On the effect of geometrical designs and failure modes in composite axial crushing: A literature review

Composite materials have been known for its low density, ease in fabrication, high structural rigidity, and wide range applications, i.e. aeronautic applications and automotive industry. Due to this, extensive studies had been conducted to evaluate its axial crushing ability to replace metallic materials. In this paper, it reviewed the usage of fibre reinforced plastic composite (FRP) as an energy absorption application device. Failure modes and geometrical designs such as shapes, geometry and triggering effect have been studied where these factors affected on peak load and specific energy absorption significantly. Accordingly, numerical analysis for axial crushing of affected factors had been simulated to predict the failure mechanisms of FRP composites.     

Science and animal welfare in France and European Union: Rules,constraints, achievements

The welfare of food-producing animals is a focus of public debate in Europe. Political institutions, have introduced regulations based on scientific data. Meanwhile, the practices of producers and transformers were modified. Implementation of care practices is added to the goal of sustainable basic health of animals. Nevertheless urban consumers still look for the “naturalness” of living animals. A brief historical perspective introduces the building process of European regulations. A short list of Directories and Recommendations provides a clue on the complexity of resulting construct. Now, this complexity is calling for simplification of rules while practices should be compatible with professional constraints. Few selected examples are brought to illustrate how the concepts initially studied by scientists (welfare, pain, stress, “consciousness”/awareness) were integrated in regulations and implemented by producers and meat industry in order to simultaneously maintain the requirements for high quality and security standards. At the same time, free trade market constraints introduced new distortions, in particular those linked to the world demand for proteins. Indeed, the controversy about animal welfare, initially brought on ethical grounds, became a case for ongoing adjustements of EU policy, requesting to combine scientific knowledge on animals, consequent evolution in the representation of animals by urban consumers with the challenge of adaptation and implemention of regulations.     

Service quality,technical efficiency and total factor productivity growth in Pakistan's post-reform electricity distribution companies

Pakistan's energy sector has undergone substantial reforms during the last three decades with the aim to improve its operational performance and to cater to the growing energy needs of the economy. In the wake of these reforms, the WAPDA Act was passed in 1998 to achieve operational and financial efficiencies. Pakistan's electricity market is still hampered by issues like extended blackouts, electricity thefts, high circular debt and poor service quality. The electricity distribution sector is thus an interesting case to investigate its efficiency in the post-reform period by examining the impact of service-quality parameters (SQPs), which have generally been neglected in the literature. Stochastic frontier analysis has been used to estimate technical efficiency, while the Malmquist Productivity Index is implemented to decompose total factor productivity (TFP) into scale change, technical change and efficiency change from 2006 to 2016. We conclude that the technical efficiency score declines from 98 percent to 36 percent with the inclusion of SQPs in the models. The results also indicate a negative trend in scale change, implying that distribution companies are not operating at the technically optimal scale. We propose that the regulatory body should change its governance regime and focus on incentive-based regulation instead of rate-of-return regulation.     

The (In)efficiency of the retail-minus rule

The Retail-Minus Rule (RMR) specifies that the rate for a mandated wholesale service is set by subtracting from the vertically integrated provider's (VIP's) retail price the costs it avoids by selling the wholesale service rather than the retail service. While the RMR offers regulators an expedient method for setting wholesale prices, we show that it is efficient only under restrictive conditions. The proper test for a price squeeze inquires whether the VIP's retail price is greater than or equal to the sum of the direct cost and the opportunity cost of supplying the retail service. The RMR passes this test only when the competing retail services are perfect substitutes.     

基于特高压交流变电站检修典型问题分析

本文在对于特高压交流变电站检修典型问题演技中,主要对于轮停检修感应电压问题及测量误差等问题进行分析,希望能够为其他特高压交流变电站检修工作提供一定帮助.     

