http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Synthesize of V4AlC3 Based MAX Phase Composites by Reactive Spark Plasma Sintering of V2O5:Al:C
Leila Sadeghi,Mansour Razavi,Mohammad Mahdi Kalantarian,Mohammad Reza Rahimipour,Mohsen Hossein‑Zadeh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12
In this research V4AlC3based composites were synthesized by reactive spark plasma sintering (RSPS) method. V2O5:Al:Cstarting materials with molar ratios of 1:6:1.5 and 1:7:1.5 were heat treated at 1400 °C. Final composition, microstructural,physical, mechanical and tribological properties of the prepared composites were compared. The X-ray diffraction analysisresults showed that the formation of V4AlC3as main phase alongside Al2O3and V2AlCby-products. Increasing the Al contentfrom 6 moles to 7 moles led to formation of VC0.845and Al2O3main phases as well as V4AlC3and V2AlCminor phases in thissample due to extraction of Al from die during RSPS operation. Microstructural studies revealed that the uniform distributionof the phases with low amount of porosities. The layered microstructure of the composites confirmed the formation ofMAX phases. Higher bending strength and is achieved for the synthesized composite prepared by 7 moles Al (490 ± 5 MPa)than the composite prepared with 6 moles Al (375 ± 11 MPa). The composite prepared with 7 moles Al also exhibited lowerwear rate (3.7 × 10− 5 mm3/Nm) than that of prepared with 6 moles Al (2.4 × 10− 4 mm3/Nm). Microstructural studies of theworn surfaces indicated that tribo oxidation is dominant mechanism for both fabricated composites.
Mohammad Hossein Ranjbar,Nahid Sadeghi,Leila Sadeghi 대한산업공학회 2018 Industrial Engineeering & Management Systems Vol.17 No.3
Stock return, as a production factor, can play an effective role in growth but the problem that can influence the other variables in investment risk economy is the investigation of the causal relationship between the stock return and economic growth. On the other hand, one important factor regarding the economic growth is the attraction of the foreign capitals which is of a particular necessity in the developing countries featuring intermediate income levels for such a reason as the competition for rare resources and this is well indicative of the crucial significance of the causal relationship between the stock return, foreign direct investment and economic growth. The present study aims at investigating the relationship between the stock exchange market’s return rates, investment risks, growth in the formation of domestic gross capital, growth in per capita domestic gross production and growth in the net input rate of foreign direct investment in eight developing countries known as D8 countries during the years from 1990 to 2015. To do so, dynamic panel data approach has been adopted and generalized method of moment (GMM) estimator has been employed to propose a model for the abovementioned five variables. The estimations were evaluated in five separate models and the results indicated that the macroeconomic variables of exert a positive and significant effect on stock return rate as well as a negative effect on the investment risk.