DOCSLIB.ORG

Investigation of the Suitability of Amorphous Semiconductors As Sensors for Optical Process Tomography

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigation of the Suitability of Amorphous Semiconductors As Sensors for Optical Process Tomography PhD Thesis R.P.Jenner 5025074 Title Investigation of the suitability of amorphous semiconductors as sensors for optical process tomography ROBERT PETER JENNER A thesis submitted in partial fulfilment of the requirements of the University of Greenwich for the Degree of Doctor of Philosophy July 2000 i f* ' ' X r c PhD Thesis R.P.Jenner Contents ABSTRACT In this work, the suitability of amorphous semiconductors as hard field optical sensors for application in optical process tomography (OPT) has been established. Two amorphous semiconductors were selected for the study, these being amorphous arsenic triselenide (a-As2Se3) and hydrogenated amorphous silicon (a-Si:H). The a- As2Se3 device was a single layered structure of 60|Um thickness fabricated upon a 2mm thick cylindrical aluminium substrate. The a-Si:H device was a multi-layered structure of 27.1fim overall thickness fabricated upon a 4mm thick cylindrical aluminium substrate. 20mm2 samples were cut from the cylinders, their surface being left free for a xerographic investigation. For a tomographic investigation, semitransparent gold (Au) contacts were sputtered onto the surface of the devices to produce single contacts or contact arrays. The study comprised of the two fields of xerography and tomography. The xerographic study comprised of the measurement of such parameters as charge acceptance, dark decay, residual potential, and photoinduced discharge. The research project has concurred with other workers in that the dark discharge mechanism in a-As2Se3 proceeds via a xerographic depletion discharge process, and a Poole-Frenkel type emission in a-Si:H. The tomographic investigation involved the study of such parameters as detectivity, responsivity, steady state photocurrent, and photoinduced fatigue. Detectivity has found to be dependant upon the magnitude of applied electric field and level of incident irradiance. Irradiance in the fj orderf\ of 3.45mW/cm2 to 9.57mW/cm2 for a- As2Se3 and 5.31mW/cm to 28.32mW/cm for a-Si:H was required in order to produce a clean and repeatable photogenerated current pulse over the range of electric fields specified (0.66xl05 V/cm to 1.66xl05 V/cm). The production of steady state current has found to be dependant upon the magnitude of electric field, the level of irradiance, and the illumination period. Irradiance of 319mW/cm2 to 1.46W/cm2 with an illumination period of 520ns was required to produce steady state photocurrent in a- As2Se3, and 693mW/cm2 to 2.62W/cm2 with an illumination period of 880ns for a- Si:H. A linear relationship between electric field and responsivity has been observed in both materials over a range of irradiance of 3.45mW/cm2 to 9.57mW/cm2. Responsivity in the order of 87.86|LiAAV to 145.19|iA/W for a-As2Se3 and 14.19(iAAV to 103.81)J,AAV for a-Si:H has been demonstrated. An investigation as to the effects of photoinduced fatigue in both a-As2Se3 and a-Si:H has been carried out by the application of pulsed visible light of various flash repetition rate (FRR) under a constant high electric field over a 30 minute illumination period. It has been shown that the rate of fatigue is dependant upon the material, time, electric field, light intensity, and FRR. A maximum operating speed of 20Hz has been determined for a- As2Se3 and lOOHz for a-Si:H. The maximum operating speed of 20Hz for a-As2Se3 was deemed unsuitable for OPT application and the a-As2Se3 material was eliminated from further tomographic investigation. Tomographic