scholarly journals Capacitor Electrical Discharge Consolidation of Metallic Powders—A Review

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 616
Author(s):  
Rosa María Aranda ◽  
Fátima Ternero ◽  
Sergio Lozano-Pérez ◽  
Juan Manuel Montes ◽  
Francisco G. Cuevas
Keyword(s):  
Electrical Discharge ◽  
Industrial Processes ◽  
Heating Process ◽  
Metallic Materials ◽  
Research Groups ◽  
Joule Effect ◽  
The World ◽  
Furnace Sintering ◽  
Powder Particles ◽  
Sintering Processes

Manufacturing metallic materials from elemental or alloyed powders is an option in many industrial processes. Nevertheless, the traditional powder metallurgy processing including furnace sintering is at times detrimental for the microstructure attained in the powders. Alternative sintering processes based on the use of electricity and the energy obtained by the Joule effect in powder particles can be quick enough to avoid microstructural changes. In particular, when the energy is stored in a capacitor and then discharged, the heating process is extremely quick, lasting milliseconds or even microseconds. This process, generally known as electrical discharge consolidation, has been applied to a wide variety of metallic materials, easily preserving the original microstructure of the powders. Both porous or homogeneous and highly densified material can be obtained, and without losing the desired properties of the consolidated material. A general overview of the process and applications, as well as the results obtained by different research groups around the world, have been reviewed in this manuscript.

scholarly journals Robots as intelligent assistants to face COVID-19 pandemic

2020 ◽  
Author(s):  
Valeria Seidita ◽  
Francesco Lanza ◽  
Arianna Pipitone ◽  
Antonio Chella
Keyword(s):  
Technological Progress ◽  
World Economy ◽  
The State ◽  
Research Groups ◽  
Negative Effects ◽  
The World ◽  
Intelligent Assistants

Abstract Motivation The epidemic at the beginning of this year, due to a new virus in the coronavirus family, is causing many deaths and is bringing the world economy to its knees. Moreover, situations of this kind are historically cyclical. The symptoms and treatment of infected patients are, for better or worse even for new viruses, always the same: more or less severe flu symptoms, isolation and full hygiene. By now man has learned how to manage epidemic situations, but deaths and negative effects continue to occur. What about technology? What effect has the actual technological progress we have achieved? In this review, we wonder about the role of robotics in the fight against COVID. It presents the analysis of scientific articles, industrial initiatives and project calls for applications from March to now highlighting how much robotics was ready to face this situation, what is expected from robots and what remains to do. Results The analysis was made by focusing on what research groups offer as a means of support for therapies and prevention actions. We then reported some remarks on what we think is the state of maturity of robotics in dealing with situations like COVID-19.

scholarly journals A Large-Scale COVID-19 Twitter Chatter Dataset for Open Scientific Research—An International Collaboration

Epidemiologia ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 315-324
Author(s):  
Juan M. Banda ◽  
Ramya Tekumalla ◽  
Guanyu Wang ◽  
Jingyuan Yu ◽  
Tuo Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Social Dynamics ◽  
Additional Data ◽  
Open Data ◽  
Data Sources ◽  
Research Projects ◽  
Research Groups ◽  
The World ◽  
Data Source

As the COVID-19 pandemic continues to spread worldwide, an unprecedented amount of open data is being generated for medical, genetics, and epidemiological research. The unparalleled rate at which many research groups around the world are releasing data and publications on the ongoing pandemic is allowing other scientists to learn from local experiences and data generated on the front lines of the COVID-19 pandemic. However, there is a need to integrate additional data sources that map and measure the role of social dynamics of such a unique worldwide event in biomedical, biological, and epidemiological analyses. For this purpose, we present a large-scale curated dataset of over 1.12 billion tweets, growing daily, related to COVID-19 chatter generated from 1 January 2020 to 27 June 2021 at the time of writing. This data source provides a freely available additional data source for researchers worldwide to conduct a wide and diverse number of research projects, such as epidemiological analyses, emotional and mental responses to social distancing measures, the identification of sources of misinformation, stratified measurement of sentiment towards the pandemic in near real time, among many others.

