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Development of Electrochemical Methods for Detection of Pesticides and Biofuel
Development of Electrochemical Methods for Detection of Pesticides and Biofuel Production Asli Sahin Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2012 © 2012 Asli Sahin All Rights Reserved ABSTRACT Development of Electrochemical Methods for Detection of Pesticides and Biofuel Production Asli Sahin Electrochemical methods coupled with biological elements are used in industrial, medical and environmental applications. In this thesis we will discuss two such applications: an electrochemical biosensor for detection of pesticides and biofuel generation using electrochemical methods coupled with microorganisms. Electrochemical biosensors are commonly used as a result of their selectivity, sensitivity, rapid response and portability. A common application for electrochemical biosensors is detection of pesticides and toxins in water samples. In this thesis, we will focus on detection of organosphosphates (OPs), a group of compounds that are commonly used as pesticides and nerve agents. Rapid and sensitive detection of these compounds has been an area of active research due to their high toxicity. Amperometric and potentiometric electrochemical biosensors that use organophosphorus hydrolase (OPH), an enzyme that can hydrolyze a broad class of OPs, have been reported for field detection of OPs. Amperometry is used for detection of electroactive leaving groups and potentiometry is used for detection of pH changes that take place during the hydrolysis reaction. Both these methods have limitations: using amperometric biosensors, very low limits of detection are achieved but this method is limited to the few OPs with electroactive leaving groups, on the other hand potentiometric biosensor can be used for detection of all OPs but they don’t have low enough limits of detection. -
Outline of Physical Science
Outline of physical science “Physical Science” redirects here. It is not to be confused • Astronomy – study of celestial objects (such as stars, with Physics. galaxies, planets, moons, asteroids, comets and neb- ulae), the physics, chemistry, and evolution of such Physical science is a branch of natural science that stud- objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explo- ies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a “physical sions, gamma ray bursts, and cosmic microwave background radiation. science”, together called the “physical sciences”. How- ever, the term “physical” creates an unintended, some- • Branches of astronomy what arbitrary distinction, since many branches of physi- cal science also study biological phenomena and branches • Chemistry – studies the composition, structure, of chemistry such as organic chemistry. properties and change of matter.[8][9] In this realm, chemistry deals with such topics as the properties of individual atoms, the manner in which atoms form 1 What is physical science? chemical bonds in the formation of compounds, the interactions of substances through intermolecular forces to give matter its general properties, and the Physical science can be described as all of the following: interactions between substances through chemical reactions to form different substances. • A branch of science (a systematic enterprise that builds and organizes knowledge in the form of • Branches of chemistry testable explanations and predictions about the • universe).[1][2][3] Earth science – all-embracing term referring to the fields of science dealing with planet Earth. Earth • A branch of natural science – natural science science is the study of how the natural environ- is a major branch of science that tries to ex- ment (ecosphere or Earth system) works and how it plain and predict nature’s phenomena, based evolved to its current state. -
Metal Complexes of Penicillin and Cephalosporin Antibiotics
I METAL COMPLEXES OF PENICILLIN AND CEPHALOSPORIN ANTIBIOTICS A thesis submitted to THE UNIVERSITY OF CAPE TOWN in fulfilment of the requirement$ forTown the degree of DOCTOR OF PHILOSOPHY Cape of by GRAHAM E. JACKSON University Department of Chernis try, University of Cape Town, Rondebosch, Cape, · South Africa. September 1975. The copyright of th:s the~is is held by the University of C::i~r:: To\vn. Reproduction of i .. c whole or any part \ . may be made for study purposes only, and \; not for publication. The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgementTown of the source. The thesis is to be used for private study or non- commercial research purposes only. Cape Published by the University ofof Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University '· ii ACKNOWLEDGEMENTS I would like to express my sincere thanks to my supervisors: Dr. L.R. Nassimbeni, Dr. P.W. Linder and Dr. G.V. Fazakerley for their invaluable guidance and friendship throughout the course of this work. I would also like to thank my colleagues, Jill Russel, Melanie Wolf and Graham Mortimor for their many useful conrrnents. I am indebted to AE & CI for financial assistance during the course of. this study. iii ABSTRACT The interaction between metal"'.'ions and the penici l)in and cephalosporin antibiotics have been studied in an attempt to determine both the site and mechanism of this interaction. The solution conformation of the Cu(II) and Mn(II) complexes were determined using an n.m.r, line broadening, technique. -