prototypes were employed to establish the a-Si:H devices ability to produce qualitative and quantitative data. The results of this investigation demonstrated that 1mm changes in water level and 0.5% changes in fluid colour could be accurately determined by the a-Si:H device at speeds required for OPT. The use of an a-Si:H device containing a Au contact array facilitated the imaging of the curvature of a pipeline and a phantom object contained within the pipeline. The results of the overall investigation have confirmed that the a- Si:H device is suitable for application as a hard field optical sensor for OPT. PhD Thesis R.P.Jenner Acknowledgements ACKNOWLEDGEMENTS I am very grateful to my supervisor Dr S.M. Vaezi-Nejad for his help, guidance and financial support throughout the course of the research project. I am also grateful to my second supervisor Dr Charles May for his interest in this work. I wish to thank the technical staff of the Medway School of Engineering, in particular Mr lan Cakebread for their help and advice. I wish to thank the Solid State Research group at Imperial College, London, for supplying the majority of the amorphous materials employed in this project. I particularly want to thank the head of the group Dr Juhasz for his help and advice. Finally I wish to thank the head of the Medway School of Engineering Professor Alan Reed for his moral and additional financial support throughout the research project. PhD Thesis R.P.Jenner Acknowledgements Author's Note All of the work contained within this thesis is the sole and original work of the author, except where otherwise stated by acknowledgement or reference. PhD Thesis R.P.Jenner Contents CONTENTS Page LIST OF FIGURES. 1 LIST OF TABLES. 7 CHAPTER 1: INTRODUCTION 8 CHAPTER 2: LITERATURE REVIEW 12 2.1 Medical tomography 12 2.2 Process tomography 19 2.2.1 Electrical impedance tomography 19 2.2.2 Ultrasonic tomography 21 2.2.3 Optical process tomography 23 2.3 Chapter summary 32 CHAPTER 3: AMORPHOUS SEMICONDUCTORS 34 3.1 Amorphous arsenic triselenide (a-As2Ses) 34 3.2 Hydrogenated amorphous silicon (a-Si:H) 36 3.3 Xerography 38 3.4 Charge acceptance 40 3.5 Dark decay 45 3.5.1 a-As2Se3 45 3.5.2 a-Si:H 56 3.6 Chapter summary 61 CHAPTER 4: EXPERIMENTAL APPARATUS AND PROCEDURES 62 4.1 Xerographic mode of operation 62 4.1.1 Sample preparation 62 4.1.2 Experimental procedures for the xerographic mode 64 of operation (i) Dark decay 64 (ii) Photoinduced discharge 66 4.1.3 Experimental apparatus in the xerographic mode 67 (i) Light tight enclosure 67 (ii) Timing/position sensor units 67 (iii) Sample translation mechanism 68 (iv) Measuring station 70 PhD Thesis R.P.Jenner Contents Page (v) Scorotron charger 72 (vi) Data acquisition 80 4.2 Electroded mode of operation 82 4.2.1 Sample preparation 89 4.2.2 Experimental procedures for electroded 91 mode of operation (i) Steady state and detectivity 91 (ii) Establishment of maximum operat 92 -ing speed through photoinduced fatigue (iii) Establishment of quantitative data 93 (iv) Establishment of qualitative data 95 (v) Production of images 95 4.2.3 Xenon flash unit 96 (i) Light source 97 (ii) Discharge mechanisms 102 (iii) Control signal generation 107 (iv) Control of light intensity / duration 109 4.2.4 Light detection mechanism 113 4.3 Chapter summary 115 CHAPTER 5: RESULTS OF XEROGRAPHIC INVESTIGATION 116 5.1 Xerographic mode of operation 116 5.1.1 a-As2Se3 116 (i) Charge acceptance 116 (ii) Dark decay 118 (iii) Photoinduced discharge 124 5.1.2 a-Si:H 127 (i) Charge acceptance 127 (ii) Dark decay 130 (iii) Photoinduced discharge 133 5.2 Chapter summary 135 PhD Thesis R.P.Jenner Contents Page CHAPTER 6: RESULTS OF TOMOGRAPHIC INVESTIGATION 140 6.1 a-As2Se3 140 6.1.1 Detectivity 140 6.1.2 Production of