Study on the Strategies for Fabrication of Die Assembly with Typical Shaped Cavity by Using Electrical Discharge Machining

2012 ◽  
Vol 192 ◽  
pp. 118-122
Author(s):  
Ren Yu Feng ◽  
Min Wang ◽  
Zhi Jian Duan
Keyword(s):  
Service Life ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Thermal Characteristics ◽  
Suitable Method ◽  
Metallic Materials ◽  
Material Hardness ◽  
The Cost ◽  
Machining Strategies ◽  
Edm Process

Die assembly is a kind of special tools for fabrication of metal or non-metallic materials parts with required design and purpose. Generally, the high material hardness for die assembly should be selected to increase the service life and reduce the cost in manufactory industry. Electrical discharge machining (EDM) is a suitable method for fabrication of die assembly as the material remove in EDM process mainly depends on the material's thermal characteristics, regardless of the hardness. In this paper, the machining strategies for fabrication of die assembly with typical shaped cavity using EDM were discussed, according to the different cavity structures, the best machining strategies were proposed

Occurrence and Treatment of Pharmaceuticals and Personal Care Products in Surface Water around the Global Region

2014 ◽  
Vol 507 ◽  
pp. 720-724
Author(s):  
Wan Qian Guo ◽  
Hai Ou Cao ◽  
Xian Jiao Zhou ◽  
Ren Li Yin
Keyword(s):  
Surface Water ◽  
Human Health ◽  
Personal Care Products ◽  
Personal Care ◽  
Research Groups ◽  
Efficient Treatment ◽  
Treatment Methods ◽  
The World ◽  
Emerging Issues

The occurrence of pharmaceuticals and personal care products (PPCPs) in surface water, and their potential impacts on human health are emerging issues all over the world. This paper summarizes the data from worldwide research groups, aiming to illustrate the occurrence of PPCPS, and their potential threatens to human health. Furthermore, the current efficient treatment methods for the PPCPS were discussed as well.

Influence of Force Fields and Flow Patterns on Boiling Heat Transfer Performance

2010 ◽  
Author(s):  
Paolo Di Marco
Keyword(s):  
Heat Transfer ◽  
Electric Fields ◽  
Heat Transfer Performance ◽  
Force Fields ◽  
Flow Boiling ◽  
Transfer Performance ◽  
Research Groups ◽  
Short Introduction ◽  
The World ◽  
Regime Transitions

Recent experimentation of boiling in different environments, namely in reduced or enhanced gravity and/or in the presence of electric fields, have shed new light on the comprehension of boiling phenomena and have focused the objectives of future investigation. The recent results achieved by the author and other research groups around the world are reported and discussed in the paper. After a short introduction on some fundamental phenomena and their dependence on force fields, pool and flow boiling are dealt with. In particular, it is stressed that due to increased coalescence peculiar flow regimes take place in reduced gravity, influencing the heat transfer performance. The application of an electric field may, in some instances, delay or avoid these regime transitions. In boiling at high flowrate, the phenomena are dominated by inertia and thus gravity-independent; however the threshold at which this occurs has still to be determined.

scholarly journals Self-Consolidation Mechanism of Nanostructured Ti5Si3Compact Induced by Electrical Discharge

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
W. H. Lee ◽  
Y. W. Cheon ◽  
Y. H. Jo ◽  
J. G. Seong ◽  
Y. J. Jo ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Single Phase ◽  
External Pressure ◽  
Surface Oxide ◽  
Complete Conversion ◽  
Rapid Cooling ◽  
Pinch Force ◽  
Powder Particles ◽  
Solid Bulk ◽  
Solid Liquid

Electrical discharge using a capacitance of 450 μF at 7.0 and 8.0 kJ input energies was applied to mechanical alloyed Ti5Si3powder without applying any external pressure. A solid bulk of nanostructured Ti5Si3with no compositional deviation was obtained in times as short as 159 μsec by the discharge. During an electrical discharge, the heat generated is the required parameter possibly to melt the Ti5Si3particles and the pinch force can pressurize the melted powder without allowing the formation of pores. Followed rapid cooling preserved the nanostructure of consolidated Ti5Si3compact. Three stepped processes during an electrical discharge for the formation of nanostructured Ti5Si3compact are proposed: (a) a physical breakdown of the surface oxide of Ti5Si3powder particles, (b) melting and condensation of Ti5Si3powder by the heat and pinch pressure, respectively, and (c) rapid cooling for the preservation of nanostructure. Complete conversion yielding a single phase Ti5Si3is primarily dominated by the solid-liquid mechanism.

scholarly journals Special Issue on Automatic Application Tuning for HPC Architectures

2014 ◽  
Vol 22 (4) ◽  
pp. 259-260 ◽  
Author(s):  
Siegfried Benkner ◽  
Franz Franchetti ◽  
Hans Michael Gerndt ◽  
Jeffrey K. Hollingsworth
Keyword(s):  
High Performance ◽  
Research Field ◽  
Performance Tuning ◽  
Full Potential ◽  
Research Groups ◽  
Special Issue ◽  
The World ◽  
And Performance ◽  
Application Tuning ◽  
Performance Computing

