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Background: Up to 8% of the general population have a rare disease, however, for lack of ICD-10 codes for many rare diseases, this population cannot be generically identified in large medical datasets. We aimed to explore frequency-based rare diagnoses (FB-RDx) as a novel method exploring rare diseases by comparing characteristics and outcomes of inpatient populations with FB-RDx to those with rare diseases based on a previously published reference list. Methods: Retrospective, cross-sectional, nationwide, multicenter study including 830,114 adult inpatients. We used the national inpatient cohort dataset of the year 2018 provided by the Swiss Federal Statistical Office, which routinely collects data from all inpatients treated in any Swiss hospital. Exposure: FB-RDx, according to 10% of inpatients with the least frequent diagnoses (i.e.1.decile) vs. those with more frequent diagnoses (deciles 2–10). Results were compared to patients having 1 of 628 ICD-10 coded rare diseases. Primary outcome: In-hospital death. Secondary outcomes: 30-day readmission, admission to intensive care unit (ICU), length of stay, and ICU length of stay. Multivariable regression analyzed associations of FB-RDx and rare diseases with these outcomes. Results: 464,968 (56%) of patients were female, median age was 59 years (IQR: 40–74). Compared with patients in deciles 2–10, patients in the 1. were at increased risk of in-hospital death (OR 1.44; 95% CI: 1.38, 1.50), 30-day readmission (OR 1.29; 95% CI 1.25, 1.34), ICU admission (OR 1.50; 95% CI 1.46, 1.54), increased length of stay (Exp(B) 1.03; 95% CI 1.03, 1.04) and ICU length of stay (1.15; 95% CI 1.12, 1.18). ICD-10 based rare diseases groups showed similar results: in-hospital death (OR 1.82; 95% CI 1.75, 1.89), 30-day readmission (OR 1.37; 95% CI 1.32, 1.42), ICU admission (OR 1.40; 95% CI 1.36, 1.44) and increased length of stay (OR 1.07; 95% CI 1.07, 1.08) and ICU length of stay (OR 1.19; 95% CI 1.16, 1.22). Conclusion(s): This study suggests that FB-RDx may not only act as a surrogate for rare diseases but may also help to identify patients with rare disease more comprehensively. FB-RDx associate with in-hospital death, 30-day readmission, intensive care unit admission, and increased length of stay and intensive care unit length of stay, as has been reported for rare diseases. [ABSTRACT FROM AUTHOR]

In the present study, the crashworthiness and the numerical simulation of circular hybrid aluminium-CFRP tubes are investigated. It can be shown that hybrids provide significant lightweight potential. The specific energy absorption is 37% higher compared to a pure aluminium structure. The post-crash analysis is done by computed tomography methods. The failure of the hybrid component shows a mixture of energy absorption mechanisms of its pure materials. Hybrid-specific energy absorption mechanisms compensate the limited primary energy absorption mechanisms of the CFRP and metal components. The simulation of axial-loaded composite structures is challenging the currently available simulation methods. In the present work, a multi shell model is used for the simulation of the hybrid structure. This approach enables an efficient design of CFRP-aluminium hybrid components. First approaches towards the simulation of hybrid specific failure modes are given. [ABSTRACT FROM AUTHOR]

A parameter investigation for manufacturing a hybrid system through the prepreg pressing process was carried out within the scope of this work to achieve optimal adhesion properties. The hybrid specimen comprises an aluminium sheet of alloy EN AW 6082 in T6 condition and a thermoset Carbon Fibre Reinforced Plastics prepreg. The prepreg pressing process allows the curing reaction of epoxy resin and the joining process to occur simultaneously to avoid an additional bonding process step. The surface of the aluminium sheet was pretreated in advance using a pulsed Nd:YAG laser to enhance the bonding properties. In the first step, the shear edge tests investigated the adhesion properties achieved with different consolidation (temperature, time and pressure) and laser parameters. Then, 3-point bending tests were carried out to investigate the influence of the consolidation parameters on the mechanical properties of the Carbon Fibre Reinforced Plastics-laminate. In this way, the optimal parameter sets for manufacturing hybrid structures were determined. [ABSTRACT FROM AUTHOR]

The corrosion behavior of a hybrid laminate consisting of laser-structured aluminum EN AW-6082 ∪ carbon fiber-reinforced polymer was investigated. Specimens were corroded in aqueous NaCl electrolyte (0.1 mol/L) over a period of up to 31 days and characterized continuously by means of scanning electron and light microscopy, supplemented by energy dispersive X-ray spectroscopy. Comparative linear sweep voltammetry was employed on the first and seventh day of the corrosion experiment. The influence of different laser morphologies and production process parameters on corrosion behavior was compared. The corrosion reaction mainly arises from the aluminum component and shows distinct differences in long-term corrosion morphology between pure EN AW-6082 and the hybrid laminate. Compared to short-term investigations, a strong influence of galvanic corrosion on the interface is assumed. No distinct influences of different laser structuring and process parameters on the corrosion behavior were detected. Weight measurements suggest a continuous loss of mass attributed to the detachment of corrosion products. [ABSTRACT FROM AUTHOR]

