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排序方式: 共有191条查询结果,搜索用时 343 毫秒
111.
Sattar Jabbar Murad Algayyim Andrew P. Wandel Talal Yusaf Saddam Al-Lwayzy 《Proceedings of the Combustion Institute》2019,37(4):4729-4739
Increasing energy demands and more stringent legislation relating to pollutants such as nitrogen oxide (NOx) and carbon monoxide (CO) from fossil fuels have accelerated the use of biofuels such as biodiesel. However, current limitations of using biodiesel as an alternative fuel for CI engines include a higher viscosity and higher NOx emissions. This is a major issue that could be improved by blending biodiesel with alcohols. This paper investigates the effect of a butanol–acetone mixture (BA) as an additive blended with biodiesel to improve the latter's properties. Macroscopic spray characteristics (spray penetration, spray cone angle and spray volume) were measured in constant volume vessel (CVV) at two injection pressures. A high-speed camera was used to record spray images. The spray's edge was determined using an automatic threshold calculation algorithm to locate the spray outline (edge) from the binary images. In addition, an engine test was carried out experimentally on a single-cylinder diesel engine. The engine's performance was measured using in-cylinder pressure, brake power (BP) and specific fuel consumption (SFC). Emission characteristics NOx, CO and UHC were also measured. Neat biodiesel and three blends of biodiesel with up to 30% added BA were tested. The experimental data were analyzed via ANOVA to evaluate whether variations in parameters due to the different fuels were significant. The results showed that BA can enhance the spray characteristics of biodiesel by increasing both the spray penetration length and the contact surface area, thereby improving air–fuel mixing. The peak in-cylinder pressure for 30% BA was comparable to neat diesel and higher than that of neat biodiesel. Brake power (BP) was slightly improved for 10% BA at an engine speed of 2000 rpm while SFC was not significantly higher for any of the BA-biodiesel blends because of the smaller heating value of BA. Comparing the effect on emissions of adding BA to biodiesel, increasing the amount of BA reduced NOx and CO (7%) and (40%) respectively compared to neat biodiesel, but increased UHC. 相似文献
112.
Polyether ether ketone (PEEK) is a semi-crystalline thermoplastic polymer having excellent mechanical and thermal properties. Exposure of this polymer to aliphatic and aromatic solvents can lead to degradation or swelling of the polymeric material. The present work described the plasticization and stability analysis of semi-crystalline PEEK under different aromatic and aliphatic solvent environment. A variety of solvents (acetone, benzene, benzyl alcohol, chloroform, methanol, and toluene), based on their Hildebrand’s Solubility Parameter, were chosen for investigation. The physico-chemical characteristics of virgin and treated polymeric samples were investigated using Gas Chromatography–Mass Spectrometry (GC–MS), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The results indicated that the solvent exposure did not significantly affect the thermal behavior and chemical structure of the polymer. However, it seems that certain components of the polymer were leached into the solvent phase as revealed by the GC–MS analysis. The present study identified PEEK as a potentially suitable polymer for the applications where high resistance to aliphatic and aromatic solvents is needed. 相似文献
113.
Amrah Nouri Ahmad Poursattar Marjani Jabbar Khalafy 《Journal of heterocyclic chemistry》2019,56(10):2912-2921
A new series of benzo[g]thiazolo[2,3‐b]quinazolin‐4‐ium and benzo[g]benzo[4,5]thiazolo[2,3‐b]quinazolin‐14‐ium hydroxide derivatives have been synthesized by the one‐pot, three‐component reaction of aryl glyoxal monohydrates, 2‐hydroxy‐1,4‐naphthoquinone, and 2‐aminothiazole or 2‐aminobenzothiazole in the presence of triethylamine and p‐toluenesulfonic acid as organocatalysts in H2O/acetone (2:1) at room temperature. This method offers mild reaction conditions, excellent yields, easy workup, and readily accessible starting materials and catalysts. 相似文献
114.