High Performance Computing architectures have become incredibly complex and exploiting their full potential is becoming more and more challenging. As a consequence, automatic performance tuning (autotuning) of HPC applications is of growing interest and many research groups around the world are currently involved. Autotuning is still a rapidly evolving research field with many different approaches being taken. This special issue features selected papers presented at the Dagstuhl seminar on “Automatic Application Tuning for HPC Architectures” in October 2013, which brought together researchers from the areas of autotuning and performance analysis in order to exchange ideas and steer future collaborations.

scholarly journals Construction of the third generation Zea mays haplotype map

2015 ◽  
Author(s):  
Robert Bukowski ◽  
Xiaosen Guo ◽  
Yanli Lu ◽  
Cheng Zou ◽  
Bing He ◽  
...  
Keyword(s):  
Zea Mays ◽  
Whole Genome Sequencing Data ◽  
Limiting Factor ◽  
Computational Pipeline ◽  
Research Groups ◽  
Sequencing Data ◽  
The Third ◽  
The World ◽  
Set Up

ABSTRACTBackgroundCharacterization of genetic variations in maize has been challenging, mainly due to deterioration of collinearity between individual genomes in the species. An international consortium of maize research groups combined resources to develop the maize haplotype version 3 (HapMap 3), built from whole genome sequencing data from 1,218 maize lines, covering pre-domestication and domesticated Zea mays varieties across the world.ResultsA new computational pipeline was set up to process over 12 trillion bp of sequencing data, and a set of population genetics filters were applied to identify over 83 million variant sites.ConclusionsWe identified polymorphisms in regions where collinearity is largely preserved in the maize species. However, the fact that the B73 genome used as the reference only represents a fraction of all haplotypes is still an important limiting factor.

scholarly journals Resilient Clinical Trial Infrastructure in Response to the COVID-19 Pandemic: Lessons Learned from the TOGETHER Randomized Platform Clinical Trial

2022 ◽  
Author(s):  
Jamie I. Forrest ◽  
Angeli Rawat ◽  
Felipe Duailibe ◽  
Christina M. Guo ◽  
Sheila Sprague ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Health System ◽  
Lessons Learned ◽  
Research Groups ◽  
Safety And Efficacy ◽  
Target Sample Size ◽  
The World ◽  
Trial Protocols ◽  
New Evidence

In response to the COVID-19 pandemic, clinical research groups across the world developed trial protocols to evaluate the safety and efficacy of treatments for COVID-19. Despite this initial enthusiasm, only a small portion of these protocols were implemented. Of those implemented, a fraction successfully recruited their target sample size to analyze and disseminate findings. More than a year and a half into the COVID-19 pandemic, only a few clinical trials evaluating treatments for COVID-19 have generated new evidence. Productive randomized platform clinical trials evaluating COVID-19 treatments may attribute their success to intentional investments in developing resilient clinical trial infrastructures. Health system resiliency discourse provides a conceptual framework for characterizing attributes for withstanding shocks. This framework may also be useful for contextualizing the attributes of productive clinical trials evaluating COVID-19 therapies. We characterize the successful attributes and lessons learned in developing the TOGETHER Trial infrastructure using a health system resiliency framework. This framework may be considered by clinical trialists aiming to build resilient trial infrastructures capable of responding rapidly and efficiently to global health threats.

scholarly journals Development of geography in Ukraine since independence: structure, schools, achievements, challenges

2013 ◽  
pp. 172-185
Author(s):  
I. Kovalchuk
Keyword(s):  
Key Words ◽  
Environmental Studies ◽  
Research System ◽  
Research Groups ◽  
Geographical Research ◽  
Scientific Schools ◽  
The World ◽  
Scientific Potential ◽  
Independence Structure

The paper describes the background of Lviv geography at the end of XX–beginning of XXI century and the structure of geographical research Lviv scientists of this period. It is shown that the trajectory of development is determined by several factors: 1) the tradition of Lviv geography in which the main areas of research are natural-geographic, social, geographic and cartographic; 2) the influence of global geography of innovation in the development of Lviv geography; 3) existing scientific potential; 4) changes in society, his requests to geography, and changes in the research system and explore the world of technology and so on. Within the geographical research, three areas of blocks were identified: 1) general, social and geographical research; 2) natural-geographical studies; 3) tourism and recreation and environmental studies. Each of these blocks in turn are allocated between four and eight research groups finding that further differentiated on 8–15 branches. The achievements and prospects of the four academic schools are described. Problem and promising areas of geographic research under the Lviv University geography are outlined. Key words: Lviv geography, scientific schools, the structure of geographical research, the problem of Lviv geography

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