Analysis of the Compartmentalized Metabolome – A Validation of the Non-Aqueous Fractionation Technique

With the development of high-throughput metabolic technologies, a plethora of primary and secondary compounds have been detected in the plant cell. However, there are still major gaps in our understanding of the plant metabolome. This is especially true with regards to the compartmental localization of these identified metabolites. Non-aqueous fractionation (NAF) is a powerful technique for the determination of subcellular metabolite distributions in eukaryotic cells, and it has become the method of choice to analyze the distribution of a large number of metabolites concurrently. However, the NAF technique produces a continuous gradient of metabolite distributions, not discrete assignments. Resolution of these distributions requires computational analyses based on marker molecules to resolve compartmental localizations. In this article we focus on expanding the computational analysis of data derived from NAF. Along with an experimental workflow, we describe the critical steps in NAF experiments and how computational approaches can aid in assessing the quality and robustness of the derived data. For this, we have developed and provide a new version (v1.2) of the BestFit command line tool for calculation and evaluation of subcellular metabolite distributions. Furthermore, using both simulated and experimental data we show the influence on estimated subcellular distributions by modulating important parameters, such as the number of fractions taken or which marker molecule is selected. Finally, we discuss caveats and benefits of NAF analysis in the context of the compartmentalized metabolome

Effect of Discrete Micro-forming on the Surface Layer

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersZiel dieser Arbeit ist es, Erkenntnisse über die Auswirkungen der System- und der Stellgrößen auf die Prozess- und die resultierenden Wirkgrößen eines mechanischen Oberflächenbearbeitungsprozesses, dem sogenannten maschinellen Oberflächen-hämmern (engl. Machine Hammer Peening - MHP), zu gewinnen. Das Verfahren basiert auf einem oszillierenden Hammerkopf, der wiederholt auf eine Werkstückoberfläche trifft. Eine Aktorik, welche die Hammerkopfbewegung ausführt, wird an einer Werkzeugmaschine oder einem Roboter befestigt und entlang einer vorgegebenen Bahn geführt. Gemäß der VDI 3416 verwendet die Technologie ein Aktorsystem, um die Oberflächenrauheit zu reduzieren, die Oberflächenhärte zu steigern und oberflächennahe Druckeigenspannungen zu erzeugen. Darüber hinaus wird in dieser Arbeit ein umfassendes Verständnis des gesamten Bearbeitungsprozesses, basierend auf Maschinenuntersuchungen sowie dem Vergleich verschiedener MHP-Aktorsysteme, geschaffen. Um jedoch gezielte Oberflächenstrukturen zu erreichen, ist die Kopplung zwischen der Dynamik der Werkzeugmaschine oder dem Robotersystem und der Hammerkopfbewegung erforderlich, welche in dieser Arbeit genauer betrachtet wird. Aufgrund der NC-gesteuerten Positionierung und der präzisen Werkzeugführung zeigt der MHP-Prozess auch die Fähigkeit unter der Anwendung funktional gestalteter Werkzeuge definierte Mikrostrukturen auf einer Werkstückoberfläche herzustellen. Im Gegensatz zu Beschichtungstechniken zur Funktionalisierung von Oberflächen erfolgt die Herstellung durch einen Mikroumformprozess. Diese Tatsache, in Kombination mit der Möglichkeit der Phasenumwandlung des Kristallgitters einer metastabilen austenitischen CrNi Legierung hin zu einer martensitischen Struktur durch den Einsatz des genannten Verfahrens, birgt großes Potenzial dieser Technologie. Um die Eignung eines piezoelektrischen Aktors zur Herstellung von Mikrostrukturen zu überprüfen, werden Experimente am Warmarbeitsstahl X38CrMoV5-1 (1.2343) durchgeführt. Neben der Strukturierung der Oberfläche wird die durch plastische Verformung induzierte Phasenumwandlungen an einem metastabilen austenitischen CrNi Werkstoff X5CrNi18 10 (1.4301) untersucht. Experimentelle Untersuchungen werden an einem Roboter sowie an Fräsbearbeitungszentren durchgeführt. Als Aktoriken sind ein elektromagnetisches, ein pneumatisches, sowie ein piezoelektrisches Aktorsystem Bestandteil der Untersuchungen. Letzteres dient zur Herstellung mikrostrukturierter Oberflächen. In einem nachgelagerten Spritzgussprozess wird gezeigt, dass die Oberflächen am Kunststoff-Formteil wasserabweisende Eigenschaften aufweisen. Im Bereich der induzierten Phasenumwandlungen eines CrNi Werkstoffes kann in den oberen Schichten des Werkstücks eine Phasenumwandlung von einer metastabilen austenitischen in eine martensitische Phase erreicht werden. Die in diesem Projekt erzielten Ergebnisse zeigen das Potenzial für eine erweiterte Anwendung von mechanischen Oberflächenbehandlungen, wie z.B. dem maschinellen Oberflächenhämmern.The objective of this research is to gain knowledge about the effects of the system- and the independent variables on the dependent variables and the resulting material properties of a mechanical surface treatment process, called machine hammer peening (MHP). MHP is based on an oscillating hammer head which strikes repeatedly on a workpiece surface. The actuator, which provides the tool movement, is attached to a machine tool or a robot in order to treat the surface with well-directed impacts. According to VDI 3416, the technology uses an actuator system to reduce surface roughness, increase surface hardness, and induce near surface compressive residual stresses. Moreover, a comprehensive understanding of the entire machining process, based on machine investigations as well as the comparison of different MHP actuators, is created in this work. However, to achieve distinctively oriented surface structures and patterns the coupling between the tool path motion and the actuator motion dynamics is required. When producing defined surface structures to influence the surface integrity by the use of MHP, the acceleration of the machining system has to be considered. Apart from the named surface properties, structured tools can also be applied for surface treatment processes to create defined surface textures. In the past, these surface properties were achieved by advanced coatings or additional finishing technologies. While both work, they have their limitations. Coatings wear off over time. This fact, in combination with the possibility of phase transformation of the crystal lattice of a processed metastable austenitic to martensitic structure by the application of machine hammer peening, contains great potential. For this purpose, a coupling between the impact frequency of the MHP-system and the speed distribution on the tool path must be realized. Along with adapted NC-controlled motion of the machining system, a predictable sequence of contacts between the tool and the workpiece can be achieved. Further, to verify the suitability of an investigated piezoelectric actuator to create microstructures, experiments are carried out on the hot work tool steel X38CrMoV5-1 (1.2343). In addition to surface texturing, the deformation induced phase transformations on a metastable austenitic CrNi material X5CrNi 18-10 (1.4301) is investigated. As a result, it is possible to create deterministic patterns on the surfaces of workpieces and influence the surface characteristics. Experimental investigations have been performed using a KUKA robot KR30-3 equipped with an electromagnetic actuator system. Another application for a vibration-based process was shown by creating micro-structured surfaces with a piezoelectric actuator for a subsequent mold injection process which show hydrophobic surface conditions on the plastic molded part. Finally, due to plastic deformation of the crystalline steel material, as caused by machine hammer peening treatment in the upper layers of the workpiece, phase transformations may be achieved, from a metastable austenitic phase to a martensitic phase. The results obtained in this project show the potential for expanded application of mechanical surface treatments, like machine hammer peening.18

