A Comparison Between Half and Full Fins at Nanofluids in Transformers

Power transformers characterize the biggest section of capital investment within the distribution substations as well as transmission. Additionally, outages of those transformers have a substantial economic influence on the functioning of an electrical network due to the fact that the power transformers are one of the utmost overpriced constituents in an electricity structure. A suggested thermal model for a distribution transformer is investigated. The temperature distribution in the three-phase transformer (250 KVA 11/.416 KV core type, mineral oil) was obtained using “COMSOL PROGRAM” after a 3D simulation utilizing a transient analysis in light of the Finite Element Method (FEM). Meanwhile, the suggested model is being used to examine the impacts of different types of oil on HOST. To test the effect of nanoparticles on heat transfer process, the insulation oil was changed with Nanofluids and hybrid nanofluids; For present work, can be concluded when add nanofluids (Al2O3, CuO, SiC) for oil of transformer under different concentration ratio (0.3,0.5,0.8,1,1.2,1.4 % wt) and add hybrid nanofluids (oil+ Al2O3+CuO), (oil+ Al2O3+SiC), (oil+ SiC +CuO) at different concentration ratio (1,1.2,1.4 % wt). The concentration of nanofluids show a direct influence on the temperature reduction for the studied cases. Finally it can be said, the proposed model was succeeded in simulating the distribution transformer, which is in good agreement with the experimental tests adopted for this work, and it could be used as a design tool with assist of COMSOL Multiphysics Package. The present model successfully accomplished for expecting the temperature distribution at any locations in the transformer when compared with practical measurement.

Nano Ag/AgCl wires photocatalyzed hydrogen production and transfer hydrogenation of Knoevenagel-type products

Investigation of the relationship between the morphology of Ag/AgCl nanostructured composites with their catalytic performance was reported. The concentration ratio of silver nitrate and hydrochloric acid was controlled to produce...

STRUKTUR PASAR DAN DAYA SAING KARET ALAM INDONESIA DI AMERIKA SERIKAT

Abstrak Karet alam Indonesia berperan penting dalam meningkatkan perekonomian nasional melalui ekspor karet alam ke berbagai negara, termasuk ke Amerika Serikat. Dalam upaya mengembangkan ekspor karet alamnya, Indonesia perlu melakukan kalkulasi posisi dan daya saing karet alam di antara negara-negara pesaing serta peluang pasarnya ke Amerika Serikat yang memiliki permintaan impor relatif tinggi. Tujuan penelitian ini adalah menganalisis struktur pasar, serta keunggulan komparatif dan kompetitif karet alam Indonesia di pasar Amerika Serikat. Analisis dilakukan selama periode tahun 2008-2019 menggunakan metode Herfindahl Index (HI), Concentration Ratio (CR4), Revealed Comparative Advantage (RCA), Export Product Dynamic (EPD), dan Diamond’s Porter. Hasil analisis menunjukkan bahwa struktur pasar karet alam Indonesia cenderung oligopoli. Dibandingkan dengan negara-negara eksportir lainnya, karet alam Indonesia memiliki keunggulan komparatif di pasar Amerika Serikat. Keunggulan kompetitif karet alam Indonesia di Amerika Serikat mengalami penurunan dari posisi lost opportunity pada periode pertama (2008-2011) menjadi retreat pada periode ketiga (2016-2019). Hasil dari Diamond’s Porter menunjukkan bahwa terdapat tujuh faktor keunggulan kompetitif dan tiga faktor kelemahan dalam industri karet alam di Indonesia. Kata Kunci: Concentration Ratio, Diamond’s Porter, EPD, Herfindahl Index, RCA Abstract Indonesian natural rubber plays a significant role in improving the national economy through exports of natural rubber to various countries, including the United States. In an effort to develop its natural rubber exports, Indonesia needs to calculate the position and competitiveness of natural rubber among competing countries and its market opportunities to the United States, which has a relatively high import demand. The purpose of this study is to analyze the market structure, as well as the comparative and competitive advantages of Indonesian natural rubber in the United States market. The analysis was carried out during the period 2008-2019 using the methods Herfindahl Index (HI), Concentration Ratio (CR4), Revealed Comparative Advantage (RCA), Export Product Dynamic (EPD), and Diamond's Porter. The results of the analysis show that the structure of the Indonesian natural rubber market tends to be an oligopoly. Compared to other exporting countries, Indonesian natural rubber has a comparative advantage in the United States market. The competitiveness of Indonesian natural rubber in the US decline over time from the lost opportunity position in the first period (2008-2011) to retreat in the third period (2016-2019). The Diamond's Porter results show that there are seven competitive advantage factors and three weakness factors in Indonesia's natural rubber industry. Keywords: Concentration Ratio, Diamond’s Porter, EPD, Herfindahl Index, RCA JEL Classification: F13, F15, F18

