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As technical solutions become more and more complex, analyzing and understanding them must become easier. Especially abstract or perception-biased fields, such as acoustics, can benefit from displaying the behavior of a noise radiating structure in an understandable manner. How can the acoustic properties of a technical component or a system be displayed in such an understandable way? Due to the current advances in technology regarding the mixed reality spectrum, the HoloLens2 was chosen as the hardware component to run an application and display structural properties visually. The application is required to display enough data to convey the information without impeding user experience. The application is divided into subprojects. Each subproject is developed and tested in a separate environment. After verification the subprojects were implemented. AR-visualization reduces the necessary effort to understand the structure's acoustic behavior. Furthermore, explicit knowledge of acoustics is not required to understand the application. In the future, this application can be expanded with additional features such as auralization or a live feed of structures.

Aims Ablation of outflow tract ventricular arrhythmias may be limited by a deep intramural location of the arrhythmogenic source. This study evaluates the acute and long-term outcomes of patients undergoing ablation of intramural outflow tract premature ventricular complexes (PVCs). Methods and results This multicenter series included patients with structurally normal heart or nonischemic cardiomyopathy and intramural outflow tract PVCs defined by: (a) ≥ 2 of the following criteria: (1) earliest endocardial or epicardial activation < 20ms pre-QRS; (2) Similar activation in different chambers; (3) no/transient PVC suppression with ablation at earliest endocardial/epicardial site; or (b) earliest ventricular activation recorded in a septal coronary vein. Ninety-two patients were included, with a mean PVC burden of 21.5±10.9%. Twenty-six patients had had previous ablations. All PVCs had inferior axis, with LBBB pattern in 68%. In 29 patients (32%) direct mapping of the intramural septum was performed using an insulated wire or multielectrode catheter, and in 13 of these cases the earliest activation was recorded within a septal vein. Most patients required special ablation techniques (one or more), including sequential unipolar ablation in 73%, low-ionic irrigation in 26%, bipolar ablation in 15% and ethanol ablation in 1%. Acute PVC suppression was achieved in 75% of patients. Following the procedure, the PVC burden was reduced to 5.8±8.4%. The mean follow-up was 15±14 months and 16 patients underwent a repeat ablation. Conclusion Ablation of intramural PVCs is challenging; acute arrhythmia elimination is achieved in 3/4 patients, and non-conventional approaches are often necessary for success.

Machine learning (ML) techniques allow for finding hidden patterns and signatures in data. Currently, these methods are gaining increased interest in engineering in general and in vibroacoustics in particular. Although ML methods are successfully applied, it is hardly understood how these black box-type methods make their decisions. Explainable machine learning aims at overcoming this issue by deepening the understanding of the decision-making process through perturbation-based model diagnosis. This paper introduces machine learning methods and reviews recent techniques for explainability and interpretability. These methods are exemplified on sound absorption coefficient spectra of one sound absorbing foam material measured in an impedance tube. Variances of the absorption coefficient measurements as a function of the specimen thickness and the operator are modeled by univariate and multivariate machine learning models. In order to identify the driving patterns, i.e. how and in which frequency regime the measurements are affected by the setup specifications, Shapley additive explanations are derived for the ML models. It is demonstrated how explaining machine learning models can be used to discover and express complicated relations in experimental data, thereby paving the way to novel knowledge discovery strategies in evidence-based modeling.

A calculus for scaled experimentation has recently appeared in the open literature founded on the continuous (metaphysical) concept of space scaling. The new theory for isotropic scaling (termed finite similitude) is a single-parameter theory that provides similitude rules that link unlimited numbers of scaled experiments to predict the behavior of any full-scale system. A facet of the theory is that it relates scalar, vectorial and tensorial coefficients and is therefore indirectly influenced by the choice of inertial-coordinate frames characterizing the full and scaled experiments. This feature is explored in this paper to relate objects that are skewed with a particular focus on thin-walled vibrating structures, which find widespread industrial usage but also benefit from anisotropic scaling in their thickness direction. The focus here is on the recently developed first-order finite similitude theory involving two scaled-down experiments for scaled vibrational analysis. The efficacy of the proposed scaling method is examined by means of analytical and numerical simulations. Case studies involving thin-walled plates and hollow beams, subject to free and forced vibration, confirm that titanium prototypes can be represented with high accuracy (∼0% error) by scaled models of identical and different materials (viz., steel and aluminum).