Avoidance of drill cap formation in CFRP-titanium stack materials by using vibration assisted drilling with defined coupling of the oscillation

Drilling of rivet holes in stacked materials consisting of CFRP and Ti-6Al-4V still represents unique challenges. It is common practice to drill the material layers using one single tool. When exiting the final metallic layer, formation of a drill cap usually leads to undesirable burrs and debris, requiring manual post-processing. In this work, a drilling process to avoid drill caps is presented. This is realized using low frequency high amplitude vibration assisted drilling with defined coupling of the rotational speed and the axial oscillations. Drilling parameters and their impact on the quality of the drilled hole in the metallic layer are also investigated. It is found that drill tip geometries and process parameters need to be tuned together to achieve a stable and repeatable process for drill cap avoidance. A highly sensorized experimental setup with multi-sensor systems including high-speed and thermal imaging was used for process evaluation

Investigation of multilayer coating of EN AW 6060 – T66 using friction surfacing

The objective of this research is to investigate observable process changes during multi-layer friction surfacing of EN AW 6060 aluminum, whether for repair, remanufacturing, or new part manufacturing. In this study, friction surfacing was performed with a 10-mm-diameter rod of EN AW 6060 aluminum at spindle speeds ranging from 1000 to 7000 rpm to create up to three layers of 40-mm-long deposits on a substrate of the same alloy. The process forces and layer temperatures were observed. Post-process measurement of flash geometry, layer geometry and microhardness were conducted with the motivation to understand the impact of multi-layer depositions on performance and identifying acceptable conditions required to achieve acceptable build quality. The thickness, deposition and joining efficiency of layers in the multilayer configuration remained consistent. Friction surfacing of EN AW 6060 aluminum allowed for high deposition rates of 9 kg/hr, when compared to other metal additive technologies

Investigation of noise transmission of a machine tool enclosure

Machine tools are highly integrated mechatronic systems consisting of dedicated mechanic design and integrated electrical equipment – in particular drive systems and the CNC-control – to realize the complex relative motion of tool towards work piece. Beside the process related capabilities, like static and dynamic stiffness as well as accuracy behavior and deviation resistance against thermal influence, safety aspects are of major interest. The machine tool enclosure must fulfill multiple requirements like retention capabilities against the moving parts of broken tools, lose work pieces or clamping components. In regular use, the noise emission have to be inhibited at the greatest possible extent by the machine tool enclosure. Nevertheless, the loading door and the moving parts of the workspace envelope are interfaces where noise transmission is harder to be avoided and therefore local noise emissions increase. The aim of the objective investigation is to analyse the noise emission of machine tools to determine the local noise transmission of a machine tool enclosure by using arrays of microphones. By the use of this measuring method, outer surfaces at the front, the side and on the top of the enclosure have been scanned. The local transient acoustic pressures have been recorded using a standard noise source placed on the machine table. In addition, an exemplary manufacturing process has been performed to analyse the frequency dependent location resolved sound emissions

A Hardware Abstraction Layer in Java

Embedded systems use specialized hardware devices to interact with their environment, and since they have to be dependable, it is attractive to use a modern, type-safe programming language like Java to develop programs for them. Standard Java, as a platform-independent language, delegates access to devices, direct memory access, and interrupt handling to some underlying operating system or kernel, but in the embedded systems domain resources are scarce and a Java Virtual Machine (JVM) without an underlying middleware is an attractive architecture. The contribution of this article is a proposal for Java packages with hardware objects and interrupt handlers that interface to such a JVM. We provide implementations of the proposal directly in hardware, as extensions of standard interpreters, and finally with an operating system middleware. The latter solution is mainly seen as a migration path allowing Java programs to coexist with legacy system components. An important aspect of the proposal is that it is compatible with the Real-Time Specification for Java (RTSJ)