Characterization of Dispersion and Residual Stress in Nanoparticle Reinforced Hybrid Carbon Fiber Composites

Hybrid carbon fiber reinforced composites are a new breed of materials that are currently being explored and characterized for next generation aerospace applications. Through the introduction of secondary reinforcements, such as alumina nanoparticles, hybrid properties including improved mechanical properties and stress sensing capabilities can be achieved. In order to maximize these properties, it is necessary to achieve a homogeneous dispersion of particulate filler. Utilizing the photoluminescent properties of alumina, it is possible to compare local levels of particle concentration through emission intensities as a way to determine the effectiveness of the tested manufacturing parameters in increasing material homogeneity. Parameters of these photoluminescence emissions have been established to be stress dependent, which allows for in situ residual stress measurements. It is shown here that the application of silane coupling agents as particle surface treatments improves particle dispersion when compared to untreated samples. Reactive silane coupling agent (RSCA) treatments were found to provide for greater dispersion improvements when compared to non-reactive silane coupling agents (NRSCA). Higher resolution investigations into these samples found that treatment with a reactive coupling agent altered the stress state of particles concentrated around the fiber from a tensile stress state to a compressive stress state. This is proposed to result from bonding of the reactive groups on the coupling agent to the organic groups on the carbon fibers which adjusts the stress state of the particle. Future mechanical tests will verify the effects of the particle surface functionalization treatments on mechanical properties of the composites

El amor, el destino y la virtud: Gertrudis Gómez de Avellaneda y su primer drama Leoncia

The success of the romantic drama Leoncia marks the beginning of Gertrudis Gómez de Avellaneda’s career in the theatre. Literary critics have seen in this work two great romantic topics, love and destiny. This essay argues that the author uses romantic rhetoric to address the issue of virtue and of its manipulation within a hierarchical structure of subordination in a patriarchal society. This concern with the concept of virtue permeates much of the work of this Spanish-Cuban author, and is part of her pioneering efforts to expose the problem of women’s subordinate role in the social hierarchy in nineteenth-century Spain.El éxito del drama romántico Leoncia marca el comienzo de la trayectoria profesional de Gertrudis Gómez de Avellaneda en el ámbito teatral. Los críticos literarios han visto en esta obra la elaboración de dos grandes tópicos románticos, el amor y el destino. En el presente ensayo se argumenta que la autora se sirve de la retórica romántica para abordar el tema de la virtud, exponiendo su manipulación dentro de la estructura jerárquica de subordinación en la sociedad patriarcal. La preocupación en torno al concepto de la virtud permea gran parte de la obra de la autora hispano-cubana y a pesar de que su discurso se presenta contaminado por la retórica patriarcal, es indicativo de su esfuerzo por trascender el papel subordinado en la jerarquía social de la España decimonónica

The Making of Leoncia: Romanticism, Tragedy, and Feminism

1 online resource (PDF, page 249-263

Immobilisation of bifidobacteria in biodegradable food-grade microparticles

The present research features a natural polymer that can be used for immobilisation of bifidobacteria as well as a method of immobilisation. We described a modified method of microencapsulation of probiotics using sodi- um alginate. The experiment studied the effect of encapsulation on probiotic stability and involved an in vitro model of human digestive tract. The test sample of microencapsulated Bifi obacterium bifi um 791 showed a decrease in the activity from 3.0×107 to 2.2×105 CFU/ml in a mouse model with pH 1.2. By contrast, the control sample, unprotected by biodegradable polymer microcapsules, demonstrated a higher death rate of bifidobacteria: from 2.6×108 CFU/ml to 5.0×103 CFU/ml. The control sample demonstrated the same downward trend in in vitro gastrointestinal models with pH values of 4.5, 6.8, 7.2, and 5.8. Because the total plate count fell down to 4.0l g CFU/ml in acidity gradients, the titres of the initial microencapsulated biomass had to be increased up to > 109 CFU/ml. According to the results of scanning electron microscopy, the new type of microcapsules obtained by using a resistant starch had a closed sur- face. Prebiotics increased the resistance of bacteria to low pH and bile salts. Bifidobacteria encapsulated with natural biodegradable polymers proved to be well-tolerated and harmless for mice. The experiment revealed that biodegrad- able polymer microcapsules did not cause any chronic or acute toxicity when administered orally at 2×107 CFU per 1 gram of animal mass. The microcapsules demonstrated neither dermonecrotic properties nor any irritant effect on the ocular mucosa and, thus, can be used for food enforcement

