Tensile behaviors of ECR-glass and high strength glass fibers after NaOH treatment

ECR-glass and high strength glass (S-glass) fibers were treated in 2 mol/l NaOH solution up to 5 h. The strength maintenance ratio and mass loss ratio of the fibers after treatment were investigated. The surface morphologies were characterized using scanning electron microscopy, and changes of chemical composition were analyzed by energy dispersive X-ray spectroscopy and Fourier transform infrared spectrometry. The alkali resistance and tensile strength of the S-glass fibers are higher compared to those of the ECR-glass fibers as they received less alkaline attack because of the more compact SiO₂ network and the formation of a protective layer on the S-glass fiber surface. The S-glass fibers have a higher mass loss due to the smaller diameter and thinner corrosion layer.     

包钢结构调整与产品的开发方向

文章对未来5年世界钢材进出口贸易流量进行了评估,根据需求发展内在和外部因素的分析,分品种进行了需求预测。结合包钢的生产现状,详细分析了产业和产品结构状况,为包钢在"十二五"期间及未来结构调整中,重点开发的钢材品种指出了方向。     

Kinetic analysis of bile salt passage across a dialysis membrane in the presence of cereal soluble dietary fibre polymers

The kinetics of passage of a model bile salt and complete porcine bile across a dialysis membrane, in the presence and absence of two cereal-derived soluble dietary fibre polysaccharides, were studied as a model for passage across the unstirred water layer that lines the small intestine. A first-order kinetic analysis allowed rate coefficients to be derived which quantified the effectiveness of barley mixed linkage β-glucan and wheat arabinoxylan in retarding the transport of bile. For both, a model bile salt and complete porcine bile, rate coefficients decreased with both concentration and viscosity. A combination of viscosity and molecular interaction effects is suggested to control the effect of the two polysaccharides on the transport of bile.     

Effect of soluble fibre (guar gum and carboxymethylcellulose) addition on technological, sensory and structural properties of durum wheat spaghetti

Incorporation in pasta of either of two soluble fibres, carboxymethylcellulose sodium salt (CMC) and guar gum (GG), was found to significantly reduce the rate of invitro starch digestion. The amount of reducing sugars produced over 300 min was reduced by 18% at 1.5% CMC incorporation and 24% at 20% GG incorporation. Negative effects on sensory and technological properties were seen at the high levels of GG needed to reduce the rate of in vitro digestion, and a ‘matty’ layer covering the surfaces of starch granules was observed by scanning electron microscopy and confocal scanning laser microscopy. By contrast, levels of CMC incorporation giving large reductions in in vitro digestion had no negative effects on pasta properties. No significant alteration in pasta structure on CMC incorporation was observed by microscopy. The large difference in the amounts of soluble fibre required to bring about equivalent reductions in digestion rate suggests that different mechanisms may be involved in the two cases.     

Integrated processing of plant-derived waste to produce value-added products based on the biorefinery concept

BackgroundPlant-derived wastes from agriculture, processing, distribution, and retail are generated in large quantities. The majority of the wastes are underutilized and may cause severe environmental problems if not properly handled. The plant-derived wastes are usually rich in lignocellulose and other valuable compounds including protein, fat, sugar, and phytochemicals. Valorization of these compounds in food waste not only reduces environmental concerns but also improves sustainability and economic competitiveness of agro-food industries.Scope and approachThis review paper first discussed different phases of the biorefinery concepts and their associated applications, and then introduced recent advances in the integrated processing of plant-derived waste for producing various value-added products. Finally, techno-economic, environmental, and social assessments along with relevant policies were introduced and discussed.Key findings and conclusionsDuring the past ten years, research attentions focused on integrated utilization of plant-derived waste to produce various products have flourished. Compared to production of a single component for food waste valorization, integrated processing of food waste via a combination of different novel technologies to produce multiple products based on a biorefinery concept has significant advantages, including full utilization of feedstocks, minimization of waste generation during processing, synergy effects of different technologies, and diversification of the revenues by covering multiple markets. With the rationale design of biorefinery processes, underutilized plant-based wastes can be valuable resources for the sustainable production of food, chemicals, and biofuels. However, detailed economic, environmental, and social analyses for the biorefinery process are still needed in the future.     

Thermodynamic optimization of the K2O-Al2O3-SiO2 system

A critical evaluation and thermodynamic optimization of experimental phase diagrams and thermodynamic properties of the K₂O-Al₂O₃-SiO₂ system was performed at 1?bar total pressure. A set of self-consistent thermodynamic functions of all phases in the K₂O-Al₂O₃-SiO₂ system was obtained. The liquid phase was described using the Modified Quasichemical Model with the KAlO₂ associate component. The set of optimized model parameters obtained for all phases reproduces available and reliable thermodynamic properties and phase diagram data as well as the melt structure of the K₂O-Al₂O₃-SiO₂ system within the experimental error limits.     

