First Order Phase Transformation in Amorphous Ge25Se75 – xSbx Glasses

Non-isothermal Differential scanning calorimetry (DSC) technique was used to study the kinetics of first order phase transformation in Ge25Se75 – xSbx glasses. The X-ray diffraction (XRD) technique was employed to investigate the amorphous and crystalline phases in Ge25Se75 – xSbx glasses. From the heating rate dependences of crystallization temperature; the activation energy for crystallization and other kinetics parameters were derived. The temperature difference (Tc – Tg) and Tc is highest for the samples with 6 % of Sb. Hence, Ge25Se69Sb6 glass is most stable. The enthalpy released is found to be less for Ge25Se69Sb6 glass which further confirms its maximum stability. The activation energy of crystallization (Ec) is found to vary with compositions indicating a structural change due to the addition of Sb. The crystallization data are interpreted in terms of recent analyses developed for non-isothermal conditions. The present investigation indicates that both the glass transition and the crystallization processes occur in a single stage. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101

AutoScor: An Automated System for Essay Questions Scoring

The automated scoring or evaluation for written student responses have been, and are still a highly interesting topic for both education and natural language processing, NLP, researchers alike. With the obvious motivation of the difficulties teachers face when marking or correcting open essay questions; the development of automatic scoring methods have recently received much attention. In this paper, we developed and compared number of NLP techniques that accomplish this task. The baseline for this study is based on a vector space model, VSM. Where after normalisation, the baseline-system represents each essay by a vector, and subsequently calculates its score using the cosine similarity between it and the vector of the model answer. This baseline is then compared with the improved model, which takes the document structure into account. To evaluate our system, we used real essays that submitted for computer science course. Each essay was independently scored by two teachers, which we used as our gold standard. The systems’ scoring was then compared to both teachers. A high emphasis was added to the evaluation when the two human assessors are in agreement. The systems’ results show a high and promising performance

Herpes Zoster Infections in SLE in a University Hospital in Saudi Arabia: Risk Factors and Outcomes

Patients with SLE carry an increased risk of infection that account for 11–23% of all hospitalized patients and 50% of all SLE patients develop major infections during the course of their disease. Globally Herpes Zoster has been reported as the most frequent viral infection in SLE patients. We determined the clinical spectrum, disease sequelae and the risk factors associated with the development of Herpes Zoster in patients with SLE and their outcomes. Retrospective case control study of Herpes Zoster infections was done in SLE patients between 1982 and 2006. Cases were matched 1:2 to controls for age, race, sex and duration of follow up. Clinical features of the cases from the time of lupus diagnosis to the time of Zoster were compared to their respective controls over similar time periods. Thirty two SLE cases were compared to sixty four controls. Cases were more likely to have received cyclophosphamide (P = .0223) and intravenous methylprednisolone pulse therapy (P = .0026), MMF (P < .02), had leucopenia (P = .0407) and hemolytic anemia (P = .0344). More cases than controls had lupus nephritis, cerebritis, thrombocytopenia but the differences did not reach statistical significance. The mean oral prednisolone dose and proportion of patients receiving immunosuppressives including pulse methylprednisolone therapy, IV Cyclophosphamide and mycophenolate was significantly higher in patients with active SLE compared to patients with SLE in remission at the time of Herpes Zoster (P < .05). Disseminated Zoster developed in patients with active SLE (7/9) compared to patients with SLE in remission (0/23). None of the patients had postherpetic neuralgia or bacterial super infection. Immunosuppressive medications were discontinued at the time of diagnosis of Zoster in 19 of 32 patients and all patients received antiviral medications.There were no permanent neurologic deficits or deaths. We conclude that Herpes Zoster infections occur at increased frequency among patients with SLE and carry significant morbidity. Immunosuppressive therapy and severe manifestations of lupus may be risk factors for the development of Herpes Zoster although not necessarily at the time of disease flare or immunosuppressive therapy. Our study suggests that although Herpes Zoster occurs frequently in patients with SLE, it has a relatively benign course

The Competitiveness of Saudi Pharmaceutical Industry Using Porter 5 Forces Analysis

Pharmaceutical industry is a challenge in both the developed and the developing countries. If a company wants to survive, it should be able to compete well in the domestic and in the international markets. The main purpose of this paper is to examine the competitiveness of the Saudi Pharmaceutical Industry (SPI) using Porter 5 forces analysis. A questionnaire has been designed, distributed and filled up by experts from the Saudi Pharmaceutical Industry. The findings show that SPI has a favorable advantage in terms of bargaining power of suppliers, bargaining power of buyers and rivalry among competitors. However, it lacks a favorable advantage concerning threat of substitutes and threat of local and global entry. Depending on the literature and the questionnaire findings, a number of strategies were recommended to SPI companies, which can also be adopted by companies in other developing countries. Keywords: Competitiveness, Pharmaceutical industry, Porter five forces, rivalry, bargaining powe

Hybrid Modeling Approach to Identify High-Risk Internal Corrosion Sites in Dry Gas Transmission Pipelines for Optimized Integrity Validation

This work presents an improved version of Dry Gas Internal Corrosion Direct Assessment (DG-ICDA) methodology to overcome key limitations in the current National Association of Corrosion Engineers (NACE) standard. The core objective is to increase the accuracy of identifying critical locations along dry gas transmission pipelines that are prone to internal corrosion. The new approach considers flow dynamics along the pipeline including pressure and gas velocity. In Addition, unlike the standard approach that assumes a fixed gas compressibility Z-factor, this model uses a neural network to dynamically calculate Z-factor along the pipeline. Also, the effect of gas composition is considered.Furthermore, there are two aiding tools are included in this new approach. The first is introducing a probabilistic excavation stopping criterion, which updates the likelihood of internal corrosion existence when no corrosion is found during field inspection. This tool applies Monte Carlo iii simulation to account for uncertainties in site conditions during field work, unlike the deterministic stopping rule used in the standard DG-ICDA, which does not account for such variability. The second aiding tool is a cost analysis module, allowing comparison between the improved model and In-Line Inspection (ILI) for decision about the optimal pipeline integrity validation approach. The new model was incorporated into a web-based application platform, making it accessible for both research and industrial use. A 15 km pipeline in Texas was utilized to demonstrate the model’s functionality. In this case study, the tool demonstrated cost savings exceeding 43% compared to ILI, even under the worst-case scenario

Reflection and Transmission of an Incident Progressive Wave by Obstacles in Homogeneous Shallow Water

The influence of a suspended fixed obstacle on an incident progressive wave inside an ideal homogeneous shallow water is studied in two dimensions. The fluid occupies an infinite channel of a constant depth, and a fixed obstacle of a small horizontal extent is partially submerged without contact with the bottom of the channel. An asymptotic double series expansion for the solution is used. The procedure enables us to calculate analytic expressions for the local perturbations up to the second order. The results of the first-order approximation indicate that no reflections exist. The second-order approximation of the solution is found to be the superposition of a progressive wave and local perturbations. For approximations of order higher than two, a secular term which increases monotonically with time and distance appears in the expressions for the progressive wave. This unacceptable result is due to a certain aspects in the mathematical procedure used. For this reason, the procedure is modified by using a suitable transformation of variables which reduces the determination of the transmitted wave to the solution of the KdV equation. As an illustration, the special case of the incident uniform flow is considered and the stream lines of the resulting flow are drawn