To improve the mechanical performance and to address current shortcomings of adhesive bonds such as bond degradation due to aging, a pulsed laser surface pretreatment of the metal surfaces of aluminum AW 6082-T6 joints with epoxy adhesive E320 is investigated. The surface treatment of the specimens resulted in increased single-lap shear (SLS) strengths before and after hydrothermal aging in 80°C hot water compared to non-pretreated reference specimens. In order to reveal the correlations of laser parameters, resulting surface morphologies and the SLS strength, differently laser pretreated surfaces were characterized at the micro- and nanoscale using optical and scanning electron microscopies. The surface enlargement was quantified with a digital image analysis of cross-sections prepared from the joint interfaces. An analysis of variances (ANOVA) of the SLS results indicated that the laser parameters power and pulse frequency were most critical for obtaining high SLS strengths. Pretreated joint surfaces with a high micro- and nano-surface enlargement and deep solidification structures provide high SLS strengths of up to 50 MPa and almost negligible aging losses of merely 4%. Undercut structures on the pretreated surfaces were found to be beneficial for the mechanical and aging properties when only limited micro- and nanostructuring was applied. [ABSTRACT FROM AUTHOR]

• Different heating methods for separating hybrid compounds was investigated. • The process window are in the range of 275 °C to 400 °C with in 15 min. • Recycling concept for the separating of Hybrid Structure was developed. Currently, resource efficiency is getting more importance due to a build-up of disposed waste in landfills. The closed raw material cycle is an important topic in industries as it is economic and pollute free. This scenario applies to both existing and innovative future materials. To tackle the pollute emission of vehicles, multi–material and hybrid structures are gaining importance in lightweight construction. Hybrid structures that are a combination of metallic materials and carbon-fibre-reinforced plastics (CFRP) are often used for lightweight structures. In the present work, a method is presented that can separate hybrid structures (metal and CFRP) using thermal process so that they can be recycled separately. The thermal process was investigated with the help of different heating techniques such as the furnace, induction, resistance, and infrared on the hybrid structures. Corresponding process windows and the boundary conditions for respective heating techniques are investigated in the current work. The influence of various heating techniques on the separation process is validated using microscopic results. [ABSTRACT FROM AUTHOR]

Materially bonded hybrid systems with precisely adjusted interfacial properties are of great scientific and industrial interest with regard to lightweight construction. In the present study, a material composite of carbon fiber reinforced plastic (CFRP) and galvanized steel is considered, where the metallic surface is laser structured in order to improve the adhesion properties. The resulting joining properties will be elicited by tensile shear tests in comparison to an alkaline cleaned surface condition and blind riveting. The potential of direct-joined hybrid systems with laser-structured substrate surfaces will also be considered using an automotive roof frame as an example. In the tensile shear test, the direct-joined hybrid joint with laser-structured metal substrate achieves significantly higher joint strengths than after alkaline cleaning. Compared to an aluminum/steel reference structure, the CFRP/steel roof frame exhibits a significant weight advantage with superior mechanical properties under flexural and compressive loading. [ABSTRACT FROM AUTHOR]

In this paper, a prospective simulation method for composite crushing under axial crash loading is presented. To this end carbon fibre-reinforced plastic (CFRP) circular crash tubes are investigated in drop tower tests. Flat specimen tests are performed to determine calibration parameters and are used for efficient re-parameterization of a transversally isotropic material card used in finite element (FE) simulation. An existing material card for CFRP based on basic tension and compression tests is used as a starting point and only a small set of material parameters is numerically reasonable adjusted to account for crushing. Once calibrated by means of flat specimens the material model is able to cover a variety of different composite layups and specimen geometries, e.g. tube specimens. Therefore, numerical simulation of drop tower testing is carried out and results show good agreement between numerical and experimental results. In addition to these tests, it can be shown that the presented approach is leading to equally good results when the material and geometry of the specimens are changed to a glass fibre-reinforced plastic (GFRP) tube structure. [ABSTRACT FROM AUTHOR]

