14 research outputs found

    Optimization of EDM Process Factors for Machining Al-Si Alloy Using Response Surface Methodology

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            يقدم هذا البحث نهجا متكاملا لنمذجة العملية والأمثلية متعددة الاهداف لمتغيرات التشغيل بالشرارة الكهربائية لسبيكة الالمنيوم سيليكون (Al-Si) اعتمادا على نمط استجابة السطح (RSM) إلى جانب تكنيك دالة الرغبة (DF). أختيرت ثلاث متغيرات منفصلة كمدخلات وهي تيار النبضة (Ip)، فترة إفراغ النبضة (Ton) وفترة توقف النبضة (Toff) للتأكد من تأثير المتغيرات الثلاث سابقة الذكر على المخرجات المتمثلة بمعدل إزالة المادة (MRR)، معدل بلى القطب (EWR) وخشونة السطح (Ra). تحليل عام للتفاوت (ANOVA) عند درجة من الأهمية مقدارها 5% لتعيين المعاملات الأكثر تأثيرا، وأنجز اختبار مدى كفاءة كافة النماذج. ولفهم السلوك الشامل لقابلية تشغيل لسبيكة الالمنيوم سيليكون (Al-Si) تحت أوضاع التشغيل المتفاوتة، تم إجراء تحليل التأثير الأساسي. بينت النتائج ان معدل الازالة المعدنية يزداد مع رفع تيار النبضة وفترة إفراغ النبضة. يمكن الاستحصال ايضا على نقصان في كل من معدل بلى القطب وخشونة السطح عن طريق خفض تيار النبضة ووقت إفراغ النبضة. ومع ذلك، فإن تيار النبضة هو العامل المتحكم (الاكثر تأثيرا) على معدل الازالة المعدنية وخشونة السطح متبوعا زمن تفريغ النبضة وزمن توقف النبضة، في حين أن في معدل بلى القطب فان تيار النبضة هو العامل الاكثر تأثيرا يليه زمن توقف النبضة وزمن إفراغ النبضة. أخيرا استعملت أسلوب الامثلية متعددة الاهداف بالاعتماد على نظرية دالة الرغبة للاستحصال على المقدار الامثل لمتغيرات التشغيل بحيث يمكن الاستحصال من خلالها على اعلى مقدار لمعدل الازالة المعدنية وأدنى مقدار لكل من متوسط بلى القطب وخشونة السطح مع المتغيرات المؤثرة.This work exhibits an incorporated way to deal with the procedure demonstrating and multi-target improvement of EDM parameters of Al-Si based on response surface methodology (RSM) combined with desirability function (DF) method. The’ effect’ of’ process’ parameters   for’ example, pulse current (Ip), pulse’ on’ time’ (Ton) as well as pulse’ off’ time’ (Toff) on’ metal removal’ rate’ (MRR), electrode’ wear’ rate’ (EWR) and’ surface’ roughness’ (Ra), were analyzed. An extensive investigation of difference (ANOVA) at fixed indicative level of 5%, was done to completely distinguish the most persuasive parameters, and the sufficiency of all fitted relapse models were checked. To completely comprehend the trademark machinability conduct under various EDM conditions, fundamental effect investigation. The results indicate that MRR increases with the rising Ip and Ton. Low EWR and Ra can be acquired by diminishing Ip and Ton. Be that as it may, the Ip is the most commanding parameter pursued by Ton and Toff for MRR and Ra whereas in the EWR, the Ip is the foremost factor, followed by the Toff and Ton. Lastly, a multi-optimization way dependent upon the desirability function (DF) idea was used to discover ideal blends of machining parameters so that it was capable to produce the the most extreme estimation of MRR and least estimations of EWR and Ra, inside the noteworthy information parameters

    Determination uranium concentration of teeth in Al-Samawa city using the CR-39 nuclear track detector

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    In this research, The uranium concentration in teeth samples was measured using a CR-39 track detector and the fission tracks registration method., for 25 samples of teeth distributed across Samawa City, each weighing (0.7) grams and (2) mm in thickness. Exposed done after preparing the samples into small spherical pellets covered with a 1x1cm2 CR-39 detector. These samples with detectors together were irradiated using an (241Am-Be) source with a neutron flux (5x103 n.cm-2.s-1) for one week. These samples were compared with standard samples to find uranium concentration. The results show that the maximum value of uranium concentration was (2.273 ppm) and value of the minimum uranium concentration was (0.626 ppm) and the concentration of uranium in females was higher than in males, the concentration of uranium was affected by several factors: the region of study, gender and age of the human.

    Relationship of Smart Cities and Smart Tourism: An Overview

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    Smart cities and smart tourism terms have become very popular in the past and present decades. Research in the field of smart tourist cities still fails to cover the developments of the smart tourist city. The aim of the study is to review the recent literature on smart cities and smart tourism and their roles in achieving a sustainable tourism sector and enhancing the competitiveness of the country’s tourism sector by making it more developed and modern. In this study, the relationship between the smart city and tourism is presented and tries to present the relationship or conceptual approach between the smart city and smart tourism. In addition, the current situation and the potential for growth and development of tourism in Iraq through the establishment and application of smart cities are identified. The recent studies that were mentioned in this study indicate that there is a close relationship between the smart city and smart tourism and also indicate that the smart city has a fundamental role in the growth and development of tourist destinations. The smart tourist cities are results of the convergence and interconnection between the smart city and the tourist city. Finally, recommendations for the smart tourism city applications in Iraq are provided. Doi: 10.28991/HIJ-2020-01-04-07 Full Text: PD

