62 research outputs found

    Supply chain inventory control for the iron and steel industry

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    A Kind of Change Management Method for Global Value Chain Optimization and Its Case Study

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    Any successful change in an organization requires an appropriate change management method and a process for involved staff and department to accept the change and become engaged in order to achieve its success. It is even more important and difficult to adopt a novel change management method to bring multiple organizations across the business value chain into the change implementation. This research does not focused on change management within a single organization but rather emphasizes a change management method, including an appropriate change framework, well-defined critical success factors (CSFs), and related tools for implementing change in multiple organizations. This article introduces one kind of change management method to support a process change through global value chain (GVC) in multiple organizations, and the method is used in a case study to achieve a successful change. In order to succeed in optimizing GVC performance, this research applies the proposed change management method to the case GVC, to support technical change by obtaining the staff's full commitment and engagement. The achieved results from the case study prove that successful change comes not only through technical solutions implemented in the problem process throughout the GVC but also through strong support and engagement from all organizations and involved staff. The proposed change management method not only helped the case GVC to implement change successfully but also can help the relevant multiple organizations to improve the GVC performance and add value by optimizing their problem process.©2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

    Towards name-based trust and security for content-centric network. In

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    Abstract-Trust and security have been considered as builtin properties for future Internet architecture. Leveraging the concept of named content in recently proposed information centric network, we propose a name-based trust and security protection mechanism. Our scheme is built with identity-based cryptography (IBC), where the identity of a user or device can act as a public key string. Uniquely, in named content network such as content-centric network (CCN), a content name or its prefixes can be used as public identities, with which content integrity and authenticity can be achieved with IBC algorithms. The trust of a content is seamlessly integrated with the verification of the content's integrity and authenticity with its name or prefix, instead of the public key certificate of its publisher. In addition, flexible confidentiality protection is enabled between content publishers and consumers. For scalable deployment purpose, we further propose to use a hybrid scheme combined with traditional public-key infrastructure (PKI) and IBC. We have implemented this scheme with CCNx open source project on Android

    Acute Effects of Microcystins on the Transcription of 14 Glutathione S-Transferase Isoforms in Wistar Rat

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    ABSTRACT: The glutathione S-transferases (GST) play important roles in the detoxification of microcystins (MCs). For better understanding of the responses of GST isforms to MCs exposure, informations about the effects of MCs on GSTs are necessary. In this experiment, we cloned the full length cDNA of 14 GST isoforms (GST alpha, kappa, mu, omega, pi, theta, zeta, and microsomal GST) from Wistar rat. The mRNA abundance of each rat GST isoform in the liver, kidney, and testis was analyzed by real time quantitative PCR. Multiple GST isoforms were constitutively expressed in all examined organs, but some isoforms were expressed at higher level in one organ than in others. The relative changes of the mRNA abundance in the liver, kidney, and testis of Wiatar rat i.v. injected with crude MCs extract at dose of 1LD 50 were also analyzed. Generally, the expression of most GSTs in the liver and testis was suppressed while that in kidney was induced after being injected with MCs. It is suggested that the transcription of GST isoforms varied in different ways within an organ and between organs of Wistar rat exposed to MCs. # 2009 Wiley Periodicals, Inc. Environ Toxicol 26: 187-194, 2011

    Quantitative Profiling of mRNA Expression of Glutathione S-transferase Superfamily Genes in Various Tissues of Bighead Carp (Aristichthys nobilis)

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    The expression of glutathione S-transferase (GST) is a crucial factor in determining the sensitivity of cells and organs in response to a variety of toxicants. In this study, we cloned the core nucleotide of alpha, kappa, mu, mGST, pi, rho, and theta-like GST genes from bighead carp (Aristichthys nobilis). Their derived amino acid sequences were clustered with other vertebrate GSTs in a phylogenetic tree, and the bighead carp GST sequences have the highest similarity with those from common carp and zebrafish. We quantified the constitutive mRNA transcription of GST isoforms in eight different tissues (liver, kidney, spleen, intestine, muscle, heart, brain, and gill). The information obtained from the present study could be distilled into a few generalized principles: multiple GST isoenzymes were ubiquitously expressed in all tissues; majority of GSTs had high constitutive expression in intestine, liver, and kidney. These findings are in agreement with the roles of these tissues in xenobiotic metabolism. At the same time, some unique findings were detected in the current experiment: (1) higher expression of most GSTs was observed in spleen; (2) the expression of GST pi was highest in almost all the studied tissues except muscle; the other two isoforms, GST alpha and rho, were also highly expressed in liver, kidney, intestine, spleen, heart, and brain of bighead carp. All these results strongly imply an important role of these GST isoforms in detoxification of ingested xenobiotics. (C) 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:250-259, 2010; View this article online at wileyonlinelibrary.com. DOI10:1002/jbt.2033

    Transcriptional alteration of cytoskeletal genes induced by microcystins in three organs of rats

