6,996 research outputs found
Pemeliharaan Mesin Hydraulic Shear Menggunakan Pendekatan Reliability Centered Maintenance dan Manajemen Suku Cadang
Production equipment that has a high operating time becomes a vital aspect in supporting the operational system, and its maintenance becomes a critical point that must be planned. This research discusses maintenance policies that focus on machine reliability and parts availability to produce proper maintenance actions, optimal maintenance scheduling and good spare-parts management. The research was conducted on a developing manufacturing company engaged the field of agricultural aids in the city of Bekasi. This study focused on hydraulic shear machines because they have the largest downtime value of 8,344.8 minutes. This problem has a negative impact on the company because it can reduce the yield. Based on these conditions, the study was conducted using the Reliability Centered Maintenance method to update the maintenance patterns and Poisson Process to determine the number of component requirements needed for the next one year. The data obtained in the form of historical damage to the machine, component cost, labor cost and production cost. This research produces an optimal preventive replacement time interval that is every 154 hours for the oil seal component, 242 hours for the shear blade component, and 324 hours for the oil hydraulic hose (1/2") component. While the number of critical components required for the next 1 year is 37 units for oil seal component, 10 units for shear blade components, and 7 units for oil hydraulic hose (1/2") component
XPS and XMCD study of Fe3O4/GaAs interface
Ultrathin Fe oxide films of various thicknesses prepared by post-growth oxidation on GaAs(100) surface have been investigated with X-ray photoelectron spectroscopy (NPS), X-ray absorption spectroscopy (XAS), and X-ray magnetic circular dichroism (XMCD). The XPS confirms that the surfaces of the oxide are Fe3O4 rather than Fe2O3. XAS and XMCD measurements indicate the presence of nsulating Fe divalent oxide phases (FeO) beneath the surface Fe-3 O-4 layer with the sample thickness above 4 mn. This FeO might act as a barrier for the spin injection into the GaAs
Peranan Pendidikan Technopreneurship Untuk Pembangunan Berkelanjutan: Studi Konseptual
This paper describes a technological business incubation model, developing integrated curriculum with technopreneurship education, as well as the involvement of Industrial Engineering of Tarumanagara University to create technology startup ecosystem. University holds the important role for enhancing technopreneurs in Indonesia. Academics or researchers as technology transfer agents, are responsible to disseminate technology entrepreneurship education broadly. Eventually, technological business incubator will able to accelerate commercialization of innovations or inventions from university researchs
INFLUENCE OF MUSCLE ACTIVITY ON SHOOTING PERFORMANCE IN ARCHERY: PRELIMINARY FINDINGS
The use of proximal muscle is advocated for consistent archery shooting due to higher tolerance for fatigue. Muscle activity was subject of investigation in several archery studies. But thus far variation in muscle activity has been ignored. This study presents the preliminary findings of the influence of proximal muscle activity and variation on score and arrow release speed in Archery. Subjects were three Malaysian National archers shooting 29-36 arrows from 70 meter distance. Surface electromyography (EMG) was recorded for triceps (bilateral), left deltoid and right trapezius muscles. Arrow release speed was recorded with a speed radar gun. Linear and curvilinear associations of muscle activation and variation with score and speed are presented. Findings show each archer has different muscle determinants influencing score and speed
PELATIHAN MASYARAKAT AKAN PEMANFAATAN REMPAH-REMPAH SEBAGAI MINUMAN HERBAL UNTUK MENINGKATKAN DAYA TAHAN
Minuman herbal merupakan salah satu olahan minuman yang berasal dari bahan alami yang banyak memiliki manfaat bagi tubuh. Minuman herbal terbuat dari bahan alami tumbuhan berupa rempah-rempah atau bagian dari tanaman, seperti akar, batang, daun, bunga tanaman. Manfaat minuman herbal adalah untuk tujuan kesehatan salah satunya adalah untuk meningkatkan sistem imunitas di dalam tubuh. Sistem imunitas tubuh sangat berperan penting untuk mempertahankan tubuh tetap dalam kondisi yang sehat sehingga dapat melawan virus yang masuk ke dalam tubuh. Tanaman herbal adalah tumbuhan atau tanaman yang mempunyai kegunaan atau khasiat dalam pengobatan kesehatan. Salah satu obat herbal adalah tanaman rempah-rempah. Beberapa contoh rempah-rempah tanaman herbal yang dapat dimanfaatkan dalam pembuatan minuman herbal seperti jahe, temulawak, kunyit, kayu manis, sereh dan rempah tanaman lainnya. Hasil kegiatan pelaksaan program pengabdian masyarakat dalam bentuk penyuluhan untuk memberikan informasi dan edukasi kepada masyarakat akan pemanfaatan rempah-rempah sebagai minuman herbal untuk meningkatkan daya tahan. Maka masyarakat dapat menambah pengetahuan dan memahami potensi rempah-rempah yang ada disekitarnya untuk diolah menjadi minuman herbal yang digunakan untuk meningkatkan data tahan tubuh
Barriers to infection of human cells by feline leukemia virus: insights into resistance to zoonosis
