The dissertation covers circuits in the field of micro-system electronics working as an interface between micro-electromechanical components and digital signal processing. The important problems of signal crosstalk and multiplication of complexity arising in conjunction with sensor- and actuator-arrays are considered. As a foundation for design the modeling of DMOS-transistors and system aspects of sensor-signal-recovery are discussed. The design and implementation of a high-voltage driver-amplifier, a modulator for sensor-signal-recovery, a correlation IC to read out arrays and a micromechanical resonator with monolithically integrated read-out-amplifier is presented. / Die Dissertation behandelt Schaltungen der Mikrosystemelektronik in ihrer Funktion als Schnittstelle zwischen mikromechanischen Komponenten und signalverarbeitender Digitalelektronik. Hierbei werden die für Sensor- und Aktorarrays besonderen Probleme Signalübersprechen und Aufwandsvervielfachung berücksichtigt. Als Entwurfsgrundlage werden die Modellierung von DMOS-Transistoren und Systemaspekte der Sensorsignalauswertung besprochen. Vorgestellt wird der Entwurf und die Realisierung eines Hochvolt-Ansteuerverstärkers, eines Modulators zur Sensorauswertung, eines Korrelator-ICs zur Arraysauswertung und eines mikromechanischen Resonators mit monolithisch integriertem Ausleseverstärker.

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Positive displacement machines working as hydraulic pumps or hydraulic motors have always been, are and will be an essential part of any hydraulic system. Current trends and future demands on energy efficient systems will not only drastically increase the number of positive displacement machines needed for modern efficient hydraulic circuits but will significantly change the performance requirements of pumps and motors. Throttleless system configurations will change the landscape of hydraulic actuation in aerospace, mobile machines, automotive and many other areas and will definitely open the door for new applications due to its enhanced competitiveness with electric and electro-mechanical systems.

Until recently, hydrostatic-mechanical power split CVT drivelines have not found a place in construction machinery. The majority of these vehicles still use hydrodynamic powershift transmissions, full-hydrostatic transmissions or mechanical direct-shift transmissions. Hydrostatic drive lines are widely used in construction machinery possessing lower engine power. The upper power range is dominated by hydrodynamic powershift transmissions. Decisions made by vehicle manufacturers about which driveline technology to be used, have been based mainly on reliability, durability, and cost. Fuel economy has also been a growing trend over the past years; however the additional cost of higher technologies must be compensated by the savings in fuel cost over a time period of 2-3 years. The transmission’s efficiency highly contributes to the vehicle’s fuel consumption. ZF has thoroughly studied the possible concepts of hydrostatic-mechanical power split transmissions. The most important requirements of reliability, durability and efficiency were taken into consideration during the concept study. An examination the most typical working cycles showed that a construction machinery transmission needs to be fully power split in all ranges and obtain equal performance in both driving directions. It was also observed that up to 60% of productive time for construction and forestry equipment was spent at a speed below 12 km/h. For this speed range, achieving the highest possible efficiency is vital. The result of this research is the ZF cPower, which is an output-coupled, fully power split transmission.

Content: For sustainable developments the chemical industry is continuously looking for technical innovations with wide potential implications. The Design of Experiments (DOE) approach has been proven to be a powerful tool in determining the relationship between factors affecting certain output variables. This is done to establish a 'cause and effect' relationship and eventually realize output optimization. In order to evaluate whether DOE can be implemented for improving our products and processes, a case study, focusing on the synthesis and production of traditional phenolic syntans was carried out within our R&D department. Although we can influence properties by application, the effect a retanning agent has on leather originates to a large extent from the chemistry involved. To understand interactions and the possibilities of targeted improvements of the production process, a DOE factorial design approach was used to identify the control parameters and their interactions in our phenolic syntan recipes that influence the various properties and effects. Instead of trial-and-error or one-factor-at-a-time practices, DOE made it possible to limit the number of lab experiments to one third (1/3) of the amount needed for completing our study. As a result, a much deeper and more consistent understanding of the building blocks’ interactions and how these influence the chemical process of phenolic syntan synthesis has been gained. This includes the amount of different building blocks, their molar ratios as well as process conditions. Aiming at achieving optimal efficiency for various projects, right now we are looking at possibilities in implementing DOE within Smit & zoon. Take-Away: The Design of Experiments (DOE) approach is a powerful tool in realizing process and product improvements. DOE factorial design can be used to identify control parameters and their interactions in a wide reage of (industrial) applications. DOE has been proven to be efficient and effective in optimizing phenolic syntan recipes and production process.

Content: Essential oils are of commercial interest primarily because of their potential antimicrobial, antifungal and antioxidant properties and for being of natural origin, which generally represents lower risk to the environment and human health. Clove essential oil not only contains many kinds of biological active compositions but also has highly effective and comprehensive antibacterial functions. Remarkably, clove has strong antimicrobial activities against a wide range of pathogenic microorganisms. To prevent chemical changes the oil is microencapsulated. The aim of this study is to develop essential oil microcapsules with gelatin and alginate. Various solutions were prepared for the capsule wall material at different concentrations. The encapsulation efficiency (%) was accessed and the microcapsules were characterized by oil content (%), oil charge (%), morphology, functional groups present, thermogravimetric analysis and by Fourier transform - infrared spectral analysis. FT-IR spectra of the clove oil shows some special peaks at 1148,01 and 1033,33 cm-1. The spectra of the capsule showed peaks 1148.34 and 1033.29 cm -1, the same peaks present in clove oil, showing that the encapsulation did not alter the structure of the oil's main assets. In case of the gelatin and alginate microcapsules containing clove oil, most of the characteristic peaks of clove oil remained unchanged, indicating the successful incorporation of clove oil into the microcapsules and the chemical stability of the clove oil after encapsulation. In otherwords, there was no significant chemical interaction between the oil and the wall of the microcapsule. Take-Away: The clove oil was microencapsulated according the FTIR spectra.