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排序方式: 共有107条查询结果,搜索用时 15 毫秒
31.
Thien An Le Tae Wook Kim Sae Ha Lee Eun Duck Park 《Korean Journal of Chemical Engineering》2017,34(12):3085-3091
The effect of alumina crystalline phases on CO and CO2 methanation was investigated using alumina-supported Ni catalysts. Various crystalline phases, such as α-Al2O3, θ-Al2O3, δ-Al2O3, η-Al2O3, γ-Al2O3, and κ-Al2O3, were utilized to prepare alumina-supported Ni catalysts via wet impregnation. N2 physisorption, H2 chemisorption, temperature-programmed reduction with H2, CO2 chemisorption, temperature-programmed desorption of CO2, and X-ray diffraction were employed to characterize the catalysts. The Ni/θ-Al2O3 catalyst showed the highest activity during both CO and CO2 methanation at low temperatures. CO methanation catalytic activity appeared to be related to the number of Ni surface-active sites, as determined by H2-chemisorption. During CO2 methanation, Ni dispersion and the CO2 adsorption site were found to influence catalytic activity. Selective CO methanation in the presence of excess CO2 was performed over Ni/γ-Al2O3 and Ni/δ-Al2O3; these substrates proved more active for CO methanation than for CO2 methanation. 相似文献
32.
Cuong Ton‐That Geoff Stockton Matthew R Phillips Thien‐Phap Nguyen Chun Hao Huang Ala Cojocaru 《Polymer International》2008,57(3):496-501
BACKGROUND: Conjugated polymers, especially those of the poly(phenylene vinylene) (PPV) family, are promising candidates as emission material in light‐emitting devices. The aim of this work was to investigate the dependence of the luminescence properties of PPV‐based derivatives on their polymer structure, especially side groups. RESULTS: Three PPV derivatives, BEHPPV, MEHPPV and MEHSPPV, were synthesised and characterised by photoluminescence (PL) and cathodoluminescence (CL) spectroscopies in the temperature range 10–300 K. PL and CL spectra of the polymers exhibit similar luminescence peaks, which undergo a blue shift with increasing temperature. The shift in wavelength is accompanied by variations in the relative intensities of emission peaks. Both BEHPPV and MEHPPV display emission characteristics of the PPV backbone, but the peak of MEHPPV shifts to a longer wavelength in comparison with the corresponding peak of BEHPPV at the same temperature. The luminescence spectra of MEHSPPV, which has a sulfanyl incorporated in the side chain, are considerably different from those of the two other derivatives. CONCLUSIONS: The results demonstrate that the luminescence properties depend strongly on the chain conformations of the conjugated backbone, which are affected by polymer side chains. Copyright © 2007 Society of Chemical Industry 相似文献
33.
Co-firing of coal and cattle feedlot biomass (FB) fuels. Part I. Feedlot biomass (cattle manure) fuel quality and characteristics 总被引:1,自引:0,他引:1
The use of cattle manure (referred to as feedlot biomass, FB) as a fuel source has the potential to solve both waste disposal problems and reduce fossil fuel based CO2 emissions. Previous attempts to utilize animal waste as a sole fuel source have met with only limited success due to the higher ash, higher moisture, and inconsistent properties of FB. Thus, a co-firing technology is proposed where FB is ground, mixed with coal, and then fired in existing pulverized coal fired boiler burner facilities. A research program was undertaken in order to determine: (1) FB fuel characteristics, (2) combustion characteristics when fired along with coal in a small scale 30 kWt (100,000 BTU/h) boiler burner facility, and (3) combustion and fouling characteristics when fired along with coal in a large pilot scale 150 kWt (500,000 BTU/h DOE-NETL boiler burner facility). These results are reported in three parts. Part I will present a methodology of fuel collection, fuel characteristics of the FB, its relation to ration fed, and change in fuel characteristics due to composting. It was found that FB has approximately half the heating value of coal, twice the volatile matter of coal, four times the N content of coal on heat basis, and due to soil contamination during collection, the ash content is almost 9-10 times that of low ash (5%) coal. The addition of <5% crop residues had little apparent effect on heating value. The main value of composting for combustion fuel would be to improve physical properties and to provide homogeneity. The energy potential of FB diminished with composting time and storage; however, the DAF HHV is almost constant for ration, FB-raw, partially composted and finished composted. The fuel N per GJ is considerably high compared to coal, which may result in increased NOx emissions. The N and S contents per GJ increase with composting of FB while the volatile ash oxide% decreases with composting. Based on heating values and alkaline oxides, partial composting seems preferable to a full composting cycle. Even though the percentage of alkaline oxides is reduced in the ash, the increased total ash percentage results in an increase of total alkaline oxides per unit mass of fuel. The adiabatic flame temperature for most of the biomass fuels can be empirically correlated with ash and moisture percentage. 相似文献
34.
