Method 7000B: Flame Atomic Absorption Spectrophotometry, Part
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Understanding Variation in Partition Coefficient, Kd, Values: Volume II
United States Office of Air and Radiation EPA 402-R-99-004B Environmental Protection August 1999 Agency UNDERSTANDING VARIATION IN PARTITION COEFFICIENT, Kd, VALUES Volume II: Review of Geochemistry and Available Kd Values for Cadmium, Cesium, Chromium, Lead, Plutonium, Radon, Strontium, Thorium, Tritium (3H), and Uranium UNDERSTANDING VARIATION IN PARTITION COEFFICIENT, Kd, VALUES Volume II: Review of Geochemistry and Available Kd Values for Cadmium, Cesium, Chromium, Lead, Plutonium, Radon, Strontium, Thorium, Tritium (3H), and Uranium August 1999 A Cooperative Effort By: Office of Radiation and Indoor Air Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, DC 20460 Office of Environmental Restoration U.S. Department of Energy Washington, DC 20585 NOTICE The following two-volume report is intended solely as guidance to EPA and other environmental professionals. This document does not constitute rulemaking by the Agency, and cannot be relied on to create a substantive or procedural right enforceable by any party in litigation with the United States. EPA may take action that is at variance with the information, policies, and procedures in this document and may change them at any time without public notice. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government. ii FOREWORD Understanding the long-term behavior of contaminants in the subsurface is becoming increasingly more important as the nation addresses groundwater contamination. Groundwater contamination is a national concern as about 50 percent of the United States population receives its drinking water from groundwater. -
A Customized Stand-Alone Photometric Raman Sensor Applicable in Explosive Atmospheres: a Proof-Of-Concept Study
J. Sens. Sens. Syst., 7, 543–549, 2018 https://doi.org/10.5194/jsss-7-543-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. A customized stand-alone photometric Raman sensor applicable in explosive atmospheres: a proof-of-concept study Marcel Nachtmann1, Shaun Paul Keck1, Frank Braun1, Hanns Simon Eckhardt2, Christoph Mattolat2, Norbert Gretz3, Stephan Scholl4, and Matthias Rädle1 1Institute for Process Control and Innovative Energy Conversion, Mannheim University of Applied Sciences, Mannheim, 68163, Germany 2tec5 AG, Oberursel/Ts, 61440, Germany 3Medical Research Center, Medical Faculty Mannheim, Heidelberg University, Mannheim, 68167, Germany 4Institute for Chemical and Thermal Process Engineering, Technical University Braunschweig, Braunschweig, 38106, Germany Correspondence: Matthias Rädle ([email protected]) Received: 29 March 2018 – Revised: 12 September 2018 – Accepted: 14 September 2018 – Published: 12 October 2018 Abstract. This paper presents an explosion-proof two-channel Raman photometer designed for chemical pro- cess monitoring in hazardous explosive atmospheres. Due to its design, alignment of components is simplified and economic in comparison to spectrometer systems. Raman spectrometers have the potential of becoming an increasingly important tool in process analysis technologies as part of molecular-specific concentration monitor- ing. However, in addition to the required laser power, which restricts use in potentially explosive atmospheres, the financial hurdle is also high. Within the scope of a proof of concept, it is shown that photometric measure- ments of Raman scattering are possible. The use of highly sensitive detectors allows the required excitation power to be reduced to levels compliant for operation in potentially explosive atmospheres. -
Input-Output Transfer Function Analysis of a Photometer Circuit Based on an Operational Amplifier