steady state current 145 6.1.3 Establishment of maximum operating speed 147 by the determination of the effects of photoinduced fatigue 6.2 a-Si:H 156 6.2.1 Detectivity 156 6.2.2 Production of steady state current 157 6.2.3 Establishment of maximum operating speed 161 by the determination of the effects of photoinduced fatigue 6.2.4 Establishment of pipeline limits 168 6.2.5 Establishment of quantitative data 172 6.2.6 Establishment of qualitative data 177 6.2.7 Production of basic images 180 (i) Curvature of the pipeline 180 (ii) Phantom object 183 6.3 Chapter summary 187 CHAPTER 7: DISCUSSION OF EXPERIMENTAL RESULTS 190 7.1 Xerographic investigation 190 7.1.1 Charge acceptance 190 (i) a-As2Se3 190 (ii) a-Si:H 190 7.1.1 Dark decay 191 (i) a-As2Se3 191 (ii) a-Si:H 192 7.2 Tomographic investigation 192 7.2.1 Detectivity 192 (i) a-As2Se3 192 (ii) a-Si:H 193 7.2.2 Production of steady state current 196 PhD Thesis R.P.Jenner Contents Page (i) a-As2Se3 196 (ii) a-Si:H 197 7.2.3 Establishment of maximum operating speed 198 by the determination of the effects of photoinduced fatigue (i) a-As2Se3 198 (ii) a-Si:H 208 7.2.4 Establishment of quantitative data 213 7.2.5 Establishment of qualitative data 216 7.2.6 Production of images 217 (i) Curvature of the pipeline 217 (ii) Phantom object 218 CHAPTER 8: CONCLUSIONS AND SUGGESTIONS 220 FOR FURTHER WORK 8.1 a-As2Se3 220 8.1.1 Xerographic investigation 220 8.1.2 Tomographic investigation 220 8.2 a-Si:H 221 8.2.1 Xerographic investigation 221 8.2.2 Tomographic investigation 221 8.3 Suggestions for further work 224 8.3.1 Effects of pulsed illumination 224 8.3.2 Light source 224 8.3.3 Effects of elevated temperature 225 8.3.4 Tomographic rig 225 8.3.5 Device design 225 REFERENCES 227 APPENDICES 234 1 Core MATLAB program 234 2 Turbo C control program listing 236 3 Establishment of optimum probe to sample surface spacing 251 and electrostatic voltmeter calibration.
Load more

Recommended publications
  • KNOWN and SUSPECTED HUMAN CARCINOGENS Carcinogens Reference List
    KNOWN AND SUSPECTED HUMAN CARCINOGENS Carcinogens Reference List SOURCE AGENCY CARCINOGEN CLASSIFICATIONS: OSHA (O) Occupational Safety and Health Administration ACGIH (G) American Conference of Governmental Industrial Hygienists A1 Confirmed human carcinogen. A2 Suspected human carcinogen. A3 Animal carcinogen. “Available evidence suggests that the agent is not likely to cause cancer in humans except under uncommon or unlikely routes or levels of exposure.” A4 Not classifiable as a human carcinogen. “There are inadequate data on which to classify the agent in terms of its carcinogenicity in humans and/or animals.” A5 Not suspected as a human carcinogen. IARC (I) International Agency for Research on Cancer (World Health Organization) 1 The agent (mixture) is carcinogenic to humans. 2A The agent (mixture) is probably carcinogenic to humans; there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. 2B The agent (mixture) is possibly carcinogenic to humans; there is limited evidence of carcinogenicity in humans in the absence of sufficient evidence of carcinogenicity in experimental animals. 3 The agent (mixture, exposure circumstance) is not classifiable as to its carcinogenicity to humans. 4 The agent (mixture, exposure circumstance) is probably not carcinogenic to humans. NTP (N) National Toxicology Program (Health and Human Services Dept., Public Health Service, NIH/NIEHS) 1 Known to be carcinogens. 2 Reasonably anticipated to be carcinogens. CP65 California Proposition 65, “Chemicals Known to the State to Cause Cancer.” Abbreviation: n.o.s. Not otherwise specified; i.e., there is no PEL or TLV. Note: CASRNs fitting the pattern 0-##-0 or 1-##-0 are generated for electronic database purposes only.
