135 research outputs found

    Desain dan Analisa Awal Struktur Rangka Manual Motorcycle Lift Dengan Menggunakan Software Ansys 17.0

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    Motorcycle lift, merupakan alat penunjang, yang dibutuhkan untuk mengurangi cedera otot akibat kegiatan perawatan dan perbaikan, dengan mengatur posisi tinggi rendahnya motor terhadap postur tubuh mekanik (montir). Walaupun motorcycle lift telah ada, tetapi alat tersebut menggunakan tenaga hidrolik atau pneumatik dengan listrik sebagai tenaga utama. Hal ini berpengaruh pada daerah yang tidak memiliki tenaga listrik. Selain itu pada studi ini, konstruksi motorcycle lift yang didesain menggunakan software Ansys 17.0. Dengan menggunakan software Ansys, analisa desain struktur lebih detail dan dapat melihat titik kritis lebih detail. Tujuan dari studi ini adalah mendesain dan menganalisa konstruksi manual motorcycle lift untuk daerah yang belum memiliki jalur listrik. Metode penelitian yang dilakukan adalah metode simulasi dengan software Ansys 17.0. Parameter yang digunakan adalah beban 3600 N, panjang alat 180 cm, lebar 78 cm, dan tinggi maksimum 60 cm. Material yang digunakan adalah baja konstruksi (karbon rendah). Bahan digunakan adalah baja konstruksi (baja karbon rendah). Analisa konstruksi terbagi atas 3 posisi ketinggian kritis, yaitu minimum ketinggian (120 mm), medium ketinggian (360 mm), dan maksimum ketinggian (600 mm). Tegangan dan regangan equivlen untuk masing-masing ketinggian dianalisa menggunakan Sofware Ansys 17.0 tersebut. Nilai maksimum terdapat pada daeran pin.The motorcycle lift is an equipment that is needed to reduce muscle injuries due to maintenance and repair activities by adjusting the height position of a motorbike to the mechanic's posture. Even though several motorcycle lifts have been produced, they use hydraulic or pneumatic with electricity as their primary power. This condition affects areas that do not have electricity. Also, in this study, the construction of the motorcycle lift is designed using Ansys 17.0 software. By using Ansys software, structural design analysis is more detailed, and the critical points are detailed. This study's aim is to design and analyze the manual construction of a motorcycle lift for areas that do not have electric lines. The research method was used is a simulation method with Ansys 17.0 software. The parameters used are 3600 N load, 180 cm tool length, 78 cm width, and 60 cm maximum height. The material used is construction steel (low carbon). The material used is construction steel (low carbon steel). Construction analysis was divided into 3 critical height positions, namely minimum height (120 mm), medium height (360 mm), and maximum height (600 mm). The equivalent stresses and strain for each height were analyzed using the Ansys 17.0 software. Maximum value were founded at pin

    Pengaruh Rasio Diameter sebagai Parameter Kinerja Aerodinamika Dual Rotor Counter-rotating Wind Turbine

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    Penggunaan energi alternatif yang ramah lingkungan (Green Energy) merupakan topik utama yang mulai banyak dibahas dewasa ini. Salah satu sumber energi terbarukan yaitu energi angin (turbin angin). Seiring dengan perkembangan teknologi, maka dikembangkan Counter Rotating Wind Turbine (CRWT). CRWT merupakan turbin angin dengan poros horisontal terdiri dari dua buah rotor yang putaran rotor saling berlawanan arah. Efisiensi konversi energi turbin angin dual rotor ini secara teoritis lebih baik dari pada rotor tunggal. Pada penelitian ini difokuskan pada CRWT dengan tipe propeler tiga blade menggunakan airfoil S826. Tujuan penelitian adalah untuk menganalisis melalui desain dan analisis rotor turbin (kajian rotor turbin) yang terdapat pada CRWT terutama pengaruh rasio diameter (D) antara rotor depan (D1) dan rotor belakang terhadap performa dari CRWT, dengan permodelan menggunakan program GAMBIT dan solver simulasi menggunakan program FLUENT CFD ANSYS.Hasil dari penelitian ini menunjukkan bahwa variasi yang dilakukan pada rasio diameter rotor memberikan pengaruh terhadap performance aerodinamika dari CRWT. Penggunaan rasio diameter D1/D2 = 1 menghasilkan torsi yang terbaik, sehingga daya dan efisiensi turbin juga semakin baik atau meningkat

    Pelatihan Perawatan Pompa Hidram untuk Kelompok Tani Utama Di Daerah Baumata

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    Dry land agriculture is a crop cultivation activity carried out in moderate to severe drought conditions during most of the growing season. As a result, special cultivation techniques, types of crops and farming systems are needed to enable sustainable production. The partner involved in the Program Kemitraan Masyarakat (PKM) is a farmer group called the main farmer group. The main farmer group is located in Baumata village, Taebenu sub-district, Kupang district. This farmer group has used appropriate technology in the form of a hydram pump. The Hydram Pump, which is located in Baumata village is a product of the LP2M through the Mechanical Engineering Study Program, Faculty of Science and Engineering in 2018and is still running and is still being used by farmer groups. Based on the survey and coordination of the implementation team to the location until December 2019, it was concluded that there was a need for field activities in the context of training activities for members of farmer groups on how to repair, maintain and deal with pump problems which decrease productivity and aspects of pump work functions accordingly with a description of the report of the members of the Farmer Group