Preterm birth and the subsequent necessary treatment in neonatal intensive care units (NICU) subjects the preterm infant to non-physiological noise exposure with potentially adverse consequences for short- and long-term development. Adjusters to improve the acoustic environment for the preterm infant need to be defined.Sound pressure level measurements during routine procedures in a NICU were performed by ¼" microphones placed inside and outside the incubator. The microphones need to be suitably positioned to measure sound pressure levels that are representative for the sound field inside and outside the incubator. The sound pressure level spectra generated by respiratory support and corresponding monitor alarms were compared.Inside the incubator, higher sound level pressures (in dBA) were generated primarily by the use of the system components of the incubator itself than outside, whereas when the incubator was closed, it had an insulating effect on sounds generated in the NICU. Non-invasive ventilation resulted in an increase in sound pressure levels from 50 to 60 dBA in the neonate's environment, with sound pressure levels increasing particularly in the frequency range above 1 kHz.Preterm infants are exposed to high sound levels, especially in the non-physiological high-frequency range, particularly during non-invasive ventilation. The continuous sound exposure could be further reduced to some extent by an optimized design of the incubator.Frühgeburt und die anschließend notwendige Behandlung auf der Neugeborenen- Intensivstation (NICU) setzen das Frühgeborene einer unphysiologischen Schallexposition mit potentiell nachteiligen Folgen für die kurz- und langfristige Entwicklung aus. Stellschrauben zur Verbesserung der akustischen Umgebung für das Frühgeborene müssen definiert werden.Schalldruckpegelmessungen während der Routineabläufe auf einer NICU wurden durch inner- und außerhalb des Inkubators angebrachte ¼“ Messmikrophone durchgeführt. Dabei müssen die Mikrofone so platziert werden, dass die gemessenen Schalldruckpegel repräsentativ für die Schallfelder innerhalb und außerhalb des Inkubators sind. Die durch Atemunterstützung, Routinemanipulationen und Monitoralarme erzeugten Schalldruckpegelspektren wurden vergleichend dargestellt.Im Inkubators entstanden während der Routineversorgung z. B. durch das Türenöffnen und die Höhenverstellung höhere Schallpegeldrücke (in dBA) als außerhalb, während der Inkubator bei geschlossenen Türen schallabsorbierend auf Umgebungsgeräusche wirkte. Nicht-invasive Beatmung führte zu einer Erhöhung des Schalldruckpegels von 50 auf 60 dBA in der Umgebung des Frühgeborenen, wobei der Schalldruckpegel insbesondere im Frequenzbereich oberhalb von 1 kHz anstieg.Frühgeborene sind besonders bei nicht-invasiver Beatmung einer hohen Schallbelastung vor allem im unphysiologischen Hochtonbereich ausgesetzt. Die Schallbelastung könnte durch eine optimierte Bauweise des Inkubators weiter verringert werden.