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® The Americas Journal of Plant Science and Biotechnology ©2011 Global Science Books Living in the O-zone: Ozone Formation, Ozone-Plant Interactions and the Impact of Ozone Pollution on Plant Homeostasis Godfrey P. Miles1 • Marcus A. Samuel2* 1 U.S. Department of Agriculture – Agricultural Research Service, 5230 Konnowac Pass Road, Wapato, WA 98951, USA 2 Department of Biological Sciences, University of Calgary, 2500, University Drive, NW, Calgary, AB, T2N 1N4, Canada Corresponding author : * [email protected] ABSTRACT Ozone (O3) is a key constituent of the terrestrial atmosphere. Unlike in the stratosphere, where O3 provides an essential barrier to incoming UV radiation, within the troposphere, it is a major secondary air pollutant that is estimated to cause more damage to plant life than all other air pollutants combined. In the troposphere, O3 is produced by photochemical oxidation of primary precursor emissions of volatile organic compounds (VOCs), carbon monoxide (CO), and sulfur dioxide (SO2) in association with elevated levels of oxides of nitrogen (NOx NO + NO2). Because of its strong oxidizing potential, ozone is damaging to plant life through oxidative damage to proteins, nucleic acids and lipids either directly or as a result of reactive oxygen species (ROS) derived from O3 decomposition. In plants, ROS, directly or indirectly derived from O3 exposure, are routinely scavenged by an array of enzymatic and non-enzymatic antioxidant defense mechanisms. The various ROS generated by O3 have strong influence on the plant’s biochemical -
Max-Planck-Institut Für Mathematik in Den Naturwissenschaften Leipzig
Max-Planck-Institut fur¨ Mathematik in den Naturwissenschaften Leipzig A formal setting for the evolution of chemical knowledge by Guillermo Restrepo and J¨urgen Jost Preprint no.: 77 2020 A formal setting for the evolution of chemical knowledge Guillermo Restrepo1;2∗and J¨urgenJost1;3y July 10, 2020 1Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany 2Interdisciplinary Center for Bioinformatics, Leipzig University, Germany 3The Santa Fe Institute, Santa Fe, NM 87501, USA Abstract Chemistry shapes and creates the disposition of the world's resources and exponentially provides new substances for the welfare and hazard of our civilisation. Over the history chemists { driven by social, semiotic and material forces { have shaped the discipline, while creating a colossal corpus of information and knowledge. Historians and sociologists, in turn, have devised causal narratives and hypotheses to explain major events in chemistry as well as its current status. In this Perspective we discuss the approaches to the evolution of the social, semiotic and material systems of chemistry. We critically analyse their reaches and challenge them by putting forward the need of a more holistic and formal setting to mod- elling the evolution of chemical knowledge. We indicate the advantages for chemistry of considering chemical knowledge as a complex dynamical system, which, besides casting light on the past and present of chemistry, allows for estimating its future, as well as the effects of hypothetical past events. We describe how this approach turns instrumental for forecasting the effects of material, semiotic and social perturbations upon chemical knowledge. Available data and the most relevant formalisms to analyse the different facets of chemical knowledge are discussed. -
MOLGEN, a Generator for Structural Formulas Adalbert Kerber
MATCH MATCH Commun. Math. Comput. Chem. 80 (2018) 733-744 Communications in Mathematical and in Computer Chemistry ISSN 0340 - 6253 MOLGEN, a Generator for Structural Formulas Adalbert Kerber Department of Mathematics, University of Bayreuth, [email protected] (Received March 10, 2017) Abstract MOLGEN, a generator of all structural formulas corresponding to a given molecular formula, is described. Its history is mentioned, applications are touched, and further re- search projects are suggested. From the history of Mathematical Chemistry The first step towards Mathematical Chemistry was the attempt to develop a mathematical model of the concept of molecule using an arithmetic description of a molecule, a molecular formula, e.g. C6H6. But this does not suffice to distinguish molecules uniquely, as Alexander von Humboldt (1769-1859) stated, cf. [25], in vol. I, page 128, of [16], published in 1797: Drei Korper¨ a, b und c konnen¨ aus gleichen Quantitaten¨ Sauerstoff, Wasserstoff, Kohlenstoff, Stickstoff und Metall zusammengesetzt und in ihrer Natur doch un- endlich verschieden seyn. Thus, Humboldt states that chemical compounds (Korper¨ ) should exist that contain the same quantities of oxygen, hydrogen, carbon, nitrogen or metal while they are essentially different. On page 127 he even uses the word ‘Bindung’ (bond). This statement turned out to be true a quarter of a century later. Humboldt had met in Gay-Lussac’s laboratory in Paris a young student, Justus Liebig. Humboldt saw immediately his talent and recommended him for a pro- fessorship in chemistry at the University of Gießen which Liebig received when he was just 21 years old. Liebig (1803-1873) proved Humboldt’s statement in 1823/1824 by an examination This work is licensed under a Creative Commons Attribution 4.0 International License. -
