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        검색결과 1,743

        82.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Predicting the quality of materials after they are subjected to plasma sintering is a challenging task because of the non-linear relationships between the process variables and mechanical properties. Furthermore, the variables governing the sintering process affect the microstructure and the mechanical properties of the final product. Therefore, an artificial neural network modeling was carried out to correlate the parameters of the spark plasma sintering process with the densification and hardness values of Ti-6Al-4V alloys dispersed with nano-sized TiN particles. The relative density (%), effective density (g/cm3), and hardness (HV) were estimated as functions of sintering temperature (oC), time (min), and composition (change in % TiN). A total of 20 datasets were collected from the open literature to develop the model. The high-level accuracy in model predictions (>80%) discloses the complex relationships among the sintering process variables, product quality, and mechanical performance. Further, the effect of sintering temperature, time, and TiN percentage on the density and hardness values were quantitatively estimated with the help of the developed model.
        4,000원
        87.
        2020.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Two commonly used ceramics in molten salt research are alumina and mullite. The two ceramics were exposed to a combination of rare earth chlorides (YCl3, SmCl3, NdCl3, PrCl3, and CeCl3; each rare earth chloride of 1.8 weight percent) in LiCl-KCl at 773 K for approximately 13 days. Scanning electron microscopy with wave dispersion spectra was utilized to investigate a formation layer or deposition of rare earths onto the ceramic. Only the major constituents of the ceramics (Al, Si, and O2) were observed during the wave dispersion spectra. X-ray fluorescence was used as well to determine concentration changes in the molten salt as a function of ceramic exposure time. This study shows no evidence of ionic exchange or layer formation between the ceramics and molten chloride salt mixture. There are signs of surface tension effects of molten salt moving out of the tantalum crucible into secondary containment.
        4,000원
        88.
        2020.09 구독 인증기관 무료, 개인회원 유료
        The calls for reform of investment treaty regime are neither novel nor entirely unexpected. And the need for that reform has recently reached its pitiful nadir where the UNCITRAL Working Group III gathered for its first meeting in Vienna back in November-December 2017 to discuss states’ concerns about investor-state dispute settlement. States’ concerns about the reform have been repeatedly referred to in recent publications, but international scholars have not yet discussed Russia's stance in detail. In the following an attempt has been made to fill the gap in literature by introducing the Russian position which contrasts nicely with Canada or the EU. Why is this important? Russia is a significant state in the UNCITRAL Working Group III and any slight shifts in its approach in the UNCITRAL reforms are closely watched. It is the right time to provide an analytical framework for understanding the Russian position in these reform dynamics.
        6,700원
        92.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Facile process for the fabrication of multi-layer graphene thin film (MLGF) is reported here. Multi-layer graphene dispersion prepared by liquid-phase exfoliation of graphite was sprayed on a glass substrate by spray pyrolysis method. The structural, optical and electrical properties of the deposited MLGF are investigated. The sheets of graphene are deposited uniformly on the substrate and distribution of small graphene sheets with size of 300–500 nm can be observed in SEM image. AFM and micro-Raman results ensured that the spray-coated graphene thin film is composed of multi-layer graphene sheets. Spray coated graphene thin film showed significant optical transparency of 57% in the visible region (400–550 nm). MLGF possessed the electrical conductivity in the order of 744 S/m with surface resistivity of 3.54 k Ω/sq. The prepared liquid-phase exfoliated graphene thin film showed superior photoelectric response. The results of this study provided a framework for fabricating an optimized MLGF using a spray pyrolysis route for optoelectronics devices.
        4,000원
        95.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We studied trichloroethylene (TCE) adsorption from aqueous solutions in equilibrium conditions by activated carbons (AC). They differ in raw materials, porous structure characteristics and chemical state of the surface. TCE adsorption isotherms were found to have a concave shape, which is characteristic of a sorbent—sorbate weak interaction. It can be a result from electrostatic repulsion of organic matter molecule from polar groups on carbon surface and adsorbed water molecules. The basic parameters of adsorption were calculated by the Dubinin–Radushkevich equation. We determined that for AG-OV-1 and SKD-515 in the coordinates of the Dubinin–Radushkevich equation, there are two linear plots suggesting adsorption in pores of different sizes or reorientation of adsorbate molecules on the activated carbon surface. The efficiency of TCE removal by the activated carbons was evaluated. To reduce the TCE to the maximum allowable, the lowest sorbent consumption was observed for AC with the highest values of surface area and micropore volume. However, the high cost and hydrophobicity of these adsorbents make it impractical to use them in adsorption columns with a fixed layer. We offered an adsorbent that reasonably combines extraction efficiency, ease of operation and economic feasibility.
        4,000원
        96.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 μg PGF2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; double AI with 200 × 106 sperm), S200 (n = 24; single AI with 200 × 106 sperm), D100 (n = 24; double AI with 100 × 106 sperm) and S100 (n = 18; single AI with 100 × 106 sperm). Ewes were inseminated within 12 to 18 h for single AI and, within 10 to 12 h and 16 to 18 h for double AI after the onset of oestrus. The onset of oestrus ranged from 28 to 76 h (54.33 ± 1.28 h). The high percentage (29.2%) of ewes showed oestrus between 51 to 60 h. The non-return rates were highest in group D200 (56.5%) and differed significantly (p < 0.05) from group S100 (11.1%). No ewes were pregnant in group S100, and the pregnancy rates among the remaining groups did not differ. The mean gestation period was 152.8 ± 0.5 days and no difference was observed among the groups. The lambing and multiple birth rates were 100% in group D200. The single and twin lambing was highest in group D100 (33.3%) and group D200 (83.3%), respectively. Only one triplet lambing and the highest lambing size (2.2 ± 0.2) was recorded in group D200. In conclusion, double AI with 200 × 106 sperm showed comparatively most practical for achieving high pregnancy rates and lambing performances in Bangladeshi ewes under field conditions.
