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Mechanical engineering curriculums at German universities have mostly theoretical approaches to design theory. Several institutes and chairs have specialized courses regarding this topic, but these are seldomly integrated. The approach IDEE – Integrated Design Engineering Education – brings the specialized fields on design theory together in one course with a highly practical focus at the beginning of the mechanical engineering studies. This is realized by a mixture of theoretical lectures and a group project. For students, this includes their first experience of a complex group project with peers and also the first oral presentation in an engineering context. With a lack of professional and soft skills, there is often friction inside groups. There is also a need for appropriate tools to work collaboratively. Due to the Corona pandemic, lectures and the group project must be held completely online. This paper describes our approach in helping the students improve their professional and personal skills by integrating new courses within the project, monitor their group dynamics, and also use digitization to provide an online-only solution. This paper presents the challenges regarding soft skills and collaborative work as well as the chosen approach on how to integrate digitization, monitoring, and self-organization skills into the lecture to face the challenges.

Scaling trends in the semiconductor industry towards smaller technology nodes and feature sizes are continuing and first consumer products manufactured with the help of EUV technology are already on the market. Major industrial players have introduced EUV lithography into their production at the 7nm technology node and with the 5nm node being on its way [1], the amount of EUV lithographic layers is expected to rise significantly and implementation of EUV double patterning is anticipated. These developments lead to more strict technological requirements especially for the corresponding EUV but also for the used high-end DUV photomasks in terms of minimum feature sizes and acceptable Edge Placement Errors (EPE). Moreover, photomask defectivity increases dramatically with shrinking feature sizes. This creates significant challenges to the industry, as in particular the most cost intensive EUV photomasks possess the highest numbers of defects. The current industry standard for high-end photomask repair tools is the MeRiT neXT [2]. To face the upcoming challenges an efficient and reliable way to repair future high-end photomasks is inevitable. A corresponding repair tool must address decreased minimum feature sizes and increased pattern complexity on high-end photomasks. In this paper we present our latest results of high-end EUV repairs carried out on the next generation photomask repair tool MeRiT LE. The tool shows improved system dynamics, makes use of a new electron beam column, which operates at a low electron beam voltage down to 400V and enables the repair of next generation ultra-small defects.

Nacre of abalone shells consists of aragonite platelets and organic material, the so-called organic matrix. During the growth process of the shell the aragonite platelets grow into a scaffold formed by the organic matrix. In this work we tried to mimic this growth process by placing a piece of the insoluble organic matrix (which is a part of the organic matrix) of the abalone Haliotis laevigata in a crystallization device which was flowed through by CaCl 2 and NaHCO 3 solutions. Using this setup amongst others flat aragonite crystals grow on the insoluble organic matrix. When investigating these crystals in a transmission electron microscope it is possible to recognize similarities to the structure of nacre, like the formation of mineral bridges and growth between layers of the insoluble organic matrix. These similarities are presented in this paper.

During the growth process of the nacre layer in abalone shells, aragonite platelets are built into a preformed organic matrix. This matrix consists of chitin and different proteins that may affect ...

Praseodymia gives rise to a rich phase diagram with a large number of phases between the limiting stoichiometries Pr 2 O 3 and PrO 2 that differ only slightly in oxygen content (Pr n O 2n-2 ). This chemical and crystallographic variability allows the system to release or incorporate lattice oxygen easily at sufficiently high temperatures and thus renders the material interesting as a catalyst for redox reactions according to a Mars-van Krevelen mechanism. Nanostructured praseodymia samples are investigated in this study with respect to their catalytic properties, focusing on methane oxidation and selective NO reduction by CO and CH 4 . To correlate catalytic activity and crystallographic changes, complementary high-temperature X-ray diffraction measurements have been carried out. The determined temperatures of transitions between different oxide phases agree well with peaks in the temperature-programmed reduction measurements, confirming the direct connection between the availability of lattice oxygen and crystallographic transformations. The catalytic activity for methane oxidation and NO reduction sets in at 450-500°C, at which temperature the starting material—mainly Pr 6 O 11 ―transforms into the next oxygen-depleted phase Pr 7 O 12 . With respect to NO reduction, the results show that it is possible to employ both methane and carbon monoxide as reducing agents in the absence of oxygen, in agreement with a Mars-van Krevelen mechanism. Nevertheless, the use of CO instead of CH 4 offers considerable advantages, as no deactivation due to carbon residues takes place in this case. Whereas, in an excess of oxygen, NO reduction is inhibited independently of the reducing agent, it is shown that NO reduction can proceed if the O 2 concentration remains below a critical concentration.

