Toward optimization of a robust low-cost sulfonated-polyethersulfone containing layered double hydroxide for PEM fuel cells

Polyethersulphone (PES) is an aromatic thermoplastic, at low environmental impact, evaluated in this work as a promising candidate for new polymer electrolytes in the PEMFCs technology. A sulfonation procedure has been tuned in order to graft sulfonic acid groups on the polymer chains (sPES) and to make it hydrophilic. Homogeneous membranes with different polymer's sulfonation degrees (SD%) have demonstrated excellent mechanical properties and very low permeability toward methanol (important in the DMFCs), even if low proton conductivity. Nanocomposite sPES membranes were prepared by dispersion of highly hydrophilic lamellar particles such as layered double hydroxide (LDH) in the polymer. Deep investigations performed by a combination of PFG-NMR, EIS, XRD, DMA, and scanning electron microscopy have evidenced the exfoliation of the lamellae in polymer matrix. However, a certain anisotropy was evidenced both in the morphology and molecular diffusion, favored in the longitudinal direction (parallel to surface), while completely inhibited in the cross-section. This finding is most likely induced by the polymer structure, therefore particular attention must be paid to the choice of the filler and preparation of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47884.     

Energy Recovery in Pressurized Hydraulic Networks

Water Resources Management - This paper aims to evaluate the possibility of using non-utilized hydraulic energy in urban water distribution systems. For this purpose, the viability and possible...     

The impacts of a GTL plant on Brazil's oil products supply and refinery expansion

This paper assesses the impacts of a GTL plant on the expansion of Brazil's oil refining segment. The GTL plant (50,000 bpd) was sized to start up operations in 2015, producing diesel and naphtha through the indirect route (FT-synthesis). This plant will consume the non-associated natural gas production from the recent discoveries at the Santos Basin (around 419 Bm³), and the associated gas production from the Campos Basin. Both basins are located in the Southeast of Brazil, the most populated, rich and industrialized region of the country. Two different criteria for refinery expansion were simulated in order to meet oil product demand scenarios. Findings show that depending on the refinery expansion criteria considered GTL will play a fundamental hole to meet the oil product demand forecast to Brazil in the next 10 years.     

半导体产业进入无利繁荣时代

在近期一次SEMI产业策略论坛发表的演讲中,Lam Research Corp.的总裁兼CEO Stephen Newberry认为,半导体产业已经进入了“无利的繁荣时代”。2003年以来,每比特/功能的价格已经比每比特/价格的成本下降得更快,使得整个产业的利润遭到侵蚀。这似乎成为了一个无法维继的市场,随着时间的推移必须进行自我修正才行。     

Continuous and Discontinuous Innovation: Overcoming the Innovator Dilemma

Challenged by competition pressures and unprecedented pace of change, firms can no longer choose whether to concentrate on the needs of today's customers or on the anticipation of those of tomorrow: they must be excellent in both. This requires managing two related balancing acts: on the one side, being excellent in both exploitation and exploration of their capabilities and, on the other side, being excellent in managing both incremental and radical innovation. These balances are critical since exploitation and exploration, on the one side, and incremental and radical innovation, on the other, require different approaches that have traditionally been considered difficult to combine within the same organization. Working on evidence and discussion from the 7th CINet Conference held in Lucca (Italy) in 2006, this Special Section is aimed at contributing to theory and practice on these two complex balancing acts that today represent a hot issue in innovation management.     

Endothelin receptors mediating vasoconstriction in rat pressurized small arteries

The effects of endothelin-1 (ET-1), a nonselective ETA and ETB receptor agonist, and sarafotoxin S6c, a selective ETB agonist, were investigated in the presence and absence of BQ123 and BQ788, ETA- and ETB-selective antagonists, respectively, in rat mesenteric small arteries, using a perfusion pressurized arteriograph in which segments of vessels were cannulated and exposed to constant pressure and flow. ET-1 (10(-13)-10(-7) M) induced vasoconstriction in both intact and endothelium-denuded arteries in a concentration-dependent manner. BQ123 (10(-7) and 10(-6) M) inhibited the effect of ET-1, displacing the concentration-response curve to the right in a concentration-dependent manner. The effect of ET-1 was not significantly affected by BQ788 (10(-7) and 10(-6) M), a selective antagonist of ETB receptors. Sarafotoxin S6c (10(-11)-10(-7) M) also induced a slight concentration-dependent vasoconstriction. The effect of sarafotoxin S6c (10(-8) M) was inhibited by the ETB-selective antagonist BQ788 (10(-7) M), but was not significantly changed by BQ123 (10(-7) M). Vasoconstriction induced by sarafotoxin S6c (10(-8) M) in a single bolus concentration was significantly greater than the contraction induced by the same concentration as part of a cumulative concentration-response curve, indicating desensitization or downregulation of ETB receptors during the latter. Repeated application of single concentrations of sarafotoxin S6c (10(-8) M) caused progressively smaller contraction of arteries. These results show the existence of both ETA and ETB vasoconstrictor receptors located on smooth muscle of small arteries. They also show that ETB receptors induce a smaller constrictor effect, and rapidly undergo desensitization after sustained or repeated activation.     

Dietary disinhibition, perceived stress, and glucose control in young, Type 1 diabetic women.

Examining the relationship of stress, dietary disinhibition, and blood glucose control in diabetic young women was the goal of this study. 65 diabetic girls and women, ranging in age from 12 to 26 yrs, completed eating behaviors and perceived stress scales during regular clinic visits. Blood glucose control was assessed by concurrent glycosylated hemoglobin measurements. Multiple regression analyses indicated that high levels of perceived stress predicted dietary disinhibition and that within the age range studied, young women were more likely than early adolescent girls to perceive their life as stressful. Contrary to previous findings that failed to show that stress can indirectly affect glucose control by interfering with compliance behaviors, the present work indicated a Stress?×?Dietary Disinhibition interaction in predicting glucose control. Blood glucose control was poorest in those diabetic women who both perceived their lives as stressful and reported medium to high disinhibition. Blood glucose control was unrelated to stress in young women who reported low levels of disinhibition. These results have implications for the development of specific interventions for young diabetic women who perceive their lives as stressful and who may respond to stress by eating. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison study of wavelet transforms for the visualization of differentially methylated regions in DNA samples

The Journal of Supercomputing - DNA methylation analysis has become an important topic in the study of human health. DNA methylation analysis requires not only a specific treatment of DNA samples...     

On the sizing of a solar thermal electricity plant for multiple objectives using evolutionary optimization

Design, implementation and operation of solar thermal electricity plants are no more an academic task, rather they have become a necessity. In this paper, we work with power industries to formulate a multi-objective optimization model and attempt to solve the resulting problem using classical as well as evolutionary optimization techniques. On a set of four objectives having complex trade-offs, our proposed procedure first finds a set of trade-off solutions showing the entire range of optimal solutions. Thereafter, the evolutionary optimization procedure is combined with a multiple criterion decision making (MCDM) approach to focus on preferred regions of the trade-off frontier. Obtained solutions are compared with a classical generating method. Eventually, a decision-maker is involved in the process and a single preferred solution is obtained in a systematic manner. Starting with generating a wide spectrum of trade-off solutions to have a global understanding of feasible solutions, then concentrating on specific preferred regions for having a more detailed understanding of preferred solutions, and then zeroing on a single preferred solution with the help of a decision-maker demonstrates the use of multi-objective optimization and decision making methodologies in practice. As a by-product, useful properties among decision variables that are common to the obtained solutions are gathered as vital knowledge for the problem. The procedures used in this paper are ready to be used to other similar real-world problem solving tasks.