    [Show full text]
  • As2se3)100 – X(Sb2se3)X Glasses by Raman and 77Se MAS NMR Using a Multivariate Curve Resolution Approach Eva Cernoˇskov´A,J.ˇ Holubov´A,B
    CORE Metadata, citation and similar papers at core.ac.uk Provided by HAL-Rennes 1 Thermoanalytical properties and structure of (As2Se3)100 { x(Sb2Se3)x glasses by Raman and 77Se MAS NMR using a multivariate curve resolution approach Eva Cernoˇskov´a,J.ˇ Holubov´a,B. Bureau, C. Roiland, V. Nazabal, R. Todorov, Z Cernoˇsekˇ To cite this version: Eva Cernoˇskov´a,J.ˇ Holubov´a,B. Bureau, C. Roiland, V. Nazabal, et al.. Thermoanalytical properties and structure of (As2Se3)100 { x(Sb2Se3)x glasses by Raman and 77Se MAS NMR using a multivariate curve resolution approach. Journal of Non-Crystalline Solids, Elsevier, 2016, 432 (B), pp.426-431. <10.1016/j.jnoncrysol.2015.10.044>. <hal-01231157> HAL Id: hal-01231157 https://hal-univ-rennes1.archives-ouvertes.fr/hal-01231157 Submitted on 20 May 2016 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. Thermoanalytical properties and structure of (As2Se3)100-x(Sb2Se3)x glasses by Raman and 77Se MAS NMR using a multivariate curve resolution approach E. Černošková1, J. Holubová3, B. Bureau2, C. Roiland2, V. Nazabal2, R. Todorov4, Z. Černošek3 1Joint Laboratory of Solid State Chemistry of IMC CAS, v.v.i., and University of Pardubice, Faculty of Chemical Technology, Studentská 84, 532 10 Pardubice, Czech Republic, [email protected] 2ISCR, UMR-CNRS 6226, University of Rennes 1, France.
    [Show full text]
  • Chemical List
    1 EXHIBIT 1 2 CHEMICAL CLASSIFICATION LIST 3 4 1. Pyrophoric Chemicals 5 1.1. Aluminum alkyls: R3Al, R2AlCl, RAlCl2 6 Examples: Et3Al, Et2AlCl, EtAlCl2, Me3Al, Diethylethoxyaluminium 7 1.2. Grignard Reagents: RMgX (R=alkyl, aryl, vinyl X=halogen) 8 1.3. Lithium Reagents: RLi (R = alkyls, aryls, vinyls) 9 Examples: Butyllithium, Isobutyllithium, sec-Butyllithium, tert-Butyllithium, 10 Ethyllithium, Isopropyllithium, Methyllithium, (Trimethylsilyl)methyllithium, 11 Phenyllithium, 2-Thienyllithium, Vinyllithium, Lithium acetylide ethylenediamine 12 complex, Lithium (trimethylsilyl)acetylide, Lithium phenylacetylide 13 1.4. Zinc Alkyl Reagents: RZnX, R2Zn 14 Examples: Et2Zn 15 1.5. Metal carbonyls: Lithium carbonyl, Nickel tetracarbonyl, Dicobalt octacarbonyl 16 1.6. Metal powders (finely divided): Bismuth, Calcium, Cobalt, Hafnium, Iron, 17 Magnesium, Titanium, Uranium, Zinc, Zirconium 18 1.7. Low Valent Metals: Titanium dichloride 19 1.8. Metal hydrides: Potassium Hydride, Sodium hydride, Lithium Aluminum Hydride, 20 Diethylaluminium hydride, Diisobutylaluminum hydride 21 1.9. Nonmetal hydrides: Arsine, Boranes, Diethylarsine, diethylphosphine, Germane, 22 Phosphine, phenylphosphine, Silane, Methanetellurol (CH3TeH) 23 1.10. Non-metal alkyls: R3B, R3P, R3As; Tributylphosphine, Dichloro(methyl)silane 24 1.11. Used hydrogenation catalysts: Raney nickel, Palladium, Platinum 25 1.12. Activated Copper fuel cell catalysts, e.g. Cu/ZnO/Al2O3 26 1.13. Finely Divided Sulfides: Iron Sulfides (FeS, FeS2, Fe3S4), and Potassium Sulfide 27 (K2S) 28 REFERRAL
    [Show full text]
  • Mechanistic in Vitro Tests for Genotoxicity and Carcinogenicity of Heavy Metals and Their Nanoparticles
    Mechanistic in vitro tests for genotoxicity and carcinogenicity of heavy metals and their nanoparticles Dissertation zur Erlangung des akademischen Grades des Doktors der Naturwissenschaften Eingereicht im Fachbereich Biologie an der Universität Konstanz vorgelegt von Barbara Munaro June 2009 ACKNOWLEDGEMENTS I would like to express my gratitude to Prof. Dr. Thomas Hartung for his supervision and support for the preparation of this PhD work. I am very grateful to all my colleagues who have helped me with the experimental work and for their friendship and support: Francesca Broggi, Patrick Marmorato, Renato Colognato and Antonella Bottini. Special thanks to Jessica Ponti and for her important help and contributions. Thanks to Marina Hasiwa and Gregor Pinski