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11.
Sevinc Korkmaz Yavuz Salt Ayca Hasanoglu Semra Ozkan 《Chemical Engineering Communications》2013,200(6):585-599
In this study using poly(vinylalcohol) (PVOH) membranes cross-linked with tartaric acid (Tac) desorption experiments were performed for selected concentrations of binary ethyl acetate (EtAc)-water mixture at temperatures of 30°, 40°, and 50°C to determine sorption of components. Sorption values measured were compared with those estimated by the Flory-Huggins approach. Additionally, desorption results were compared with pervaporation results of another study in terms of solution-diffusion theory, and the effect of thermodynamic interactions on selective transport of the binary mixture and membrane system was investigated. The results obtained show that selective transport of EtAc-water mixture was influenced by increasing temperature and water content in the feed. It is shown that preferential sorption is more effective for pervaporation selectivity than diffusion selectivity. 相似文献
12.
In this study, pumpkin seeds, called as “Ürgüp Sivrisi” and grown in Cappadocia region, were used as plant materials because of high aroma contents. In the supercritical fluid extraction of pumpkin seed oil, the effect of main process parameters as the particle size (250-2360 μm), the volumetric flow rate of supercritical solvent (0.06-0.30 L/h), the operating pressure (20-50 MPa), the operating temperature (40-70 °C), the type of entrainer (ethanol and n-hexane) and those concentrations (0-10 vol.%) on the extraction yield, the oil solubility and the initial extraction rate were investigated. A cross-over effect for the extraction of pumpkin seed oil using supercritical CO2 was determined at the operating pressure of 20-30 MPa. The maximum extraction yield obtained with entrainer free was reached 0.50 g oil/g dry seed at 600-1180 μm, 0.12 L/h, 50 MPa and 70 °C for the operation time of 5 h. The maximum extraction yield obtained with ethanol as an entrainer in the experiments was reached 0.54 g oil/g dry seed at the conditions of 600-1180 μm, 0.12 L/h, 30 MPa, 40 °C and 8 vol.% for the operating time of 2 h. The oil compositions were determined by gas chromatography analysis and the results showed that the compositions of pumpkin seed oil which were obtained by means of organic solvent extraction and supercritical fluid extraction were similar. The average oil compositions determined as 9.3 (±0.43)% palmitic acid, 7.5 (±0.6)% stearic acid, 32.3 (±0.6)% oleic acid, 48.1 (±0.6)% linoleic acid and 0.7 (±0.3)% linolenic acid. The morphological changes in the seeds were determined by the scanning electron microscopy analysis. 相似文献
13.
Alper Kasgoz Mehmet Korkmaz Mine Begum Alanalp Ali Durmus 《Journal of Polymer Research》2017,24(9):148
In this study, effect of processing method on microstructure formation and related electrical conductivity and electromagnetic interference shielding effectiveness of carbon nanofiber (CNF) filled thermoplastic polyurethane (TPU) composites, prepared via three different processing techniques; (i) melt compounding (MC) in a twin screw extruder, (ii) simple solution mixing (SM) on a magnetic stirrer, and (iii) solution mixing with sonication (SM-U) were investigated. It was found that the electrical conductivity values of samples decreased in the order of SM > SM-U > MC for a particular amount of CNF. The electromagnetic test results showed that the samples prepared with SM and SM-U methods yielded higher total shielding effectiveness (SET) values than those prepared with MC. SET values of samples including of 20 phr of CNF prepared with MC, SM-U and SM methods were varied in the range of 10–30 dB, 20–60 dB and 20–80 dB, respectively within a frequency range of 1–12 GHz. 相似文献
14.
Yüksel Korkmaz Behrus Puladi Kerstin Galler Peer W. Kmmerer Agnes Schrder Lina Glz Tim Sparwasser Wilhelm Bloch Andreas Friebe James Deschner 《International journal of molecular sciences》2021,22(2)
Nitric oxide (NO) binds to soluble guanylyl cyclase (sGC), activates it in a reduced oxidized heme iron state, and generates cyclic Guanosine Monophosphate (cGMP), which results in vasodilatation and inhibition of osteoclast activity. In inflammation, sGC is oxidized and becomes insensitive to NO. NO- and heme-independent activation of sGC requires protein expression of the α1- and β1-subunits. Inflammation of the periodontium induces the resorption of cementum by cementoclasts and the resorption of the alveolar bone by osteoclasts, which can lead to tooth loss. As the presence of sGC in cementoclasts is unknown, we investigated the α1- and β1-subunits of sGC in cementoclasts of healthy and inflamed human periodontium using double immunostaining for CD68 and cathepsin K and compared the findings with those of osteoclasts from the same sections. In comparison to cementoclasts in the healthy periodontium, cementoclasts under inflammatory conditions showed a decreased staining intensity for both α1- and β1-subunits of sGC, indicating reduced protein expression of these subunits. Therefore, pharmacological activation of sGC in inflamed periodontal tissues in an NO- and heme-independent manner could be considered as a new treatment strategy to inhibit cementum resorption. 相似文献
15.
This study presents both a numerical and an experimental solution to seepage from a rectangular ditch or elongated pond to a groundwater table of infinite horizontal extent. Because of the unknown location of the free surface, the flow domain is transformed into the complex potential plane using the inverse formulation method, where the free surface becomes a straight line. The method of finite differences was used to solve the boundary value problem. The problem was also investigated experimentally using a sand tank model. For comparison purposes, a one-dimensional analytical solution is also presented. The results were compared with each other and with those available in the literature obtained with other solution techniques. The parameters affecting the seepage rate were investigated and the resulting relationships are presented in dimensionless graphs. It is believed that these graphs may be of use in design problems. The conditions for which the simplified one-dimensional analytical solution agrees well with the results of the sophisticated two-dimensional numerical solution are identified. 相似文献
16.
