Does the use of Solar Home Systems (SHS) contribute to climate protection?

The paper addresses planners and decision-makers in the field of international development cooperation and also institutions concerned with the impacts of project- and technology promotion. The primary aim of the dissemination of Solar Home Systems (SHS) in off grid areas in developing countries is to improve the living conditions of the population in a cost–effective manner. A large-scale dissemination is essential both for significant contributions to development and for climate effectiveness. However, the contribution of SHS to climate protection is disputed. This analysis presents the most important parameters affecting the contribution of SHS to climate protection and quantifies the influence of those parameters. The case considered presupposes the commercial dissemination of SHS. Greenhouse gas (GHG) emissions are affected by the marketing decisions of the supplier of SHS. With regard to the impact on GHG emissions, a comparison is made between traditional lighting with petroleum lamps and the use of dry cell batteries to operate small devices (baseline case) on the one hand and SHSs on the other. The comparison shows GHG savings of around 9 tonnes of CO₂ equivalent GHG emissions within a 20-year period of use of one single 50 Wp SHS compared with the baseline case. The result is robust with respect to variations in GHG-affecting variables. Petroleum consumption and dry cell batteries dominate GHG emissions balances to such an extent that scarcely any importance can be attached to GHG emissions from the transportation and manufacture of SHS. Therefore, it is permissible to use simplified GHG inventories which ignore the GHG emissions arising from the transportation and manufacture of SHS. Therefore the conclusion is, if SHS are commercially disseminated and used cost efficiently to substitute kerosene and dry cell batteries they reduce GHG emissions effectively. In that case SHS can make a significant contribution to climate protection by the dissemination of large numbers.     

Preparation and analysis of high capacity polysulfone capsules

Since the concept of solvent impregnated resins was introduced in the early 1980s, the technique has been applied to a limited amount of applications. The main disadvantage of the resins was that the amount of solvent inside was limited to approximately 1.5 ml/g polymer. A new generation of solvent impregnated resins is introduced. These capsules can contain up to 11.8 ml solvent/g polymer and were prepared using a modified dry impregnation technique. Due to the high solvent loading, the capacity per volume of capsule for extracting products from aqueous phases is therefore dramatically increased.     

Measuring lateral skin temperature profile of premature infants in incubators with thermography

Tuberculosis is still one of the most widespread infection known to mankind. Although lung is the predominant site of disease, a sizeable population in Pakistan gets intestinal disease. Clinical presentation, radiologic and endoscopic examination provide clues to the diagnosis. However, a definitive diagnosis requires biopsy material with granulomas and/or caseation complemented by acid fast staining and culture. There are many occasions when biopsy material is scanty and even in some intestinal resection cases histologic evaluation fails to confirm or rule out tuberculosis. Therefore, an investigation was conducted to assess the efficacy of PCR in the detection of mycobacterial DNA in paraffin embedded intestinal tissue. In this study 12 histologically confirmed cases of intestinal tuberculosis and 2 cases with non specific inflammation but clinically suspected for abdominal tuberculosis were selected. One case of rectal polyp was included to serve as a negative control. M. tuberculosis DNA was amplified in 8 out of 12 histologically confirmed cases and in 2 cases diagnosed with non specific inflammation. Amplified products were obtained in 6 out of 10 PCR positive specimens with IS6110 region specific primers while 4 samples were negative, suggesting the absence of insertion sequence 6110 in these strains. However, amplification was obtained in these negative specimens with a second primer pair confirming them as M. tuberculosis complex species. On the basis of this study we conclude that; (1) Processed and paraffin embedded tissue material is suitable for PCR analysis, (2) PCR assay can be used to complement the diagnosis of intestinal tuberculosis especially in situations where a definite conclusion can not be drawn by conventional methods, (3) M. tuberculosis species lacking insertion sequence 6110 element are present in our population. Therefore, several primer pair sets should be included when applying PCR for the detection of mycobacterial DNA.     

Antimicrobial activity of bovine β-lactoglobulin against mastitis-causing bacteria

Bovine mastitis is one of the most economically deleterious diseases affecting dairy herds and results from an infection of the udder by pathogenic microorganisms such as Staphylococcus aureus, Streptococcus uberis, and Escherichia coli. The mammary gland is capable of preventing and combating bacterial infection by means of a complex network of innate and adaptive immune mechanisms. Lactoferrin is an 86-kDa protein with antibacterial activity that plays a role in the mammary gland's defense against infection. β-Lactoglobulin (β-LG) is an 18-kDa protein that is present in most mammals but is notably absent in humans, rodents, and lagomorphs. Different genetic variants of this protein exist, with β-LG A and β-LG B being the most common. In spite of being well studied, the biological function of β-LG is not thoroughly understood, and most noticeably, no reports exist on the effects of the native protein on bacterial growth. Hence, the objective of this study was to assess the potential antibacterial activity of β-LG against mastitis agents. To do this, we purified β-LG from normal bovine milk using a mild, nondenaturing method and performed in vitro growth inhibition assays with Staph. aureus, E. coli, and Strep. uberis. β-Lactoglobulin inhibited the growth of Staph. aureus and Strep. uberis but had no effect on E. coli. The antimicrobial activity against Staph. aureus and Strep. uberis was concentration dependent and was elicited by the intact protein because Tricine-sodium dodecyl sulfate-PAGE and analytical gel filtration chromatography did not reveal the presence of short degradation peptides. Analysis of the genetic variants of β-LG showed that β-LG A has higher inhibitory activity against Staph. aureus and Strep. uberis than β-LG B. Coincubation of β-LG and lactoferrin resulted in an augmented antibacterial activity against Staph. aureus, suggesting an additive effect of the proteins. This result, along with the proteins’ complementary spectrum of action, suggests that β-LG and lactoferrin may complement each other in the mammary gland's defenses against bacterial infection.     

