High Performance Thermal Conductive Sheets Made of Carbon Fibers

2011 ◽  
Author(s):  
Keisuke Aramaki ◽  
Hiroyuki Ryoson ◽  
Yuichi Ishida
Keyword(s):  
Thermal Conductivity ◽  
Carbon Fibers ◽  
High Performance ◽  
Large Scale ◽  
Cooling System ◽  
Thermal Contact ◽  
Thickness Direction ◽  
High Quality ◽  
Process Step

Today, the quality of LCD (Liquid Crystal Display) TVs has improved along with the quality of the installed LSI (Large Scale Integration) Thus, the cooling system needs to have high performance. However, LCD TV requires a large area but thin cooling system, so the TIM in which used in LCD TV requires highly softness. Thus we have developed high-quality yet soft thermal conductive sheets in which carbon fibers are directed in the thickness direction. The thermal conductivity of the 2-mm-thick sheets is more than 23 W/mK, and the compressibility is more than 10%. In this case the thermal conductivity was measured in accordance with ASTM D5470. The compressibility means the ratio of the difference between the initial thickness and the thickness when the sheets were loaded. The carbon fibers are more than 100 μm long and about 10 μm in diameter. This sheet contains alumina and aluminum nitride particles. The manufacturing process for the sheet is as follows. Step 1: The mixing process. Step 2: The resin including the carbon fibers and the particles is pressed into a long rectangular cast. Step 3: The resin is heated to harden it. Step 4: The resin is sliced into sheets. In step 1, because the carbon fibers are long, the fibers are likely affected by shear stress. Thus, the fibers are aligned in a lengthwise direction. In Step 4, we used a supersonic wave cutter to achieve ideal slicing, thereby reducing the thermal contact resistance. These processes produced high-quality yet soft thermal conductive sheets. In these processes, the carbon fibers aligned in the thickness direction, which was determined in an SEM observation. Moreover, we found that, by slicing in the orientation direction at inclining angles, only the softness improved, without any deterioration in the thermal conductivity.

Thermal Laser Separation – A Novel Dicing Technology Fulfilling the Demands of Volume Manufacturing of 4H-SiC Devices

2015 ◽  
Vol 821-823 ◽  
pp. 528-532 ◽  
Author(s):  
Dirk Lewke ◽  
Karl Otto Dohnke ◽  
Hans Ulrich Zühlke ◽  
Mercedes Cerezuela Barret ◽  
Martin Schellenberger ◽  
...  
Keyword(s):  
Experimental Data ◽  
Process Control ◽  
Tool Wear ◽  
Large Scale ◽  
State Of The Art ◽  
Scale Production ◽  
High Quality ◽  
Large Scale Production ◽  
Laser Separation

One challenge for volume manufacturing of 4H-SiC devices is the state-of-the-art wafer dicing technology – the mechanical blade dicing which suffers from high tool wear and low feed rates. In this paper we discuss Thermal Laser Separation (TLS) as a novel dicing technology for large scale production of SiC devices. We compare the latest TLS experimental data resulting from fully processed 4H-SiC wafers with results obtained by mechanical dicing technology. Especially typical product relevant features like process control monitoring (PCM) structures and backside metallization, quality of diced SiC-devices as well as productivity are considered. It could be shown that with feed rates up to two orders of magnitude higher than state-of-the-art, no tool wear and high quality of diced chips, TLS has a very promising potential to fulfill the demands of volume manufacturing of 4H-SiC devices.

scholarly journals Scientific and practical fundamentals of growing cabbage (Brassica capitata lizg.) in Uzbekistan

2021 ◽  
Vol 939 (1) ◽  
pp. 012044
Author(s):  
A J Shokirov ◽  
S S Lapasov ◽  
K J Shokirov
Keyword(s):  
Large Scale ◽  
Scientific Research ◽  
Mineral Fertilizers ◽  
Biological Productivity ◽  
High Quality ◽  
Planting Time ◽  
Yield And Quality ◽  
White Cabbage ◽  
Urgent Task

Abstract At present, scientific research is underway to further develop vegetable growing in the secondary crop, in particular to further increase the yield and quality of white cabbage, to select a system of planting time-sowing scheme that maximizes the biological productivity of varieties, and to apply the most optimal standards of fertilization and irrigation. In this regard, the urgent task remains to determine the optimal varieties of cabbage that can be grown in repeated crops, their optimal planting scheme, timing, development and implementation of optimal standards for each variety of mineral fertilizers and irrigation, and its solution is large-scale throughout the country. Besides that a number of problematic issues are addressed, which could allow to get high and high-quality harvest of white cabbage in repeated sowing in grain-free areas.