    Attribution of space-time variability in global-ocean dissolved inorganic Carbon

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    The inventory and variability of oceanic dissolved inorganic carbon (DIC) is driven by the interplay of physical, chemical, and biological processes. Quantifying the spatiotemporal variability of these drivers is crucial for a mechanistic understanding of the ocean carbon sink and its future trajectory. Here, we use the Estimating the Circulation and Climate of the Ocean-Darwin ocean biogeochemistry state estimate to generate a global-ocean, data-constrained DIC budget and investigate how spatial and seasonal-to-interannual variability in three-dimensional circulation, air-sea CO2 flux, and biological processes have modulated the ocean sink for 1995–2018. Our results demonstrate substantial compensation between budget terms, resulting in distinct upper-ocean carbon regimes. For example, boundary current regions have strong contributions from vertical diffusion while equatorial regions exhibit compensation between upwelling and biological processes. When integrated across the full ocean depth, the 24-year DIC mass increase of 64 Pg C (2.7 Pg C year−1) primarily tracks the anthropogenic CO2 growth rate, with biological processes providing a small contribution of 2 (1.4 Pg C). In the upper 100 m, which stores roughly 13 (8.1 Pg C) of the global increase, we find that circulation provides the largest DIC gain (6.3 Pg C year−1) and biological processes are the largest loss (8.6 Pg C year−1). Interannual variability is dominated by vertical advection in equatorial regions, with the 1997–1998 El Niño-Southern Oscillation causing the largest year-to-year change in upper-ocean DIC (2.1 Pg C). Our results provide a novel, data-constrained framework for an improved mechanistic understanding of natural and anthropogenic perturbations to the ocean sink. © 2022. The Authors

    Structural changes during the switching transition of chalcogenide selector devices

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    Ovonic threshold switches are a favored choice for chalcogenide-based amorphous (a-) GeSex selector devices used in cross-point arrays of nonvolatile memories. Previous models of their nonlinear high-field conduction proposed a largely electronic-only switching mechanism, within a fixed density of electronic states. Here, we use a density functional molecular-dynamics supercell calculation to show that the high-current excited state configuration of a-GeSex has structural changes such as additional Ge-Ge bonds and overcoordinated Ge sites, giving lower effective mass, more delocalized conduction states, and a lower ON resistance.We acknowledge the funding from the EC H2020 project Phase change switch

    The response of the Antarctic Circumpolar Current to recent climate change

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    Observations show a significant intensification of the Southern Hemisphere westerlies, the prevailing winds between the latitudes of 30° and 60° S, over the past decades. A continuation of this intensification trend is projected by climate scenarios for the twenty-first century. The response of the Antarctic Circumpolar Current and the carbon sink in the Southern Ocean to changes in wind stress and surface buoyancy fluxes is under debate. Here we analyse the Argo network of profiling floats and historical oceanographic data to detect coherent hemispheric-scale warming and freshening trends that extend to depths of more than 1,000 m. The warming and freshening is partly related to changes in the properties of the water masses that make up the Antarctic Circumpolar Current, which are consistent with the anthropogenic changes in heat and freshwater fluxes suggested by climate models. However, we detect no increase in the tilt of the surfaces of equal density across the Antarctic Circumpolar Current, in contrast to coarse-resolution model studies. Our results imply that the transport in the Antarctic Circumpolar Current and meridional overturning in the Southern Ocean are insensitive to decadal changes in wind stress

    Long-term kidney function recovery and mortality after COVID-19-associated acute kidney injury: An international multi-centre observational cohort study

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    Background: While acute kidney injury (AKI) is a common complication in COVID-19, data on post-AKI kidney function recovery and the clinical factors associated with poor kidney function recovery is lacking. Methods: A retrospective multi-centre observational cohort study comprising 12,891 hospitalized patients aged 18 years or older with a diagnosis of SARS-CoV-2 infection confirmed by polymerase chain reaction from 1 January 2020 to 10 September 2020, and with at least one serum creatinine value 1–365 days prior to admission. Mortality and serum creatinine values were obtained up to 10 September 2021. Findings: Advanced age (HR 2.77, 95%CI 2.53–3.04, p < 0.0001), severe COVID-19 (HR 2.91, 95%CI 2.03–4.17, p < 0.0001), severe AKI (KDIGO stage 3: HR 4.22, 95%CI 3.55–5.00, p < 0.0001), and ischemic heart disease (HR 1.26, 95%CI 1.14–1.39, p < 0.0001) were associated with worse mortality outcomes. AKI severity (KDIGO stage 3: HR 0.41, 95%CI 0.37–0.46, p < 0.0001) was associated with worse kidney function recovery, whereas remdesivir use (HR 1.34, 95%CI 1.17–1.54, p < 0.0001) was associated with better kidney function recovery. In a subset of patients without chronic kidney disease, advanced age (HR 1.38, 95%CI 1.20–1.58, p < 0.0001), male sex (HR 1.67, 95%CI 1.45–1.93, p < 0.0001), severe AKI (KDIGO stage 3: HR 11.68, 95%CI 9.80–13.91, p < 0.0001), and hypertension (HR 1.22, 95%CI 1.10–1.36, p = 0.0002) were associated with post-AKI kidney function impairment. Furthermore, patients with COVID-19-associated AKI had significant and persistent elevations of baseline serum creatinine 125% or more at 180 days (RR 1.49, 95%CI 1.32–1.67) and 365 days (RR 1.54, 95%CI 1.21–1.96) compared to COVID-19 patients with no AKI. Interpretation: COVID-19-associated AKI was associated with higher mortality, and severe COVID-19-associated AKI was associated with worse long-term post-AKI kidney function recovery. Funding: Authors are supported by various funders, with full details stated in the acknowledgement section
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