245 research outputs found

    Robustness of Firm-Specific and Macroeconomic Determinants of Exploration Investments: Implications from Egyptian Oil & Gas Industry

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    The uncertainty that surrounds Oil and Gas exploration environments call for an examination at different angles. In terms of robustness, this study focuses on three performance measurements: (a) the amount of exploration investments, (b) the growth rate of exploration investments and (c) the Value at Risk (VaR) of exploration investments.The study utilizes the properties of discriminant analysis for deriving Z-score models that can be used for monitoring firms\u27 performance. A co-integration analysis is utilized as well in order to examine the level of co-integration between predictors of each performance measure. The sample includes annual data for forty one firms (local and multinational) working in the Oil and Gas industry in Egypt for the period 2009-2014.The results show that (a) amount and growth of exploration investment are quite robust performance measures in the Oil and Gas industry, (b) VaR of exploration investment is sporadic as it firm-specific, (c) GDP, Capital expenditure and operating expenditure are quite relevant for managing and monitoring growth of exploration investments.The study offers robust evidence that amount and growth of exploration investment are quire relevant firm performance in the Oil and Gas Industry

    Seismic Response of Seismic Isolated Structures subject to Near Fault &Far Fault Ground Motions

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    Seismic isolation systems are one of the most effective technologies for protecting structures from lateral loading, improving the seismic performance of the buildings against dynamic loads and base-isolated buildings have benefits in mitigating damage to the superstructure. Non-linear time history analysis is used to investigate the seismic response of fixed base and base-isolated building frames under far-fault ground motions and near-fault ground motions with fling step and forward directivity characteristics. Peak floor displacement, inter-story drift, absolute acceleration, base shear, and isolator displacement are some of the response characteristics that have been studied and examined as results of the analysis. The results demonstrated that using base isolators improves the seismic behavior of the used building, but it found that the isolator displacement is very large, during near-fault ground motion with the fling step effect particularly. For mitigating large isolator displacement during near-field earthquakes, the influence of a combination of the isolator and friction supplemental damper on the seismic response of a base-isolated 2D building frame is studied, and results demonstrated that using base isolators combined with viscous dampers can reduce the isolator\u27s displacement

    Medical system based on thermal optical system and neural network

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    Military personnel in the training or operational phases always need constant medical examination, but the presence of efficient medical care is difficult to implement in real-time for such cases. A wireless system for thermal tracking of soldiers was proposed, as well as tracking their vital signs in real time. Thermal cameras are used with an optical system designed to increase the accuracy of the thermal images captured as the change in the electro-cardiogram, heart rate, and temperature measurements are measured using a specially designed circuit. The results from both the thermal system and the biometric system are combined and sent to a computer for analysis using a model prepared with neural network technology. The proposed system was tested, and a database was created for 127 males and 110 females during training and rest times. The neural network model achieved a response time of 85 seconds until the release of the final analysis, and the accuracy of the proposed tracking system is 96%. The main contribution of this paper is the design of an integrated portable system for rapid, in-field, real-time military medical diagnostics

    High-Content Lignocellulosic Fibers Reinforcing Starch-Based Biodegradable Composites: Properties and Applications

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    Natural source-based composites became promising substitutes and synthetic petrochemical-based counterparts. So far, thermoplastic starch and lignocellulosic fibers are the most common materials for making such eco-friendly ?green? materials. Low cost, abundance, and renewability are the factors that lead to deploying these two types of materials. In this chapter, we are conducting further analysis for previously published results of six types of high-content natural fiber-reinforced starch-based composites. All composites were prepared by compression molding under pressure from 5 to 20 MPa and temperature from 130 to 160°C. Composites exhibited highest tensile strength and modulus of elasticity at fiber weight content from 50 to 70%, and then mechanical properties deteriorated significantly at 80% fiber content due to the insufficient starch resin. For instance, the tensile strength was boosted up from 2-12 MPa for thermoplastic starch to reach 55, 45, 32, 28, 44, 365 MPa for flax, bagasse, date palm fiber (DPF), banana, bamboo, and hemp composites, when fiber content was increased from 0% to the optimum fiber content (50-70%). Kelly-Tyson (random 2d) was the optimum model to predict random fiber composite. Increasing the fiber content and choosing a fiber with high cellulose content significantly improve the moisture resistance of the composites. Fick’s law of diffusion predicted the water uptake property successfully. The thermal stability of composites was improved with increasing the fiber weight content as well. This is attributed to the high thermal stability of cellulose when compared to starch. Properties exhibited by starch-based high-content natural fiber composite are promising for many industrial and biomedical applications