Zusammenfassung Fragestellung Ziel dieser Studie war es, den Unterschied im Behandlungserfolg nach phototherapeutischer Keratektomie (PTK) bei Salzmannʼscher nodulärer Degeneration (SND) mittels zweier Excimerlaser mit unterschiedlichen Spezifikationen zu untersuchen. Patienten und Methoden Im Zeitraum von 2007 bis 2017 wurden 272 PTKs, die an 246 Augen mit SND von 181 Patienten durchgeführt wurden, retrospektiv untersucht. Bis 2014 wurde für die PTK nach manueller Pannektomie der Excimerlaser MEL70 (Carl Zeiss Meditec Vertriebsgesellschaft mbH, Oberkochen, Deutschland) verwendet, danach der Amaris 750S (Schwind eye-tech-solutions GmbH, Kleinostheim, Deutschland). Der Therapieerfolg wurde anhand folgender Parameter beurteilt: Visus, Refraktion und Astigmatismus sowie die Pachymetrie und die Endothelzellmessung zu den Zeitpunkten T1 = präoperativ, T2 = 6-Wochen-Kontrolle, T3 = 6-Monats-Kontrolle. Zum Vergleich der Daten wurden der Wilcoxon-Mann-Whitney-U-Test und der Chi-Quadrat-Test mit einem Signifikanzniveau von 5% genutzt. Ergebnisse Nach 6 Monaten stieg der Visus nur in der Schwind-Gruppe signifikant um 0,17 ± 0,33 (logMAR p Schlussfolgerung In beiden Studiengruppen profitierten die Patienten von einer PTK bei SND. Für die Schwind-Gruppe konnte jedoch eine signifikant größere Verbesserung von Visus und Refraktion festgestellt werden als für die Zeiss-Gruppe. Im Gegensatz zum üblichen hyperopisierenden Effekt der PTK bei anderen Diagnosen zeigte sich bei SND ein sog. „myopic shift“, der sich aus den oft mittelperipher liegenden SND-Knoten und dem damit verbundenen asymmetrischen Tränenfilmpooling präoperativ erklären lässt.

The wide-ranging product applications in the food and beverage (F&B) industry, owing to its rich taste and creaminess, are among the primary factors driving the table butter market. In line with this, the growing demand for table butter as a condiment or spread on toasted bread items is further catalyzing the market growth.

The escalating consumer concerns towards the spread of water-borne diseases are among the primary factors driving the bottled water market. Besides this, the elevating awareness regarding the health hazards of sugar and artificial sweeteners that are present in carbonated drinks is further catalyzing the market growth. Moreover, the emerging trend of premium bottled water variants is acting as another significant growth-inducing factor.

The expanding construction industry is primarily driving the medium-density fiberboard market. Additionally, MDF is comprised of superior quality wood fibers and is usually available at significantly lower prices when compared to its counterparts, including hardboard, particleboard, dimensional lumber, etc., which is further catalyzing the market growth.

The rising consumer inclination towards high-end and premium personal grooming products is primarily driving the US professional skincare market. Moreover, the widespread adoption of skin care regimes to protect the skin from any damage caused by dust, ultraviolet (UV) rays, humidity., etc., is also catalyzing the market growth. Besides this, numerous manufacturers are using organic and herbal product variants to expand their customer base, which is further augmenting the regional market.

The expanding construction sector and the growing number of housing, commercial, industrial, and mega real estate development projects are among the key factors driving the PVC pipes market. Besides this, the rising demand for PVC pipes in sewage and water utility services is further catalyzing the market growth. Moreover, PVC pipes offer high cost-efficiency, easy installation, and low maintenance costs by mitigating the need for welding, unlike the traditional metal pipes, which is acting as another significant growth-inducing factor.

The widespread adoption of outdoor illumination systems, across various commercial and industrial areas, including security perimeters, stadiums, warehouses, etc., owing to their capacity to withstand harsh conditions, such as vibrations, rough weather, external shocks, etc., is primarily driving the LED down lights market. Additionally, the increasing popularity of LED retrofitting for excellent lumen power and better service life at less wattage is further catalyzing the market growth.

The growing health consciousness among consumers is propelling the demand for functional foods that contain high quantities of proteins and other vital nutrients. This, in turn, is among the primary factors driving the GCC protein ingredients market. In addition to this, the escalating popularity of vegan, vegetarian, and gluten-free product variants is further catalyzing the market growth. Moreover, the emerging fitness trend and the inflating product usage in protein-rich foods, which are essential for muscle building and weight management, are acting as significant growth-inducing factors.