Motivated by the necessity to consider probabilistic approaches to future designs, probability and switching energy characteristics of probabilistic CMOS (PCMOS) circuits are analysed. Using 90 and 65 nm processes, detailed analytical models for the probability of correctness (p) of these circuits are developed and verified through circuit simulations. 相似文献
17.
Shape memory wool fabrics having both temperature and moisture responsiveness were fabricated by a functional nanocomposite treatment comprising of shape memory polyurethane (SMPU) and cellulose nanowhisker (CNW). Water vapor permeability and sweat absorption properties were investigated under different temperature or relative humidity values to test smart comfort capabilities of the treated fabrics. Besides, felting shrinkage and weight loss of the fabrics after repeated washing cycles were investigated for end use performance. It was found out that the wool fabrics functionalized by nanocomposite treatments exhibited dynamic breathability and sweat absorption changing with temperature and relative humidity of body or environment. Moreover, nanocomposite application enhanced rigidity, tear strength, anti-felting and weight loss performances of the wool fabric. 20 wt% CNW concentration can be suggested for thermal comfort, mechanical and end use performance enhancements to obtain smart garments having dynamic responsiveness to both body physiological and environmental changes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48674. 相似文献
18.
Emily R. Hawken Dancho Dilkov Emil Kaludiev Selcuk Simek Felicia Zhang Roumen Milev 《International journal of molecular sciences》2016,17(3)
Recently, strategies beyond pharmacological and psychological treatments have been developed for the management of obsessive-compulsive disorder (OCD). Specifically, repetitive transcranial magnetic stimulation (rTMS) has been employed as an adjunctive treatment in cases of treatment-refractory OCD. Here, we investigate six weeks of low frequency rTMS, applied bilaterally and simultaneously over the sensory motor area, in OCD patients in a randomized, double-blind placebo-controlled clinical trial. Twenty-two participants were randomly enrolled into the treatment (ACTIVE = 10) or placebo (SHAM = 12) groups. At each of seven visits (baseline; day 1 and weeks 2, 4, and 6 of treatment; and two and six weeks after treatment) the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was administered. At the end of the six weeks of rTMS, patients in the ACTIVE group showed a clinically significant decrease in Y-BOCS scores compared to both the baseline and the SHAM group. This effect was maintained six weeks following the end of rTMS treatment. Therefore, in this sample, rTMS appeared to significantly improve the OCD symptoms of the treated patients beyond the treatment window. More studies need to be conducted to determine the generalizability of these findings and to define the duration of rTMS’ clinical effect on the Y-BOCS. Clinical Trial Registration Number (NCT) at www.clinicaltrials.gov: . NCT00616486相似文献
19.
This paper undertakes to explore the gerontological and social science literature for the purpose of highlighting that while ageing is a common phenomenon across all world societies it nevertheless remains a unique personal experience. Drawing upon the metaphorical construct of the life journey, the authors use the cultural context of ageing to illustrate how the life-path for each individual, whether long or short, is necessarily unpredictable and involves a dynamic interaction between history and biography within a particular society and cultural framework. The authors challenge prospective readers to use their sociological imagination as proffered by the renowned sociologist C.W. Mills in the interest of moving beyond the biological dimension in order to see more clearly that ??ageing into old age?? is in essence a unique personal life story. The life story of each individual is seen to represent a compilation of ongoing levels of compliance and /or tension between the individual??s subjective world and external forces the consequence of the individual being a thinking, willing and feeling person, an existential entity with potential for meaning making, self organization and adaptive responses to changing life circumstances. Notwithstanding the diverse cultural, racial and ethnic differences between people worldwide the ageing experience is shown to be a phenomenon displaying cross-cultural variability warranting further ongoing anthropological research. An examination of the many pathways to ageing utilizing a series of interactive factors helps to explain the existence of advantages and disadvantages leading to variations in availability and access to ??life chances?? resulting in many people experiencing unacceptable levels of ill-health, poverty, racism, ageism, inequality and widespread levels of social injustice and abuse of human rights. 相似文献
20.
Gizem Korkmaz Chris J. Kuhlman S. S. Ravi Fernando Vega-Redondo 《World Wide Web》2018,21(5):1187-1221
Contagion models have been used to study the spread of social behavior among agents of a networked population. Examples include information diffusion, social influence, and participation in collective action (e.g., protests). Key players, which are typically agents characterized by structural properties of the underlying network (e.g., high degree, high core number or high centrality) are considered important for spreading social contagions. In this paper, we ask whether contagions can propagate through a population that is devoid of key players. We justify the use of Erd?s-Rényi random graphs as a representation of unstructured populations that lack key players, and investigate whether complex contagions—those requiring reinforcement—can spread on them. We demonstrate that two game-theoretic contagion models that utilize common knowledge for collective action can readily spread such contagions, thus differing significantly from classic complex contagion models. We compare contagion dynamics results on unstructured networks to those on more typically-studied, structured social networks to understand the role of network structure. We test the classic complex contagion and the two game-theoretic models with a total of 18 networks that range over five orders of magnitude in size and have different structural properties. The two common knowledge models are also contrasted to understand the effects of different modeling assumptions on dynamics. We show that under a wide range of conditions, these two models produce markedly different results. Finally, we demonstrate that the disparity between classic complex contagion and common knowledge models persists as network size increases. 相似文献