Materials Science and Engineering Commons^™

Radiolabeled Protein Composition And Method For Radiation Synovectomy, D. E. Day, Gary J. Ehrhardt, Kurt R. Zinn

Materials Science and Engineering Faculty Research & Creative Works

A radiolabeled protein composition adapted for radiation therapy which comprises a radioisotope and a protein material containing about 6 or more percent amino acids which have a sulfhydryl-containing side chain. A method for carrying out radiation synovectomy of arthritic joints. Rhenium radiolabeled protein micro- spheres are administered which contain cysteine and other amino acids. A method for radiolabeling a protein composition whereby the composition is treated with a reducing agent capable of reducing disulfides to sulfhydryls prior to radiolabeling.

An Analysis Of The Disposition Of Used Foundry Sand With Thermal Reclamation, Douglas Miller

Graduate Research Papers

The purpose of this study was to identify the economic and environmental concerns for the disposal, reuse, or reclamation of used foundry sand and show how foundries have developed options to landfills. The sand type and the reclamation processes available are the factors to use in determining whether disposal, reuse, or reclamation is appropriate. The continued use of landfills for disposal of used sand strongly indicates that reclamation and reuse techniques were either not understood or not as economical as disposal. Public concerns and new environmental laws demand that alternate means of disposal for used foundry sand should be developed …

An Investigation Of Hole Size Effects In A Composite Material During Tensile Fracture, David Floyd Moore

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental investigation was conducted to evaluate the hole size effects, i.e., the reduction in strength with an increase in hole size at a constant stress concentration factor, for a glass fiber reinforced epoxy crossply laminate during tensile fracture. The characteristic dimension according to the point-stress and average-stress criteria of the two-parameter models proposed by Whitney and Nuismer were determined and compared for a circular hole, optimized circular hole, square hole with radiused corners and square hole with sharp corners. Modified versions of the two-parameter models proposed by Karlak and Pipes, Wetherhold, and Gillespie were also compared. On the basis …

Thermal Effects On Y2O3:Eu3+ For Fiber Optic Temperature Sensing, Arnel C. Lavarias

Electrical & Computer Engineering Theses & Dissertations

Fiber optic methods have gained acceptance in the past several years as non­ intrusive optical techniques of measuring environmental variables, particularly under hostile conditions. Fiber optic temperature sensors are required for many applications which have a large operating range. One way to implement this sensor is to introduce rare earth-doped materials into a fiber showing temperature-dependent optical emission characteristics. The thermal effects on optical emission characteristics of Y₂O₃:Eu³⁺ were studied. The thermal broadening and temperature dependence of the lifetime (τ) of the 611.4 nm emission due to the ⁵D₀ ➔ 7F …

Identification And Characterization Of The Iron-Zinc Intermetallics Formed In Galvanneal Steel, Richard Frederick George Grant

Physics Theses & Dissertations

The demand to improve the corrosion resistance of steel sheet, particularly for use within the automotive industry, has led to a dramatic increase in the use of coated steels in place of cold-rolled sheet steel. Galvanneal steel results from the post annealing of the zinc-coated steel sheet, in which iron and zinc are interdiffused to form an iron-zinc alloy coating. Within this alloy coating, four main iron-zinc phases, Zeta, Delta, Gamma-1, and Gamma may be present. Manufacture of the most suitable coating requires identifying which phases form during the galvannealing process, an understanding of the properties of each phase and …

Evidence Of Heterogeneous Substructure Development During Primary Creep Of Ti-6al-2sn-4zr-2mo, R. W. Hayes, Cecil Rhodes, Blair London

Materials Engineering

No Abstract.

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

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A Photoelectrochemical Investigation Of Zirconium Oxide Film, Maizhi Yang, Ping Wei, Di Quarto F., Piazza S., Sunseri C.

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 ZrO₂ and the external layer ZrO₂·(H₂O)_n. The photocurrent included photogenerated carrier ininternal and external oxide films, as well as internal photoinjection process for electrons from thesubstrate metal into the …

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

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 the deposition of polymer with zinc phospate exhibits a high inbihition efficiency. The inhibition mechanism of the inhibitor in electrocoating has been studied.

