Eco-efficiency of take-back and recycling, a comprehensive approach

A key question in setting up take-back systems for discarded consumer electronics is how much environmental improvement can be realized per amount of money invested. With the eco-efficiency concept developed, the environmental and economic performance of single products within various end-of-life scenarios can be quantified as well as the contribution of individual materials and material fractions to this performance. Also analysis the effectiveness and efficiency of optimization and changes in the take-back system like, glass recycling and plastic recycling, and Design for End-of-Life activities is determined. Moreover, the environmental effectiveness and cost-efficiency effects of the European Waste of Electrical and Electronic Equipment (WEEE) Directive is reviewed. Based on the eco-efficiency analyses, an implementation roadmap for this legislation is proposed in order to further improve environmental performance on one hand and to minimize costs on the other hand.     

Verification of a sliding window protocol in μCRL and PVS

We prove the correctness of a sliding window protocol with an arbitrary finite window size n and sequence numbers modulo 2n. The correctness consists of showing that the sliding window protocol is branching bisimilar to a queue of capacity 2n. The proof is given entirely on the basis of an axiomatic theory, and has been checked in the theorem prover PVS. Received November 2004 Revised June 2005 Accepted July 2005 by J. V. Tucker     

The reliability of approximate testability measures

Techniques for gauging the accuracy of approximate testability measures that estimate the random-pattern testability of gate-level faults in designs with combinational logic are considered. The measures examined are overall fault-exposure distribution, high coverage, and fault grading. Sampling techniques are compared with the Stafan and Protest approximate testability measures. For random-pattern testing, it is clear that state-of-the-art testability measures like Stafan and Protest do provide some information about the testability of single faults or complete designs, but this information is not accurate; in many areas of use they cannot compete with carefully chosen sampling techniques. The three techniques described here are applicable to testing strategies other than the random-pattern testing of stuck-at faults; they are equally useful in a weighted random-pattern testing environment, for example     

Computer-based learning in a University Zoology course

The Biology Department of the University of Nijmegen (Netherlands) has been facing many of the problems encountered by other university faculties in these economically depressed times: cutbacks in government funding, demands for curriculum revisions, increased teacher workloads, shortage of assistantships. Because of the desire to maintain high standards of research and the well known preference of most scientists to perform research rather than teaching, the quality of instruction for students may suffer. University Zoology Departments must also respond to an increasing number of students who express “moral” objections against experiments with animals and others questioning the usefulness of such experimentation in the early phase of their study. Nevertheless the university must still provide fully equipped (and costly) laboratories for student usage.Given this range of problems and constraints it is not surprising that eventually some introduction of mediated, self-study, or automated forms of instruction come under consideration. This article will describe a project which attempts to remedy a number of the above mentioned problems in teaching a second year Zoology course (Animal Physiology), and more specifically the problems surrounding an animal experiment contained therein, through the use of videotape and computer-assisted instruction.     

Myocardial infarct in the puerperium

Two women of 34 and 31 years suffered an acute myocardial infarction in the puerperium. One of them had many risk factors for atherosclerosis: hypercholesterolaemia, hypertriglyceridaemia, diabetes mellitus, hypertension, obesity, nicotine abuse and a positive family history for cardiovascular disease. She had an occluded right coronary artery and was successfully treated with percutaneous transluminal coronary angioplasty. The other patient had an acute myocardial infarction after her first delivery. She was known with hypercholesterolaemia, obesity and nicotine abuse. During her latest pregnancy she was treated with acetylsalicylic acid. Again she developed an acute myocardial infarction in the puerperium, probably due to coronary dissection. Although the incidence of acute myocardial infarction is low in the peripartal period (less than 1 in 10,000) the diagnosis should be considered when a woman presents with chest pain or dyspnoea.     

Hb Grady and alpha thalassemia: a contribution to the problem of the number of Hb alpha structural loci in man

Hematological evaluation and data from chain synthesis analyses in six members of the family with two members having Hb Grady (i.e., and alpha chain variant with elongated chains due to an insertion of three amino acid residues [1]) indicate the presence of multiple nonallelic Hb alpha structural loci in the single Hb Grady heterozygote. The data support the earlier stated hypothesis that the Hb alpha Grady locus resulted from a crossing over between chromosomes of two tandemly repeated Hb alpha loci. The presence of an alpha thalassemia condition in one of the two Hb Grady heterozygotes increases the relative production of the alpha Grady chain by a factor of two.     

A three-phase to three-phase series-resonant power converter withoptimal input current waveforms. II. Applications and results

For pt.I see ibid., vol.35, no.2, p.263-8 (1988). A 15 kW three-phase prototype series-resonant power converter is constructed. The converter features sinusoidal output voltage and sinusoidal input currents. The control concepts and necessary electronics, as well as the layout of the power circuit, are discussed. Low distortion levels are achieved for both the output voltages and the input currents, and measurements show the very fast (milliseconds) reaction capabilities of this type of equipment     

Effect of winding speed on the physical structure of as-spun poly(ethylene terephthalate) fibers,including orientation-induced crystallization

As-spun fibers of poly(ethylene terephthalate), PET, made at winding speeds ranging from 2000 to 6000 m/min exhibit quite different physical structures. Yarns wound at relatively low speeds are amorphous, whereas those spun at high speeds contain well-developed crystals of closely packed molecules. In this study the structures have been characterized by means of various techniques such as differential scanning calorimetry, x-ray diffraction, density, and pulse propagation measurements. Based on the results obtained, an arrangement of the molecules in the various yarns is proposed. It is shown that these arrangements can account for the extreme wide variety in contraction behavior found experimentally. Finally, the results obtained are compared with those of other investigations into orientation-induced crystallization.     

Interdependent technology attributes and the diffusion of consumer electronics

In many studies on innovation diffusion, five attributes of innovations by Rogers [Rogers, E.M., 2003. Diffusion of Innovations. Free Press, New York] are used to explain the adoption of innovations. These five attributes (relative advantage, compatibility, complexity, trialability and observability) are related to each other. This paper develops a theoretical framework on how these attributes are interrelated. We show empirically that modelling the theoretical interdependencies leads to better results in predicting the adoption of consumer electronics. Further, we show that our framework is not only valid on a product-domain level, but also for separate clusters within the product domain.