...Week 7 SPECTROSCOPY Learning outcomes • Describe what a photon is, and calculate the energy, frequency and wavelength of a given photon in relation to electromagnetic radiation. • Describe the process where a UV/visible photon is absorbed by an atom or molecule. • Interpret the data from UV/visible spectrum: – Complete dilution calculations in order to produce a standard curve. – Determine an equation for the line of best fit to a linear set of data. – Use the equation, y = mx + c in order to determine the concentration of an unknown solution. Electromagnetic Radiation • Electromagnetic radiation consists of an oscillating electric and magnetic field that carries energy through space at the speed of light, c, Amplitude c= × C = speed of light, 3.00 x108 m/s = wavelength, m = frequency, (number of waves per second) s-1 Maxwell ‘s description of behaviour of light Longer Lower Wavelength (SI unit : meter) Frequency (SI unit : second-1/ Hz) 1 MHz = 106 Hz 1 GHz = 109 Hz 1 THz = 1012 Hz 1 m = 10-6 m 1 nm = 10-9 m 1 pm = 10-12 m Example 7.1 The wavelength of the green light from a traffic signal is centered at 522 nm. What is the frequency of this radiation? Solution c= × ������ = Try this: 7.9 The average distance between Mars and Earth is about 1.3 x 108 miles. How long (in minutes) would it take TV pictures transmitted from the Viking space vehicle on Mars’ surface to reach earth? (1 mile = 1.61 km) ������������������������������������������������...
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...Fachhochschule Bonn-Rhein-Sieg University of Applied Sciences Fachbereich Angewandte Naturwissenschaften Department of Applied Sciences Laboratory Course in Instrumental Analysis WS 2014 - 2015 Instructor: Tutors: Dr. G. Holl Dipl. Ing (FH) Olav Schweiger Dipl. Chem Michel Bergs Experiment: UV/VIS spectroscopy – Principles Note: Please use the gaps in this instruction for your answers, if needed use the back of the sheet. Do not use any extra sheets of paper. Handwriting is OK you don’t need a computer for your protocol. Instrumental Analysis Lab UV/VIS spectroscopy - Principles 1.1. Basic Principles - What is a UV-visible Spectrum? Introduction A spectrum is a graphical representation of the amount of light absorbed or transmitted by matter as a function of wavelength. A UV-visible spectrophotometer measures absorbance or transmittance from the UV range to which the human eye is not sensitive to the visible wavelength range to which the human eye is sensitive. In the following experiment the spectra of a coloured and an uncoloured compound is measured. It will be demonstrated that in many cases uncoloured compounds have a UV absorbance. Reagents and Equipment O H3C Caffeine (a) Erythrosine deionized water CH3 N Two 1.0 L volumetric flasks 0.5 mL syringe or pipette Disposable glass pipettes (minimum 3) 10-mm path length quartz cell, 3 ml volume O N N N CH3 (a) ...
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...APPLICATIONS OF ELECTRON MICROSCOPY IN MATERIALS AND METALLURGICAL ENGINEERING A TERM PAPER PRESENTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE POSTGRADUATE COURSE MME 604 [ELECTON OPTICS AND MICROSCOPY] BY MARK, UDOCHUKWU 20044449298 SUBMITTED TO ENGR. PROF. O. O. ONYEMAOBI [EXAMINER] DEPARTMENT OF MATERIALS AND METALLURGICAL ENGNEERING FEDERAL UNIVERSITY OF TECHNOLOGY, OWERRI AUGUST 2005 i Markudo [2005] PREFACE The electron microscope is an indispensable modern analytical and research tool. Microscopy is employed in all branches of science to identify materials, characterize unknown substances or study the properties of known materials. This term paper surveys the applications of electron microscopy in the field of materials and metallurgical engineering. I hereby acknowledge my lecturer on Electron Optics and Microscopy (MME 604), Engr. Prof. O. O. Onyemaobi. He has been sharpening my research and writing skills since my undergraduate days. This is the third term paper I will be submitting to him. ii TABLE OF CONTENTS Title Page Preface Table of Contents CHAPTER ONE 1.0 1.1 1.2 1.2.1 1.2.2 1.2.3 Introduction Materials and Metallurgical Engineering Microscopes and Microscopy Levels of Structure Methods of Structural and Compositional Elucidation Microscopy i ii iii-v 1-12 1 1 3 4 6 8 13-24 13 13 14 16 17 18 19 21 CHAPTER TWO 2.0 2.1 2.2 2.3 2.3.1 2.3.2 2.3.3 2.3.4 Transmission Electron Microscopy Interaction of Electrons...
