267 research outputs found

    Kajian Teknis dan Ekonomis Bunkering LNG untuk Pemenuhan Bahan Bakar Gas Kapal Pelni

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    Penggunaan bahan bakar gas pada bidang perkapalan merupakan suatu keuntungan karena dapat menghemat biaya operasi dan mengurangi emisi gas buang. Pemanfaatan gas juga sesuai dengan tujuan pemerintah yang terdapat pada PP No.55/2009 tentang alokasi produksi gas dalam negeri untuk penggunaan lokal sebesar 25%. Proses pengisian bahan bakar (bunkering) LNG pada umumnya dapat dilakukan dengan tiga skema yaitu ship to ship, truck to ship dan onshore to ship. Untuk itu perlu dilakukan kajian untuk menentukan lokasi dan skema bunkering LNG yang akan digunakan pada studi kasus kali ini, yaitu untuk armada kapal PT. Pelni. Penentuan lokasi bunkering dilakukan dengan memperhatikan frekuensi kedatangan dan kebutuhan bunkering LNG pada setiap pelabuhan. Konversi kebutuhan bahan bakar minyak menjadi bahan bakar gas memakai asumsi bahwa motor diesel dimodifikasi menjadi duel fuel engine menggunakan konverter yang dapat dioperasikan dengan rasio bahan bakar HSD dengan LNG sebesar 50:50. Dari hasil didapatkan pada skenario I adalah Jakarta, Surabaya, Balikpapan, Makassar, Ambon dan Sorong. Skenario II dengan penambahan Bau-bau dan Skenario III dengan penambahan Jayapura. Untuk skema bunkering yang akan dipilih ditentukan dengan menggunakan metode Analytical Hierarchy Process (AHP) dengan kriteria yang dipakai diantaranya teknis, keselamatan dan biaya. Dari hasil pembobotan yang terpilih adalah skema truck to ship. Studi ditutup dengan kajian ekonomi dari sisi penyedia LNG dan dari sisi pemilik kapal. Beberapa parameter yang dipakai adalah Net Present Value, Internal Rate Return, dan Payback Period

    Analysis of generalized negative binomial distributions attached to hyperbolic Landau levels

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    To each hyperbolic Landau level of the Poincar\'e disc is attached a generalized negative binomial distribution. In this paper, we compute the moment generating function of this distribution and supply its decomposition as a perturbation of the negative binomial distribution by a finitely-supported measure. Using the Mandel parameter, we also discuss the nonclassical nature of the associated coherent states. Next, we determine the L\'evy-Kintchine decomposition its characteristic function when the latter does not vanish and deduce that it is quasi-infinitely divisible except for the lowest hyperbolic Landau level corresponding to the negative binomial distribution. By considering the total variation of the obtained quasi-L\'evy measure, we introduce a new infinitely-divisible distribution for which we derive the characteristic function

    Mapping the spatiotemporal dynamics of calcium signaling in cellular neural networks using optical flow

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    An optical flow gradient algorithm was applied to spontaneously forming net- works of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling with single pixel resolution. Optical flow estimates the direction and speed of motion of objects in an image between subsequent frames in a recorded digital sequence of images (i.e. a movie). Computed vector field outputs by the algorithm were able to track the spatiotemporal dynamics of calcium signaling pat- terns. We begin by briefly reviewing the mathematics of the optical flow algorithm, and then describe how to solve for the displacement vectors and how to measure their reliability. We then compare computed flow vectors with manually estimated vectors for the progression of a calcium signal recorded from representative astrocyte cultures. Finally, we applied the algorithm to preparations of primary astrocytes and hippocampal neurons and to the rMC-1 Muller glial cell line in order to illustrate the capability of the algorithm for capturing different types of spatiotemporal calcium activity. We discuss the imaging requirements, parameter selection and threshold selection for reliable measurements, and offer perspectives on uses of the vector data.Comment: 23 pages, 5 figures. Peer reviewed accepted version in press in Annals of Biomedical Engineerin

    Establishing a Target Exposure for Once-Daily Intravenous Busulfan Given with Fludarabine and Thymoglobulin before Allogeneic Transplantation