Energy Technology and Management
ENERGY TECHNOLOGY AND MANAGEMENT Edited by Tauseef Aized Energy Technology and Management Edited by Tauseef Aized Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Iva Simcic Technical Editor Teodora Smiljanic Cover Designer Jan Hyrat Image Copyright Sideways Design, 2011. Used under license from Shutterstock.com First published September, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from [email protected] Energy Technology and Management, Edited by Tauseef Aized p. cm. ISBN 978-953-307-742-0 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Part 1 Energy Technology 1 Chapter 1 Centralizing the Power Saving Mode for 802.11 Infrastructure Networks 3 Yi Xie, Xiapu Luo and Rocky K. -
Mathematical Chemistry! Is It? and If So, What Is It?
Mathematical Chemistry! Is It? And if so, What Is It? Douglas J. Klein Abstract: Mathematical chemistry entailing the development of novel mathe- matics for chemical applications is argued to exist, and to manifest an extreme- ly diverse range of applications. Yet further it is argued to have a substantial history of well over a century, though the field has perhaps only attained a de- gree of recognition with a formal widely accepted naming in the last few dec- ades. The evidence here for the broad range and long history is by way of nu- merous briefly noted example sub-areas. That mathematical chemistry was on- ly recently formally recognized is seemingly the result of its having been somewhat disguised for a period of time – sometimes because it was viewed as just an unnamed part of physical chemistry, and sometimes because the rather frequent applications in other chemical areas were not always viewed as math- ematical (often involving somewhat ‘non-numerical’ mathematics). Mathemat- ical chemistry’s relation to and distinction from computational chemistry & theoretical chemistry is further briefly addressed. Keywords : mathematical chemistry, physical chemistry, computational chemistry, theoretical chemistry. 1. Introduction Chemistry is a rich and complex science, exhibiting a diversity of reproduci- ble and precisely describable predictions. Many predictions are quantitative numerical predictions and also many are of a qualitative (non-numerical) nature, though both are susceptible to sophisticated mathematical formaliza- tion. As such, it should naturally be anticipated that there is a ‘mathematical chemistry’, rather likely with multiple roots and with multiple aims. Mathe- matical chemistry should focus on mathematically novel ideas and concepts adapted or developed for use in chemistry (this view being much in parallel with that for other similarly named mathematical fields, in physics, or in biology, or in sociology, etc. -
Mathematical Thinking in Chemistry
Mathematical Thinking in Chemistry Guillermo Restrepo and José L. Villaveces Abstract: Mathematical chemistry is often thought to be a 20 th -century sub- discipline of chemistry, but in this paper we discuss several early chemical ide- as and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl’s description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cas- es we discuss are Plato’s triangles, Geoffroy’s affinity table, Lavoisier’s classifi- cation of substances and their relationships, Mendeleev’s periodic table, Cay- ley’s enumeration of alkanes, Sylvester’s association of algebra and chemistry, and Wiener’s relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a cen- tury of history. Keywords : mathematical chemistry, mathematical way of thinking, functional thinking, chemical graphs, QSAR . 1. Introduction Mathematical chemistry, or better, discrete mathematical chemistry (Re- strepo & Villaveces 2012), appeared as a new subdiscipline in the second half of the 20 th century. Instances of it are the launching of three scientific jour- nals 1 devoted to mathematical chemistry, the creation of the International Academy of Mathematical Chemistry,2 the publication of specialized books on mathematical chemistry, and the scientific meetings on the subject that currently gather a growing scientific community. The fact of having consoli- dated a community in the second half of the 20 th century suggests that the relationship between mathematics and chemistry is something new, perhaps beginning in the 20 th century. -
Mathematical Aspects of the Periodic Law