Thermal Contact Resistance of Phase Change and Grease Type Polymeric Materials

2000 ◽  
Author(s):  
Ravi S. Prasher ◽  
Craig Simmons ◽  
Gary Solbrekken
Keyword(s):  
Thermal Conductivity ◽  
Contact Resistance ◽  
Phase Change ◽  
High Performance ◽  
Phase Change Materials ◽  
Thermal Contact ◽  
Polymeric Materials ◽  
Thermal Interface Material ◽  
Heat Spreader ◽  
Thermal Grease

Abstract Thermal interface material (TIM) between the die and the heat spreader or between the heat spreader and the heat sink in any electronic package plays a very important role in the thermal management of electronic cooling. Due to increased power and power density high-performance TIMs are sought every day. Phase change materials (PCM) seem to be very good alternative to traditionally used thermal greases because of various reasons. These phase change materials also have the advantage of being reworked easily without damaging the die. Typically these phase change materials are polymer based and are particle laden to enhance their thermal conductivity. The thermal conductivity of these materials is relatively well understood than their contact resistance. Current work focuses on explicitly measuring the contact resistance and the thermal conductivity of a particular phase change TIM and some silicon-based greases. Effect of various parameters, which can affect the contact resistance of theses TIMs and Greases, are also captured. The steady state measurements of the thermal conductivity and the contact resistance was done on an interface tester. In general the work on the contact resistance of fluid-like polymer based TIM, such as thermal grease or phase change polymer has been experimental in the past. A semi-analytical model, which captures the various parameters affecting the contact resistance of two class of materials; the phase change and the thermal grease is also developed in this paper. This model fits very well with the experimental data.

Interaction of Physiology Character - Secondary Metabolic of Fusarium oxysporum on Tomatoes of Fusarium Wilt Symptom

2019 ◽  
Vol 967 ◽  
pp. 95-100
Author(s):  
Abdul Azis Ambar ◽  
Henny Setyawati ◽  
Nur Ilmi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
High Performance ◽  
Secondary Compounds ◽  
High Quality ◽  
Code Analysis ◽  
Wilt Symptom ◽  
The Relationship

Fusarium oxysporum (F. oxysporum) is the pathogen that caused fusarium wilt diseases on the tomatoes. The rise of the symptom was caused by secondary metabolic produced by F. oxysporum. The associated with the level of secondary metabolic pathogenesis that cause symptoms of wilt on tomatoes, but secondary metabolic excreted by F. oxysporum was not necessarily wilt in a plant. The phenomenon caused F. oxysporum producing secondary metabolic in the different concentration, either its quantity or quality. The nature of physiology being tested, observed by growing 4 isolates using a medium PDA on the temperature of 10, 15, 20, 25, 30, and 35 °C. The content of secondary metabolic measured on the four isolates using the Notz et al., (2002) and analyzed by using High-Performance Liquid Chromatography (HPLC). The results of the analysis of the nature of the physiological (colour colonies) were that every isolate planted for 8 days shows the variation of white, white redness, white yellowness until purpleness. Based on Methuen Handbook of Colour (Kornerup & Wanscher, 1978), generally isolates tested shows a bright colour, signaled with A letter at every code. Analysis HPLC on the results of secondary metabolic, either quantity or quality, sequentially were: isolates BAR (3; 1,997 ppm); ENR (3; 5,105 ppm); SID (4; 2,135 ppm) and MAL (5; 2,065 rpm). If it was seen by the relationship between the colour of colonies with the production of the secondary metabolic compound, it seemed that the older or darker colonies’ colour the more secondary compounds formed, but dark or old colonies’ colour does not determine a high quality of acid fusaric produced. Keywords: Colonies colour, F. oxysporum, secondary metabolic .

