1,518 research outputs found

    Bayesian Analysis of Simple Random Densities

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    A tractable nonparametric prior over densities is introduced which is closed under sampling and exhibits proper posterior asymptotics.Comment: 19 pages; 6 figure

    Predictive analysis of microarray data

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    Microarray gene expression data are analyzed by means of a Bayesian nonparametric model, with emphasis on prediction of future observables, yielding a method for selection of differentially expressed genes and a classifier

    Chemical changes of heat treated pine and eucalypt wood monitored by FTIR

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    A hardwood, Eucalyptus globulus Labill., and a softwood Pinus pinaster Aiton., were heat treated at temperatures between 170 and 210ºC in an oven and in an autoclave. The samples were pre-extracted with dichloromethane, ethanol and water and ground prior to Fourier Transform Infrared (FTIR) spectroscopic analysis. The heat treatment caused significant changes in the chemical composition and structure of wood, in lignin and polysaccharides. Hemicelluloses were the first to degrade as proved by the initial decrease of the 1730 cm-1 peak due to the breaking of acetyl groups in xylan. Hardwood lignin changed more than softwood lignin, with a shift of maximum absorption from 1505 cm-1 to approximately 1512 cm-1 due to decrease of methoxyl groups, loss of syringyl units or breaking of aliphatic side-chains. The macromolecular structure becomes more condensed and there is a clear increase of non-conjugated (1740 cm-1) in relation to conjugated groups (1650 cm-1). However, the changes induced by the thermal treatment are difficult to monitor by FTIR spectroscopy due to the different chemical reactions occurring simultaneously.info:eu-repo/semantics/publishedVersio

    Industrial multimedia put into practice

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    Recent developments in the factory floor technologies together with the widespread use of TCP/IP and the Internet are increasing the eagerness to support a new wide class of devices and applications, such as industrial multimedia applications, in factory floor networks. This paper presents how this new field of applications can be put into practice, via a manufacturing cell field trial being implemented. This manufacturing automation field trial involves the use of traditional distributed computer control systems and 'factory-floor-oriented' multimedia (e.g. voice, video) application services

    A time of flight method to measure the speed of sound using a stereo sound card

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    We present an inexpensive apparatus for measuring the speed of sound, with a time of flight method, using a computer with a stereo sound board. Students measure the speed of sound by timing the delay between the arrivals of a pulse to two microphones placed at different distances from the source. It can serve as a very effective demonstration, providing a quick measurement of the speed of sound in air; we have used it with great success in Open Days in our Department. It can also be used for a full fledged laboratory determination of the speed of sound in air.Comment: Accepted for publication in The Physics Teache

    Quality Assessment of Laser Welding Dual Phase Steels

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    Since non-conforming parts create waste for industry, generating undesirable costs, it is necessary to set up quality plans that not only guarantee product conformity but also cut the root causes of welding defects by developing the concept of quality at origin. Due to their increasing use in automotive industry, dual phase (DP) steels have been the chosen material for this study. A quality plan for welding DP steel components by laser was developed. This plan is divided into three parts: pre-welding, during and post-welding. A quality assessment regarding mechanical properties, such as hardness, microstructure and tensile strength, was also performed. It was revealed that DP steel does not present considerable weldability problems, except for the usual softening of the heat affected zone (HAZ) and the growth of martensite in the fusion zone (FZ), and the best analysis techniques to avoid failures in these steels are finite element method (FEM), visual techniques during welding procedure and digital image correlation (DIC) for post-weld analysis.The present work was done and funded under the scope of projects UIDB/00481/2020 and UIDP/00481/2020—FCT—Fundação para a Ciencia e a Tecnologia; and CENTRO-01-0145-FEDER- 022083—Centro Portugal Regional Operational Programme (Centro2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. LAETA/INEGI/CETRIB is acknowledge due to the support provided in all research activities.info:eu-repo/semantics/publishedVersio

