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Articles 30511 - 30540 of 34557

Full-Text Articles in Physical Sciences and Mathematics

The Relationship Between Interfacial Structure And Electrochemical Properties Of Electrodes Modified With Organic Mercaptans, Mark Anderson, Minhui Zhang, Mark Evaniak, Jimin Huang Mar 1995

The Relationship Between Interfacial Structure And Electrochemical Properties Of Electrodes Modified With Organic Mercaptans, Mark Anderson, Minhui Zhang, Mark Evaniak, Jimin Huang

Mark R. Anderson

No abstract is currently available.


61. Marian Kryszewski, Otto Vogl Mar 1995

61. Marian Kryszewski, Otto Vogl

Otto Vogl

No abstract provided.


Studies Of Elecctrochcmical Oscillation Of Au/Hcl In Presence Of ″Positive Feedback ″Of Substrate Electrodes, Bin Ren, Bingwei Mao, Xiongwei Cai, Tao Jiang, Jiqian Mu Feb 1995

Studies Of Elecctrochcmical Oscillation Of Au/Hcl In Presence Of ″Positive Feedback ″Of Substrate Electrodes, Bin Ren, Bingwei Mao, Xiongwei Cai, Tao Jiang, Jiqian Mu

Journal of Electrochemistry

No abstract provided.


Electroreduction Of Holmium Ion On Iron Electrde In Molten Cholorides, Qiqin Yang, Guankun Liu, Yuzhi Su Feb 1995

Electroreduction Of Holmium Ion On Iron Electrde In Molten Cholorides, Qiqin Yang, Guankun Liu, Yuzhi Su

Journal of Electrochemistry

The cyclic voltammetry,open circuit potential-time curve after poteritiostaticelectrolysis,current-time curve at potential step,x-ray diffraction and electron probe microanalysiswere used to investigate the electrode process of Ho(Ⅲ)reduced on iron electrode in molten chloridesand the phases of surface alloy layer.The Ho-Fe alloys are formed at first,and then the metallicholmium is deposited when Ho(Ⅲ)is reduced on iron electrede. The charge transfer is reversible. Thefree energies of formation for the four intermetallic compounds of Ho-Fe system,the diffusioncoefficients and diffusion activation energy of Ho in alloyed cathode are determined.


The Ehect Of Some Ions On Anodic Formation Process At Pt And Pbo_2 Electrodes, Shixiong Jin, Zhigang Zhou, Lan Wang Feb 1995

The Ehect Of Some Ions On Anodic Formation Process At Pt And Pbo_2 Electrodes, Shixiong Jin, Zhigang Zhou, Lan Wang

Journal of Electrochemistry

The influence of Ag_2SO_4,Li_2SO_4,Na_2SO_4,K_2SO_4,NH_4)_2SO_4,MgSO_4 and KF onthe evolution of O_2 and the formation of Cr_2O at Pt and PbO_2 anodes was investigated in mixedH_2SO_4-Cr_2(SO_2)_3 solutions.The kinetic data related respectively to Cr_2O formation and O_2 evolutionat Pt and PbO_2 anodes were measured by method of resolving the steady-state polarization curve.TheTafel slope of steady-state ~1g i relationships for Cr_2O formation reaction is close to 2×2. 303RT/βF,whereas for O_2 evolution it is close to 2.303 RT/βF(with β=0.5). The results indicate thatthe current efficiency for Cr_2O formation is increased by adding Ag ̄+ ions to the anolyte and decreasedby adding Li ̄+,Na ̄+,K ̄+,NH and Mg ̄(2+) ions to …


Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan Feb 1995

Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/Al_Xga_(1-X)As Electrode, Liuyao Liuyao, Xurui Xiao, Liyuan Liyuan

Journal of Electrochemistry

Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well(MQW)GaAs/Al_(0.3)Ga_(0.7)As electredes were studied in the 1 ×10 ̄(-2)mol·dm ̄(-3)ferrocene([Fc ̄0]/[Fc) ̄+]=9/1)-0.1 mol·dm ̄(-3)tetrabutylammonium tetrafluoroborate acetonitrile solutionin order to examine the relaxation photoprocesses and to evaluate kinetic parameters of superlattice electrodes. GaAs/Al_(0.3)Ca_(0. 7)As MQW electrode consisting of 10 periods with each of GaAs well(5.3nm)and Al_(0. 3)Ga_(0. 7)As barrier(10nm)showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum,corresponding to the theoretical allowedexcitonic transitions(Δn=0) for heavy holes(H11,H22)in the quantum well respectively. Transient photocurrent spectra were measured by a monochromatic light pulse with 7 μs pulsewidth and 9 nJ·cm ̄(-2) of …


Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang Feb 1995

Study Of Electrochemical Properties Of Ni(Oh)_2 /Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang

Journal of Electrochemistry

Electrochemical reactions of Ni(OH)_2 /NiOOH system were studied by using in-situ spectroscopic ellipsometry and the conventional electrochemical metheds.By fitting data fromellipsometric measurements,a transformation medel of the surface film was obtained for cathedic andanodic processes. The results indicated that the transformation medel after cobalt implantation almostremained the same as that before cobalt implantation,but the electrochemical properties wereaffectedobviously by implantation of cobalt.


Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/Sb_(Ad) Electrode, Hong Li, Lincai Jiang, Xiong Jiang Feb 1995

Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/Sb_(Ad) Electrode, Hong Li, Lincai Jiang, Xiong Jiang

Journal of Electrochemistry

The electrocatalytic activity for the oxidation of formaldehyde and formic acid ona Sb-modified platinum (Pt/Sb_(ad))was investigated.Results showed that the Pt/Sb_(ad) electrode waselectrocatalytically more active than a Pt electrode in the anodic oxidation of formaldehyde and formicacid.In the case of formaldehyde,an oxidation peak appeared at a potential of ca.0.7V.During theoxidation of formic acid,a 4-fold increase in the 1st peak current was observed.The Sb-modifiedplatinum electrode was found to be most electrocatalytically active at a coverage of 0.75±0.05.Theelectrocatalytic activity of the Pt/Sb_(ad) electrode can be best explained in terms of the geometrical effect,which may lead to the inhibition of the formation of the …


A Investigation Of Hydrogen-Storage Alloy As Catalytic Electrode For Hydrogenation Of Nitrobenzene, Shigang Lu, Hanxi Yang, Changfa Wan Feb 1995

A Investigation Of Hydrogen-Storage Alloy As Catalytic Electrode For Hydrogenation Of Nitrobenzene, Shigang Lu, Hanxi Yang, Changfa Wan

Journal of Electrochemistry

Since hydrogen.storage alloy ean not only absorb hydrogen atoms to form highlyreactive metal hydride as hydrogen source by electrolysis but also possesses a certain catalytic activityfor hydrogenation,it is thus feasible to utilize the allov as a novel electrOde for electrolvtichydrogenation in organic electrored uction. This work employed misch metal AB_5 type alloy as acatalytic electrode and studied the electrochemical hydrogenation of nitrobenzene. The hydrogen-storage electrede(MH)was a plastic bonded electrede sheet made from a paste ofMm(NiCoMnAl)_5 alloy powder and teflon emulsion. The electrolysis was performed at constantcurrent and controlled potential in a three electrede cell of H-type configuration. The electrolyte was0.5 …


Atomic And Molecular-Perspectives In Electrochemical Interfaces, Zhaowu Tian Feb 1995

Atomic And Molecular-Perspectives In Electrochemical Interfaces, Zhaowu Tian

Journal of Electrochemistry

The following recent studies on the atomic and molecular-perspectives atelectrochemical interfaces using Raman,IR,STM and quantum chemical methed by electrOchemistrygroup in Xiamen University are briefly reviewed. 1.Orientation,charge transfer and bonding of adsorbed molecules. 2.Adsorption effect,electrode potential effect and adatom effect on the electron populations and strength of intramolec ular bonds of the adsorbed molecules. 3.Detailed classification into various types(e. g.,competitive,chemically inductive, physical inductive etc.)of coadsorption on electrodes according to the above-mentioned effects. 4. Single crystal face structure effect and adatom effect on the kinetics and the mechanisms of electrocatalytic oxidation processes of small organic molecules. 5.Electrochemical scanning tunneling microscopy(ECSTM)specially designed for …


Self Assembly Via Layer By Layer Surface Reaction On Gold Electrodes And The Electrochcmical Characterization, Xiandui Dong, Juntao Lu, Chuanxin Cha Feb 1995

Self Assembly Via Layer By Layer Surface Reaction On Gold Electrodes And The Electrochcmical Characterization, Xiandui Dong, Juntao Lu, Chuanxin Cha

Journal of Electrochemistry

The self-assembled monolayers,which were built by spontaneous adsorption of ω-carboxylic acid thiols on gold surface,were used as substrate for further modification through later bylayer amide surface reactions.At each stage of modification,the gold surface was characterizedelectochemieally. The results demonstrated that the strategies of layer by layer self assembly is ofsignificant potential for fabrieating functionalized ultrathin layers.


