Development and performance evaluation of natural thermal-insulation materials composed of renewable resources

Because energy efficiency in buildings will be evaluated not only based upon heating demand, but also according to the primary energy demand, the ecological properties of the building materials for the whole assessment has become essential. The demand for green building materials is rising sharply, especially insulating materials from renewable resources. The application of natural materials has become increasingly important as a consequence of the increasing need to conserve energy, use natural materials, incorporate architecture and construction into sustainable development processes, and the recently promulgated discussions on appropriate disposal of used insulation materials such as polystyrene (EPS).Due to the fact that natural materials are more sensitive to moisture, decomposition factors such as temperature, material moisture content, attacks by microorganisms, and possible decomposition of the material or shorter durability, it is necessary to evaluate the degradation rate of built-in materials and also determine their real in situ hygrothermal properties according to their moisture content, and volume changes.This paper describes the results of a research project carried out at the Vienna University of Technology and Brno University of Technology. The objective is to use jute, flax, and hemp to develop a new insulating material from renewable resources with comparable building physics and mechanical properties to commonly used insulations materials. All input components are varied in the tests. The impact of moisture content changes in relation to the rate of change of other properties was the focus of the investigation. The tests results show that the correct combination of natural materials is absolutely comparable with convectional materials.     

Time-of-flight distance sensor with MOSFET lowpass filter as key element for suppression of ambient light

A lowpass filter consisting of small MOSFET transistors is presented for application in a time-of-flight distance sensor. As a decisionmaking element, it activates the mechanism for background-light suppression in combination with some logic components. The cutoff frequency around 1 MHz is designed to smooth a signal with 10 MHz ripple. A filter attenuation of -35 dB/decade is achieved at smaller area compared to an RC-filter of only first order in the used 0.6 μm BiCMOS technology. The functionality is proven by distance measurements up to 150 klx of extraneous light with centimetre accuracy, exceeding the performance of existing sensors.     

Die neue H2A-Plattform — ein Netzwerk als Basis für Akzeptanz einer neuen Technologie

If hydrogen is to be promoted as a fuel of the future, established and tried-and-tested organisational structures and working methods must be complemented by flexible instruments capable of ensuring a maximum of innovation, productivity and information exchange with a wide range of players. The platform structure provides the ideal environment for sustainable development processes.     

电流变流体和磁流变流体在工程上的应用

阐述了ER和MR流体的组成及发展过程，并对它们的物理和化学性能进行了对比分析，总结了现有ER和MR流体的理论计算模型、应用领域和应用状况，提出了ER和MR流体阻尼装置的分类方法及使用时应注意的几个问题，最后对ER和MR流体现存的问题和发展方向作了分析和展望。     

The benefits of a graduated training program for security officers on physical performance in stressful situations.

This study examined the benefits of a graduated training program for security officers on physical performance in stressful situations and identified predictors of effective coping with stress. In addition, a comprehensive model was developed to present the relationship between physical and psychological performance. Training effectiveness was determined by comparing the differences between performance under normal conditions and under conditions of stress in preintervention and postintervention phases. Measures included a battery of physical and psychological tests. Findings showed that training had a significant effect on performance. Stress had a negative effect only on performance of complex tasks, and this effect disappeared by the end of the course. The authors concluded that security forces can be trained to deal effectively with stressful situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shape‐memory polymer networks with Fe3O4 nanoparticles for remote activation

Shape‐memory polymers (SMPs) have recently shown the capacity to actuate by remote heating via the incorporation of magnetic nanoparticles into the polymer matrix and exposure to an alternating magnetic field. In this study, methacrylate‐based thermoset SMP networks were synthesized through free‐radical polymerization with varying amounts of Fe₃O₄ magnetite (0, 1, and 2.5 wt %). Furthermore, the chemistry of the networks was controlled to maintain a constant glass transition temperature (T_g) while varying the degree of chemical crosslinking. Remote heating of the networks was shown to be a direct function of the nanoparticle concentration and independent of the chemistry. Magnetite reinforcement was shown to influence the thermomechanical properties of the networks; increasing Fe₃O₄ concentrations led to decreases in T_g and rubbery modulus. However, networks with a higher degree of crosslinking were more resistant to thermomechanical changes with respect to magnetite concentration. Strain to failure was shown to decrease with the addition of nanoparticles and the free‐strain shape‐memory cycle was investigated for all of the networks. Networks with lower degrees of crosslinking and high magnetite concentrations showed a significant amount of irrecoverable strain. Last, the use of remotely heated shape‐memory materials is discussed in light of potential biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Enthalpy recovery and free volume relaxation in a Zr44Ti11Ni10Cu10Be25 bulk metallic glass

We report on the free volume of the Zr₄₄Ti₁₁Ni₁₀Cu₁₀Be₂₅ bulk metallic glass in terms of its enthalpy recovery and volumetric relaxation below the glass transition temperature, T_g. Glassy samples are isothermally annealed below T_g using differential scanning calorimetry and the resulting enthalpy recovery, ΔH_r, is measured upon re-heating into the supercooled liquid region. Volumetric changes below T_g are measured isothermally using Thermo-Mechanical Analysis. The total changes in the relative free volume, Δν_f/ν_m, between the initially glassy state and the equilibrium liquid are calculated from the volumetric relaxation. The measured values of ΔH_r and Δν_f/ν_m correlate well within the framework of free volume theory and a linear relationship is found between the two.     

Subtypes of partner violence perpetrators among male and female psychiatric patients.

The goal of this naturalistic study was to examine heterogeneity among female and male civil psychiatric patients with a history of intimate partner violence (IPV) perpetration. Participants were 567 patients drawn from the MacArthur Violence Risk Assessment Study (J. Monahan et al., 2001). The authors examined subtype composition among 138 women and 93 men with positive histories of IPV and compared these groups with 111 women and 225 men with no histories of IPV. Findings for men and women were consistent with reports from studies of male perpetrators in forensic and community settings in that generally violent/antisocial, borderline/dysphoric, and family only/low-psychopathology subtypes of perpetrators were identified in both men and women. This study provides preliminary evidence for the generalizability of typologies derived from nonpsychiatric partner violence perpetrators to psychiatric populations and suggests that typologies derived from studies of male IPV perpetrators may provide useful guidance for the investigation of female IPV perpetration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)