517 research outputs found
Engineering characteristics of Egyptian limestone
Purpose. Study of physical properties such as porosity, density and mechanical properties such as compressive strength and tensile strength of Egyptian limestone based on experimental investigations.
Methods. In this paper using physical and mechanical properties to evaluate the Egyptian limestone according to the relationship between their properties especially the degree of water saturation. Samples were obtained from six different locations (Helwan, Minia, Assuit, Qena, Sohag, and Aswan).
Findings. The strong correlation between porosity and density, and good correlations between uniaxial strength and tensile strength. Carried out results indicated that, small porosity results in greater rock strength and vice versa.
Originality. Applying the fitting curve technique to check the best correlation between the different property of limestone to identify the best relationship to apply the prediction to find the limestone property in other location as regards applying conditions.
Practical implications. Results carried out that the strong correlation between porosity and density, and good correlations between uniaxial strength and tensile strength as summarize in the outcome of data interpretation. Highest quality stones, in terms of their hydric behavior and mechanical properties, are the index for the suitability of using limestone.Мета. Вивчення фізичних та механічних властивостей вапняку родовищ Єгипту на основі експериментальних досліджень.
Методика. Зразки вапняку відбирались з родовищ шести різних провінцій (Helwan, Minia, Assuit, Qena, Sohag, Aswan). Зразки кернів були підготовлені з використанням бурильного станка відповідно до критеріїв стандарту ISRM. Підготовка до випробування зразків керна проводилася перпендикулярно площинам нашарування. Відповідні властивості для виробництва заповнювача були перевірені з точки зору вмісту води, щільності, стійкості до стирання та стійкості до стирання в кінцевому підсумку на вапняковій ділянці, який більше підходить для виготовлення бетону і асфальту. Фізичні властивості (щільність та пористість) і механічні властивості (міцність на стиск, міцність на розрив і коефіцієнт динамічного дроблення) були досліджені за стандартними методиками для дев’яти зразків вапняку кожної з шести провінцій.
Результати. Для вапняку родовищ Єгипту експериментально виявлено високу кореляцію між пористістю та щільністю, а також хороші кореляції між міцністю на одновісний стиск і міцністю на розрив, що характеризує інженерні вимоги до його використання у цивільному та промисловому будівництві. Проведені результати показали, що низька пористість призводить до більшої міцності порід і навпаки.
Наукова новизна. Полягає у використанні техніки підгонки кривої для перевірки найкращої кореляції між різними властивостями вапняку при встановленні найкращого відношення, застосовуючи цей прогноз для вивчення властивостей вапняку в іншому місці.
Практична значимість. Отримані показники фізичних та механічних характеристик вапняку є корисними для визначення можливої області його застосування в цивільному та промисловому будівництві, тощо.Цель. Изучение физических и механических свойств известняка месторождений Египта на основе экспериментальных исследований.
Методика. Образцы известняка отбирались с месторождений шести различных провинций (Helwan, Minia, Assuit, Qena, Sohag, Aswan). Образцы кернов были подготовлены с использованием бурильного станка согласно критериям стандарта ISRM. Подготовка к испытанию образцов керна проводилась перпендикулярно плоскостям напластований. Подходящие свойства для производства заполнителя были проверены с точки зрения содержания воды, плотности, устойчивости к истиранию и стойкости к истиранию в конечном итоге на известняковом участке, который больше подходит для изготовления бетона и асфальта. Физические свойства (плотность и пористость) и механические свойства (прочность на сжатие, прочность на разрыв и коэффициент динамического дробления) были исследованы по стандартным методикам для девяти образцов известняка каждой из шести провинций.
Результаты. Для известняка месторождений Египта экспериментально обнаружена высокая корреляция между пористостью и плотностью, а также хорошие корреляции между прочностью на одноосное сжатие и прочностью на разрыв, характеризующие инженерные требования к его использованию в гражданском и промышленном строительстве. Проведенные результаты показали, что низкая пористость приводит к большей прочности пород и наоборот.
Научная новизна. Заключается в использовании техники подгонки кривой для проверки наилучшей корреляции между различными свойствами известняка при установлении наилучшего отношения, применяя этот прогноз для определения свойств известняка в другом месте.