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    AbstractA combination of fludarabine (Flu) and daily i.v. busulfan (Bu) is well tolerated and effective in patients undergoing allogeneic hematopoietic stem cell transplantation. Although there is some evidence that Bu exposures exceeding 6000 μM/min may lead to excessive toxicity, there is little information on the effect of exposures below this level on outcomes. We studied Bu exposure, as measured by area under the concentration-time curve (AUC), in 158 patients with various hematologic malignancies in an attempt to identify an optimal range for targeted therapy. The preparative chemotherapy regimen comprised Flu 50 mg/m2 on days -6 to -2 and i.v. Bu 3.2 mg/kg on days -5 to -2 inclusive. Graft-versus-host disease (GVHD) prophylaxis included methotrexate, cyclosporin A, and antithymocyte globulin. Patients with Bu exposures below the median AUC of 4439 μM/min were at increased risk for acute GVHD grade II-IV (hazard ratio [HR], 2.30; 95% confidence interval [CI], 1.19 to 4.49; P = .014). Those in the highest and lowest Bu exposure quartiles (daily AUC <3814 μM/min and >4993 μM/min) had an increased risk of nonrelapse mortality (subdistribution HR, 3.32; 95% CI, 1.46 to 7.54; P = .004), as well as worse disease-free survival (HR, 1.81; 95% CI, 1.09 to 2.99; P = .021) and overall survival (HR, 1.94; 95% CI, 1.12 to 3.37; P = .018). Bu exposures between 4440 and 4993 μM/min were accompanied by the lowest risk of both nonrelapse mortality and acute GVHD

    An improved model and performance analysis for grid-connected photovoltaic system in Oman

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    The PV systems' sources are environmentally friendly, but at the same time, they are constantly changing with time. When evaluating solar energy resources, it is necessary to consider the variability and effects of different environmental operation parameters like solar irradiances, ambient temperature, and module temperature. The study introduces a method to simulate an existing photovoltaic system using a mathematical model that permits intelligent strategies to optimise the efficiency and adjust the most effective operational parameters for the solar energy systems. A mathematical analysis for the data framework, including correlation and regression coefficients, was calculated to identify and chart the relationships between the system's most influential parameters and the generated power from the PV system. An improved mathematical model was built with the most influential parameters. The improved model was simple, accurate, and based on the loss ratio by eliminating the unknown parameters. The system's efficiency was analysed using an existing data framework-recorded hourly from 1 January 2017 to December 2018 for a grid-connected photovoltaic system installed in the south of Oman. The results showed that the most influential parameters on the efficiency were the module's solar irradiance and surface temperature. The operating parameters such as ambient temperature, wind speed, and air humidity had a negligible effect on the generated power compared to the cell temperatures and solar radiation. The dissipation factor was used in the new output current and voltage equations to stimulate the output power of the PV model. The improved model was validated in a MATLAB Simulink and showed a more promising output with a lower RMSE of 5 %. [Abstract copyright: © 2022 The Author(s).

    1,2,3-Triazolyl-tetrahydropyrimidine conjugates as potential Sterol Carrier Protein-2 Inhibitors: Larvicidal activity against the Malaria Vector Anopheles arabiensis and In Silico Molecular Docking Study

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    Alteration of insect growth regulators by the action of inhibitors is becoming an attractive strategy to combat disease-transmitting insects. In the present study, we investigated the larvicidal effect of 1,2,3-triazolyl-pyrimidinone derivatives against the larvae of the mosquito Anopheles arabiensis, a vector of malaria. All compounds demonstrated insecticidal activity against mosquito larvae in a dose-dependent fashion. A preliminary study of the structure–activity relationship indicated that the electron-withdrawing substituent in the para position of the 4-phenyl-pyrimidinone moiety enhanced the molecules’ potency. A docking study of these derivatives revealed favorable binding affinity for the sterol carrier protein-2 receptor, a protein present in the intestine of the mosquito larvae. Being effective insecticides against the malaria-transmitting Anopheles arabiensis, 1,2,3-triazole-based pyrimidinones represent a starting point to develop novel inhibitors of insect growth regulators.Fil: Venugopala, Katharigatta N.. Durban University Of Technology; Sudáfrica. King Faisal University; Arabia SauditaFil: Shinu, Pottathil. King Faisal University; Arabia SauditaFil: Tratrat, Christophe. King Faisal University; Arabia SauditaFil: Deb, Pran Kishore. Philadelphia University Jordan; JordaniaFil: Gleiser, Raquel M.. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinar de Biología Vegetal (P). Grupo Vinculado Centro de Relevamiento y Evaluación de Recursos Agrícolas y Naturales; ArgentinaFil: Chandrashekharappa, Sandeep. National Institute Of Pharmaceutical Education And Research, Raebareli; IndiaFil: Chopra, Deepak. Indian Institute Of Science Education And Research Bhopal; IndiaFil: Attimarad, Mahesh. King Faisal University; Arabia SauditaFil: Nair, Anroop B.. King Faisal University; Arabia SauditaFil: Sreeharsha, Nagaraja. Vidya Siri College Of Pharmacy; India. King Faisal University; Arabia SauditaFil: Mahomoodally, Fawzi M.. University Of Mauritius; MauricioFil: Haroun, Michelyne. King Faisal University; Arabia SauditaFil: Kandeel, Mahmoud. Faculty Of Veteinary Medicine; Egipto. King Faisal University; Arabia SauditaFil: Asdaq, Syed Mohammed Basheeruddin. Almaarefa University; Arabia SauditaFil: Mohanlall, Viresh. Durban University Of Technology; SudáfricaFil: Al-Shari, Nizar A.. Jordan University Of Science And Technology; JordaniaFil: Morsy, Mohamed A.. King Faisal University; Arabia Saudita. Faculty Of Medicine; Egipt