    Preoperative Serum IL-12p40 Is a Potential Predictor of Kasai Portoenterostomy Outcome in Infants with Biliary Atresia

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    The standard-of-care treatment for biliary atresia (BA) is surgical restoration of bile flow by Kasai portoenterostomy. We aimed to study serum interleukin- (IL-) 12p40, a natural antagonist for the proinflammatory IL-12p70, and its relation to surgical outcomes of BA. The study included 75 infants with neonatal cholestasis: BA group (n=25), non-BA cholestasis group (n=30), and neglected BA group (n=20), in addition to thirty healthy neonates serving as controls. IL-12p40 was measured by ELISA in all individuals and a second assessment was performed 3 months postoperatively in the BA group. The surgical outcomes were classified as successful (bilirubin ≤ 2 mg/dl) or failed (bilirubin > 2 mg/dl). IL-12p40 was higher in BA compared to that in the non-BA and control groups (P values were 0.036 and <0.0001, resp.) but comparable to that in the neglected BA group. Preoperative IL-12p40 levels in BA patients were significantly higher in successful Kasai compared with failed Kasai and a cutoff level of 547.47 pg/ml could predict the successful outcome with 87.5% sensitivity and 82.4% specificity. Three-month postoperative IL-12p40 tended to decrease in both the successful and failed groups. In conclusion, preoperative serum IL-12p40 is a potential predictor of Kasai outcome. Serial postoperative measurements may anticipate the failure of an initially successful operation, hence the need for liver transplantation

    Rural Fishermen Benefit From the Activities of Cooperative Societies in Aswan Governorate, Egypt

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    The research aimed to identify the degree of benefit and satisfaction of rural fishermen with the activities and services provided by cooperative societies for rural fishermen in Aswan Governorate. The research carried out on a random sample of rural fishermen which consisting of 302 respondents. Data were collected by personal interview questionnaire. Percentages, frequency distribution, graph and weighted average were used to show and describe the research data. Excel was used to prepare the graphs. Spearman’s correlation coefficient for ranks was used to determine the relationship between the search variables by SPSS. Results were showed that: The most beneficial activities were: lending to fishermen and their families, establishing and managing fish farms, establishing centers for collecting fish, which are arranged in descending order with a weighted average respectively (2.85, 2.82, 2.71). The degree of satisfaction of the respondents was high with one of the services provided by cooperative societies were: issuing official papers, with a weighted average of 2.69. The degree of benefit of the respondents was positively related to years of work in fishing, age, and the number of years of education. The degree of respondents' satisfaction was positively correlated with age, years of education, level of ambition, years of work in fishing at the significant level 0.01, 0.05. The most important suggestions for activating the role of fishermen's cooperative societies were: the necessity of insuring fishermen and their boats (99.7%), providing protection for fishermen's families (99.3%), and helping to solve problems (98%)

    Validity of sphenoid ostium in relation to posterior wall of maxillary sinus by computed tomography

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    Background: Sphenoid sinus is the most inaccessible paranasal sinus, enclosed within the sphenoid bone and intimately related to numerous vital neural and vascular structures. Anatomic variation of the sphenoid sinus is well documented and may complicate surgery in such a place.Objective: To assess the reliability of preoperative computed tomography (CT) in determination of the distance between the posterior wall of maxillary sinus (PWMS) and the sphenoid sinus ostium (SSO) in the coronal plane.Patients and methods: This was a prospective study of the distance between the SSO and the PWMS in the coronal plane, which was measured both radiologically in preoperative CT and intraoperatively during endoscopic sinus surgery for patients in need for middle meatal antrostomy and sphenoid sinusotomy at the same side. Distances obtained by both techniques have been tested for the degree of correlation. Number of the included patients was 25.Results: Forty four nasal sides were included in the study. The mean distance between the sphenoid sinus ostium and posterior wall of maxillary sinus in the coronal plane was 6.6 ± 1.8 mm when measured by preoperative CT and 6.9 ± 1.9 mm when measured directly during surgery. No significant difference was found between the mean distances measured by both techniques (p = 0.246) with good agreement between them (r = 0.864).Conclusion: Preoperative CT may be a reliable tool to preoperatively determine the difference in depth between the PWMS and the SSO