Developing a scale for measuring high performance partnerships

2015 ◽  
Vol 8 (1) ◽  
pp. 87-108 ◽  
Author(s):  
André de Waal ◽  
Robert Goedegebuure ◽  
Eveline Hinfelaar
Keyword(s):  
Value Chain ◽  
High Performance ◽  
Strong Relationship ◽  
Literature Study ◽  
High Quality ◽  
Content Type ◽  
World Class ◽  
Potential Factors ◽  
Cable Company

Purpose – The importance of partnerships to organizational success has increased considerably the past decennia and many organizations strive at creating high-performance partnerships (HPPs). For this to happen, organizations in the partnerships have to be of high quality and their collaborations should be world-class. Whereas the factors that create high-performance organizations (HPO) are by now reasonably well established, the HPP factors are still unclear. The purpose of this paper is to develop a scale for measuring the factors of importance for creating and maintaining HPPs, and relates these factors to the factors of the HPO framework and to the success of the partnership. Design/methodology/approach – During a literature study ten potential factors of importance for creating and maintaining HPPs were identified. These potential factors were put in a questionnaire, together with the factors that create the HPO and the factor that measures the success of the partnership. This questionnaire was administered to a cable company, which was working on becoming an HPO, and four of its main suppliers. The data were subjected to a factor analysis which yielded a HPP framework consisting of three factors and 19 underlying characteristics. In addition, these HPP factors were put in a regression analysis with the factors of the HPO framework and the success of the partnership factor. Findings – The research results show a strong relationship between three HPP factors, the five HPO factors, and the success of a partnership factor. Research limitations/implications – This research adds to the literature by extending the concept of HPOs to the value chain these HPOs operate in. Thus the research into the factors of successful partnerships has been brought forward. The practical benefit of the research is that organizations can use the HPP factors to increase the quality of the partnerships they have with their suppliers and customers. Originality/value – There is much literature on partnerships but not so much on partnerships between organizations which strive to become a HPOs, and in the process need to create partnership of high quality.

HIGH-PERFORMANCE PARALLEL VISUALIZATION LIBRARY FOR VARIOUS SIMULATION ENVIRONMENTS

2008 ◽  
Vol 05 (02) ◽  
pp. 273-287
Author(s):  
LI CHEN ◽  
HIROSHI OKUDA
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Unstructured Grids ◽  
Structured Grids ◽  
The Earth ◽  
Parallel Frameworks ◽  
Parallel Visualization ◽  
Simulation Environments

This paper describes a parallel visualization library for large-scale datasets developed in the HPC-MW project. Three parallel frameworks are provided in the library to satisfy different requirements of applications. Meanwhile, it is applicable for a variety of mesh types covering particles, structured grids and unstructured grids. Many techniques have been employed to improve the quality of the visualization. High speedup performance has been achieved by some hardware-oriented optimization strategies on different platforms, from PC clusters to the Earth Simulator. Good results have been obtained on some typical parallel platforms, thus demonstrating the feasibility and effectiveness of our library.

scholarly journals TESTS OF RANDOM NUMBER GENERATORS USING ISING MODEL SIMULATIONS

1996 ◽  
Vol 07 (03) ◽  
pp. 295-303 ◽  
Author(s):  
P. D. CODDINGTON
Keyword(s):  
Monte Carlo ◽  
Ising Model ◽  
Monte Carlo Simulations ◽  
High Performance ◽  
Large Scale ◽  
Random Number ◽  
Random Number Generators ◽  
Lattice Monte Carlo ◽  
High Performance Computers

Large-scale Monte Carlo simulations require high-quality random number generators to ensure correct results. The contrapositive of this statement is also true — the quality of random number generators can be tested by using them in large-scale Monte Carlo simulations. We have tested many commonly-used random number generators with high precision Monte Carlo simulations of the 2-d Ising model using the Metropolis, Swendsen-Wang, and Wolff algorithms. This work is being extended to the testing of random number generators for parallel computers. The results of these tests are presented, along with recommendations for random number generators for high-performance computers, particularly for lattice Monte Carlo simulations.

