Effect of Free-Edges on Melt Pool Geometry and Solidification Microstructure in Beam-Based Fabrication of Bulky 3-D Structures

The success of laser and electron beam-based fabrication processes for additive manufacture and repair applications requires the ability to control melt pool geometry while still maintaining a consistent and desirable microstructure. To this end, previous work by the authors has employed point heat source solutions to investigate the effects of process variables (beam power and velocity) on melt pool geometry and solidification microstructure (grain size and morphology) in beam-based fabrication of bulky 3-D structures. However, these results were limited to steady-state conditions away from free-edges. The current work extends the approach to investigate transient behavior in the vicinity of free-edges, and follows the authors’ recent work for 2-D thin-wall geometries [1].Mechanical Engineerin

Effect on Free-Edges on Melt Pool Geometry and Solidification Microstructure in Beam-Based Fabrication of Thin-Wall Structures

The success of both laser and electron beam-based fabrication processes for additive manufacturing and repair applications requires the ability to control melt pool geometry while still maintaining a consistent and desirable microstructure. To this end, previous work by the authors has employed point-heat source solutions to investigate the effects of process variables (beam power and velocity) on melt pool geometry and solidification microstructure (grain size and morphology) in beam-based fabrication of thin-wall structures. However, these results were limited to steady-state conditions away from free-edges. The current work extends the approach to investigate transient behavior in the vicinity of a free-edge.Mechanical Engineerin

Discharge Teaching, Readiness for Discharge, and Post-discharge Outcomes in Parents of Hospitalized Children

Purpose This study explored the sequential relationships of parent perceptions of the quality of their discharge teaching and nurse and parent perceptions of discharge readiness to post-discharge outcomes (parental post-discharge coping difficulty, readmission and emergency department visits). Design/methods In this secondary analysis of data from a longitudinal pilot study of family self-management discharge preparation, the correlational design used regression modeling with data from a convenience sample of 194 parents from two clinical units at a Midwest pediatric hospital. Data were collected on the day of discharge (Quality of Discharge Teaching Scale; Readiness for Hospital Discharge Scale), at 3 weeks post-discharge (Post-Discharge Coping Difficulty Scale), and from electronic records (readmission, ED visits). Results Parent-reported quality of discharge teaching delivery (the way nurses teach), but not the amount of content, was positively associated with parent perception (B = 0.54) and nurse assessment (B = 0.16) of discharge readiness. Parent-reported discharge readiness was negatively associated with post-discharge coping difficulty (B = − 0.52). Nurse assessment of discharge readiness was negatively associated with readmission; a one point increase in readiness (on a 10 point scale) decreased the likelihood of readmission by 52%. Conclusion There is a sequential effect of quality of discharge teaching delivery on parent discharge readiness, which is associated with parent coping difficulty and child readmission. Practice Implications Efforts to improve discharge outcomes should include strategies to build nurse teaching skills for high-quality delivery of discharge teaching. In addition, routine nurse assessment of discharge readiness can be used to identify children at risk for readmission and trigger anticipatory interventions

Gain in Three-Dimensional Metamaterials utilizing Semiconductor Quantum Structures

We demonstrate gain in a three-dimensional metal/semiconductor metamaterial by the integration of optically active semiconductor quantum structures. The rolling-up of a metallic structure on top of strained semiconductor layers containing a quantum well allows us to achieve a three-dimensional superlattice consisting of alternating layers of lossy metallic and amplifying gain material. We show that the transmission through the superlattice can be enhanced by exciting the quantum well optically under both pulsed or continuous wave excitation. This points out that our structures can be used as a starting point for arbitrary three-dimensional metamaterials including gain

The transfer rate of Salmonella Typhimurium from contaminated parsley to other consecutively chopped batches via cutting boards under different food handling scenarios

publisher: Elsevier articletitle: The transfer rate of Salmonella Typhimurium from contaminated parsley to other consecutively chopped batches via cutting boards under different food handling scenarios journaltitle: Food Research International articlelink: http://dx.doi.org/10.1016/j.foodres.2016.09.001 content_type: article copyright: © 2016 Elsevier Ltd. All rights reserved

Investigating a link of two different types of food business management to the food safety knowledge, attitudes and practices of food handlers in Beirut, Lebanon

Although Lebanon has a flourishing traditional and modern food businesses, which are typical both Middle Eastern (ME) and Mediterranean cuisines, knowledge and practice of food safety performance of the food service sector are limited in the whole ME region and lacking in Lebanon. To address this, a survey was conducted in Beirut to evaluate the knowledge, attitudes and practices related to food safety issues of food handlers (n = 80) in food service establishments (n = 50) and to assess the influence of management type on enactment of safe practices on food premises. Our data suggest that while respondents have limited knowledge of some aspects of food safety, substantial gaps in their knowledge and self-reported practices associated with critical temperature of foods and cross contamination remain, therefore posing health risks to consumer health. Food handlers in corporatemanaged food outlets showed a significantly higher awareness on food safe practices. It is concluded that the management type is an integral element of TPB (Theory of Planned Behaviour) that influence food handlers' practices and substantiate the need for more research work on safe food handling in the context of food safety culture framework in food businesses. Our data revealed the critical need for food safety education interventions and technical guidance fostered by synergistic participation of the private and public sector to support food handlers in SME's (small and medium sized enterprises)

Allosteric inhibition of carnosinase (CN1) by inducing a conformational shift

In humans, low serum carnosinase (CN1) activity protects patients with type 2 diabetes from diabetic nephropathy. We now characterized the interaction of thiol-containing compounds with CN1 cysteine residue at position 102, which is important for CN1 activity. Reduced glutathione (GSH), N-acetylcysteine and cysteine (3.2 \uc2\ub1 0.4, 2.0 \uc2\ub1 0.3, 1.6 \uc2\ub1 0.2 \uc2\ub5mol/mg/h/mM; p <.05) lowered dose-dependently recombinant CN1 (rCN1) efficiency (5.2 \uc2\ub1 0.2 \uc2\ub5mol/mg/h/mM) and normalized increased CN1 activity renal tissue samples of diabetic mice. Inhibition was allosteric. Substitution of rCN1 cysteine residues at position 102 (Mut1C102S) and 229 (Mut2C229S) revealed that only cysteine-102 is influenced by cysteinylation. Molecular dynamic simulation confirmed a conformational rearrangement of negatively charged residues surrounding the zinc ions causing a partial shift of the carnosine ammonium head and resulting in a less effective pose of the substrate within the catalytic cavity and decreased activity. Cysteine-compounds influence the dynamic behaviour of CN1 and therefore present a promising option for the treatment of diabetes