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Surface profile gradient in amorphous Ta2O5 semi conductive layers regulates nanoscale electric current stability
No full textAbstractA link between the morphological characteristics and the electric properties of amorphous layers is established by means of atomic, conductive, electrostatic force and thermal scanning microscopy. Using amorphous Ta2O5 (a-Ta2O5) semiconductive layer, it is found that surface profile gradients (morphological gradient), are highly correlated to both the electron energy gradient of trapped electrons in interactive Coulombic sites and the thermal gradient along conductive paths and thus thermal and electric properties are correlated with surface morphology at the nanoscale.Furthermore, morphological and electron energy gradients along opposite conductive paths of electrons intrinsically impose a current stability anisotropy. For either long conductive paths (L>1μm) or along symmetric nanodomains, current stability for both positive and negative currents i is demonstrated. On the contrary, for short conductive paths along non-symmetric nanodomains, the set of independent variables (L, i) is spanned by two current stability/intability loci. One locus specifies a stable state for negative currents, while the other locus also describes a stable state for positive currents
Effect of carbonization on the processing characteristics of rubber seed shell
No full textAbstractThe effect of carbonization on the processing characteristics of rubber seed shell powder was studied. Rubber seed shells were carbonized at different temperatures and then ground into fine powder. The various powders obtained were then characterized by pH, bulk density, moisture content, iodine adsorption value, yield%, conductivity and loss on ignition. The results show that there was a significant change in the pH as the heating temperature increases. The bulk density and moisture content decrease with increasing heating temperature while the iodine adsorption number and the loss on ignition increase with increasing heating temperature thus showing that carbonization has a significant influence on the processing characteristics of rubber seed shell
Will video caching remain energy efficient in future core optical networks?
No full textAbstractOptical networks are expected to cater for the future Internet due to the high speed and capacity that they offer. Caching in the core network has proven to reduce power usage for various video services in current optical networks. This paper investigates whether video caching will still remain power efficient in future optical networks. The study compares the power consumption of caching in a current IP over WDM core network to a future network. The study considers a number of features to exemplify future networks. Future optical networks are considered where: (1) network devices consume less power, (2) network devices have sleep-mode capabilities, (3) IP over WDM implements lightpath bypass, and (4) the demand for video content significantly increases and high definition video dominates. Results show that video caching in future optical networks saves up to 42% of power consumption even when the power consumption of transport reduces. These results suggest that video caching is expected to remain a green option in video services in the future Internet
Lifetime vs. rate capability: Understanding the role of FEC and VC in high-energy Li-ion batteries with nano-silicon anodes
No full textAbstractFluoroethylene carbonate (FEC) and vinylene carbonate (VC) are the most frequently used electrolyte components to enhance the lifetime of anode materials in Li-ion batteries, but for silicon it is still ambiguous when FEC or VC is more beneficial. Herein, a nanostructured silicon/carbon anode derived from low-cost HSiCl3 is tailored by the rational choice of the electrolyte component, to obtain an anode material outperforming current complex silicon structures. We demonstrate highly reversible areal capacities of up to 5mAh/cm2 at 4.4mg/cm2 mass loading, a specific capacity of 1280mAh/gElectrode, a capacity retention of 81% after 500 deep-discharge cycles versus lithium metal and successful full-cell tests with high-voltage cathodes meeting the requirements for real application. Electrochemical impedance spectroscopy and post-mortem investigation provide new insights in tailoring the interfacial properties of silicon-based anodes for high performance anode materials based on an alloying mechanism with large volume changes. The role of fluorine in the FEC-derived interfacial layer is discussed in comparison with the VC-derived layer and possible degradation mechanisms are proposed. We believe that this study gives a valuable understanding and provides new strategies on the facile use of additives for highly reversible silicon anodes in Li-ion batteries
QSAR and docking studies of coumarin derivatives as potent HIV-1 integrase inhibitors
