Vorarlberg University of Applied Sciences
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Laser-tissue interaction of pump-probe elastography (PPE) on human teeth
No full textThe utilization of lasers in dentistry expands greatly in recent years. For instance, fs-lasers are effective for both drilling and caries prevention, while cw-lasers are useful for adhesive hardening. A cutting-edge application of lasers in dentistry is the debonding of veneers. While there are pre-existing tools for this purpose, there is still potential for improvement. Initial efforts to investigate laser assisted debonding mechanisms with measurements of the optical and mechanical properties of teeth and prosthetic ceramics are presented. Preliminary tests conducted with a laser system used for debonding that is commercially available showed differences in the output power set at the systems console to that at specified distances from the handpiece. Furthermore, the optical properties of the samples (human teeth and ceramics) were characterised. The optical properties of the ceramics should closely resemble those of teeth in terms of look and feel, but they also influence the laser assisted debonding technique and thus must be taken into account. In addition first attempts were performed to investigate the mechanical properties of the samples by means of pump-probe-elastography under a microscope. By analyzing the sample surface up to 20 ns after a fs-laser pulse impact, pressure and shock waves could be detected, which can be utilized to determine the elastic constants of specific materials. Together such investigations are needed to shape the basis for a purely optical approach of debonding of veneers utilizing acoustic waves
Erfassung von Belastungsfaktoren, protektiven Faktoren und Technikakzeptanz von Pflegepersonen und der von ihnen betreuten zu Hause lebenden älteren Menschen
Get PDFIm Rahmen des Projekts TeleCareHub wurde eine Fragebogen-Erhebung mit 153 pflegen-den Angehörigen und 221 zu Hause gepflegten Personen aus Vorarlberg, Tirol, Salzburg und Kärnten durchgeführt. Die Studie zeigt, dass fast die Hälfte (46%) der pflegenden An-gehörigen durch die Pflegesituation stark belastet ist. Die Ergebnisse ergibt weiters, dass die erhobenen Belastungsfaktoren (Einsamkeit, Depressivität) und protektiven Faktoren (Selbstwirksamkeit, Beziehungsqualität zur pflegebedürftigen Person) die Pflegebelastung maßgeblich beeinflussen. Auch die pflegebedürftigen Personen selbst leiden unter der Situa-tion: 21% der Befragten fühlen sich einsam und 20% zeigen moderate bis schwere depres-sive Symptome. Weiters konnte festgestellt werden, dass sowohl bei pflegenden Angehörigen als auch bei pflegebedürftigen Personen die Technikaffinität mit zunehmendem Alter und geringerem Bildungsniveau abnimmt. Die vorliegende Studie liefert wichtige Erkenntnisse für die Entwicklung von internet-basierten Unterstützungsangeboten für pflegende Angehö-rige und pflegebedürftige Personen
Comparison of demand response strategies using active and passive thermal energy storage in a food processing plant
Get PDFDemand side management holds potential for improving energy efficiency and cutting energy consumption within the food industry. This research introduces a demand response approach tailored for an industrial food processing facility, utilizing a chilled water buffer as active thermal energy storage and the plant building as passive thermal energy storage. The plant building and production process are modeled using transient thermal energy balances and the demand side management problem is formulated as a linear program. Model predictive control is employed to manage uncertainties in the optimization process. A simulated case study of an Austrian food processing plant shows reductions in electrical power consumption by up to 18%, electricity costs by up to 24%, and peak load by up to 36% in three distinct optimization scenarios. Simple prediction approaches via averaging historical data already lead to nearly optimal results concerning energy consumption and cost reduction. Highly accurate predictions are necessary for peak load reduction, as considering the simple prediction method only roughly a third of the potential reductions are achieved
Enhanced violation-mitigation-based method using voltage/current sensitivities for PV hosting capacity quantification in low-voltage grids
No full textPV hosting capacity quantification is currently of importance for distribution system operators to manage upcoming PV installation requests, especially within low-voltage grids. The violation-mitigation-based (VMB) method presented a novel downward approach to quantify the PV hosting capacity in low-voltage grids, having the advantage of also quantifying possible expansions in the hosting capacity. The VMB method, however, requires typically hundreds of power flow simulations to quantify the hosting capacity in a low-voltage grid. In this paper, we address this issue by introducing sensitivity matrices to optimize the downward process of quantification. Evaluated in 79 low-voltage feeders from Austria, the enhanced VMB method reduces the number of iterations required from a median of 1764 to 7 while obtaining the same or higher hosting capacity values. The reduced computational effort permits the application of the method proposed at a large-scale. The application of the method proposed on the standard CIGRE residential low-voltage grid is also presented for possible comparison with other methods
Natur als Stresslöser im Homeoffice