Nacre, the inner iridescent layer of mollusc shells, is a typical example of a material that is formed by such biomineralization processes. Nacre is composed of the CaCO3-polymorph aragonite and a small amount (about 5 wt.%) of organic matter. The authors studied the structure of the aragonite platelets of Haliotis laevigata nacre, using conventional transmission electron microscopy, Z-contrast, electron tomography, energy-dispersive X-ray analysis (EDX)and electron energy-loss spectroscopy (EELS). The authors observed faceted voids several nanometers wide within the aragonite platelets. The electron tomography investigations showed that the voids are distributed more or less randomly in the studied specimen and allowed an estimation of the order of magnitude of the width and the volumetric content of the voids. The voids are located within the aragonite platelets, so that they are not an artifact of preparation. Furthermore, a first proposal for a three-dimensional model of the voids was made. EDX and EELS measurements revealed that the voids include a larger amount of carbon in comparison to the bulk material. The questions why these voids are formed and how have still to be answered. A speculative function of the voids could be the decreased propagation of cracks in the shell providing an increased fracture toughness.

In scanning transmission electron microscopy using a high-angle annular dark field detector, image intensity strongly depends on specimen thickness and composition. In this paper we show that measurement of image intensities relative to the intensity of the incoming electron beam allows direct comparison with simulated image intensities, and thus quantitative measurement of specimen thickness and composition. Simulations were carried out with the frozen lattice and absorptive potential multislice methods. The radial inhomogeneity of the detector was measured and taken into account. Using a focused ion beam (FIB) prepared specimen we first demonstrate that specimen thicknesses obtained in this way are in very good agreement with a direct measurement of the thickness of the lamella by scanning electron microscopy in the FIB. In the second step we apply this method to evaluate the composition of Al x Ga 1 - x N / GaN layers. We measured ratios of image intensities obtained in regions with unknown and with known Al-concentration x , respectively. We show that estimation of the specimen thickness combined with evaluation of intensity ratios allows quantitative measurement of the composition x . In high-resolution images we find that the image intensity is well described by simulation if the simulated image is convoluted with a Gaussian with a half-width at half-maximum of 0.07 nm.

The biogenic polymer/mineral composite nacre is a non-brittle biological ceramic, which self-organises in aqueous environment and under ambient conditions. It is therefore an important model for new sustainable materials. Its highly controlled structural organization of mineral and organic components at all scales down to the nano - and molecular scales is guided by organic molecules. These molecules then get incorporated into the material to be responsible for properties like fracture mechanics, beauty and corrosion resistance. We report here on structure, properties and growth of columnar (gastropod) nacre with emphasis on the genus Haliotis in contrast to sheet nacre of many bivalves.

Transient tachypnea of the newborn (TTN) is the most common cause of neonatal respiratory distress; its estimated incidence is 1 % to 2%. Although a number of risk factors for TTN have been identified, the main risk factors include elective cesarean section (ECS), lower gestational age, male gender, and low birth weight. Previous studies have shown a positive impact of labor on respiratory outcomes among infants with TTN, but the impact of labor on the severity of TTN has not been investigated. This population-based cohort study investigated the effect of labor on the risk and course of TTN in a large, representative sample of term singleton neonates in Germany. Between 2001 and 2005, perinatal databases in the federal states of Hesse and Saarland were used to identify cases of TTN among singletons born at a gestational age ≥37 weeks, and to examine neonatal outcomes in all infants admitted to a neonatal center. Data for the TTN group was compared with national perinatal data for term singletons (control group) born during the study period. The International Classification of Diseases, 10th Revision was used to diagnosis TTN. Of the 239,971 term births included in the final analysis, 13,346 (5.6%) were transferred to a neonatal ward and 1423 (0.59%) cases of TTN were diagnosed. This represented an overall TTN incidence of 5.9 cases per 1000 singleton live births. Risk factors for TTN included ECS, low gestational age, male gender, and low birth weight. There was a significant association between the absence of labor before birth and longer duration of oxygen supplementation (P < 0.02), and an increased risk of TTN and severity of TTN at term. Prolonged labor reduced the need for oxygen supplementation and conversely, a decrease in labor duration increased the need (P < 0.028). These findings show that ECS and the absence of labor at term are strong risk factors for the development of TTN. Absence of labor or reduced labor duration is associated with increased severity of TTN and the need for oxygen supplementation.

