scholarly journals High-performance process fluids used for vibration finishing of parts with granular media made of natural material “Baykalit”

2021 ◽  
Vol 2131 (4) ◽  
pp. 042028
Author(s):  
V Lebedev ◽  
V Shumyacher ◽  
Ye Kolganova ◽  
D Krivosheev
Keyword(s):  
High Performance ◽  
Granular Media ◽  
Cutting Tool ◽  
High Hardness ◽  
Natural Material ◽  
Initial Surface ◽  
Fine Grained ◽  
Siliceous Rock ◽  
Process Fluid ◽  
Quartz Grains

Abstract The results of studies of the technological capabilities of granular media made of natural material “Baykalit” in the conditions of vibration technological systems are presented. Baikalit is a siliceous rock-fine-grained quartzite (microquartzite) - with an aggregate structure of quartz grains measuring 1.5-3 microns with sharp boundaries between these very grains. The granules obtained as a result of crushing the mineral rock Baikalit have a sufficiently high hardness (at least 6.0 - 7.0 on the Mohs scale). The presence of many wedge-shaped vertices along the perimeter of the granules and the arbitrariness of the shape allows us to consider them as a universal cutting tool that has access to various surfaces of complexity. It is shown that vibration treatment with granular media made of natural material “Baykalit” reduces the height of the initial surface micrprofile by 0.2-0.3 microns and is an effective way to remove burrs when processing parts with a surface microprofile height of more than 0.63 microns. The use of process fluids, which include increasing the wetting capacity of both Baikalit and processed workpieces, reduces the technological time of vibration processing by 1.5 times. The presence of components in the process fluid, such as protective colloids (Na CMC), prevents the sludge from sticking to the galtovochnye bodies, that is, prevents the “salting” of their profile, reduces the rigidity of the layer on the surface of the galtovochnyh bodies and workpieces, which contributes to productivity growth.

High-Pressure Synthesis of High-Purity and High-Performance Diamond and cBN Ceramics

2006 ◽  
Vol 45 ◽  
pp. 885-892 ◽  
Author(s):  
Hitoshi Sumiya
Keyword(s):  
High Pressure ◽  
Diffusion Process ◽  
High Purity ◽  
High Performance ◽  
High Efficiency ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
High Hardness ◽  
Secondary Phases ◽  
Fine Grained

High-purity, single-phase polycrystalline diamond and cBN have been successfully synthesized by direct conversion sintering from graphite and hBN, respectively, under static high pressure and high temperature. The high-purity polycrystalline diamond synthesized directly from graphite at ≧15 GPa and 2300-2500 °C has a mixed texture of a homogeneous fine structure (grain size : 10-30 nm, formed in a diffusion process) and a lamellar structure (formed in a martensitic process). The polycrystalline diamond has very high hardness equivalent to or even higher than that of diamond crystal. The high-purity polycrystalline cBN synthesized from high-purity hBN at 7.7 GPa and 2300 °C consists of homogeneous fine-grained particles (<0.5 μm, formed in a diffusion process). The hardness of the fine-grained high-purity polycrystalline cBN is obviously higher than that of single-crystal cBN. The fine microstructure features without any secondary phases and extremely high hardness of the nano-polycrystalline diamond and the fine-grained polycrystalline cBN are promising for applications in next-generation high-precision and high-efficiency cutting tools.

TATMO V-N

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
Nitrogen Addition ◽  
Aisi Type ◽  
End Mills ◽  
Red Hardness ◽  
Edge Toughness

Abstract TATMO V-N is an AISI Type M7 high-speed steel modified by alloy balancing and a nitrogen addition to develop superior hardness response in heat treatment. It is an excellent grade for many cutting-tool applications requiring an optimum balance of red hardness, edge toughness and wear resistance, such as drills, taps, end mills, reamers and milling cutters. Its combination of outstanding properties and high hardness makes Tatmo V-N a logical alternate for cobalt high-speed steels in many cutting-tool applications. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-452. Producer or source: Latrobe Steel Company.