STRUCTURE, BEHAVIOR, AND MARKET PERFORMANCE ON MARKETING OF PATCHIE OIL IN BUKUT VILLAGE, TERANGUN DISTRICT GAYO LUES DISTRICT

Patchouli (Pogostemon cablin Benth) is an essential oil-producing plant which is a source of foreign exchange for the country. Indonesia is currently the world's producer of patchouli oil with a contribution of 90%, for that it is necessary to maintain market opportunities by increasing production through appropriate cultivation techniques, improving the quality of patchouli oil and developing patchouli plantings in areas that have bright prospects seen from the level of suitability. land and climate.The purpose of this study was to determine market structure, market behavior (various forms of collusion) and market appearances that occurred in the marketing of nimal oil in Bukut Village, Terangun District, Gayo Lues Regency. The data used are primary data and secondary data, for market participants, snowball sampling is used. The method used to analyze the market structure is Concentration Ratio analysis tools (Market Share, Herfindal Index and Concentration Ratio for Biggest Four or ), Degree of Product Differentiation, Barriers to Market Entry and Level of Market Knowledge. To analyze Market Behavior, it is descriptively analyzed about collusion and strategies that occur. To analyze the Market Performance used the analysis tools of Marketing Margin, Share Price, and Cost and Profit Ratio.〖CR〗_4.Market share at the collector levelthere is an oligopoly marketing system for patchouli oil with loose concentration. The concentration of buyers in marketing patchouli oil in Bukut village, both collectors, village collectors, and representative warehouses/ wholesalers is oligopsony. The marketing structure of Patchouli Oil in Gayo Lues, at the level of collector traders is a loose oligopoly with a CR4 value of 0.5421, at the level of a village collector it is a tight oligopoly with a CR4 value of 0.8855, while at the warehouse representative/ wholesaler level it is a tight oligopoly with a CR value, reaching 1.00. should have a value of 1.00 is a monopoly, but because there are still three competing companies, it is categorized as a strict oligopoly.

Tissue Distribution of Mercury and Its Relationship with Selenium in Atlantic Bluefin Tuna (Thunnus thynnus L.)

Mercury (Hg) is an important heavy metal to consider in marine predators, while selenium (Se) has a natural antagonistic effect on this metal in fish. The Atlantic bluefin tuna (ABFT, Thunnus thynnus) is a pelagic top-level predator of the trophic web and their Hg muscular content is an object of concern in food safety. Nevertheless, little is known about levels of this metal in remaining tissues, which may be important as by-product source, and its relationship with Se. Thus, concentration of both elements in liver, kidney, brain, gill and bone, in addition to muscle, of ABFT were determined. The kidney was the tissue with the highest concentration of Hg (Total-Hg, THg) and Se, and the Se/THg concentration ratio was similar in all tissues, except bone and muscle. The Selenium Health Benefit Value (HBVSe) was positive in each specimen and tissue, indicating that the Se plays an important role against Hg not only in the muscle.

Analisis Struktur Pasar Kentang Pada Pasar Relokasi di Plaju Palembang

Pasar Modern Plaju is a modern market, which was relocated from the traditional market Pasar Plaju so that there is a change in management of the market. Vegetables are the most widely sold commodity in the market, one of which is potatoes. Potatoes harvested area and production in South Sumatra had fluctuated in the past five years. Producer and consumer prices also fluctuated but have positive trends. Changes in market management and potato prices are always fluctuating, which would affect the market structure. The study aimed at determining the buying and selling activities and the structure of the potato market in Pasar Modern Plaju. The data came from 10 potato retailers. The data collected is daily data from buying and selling activities during January 2020 and was analyzed quantitatively. The analysis used was market concentration ratio (CR) and HHI (Herfindal-Hirschman Index). The result showed the diluent traders bought potatoes from a collector at a maximum of 600 kg per purchase, did not do grading, and the payment system was in cash. The market concentration ratio showed 59,18% CR4 and 93,27% CR8 was indicated that the structure of the potato market in Pasar Modern Plaju was oligopsony. HHI value 1.313 also showed that the potatoes market structure trend to word oligopsony market. These findings imply that the structure market can be influenced by the type of market.

