843 research outputs found
Quantum Size Effects on the Chemical Sensing Performance of Two-Dimensional Semiconductors
We investigate the role of quantum confinement on the performance of gas
sensors based on two-dimensional InAs membranes. Pd-decorated InAs membranes
configured as H2 sensors are shown to exhibit strong thickness dependence, with
~100x enhancement in the sensor response as the thickness is reduced from 48 to
8 nm. Through detailed experiments and modeling, the thickness scaling trend is
attributed to the quantization of electrons which favorably alters both the
position and the transport properties of charge carriers; thus making them more
susceptible to surface phenomena
Synchronizing inventory and transport within supply chain management
The problem considers synchronized optimization of inventory and transport, and focuses on producer-distributor relations. Particular attention is paid to developing a mathematical model and an optimization problem that can be used to minimize the overall distribution cost by an appropriate placement of warehouses and cross-docking points. Solutions to this problem are explored using genetic algorithms and ideas from graph/network theory.
Note: there are three separate reports contained within the uploaded .pdf file
Building cloud applications for challenged networks
Cloud computing has seen vast advancements and uptake in many parts of the world. However, many of the design patterns and deployment models are not very suitable for locations with challenged networks such as countries with no nearby datacenters. This paper describes the problem and discusses the options available for such locations, focusing specifically on community clouds as a short-term solution. The paper highlights the impact of recent trends in the development of cloud applications and how changing these could better help deployment in challenged networks. The paper also outlines the consequent challenges in bridging different cloud deployments, also known as cross-cloud computing
Cardiosphere-derived cells suppress allogeneic lymphocytes by production of PGE2 acting via the EP4 receptor
derived cells (CDCs) are a cardiac progenitor cell population, which have been shown to possess cardiac regenerative properties and can improve heart function in a variety of cardiac diseases. Studies in large animal models have predominantly focussed on using autologous cells for safety, however allogeneic cell banks would allow for a practical, cost-effective and efficient use in a clinical setting. The aim of this work was to determine the immunomodulatory status of these cells using CDCs and lymphocytes from 5 dogs. CDCs expressed MHC I but not MHC II molecules and in mixed lymphocyte reactions demonstrated a lack of lymphocyte proliferation in response to MHC-mismatched CDCs. Furthermore, MHC-mismatched CDCs suppressed lymphocyte proliferation and activation in response to Concanavalin A. Transwell experiments demonstrated that this was predominantly due
to direct cell-cell contact in addition to soluble mediators whereby CDCs produced high levels of PGE2
under inflammatory conditions. This led to down-regulation of CD25 expression on lymphocytes via the
EP4 receptor. Blocking prostaglandin synthesis restored both, proliferation and activation (measured via CD25 expression) of stimulated lymphocytes. We demonstrated for the first time in a large animal model that CDCs inhibit proliferation in allo-reactive lymphocytes and have potent immunosuppressive activity mediated via PGE2
A framework for the successful implementation of food traceability systems in China
Implementation of food traceability systems in China faces many challenges due to the scale, diversity and complexity of China’s food supply chains. This study aims to identify critical success factors specific to the implementation of traceability systems in China. Twenty-seven critical success factors were identified in the literature. Interviews with managers at four food enterprises in a pre-study helped identify success criteria
and five additional critical success factors. These critical success factors were tested through a survey of managers in eighty-three food companies. This study identifies six dimensions for critical success factors: laws, regulations and standards; government support; consumer knowledge and support; effective management and communication; top management and vendor support; and information and system quality
Uncovering the novel characteristics of Asian honey bee, Apis cerana, by whole genome sequencing
Citation: Park, D., Jung, J. W., Choi, B. S., Jayakodi, M., Lee, J., Lim, J., . . . Kwon, H. W. (2015). Uncovering the novel characteristics of Asian honey bee, Apis cerana, by whole genome sequencing. Bmc Genomics, 16, 16. doi:10.1186/1471-2164-16-1Background: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. Results: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A. cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. Conclusions: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory.Citation: Park et al.: Uncovering the novel characteristics of Asian honey bee, Apis cerana, by whole genome sequencing. BMC Genomics 2015 16:1
Coupling emission from single localized defects in 2D semiconductor to surface plasmon polaritons
Coupling of an atom-like emitter to surface plasmons provides a path toward
significant optical nonlinearity, which is essential in quantum information
processing and quantum networks. A large coupling strength requires
nanometer-scale positioning accuracy of the emitter near the surface of the
plasmonic structure, which is challenging. We demonstrate the coupling of
single localized defects in a tungsten diselenide (WSe2) monolayer self-aligned
to the surface plasmon mode of a silver nanowire. The silver nanowire induces a
strain gradient on the monolayer at the overlapping area, leading to the
formation of localized defect emission sites that are intrinsically close to
the surface plasmon. We measure a coupling efficiency with a lower bound of 39%
from the emitter into the plasmonic mode of the silver nanowire. This technique
offers a way to achieve efficient coupling between plasmonic structures and
localized defects of 2D semiconductors
An integrative knowledge management framework to support ERP implementation for improved management decision making in industry
Development of a novel corrugated polyvinylidene difluoride membrane via improved imprinting technique for membrane distillation
© 2019 by the authors. Membrane distillation (MD) is an attractive technology for desalination, mainly because its performance that is almost independent of feed solute concentration as opposed to the reverse osmosis process. However, its widespread application is still limited by the low water flux, low wetting resistance and high scaling vulnerability. This study focuses on addressing those limitations by developing a novel corrugated polyvinylidene difluoride (PVDF) membrane via an improved imprinting technique for MD. Corrugations on the membrane surface are designed to offer an effective surface area and at the same time act as a turbulence promoter to induce hydrodynamic by reducing temperature polarization. Results show that imprinting of spacer could help to induce surface corrugation. Pore defect could be minimized by employing a dual layer membrane. In short term run experiment, the corrugated membrane shows a flux of 23.1 Lm-2h-1 and a salt rejection of > 99%, higher than the referenced flat membrane (flux of 18.0 Lm-2h_asuf and similar rejection). The flux advantage can be ascribed by the larger effective surface area of the membrane coupled with larger pore size. The flux advantage could be maintained in the long-term operation of 50 h at a value of 8.6 Lm-2h-1. However, the flux performance slightly deteriorates over time mainly due to wetting and scaling. An attempt to overcome this limitation should be a focus of the future study, especially by exploring the role of cross-flow velocity in combination with the corrugated surface in inducing local mixing and enhancing system performance
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