信息与通讯技术产品的环境指标--基于四个阶段的实践方法

人们对于污染、危险物、全球变暖和可持续性的广泛关注引起社会的普遍反响。这可以从公共政策或消费者行为的变化反映出来。对于电子电气设备而言,欧盟已颁布的一系列指令比如《关于报废电子电气设备指令》(WEEE)和《关于在电子电气设备中限制使用某些有害物质的指令》(RoHS)以及即将实施的指令诸如《耗能产品生态设计指令》(EuP)已经和将要对如何进行产品的设计、构造、使用和寿命终期的处理产生显著的影响。为应对这些挑战,急需用于评价和展示产品环境性能的标准,并且要求该标准应具有可量化且通俗易懂的特性。生命周期评价法(LCA)是一种能够全面可靠的进行产品环境评价的主要方法。这种业已证实的科学方法用于进行产品的整个生命周期环境评价,可以得到有用确切的结果。该方法涵盖了从原材料信息收集到产品寿命终期管理的整个生命周期过程,同时还涉及了产品特性(比如重量、使用的原材料、使用过程中的能耗)和在整个生命周期过程中相关的输入和输出(比如能量、原材料、排放量)。为了改善产品环境效能,对于产品设计者而言,所提出的生态设计建议应当是可靠的并且容易实施的。基于技术产品特性和生命周期评价法的环境性能指标应该能够有效地改善产品的环境概貌。由于只需要输入很少的一部分信息,因此该途径提供了一种专用而又简单的环境性能指标的方法。本文介绍一种用于完善信息与通讯技术产品环境性能指标的一致性方法。     

Förderanlagen für Schnittholztrockner

The transportation problem at a timber drying plant had to be settled by means of a special truck. This truck, must be able to manipulate the timber piles in front of the kilns, in the socalled green-wood area, as well as after kiln drying, in the dry-wood-area. The special truck “Telemobil” itself and its applicability are discussed.     

Förderanlagen für Schnittholztrockner

The installment of machinery according to a costumer's order is described. Both on working-days and on free weekends a kiln drying plant shall continuously furnish dried timber piled on rail carriers and transmit it to a buffer store. It is demonstrated that these requirements may be met with by installing a discontinuously working plant with automatic carrier return.     

Analysis of the velocity field of granular hopper flow

We report the analysis of radial characteristics of the flow of granular material through a conical hopper. The discharge is simulated for various orifice sizes and hopper opening angles. Velocity profiles are measured along two radial lines from the hopper cone vertex: along the main axis of the cone and along its wall. An approximate power law dependence on the distance from the orifice is observed for both profiles, although differences between them can be noted. In order to quantify these differences, we propose a Local Mass Flow Index that is a promising tool in the direction of a more reliable classification of the flow regimes in hoppers.     

Tensile stress relaxation in unsaturated granular materials

The mechanics of granular media at low liquid saturation levels remain poorly understood. Macroscopic mechanical properties are affected by microscale forces and processes, such as capillary forces, inter-particle friction, liquid flows, and particle movements. An improved understanding of these microscale mechanisms is important for a range of industrial applications and natural phenomena (e.g. landslides). This study focuses on the transient evolution of the tensile stress of unsaturated granular media under extension. Experimental results suggest that the stress state of the material evolves even after cessation of sample extension. Moreover, we observe that the packing density strongly affects the efficiency of different processes that result in tensile stress relaxation. By comparing the observed relaxation time scales with published data, we conclude that tensile stress relaxation is governed by particle rearrangement and fluid redistribution. An increased packing density inhibits particle rearrangement and only leaves fluid redistribution as the major process that governs tensile stress relaxation.     

Particle–Fluid–Structure Interaction for Debris Flow Impact on Flexible Barriers

Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, the development of a numerical tool for the rational design of such structures is still a challenge. In this work, a hybrid computational framework is presented, using a total Lagrangian formulation of the finite element method to represent a flexible barrier. The actions exerted on the structure by a debris flow are obtained from simultaneous simulations of the flow of a fluid‐grain mixture, using two conveniently coupled solvers: the discrete element method governs the motion of the grains, while the free‐surface non‐Newtonian fluid phase is solved using the lattice Boltzmann method. Simulations on realistic geometries show the dependence of the momentum transfer on the barrier on the composition of the debris flow, challenging typical assumptions made during the design process today. In particular, we demonstrate that both grains and fluid contribute in a nonnegligible way to the momentum transfer. Moreover, we show how the flexibility of the barrier reduces its vulnerability to structural collapse, and how the stress is distributed on its fabric, highlighting potential weak points.     

Fusion of indigenous knowledge and gamma spectrometry for soil mapping to support knowledge-based extension in Tanzania

Food shortages often threaten central Tanzania. Sustainable action adapted to local environmental conditions is desperately needed. In the framework of the TransSEC project, two food value chains in the Dodoma region of Tanzania were inspected in order to make propositions for improvement , spanning from soil preparation to product consumption. Therefore, soil mapping approaches were required to obtain rapid and reliable information. This would enable local farmers to participate in the development of upgrading strategies and extensionists to develop recommendations that take local soil conditions into account. In this study, a combination of participatory soil mapping and gamma ray spectrometry-assisted transect mapping was applied to establish local soil maps of two villages in the Dodoma region. Participatory mapping included key informant interviews, group discussions and transect walks. Local farmers indicated reference profiles for local soil types. Their gamma radiation signatures delivered base information for further soil exploration and soil unit delineation in the field. Finally, high resolution satellite images were used to establish the village soil maps. This approach allows capture of the major soil differences within a village territory and reduction of the costs of chemical analyses. Challenges were soil unit separation with gamma ray spectrometry due to erosional redistribution processes at the surface, correct translation of specific terms from local tongues as well as variable individual soil knowledge of local participants. Ultimately, the combination of local soil knowledge with innovative scientific mapping yielded quick results with sufficient spatial resolution for extension work.     

Microstructure of the HMX‐Based PBX KS32 after Mechanical Loading

Non‐destructive X‐ray diffraction techniques were applied in order to monitor the influence of mechanical and shock‐loading on the microstructure of the plastic‐bonded high explosive KS32. The investigations uncovered damage to embedded coarse HMX crystals and to the binder system HTPB‐IPDI. Damage to the crystals occurred already during the kneading process in terms of deformation twinning. On higher loading between 400 MPa (static) and 480 MPa (dynamic) also crystal fracture was observed. The change in the binder structure was found after both static and dynamic loading, but not in the cured, differently kneaded samples. Moreover, the change in binder structure after dynamic loading was verified by dynamic mechanical analysis, and interpreted as a partial damage of the binder rubber shell around the explosive particles. The results are compared to literature data from imaging techniques.     

Diazoverbindungen. 72. (Diazoalkyl)phosphane – Synthese durch elektrophile Diazoalkansubstitution und oxidative Additionsreaktionen am Phosphor

Diazo Compounds. 72. Diazoalkylphosphanes – Synthesis by Electrophilic Diazoalkane Substitution and Oxidative Addition Reactions at Phosphorus Electrophilic diazoalkane substitution of the diazomethyl compounds 1a,b with the chloro phosphanes 2a-o in the presence of lithium diethylamide yields the diazoalkyl phosphanes 3a-z . Oxidative addition of oxygen, sulfur and selenium at phosphorus leads into the series of oxo, thioxo and selenoxo phosphanes having diazoalkyl substituents ( 4a-d, 5a-m and 7a-d ). The silyl group of 5n,o is cleaved by chromatography on aluminium oxide to yield the (diazomethyl)phosphane sulfides 6a,b .