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...Analysis was performed at 25 ± 2oC. The NLC dispersion was diluted with double distilled water. Few drops of the dispersion were placed on the cover slip and allowed to dry in rotator drier to form a hard film. After formation, the images were captured (Fig. 5.4). Fig. 5.4: SEM analysis of of NLC. 5.4.2 Determination of particle size, polydispersity index These measurements were performed in triplicates. The particle size and polydispersity index (PI) of nanostructured lipids were determined by Zetasizer Nano ZS (Malvern Instrument), Malvern, UK) at a temperature of 25±2oC at 90oC to the incident beam applying the principle of photon correlation spectroscopy. Dispersion were diluted with double distilled water to ensure that light scattering intensity, was within the instrument intensity range (Table...
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...Brownian motion is the random thermal, translational, and rotational motion (diffusion) of the particles in the solution. When these particles come in the path of laser light, they scatter the light. Because of the constant motion of the particles, there is a temporal variation in the intensity of the scattered light. These variations are recorded and detected by the detectors in the form of intensity versus time profile. The autocorrelator of the instrument creates a correlation function, which is an exponentially decaying time function. The decay constant of this function is related to the diffusion coefficient in the Stokes-Einstein equation (Equation...
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...Final examination Theory 1. Explain the dispersion of light by a transparent dielectric material. The phenomen of dispersion is connected to the fact that the refractive index is dependent on the wavelength. Due to dispersion, the light waves from a complex radiation are bent by different angles as they enter a dispersive medium and they may be visualized separately. The index of refraction of a transparent dielectric medium is defined as the ratio of the speed of an electromagnetic wave in empty space to its speed in the medium. . It is a measure of the slowing factor for light traveling in that medium The refractive index can be expressed as a function of the electric and magnetic properties of the medium . For most of the materials that are transparent to visible light and . Hence the magnetic properties have a small effect on the light propagation. When an electromagnetic wave is incident on a medium, it electrically polarizes the molecules. This changes the value of which in its turn, determines the index of refraction. The process is wavelength dependent: different wavelengths will induce different polarizations of the molecules and, as a result, and will be different. So, the index of refraction changes with wavelength: The phenomenon described above is known as the dispersion of light. Equation is the dispersion relation. For most of the materials, decreases with the wavelength (see figure1). This phenomenon is known as normal dispersion...
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...HEAD | PREVIOUS | Chapter 1 Introduction 1.1 What is a Plasma? 1.1.1 An ionized gas A plasma is a gas in which an important fraction of the atoms is ionized, so that the electrons and ions are separately free. When does this ionization occur? When the temperature is hot enough. Balance between collisional ionization and recombination: | Figure 1.1: Ionization and Recombination Ionization has a threshold energy. Recombination has not but is much less probable. Threshold is ionization energy (13.6eV, H). χi | Figure 1.2: Ionization and radiative recombination rate coefficients for atomic hydrogen Integral over Maxwellian distribution gives rate coefficients (reaction rates). Because of the tail of the Maxwellian distribution, the ionization rate extends below T = χi. And in equilibrium, when | nionsnneutrals | = | < σi v >< σr v > | , | | (1.1) | the percentage of ions is large ( ∼ 100%) if electron temperature: Te >~χi/10. e.g. Hydrogen is ionized for Te >~1eV (11,600°k). At room temp r ionization is negligible. For dissociation and ionization balance figure see e.g. Delcroix Plasma Physics Wiley (1965) figure 1A.5, page 25. 1.1.2 Plasmas are Quasi-Neutral If a gas of electrons and ions (singly charged) has unequal numbers, there will be a net charge density, ρ. ρ = ne(−e) + ni(+e) = e (ni − ne) | | (1.2) | This will give rise to an electric field via ∇ . E= | ρϵ0 | = | eϵ0 | (ni − ne) | | (1.3) | Example:...
