of the future, and the impact of the Internet. MGI is led by McKinsey & Company directors Richard Dobbs and James Manyika. Yougang Chen, Michael Chui, Susan Lund, and Jaana Remes serve as MGI principals. Project teams are led by a group of senior fellows and include consultants from McKinsey’s offices around the world. These teams draw...
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...Answers to Conceptual Integrated Science End-of-Chapter Questions Chapter 1: About Science Answers to Chapter 1 Review Questions 1 The era of modern science in the 16th century was launched when Galileo Galilei revived the Copernican view of the heliocentric universe, using experiments to study nature’s behavior. 2 In Conceptual Integrated Science, we believe that focusing on math too early is a poor substitute forconcepts. 3 We mean that it must be capable of being proved wrong. 4 Nonscientific hypotheses may be perfectly reasonable; they are nonscientific only because they are not falsifiable—there is no test for possible wrongness. 5 Galileo showed the falseness of Aristotle’s claim with a single experiment—dropping heavy and lightobjects from the Leaning Tower of Pisa. 6 A scientific fact is something that competent observers can observe and agree to be true; a hypothesis is an explanation or answer that is capable of being proved wrong; a law is a hypothesis that has been tested over and over and not contradicted; a theory is a synthesis of facts and well-tested hypotheses. 7 In everyday speech, a theory is the same as a hypothesis—a statement that hasn’t been tested. 8 Theories grow stronger and more precise as they evolve to include new information. 9 The term supernatural literally means “above nature.” Science works within nature, not above it. 10 They rely on subjective personal experience and do not lead to testable hypotheses. They lie outside...
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...*Physics Prelims (1-7).qxd 12/11/08 1:00 PM Page 1 SCIENCE VISUAL RESOURCES PHYSICS An Illustrated Guide to Science The Diagram Group *Physics Prelims (1-7).qxd 12/11/08 1:00 PM Page 2 Physics: An Illustrated Guide to Science Copyright © 2006 The Diagram Group Author: Derek McMonagle BSc PhD CSci CChem FRSC Editors: Catherine Gaunt, Jamie Stokes Design: Anthony Atherton, Richard Hummerstone, Lee Lawrence, Tim Noel-Johnson, Phil Richardson Illustration: Peter Wilkinson Picture research: Neil McKenna Indexer: Martin Hargreaves All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 For Library of Congress Cataloging-in-Publication Data, please contact the Publisher ISBN 0-8160-6167-X Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at 212/967-8800 or 800/322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Printed in China CP Diagram 10 9 8 7 6 5 4 3 2 This book is printed on acid-free paper. *Physics Prelims (1-7).qxd 12/11/08 1:00 PM Page...
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...NOTE: This PDF document has a handy set of “bookmarks” for it, which are accessible by pressing the Bookmarks tab on the left side of this window. ***************************************************** We are the last. The last generation to be unaugmented. The last generation to be intellectually alone. The last generation to be limited by our bodies. We are the first. The first generation to be augmented. The first generation to be intellectually together. The first generation to be limited only by our imaginations. We stand both before and after, balancing on the razor edge of the Event Horizon of the Singularity. That this sublime juxtapositional tautology has gone unnoticed until now is itself remarkable. We're so exquisitely privileged to be living in this time, to be born right on the precipice of the greatest paradigm shift in human history, the only thing that approaches the importance of that reality is finding like minds that realize the same, and being able to make some connection with them. If these books have influenced you the same way that they have us, we invite your contact at the email addresses listed below. Enjoy, Michael Beight, piman_314@yahoo.com Steven Reddell, cronyx@gmail.com Here are some new links that we’ve found interesting: KurzweilAI.net News articles, essays, and discussion on the latest topics in technology and accelerating intelligence. SingInst.org The Singularity Institute for Artificial Intelligence: think tank devoted to increasing...