No full textAbstractHuman immunodeficiency virus integrase (HIV-1IN) is an emerging and potential drug target for anti-HIV therapy. It is an enzyme essential for 3′ processing and integration step in the life cycle of HIV. In the present study a series of coumarin derivatives (containing 26 compounds) as HIV-1IN inhibitors was subjected to quantitative structure–activity relationship (QSAR) analysis. For building the regression models two different variable selection approaches namely, genetic function approximation (GFA) and sequential multiple linear regression (SQ-MLR) were used and compared to predict the HIV-1IN inhibition activity. Based on prediction, the best validation model for 3′ processing inhibition activity with squared correlation coefficient (r2)=0.8965, cross validated correlation coefficient (Q2)=0.8307 and external prediction ability pred_r2=0.5400 showed that Henry’s law Constant (HLC), Partition Coefficient (PC) and Dipole moment-Z component (D3) were the positive contributors, whereas for integration inhibition activity, parameters r2=0.8904, Q2=0.8174 and pred_r2=0.7159 showed HLC, Logarithm of Partition Coefficient (LogP) and Dipole moment-Y component (D2) contributed positively to the activity. The binding mode pattern of the compounds to the binding site of integrase enzyme was confirmed by docking studies. The results of the present study may be useful for designing more potent HIV-1IN inhibitors
Polarization of photons emitted by decaying dark matter
No full textAbstractRadiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state
Alisporivir inhibits MERS- and SARS-coronavirus replication in cell culture, but not SARS-coronavirus infection in a mouse model
No full textAbstractCurrently, there is no registered treatment for infections with emerging zoonotic coronaviruses like SARS- and MERS-coronavirus. We here report that in cultured cells low-micromolar concentrations of alisporivir, a non-immunosuppressive cyclosporin A-analog, inhibit the replication of four different coronaviruses, including MERS- and SARS-coronavirus. Ribavirin was found to further potentiate the antiviral effect of alisporivir in these cell culture-based infection models, but this combination treatment was unable to improve the outcome of SARS-CoV infection in a mouse model. Nevertheless, our data provide a basis to further explore the potential of Cyp inhibitors as host-directed, broad-spectrum inhibitors of coronavirus replication
Personalized heating – Comparison of heaters and control modes
No full textAbstractPersonalized conditioning systems represent a promising solution to two major challenges in building industry – high energy consumption of the buildings and still only mediocre thermal comfort. These systems create a microenvironment adapted for each user. Therefore, individual demands for thermal comfort can be met and energy can be saved due to higher effectiveness compared to the traditional HVAC systems. This study investigates two aspects of personalized heating – effectiveness of different heaters and impact of different control modes. Personalized heating system consisting of a heated chair, a heated desk mat, and a heated floor mat was tested with 13 test subjects in a climate chamber under operative temperature of 18 °C. The heaters were tested separately and in combination as user controlled. Furthermore, the complete system was tested with fixed setting and automatic control using hand skin temperature as a control signal. The heated chair and the heated desk mat as well as the complete system significantly improved thermal comfort, while the heated chair was found to the most effective heater. The automatic control mode could provide the same level of thermal comfort as user control in this study
GIFT-Cloud: A data sharing and collaboration platform for medical imaging research
No full textAbstractObjectivesClinical imaging data are essential for developing research software for computer-aided diagnosis, treatment planning and image-guided surgery, yet existing systems are poorly suited for data sharing between healthcare and academia: research systems rarely provide an integrated approach for data exchange with clinicians; hospital systems are focused towards clinical patient care with limited access for external researchers; and safe haven environments are not well suited to algorithm development. We have established GIFT-Cloud, a data and medical image sharing platform, to meet the needs of GIFT-Surg, an international research collaboration that is developing novel imaging methods for fetal surgery. GIFT-Cloud also has general applicability to other areas of imaging research.MethodsGIFT-Cloud builds upon well-established cross-platform technologies. The Server provides secure anonymised data storage, direct web-based data access and a REST API for integrating external software. The Uploader provides automated on-site anonymisation, encryption and data upload. Gateways provide a seamless process for uploading medical data from clinical systems to the research server.ResultsGIFT-Cloud has been implemented in a multi-centre study for fetal medicine research. We present a case study of placental segmentation for pre-operative surgical planning, showing how GIFT-Cloud underpins the research and integrates with the clinical workflow.ConclusionsGIFT-Cloud simplifies the transfer of imaging data from clinical to research institutions, facilitating the development and validation of medical research software and the sharing of results back to the clinical partners. GIFT-Cloud supports collaboration between multiple healthcare and research institutions while satisfying the demands of patient confidentiality, data security and data ownership