Sensors 2008, 8, 35-50 sensors ISSN 1424-8220 © 2008 by MDPI www.mdpi.org/sensors Input-output Transfer Function Analysis of a Photometer Circuit Based on an Operational Amplifier Wilmar Hernandez Department of Circuits and Systems in the EUIT de Telecomunicacion at the Universidad Politecnica de Madrid (UPM), Campus Sur UPM, Ctra. Valencia km 7, Madrid 28031, Spain Phone: +34913367830. Fax: +34913367829. E-mail: [email protected] Received: 22 December 2007 / Accepted: 7 January 2008 / Published: 9 January 2008 Abstract: In this paper an input-output transfer function analysis based on the frequency response of a photometer circuit based on operational amplifier (op amp) is carried out. Op amps are universally used in monitoring photodetectors and there are a variety of amplifier connections for this purpose. However, the electronic circuits that are usually used to carry out the signal treatment in photometer circuits introduce some limitations in the performance of the photometers that influence the selection of the op amps and other electronic devices. For example, the bandwidth, slew-rate, noise, input impedance and gain, among other characteristics of the op amp, are often the performance limiting factors of photometer circuits. For this reason, in this paper a comparative analysis between two photodiode amplifier circuits is carried out. One circuit is based on a conventional current- to-voltage converter connection and the other circuit is based on a robust current-to-voltage converter connection. The results are satisfactory and show that the photodiode amplifier performance can be improved by using robust control techniques. Keywords: photometer circuit, current-to-voltage converter connection, frequency response, robust control Sensors 2008, 8 36 1. -
Modeling Gas Absorption
Project Number: WMC 4028 Modeling Gas Absorption A Major Qualifying Project Report submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science by _______________________________________ Yaminah Z. Jackson Date: April 24, 2008 Approved: _________________________________________ Professor William M. Clark, Project Advisor ABSTRACT This project sought to analyze the gas absorption process as an efficient way in which to remove pollutants, such as carbon dioxide from gas streams. The designed absorption lab for CM 4402 was used to collect data based on the change in composition throughout the column. The recorded and necessary calculated values were then used to create a simulation model using COMSOL Multiphysics, as a supplemental learning tool for students in CM 4402. 2 TABLE OF CONTENTS ABSTRACT ................................................................................................................................................................. 2 TABLE OF CONTENTS ............................................................................................................................................ 3 INTRODUCTION ....................................................................................................................................................... 5 ANTHROPOGENIC SOURCES ..................................................................................................................................... 5 FINDING A SOLUTION -
Carbon Dioxide Capture by Chemical Absorption: a Solvent Comparison Study
Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha Kothandaraman B. Chem. Eng. Institute of Chemical Technology, University of Mumbai, 2005 M.S. Chemical Engineering Practice Massachusetts Institute of Technology, 2006 SUBMITTED TO THE DEPARTMENT OF CHEMICAL ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN CHEMICAL ENGINEERING PRACTICE AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY JUNE 2010 © 2010 Massachusetts Institute of Technology All rights reserved. Signature of Author……………………………………………………………………………………… Department of Chemical Engineering May 20, 2010 Certified by……………………………………………………….………………………………… Gregory J. McRae Hoyt C. Hottel Professor of Chemical Engineering Thesis Supervisor Accepted by……………………………………………………………………………….................... William M. Deen Carbon P. Dubbs Professor of Chemical Engineering Chairman, Committee for Graduate Students 1 2 Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha Kothandaraman Submitted to the Department of Chemical Engineering on May 20, 2010 in partial fulfillment of the requirements of the Degree of Doctor of Philosophy in Chemical Engineering Practice Abstract In the light of increasing fears about climate change, greenhouse gas mitigation technologies have assumed growing importance. In the United States, energy related CO2 emissions accounted for 98% of the total emissions in 2007 with electricity generation accounting for 40% of the total1. Carbon capture and sequestration (CCS) is one of the options that can enable the utilization of fossil fuels with lower CO2 emissions. Of the different technologies for CO2 capture, capture of CO2 by chemical absorption is the technology that is closest to commercialization. While a number of different solvents for use in chemical absorption of CO2 have been proposed, a systematic comparison of performance of different solvents has not been performed and claims on the performance of different solvents vary widely. -
