Computerized simulation of shortened ingots with a controlled crystallization for manufacturing of high-quality forgings

2019 ◽  
Vol 103 (5-8) ◽  
pp. 3057-3065 ◽  
Author(s):  
Oleg E. Markov ◽  
Oleksiy V. Gerasimenko ◽  
Alexander A. Shapoval ◽  
Oleksandr R. Abdulov ◽  
Roman U. Zhytnikov
Keyword(s):  
High Quality ◽  
Controlled Crystallization ◽  
Computerized Simulation

The Preparation of Crystalline NbSe2/TiSe2 Superlattices from Modulated Elemental Reactants

1995 ◽  
Vol 382 ◽  
Author(s):  
Myungkeun Noh ◽  
James Thiel ◽  
David C. Johnson
Keyword(s):  
Diffraction Data ◽  
Substrate Surface ◽  
Domain Size ◽  
High Angle ◽  
High Quality ◽  
Rocking Curve ◽  
Modulated Elemental Reactants ◽  
Unit Cells ◽  
Controlled Crystallization ◽  
Elemental Reactants

ABSTRACTThree new crystalline NbSe2/TiSe2 superlattice compounds with 43.472±0.005A, 80.66±0.03A and 117.9±0.1Å unit cells in thec direction were prepared through controlled crystallization of Ti/Se/Nb/Se superlattice reactants with different compositional layer thicknesses. Theta-theta and rocking curve data were collected using a theta-theta diffractometer to study the evolution of the initially layered reactants into the crystalline superlattices as a function of temperature. Low angle diffraction data demonstrates that the initial layered reactant contracts in the c-axis direction upon initial annealing and suggests that the interfaces become smoother during this initial interdiffusion. High angle rocking curve diffraction data shows the development of caxis oriented NbSe2fTiSe2 crystal growth perpendicular to the substrate surface. Theta-theta scans show a gradual decrease of the (001) diffraction linewidths of the growing compound as a function of annealing time and temperature indicating an increase in the c-axis domain size. High quality caxis oriented TiSe2/NbSe2 crystalline superlattices result from annealing at the relatively low temperature of 500ºC. The rational synthesis of intergrowth compounds from superlattice reactants as described herein will permit the tailoring of physical properties as a function of compositional layer thicknesses and nativeproperties of the parent compounds.

scholarly journals 3-D Simulation of Double-Bar Plush Fabrics with Jacquard Patterns

2018 ◽  
Vol 18 (3) ◽  
pp. 243-250
Author(s):  
Aijun Zhang ◽  
Xinxin Li ◽  
Gaoming Jiang ◽  
Zhijia Dong ◽  
Honglian Cong
Keyword(s):  
Development Process ◽  
Model Simulation ◽  
Simulation Method ◽  
Simulation Approach ◽  
High Quality ◽  
Time Saving ◽  
Perlin Noise ◽  
Geometry Shader ◽  
Simulation Results ◽  
Computerized Simulation

Abstract A realistic computerized simulation of double-bar plush fabrics can result in a time-saving development process with high quality. Based on basic analysis of jacquard principles, a fast 3-D simulation method of warp-knitted plush fabrics is proposed by using a geometry shader on GPU. Firstly, pile areas and non-pile areas are identified according to the jacquard design graphs and chain notations. According to the directions of observation and raised pile, two layered chips are formed in the geometry shader with an approach of multi-layered textures. To ensure that the simulated piles resemble the real ones, the directions of the piles are randomized with the Perlin noise method. One pile is generated along its length with numerous layers in the plush fabric model. Simulation results of piles on both the technical face and technical back are obtained via the model built above, which is confirmed with practicability and efficiency. This 3D simulation approach improves the visualization appearance of piles just as they are actually raised.

scholarly journals Surface-Tension-Controlled Crystallization for High-Quality 2D Perovskite Single Crystals for Ultrahigh Photodetection

