A Feasibility Study on Advanced Methodology to Produce High-Performance Nano WC-Co Granule Feedstock for Thermal Spraying

2005 ◽  
Vol 475-479 ◽  
pp. 2891-2894
Author(s):  
H.W. Jun ◽  
Hyun Kwang Seok ◽  
Joo Sun Kim ◽  
Hai Won Lee
Keyword(s):  
Spray Drying ◽  
Feasibility Study ◽  
High Performance ◽  
Thermal Spraying ◽  
The Other ◽  
Other Hand ◽  
Heat Treated ◽  
Morphological Defects ◽  
Spraying Process

A feasibility study was conducted, in order to fabricate WC-Co powder granule as high-performance feedstock for thermal spraying process, by spray drying weakly flocculated nano-particulate slurries under various conditions. The defects were evaluated with respect to the amount of additives to prepare spherical WC-Co feedstock powders with few morphological defects and homogeneous microstructures. The characteristics of feedstock powders heat-treated at 850~ 1200ı were analyzed using SEM, EPMA, and Hg-porosimetry. The microstructure investigation revealed that the relative portion of larger pores around 10 µm increased with increasing heattreatment temperature. On the other hand, the relative portion of smaller pores of 1 µm decreased due to the coalescence of WC particles, leading to dense feedstock powders with less defects such as hollow or craters. The hardness of thermal-sprayed coat developed with the feedstock in this study, which had exceptionally high feedstock strength, was superior to that of any other sprayed coat obtained with commercial feedstock powders.

Hydrogen Diffusivity and Solubility in Pd Alloys Containing Nanometric Oxides

2009 ◽  
Vol 7 ◽  
pp. 81-86
Author(s):  
Viviane M. Azambuja ◽  
Dílson S. dos Santos ◽  
Daniel Fruchart
Keyword(s):  
Internal Oxidation ◽  
Cold Working ◽  
Hydrogen Permeation ◽  
The Other ◽  
Hydrogen Solubility ◽  
Hydrogen Diffusivity ◽  
Other Hand ◽  
Heat Treated ◽  
Cold Worked

. The Pd0.97Zr0.03, Pd0.97Ce0.03 and Pd0.97Ce0.015 Zr0.015 alloys were produced and studied in the present paper with respect to the hydrogen diffusivity and solubility. These alloys in the conditions as melted and cold worked, heat treated and also internally oxidized were submitted to hydrogen permeation tests. It was observed that the hydrogen diffusivity is strongly affected by the internal oxidation due to nano-oxides formation in the samples. On the other hand, the hydrogen solubility increases with introduction of defects as dislocations and vacancies introduced by cold working as well as the precipitates due to the internal oxidation. The nature, size and distribution of the precipitates and their influence on the hydrogen permeation parameters are discussed in this work.

Flexible PLED displays and related technologies

2004 ◽  
Vol 814 ◽  
Author(s):  
G. Nisato ◽  
C. Mutsaers ◽  
H. Buijk ◽  
P. Duineveld ◽  
E. Janssen ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Integrity ◽  
Low Voltage ◽  
Flexible Substrate ◽  
Fast Response ◽  
Industrial Applications ◽  
Hole Transport ◽  
The Other ◽  
Enabling Technology ◽  
Other Hand

AbstractFlexible, free shape displays are the enabling technology for new robust, lightweight, extremely thin, portable electronic devices. Polymer Light Emitting Diodes (PLED) are especially suited for these applications, due to their fast response time, low voltage, high luminous efficiency and viewing angle performance. On the other hand, PLED displays are extremely sensitive to moisture and oxygen. Substrate materials provided with high performance hermetic and conducting layers are therefore an essential component for manufacturing these flexible devices. Polymer based substrates provide the necessary mechanical flexibility; they also require several thin, brittle, functional inorganic layers such diffusion barriers and transparent electrodes. The structural integrity, dimensional stability and thermal properties of the substrate stack are crucial to insure device functionality and reliability. For polymer-based substrate several effects lead to dimensional variation of the substrates, such as solvent uptake, physical ageing of the polymer base, thermal expansion and stress induced deformations. These effects must be taken into account to successfully perform classic photolithographic steps.Ink-jet printing is a critical enabling technology for flexible PLED displays, providing a customizable means to dispense solution-based polymers onto a flexible substrate, allowing for multi-color devices. On the other hand, IJP must meet several challenges, especially to comply with industrial applications. For example, accurate landing position of the droplets to form homogeneous hole-transport and electroluminescent layers as well as good wetting characteristic of the substrates must be obtained with reliable high throughput techniques.

