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Legume proteins are increasingly used in structuring various foods under the influence of heating and stirring energy. Based on available studies, this structuring potential is not yet fully understood. This raises the question of the suitability of legume isolates and concentrates for structuring in emulsion gels and the effect of heat and oil on the gel properties. In this study, soy- and pea-based suspensions and emulsions were prepared with the least gelling concentration using different oil concentrations (0%, 7.5%, 15%, 22.5%, and 30%). The viscoelastic properties were measured before and after heating cycles (65 °C and 95 °C). Scanning electron microscopy images complemented the results. All gels measured showed viscoelastic solid behavior. Thermal treatment showed a positive effect on the gel properties for most samples, especially for concentrates (reduction in the loss factor and networking factor > 1). The concentrates showed much higher networking factors and tighter cross-linking than the isolates. The rheological and microstructural properties of the emulsion gels are influenced by a number of factors, such as carbohydrate content, protein chemistry, the protein purification method, and initial viscosity. Moreover, the influence of oil on the rheological properties depends on the material used and whether oil droplets act as an active or inactive filler. [ABSTRACT FROM AUTHOR]

The success of an application programming interface (API) crucially depends on how well its documentation meets the information needs of software developers. Previous research suggests that these information needs have not been sufficiently understood. This article presents the results of a series of semistructured interviews and a follow-up questionnaire conducted to explore the learning goals and learning strategies of software developers, the information resources they turn to and the quality criteria they apply to API documentation. Our results show that developers initially try to form a global understanding regarding the overall purpose and main features of an API, but then adopt either a concepts-oriented or a code-oriented learning strategy that API documentation both needs to address. Our results also show that general quality criteria such as completeness and clarity are relevant to API documentation as well. Developing and maintaining API documentation therefore need to involve the expertise of communication professionals.

Electrical discharge machining (EDM) has demonstrated its promising potential for surface modification. The integration of materials from tool electrode or powder that is mixed into the dielectric fluid has proven to modify the workpiece surface to enhance its mechanical properties, realize antibacterial effects, or increase biocompatibility. Recent EDM studies showed that due to non-contact forces, properties of the modified surface such as roughness values and the thickness of modified layer were significantly influenced when using magnetic field assisted EDM. Consequently, in this study, an external magnetic field with a strength of 0.66 T is used to assist the material transfer from tool electrode to workpiece surfaces during the EDM process. Pure silver and copper tools with a diameter of 2 mm are used to modify surfaces of Ti6Al4V workpieces at a discharge energy of 125 µJ with different polarities. Results show that the assistance by magnetic field significantly increases the content of transferred material from tool electrode to the workpiece surface. Additionally, it increases material removal rate and reduces the modified layer thickness. Magnetic field assisted EDM is a potential technology for improving the efficacy of the EDM surface modification. [ABSTRACT FROM AUTHOR]

Powder mixed electrical discharge machining (PMEDM) with silver nano-powder has demonstrated its potential capability in antibacterial surface modification. Analyses in the cross-sectional layer showed that silver was mainly integrated near the topmost surface layer, and its content is reduced within the layer towards the substrate. However, to achieve a long-term antibacterial efficacy, silver needs to be deeply integrated in the modified layer. Previous studies indicated that ultrasonic vibration (UV) assisted PMEDM can homogenize the silver content in the deposited layer. In this study, the effect of UV on the silver distribution within the modified layer is investigated. Ti6Al4V workpieces were stimulated by UV with a frequency of 22.3 kHz and an amplitude of 2.5 µm. Hydrocarbon-based dielectric fluid, mixed with silver nano-powder with concentrations up to 15 g/L, were internally flushed through a hollow tool with a pressure of 4 bar. PMEDM without UV was investigated for comparison. The layer thickness, micro-cracks and the cross-sectional distribution of deposited silver were analysed by confocal microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Results indicate that applying UV leads to the highest silver content in the middle region of the layer, a significant decrease of micro-cracks and a slight reduction of the layer thickness. [ABSTRACT FROM AUTHOR]