MATHEMATICAL ASPECTS OF THE PERIODIC LAW ¶ Guillermo Restrepo*§ and Leonardo A. Pachón** *Laboratorio de Química Teórica, Universidad de Pamplona, Pamplona, Norte de Santander, Colombia. ** Escuela de Física, Facultad de Ciencias, Universidad Industrial de Santander, Santander, Colombia. Abstract: We review different studies of the Periodic Law and the set of chemical elements from a mathematical point of view. This discussion covers the first attempts made in the 19th century up to the present day. Mathematics employed to study the periodic system includes number theory, information theory, order theory, set theory and topology. Each theory used shows that it is possible to provide the Periodic Law with a mathematical structure. We also show that it is possible to study the chemical elements taking advantage of their phenomenological properties, and that it is not always necessary to reduce the concept of chemical elements to the quantum atomic concept to be able to find interpretations for the Periodic Law. Finally, a connection is noted between the lengths of the periods of the Periodic Law and the philosophical Pythagorean doctrine. Key words Chemical Elements, Periodic Law, Number Theory, Information Theory, Order Theory, Set Theory, Topology, Mathematical Chemistry 1. INTRODUCTION One of the most important constructs of chemical knowledge is the Periodic Table. This graphical representation of the underlying law of the chemical elements, the Periodic Law, has been studied from several points of view, the majority of them related to physics (Scerri et al., 1998). These studies are focused on the atom as a refinement of the concept of element to try to explain the similarities and trends among the chemical elements, which is what at the end, the Periodic Law shows. -
Advanced Certification in Science - Level I
Advanced Certification in Science - Level I www.casiglobal.us | www.casi-india.com | CASI New York; The Global Certification body. Page 1 of 391 CASI New York; Reference material for ‘Advanced Certification in Science – Level 1’ Recommended for college students (material designed for students in India) About CASI Global CASI New York CASI Global is the apex body dedicated to promoting the knowledge & cause of CSR & Sustainability. We work on this agenda through certifications, regional chapters, corporate chapters, student chapters, research and alliances. CASI is basically from New York and now has a presence across 52 countries. World Class Certifications CASI is usually referred to as one of the BIG FOUR in education, CASI is also referred to as the global certification body CASI offers world class certifications across multiple subjects and caters to a vast audience across primary school to management school to CXO level students. Many universities & colleges offer CASI programs as credit based programs. CASI also offers joint / cobranded certifications in alliances with various institutes and universities. www.casiglobal.us CASI India CASI India has alliances with hundreds of institutes in India where students of these institutes are eligible to enroll for world class certifications offered by CASI. The reach through such alliances is over 2 million citizens CASI India also offers cobranded programs with Government Polytechnic and many other institutes of higher learning. CASI India has multiple franchises across India to promote certifications especially for school students. www.casi-india.com Volunteering @ CASI NY CASI India / CSR Diary also provide volunteering opportunities and organizes mega format events where in citizens at large can also volunteer for various causes. -
Computer Chemistry
Computer Chemistry Computational chemistry is a branch of chemistry that uses principles of computer science to assist in solving chemical problems. It uses the results of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures and properties of molecules and solids. Its necessity arises from the well- known fact that apart from relatively recent results concerning the hydrogen molecular ion (see references therein for more details), the quantum n-body problem cannot be solved analytically, much less in closed form. While its results normally complement the information obtained by chemical experiments, it can in some cases predict hitherto unobserved chemical phenomena. It is widely used in the design of new drugs and materials. Examples of such properties are structure (i.e. the expected positions of the constituent atoms), absolute and relative (interaction) energies, electronic charge distributions, dipoles and higher multipole moments, vibrational frequencies, reactivity or other spectroscopic quantities, and cross sections for collision with other particles. The methods employed cover both static and dynamic situations. In all cases the computer time and other resources (such as memory and disk space) increase rapidly with the size of the system being studied. That system can be a single molecule, a group of molecules, or a solid. Computational chemistry methods range from highly accurate to very approximate; highly accurate methods are typically feasible only for small systems. Ab initio methods are based entirely on theory from first principles. Other (typically less accurate) methods are called empirical or semi- empirical because they employ experimental results, often from acceptable models of atoms or related molecules, to approximate some elements of the underlying theory.