Nanostructure and mechanical properties of aromatic polyamide and reactive organoclay nanocomposites

Aromatic polyamide/organoclay nanocomposites were synthesized using the solution blending technique. Treatment of montmorillonite clay with p-phenylenediamine produced reactive organophilic clay for good compatibility with the matrix. Polyamide chains were prepared by condensing a mixture of 1,4-phenylenediamine and 4-4′-oxydianiline with isophthaloyl chloride under anhydrous conditions. These chains were end capped with carbonyl chloride using 1% extra acid chloride near the end of reaction to develop the interactions with organoclay. The dispersion and structure–property relationship were monitored using FTIR, XRD, FE-SEM, TEM, DSC and tensile testing of the thin films. The structural investigations confirmed the formation of delaminated and disordered intercalated morphology with nanoclay loadings. This morphology of the nanocomposites resulted in their enhanced mechanical properties. The tensile behavior and glass transition temperature significantly augmented with increasing organoclay content showing a greater interaction between the two disparate phases.     

A hybrid root transformation and decision on belief approach to monitor multiattribute Poisson processes

Most of industrial applications of statistical process control involve more than one quality characteristics to be monitored. These characteristics are usually correlated, causing challenges for the monitoring methods. These challenges are resolved using multivariate quality control charts that have been widely developed in recent years. Nonetheless, multivariate process monitoring methods encounter a problem when the quality characteristics are of the attribute type and follow nonnormal distributions such as multivariate binomial or multivariate Poisson. Since the data analysis in the latter case is not as easy as the normal case, more complexities are involved to monitor multiattribute processes. In this paper, a hybrid procedure is developed to monitor multiattribute correlated processes, in which number of defects in each characteristic is important. Two phases are proposed to design the monitoring scheme. In the first phase, the inherent skewness of multiattribute Poisson data is almost removed using a root transformation technique. In the second phase, a method based on the decision on belief concept is employed. The transformed data obtained from the first phase are implemented on the decision on belief (DOB) method. Finally, some simulation experiments are performed to compare the performances of the proposed methodology with the ones obtained using the Hotelling T ² and the MEWMA charts in terms of in-control and out-of-control average run length criteria. The simulation results show that the proposed methodology outperforms the other two methods.     

A new input indicator for the assessment of science &; technology research?

Traditional input indicators of research performance, such as research funding, number of active scientists, and international collaborations, have been widely used to assess countries’ publication output. However, while publication in today’s English-only research world requires sound research in readable English, English proficiency may be a problem for the productivity of non-native English-speaking (NNES) countries. Data provided by the Brazilian National Research Council (CNPq) containing the academic profile of 51,223 Brazilian researchers show a correlation between English proficiency and publication output. According to our results, traditional input indicators may fall short of providing an accurate representation of the research performance of NNES developing countries.     

Belgrade, Serbia

Few cities in Europe have a history as dramatic and tumultuous as that of the Serbian capital of Belgrade. The gracious “White City,” which rises spectacularly along the banks of the Danube and the Sava River, has been the site of wars, conquests and rapidly changing fortunes for much of its thousands-years long history. Belgrade suffered heavy destruction under both World Wars, and it has the unfortunate distinction of being the only European capital to be bombed at the end of the 20th century. Its modern history is marked by abrupt shifts in political status: from a capital of a relatively small nation-state, to a center of a larger and prosperous multi-national federation, to a capital of a nation-state once again. These shifts parallel the changing geopolitical position of Serbia/Yugoslavia in Europe. In this City Profile, I present the evolution of the built environment of Belgrade in five historic stages: ancient/medieval/Ottoman, early modern, communist, transitional, and contemporary. I show how each period left a distinct spatial imprint on Belgrade’s fabric. Finally, I discuss some contemporary challenges and opportunities in planning Belgrade’s future.     

Polar classification with correspondence analysis for fault isolation

Data collected from operating plants can be mined to extract information related to both normal and fault modes of operation. Correspondence analysis (CA), that decomposes a measure of row–column association, to generate the lower dimensional space has been recently proposed [1] for this task. CA represents the association between samples and variables in terms of angle based measures on a biplot. Thus, toward clearer resolution of the faults, polar clustering and classification procedures are necessary. In this paper, we develop a methodology to mine the operating data and build such clusters. We demonstrate the application of this methodology on data generated from simulations and experiments involving representative systems,for detecting parametric changes and resolving sensor and actuator biases.     

Thymoquinone effects on DMH-induced erythrocyte oxidative stress and haematological alterations during colon cancer promotion in rats

The effect of thymoquinone (TQ), the abundant component of black cumin seed (Nigella sativa) oil extract, was evaluated on 1,2-dimethylhydrazine (DMH)-induced erythrocyte oxidative stress and haematological perturbations during colon cancer promotion in rats. Two TQ approaches, the pre- and post-treatment, were used. DMH promoted erythrocyte oxidative damage in rats by enhancing lipid peroxidation (30%) and decreasing antioxidant enzymes activities (20–35%). This was associated with the decline of erythrocyte count, haemoglobin concentration and haematocrit (20%) and the count increase of white blood cell (60%) and platelet (180%). TQ pre-treatment repaired DMH-induced erythrocyte oxidative stress, anaemia, leukocytosis, and thrombocytosis and allowed a 60% of tumour incidence decline. TQ post-treatment exerted a slight effect on erythrocyte oxidative stress and reduced colon cancer incidence by 30% only. Thus, TQ efficacy in preventing DMH-induced colon cancer promotion was related to its virtue antioxidant effect on erythrocyte oxidative stress.     

Occurrence of sotolon,abhexon and theaspirane‐derived molecules in Gueuze beers. Chemical similarities with ‘yellow wines’

The typical Belgian Gueuze beers are produced with aged hop from a grist of malt and wheat, according to a very long oxidation process (extended boiling, cooling overnight in an open‐air container, oak‐barrel ageing). Two theaspirane‐oxidation‐derived products, dihydrodehydro‐β‐ionone and 4‐hydroxy‐7,8‐dihydro‐β‐ionone, are evidenced here for the first time in Gueuze beers. Both compounds have been recently identified in oxidative wines such as Jura Flor‐Sherry and Sauternes wines. Another analogy with Jura Flor‐Sherry wines was the presence of the nutty/curry odorants sotolon and abhexon, although at lower concentrations. Copyright © 2012 The Institute of Brewing & Distilling