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71.
Alcohols have been used as a fuel for engines since 19th century. Among the various alcohols, ethanol is known as the most suited renewable, bio-based and ecofriendly fuel for spark-ignition (SI) engines. The most attractive properties of ethanol as an SI engine fuel are that it can be produced from renewable energy sources such as sugar, cane, cassava, many types of waste biomass materials, corn and barley. In addition, ethanol has higher evaporation heat, octane number and flammability temperature therefore it has positive influence on engine performance and reduces exhaust emissions. In this study, the effects of unleaded gasoline (E0) and unleaded gasoline–ethanol blends (E50 and E85) on engine performance and pollutant emissions were investigated experimentally in a single cylinder four-stroke spark-ignition engine at two compression ratios (10:1 and 11:1). The engine speed was changed from 1500 to 5000 rpm at wide open throttle (WOT). The results of the engine test showed that ethanol addition to unleaded gasoline increase the engine torque, power and fuel consumption and reduce carbon monoxide (CO), nitrogen oxides (NOx) and hydrocarbon (HC) emissions. It was also found that ethanol–gasoline blends allow increasing compression ratio (CR) without knock occurrence. 相似文献
72.
Yogurt and bio-yogurts were made from goat’s milk using a starter culture and probiotic culture, with or without cysteine addition (0.5%). Incubation was carried out at 37 and 42 °C until pH 4.6 was reached and yogurts were stored 4 ± 1 °C for 14 days. Yogurts were analysed 1, 7 and 14 days after production. The addition of cysteine, incubation temperature and storage time significantly influenced overall properties of the samples. During storage, whey separation, pH and acetaldehyde decreased, while lactic acid increased. Viable bacterial counts in all bio-yogurts were above 107 cfu g−1 at the end of storage. Whey separation, titratable acidity and lactic acid contents were lower, while acetaldehyde and viable bacterial counts were higher in the bio-yogurts incubated at 37 °C and supplemented with cysteine, in comparison to other samples. This indicates that lower temperature incubation and addition of cysteine can be used satisfactorily for the manufacture of bio-yogurt. 相似文献
73.
Shaz Qadeer Serdar Tasiran 《International Journal on Software Tools for Technology Transfer (STTT)》2012,14(3):291-305
We give an overview of correctness criteria specific to concurrent shared-memory programs and runtime verification techniques for verifying these criteria. We cover a spectrum of criteria, from ones focusing on low-level thread interference such as races to higher-level ones such as linearizability. We contrast these criteria in the context of runtime verification. We present the key ideas underlying the runtime verification techniques for these criteria and summarize the state of the art. Finally, we discuss the issue of coverage for runtime verification for concurrency and present techniques that improve the set of covered thread interleavings. 相似文献
74.
Ana Cetkovic Alessandro Bellapianta Mihai Irimia-Vladu Jakob Hofinger Cigdem Yumusak Andrea Corna Markus Clark Scharber Günther Zeck Niyazi Serdar Sariciftci Matthias Bolz Ahmad Salti 《International journal of molecular sciences》2022,23(15)
Millions of people worldwide are diagnosed with retinal dystrophies such as retinitis pigmentosa and age-related macular degeneration. A retinal prosthesis using organic photovoltaic (OPV) semiconductors is a promising therapeutic device to restore vision to patients at the late onset of the disease. However, an appropriate cytotoxicity approach has to be employed on the OPV materials before using them as retinal implants. In this study, we followed ISO standards to assess the cytotoxicity of D18, Y6, PFN-Br and PDIN individually, and as mixtures of D18/Y6, D18/Y6/PFN-Br and D18/Y6/PDIN. These materials were proven for their high performance as organic solar cells. Human RPE cells were put in direct and indirect contact with these materials to analyze their cytotoxicity by the MTT assay, apoptosis by flow cytometry, and measurements of cell morphology and proliferation by immunofluorescence. We also assessed electrophysiological recordings on mouse retinal explants via microelectrode arrays (MEAs) coated with D18/Y6. In contrast to PFN-Br and PDIN, all in vitro experiments show no cytotoxicity of D18 and Y6 alone or as a D18/Y6 mixture. We conclude that D18/Y6 is safe to be subsequently investigated as a retinal prosthesis. 相似文献
75.
Serdar Bar 《International Journal of Engineering Science》2005,43(19-20):1471-1485
This paper is concerned with applying the mixture theory of two chemically inert incompressible Newtonian fluids to some simple unsteady flows in the annular region between two infinitely long coaxial cylinders. The equations governing the motion of the binary mixture under discussion are reduced to a system of coupled partial differential equations. With the help of finite Hankel transforms, the exact solutions of these equations are obtained in series form for the following three problems: (i) unsteady axial Couette flow in an annulus, (ii) unsteady Poiseuille flow in an annulus, (iii) unsteady circular Couette flow in an annulus. 相似文献
76.