Microwave-assisted catalytic oxidative desulfurization of gasoil fuel using synthesized CuO-ZnO nanocomposites 《燃料化学学报》2019,47(9):1075-1082
Recently,organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests.Therefore,improved approaches to remove sulfur are still essential.In the present work,a simple catalytic oxidative desulfurization(CODS)system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts,and H_2O_2 as oxidant under microwave irradiation.The main reaction parameters influencing sulfur conversion including microwave power,irradiation time,catalyst dosage and H_2O_2 to gasoil volume ratio have been investigated.The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD,FE-SEM,AFM and BET surface area methods.The results reveal that,high sulfur conversion(93%)has been achieved under suitable conditions of microwave CODS as follows:microwave power of 540 W,irradiation time of 15 min,catalyst dosage of 8 g/L(0.4 g),and H_2O_2:gasoil volume ratio of 0.3.The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity. 相似文献
115.
Saima Arshed Anjan Biswas Mahmoud Abdelaty Qin Zhou Seithuti P. Moshokoa Milivoj Belic 《Chinese Journal of Physics (Taipei)》2018,56(6):2879-2886
This paper employs two integration procedures to obtain soliton solutions to the perturbed Gerdjikov–Ivanov equation. They are G′/G2–expansion method and the sine–cosine method. Bright, dark and singular solitons are revealed along with a few of the combo–soliton solutions. The existence criteria of these solitons are also given. 相似文献
116.
In this paper, two integrating strategies namely exp[-Φ(X)] and G'/G~2-expansion methods together with the attributes of local-M derivatives have been acknowledged on the electrical microtubule(MT) model to retrieve soliton solutions. The said model performs a significant role in illustrating the waves propagation in nonlinear systems. MTs are also highly productive in signaling, cell motility, and intracellular transport. The proposed algorithms yielded solutions of bright, dark, singular, and combo fractional soliton type. The significance of the fractional parameters of the fetched results is explained and presented vividly. 相似文献
117.
Application of capillary immunoelectrophoresis revealed an age‐ and gender‐dependent regulated expression of PrPC in liver
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Amandeep Singh Arora Saima Zafar Otto Kollmar Franc Llorens Waqas Tahir Sven Vanselow Prateek Kumar Mary Jo Schmerr Matthias Schmitz Inga Zerr 《Electrophoresis》2015,36(24):3026-3033
The cellular prion protein (PrPC) is a glycoprotein, anchored to the plasma membrane and abundantly expressed in the central nervous system. The expression of PrPC in the peripheral tissues is low and only little information is available on its functions in the nonneuronal tissues. The antioxidant function of PrPC during the activation of hepatic stellate cells has already been reported. Therefore, the aim of the study was to expand our knowledge on the functions of PrPC by detailed characterization of its expressional profile in the liver. In a combined strategy by using capillary immunoelectrophoresis and standard techniques, we have shown a sexually dimorphic expression of PrPC in mice and human liver tissues. Further, we showed a significant age‐dependent upregulation of PrPC expression in the liver of 14‐ and 9‐month‐old mice as compared to 3 months of age. Therefore, this study may provide new insights into the gender‐specific role of PrPC in the liver, which may further be linked to its protective role against oxidative stress during aging. In addition, the current study also shows an application of immunoelectrophoresis with a low coefficient of variation to analyze the miniscule amount of PrPC in the mouse liver tissue. 相似文献
118.
119.
Choudhary MI Jalil S Todorova M Trendafilova A Mikhova B Duddeck H Atta-ur-Rahman 《Natural product research》2007,21(11):1032-1036
Achillea species are widely used in folk medicine for treatment of inflammatory diseases. The inhibitory effect on the human neutrophils respiratory burst activity of total extracts, their fractions and some main constituents of the flower heads from Achillea asplenifolia, A. collina and A. distans belonging to A. millefolium complex of Bulgarian origin, were tested by the modified method of Tan and Berridge. Seven from the investigated fractions showed activity similar or higher than that of indomethacine and might be evaluated as nonsteroidal anti-inflammatory agents. 相似文献
120.
Mubeen Muhammad Khalid Muhammad Adnan Mukhtar Maria Shahrum Saba Zahra Shanila Shabbir Saima Iqbal Azhar 《Journal of fluorescence》2021,31(4):1055-1063
Journal of Fluorescence - Employing natural or artificial sunscreens is essential to protect the skin from ultraviolet radiations that cause premature aging and develop melanoma and other forms of... 相似文献