scholarly journals Massively multi-user online platform for large-scale applications

2021 ◽  
Author(s):  
Allen Yen-Cheng Yu
Keyword(s):  
Grid Computing ◽  
High Performance ◽  
Large Scale ◽  
Distributed Applications ◽  
Service Architecture ◽  
Online Application ◽  
Online Platform ◽  
Massively Multiplayer Online Game ◽  
And Performance

Many large-scale online applications enable thousands of users to access their services simultaneously. However, the overall service quality of an online application usually degrades when the number of users increases because, traditionally, centralized server architecture does not scale well. In order to provide better Quality of Service (QoS), service architecture such as Grid computing can be used. This type of architecture offers service scalability by utilizing heterogeneous hardware resources. In this thesis, a novel design of Grid computing middleware, Massively Multi-user Online Platform (MMOP), which integrates the Peer-to-Peer (P2P) structured overlays, is proposed. The objectives of this proposed design are to offer scalability and system design flexibility, simplify development processes of distributed applications, and improve QoS by following specified policy rules. A Massively Multiplayer Online Game (MMOG) has been created to validate the functionality and performance of MMOP. The simulation results have demonstrated that MMOP is a high performance and scalable servicing and computing middleware.

scholarly journals Obtaining High-Quality Label by Distinguishing between Easy and Hard Items in Crowdsourcing

2017 ◽  
Author(s):  
Wei Wang ◽  
Xiang-Yu Guo ◽  
Shao-Yuan Li ◽  
Yuan Jiang ◽  
Zhi-Hua Zhou
Keyword(s):  
Large Scale ◽  
Experimental Results ◽  
Training Set ◽  
High Quality ◽  
Quality Label ◽  
Large Scale Data ◽  
Voluntary Workers ◽  
Scale Data

Crowdsourcing systems make it possible to hire voluntary workers to label large-scale data by offering them small monetary payments. Usually, the taskmaster requires to collect high-quality labels, while the quality of labels obtained from the crowd may not satisfy this requirement. In this paper, we study the problem of obtaining high-quality labels from the crowd and present an approach of learning the difficulty of items in crowdsourcing, in which we construct a small training set of items with estimated difficulty and then learn a model to predict the difficulty of future items. With the predicted difficulty, we can distinguish between easy and hard items to obtain high-quality labels. For easy items, the quality of their labels inferred from the crowd could be high enough to satisfy the requirement; while for hard items, the crowd could not provide high-quality labels, it is better to choose a more knowledgable crowd or employ specialized workers to label them. The experimental results demonstrate that the proposed approach by learning to distinguish between easy and hard items can significantly improve the label quality.

scholarly journals Massively multi-user online platform for large-scale applications

2021 ◽  
Author(s):  
Allen Yen-Cheng Yu
Keyword(s):  
Grid Computing ◽  
High Performance ◽  
Large Scale ◽  
Distributed Applications ◽  
Service Architecture ◽  
Online Application ◽  
Online Platform ◽  
Massively Multiplayer Online Game ◽  
And Performance

Many large-scale online applications enable thousands of users to access their services simultaneously. However, the overall service quality of an online application usually degrades when the number of users increases because, traditionally, centralized server architecture does not scale well. In order to provide better Quality of Service (QoS), service architecture such as Grid computing can be used. This type of architecture offers service scalability by utilizing heterogeneous hardware resources. In this thesis, a novel design of Grid computing middleware, Massively Multi-user Online Platform (MMOP), which integrates the Peer-to-Peer (P2P) structured overlays, is proposed. The objectives of this proposed design are to offer scalability and system design flexibility, simplify development processes of distributed applications, and improve QoS by following specified policy rules. A Massively Multiplayer Online Game (MMOG) has been created to validate the functionality and performance of MMOP. The simulation results have demonstrated that MMOP is a high performance and scalable servicing and computing middleware.

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