131 research outputs found

    Effect of corner radii on the thermal & fluid flow performance of the laminar flow through rectangular micro channel

    Get PDF
    Metallic micro channels have the advantage of high thermal conductivity to strength ratio. The recent advances in the manufacturing processes, has increased the feasibility of realizing metallic micro channels with close dimensional control. Presently, various types of micro manufacturing processes are available for the realization of the metallic micro channels. However it is not practical to manufacture any dimensional feature with sharp corner. Depending on the choice of the manufacturing process, the corners get rounded to varying degree. When compared with the dimensions of micro channels the magnitude of the corner radius is considerable. In this paper an attempt has been made to study numerically the effect of corner radius on the performance of the micro channels. Commercially available computational fluid dynamics software ANSYS CFX was used for the simulation of micro channels performance. The thermal & fluid flow performance of the micro channel was simulated by varying the corner radius from 50 microns to 200 microns. The coolant flow velocities were varied from 0.48m/s to 1.27m/s. The Temperature dependent material properties have been used in the analysis. The simulation results were validated using published literature

    Experimental & numerical study of forced convection laminar flow through copper micro channel heat sink

    Get PDF
    A rectangular micro channels having 500 microns width & 1500 microns depth have been machined out of Oxygen free high conductivity Copper material on an area of 12.5mm X25mm. De-ionized water was used as a coolant. The thermal & fluid flow performances have been tested for the flow velocities ranging from 0.5m/s to 1.2m/s. Micro channels performances have been numerically simulated using commercially available computational fluid dynamics software ANSYS CFX. The simulated results have been validated with the experimental results and published literature . The effects of Temperature dependent material properties on simulation have been examine

    The contemporary framework on social media analytics as an emerging tool for behavior informatics, HR analytics and business process

    Get PDF
    Organizations can use social media analytics as an effective assessment tool from behavioral perspectives, HR as well as business process to collaboratively build competency framework. The present piece of work is an attempt to put forth social media as a contemporary model in the light of the existing literature. Providing literature reviews, this paper also highlights current practices of social media analytics as to how organizations are accessing vast amount of live data from social media in order to understand work-related behavioral aspects of the employees and their employability for both HR process and the business. The analyzed data on customers is also being taken into account to highlight patterns and customers’ sentiments related to the marketing efforts. Furthermore, on the basis of the above presented discussion this paper suggests the road map to how organizations can foster the social media practices. Finally, this paper raises some significant plausible research questions to be empirically researched in order to methodically validate or discard the presented framework on this rapidly emerging phenomenon

    Gamma oscillatory activity in vitro: a model system to assess pathophysiological mechanisms of comorbidity between autism and epilepsy.

    Get PDF
    Autism spectrum disorder (ASD) and temporal lobe epilepsy exhibit remarkable comorbidity, but for reasons not clearly understood. To reveal a common pathophysiological mechanism, we here describe and characterize an in vitro epileptiform activity in the rat hippocampus that exhibits common features with in vivo activity in rodent ASD models. We discovered the development of this activity in the CA1 region of horizontal slices after prolonged interictal-like epileptiform activity in the CA3 region that was provoked by incubation in high potassium artificial cerebrospinal fluid. The CA1 epileptiform bursts were insensitive to blockers of glutamatergic transmission, and were carried by synaptic as well as extrasynaptic, tonically activated gamma-aminobutyric acid type A (GABA(A)) receptors. The bursts bear resemblance to in vivo gamma-oscillatory activity found in rat ASD models with respect to their gamma frequency spectrum, their origin (in the CA1), and their sensitivity to blockers of cation-chloride pumps (NKCC1 and KCC2), as well as to oxytocin. Considering this bursting activity as an in vitro model for studying comorbidity between epilepsy and ASD may help to disentangle the intricate interactions that underlie the comorbidity between both diseases and suggests that extrasynaptic tonic GABAergic transmission could represent a potential target for ASD

    Transverse Wave Propagation in Relativistic Two-fluid Plasmas in de Sitter Space

    Full text link
    We investigate transverse electromagnetic waves propagating in a plasma in the de Sitter space. Using the 3+1 formalism we derive the relativistic two-fluid equations to take account of the effects due to the horizon and describe the set of simultaneous linear equations for the perturbations. We use a local approximation to investigate the one-dimensional radial propagation of Alfv\'en and high frequency electromagnetic waves and solve the dispersion relation for these waves numerically.Comment: 19 pages, 12 figure

