Kombinierte Methode zur Bestimmung der Flussdichteverteilung am Beispiel Solugas

Turmkraftwerke weisen einen hohen Wirkungsgrad und große Kostensenkungs-potenziale auf. Zur Bestimmung der Wirkungsgrade und Eintrittsleistung und zur Optimierung des Betriebs dient die Messung der solaren Flussdichteverteilung in der Ebene der Eintrittsapertur des Receivers. Flussdichtemesssysteme nutzen häufig einen diffus reflektierenden Schwenkbalken, der sich vor dem Receiver vorbeibewegt, während eine CCD-Kamera die Helligkeitsverteilung der am Balken reflektierten solaren Strahlung aufnimmt. Anschließend wird das Bild mit Radio-meterwerten kalibriert. An kommerziellen Turmkraftwerken höherer Leistung und entsprechend größerer Apertur sind mechanische Schwenkbalken sehr groß und daher nur bedingt geeignet. Aus diesem Grund werden Messmethoden untersucht, die ohne Schwenkbalken auskommen [1]. Eine Methode kombiniert eine Raytracing-Simulation mit einer vereinfachten Messung im Bereich des Strahlungsschutzes. Die Messung dient dabei zur Validierung der Simulationen. Aus dem Simulationsergebnis lassen sich dann alle wichtigen Größen zur Charakterisierung des Kraftwerkes ableiten. Dieses Poster präsentiert die Anwendung dieser Methode an dem Demonstrationskraftwerk SOLUGAS, einem Cavityrohrreceiver mit Mikrogasturbine [2]

Einfluss kurzkettiger Fettsäuren und sekundärer Pflanzenstoffe auf den Glutathion S-Transferasen - Status im Kolon

Ein möglicher Mechanismus in der Krebsprävention ist die Induktion körpereigener Schutzsysteme, zu denen die Glutathion S-Transferasen (GST) als wichtige Phase-II-Enzyme zählen. In der vorliegenden Arbeit wurde die Wirkung von kurzkettigen Fettsäuren und sekundären Pflanzenstoffen mit antikarzinogenem Potential auf die Expression und Aktivität der cytosolischen GSTs im Kolon untersucht. Als Basis für die Untersuchungen wurde der GST-Status im Kolongewebe von 15 Patienten bestimmt. Die Experimente zur Induktion, welche an Zellmodellen (Kolontumorzelllinien, primäre Kolonfibroblastenkulturen) durchgeführt wurden, zeigten, dass die GSTs durch Butyrat und grünen Teeextrakt induzierbar sind. Die abschließenden Untersuchungen zu den funktionellen Konsequenzen eines erhöhten GST-Status ergaben eine deutlich verminderte Genotoxizität von 4-Hydroxy-2-nonenal in Zellen mit induzierter GST, was auf die Stimulierung der Entgiftungskapazität der GST zurückgeführt werden kann

Techniques to Measure Solar Flux Density Distribution on Large-Scale Receivers

Flux density measurement applied to central receiver ystems delivers the spatial distribution of the concentrated solar radiation on the receiver aperture, measures receiver input power, and monitors and might control heliostat aimpoints. Commercial solar tower plants have much larger aperture surfaces than the receiver prototypes tested in earlier research and development (R&D) projects. Existing methods to measure the solar flux density in the receiver aperture face new challenges regarding the receiver size. Also, the requirements regarding costs, accuracy, spatial resolution, and measuring speed are different. This paper summarizes existent concepts, presents recent research results for techniques that can be applied to large-scale receivers and assesses them against a catalog of requirements. Direct and indirect moving bar techniques offer high measurement accuracy, but also have the disadvantage of large moving parts on a solar tower. In the case of external receivers, measuring directly on receiver surfaces avoids moving parts and allows continuous measurement but may be not as precise. This promising technique requires proper scientific evaluation due to specific reflectance properties of current receiver materials. Measurement-supported simulation techniques can also be applied to cavity receivers without installing moving parts. They have reasonable uncertainties under ideal conditions and require comparatively low effort

Labels, instructions and features of convertible Child Restraint Systems (CRS): evaluating their effects on CRS installation errors

