Dynamically vulcanized PP/EPDM blends: Influence of curing agents on the morphology evolution

Thermoplastic vulcanizates (TPE‐Vs) are a special class of thermoplastic elastomers (TPEs), where the rubber phase is dynamically crosslinked in the presence of a thermoplastic matrix. The goal of this work is to compare the behavior of two curing agents systems, conventional peroxide named Peroximon and bismaleimide/dicumyl peroxide, in TPE‐Vs based on PP/EPDM 35/65 w/w. It was also investigated the TPE‐Vs morphological evolution and samples was collected at different times during the mixture and dynamic crosslinking. The materials were characterized by some techniques, which allowed investigating mechanical, morphological, hardness, and swelling properties. Considering the used curing agents contents, the TPE‐Vs obtained by using Peroximon presented lower tensile strength, lower swelling degree, and remarkable lower deformation than those obtained with BMI/DCP system. The hardness properties were not significantly affected by the content of the curing agent, showing only a slight decrease when the Peroximon content was increased. The study of the evolution of morphology showed the rubber phase undergoes crosslinking after adding the curing agent. It could be observed by the increase of the torque and by the appearance of domains in the micrographs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Using Bayesian neural networks with ARD input selection to detect malignant ovarian masses prior to surgery

In this paper, we applied Bayesian multi-layer perceptrons (MLP) using the evidence procedure to predict malignancy of ovarian masses in a large (n = 1,066) multi-centre data set. Automatic relevance determination (ARD) was used to select the most relevant inputs. Fivefold cross-validation (5CV) and repeated 5CV was used to select the optimal combination of input set and number of hidden neurons. Results indicate good performance of the models with area under the receiver operating characteristic curve values of 0.93–0.94 on independent data. Comparison with a linear benchmark model and a previously developed logistic regression model shows that the present problem is very well linearly separable. A resampling analysis further shows that the number of hidden neurons specified in the ARD analyses for input selection may influence model performance. This paper shows that Bayesian MLPs, although not frequently used, are a useful tool for detecting malignant ovarian tumours.     

Understanding the chemical reaction and mass-transfer phenomena in a recirculating enzymatic membrane reactor for green ester synthesis in ionic liquid/supercritical carbon dioxide biphasic systems

The synthesis of butyl propionate in a recirculating bioreactor in room temperature ionic liquid/supercritical carbon dioxide biphasic systems at 50 °C and 80 bar was studied. In these systems, α-alumina microporous membranes with immobilized Candida antarctica lipase B were coated with four different ionic liquids based on 1-n-alkyl-3-imidazolium cations and hexafluorophosphate and bis{(trifluoromethyl)sulfonyl}imide anions. Selectivity increased (reaching >99.5%) when room temperature ionic liquid/supercritical carbon dioxide biphasic systems were used rather than in supercritical carbon dioxide alone. To understand the behaviour of the enzyme and the mass-transfer phenomena in these biphasic systems, the reaction was also carried out in ionic liquids and in ionic liquid/hexane biphasic systems, and the ionic liquid/hexane partition coefficients of the compounds involved in the transesterification reaction were determined. It was observed that the activity in room temperature ionic liquid/supercritical carbon dioxide biphasic systems depends on the effect of the ionic liquid media on the enzyme and the diffusional limitations across the IL-layer around the biocatalyst.     

Polygons, Diagonals, and the Bronze Mean

This article furthers the study of the Metallic Means and investigates the question of whether or not there exists a polygon corresponding to the Bronze Mean as the pentagon and the octagon correspond respectively to the Golden and Silver Means.     

Gonzalez住宅

这个房子为一家人而设计，家庭成员有父母和6个孩子。建筑用地在一块水平、不规则形状的地上，位于圣地亚哥东边单一家庭住宅区附近。     

Effect of High-Pressure Processing on the Microbiology,Proteolysis, Biogenic Amines and Flavour of Cheese Made from Unpasteurized Milk

Food and Bioprocess Technology - Cheese varieties with long ripening periods are prone to form biogenic amines and develop off-flavours. High-pressure processing (HPP), which inactivates...     

Skeletal Muscle Mitochondrial Energetic Efficiency and Aging

Aging is associated with a progressive loss of maximal cell functionality, and mitochondria are considered a key factor in aging process, since they determine the ATP availability in the cells. Mitochondrial performance during aging in skeletal muscle is reported to be either decreased or unchanged. This heterogeneity of results could partly be due to the method used to assess mitochondrial performance. In addition, in skeletal muscle the mitochondrial population is heterogeneous, composed of subsarcolemmal and intermyofibrillar mitochondria. Therefore, the purpose of the present review is to summarize the results obtained on the functionality of the above mitochondrial populations during aging, taking into account that the mitochondrial performance depends on organelle number, organelle activity, and energetic efficiency of the mitochondrial machinery in synthesizing ATP from the oxidation of fuels.     

The Compelling Case for Indentation as a Functional Exploratory and Characterization Tool

The utility of indentation testing for characterizing a wide range of mechanical properties of brittle materials is highlighted in light of recent articles questioning its validity, specifically in relation to the measurement of toughness. Contrary to assertion by some critics, indentation fracture theory is fundamentally founded in Griffith–Irwin fracture mechanics, based on model crack systems evolving within inhomogeneous but well‐documented elastic and elastic–plastic contact stress fields. Notwithstanding some numerical uncertainty in associated stress intensity factor relations, the technique remains an unrivalled quick, convenient and economical means for comparative, site‐specific toughness evaluation. Most importantly, indentation patterns are unique fingerprints of mechanical behavior and thereby afford a powerful functional tool for exploring the richness of material diversity. At the same time, it is cautioned that unconditional usage without due attention to the conformation of the indentation patterns can lead to overstated toughness values. Limitations of an alternative, more engineering approach to fracture evaluation, that of propagating a precrack through a “standard” machined specimen, are also outlined. Misconceptions in the critical literature concerning the fundamental nature of crack equilibrium and stability within contact and other inhomogeneous stress fields are discussed.