FE calculations on a three stage metal forming process of Sandvik Nanoflex

Sandvik NanoflexTM combines good corrosion resistance with high strength. This steel has good deformability in\ud austenitic conditions. It belongs to the group of metastable austenites, which means that during deformation a strain-induced\ud transformation into martensite takes place. After deformation, transformation continues as a result of internal stresses. Both\ud transformations are stress-state and temperature dependent. A constitutive model for this steel has been formulated, based\ud on the macroscopic material behaviour measured by inductive measurements. Both the stress-assisted and the strain-induced\ud transformation into martensite have been incorporated in this model. Path-dependent work hardening has also been taken\ud into account. This article describes how the model is implemented in an internal Philips FE code called CRYSTAL, which is\ud a dedicated robust and accurate finite element solver. The implementation is based on lookup tables in combination with\ud feed-forward neural networks. The radial return method is used to determine the material state during and after plastic\ud flow, however, it has been extended to cope with the stiff character of the partial differential equation that describes the\ud transformation behaviour

Preparation, testing, and delivery of low density polyimide foam panels

Plastic foams based on polyimide resins were shown to be stable at relatively high temperatures, and to possess very low flame spread and smoke generation characteristics. A system and process were developed to prepare low-density polyimide foam from a liquid formulation. The system is based on the reaction of micropulverized grade pyromellitic dianhydride with a polymeric diisocyanate. The panels produced were postcured at elevated temperatures to achieve maximum thermal and fire resistance, and incorporation of a fire retardant into the formulation was considered. The effects of a flame retardant (Flameout 5600B1) were investigated, but eliminated in preference to the postcuring approach

Testing for Stochastic Dominance Efficiency

We propose a new test of the stochastic dominance efficiency of a given portfolio over a class of portfolios. We establish its null and alternative asymptotic properties, and define a method for consistently estimating critical values. We present some numerical evidence that our tests work well in moderate sized samples

From Letters to Logistics - The enabling role of a lean transformation programme in a national postal service: The case of An Post, Ireland

From Letters to Logistics - The enabling role of a lean transformation programme in a national postal service: The case of An Post, Ireland Seamus O’Reilly (Cork University Business School), David Murray (An Post) and Joe Aherne (Leading Edge Group) Abstract Purpose This paper investigates the role of a lean transformation programme in supporting the transition of a national postal (mail) service from a traditional letter delivery service to a competitive parcel delivery service. Methodology Given the objective an intrinsic case study (Stake, 2005) approach was adopted, as this specific case was of interest. To support this approach the researchers had access to a range of data sources including, archives (e.g. strategy documents), reports (e.g. project reports and outputs), and access to management involved in the transformation programme. Findings The findings highlight the fundamental role of leadership, at all levels, and organisational culture in supporting a LSS transformation programme. The balance between dedicated experts and larger projects on one hand and wider engagement throughout the organisation on the other hand was instrumental to embedding an LSS culture. In this regard frontline managers had a key role to play. Limitations As with any case study research we must be careful when generalising the findings. Furthermore, given the relatively recent strategy deployment within the case organisation, further follow-up studies are required to establish the sustainability of the culture change and benefits achieved. Originality On the basis of a systematic literature review, Danese et al. (2018) call for exploratory case studies/action research to better understand how lean could be implemented in public sector. This intrinsic case approach adopted responds to this. Practical Implications The study links research and practice through assessment of the organisational journey and consideration of the findings in the context of success factors identified in the literature. Management behaviour and practices at all levels were fundamental to achieving a LSS transformation culture, including ‘go and see’ for senior management and active daily huddles facilitated by frontline management. Key Words: Lean Six Sigma, Public Sector, Service Sector, National Mail Service

A general approximation of quantum graph vertex couplings by scaled Schroedinger operators on thin branched manifolds

We demonstrate that any self-adjoint coupling in a quantum graph vertex can be approximated by a family of magnetic Schroedinger operators on a tubular network built over the graph. If such a manifold has a boundary, Neumann conditions are imposed at it. The procedure involves a local change of graph topology in the vicinity of the vertex; the approximation scheme constructed on the graph is subsequently `lifted' to the manifold. For the corresponding operator a norm-resolvent convergence is proved, with the natural identification map, as the tube diameters tend to zero.Comment: 19 pages, one figure; introduction amended and some references added, to appear in CM

Merging fragments of classical logic

We investigate the possibility of extending the non-functionally complete logic of a collection of Boolean connectives by the addition of further Boolean connectives that make the resulting set of connectives functionally complete. More precisely, we will be interested in checking whether an axiomatization for Classical Propositional Logic may be produced by merging Hilbert-style calculi for two disjoint incomplete fragments of it. We will prove that the answer to that problem is a negative one, unless one of the components includes only top-like connectives.Comment: submitted to FroCoS 201

The Effect of Pulmonary Infection (Actinobacillus Pleuropneumoniae), Endotoxin and Dexamethasone on Enrofloxacin Pharmacokinetic Parameters in Swine.