This report documents a study of how CRS features, labels, and instructions contribute to CRS installation errors. Task 1A focused on assessing different physical features of 16 convertible CRS, while Task 1B evaluated baseline and modified versions of labels and instructions for two CRS models. For each phase of testing, 32 subjects were recruited based on their education level (high or low) and experience with installing CRS (none or experienced). Each subject was asked to perform four child restraint installations in a 2006 Pontiac G6 sedan. An 18-month-old CRABI anthropometric test device (ATD) weighing 25 lb was used for all installations. Each subject installed two CRS forward-facing (FF), one with LATCH and one with seatbelt, and two CRS rear-facing (RF), one with LATCH and one with the seatbelt. For Task 1A, each subject installed four of the sixteen convertible CRS. For Task 1B, each subject installed a Graco ComfortSport and Evenflo Titan twice, where each CRS had one of eight alternate instruction manuals and one of eight alternate label conditions. After each installation, the experimenter evaluated 42 factors for each installation, such as choice of belt routing path, tightness of installation, and harness snugness. Analyses used linear mixed models to identify CRS installation outcomes associated with CRS features or label/ instruction type. LATCH connector type, LATCH belt adjustor type, and the presence of belt lockoffs are associated with the tightness of the CRS installation. The type of harness shoulder height adjuster is associated with the rate of achieving a snug harness. Correct tether use is associated with the tether storage method. In general, subject assessments of the ease of use of CRS features are not highly correlated with the quality of their installation, suggesting a need for feedback with incorrect installations. The results of testing alternative labels and instructions indicate that no alternative condition significantly improved CRS installation compared to baseline conditions across all potential installation errors that were evaluated. An unintended consequence of using “combined” labels (incorporating all of the variations recommended by human factors experts that were tested individually in other conditions) is that subjects were less likely to use the CRS manual. The most promising alternative manual is a video version. Neither the labels nor manuals with improved graphics showed substantial benefit compared to baseline, even though graphics-based manuals and labels score well using the ISO and NHTSA ease-of-use rating system. The effects of varying labels and manuals on installation error are small compared to the effects of different CRS designs. The data from this study provide quantitative assessments of some CRS features that are associated with reductions in CRS installation errors. This information can be used to update the NHTSA CRS ease-of-use rating system to account for recently developed CRS features. Based on human factors recommendations, suggestions are made for assessing “clear” labels and instructions and modifying FMVSS 213 requirements to facilitate clearer labels and instructions.VTTI, National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89861/1/102795.pd

Expression of a Cu,Zn superoxide dismutase typical for familial amyotrophic lateral sclerosis increases the vulnerability of neuroblastoma cells to infectious injury

<p>Abstract</p> <p>Background</p> <p>Infections can aggravate the course of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Mutations in the anti-oxidant enzyme Cu,Zn superoxide dismutase (EC 1.15.1.1, SOD1) are associated with familial ALS. Streptococcus pneumoniae, the most frequent respiratory pathogen, causes damage by the action of the cholesterol-binding virulence factor pneumolysin and by stimulation of the innate immune system, particularly via Toll-like-receptor 2.</p> <p>Methods</p> <p>SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) and SH-SY5Y neuroblastoma cells transfected with wildtype SOD1 were both exposed to pneumolysin and in co-cultures with cultured human macrophages treated with the Toll like receptor 2 agonist N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine × 3 HCl (Pam₃CSK₄). Cell viability and apoptotic cell death were compared morphologically and by in-situ tailing. With the help of the WST-1 test, cell viability was quantified, and by measurement of neuron-specific enolase in the culture supernatant neuronal damage in co-cultures was investigated. Intracellular calcium levels were measured by fluorescence analysis using fura-2 AM.</p> <p>Results</p> <p>SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) were more vulnerable to the neurotoxic action of pneumolysin and to the attack of monocytes stimulated by Pam₃CSK₄ than SH-SY5Y cells transfected with wild-type human SOD1. The enhanced pneumolysin toxicity in G93A-SOD1 neuronal cells depended on the inability of these cells to cope with an increased calcium influx caused by pores formed by pneumolysin. This inability was caused by an impaired capacity of the mitochondria to remove cytoplasmic calcium. Treatment of G93A-SOD1 SH-SY5Y neuroblastoma cells with the antioxidant N-acetylcysteine reduced the toxicity of pneumolysin.</p> <p>Conclusion</p> <p>The particular vulnerability of G93A-SOD1 neuronal cells to hemolysins and inflammation may be partly responsible for the clinical deterioration of ALS patients during infections. These findings link infection and motor neuron disease and suggest early treatment of respiratory infections in ALS patients.</p

