400 research outputs found

    Effective Dynamic Range in Measurements with Flash Analog-to-Digital Convertor

    Full text link
    Flash Analog to Digital Convertor (FADC) is frequently used in nuclear and particle physics experiments, often as the major component in big multi-channel systems. The large data volume makes the optimization of operating parameters necessary. This article reports a study of a method to extend the dynamic range of an 8-bit FADC from the nominal 28\rm{2^8} value. By comparing the integrated pulse area with that of a reference profile, good energy reconstruction and event identification can be achieved on saturated events from CsI(Tl) crystal scintillators. The effective dynamic range can be extended by at least 4 more bits. The algorithm is generic and is expected to be applicable to other detector systems with FADC readout.Comment: 19 pages, 1 table, 10 figure

    Information and knowledge leakage in supply chain

    Get PDF
    The current world of post industrial value generation sees companies increasingly analyzing their internal operations against their external organizations to identify supply/demand fluctuations along the supply chain. Within these integrated relationships between internal and external parties in the supply chain, knowledge and information have become very important production resources. The existence and success of an increasing number of organizations strongly depend on their capabilities to utilize knowledge and information for profit generation. By managing more efficient information sharing, the volume of company confidential information passing through the supply chain increases, and this brings about more incidences of knowledge leakage and information leakage. A survey by PricewaterhouseCoopers in 2014 shows information security spending over the next 12 months would increase 60.27 % in Asia and 48.98 % in all regions. This emphasizes the importance of information privacy and therefore the necessity to study the information and knowledge leakage in integrated supply chain. The objectives of this study are to investigate the factors triggering information and knowledge leakage and create a mitigation framework to soften the impact of leakages on performance. The above objectives will be met by formulating and examining several hypotheses of a conceptualized information leakage (IL) and knowledge leakage (KL) framework. A case study derived from a structured interview is adopted as a methodology in this research. As a result, this paper contributes a novel theoretical model that characterizes information and knowledge leakage in an integrated supply chain. Therefore, it also adds new knowledge of managing information and knowledge leakage to supply chain management

    Pulse Shape Discrimination Techniques in Scintillating CsI(Tl) Crystals

    Full text link
    There are recent interests with CsI(Tl) scintillating crystals for Dark Matter experiments. The key merit is the capability to differentiate nuclear recoil (nr) signatures from the background β/γ\beta / \gamma-events due to ambient radioactivity on the basis of their different pulse shapes. One of the major experimental challenges is to perform such pulse shape analysis in the statistics-limited domain where the light output is close to the detection threshold. Using data derived from measurements with low energy γ\gamma's and nuclear recoils due to neutron elastic scatterings, it was verified that the pulse shapes between β/γ\beta / \gamma-events are different. Several methods of pulse shape discrimination are studied, and their relative merits are compared. Full digitization of the pulse shapes is crucial to achieve good discrimination. Advanced software techniques with mean time, neural network and likelihood ratios give rise to satisfactory performance, and are superior to the conventional Double Charge method commonly applied at higher energies. Pulse shape discrimination becomes effective starting at a light yield of about 20 photo-electrons. This corresponds to a detection threshold of about 5 keV electron-equivalence energy, or 40-50 keV recoil kinetic energy, in realistic experiments.Comment: 20 pages, 7 figure

    Measurement of the Intrinsic Radiopurity of Cs-137/U-235/U-238/Th-232 in CsI(Tl) Crystal Scintillators

    Full text link
    The inorganic crystal scintillator CsI(Tl) has been used for low energy neutrino and Dark Matter experiments, where the intrinsic radiopurity is an issue of major importance. Low-background data were taken with a CsI(Tl) crystal array at the Kuo-Sheng Reactor Neutrino Laboratory. The pulse shape discrimination capabilities of the crystal, as well as the temporal and spatial correlations of the events, provide powerful means of measuring the intrinsic radiopurity of Cs-137 as well as the U-235, U-238 and Th-232 series. The event selection algorithms are described, with which the decay half-lives of Po-218, Po-214, Rn-220, Po-216 and Po-212 were derived. The measurements of the contamination levels, their concentration gradients with the crystal growth axis, and the uniformity among different crystal samples, are reported. The radiopurity in the U-238 and Th-232 series are comparable to those of the best reported in other crystal scintillators. Significant improvements in measurement sensitivities were achieved, similar to those from dedicated massive liquid scintillator detector. This analysis also provides in situ measurements of the detector performance parameters, such as spatial resolution, quenching factors, and data acquisition dead time.Comment: 28 pages, 12 figure