The elevating alcohol consumption levels across the globe are among the primary factors driving the glass bottles market. In addition to this, the growing adoption of glass-based packaging solutions in the personal grooming sector for catering to the safe and seamless transportation and storage of various fragrances and cosmetic products is further catalyzing the market growth.

The growing sales of passenger vehicles and the increasing product adoption as an alternative to fossil fuels are primarily driving the ethanol market. In line with this, the development of bioethanol, which is biodegradable, relatively less toxic, and does not cause environmental pollution when compared to conventional fuels, is further catalyzing the market growth.

The expanding information technology (IT) industry across the globe is primarily driving the laptops market. Besides this, the widespread adoption of bring-your-own-device (BYOD) trends by various organizations to ease operations is further stimulating the market growth.

The expanding number of power transmission and distribution plants is primarily driving the electrical wire market. Additionally, the widespread product adoption in electronic entertainment devices, heating, ventilation and air conditioning (HVAC) systems and lighting solutions in smart homes is further catalyzing the market growth. Besides this, the increasing utilization of electrical wires in underground cabling for utility distribution networks and to provide a connection between transformers and generators is acting as another significant growth-inducing factor.

The growing product adoption as a gelling agent to thicken the consistency of various fruit-based products, such as jams, marmalades, jellies, etc., is primarily driving the pectin market. Additionally, the escalating demand for natural and clean label ingredients, on account of the increasing consumer inclination towards functional supplements, is further catalyzing the market growth.

The escalating number of fast-food chains is among the primary factors driving the cheese market. In line with this, the growing demand for ready-to-eat (RTE) food items is further bolstering the market growth. Moreover, the emerging trend of Westernization of food consumption patterns, especially in developing countries, such as India and China, is acting as another significant growth-inducing factor. Apart from this, the expanding organized retail sector and the rising improvements in cold chain infrastructures are also augmenting the global market.

The rising product demand in the commercial and residential sectors, owing to the expanding construction industry, is among the key factors driving the float glass market. Besides this, float glass is utilized in architectural and interior design applications, such as flooring, ceiling, insulated glass, mirrors, reflective windows, tabletops, etc., which is further catalyzing the market growth.

The growing levels of power consumption across countries are among the primary factors driving the LED bulb market. Moreover, several government bodies are providing steep power subsidies to propel electrification rates, especially in rural areas, which is further catalyzing the market growth.

The growing levels of commercial livestock production are among the primary factors driving the US animal feed market. Additionally, the widespread product adoption as a source of energy and nutrition to support muscular activity and sustain life processes in the animals is further catalyzing the market growth. Besides this, the increasing consumer awareness towards the various health benefits of algae-based ingredients in animal feed is acting as another significant growth-inducing factor.

The elevating urbanization levels and the growing electrification rates are among the key factors driving the GCC power inverter market. In line with this, the rising demand for consumer electronic appliances and gadgets is further catalyzing the market growth. Moreover, the inflating need to ensure uninterrupted power supply, especially in urban areas, is propelling the usage of power inverters as alternate backup solutions in case of outages. Besides this, these products are noise-free and eco-friendly in nature since they do not emit carbon emissions and extinguish the need for gasoline, which is needed for running generators.

The expanding construction industry is among the primary factors driving the GCC gypsum board market. In line with this, the inflating demand for commercial and residential building projects, owing to the growing population and elevating urbanization levels, is further catalyzing the market growth. Moreover, the escalating number of renovation and restoration undertakings for structural complexes is acting as another significant growth-inducing factor. In addition to this, the emerging trend of wood-frame construction, which uses gypsum boards as essential components, is also bolstering the market growth.

The launch of various favorable policies by government bodies aimed at spreading awareness towards the usage of modern medicines for HIV treatments and early detection is among the key factors driving the GCC HIV drugs market. Besides this, the widespread adoption of advanced medical solutions is propelling the demand for HIV drugs that aid the immune system in keeping the levels of the virus at a minimal level, thereby leading to prolonged life expectancy in patients.

