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The impact of work environment factors has to be considered in an integrated ergonomic analyzing and designing process. To capture relevant environmental exposures, measurements must be carried out. In companies, an increasing use of smartphones for initial measurements of work environment factors can be noticed. Here, the question arises whether it is possible to determine adequate data for scientific work analyses by using built-in sensors in smartphones. For that purpose, the operational readiness of smartphone applications to measure the work environment factors noise, climate and lighting is investigated. Here, the assessing of measuring accuracy and the recordable measurement quantities for different combinations of applications and smartphones is analyzed. In result, a wide variety of the measurement accuracy for the analyzed environmental factors can be observed.
This bachelor thesis is about the development and design of the suture-based HeartStitch MR device for functional restoration of the mitral valve when a mitral regurgitation is present. The mitral valve is one of the four existing heart valves and due to their load, the mitral valve is most commonly affected by valve defects. In case of a mitral regurgitation, the leaflets of the mitral valve are not closing tight enough, which causes a reflux of the oxygenated blood from the left ventricle into the left atrium. As consequence, the human body won't be sufficiently supplied with oxygen anymore, which results in a disproportionate cardiac output. Untreated, this can lead to respiratory dis-tress, cardiac arrhythmias and stroke or even to death. In this case, a heart surgery is essential to improve the patient
Boron-doped diamond (BDD) electrodes offer some excellent electrochemical properties, including the widest potential window in aqueous solutions, low background currents and good chemical and mechanical stability. They can also be produced transparent and could offer a great potential for spectroelectrochemical (SEC) experiments. However, to reach the mentioned electrical properties for such optically transparent electrodes (OTE), heavy doping is needed to increase conductivity. The introduction of boron in return reduces the transparency significantly. This work investigates the effect of introducing an alternative path for electrons in the form of an highly conductive get transparent interlayer which could increase the conductivity without increasing the BDD film or the doping level supporting high transparency in the visible (Vis) and ultraviolet (UV) regime. This work furthermore investigates possible interlayers for this application and implements four of them in two BDD OTE samples which are extensively studied by electrical, optical and electrochemical methods. An ultra-thin metal film (UTMF) of titanium (Ti) is shown to decrease the electrochemical resistance by 2.4kOhms while decreasing the transparency of a BDD OTE by only 11%.
The birefringence of single crystal diamonds is quantified using a birefringence measurement setup and a Matlab program for the calculation. The theoretical backgrounds of the polarization of light and polarization changing equipment is used for selecting a plane polariscope measurement method. Here, a birefringent sample is placed between two optical polarizers. The equipment, as well as its theoretical and practical behavior in the measurement setup is discussed. The equations for birefringence measurements are given and a practical Matlab program is introduced to simplify the birefringence calculation for the user. Possible influences on the birefringence value due to inaccuracies of the laser, the polarizers, the diamond sample, the magnification lenses and the camera are discussed and taken into account. Intensity fluctuations and polarization changes of the laser beam are studied. The direction of the transmission axis of the polarizer and the analyzer is examined. A retarder is inserted into the measurement setup to check the accuracy of the birefringence measurement since a retarder has a known phase retardation. This retarder measurement should qualify the measurement setup to quantify birefringence of the diamond sample. The measurement results show that intensity fluctuations of the laser and the handling inaccurracies of the polarizers have a major influence on the accurracy of the birefringence measurement. This measurement setup is not qualitfied to measure birefringence accurate yet. Steps to improve the measurement setup and the birefringence calculation are discussed.
To improve the quality of education in applied laser physics, a new and innovative educational platform was designed, realized and tested. The system focusses on the improvement of the theoretical, experimental and numerical skills in the topics of ultra-short pulsed fiber based laser systems and related measurement techniques. The main content of the platform is the fundamental understanding of the technologies of an ytterbium-doped fiber based Master-Oscillator Power-Amplifier and a 2nd order intensity autocorrelator. A wide range of system parameters are variable and metrologically accessible. Thus the underlying physical mechanisms are illustrated and, by this the fundamental understanding of the system, improved. To transfer actual industrial and scientific topics into the experimental education of students, the complex lab course aims for a full characterization of the system by experimental work and a numerical analysis by simulating the system dynamics. A state-of-the-art educational tool was created to demonstrate current industrial sys-tems. An amplification of 37.2 dB was achieved. The pulses with a temporal width of 30.6 picoseconds possessed a pulse peak power of 14.2 kW. By the analysis of the material specific spectral properties, the rate equation model can be applied and im-portant system parameters determined.
The leading question, which political system is better suited for an emerging economy with a large population to ensure an effective climate protection, builds the nucleus of this thesis. The People's Republic of China and the Republic of India, which share similar demographic conditions and represent an autocratic and a democratic form of government, are compared in terms of the formulation and implementation of climate protection strategies and measures to draw conclusions about the characteristics of the respective systems.