Thermal Performance of a Water-Cooled Microchannel Heat Sink With Grooves and Obstacles

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Yonghui Xie ◽  
Zhongyang Shen ◽  
Di Zhang ◽  
Jibing Lan
Keyword(s):  
Energy Saving ◽  
Thermal Performance ◽  
Microelectromechanical Systems ◽  
Rapid Development ◽  
Air Cooling ◽  
Orientation Field ◽  
Rectangular Microchannel ◽  
Simple Modification ◽  
Cooling Enhancement ◽  
High Level

With the rapid development of microelectromechanical systems (MEMS) in IT industry, the heat flux in microchannel has reached a high level which demands preferable cooling technology. Water cooling has become a favor cooling approach in electronic microdevices due to better thermal performance than air cooling method. In the present paper, thermal performance in microchannels with grooves and obstacles are investigated numerically. The height and width of the rectangular microchannel are 200 and 50 μm, respectively. As a simple modification of dimple/protrusion, the groove/obstacle diameter is 100 μm and the depth is 20 μm. Different arrangements of grooves and obstacles are considered on Reynolds range of 100–900. The numerical results show that groove/obstacle structure is effective for cooling enhancement in microchannel. Among the cases in this research, the normalized Nusselt number Nu/Nu0 is within the range of 1.446–26.19, while the pressure penalty f/f0 has a much larger range from 0.86 to 110.18 depending on specific orientation. Field synergy analysis and performance evaluation plot are adopted to discuss the mechanism of heat transfer enhancement and energy saving performance integrating the pumping performance. From the viewpoint of energy saving, groove on single surface (case 1) has the best performance. Furthermore, performances of grooved microchannels are compared with that of dimpled microchannels which were discussed in the author’s previous research. The results indicate grooved microchannels have larger range of both Nu/Nu0 and f/f0 and some grooved cases possess high TP than dimpled microchannels.

scholarly journals Mobile Networks and Internet of Things Infrastructures to Characterize Smart Human Mobility

Smart Cities ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 894-918
Author(s):  
Luís Rosa ◽  
Fábio Silva ◽  
Cesar Analide
Keyword(s):  
Internet Of Things ◽  
Mobile Networks ◽  
Smart Cities ◽  
Human Mobility ◽  
Rapid Development ◽  
Disruptive Technology ◽  
New Paradigm ◽  
Design And Optimization ◽  
High Level

The evolution of Mobile Networks and Internet of Things (IoT) architectures allows one to rethink the way smart cities infrastructures are designed and managed, and solve a number of problems in terms of human mobility. The territories that adopt the sensoring era can take advantage of this disruptive technology to improve the quality of mobility of their citizens and the rationalization of their resources. However, with this rapid development of smart terminals and infrastructures, as well as the proliferation of diversified applications, even current networks may not be able to completely meet quickly rising human mobility demands. Thus, they are facing many challenges and to cope with these challenges, different standards and projects have been proposed so far. Accordingly, Artificial Intelligence (AI) has been utilized as a new paradigm for the design and optimization of mobile networks with a high level of intelligence. The objective of this work is to identify and discuss the challenges of mobile networks, alongside IoT and AI, to characterize smart human mobility and to discuss some workable solutions to these challenges. Finally, based on this discussion, we propose paths for future smart human mobility researches.

Rapid development of distributed applications using high-level communication support

2011 ◽  
Vol 34 (1) ◽  
pp. 172-182 ◽  
Author(s):  
Mingyu Lim ◽  
Bart Kevelham ◽  
Niels Nijdam ◽  
Nadia Magnenat-Thalmann
Keyword(s):  
Rapid Development ◽  
Distributed Applications ◽  
Communication Support ◽  
High Level

Study on the Thermal Performance of the Vernacular Dwellings in Wei-He Plain of Shaanxi Province

2012 ◽  
Vol 476-478 ◽  
pp. 1589-1595
Author(s):  
Yi Ping Zhu ◽  
Xi Liao ◽  
Shu Yun Wu ◽  
Jing Luo ◽  
Yuan Jiang ◽  
...  
Keyword(s):  
Energy Saving ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Thermal Environment ◽  
Local Area ◽  
Shaanxi Province ◽  
Indoor Thermal Environment ◽  
Questionnaire Surveys

Based on indoor thermal environment test and questionnaire surveys, the paper studies on thermal insulation capacity and indoor thermal environment of the vernacular dwellings in Wei-he Plain of Shaanxi Province, China, and analyses their heating methods and application status. Besides, the popularity of sustainable techniques in local area has been evaluated and summarized. Moreover, the paper discusses the present problems in local indoor thermal environment and energy-saving status.

Constructing Three-dimensional Nano-crystalline Diamond Network within Polymer Composites for Enhanced Thermal Conductivity

Nanoscale ◽  
2021 ◽  
Author(s):  
Shaoyang Xiong ◽  
Yue Qin ◽  
Linhong Li ◽  
Guoyong Yang ◽  
Maohua Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Polymer Composites ◽  
Thermal Performance ◽  
Thermal Transport ◽  
High Performance ◽  
Rapid Development ◽  
Electronic Devices ◽  
Three Dimensional ◽  
Nano Crystalline ◽  
Enhanced Thermal Conductivity

In order to meet the requirement of thermal performance with the rapid development of high-performance electronic devices, constructing a three-dimensional thermal transport skeleton is an effective method for enhancing thermal...

scholarly journals High-Level Carbapenem Resistance in OXA-232-Producing Raoultella ornithinolytica Triggered by Ertapenem Therapy