Photoelectric Spectrophotometry by the Null Method'
. PHOTOELECTRIC SPECTROPHOTOMETRY BY THE NULL METHOD' By K. S. Gibson CONTENTS Page I. Introduction 325 II. Spectral transmission 329 1. Apparatus 329 2. Method 333 3 Errors and accuracy 337 III. Diffuse spectral reflection 348 IV. Other applications 350 V. Summary 352 I. INTRODUCTION Anyone who has had experience in trying to make spectro- photometric measurements of transmission or reflection in the blue and violet parts of the spectrum is well aware of the difficulty of obtaining reliable determinations in this region. Nearly all methods have relatively low sensitivity, or else are inaccurate for other reasons, from wave lengths 400 to 500 millimicrons (m/x). Radiometric methods, which are so suitable for infra-red work and which have been used also in the visible and even in the ultra- violet, are, nevertheless, not of the highest accuracy in these latter regions because of the relatively low radiant power of all sources used for this kind of work, the radiant power decreasing continuously with the wave length. It is very difficult to obtain accurate determinations below 500 m/x by the usual radiometric methods. Any visual method is limited in the blue and violet because of the combined low visibility of the human eye and the low radiant power of the sources used, except at the few wave lengths where monochromatic light of great intensity can be ob- tained, as from the mercury arc. The Hilger sector photometer method, which is the only photographic method of speed and reliability, also has its limitations for this region. Being such a 1 An abst-act of this paper was presented to the Optical Society of America at the Baltimore meet- ing, Dec, 27, 1918. -
Application of Filter Photometers in the Production of Ethylene and Propylene
Analytical Products Sales Engineering Application of Filter Photometers in the Production of Ethylene and Propylene SC7-66-403 Gary D. Brewer APPLICATION OF FILTER PHOTOMETERS IN THE PRODUCTION OF ETHYLENE AND PROPYLENE Gary D. Brewer Product Manager, Photometers ABB Inc. 843 N. Jefferson St. Lewisburg, WV 24901 KEYWORDS Photometer, Infrared Spectroscopy, IR, Near Infrared Spectroscopy, NIR, Ultraviolet Spectroscopy, UV, Ethylene, Propylene ABSTRACT There have been several successful applications of process filter photometers in ethylene plants throughout the world. The process of manufacturing ethylene is extremely fast; therefore, the continuous measurements provided by filter photometers allow for a fast response to process changes for better control and process optimization. The capability of the current generation of filter photometers to use several analytical wavelengths to compensate for spectral interferences have allowed their use in measurements that previously could not be done by photometers. The high reliability and simplicity of filter photometers make them a valuable tool in the process control of an olefins plant. Applications in the IR and NIR spectral regions in both the vapor and liquid phases will be discussed to demonstrate their capabilities and benefits in this manufacturing process. Applications that will be discussed include the measurement of acetylene and ethane at the acetylene converters and the measurement of methyl acetylene and propadiene (MAPD) at the MAPD converters can be measured on a single infrared photometer. Applications at the caustic wash tower and the measurement of carbon dioxide at the furnace decoke will also be discussed. INTRODUCTION Ethylene is one of the highest volume chemicals produced in the world. -
Raman Spectroscopy Protocol