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...ANALYSIS OF FOOD PRODUCTS FOOD SCIENCE 581 Instructor Prof. D. Julian McClements Room 238, Chenoweth Lab Tel: 545 1019 Email: mcclements@foodsci.umass.edu Course Description Food products are analyzed for a variety of reasons, e.g., compliance with legal and labeling requirements, assessment of product quality, determination of nutritive value, detection of adulteration, research and development. The lectures will cover the basic principles of analytical procedures and techniques commonly used to provide information about the chemical composition, structure and physical properties of food materials. The aim of the laboratory classes is to give students experience in performing food analysis experiments, analyzing data and reporting their findings. In addition, students are expected to work in teams on a special project where they will identify and critically assess the most appropriate analytical methods for analyzing the properties of a particular food product. [4 Credits]. Textbooks * Introduction to Food Analysis. S.S. Nielsen, 1998. Aspen Publishers - The best general overview of food analysis techniques currently available. (Required). * Food Analysis: Theory and Practice. Y. Pomeranz and C.E. Meloan, Chapman and Hall - General overview of food analysis techniques (Useful) * Food Analysis: Principles and Techniques. D.W. Gruenwedel and J.R. Whitaker, Marcel Dekker - General overview of food analysis techniques (Useful) * Analytical Chemistry of Foods...
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...Chapter 10 : The Sun THE SUNS ATMOSPHERE * the sun is so hot that it neither has a liquid or solid matter anywhere inside of it * moving down into the sun there is denser and hotter masses Photosphere (“sphere of light”) * The photosphere is the innermost of layer of the three layers that comprise the suns atmosphere * A gas layer of the sun that has the most visible light * It is about 400 km thick * Density of the photosphere is low by the earth standards about 0.01% as the air we breathe * Photosphere has a blackbody spectrum that corresponds to an average temp of 5800K * The photosphere appears darkest toward the edge or limb of the solar disk , a phenomenon called limb darkening, * This occurs b/c we see regions of different temp at different depths of the photosphere Granules * lightly colored convection features about 100 km in diameter seen constantly in the solar photosphere * time lapse photography shows that granules form, disappear then reform in cylces that last several minutes Chromosphere (“sphere of color”) * is a dim layer of less dense stellar gas that is above the photosphere * It is the layer we normally see * Astronomers can also study the chromosphere through filters that pass light with specific wavelengths strongly emitted by it – but not by the photosphere – or through telescope sensitive to nonvisble wavelengths that the chromosphere emits intensely Spicules - Are...
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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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...Maria Vasilenko 223901 Feasibility of using biosensors for heavy metal detection in complex matrices such as bio-slurries. Master of Science Thesis Examiners: Professor Matti Karp Professor Raghida Lepistö Examiner and topic approved in The Science and Bioengineering Department Council meeting on 7.11.2012 Abstract TAMPERE UNIVERSITY OF TECHNOLOGY Master‟s Degree Programme in Science and Bioengineering Vasilenko Maria: Feasibility of using biosensors for heavy metal detection in complex matrices such as bio-slurries. Seminar paper, 97 pages November 2012 Major: Biotechnology Examiners: Matti Karp, Raghida Lepisto Keywords: environmental pollution, heavy metals, biosensors, slurries The quality of bioslurries that are used in industrial production and agriculture need to be watched very closely to avoid spreading of contaminants on area and poisoning of humans and animals. Because heavy metals are very stable and toxic in many chemical compositions, their amount should be estimated very thoroughly. A new approach that involved biosensors was tested in this study. Because the slurries are complex non-unified matrices which composed of two phases – solid and liquid, the cell behavior can varies a lot from the one that explained in water and so the estimation of ion concentration can be not reliable. It was shown that the cell actually behave different in the slurries. Normally the dissolved compounds suppress the biosensor activity and, in the same time, the ions in the...