Önder Metin Sally Fae Ho Cemalettin Alp Hasan Can Max N. Mankin Mehmet Serdar Gültekin Miaofang Chi Shouheng Sun 《Nano Research》2013,6(1):10-18
Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential reduction of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs have a narrow size distribution with a mean particle size of 10 nm and a standard deviation of 5% with respect to the particle diameter. Mechanistic studies showed that the presence of TOP was essential to control the reductive decomposition of Ni-TOP and Pd-TOP, and the formation of Ni/Pd core/shell NPs. Using the current synthetic protocol, the composition of the Ni/Pd within the core/shell structure can be readily tuned by simply controlling the initial molar ratio of the Ni and Pd salts. The as-synthesized Ni/Pd core/shell NPs were supported on graphene (G) and used as catalyst in Suzuki-Miyaura cross-coupling reactions. Among three different kinds of Ni/Pd NPs tested, the Ni/Pd (Ni/Pd = 3/2) NPs were found to be the most active catalyst for the Suzuki-Miyaura cross-coupling of arylboronic acids with aryl iodides, bromides and even chlorides in a dimethylformamide/water mixture by using K2CO3 as a base at 110 °C. The G-Ni/Pd was also stable and reusable, providing 98% conversion after the 5th catalytic run without showing any noticeable Ni/Pd composition change. The G-Ni/Pd structure reported in this paper combines both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst, and is promising catalyst candidate for various Pd-based catalytic applications. 相似文献
77.
Fabrication,characterization, and performance of YbDSB ternary compounds for IT‐SOFC applications 下载免费PDF全文
Serdar Yilmaz Esra Yildiz Bekir Kavici 《International Journal of Applied Ceramic Technology》2017,14(4):550-561
(Yb2O3)x(Dy2O3)y(Bi2O3)1?x?y (0.04≤x+y≤0.20) powders (xYbyDSB) were synthesized by modified sol‐gel Pecchini method. The powders were characterized for structural, surface morphological, thermal, and electrical properties and power density measurements by means of X‐ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis/thermal gravimetry (DTA/TG), and impedance spectroscopy, respectively. Lattice parameters and crystalline size of δ‐phase of Yb2O3‐ and Dy2O3‐doped Bi2O3 samples were calculated from the X‐ray diffraction data. Surface and grain properties of the related phases were determined by SEM analysis. In the investigated system, the maximum electrical conductivity was observed as σ=0.954 S cm?1 for 6% mol Yb2O3 and 6% mol Dy2O3 at 800°C among all δ‐YbDSB systems. Cathode supported electrochemical cell was fabricated and 6Yb6DSB was used as the electrolyte. Maximum power density of single cell with an active area of 1.5 cm2 is 72.50 mW/cm2 at 700°C. 相似文献
78.
Urberg Kathryn A.; De?irmencio?lu Serdar M.; Pilgrim Colleen 《Canadian Metallurgical Quarterly》1997,33(5):834
The relative influence of adolescents' closest friends and their friendship group on their cigarette smoking and alcohol use was investigated in a short-term, longitudinal study of 1,028 students in the 6th, 8th and 10th grades in 2 school systems. The amount of influence over the school year was modest in magnitude and came from the closest friend for initiation of cigarette and alcohol use. Only the friendship group use predicted transition into current cigarette use, whereas only the close friend use predicted transition into current alcohol use. Both group and close friends independently contributed to the prediction of adolescents' drinking to intoxication. No difference in the amount of influence, was found between stable and unstable close friendships or friendship groups; neither grade nor gender of the adolescents related to the amount of influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
79.
A new generation multihollow opaque polymer pigment was synthesized by suspension polymerization of “water‐in‐oil‐in‐water” emulsion method, where methyl methacrylate and ethylene glycol dimethacrylate monomer mixture was used as oil phase. The effects of surfactant and cosurfactant composition in terms of “hydrophilic/lipophilic balance” on the stability of the “water‐in‐oil” emulsion and the size of water droplets were studied. Low droplet sizes and the optimum stability were obtained with “Span 80&Tween 80” surfactant mixture at an HLB value of 8. The desired size distribution was obtained at “monomer/surfactant/water” ratio of 75.5/9.4/15.1 at an ultrasonic mixing power of 80 W lasting for 30 s. The surface morphology and hollow structure of polymer pigments were analyzed by scanning and transmission electron microscopy techniques. L*a*b color and gloss properties of polymer pigments were examined. The opacity values were assessed by contrast ratio measurements, and the pigments provided up to 97.3% opacity with 50% v/v solid content in resin. In addition, the pigments exhibited low gloss values and yielded matte films. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43696. 相似文献
80.