raman-prtkl4.doc 1/15 10.07.07 Raman Spectroscopy Comparison of Infrared Spectra with those gathered by Raman Spectroscopy of selected substances Protocol June 9th and 11th 1999, August 19th and 20th 1999, February 28th and 29th 2000 Headed by: Dr. M. Musso Handed in by : Pierre Madl (Mat-#: 9521584) Maricela Yip (Mat-#: 9424495) Salzburg, August 28th 2000 raman-prtkl4.doc 2/15 10.07.07 Introduction When radiation passes through a transparent medium, the species present scatter a fraction of the beam in all directions. In 1928, the Indian physicist C.V.Raman discovered that the wavelength of a small fraction of the radiation scattered by certain molecules differ from that of the incident beam; furthermore, the shifts in wavelength depend upon the chemical structure of the molecules responsible for scattering. The theory of Raman scattering, which now is well understood, shows that the phenomenon results from the same type of quantized vibrational changes that are associated with infrared (IR) absorption. Thus, the difference in wavelength between the incident and scattered radiation corresponds to wavelengths in the mid-infrared region. Indeed, Raman scattering spectrum and infrared spectrum for a given species often resemble one another quite closely. There are, however, enough differences between the kinds of groups that are infrared active and those that are Raman active to make the techniques complementary rather than competitive. For some problems, the infrared method is the superior tool, for others, the Raman procedure offers more useful spectra. An important advantage of Raman spectra over infrared lies in the fact that water does not cause interference; indeed, Raman spectra can be obtained form aqueous solutions. -
The CU 2-D-MAX-DOAS Instrument – Part 2: Raman Scattering Probability Measurements and Retrieval of Aerosol Optical Properties
Atmos. Meas. Tech., 9, 3893–3910, 2016 www.atmos-meas-tech.net/9/3893/2016/ doi:10.5194/amt-9-3893-2016 © Author(s) 2016. CC Attribution 3.0 License. The CU 2-D-MAX-DOAS instrument – Part 2: Raman scattering probability measurements and retrieval of aerosol optical properties Ivan Ortega1,2, Sean Coburn1,2, Larry K. Berg3, Kathy Lantz2,4, Joseph Michalsky2,4, Richard A. Ferrare5, Johnathan W. Hair5, Chris A. Hostetler5, and Rainer Volkamer1,2 1Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, USA 2Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, USA 3Pacific Northwest National Laboratory, Richland, WA, USA 4Global Monitoring Division, Earth System Research Laboratory, NOAA, Boulder, CO, USA 5NASA Langley Research Center, Hampton, VA, USA Correspondence to: Rainer Volkamer ([email protected]) Received: 8 December 2015 – Published in Atmos. Meas. Tech. Discuss.: 18 January 2016 Revised: 12 July 2016 – Accepted: 13 July 2016 – Published: 23 August 2016 Abstract. The multiannual global mean of aerosol optical retrievals of AOD430 and g with data from a co-located depth at 550 nm (AOD550/ over land is ∼ 0.19, and that over CIMEL sun photometer, Multi-Filter Rotating Shadowband oceans is ∼ 0.13. About 45 % of the Earth surface shows Radiometer (MFRSR), and an airborne High Spectral AOD550 smaller than 0.1. There is a need for measurement Resolution Lidar (HSRL-2). The average difference (rela- techniques that are optimized to measure aerosol optical tive to DOAS) for AOD430 -
An Infrared Photon-Counting Photometer Based on the Edge-Illuminated Solid-State Photomultiplier
An Infrared Photon-counting Photometer Based on the Edge-illuminated Solid-State Photomultiplier Dae-Sik Moon1234, Stephen S. Eikenberry54, and Giovanni G. Fazio6 1Division of Physics, Mathematics and Astronomy, Caltech, MC 103–33, Pasadena, CA 91125; 2Robert A. Millikan Fellow; 3Space Radiation Laboratory, Caltech, MC 220–47, Pasadena, CA 91125; 4Department of Astronomy, Cornell University, Ithaca, NY 14853; 5Department of Astronomy, University of Florida, Gainesville, FL 32611; 6Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA ABSTRACT We present the design, construction, and test observations of a new infrared (IR) photon-counting photometer for astronomy based on the edge-illuminated solid-state photomultiplier (EISSPM). The EISSPM has a photon- counting capability over the 0.4–28 µm range with a nanosecond-scale intrinsic detector time resolution. Its quantum efficiency (QE) peaks ≥ 30 % in the near-IR, which is much higher than the previous SSPM with back illumination. After characterizing the dark noise of the EISSPM at its operational temperature range, we develop an EISSPM-based IR photon-counting