Electroreduction Of The Nittobenzene On Titanium Electrode Implanted With Palladium, Zhongda Wu, Xianjun Zhu, Hongsen Wang Feb 1995

Electroreduction Of The Nittobenzene On Titanium Electrode Implanted With Palladium, Zhongda Wu, Xianjun Zhu, Hongsen Wang

Journal of Electrochemistry

The titanium substrates were bombarded with 1×10 ̄(17)~5×10 ̄(17)ions·cm ̄(-2) ofpalladium at the room temperature. The surface composition of implanted electrede and concentration-depth profiles of various elements were measured by AES. The electrored uction processes ofnitrobenzene(NB)in 0.1 mol/L NaOH solution at Pd/Ti electrodes have been investigated by cyclicvoltaivimetry.The results show that the palladium implanted titanium electrodes exhibit a high catalyticactivity in the electroreduction of NB. The NB radical anion,which is the product of one-electronelectroreduction of NB,was detected by ESR in-situ in conjunction with electrochemical methods. Aniline was also detected as a product of electroreduction of NB by using UV-spectra in-situ. According to the …


A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang Feb 1995

A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang

Journal of Electrochemistry

A photoelectrochemical investigation has been carried out on zirconium initialoxide film and its oxide film grownanodically at constant rate up to different thickness. Both anodicand cathedic photocurrents on the photocurrent spectrum depended on the potential,but had littlerelation with the forming anedic films or measuring solutions. Photocurrent spectrum and photocurrenttransients suggested that the oxide films on zirconium were duplex layers structure. The internal layerwas ZrO_2 and the external layer ZrO_2·(H_2O)_n. The photocurrent included photogenerated carrier ininternal and external oxide films,as well as internal photoinjection process for electrons from thesubstrate metal into the electrode/electolyte interface reacting with the redox couple. The analysis …


The Study Of The Growth Processes Of The Oxides On Lead Electrodes In Sulfuric Acid Solution, Hesheng Zhai, Xuguang Chen, Jinkua You, Yong Yang, Zugeng Lin Feb 1995

The Study Of The Growth Processes Of The Oxides On Lead Electrodes In Sulfuric Acid Solution, Hesheng Zhai, Xuguang Chen, Jinkua You, Yong Yang, Zugeng Lin

Journal of Electrochemistry

The growth processes of PbO and PbO_2 on lead electrodes have been investigatedby using in-situ methods that are combined with temporary AC resistance measurment technique andin-situ laser scanning photoelectrochemical microscopy.It is found that a linear relationship existsbetween the electrode resistance(R)and ̄(1/2) after the electrode is oxidized at +0.6 V(vs.Hg/H_2SO_4/35%H_2SO_4)for more than 5 min.This result suggests that the growth of PbO is well distributedduring the early stage of oxidation.The study by using laser scanning photoelectrochemical microscopyhas further proved this point.The results also show that the growth of PbO_2 takes place and develops.


Synthesis Of Li_Xcoo_2 And Its Behaviour In Rechargeable Lithium Battery, Mingfeng Guo, Ruimin Yang, Zebo Zhang, Jincao Ye Feb 1995

Synthesis Of Li_Xcoo_2 And Its Behaviour In Rechargeable Lithium Battery, Mingfeng Guo, Ruimin Yang, Zebo Zhang, Jincao Ye

Journal of Electrochemistry

The Variations of crystal lattice parameters of Li_xCoO_2 during charge anddischarge have been st ud ied by XRD and AAR spectroscopy.It was found that the Li_xCoO_2 crystalvolume expanded during charge and contracted during discharge.The crystal lattice structure wasbroken because of the formation of Co_3O_4 when deeply charge.The variation of lattice parameter C_0value in cycling process was similar to that in charge process.The variation of 006 peak was the mostsensitive in every case.In case of preheating for 20 hours at 700℃ before operating hightemperature,the 006 peak obtained an enhancement obviously.It has had the good rechargeability inmeasurement of the cyclic voltammograms,the CV …


Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo Feb 1995

Application Of Inhibitor To Improve The Anticorrosion Performance Of Electrophoretic Coating, Changshou Cai, Fangteng Su, Bihuan Liu, Guomou Wen, Jingdong Guo

Journal of Electrochemistry

To improve the anti-corrosion performance of electrocoating,organic andinorganic inhibitors are applied in an anodic electrophoretic-coating.The results show that thedeposition of polymer with zinc phospate exhibits a high inbihition efficiency.The inhibitionmechanism of the inhibitor in electrocoating has been studied.