scholarly journals Bonding evolution with sintering temperature in low alloyed steels with chromium

2009 ◽  
Vol 41 (2) ◽  
pp. 161-173 ◽  
Author(s):  
L. Fuentes-Pacheco ◽  
M. Campos
Keyword(s):  
Carbothermic Reduction ◽  
High Performance ◽  
Sintering Temperature ◽  
Surface Oxide ◽  
Dew Point ◽  
Processing Route ◽  
Initial Surface ◽  
Sintered Steels ◽  
Controlling Mechanism ◽  
Die Compaction

At present, high performance PM steels for automotive applications follow a processing route that comprises die compaction of water-atomized powder, followed by sintering and secondary treatments, and finishing operations. This study examines Cr-alloyed sintered steels with two level of alloying. In chromium-alloyed steels, the surface oxide on the powder is of critical importance for developing the bonding between the particles during sintering. Reduction of this oxide depends mainly on three factors: temperature, dew point of the atmosphere, and carbothermic reduction provided by the added graphite. The transformation of the initial surface oxide evolves sequence as temperature increases during sintering, depending on the oxide composition. Carbothermic reduction is supposed to be the controlling mechanism, even when sintering in hydrogen-containing atmospheres. The effect of carbothermic reduction can be monitored by investigating the behavior of the specimens under tensile testing, and studying the resultant fracture surfaces.

scholarly journals Accurate Filtering of Privacy-Sensitive Information in Raw Genomic Data

2018 ◽  
Author(s):  
Jérémie Decouchant ◽  
Maria Fernandes ◽  
Marcus Völp ◽  
Francisco M Couto ◽  
Paulo Esteves-Veríssimo
Keyword(s):  
High Performance ◽  
Genomic Data ◽  
Sensitive Information ◽  
Sensitive Data ◽  
Variable Regions ◽  
Fine Grained ◽  
Sequencing Errors ◽  
Sequencing Technologies ◽  
Human Genomes ◽  
Long Reads

AbstractSequencing thousands of human genomes has enabled breakthroughs in many areas, among them precision medicine, the study of rare diseases, and forensics. However, mass collection of such sensitive data entails enormous risks if not protected to the highest standards. In this article, we follow the position and argue that post-alignment privacy is not enough and that data should be automatically protected as early as possible in the genomics workflow, ideally immediately after the data is produced. We show that a previous approach for filtering short reads cannot extend to long reads and present a novel filtering approach that classifies raw genomic data (i.e., whose location and content is not yet determined) into privacy-sensitive (i.e., more affected by a successful privacy attack) and non-privacy-sensitive information. Such a classification allows the fine-grained and automated adjustment of protective measures to mitigate the possible consequences of exposure, in particular when relying on public clouds. We present the first filter that can be indistinctly applied to reads of any length, i.e., making it usable with any recent or future sequencing technologies. The filter is accurate, in the sense that it detects all known sensitive nucleotides except those located in highly variable regions (less than 10 nucleotides remain undetected per genome instead of 100,000 in previous works). It has far less false positives than previously known methods (10% instead of 60%) and can detect sensitive nucleotides despite sequencing errors (86% detected instead of 56% with 2% of mutations). Finally, practical experiments demonstrate high performance, both in terms of throughput and memory consumption.

scholarly journals Denudation systematics inferred from in situ cosmogenic <sup>10</sup>Be concentrations in fine (50–100 µm) and medium (100–250 µm) sediments of the Var River basin, southern French Alps

2019 ◽  
Vol 7 (4) ◽  
pp. 1059-1074 ◽  
Author(s):  
Apolline Mariotti ◽  
Pierre-Henri Blard ◽  
Julien Charreau ◽  
Carole Petit ◽  
Stéphane Molliex ◽  
...  
Keyword(s):  
Glacial Cycles ◽  
Size Fractions ◽  
French Alps ◽  
Fine Grained ◽  
Denudation Rates ◽  
Variable Morphology ◽  
Cosmogenic 10Be ◽  
The Impact ◽  
Quartz Grains

