Investigations regarding the behaviour of historic glass and its surface layers towards different wavelengths applied for laser cleaning

The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy.     

Physical and metabolic demands of training and match-play in the elite football player

In soccer, the players perform intermittent work. Despite the players performing low-intensity activities for more than 70% of the game, heart rate and body temperature measurements suggest that the average oxygen uptake for elite soccer players is around 70% of maximum (VO(2max). This may be partly explained by the 150 - 250 brief intense actions a top-class player performs during a game, which also indicates that the rates of creatine phosphate (CP) utilization and glycolysis are frequently high during a game. Muscle glycogen is probably the most important substrate for energy production, and fatigue towards the end of a game may be related to depletion of glycogen in some muscle fibres. Blood free-fatty acids (FFAs) increase progressively during a game, partly compensating for the progressive lowering of muscle glycogen. Fatigue also occurs temporarily during matches, but it is still unclear what causes the reduced ability to perform maximally. There are major individual differences in the physical demands of players during a game related to physical capacity and tactical role in the team. These differences should be taken into account when planning the training and nutritional strategies of top-class players, who require a significant energy intake during a week.     

Zeitökonomische Aspekte der Nachfrage nach Vereinsleichtathletik im europäischen Vergleich

In a joint project involving European association staff and sports scientists, basic structural data were collected on British, Swedish, Spanish and German athletics clubs to be used for analysis of hypotheses concerning conditions of participation in sports clubs, particularly by children and adolescents. The results showed clear differences in organizational level as well as membership and activity structures in comparisons between European countries and within Germany. The findings revealed the differential functions and significance of sports clubs in the context of the respective institutions and cultures.     

Teaching Critical Thinking and Problem Defining Skills

Critical thinking and skills in defining problems have been among the goals of a computers and society course that had its credits reduced and student number increased. In an attempt to prevent worsening the students' learning, four measures were taken. The results actually improved from a failure rate of 21.5% to 0.7%. This was mainly due to tighter project structure and additional student work. Reduced course material and improved teacher preparation did not seem to have any effect, while more focused project teaching may have contributed to the decreased failure rate. Further improvements may be gained through time estimation in the problem definition process.     

Objektorientierter Entwurf eines flexiblen Workflow-Management-Systems

Zusammenfassung.   Dieser Beitrag enth?lt die wesentlichen konzeptionellen überlegungen zur Entwicklung eines flexiblen Workflow-Management-Systems. Ausgehend von einer Diskussion m?glicher Modellierungsalternativen wird unter Verwendung objektorientierter Modellierungstechniken ein Workflow-Meta-Schema entwickelt, das die relevanten Entit?ten klassifiziert und ihre Beziehungen abbildet. Anhand eines Beispiels werden die getroffenen Entwurfentscheidungen ausführlich begründet. Schlie?lich werden Zust?nde und Zustandsüberg?nge von Workflow-Instanzen beschrieben, und es wird diskutiert, wie dynamische Ver?nderungen von Workflows zur Laufzeit durchgeführt werden k?nnen, um laufende Workflows dynamisch an ver?nderte Umweltbedingungen anzupassen. Eingegangen am 20. Dezember 1997 / Angenommen am 24. Juli 1998     

Weekday–weekend variations in mother-/father–child physical activity and screen time relationship: A cross-sectional study in a random sample of Czech families with 5- to 12-year-old children

This study assessed the associations between these factors in a random sample of Czech families with preschool and school-aged children. A nationally representative sample comprised 185 families with preschool children and 649 families with school-aged children (dyads; both parents and child n?=?365, mother and child n?=?730, and father and child n?=?469). The participants wore Yamax Digiwalker SW-200 pedometers at least four weekdays and both weekend days and completed family logbooks (anthropometric parameters, daily step counts (SC), and screen time (ST)). When a parent (fathers at weekends and mothers both on weekdays and at weekends) achieved 10,000 SC per day, their children were also significantly (OR?=?2.93–6.06, 95% CI?=?2.02–9.26) more likely to meet the daily SC recommendation. On the contrary, the involvement of fathers in organized leisure-time PA reduced their children's odds of meeting the SC recommendation on weekdays (OR?=?0.53, 95% CI?=?0.31–0.89) and at weekends (OR?=?0.41, 95% CI?=?0.24–0.72). The excessive ST of parents at weekends reduced the odds of their children meeting the SC recommendation (mother–child dyads: OR?=?0.44, 95% CI?=?0.26–0.72; father–child dyads: OR?=?0.63, 95% CI?=?0.37–1.06). High levels of parents’ PA contribute to the achievement of the recommended daily PA in children on weekdays and at weekends. Excessive weekend ST of parents reduces their odds of their children achieving the recommended daily PA; however, the influence of parents’ PA on their children’s achieving the recommended daily PA is stronger than the inhibitory effect of ST.     

Complex three-dimensional high aspect ratio microfluidic network manufactured in combined PerMX dry-resist and SU-8 technology

In this paper we present a new fabrication method that combines for the first time popular SU-8 technology and PerMX dry-photoresist lamination for the manufacturing of high aspect ratio three-dimensional multi-level microfluidic networks. The potential of this approach, which further benefits from wafer-level manufacturing and accurate alignment of fluidic levels, is demonstrated by a highly integrated three-level microfluidic chip. The hereby achieved network complexity, including 24 fluidic vias and 16 crossing points of three individual microchannels on less than 13 mm(2) chip area, is unique for SU-8 based fluidic networks. We further report on excellent process compatibility between SU-8 and PerMX dry-photoresist which results in high interlayer adhesion strength. The tight pressure sealing of a fluidic channel (0.5 MPa for 1 h) is demonstrated for 150 μm narrow SU-8/PerMX bonding interfaces.     

Kids speak: preferred parental behavior at youth sport events

News reports (e.g., Abrams, 2008) and scholarly research (e.g., Wiersma & Fife, 2005) have indicated increasing concern that parent-spectator behavior at youth sport events may be problematic. Multiple strategies have been used to influence spectator behavior in youth sport contexts (e.g., "Silent Sundays"). However it is unlikely that interventions aimed at changing parent-spectator behaviors have adequately considered young athletes' perspectives, because little is known about how children want parents to behave during youth sport events. Therefore, children (ages 7-14 years) were asked to describe how parents actually behaved at youth sport events and how they wanted parents to behave. Through grounded theory analysis (Charmaz, 2000), three parent "roles" emerged from the data-supportive parent, demanding coach, and crazed fan.