Edaq530: a transparent, open-end and open-source measurement solution in natural science education

We present Edaq530, a low-cost, compact and easy-to-use digital measurement solution consisting of a thumb-sized USB-to-sensor interface and a measurement software. The solution is fully open-source, our aim being to provide a viable alternative to professional solutions. Our main focus in designing Edaq530 has been versatility and transparency. In this paper, we shall introduce the capabilities of Edaq530, complement it by showing a few sample experiments, and discuss the feedback we have received in the course of a teacher training workshop in which the participants received personal copies of Edaq530 and later made reports on how they could utilise Edaq530 in their teaching

Catalytic autothermal reforming of hydrocarbon fuels for fuel cells.

Fuel cell development has seen remarkable progress in the past decade because of an increasing need to improve energy efficiency as well as to address concerns about the environmental consequences of using fossil fuel for producing electricity and for propulsion of vehicles [1]. The lack of an infrastructure for producing and distributing H{sub 2} has led to a research effort to develop on-board fuel processing technology for reforming hydrocarbon fuels to generate H{sub 2} [2]. The primary focus is on reforming gasoline, because a production and distribution infrastructure for gasoline already exists to supply internal combustion engines [3]. Existing reforming technology for the production of H{sub 2} from hydrocarbon feedstocks used in large-scale manufacturing processes, such as ammonia synthesis, is cost prohibitive when scaled down to the size of the fuel processor required for transportation applications (50-80 kWe) nor is it designed to meet the varying power demands and frequent shutoffs and restarts that will be experienced during normal drive cycles. To meet the performance targets required of a fuel processor for transportation applications will require new reforming reactor technology developed to meet the volume, weight, cost, and operational characteristics for transportation applications and the development of new reforming catalysts that exhibit a higher activity and better thermal and mechanical stability than reforming catalysts currently used in the production of H{sub 2} for large-scale manufacturing processes

Are adolescents chronically sleep-deprived? An investigation of sleep habits of adolescents in the Southwest of Germany

Background: Adolescent sleep receives increasing attention. Several studies have shown that adolescents generally do not sleep enough. This survey assessed adolescents’ sleep patterns, and results were compared with sleep logs. Methods: A total of 818 students aged 12–18 attending three different school types were asked to complete a questionnaire, adapted from the ‘School Sleep Habits Survey’, and filled in a sleep protocol over 2 weeks. Information on sleep patterns and demographic data were obtained additionally. Results: A total of 601 students completed the questionnaire (i.e. 73.5% return rate), 55.1% female and 44.9% male. Average sleep duration during the week amounted to 8.04 ± 0.89 h and 9.51 ± 1.65 h on weekends. Sleep duration times on school days decreased from an average 8.64 ± 0.83 h for the age category 12–13 years to 7.83 ± 0.72 h for students above 16 years. 91.6% of all students slept less than 9.2 h per night during the week. Data from the 153 returned sleep logs showed even lower sleep times (7.75 ± 0.82 h for school nights). Conclusions: The main hypothesis that students sleep on average considerably less than the recommended 9 h during weekdays was confirmed. Bedtimes changed throughout the week with the latest on Friday and Saturday nights and the least sleep around midweek. There were no significant group differences regarding school type and environment (rural vs. urban). Interestingly, the majority reported only little daytime sleepiness and no impaired performance. Results regarding the consequences of chronic sleep deprivation in the literature are inconclusive. The impact on physiological parameters, especially metabolic functions, requires further investigations

Water balance in fuel cells systems.

Fuel cell systems are attractive for their high efficiency (i.e., electric power generated per weight/volume of fuel,) and lower emissions. These systems are being developed for applications that include transportation (propulsion and auxiliary), remote stationary, and portable. Where these systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For utility applications, this water may be available on-site, but for most applications, the process water must be recovered from the fuel cell system exhaust gas. For such applications, it is critically important that the fuel cell system be a net water-producing device. A variety of environmental conditions (e.g., ambient temperature, pressure), fuel cell system design, and operating conditions determine whether the fuel cell system is water-producing or water-consuming. This paper will review and discuss the conditions that determine the net-water balance of a generic fuel cell system and identify some options that will help meet the water needs of the fuel processor

Die Folgen des Schlafentzugs bei Jugendlichen: Kognitive, psychometrische und physiologische Effekte verschiedener Schlafprotokolle

No abstract availabl

The cost of sleep deprivation for adolescents: Cognitive, psychometric and physiological effects after sleep curtailment

No abstract availabl

BMBF-Projekt Neurowissenschaften – Instruktion – Lernen: Elternedukation bei Grundschülern und Schlafrestriktion bei Jugendlichen

No abstract availabl

Sleep and memory in healthy children and adolescents – A critical review

There is mounting evidence that sleep is important for learning, memory and the underlying neural plasticity. This article aims to review published studies that evaluate the association between sleep, its distinct stages and memory systems in healthy children and adolescents. Furthermore it intends to suggest directions for future research. A computerised search of the literature for relevant articles published between 1966 and March 2008 was performed using the keywords “sleep”, “memory”, “learn”, “child”, “adolescents”, “adolescence” and “teenager”. Fifteen studies met the inclusion criteria. Published studies focused on the impact of sleep on working memory and memory consolidation. In summary, most studies support the hypothesis that sleep facilitates working memory as well as memory consolidation in children and adolescents. There is evidence that performance in abstract and complex tasks involving higher brain functions declines more strongly after sleep deprivation than the performance in simple memory tasks. Future studies are needed to better understand the impact of a variety of variables potentially modulating the interplay between sleep and memory, such as developmental stage, socioeconomic burden, circadian factors, or the level of post-learning sensory and motor activity (interference). This line of research can provide valuable input relevant to teaching, learning and public health policy

Fuel-flexible partial oxidation reforming of hydrocarbons for automotive applications.

Micro-reactor tests indicate that our partial oxidation catalyst is fuel-flexible and can reform conventional (gasoline and diesel) and alternative (ethanol, methanol, natural gas) fuels to hydrogen rich product gases with high hydrogen selectivity. Alcohols are reformed at lower temperatures (< 600 C) while alkanes and unsaturated hydrocarbons require slightly higher temperatures. Cyclic hydrocarbons and aromatics have also been reformed at relatively low temperatures, however, a different mechanism appears to be responsible for their reforming. Complex fuels like gasoline and diesel, which are mixtures of a broad range of hydrocarbons, require temperatures of > 700 C for maximum hydrogen production