    Improving the Mechanical Strength of Ductile Cast Iron Welded Joints Using Different Heat Treatments

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    The main advantage of welding cast iron is to recover parts by repairing defects induced by casting processes (porosities, etc.), before they enter their working cycle, as well as repair cracks or fractures when already in service. This method contributes to decreased foundry industrial waste and avoids the additional energy costs of their immediate recycling. Therefore, it is necessary to have a welded joint with similar or better characteristics than the parent material. The major problem of welding cast iron is that this material has a very high content of carbon in comparison to steel (≈3%). Therefore, when it is heated by the very high temperatures from arc welding and during its process of solidification, very hard and brittle phases originate, known as ledeburite and martensite, and appear in the partially melted zone and in the heat-affected zone. Eventually, this problem can be solved by implementing heat treatments such as preheat or post weld heat treatments under specific parameters. Therefore, in this study, the aim is to collect data about the effects of heat treatments performed at different temperatures on welded joints of high strength ductile cast iron (SiboDur® 450), and to evaluate the effects of heat treatments performed at diverse temperatures on welded joints of this type of material, using Shield Metal Arc Welding and nickel electrodes. Mechanical strength, hardness, and microstructure were analyzed, showing that the best mechanical strength in the joint (380 MPa) was obtained using two passes of E C Ni-Cl (ISO EN 1071:2015) filler metal and post weld heat treatments (PWHT) of 400 °C for two hours.info:eu-repo/semantics/publishedVersio

    EXPERIMENTAL ANALYSIS OF A HEAT PUMP ASSISTED RECUPERATIVE AIR DEHUMIDIFIER

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    This paper describes the experimental analysis of a heat pump assisted recuperative air dehumidifier. The system consisted of an air-to-air vapor compression heat pump, coupled to the air ducting. Dehumidification was generated by reduction of the air temperature through the evaporator below the dew point, and thus promoting the condensation of the water vapor. Moist air was then warmed up in the condenser, resulting in a lowtemperature low-humidity air stream. Low energy consumption values are achieved in such systems as the latent heat of the water vapor acts as the heat pump own heat source. Occasionally, the compressor heat is also recoverable. The innovative feature of the present analysis was the introduction of an air-to-air plate recuperator, to further promote dehumidification, yet at the expense of greater compressor energy consumption. An experimental apparatus was constructed to perform comparative tests of the dehumidifier operating with and without the recuperator. A closed air circuit was employed, with the air mass flow rate as the controlling parameter of the experiment. Tests were also carried out with an open circuit

    Quality of life in Amazonian women during cervical cancer treatment: the moderating role of spirituality

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    This study aimed to examine the contribution of psychological variables to quality of life (QoL) of Amazonian women and to analyze the moderating role of spirituality in the relationship between psychological morbidity and Qol and between illness perception and QoL. This cross-sectional study included 119 women undergoing treatment for cervical cancer (CC). The Pearson correlation test was used to evaluate the relationship between sociodemographic, clinical, and psychological variables. To test how psychological morbidity, illness perception, and spirituality contribute to QoL, a path analysis was performed and to test the moreating role of spirituality, a moderation analysis was conducted. The results revealed that the presence of symptoms, high psychological morbidity, negative body image, and threatening illness perception were predictors of lower QoL. Spirituality moderated the relationship between psychological morbidity and QoL, and between illness perception and QoL. The moderating role of spirituality emphasizes its role as a coping strategy and should be included in cancer treatment. Interventions should target psychological morbidity, threatening illness perception, and address women’s concerns with body image and sexual concerns. CC treatment should include interprofessional healthcare teams addressing the biological and psychosocial factors of Amazonian women. As a result of this study a mobile application to monitor women’s health, adapted to cultural and social characteristics, was created.This study was conducted at the Psychology Research Centre (PSI/01662), School of Psychology, University of Minho, supported by the Foundation for Science and Technology (FCT) through the Portuguese State Budget (Ref: UIDB/PSI/01662/2020)
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