High Performance Fabrics in Body Protective Systems

2016 ◽  
Vol 880 ◽  
pp. 132-135 ◽  
Author(s):  
Selim Gürgen ◽  
Melih Cemal Kuşhan
Keyword(s):  
Kinetic Energy ◽  
High Performance ◽  
The Other ◽  
Body Armor ◽  
Personal Protection ◽  
Military Vehicles ◽  
Living Space ◽  
Other Hand ◽  
Lightweight Structure ◽  
Protective Systems

High performance fabrics are preferable for armor systems due to their lightweight structure and flexibility. High performance fabrics are generally used in body armor design for personal protection. However, these fabrics are utilized to cover the living space in military vehicles such as helicopters and armored vehicles. Besides, pilot seats in combat helicopters are included in utilization area of high performance fabrics. On the other hand armor is defined as a defensive covering to protect body or something against attacking threats. Protection is provided by absorbing the kinetic energy of the attacking threats and stopping them before any damage occurs in the target. This paper offers an overview of high performance fabrics in armor systems.

Study on the Subsonic Thermal Sprayed Ti/Bioglass Composite Coatings on Titanium Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 2427-2430 ◽  
Author(s):  
Mu Qin Li ◽  
Da Shan Shang ◽  
Chen Ma ◽  
Shi Qin Yang
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Bond Strength ◽  
Composite Coatings ◽  
Thermal Spraying ◽  
Interface Layer ◽  
Heat Treated ◽  
Metallurgical Bond ◽  
Spraying Process ◽  
Scanning Electron

Ti/bioglass composite coatings on titanium alloy were prepared by a subsonic thermal spraying technology. Mixtures of titanium and bioglass powders with different proportions were used as feedstock. The effect of soaking of bioglass on the bond strength of between coatings and substrate was discussed. The bond strength and residual stress were investigated. The morphology was observed using scanning electron microscopy (SEM). The results showed that TiO2, CaTi4(PO4)6, CaTiO3, NaTi2(PO4)3 formed during thermal spraying process and the residual stress in the coatings was in compressive state. After the coatings were heat-treated, soaking of bioglass made some particles achieve metallurgical bond. Furthermore, new bioglass was formed and the compressive stress was increased. The phenomenon of bioglass healing up the cracks in the heat-treated coatings was observed through SEM, which reduced the porosity of the interface layer resulting in the significant increase of the bond strength.

scholarly journals Authentication of Straight Whiskey by Determination of the Ratio of Furfural to 5-Hydroxymethyl-2-Furaldehyde

1999 ◽  
Vol 82 (4) ◽  
pp. 997-1001 ◽  
Author(s):  
James Jaganathan ◽  
Sumer M Dugar
Keyword(s):  
High Performance ◽  
Chromatographic Method ◽  
High Performance Liquid Chromatographic ◽  
The Other ◽  
Color Intensity ◽  
Other Hand ◽  
Liquid Chromatographic Method ◽  
Oak Barrels ◽  
Liquid Chromatographic

Abstract Bureau of Alcohol, Tobacco and Firearms regulations require that a straight whiskey be aged in a freshly charred oak barrel for a minimum of 2 years and that it not be colored with added caramel. The regulations, however, permit addition of caramel in blended whiskeys. Blended whiskeys are usually produced by mixing a straight whiskey with neutral spirits which causes loss of color intensity. Caramel addition is permitted to compensate for this loss. Thus, it is not possible to authenticate the standard of identity of a straight whiskey by measurement of color intensity. Our investigations suggest that furfural (2-furaldehyde) and 5-hydroxymethyl-2-furaldehyde are imparted into a straight whiskey during aging in a freshly charred oak barrel. Caramel, on the other hand, imparts only 5-hydroxymethyl-2-furaldehyde. Thus, the measurement of the concentrations of furfural and 5-hydroxymethyl-2-furaldehyde and their ratio could effectively authenticate the standard of identity of straight whiskeys. This study shows that straight whiskeys aged in freshly charred oak barrels for a period of 2 years or more have a 2:1 or higher ratio of furfural to 5-hydroxymethyl-2-furaldehyde. A high-performance liquid chromatographic method for the determination of furfural and 5-hyroxy- methyl-2-furaldehyde at low parts-per-million levels is described.