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...IUBMB Life, 00(00): 000–000, Month 2012 Research Communication Fluorescent Protein Engineering by In Vivo Site-directed Mutagenesis Melvys Valledor1,2, Qinghua Hu3, Paul Schiller1,2,4, and Richard S. Myers1 1 Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA Geriatric Research, Education, and Clinical Center, and Research Service, Veteran’s Affairs Medical Center, Miami, FL, USA 3 Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA 4 Department of Orthopedics, University of Miami Miller School of Medicine, Miami, FL, USA 2 Summary In vivo site-directed mutagenesis by single-stranded deoxyribonucleic acid recombineering is a facile method to change the color of fluorescent proteins (FPs) without cloning. Two different starting alleles of GFP were targeted for mutagenesis: gfpmut3* residing in the Escherichia coli genome and egfp carried by a bacterial/mammalian dual expression lentiviral plasmid vector. Fluorescent protein spectra were shifted by subtle modification of the chromophore region and residues interacting with the chromophore of the FP. Eight different FPs (Violeta, Azure, Aqua, Mar, Celeste, Amarillo, Mostaza, and Bronze) were isolated and shown to be useful in multicolor imaging and flow cytometry of bacteria and transgenic human stem cells. To make in vivo sitedirected mutagenesis more efficient, the recombineering method was optimized using the...
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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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...Chemistry Modern Analytical Chemistry David Harvey DePauw University Boston Burr Ridge, IL Dubuque, IA Madison, WI New York San Francisco St. Louis Bangkok Bogotá Caracas Lisbon London Madrid Mexico City Milan New Delhi Seoul Singapore Sydney Taipei Toronto McGraw-Hill Higher Education A Division of The McGraw-Hill Companies MODERN ANALYTICAL CHEMISTRY Copyright © 2000 by The McGraw-Hill Companies, Inc. All rights reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of the publisher. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 KGP/KGP 0 9 8 7 6 5 4 3 2 1 0 ISBN 0–07–237547–7 Vice president and editorial director: Kevin T. Kane Publisher: James M. Smith Sponsoring editor: Kent A. Peterson Editorial assistant: Jennifer L. Bensink Developmental editor: Shirley R. Oberbroeckling Senior marketing manager: Martin J. Lange Senior project manager: Jayne Klein Production supervisor: Laura Fuller Coordinator of freelance design: Michelle D. Whitaker Senior photo research coordinator: Lori Hancock Senior supplement coordinator: Audrey A. Reiter Compositor: Shepherd, Inc. Typeface: 10/12 Minion Printer: Quebecor Printing Book Group/Kingsport Freelance cover/interior designer: Elise Lansdon Cover image: © George Diebold/The...
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...NaNotechNology applicatioNs for cleaN Water Micro & NaNo TechNologies series editor: Jeremy ramsden Professor of Nanotechnology Microsystems and Nanotechnology Centre, Department of Materials Cranfield University, United Kingdom the aim of this book series is to disseminate the latest developments in small scale technologies with a particular emphasis on accessible and practical content. these books will appeal to engineers from industry, academia and government sectors. for more information about the book series and new book proposals please contact the publisher, Dr. Nigel hollingworth at nhollingworth@williamandrew.com. http://www.williamandrew.com/MNt NaNotechNology applicatioNs for cleaN Water edited by Nora savage Office of Research and Development, US Environmental Protection Agency and (in alphabetical order) Mamadou Diallo Materials and process simulation center, Division of chemistry and chemical engineering, california institute of technology Jeremiah Duncan Nanoscale Science and Engineering Center, University of Wisconsin-Madison anita street Office of Research and Development, US Environmental Protection Agency and Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign richard sustich N o r w i c h , N Y, U S A copyright © 2009 by William andrew inc. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying...
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