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    This study explored the mechanisms of toxicity of microcystins by measuring the transcription levels of nine cytoskeletal genes (actin, tubulin, vimentin, ezrin, radixin, moesin, MAP1b, tau, stathmin) in the liver, kidney and spleen of male Wistar rats treated with microcystins at a dose of 80 mu g MC-LReq kg(-1) bw. Microcystins disrupted the transcriptional homeostasis of cytoskeletal genes in these organs. Changes in the transcription of four genes (beta-actin, ezrin, radixin and tau) in liver, one gene (stathmin) in kidney, and one gene (radixin) in spleen were significantly correlated with the tissue concentration of microcystins. However, the influences on the transcription of most genes we studied were greater in the liver than in the kidney or spleen. The effects of microcystins on the transcription of cytoskeletal genes may explain some of the morphological and pathological changes observed in these organs and provide new information on the hepatotoxicity of these compounds. Additionally, transcriptional changes in tumor-associated cytoskeletal genes (ezrin, moesin and stathmin) that were observed in the present study provide a possible clue to the tumor-promoting potential of microcystins and their influences on the transcription of MAP1b and tau imply possible neurological toxicity of microcystins in vertebrates. (C) 2010 Published by Elsevier Ltd

    Enhancing ion extraction with an inverse sheath in negative hydrogen ion sources for NBI heating

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    Negative hydrogen ion (H−) sources employed in neutral beam injection (NBI) systems are subject to extraction efficiency issues due to the considerable volumetric losses of negative hydrogen ions. Here, we propose to improve the H− extraction by activating an alternative sheath mode, the electronegative inverse sheath, in front of the H− production surface, which features zero sheath acceleration for H− with a negative sheath potential opposite to the classic sheath. With the inverse sheath activated, the produced H− exhibits smaller gyration, a shorter transport path, less destructive collisions, and therefore higher extraction probability than the commonly believed space-charge-limited (SCL) sheath. Formation of the proposed electronegative inverse sheath and the SCL sheath near the H–-emitting surface is investigated by the continuum kinetic simulation. Dedicated theoretical analyses are also performed to characterize the electronegative inverse sheath properties, which qualitatively agree with the simulation results. We further propose that the transition between the two sheath modes can be realized by tuning the cold ion generation near the emissive boundary. The electronegative inverse sheath is always coupled with a plasma consisting of only hydrogen ions with approximately zero electron concentration, which is reminiscent of the ion–ion plasma reported in previous NBI experiments

    An alternative simulation approach for surface flashover in a vacuum using a 1D2V continuum and kinetic model

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    Surface flashover across an insulator in a vacuum is a destructive plasma discharge which undermines the behaviors of a range of applications in electrical engineering, particle physics and space engineering, etc. This phenomenon is widely modeled by the particle-in-cell (PIC) simulation, here the continuum and kinetic simulation method is first proposed and implemented as an alternative solution for flashover modeling, aiming for the prevention of unfavorable particle noises in PIC models. A one dimension in space, two dimensions in velocity kinetic simulation model is constructed. Modeling setup, physical assumptions, and simulation algorithm are presented in detail, and a comparison with the well-known secondary electron (SE) emission avalanche analytical expression and existing PIC simulation are made. The obtained kinetic simulation results are consistent with the analytical prediction, and feature noise-free data of surface charge density as well as fluxes of primary and SEs. Discrepancies between the two simulation models and analytical predictions are explained. The code is convenient for updating and to include additional physical processes. The possible implementations of outgassing and plasma species for the final breakdown stage are discussed. The proposed continuum and kinetic approach are expected to inspire future modeling studies for the flashover mechanism and mitigation

    Indoor air quality and health in schools: a critical review for developing the roadmap for the future school environment

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    Several research studies have ranked indoor pollution among the top environmental risks to public health in recent years. Good indoor air quality is an essential component of a healthy indoor environment and significantly affects human health and well-being. Poor air quality in such environments may cause respiratory disease for millions of pupils around the globe and, in the current pandemic-dominated era, require ever more urgent actions to tackle the burden of its impacts. The poor indoor quality in such environments could result from poor management, operation, maintenance, and cleaning. Pupils are a different segment of the population from adults in many ways, and they are more exposed to the poor indoor environment: They breathe in more air per unit weight and are more sensitive to heat/cold and moisture. Thus, their vulnerability is higher than adults, and poor conditions may affect proper development. However, a healthy learning environment can reduce the absence rate, improves test scores, and enhances pupil/teacher learning/teaching productivity. In this article, we analyzed recent literature on indoor air quality and health in schools, with the primary focus on ventilation, thermal comfort, productivity, and exposure risk. This study conducts a comprehensive review to summarizes the existing knowledge to highlight the latest research and solutions and proposes a roadmap for the future school environment. In conclusion, we summarize the critical limitations of the existing studies, reveal insights for future research directions, and propose a roadmap for further improvements in school air quality. More parameters and specific data should be obtained from in-site measurements to get a more in-depth understanding at contaminant characteristics. Meanwhile, site-specific strategies for different school locations, such as proximity to transportation routes and industrial areas, should be developed to suit the characteristics of schools in different regions. The socio-economic consequences of health and performance effects on children in classrooms should be considered. There is a great need for more comprehensive studies with larger sample sizes to study on environmental health exposure, student performance, and indoor satisfaction. More complex mitigation measures should be evaluated by considering energy efficiency, IAQ and health effects
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