Abstract. Marine sedimentary archives are well dated and often span several glacial cycles; cosmogenic 10Be concentrations in their detrital quartz grains could thus offer the opportunity to reconstruct a wealth of past denudation rates. However, these archives often comprise sediments much finer (<250 µm) than typically analyzed in 10Be studies, and few studies have measured 10Be concentrations in quartz grains smaller than 100 µm or assessed the impacts of mixing, grain size, and interannual variability on the 10Be concentrations of such fine-grained sediments. Here, we analyzed the in situ cosmogenic 10Be concentrations of quartz grains in the 50–100 and 100–250 µm size fractions of sediments from the Var basin (southern French Alps) to test the reliability of denudation rates derived from 10Be analyses of fine sands. The Var basin has a short transfer zone and highly variable morphology, climate, and geology, and we test the impact of these parameters on the observed 10Be concentrations. Both analyzed size fractions returned similar 10Be concentrations in downstream locations, notably at the Var's outlet, where concentrations ranged from (4.02±0.78)×104 to (4.40±0.64)×104 atoms g−1 of quartz. By comparing expected and observed 10Be concentrations at three major river junctions, we interpret that sediment mixing is efficient throughout the Var basin. We resampled four key locations 1 year later, and despite variable climatic parameters during that period, interannual 10Be concentrations were in agreement within uncertainties, except for one upper subbasin. The 10Be-derived denudation rates of Var subbasins range from 0.10±0.01 to 0.57±0.09 mm yr−1, and spatial variations are primarily controlled by the average subbasin slope. The integrated denudation rate of the entire Var basin is 0.24±0.04 mm yr−1, in agreement with other methods. Our results demonstrate that fine-grained sediments (50–250 µm) may return accurate denudation rates and are thus potentially suitable targets for future 10Be applications, such as studies of paleo-denudation rates using offshore sediments.

scholarly journals CURRENT STATE OF APPLIENCE ZIRCONIUM DIOXIDE IN BIOENGINEERING

2020 ◽  
Vol 4 ◽  
pp. 39-42
Author(s):  
Oksana Morozova ◽  
Edwin Gevorkyan
Keyword(s):  
Fracture Toughness ◽  
Composite Materials ◽  
Zirconium Dioxide ◽  
High Performance ◽  
Current Knowledge ◽  
High Hardness ◽  
Color Stability ◽  
Orthopedic Implants ◽  
Advantages And Disadvantages ◽  
Alternative Material

This descriptive review presents current knowledge about the bioengineering use of a zirconium dioxide, the advantages and disadvantages of the material, and the prospects for research in this direction. The work reflects the success of the practical application of the zirconium dioxide as a material for dental structures and biological implants. Such practical characteristics, such as color-stability, chemical stability, good aesthetics, biocompatibility and durability, allowed to actively use the zirconium dioxide as a material for producing various dental structures. In comparison with other ceramics, the presence of high-performance of strength and fracture toughness of the zirconium dioxide enables the use of this material as an alternative material for the reconstructions in the readings with considerable loads. High hardness determines the zirconium dioxide as an excellent material for articular prostheses, because of its hardness, provides a low level of wear and excellent biocompatibility. However, along with positive characteristics, a widespread practical problem of using the zirconium dioxide in dentistry is a chip or fracture of veneering ceramics. It has also been reported that there is a shortage of orthopedic implants such as hydrothermal stability. The solution of such problems is indicated and the use of composite materials based on the zirconium dioxide, which allows to solve a similar problem, as well as to increase the service life and reliability of orthopedic implants by providing a higher fracture toughness and mechanical strength. The existence of such composite materials based on the zirconium dioxide provides a significant increase in the wear resistance of orthopedic implants, which is essential for successful prosthetics

