Benchmarking and validation of a combined CFD-optics solver for micro-scale problems

In this work, we present a new approach for coupled CFD-optics problems that consists of a combination of a finite element method (FEM) based flow solver with a ray tracing based tool for optic forces that are induced by a laser. We combined the open-source computational fluid dynamics (CFD) package FEATFLOW with the ray tracing software of the LAT-RUB to simulate optical trap configurations. We benchmark and analyze the solver first based on a configuration with a single spherical particle that is subjected to the laser forces of an optical trap. The setup is based on an experiment that is then compared to the results of our combined CFD-optics solver. As an extension of the standard procedure, we present a method with a time-stepping scheme that contains a macro step approach. The results show that this macro time-stepping scheme provides a significant acceleration while still maintaining good accuracy. A second configuration is analyzed that involves non-spherical geometries such as micro rotors. We proceed to compare simulation results of the final angular velocity of the micro rotor with experimental measurements

Results of an interlaboratory method performance study for the size determination and quantification of silver nanoparticles in chicken meat by single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS)

Single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) promises fast and selective determination of nanoparticle size and number concentrations. While several studies on practical applications have been published, data on formal, especially interlaboratory validation of sp-ICP-MS, is sparse. An international interlaboratory study was organized to determine repeatability and reproducibility of the determination of the median particle size and particle number concentration of Ag nanoparticles (AgNPs) in chicken meat. Ten laboratories from the European Union, the USA, and Canada determined particle size and particle number concentration of two chicken meat homogenates spiked with polyvinylpyrrolidone (PVP)-stabilized AgNPs. For the determination of the median particle diameter, repeatability standard deviations of 2 and 5% were determined, and reproducibility standard deviations were 15 and 25%, respectively. The equivalent median diameter itself was approximately 60% larger than the diameter of the particles in the spiking solution. Determination of the particle number concentration was significantly less precise, with repeatability standard deviations of 7 and 18% and reproducibility standard deviations of 70 and 90%

A study of imprint and etching behavior on fused silica of a new tailored resist mr-NIL213FC for soft UV-NIL

A new type of a specifically tailored resist for Soft Nanoimprint Lithography (Soft UV-NIL) namely mr-NIL213FC has been developed. It aims for a significant improvement of its etch-resistance with regard to underlying oxide substrates such as glass. This work demonstrates the first study of its imprint performance and etching behavior against fused silica wafers. First of all, the resist shows full compatibility with automated Soft UV-NIL using PDMS-based soft stamps and at ambient (oxygen containing) conditions for both step-and-repeat and full-wafer approaches. Moreover, the selectivity of the resist to the underlying fused silica substrate, in a high power and high etch rate condition, has reached to over 0.6, which is a significant step-up among most products in this context. The improved resistance of the resist facilitates direct etching processes for high resolution and high structure fidelity

Highly anisotropic fluorine-based plasma etching of ultralow expansion glass

Deep etching of glass and glass ceramics is far more challenging than silicon etching. For thermally insensitive microelectromechanical and microoptical systems, zero-expansion materials such as Zerodur or ultralow expansion (ULE) glass are intriguing. In contrast to Zerodur that exhibits a complex glass network composition, ULE glass consists of only two components, namely, TiO2 and SiO2. This fact is highly beneficial for plasma etching. Herein, a deep fluorine-based etching process for ULE 7972 glass is shown for the first time that yields an etch rate of up to 425 nm min^-1 while still achieving vertical sidewall angles of 87°. The process offers a selectivity of almost 20 with respect to a nickel hard mask and is overall comparable with fused silica. The chemical surface composition is additionally investigated to elucidate the etching process and the impact of the tool configuration in comparison with previously published etching results achieved in Zerodur. Therefore, deep and narrow trenches can be etched in ULE glass with high anisotropy, which supports a prospective implementation of ULE glass microstructures, for instance, in metrology and miniaturized precision applications

An exceptional Albanian family with seven children presenting with dysmorphic features and mental retardation: maternal phenylketonuria

