Search results

The composites' grain structure demonstrated a uniform distribution of reinforcing phase of Al 6063 Alloy.
In the chemistry department of the University of Lagos, Akoka, Nigeria, the gold nanoparticles (AuNps) from aloe vera leaf (bought from a local farm in Lagos, Nigeria) needed for reinforcing was extracted.
A combination of the AuNps weight fraction and heat treatment results in the composites having a more refined structure and smaller particles, as shown in the OM.

The obtained PolyHIPEs showed an open cell and a secondary pore structure with surface areas of approximately 400m2/g.
A lot of effort was invested to determine the factors which affect the cellular structure and cell size of the resulting porous polymers, and in 1997, Neil R.
Mondain-Monval, Development of a New Ultraporous Polymer as Support in Organic Synthesis, Bioorganic & Medicinal Chemistry Letters. 12 (2002) 1877-1880

The coating structures were analyzed by X-ray diffraction (XRD) using Cu Ka radiation.
Cr film, (CrN) film, and TiCrN film all had certain chemistry stability.
So, the coatings had the composite structure.
In our work, the Cr film may be having the fcc structure.
TiN was in the same crystal structure with CrN.

PR-382F has fast drying and is good for RDF composite structure.
An increase of extrusion pressure can density the particles but cannot change moisture absorption of RDF structure, rice husk.
An increase of extrusion temperature impairs properties of binders, and binders are carbonized, while an increase of extrusion temperature destroys the bonding structure between particles and binders, and the structure is fragile.
Journal of Fuel Chemistry and Technology Vol. 34-3,(2008),p.34-65.

A hybrid mesh (not shown) was generated using ANSYS CFX-meshing tool with structured grid in the near wall region and unstructured grid away from wall.
Later, three set of structured grids were generated using Gambit meshing tool, resulting a baseline block-structured mesh of 182,000 elements for present study.
RANS code SCRAMIN (MacCormack time-accurate, explicit prediction-correction method), three contraction ratios, Reynolds numbers, 2 Berry et al., 2000 [11] X-43 (Hyper-X) forced transition experiment of Mach 6 at NASA LaRC 20-inch air tunnel, 1/3 scaled model, Angle of Attack=0,2,4 degrees, Re=1.2 – 15.4 million, various roughness elements 3 Holden et al., 2002, AFRL-SR-BL-TR-02-0738 Experiment, part I: code validation of double-cone flow (still a good validation case); part II: scramjet intake flow (Mach 7 of Air Force Hy-Tech configuration, results include wall pressure and heat transfer, Schlieren photographs) 4 Reinartz et al., 2002, AIAA 2002–0506 Computation of wall heat flux, block-structured FV RANS + k-w model FLOWer), supersonic Mach 2.5 for scramjet inlet and hypersonic M=7.7 compression corner flow 5 Ferrier et al., AIAA paper 2006-8092, AIAA 2008-2599 Transition prediction of forebody BL at Ma=2, 4, 6 by linear stability analysis (LSA) coupled with eN method, 6 Krause et al
Malik, Hypersonic flight transition data analysis using parabolized stability equations with chemistry effects, Journal of Spacecraft Rockets, 40(3):332–44, 2003

Active Screen Plasma Nitriding of Titanium Alloy Using Titanium Double Screen Akio Nishimoto1, a * and Kunishige Nakazawa2, b 1Department of Chemistry and Materials Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan 2Graduate School of Science and Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan aakionisi@kansai-u.ac.jp, bk281580@kansai-u.ac.jp Keywords: Titanium alloy, plasma nitriding, active screen, surface engineering, wear resistance, titanium nitride.
The screen was made by double screen structure to produce large amounts of ion and active species on the cathodic screen.
The phase structures on the nitrided surface were determined by theta-2theta x-ray diffraction (XRD; RIGAKU, Japan, RINT-2550V) studies.
In the sample treated by ASPN, the duplex structure of the titanium nitride layer on the top surface followed by the nitrogen-diffusion layer was demonstrated by microstructure observation and elemental analysis of GD-OES, as shown in Figs. 5 and 6.
Fig. 6 Cross-sectional GD-OES analyses of Ti-6Al-4V samples plasma nitrided at 600ºC under 200 Pa using a titanium double screen Fig. 7 Wear track appearance and the cross-sectional profile of Ti-6Al-4V samples plasma nitrided for 25 hours at 600ºC under 200 Pa using a titanium double screen Therefore, the duplex structure of the TiN coating and the nitrogen-diffusion layer resulted in the high hardness and superior wear resistance of the titanium alloy.

Effect of Oleic Acid on Properties of Natural Rubber Filled Bacterial Cellulose Saowaluk Boonyod1, a and Chaiwute Vudjung1, b* 1Laboratory of Advanced Polymer and Rubber Materials (LAPRM), Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 Thailand asaowaluk_boonyod@hotmail.com, bchaiwute2110@gmail.com, bscchaivu@ubu.ac.th Keywords: Natural rubber, Bacterial cellulose, Oleic acid, Rubber fillers Abstract.
It has molecular structure like plant cellulose, but it has an ultrafine nanofiber network.
Singhal [3] was undertaken to introduce hydrophobicity in guar gum which has a hydroxyl group in its structure by esterification with oleic acid (OA).
The dispersion of filler in rubber and Mooney viscosity decrease due to reduction of filler-filler interaction caused BC is long strands of molecules interwoven to form a linear and string-like structure.
The relationship between crosslink system, network structure and material properties of carbon black reinforced EPDM.

The weld metal (WM) solidifies into coarse columnar structures virtually in a completely ferritic matrix and g-phase grows at the ferrite grain boundaries either allotriomorphic (AA) and Widmanstätten (WA) shaped or acicular intragranularly (AcA) [1-2, 4].
Review of the literature shows that while there are attempts to refine the weld metal grain structure of austenitic and ferritic stainless steels [12-13] there is not research in terms of grain refinement of DDS´s d matrix during welding to promote an increase of sites for nucleation and growth of g-phase.
These structures are generated at lower temperatures with a greater undercooling, acting as the driving force the vibration induced with the electromagnetic interaction.
Sundaresan, Effect of weld metal chemistry and heat input on the structure and properties of duplex stainless steel welds, Materials Science and Engineering 358 (2003) 9-16

The structures of the milled powders were characterized with X-ray diffractometer (XRD) and the microstructures of consolidated composites were examined with electron microscopes.
To reveal the grain structure of MoSi2 matrix, the bulk samples were thermally etched and observed by a scanning electron microscope with EDS attachment for composition analysis.
For the compound powder mixtures milled in a lower energy mode for 1 hr, the structures of SiC and MoSi2 ingredients were still reserved.
Combination of microstructures such as fine grain structure, uniformly distributed SiC particles, reduced silica phase, higher bulk density and fewer pores is responsible for higher fracture toughness.
Lide: Handbook of Chemistry and Physics (CRC Press, 1993)

The measuring samples are GaAs/GaAsP quantum well structure.
The material of the sample is the GaAs/GaAs1-xPx quantum well structure, where x is the material proportion and the value is 0.21, constructed by GaAs and GaP, and grown on the base plate of GaAs by MOVPE (Metal Organic Vapor Phase Epitaxy).
The way to produce quantum well or quantum point structure in semi-conductor component can increase the efficiency and lighting strength effectively.
Gfroerer, in Encyclopedia of Analytical Chemistry edited by R.A.
Macrander, Materials Aspects of GaAs and InP based Structures, Prentice Hall, Englewood Cliffs, N.J., (1991).