        4,000원
        97.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study aimed to investigate the conceptus-related changes during early pregnancy in the Black Bengal breed of goat. A total of 22 gravid genitalia of the Black Bengal goats were collected from local slaughterhouses. The crown-rump lengths (CRL) of the conceptuses were determined to estimate the gestational age (GA). The length and diameter of uterine horn and amniotic sac were measured, and volume of amniotic and allantoic fluid formed by individual conceptus were recorded. The results reveal that the CRL is positively correlated with GA of the conceptus (R2 = 0.89, p < 0.05); however, CRL was not influenced by number of conceptus. Both the left and the right uterine horn gradually increased in size with the advancement of pregnancy irrespective of conceptus number present in the horn. The size of the amniotic sac of conceptus gradually increased with the conceptus age but maintained spherical shape from 5 to 7 weeks of pregnancy. The amniotic fluid formed by individual conceptus rapidly increased from 5 weeks (3.4 ± 0.3 mL) to 7 weeks (21.0 ± 2.0 mL) and 9 weeks (111.5 ± 4.0 mL). The volume of allantoic fluid formed by individual conceptus was steadily increased until 7 weeks (60.0 ± 5.0 mL) and began to decline slowly thereafter (50.0 ± 5.0 mL at 9 weeks). Notably, there was no effect of conceptus number per pregnancy on individual amniotic and allantoic fluid volume. The cotyledons have first appeared on the allanto-chorionic surface from 4 to 5 weeks of pregnancy. The closed eye, nostril and hooves of the conceptus became visible at 7 weeks of pregnancy. The present study has shown the basic information on conceptus-related developmental changes during early pregnancy up to 9 weeks in Black Bengal goat.
        4,000원
        98.
        2020.06 구독 인증기관 무료, 개인회원 유료
        This study pertains to direction of exports direction of major agricultural commodities viz., rice, maize, bengal gram, chillies and cotton from India. In the ensuing next decade during 21st century, India is likely to witness changes in the export pattern of these commodities due to both internal and external constraints. One of the major internal constraints is mounting cost of production. Similarly, one of the most important external constraints include excessive subsidization by importing countries that makes Indian commodities less competitive in the international market. So, the important research question is to analyse the direction of exports of major agricultural commodities from India during post-WTO regime. The dynamic nature of trade pattern of the selected commodities was analyzed by employing the first order Markov process by examining gains and losses in respect of export shares of major Indian agricultural commodities to different countries. During the post-WTO regime, it was found that Saudi Arabia for rice, Bangladesh for maize, Pakistan for bengal gram, Malaysia for (dry) chillies, China, mainland for cotton are the loyal destinations for the commodities. The increasing demand for the selected commodities in countries like Saudi Arabia, Côte d'Ivoire for rice; Malaysia for maize; Pakistan and Algeria for Bengal gram; USA and Sri Lanka for (dry) chillies and Vietnam, Pakistan and Indonesia for cotton need to be explored for augmenting the exports. In order to achieve this goal, it is essential that consumer preferences in newer markets, market intelligence and impediments for augmenting exports need to be researched. It is also high time to analyze the export competitiveness of selected commodities across these importing countries.
        4,600원
        99.
        2020.06 구독 인증기관 무료, 개인회원 유료
        Malaysia announced to reduce emission during the 15th Conference of Parties in Copenhagen 2009 by 6th Malaysia Prime Minister YAB Dato’ Sri Mohd Najib Tun Abdul Razak. While, one of the major energy consumption and emission producers are port systems. Therefore, port must minimise emission and pollution, to become green and environmental friendly. Thus, this study looked for the external environmental factors that influencing port become green. The external environmental factors determined using PESTEL analysis; there are political, economic, social, technology, environment, and legal. Next, the priority dominant external environmental for main factors and sub-factors identified using AHP analysis (Analytic Hierarchy Process). Questionnaires used to collect data from expert, and generated from literature review and pilot test. The initial results showed that the first priority main factor is economic, the second priority main factor is technology, and the third priority main factor is environment. At the same time, the results also highlighted that the first priority sub-factor is economic growth, the second priority sub-factor is reduce pollution, and the third priority sub-factor is research and development. The CR (Consistency Ratio) value is less than 0.1 and indicated that the data is considered acceptable. The advance and green technology and system revolution require financial support, and the Environmental Kuznets Curve (EKC) highlighted that people will looking for environmental protection while economic output per capita achieving certain turning point. Thus, the economic growth is significant contributed and influenced Malaysia Port to become green and environmental friendly.
        4,000원
        100.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        스리랑카는 채소의 주년 생산에 적합한 기후를 갖고 있는 열대국가이다. 열대, 아열대 채소의 재배면적은 전체 농지(105,062 ha)의 약 3%이다. 지난 50년 동안 스리랑카에서 채소 육종에 관한 체계적인 연구가 이루어졌고 채소 부문은 지속적으로 증가하였다. 하지만 채소 육종, 재배 및 가공과 관련된 기술이 선진국에 비해 많이 뒤떨어져 있는 형편이다. 전통 육종법을 통해 개발된 다양한 농업적 형질을 가진 품종이 현재까지 스리랑카의 채소 생산에 이용되고 있지만 생명공학적 방법을 접목한 채소 품종 육종법의 중요성이 점차로 부각되고 있다. 본 논문은 스리랑카에서 중요한 채소 작물인 토마토, 고추류, 콩류, 가지 및 여주의 육종과 품종 현황을 소개하고 향후 스리랑카 육종 전망에 대해 논의하였다.
        4,000원
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