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...1 KHYBER PAKHTUNKHWA PUBLIC SERVICE COMMISSION SYLLABUS FOR PROVINCIAL MANAGEMENT SERVICE COMPETITIVE EXAMINATION The Syllabus and standard for the Competitive Examination for the Provincial Management Service shall be as under : 1. The Examination shall include compulsory and optional subjects, and every candidate shall take all the compulsory subjects and opt for three of the optional subjects carrying 600 marks in all but not more than 200 marks from a single group. 2. A candidate shall answer the language papers in the language concerned. The question paper in Islamiat is to be answered in Urdu or English. All other papers must be answered in English. Violation of this instruction shall incur cancellation of the concerned paper(s) and consequently award of Zero. 3. The compulsory and optional subjects and maximum marks fixed for each subject shall be as below: Sr. No. 1 2 3 COMPULSORY SUBJECTS Subjects English (Précis & Composition) English Essay General Knowledge (a) Current Affairs 100 (b) Every Day Science 100 (c) Pakistan Affairs 100 Islamiat Viva Voce Total Maximum Marks 100 100 300 100 300 900 600 120 4 5 Qualifying marks in the aggregate of written papers: Qualifying marks in the Viva Voce: The non-Muslim candidates will have the option to take Islamiat as a compulsory subject or otherwise Pakistan Affairs (General Knowledge PaperIII) will be treated of 200 marks and counted in lieu of Islamiat. A candidate who fails to appear in any of the compulsory...
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...ate Aptitude Test in Engineering GATE 2014 Brochure Table of Contents 1. Introduction .............................................................................................................1 2. About GATE 2014 ......................................................................................................1 2.1. Financial Assistance ............................................................................................................................ 1 2.2 Employment ............................................................................................................................................ 2 2.3 Administration ....................................................................................................................................... 2 3.1 Changes Introduced in GATE 2013 that will continue to remain in force for GATE 2014 .......................................................................................................................................................... 3 4.1 Eligibility for GATE 2014 ................................................................................................................... 4 4.2 GATE Papers ............................................................................................................................................ 5 4.3 Zone-Wise List of Cities in which GATE 2014 will be Held ................................................... 6 4.4 Zone-Wise List of Cities for 3rd...
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...2014-2015 Undergraduate Academic Calendar and Course Catalogue Published June 2014 The information contained within this document was accurate at the time of publication indicated above and is subject to change. Please consult your faculty or the Registrar’s office if you require clarification regarding the contents of this document. Note: Program map information located in the faculty sections of this document are relevant to students beginning their studies in 2014-2015, students commencing their UOIT studies during a different academic year should consult their faculty to ensure they are following the correct program map. i Message from President Tim McTiernan I am delighted to welcome you to the University of Ontario Institute of Technology (UOIT), one of Canada’s most modern and dynamic university communities. We are a university that lives by three words: challenge, innovate and connect. You have chosen a university known for how it helps students meet the challenges of the future. We have created a leading-edge, technology-enriched learning environment. We have invested in state-of-the-art research and teaching facilities. We have developed industry-ready programs that align with the university’s visionary research portfolio. UOIT is known for its innovative approaches to learning. In many cases, our undergraduate and graduate students are working alongside their professors on research projects and gaining valuable hands-on learning, which we believe is integral...
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...Employment News 31 May - 6 June 2014 www.employmentnews.gov.in 21 UNION PUBLIC SERVICE COMMISSION EXAMINATION NOTICE NO. 09/2014-CSP (LAST DATE FOR RECEIPT OF APPLICATIONS : 30/06/2014) DATE :31.05.2014 CIVIL SERVICES EXAMINATION, 2014 (Commission’s website-http://upsc.gov.in) F. No. 1/5/2013-E.I(B) : Preliminary Examination of the Civil Services Examination for recruitment to the Services and Posts mentioned below will be held by the Union Public Service Commission on 24th Aug., 2014 in accordance with the Rules published by the Department of Personnel & Training in the Gazette of India Extraordinary dated 31st May, 2014. (i) Indian Administrative Service. (ii) Indian Foreign Service. (iii) Indian Police Service. (iv) Indian P & T Accounts & Finance Service, Group ‘A’. (v) Indian Audit and Accounts Service, Group ‘A’. (vi) Indian Revenue Service (Customs and Central Excise), Group ‘A’. (vii) Indian Defence Accounts Service, Group ‘A’. (viii) Indian Revenue Service (I.T.), Group ‘A’. (ix) Indian Ordnance Factories Service, Group ‘A’ (Assistant Works Manager, Administration). (x) Indian Postal Service, Group ‘A’. (xi) Indian Civil Accounts Service, Group ‘A’. (xii) Indian Railway Traffic Service, Group ‘A’. (xiii) Indian Railway Accounts Service, Group 'A'. (xiv) Indian Railway Personnel Service, Group ‘A’. (xv) Post of Assistant Security Commissioner in Railway Protection Force, Group ‘A’ (xvi) Indian Defence Estates Service, Group...
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