Application Of Voltammetry In Analysis Of Electroplating Baths, Jiayuan Xu, Shaomin Zhou Feb 1995

Application Of Voltammetry In Analysis Of Electroplating Baths, Jiayuan Xu, Shaomin Zhou

Journal of Electrochemistry

Based upon the electrochemical characteristics of the components or impurities tobe determined in the electroplating baths,and the inhibition or activation effect of the additives usedon the electrodepcosition processes of metals and alloys,direct voltammetry,indirect voltammetry andvoltammetry with anodic stripping of metallic deposits,were suggested to determine the concentrationof some components,several impurities and the additives usually used in the electroplating baths.Theprocedure of those methtods are simple and rapid,and are suitable to be used for in situ control inelectroplating workshops.


The Device Of Wy-Ⅱ Type Cyanide Monitor And Its Applications, Xianmin Wang Feb 1995

The Device Of Wy-Ⅱ Type Cyanide Monitor And Its Applications, Xianmin Wang

Journal of Electrochemistry

A device of WY-Ⅱtype micro-computerized cyanide monitor is presented,inwhich the cyanide analvsis is carried out by means of microcoulomb-iodimetric with automaticfollowing system.This instrument can be successifully employed to analyze the cyanides in industrial waste-waterfor vavious departments of chemical industry.A serious of experimental tests showed that theanalytical sensitivity went up to 0.01 mg/L and the accuracy of determination was excellentlycoincided with that of National standard method and other methods.


The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan Feb 1995

The Electrode Process Of Y(Ⅲ)On Copper Electrode And Its Surface Metallizing, Chungen Zhou, Shuzhen Duan

Journal of Electrochemistry

The reduction of yttrium ion on copper electrode in NaCl-KCl-YCl_3 molten saltshas been investigated.The results indicate that the formation of intermetallic compounds is occuredbefore the metallic yttrium to be formed.The formation of intermetallic compounds is controlled bythe process of which yttrium atoms are diffusing into copper electrode.The kinetic characters todiffusion of yttrium atoms were also discussed.


The Catalytic Behavior For Ni-W Electrode Modified By Carbon Ion Beam Implantion, Jishuang Zhang, Yaojiao Lv, Qinglian Li Feb 1995

The Catalytic Behavior For Ni-W Electrode Modified By Carbon Ion Beam Implantion, Jishuang Zhang, Yaojiao Lv, Qinglian Li

Journal of Electrochemistry

The hydrogen evolution activity in acidic and basic mediums for Ni-W electrodemodified by carbon ion beam implantation was investigated.The experimental results show thiselectrode has superior catalytic activity for the hydrogen evolution reaction than that of the unmodifiedNi-electrode.Long period testing of electrolysis under high current density show that this electrode hasalonger useful life hence it is a practical electrode material.The temperature effect of electrocatalyticproperty was also inverstigated.The experimental regularities are explained on the basis of the formation of surface m uItialloys of Ni-W-WC.


Are Multifragment Emission Probabilities Reducible To An Elementary Binary Emission Probability, L. G. Moretto, L. Phair, K. Tso, K. Jing, G. J. Wozniak, R. T. Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu Feb 1995

Are Multifragment Emission Probabilities Reducible To An Elementary Binary Emission Probability, L. G. Moretto, L. Phair, K. Tso, K. Jing, G. J. Wozniak, R. T. Souza, D. R. Bowman, N. Carlin, C. K. Gelbke, W. G. Gong, Y. D. Kim, M. A. Lisa, W. G. Lynch, Graham F. Peaslee, M. B. Tsang, F. Zhu

Faculty Publications

Experimental intermediate-mass-fragment multiplicity distributions for the EA=80 and 110 MeV Ar36 + Au197reactions are shown to be binomial at all excitation energies. From these distributions, a single binary event probability p can be extracted that has a thermal dependence. Thus, it is inferred that multifragmentation is reducible to a combination of nearly independent emission processes. If sequential decay is assumed, the increase of p with excitation energy implies a contraction of the time scale that is qualitatively consistent with recent fragment-fragment correlation data.