Listeria monocytogenes in ready-to-eat foods in Italy: Prevalence of contamination at retail and characterisation of strains from meat products and cheese

In the framework of a European Union (EU) Coordinated Monitoring Programme, different types of ready-to eat (RTE) products, including soft and semi-soft cheese (n = 398) and cooked meat products (n = 403), were collected at retail in Italy and tested for detection and enumeration of Listeria monocytogenes. An Integrative Survey of 2696 samples, including soft and semi-soft cheese (n = 894) and cooked meat products (n = 1802) was carried out to have statistically representative results at the national level. Considering the results obtained both from the EU and the national Integrative Survey, prevalence of contamination of meat products was 1.66% (95% CL: 1.02–2.73%) at the arrival of the samples at the laboratory and 1.92% (95% CL: 1.31%–2.82%) at the end of shelf-life. Spalla cotta was the most frequently contaminated meat product. Prevalence of contamination in cheese was 2.13% (95% CL: 1.37%–3.3%) at the arrival at the laboratory and 1.01% (95% CL: 0.41%–2.55%) at the end of shelf-life. To get information about differences between cheese rinds and pastes, these two parts were separately analysed in the Integrative Survey samples. L. monocytogenes was detected in 4.02% (95% CL: 2.60%–6.19%) of cheese rinds (n = 473), whereas only the 0.34% (95% CL: 0.12%–0.98%) of cheese pastes (n = 894) were contaminated. This difference was statistically significant (χ² = 10.026, P < 0.05). Gorgonzola and Taleggio were the most frequently contaminated cheeses. Non-compliance with EU official criteria (100 CFU/g) was reported in 0.55% of meat products at arrival at the laboratory, in 0.46% at the end of shelf-life, and in 1.9% of cheese rinds. PFGE showed that cheese rinds could have been the origin of the few pastes' contamination, highlighting genetic similarity between isolates found in these two cheese components. Genetic subtyping also showed the presence of different pulsotypes, usually belonging to different clusters, in isolates from different food types. The presence of some pulsotypes predominantly prevalent over the others, in products from the same manufacturer, could suggest environmental strains as the main source of contamination.     

Qualitative risk assessment of introduction of anisakid larvae in Atlantic salmon (Salmo salar) farms and commercialization of products infected with viable nematodes

In this study, the likelihood of introduction of anisakid larvae in Atlantic salmon (Salmo salar) farms and subsequent commercialization of fish infected by at least one vital parasite was formally assessed using an adaptation of the risk assessment framework for importation of animals and animal products of the World Organization for Animal Health (OIE). The different plausible pathways were identified and outlined. The most recent information concerning the parasite, its definitive, intermediate hosts and the farming practices typical of Atlantic salmon farms were reviewed and used to assess the likelihoods of each key step along the pathways. A matrix for the conditional probabilities was adopted to combine the qualitative estimations and obtain an objective and transparent overall risk of introduction along each route. In order to avoid misinterpretation and overconfidence on the outcome, the uncertainties surrounding the estimations were considered. The only situation for which the assessed risk in a typical Atlantic salmon farm was deemed to be non-negligible involved the ingestion of infected hosts that penetrate the harvesting cages. In this event, the overall risk was estimated as ‘Very Low’ with a high degree of uncertainty because of the scarcity of information in some of the key steps along the pathway. However, the scientific evidence in support of the overall estimation suggests that the availability of additional data would be unlikely to increase the final estimated risk. On the basis of the available information of the system, the estimated risk of introduction and commercialization of farmed Atlantic salmons infected by viable nematodes resulted ‘Very Low’ even under a conservative approach. The proposed qualitative model is an objective and transparent method to assess the risk when data and information are scarce and provides a framework for the qualitative assessment of the introduction of alive parasites in aquaculture/mariculture implants and subsequent commercialization of infested fishery products. The framework could be easily adapted to other parasite-host interactions besides anisakid nematodes in Farmed Atlantic salmons.     

Thermo-mechanical,structural characterization and antibacterial performance of solvent casted polylactide/cinnamon oil composite films

Polylactic acid (PLA) based composite films were prepared by incorporating polyethylene glycol (PEG) and cinnamon oil (CIN) (25 and 50% w/w of PLA) via solution casting method. Morphological, structural, thermo-mechanical, spectral, and antibacterial properties of PLA/PEG/CIN films were investigated. Tensile strength (TS) and tensile modulus (TM) of the film decreased, while the elongation at break (EAB) increased by increasing CIN concentration. Using the principle of time-temperature superposition, the viscous modulus and the complex viscosity of composite films at selected temperatures and frequencies (time scales) were superimposed well in an extended frequency range. Thermal properties decreased substantially with incorporation of CIN. Significant changes in molecular organisation and intermolecular interactions between CIN and PLA/PEG matrix were observed through the FTIR spectroscopy. Scanning electron microscopic (SEM) revealed rough surfaces of the composite films. The effectiveness of composite films was tested against Listeria monocytogenes and Salmonella typhimurium inoculated in chicken samples, and it was found that the film containing 50% CIN showed an antibacterial activity during 16 days storage at refrigerated condition. The developed film has a potential for packaging of chicken samples with extended storage.     

3—THE FINITE-DEFORMATION THEORY OF PLAIN-WEAVE FABRICS PART I: THE BIAXIAL-DEFORMATION THEORY

Theories of the biaxial tensile properties, the uniaxial tensile properties, and the shear-deformation properties of plain-weave fabrics are presented in a general form, a simplified stereo-model of the structure of plain-weave fabrics being used throughout these theories.

In the first part of this series, the biaxial tensile-deformation theory is presented with the aid of the model, and the forces required to stretch the fabric along the warp and weft directions at the same time are theoretically calculated from the properties of yarns and from the structure of the fabrics. In this biaxial theory, both warp and weft yarns are assumed to be perfectly flexible, and the forces caused by yarn-bending are ignored. The compressibility of the yarn under the action of a lateral compressive force is also introduced into the theory, and it is shown that the compressive properties of yarns have a great influence on the tensile properties of the fabrics.