35.
Tu Nguyen Anh Huynh-The Thien Wong Kok-Seng Demirci M. Fatih Lee Young-Koo 《The Journal of supercomputing》2021,77(12):14374-14404
The Journal of Supercomputing - Nowadays, the explosion of CCTV cameras has resulted in an increasing demand for distributed solutions to efficiently process the vast volume of video data.... 相似文献
36.
37.
Qibai Wu Thien Ching Qiang Guoxun Zeng Haiyan Zhang Ye Huang Yaodong Wang 《International Journal of Hydrogen Energy》2017,42(37):23871-23877
Palm oil is one of the most important oils in the world and huge amounts of palm biomass wastes are generated through palm oil extracting process which could endanger the environment. Meanwhile, electricity shortage is getting worse due to lack of fossil fuel. To convert biomasses from palm oil industry for power generation is a beneficial approach for both power shortage and environmental degradation. In order to investigate and optimize the generation process of power and heat from the waste biomass in palm oil industry, an analytic study of a combined heat and power plant in a palm oil mill fuelled with sustainable and renewable biomass wastes was conducted using ECLIPSE software through a case study in Malaysia. The resources of the biomass wastes in the mill were identified and the samples were collected on site. The waste samples were analysed in laboratory and their calorific value, chemical composition and biomethane potential were found. A simulation model was then set up using ECLIPSE software and the model was validated using the practical data of the CHP plant. Three different combinations of the biomass wastes, including EFB and Shell as fuel for power generation, MF co-firing with Biogas, and power generation using KS, EFB and Biogas with preheaters, were used in the simulation. It was found that all of the three combinations were able to produce enough electrical power and heat (steam) to meet the power and heat demand for the production process. The simulation results indicated that the palm solid biomass wastes and the biogas produced by mill effluent were able to provide enough sustainable and renewable fuel for the palm oil production process; and it is possible to provide extra electricity for the nearby area, which is one of the best option for utilization of palm oil biomass wastes. 相似文献
38.
Duong Trang An Erkinov Farruhk Nguyen Hoang Thien Khoi Ahn Chang Won Kim Byeong Woo Han Hyoung-Su Lee Jae-Shin 《Journal of Electroceramics》2020,45(4):164-171
Journal of Electroceramics - The formation of a morphotropic phase boundary (MPB) in piezoelectric ceramics is one of the most important techniques to enhance their dielectric and piezoelectric... 相似文献
39.
Technology transfer from the government sector to industry has emerged as an important activity in developed and developing countries as governments are increasing their funding for the national innovation systems with an objective of developing technologies which will improve and enhance the country’s national competitiveness. However, this endeavor requires good technology transfer practices from the government R&D facilities to industry. Developed countries have embarked on this process for the past two decades and have gained some success, but further improvements are still needed. This paper compares the status of government technology transfer in a developed country, the US, and that in a developing country, Vietnam. 相似文献
40.
Saether T Tran TN Rootwelt H Grav HJ Christophersen BO Haugen TB 《Reproduction (Cambridge, England)》2007,133(2):467-477
On the molecular level, essential fatty acid deficiency (EFAD) has been associated with induced fatty acid (FA) desaturase expression and activity in several tissues. However, there seem to be exceptions. In the present study, we examine the effects of EFAD in the male rat genital tract, combining FA analysis, gene expression studies, and morphological evaluation of epididymal spermatozoa. When feeding 21-day-old Wistar rats, a fat-free diet for 6 weeks, an increase in 18:1n-9 and 20:3n-9 and a concomitant decrease in the 18:2n-6 and 20:4n-6 species are seen in testis, as well as in liver. However, with regard to desaturase expression the rat testis seems to be unresponsive to EFAD conditions, in contrast to other organs studied. In the sexually mature testis none of the desaturases (SCD1, SCD2, D5D, or D6D) are induced in response to lowered contents of polyunsaturated FAs. This also applies to caput epididymis, while EFAD sensitivity is regained in cauda epididymis, where the desaturases are upregulated. The FA profile of epididymal spermatozoa is increasingly affected by EFAD during the transport from testis to cauda epididymis. Furthermore, a significant increase in the number of abnormal spermatozoa is observed in cauda epididymis. 相似文献