BACKGROUND: Phenylketonuria is an inborn error of amino acid metabolism which can cause severe damage to the patient or, in the case of maternal phenylketonuria, to the foetus. The maternal phenylketonuria syndrome is caused by high blood phenylalanine concentrations during pregnancy and presents with serious foetal anomalies, especially congenital heart disease, microcephaly and mental retardation. CASE PRESENTATION: We report on an affected Albanian woman and her seven children. The mother is affected by phenylketonuria and is a compound heterozygote for two pathogenetic mutations, L48S and P281L. The diagnosis was only made in the context of her children, all of whom have at least one severe organic malformation. The first child, 17 years old, has a double-chambered right ventricle, vertebral malformations and epilepsy. She is also mentally retarded, microcephalic, exhibits facial dysmorphies and small stature. The second child, a girl 15 years of age, has severe mental retardation with microcephaly, small stature and various dysmorphic features. The next sibling, a boy, died of tetralogy of Fallot at the age of three months. He also had multiple vertebral and rib malformations. The subsequent girl, now eleven years old, has mental retardation, microcephaly and epilepsy along with facial dysmorphy, partial deafness and short stature. The eight-year-old child is slightly mentally retarded and microcephalic. A five-year-old boy was a premature, dystrophic baby and exhibits mental retardation, dysmorphic facial features, brachydactyly and clinodactyly of the fifth finger on both hands. Following a miscarriage, our index case, the youngest child at two years of age, is microcephalic and mentally retarded and shows minor facial anomalies. All children exhibit features of phenylalanine embryopathy caused by maternal phenylketonuria because the mother had not been diagnosed earlier and, therefore, never received any diet. CONCLUSION: This is the largest family suffering from maternal phenylketonuria reported in the literature. Maternal phenylketonuria remains a challenge, especially in woman from countries without a neonatal screening program. Therefore, it is mandatory to be alert for the possibility of maternal phenylketonuria syndrome in case of a child with the clinical features described here to prevent foetal damage in subsequent siblings

Modellierung und Messung von Emissionen an Transceiverpins in Automotive-System-ICs, verursacht durch integrierte DC/DC-Wandler

Die Integration von DC/DC-Wandlern mit Transceivern in Automotive-System-ICs führt zu neuen Herausforderungen im Bezug auf die Einhaltung der Emissionsgrenzwerte an den Transceiverpins. An einem Test-IC werden die Emissionen des DC/DC-Wandlers an verschiedenen Transceiverpins ermittelt. Der Substratübertragungspfad wird mit Hilfe eines neuartigen Substratextraktors modelliert, und zur Beschreibung induktiver Bonddrahtkopplungen wird ein HFSS-Packagemodell verwendet. Der Vergleich zwischen Modellvorhersage und Messung zeigt typ. eine Abweichung von unter _6 dB bis 1 GHz

Vergleich von dynamisch-interaktiver Geometriesoftware für die Maßsynthese von ebenen Getrieben

Die Nutzung von dynamisch-interaktiver Geometriesoftware im Rahmen der Getriebeentwicklung ist noch nicht fester Bestandteil der Konstrukteurs-Praxis, obwohl solche Programme bereits in einem sehr frühen Stadium derEntwicklung eingesetzt werden können. Da es eine Vielzahl von Geometrie-Programmen mit großen Unterschieden bezüglich der Verwendung von Syntheseverfahren, der grafischen enutzeroberflächen oder auch der Benutzerfreundlichkeit gibt, wird in diesem Beitrag ein objektiver Vergleich von Getriebesoftware vorgestellt. Schlussendlich wird eine Empfehlung gegeben, welche Getriebesoftware effizient für die Lösung einer bestimmten Syntheseaufgabe im Rahmen der Getriebeentwicklung genutzt werden kann.Using dynamic-interactive geometry software within the process of mechanism development has not become common practice, although this software can be applied in an early stage of mechanism development. Available nowadays is a huge number of software differing from the implementable dimensional synthesis procedure, the graphic user interface and the userfriendliness. Thus, an impartial comparison of dynamic-interactive geometry software can be carried out. Finally, a recommendation linking software with a certain synthesis procedure is published

A Mobile and Compact Control Center for Quick Decentral Satellite Access

Compact and inexpensive Earth observation satellites in low Earth orbit are now routinely developed by universities, "New Space" businesses, and space agencies. They enable new opportunities for fast turnaround times of imaging data takes, which is e. g. particularly important for disaster response. For this kind of satellites and the missions enabled by them a ground system exhibiting the same characteristics, namely being compact and mobile, yet inexpensive and flexible, is desired. We present DLR's approach for the provisioning of a ground segment fit for the kind of missions outlined above. The objective of this project consists of the engineering, delivery, and demonstration of a compact and yet complete Mission Operations System, runnable on commodity mobile hardware, enabling fully automated workflow-driven operations of alike missions from anywhere in the world with access to a ground station or ground station network. Just as disasters strike suddenly, the ground segment needs to be set up and spun up in a timely manner. This leads to the requirement of being able to quickly roll out the system on new hardware, possibly even several of these systems in parallel. Our paper provides insight on how we perform the automatic deployment and provisioning. Because the system is supposed to be decentralized and used in the field, particular challenges need to be overcome resulting from the lack of all of the infrastructure typically present in conventional control centers, such as network connectivity. An embedded Flight Dynamics system is taking care of automated orbit determination and related event generation to support the mission needs and maneuver capabilities. Special effort is made to cope with auxiliary data that may not be updated on a regular basis in a closed mission environment. The feasibility of the concept is demonstrated by a first system deployment as drop-in replacement for the existing conventional Mission Operations System for DLR's BIROS satellite at the GSOC control center. A second demonstration campaign is performed from a remote location without access to control center infrastructure