This diploma thesis deals with the determination of the material acoustic absorption in an impedance tube. The aim of the work is to propose a measuring experiment and to design measuring device with the intention of reducing costs. The aim is to carry out a measuring experiment on a manufactured measuring device. The results of the experiment are evaluated in terms of meeting the requirements formeasuring device. The results of the tested materials are compared with the values from the supplier.

This project is focused on the magnetic loop antenna with automatic tuner in band short waves. This antenna is only the magnetic part of the electromagnetic radio wave used. At the beginning work are lumped most important characteristics these antennas and discuss individual parts antennas. Next part is proposal antennas with presentation progress and relations needed to their proposal. Emphasis is placed on a proposal tuning capacitor. Last part discuss possibilities automatic antennas tuning by the help of microprocessor.

The EU integration process has led to severe changes in policy-making. On the one hand, authority shifted from the national level to the EU. On the other hand, national level executives have gained power relative to the national legislatures. However, since the Treaty of Lisbon entered into force, scholars argue for a comeback of national legislatures. In Germany, parliamentary standing committees have gained considerable power throughout these developments. Nonetheless, their traditional role as policy shaper is contested among scholars. Thus, clarification of their role is needed. While, previous analysis has mainly focused on the Bundestag as a unitary actor. This thesis investigates the role of two standing committees of the Bundestag – Ausschuss für Landwirtschaft und Ernährung and Ausschuss für Gesundheit – in the EU policy-making process across two different competence areas emerging due to the Lisbon Treaty. To answer the research questions, semi-structured interviews with committee members have been conducted. The results of the study show a diverging picture. The members of the Ausschuss für Landwirtschaft und Ernährung are considerably constrained in their ability to act as a policy shaper. The members of the Ausschuss für Gesundheit can secure their policy-shaping powers to a great extent. The former committee lacks these qualities concerning the shift of an increasing amount of policy authority in agriculture to the EU, the restricted use and abilities of the Early Warning Mechanism and the constrained ability to influence the minister’s position in the Council. The members of the latter are more successful in securing policy authority in public health at the national level by making use of the EWM. Nonetheless, the restricted ability to influence the minister’s position in the Council is present, too. We can conclude that the Ausschuss für Landwirtschaft und Ernährung has inherited the role of a scrutiniser and executer meanwhile the Ausschuss für Gesundheit can be described as policy shaper.

The problem of this study was to determine the relationship of teacher and peer preferences of selected fifth grade students to socio-economic level as measured by the occupation of the head of the household, academic standing as computed from the marks assigned by the teacher, achievement test score results, intelligence test scores, and the sex of the child.

The thesis examines the adhesive interaction between graphite layers and atomically thin MoS2 crystals. Vertical van der Waals(vdW) heterostructures are fabricated by stacking different two-dimensional (2D) materials on top of each other. Blister test is used to measure the adhesive interactions between 2D heterostructures and their transferred substrates and between the layers themselves. This adhesive interaction is important in maintaining the mechanical integrity of the device during mechanical loadings and its understanding will help pave the way to the design and fabrication of micromechanical device from 2D heterostructures. Furthermore, applying controlled strains can be used to alter the electrical and optical properties thereby improving efficiency and performance. At first, we grew MoS2 and graphene by CVD and stacked the layers on top of each other using a dry transfer method. The MoS2/graphene heterostructure was then transferred onto pre-etched cavities on a silicon wafer. The blister test was used for controllably introducing strain into the heterostructure. Atomic Force Microscopy was used for measuring the shape of the deformed blister and Raman and Photoluminescence(PL) measured the optical response. The strain mismatch between the biaxial strain and a PL-converted strain suggests crumpling of the graphene layer and a substantial softening of the mechanical response. Lastly, we created graphite holes with photolithography to measure the work of separation between an atomically smooth graphite surface and MoS2. We found this value to be at least 320mJ/m2 which is higher than the MoS2/SiOx areas that was previously studied. / 2023-07-02T00:00:00Z

abstract: Most studies that explored the health benefits of interrupting sitting time focused on using different modalities (i.e., comparing walking vs standing breaks)33,36,59. However, experimental studies that directly compare patterns of interrupting sitting time through standing only are needed to advance the field. This study aimed to (i) determine if there is a difference in glucose response between continuous sitting (CS) and two intermittent standing regimes (high frequency, low duration breaks (HFLD) and low frequency, high duration breaks (LFHD)) and (ii) to determine if there is a difference in glucose response between the two strategies (HFLD vs. LFHD). Ten sedentary employees (mean±SD age 46.8±10.6 years; 70% female) with impaired fasting glucose (mean glucose= 109.0±9.8 mg/dL) participated. Eligible participants were invited to three 7.5 hour laboratory visits where they were randomized to perform each study conditions: (i) CS, (ii) HFLD and (iii) LFHD. Standardized meals (breakfast and lunch) were given with each meal providing 33% of the participant’s total daily caloric needs following a typical American diet (50-60% carbohydrates, 25-30% fat, and 10-20% protein). Participants wore an activPAL device to measure compliance with the sit-stand condition and a continuous glucose monitor to measure post-prandial glucose response. Post-prandial mean glucose, incremental area under the curve and mean amplitude glycemic excursion between conditions were evaluated using linear mixed models. Participants demonstrated high compliance with the study condition. The results indicated that the mean glucose of the HFLD condition were significantly lower (p< .01) than the CS condition with mean difference of -7.70 (-11.98, -3.42) mg/dL·3.5h and -5.76 (-9.50, -2.03) mg/dL·7h for lunch and total time, respectively. Furthermore, the mean post-prandial glucose during lunch and total time were significantly lower in the HFLD condition compared to the LFHD condition with mean difference of -9.94 (-14.13, -5.74) mg/dL·3.5h and -6.23 (-9.93, -2.52) mg/dL·7h, respectively. No differences were found between the CS and LFHD conditions. This study provides evidence favoring the use of frequent interruptions in sitting time to improve glycemic control of prediabetic individuals. In contrast, less frequent, although longer bouts of standing resulted in similar post-prandial glucose profile to that of the continuous sitting condition despite total standing time being equal to the LFHD condition. / Dissertation/Thesis / Doctoral Dissertation Physical Activity, Nutrition and Wellness 2019

