The utilization of carbonaceous reinforcement-based polymer matrix composites in structural applications has become a hot topic in composite research. Although conventional carbon fiber-reinforced polymer composites (CFRPs) have revolutionized the composite industry by offering unparalleled features, they are often plagued with a weak interface and lack of toughness. However, the promising aspects of carbon fiber-based fiber hybrid composites and hierarchical composites can compensate for these setbacks. This review provides a meticulous landscape and recent progress of polymer matrixbased different carbonaceous (carbon fiber, carbon nanotube, graphene, and nanodiamond) fillers reinforced composites’ mechanical properties. First, the mechanical performance of neat CFRP was exhaustively analyzed, attributing parameters were listed down, and CFRPs’ mechanical performance barriers were clearly outlined. Here, short carbon fiber-reinforced thermoplastic composite was distinguished as a prospective material. Second, the strategic advantages of fiber hybrid composites over conventional CFRP were elucidated. Third, the mechanical performance of hierarchical composites based on carbon nanotube (1D), graphene (2D) and nanodiamond (0D) was expounded and evaluated against neat CFRP. Fourth, the review comprehensively discussed different fabrication methods, categorized them according to performance and suggested potential future directions. From here, the review sorted out three-dimensional printing (3DP) as the most futuristic fabrication method and thoroughly delivered its pros and cons in the context of the aforementioned carbonaceous materials. To conclude, the structural applications, current challenges and future prospects pertinent to these carbonaceous fillers reinforced composite materials were elaborated.
세네갈은 농촌진흥청의 아프리카 국제협력사업의 일환으로 수행되는 「아프리카 다수성 벼 품종개발 ·보급」사업의 주요 회원국으로 본 사업의 효율적 추진을 위해 세네갈의 쌀의 중요성, 쌀 생산 및 육종 현황에 대한 기초정보를 얻고자 조사하였다. 1. 현재 세네갈의 일인당 연간 쌀 소비량은 85kg로서 인구 증가, 도시화 및 쌀의 편의성으로 쌀 수요가 급격히 증가하고 있으나 쌀 생산 부족으로 국내 쌀 전체 수요량의 44%를 해외 수입쌀에 의존하고 있어 쌀 자급자족은 세네갈의 국가정책의 가장 중요한 목표이다. 2. 세네갈에서 쌀 생산은 세네갈 북부에 있는 관개농업과 이기작이 가능한 ‘Senegal River Valley’와 남부세네갈의 까자망스 지역의 천수답지대에서 이루어지고 있으나, 가뭄, 냉해, 염 해, 철분독성 불량토양, 비료 및 제초제 부족, 조류 및 잡초 피해 등 생물학적 제한 요인과 수확후 관리 기반시설 부족, 쌀 운송, 시장형성 등 제도적 제한요인 등으로 쌀 생산이 저해되고 있는 실정이다. 3. 세네갈의 벼 품종개발은 UN산하 농업연구기관인 AfricaRice, IRRI 등과 인도, 스리랑카, 중국, 한국 등 국가 협력과 지원으로 이루어져 왔으며, 1994년 이래 60개의 품종이 개발· 보급 되었다. 그러나 2017년 이후 세네갈 국가육종기관에 의한 품종개발도 이루어지고 있으며 조생종, 수량성, 향을 보유한 품종개발이 주된 육종 목표이다. 4. 현재 세네갈 국내 쌀의 품질과 밥맛에서 수입쌀에 비해 열악하여 소비자로부터 외면당하고 있는 실정으로 향후 세네 갈의 품종육성 목표는 쌀의 품질, 밥맛 및 수량을 동시에 올리기 위한 전략이 최우선시 되었다. 이를 위해 역사적으로 한국의 통일형 품종개발 및 아시아 녹색혁명을 창생시킨 IRRI 의 IR8에서 증명된 바와 같이 자포니카와 아프리카 품종과의 교배를 통한 아프리카 적응 통일형 품종을 육성하는 육종전략이 필요하다.
In this paper, rheological characteristics of Metal Injection Moulding (MIM) feedstock using locally binder of palm stearin are presented. The feedstock consisted of 316L-grade stainless steel powder with three different particle sizes and the binders comprise palm stearin and polyethylene. The viscosity of MIM feedstock at different temperatures and shear rates was measured and evaluated. Results showed that, the feedstock containing palm stearin exhibited suitable rheological properties and suitable to produce a homogeneous feedstock that is favorable for injection molding process.
We present the Programme of Monitoring of Flare Stars in the Orion aggregate by. CCD based. Photometer mounted at the Newtonian focus of 70/98/210-cm meniscus telescope through glass imaging quality C1 filter (3900Å/800Å) with a time resolution of 0.5-1.0 min.
The results on the deep low dispersion (1250 Å/mm at Hɤ, 30° < I < 165°, 195° < I < 210°, |b| < 5°; 7000Å/mm at A band, 50° < I < 115°, b=0°, b=±3.5°) spectral surveys of the MILKY WAY are presented. More than 2250 carbon stars were identified among them 1440 new ones. The C/M5+ ratio increases from 0.02 to 0.3 when longitude varies from 30° to 210°. On the basis of A GENERAL CATALOG OF GALACTIC COOL CARBON STARS the surface distribution of carbon stars has been studied.
The photometry is reported for galaxies in two clusters A1983, 2065 with redshifts 0.046, 0.072 respectively. The luminosity segregation is observed only within a magnitude from the brightest galaxy. The alignment of the galaxy major axis is observed in the Corona Borealis cluster. The intermediate distance clusters (0.05 < z < 0.15) will be studied by CCD mounted on 125cm RCh and 70cm meniscus type telescopes.
The purpose of this study is to analyze the determinants of risk factor model for the Jordanian banking stocks from 2006 to 2018. This study employs the Five-factor Fama and French’s (2015) methodology and uses the annual returns of all Jordanian banks including 2 Islamic and 13 commercial banks listed on the Amman Stock Exchange (ASE) over a period of 13 years. The results show that the factors of value and profitability have an important role in evaluating the expected return in Jordanian banking stocks. Moreover, the value HML and profitability RMW factors provide the highest cumulative returns among these five factors, while the investment CMA and size SMB factors are still around zero cumulative returns. For the market factor, it provides the least negative cumulative returns. The results showed that the largest correlation is between value and investment factors which means that banks with a high book to market value become banks with a conservative investment strategy. The result of the sub-periods confirmed the value and profitability results. The findings of this study suggest that the five-factor Fama and French model is the choice of building an investment portfolio, especially the factors of value and profitability.
The aim of this study is to explore the effect of injustice perception on work alienation and the mediating role played by the employee’s cynicism between injustice perception and work alienation in the healthcare sector in Oman. By utilizing a simple random sampling technique, data were collected using a questionnaire consisting of 306 nurses working in private healthcare providing organizations in Oman. The collected data was then analyzed using AMOS program through the Structural Equation Modeling (SEM). The results of study show that the levels of perception of injustice and cynicism of nurses in the private healthcare centers were low, while the work alienation was found to be at moderate level in these healthcare organizations. The findings of the empirical study reveal that injustice perception and employee’s cynicism significantly affect work alienation. The impact of injustice perception in creating employee’s cynicism was also observed. The hypothesis that the mediating role played by employee’s cynicism in injustice perception and work alienation relationship was partially supported. Moreover, injustice perception and cynicism directly affect work alienation, therefore, these hospitals should consider organizational policies and procedures to achieve equality and justice among nursing personnel, and to eliminate the factors that cause cynicism and work alienation.