Composition Profiles In Electrodeposited Ceramic Superlattices, Jay A. Switzer, Richard J. Phillips, Teresa D. Golden Feb 1995

Composition Profiles In Electrodeposited Ceramic Superlattices, Jay A. Switzer, Richard J. Phillips, Teresa D. Golden

Chemistry Faculty Research & Creative Works

Superlattices in the Pb-Tl-O system with layer thicknesses in the 4-6 nm range were electrodeposited from a single aqueous solution by pulsing the applied potential during deposition. The current-time transients that resulted from the potential steps were monitored to both calculate and tailor the composition profiles of the superlattices during growth. The Cottrell method was used to determine that Tl(l) oxidation was diffusion limited at high potentials. The diffusion limitation resulted in a composition profile that was graded throughout the layer with a t-1/2 dependence. Superlattices grown at lower potentials in which both reactants were under kinetic control had …


Multifragment Emission Times In Xe Induced Reactions, A. Moroni, D. R. Bowman, M. Bruno, P. Buttazzo, L. Celano, N. Colonna, M. D'Agostino, J. D. Dinius, A. Ferrero, M. L. Fiandri, K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, D. Horn, Wen-Chien Hsi, M. Huang, I. Iori, M. Lisa, W. G. Lynch, G. V. Margagliotti, P. F. Mastinu, P. M. Milazzo, C. Montoya, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Rud, R. Scardaoni, C. Schwarz, B. Tsang, G. Vannini, C. Williams Feb 1995

Multifragment Emission Times In Xe Induced Reactions, A. Moroni, D. R. Bowman, M. Bruno, P. Buttazzo, L. Celano, N. Colonna, M. D'Agostino, J. D. Dinius, A. Ferrero, M. L. Fiandri, K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, D. Horn, Wen-Chien Hsi, M. Huang, I. Iori, M. Lisa, W. G. Lynch, G. V. Margagliotti, P. F. Mastinu, P. M. Milazzo, C. Montoya, Graham F. Peaslee, L. Phair, F. Petruzzelli, R. Rud, R. Scardaoni, C. Schwarz, B. Tsang, G. Vannini, C. Williams

Faculty Publications

Multifragment emission is studied in reactions. The emission process for central collisions occurs on a time scale of ≈ 200 fm/c at 30 MeV/n. Intermediate-mass-fragment yields, velocity correlation functions and emission velocities of Z=6 fragments are compared with predictions of statistical decay models.


Multifragmentation And Flow: Peripheral Vs. Central Collisions, J. Pochodzalla, S. Aiello, M. Begemann-Blaich, Th. Blaich, D. R. Bowman, R. J. Charity, A. Cosmo, A. Ferrero, C. K. Gelbke, W. C. Hsi, J. Hubele, G. Imme, I. Iori, J. Kempter, P. Kreutz, G. J. Kunde, W. D. Kunze, V. Lindenstruth, M. A. Lisa, W. G. Lynch, U. Lynen, M. Mang, L. G. Moretto, A. Moroni, W. F.J. Müller, M. Neumann, B. Ocker, C. A. Ogilive, V. Pappalardo, Graham F. Peaslee, G. Raciti, F. Rosenberger, T. Rubehn, H. Sann, R. Scardaoni, A. Schüttauf, W. Seidei, V. Serfling Feb 1995

Multifragmentation And Flow: Peripheral Vs. Central Collisions, J. Pochodzalla, S. Aiello, M. Begemann-Blaich, Th. Blaich, D. R. Bowman, R. J. Charity, A. Cosmo, A. Ferrero, C. K. Gelbke, W. C. Hsi, J. Hubele, G. Imme, I. Iori, J. Kempter, P. Kreutz, G. J. Kunde, W. D. Kunze, V. Lindenstruth, M. A. Lisa, W. G. Lynch, U. Lynen, M. Mang, L. G. Moretto, A. Moroni, W. F.J. Müller, M. Neumann, B. Ocker, C. A. Ogilive, V. Pappalardo, Graham F. Peaslee, G. Raciti, F. Rosenberger, T. Rubehn, H. Sann, R. Scardaoni, A. Schüttauf, W. Seidei, V. Serfling