for their help and advices. On the private side I wish to dedicate this thesis to my daughter Aurora. I would like to express a warm thank to my husband Nicola for his support and love. Special thanks to my mother, my father and my brother Marco who have always encouraged me throughout life. I Abbreviations 3Rs= Reduction, Refinement, Replacement ADME= adsorption, distribution, metabolism and excretion ANOVA= Analysis of variances AS3MT= arsenic III methyl transferase BN= binucleated cells BNMN= binucleated micronucleated cells BAS= bovine serum albumin CA= chromosomal aberration CBPI= cytokinesis block proliferation index CFE= Colony Forming Efficiency Co-nano= cobalt nanoparticle CTA= Cell Transformation Assay DEG= diethyl glycol DLS= Dynamic Light Scattering DMA= dimethylated arsenic
    [Show full text]
  • High Purity Inorganics
    High Purity Inorganics www.alfa.com INCLUDING: • Puratronic® High Purity Inorganics • Ultra Dry Anhydrous Materials • REacton® Rare Earth Products www.alfa.com Where Science Meets Service High Purity Inorganics from Alfa Aesar Known worldwide as a leading manufacturer of high purity inorganic compounds, Alfa Aesar produces thousands of distinct materials to exacting standards for research, development and production applications. Custom production and packaging services are part of our regular offering. Our brands are recognized for purity and quality and are backed up by technical and sales teams dedicated to providing the best service. This catalog contains only a selection of our wide range of high purity inorganic materials. Many more products from our full range of over 46,000 items are available in our main catalog or online at www.alfa.com. APPLICATION FOR INORGANICS High Purity Products for Crystal Growth Typically, materials are manufactured to 99.995+% purity levels (metals basis). All materials are manufactured to have suitably low chloride, nitrate, sulfate and water content. Products include: • Lutetium(III) oxide • Niobium(V) oxide • Potassium carbonate • Sodium fluoride • Thulium(III) oxide • Tungsten(VI) oxide About Us GLOBAL INVENTORY The majority of our high purity inorganic compounds and related products are available in research and development quantities from stock. We also supply most products from stock in semi-bulk or bulk quantities. Many are in regular production and are available in bulk for next day shipment. Our experience in manufacturing, sourcing and handling a wide range of products enables us to respond quickly and efficiently to your needs. CUSTOM SYNTHESIS We offer flexible custom manufacturing services with the assurance of quality and confidentiality.
    [Show full text]
  • Model Creation and Electronic Structure Calculation Of
    MODEL CREATION AND ELECTRONIC STRUCTURE CALCULATION OF AMORPHOUS HYDROGENATED BORON CARBIDE A THESIS IN Physics Presented to the F c!"ty o# the Uni$ersity o# Misso!ri%& ns s City in p rti " f!"#i""(ent o# the re)!ire(ents for the de*ree MASTER OF SCIENCE +y MOHAMMED BELHAD, LARBI B. S., Uni$ersity o# H ssi+ Ben%Bo! "i Ch"e#, A"*eri , 2010 M. S., Uni$ersity o# H ssi+ Ben%Bo! "i Ch"e#, A"*eri , 201/ & ns s City, Misso!ri /012 2015 MO HAMMED BELHADJ LARBI ALL RIGHTS RESERVED MODEL CREATION AND ELECTRONIC STRUCTURE CALCULATION OF AMORPHOUS HYDROGENATED BORON CARBIDE Moh ((ed Be"h dj L r+i, C ndid te for the M ster o# Science De*ree Uni$ersity o# Misso!ri%& ns s City, 2012 ABSTRACT Boron%rich so"ids re o# *re t interest #or ( ny ''"ic tions, ' rtic!" r"y. (or'ho!s hydro*en ted +oron c r+ide 5 %BC6H7 thin #i"(s re "e din* c ndid te #or n!(ero!s ''"ic tions s!ch s6 heterostr!ct!re ( teri "s, ne!tron detectors, nd 'hoto$o"t ic ener*y con$ersion. Des'ite this i('ortance, the "oc " str!ct!r " 'roperties o# these ( teri "s re not 8e""%9no8n, nd $ery #e8 theoretic " st!dies #or this # (i"y o# disordered so"ids e:ist in the "iter t!re. In order to opti(i;e this ( teri " #or its 'otenti " ''"ic tions the str!ct!re 'roperty re" tionshi's need to +e disco$ered.