The human genome displays a rich fossil record of past gamma-retrovirus infections, yet no current epidemic is evident, despite environmental exposure to viruses that infect human cells in vitro. Feline leukemia viruses (FeLVs) rank high on this list, but domestic or workplace exposure has not been associated with detectable serological responses. Non-specific inactivation of gamma-retroviruses by serum factors appears insufficient to explain these observations. To investigate further we explored the susceptibility of primary and established human cell lines to FeLV-B, the most likely zoonotic variant. Fully permissive infection was common in cancer-derived cell lines, but was also a feature of non-transformed keratinocytes and lung fibroblasts. Cells of haematopoietic origin were less generally permissive and formed discrete groups on the basis of high or low intracellular protein expression and virion release. Potent repression was observed in primary human blood mononuclear cells and a subset of leukemia cell lines. However, the early steps of reverse transcription and integration appear to be unimpaired in non-permissive cells. FeLV-B was subject to G->A hypermutation with a predominant APOBEC3G signature in partially permissive cells but was not mutated in permissive cells or in non-permissive cells that block secondary viral spread. Distinct cellular barriers that protect primary human blood cells are likely to be important in protection against zoonotic infection with FeLV
A Jurassic (Bathonian-Callovian) Daghanirhynchia brachiopod fauna from Jordan
A Jurassic (Bathonian-Callovian) brachiopod fauna from Jordan consists of seven rhynchonellid species all belonging to the genus Daghanirhynchia of which two are new: Daghanirhynchia rawyaensis and D. jordanica. Emended diagnoses are given for Daghanirhynchia daghaniensis and D. macfadyeni. Additional taxa described include Daghanirhynchia angulocostata, D. susanae and D. triangulata. Threedimensional reconstructions illustrate the internal morphology of the articulated shells for the first time in this genus. The material studied herein was collected from Wadi Zarqa in northwestern Jordan, almost due north of the Dead Sea, and to the east of the Rift Valley. Most species seem to be geographically restricted within the Jurassic Ethiopian Province, however specimens from Somalia and Ethiopia are larger in size than in other parts of the Province and shell size increases in stratigraphically younger specimens. The occurrence of Daghanirhynchia in India is the only appearance of the genus outside the Ethiopian Province
The influence of perfusion solution on renal graft viability assessment
BACKGROUND: Kidneys from donors after cardiac or circulatory death are exposed to extended periods of both warm ischemia and intra-arterial cooling before organ recovery. Marshall’s hypertonic citrate (HOC) and Bretschneider’s histidine-tryptophan-ketoglutarate (HTK) preservation solutions are cheap, low viscosity preservation solutions used clinically for organ flushing. The aim of the present study was to evaluate the effects of these two solutions both on parameters used in clinical practice to assess organ viability prior to transplantation and histological evidence of ischemic injury after reperfusion. METHODS: Rodent kidneys were exposed to post-mortem warm ischemia, extended intra-arterial cooling (IAC) (up to 2 h) with preservation solution and reperfusion with either Krebs-Hensleit or whole blood in a transplant model. Control kidneys were either reperfused directly after retrieval or stored in 0.9% saline. Biochemical, immunological and histological parameters were assessed using glutathione-S-transferase (GST) enzymatic assays, polymerase chain reaction and mitochondrial electron microscopy respectively. Vascular function was assessed by supplementing the Krebs-Hensleit perfusion solution with phenylephrine to stimulate smooth muscle contraction followed by acetylcholine to trigger endothelial dependent relaxation. RESULTS: When compared with kidneys reperfused directly post mortem, 2 h of IAC significantly reduced smooth muscle contractile function, endothelial function and upregulated vascular cellular adhesion molecule type 1 (VCAM-1) independent of the preservation solution. However, GST release, vascular resistance, weight gain and histological mitochondrial injury were dependent on the preservation solution used. CONCLUSIONS: We conclude that initial machine perfusion viability tests, including ischemic vascular resistance and GST, are dependent on the perfusion solution used during in situ cooling. HTK-perfused kidneys will be heavier, have higher GST readings and yet reduced mitochondrial ischemic injury when compared with HOC-perfused kidneys. Clinicians should be aware of this when deciding which kidneys to transplant or discard
Study of Near-Cup Droplet Breakup of an Automative Electrostatic Rotary Bell (ESRB) Atomizer Using High-Speed Shadowgraph Imaging
Electrostatic Rotary bell (ESRB) atomizers are used as the dominant means of paint application by the automotive industry. They utilize the high rotational speed of a cup to induce primary atomization of a liquid along with shaping air to provide secondary atomization and transport. In order to better understand the fluid breakup mechanisms involved in this process, high-speed shadowgraph imaging was used to visualize the edge of a serrated rotary bell at speeds varying between 5000 and 12,000 RPM and with a water flow rate of 250 ccm. A multi-step image processing algorithm was developed to differentiate between ligaments and droplets during the primary atomization process. The results from this experiment showed that higher bell speeds resulted in a 26.8% reduction in ligament and 22.3% reduction in droplet Sauter Mean Diameters (SMD). Additionally, the ligament (ranging from 40 to 400 μm) diameters formed bimodal distributions, while the droplet (ranging from 40 to 300 μm) diameters formed a normal distribution. Velocities were also measured using particle tracking velocimetry, in which size-dependent velocities could then be computed. Droplet velocities were affected more by rotational speed than droplet SMD, while ligaments were affected by other factors than the rotational speed and ligament SMD
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