6,649 research outputs found
Corrosion Resistance Studies of Austenitic Stainless Steel Grades in Molten Zinc-Aluminum Alloy Galvanizing Bath
The corrosion inhibition performance and
mechanical behavior of galvanized and heat-treated four
newly developed austenitic stainless steel grades and type
316L austenitic stainless steel for application as sink rolls
in galvanizing baths of 0.14–0.21 wt.% aluminum was
investigated and compared through immersion corrosion
test to determine the weight loss between 168 and 504 h,
tensile test, and Charpy impact test. The delta ferrite content
of the test samples was observed and estimated
through optical microscopy, feritscope, and ONRL diagram.
Scanning electron microscopy and energy dispersive
spectroscopy were used to characterize the surface
microstructure, morphology, and chemical composition of
the galvanized coating of the steel samples. Result showed
that only two of the newly developed stainless steel compositions
were selected for use in fabrication of galvanizing
hardware based on the comparisons of corrosion and
mechanical performances of tested alloy
High-throughput screening of encapsulated islets using wide-field lens-free on-chip imaging
Islet microencapsulation is a promising solution to diabetes treatment, but
its quality control based on manual microscopic inspection is extremely
low-throughput, highly variable and laborious. This study presents a
high-throughput islet-encapsulation quality screening system based on lens-free
on-chip imaging with a wide field-of-view of 18.15 cm^2, which is more than 100
times larger than that of a lens-based optical microscope, enabling it to image
and analyze ~8,000 microcapsules in a single frame. Custom-written image
reconstruction and processing software provides the user with clinically
important information, such as microcapsule count, size, intactness, and
information on whether each capsule contains an islet. This high-throughput and
cost-effective platform can be useful for researchers to develop better
encapsulation protocols as well as perform quality control prior to
transplantation
A mathematical framework for combining decisions of multiple experts toward accurate and remote diagnosis of malaria using tele-microscopy.
We propose a methodology for digitally fusing diagnostic decisions made by multiple medical experts in order to improve accuracy of diagnosis. Toward this goal, we report an experimental study involving nine experts, where each one was given more than 8,000 digital microscopic images of individual human red blood cells and asked to identify malaria infected cells. The results of this experiment reveal that even highly trained medical experts are not always self-consistent in their diagnostic decisions and that there exists a fair level of disagreement among experts, even for binary decisions (i.e., infected vs. uninfected). To tackle this general medical diagnosis problem, we propose a probabilistic algorithm to fuse the decisions made by trained medical experts to robustly achieve higher levels of accuracy when compared to individual experts making such decisions. By modelling the decisions of experts as a three component mixture model and solving for the underlying parameters using the Expectation Maximisation algorithm, we demonstrate the efficacy of our approach which significantly improves the overall diagnostic accuracy of malaria infected cells. Additionally, we present a mathematical framework for performing 'slide-level' diagnosis by using individual 'cell-level' diagnosis data, shedding more light on the statistical rules that should govern the routine practice in examination of e.g., thin blood smear samples. This framework could be generalized for various other tele-pathology needs, and can be used by trained experts within an efficient tele-medicine platform
Static index pruning in web search engines: Combining term and document popularities with query views
Cataloged from PDF version of article.Static index pruning techniques permanently remove a presumably redundant part of an inverted file, to reduce the file size and query processing time. These techniques differ in deciding which parts of an index can be removed safely; that is, without changing the top-ranked query results. As defined in the literature, the query view of a document is the set of query terms that access to this particular document, that is, retrieves this document among its top results. In this paper, we first propose using query views to improve the quality of the top results compared against the original results. We incorporate query views in a number of static pruning strategies, namely term-centric, document-centric, term popularity based and document access popularity based approaches, and show that the new strategies considerably outperform their counterparts especially for the higher levels of pruning and for both disjunctive and conjunctive query processing. Additionally, we combine the notions of term and document access popularity to form new pruning strategies, and further extend these strategies with the query views. The new strategies improve the result quality especially for the conjunctive query processing, which is the default and most common search mode of a search engine
Modelling of Gas Transport through Polymer/MOF Interfaces: A Microsecond-Scale Concentration Gradient-Driven Molecular Dynamics Study
Membrane-based separation technologies offer a cost-effective alternative to many energy-intensive gas separation processes, such as distillation. Mixed matrix membranes (MMMs) composed of polymers and metal–organic frameworks (MOFs) have attracted a great deal of attention for being promising systems to manufacture durable and highly selective membranes with high gas fluxes and high selectivities. Therefore, understanding gas transport through these MMMs is of significant importance. There has been longstanding speculation that the gas diffusion behavior at the interface formed between the polymer matrix and MOF particles would strongly affect the global performance of the MMMs due to the potential presence of nonselective voids or other defects. To shed more light on this paradigm, we have performed microsecond long concentration gradient-driven molecular dynamics (CGD-MD) simulations that deliver an unprecedented microscopic picture of the transport of H2 and CH4 as single components and as a mixture in all regions of the PIM-1/ZIF-8 membrane, including the polymer/MOF interface. The fluxes of the permeating gases are computed and the impact of the polymer/MOF interface on the H2/CH4 permselectivity of the composite membrane is clearly revealed. Specifically, we show that the poor compatibility between PIM-1 and ZIF-8, which manifests itself by the presence of nonselective void spaces at their interface, results in a decrease of the H2/CH4 permselectivity for the corresponding composite membrane as compared to the performances simulated for PIM-1 and ZIF-8 individually. We demonstrate that CGD-MD simulations based on an accurate atomistic description of the polymer/MOF composite is a powerful tool for characterization and understanding of gas transport and separation mechanisms in MMMs
Possible Single Resonant Production of the Fourth Generation Charged Leptons at Colliders
Single resonant productions of the fourth standard model generation charged
lepton via anomalous interactions at gamma e colliders based on future linear
e^+ e^- colliders with 500 GeV and 1 TeV center of mass energies are studied.
Signatures of and
anomalous processes followed by the hadronic and leptonic decay of the Z boson
and corresponding standard model backgrounds are discussed in details. The
lowest necessary luminosities to observe these processes and the achievable
values of the anomalous coupling strengths are determined.Comment: 9 pages, 6 figures, 4 table
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