scholarly journals Gate-All-Around FETs: Nanowire and Nanosheet Structure

2020 ◽  
Author(s):  
Jun-Sik Yoon ◽  
Jinsu Jeong ◽  
Seunghwan Lee ◽  
Junjong Lee ◽  
Rock-Hyun Baek
Keyword(s):  
Low Power ◽  
High Performance ◽  
The Other ◽  
Short Channel ◽  
Technology Node ◽  
Channel Characteristics ◽  
Other Hand ◽  
Rc Delay

DC/AC performances of 3-nm-node gate-all-around (GAA) FETs having different widths and the number of channels (Nch) from 1 to 5 were investigated thoroughly using fully-calibrated TCAD. There are two types of GAAFETs: nanowire (NW) FETs having the same width (WNW) and thickness of the channels, and nanosheet (NS) FETs having wide width (WNS) but the fixed thickness of the channels as 5 nm. Compared to FinFETs, GAAFETs can maintain good short channel characteristics as the WNW is smaller than 9 nm but irrespective of the WNS. DC performances of the GAAFETs improve as the Nch increases but at decreasing rate because of the parasitic resistances at the source/drain epi. On the other hand, gate capacitances of the GAAFETs increase constantly as the Nch increases. Therefore, the GAAFETs have minimum RC delay at the Nch near 3. For low power applications, NWFETs outperform FinFETs and NSFETs due to their excellent short channel characteristics by 2-D structural confinement. For standard and high performance applications, NSFETs outperform FinFETs and NWFETs by showing superior DC performances arising from larger effective widths per footprint. Overall, GAAFETs are great candidates to substitute FinFETs in the 3-nm technology node for all the applications.

scholarly journals A Unified FPGA Virtualization Framework for General-Purpose Deep Neural Networks in the Cloud

2022 ◽  
Vol 15 (3) ◽  
pp. 1-31
Author(s):  
Shulin Zeng ◽  
Guohao Dai ◽  
Hanbo Sun ◽  
Jun Liu ◽  
Shiyao Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
High Performance ◽  
Deep Neural Networks ◽  
Cost Effective ◽  
General Purpose ◽  
The Other ◽  
Private Cloud ◽  
Single Task ◽  
Other Hand

INFerence-as-a-Service (INFaaS) has become a primary workload in the cloud. However, existing FPGA-based Deep Neural Network (DNN) accelerators are mainly optimized for the fastest speed of a single task, while the multi-tenancy of INFaaS has not been explored yet. As the demand for INFaaS keeps growing, simply increasing the number of FPGA-based DNN accelerators is not cost-effective, while merely sharing these single-task optimized DNN accelerators in a time-division multiplexing way could lead to poor isolation and high-performance loss for INFaaS. On the other hand, current cloud-based DNN accelerators have excessive compilation overhead, especially when scaling out to multi-FPGA systems for multi-tenant sharing, leading to unacceptable compilation costs for both offline deployment and online reconfiguration. Therefore, it is far from providing efficient and flexible FPGA virtualization for public and private cloud scenarios. Aiming to solve these problems, we propose a unified virtualization framework for general-purpose deep neural networks in the cloud, enabling multi-tenant sharing for both the Convolution Neural Network (CNN), and the Recurrent Neural Network (RNN) accelerators on a single FPGA. The isolation is enabled by introducing a two-level instruction dispatch module and a multi-core based hardware resources pool. Such designs provide isolated and runtime-programmable hardware resources, which further leads to performance isolation for multi-tenant sharing. On the other hand, to overcome the heavy re-compilation overheads, a tiling-based instruction frame package design and a two-stage static-dynamic compilation, are proposed. Only the lightweight runtime information is re-compiled with ∼1 ms overhead, thus guaranteeing the private cloud’s performance. Finally, the extensive experimental results show that the proposed virtualized solutions achieve up to 3.12× and 6.18× higher throughput in the private cloud compared with the static CNN and RNN baseline designs, respectively.

scholarly journals A Tale of Two Transitions: Unraveling Two Distinct Polymorph Transition Mechanisms in One n-Type Single Crystal for Dynamic Electronics

2021 ◽  
Author(s):  
Daniel W. Davies ◽  
Sang Kyu Park ◽  
Stephen B. Shiring ◽  
Hyunjoong Chung ◽  
Prapti Kafle ◽  
...  
Keyword(s):  
Single Crystal ◽  
Growth Mechanism ◽  
High Performance ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Nucleation And Growth ◽  
The Other ◽  
Resonance Spectroscopy ◽  
Other Hand ◽  
Nucleation And Growth Mechanism