The escalating demand for on-the-go food products is among the key factors driving the GCC specialty paper market. In line with this, the widespread product adoption as a packaging material in the food and beverage (F&B) industry is further catalyzing the market growth. Besides this, the growing consumer inclination towards specialty paper alternatives, on account of the several stringent regulations related to the usage of plastic bags, is acting as another significant growth-inducing factor.

The increasing prevalence of chronic diseases, including obesity, diabetes, cardiovascular diseases (CVDs), etc., is primarily driving the self-care medical devices market. Additionally, the growing consumer inclination towards various self-care devices, such as wearable and smart trackers, to self-monitor their physical well-being is further catalyzing the market growth. Besides this, self-care medical devices aid in reducing the patient burden in terms of hospital visits for minor medical conditions and enable the timely diagnosis of an ailment which is acting as another significant growth-inducing factor.

The widespread product adoption as a source of backup or emergency power across the industrial sector is primarily driving the US portable gas generator market. In line with this, the increasing utilization of standby power sources to meet the inflating need for reliable and regular electricity supply is further catalyzing the market growth. Moreover, the launch of numerous favorable policies by the government bodies to promote the usage of environment-friendly gas generators that can be powered by biofuels and other sustainable energy sources, on account of the growing consumer concerns towards harmful greenhouse gas emissions, is acting as another significant growth-inducing factor.

The elevating consumer awareness towards the importance of regular household cleaning is primarily driving the glass cleaning spray market. Additionally, the widespread product adoption, owing to its simple and disposable nature, to ensure a clean and spotless home at minimal effort is further catalyzing the market growth. Besides this, the development of glass cleaning sprays that are skin-friendly, biodegradable, and possess a thick formulation for better dispensing control is acting as another significant growth-inducing factor.

The growing consumer inclination towards ready-to-eat food products, on account of the rising hectic lifestyles, is primarily driving the cakes and pastries market. Additionally, the widespread adoption of various bakery items, including cakes, pastries, pies, etc., that are sugar-free, gluten-free, whole-wheat, etc., by health-conscious individuals is further catalyzing the market growth. Besides this, the increasing utilization of cakes and pastries on numerous ceremonial and formal occasions, owing to their palatability, appearance, easily digestible nature, etc., is acting as another significant growth-inducing factor.

The global weight management market is primarily driven by the rising prevalence of obesity and weight-related health issues. Besides this, the expanding fast-food industry, hectic work schedules, and a lack of physical activity are resulting in numerous lifestyle diseases, which in turn are putting a significant strain on public healthcare budgets. These factors have prompted the government bodies across several countries to host health awareness and wellness programs, thereby augmenting the demand for weight management services.

The increasing demand for ready-to-eat (RTE) and ready-to-cook (RTC) food items is among the key factors driving the frozen fish and seafood market. Besides this, the elevating consumer awareness towards the health benefits of consuming seafood is further catalysing the market growth. Moreover, the escalating demand for frozen seafood as a thickening agent in numerous food-processing applications is acting as another significant growth-inducing factor.

Measurements of acoustic properties of sound absorbing materials in impedance tubes show poor reproducibility, which was demonstrated in round robin tests. The impedance tube measurements are standardized but lack precise definitions of the actual measurement setup, specimen preparation, and other factors that introduce uncertainty in practice. In this paper, machine learning models identify those factors that mostly affect the sound absorption coefficient from a large data set of more than 3000 absorption spectra measured in one impedance tube. The specimens are manufactured from one polyurethane foam, and different cutting technologies, different operators, different specimen diameters, different specimen thicknesses, and two different approaches to mount the specimens in the impedance tube are considered. Explainable machine learning techniques allow the identification and quantification of the most influential factors and, furthermore, the frequency ranges that are the most affected by the choice of these setup factors. The results indicate that besides the specimen thickness, also the operator affects the absorption coefficient by a directional and non-random relationship. Hence, it needs to be controlled carefully. The method proves to be a promising pathway for knowledge discovery from acoustic measurement data using explainability approaches for machine learning models.