Практическая значимость. Полученные показатели физических и механических характеристик известняка являются полезными для определения возможной области его применения в гражданском и промышленном строительстве и т.д.This research was partially supported by Mining and Petroleum Engineering Department, Faculty of Engineering Al-Azhar University, Egypt, that provided machines to finish the research
Improving Leadership Skills by Using Neuro Linguistic Programming (NLP)
The purpose of this thesis is developing leadership skills to leaders, managers, teachers, and followers by using Neuro-Linguistic Programming. The leaders have many challenges when they lead their teams. These problems are communicating with others, building trust with their teams, and establishing rapport with their followers. NLP has many techniques such as anchoring, mirroring, and some skills like feedback, affinity, and coaching which can improve and develop the relationship and communication between the leaders and their followers. This paper relies on qualitative research because it provides human experience, actions, and feelings. In addition to, it gives a chance to analyze the data in depth. My master thesis relies on original interviews and secondary interviews. Furthermore, the initial interviews are done by emails because of lack time to NLP coaches. The findings proved that NLP could enhance leadership skills as follow: Model can help the people to model top leaders. Model is different from copying. The person can select the suitable technique from the model leaders. On another hand, the people take every method by copying even if it doesn't fit his personality. Rapport helps managers to have a high channel of communicating with their teams. Feedback is beneficial for leaders and followers as well. The boss needs input from his teamwork as he gives feedback to them. We can summarize that NLP helps the leaders, managers, and teachers to improve and develop their skills regarding their relationship way with their teamwork and their influencing on them. NLP enhances the communicating way between followers and their boss via rapport, model, and feedback.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format
Study of Customer Satisfaction in the Banking Sector in Libya
The purpose of this paper is to evaluate the customer satisfaction of the banks sector in Libya, based on customer perception regarding service quality. This is an empirical study using mainly primary data collected through a well-structured questionnaire. The method of the study Validity and reliability testing of questionnaire using SPSS program for windows version 19The questionnaire has been personally administered on a sample size of 204 bank customers. This paper makes a useful contribution as there are only a few studies dealing with the assessment of service quality in banking sector of Libya. The findings based on three different independent variables (service quality, customer loyalty and security) showed that all these variables influenced con-sumers satisfaction in Libyan banking sector. There is a positive impact and significant relationship between the customer satisfaction and two variables (service quality and customer loyalty), and also there is a negative relationship between security and customer satisfaction
A Framework For Quantifying Sustainability Of Lean Implementation In Healthcare Organizations
Due to the remarkable positive effect of lean adoption in various firms in the manufacturing sector, it has been adopted by several organizations within the healthcare industry. Although the rate of adopting lean by hospitals in the developed countries is slower than it should be, it proved to be effective in helping healthcare organizations maintain or even improve their quality of care while containing their related costs. However, such adoption did not take place until the beginning of the new millennium. And with such adoption, it has been accompanied with major challenges related to proper lean implementation, sustainability of achieved levels of performance, and staff engagement in infinite cycles of continuous improvement towards perfection. Thus, the purpose of this study is to develop a framework that helps healthcare organizations quantify their experience with lean. Such quantification is obtained by measuring the agreement level of hospital staff members about the degree of adopting two sets of critical factors of successful lean implementation within their hospital. These two sets of factors are classified as process factors and organizational factors. The proposed framework has been validated by determining the sustainability level of lean implementation within one of U.S. hospitals in the State of Florida. The developed framework provides a balanced assessment of both process and organizational factors essential for achieving sustainable levels of lean implementation. In order to accommodate for the observed variation in lean adoption in hospitals, individual hospital iv departments are considered the ―analysis units‖ of the developed framework. In order to quantify the implementation status of lean within a hospital department, a survey-based lean sustainability assessment tool has been developed based on the defined sets of factors. The sustainability level of lean implementation of a hospital can be obtained by combining various responses of its surveyed departments. The developed framework is the first that addresses both process and organizational factors of sustainable lean implementation in a balanced manner while fulfilling the assessment needs of all healthcare organizations regardless of their current level of lean adoption. In addition, utilizing the framework within a hospital enhances employee involvement and respect for employee which are essential for sustainable lean implementation. Finally, the developed framework provides healthcare supervising authorities (i.e. ministries of health or corporate offices of hospitals’ groups) a macro-level benchmarking view regarding the progress of their hospitals towards implementing sustainable levels of lean
Using learning from demonstration to enable automated flight control comparable with experienced human pilots