    Insights in the global genetics and gut microbiome of black soldier fly, Hermetia illucens: implications for animal feed safety control

    Get PDF
    Open Access Journal; Published online: 07 July 2020The utilization of the black soldier fly (BSF) Hermetia illucens L. for recycling organic waste into high-quality protein and fat biomass for animal feeds has gained momentum worldwide. However, information on the genetic diversity and environmental implications on safety of the larvae is limited. This study delineates genetic variability and unravels gut microbiome complex of wild-collected and domesticated BSF populations from six continents using mitochondrial COI gene and 16S metagenomics. All sequences generated from the study linked to H. illucens accessions KM967419.1, FJ794355.1, FJ794361.1, FJ794367.1, KC192965.1, and KY817115.1 from GenBank. Phylogenetic analyses of the sequences generated from the study and rooted by GenBank accessions of Hermetia albitarsis Fabricius and Hermetia sexmaculata Macquart separated all samples into three branches, with H. illucens and H. sexmaculata being closely related. Genetic distances between H. illucens samples from the study and GenBank accessions of H. illucens ranged between 0.0091 and 0.0407 while H. sexmaculata and H. albitarsis samples clearly separated from all H. illucens by distances of 0.1745 and 0.1903, respectively. Genetic distance matrix was used to generate a principal coordinate plot that further confirmed the phylogenetic clustering. Haplotype network map demonstrated that Australia, United States 1 (Rhode Island), United States 2 (Colorado), Kenya, and China shared a haplotype, while Uganda shared a haplotype with GenBank accession KC192965 BSF from United States. All other samples analyzed had individual haplotypes. Out of 481,695 reads analyzed from 16S metagenomics, four bacterial families (Enterobactereaceae, Dysgonomonadaceae, Wohlfahrtiimonadaceae, and Enterococcaceae) were most abundant in the BSF samples. Alpha-diversity, as assessed by Shannon index, showed that the Kenyan and Thailand populations had the highest and lowest microbe diversity, respectively; while microbial diversity assessed through Bray Curtis distance showed United States 3 (Maysville) and Netherlands populations to be the most dissimilar. Our findings on genetic diversity revealed slight phylogeographic variation between BSF populations across the globe. The 16S data depicted larval gut bacterial families with economically important genera that might pose health risks to both animals and humans. This study recommends pre-treatment of feedstocks and postharvest measures of the harvested BSF larvae to minimize risk of pathogen contamination along the insect-based feed value chain

    Magnetogenesis and the dynamics of internal dimensions

    Full text link
    The dynamical evolution of internal space-like dimensions breaks the invariance of the Maxwell's equations under Weyl rescaling of the (conformally flat) four-dimensional metric. Depending upon the number and upon the dynamics of internal dimensions large scale magnetic fields can be created. The requirements coming from magnetogenesis together with the other cosmological constraints are examined under the assumption that the internal dimensions either grow or shrink (in conformal time) prior to a radiation dominated epoch. If the internal dimensions are growing the magnitude of the generated magnetic fields can seed the galactic dynamo mechanism.Comment: 27 in RevTex style, four figure

    Quantitative analyses and modelling to support achievement of the 2020 goals for nine neglected tropical diseases

    Get PDF
    Quantitative analysis and mathematical models are useful tools in informing strategies to control or eliminate disease. Currently, there is an urgent need to develop these tools to inform policy to achieve the 2020 goals for neglected tropical diseases (NTDs). In this paper we give an overview of a collection of novel model-based analyses which aim to address key questions on the dynamics of transmission and control of nine NTDs: Chagas disease, visceral leishmaniasis, human African trypanosomiasis, leprosy, soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. Several common themes resonate throughout these analyses, including: the importance of epidemiological setting on the success of interventions; targeting groups who are at highest risk of infection or re-infection; and reaching populations who are not accessing interventions and may act as a reservoir for infection,. The results also highlight the challenge of maintaining elimination 'as a public health problem' when true elimination is not reached. The models elucidate the factors that may be contributing most to persistence of disease and discuss the requirements for eventually achieving true elimination, if that is possible. Overall this collection presents new analyses to inform current control initiatives. These papers form a base from which further development of the models and more rigorous validation against a variety of datasets can help to give more detailed advice. At the moment, the models' predictions are being considered as the world prepares for a final push towards control or elimination of neglected tropical diseases by 2020
    corecore