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The most common way to measure postural stability is to examine the displacement of the center of pressure (CoP). But some scientists claim that the center of mass (CoM) is what really indicates the sway of the whole body, since the body is a multi-joint system. Many previous studies of human balance have targeted groups with diffrent kinds of balance impairments. In a recent study C. Lidbeck investigated factors influencing standing in children with bilateral spastic cerebral palsy (BSCP). The conclusion of that study was that the crouched position, that is common with this kind of disability, was not found to be related to strength and not entirely related to the degree of their motor disorders. In this thesis a number methods were chosen to assess the postural stability of children with BSCP, using both the CoP and the CoM. The hypothesis was that the different methods would show different aspects of the children's balance impairment. Also, the influence of visual stimuli on the crouching position was examined. The long term aim is that the results may contribute to a deeper understanding of the balance disturbances that often accompany this group of children. 16 children with BSCP (GMFCS level I-III) and 20 typically developing (TD) children were included in the study. Data was collected, before the start of this project, using two force plates and an eight-camera 3D motion analysis system with passive markers. The children performed three different standing tasks during 30 seconds each; quiet standing, blindfolded and an attention-task. Five methods were chosen (based on previous literature) and implemented in Matlab to examine the postural stability of the two groups during the three tasks. Result shows that all methods used can clearly distinguish between the balance in the BSCP group and the TD group. When comparing the quiet standing task with the blindfolded task in the BSCP group, there were some significant results from the statistical evaluation (P$&lt;$0.05). The result from several of the methods indicated that the children of this group have better postural stability when blindfolded, which is not in agreement with previous literature. In contrast, one method using the total mean velocity indicated that the postural stability decreased. During the attention-task, the methods disagreed with each other, implying a change in balance strategy in the BSCP group that was different from the TD group. Four methods are suggested for future studies, two using the CoP and two using the CoM. These four methods highlighted different aspects of the data and in combination they may provide a bigger picture of the postural stability of children with BSCP. Even though there were no significant difference in the vertical displacement of the CoM between the BSCP and the TD group, the CoM was slightly elevated during the attention-task in the BSCP group. In the TD group the CoM was lowered during the same task. This indicates that the children with BSCP in this study straighten up a bit when they can focus on something outside of their own body.

PURPOSE/BACKGROUND: Muscle fatigue is related to a decline in force output and proprioception. These can ultimately have an adverse effect on neuromuscular control and functional performance. Local muscle fatigue has been shown to have adverse consequences on dynamic standing balance; however, much less is known regarding the relationship between distant fatigue and dynamic standing. The purpose of this study was to investigate the effects of upper body fatigue on dynamic standing balance. It was hypothesized that distant fatigue in upper body musculature would show a significant decrease in dynamic standing balance as assessed by the Lower Quarter Y-Balance Test (YBT-LQ). METHODS: TWENTY HEALTHY INDIVIDUALS (AGE: 25.0 ± 3.42 years, height: 172.72 ± 13.11 cm, mass: 71.36 ± 13.50 kg) participated in this study. A kayak ergometer was used to implement a fatigue protocol for the upper body. The protocol consisted of a graded intensity session ranging from 50% to 90% of maximum effort lasting ten minutes in duration (2 minutes each at 50% 60%, 70%, 80%, and 90%). The anterior (ANT), posteromedial (PM), and posterolateral (PL) reach directions were normalized to leg length and measured on the YBT-LQ before and after the fatigue protocol for each participant. A fourth value termed overall balance was calculated as the sum of the furthest reach distance of the three directions. Blood lactate analysis taken before and immediately after the fatigue protocol was used to quantify fatigue. Multiple paired t-tests were performed for pre-fatigue and post-fatigue balance assessment. A Bonferroni correction was applied to set the significance value ≤0.0125 a priori. Effect size was calculated using the effect size index. RESULTS: Blood lactate values immediately following the fatigue protocol had an average concentration of 6.15 millimoles (pre: 2.3, post: 8.4). The ANT reach direction (ρ = 0.004) and the calculated overall balance (ρ = 0.011) significantly decreased post-fatigue in the dominant lower extremity. No significant differences were found for the PM (ρ = 0.017) or PL (ρ = 0.021) directions. The ANT reach direction (0.64) and overall balance (0.44) also showed a moderate effect size based on the effect size index. CONCLUSIONS: ANT and overall dynamic standing balance were negatively affected after completing the upper body fatigue protocol. The findings of this research demonstrate that upper body fatigue has adverse effects on dynamic standing balance, as measured by performance on the YBT-LQ. Significant and clinically relevant differences were noted in ANT and overall dynamic standing balance. CLINICAL RELEVANCE: Physical therapists should be aware of the adverse influence distant fatigue may exhibit on neuromuscular control in muscles not actively involved in the fatiguing exercise. The balance deficits noted may indicate an increased risk of injury with muscle fatigue in muscles not directly contributing to standing balance. LEVEL OF EVIDENCE: 3b, Case-control study.