Optimasi Produksi Lapangan Gas dengan Analisis Nodal

Produktivitas sumur ditunjukkan dari kemampuan suatu formasi untuk memproduksi fluida yangdikandungnya pada kondisi tertentu. Evaluasi produktivitas sumur-sumur pada Lapangan“Parahita” ini dilakukan dengan Analisa Nodal. Permintaan gas dari konsumen sebesar 250MMscfd. Oleh karena itu perlu dianalisa berapa laju alir yang dapat diproduksikan olehmasing-masing sumur untuk memenuhi permintaan tersebut tanpa melewati batasan kritisnya.Metode yang digunakan menggunakan analisa nodal, perhitungan laju alir kritis, danperamalan produksi dengan plateau rate tertentu. Perhitungan dan analisa dibantu dengansoftware Prosper dan MBAL. Makalah ini menyajikan cara dan hasil optimasi produksi dari sumursumurdi Lapangan Gas “Parahita”

Power computation for the triboelectric nanogenerator

We consider, from a mathematical perspective, the power generated by a contact-mode triboelectric nanogenerator, an energy harvesting device that has been well studied recently. We encapsulate the behaviour of the device in a differential equation, which although linear and of first order, has periodic coefficients, leading to some interesting mathematical problems. In studying these, we derive approximate forms for the mean power generated and the current waveforms, and describe a procedure for computing the Fourier coefficients for the current, enabling us to show how the power is distributed over the harmonics. Comparisons with accurate numerics validate our analysis

Employers’ responses to the HIV epidemic in sub-Saharan Africa: Revisiting the evidence

Do employers have a role to play to support people living with HIV? The literature on sub-Saharan Africa points to the existence of a positive business case that sees firms as incentivised to provide HIV-related services to HIV positive workers4. However, the evidence is narrow and incomplete, with the business case holding for a limited number of formal sector skilled workers, leaving out the majority of people living with HIV. If employers are to play a role, policy makers need to create conducive conditions for positive responses, in addition to – not in replacement of – strengthening public health care systems

Towards a political economy of the use of research assistants: reflections from fieldwork in Tanzania and Mozambique

Research assistants play a vital role in the research process, often acting as more than just translators or interpreters. However, their contributions to and impacts on the research process and outcomes often remain unacknowledged or unaccounted for. We build on previous work that looks at the subjective relations between the researcher, research assistant and research participant to explore this issue. In particular, drawing on a political economy approach, we look at how research assistants, through their objective position, mediate relations between researcher and participants, and also how power relations and different configurations of roles influence the research process and outcomes. Our analysis concludes that ignoring the role of research assistants in empirical research will lead to flawed processes, biased data and possibly misleading results

The effect of drugs in altering susceptibility to motion sickness in aerobatics and the slow rotation room

Drugs altering susceptibility to motion sickness in aerobatics and slow rotation roo

Routine repeat head CT may not be necessary for patients with mild TBI.

Background:Routine repeat cranial CT (RHCT) is standard of care for CT-verified traumatic brain injury (TBI). Despite mixed evidence, those with mild TBI are subject to radiation and expense from serial CT scans. Thus, we investigated the necessity and utility of RHCT for patients with mild TBI. We hypothesized that repeat head CT in these patients would not alter patient care or outcomes. Methods:We retrospectively studied patients suffering from mild TBI (Glasgow Coma Scale (GCS) score 13-15) and treated at the R Adams Cowley Shock Trauma Center from November 2014 through January 2015. The primary outcome was the need for surgical intervention. Outcomes were compared using paired Student's t-test, and stratified by injury on initial CT, GCS change, demographics, and presenting vital signs (mean ± SD). Results:Eighty-five patients met inclusion criteria with an average initial GCS score=14.6±0.57. Our center sees about 2800 patients with TBI per year, or about 230 per month. This includes patients with concussions. This sample represents about 30% of patients with TBI seen during the study period. Ten patients required operation (four based on initial CT and others for worsening GCS, headaches, large unresolving injury). There was progression of injury on repeat CT scan in only two patients that required operation, and this accompanied clinical deterioration. The mean brain Abbreviated Injury Scale (AIS) score was 4.8±0.3 for surgical patients on initial CT scan compared with 3.4±0.6 (P<0.001) for non-surgical patients. Initial CT subdural hematoma size was 1.1±0.6 cm for surgical patients compared with 0.49±0.3 cm (P=0.05) for non-surgical patients. There was no significant difference between intervention groups in terms of other intracranial injuries, demographics, vital signs, or change in GCS. Overall, 75 patients that did not require surgical intervention received RHCT. At $340 per CT,$51 000 was spent on unnecessary imaging ($367 000/year, extrapolated). Discussion:In an environment of increased scrutiny on healthcare expenditures, it is necessary to question dogma and eliminate unnecessary cost. Our data questions the use of routine repeat head CT scans in every patient with anatomic TBI and suggests that clinically stable patients with small injury can simply be followed clinically. Level of evidence:Level III

Employers’ responses to the HIV epidemic in sub-Saharan Africa: revisiting the evidence

Do employers have a role to play to support people living with HIV? The literature on sub-Saharan Africa points to the existence of a positive business case that sees firms as incentivised to provide HIV-related services to HIV positive workers . However, the evidence is narrow and incomplete, with the business case holding for a limited number of formal sector skilled workers, leaving out the majority of people living with HIV. If employers are to play a role, policy makers need to create conducive conditions for positive responses, in addition to – not in replacement of – strengthening public health care systems

Evaluasi Kelayakan Proyek Berdasarkan Analisis Kriteria Investasi

Perkembangan hunian dari waktu ke waktu semakin meningkat Hal ini seiring dengan perkembangan proyek apartement dengan tujuan guna untuk memenuhi kebutuhan masyarakat akan hunian yang nyaman. Namun dalam pelaksanaaanya investor atau pihak pengembang perlu mengetahui kepastian akan investasi yang ditanamkan menyangkut sejumlah besar dana, dengan demikian dapat memperoleh gambaran sebagai acuan bagi para investor dalam pengembanganya pada tahap berikutnya. Sehubungan dengan itu perlu dilakukan evaluasi, guna untuk menganalisis terhadap proyek yang akan direncanakan, atau pun yang sedang berjalan sebagai bahan penilaian pelaksanaan proyek tersebut. Evaluasi kelayakan proyek berdasarkan analisis kriteria investasi, dalam penulisan ini ditinjau dari aspek financial, evaluasi proyek hanya menganalisis biaya (cost) dan keuntungan (benefit). Adapun kriteria investasi yang dipakai untuk menilai benefit dan cost yaitu Groos Benefit / Cost Ratio (Groos B/C), Proifatibility Ratio, Nert Present Value, Imternal Rate Of Return and payback periode. Setelah diadakan analisis dengan mengunakan metode tersebut maka diperoleh, GroosBenevit / Cost Ratio >1, Profitability Ratio >1, Net Present Value > 0, Internal Rate Of Return 22,3% Lebih Tinggi dari discount rate yang diambilyaitu 9% - 18%, dan Payback Period untuk investasi yang bernilai Rp. 200.848.061.120,- diproyeksikan dapat kembali pada 3,3 Tahun kedepan, dengan memenuhinya setiap criteria investasi tersebut diatas maka proyek apartement dapat dikatakan menguntungkan dan layak untuk dilaksanakan