A stochastic local search algorithm for constrained continuous global optimization

This paper presents a new stochastic local search algorithm known as feasible–infeasible search procedure (FISP) for constrained continuous global optimization. The proposed procedure uses metaheuristic strategies for combinatorial optimization as well as combined strategies for exploring continuous spaces, which are applied to an efficient process in increasingly refined neighborhoods of current points. We show effectiveness and efficiency of the proposed procedure on a standard set of 13 well‐known test problems. Furthermore, we compare the performance of FISP with SNOPT (sparse nonlinear optimizer) and with few successful existing stochastic algorithms on the same set of test problems.     

Evaluation of thermal and mechanical properties of rubber compositions based on SBR extended with safe oils

The extender oil usually employed in compositions of rubbers based on styrene and butadiene (SBR) 1712 is the distilled aromatic extract (DAE). In this work, this oil was substituted by oils with low levels of polycyclic aromatic hydrocarbons (PAHs): treated residual aromatic extract (TRAE) and two naphthenic oils from different suppliers (HN1 and HN2). This substitution was performed in response to REACH Regulation (EC No. 1907/2006 European Parliament and the Council of December 18, 2006, Annex XVII), which state that the sum of individual PAHs should be below 10 mg/kg and the levels of benzo (a) pyrene (BaP) should not exceed 1 mg/kg. Infrared spectroscopy was employed to characterize the structure of crude oils and respective SBR compositions. Thermal properties of the materials were evaluated by thermogravimetry and differential scanning calorimetry. Mechanical properties as tension tests, hardness, abrasion resistance, and resilience were also determined. The final results showed that it is possible to replace the extender oil DAE for any of the oils tested, specially the naphthenic HN1, without any loss of the properties evaluated in this study for the SBR compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The questionable promise of social media for education: connective learning and the commercial imperative

Facebook and other social media have been hailed as delivering the promise of new, socially engaged educational experiences for students in undergraduate, self‐directed, and other educational sectors. A theoretical and historical analysis of these media in the light of earlier media transformations, however, helps to situate and qualify this promise. Specifically, the analysis of dominant social media presented here questions whether social media platforms satisfy a crucial component of learning – fostering the capacity for debate and disagreement. By using the analytical frame of media theorist Raymond Williams, with its emphasis on the influence of advertising in the content and form of television, we weigh the conditions of dominant social networking sites as constraints for debate and therefore learning. Accordingly, we propose an update to Williams' erudite work that is in keeping with our findings. Williams' critique focuses on the structural characteristics of sequence, rhythm, and flow of television as a cultural form. Our critique proposes the terms information design, architecture, and above all algorithm, as structural characteristics that similarly apply to the related but contemporary cultural form of social networking services. Illustrating the ongoing salience of media theory and history for research in e‐learning, the article updates Williams' work while leveraging it in a critical discussion of the suitability of commercial social media for education.     

Increasing X-ray image interpretation competency of cargo security screeners

X-ray screening of containers and unit load devices in the area of cargo shipping is becoming an essential and common feature at ports and airports all over the world. The detection of prohibited items in X-ray images is a challenging task for screening officers as they need to know which items are prohibited and what they look like in X-ray images. The main aim of this study was to investigate whether X-ray image interpretation competency of cargo security screeners can be increased by computer-based training. More specifically, effects of training were investigated by conducting tests before training started and after approximately three months of training. Moreover, it was examined whether viewing X-ray images in pseudo color would lead to a better detection performance compared to when X-ray images are shown in greyscale. Recurrent computer-based training resulted in large performance increases after three months. No significant difference in detection performance could be found for tests when using X-ray images in greyscale vs. pseudo color.     

Absence of sterol biosynthesis in oyster tissue culture

An oyster heart tissue culture was used to investigate the ability of the American oyster (Crassostrea virginica) to synthesize sterols from [¹⁴C]acetate. Lipids were extracted from cultured oyster heart cells and no label was found in the purified fatty acid fraction, 90% of which was located in the saturated and monounsaturated fractions. Although these results cannot rule out the possibility of sterol synthesis in other oyster tissues, this and previous evidence are in support of the hypothesis that the American oyster is unable to synthesize sterols.     

