Neural network approximations in a simulated annealing based optimal structural design

The present paper examines the feasibility of using neural network based function approximations in conjunction with a simulated annealing (SA) strategy for optimization of structural systems. Such a stochastic search method is more tolerant of errors in objective and constraint function information than the more traditional mathematical programming techniques. The improved counterpropagation (CP) neural network is used to generate these approximations, and includes features such as dynamic adjustment of the network size, optimization based training of outstar weights, andfuzzification of output. The CP network is easy to train, and preliminary numerical results indicate that the modifications to the network significantly improve the quality of function approximations. The SA based search for optimal designs is illustrated by the sizing of planar and spatial truss structures for minimum weight and constraints on allowable stress levels.     

Characteristics of a double-orifice nebulizer

Aerosol generation in a pneumatic nebulizer with a double-orifice nozzle was studied in the particle size range of 0.8–10 μm. It was found that the aerosol generation rate can be changed without significant changes in the aerosol size distribution by changing the distance between the orifices. The aerosol size distribution was modified by changing the input air pressure. A Wright type nebulizer was modified to produce a wider spectrum of particles.     

Tocopherols and Tocotrienols—Bioactive Dietary Compounds; What Is Certain,What Is Doubt?

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers’ interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.     

Flavonoid and Phenolic Acids Content and In Vitro Study of the Potential Anti-Aging Properties of Eutrema japonicum (Miq.) Koidz Cultivated in Wasabi Farm Poland

Skin aging is a natural, unavoidable, and complex process caused by oxidative stress. As a consequence, it leads to an increase in the activation of extracellular matrix disruption enzymes and DNA damage. The search for natural sources that inhibit these mechanisms can be a good approach to prevent skin aging. The purpose of our study was to evaluate the composition of flavonoids and phenolic acids in the extracts obtained from the flowers, roots, and leaves of Eutrema japonicum cultivated in Poland. Then, the resultant extracts were subjected to an assessment of antioxidant, anti-collagenase, anti-elastase, anti-hyaluronidase, antibacterial, and cytotoxic properties. It was demonstrated that the extract from the flowers had the highest content of flavonoid glycosides (17.15 mg/g DE). This extract showed the greatest antioxidant, anti-collagenase, anti-elastase, and anti-hyaluronidase activities compared to the other samples. Importantly, the collagenase inhibitory activity of this extract (93.34% ± 0.77%) was better than that of positive control epigallocatechin gallate (88.49% ± 0.45%). An undeniable advantage of this extract was also to possess moderate antibacterial properties and no cytotoxicity towards normal human skin fibroblasts. Our results suggest that extracts from E. japonicum flowers may be considered as a promising antiaging compound for applications in cosmetic formulations.     

SPINS: Security Protocols for Sensor Networks

Wireless sensor networks will be widely deployed in the near future. While much research has focused on making these networks feasible and useful, security has received little attention. We present a suite of security protocols optimized for sensor networks: SPINS. SPINS has two secure building blocks: SNEP and TESLA. SNEP includes: data confidentiality, two-party data authentication, and evidence of data freshness. TESLA provides authenticated broadcast for severely resource-constrained environments. We implemented the above protocols, and show that they are practical even on minimal hardware: the performance of the protocol suite easily matches the data rate of our network. Additionally, we demonstrate that the suite can be used for building higher level protocols.     

Oxidation of silicon by oxygen: a rate equation

A new rate equation fits data on the oxidation of silicon by oxygen. It can be derived from a model of molecular diffusion in the oxide layer and the influence of strain on this diffusion.[/p]     

Treatment with human recombinant erythropoietin and nutritional status of patients on lon term dialysis

In order to assess the effect of long term erythropoietin (EPO) therapy on the nutritional status of hemodialysed (HD) patients 2 groups of HD patients were studied: I-EPO treated for 72 +/- 8 mo, 12 patients, HD for 138 +/- 66 mo, II-control group, 14 patients with Ht 30%, HD for 121 +/- 35 mo. At the onset and after 6 years of follow up patients underwent the following examination: length, body weight, body mass index, body fat stores, arm muscle circumference and total serum protein, serum albumin, lymphocyte count, creatinine, urea, cholesterol and PTH. In EPO group mean BMI, body fat, arm muscle circumference, visceral protein and total lymphocyte count were not change. In control group the decrease in height, body weight, BMI, body fat stores, arm muscle circumference and albumin were observed. Elevation of PTH estimated in half of patients in EPO group and 75% of patients in control group could influence the nutritional status of hemodialysed patients. Conclusion: 1. Nutritional status of majority of hemodialysed patients was not change during six years EPO therapy. 2. Non EPO treated patients showed the decrease of anthropometric measurements and serum albumin.     

A Study of the Deformation and Fracture of a Dual-Phase Steel

A metallographic study of the tensile deformation and fracture of a commercial dual-phase steel shows that extensive plastic deformation of the martensite occurs mainly in the neck of the tensile specimen. The average load-transfer stress in martensite was roughly calculated from a shear-lag model, and it was found that it exceeds the estimated martensite yield stress value at strains corresponding to the ultimate uniform elongation, and beyond. Ductile fracture begins with void formation at martensite-ferrite interfaces, most frequently at the poles of closely spaced martensite particles situated on ferrite grain boundaries. Large inclusions and martensite banding also affect the fracture process.     

Kinetics of extracted bioactive components from mushrooms in artificial digestive juices

This article presents a study on fruiting bodies of Boletus badius, Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, Leccinum scabrum, Suillus bovinus, Suillus luteus, Pleurotus ostreatus, Tricholoma equestre, Armillaria mellea, Agaricus bisporus, and Auricularia polytricha. The amounts of their health-promoting bioelements and physiologically significant indole and phenolic compounds were determined. The significance of edible mushrooms in the human diet and in disease prevention were also established. The high-performance liquid chromatography was used to assess the contents of indole compounds and phenolic acids. The atomic absorption spectroscopy was applied to determine bioelements. In all samples, the content of 5-hydroxy-L-tryptophan was studied. The highest extraction amount of serotonin was found for P. ostreatus species. Phenolic compounds were determined in the conditions described in the present study for the first time. Additionally, protocatechuic, p-hydroxybenzoic, syringic, and gallic acids were determined.