    [Show full text]
  • Chemical Names and CAS Numbers Final
    Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number C3H8O 1‐propanol C4H7BrO2 2‐bromobutyric acid 80‐58‐0 GeH3COOH 2‐germaacetic acid C4H10 2‐methylpropane 75‐28‐5 C3H8O 2‐propanol 67‐63‐0 C6H10O3 4‐acetylbutyric acid 448671 C4H7BrO2 4‐bromobutyric acid 2623‐87‐2 CH3CHO acetaldehyde CH3CONH2 acetamide C8H9NO2 acetaminophen 103‐90‐2 − C2H3O2 acetate ion − CH3COO acetate ion C2H4O2 acetic acid 64‐19‐7 CH3COOH acetic acid (CH3)2CO acetone CH3COCl acetyl chloride C2H2 acetylene 74‐86‐2 HCCH acetylene C9H8O4 acetylsalicylic acid 50‐78‐2 H2C(CH)CN acrylonitrile C3H7NO2 Ala C3H7NO2 alanine 56‐41‐7 NaAlSi3O3 albite AlSb aluminium antimonide 25152‐52‐7 AlAs aluminium arsenide 22831‐42‐1 AlBO2 aluminium borate 61279‐70‐7 AlBO aluminium boron oxide 12041‐48‐4 AlBr3 aluminium bromide 7727‐15‐3 AlBr3•6H2O aluminium bromide hexahydrate 2149397 AlCl4Cs aluminium caesium tetrachloride 17992‐03‐9 AlCl3 aluminium chloride (anhydrous) 7446‐70‐0 AlCl3•6H2O aluminium chloride hexahydrate 7784‐13‐6 AlClO aluminium chloride oxide 13596‐11‐7 AlB2 aluminium diboride 12041‐50‐8 AlF2 aluminium difluoride 13569‐23‐8 AlF2O aluminium difluoride oxide 38344‐66‐0 AlB12 aluminium dodecaboride 12041‐54‐2 Al2F6 aluminium fluoride 17949‐86‐9 AlF3 aluminium fluoride 7784‐18‐1 Al(CHO2)3 aluminium formate 7360‐53‐4 1 of 75 Chemical Abstract Chemical Formula Chemical Name Service (CAS) Number Al(OH)3 aluminium hydroxide 21645‐51‐2 Al2I6 aluminium iodide 18898‐35‐6 AlI3 aluminium iodide 7784‐23‐8 AlBr aluminium monobromide 22359‐97‐3 AlCl aluminium monochloride
    [Show full text]
  • Photosensitivity at 1550 Nm and Bragg Grating Inscription in As2se3
    Photosensitivity at 1550 nm and Bragg grating inscription in As2Se3 microwires Raja Ahmad* and Martin Rochette Department of Electrical and Computer Engineering, McGill University, Montreal (QC), Canada, H3A 2A7 *Corresponding author: [email protected] Abstract We report the first experimental observation of photosensitivity in As2Se3 glass at a wavelength of 1550 nm. We utilize this photosensitivity to induce the first Bragg gratings using a laser source at a wavelength of 1550 nm. We quantify the photosensitivity thresholds related to exposition intensity and exposition time. Finally, we demonstrate that As2Se3 Bragg gratings are widely tunable in wavelength as the microwire can withstand an applied longitudinal strain of 4 × 104 µε. Keywords: Chalcogenide; Arsenic triselenide As2Se3; Photosensitivity; Microwires; Bragg gratings PACS: 42.70.Gi; 42.79.Dj; 42.70.Ce In recent years, chalcogenide glasses have attracted a lot of interest for applications such as sensing, mid- infrared light transmission and high data rate signal processing [1]. This interest of chalcogenide glasses is attributed to their large photosensitivity, large nonlinear coefficient and a wide transmission window covering the telecommunication band around 1.55 µm and up to 20 µm in the mid-infrared [2]. In the past, the photosensitivity of chalcogenide glasses has been utilized to write Bragg gratings in fibers as well as in waveguides [3, 4]. Recently, we have reported the first side-written Bragg gratings in As2Se3 microwires [5]. However, in all of these cases, light at a wavelength (λ) corresponding to a photon energy 1 (Ev) equal or close to the material bandgap (Ev = 1.9 eV or λ=650 nm for As2Se3 and Ev=2.4 eV or λ=820 nm for As2S3) was used to realize a refractive index modulation that induces a Bragg grating.