Lightweight design is a common approach to reduce energy demand in the use stage of vehicles. The production of lightweight materials is usually associated with an increase in energy demand, so the environmental impacts of lightweight structures need to be assessed holistically using a life cycle assessment. To estimate the life cycle environmental impacts of a product in its developmental stage, for example, by life cycle engineering, future changes in relevant influencing factors must be considered. Prospective life cycle assessment provides methods for integrating future scenarios into life cycle assessment studies. However, approaches for integrating prospective life cycle assessment into product development are limited. The objective of this work is to provide the methodological foundation for integrating future scenarios of relevant influencing factors in the development of lightweight structures. The applicability of the novel methodology is demonstrated by a case study of a structural component in a steel, aluminium, and hybrid design. The results show that appropriate decarbonisation measures can reduce the life cycle greenhouse gas emissions by up to 95 percent until 2050. We also found that shifts in the environmentally optimal design are possible in future scenarios. Therefore, the methodology and data provided contribute to improved decision-making in product development. [ABSTRACT FROM AUTHOR]

In this study, nanocrystalline ZnO (NC ZnO) films are considered as interface layers for polymer/metal bonds consisting of hot-dip galvanised steel (HDG) and epoxy resin. NC ZnO films with a thickness of less than one micrometre were deposited on HDG through hydrothermal deposition from aqueous Zn nitrate/hexamethylenetetramine electrolytes. Furthermore, 3-aminopropylphosphonic acid (APPA) and 3-aminopropyltriethoxysilane (γ-APS) were considered for molecular adhesion-promoting layers. 90°-peel tests of water-saturated epoxy films confirm the improvement of bond strength under humid environments. Electrochemical properties of the thin film coatings analysed by current density potential curves indicate effective inhibition of oxygen reduction and metal alloy dissolution. Scanning Kelvin probe (SKP) measurements confirm that the corrosive delamination of the polymer from the metal substrate is significantly slowed down by the considered surface modifications. The combination of NC ZnO films with APPA as an adhesion promoting molecule showed the best performances. [ABSTRACT FROM AUTHOR]

Heat-assisted forming processes are becoming increasingly important in the manufacturing of sheet metal parts for body-in-white applications. However, the non-isothermal nature of these processes leads to challenges in evaluating the forming limits, since established methods such as Forming Limit Curves (FLCs) only allow the assessment of critical forming strains for steady temperatures. For this reason, a temperature-dependent extension of the well-established GISSMO (Generalized Incremental Stress State Dependent Damage Model) fracture indicator framework is developed by the authors to predict forming failures under non-isothermal conditions. In this paper, a general approach to combine several isothermal FLCs within the temperature-extended GISSMO model into a temperature-dependent forming limit surface is investigated. The general capabilities of the model are tested in a coupled thermo-mechanical FEA using the example of warm forming of an AA5182-O sheet metal cross-die cup. The obtained results are then compared with state of the art of evaluation methods. By taking the strain and temperature path into account, GISSMO predicts greater drawing depths by up to 20 % than established methods. In this way the forming and so the lightweight potential of sheet metal parts can by fully exploited. Moreover, the risk and locus of failure can be evaluated directly on the part geometry by a contour plot. An additional advantage of the GISSMO model is the applicability for low triaxialities as well as the possibility to predict the materials behavior beyond necking up to ductile fracture. [ABSTRACT FROM AUTHOR]

Automotive lightweight design is a considerable measure to meet the worldwide need for reducing CO 2 emissions. However, the lightweight potential of common materials like high strength steels or aluminium is limited. Hybrid materials allow to combine metals and CFRP in a manner to offset the drawbacks of every single material and reach an optimum of mechanical properties (Wang et al., 2016). Nonetheless, an essential shortcoming of hybrids are thermally induced residual stresses after cooling down from moulding temperature, driven by varying coefficients of thermal expansion and chemical shrinkage of the FRP. For a reliable prediction of the residual stress evolution in hybrid-structures during curing and after cooling down, a numerical homogenization technique of representative unit cells is proposed to calculate effective cure-dependent properties. Starting from a heterogeneous microstructure, a thermo-chemical-mechanical constitutive model for the curing process of the epoxy resin is presented and applied to two representative volume elements (RVE). The transition between the micro- and macro-scale is done by using a numerical homogenization framework. The effective cure-dependent properties predicted by the homogenization are used to simulate the curing-process and analyses the residual stresses of a metal-CFRP plate. The results are compared with experimental data obtained by the incremental hole drilling measurement. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, the issues of environmental protection as well as energy and resource efficiency become of increasing importance. Especially in the automotive industry, the effort to realize an efficient manufacturing of lightweight structures is immense. Thereby a current trend is the fabrication of hybrid structures by using innovative procedures. As a consequence, the generation of a strong and durable connection between dissimilar materials is the toughest challenge. In this study, the influence of a laser based nano-structuring on the shear strength of hybrid structures out of carbon fibre reinforced plastics (CFRP) and micro-alloyed steel (1.0548) fabricated by a Vacuum Assisted Resin Transfer Molding (VARTM) process is presented. Furthermore, the failure behaviour is analysed. The exact stress distribution in the overlap area is investigated by using a Finite Element (FE) analysis. To this end, the input data for the interface are based on the results of butt bonded hollow cylinder-tests. [ABSTRACT FROM AUTHOR]

