Life-cycle assessment of hydrogen technologies with the focus on EU critical raw materials and end-of-life strategies

We present the results of a life-cycle assessment (LCA) for the manufacturing and end-of-life (EoL) phases of the following fuel-cell and hydrogen (FCH) technologies: alkaline water electrolyser (AWE), polymer-electrolyte-membrane water electrolyser (PEMWE), high-temperature (HT) and low-temperature (LT) polymer-electrolyte-membrane fuel cells (PEMFCs), together with the balance-of-plant components. New life-cycle inventories (LCIs), i.e., material inputs for the AWE, PEMWE and HT PEMFC are developed, whereas the existing LCI for the LT PEMFC is adopted from a previous EU-funded project. The LCA models for all four FCH technologies are created by modelling the manufacturing phase, followed by defining the EoL strategies and processes used and finally by assessing the effects of the EoL approach using environmental indicators. The effects are analysed with a stepwise approach, where the CML2001 assessment method is used to evaluate the environmental impacts. The results show that the environmental impacts of the manufacturing phase can be substantially reduced by using the proposed EoL strategies (i.e., recycled materials being used in the manufacturing phase and replacing some of the virgin materials). To point out the importance of critical materials (in this case, the platinum-group metals or PGMs) and their recycling strategies, further analyses were made. By comparing the EoL phase with and without the recycling of PGMs, an increase in the environmental impacts is observed, which is much greater in the case of both fuel-cell systems, because they contain a larger quantity of PGMs.     

Persönlichkeit 2.0

Online Social Networks (OSNs) wie MySpace, Facebook und StudiVZ sind inzwischen zu einem wichtigen Bestandteil des allt?glichen Miteinanders geworden. Entgegen der weit verbreiteten Meinung vermitteln Profile in OSNs kein verf?lschtes, selbstidealisiertes, sondern ein sehr genaues Bild von der Pers?nlichkeit der Profilbesitzer. Dies k?nnte ein wichtiger Grund für die Beliebtheit sozialer Netzwerke sein: Sie bieten eine Plattform für reale soziale Interaktionen und erm?glichen den Ausdruck der eigenen Pers?nlichkeit. Implikationen für den Datenschutz in OSNs werden diskutiert.     

Automatic Generation of Language-based Tools

Many tools can be automatically derived from formal language definitions, such as compilers/interpreters, editors, analyzers, visualizers/animators, etc. Some examples of language-based tools generated automatically by the LISA system are described in the paper. In addition the specification of an algorithm animator and program visualizer, Alma, generated from an extended LISA input-grammar is discussed; LISA principles and code are reused in Alma implementation.     

Reconfigurable digital controller for a buck converter based on FPGA

This paper presents a complete digitally controlled dc–dc buck converter performed by FPGA circuitry. All tasks, analog to digital conversion, control algorithm and pulse width modulation, were implemented in the FPGA. This approach enables high-speed dynamic response and programmability by the controller, without external passive components. In addition, the controller’s structure can be easily changed without external components. The applied algorithm enables a switching frequency of 100 kHz.     

Temperature profile modelling in fuel-coolant interaction codes

To improve the determination of heat and mass transfer in fuel-coolant interaction codes appropriate knowledge of the conditions inside the melt droplets is needed. A simplified mathematical model for the determination of the melt droplet conditions is introduced, considering the material physical properties of the melt droplet. Since the computational demand of the mathematical model would significantly increase the overall computational time of the fuel-coolant interaction codes, a simplification based on the temperature profile approach is presented. Finally, a physically-based approach, which is simple enough to be practical for the implementation into computer codes and complex enough to consider adequately the material properties, is proposed and validated.     

Assessing readiness for change in the eating disorders: The psychometric properties of the readiness and motivation interview.

This study examined the psychometric properties of the Readiness and Motivation Interview (RMI), a symptom-specific measure of readiness and motivation for change in the eating disorders. For 4 symptom domains, the RMI assesses the extent to which individuals are in precontemplation, contemplation, and action/maintenance, and the extent to which change is made for internal versus external reasons. Ninety-nine individuals with eating disorders completed the RMI and measures to assess convergent, divergent, and criterion validity. RMI profiles revealed differences in readiness and motivation across symptom domains. The RMI demonstrated good reliability and construct validity, and RMI scores predicted anticipated difficulty of recovery activities, completion of recovery activities, decision to enroll in an intensive symptom-reduction program, and treatment dropout. The RMI may have important clinical applications by providing much-needed information on client readiness for action-oriented treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of hyperglycemia and hyperinsulinemia in the pathogenesis of diabetic angiopathy

The small and large vessel disease associated with diabetes mellitus is responsible for its morbidity and mortality. Although much of the pathogenesis remains to be clarified, the role of hyperinsulinemia and hyperglycemia per se in the progression of vascular disease is beginning to emerge. Hyperinsulinemia increases the release of very low density lipoprotein (VLDL) and may also be responsible for the low HDL cholesterol levels in patients with diabetes. Hyperinsulinemia also contributes to increased blood pressure, which independently promotes vascular disease. High glucose concentrations have direct influence on intracellular signal transduction, including effects on sorbitol pathway and associated changes of pyridine nucleotides, the de novo synthesis of diacylglycerol with subsequent stimulation of protein kinase C, and possibly changes in the cellular generation of myoinositol. Hyperglycemia also exerts long-lasting changes in cellular function, which result from non-enzymatic glycosylation of matrix and membrane proteins with subsequent binding of these proteins to specific receptors. These receptors are termed the advanced glycosylation end-products (AGE) receptors. Their activation leads to an increased release of cytokines and growth factors including PDGF, interleukins, TNF-alpha, and TGF-beta, all of which may act concomitantly in the disease process.     

Numerical Modeling of Heat Transfer and Flow Phenomena in an Axial Rotating Rotor Cascade

This paper presents a study of heat transfer in a rotating axial rotor. The study was done on the basis of computational fluid dynamics simulations and validated with an infrared thermocamera experimental setup. The influence of full turbulence vs. Menter's boundary layer method was studied in terms of heat transfer and flow phenomena. Additionally it was found out that a thin paint layer has a major influence on heat transfer phenomena and acts as insulation. For comparison of numerical results with experimental, a model of the actual rotor was established. Results were found to be in good agreement, so the effect of rotation on heat transfer was studied. Results are presented in terms of Nusselt number distribution and an empirical model of heat transfer.