    [Show full text]
  • RIVM Report 711701 025 Re-Evaluation
    research for RIJKSINSTITUUT VOOR VOLKSGEZONDHEID EN MILIEU man and environment NATIONAL INSTITUTE OF PUBLIC HEALTH AND THE ENVIRONMENT RIVM report 711701 025 Re-evaluation of human-toxicological maxi- mum permissible risk levels A.J. Baars, R.M.C. Theelen, P.J.C.M. Janssen, J.M. Hesse, M.E. van Apeldoorn, M.C.M. Meijerink, L. Verdam, M.J. Zeilmaker March 2001 This investigation has been performed as part of RIVM project 711701, “Risk in relation to Soil Quality”, by order and for the account of the Directorate-General for Environmental Protection, Directorate for Soil, within the framework of project 711701. RIVM, P.O. Box 1, 3720 BA Bilthoven, telephone: 31 - 30 - 274 91 11; telefax: 31 - 30 - 274 29 71 page 2 of 297 RIVM report 711701 025 Abstract Soil Intervention Values are generic soil quality standards based on potential risks to humans and ecosystems. They are used to determine whether or not contaminated soils meet the crite- ria for “serious soil contamination” of the Dutch Soil Protection Act. Regarding the potential risks to humans, MPR values quantifying the human-toxicological risk limits (i.e., tolerable daily intake, tolerable concentration in air, oral cancer risk and/or inhalation cancer risk) for some 50 chemicals and chemical classes were derived in the period 1991-1993. These MPRs have now been updated. Together the compounds comprise 12 met- als (including cadmium, lead and mercury), 10 aromatic compounds (including the polycyclic aromatics), 13 chlorinated hydrocarbons (including dioxins and polychlorinated biphenyls), 6 pesticides (including DDT and the drins) and 7 other compounds including cyanides and total petroleum hydrocarbons.