    Combination of GIS with Different Technologies for Water Quality: An Overview

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    Water is one of the most important requirements in daily life, which represents the largest part of the Earth. As a result, economic, industrial, and social development in most countries has led to increased pollution of water resources. It is, therefore, necessary to monitor water quality continuously to prevent a future catastrophe that adversely affects the quality and quantity of water wealth. A Geographic Information System (GIS) is used in various fields to monitor and analyze data collected from different geographical locations. Integration of GIS and other technologies has become an indispensable tool. This gives us direct control over solution expansion, cost reduction, powerful complex case analysis, as well as increased accuracy and efficiency of geospatial data. In recent years, many combinations of GIS with different technologies such as remote sensing, wireless sensor networks, and internet of things approaches have been proposed due to the rapid progress of technology development in many applications. However, in the last several years, no review articles have been published about water quality using the integration of GIS and other technologies. Therefore, this paper investigates the status of continuous search in the field of GIS and its integration with other technologies (Remote Sensing, Internet of Things, Web, etc.) for water quality management and monitoring to maintain the water resources in a proper way. Finally, the integration of GIS with these technologies creates a powerful platform for analyzing and processing big data and mapping geographic remotely in less time, at a lower cost, at a higher speed, with more accurate details, and in real time when compared to traditional geographic information systems. This paper also highlights future research trends on the cooperation of GIS with other technologies for matters that are related to water quality. Doi: 10.28991/HIJ-2021-02-03-10 Full Text: PD

    Dynamic characteristics of cracked simply supported bidirectional functionally graded Rayleigh beam

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    This paper investigates the dynamic behavior of cracked Rayleigh beams constructed from bidirectional functionally graded (BDFG) materials under simple boundary conditions. A torsional massless spring is employed to model the beam's open crack type. The vibration equations are obtained using Hamilton's principle. The graded beam material properties are varied throughout the thickness based on the power-law distribution and in the longitudinal direction using the exponential material distribution. To solve the dynamic equations, Galerkin's approach is employed. The paper evaluates the impacts of the axial index, gradient property index, beam modulus ratio, and crack parameters on the natural frequencies of the FG beam. The results indicate that the dimensionless natural frequencies of intact graded beams decrease with increased gradient index k. In contrast, they increase with a rise in the modulus ratio. Additionally, the results demonstrate that an increase in the crack depth ratio decreases dimensionless natural frequencies

    The Effect of Orally -Administered Calcium Carbonate to Pregnant Women with Mild Pre-eclampsia

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    Pre-eclampsia is the most common medical complication of pregnancy associated with increased maternal and infant mortality and morbidity. Its exact etiology is not known, although several evidences indicate that various elements might play an important role in pre-eclampsia. This study was carried out to analyze and to compare the concentration of calcium, in mild pre-eclampsia and in normal pregnant women , and to determine the effect of oral supplementation with calcium on mild pre-eclampsia  , and whether this effect is related to the change in the level of serum calcium. Forty- five women  in the third trimester of pregnancy were selected to participate in this study and divided  into: fifteen apparently healthy, normotensive pregnant  women  served as a control group; thirty clinically diagnosed patients with mild pre-eclampsia ( 15 mild pre-eclamptic un-treated group , 15 mild pre-eclamptic treated with calcium carbonate 500 mg twice daily) , the serum calcium  were estimated with an atomic absorption spectrophotometer .the data were analyzed using the un- paired Student’s-test.The serum calcium in mild pre-eclmpatic un-treated group was significantly lower than that in normal pregnant women (8.84 ± 1.14 Vs. 9.66 ± 0.87   , p<0.05) , Serum calcium level significantly increased in mild pre-eclamptic treated with calcium carbonate 500mg twice daily as compared to mild pre-eclamptic un-treated group (9.76 ±0.96 Vs 8.84±1.14 ,p<0.05) . Systolic ,diastolic, and mean arterial blood pressure were significantly reduced after one  month of treatment with calcium carbonate 500 mg twice daily as compared to mild pre-eclamptic  un –treated group.(134.83 ± 7.5 Vs139.33 ± 5.30, 88.46 ± 3.27 Vs 91 ± 3.38, 103.90 ± 3.8Vs106.66 ± 3.08 ,p<0.05) respectively.This study showed that serum calcium level in mild pre-eclampsia are lower than in normotensive pregnant women   ,this finding support the hypothesis that hypocalcemia is a possible etiology in pre-eclampsia ; additionally this study showed  the possible beneficial effect of calcium supplementation in controlling pre-eclampsia and reducing blood pressure  by increasing serum calcium level . Key words: Mild Pre-eclampsia, Calcium carbonate tablet, Pregnant women, Serum calciu

    An overview of nanoparticles in drug delivery: Properties and applications

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    Today, in diverse medical and clinical fields, including cancer treatment, nanoscience has evolved and evolved. Cancer and its forms, on the other hand, have been rumored and inclusive, and many individuals suffer from this fatal and lethal condition. Actually, even with the medicinal effect, current therapeutic approaches, including chemotherapy, radiotherapy, etc., create symptoms that are inconvenient for patients. Scientists and scholars are also working to establish and, strengthen the options and methods of therapy to deal with this dangerous illness. Nanoscience and nanotechnology have been popular today, their different areas, including nanoparticles, are commonly used for a number of applications, especially for drug delivery and diagnostic products, and cases of imaging. Release mechanisms focused on nanotechnology have a profound effect on the release of cancer drugs. Biomaterials and bio-engineering developments are leading to novel approaches to nanoparticles that could offer a new way for cancer patients to improve. In the drug release method, Nano-technology has had a great effect on the selection of cancer cells, the release of a targeted drug, and the overcoming of traditional chemotherapy limitations. This article discusses the drug delivery to tumor tissue, a method that is more effective than traditional drug delivery methods, also many new nanoparticles have solved the problem of cell resistance to the drug, provided a new field in the treatment of cancer

    Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

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    OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally
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