Analyse der Störfestigkeit nichtlinearer Schaltungen gegenüber leitungsgebundenen elektromagnetischen Störungen mit multi-input Wiener/Hammerstein-Modellen

In dieser Arbeit wird der Einfluss von leitungsgebundenen Störungen untersucht, welche in einen beliebigen Eingang (Signaleingang, Spannungsversorgung, Masse-Potenzial, etc.) einer Analogschaltung einkoppeln. Die zu untersuchende Schaltung wird dazu durch einen Wiener/Hammerstein-Ansatz als nichtlineares System mit zwei Eingängen modelliert. Mit Hilfe dieses Blockmodells werden analytische Ausdrücke derjenigen Frequenzanteile bestimmt, die durch Intermodulationen zwischen Stör- und Eingangssignal am Ausgang einer Schaltung entstehen.BMBF/03X4604

Global life cycle paper flows, recycling metrics and material efficiency

Despite major improvements in recycling over the last decades, the pulp and paper sector is a significant contributor to global greenhouse gas emissions and other environmental pressures. Further reduction of virgin material requirements and environmental impacts requires a detailed understanding of the global material flows in paper production and consumption. This study constructs a Sankey diagram of global material flows in the paper life cycle, from primary inputs to end-of-life waste treatment, based on a review of publicly available data. It then analyses potential improvements in material flows and discusses recycling and material efficiency metrics. The article argues that the use of the collection rate as a recycling metric does not directly stimulate avoidance of virgin inputs and associated impacts. An alternative metric compares paper for recycling (recovered paper) with total fibrous inputs and indicates that the current rate is at just over half of the technical potential. Material efficiency metrics are found to be more useful if they relate to the reuse potential of wastes. The material balance developed in this research provides a solid basis for further study of global sustainable production and consumption of paper. The conclusions on recycling and efficiency should be considered for improving environmental performance assessment methods

An identification procedure of multi-input Wiener models for the distortion analysis of nonlinear circuits

In this contribution, a system identification procedure of a two-input Wiener model suitable for the analysis of the disturbance behavior of integrated nonlinear circuits is presented. The identified block model is comprised of two linear dynamic and one static nonlinear block, which are determined using an parameterized approach. In order to characterize the linear blocks, an correlation analysis using a white noise input in combination with a model reduction scheme is adopted. After having characterized the linear blocks, from the output spectrum under single tone excitation at each input a linear set of equations will be set up, whose solution gives the coefficients of the nonlinear block. By this data based black box approach, the distortion behavior of a nonlinear circuit under the influence of an interfering signal at an arbitrary input port can be determined. Such an interfering signal can be, for example, an electromagnetic interference signal which conductively couples into the port of consideration

Limitations of the waste hierarchy for achieving absolute reductions in material throughput

Dematerialization can serve as a measurable and straightforward strategy for sustainability and requires changes in management of material inputs and waste outputs of the economy. Currently, waste man- agement is strongly inspired by the waste hierarchy, an in fl uential philosophy in waste and resource management that prioritizes practices ranging from waste prevention to land fi ll. Despite the inclusion and prioritization of prevention in the hierarchy, the positive contribution of the application of the waste hierarchy to dematerializing the economy is not inevitable, nor has it been conclusively studied. In this paper, the waste hierarchy is analyzed on a conceptual level by studying its original aims, its potential to ful fi ll those aims, and its actual policy implementation. Issues with the hierarchy include limited spec- i fi cation and implementation of prevention, a lack of guidance for choosing amongst the levels of the hierarchy and the absence of a distinction between open-loop and closed-loop recycling. Also, the hi- erarchy only communicates relative priorities and therefore does not support decisions that affect other sectors as well as waste management. The article concludes that the waste hierarchy in its current form is an insuf fi cient foundation for waste and resource policy to achieve absolute reductions in material throughput. Suggested improvements are the adoption of a value-based conception of waste and related collection practices, more stringent and targeted policies on least desirable options like land fi ll, the speci fi cation of waste management targets based on dematerialization ambitions, and the use of the waste hierarchy within a resource productivity-oriented framework

Meeting commentary-"Medicines for older adults: Learning from practice to develop patient centric drug products"

A meeting jointly organised by the Academy of Pharmaceutical Sciences (APSGB), the Geriatric Medicine Society and the UCL School of Pharmacy took place on the 13th of March 2013, in Stevenage, UK [*]. The meeting was attended by a number of experts involved with the treatment and development of drugs for the older adult, including clinicians, pharmacists, academics, regulators and representatives from industry. The event created the platform to discuss the provision of medicines for older adults from a pharmaceutical sciences perspective

Multi crystalline silicon thin films grown directly on low cost soda lime glass substrates

Liquid phase crystallization of silicon is a promising technology platform to grow multi crystalline silicon thin films on foreign substrates. For solar cell application it has already been demonstrated that open circuit voltages of up to 661 mV [1] and efficiencies of up to 15.9 [2] can be achieved on a silicon layer of a few microns only. However, while the quality of the material has been continuously improved, the cost factor of the utilized substrate has been given little attention. The present work focuses on the technology transfer from technical glass substrates to low cost soda lime glass substrates to become more attractive for commercial applications. We demonstrate that despite a large difference in the expansion coefficient between soda lime glass and silicon absorber layer, adhesive silicon thin films can be produced under certain conditions. On these first layers, we were able to fabricate solar cells, which in their cell and material properties were only 30 below the values of their technical glass counterpart

A mouse model of post-stroke pneumonia induced by intra-tracheal inoculation with Streptococcus pneumoniae

Background: Stroke-induced immunodeficiency increases the risk of infectious complications, which adversely affects neurological outcome. Among those, pneumonia affects as many as one third of stroke patients and is the main contributor to mortality in the post-acute phase of stroke. Experimental findings on post-stroke susceptibility to spontaneous pneumonia in mice are contradictory. Here, we established a mouse model inducing standardized bacterial pneumonia and characterized the impaired pulmonary cellular and humoral immune responses after experimental stroke. Methods: Bacterial pneumonia was induced by intra-tracheal inoculation with Streptococcus pneumoniae at different time points after transient middle cerebral artery occlusion (MCAO). Bacterial counts in lungs and blood, histological changes, and cytokine production in the lungs were assessed. Furthermore, we investigated the effect of pneumonia on stroke outcome. Results: Intra-tracheal inoculation resulted in reproducible pneumonia and bacteraemia, and demonstrated post-stroke susceptibility to streptococcal pneumonia developing with a delay of at least 24 h after MCAO. Higher bacterial counts in mice infected 3 days after stroke induction correlated with reduced neutrophil and macrophage infiltration in the lungs and lower levels of pro-inflammatory cytokines in the broncho-alveolar lavage compared to sham-operated animals. Pneumonia increased mortality without affecting brain-infiltrating leukocytes. Conclusions: In this standardized mouse model of post-stroke pneumonia, we describe attenuated leukocyte infiltration and cytokine production in response to bacterial infection in the lungs that has a profound effect on outcome