Development and Applications of Self-learning Simulation in Finite Element Analysis

Numerical analysis such as the finite element analysis (FEA) have been widely used to solve many engineering problems. Constitutive modelling is an important component of any numerical analysis and is used to describe the material behaviour. The accuracy and reliability of numerical analysis is greatly reliant on the constitutive model that is integrated in the finite element code. In recent years, data mining techniques such as artificial neural network (ANN), genetic programming (GP) and evolutionary polynomial regression (EPR) have been employed as alternative approach to the conventional constitutive modelling. In particular, EPR offers great advantages over other data mining techniques. However, these techniques require a large database to learn and extract the material behaviour. On the other hand, the link between laboratory or field tests and numerical analysis is still weak and more investigation is needed to improve the way that they matched each other. Training a data mining technique within the self-learning simulation framework is currently considered as one of the solutions that can be utilised to accurately represent the actual material behaviour. In this thesis an EPR based machine learning technique is utilised in the heart of the self-learning framework with an automation process which is coded in MATLAB environment. The methodology is applied to simulate different material behaviour in a number of structural and geotechnical applications. Two training strategies are used to train the EPR in the developed framework, total stress-strain and incremental stress-strain strategies. The results show that integrating EPR based models in the framework allows to learn the material response during the self-learning process and provide accurate predictions to the actual behaviour. Moreover, for the first time, the behaviour of a complex material, frozen soil, is modelled based on the EPR approach. The results of the EPR model predictions are compared with the actual data and it is shown that the proposed model can capture and reproduce the behaviour of the frozen soil with a very high accuracy. The developed EPR based self-learning methodology presents a unified approach to material modelling that can also help the user to gain a deeper insight into the behaviour of the materials. The methodology is generic and can be extended to modelling different engineering materials

Evaluation of discharge prescriptions for secondary prevention in patients with acute coronary syndromes in Iraq

Background: Optimal prescribing of secondary prevention medications after acute coronary syndrome (ACS) events has been shown to reduce morbidity and mortality. However, it is unknown whether these medications are optimally prescribed at discharge from acute care in Iraq. Objective: To evaluate whether patients with ACS received optimal secondary prevention medications: antiplatelets, statins, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEI/ARBs), and beta-blockers at discharge from a cardiology unit, and to assess whether statins, ACEI/ARBs and beta-blockers were prescribed at target doses based on the American Heart Association/American College of Cardiology (AHA/ACC) guidelines. Methods: Observational retrospective cross-sectional study of patients with ACS admitted to a hospital in Baghdad and survived to discharge between May 2016 and January 2017. Patient-level data and secondary prevention medications at discharge were extracted from routine medical records. Optimal dosing was defined as ≥75%, moderate dosing as 50–74%, and low dosing a

A new approach to modeling the behavior of frozen soils

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordIn this paper a new approach is presented for modeling the behavior of frozen soils. A data-mining technique, Evolutionary Polynomial Regression (EPR), is used for modeling the thermo-mechanical behavior of frozen soils including the effects of confining pressure, strain rate and temperature. EPR enables to create explicit and well-structured equations representing the mechanical and thermal behavior of frozen soil using experimental data. A comprehensive set of triaxial tests were carried out on samples of a frozen soil and the data were used for training and verification of the EPR model. The developed EPR model was also used to simulate the entire stress-strain curve of triaxial tests, the data for which were not used during the training of the EPR model. The results of the EPR model predictions were compared with the actual data and it was shown that the proposed methodology can extract and reproduce the behavior of the frozen soil with a very high accuracy. It was also shown that the EPR model is able to accurately generalize the predictions to unseen cases. A sensitivity analysis revealed that the model developed from raw experimental data is able to extract and effectively represent the underlying mechanics of the behavior of frozen soils. The proposed methodology presents a unified approach to modeling of materials that can also help the user gain a deeper insight into the behavior of the materials. The main advantages of the proposed technique in modeling the complex behavior of frozen soil have been highlighted

Improving the infrastructure to establish e-government project in Developing Countries with alternative solution: First Steps from Libya The 6th International Multi-Conference on Society, Cybernetics and Informatics (IMSCI

