381 research outputs found

    PENGARUH PERUBAHAN BEBAN PADA GI PAYAKUMBUH TERHADAP SUHU KONEKTOR UTAMA

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    Hotspot adalah salah satu fenomena yang terjadi pada peralatan listrik. Ini juga terjadi pada gardu tegangan tinggi, terutama pada konduktor-konektor antara peralatan utama di gardu induk. Hot spot dapat menyebabkan suhu konektor naik sehingga pada titik tertentu, dapat merusak koneksi dan menyebabkan masalah dengan distribusi listrik. Perubahan suhu pada konektor tidak dapat dipisahkan dari perubahan arus yang terjadi pada koneksi.. Tesis ini membuat pendekatan untuk memodelkan hubungan antara arus yang mengalir di konduktor dan suhu di koneksi konduktor-konektor. Dengan model pendekatan ini, prediksi dibuat untuk memperkirakan perubahan suhu yang terjadi berdasarkan data yang dimiliki sebelumnya. Pembacaan arus saat ini didasarkan pada meter yang dipasang pada sistem, sedangkan pembacaan suhu dilakukan menggunakan peralatan thermovisi. Perkiraan perubahan beban atau arus dengan beberapa skenario dilakukan menggunakan perangkat lunak DigSilent. Sedangkan perubahan suhu terhadap arus dapat diperdiksi menggunakan regresi linear menggunakan dua variabel dengan persamaan T (°C) = a . I(A) + b Hasil dapat digunakan sebagai referensi untuk perubahan suhu yang terjadi pada koneksi, sebagai salah satu cara analisis pemeliharaan prediktif dan untuk memperkirakan kemampuan termal dari peralatan yang harus dipasang

    Microbiome–microglia connections via the gut–brain axis

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    Microglia, the resident immune cells in the brain, are essential for modulating neurogenesis, influencing synaptic remodeling, and regulating neuroinflammation by surveying the brain microenvironment. Microglial dysfunction has been implicated in the onset and progression of several neurodevelopmental and neurodegenerative diseases; however, the multitude of factors and signals influencing microglial activity have not been fully elucidated. Microglia not only respond to local signals within the brain but also receive input from the periphery, including the gastrointestinal (GI) tract. Recent preclinical findings suggest that the gut microbiome plays a pivotal role in regulating microglial maturation and function, and altered microbial community composition has been reported in neurological disorders with known microglial involvement in humans. Collectively, these findings suggest that bidirectional crosstalk between the gut and the brain may influence disease pathogenesis. Herein, we discuss recent studies showing a role for the gut microbiome in modulating microglial development and function in homeostatic and disease conditions and highlight possible future research to develop novel microbial treatments for disorders of the brain

    Investigating the Success and the Advantages of Using ERP System in KSA Context

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    Enterprise resource planning (ERP) is an important innovation, affecting the business world by generating improvements both tangible and intangible in large companies and small and medium enterprises (SME). This study focuses on the determinants of success and the advantages of the adoption of this technology. To address these points, a comprehensive literature survey was carried out in order to formulate an original research model for ERP success evaluation and provide a prospect for IT infrastructure and integration. The model, thus suggested and taken within the Kingdom of Saudi Arabia (KSA) context, examines in a systematic approach the relation between the ERP acceptance determinants, the effects of the process of ERP systems diffusion, and the impacts expected on organizational performance. Obtained results underline two key determinants of ERP projects success: First, the preponderance of information control and the improvement in the use of competences. The second factor is the quality of team projects, the definition of team’s mission, training, business processes reengineering, user acceptance, top management support and the selection of the ERP solution

    Anisotropic electrical and thermal magnetotransport in the magnetic semimetal GdPtBi

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    The half-Heusler rare-earth intermetallic GdPtBi has recently gained attention due to peculiar magnetotransport phenomena that have been associated with the possible existence of Weyl fermions, thought to arise from the crossings of spin-split conduction and valence bands. On the other hand, similar magnetotransport phenomena observed in other rare-earth intermetallics have often been attributed to the interaction of itinerant carriers with localized magnetic moments stemming from the 4f4f-shell of the rare-earth element. In order to address the origin of the magnetotransport phenomena in GdPtBi, we performed a comprehensive study of the magnetization, electrical and thermal magnetoresistivity on two single-crystalline GdPtBi samples. In addition, we performed an analysis of the Fermi surface via Shubnikov-de Haas oscillations in one of the samples and compared the results to \emph{ab initio} band structure calculations. Our findings indicate that the electrical and thermal magnetotransport in GdPtBi cannot be solely explained by Weyl physics and is strongly influenced by the interaction of both itinerant charge carriers and phonons with localized magnetic Gd-ions and possibly also paramagnetic impurities.Comment: 11 figure

    Maintaining multipotent trunk neural crest stem cells as self-renewing crestospheres

