A systematic approach to atomicity decomposition in Event-B

Event-B is a state-based formal method that supports a refinement process in which an abstract model is elaborated towards an implementation in a step-wise manner. One weakness of Event-B is that control flow between events is typically modelled implicitly via variables and event guards. While this fits well with Event-B refinement, it can make models involving sequencing of events more difficult to specify and understand than if control flow was explicitly specified. New events may be introduced in Event-B refinement and these are often used to decompose the atomicity of an abstract event into a series of steps. A second weakness of Event-B is that there is no explicit link between such new events that represent a step in the decomposition of atomicity and the abstract event to which they contribute. To address these weaknesses, atomicity decomposition diagrams support the explicit modelling of control flow and refinement relationships for new events. In previous work,the atomicity decomposition approach has been evaluated manually in the development of two large case studies, a multi media protocol and a spacecraft sub-system. The evaluation results helped us to develop a systematic definition of the atomicity decomposition approach, and to develop a tool supporting the approach. In this paper we outline this systematic definition of the approach, the tool that supports it and evaluate the contribution that the tool makes

Tensile Properties of Angle Cured Laminated Composites Structures under Gravity Effects

As the usage of composites materials are significant in the industries of automobiles,shipping and constructions due to their non-corrosive and high strength to weight ratio. Anyway, the production of composites needed to be increased to meet the demand. At this stage, problem faced by Small and Medium Industries / Entrepreneurs (SMI/E) is the confined and limited space available that restricts the optimum productivity. They commonly cure the composites horizontally that requires ample space and unable to afford for high-end equipment such as mechanical oven and autoclave in the production as a result of high capital cost.This research is carried out to study the feasibility of the gravity effects on curing position of the laminated composite structures to enhance the curing space needed. The aim of the research was to investigate the tensile properties of the thermosetting laminated composite by curing the laminate at different angle using vacuum bagging technique. From the testing, SN 5 which denominated to be 60˚ found to have the best tensile properties in term of maximum force exerted and Young’s modulus

Refining Nodes and Edges of State Machines

State machines are hierarchical automata that are widely used to structure complex behavioural specifications. We develop two notions of refinement of state machines, node refinement and edge refinement. We compare the two notions by means of examples and argue that, by adopting simple conventions, they can be combined into one method of refinement. In the combined method, node refinement can be used to develop architectural aspects of a model and edge refinement to develop algorithmic aspects. The two notions of refinement are grounded in previous work. Event-B is used as the foundation for our refinement theory and UML-B state machine refinement influences the style of node refinement. Hence we propose a method with direct proof of state machine refinement avoiding the detour via Event-B that is needed by UML-B

Crystal Structure of Nd1.2FeO3 Oxide Material and Its Rietveld Refinement Analysis

The crystal structure of Nd1.2FeO3 oxide material synthesized by varying calcination temperatures was determined using the X-ray diffraction method. Further analysis by Rietveld refinement using software Rietica showed that all of the samples have an orthorhombic phase structure. The lattice constants of each a sample with variation of calcination temperature is a = 5.581059 ± 0.000736 Å, b = 7.758627 ± 0.000947 Å, c = 5.448341 ± 0.000665 Å; a = 5.580203 ± 0.000695 Å, b = 7.756789 ± 0.000908 Å, c = 5.447646 ± 0.000626 Å; and a = 5.580402 ± 0.000704 Å, b = 7.758957 ± 0.000919 Å, c = 5.449350 ± 0.000634 Å, respectively. The results of lattice constant were associated with the value of Goodness of Fit (GoF) is 0.9101%, 0.8726%, and 0.9303%, respectively. That has a strong indication of a qualified matching between the NdFeO3 model numbers of COD 2003124 with the current experimental results. The value of FWHM and the crystal size of Nd1.2FeO3 samples are 0.22o and 372 nm. The results showed that the variation of calcination temperature has not a significant change in the crystal size and homogeneity of the atomic crystal structure. These results are confirmed by simulation of the atomic structure using the Diamond software, the dominant peak of hkl (121)

Refinement Analysis using the Rietveld Method of Nd[1.2]Fe[1]O[3] Oxide Material Synthesized by Solid-State Reaction

Neodymium Ferrite Oxide (Nd1.2FeO3) has been successfully synthesized using solid state reaction by varying annealing time. Structural crystallographic characteristics were obtained by X-ray diffraction. The results of X-ray diffraction analysis showed the samples had been identified composed of NdFeO3 and Nd2- O3 phase, with peak dominant correspond to hkl (121), FWHM value of 0.22° and estimated crystal size of 393 nm. Analysis using Rietveld methods obtained Nd1.2FeO3 oxide material has a crystal structure is orthorhombic with space-group of PNMA. The results are comparable as was reported elsewhere that the oxide material is useful for gas sensor application

Influence of Annealing Time Variation on Crystal Structure and Morphology of Oxide Material Nd1.2FeO3 by Solid-State Reaction Method

NdFeO3 is one of the oxide material can be detected various gases, like S/O2, CO, H2S, etc. In this research, Nd1.2FeO3 as oxide material have been synthesized by solid-state reaction with a variation of annealing time. Characterized by XRD shows that the samples have form crystal perovskite structure with dominant phase and peak intensity correspond to hkl (121). FWHM value for the dominant peak was 0.22°. The crystallite of the samples was determined using Debye Scherer formula were 393.08, 393.10, and 393.10 nm, respectively. While the SEM characterized showed the morphology of the samples was homogenous with grain size estimates of 0.2μm. These results indicate the variation of annealing time 1, 2, and 3 hours did not significantly affect the crystallinity and morphology of Nd1.2FeO3 oxide material