Designing the vibroacoustic properties of thin-walled structures is of particularly high practical relevance in the design of vehicle structures. The vibroacoustic properties of thin-walled structures, e.g., vehicle bodies, are usually designed using finite element models. Additional development effort, e.g., experimental tests, arises if the quality of the model predictions are limited due to inherent model uncertainty. Model uncertainty of finite element models usually occurs in the modeling process due to simplifications of the geometry or boundary conditions. The latter highly affect the vibroacoustic properties of a thin-walled structure. The stiffness of the boundary condition is often assumed to be infinite or zero in the finite element model, which can lead to a discrepancy between the measured and the calculated vibroacoustic behavior. This paper compares two different boundary condition assumptions for the finite element (FE) model of a simply supported rectangular plate in their capability to predict the vibroacoustic behavior. The two different boundary conditions are of increasing complexity in assuming the stiffness. In a first step, a probabilistic model parameter calibration via Bayesian inference for the boundary conditions related parameters for the two FE models is performed. For this purpose, a test stand for simply supported rectangular plates is set up and the experimental data is obtained by measuring the vibrations of the test specimen by means of scanning laser Doppler vibrometry. In a second step, the model uncertainty of the two finite element models is identified. For this purpose, the prediction error of the vibroacoustic behavior is calculated. The prediction error describes the discrepancy between the experimental and the numerical data. Based on the distribution of the prediction error, which is determined from the results of the probabilistic model calibration, the model uncertainty is assessed and the model, which most adequately predicts the vibroacoustic behavior, is identified.

Scaling laws are used to scale-up calculation or measurement results from a prototype structure to those of an original structure or vice versa. The scaling laws of mechanical structures are usually obtained from their equations of motion or from a dimensional analysis. This paper proposes scaling laws that are represented by a power law. The power law is directly deduced from the Π -theorem of similitude theory and the coefficients of the power law are obtained from first order sensitivities (sensitivity-based scaling laws). Among existing similitude analysis methods such as dimensional analysis the sensitivity-based scaling laws can be directly obtained from a model without a priori knowledge of its scaling behavior, e.g., from a finite element (FE) model. The applicability of the sensitivity-based scaling laws is demonstrated in three case studies. A simply supported rectangular plate subject to mechanical vibrations is modeled by an analytical approach based on the Kirchhoff plate theory and by an FE model based on the Mindlin-Reissner theory. The plate’s dimensions are considered as design parameters for the sensitivity-based scaling laws. It is found in the first case study that the sensitivity-based scaling laws exactly predict the natural frequencies and the mean squared transfer admittances of scaled models from those of the original plate. This is in agreement with current literature and, thus, the method proposed in this paper can be considered verified. In the second case study the sensitivity-based scaling laws are directly obtained from the FE model. A good accuracy of the predicted vibration responses of the scaled models is found since (1) the scaled model and the original one are in similitude, i.e., the mode shape order and the damping are kept, and (2) the scaled plate can still be considered thin. The latter is assessed by the length (or width) to thickness ratios of the investigated plates and a lower bound is proposed. The third case study comprises a simplified car undercarriage to demonstrate the applicability of the method in practical design engineering. Besides the geometry parameters the material properties are incorporated in the sensitivity-based scaling laws as well. It is found that the natural frequencies as well as the vibration velocities at an arbitrarily chosen receiver point of the scaled models can be accurately predicted from those of the original one for complete similitude conditions.