    [Show full text]
  • 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
    Appendix B Classification of common chemicals by chemical band 1 1 EXHIBIT 1 2 CHEMICAL CLASSIFICATION LIST 3 4 1. Pyrophoric Chemicals 5 1.1. Aluminum alkyls: R3A1, R2A1C1, RA1C12 6 Examples: Et3A1, Et2A1C1, EtA.1111C12, Me3A1, Diethylethoxyaluminium 7 1.2. Grignard Reagents: RMgX (R=alkyl, aryl, vinyl X=halogen) 8 1.3. Lithium Reagents: RLi (R 7 alkyls, aryls, vinyls) 9 Examples: Butyllithium, Isobutylthhium, sec-Butyllithium, tert-Butyllithium, 10 Ethyllithium, Isopropyllithium, Methyllithium, (Trimethylsilyl)methyllithium, 11 Phenyllithiurn, 2-Thienyllithium, Vinyllithium, Lithium acetylide ethylenediamine 12 complex, Lithium (trimethylsilyl)acetylide, Lithium phenylacetylide 13 1.4. Zinc Alkyl Reagents: RZnX, R2Zn 14 Examples: Et2Zn 15 1.5. Metal carbonyls: Lithium carbonyl, Nickel tetracarbonyl, Dicobalt octacarbonyl 16 1.6. Metal powders (finely divided): Bismuth, Calcium, Cobalt, Hafnium, Iron, 17 Magnesium, Titanium, Uranium, Zinc, Zirconium 18 1.7. Low Valent Metals: Titanium dichloride 19 1.8. Metal hydrides: Potassium Hydride, Sodium hydride, Lithium Aluminum Hydride, 20 Diethylaluminium hydride, Diisobutylaluminum hydride 21 1.9. Nonmetal hydrides: Arsine, Boranes, Diethylarsine, diethylphosphine, Germane, 22 Phosphine, phenylphosphine, Silane, Methanetellurol (CH3TeH) 23 1.10. Non-metal alkyls: R3B, R3P, R3As; Tributylphosphine, Dichloro(methyl)silane 24 1.11. Used hydrogenation catalysts: Raney nickel, Palladium, Platinum 25 1.12. Activated Copper fuel cell catalysts, e.g. Cu/ZnO/A1203 26 1.13. Finely Divided Sulfides:
    [Show full text]
  • Hollow Multilayer Photonic Bandgap Fibers for NIR Applications
    Hollow multilayer photonic bandgap fibers for NIR applications Ken Kuriki, Ofer Shapira, Shandon D. Hart, Gilles Benoit, Yuka Kuriki, Jean F Viens, Mehmet Bayindir, John D. Joannopoulos and Yoel Fink Research Laboratory of Electronics and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA [email protected] http://mit-pbg.mit.edu/ Abstract: Here we report the fabrication of hollow-core cylindrical photonic bandgap fibers with fundamental photonic bandgaps at near- infrared wavelengths, from 0.85 to 2.28 µm. In these fibers the photonic bandgaps are created by an all-solid multilayer composite meso-structure having a photonic crystal lattice period as small as 260 nm, individual layers below 75 nm and as many as 35 periods. These represent, to the best of our knowledge, the smallest period lengths and highest period counts reported to date for hollow PBG fibers. The fibers are drawn from a multilayer preform into extended lengths of fiber. Light is guided in the fibers through a large hollow core that is lined with an interior omnidirectional dielectric mirror. We extend the range of materials that can be used in these fibers to include poly(ether imide) (PEI) in addition to the arsenic triselenide (As2Se3) glass and poly(ether sulfone) (PES) that have been used previously. Further, we characterize the refractive indices of these materials over a broad wavelength range (0.25 – 15 µm) and incorporated the measured optical properties into calculations of the fiber photonic band structure and a preliminary loss analysis. 2004 Optical Society of America OCIS codes: (060.2280) Fiber design and fabrication, (230.4170) Multilayers, (160.4670) Optical materials References and links 1.
    [Show full text]
  • Toxicological Profile for Arsenic
    TOXICOLOGICAL PROFILE FOR ARSENIC U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service Agency for Toxic Substances and Disease Registry August 2007 ARSENIC ii DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. ARSENIC iii UPDATE STATEMENT A Toxicological Profile for Arsenic, Draft for Public Comment was released in September 2005. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: Agency for Toxic Substances and Disease Registry Division of Toxicology and Environmental Medicine/Applied Toxicology Branch 1600 Clifton Road NE Mailstop F-32 Atlanta, Georgia 30333 ARSENIC iv This page is intentionally blank. v FOREWORD This toxicological profile is prepared in accordance with guidelines developed by the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA). The original guidelines were published in the Federal Register on April 17, 1987. Each profile will be revised and republished as necessary. The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for the hazardous substance described therein. Each peer-reviewed profile identifies and reviews the key literature that describes a hazardous substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies. The profile is not intended to be an exhaustive document; however, more comprehensive sources of specialty information are referenced. The focus of the profiles is on health and toxicologic information; therefore, each toxicological profile begins with a public health statement that describes, in nontechnical language, a substance's relevant toxicological properties.
    [Show full text]