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Alina Iovleva ◽  
Roberta T. Mettus ◽  
Christi L. McElheny ◽  
Marissa P. Griffith ◽  
Mustapha M. Mustapha ◽  
...  
Keyword(s):  
Rapid Development ◽  
Carbapenem Resistance ◽  
Resistant Isolate ◽  
Clinical Microbiology Laboratory ◽  
Loss Of Function ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Class D ◽  
Fold Reduction ◽  
High Level

ABSTRACT OXA-232 is an OXA-48-group class D β-lactamase that hydrolyzes expanded-spectrum cephalosporins and carbapenems at low levels. Clinical strains producing OXA-232 are sometimes susceptible to carbapenems, making it difficult to identify them in the clinical microbiology laboratory. We describe the development of carbapenem resistance in sequential clinical isolates of Raoultella ornithinolytica carrying blaOXA-232 in a hospitalized patient, where the ertapenem MIC increased from 0.5 μg/ml to 512 μg/ml and the meropenem MIC increased from 0.125 μg/ml to 32 μg/ml during the course of ertapenem therapy. Whole-genome sequencing (WGS) analysis identified loss-of-function mutations in ompC and ompF in carbapenem-resistant isolates that were not present in the initial carbapenem-susceptible isolate. Complementation of a carbapenem-resistant isolate with an intact ompF gene resulted in 16- to 32-fold reductions in carbapenem MICs, whereas complementation with intact ompC resulted in a 2-fold reduction in carbapenem MICs. Additionally, blaOXA-232 expression increased 2.9-fold in a carbapenem-resistant isolate. Rapid development of high-level carbapenem resistance in initially carbapenem-susceptible OXA-232-producing R. ornithinolytica under selective pressure from carbapenem therapy highlights the diagnostic challenges in detecting Enterobacteriaceae strains producing this inefficient carbapenemase.

The Infection of the ventriculus of the adult honeybee by Nosema apis (Zander)

Parasitology ◽  
1955 ◽  
Vol 45 (1-2) ◽  
pp. 86-94 ◽  
Author(s):  
L. Bailey
Keyword(s):  
Calcium Phosphate ◽  
Central Region ◽  
Polar Filament ◽  
Rapid Development ◽  
Nosema Apis ◽  
Anaerobic Conditions ◽  
Free Living ◽  
Initial Infection ◽  
High Level

1. Spores of Nosema apis nearly all germinate within 30 min. after entering the ventriculus of the honeybee.2. The cause of germination in vivo remains unknown, but is probably not a change of osmotic pressure or pH and is probably not due to anaerobic conditions or an enzyme. The agent causing germination is probably unstable and is destroyed when removed from the bee.3. The anterior end of the ventriculus receives an initial heavy infection and the circumstantial evidence which this provides supports the theory that a free living ‘planont’ stage does not exist but that the parasite is injected directly into the host cell from the spore via the hollow polar filament.4. The central region of the ventriculus which contains many granules of calcium phosphate receives the lowest initial infection. It is considered possible that the granules inhibit the initial rapid development of the parasite by maintaining an unfavourably high level of pH until they are eventually dissolved by the slowly developing organism.

scholarly journals Quick and efficient approach to develop genomic resources in orphan species: Application in Lavandula angustifolia

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243853
Author(s):  
Berline Fopa Fomeju ◽  
Dominique Brunel ◽  
Aurélie Bérard ◽  
Jean-Baptiste Rivoal ◽  
Philippe Gallois ◽  
...  
Keyword(s):  
Large Scale ◽  
De Novo ◽  
Rapid Development ◽  
Genetic Distances ◽  
Lavandula Angustifolia ◽  
Distance Analysis ◽  
Alternative Medicines ◽  
Dna And Rna ◽  
Snp Development ◽  
High Level

Next-Generation Sequencing (NGS) technologies, by reducing the cost and increasing the throughput of sequencing, have opened doors to generate genomic data in a range of previously poorly studied species. In this study, we propose a method for the rapid development of a large-scale molecular resources for orphan species. We studied as an example the true lavender (Lavandula angustifolia Mill.), a perennial sub-shrub plant native from the Mediterranean region and whose essential oil have numerous applications in cosmetics, pharmaceuticals, and alternative medicines. The heterozygous clone “Maillette” was used as a reference for DNA and RNA sequencing. We first built a reference Unigene, compound of coding sequences, thanks to de novo RNA-seq assembly. Then, we reconstructed the complete genes sequences (with introns and exons) using an Unigene-guided DNA-seq assembly approach. This aimed to maximize the possibilities of finding polymorphism between genetically close individuals despite the lack of a reference genome. Finally, we used these resources for SNP mining within a collection of 16 commercial lavender clones and tested the SNP within the scope of a genetic distance analysis. We obtained a cleaned reference of 8, 030 functionally in silico annotated genes. We found 359K polymorphic sites and observed a high SNP frequency (mean of 1 SNP per 90 bp) and a high level of heterozygosity (more than 60% of heterozygous SNP per genotype). On overall, we found similar genetic distances between pairs of clones, which is probably related to the out-crossing nature of the species and the restricted area of cultivation. The proposed method is transferable to other orphan species, requires little bioinformatics resources and can be realized within a year. This is also the first reported large-scale SNP development on Lavandula angustifolia. All the genomics resources developed herein are publicly available and provide a rich pool of molecular resources to explore and exploit lavender genetic diversity in breeding programs.

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