Subject Evaluation of Devices Intended to Reduce Risk of Seatbelt Entanglement

Since 2000, there have been over 200 incidents reported where a rear seat occupant became entangled in the seatbelt when they inadvertently switched it from emergency locking mode (ELR) to automatic locking mode (ALR). While a method is needed to lock the seatbelt when using it for child restraint system (CRS) installation, the National Highway Traffic Safety Administration (NHTSA) commissioned tool, inc. to develop prototype devices that could reduce the risk of seatbelt entanglement resulting from the lockability requirement. The purpose of this study is to perform testing with volunteer subjects to evaluate these prototype devices in comparison to standard seatbelt system by assessing how different designs would be used to install CRS, the quality of the resulting installations, how users would disentangle a trapped child surrogate, as well as to identify volunteer experience when using the belts themselves. Four prototype devices were evaluated in two phases of testing. In phase 1, D1, D2, and D3 were compared to standard seatbelt and LATCH using two forward-facing and two rear-facing CRS. In phase 2, D1 and D4 were compared to standard seatbelt using three forward-facing CRS. Phase 1 tested 16 subjects while Phase 2 tested 24. Subjects were recruited to include men and women of different ages with and without previous CRS installation experience; phase 1 also included education level as a criteria, while phase 2 included subject size. After the first installation trial using each device, the subject was presented with a crash dummy entangled in same device belt system, and instructed to free the dummy. In phase 2, subjects also participated in “comfort” trials where they sat in the vehicle seat, donned the seatbelt, and performed a reaching task intended to trigger a nuisance locking scenario. All four prototype devices had shorter disentanglement times than trials with the standard seatbelt, but there was not a statistically significant difference between the devices. There were no substantial differences in the quality of child restraint installation among the prototype devices. In phase 2, subjects viewed video instructions midway through the installation trials, which had a strong effect on reducing installation errors. In nuisance locking trials, subjects with higher BMI or taller stature were most likely to experience unintended seatbelt locking while performing a reach task.Tool, Inc.http://deepblue.lib.umich.edu/bitstream/2027.42/170921/1/UMTRI-2018-7.pdfDescription of UMTRI-2018-7.pdf : Technical Report FinalSEL

Toddler Lower Extremity Posture in Child Restraint Systems

Technical ReportThe postures of 28 toddlers 18 to 36 months old were analyzed in conditions simulating rear-facing and forward facing child restraints. Rear-facing conditions included a narrow and wide child restraint configuration, while the forward-facing conditions used a shorter and longer cushion length. Data collected include 3D coordinates of key body landmarks as well as surface scans focusing on the lower extremities. In addition, standard anthropometry measures and full body scans in standing and seated postures were collected for each subject. An overhead photo of each child’s posture was taken at one-second intervals throughout the test session. The number of different postures for each subject was tabulated and categorized. For rear-facing test conditions, the most common lower-extremity postures were legs relaxed, feet together with knees bent outward, knees pulled back towards torso, and both legs straight and elevated. For the forward-facing test conditions, the most common lower extremity postures were legs relaxed, feet together with knees bent and rotated outward, one leg bent and one leg straight, and legs crossed. There were no distinct trends with selected posture and the subjects’ age or size. Analysis of the measured subject postures showed variations in lower-extremity posture with child restraint condition. The narrow rear-facing condition more often had subjects with lower extremities in a relaxed posture, while the wide condition had more children with their feet flat together or their legs extended. For forward-facing, there was less variation in posture with the shorter cushion length; more children chose the frog leg or extended leg postures with the longer cushion length. Distribution of measured lower-extremity postures varied with age group. An attempt was made to position the lower extremities of the HIII 3YO and 18MO ATDs in the most common rear facing configurations chosen by the subjects. Although the more limited range of motion of the ATDs did not allow them to be placed in the most extreme positions chosen by subjects, the ATD posture could be adjusted to several postures commonly chosen by subjects without modifications to the ATD.National Highway Traffic Safety Administrationhttps://deepblue.lib.umich.edu/bitstream/2027.42/149099/1/UMTRI-2018-8.pdfDescription of UMTRI-2018-8.pdf : Technical Repor