Engineers often use similitude analyses to design small scale models for experimental tests or to design size ranges of mechanical structures such as drive technology systems. This paper is concerned with similitude analysis methods for vibration analyses of rectangular plates. If their geometry is scaled by different factors (distorted similitude), the scaling laws approximate the actual vibration responses with a certain accuracy only. This paper introduces a performance measure that reliably assesses how well the scaling laws approximate the actual vibration responses of rectangular plates. This measure, the so-called Mahalanobis distance, applies in a-posteriori analyses, where the vibration responses obtained from the scaling laws are compared to the actual ones. Numerical and experimental investigations on vibrating rectangular plates validate that the Mahalanobis distance is suitable to assess the performance of similitude analyses. The Mahalanobis distance can be linked to the geometrical properties of the rectangular plates in order to define a maximum permissible distortion of the geometry. Scaling laws approximate the vibration responses of the rectangular plates sufficiently well up to this maximum permissible distortion. Furthermore, the performance of two different state-of-the-art similitude analysis methods is compared. Both similitude analysis methods are found to perform well up to the maximum permissible amount of geometrical distortion.

Neonatal incubators provide suitable environmental conditions for premature newborns and allow for medical treatment such as medication and monitoring of vital functions such as blood pressure. The incubator includes several system components such as a control system, an oxygen supply, a scale or flaps and drawers for patient care and storage of medical material, respectively. These system components generate noise such as monitoring alarms, noise of the oxygen supply, or noise due to opening and closing of flaps during medical treatments. The noise leads to a significantly increased sound exposure inside the incubator. Increased sound exposure is known to cause distress and to increase the risk of acute or chronic diseases in the preterm neonate. This paper presents acoustic measurements on an incubator in a neonatal intensive care unit. Several vibration and acoustic measurements are performed inside the incubator as well as in the surrounding environment in order to characterize typical acoustic scenes from everyday life on the neonatal intensive care unit. Based on the measurement results, the scenes are categorized in terms of sound exposure. This forms the basis for a future design for acoustics of the incubator.

In structures, high vibration levels can destroy components; therefore, the reduction of the vibration levels represents a fundamental target in the industrial field. The structural intensity (STI) field provides information about the energy flow that propagates within a structure. It shows the position of dampers in structures, thus, it can be used for solving structure-borne noise problems. The analysis of the energy distribution on a structure allows to understand where to implement locally concentrated modifications introducing damping patches in order to reduce structure-borne noise. The aim of this paper is to investigate the structural intensity in composite structures and to evaluate the influence of some modeling parameters, such as mesh density, structural damping, etc., on the accuracy of the results. In this paper, numerical investigations on the STI in a fiber composite plate are carried out. Two different numerical models are considered: the first one with solid elements, the second one with shell elements. The two-dimensional model does not allow to analyze and study the composite plate on micro level. The first law of thermodynamics allows to define the accuracy of the STI evaluations. The investigation on two-dimensional and three-dimensional composite structure modeling presents the limits and the advantages of the two different types of approach. The different characteristics of the STI fields provided by these models are analyzed in order to understand the difference between local and global approach.

Noise and vibration engineering faces increasing demands of customers such as noise limits or comfort issues and also requires cost-efficient and adaptable design engineering methods due to shorter product life cycles. Taking advantage of similitudes of designs can address these needs by using scaled prototypes in experimental investigations or by designing size ranges and kits. However, a reliable prognosis of noise and vibration of an original design requires scaling laws that transfer the measurement results from the scaled prototype to the original design or from one design to another one within a size range. Similitude analysis lacks efficient and straightforward methods to derive scaling laws, thus, contradicting the demand for cost-efficient design engineering methods. Furthermore, scaling laws are often limited to complete similitude conditions such as equal damping values of the scaled prototype and of the original design or perfect geometrical similitude of a size range, which are hardly fulfilled in practice. This thesis aims at developing a procedure to straightforwardly derive scaling laws of mechanical structures by combining similitude analysis with sensitivity analysis, which determines the effect of design parameters on the vibration behavior of a mechanical structure. From this, the noise and vibration behavior of mechanical structures can be predicted even if incomplete similitude conditions persist. Similitude analysis and sensitivity analysis methods are first illustrated by potential applications in noise and vibration engineering using a double mass oscillator as a comprehensible example of a mechanical structure. A new scaling method is developed that combines similitude analyses with sensitivity analyses. This allows for deriving scaling laws, which incorporate sensitivities as coefficients. The scaling laws of rectangular plates in complete similitude are directly derived from analytical and finite element calculations for global and local vibration responses such as surface-averaged frequency response functions or vibration velocities at a local receiver point. These scaling laws match those derived from state-of-the-art similitude analysis methods, which verifies the new scaling method. Applying the new scaling method to plate-like structures in complete similitude demonstrates that scaling laws can be straightforwardly derived, whereas state-of-the-art similitude analysis methods would be too time-consuming. The scaling laws derived from the new scaling method accurately predict the vibration responses of scaled structures using the vibration responses of an original structure, which are obtained from numerical calculations or experimental measurements. The new scaling method even replicates the vibration responses of structures in geometrically incomplete similitude sufficiently well by using another scaled structure, which is in complete similitude to the original structure. In order to assess the accuracy of the scaled vibration responses an error measure is developed and validated in a-posteriori analyses. Finally, a size range of gear boxes in geometrically incomplete similitude demonstrates that the natural frequencies of an entire size range can be predicted with a sufficient accuracy by the new scaling method. The new scaling method can be enhanced towards kits since the natural frequencies of the gear boxes with various lumped masses attached can be replicated sufficiently well.