A game for emotional regulation in adolescents: The (body) interface device matters

The aim of this study is to evaluate the role of the type of interface device in the efficacy of a serious game that teaches emotional regulation (ER) strategies in a non-clinical sample of adolescents. We conducted a between-participants experiment in which participants (N = 61) played a frustration induction game, and then an ER game (a breathing strategy game), using one of three types of devices (computer, smartphone, and RGB-D camera). Frustration mood and perceived arousal were the main variables measured. Results revealed a significant interaction between moment (pre-induction phase, post-induction phase, and regulation phase) and the type of interface device used in the frustration mood scores. In participants who used the computer and smartphone, frustration increased after the induction phase and decreased after the regulation phase. However, for participants who used the RGB-D camera, frustration decreased significantly after the induction phase, and this change was maintained after the regulation phase. Changes in arousal were similar with the three devices. This study highlights that the type of interface device (and specifically, the participation of the body) is a crucial variable in the efficacy of serious games affecting users’ emotional experience.     

An Equalization Time Reduction Method Using a Pseudo‐Random Number Sequence for a Cell Voltage Equalization Circuit with an LC Series Circuit

When the cells of energy storage devices such as electric double‐layer capacitors are connected in series, it results in voltage imbalance in each cell because of the nonuniform properties of the individual cells. In a previous research, the authors proposed a novel cell voltage equalization circuit using an LC series circuit, and they examined the effectiveness of this circuit. However, the characteristics of the cell voltage equalization operation depend on each cell voltage difference. Therefore, the proposed circuit has a disadvantage that the equalization time tends to be longer than other cell voltage equalization circuits with a boosting circuit. This paper proposes an equalization time reduction method that uses a pseudo‐random number sequence generated by the linear congruential generators. The proposed method can reduce the average equalization time without adding any other active or passive elements. The effectiveness of the proposed method is verified through the experimental results. According to the experimental results, the proposed equalization time reduction method reduces the equalization time to 86.5% of the conventional method.     

The significance of the Convention on Environmental Impact Assessment in a Transboundary Context (Espoo Convention) in international environmental law: examining the implications of the Danube Delta case

The Convention on Environmental Impact Assessment in a Transboundary Context, providing for a concrete framework of procedural regulation on environmentally harmful activities, has several features and is one of the most progressive multilateral environmental agreements (MEAs). This convention may offset some of the limits of substantial regulation and strengthen procedural regulation in various respects where an activity, to which the convention applies, is also regulated by other MEAs. The Danube Delta case concerning the Bystroe Canal project of Ukraine may be one such precedent. This convention takes several distinctive functions, derived from the features, in the complex interaction of the management processes under five MEAs and the UNESCO MAB Programme, as well as by the European Commission. This gives us some hints of an answer regarding some questions on overlap between different MEAs.     

Axial crushing and optimal design of square tubes with graded thickness

Introducing thickness gradient in cross-section is a quite promising approach to increase the energy absorption efficiency and crashworthiness performance of thin-walled structures. This paper addresses the deformation mode and energy absorption of square tubes with graded thickness during axial loading. Experimental study is firstly carried out for square tubes with two types of thickness distributions and numerical analyses are then conducted to simulate the experiment. Both experimental and numerical results show that the introduction of graded thickness in cross-section can lead to up to 30–35% increase in energy absorption efficiency (specific energy absorption) without the increase of the initial peak force. In addition, structural optimization of the cross-section of a square tube with graded thickness is solved by response surface method and the optimization results validate that increasing the material in the corner regions can indeed increase the energy absorption efficiency of a square tube.     

Experimental study of the burner for FAA fire test: NexGen burner

The NexGen (Sonic) burner is the new burner developed by the Federal Aviation Administration, FAA, to replace old oil burners used for the required fire certification tests on power plant‐related materials, as it provides the capability to control both air and fuel flow rates. During a fire test, the burner is supposed to simulate a certain fire condition, so the flame properties should be robust and repeatable. The NexGen burner can achieve this due to the precise fuel and air controls. However, the current calibration criterion (ISO2685:1998 and AC20‐135) may not be good enough to ensure consistent flame properties. In the presented work, the sensitivity of the burner performance to air and fuel flow rate, as measured by the temperature and heat flux for calibration purposes, was studied. Additionally, the influence of the turbulator and the thermocouple size used for flame calibration was also studied. The impact of varying fuel/air ratio and thermocouple sizes was studied by conducting fire tests on aluminum samples, to show the inadequacies in the current calibration standards.