Matter ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 465-480 ◽  
Author(s):  
Yucheng Liu ◽  
Haochen Ye ◽  
Yunxia Zhang ◽  
Kui Zhao ◽  
Zhou Yang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Single Crystals ◽  
High Quality ◽  
Controlled Crystallization

Preparation of β-Calcium Metaphosphate (β-CMP) Whiskers

2007 ◽  
Vol 330-332 ◽  
pp. 15-18
Author(s):  
Li Liao ◽  
Lin Chen ◽  
Ai Zheng Chen ◽  
Xi Ming Pu ◽  
Yun Qing Kang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Distilled Water ◽  
High Quality ◽  
Aspect Ratios ◽  
Factors Influencing ◽  
Controlled Crystallization ◽  
Optimized Conditions ◽  
Component Time

To increase the mechanical properties of PLA used for fracture inner fixation, β-calcium metaphosphate whiskers were prepared by controlled crystallization in the glass. The factors influencing the morphology of the samples, such as component, time and temperature of crystallization were discussed. Results showed that the high quality of β-calcium metaphosphate whiskers can be obtained by crystallization treating for 36 hours and washing for 48 hours at 80°C distilled water. β-calcium metaphosphate whiskers having high aspect ratios of 20-100 with diameters of 1-5μm were achieved at the optimized conditions.

The Synthesis and Superconducting Behavior of Crystalline Superlattices: (TiSe2)m(NbSe2)n

1996 ◽  
Vol 441 ◽  
Author(s):  
Myungkeun Noh ◽  
David C. Johnson
Keyword(s):  
Annealing Temperature ◽  
Substrate Surface ◽  
Domain Size ◽  
Bragg Diffraction ◽  
Conductivity Measurements ◽  
High Quality ◽  
Rocking Curve ◽  
Integral Number ◽  
Controlled Crystallization ◽  
Diffraction Peaks

AbstractA series of kinetically stable, crystalline superlattices containing an integral number of intergrown TiSe2 and NbSe2 layers have been synthesized by controlled crystallization of elementally modulated reactants. Theta-theta and rocking curve data were collected to study the evolution of the initially layered reactants into the crystalline superlattices as a function of temperature. Nucleation of the dichalcogenide structure occurs upon annealing at temperatures above 200°C with the c-axis oriented perpendicular to the substrate surface. The [00l] diffraction linewidths decrease with increased annealing time and temperature suggesting growth of the c-axis domain size. High quality c-axis oriented dichalcogenide crystalline superlattices result from extended annealing at the relatively low annealing temperature of 500°C. The large number of well resolved [00l] Bragg diffraction peaks confirm the well developed crystal structure of the product superlattices in this direction. Four probe electrical conductivity measurements were used to determine the variation of the superconducting critical temperature as a function of the number of TiSe2 and NbSe2 layers in the superlattice.

Some problems of objective-prism spectra classification

1966 ◽  
Vol 24 ◽  
pp. 51-52
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya
Keyword(s):  
Short Wave ◽  
High Quality ◽  
Stellar Spectra ◽  
Objective Prism

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.

A non-cyanide method of electropolishing silver

1978 ◽  
Vol 36 (1) ◽  
pp. 146-147
Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger
Keyword(s):  
Electron Microscopy ◽  
Sulphuric Acid ◽  
Methyl Alcohol ◽  
Health Hazards ◽  
Silver Alloy ◽  
High Quality ◽  
Silver Alloys ◽  
Free Sample ◽  
Specimen Quality ◽  
Standard Techniques

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).

A High Resolution Scanning Microscope

1968 ◽  
Vol 26 ◽  
pp. 356-357
Author(s):  
A. V. Crewe ◽  
J. Wall ◽  
L. M. Welter
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Spherical Aberration ◽  
Focal Length ◽  
Spot Size ◽  
Emission Source ◽  
Field Of View ◽  
Scanning Microscope ◽  
Magnetic Lens ◽  
High Quality

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

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