3,305 research outputs found

    Via and embedded resistor production in low cost lithographically printed substrates

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    Lithographic printing of silver based conductive inks to form circuit tracking provides a very low cost, environmentally friendly method of production. It allows circuits with line widths down to 100 μm and a sheet resistance of 0.3 Ω per square to be produced at rates of up to 10000 impressions per hour. The process makes use of low capital cost equipment and has low set up costs. To date, an equally cost effective method of manufacturing vias in these circuits has not been developed. This paper proposes two new techniques for via production which are compatible with the rest of the manufacturing process. In the first technique, suitably profiled holes are laser drilled for subsequent filling as part of the lithographic printing. In the second technique laser energy is used to melt the substrate material so that it is able to mix with the conductive ink and so form a conductive path. The paper describes the proposed production techniques and discusses the factors affecting each method and in particular the substrate properties affecting production. The substrate materials considered in detail are Glossart and Teslin. The optical absorption and ablation characteristics of these materials for excimer and CO2 lasers are reported, as are the thermal diffusivities

    Increasing Short-Stay Unplanned Hospital Admissions among Children in England; Time Trends Analysis '97-'06

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    BACKGROUND: Timely care by general practitioners in the community keeps children out of hospital and provides better continuity of care. Yet in the UK, access to primary care has diminished since 2004 when changes in general practitioners' contracts enabled them to 'opt out' of providing out-of-hours care and since then unplanned pediatric hospital admission rates have escalated, particularly through emergency departments. We hypothesised that any increase in isolated short stay admissions for childhood illness might reflect failure to manage these cases in the community over a 10 year period spanning these changes. METHODS AND FINDINGS: We conducted a population based time trends study of major causes of hospital admission in children 2 days. By 2006, 67.3% of all unplanned admissions were isolated short stays <2 days. The increases in admission rates were greater for common non-infectious than infectious causes of admissions. CONCLUSIONS: Short stay unplanned hospital admission rates in young children in England have increased substantially in recent years and are not accounted for by reductions in length of in-hospital stay. The majority are isolated short stay admissions for minor illness episodes that could be better managed by primary care in the community and may be evidence of a failure of primary care services

    Extracellular Matrix Aggregates from Differentiating Embryoid Bodies as a Scaffold to Support ESC Proliferation and Differentiation

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    Embryonic stem cells (ESCs) have emerged as potential cell sources for tissue engineering and regeneration owing to its virtually unlimited replicative capacity and the potential to differentiate into a variety of cell types. Current differentiation strategies primarily involve various growth factor/inducer/repressor concoctions with less emphasis on the substrate. Developing biomaterials to promote stem cell proliferation and differentiation could aid in the realization of this goal. Extracellular matrix (ECM) components are important physiological regulators, and can provide cues to direct ESC expansion and differentiation. ECM undergoes constant remodeling with surrounding cells to accommodate specific developmental event. In this study, using ESC derived aggregates called embryoid bodies (EB) as a model, we characterized the biological nature of ECM in EB after exposure to different treatments: spontaneously differentiated and retinoic acid treated (denoted as SPT and RA, respectively). Next, we extracted this treatment-specific ECM by detergent decellularization methods (Triton X-100, DOC and SDS are compared). The resulting EB ECM scaffolds were seeded with undifferentiated ESCs using a novel cell seeding strategy, and the behavior of ESCs was studied. Our results showed that the optimized protocol efficiently removes cells while retaining crucial ECM and biochemical components. Decellularized ECM from SPT EB gave rise to a more favorable microenvironment for promoting ESC attachment, proliferation, and early differentiation, compared to native EB and decellularized ECM from RA EB. These findings suggest that various treatment conditions allow the formulation of unique ESC-ECM derived scaffolds to enhance ESC bioactivities, including proliferation and differentiation for tissue regeneration applications. © 2013 Goh et al

    Sur les fonctions de Sturm

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    Analisis Usahatani Jagung dan Kontribusinya Terhadap Pendapatan Keluarga Petani di Desa Bayu Bagasan, Kecamatan Tanah Jawa, Kabupaten Simalungun

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    Tujuan penelitian untuk mengetahui biaya produksi yang dikeluarkan usahatani jagung per hektar per musim tanam, pendapatan petani per ha per musim tanam dan kontribusi bersih usahatani terhadap pendapatan keluarga. Data dianalisis data satu musim tanam pada musim Tanam I ( Januari-April) 2021. Populasi penelitian adalah petani yang mengusahakan usahatani jagung. Metode penentuan sampel dengan metode sensus (sampel jenuh) yaitu semua populasi menjadi sampel penelitian sebanyak 33 KK. Hasil penelitian menunjukkan&nbsp; rata-rata biaya produksi terbesar untuk komponen tenaga kerja, rata-rata pendapatan bersih cukup menguntungkan untuk meningkatkan pendapatan petani, dan kontribusi pendapatan petani jagung terhadap total pendapatan keluarga di desa penelitian tergolong rendah

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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