Dietary arachidonic acid reduces fatty liver,increases diet consumption and weight gain in ethanol-fed rats

We fed young male Sprague-Dawley rats for 4 wk ad libitum liquid diets containing 34% of the calories as ethanol and 35% as fat with (AA+) and without (AA−) arachidonic acid (20∶4). Additional rats in the control groups were fed similar diets made isocaloric with dextrose with (CA+) and without (CA−) 20∶4. The liver triglyceride (TG) content of rats in the AA+ group was reduced ca. 3-fold over that of rats in the AA-group. The diet consumption and body wts of rats in the AA+ group were significantly greater than those of rats fed alcohol without the 20∶4 supplement (AA−). Also livers from rats in the AA+ group were as large as those from rats in control groups (CA+, CA−) and ca. twice as large as those from rats in the AA-group. The fatty acid composition of liver TG in rats fed the alcohol diet was similar to that of dietary fat. Levels of 20∶4 and docosatetraenoic acid (22∶4) in liver TG fatty acids from rats fed diets without arachidonate (AA−, CA−) were low (trace to 1.6%). After ingestion of arachidonic acid, 20∶4 increased to ca. 10% and 22∶4 to ca. 5%. The content of liver phospholipids was higher in livers of rats fed ethanol (AA−) than in those of controls (CA−). Presented at the ISF/AOCS World Congress, April 27-May 1, 1980, New York City.     

Influence of chemical structure of hardener on mechanical and adhesive properties of epoxy polymers

The mechanical and adhesive properties of epoxy formulations based on diglycidyl ether of bisphenol A cured with various aliphatic amines were evaluated in the glass state. Impact and uniaxial compression tests were used to determine the impact energy, elastic modulus and yield stress, respectively. The adhesion tests were carried out in steel–steel joints using single‐lap shear, T‐peel, and impact adhesive joints geometry. The better mechanical and adhesive behavior of the networks is obtained when exists high flexibility of chain between crosslink and/or high elastic modulus. The 1‐(2‐aminoethyl)piperazine epoxy network presents the best adhesive properties, high flexibility, and the largest impact energy. However, it possesses low elastic modulus and yield stress. Also, exhibits increases in peel strength and impact energy while reductions in lap shear strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Sigma流量计在市政排水管网的成功应用

美国内珀维尔市通过安装准确耐用的流量计,消除了传感器的漂移,为流量监测系统提供了可靠的数据。通过这些可靠的流量和液位数据,能够分析市政排水管网的状态,判断入流和渗漏问题,优化对市政排水管网的维护和管理,执行最优的污水管道修复策略,最终减少因入流和渗漏问题对污水处理厂造成的流量冲击。     

Inhaled PYY(3–36) dry-powder formulation for appetite suppression

Objective: Peptide YY3–36 [PYY(3–36)] has shown efficacy in appetite suppression when dosed by injection modalities (intraperitoneal (IP)/subcutaneous). Transitioning to needle-free delivery, towards inhalation, often utilizes systemic pharmacokinetics as a key endpoint to compare different delivery methods and doses. Systemic pharmacokinetics were evaluated for PYY3–36 when delivered by IP, subcutaneous, and inhalation, the systemic pharmacokinetics were then used to select doses in an appetite suppression pharmacodynamic study.

Methods: Dry-powder formulations were manufactured by spray drying and delivered to mice via nose only inhalation. The systemic plasma, lung tissue, and bronchoalveolar lavage fluid pharmacokinetics of different inhalation doses of PYY(3–36) were compared to IP and subcutaneous efficacious doses. Based on these pharmacokinetic data, inhalation doses of 70:30 PYY(3–36):Dextran T10 were evaluated in a mouse model of appetite suppression and compared to IP and subcutaneous data.

Results: Inhalation pharmacokinetic studies showed that plasma exposure was similar for a 2?×?higher inhalation dose when compared to subcutaneous and IP delivery. Inhalation doses of 0.22 and 0.65?mg/kg were for efficacy studies. The results showed a dose-dependent (not dose proportional) decrease in food consumption over 4?h, which is similar to IP and subcutaneous delivery routes.

Conclusions: The pharmacokinetic and pharmacodynamics results substantiate the ability of pharmacokinetic data to inform pharmacodynamics dose selection for inhalation delivery of the peptide PYY(3–36). Additionally, engineered PYY(3–36):Dextran T10 particles delivered to the respiratory tract show promise as a non-invasive therapeutic for appetite suppression.