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    Neural crest cells have broad migratory and differentiative ability that differs according to their axial level of origin. However, their transient nature has limited understanding of their stem cell and self-renewal properties. While an in vitro culture method has made it possible to maintain cranial neural crest cells as self-renewing multipotent crestospheres (Kerosuo et al., 2015), these same conditions failed to preserve trunk neural crest in a stem-like state. Here we optimize culture conditions for maintenance of avian trunk crestospheres, comprised of both neural crest stem and progenitor cells. Our trunk-derived crestospheres are multipotent and display self-renewal capacity over several weeks. Trunk crestospheres display elevated expression of neural crest cell markers as compared to those characteristic of ventrolateral neural tube or mesodermal fates. Moreover, trunk crestospheres express increased levels of trunk neural crest-enriched markers as compared to cranial crestospheres. Finally, we use lentiviral transduction as a tool to manipulate gene expression in trunk crestospheres. Taken together, this method enables long-term in vitro maintenance and manipulation of multipotent trunk neural crest cells in a premigratory stem or early progenitor state. Trunk crestospheres are a valuable resource for probing mechanisms underlying neural crest sternness and lineage decisions as well as accompanying diseases.Peer reviewe

    Multidrug-Resistant Pseudomonas aeruginosa Infection in a Child with Cystic Fibrosis

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    ABSTRACT We describe a pediatric cystic fibrosis patient who developed a pulmonary exacerbation due to two multidrug-resistant (MDR) Pseudomonas aeruginosa isolates. In addition to these MDR organisms, the case was further complicated by β-lactam allergy. Despite the MDR phenotype, both isolates were susceptible to an antimicrobial combination

    Hands on MINT: Praxisphasen in der Studieneingangsphase von MINT-Fächern

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    Technische und naturwissenschaftliche Studiengänge an Hochschulen - die sogenannten MINT-Fächer - bieten Absolventen und Absolventinnen gute Chancen für eine erfolgreiche Berufslaufbahn. In diesen anspruchsvollen Studiengängen einen Abschluss zu erhalten, ist jedoch nicht leicht: Vor Vor- und Zwischenprüfungen fallen oft mehr als 50 Prozent der Studienanfänger/-innen endgültig durch. Ziel der Hochschulen muss es daher sein, die Anzahl der Studienabbrecher/-innen zu reduzieren. Zwei mögliche Zielrichtungen für Maßnahmen sind somit die Motivation der Studierenden und die Vermittlung von Arbeits- und Lerntechniken

    Scaling-up co-trimoxazole prophylaxis in HIV-exposed and HIV-infected children in high HIV-prevalence countries.

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    Co-trimoxazole (trimethoprim-sulfamethoxazole) is a widely available antibiotic that substantially reduces HIV-related morbidity and mortality in both adults and children. Prophylaxis with co-trimoxazole is a recommended intervention of proven benefit that could serve not only as an initial step towards improving paediatric care in young children with limited access to antiretroviral treatment, but also as an important complement to antiretroviral therapy in resource-limited settings. Despite co-trimoxazole's known clinical benefits, the potential operational benefits, and favourable recommendations by WHO, UNAIDS, and UNICEF, its routine use in developing countries--particularly sub-Saharan Africa--has remained limited. Out of an estimated 4 million children in need of co-trimoxazole prophylaxis (HIV-exposed and HIV-infected), only 4% are currently receiving this intervention. We discuss some of the major barriers preventing the scale-up of co-trimoxazole prophylaxis for children in countries with a high prevalence of HIV and propose specific actions required to tackle these challenges

    Equilibrium, kinetic and thermodynamic studies on the removal of U(VI) by low cost agricultural waste

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    In this research, biosorption efficiency of different agro-wastes were evaluated with rice husk showing maximum biosorption capacity among the selected biosorbents. Optimization of native, SDS-treated and immobilized rice husk adsorption parameters including pH, biosorbent amount, contact time, initial U(VI) concentration and temperature for maximum U(VI) removal was investigated. Maximum biosorption capacity for native (29.56 mg g-1) and immobilized biomass (17.59 mg g-1) was observed at pH 4 while SDS-treated biomass showed maximum removal (28.08 mg g-1) at pH 5. The Langmuir sorption isotherm model correlated best with the U(IV) biosorption equilibrium data for the 10-100 mg L-1 concentration range. The kinetics of the reaction followed pseudo-second order kinetic model. Thermodynamic parameters like free energy (ΔG°) and enthalpy (ΔH°) confirmed the spontaneous and exothermic nature of the process. Experiments to determine the regeneration capacity of the selected biosorbents and the effect of competing metal ions on biosorption capacity were also conducted. The biomass was characterised using scanning electron microscopy, surface area analysis, Fourier transformed infra-red spectroscopy and thermal gravimetric analysis. The study proved that rice husk has potential to treat uranium in wastewater
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