Further Developments in Process Mapping and Modelling in Direct Metal Selective Laser Melting

This paper advances previous reported work on the mapping and modelling of single tracks and layers produced in powder beds of tool steel and stainless steel powders by a CO2 laser. For single tracks it reports on predicted and simulated track masses. It validates the simulations, including the use of absorption close to 1.0 when cylindrical tracks are formed. It also reports on melt pool temperature calculations and estimated melt pool dimensions which are used, in conjunction with bed physical properties, to explain why the single tracks form as either continuous with a crescent shape cross-section, continuous with an elliptical section, discontinuously irregularly broken, discontinuously balled or only partially melted as scan speeds and laser powers change. It then extends its scope, experimentally, to consider effects of scan spacing on single layer formation.Mechanical Engineerin

In situ synthesis of size-controlled, stable silver nanoparticles within ultrashort peptide hydrogels and their anti-bacterial properties

We have developed a silver-releasing biomaterial with promising potential for wound healing applications. The material is made of ultrashort peptides which can self-assemble in water to form hydrogels. Silver nanoparticles (Ag NPs) were synthesized in situ within the biomaterial, using only UV irradiation and no additional chemical reducing agents. The synthetic strategy allows precise control of the nanoparticle size, with the network of peptide fibers preventing aggregation of Ag NPs. The biomaterial shows increased mechanical strength compared to the hydrogel control. We observed a sustained release of Ag NPs over a period of 14 days. This is a crucial prerequisite for effective anti-bacterial therapy. The ability to inhibit bacterial growth was tested using different bacterial strains, namely gram-negative Escherichia coli and Pseudomonas aeruginosa and gram-positive Staphylococcus aureus. Inhibition of bacterial growth was observed for all strains. The best results were obtained for Pseudomonas aeruginosa which is known for exhibiting multidrug resistance. Biocompatibility studies on HDFa cells, using Ag NP-containing hydrogels, did not show any significant influence on cell viability. We propose this silver-releasing hydrogel as an excellent biomaterial with great potential for applications in wound healing due to its low silver content, sustained silver nanoparticle release and biocompatibility

Charge storage effects in Mylar resulting from electron irradiation, June 1965 - June 1966

Charge storage effects in Mylar from electron irradiatio

Shame and Resilience Among Mental Health Trainees: A Scale Construction Study

Contemporary research has revitalized interest in the construct of shame, and the pervasive nature with which it impacts psychological functioning. It has been argued that mental health professionals encounter shame regularly in the therapeutic milieu and must be equipped to assist clients in developing shame resilience. The process of learning to provide shame attendant therapy begins during graduate training, as mental health trainees (MHTs) gain first hand experience with feeling shame through the evaluative nature of the training process. Although shame in the MHT role has been discussed in prior literature, it is difficult to study due to lacking instrumentation. Therefore, the purpose of this study was to construct a quantitative instrument for measuring shame and shame resilience among graduate students in mental health training. Using a mixed methods approach, this study included item generation, exploratory factor analysis, and validity estimates with previously published scales. The result is the Shame and Resilience Among Mental Health Trainees Scale (SRMHT), a four-factor, scenario-based instrument, that measures shame proneness as well as shame resilience. The SRMHT demonstrated strong internal consistency reliability and construct validity, and produced a factor structure that closely aligns with the tenets of shame resilience theory. Overall, this study provides support for prior research and theory, while generating a novel tool for use in mental health trainee development. Advisor: M. Meghan Davidso

Growth control of GaAs nanowires using pulsed laser deposition with arsenic over pressure

Using pulsed laser ablation with arsenic over pressure, the growth conditions for GaAs nanowires have been systematically investigated and optimized. Arsenic over pressure with As$_2$ molecules was introduced to the system by thermal decomposition of polycrystalline GaAs to control the stoichiometry and shape of the nanowires during growth. GaAs nanowires exhibit a variety of geometries under varying arsenic over pressure, which can be understood by different growth processes via vapor-liquid-solid mechanism. Single-crystal GaAs nanowires with uniform diameter, lengths over 20 $\mu$m, and thin surface oxide layer were obtained and can potentially be used for further electronic characterization

The large scale gas and dust distribution in the galaxy: Implications for star formation

Infrared Astronomy Observations are presented for the diffuse infrared (IR) emissions from the galactic plane at wavelengths of 60 and 100 microns and the total far infrared intensity and its longitudinal variations in the disk were derived. Using available CO, 5 GHz radio-continuum, and HI data, the IR luminosity per hydrogen mass and the ingrared excess (IRE) ratio in the Galaxy were derived. The longitudinal profiles of the 60 and 100 micron emission were linearly decomposed into three components that are associated with molecular (H2), neutral (HI), and ionized (HII) phases in the interstellar medium (ISM), and the relevant dust properties were derived in each phase. Implications of the findings for various models of the diffuse IR emisison and for star formation in the galactic disk are discussed

Maximal multihomogeneity of algebraic hypersurface singularities

From the degree zero part of logarithmic vector fields along an algebraic hypersurface singularity we indentify the maximal multihomogeneity of a defining equation in form of a maximal algebraic torus in the embedded automorphism group. We show that all such maximal tori are conjugate and in one-to-one correspondence to maxmimal tori in the degree zero jet of the embedded automorphism group. The result is motivated by Kyoji Saito's characterization of quasihomogeneity for isolated hypersurface singularities and extends its formal version and a result of Hauser and Mueller.Comment: 5 page

Rasch-progrediente Glomerulonephritis: Bewährte und neuere Therapieansätze

Zusammenfassung: Die rapid progrediente Glomerulonephritis (RPGN) ist als klinisches Syndrom durch die zeitliche Veränderung der Nierenfunktion definiert. Frühes Erkennen und sofortige immunsuppressive Behandlung verbessern die Prognose. Die Nierenbiopsie und die Autoantikörperserologie ermöglichen die genaue diagnostische Zuordnung der RPGN. Es werden ihre Einteilung aufgrund der Immunhistologie, der antineutrophil zytoplasmatische Antikörper (ANCA) und der antiglomerulären Basalmembran-Antikörper (anti-GBM) diskutiert. Anhand von Ergebnissen randomisiert kontrollierter Studien werden die Möglichkeiten der differenzierten Behandlung erläuter