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 electroreduction. This work employed misch metal AB₅ type alloy as acatalytic electrode and studied the electrochemical hydrogenation of nitrobenzene.

The hydrogen-storage electrode (MH) was a plastic bonded electrode sheet made from a paste of Mm(NiCoMnAl)₅ alloy powder and teflon emulsion. The electrolysis was performed at constantcurrent and controlled potential in a three electrode cell of H-type …

Transient Photocurrent Behavior Of Multiple Quantum Well Gaas/AlXGa(1-X)As Electrode, Liu Yao, Xurui Xiao, Yuan Lin, Yiping Zeng, Dianzhao Sun, Haiqun Zheng

Journal of Electrochemistry

Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well (MQW)GaAs/Al_0.3)Ga_0.7 As electrodes were studied in the 1 ×10^-2 mol·dm^-3 ferrocene([Fc⁰]/[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_0.3Ca_0.7 As MQW electrode consisting of 10 periods with each of GaAs well (5.3 nm) and Al_0.3Ga_0.7. As barrier (10 nm) showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum, corresponding to the …

Synthesis Of LiXCoo2 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_xCoO₂ during charge anddischarge have been st ud ied by XRD and AAR spectroscopy. It was found that the Li_xCoO₂ crystalvolume expanded during charge and contracted during discharge. The crystal lattice structure was broken because of the formation of Co₃O₄ when deeply charge.The variation of lattice parameter C₀ value 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 high temperature, the …

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

Journal of Electrochemistry

The titanium substrates were bombarded with 1×10¹⁷～5×10¹⁷ ions·cm^-2 ofpalladium at the room temperature. The surface composition of implanted electrode 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 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 poteritiostatic electrolysis, 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 metallic holmium is deposited when Ho(Ⅲ) is reduced on iron electrode. The charge transfer is reversible. The free energies of formation for the four inter metallic compounds of Ho-Fe system, the diffusion coefficients and diffusion activation energy of Ho in alloyed cathode are determined.

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 PbO₂ on lead electrodes have been investigatedby using in-situ methods that are combined with temporary AC resistance measurment technique and in-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/H₂SO₄/35% H₂SO₄) for more than 5 min. This result suggests that the growth of PbO is well distributed during the early stage of oxidation. The study by using laser scanning photoelectrochemical microscopy has further proved this point. The results also …

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-YCl₃ 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, Baoen Shen

Journal of Electrochemistry

The hydrogen evolution activity in acidic and basic mediums for Ni-W electrodemodified by carbon ion bean implantation was investigated. The experimental results show thiselectrode has superior catalytic activity for the hydrogen evolution reaction than that of the unmodified Ni-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 electrocatalytic property was also inverstigated. The experimental regularities are explained on the basis of the formation of surface multialloys of Ni-W-WC.

Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/SbAd 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 was electrocatalytically 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 the oxidation of formic acid, a 4-fold increase in the 1st peak current was observed. The Sb-modified platinum electrode was found to be most electrocatalytically active at a coverage of 0.75±0.05. The electrocatalytic activity of the Pt/Sb_ad electrode can be best …

The Effect Of Some Ions On Cr2O72- Anodic Formation Process At Pt And Pbo2 Electrodes, Shixiong Jin, Zhigang Zhou, Lan Wang

Journal of Electrochemistry

The influence of Ag₂SO₄, Li₂SO₄, Na₂SO₄, K₂SO₄, (NH₄)₂SO₄,MgSO₄ and KF on the evolution of O₂ and the formation of Cr₂O at Pt and PbO₂ anodes was investigated in mixed H₂SO₄-Cr₂(SO₂)₃ solutions. The kinetic data related respectively to Cr₂O formation and O₂ evolution at Pt and PbO₂ anodes were measured by method of resolving the steady-state polarization curve. The Tafel slope …

Development Of Nial-Based Intermetallic Alloys: Effect Of Chromium Addition, R. Tiwari, Surendra N. Tewari, R. Asthana, A. Garg

Chemical & Biomedical Engineering Faculty Publications

The mechanical behavior of dual-phase NiAl(Cr) microstructures, consisting of elongated primary NiAl grains aligned with an intergranular NiAl-Cr eutectic phase, produced by extrusion of a cast NiAl(Cr) alloy, has been examined. Chromium addition to create a dual phase NiAl-based aligned microstructure leads to large increases in the yield strength but no significant toughness improvement. This is achieved primarily by solid solution hardening and precipitation hardening. The constitutional hardening rate resulting from deviations from stoichiometry in the nickel-rich NiAl was estimated to be about 66 MPa per atomic per cent of nickel.

