Thermodynamics of Organic Chemical Partition in Soils. 2. Nonlinear Partition of Substituted Phenylureas from Aqueous Solution

1994 ◽  
Vol 28 (6) ◽  
pp. 996-1002 ◽  
Author(s):  
Frank C. Spurlock ◽  
James W. Biggar
Keyword(s):  
Aqueous Solution ◽  
Organic Chemical ◽  
Chemical Partition

Reply to Comment on "Thermodynamics of Organic Chemical Partition in Soils"

1995 ◽  
Vol 29 (5) ◽  
pp. 1423-1424 ◽  
Author(s):  
Frank C. Spurlock ◽  
James W. Bigger
Keyword(s):  
Organic Chemical ◽  
Chemical Partition

Synthesis and Photocatalytic Properties of Iron Disilicide/SiC Composite Powder

MRS Advances ◽  
2017 ◽  
Vol 2 (8) ◽  
pp. 471-476
Author(s):  
Kensuke Akiyama ◽  
Yuu Motoizumi ◽  
Tetsuya Okuda ◽  
Hiroshi Funakubo ◽  
Hiroshi Irie ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Composite Powder ◽  
Eutectic Reaction ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Iron Disilicide ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTSemiconducting iron disilicide (β-FeSi2) island grains of 50-100 nanometers in size were formed on the surface of Au-coated 3C-SiC powder by metal-organic chemical vapor deposition. On the surface of 3C-SiC powder, the Au-Si liquidus phase was obtained via a Au-Si eutectic reaction, which contributed to the formation of the β-FeSi2 island grains. This β-FeSi2/SiC composite powder could evolve hydrogen (H2) from methyl-alcohol aqueous solution under irradiation of visible light with wavelengths of 420-650 nm.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

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