Cooperativity is used by living systems to circumvent energetic and entropic barriers to yield highly efficient molecular processes. Cooperative structural transitions involve the simultaneous, concerted displacement of molecules in a crystalline material, in stark contrast to the more typical molecule-by-molecule nucleation and growth mechanism often breaking the single crystallinity. Cooperative transitions have acquired much attention in the research community for their low transition barriers, ultrafast kinetics, and structural reversibility. On the other hand, cooperative transitions are rarely observed in molecular crystals and the molecular origin is not well understood. Single crystals of 2-dimensional quinoidal terthiophene (2DQTT-o-B), a high-performance n-type organic semiconductor, demonstrate two thermally-activated, reversible phase transitions with one exhibiting a cooperative mechanism and the second exhibiting a nucleation and growth mechanism. In situ microscopy, single crystal and grazing incidence X-ray diffraction (GIXD), along with Raman spectroscopy suggest a reorientation of the alkyl side chains results in a cooperative transition behavior. On the other hand, the nucleation and growth transition is coincident with both side chain melting and the emergence of new spin-spin interactions between conjugated cores, confirmed through in situ electron paramagnetic resonance spectroscopy (EPR). This is the first observation of biradical interactions directly initiating a structural transition. Through studying these fundamental mechanisms, we establish alkyl chain conformation and disorder as integral to rationally controlling these polymorphic behaviors for novel electronic applications.

scholarly journals Propagation of Selected Pear and Quince Rootstocks By Hardwood Cuttings

2016 ◽  
Vol 64 (4) ◽  
pp. 1211-1217 ◽  
Author(s):  
Tomáš Nečas ◽  
Luděk Laňar ◽  
Ivo Ondrášek ◽  
Jan Náměstek ◽  
Jakub Láčík ◽  
...  
Keyword(s):  
Ethanol Solution ◽  
The Other ◽  
Naphthalene Acetic Acid ◽  
Rooted Cuttings ◽  
Beneficial Effects ◽  
Heat Stimulation ◽  
Other Hand ◽  
Heat Treated ◽  
The Difference ◽  
Made In

As long as new rootstocks continue to be developed, there will always the need for new genotypes to be controlled and evaluated. This study involves verification of selected rootstocks with reference to growth, propagation ability and other characteristics. Different rootstocks, different growth stimulators and different kinds of cuttings techniques were adopted for these experiments. Stimulators used for evaluations included: 1 % Racine (2.5 % naphthalene acetic acid - NAA), 0.5 % Rhizopon AA (2.5 % indole-3-butyric acid - IBA) and 0.25 % IBA in 50 % ethanol solution. There were three sets of experiments in all. In Experiment 1, the bases of cuttings were treated with the stimulators and part of them was also treated with heat before planting. Results from Experiment 1 indicated that cuttings treated with Rhizopon AA produced the best effect after heat treatment (with an overall average of 36.9 % of rooted cuttings). Pyrodwarf (78.7 %), Cydomalus (73.9 %) and Pyroplus (60.6 %) were the best performing rootstocks among the evaluated ones. In Experiment 2, we evaluated the influence of the date of harvesting the cuttings on rooting (comparisons were made between cuttings prepared in December [early] and March [late]). For BA29 rootstock cuttings, the best performance was attained by cuttings taken in March. The difference in rooting between March and December was 43.9 %. On the other hand, early harvested rootstocks (cuttings taken in December) for Cydomalus showed the best performance, with an 18.7 % difference between cuttings made in December and in March. Results from other evaluated rootstocks were not significant enough. In Experiment 3, the effect of chemical (phytohormone) stimulation and heat stimulations was compared. The best result was obtained by combinations of treatments without heat stimulations, when the cuttings were stored at 5°C and later treated with 0.25 % IBA in 50 % ethanol solution. The least rooting results, on the other hand, were observed in heat treated cuttings, in cuttings stimulated with IBA and subsequently with heat and in cuttings treated with a 3 cm radial cut at the base. Based on our findings we cannot prove clearly that heat stimulation and the phytohormones used have beneficial effects on rooting of especially new rootstock genotypes with an unknown propagation coefficient. This means that propagation using cuttings still remains an interesting topic to be further researched.

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