Modern autopilots fall under the domain of Control Theory which utilizes Proportional Integral Derivative (PID) controllers that can provide relatively simple autonomous control of an aircraft such as maintaining a certain trajectory. However, PID controllers cannot cope with uncertainties due to their non-adaptive nature. In addition, modern autopilots of airliners contributed to several air catastrophes due to their robustness issues. Therefore, the aviation industry is seeking solutions that would enhance safety. A potential solution to achieve this is to develop intelligent autopilots that can learn how to pilot aircraft in a manner comparable with experienced human pilots. This work proposes the Intelligent Autopilot System (IAS) which provides a comprehensive level of autonomy and intelligent control to the aviation industry. The IAS learns piloting skills by observing experienced teachers while they provide demonstrations in simulation. A robust Learning from Demonstration approach is proposed which uses human pilots to demonstrate the task to be learned in a flight simulator while training datasets are captured. The datasets are then used by Artificial Neural Networks (ANNs) to generate control models automatically. The control models imitate the skills of the experienced pilots when performing the different piloting tasks while handling flight uncertainties such as severe weather conditions and emergency situations. Experiments show that the IAS performs learned skills and tasks with high accuracy even after being presented with limited examples which are suitable for the proposed approach that relies on many single-hidden-layer ANNs instead of one or few large deep ANNs which produce a black-box that cannot be explained to the aviation regulators. The results demonstrate that the IAS is capable of imitating low-level sub-cognitive skills such as rapid and continuous stabilization attempts in stormy weather conditions, and high-level strategic skills such as the sequence of sub-tasks necessary to takeoff, land, and handle emergencies
Antegrade Intermittent Cold Cardioplegia in Comparison to Antegrade Intermittent Warm Cardioplegia in Heart Valve Surgery
Paper withdrawn upon authors request:
Request received: 22 May 2020
Paper withdrawn: 22 May 2020
 
The Burr XII-Burr XII Distribution: Mathematical Properties and Characterizations
We introduce a new continuous distribution called the Burr XII-Burr XII distribution. Some of its properties are derived. The method of maximum likelihood is used to estimate the unknown parameters. An application is provided with details to illustrate the importance of the new. The new model provides adequate fits as compared to other related models with smallest values for A-IC, B-IC, CA-IC and HQ-IC. Characterization results are presented based on two truncated moments, hazard function as well as based on the conditional expectation
The Transmuted Weibull-Pareto Distribution
A new generalization of the Weibull-Pareto distribution called the transmuted Weibull-Pareto distribution is proposed and studied. Various mathematical properties of this distribution including ordinary and incomplete moments, quantile and generating functions, Bonferroni and Lorenz curves and order statistics are derived. The method of maximum likelihood is used for estimating the model parameters. The flexibility of the new lifetime model is illustrated by means of an application to a real data set
NDM-536: EFFECT OF WIND SPEED AND TERRAIN EXPOSURE ON THE WIND PRESSURES FOR ELEVATED STEEL CONICAL TANKS
Steel liquid storage tanks in the form of truncated cones are commonly used as containment vessels for water supply or storing chemicals. A number of failures have been recorded in the past few decades for steel liquid tanks and silos under wind loading. A steel conical tank vessel will have a relatively small thickness making it susceptible to buckling under wind loads especially when they are not fully-filled. In this study, a wind tunnel pressure test is performed on an elevated conical tank in order to estimate the external wind pressures when immersed into a boundary layer. The tested tank configuration represents combined conical tanks where the cone is capped with a cylinder. In addition, the effect of terrain exposure and wind speed on the pressure values and wind forces is assessed. The mean and rms pressure coefficients are presented for different test cases in addition to the mean and rms total drag forces that are obtained by integrating the pressure coefficient over the tank model’s surface. It is found that the total mean and rms drag forces are highly-dependent on Reynolds number which is a function of wind speed and they have a maximum value at mid-height for the lower cylinder, at top for the conical part, and at bottom for the upper cylindrical part
Diagnosis of papilledema and pseudopapilledema using optical coherence tomography
Background: Papilledema is a common clinical problem where the ophthalmologist plays an important role in its diagnosis. Optical coherence tomography (OCT) provides high resolution images of the retina and the retinal nerve fiber layer (RNFL).Objective: The aim of the work was early and non- invasive diagnosis of papilledema and differentiating it from pseudopapilledema using optical coherence tomography (OCT).Patients and methods: This observational case control study included a total of 45 eyes stratified into 3 equally groups, 15 each, (Group-1): eyes of healthy normal subjects, (Group-2) eyes with papilledema and (Group-3) eyes with pseudo-papilledema. Patients presented at Ophthalmology Outpatient Clinic, Zagazig University Hospitals. Follow-up visits included an interview with the patient for assessing the presence of ocular symptoms, and for ophthalmologic examination to register all the clinical findings.Results: There is statistically significant difference between the studied groups regarding result of fundus examination. Normal control group had normal appearance of fundus. Concerning pseudo papilledema, 73.3% had crowded disc and 26.7% had dusen. Concerning papilledema, 40% had mild lesion, 20% had moderate and remaining 40% had severe lesion. There is statistically significant difference between the studied groups regarding morphological changes. Crowded disc and buried optic disc drusen occurred in 73.3% and 26.7% of pseudopapilledema group respectively). There is statistically significant difference between the studied groups regarding superior RNFL. On LSD comparison, the difference is significant between each individual groups. There is statistically significant difference between the studied groups regarding inferior RNFL.Conclusion: It could be concluded that spectral domain optical coherence tomography can differentiate between papilledema, pseudopapilledema, and a normal disc
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