Selective laser melting (SLM) is an additive manufacturing process allowing for the production of metallic high performance materials and components with complex geometries. Therefore, possible applications are direct production of casting molds, tools or turbine blades with internal cooling channels for an optimized cooling efficiency. A disadvantage of the technology is the process-inherent surface roughness, which is critical especially under fatigue loading conditions. Since internal surfaces often cannot be smoothened due to limited accessibility, the objective of this study is to assess the fatigue properties of Ti-6Al-4V samples designed with internal axial channels featuring a rough as-built surface. Samples with various diameters and numbers of channels have been tested not always exhibiting a deterioration of the fatigue performance compared to solid samples. Subsequent fractography by scanning electron microscopy revealed distinct failure mechanisms. Besides the fatigue crack initiation on features of the unmodified internal surfaces, residual porosity in the bulk, i.e. lack-of-fusion defects, keyhole defects and gas pores, respectively, could be identified as crack origin. Relatively low scatter of fatigue lives found is attributed to rapid crack initiation and, thus, the dominant influence of the (micro-) crack growth regime. [ABSTRACT FROM AUTHOR]

In the scope of the present study, microstructural and mechanical characterizations of duplex stainless steel UNS S31803 processed by selective laser melting (SLM) are conducted. The findings shed light on the phase arrangement evolving in the as-built condition and in several heat-treated conditions. In the as-built condition, austenite formation is almost suppressed due to process-related high cooling rates. Therefore, several heat treatments ranging from 900 °C to 1200 °C for 5 min each were performed in order to adjust to the desired austenitic-ferritic microstructure. Results generated by transmission electron microscopy (TEM) reveal a high dislocation density induced during SLM fabrication, such that a recrystallized microstructure prevails after the heat treatment. Tensile tests display the severe impact of the heat treatment on the resulting mechanical response. The nearly complete ferritic as-built specimens obtain a higher ultimate tensile strength and a reduced elongation at fracture compared to the heat-treated specimens. [ABSTRACT FROM AUTHOR]

[Display omitted] The corrosion behavior of a hybrid material consisting of intrinsically bonded carbon fiber-reinforced epoxy resin with laser-structured EN AW 6082 metal was investigated. Particular attention was paid to the effects of the laser-structuring, surface topography and the contacting. Pristine and hybridized specimens were corroded in aqueous NaCl electrolyte (0.1 mol/l) using a potentiodynamic polarization technique and subsequently analyzed using computed tomography, scanning electron-, light- and laser scanning microscopy. The results show that the corrosive reaction arises mainly from the aluminum component. Surface pretreatment of the aluminum resulted in increasing corrosion rates, but showed no influence on the hybrids corrosion properties. Optical micrographs suggest that the epoxy resin acts as a sealant preventing galvanic corrosion between the aluminum and carbon fibers by hindering the diffusion of the electrolyte into the joints. While corrosion effects were observed locally at the aluminum surface, they were, contrary to expectations, not enhanced on the hybrid interfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • Slit formation is controlled by slit dimensions in CAD model and down-skin parameters. • μCT is suitable technique for analysis of slit formation in as-built parts. • Slits in soft-magnetic iron-silicon alloys reduce power loss during magnetization. Laser beam melting of rotors of soft-magnetic iron-silicon-based alloys with a graded cross-section promises a significant reduction of power losses during the operation of electric motors. In this work, graded cross-sections are designed with slits at different positions. The novel approach to design and implement the graded cross-section in laser beam melted FeSi3 alloy is presented. It is based on an interaction between initial slit thickness defined in the CAD-model and down skin parameters, i.e. laser power and the number of layers processed with down-skin parameters. This approach allows precisely to influence the resulting slit geometry, i.e. porous or continuous gaps filled with unmolten powder, and their thickness. The effect of both, the slit geometry and their position in ring specimens on the power losses during magnetization and demagnetization at different frequencies is analyzed and discussed. The obtained results reveal the significance of proper design and accurate control of the slit geometry in parts with graded cross-section. As it is shown, cross-sections with slits designed as continuous gaps result in a reduction of up to 43 % regarding the power losses in comparison to the bulk cross-section. Thus, the presented method for grading the cross-section can be relatively simply implemented in the design and manufacturing process of laser beam-melted rotors and allows to improve their performance in comparison with bulk AM rotors. [ABSTRACT FROM AUTHOR]