ABSTRACT In developing countries, people are not aware of technologies and the worst case when we talk about Internet technology. Thus, any plan from the government to communicate with the public using it is bound to face difficulties. Launching an e-government website has several advantages such as no boundaries, distance barriers and more. To be precise, several factors are to be accounted for when government launches such an electronic service and wants it to be successful. These factors are: public awareness, this could be awareness of the computer literacy, linguistic skills, internet skills, awareness of egovernment website(s), and readiness to use its services. Several surveys were conducted considering the above factors among Stakeholders (Students, Experts and Farmers) in many Libyan cities. Moreover, after analysis of the collected data; we learned many important points that should be taken into account when lunching an egovernment services to reach the optimum citizen participation and we discussed these points with observations/recommendations on how to improve upon the shortcomings. In addition, we have shown how to use alternative channel(s) such as mobile phones in case of facing infrastructure technical difficulties. Besides, conducted some of the successful local case-studies to draw more valuable results and recommendations

Amelioration of exosome and mesenchymal stem cells in rats infected with diabetic nephropathy by attenuating early markers and aquaporin-1 expression

Abstract Diabetic nephropathy (DN) is a prevalent diabetic microvascular condition. It is the leading cause of kidney disease in the advanced stages. There is no currently effective treatment available. This research aimed to investigate the curative potentials of exosomes isolated from mesenchymal stem cells affecting DN. This study was performed on 70 male adult albino rats. Adult rats were randomized into seven groups: Group I: Negative control group, Group II: DN group, Group III: Balanites treated group, Group IV: MSCs treated group, Group V: Exosome treated group, Group VI: Balanites + MSCs treated group and Group VII: Balanites + exosome treated group. Following the trial period, blood and renal tissues were subjected to biochemical, gene expression analyses, and histopathological examinations. Results showed that MDA was substantially increased, whereas TAC was significantly decreased in the kidney in the DN group compared to normal health rats. Undesired elevated values of MDA levels and a decrease in TAC were substantially ameliorated in groups co-administered Balanites aegyptiacae with MSCs or exosomes compared to the DN group. A substantial elevation in TNF-α and substantially diminished concentration of IGF-1 were noticed in DN rats compared to normal health rats. Compared to the DN group, the co-administration of Balanites aegyptiacae with MSCs or exosomes substantially improved the undesirable elevated values of TNF-α and IGF-1. Furthermore, in the DN group, the mRNA expression of Vanin-1, Nephrin, and collagen IV was significantly higher than in normal healthy rats. Compared with DN rats, Vanin-1, Nephrin, and collagen IV Upregulation were substantially reduced in groups co-administered Balanites aegyptiacae with MSCs or exosomes. In DN rats, AQP1 expression was significantly lower than in normal healthy rats. Furthermore, the groups co-administered Balanites aegyptiacae with MSCs or exosomes demonstrated a substantial increase in AQP1 mRNA expression compared to DN rats

Trace elements disturbance and Liver toxicity in Sudanese Fuel Stations Workers

Abstract: Workers in benzene stations are more susceptible to hepatotoxicity. This study was aimed to assess serum levels of trace elements and liver enzymes activity as indicator of hepatotoxicity in benzene station workers. In a matched case control study conducted in Khartoum State -Sudan during the period from October 2015 to January 2016. After signing written informed consent blood specimen was collected from 50 individual working in petrol station as case group and 20 healthy individuals not working in petrol station as control group aged from (20-50) years and serum levels of AST,ALT.GGT activity and Copper and Zink was measured using spectrophotometrical and atomic absorption methods. Data were collected using structural questionnaire. Data analysis was carried out by means of statistical package for social science (SPSS version 16). The mean level of Copper and Zinc was significantly decreased in comparison with control group (p < .05). There was no significant correlation of serum level of trace elements zinc and copper with duration, BMI, AST, ALT, and GGT activities. Working in petrol station is associated with decreased level of copper and Zink however the disturbance in these trace elements dose not correlated with abnormalities in liver enzymes

The Pecking Order Theory and Start-up Financing of Small and Medium Enterprises: Insight into Available Literature in the Libyan Context

The Pecking Order Theory states that internal financing is preferred when available; and, if external financing is required, debt is preferred over equity. Thus, this paper aims to test the application of The Pecking Order Theory as an exploitation of start-up financing of Small and Medium Enterprises in Libya