photometer for astronomical observations. This includes the design and construction of a full optical, cryo-mechanical, and electronics system as well as the software for operating the instrument on telescopes. We report the results of our test observations of the Crab Nebula pulsar using this new instrument on the Palomar Hale 5-m telescope with 10-µs time resolution. Keywords: infrared, instrumentation, detectors, photometers 1. INTRODUCTION A photon-counting capability with > 100 Hz sampling rate (and potentially up to ∼106 Hz sampling rate) has diverse interesting applications in modern astronomy, involving both observational and technological aspects. -
Computational and Experimental Models for the Prediction of Intestinal Drug Solubility and Absorption
&RPSUHKHQVLYH6XPPDULHVRI8SSVDOD'LVVHUWDWLRQV IURPWKH)DFXOW\RI3KDUPDF\ &RPSXWDWLRQDODQG([SHULPHQWDO 0RGHOVIRUWKH3UHGLFWLRQ RI,QWHVWLQDO'UXJ6ROXELOLW\ DQG$EVRUSWLRQ %< &+5,67(/$6%(5*675g0 $&7$81,9(56,7$7,6836$/,(16,6 8336$/$ Dissertation for the Degree of Doctor of Philosophy (Faculty of Pharmacy) in Pharmaceutics presented at Uppsala University in 2003 ABSTRACT Bergström, C. A. S., 2003. Computational and Experimental Models for the Prediction of Intestinal Drug Solubility and Absorption. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy 295. 66 pp. Uppsala. ISBN 91-554-5747-9. New effective experimental techniques in medicinal chemistry and pharmacology have resulted in a vast increase in the number of pharmacologically interesting compounds. However, the number of new drugs undergoing clinical trial has not augmented at the same pace, which in part has been attributed to poor absorption of the compounds. The main objective of this thesis was to investigate whether computer-based models devised from calculated molecular descriptors can be used to predict aqueous drug solubility, an important property influencing the absorption process. For this purpose, both experimental and computational studies were performed. A new small-scale shake flask method for experimental solubility determination of crystalline compounds was devised. This method was used to experimentally determine solubility values used for the computational model development and to investigate the pH-dependent solubility of drugs. In the computer-based studies, rapidly calculated molecular descriptors were used to predict aqueous solubility and the melting point, a solid state characteristic of importance for the solubility. To predict the absorption process, drug permeability across the intestinal epithelium was also modeled. -
Sphinx: the Solar Photometer in X-Rays
Solar Phys DOI 10.1007/s11207-012-0201-8 SphinX: The Solar Photometer in X-Rays Szymon Gburek · Janusz Sylwester · Miroslaw Kowalinski · Jaroslaw Bakala · Zbigniew Kordylewski · Piotr Podgorski · Stefan Plocieniak · Marek Siarkowski · Barbara Sylwester · Witold Trzebinski · Sergey V. Kuzin · Andrey A. Pertsov · Yurij D. Kotov · Frantisek Farnik · Fabio Reale · Kenneth J.H. Phillips Received: 10 April 2012 / Accepted: 19 November 2012 © Springer Science+Business Media Dordrecht 2012 Abstract Solar Photometer in X-rays (SphinX) was a spectrophotometer developed to ob- serve the Sun in soft X-rays. The instrument observed in the energy range ≈ 1–15 keV with resolution ≈ 0.4 keV. SphinX was flown on the Russian CORONAS–PHOTON satellite placed inside the TESIS EUV and X telescope assembly. The spacecraft launch took place on 30 January 2009 at 13:30 UT at the Plesetsk Cosmodrome in Russia. The SphinX exper- iment mission began a couple of weeks later on 20 February 2009 when the first telemetry dumps were received. The mission ended nine months later on 29 November 2009 when data transmission was terminated. SphinX provided an excellent set of observations dur- ing very low solar activity. This was indeed the period in which solar activity dropped to the lowest level observed in X-rays ever. The SphinX instrument design, construction, and operation principle are described. Information on SphinX data repositories, dissemination methods, format, and calibration is given together with general recommendations for data users. Scientific research areas in which SphinX data find application are reviewed. S. Gburek () · J. Sylwester · M. Kowalinski · J. Bakala · Z. Kordylewski · P. Podgorski · S.