    The serum thyroid hormone profile in mechanically ventilated children: Does euthyroid sick syndrome exist?

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    Background: The term "euthyroid sick syndrome" refers to alterations in thyroid function testing during critical illness. Mechanically ventilated children's thyroid hormone levels may be altered, although the reason for this remains a mystery.Objective: This study was aimed to evaluate thyroid hormone profile in mechanically ventilated children and their correlation with mortality.Patients and Methods: Thirty-four mechanically ventilated children were enrolled in a prospective cohort study. On the first and third days of mechanical ventilation, serum TSH, FT3, FT4 and reverse T3 were measured.Results: The mean age of the studied patients was of 31.06 ± 35.94 months. After three days of mechanical ventilation, the serum levels of FT3 and FT4 in the blood were significantly lower than the serum levels on the first day. The serum reverse T3 levels increased significantly on the third day of mechanical ventilation compared to the first day. There was a statistically significant increase in the number of patients with low FT3 and FT4 serum levels on the third day compared to the first day. Twenty-two patients (64.7%) died, and the frequency of low FT3 among dead patients was signiisignificantlycantly higher than among surviving patients.Conclusions: It could be concluded that the mechanically ventilated children had signs of euthyroid sick syndrome, shown by low levels of FT3 and FT4 and a rise in rT3 without a compensatory rise in TSH. Serum FT3 and FT4 decreased, but reverse T3 increased, on the third day of mechanical ventilation compared to the first day. Patients who had low FT3 levels died at a higher rate

    The impact of excision of benign nonendometriotic ovarian cysts on ovarian reserve: a systematic review

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    Background Benign nonendometriotic ovarian cysts are very common and often require surgical excision. However, there has been a growing concern over the possible damaging effect of this surgery on ovarian reserve. Objective The aim of this metaanalysis was to investigate the impact of excision of benign nonendometriotic ovarian cysts on ovarian reserve as determined by serum anti-Müllerian hormone level. Data Sources MEDLINE, Scopus, ScienceDirect, and Embase were searched electronically. Study Design All prospective and retrospective cohort studies as well as randomized trials that analyzed changes of serum anti-Müllerian hormone concentrations after excision of benign nonendometriotic cysts were eligible. Twenty-five studies were identified, of which 10 were included in this analysis. Data Extraction Two reviewers performed the data extraction independently. Results A pooled analysis of 367 patients showed a statistically significant decline in serum anti-Müllerian hormone concentration after ovarian cystectomy (weighted mean difference, –1.14 ng/mL; 95% confidence interval, –1.36 to –0.92; I2 = 43%). Subgroup analysis including studies with a 3-month follow-up, studies using Gen II anti-Müllerian hormone assay and studies using IOT anti-Müllerian hormone assay improved heterogeneity and still showed significant postoperative decline of circulating anti-Müllerian hormone (weighted mean difference, –1.44 [95% confidence interval, –1.71 to –1.1; I2 = 0%], –0.88 [95% confidence interval, –1.71 to –0.04; I2 = 0%], and –1.56 [95% confidence interval, –2.44 to –0.69; I2 = 22%], respectively). Sensitivity analysis including studies with low risk of bias and excluding studies with possible confounding factors still showed a significant decline in circulating anti-Müllerian hormone. Conclusion Excision of benign nonendometriotic ovarian cyst(s) seems to result in a marked reduction of circulating anti-Müllerian hormone. It remains to be established whether this reflects a real compromise to ovarian reserve
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