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排序方式: 共有516条查询结果,搜索用时 15 毫秒
21.
Tuğçe P. Öztürk Onur B. Özdemir Ali Gelir Nahid A. Keshtiban Önder Yargı Selin Pıravadılı Mucur Alper Seçgin 《应用聚合物科学杂志》2024,141(4):e54854
Solid-state electrolytes such a further novel finding is going to have great importance because of the disadvantages of liquid electrolytes such as electrochemical instability, low ion selectivity, and interface contact. It is anticipated that the use of solid-state electrolytes including supercapacitors (SCs) will become widespread with decreasing self-leakage and environmental damage more than liquid electrolytes. In this study, SCs with graphene/PEDOT: PSS coated electrodes and binary PVA gel electrolytes with a conductive layer were designed and the electrochemical performance of the configurations was characterized. The effects of the conductive layer between binary electrolytes and the concentration of the KOH solution in the electrolytes were studied. It was observed that the conductive layer used between the gel electrolytes causes additional charging at the electrolyte/conductive layer interface and behaves like a serially connected capacitor to the double-layer capacitor. Interestingly, at a slow sweep rate (5 mV/s), the specific capacitance values of the assembled SCs decreased when a conductive layer was used but it increased when the sweep rate was fast (100 mV/s). 相似文献
22.
JanP.K. Reynhardt Yong Yang Abdelhamid Sayari Howard Alper 《Advanced Synthesis \u0026amp; Catalysis》2005,347(10):1379-1388
Polyamidoamine (PAMAM) dendrimers up to the third generation were grown for the first time on the surface of a large‐pore (18 nm) Davisil silica support. The supported dendrimers of generations 0, 1, 2 and 3 were phosphinomethylated and complexed with rhodium. All the generations were found to be very active for the hydroformylation of olefins. The hydroformylation of 1‐octene was accomplished with a turnover frequency of 1700 h−1 at 70 °C. The G(1) material was found to be the most active when the different generations were compared at 50% conversion at 70 °C 相似文献
23.
Boon Peng Chang Mohamed A. Abdelwahab Alper Kiziltas Deborah F. Mielewski Amar K. Mohanty Manjusri Misra 《大分子材料与工程》2021,306(5):2000680
Advanced hybrid biocomposites are engineered from nylon 6, waste wood biosourced carbon (biocarbon) with a low content of synthetic fiber for lightweight auto-parts uses. The novel engineering process through direct injection molding of only 2 wt% synthetic fibers in the form of masterbatch with 20 wt% biocarbon, results outstanding performance of the resulting nylon biocomposites. Such uniquely developed biocomposites show tensile strength of 105 MPa and tensile modulus of 5.14 GPa with a remarkable heat deflection temperature (HDT) of 206 °C. The direct injection molding of synthetic fiber retains the length ≈3 times higher as compared to traditional extrusion and injection molding; resulting greater degree of entanglement and composite reinforcement effectiveness in the hybrid biocomposites. Highly dimensionally stable nylon 6 biocomposites with a very low coefficient of linear thermal expansion results through reinforcing ability of the sustainable biocarbon and small amount of synthetic fiber. 相似文献
24.
Sayli Devdas Bote Alper Kiziltas Ian Scheper Deborah Mielewski Ramani Narayan 《应用聚合物科学杂志》2021,138(29):50690
In this study, biobased polyester-ether polyols derived from meso-lactide and dimer acids were evaluated for flexible polyurethane foams (PUF) applications. Initially, the catalyst concentration was optimized for the biobased PUF containing 30% of biobased polyol (70% petroleum-based polyol). Then, the same formulation was used for biobased PUF synthesis containing 10%–40% of biobased polyols. The performance of biobased PUF was compared with the performance of the control foam made with 100% petroleum-based polyol. The characteristic times (cream, top of the cup, string gel, rise, tack-free) of biobased PUF were determined. The biobased PUF were evaluated for the mechanical (tensile and compressive) and morphological properties. As the wet compression set is important for automotive applications, it was measured for all biobased PUF. The thermal degradation behavior of biobased PUF was also evaluated and compared with the control foam. The effect of different hydroxyl and acid values of polyols on the mechanical properties of biobased PUF is also discussed. The miscibility of all components of PUF formulations is crucial in order to produce a foam with uniform properties. Thus, the miscibility of biobased polyols with commercial petroleum-based polyol was studied. 相似文献
25.
A major source of inaccuracy in CNC machines is unwanted vibrations induced by the frequency spectra of reference motion trajectory. This paper presents a novel approach where instead of filtering techniques, axis motion commands are generated with optimal frequency spectra in the first place. Tangential feedrate profile is defined as parametric spline, and its frequency spectrum is optimized with respect to structural dynamics of the machine. The optimization problem is solved efficiently using Quadratic Programming. Experimental results confirm that proposed technique can greatly improve surface finish during machining spline tool-paths without sacrificing from cycle time and contouring performance. 相似文献
26.