Efficacy studies are often done on diseased animals while pharmacokinetic studies are done on healthy animals. Disease models are inherently difficult to standardize because of the many variables associated with measuring pharmacokinetic parameters in abnormal animals. Information derived from pharmacokinetic studies with diseased animals could be useful to determine if therapeutic doses of a drug or antimicrobial becomes less effective or toxic due to changes in distribution and clearance. The objectives of this study were to: characterize a pulmonary infection model in swine using Actinobacillus pleuropneumoniae; evaluate the pharmacokinetic changes associated with the pulmonary infection model and dexamethasone after the infusion of enrofloxacin and urine enrofloxacin and ciprofloxacin concentrations; and the comparison endotoxin administration and dexamethasone to the pharmacokinetic changes of the infection model. In the infection study, infected pigs became ill within two hours of inoculation and had microscopic lesions of necrotizing, fibrinopurulent pneumonia consistent with Actinobacillus pleuropneumoniae infection; plasma interleukin-6 was slightly elevated in the infected pigs and not the dexamethasone pigs; clearance of enrofloxacin was increased in the dexamethasone treated pigs; volume of distribution of the elimination phase and at steady state were decreased in the infection; and the urine enrofloxacin/creatinine ratios were decreased in the dexamethasone treated pigs. In the endotoxin study, the endotoxin treated pigs exhibited toxic signs within 30 minutes; the plasma interleukin-6 concentrations were markedly elevated in the endotoxin treated pigs; the dexamethasone treated pigs showed an increased clearance of enrofloxacin; volumes of distribution was increased in the dexamethasone treated pigs; the urine enrofloxacin/creatinine ratios were elevated in the endotoxin group compared to control, dexamethasone and endotoxin-dexamethasone groups while the ciprofloxacin/creatinine ratios in the endotoxin group was elevated and the dexamethasone treated pigs had elevated urine ciprofloxacin/creatinine ratio at 24 h but decreased at 48 and 72 h. These results show that the infection model was reliable, infection had no effect on enrofloxacin distribution and clearance, dexamethasone concurrent administration with enrofloxacin may reduce efficacy because of increased clearance and the comparison of the endotoxin model compared to the infection model gave incongruous results

Renal health after long-term exposure to tenofovir disoproxil fumarate (TDF) in HIV/HBV positive adults in Ghana

Objectives: The study assessed markers of renal health in HIV/HBV co-infected patients receiving TDF- containing antiretroviral therapy in Ghana. Methods: Urinary protein-to-creatinine ratio (uPCR) and albumin-to-protein ratio (uAPR) were measured cross-sectionally after a median of four years of TDF. At this time, alongside extensive laboratory testing, patients underwent evaluation of liver stiffness and blood pressure. The estimated glomerular filtration rate (eGFR) was measured longitudinally before and during TDF therapy. Results: Among 101 participants (66% women, median age 44 years, median CD4 count 572 cells/mm 3 ) 21% and 17% had detectable HIV-1 RNA and HBV DNA, respectively. Overall 35% showed hypertension, 6% diabetes, 7% liver stiffness indicative of cirrhosis, and 18% urinary excretion of Schistosoma antigen. Tubular proteinuria occurred in 16% of patients and was independently predicted by female gender and hypertension. The eGFR declined by median 1.8 ml/min/year during TDF exposure (IQR −4.4, −0.0); more pronounced declines ( ≥5 ml/min/year) occurred in 22% of patients and were associated with receiv-ing ritonavir-boosted lopinavir rather than efavirenz. HBV DNA, HBeAg, transaminases, and liver stiffness were not predictive of renal function abnormalities. Conclusions: The findings mandate improved diagnosis and management of hypertension and suggest targeted laboratory monitoring of patients receiving TDF alongside a booster in sub-Saharan Africa