The interlaminar strength of mechanically interlocked polymer-metal hybrids is strongly determined by the surface geometry at the interface. To improve the interlaminar strength, laser beam machining is among the most applied technologies for manufacturing a predefined and complex surface structure. Previously, the fractal dimension of interfaces in polymer-metal-hybrids has been introduced as scale-independent measure. It has been correlated quantitatively with the interlaminar strength using values derived from cross-sectional images. Therefore, the quality of the prediction directly depends on the accuracy of the measured surface data. However, a holistic acquisition of surface structure for the determination of the fractal dimension including 3D methods has not been investigated so far. In this study, laser machining was used to generate five different pin-structures on samples of the aluminum alloy EN AW-6082. Surface characterization was realized by light microscopy (2D), laser scanning microscopy (3D) and X-ray microscopy (3D). Subsequently, the fractal dimension was determined using a box-counting algorithm as well as slit-island method. The results show that all methods regarded are appropriate to determine the fractal dimension, but differ in the specific results. The functional characteristics of each method are described in detail and potentials for applications are outlined. [ABSTRACT FROM AUTHOR]

Polymer-metal hybrids are a lightweight solution for many industrial applications, especially in the automotive or aircraft sector. However, due to their poor chemical bonding the manufacturing of such compounds requires the use of adhesive layers or the conditioning of the metallic surface to achieve form closure and high joint strength. Ultrasonic Vibration Assisted Deformational Machining (UVADM) is a novel process that generates functional microstructures with high production rates, aiming to form defined burr structures with undercuts, that have a significant impact on the interlaminar strength of polymer-metal hybrids (PMH). A 3D FEM simulation using Abaqus/Explicit software was applied to design and analyze process conditions including tool geometry. Material deformation was described by the Johnson-Cook model. Simulation results were validated experimentally using two different MCD tools. For the UVADM experiments, specimens of the aluminum alloy EN AW-6082 were used. In the tests, a constant ultrasonic frequency (20.42 kHz), machining speed (100 m/min and 200 m/min), and peak-to-peak amplitude (7 µm) were used. Geometrical surface properties were analyzed by optical methods and SEM. The study demonstrates a conformity between simulated and experimental results, highlighting the potential of UVADM for an increased productivity in the surface conditioning for polymer-metal hybrids. [ABSTRACT FROM AUTHOR]

Ultrasonic vibration superimposed milling (UVSM) with an oscillating movement of the specimen in the direction of the tool axis is an efficient method for the generation of microstructured functional surfaces. The application of end milling cutters with a diameter smaller than the length and the width of the surface to be structured generally results in recuts and path overlaps. In order to avoid surface recutting, a small lead angle was realized by slightly tilting the ultrasonic system with the specimen. The overlapping area of two adjacent paths was kinematically simulated for different widths of cut (from 70% to 90% of the tool diameter). Cutting experiments were carried out by UVSM of X46Cr13 and X40CrMoV5-1 steel specimens to investigate the influence of the width of cut on the surface generated in the overlapping area and also the adherence of a subsequently deposited CVD diamond layer. For this purpose, 3-D laser scanning microscopy and SEM analysis were applied. The knowledge gained allows for designing UVSM processes, especially regarding 3-D freeform surfaces with defined microstructures subjected to CVD diamond coating. [ABSTRACT FROM AUTHOR]

In this article, the particle concentration of finely dispersed copper(II) oxide nanosuspensions as precursors for reductive laser sintering (RLS) is optimized on the basis of rheological investigations. For this metallization process, a smooth, homogeneous and defect-free precursor layer is a prerequisite for adherent and reproducible copper structures. The knowledge of the rheological properties of an ink is crucial for the selection of a suitable coating technology as well as for the adjustment of the ink formulation. Different dilutions of the nanosuspension were examined for their rheological behavior by recording flow curves. A strong shear thinning behavior was found and the viscosity decreases exponentially with increasing dilution. The viscoelastic behavior was investigated by a simulated doctor blade coating process using three-interval thixotropy tests. An overshoot in viscosity is observed, which decreases with increasing thinning of the precursor. As a comparison to these results, doctor blade coating of planar glass and polymer substrates was performed to prepare precursor layers for reductive laser sintering. Surface morphology measurements of the resulting coatings using laser scanning microscopy and rheological tests show that homogeneous precursor layers with constant thickness can be produced at a particle–solvent ratio of 1.33. A too-high particle content results in an irregular coating layer with deep grooves and a peak-to-valley height S z of up to 7.8 μm. Precise dilution control allows the fabrication of smooth surfaces with a S z down to 1.5 μm. [ABSTRACT FROM AUTHOR]