    Mammal species composition and habitat associations in a commercial forest and mixed-plantation landscape

    Get PDF
    Commercial forest plantations of fast-growing species have been established globally to meet increasing demands for timber, pulpwood, and other wood products. Industrial plantations may contribute to tropical forest conservation by reducing exploitation of primary and secondary natural forests. Whether such plantations can support critical elements of biodiversity, including provision of habitat and movement corridors for species of conservation concern, is an important question in Southeast Asia. Our objectives were to investigate relationships between habitat gradients and community attributes of medium-sized to large mammals in a mixed plantation mosaic in Bengkoka Peninsula, Sabah, East Malaysia. Data on mammals were collected using 59 remote camera stations deployed for a minimum of 21 days (24-hour sampling occasions) in three major land-use types: natural forest, Acacia plantations, and non-Acacia plantations (oil palm, rubber, young Eucalyptus pellita). We used sample-based rarefaction to evaluate variation in species richness with land use. We used generalized linear models and ordination analyses to evaluate whether variation in mammal detections and species composition was associated with habitat gradients. We recorded >22 mammal species over 1572 sampling occasions. Natural forest area was positively associated with mammal species richness and detections of threatened mammals. Overall detections of mammals increased with decreasing elevation, but decreased within, and close to, Acacia plantations. Detections of threatened mammals increased with greater proportions of natural forest and Acacia and increasing proximity to roads. Sample-based rarefaction indicated that species richness of mammals in Acacia and natural forest was considerably higher than observed. Both natural forest and Acacia plantations shared similar values for species richness and diversity, but non-Acacia plantations scored lower in both metrics. Mammal species composition differed among different types of land use. Smaller generalists used non-Acacia plantation forests. A variety of other mammals including some threatened species used natural forest, Acacia, or a combination of the two. Acacia plantations possess attributes supporting a diversity of mammal species, including those we defined as threatened based on IUCN criteria. However, this is likely a function of the habitat mosaic with natural forest in the study area and the mangrove forests on the fringes of the peninsula serving as refuges of mammal diversity. Retention and restoration of natural and mangrove forests may therefore enhance the conservation potential of industrial Acacia plantations. Additionally, controlled road access in conjunction with anti-poaching operations and strengthening public awareness are essential to reduce the threat of overexploitation

    Studies of Prototype CsI(Tl) Crystal Scintillators for Low-Energy Neutrino Experiments

    Full text link
    Crystal scintillators provide potential merits for the pursuit of low-energy low-background experiments. A CsI(Tl) scintillating crystal detector is being constructed to study low-energy neutrino physics at a nuclear reactor, while projects are underway to adopt this technique for dark matter searches. The choice of the geometrical parameters of the crystal modules, as well as the optimization of the read-out scheme, are the results of an R&D program. Crystals with 40 cm in length were developed. The detector requirements and the achieved performance of the prototypes are presented. Future prospects for this technique are discussed.Comment: 32 pages, 14 figure

    Complement-Mediated Differential Immune Response of Human Macrophages to Sporothrix Species Through Interaction With Their Cell Wall Peptidorhamnomannans

    Get PDF
    Funding This work was supported by Fundação de Apoio à Pesquisa do Distrito Federal (FAP-DF)/CNPq, PRONEX grant ID: (FAP-DF, 0193.001.200/2016). VA is supported by the Centre Franco-Indien pour la Promotion de la Recherche Avancée (CEFIPRA) grant No. 5403-1 and ANR-DFG AfuINF grant. IG, VA, and CS were supported by the ANR-FUNHYDRO (ANR-16S-CE110020-01) grant. NG, GB and JW are supported by the Welcome Trust (102705, 097377, 101873, 215599 and 200208) and the Medical Research Council Centre for Medical Mycology (MR/N006364/2). Acknowledgments The authors acknowledge Dr. Lars Erwig, Dr. Jude Bain, and Dr. Kevin MacKenzie of University of Aberdeen for the scientific and technical support in the video microscopy experiments. LMLB was a research fellow of Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). We acknowledge Fundação Carlos Chagas Filho de Amparo a Pesquisa do estado do Rio de Janeiro (Faperj) and Pasteur-Roux-Cantarini postdoctoral fellowship for the research fellowships given to GWPN and SSWW, respectively.Peer reviewedPublisher PD
    corecore