Piezo-, photo- and piezophotocatalytic activity of electrospun fibrous PVDF/CTAB membrane

A composite material based on polyvinylidene fluoride (PVDF) nanofibers modified with cetyltrimethylammonium bromide (CTAB) was synthesized by coaxial electrospinning. The morphology and structure of the material were studied by SEM, FTIR spectroscopy, X-ray diffraction analysis, XPS, and the piezo-photo- and piezo-photocatalytic activity during the decomposition of the organic dye Methylene blue (MB) was studied. It is shown that the addition of CTAB promotes additional polarization of the PVDF structure due to ion-dipole interaction. It has been shown for the first time that the addition of CTAB promotes the photosensitivity of the wide-gap dielectric polymer PVDF (the band gap is more than 6 eV). It was demonstrated that the photocatalytic decomposition efficiency was 91% in 60 minutes. The material exhibits piezocatalytic activity – 73% in 60 minutes. Experiments on trapping active oxidizing forms have established that OH hydroxyl radicals play the main role in the photocatalytic process

New Lyssavirus Genotype from the Lesser Mouse-eared Bat (Myotis blythi), Kyrghyzstan

The Aravan virus was isolated from a Lesser Mouse-eared Bat (Myotis blythi) in the Osh region of Kyrghyzstan, central Asia, in 1991. We determined the complete sequence of the nucleoprotein (N) gene and compared it with those of 26 representative lyssaviruses obtained from databases. The Aravan virus was distinguished from seven distinct genotypes on the basis of nucleotide and amino acid identity. Phylogenetic analysis based on both nucleotide and amino acid sequences showed that the Aravan virus was more closely related to genotypes 4, 5, and—to a lesser extent—6, which circulates among insectivorus bats in Europe and Africa. The Aravan virus does not belong to any of the seven known genotypes of lyssaviruses, namely, rabies, Lagos bat, Mokola, and Duvenhage viruses and European bat lyssavirus 1, European bat lyssavirus 2, and Australian bat lyssavirus. Based on these data, we propose a new genotype for the Lyssavirus genus

NUTRITIONAL SUPPLEMENT FOR CONTROL OF DIABETES

Analysis of diabetic patients’ dietary habits indicate that there is an imbalance of selected vitamins and minerals. A nutrient supplement composition; intended for prophylactic administration, was developed to correct this imbalance. It was composed of dried eggs and yeast component (60%), vitamin В1 (0.02%) and nicotinamide (0.04%), chromium chelate (0.02%), “selen-active” (0.02%) and lecithin (39.9%). The dried eggs and yeast component was prepared by homogenization of lysozyme rich chicken eggs and yeast followed by storage and drying at a pre-defined temperature and to a set water content respectively. The nutritional supplement was incorporated at 5% concentration into a cooked sausage recipe. An assessment of the safety and efficacy of the prophylactic nutritional supplement was performed in an alloxan induced diabetic rat model. The developed composition, as a part of feedstuff, improved metabolic processes, increased antioxidant activity, reduced lipid peroxidation, decreased blood cholesterol, and improved the carbohydrate metabolism

Nutritional supplement for control of diabetes

The analysis of diabetic patients’ dietary habits indicate that there is an imbalance of selected vitamins and minerals. A nutrient supplement composition, intended for prophylactic administration, was developed to correct this imbalance. It was composed of dried eggs and a yeast component (60%), vitamin Â1 (0.02%) and nicotinamide (0.04%), chromium chelate (0.02%), “selen-active” (0.02%) and lecithin (39.9%). The dried eggs and yeast component were prepared by the homogenization of lysozyme rich chicken eggs and yeast followed by storage and drying at a pre-defined temperature and to a set water content respectively. The nutritional supplement was incorporated at 5% concentration into a sausage recipe which was subsequently cooked into animal feed. An assessment of the safety and efficacy of the prophylactic nutritional supplement was performed in an alloxan induced diabetic rat model. The developed composition, as a part of the animal feed, improved metabolic processes, increased antioxidant activity, reduced lipid peroxidation, decreased blood cholesterol, and improved carbohydrate metabolism in the experimental animals

Novel Lyssaviruses Isolated from Bats in Russia

Two new rabies-related viruses were discovered in Russia during 2002. Viruses were isolated from bats in Eastern Siberia near Baikal Lake and in the western Caucasus Mountains. After preliminary antigenic and genetic characterization, we found that both viruses should be considered as new putative lyssavirus genotypes