Laser Cladding of Alumina Material Coating: Effects on Deposition Quality

2016 ◽  
Author(s):  
Yuzhou Li ◽  
Weilong Cong ◽  
Fuda Ning ◽  
Rongxia Huang
Keyword(s):  
Laser Cladding ◽  
High Performance ◽  
Ceramic Coating ◽  
High Hardness ◽  
Alumina Ceramic ◽  
Properties Of Coatings ◽  
Surface Protection ◽  
Laser Head ◽  
Coating Methods ◽  
Input Variables

Alumina ceramic is a high performance engineering material with excellent properties, including high melting point, high hardness and brittle nature make the alumina ceramic difficult to machine and needing high cost by using conventional manufacturing methods. Coating is an important method for alumina fabrication. The excellent properties of coatings can be used for special surface protection and ceramic parts repairing. Comparing with other coating methods, laser cladding method has many good properties to overcome the drawbacks. The reported investigations on laser cladding provide little information about alumina materials for ceramic coating. In this paper, effects of different input variables of laser cladding of alumina materials for ceramic coating were studied. And this paper for the first time reported the relationship between the properties (including surface roughness, flatness and powder efficiency) and input variables such as laser power, powder feeding rate and laser head moving rate. The obtained results will be helpful to establish efficient and effective processes for ceramics coating.

A Novel Hybrid Approach for Multi-Dimensional Data Anonymization for Apache Spark

2022 ◽  
Vol 25 (1) ◽  
pp. 1-25
Author(s):  
Sibghat Ullah Bazai ◽  
Julian Jang-Jaccard ◽  
Hooman Alavizadeh
Keyword(s):  
Critical Analysis ◽  
Data Privacy ◽  
High Performance ◽  
Distributed Processing ◽  
Hybrid Approach ◽  
Relative Size ◽  
Optimal Number ◽  
Data Anonymization ◽  
Fine Grained ◽  
Message Exchange

Multi-dimensional data anonymization approaches (e.g., Mondrian) ensure more fine-grained data privacy by providing a different anonymization strategy applied for each attribute. Many variations of multi-dimensional anonymization have been implemented on different distributed processing platforms (e.g., MapReduce, Spark) to take advantage of their scalability and parallelism supports. According to our critical analysis on overheads, either existing iteration-based or recursion-based approaches do not provide effective mechanisms for creating the optimal number of and relative size of resilient distributed datasets (RDDs), thus heavily suffer from performance overheads. To solve this issue, we propose a novel hybrid approach for effectively implementing a multi-dimensional data anonymization strategy (e.g., Mondrian) that is scalable and provides high-performance. Our hybrid approach provides a mechanism to create far fewer RDDs and smaller size partitions attached to each RDD than existing approaches. This optimal RDD creation and operations approach is critical for many multi-dimensional data anonymization applications that create tremendous execution complexity. The new mechanism in our proposed hybrid approach can dramatically reduce the critical overheads involved in re-computation cost, shuffle operations, message exchange, and cache management.

High-Performance Reconfigurable Computing

2019 ◽  
pp. 731-744
Author(s):  
Mário Pereira Vestias
Keyword(s):  
Power Consumption ◽  
Integrated Circuit ◽  
Reconfigurable Computing ◽  
High Performance ◽  
General Purpose ◽  
Reconfigurable Hardware ◽  
Coarse Grained ◽  
Lower Power ◽  
Fine Grained ◽  
Application Specific

High-performance reconfigurable computing systems integrate reconfigurable technology in the computing architecture to improve performance. Besides performance, reconfigurable hardware devices also achieve lower power consumption compared to general-purpose processors. Better performance and lower power consumption could be achieved using application-specific integrated circuit (ASIC) technology. However, ASICs are not reconfigurable, turning them application specific. Reconfigurable logic becomes a major advantage when hardware flexibility permits to speed up whatever the application with the same hardware module. The first and most common devices utilized for reconfigurable computing are fine-grained FPGAs with a large hardware flexibility. To reduce the performance and area overhead associated with the reconfigurability, coarse-grained reconfigurable solutions has been proposed as a way to achieve better performance and lower power consumption. In this chapter, the authors provide a description of reconfigurable hardware for high-performance computing.

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