Influence Of Interfacial Reactions On The Fiber-Matrix Interfacial Shear-Strength In Sapphire Fiber-Reinforced Nial(Yb) Composites, Surendra N. Tewari, R. Asthana, R. Tiwari, R. R. Bowman, J. Smith

Chemical & Biomedical Engineering Faculty Publications

The influence of microstructure of the fiber-matrix interface on the interfacial shear strength, measured using a fiber-pushout technique, has been examined in a sapphire-fiber-reinforced NiAl(Yb) matrix composite under the following conditions: (1) as-fabricated powder metallurgy (PM) composites, (2) PM composites after solid-state heat treatment (HT), and (3) PM composites after directional solidification (DS). The fiber-pushout stress-displacement behavior consisted of an initial ''pseudoelastic'' region, wherein the stress increased linearly with displacement, followed by an ''inelastic'' region, where the slope of the stress-displacement plot decreased until a maximum stress was reached, and the subsequent gradual stress decreased to a ''frictional'' stress. Energy-dispersive …

Low Pressure Chemical Vapor Deposition Of Silicon Nitride Films From Tridimethylaminosilane, Xin Lin

Theses

In this study amorphous stoichiometric silicon nitride films were synthesized by low pressure chemical vapor deposition (LPCVD) using tri(dimethylamino) silane (TDMAS) and ammonia (NH₃). The growth kinetics were determined as a function of temperature in the range of 650 - 900 °C, total pressure in the range of 0.15 - 0.60 Torr, and NH₃/TDMAS flow ratio in the range of 0 - 10. At constant condition of pressure (0.5 Torr), TDMSA flow rate (10 sccm) and NH₃ flow rate (100 sccm), the deposition rate of as-deposited silicon nitride films was found to follow an Arrehnius …

Molten Salt Electrolytes For Electrodeposition Of Cdte Films, Arif Raza, Robert Engelken, Brandon Kemp, Arees Siddiqui, Omer Mustafa

Journal of the Arkansas Academy of Science

We report preliminary investigation of several molten salt electrolytes containing CdCl2 and TeCl4 for the electrodeposition of CdTe films at temperatures well above (>250 °C) those used with aqueous and organic electrolytes. These high temperatures have potential todramatically increase the crystallite size (Poole, Engelken, et al., 1994), as is important for optoelectronic device applications of CdTe, a leading II-VIsemiconductor. This paper willsurvey the results obtained withelectrolytes such as B2O,/HBO2 (m.p. - 230'C), NaCH3COO (m.p. » 324°C), ZnCl2 (m.p. - 283*C), and LiCl/KCl (m.p. * 350 °C), with an emphasis on the latter two. Key material to be presented includes …

Thermoplastic Composites Of Recycled High Density Polyethylene And Recycled Tire Particles, James N. Mckirahan Jr.

Masters Theses

This study identified the mechanical properties and processibility of composite materials of recycled high density polyethylene (HDPE), recycled rubber tire particles, and/or ethyl co-vinyl acetate and poly (e-caprolactone). The composites were processed using a single screw extrusion system.