Teoman Dogru Ali Kirik Hasan Gurel Ali A. Rizvi Manfredi Rizzo Alper Sonmez 《International journal of molecular sciences》2021,22(12)
Nonalcoholic fatty liver disease (NAFLD) is strongly associated to the features of metabolic syndrome which can progress to cirrhosis, liver failure and hepatocellular carcinoma. However, the most common cause of mortality in people with NAFLD is not liver-related but stems from atherosclerotic cardiovascular disease (CVD). The prevalence of NAFLD is on the rise, mainly as a consequence of its close association with two major worldwide epidemics, obesity and type 2 diabetes (T2D). The exact pathogenesis of NAFLD and especially the mechanisms leading to disease progression and CVD have not been completely elucidated. Human fetuin-A (alpha-2-Heremans Schmid glycoprotein), a glycoprotein produced by the liver and abundantly secreted into the circulation appears to play a role in insulin resistance, metabolic syndrome and inflammation. This review discusses the links between NAFLD and CVD by specifically focusing on fetuin-A’s function in the pathogenesis of NAFLD and atherosclerotic CVD. 相似文献
27.
Journal of Applied Electrochemistry - In this study, within the defined orthogonal array of Taguchi design, the hydrothermal process parameters have been optimized for fabricating the smallest... 相似文献
28.
Li Huijun; Lee Donghyuck; Pfeiffer Steven I.; Kamata Akihito; Kumtepe Alper T.; Rosado Javier 《Canadian Metallurgical Quarterly》2009,24(3):186
This study examined measurement invariance of the Gifted Rating Scales—School Form (GRS–S) across the United States, Puerto Rico, China, South Korea, and Turkey, using multigroup confirmatory factor analysis. A total of 1,817 students were rated by 287 teachers using either translated versions of GRS–S or the original English GRS–S. Results indicate a similar factor structure for the GRS–S across the five locations; six factors with each of the 72 items equivalently loaded to the same latent variable across groups. The metric invariance test and the factor variance and covariance invariance tests reveal that the patterns of factor loadings and the factor variances and covariances are invariant across the five groups. Moreover, the scalar invariance test indicates that item means are equivalent across the groups. These results suggest that the GRS–S has intercultural utility and can be similarly interpreted. Implications and limitations of the present research for gifted identification are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
Tuba Karahan Ismail Duman Muzeyyen Marsoglu 《JOM Journal of the Minerals, Metals and Materials Society》2009,61(11):30-32
The only method so far used industrially to produce primary aluminum is the combination of the Bayer process with the Hall-Héroult process. The production process of aluminum which was patented by Charles Martin Hall and Paul Louis Toussaint Héroult in 1886, has long been important in our daily lives and that importance is likely to increase year by year. In this study, different subsonic and sonic vibrations, which were obtained from a 0.30 kW, 1,400 rpm three-phase motor, also a 0.55 kW, 2,800 rpm three-phase motor and 0.75 kW frequency converter, were applied to a laboratory-type aluminum electrolysis cell and the possibility of eliminating the anode effect was investigated. 相似文献
30.
Cengiz Duran Atiş Cahit Bilim Özlem Çelik Okan Karahan 《Construction and Building Materials》2009,23(1):548-555
The development of new binders, as an alternative to traditional cement, by the alkaline activation of industrial by-products (i.e. ground granulated slag and fly ash) is an ongoing research topic in the scientific community [Puertas F, Amat T, Jimenez AF, Vazquez T. Mechanical and durable behaviour of alkaline cement mortars reinforced with polypropylene fibres. Cem Concr Res 2003;33(12): 2031–6]. The aim of this study was to investigate the feasibility of using and alkaline activated ground Turkish slag to produce a mortar without Portland cement (PC).Following the characterization of the slag, mortar specimens made with alkali-activated slag were prepared. Three different activators were used: liquid sodium silicate (LSS), sodium hydroxide (SH) and sodium carbonate (SC) at different sodium concentrations. Compressive and flexural tensile strength of alkali-activated slag mortar was measured at 7-days, 28-days and 3-months. Drying shrinkage of the mortar was measured up to 6-months. Setting times of the alkali-activated slag paste and PC paste were also measured.Setting times of LSS and SH activated slag pastes were found to be much slower than the setting time of PC paste. However, slag paste activated with SC showed similar setting properties to PC paste.LSS, SH and SC activated slag mortar developed 81, 29, and 36 MPa maximum compressive strengths, and 6.8, 3.8, and 5.3 MPa maximum flexural tensile strengths at 28-days. PC mortar developed 33 MPa compressive strength and 5.2 MPa flexural tensile strength. LSS and SH activated slag mortars were found to be more brittle than SC activated slag and PC mortars.Slag mortar made with LSS had a high drying shrinkage, up to six times that of PC mortar. Similarly, slag mortar made with SH had a shrinkage up to three times that of PC mortar. However, SC activated slag mortar had a lower or comparable shrinkage to PC mortar. Therefore, the use of SC as an activator for slag mortar is recommended, since it results in adequate strength, similar setting times to PC mortar and comparable or lower shrinkage. 相似文献