In this paper we demonstrate a quantitative method for composition evaluation based on comparison of normalized image intensity with simulations carried out with the frozen lattice approximation. The method is applied to evaluate composition profiles of AlxGa1?xN/GaN layers. We measure ratios of image intensities obtained in regions with unknown and with known Al-concentration x, respectively. We show that estimation of specimen thickness combined with evaluation of intensity ratios allows quantitative measurement of composition profiles. Delocalization effects at interfaces due to instrumental resolution and dynamic electron diffraction are simulated. These effects can well be described by convolution with a Lorentzian. Measured intensity profiles can be corrected for delocalization effects using statistical parameter estimation so that deconvolution is avoided.

In this work, we studied the correlation of the orientation of stacked aragonite platelets of Haliotis laevigata nacre, using selected area diffraction (SAD) in transmission electron microscopy (TEM). From the position of the center of Laue circle (COLC) within the diffraction patterns the tilt angles of the investigated platelets relatively to a reference platelet (oriented in zone axis) are determined. The strong correlation of the platelets supports the existence of mineral bridges, which connect the stacked platelets and enable a transfer of the platelet orientation during growth. Electron tomography and subsequent reconstruction of the obtained data yield information about the shape of the mineral bridges. The crystalline structure of the material within the mineral bridges was investigated by high resolution TEM (HRTEM).

Nacre of the mollusc Haliotis laevigata was investigated using transmission electron microscopy (TEM). Nacre, the inner iridescent layer of mollusc shells, is a typical example for a material which is formed by biomineralization processes. It is composed of the CaCO3-polymorph aragonite and a small amount of about 5wt% organic matter [1]. The polygonal shaped aragonite platelets show a width which ranges from 5µm to 10µm and a thickness of about 500nm [2]. They are laterally arranged in layers and vertically in stacks. The aragonite crystal structure can be described by the space group Pmcn 62 with the c-axis perpendicular to the face of the platelets and thus to the surface of the shell [3]. The platelets are separated by layers of organic material, the organic matrix. This arrangement resembles a brick and mortar like structure. The combination of stiff crystalline material and soft organic material, as well as the layered structure increase the fracture toughness in comparison with pure (geological) aragonite.

* Forschungszentrum Karlsruhe, Institute for Nanotechnology, 76344 Eggenstein-Leopoldshafen, Germany ** Fraunhofer IFAM, Wiener Strase 12, 28355 Bremen, Germany *** University of Bremen, Institute of Biophysics, Otto-Hahn-Allee 1, 28359 Bremen, Germany **** The University of York, Department of Physics, Heslington, York YO10 5DD, United Kingdom ***** University of Bremen, Institute for Solid State Physics, Otto-Hahn-Allee 1, 28359 Bremen, Germany

Investigation of composition in InGaN quantum wells and quantum dots by TEM is hampered by formation of electron beam induced agglomeration of indium, which occurs if the specimen is exposed to the electron beam for a few minutes. In this contribution we demonstrate that compositional analysis of InGaN nanostructures is possible without this artifact if STEM Z-contrast imaging is applied instead of parallel beam illumination. The suggested method for composition analysis in InGaN is based on a comparison of intensity normalized with respect to the incident electron beam with simulated image intensity. Simulations are performed with the STEMsim program using the frozen lattice multislice approximation for which static atomic displacements were taken into account.