Get PDFDie Wahl des Themas dieser Arbeit wurde durch die wachsende Bedeutung von Homeoffice und die damit verbundenen psychologischen Herausforderungen beeinflusst. Der Fokus liegt besonders auf den Auswirkungen auf die mentale Gesundheit und die Stressbewältigung. Die zentrale Forschungsfrage lautet: „Wie beeinflusst die natürliche Umgebung den Ressourcenaufbau und die Stressbewältigung von Homeoffice-Arbeitnehmenden in Vorarlberg?“ Laut der Attention Restoration Theory (ART) von Kaplan und Kaplan fördern natürliche Umgebungen die Erholung von mentaler Ermüdung und verbessern die kognitive Funktion durch restaurative Erlebnisse (Kaplan & Kaplan, 1989), was erklärt, warum Naturerlebnisse effektiv zur Stressreduktion und zum Aufbau persönlicher Ressourcen beitragen. Für die methodische Vorgehensweise wurde ein Fragebogen entwickelt, der sowohl demo-graphische Daten als auch spezifische Dimensionen zur Nutzung von Naturerlebnissen zur Stressbewältigung und zum Ressourcenaufbau erfasste. Die wesentlichen Ergebnisse zeigen, dass ein regelmäßiger Aufenthalt in der Natur sowie Aktivitäten wie Wandern, Spazieren und Zeit am Wasser positiv zur Stressreduktion und zum Aufbau persönlicher Ressourcen beitragen. Die Ergebnisse zeigten ebenfalls, dass Homeoffice-Arbeitnehmende, die während der Arbeitszeit häufig aus dem Fenster auf natürliche Landschaften blicken, eine stärkere Entspannung erfahren. Diese Ergebnisse unterstreichen die Bedeutung der natürlichen Umgebung für das Stressmanagement und den Ressourcenaufbau von Homeoffice-Arbeitenden. Unternehmen und Einzelpersonen können Strategien zur Stressbewältigung entwickeln, die auf regelmäßigen Naturerlebnissen basieren, um die mentale Gesundheit und Lebensqualität zu verbessern. Die empirischen Daten liefern wertvolle Empfehlungen für die effektive Nutzung natürlicher Umgebungen zur Stressreduktion im Homeoffice.The choice of this thesis topic was influenced by the growing importance of home office work and the associated psychological challenges. The focus is particularly on the impact on mental health and stress management. The central research question is: "How does the natural environment influence resource building and stress management for home office employees in Vorarlberg?" According to the Attention Restoration Theory (ART) by Kaplan and Kaplan, natural environments promote recovery from mental fatigue and improve cognitive function through restorative experiences (Kaplan & Kaplan, 1989), which explains why nature experiences are effective in reducing stress and building personal resources. A questionnaire was developed to collect demographic data and specific dimensions of the use of nature experiences for stress management and resource building. The main findings show that regular exposure to nature and activities such as hiking, walking, and spending time near water positively contribute to stress reduction and resource building. Additionally, the results indicated that home office employees who frequently look out of the window at natural landscapes during work experience greater relaxation. These findings underscore the importance of natural environments for stress management and resource building for home office employees. Companies and individuals can develop stress management strategies based on regular nature experiences to improve mental health and quality of life. The empirical data provide valuable recommendations for the effective use of natural environments for stress reduction in the home office context
Drivers of high performing teams
Get PDFIn this study, the methodology of systems thinking was applied to the structure of high-performance teams. As a first step, all relevant factors that have an influence on team performance were identified. This was done using surveys, AI queries and a literature review. The large number of factors were then aggregated into a manageable number of 12 core variables. The selection of variables was checked and confirmed using a criteria check for system completeness. The mutual influence of these variables was then worked out and assessed in workshops. The result was a sensitivity map, which was used to derive basic system characteristics. It turned out that team performance systems are unstable in the selected setup. Finally, a possible systemic model was created, presented in more detail and analysed. A total of 5 hypotheses emerged from the work
512-channel SiN-based AWG-spectrometer for OCT on a chip
No full textWe present design, technological verification, and optimization of a compact 512-channel silicon nitride-based AWG-spectrometer developed for the realization of an on-chip spectral domain optical coherence tomography system. The spectrometer was designed for TM-polarized light with a central wavelength of 850 nm and having a resolution of 0.1 nm. For the design the AWG-Parameters tool was used. Simulations were performed using Optiwave’s PHASAR photonics tool and the designed structure was fabricated in a standard CMOS foundry process. The simulated and measured optical spectra were evaluated and used to further optimize the AWG structure. The AWG-spectrometer was integrated onto the chip and the OCT measurements proved its suitability for OCT on chip applications
A source of entangled photons based on a cavity‑enhanced and strain‑tuned GaAs quantum dot
Get PDFA quantum-light source that delivers photons with a high brightness and a high degree of entanglement is fundamental for the development of efficient entanglement-based quantum-key distribution systems. Among all possible candidates, epitaxial quantum dots are currently emerging as one of the brightest sources of highly entangled photons. However, the optimization of both brightness and entanglement currently requires different technologies that are difficult to combine in a scalable manner. In this work, we overcome this challenge by developing a novel device consisting of a quantum dot embedded in a circular Bragg resonator, in turn, integrated7 onto a micromachined piezoelectric actuator. The resonator engineers the light-matter interaction to empower extraction efficiencies up to 0.69(4). Simultaneously, the actuator manipulates strain fields that tune the quantum dot for the generation of entangled photons with corrected fidelities to a maximally entangled state up to 0.96(1). This hybrid technology has the potential to overcome the limitations of the key rates that plague QD-based entangled sources for entanglement-based quantum key distribution and entanglement-based quantum networks