Use of the Cone Calorimeter and ConeTools software for development of innovative intumescing graphite systems

The Cone Calorimeter test method has been one of the most used small‐scale fire test method for years now and is at present widely spread over the world. In contrast to many other fire test methods, the Cone Calorimeter provides a range of data with sound scientific basis, which allows a wide range of applications. It can be used for modelling and also for enhanced product development. This paper describes the use of the Cone Calorimeter for the development of new innovative materials in combination with a mathematical model. As example, the cost effective development of an innovative intumescing graphite system for protecting particle board is explained. The performance goal of the project is to obtain the threshold values for a B class in the Single Burning Item (SBI) test method used for the newly developed Euroclass system. The focus of this paper is on the development tools and not on the chemical development of the protective system. During the research it was necessary to develop a new sample holder for the Cone Calorimeter. The results from the project show that the industry can save development time and resources by using the Cone Calorimeter in combination with a simple mathematical model. Copyright © 2010 John Wiley & Sons, Ltd.     

High performance PEEK/carbon nanotube composites compatibilized with polysulfones-I. Structure and thermal properties

Poly(ether ether ketone) (PEEK)/single-walled carbon nanotube (SWCNT) composites incorporating polysulfones as compatibilizers were fabricated by melt-blending, after pre-processing based on ball milling and mechanical treatments in an organic solvent. Their structure, morphology and thermal properties have been investigated. Microscopic observations showed a uniform distribution of the CNTs and good miscibility between the compatibilizer and matrix phases. The incorporation of wrapped SWCNTs leads to a remarkable increase in the degradation temperatures of the matrix in comparison with non-compatibilized samples, attributed to the high thermal stability of the polysulfones and the compatibilizing effect. The addition of very small CNT loadings raises the crystallization temperature and the degree of crystallinity of PEEK. At higher concentrations, the inactive nucleating activity of the nanofillers, the confinement of the polymer chains within the CNT network and the presence of an amorphous compatibilizer moderately hinder PEEK crystallization. Synchrotron X-ray diffraction experiments indicate the existence of reorganization phenomena of the matrix crystals during the heating of the composites. Improved thermal properties are found for composites incorporating arc-purified SWCNTs, attributed to the higher degree of debundling and lower metal content of these CNTs. These compatibilized composites are new materials for potential high-temperature structural applications.     

Influence of processing on the levels of amines and proline and on the physico-chemical characteristics of concentrated orange juice

The influence of processing on the levels of bioactive amines and proline as well as on some physico-chemical characteristics of concentrated orange juice was investigated. Samples were collected at seven points of a production line on three non-consecutive days, and analysed for the levels of 12 bioactive amines, proline, and reducing and non-reducing sugars, and for some physico-chemical characteristics. Among the amines analysed, only putrescine, spermidine and synephrine were found in the samples at all processing stages. Significant differences were observed for spermidine and total amine levels throughout processing. Synephrine and putrescine were resistant to processing. Proline levels changed significantly throughout processing, as did levels of reducing and non-reducing sugars. The pH varied from 3.59 to 3.72, acidity from 0.873 to 0.918 g citric acid/100 mL, and density from 1.0378 to 1.0970 g/mL. Among these parameters, pH, acidity and density were significantly affected by processing.     

Relationship of early life stress and psychological functioning to blood pressure in the CARDIA study.

[Correction Notice: An erratum for this article was reported in Vol 28(4) of Health Psychology (see record 2009-10284-005). A URL for supplemental materials was included due to a production error. There are no supplemental materials for this article.] Objective: Low childhood socioeconomic status (CSES) and a harsh early family environment have been linked with health disorders in adulthood. In this study, the authors present a model to help explain these links and relate the model to blood pressure change over a 10-year period in the Coronary Artery Risk Development in Young Adults sample. Design: Participants (N = 2,738) completed measures of childhood family environment, parental education, health behavior, and adult negative emotionality. Main Outcome Measures: These variables were used to predict initial systolic and diastolic blood pressure (SBP and DBP, respectively) and the rate of blood pressure change over 10 years. Results: Structural equation modeling indicated that family environment was related to negative emotions, which in turn predicted baseline DBP and SBP and change in SBP. Parental education directly predicted change in SBP. Although African American participants had higher SBP and DBP and steeper increases over time, multiple group comparisons indicated that the strength of most pathways was similar across race and gender. Conclusion: Low CSES and harsh family environments help to explain variability in cardiovascular risk. Low CSES predicted increased blood pressure over time directly and also indirectly through associations with childhood family environment, negative emotionality, and health behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypolipidemic effects of proanthocyanidins and their underlying biochemical and molecular mechanisms

Proanthocyanidins are the most abundant polyphenols in human diets. Epidemiological studies strongly suggest that proanthocyanidins protect against cardiovascular diseases. Despite the antioxidant and anti‐inflammatory properties of these flavonoids, one of the mechanisms by which proanthocyanidins exert their cardiovascular protection is improving lipid homeostasis. Animal studies demonstrate that proanthocyanidins reduce the plasma levels of atherogenic apolipoprotein B‐triglyceride‐rich lipoproteins and LDL‐cholesterol but increase antiatherogenic HDL‐cholesterol. The results in humans, however, are less clear. This review summarizes the results that have been published on plasma triglyceride, apolipoprotein B, HDL‐cholesterol and LDL‐cholesterol levels in humans and animal models in response to proanthocyanidin extracts and proanthocyanidin‐rich foods. The physiological processes and biochemical pathways that are related to lipid homeostasis and affected by proanthocyanidin consumption are also discussed. Intestinal lipid absorption, chylomicron secretion by the intestine and VLDL secretion by the liver are the processes that are most repressed by proanthocyanidins, which, therefore, induce hypolipidemic effects.