Predicting the Effects of Carbapenem/Carbapenemase Inhibitor Combinations against KPC-Producing Klebsiella pneumoniae in Time-Kill Experiments: Alternative versus Traditional Approaches to MIC Determination

Traditionally, the antibacterial activity of β-lactam antibiotics in the presence of β-lactamase inhibitors is determined at the fixed inhibitor concentration. This traditional approach does not consider the ratio of antibiotic-to-inhibitor concentrations achieved in humans. To explore whether an alternative pharmacokinetically based approach to estimate MICs in combinations is predictive of antimicrobial efficacy, the effects of imipenem and doripenem alone and in combination with relebactam were studied in time-kill experiments against carbapenemase-producing Klebsiella pneumoniae. The carbapenem-to-relebactam concentration ratios in time-kill assays were equal to the therapeutic 24-h area under the concentration-time curve (AUC) ratios of the drugs (1.5/1). The simulated levels of carbapenem and relebactam were equal to their concentrations achieved in humans. When effects of combined regimens were plotted against respective C/MICs, a sigmoid relationship was obtained only with MICs determined by pharmacokinetically based method. The effectiveness of both carbapenems in the presence of relebactam was comparable by the results of time-kill experiments. These findings suggest that (1) antibiotic/inhibitor MICs determined at a pharmacokinetically based concentration ratio allow an adequate assessment of carbapenem susceptibility in carbapenemase-producing K. pneumoniae strains and can be used to predict antibacterial effects; (2) in time-kill experiments, the effects of imipenem and doripenem in the presence of relebactam are comparable.

Evaluation of Foam-Gels for Conformance Control in High Temperature High Salinity Carbonates

In naturally fractured reservoirs, conformance control prior to enhanced oil recovery (EOR) application might be essential to ensure optimal contact and sufficient sweep. Recently, few studies investigated combining foams and gels into what is commonly coined as foamed-gels. Foamed-gels have been tested and shown to be potential for some field conditions. Yet, very limited studies were performed for high temperature and high salinity carbonates. Therefore, in this work, we study the potential of foamed-gels for high temperature and high salinity carbonates. The objective is to evaluate the potential of such synergy and to compare its value to the individual processes. For that purpose, in this work, we rely on bulk and core-scale tests. Bulk tests were used for initial screening. Wide range of foam-gel solutions were prepared with different polymer types and polymer concentrations. Test tubes were hand shacked thoroughly to generate foams. Foam heights were then measured from the test tubes. Heights were used to screen foaming agents and to study gelant effects on foamers in terms of foam strength (heights). The effect of foamers on gelation was evaluated through bottle tests. Based on the results, an optimal concentration ratio of gelant to foamer was determined and used in core-scale displacements, to further study the potential of this hybrid foam-gel process. Bulk results suggested that addition of the gelant up to a 4:1 foam to gel concentration ratio resulted in sufficient foam generation in some of the polymer samples. Yet, only two of the foam-gel samples generated a strong gel. Increasing the foamer concentration delayed the gelation time and in some samples, the solution did not gel. Through the coreflooding experiment, resistance factor (RF) and residual resistance factor (RRF) were obtained for different conformance control processes including foam, foam-gel, and gel. Foam-gel injection exhibited higher RF and RRF values than conventional foams. However, conventional gels showed even higher RF and RRF values than foam-gels. Combining two of the most widely used conformance control methods (foams and gels) can strike a balance. Foam-gel may offer a treatment that is deeper and more sustainable than foams and on the other a treatment that is more practical, and lower-cost than gels. Our laboratory results also demonstrate that such synergetic conformance control can be achieved in high salinity and high temperature carbonates with pronounced impact.