Faculty Publications

Multifragment decays of heavy nuclei have been studied at the ALADIN spectrometer system at beam energies between 100 and 1000 MeV per nucleon. The observed fragment distributions signal a universality of spectator decays at bombarding energies . The role of the radial flow for the fragmentation process is explored by comparing fragment distributions measured for Au+Au collisions at in central collisions and at in more peripheral reactions. At both energies the maximum multiplicity of intermediate mass fragments (IMFs) normalized to the size of the decaying system is about one IMF per 30 nucleons but the element distributions show significant differences. …


A Nanosecond Ord Study Of Hemoglobin, Lawrence J. Parkhurst Feb 1995

A Nanosecond Ord Study Of Hemoglobin, Lawrence J. Parkhurst

Lawrence Parkhurst Publications

This year marks the one hundredth anniversary of the first observation of CO photodissociation from HbCO, with the correct interpretation and publication following in the next year (Haldane and Smith, 1896). Little of kinetic importance could be learned from this photosensitivity, however, until the development of sensitive photodetectors and short duration high intensity light sources. These allowed Gibson, in pioneering discoveries in the mid to late 1950's (Gibson, 1956, 1959), to discover “Hb*,” a rapidly reacting form of hemoglobin, which we now associate with deoxy Hb in the tertiary relaxed “r” 9 state with the protein in the quaternary R …


62. David M Solomon, Otto Vogl, Kenneth Ghiggino Feb 1995

62. David M Solomon, Otto Vogl, Kenneth Ghiggino

Otto Vogl

No abstract provided.


Observation Of Parity-Unfavored Transitions In The Nonresonant Photoionization Of Argon, B. Langer, J. Viefhaus, Oliver Hemmers, A. Menzel, R. Wehlitz, U. Becker Feb 1995

Observation Of Parity-Unfavored Transitions In The Nonresonant Photoionization Of Argon, B. Langer, J. Viefhaus, Oliver Hemmers, A. Menzel, R. Wehlitz, U. Becker

Environmental Studies Faculty Publications

Single-photon ionization of an atom or molecule can be subdivided into parity-favored and -unfavored transitions, the latter characterized by electron emission, preferentially perpendicular to the electric vector. The nonresonant existence of these transitions is shown experimentally and studied over an extended energy range for a variety of satellite transitions in atomic argon. The spectra exhibit several clearly resolved satellite lines with strongly negative β values close to -1, independent of the photon energy. The results confirm the corresponding predictions of angular-momentum transfer theory.


Design And Performance Of The Advanced-Light-Source Double-Crystal Monochromator, G. Jones, S. Ryce, Dennis W. Lindle, B. A. Karlin, J. C. Woicik, Rupert C. Perera Feb 1995

Design And Performance Of The Advanced-Light-Source Double-Crystal Monochromator, G. Jones, S. Ryce, Dennis W. Lindle, B. A. Karlin, J. C. Woicik, Rupert C. Perera

Chemistry and Biochemistry Faculty Research

A new “Cowan type” double-crystal monochromator, based on the boomerang design used at National Synchrotron Light Source (NSLS) beamline X-24A, has been developed for beamline 9.3.1 at the Advanced Light Source (ALS), a windowless ultrahigh vacuum beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design of the monochromator has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline …


High-Brightness Beamline For X-Ray Spectroscopy At The Advanced Light Source, Rupert C. Perera, G. Jones, Dennis W. Lindle Feb 1995

High-Brightness Beamline For X-Ray Spectroscopy At The Advanced Light Source, Rupert C. Perera, G. Jones, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goals of high energy resolution, high flux, and high brightness at the sample. When completed later this year, it will be the first ALS monochromatic hard-x-ray beamline, and its brightness will be an order-of-magnitude higher than presently available in this energy range. In addition, it will provide flux and resolution comparable to any other beamline now in operation. To achieve these goals, two technical improvements, relative to existing x-ray beamlines, were incorporated. First, a somewhat novel optical design …


Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami Jan 1995

Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami

Theses

Removal of trichloroethylene, monochlorobenzene and 1,3 dichlorobenzene from water by air stripping and solvent sublation into an organic phase was investigated. The sublation solvents used were paraffin oil and decyl alcohol. The rate of removal from water by solvent sublation and air stripping was highest for trichloroethylene, followed by chlorobenzene and finally 1,3 dichlorobenzene. For the three compounds, solvent sublation had the greatest advantage over air stripping in the reduction of emission of the compounds to the atmosphere. For the three compounds, the removal was enhanced at higher flowrate in both air stripping and solvent sublation. For the removal of …