1,523 research outputs found

    Lunar subsurface architecture enhanced by artificial biosphere concepts

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    The integration of artificial biosphere technology with subselene architecture can create a life-enhancing, productive habitat that is safe from solar radiation and extreme temperature fluctuations while maximizing resources brought from Earth and derived from lunar regolith. In the short term, the resulting biotectural (biosphere and architectural) designs will not only make the structures more habitable, productive, and manageable, but will ultimately provide the self-sufficiency factors necessary for the mature lunar settlement. From a long-term perspective, this biotecture approach to astronautics and extraterrestrial development (1) helps reduce mass lift requirements, (2) contributes to habitat self-sufficiency, and (3) actualizes at least one philosophy of solar system exploration, which is to exploit nonterrestrial resources in an effort to conserve our natural resources on this planet

    Parental support for physical activity in schoolchildren and its influence on nutritional status and fitness = Apoyo parental para realizar actividad física en escolares de 6 años de edad: influencia sobre el estado nutricional y fitness

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    Introduction: Parents are key models for transmitting and teaching healthy lifestyle habits to their children. Our objective was to determine the influence of the economic and motivational support, and parental involvement in their children physical activity (PA) and its relationship with nutritio nal status and cardiorespiratory fitness. Subjects and Method: Cross-sectional study which included 70 six-year-old schoolchildren. Parents completed the “The Parental Influence on Physical Activity Scale” questionnaire. Anthropometric variables were measured according to the Chilean Ministerial Technical Standard for the supervision of children from 0 to 9 years old; PA intensity was measured with triaxial accelerometers GT3X and the VO2max estimation was performed using the Navette Course test. Results: The average body mass index was 17.9 ± 2.9 kg/m2, the obesity prevalence and VO2max were 57.1%, and 38.05 ± 16.9 ml/kg/min, respectively. Moderate PA during the physical education (PE) class was significantly higher in boys compared to girls (p < 0.006). The economic and motivational support of the parents did not significantly influence the body weight of the children, BMI, waist circumference, PA intensity, and VO2max. Children supported by their parent showed significant differences with moderate PA performed in PE compared to those who were not suppor ted by parents (p = 0.023). Conclusions: Parental support of their children in performing physical activity influences the levels of moderate PA that they do during PE classes. This type of study should be continued and the PA should be measured daily

    Control of the deposition ratio of Bi2Te3 and Sb2Te3 in a vacuum evaporator for fabrication of Peltier elements

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    This article reports the main problem and the corresponding solution of the co-evaporation of Bi2Te3 and Sb2Te3 films for the fabrication of Peltier elements. This main problem consists in the control of the deposition rates of the two elements: Bi or Sb and Te, which have very different vapor pressures. The control of the deposition ratio was achieved by means of a PID controller, which permitted the fabrication of thin-film Peltier elements that produce a temperature gradient in the order of 2C between their hot and cold junctions, when measured at free air conditions.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/18142/2004.Agencia de Inovação (MPYROM)

    SGML documents : where does quality go?

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    Quality control in electronic publications should be one of the major concerns of everyone who is managing a project. Big projects, like digital libraries, try to gather information from a series of different sources: libraries, museums, universities, and other scientific or cultural organizations. Collecting and treating information from several different sources raises very interesting problems, one being the assurance of quality. Quality in electronic publications can be reflected in several forms, from the visual aspects of the interface, to linguistic and literary aspects, to the correctness of data. With SGML we can solve part of the problem, structural/syntactic correctness. SGML provides a nice way to specify the structure of documents keeping a complete separation between structure (syntax) and typesetting. Today there are lots of editors and environments that can assist the user producing well-formed and valid SGML documents (validating their structure). However, current software still gives the user too much freedom. The user has full control of the data being introduced, creating a margin for errors. In this context there are situations where pre-conditions over the information being introduced should be enforced in order to prevent the user from introducing erroneous data; we shall call this process data semantics validation. The idea is to constrain the values of some structural elements of a document according to its final purpose. This way the user (who writes the documents according to that DTD) will not have full control of his data; he will be forced to obey certain domain range limitations or certain information relationships. SGML does not have the necessary constructs to implement this extra validation task. In this paper we will present and discuss ways of associating a constraint language with the SGML model. We will present the steps towards the implementation of that language. In the end, we present a new SGML authoring and processing model which has an extra validation task: semantic validation. Along the paper we will show some case studies that could have their quality improved with this new working scheme

    Matrix Assisted Formation of Ferrihydrite Nanoparticles in a Siloxane/Poly(Oxyethylene) Nanohybrid

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    Matrix-assisted formation of ferrihydrite, an iron oxide hydroxide analogue of the protein ferritin-core, in a sol-gel derived organic-inorganic hybrid is reported. The hybrid network (named di-ureasil) is composed of poly(oxyethylene) chains of different average polymer molecular weights grafted to siloxane domains by means of urea cross-linkages and accommodates ferrihydrite nanoparticles. Magnetic measurements, Fourier transform infrared and nuclear magnetic resonance spectroscopy reveal that the controlled modification of the polymer molecular weight allows the fine-tuning of the ability of the hybrid matrix to assist and promote iron coordination at the organic-inorganic interface and subsequent nucleation and growth of the ferrihydrite nanoparticles whose core size (2-4 nm) is tuned by the amount of iron incorporated. The polymer chain length, its arrangement and crystallinity, are key factors on the anchoring and formation of the ferrihydrite particles.Comment: 7 pages, 6 figures. To be published in J. Mater. Che

    On-chip array of thermoelectric peltier microcoolers

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    This article reports on the theoretical modelling, the Finite Element Modelling (FEM) simulation, the fabrication process and preliminary results of the first on-chip thermoelectric microcooler array (64 pixels arranged in a 8×8 array), with each pixel independently controlled. This microcooler array uses co-evaporated V–VI compounds of Bi2Te3 and Sb2Te3 as thermoelectric layers, and can be fabricated using planar thin-film technology, lithography and wet etching, on top of a silicon wafer where the CMOS electronic circuits were previously made

    Misconceptions of Synthetic Biology: Lessons from an Interdisciplinary Summer School

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    In 2014, an international group of scholars from various fields analysed the "societal dimensions" of synthetic biology in an interdisciplinary summer school. Here, we report and discuss the biologists' observations on the general perception of synthetic biology by non-biologists who took part in this event. Most attendees mainly associated synthetic biology with contributions from the best-known public figures of the field, rarely mentioning other scientists. Media extrapolations of those contributions appeared to have created unrealistic expectations and irrelevant fears that were widely disconnected from the current research in synthetic biology. Another observation was that when debating developments in synthetic biology, semantics strongly mattered: depending on the terms used to present an application of synthetic biology, attendees reacted in radically different ways. For example, using the term "GMOs" (genetically modified organisms) rather than the term "genetic engineering" led to very different reactions. Stimulating debates also happened with participants having unanticipated points of view, for instance biocentrist ethicists who argued that engineered microbes should not be used for human purposes. Another communication challenge emerged from the connotations and inaccuracies surrounding the word "life", which impaired constructive debates, thus leading to misconceptions about the abilities of scientists to engineer or even create living organisms. Finally, it appeared that synthetic biologists tend to overestimate the knowledge of non-biologists, further affecting communication. The motivation and ability of synthetic biologists to communicate their work outside their research field needs to be fostered, notably towards policymakers who need a more accurate and technical understanding of the field to make informed decisions. Interdisciplinary events gathering scholars working in and around synthetic biology are an effective tool in addressing those issues
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