A method for the efficient experimental validation of stochastic sensitivity analyses is proposed and tested using a smart system for vibration reduction. Stochastic analyses are needed to assess the reliability and robustness of smart systems. A model-based design of experiments combines an experimental design with the results of a previous numerical sensitivity analysis. To test this method, a system of structural dynamics is used. Active suppression of disturbing vibrations of a cantilever beam by means of active piezoelectric elements is considered. The observed target variables are the level of vibration reduction at the beam’s end and the fundamental frequency considering five uncertain system variables. Based on a numerical model of the piezoelectric beam, a variance-based sensitivity analysis is performed to determine each design variable’s impact on the target variables. According to these numerical results, a model-based experimental design is established and the experiments are conducted. In comparison to a fully five-factor factorial experimental design, the model-based approach reduced the experimental effort by 50%, without great loss of information.

A multicore fiber (MCF) based temperature sensor was fabricated and packaged into a stainless-steel tube to protect the bare-fiber, and it offers a commercial friendly form factor. The sensor displayed a periodic supermode interference pattern that red-shifts with increasing temperature, which was used to calibrate the sensor. Additionally, an economical photodiode-based interrogator was fabricated from off-the-shelf parts and used to calibrate the sensor in both liquid and gas mediums. The response time to changes in temperature for the MCF sensor was found to be an order of magnitude faster than a thermocouple of identical diameter, 0.09 s compared to >1.0 s, respectively.

Follicle-stimulating hormone (FSH) is essential for primate reproduction and acts via the FSH-receptor (FSHR). Although the FSHR expression is highly cell-specific, knowledge of the FSHR promoter and its transcriptional regulation is very limited. We applied a comparative genomic approach of important primate lineages to characterize the FSHR core promoter region. The core promoter sequences of the human and different primate species display significant variations in species-specific promoter activities shown by relative luciferase activity (RLA), ranging from 0.7-fold in the bonobo up to 3.5-fold in the chimpanzee compared to human. Comparison of the core promoter sequences revealed only very few interspecies nucleotide mismatches. Sequence homology ranged between 88% in the marmoset to 98% in chimpanzee compared to human FSHR. Mutagenesis of a single nucleotide next to a putative E-twenty-six (ETS) binding site caused a significant increase for human and a decrease for chimpanzee in RLA. An accompanying change in the pattern of protein binding to mutated human and chimpanzee ETS binding sites was demonstrated by EMSA, confirming a hitherto unknown role for this ETS binding site in FSHR promoter activity. Although the FSHR promoter displays a great sequence homology among primates, single nucleotide changes have significant impact on FSHR promoter activity. Thus promoter studies of closely related species could yield important insights into different regulatory promoter elements caused by nucleotide substitutions.