Three groups of experiments were conducted, on the composites in their extruded form to investigate the mechanical properties of ultimate tensile strength, percent elongation, and hardness. The first experiment investigated the effect of recycled rubber particle concentration in the composites up to 25 percent. The second experiment investigated the effect of recycled rubber particle size on the composites of recycled HDPE and …

Influence Of Fabrication Technique On The Fiber Pushout Behavior In A Sapphire-Reinforced Nial Matrix Composite, R. Asthana, R. R. Bowman, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

Directional solidification (DS) of ''powder-cloth'' (PC) processed sapphire-NiAl composites was carried out to examine the influence of fabrication technique on the fiber-matrix interfacial shear strength, measured using a fiber-pushout technique. The DS process replaced the fine, equiaxed NiAl grain structure of the PC composites with an oriented grain structure comprised of large columnar NiAl grains aligned parallel to the fiber axis, with fibers either completely engulfed within the NiAl grains or anchored at one to three grain boundaries. The load-displacement behavior during the pushout test exhibited an initial ''pseudoelastic'' response, followed by an ''inelastic'' response, and finally a ''frictional'' sliding …

Semiempirical Model For The Electrical Properties Of La1-Xcaxcoo3, S. R. Sehlin, Harlan U. Anderson, Don M. Sparlin

Materials Science and Engineering Faculty Research & Creative Works

A semiempirical model of the Seebeck coefficient for a small polaron hopping conductor is presented. The population of small polarons is allowed to change as a function of temperature via the mechanism of charge disproportionation. The energy required for polaron formation by the disproportionation mechanism is modeled as screened by a Coulomb interaction with nearby small polarons. The charge carrier site occupancies generated by the model are used to successfully predict the electrical conductivity and Seebeck coefficient for compositions in the La1-xCaxCoO3 system. Cobalt ion valence populations predicted by the model are used to calculate effective paramagnetic moments for LaCoO3, …

Structure And Electrical Properties Of La1-Xsrxco1-Yfeyo3. Part 1. The System La0.8sr0.2co1-Yfeyo3, L. W. Tai, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin, S. R. Sehlin

Materials Science and Engineering Faculty Research & Creative Works

Crystal structure, thermal expansion, thermogravimetry, thermoelectricity, and electrical conductivity of compositions in the system La0.8Sr0.2Co1-yFeyO3 with 0 ≤ y ≤ 1 were studied as function of Co Fe ratio and temperature, in air. The electrical conduction mechanism is attributed to the adiabatic-hopping of p-type small polarons. At high temperatures, oxygen deficiency causes lattice expansion and a reduction in electrical conductivity. The observed temperature dependence of the Seebeck coefficient is attributed to changes in carrier concentration caused by a thermally excited charge disproportionation of Co3+ ions and by the ionic compensation of induced oxygen vacancies. The measured electrical conductivity and Seebeck …

Structure And Electrical Properties Of La1 - Xsrxco1 - Yfeyo3. Part 2. The System La1 - Xsrxco0.2fe0.8o3, L. W. Tai, M. M. Nasrallah, Harlan U. Anderson, Don M. Sparlin, S. R. Sehlin

Materials Science and Engineering Faculty Research & Creative Works

Crystal structure, thermal expansion, oxygen stoichiometry, thermoelectricity, and electrical conductivity of compositions in the system La1 - xSrxCo0.2Fe0.8O3 with 0 ≤ x ≤ 0.6 were studied as function of temperature and Sr content, in air. The solubility of Sr in the sintered perovskite-type oxide (ABO3) was limited to x ≤ 0.4. The observed p-type electrical conduction appeared to occur via a small-polaron hopping mechanism. The thermally induced oxygen loss caused a lattice expansion plus decreases in both the carrier concentration and the carrier mobility. A semi-empirical model was developed which takes into account the thermally activated disproportionation of Co3+ ions …

Electrical And Thermal Transport Properties Of (La,Ca)(Cr,Co)O3, Rasit Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

DC electrical conductivity and Seebeck data as functions of temperature and oxygen activity were used to explain the electrical and thermal transport properties of (La,Ca) (Cr,Co)O3. The electrical conductivity data of La (Cr,Co)O3 suggested that it depends upon Co content. At Co concentrations less than 20 mol%, Co acted as traps for the carriers and decreased the electrical conductivity of the compositions at temperatures less than 900 °C. As the Co concentration increased to above 20 mol%, electrical conductivity increased significantly due to a connecting path of available Co sites. Additional Ca substitution for La increased the electrical conductivity in …