    Applicability and generalisability of the results of systematic reviews to public health practice and policy: a systematic review

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    <p>Abstract</p> <p>Background</p> <p>The purpose of the study was to evaluate systematic reviews of research into two public health priorities, tobacco consumption and HIV infection, in terms of the reporting of data related to the applicability of trial results (i.e., whether the results of a trial can be reasonably applied or generalized to a definable group of patients in a particular setting in routine practice, also called external validity or generalisability).</p> <p>Methods</p> <p>All systematic reviews of interventions aimed at reducing or stopping tobacco use and treating or preventing HIV infection published in the Cochrane database of systematic reviews and in journals indexed in MEDLINE between January 1997 and December 2007 were selected. We used a standardized data abstraction form to extract data related to applicability in terms of the context of the trial, (country, centres, settings), participants (recruitment, inclusion and exclusion criteria, baseline characteristics of participants such as age, sex, ethnicity, coexisting diseases or co-morbidities, and socioeconomic status), treatment (duration, intensity/dose of treatment, timing and delivery format), and the outcomes assessment from selected reviews.</p> <p>Results</p> <p>A total of 98 systematic reviews were selected (57 Cochrane reviews and 41 non-Cochrane reviews); 49 evaluated interventions aimed at reducing or stopping tobacco use and 49 treating or preventing HIV infection. The setting of the individual studies was reported in 45 (46%) of the systematic reviews, the number of centres in 21 (21%), and the country where the trial took place in 62 (63%). Inclusion and exclusion criteria of the included studies were reported in 16 (16%) and 13 (13%) of the reviews, respectively. Baseline characteristics of participants in the included studies were described in 59 (60%) of the reviews. These characteristics concerned age in about half of the reviews, sex in 46 (47%), and ethnicity in 9 (9%).</p> <p>Applicability of results was discussed in 13 (13%) of the systematic reviews. The reporting was better in systematic reviews by the Cochrane Collaboration than by non-Cochrane groups.</p> <p>Conclusions</p> <p>Our study highlighted the lack of consideration of applicability of results in systematic reviews of research into 2 public health priorities: tobacco consumption and HIV infection.</p

    Sialylation of MUC4β N-glycans by ST6GAL1 orchestrates human airway epithelial cell differentiation associated with type-2 inflammation

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    Although type-2-induced (T2-induced) epithelial dysfunction is likely to profoundly alter epithelial differentiation and repair in asthma, the mechanisms for these effects are poorly understood. A role for specific mucins, heavily N-glycosylated epithelial glycoproteins, in orchestrating epithelial cell fate in response to T2 stimuli has not previously been investigated. Levels of a sialylated MUC4 beta isoform were found to be increased in airway specimens from asthmatic patients in association with T2 inflammation. We hypothesized that IL-13 would increase sialylation of MUC4 beta, thereby altering its function and that the beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1) would regulate the sialylation. Using human biologic specimens and cultured primary human airway epithelial cells (HAECs), we demonstrated that IL-13 increases ST6GAL1-mediated sialylation of MUC4 beta and that both were increased in asthma, particularly in sputum supernatant and/or fresh isolated HAECs with elevated T2 biomarkers. ST6GAL1-induced sialylation of MUC4 beta altered its lectin binding and secretion. Both ST6GAL1 and MUC4 beta inhibited epithelial cell proliferation while promoting goblet cell differentiation. These in vivo and in vitro data provide strong evidence for a critical role for ST6GAL1-induced sialylation of MUC4 beta in epithelial dysfunction associated with T2-high asthma, thereby identifying specific sialylation pathways as potential targets in asthma.NIH [R01 HL069174]; National Heart, Lung, and Blood Institute [R01 HL064937, R01 HL069116, P01 HL103453, R01 HL69167, U01 HL109086, U10 HL109152, R21 AI122071]; National Institute of Allergy and Infectious Diseases [P01 AI106684]; Nikon A1 [NIH 1S10OD019973-01]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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