Validity of the prosthetic activity monitor to assess the duration and spatio-temporal characteristics of prosthetic walking

The prosthetic activity monitor (PAM) is an instrument to assess over the long-term the duration and spatio-temporal characteristics of walking of amputees, during normal daily life. In this study, the validity of PAM-derived measurements was investigated. Twelve transtibial amputees performed an activity protocol, consisting of stationary and walking activities, and activities associated with nonlocomotor movements. The protocol also included potential sources of error and activities assumed to be prone to misdetection. Measurements consisted of the PAM and video recordings. Agreement between video analysis and PAM output was the main outcome measure. The PAM generally correctly classified stationary activities (100% inactive, 0% active, 0% locomotion), nonlocomotor activities (45% inactive, 55% active, 0% locomotion) and walking activities (0% inactive, 1.8% active, 98.2% locomotion). When walking, the number of strides taken was slightly underestimated (-1.0%). The underestimation of distance travelled (-6.2%) and walking speed (-5.8%) was greater. The agreement with video output decreased when the PAM was misaligned, when persons walked at a speed below the defined minimum speed, and when persons walked with crutches. The PAM provides valid data on activity classes and number of strides. Although the majority of the distance data was satisfactory, in some cases considerable differences were found between the PAM and the video data. The impact of alignment, walking speed, and use of assistive devices on the PAM's operation should be considered.     

通信电源系统的可靠性保护

随着电信业的发展，其电力系统的可靠性将变得越来越重要。不必要的电力中断会导致极大的浪费。在对电信工业撤消管制之前，大多数系统的设计与安装是由此领域的专家遵照Bellcore制定的标准来完成的。在撤消管制之后，激烈的竞争迫使许多公司将某些设计与安装工作外包给其他生产者。对设备制造商的要求越来越高，不但要配置设备，而且涉及到设备的配电和安装，尽管标准中也对这些生产过程有规定，但实际的操作可能并且确实使可靠性大打折扣。     

Whole-body impedance control of wheeled mobile manipulators

Humanoid service robots in domestic environments have to interact with humans and their surroundings in a safe and reliable way. One way to manage that is to equip the robotic systems with force-torque sensors to realize a physically compliant whole-body behavior via impedance control. To provide mobility, such robots often have wheeled platforms. The main advantage is that no balancing effort has to be made compared to legged humanoids. However, the nonholonomy of most wheeled systems prohibits the direct implementation of impedance control due to kinematic rolling constraints that must be taken into account in modeling and control. In this paper we design a whole-body impedance controller for such a robot, which employs an admittance interface to the kinematically controlled mobile platform. The upper body impedance control law, the platform admittance interface, and the compensation of dynamic couplings between both subsystems yield a passive closed loop. The convergence of the state to an invariant set is shown. To prove asymptotic stability in the case of redundancy, priority-based approaches can be employed. In principle, the presented approach is the extension of the well-known and established impedance controller to mobile robots. Experimental validations are performed on the humanoid robot Rollin’ Justin. The method is suitable for compliant manipulation tasks with low-dimensional planning in the task space.     

New smoothed particle hydrodynamics (SPH) formulation for modeling heat conduction with solidification and melting

When modeling the phase change, the latent heat released (absorbed) during solidification (melting) must be included in the heat transfer equation. In this paper, different smoothed particle hydrodynamics (SPH) methods for the implementation of latent heat, in the context of transient heat conduction, are derived and tested. First, SPH discretizations of two finite element methods are presented, but these prove to be computationally expensive. Then, by starting from a simple approximation and enhancing accuracy using different numerical treatments, a new SPH method is introduced, that is fast and easy to implement. An evaluation of this new method on various analytical and numerical results confirms its accuracy and robustness.     

A high-dynamic-range CMOS image sensor for automotive applications

In this paper, a 256×256 pixel CMOS imager is described that exhibits 120 dB dynamic range, 56 dB signal-to-noise ratio (SNR), 65% fill factor, and an effective frame rate of 50 Hz. This has been achieved using a unique combination of a multiexposure and a multigain linear readout. The imager has been integrated in 1 μm double-metal CMOS technology. The intended application is for driver's assistant systems, but the imager can be used for a wide range of applications requiring high dynamic range