153 research outputs found

    Fatigue resistance of low pressure nitrided Cr-Mo low alloy steels

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    Fatigue resistance of steel parts can be improved by nitriding, the more the deeper is the layer affected by nitrogen diffusion, as stated by the Lessells-Firrao law. Low-pressure nitriding has been applied to wheel's hubs fabricated with a quenched and tempered Cr-Mo low alloy steel. N diffusion depths have been compared to similar results obtained with the same type of automotive parts subjected to classical gas nitriding. 12 h total low-pressure treatment time provided an almost 100% increase of hardened depth over 40 h gas nitrided parts. Both treatments allowed reaching an adequate fatigue life, whereas induction hardened parts did not. X-ray diffraction analysis provided phase constitution of top converted layers in both nitriding cases. A rationale based on the effect of early treatment stage top layer formation has been developed

    Assessment of the composition of Silicon-Rich Oxide films for photovoltaic applications by optical techniques

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    Abstract The deposition of sub-stoichiometric silicon rich oxide (SRO) is the first step to obtain well ordered silicon Quantum Dots (QDs) in a dielectric matrix. This structure is used also for third generation photovoltaic devices operating in a tandem architecture. A precise control and assessment of the stoichiometry of these films is crucial to tune the electrical and optical properties of the device. In this paper we discuss two optical techniques to assess the composition of such films and we compare their results

    PGC-1α induced browning promotes involution and inhibits lactation in mammary glands

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    The PPARγ coactivator 1α (PGC-1α) is a transcriptional regulator of mitochondrial biogenesis and oxidative metabolism. Recent studies have highlighted a fundamental role of PGC-1α in promoting breast cancer progression and metastasis, but the physiological role of this coactivator in the development of mammary glands is still unknown. First, we show that PGC-1α is highly expressed during puberty and involution, but nearly disappeared in pregnancy and lactation. Then, taking advantage of a newly generated transgenic mouse model with a stable and specific overexpression of PGC-1α in mammary glands, we demonstrate that the re-expression of this coactivator during the lactation stage leads to a precocious regression of the mammary glands. Thus, we propose that PGC-1α action is non-essential during pregnancy and lactation, whereas it is indispensable during involution. The rapid preadipocyte–adipocyte transition, together with an increased rate of apoptosis promotes a premature mammary glands involution that cause lactation defects and pup growth retardation. Overall, we provide new insights in the comprehension of female reproductive cycles and lactation deficiency, thus opening new roads for mothers that cannot breastfeed

    Pengendalian Frekuensi Dengan Menggunakan Kontrol Fuzzy Prediktif Pada Simulator Plant Turbin-Generator Pada PLTU

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    Sistem pembangkit dirasakan sangat perlu guna memenuhi kebutuhan tenaga listrik yang semakin meningkat, kestabilan sangat dibutuhkan pada proses pembangkit sehingga sistem pengendalian digunakan untuk menjaga variabel proses tersebut tetap stabil. Salah satunya adalah dengan melakukan pengendali frekuensi pada tubin-generator suatu pembangkit listik, contohnya PLTU (Pembangkit Listrik Tenaga Uap). Frekuensi dari turbin uap harus dijaga kestabilannya agar keluaran daya listrik di generator berjalan dengan baik. Fluktuasi frekuensi adalah salah satu kendala penyampaian daya listrik ke beban, juga waktu kembali yang tidak segera ke kondisi normal akan mengakibatkan kerusakan pada sistem seperti patahnya poros turbin-generator dan kemungkinan terjadi gangguan pada jaringan listrik, sehingga perlu dilakukan pengaturan laju aliran uap yang masuk ke turbin. Kontroler yang digunakan untuk menjaga Perubahan frekuensi adalah kontrol fuzzy prediktif, dengan penambahan gain K1 pada kontrol fuzzy prediktif sebesar 42.35 yang bekerja secara sucsessive kontroler ini dapat mengurangi error sebesar 1,04% jika sistem hanya menggunakan kontroler fuzzy pada saat terjadi Perubahan beban

    Introduction and methods of the evidence-based guidelines for the diagnosis and management of autism spectrum disorder by the Italian National Institute of Health

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    BACKGROUND: Autism Spectrum Disorder (ASD) is a neuro-developmental disorder that affects communication and behavior with a prevalence of approximately 1% worldwide. Health outcomes of interventions for ASD are largely Participant Reported Outcomes (PROs). Specific guidelines can help support the best care for people with ASD to optimize these health outcomes but they have to adhere to standards for their development to be trustworthy. OBJECTIVE: The goal of this article is to describe the new methodological standards of the Italian National Institute of Health and novel aspects of this guideline development process. This article will serve as a reference standard for future guideline development in the Italian setting. METHODS: We applied the new standards of the Italian National Institute of Health to the two guidelines on diagnosis and management of children/adolescents and adults with ASD, with a focus on the scoping, panel composition, management of conflict of interest, generation and prioritization of research questions, early stakeholders' involvement, and PROs. Recommendations are based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence-to-Decision frameworks. RESULTS: Following a public application process, the ISS established two multidisciplinary panels including people with ASD and/or their caregivers. Seventy-nine research questions were identified as potentially relevant for the guideline on children and adolescents with ASD and 31 for the one on adults with ASD. Questions deemed to have the highest priority were selected for inclusion in the guidelines. Other stakeholders valued their early involvement in the process which will largely focus on PROs. The panels then successfully piloted the development of recommendations using the methodological standards and process set by the ISS with a focus on PROs. CONCLUSIONS: In this article, we describe the development of practice guidelines that focus on PROs for the diagnosis and management of ASD based on novel methods for question prioritization and stakeholder involvement. The recommendations allow for the adoption or adaptation to international settings

    The effect of seasoning with herbs on the nutritional, safety and sensory properties of reduced-sodium fermented Cobrançosa cv. table olives

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    This study aimed at evaluating the effectiveness of seasoning Cobrancosa table olives in a brine with aromatic ingredients, in order to mask the bitter taste given by KCl when added to reduced-sodium fermentation brines. Olives were fermented in two different salt combinations: Brine A, containing 8% NaCl and, Brine B, a reduced-sodium brine, containing 4% NaCl + 4% KCl. After the fermentation the olives were immersed in seasoning brines with NaCl (2%) and the aromatic herbs (thyme, oregano and calamintha), garlic and lemon. At the end of the fermentation and two weeks after seasoning, the physicochemical, nutritional, organoleptic, and microbiological parameters, were determined. The olives fermented in the reduced-sodium brines had half the sodium concentration, higher potassium and calcium content, a lower caloric level, but were considered, by a sensorial panel, more bitter than olives fermented in NaCl brine. Seasoned table olives, previously fermented in Brine A and Brine B, had no significant differences in the amounts of protein (1.23% or 1.11%), carbohydrates (1.0% or 0.66%), fat (20.0% or 20.5%) and dietary fiber (3.4% or 3.6%). Regarding mineral contents, the sodium-reduced fermented olives, presented one third of sodium, seven times more potassium and three times more calcium than the traditional olives fermented in 8% NaCl. Additionally, according to the panelists' evaluation, seasoning the olives fermented in 4% NaCl + 4% KCl, resulted in a decrease in bitterness and an improvement in the overall evaluation and flavor. Escherichia coli and Salmonella were not found in the olives produced.info:eu-repo/semantics/publishedVersio

    Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

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    High material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. This paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 °C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition, examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. This covers a broad field of research from fundamental to technological investigations of various types of materials and components
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