The Effects of Calcination Temperatures on Crystal Structures and Morphologies of Nd1.2FeO3 Synthesized by Solid-State Reaction

NdFeO3 is one of the oxide alloys that can be used as a raw material for gas sensor. The NdFeO3 have been synthesized using solid state reaction method by varying calcination temperatures of 750oC, 850oC, and 950oC for 6 h. All of the Nd1.2FeO3 samples were characterized using scanning electron microscope (SEM) and x-ray diffraction (XRD) to identify their morphologies and phases. The results show that all of the samples formed major phase is NdFeO3 and minor phase of Nd2O3 and have homogenous morphology with estimating grain size is 0,2 μm for all samples. The value of FWHM and the crystal size of Nd1.2FeO3 was obtained for each sample is 0.22º and 372 nm. The orthorhombic phase with a dominant peak at hkl (121) is an indication that material has potential application as a gas senso

Influence of High Sintering Temperature Variation on Crystal Structure and Morphology of Nd1.2FeO3 Oxide Alloy Material by Solid-State Reaction Method

Nd1.2FeO3 powders type perovskite structure was prepared by a solid-state reaction method. This research has been conducted with the recurring heating process at high temperature. The raw material consisted of Nd2O3 (99.99 %) and Fe2O3 (99.99 %) which characterized by XRD to confirm the phase and using SEM to identify the morphology structure of the sample. Result characterized by XRD confirms the phase of NdFeO3 and Nd2O3 with the formation of NdFeO3 having the orthorhombic structure (perovskite type). The value of FWHM and the average crystal size of NdFeO3 was obtained for each sample is 0.20º and 409 nm. While SEM studies showed the surface morphology of Nd1.2FeO3 has homogeneous granules with grain size estimates is 0.2 μm. These results indicate that sample Nd1.2FeO3 was a good candidate for gas sensor materials

Religion and religious education : comparing and contrasting pupils’ and teachers’ views in an English school

This publication builds on and develops the English findings of the qualitative study of European teenagers’ perspectives on religion and religious education (Knauth et al. 2008), part of ‘Religion in Education: A contribution to dialogue or a factor of conflict in transforming societies of European countries?’ (REDCo) project. It uses data gathered from 27 pupils, aged 15-16, from a school in a multicultural Northern town in England and compares those findings with data gathered from ten teachers in the humanities faculty of the same school, collected during research for the Warwick REDCo Community of Practice. Comparisons are drawn between the teachers’ and their pupils’ attitudes and values using the same structure as the European study: personal views and experiences of religion, the social dimension of religion, and religious education in school. The discussion offers an analysis of the similarities and differences in worldviews and beliefs which emerged. These include religious commitment/observance differences between the mainly Muslim-heritage pupils and their mainly non-practising Christian-heritage teachers. The research should inform the ways in which the statutory duties to promote community cohesion and equalities can be implemented in schools. It should also facilitate intercultural and interreligious understanding between teachers and the pupils from different ethnic and religious backgrounds

Prognostic Value of N-terminal B-type Natriuretic Peptide in Patients with Acute Myocardial Infarction: A Multicenter Study

Background: Several models have been developed to help the clinician in risk stratification for Acute Coronary Syndrome (ACS),such as the TIMI and GRACE risk scores. However, there is conflicting evidence for the prognostic value of NT-ProBNP in acute myocardial infarction (AMI). Objective: (1) To explore the association of NT-proBNP with 30-day clinical outcome in AMI patients. (2) To compare the prognostic value of NT-proBNP with TIMI and GRACE risk scores in AMI patients. Methods: We conducted a multicenter, prospective observational study recruiting patients presented with AMI between 29-October-2015 and 14-January-2017, involving 1 cardiology referral centre and 4 non-cardiology hospitals. NT-proBNP level (Alere Triage®, US)was measured within 24 hours fromthe diagnosis of AMI. Patientswere followed-up for 1 month. Results: A total of 186 patients were recruited, 143 from tertiary cardiology centre and 43 from non-cardiology hospitals. Mean age was 54.7±10.0 years, 87.6% male and 64% were STEMI. The NT-proBNP level ranged from 60 to 16700pg/ml, with a median of 714pg/ml. Using the 75th centile as the cutoff, Kaplan-Meier survival analysis for the 30-day cardiac related mortality was significantly higher for patient with NT-proBNP level of ≥1600pg/ml (6.4% vs. 0.7%, p=0.02). Cox-regression analysis showed that NT-proBNP level of ≥1600pg/ml was an independent predictor of 30-day cardiac related mortality, regardless of TIMI risk score, GRACE score, LV ejection fraction and study hospitals (HR 9.274, p=0.054, 95%CI 0.965, 89.161). Readmission for heart failure at 30-day was also higher for patient with NT-proBNP level of ≥1600pg/ml (HR 9.308, p=0.053, 95%CI 0.969, 89.492). NT-proBNP level was not associated with all-cause mortality, risk of readmission for ACS, arrhythmia and stroke (pN0.05). By adding 50 score to GRACE risk score for NT-proBNP level of ≥1600pg/ml, combination of GraceNT-proBNP scores of more than 200 appeared to be a better independent predictor for 30-day cardiac related mortality (HR:28.28, p=0.004, 95%CI 2.94, 272.1). ROC analysis showed that this new score had 75% sensitivity and 91.2% specificity in predicting 30-day cardiac related mortality (AUC 0.791, p=0.046). Conclusions: NT-proBNP is a useful point-of-care risk stratification biomarker in AMI. It can be combined to the current risk score model for better risk stratification in AMI patients