Dielectric properties of Cu0.5Tl0.5Ba2Ca2Cu3O10-δ superconductor added with nano-Fe2O3

A series of high-temperature superconducting samples of type Cu0.5Tl0.5Ba2Ca2Cu3O10-δ, (Cu0.5Tl0.5)-1223, added with nano-Fe2O3 (0.0- 1.0 wt. %) was prepared by a solid-state reaction technique via short time preparation procedure and under ambient pressure. The prepared samples were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) for phase analysis and microstructure examination. The volume fraction results indicated that nano-Fe2O3 addition was significant in enhancing the formation rate of the (Cu0.5Tl0.5)-1223 phase, especially for x ≤ 0.2 wt. % samples. The electrical resistivity of the prepared samples was measured by the conventional four-probe technique from room temperature down to the zero superconducting transition temperature (T0). An increase in the superconducting temperature, Tc, is observed up to x = 0.2 wt. %, followed by a systematic decrease with increasing nano-Fe2O3 addition. The dielectric constants (ε\u27 and ε\u27\u27), dissipation factor (tan Δ) and real ac conductivity (σ\u27ac) were investigated as a function of temperature (113- 293 K) and frequency (102- 106 Hz). The results clarified that all these dielectric parameters show a strong dispersion with temperatures at low and moderate frequency ranges. Moreover, they are strongly dependent on nano-Fe2O3 addition. Furthermore, the high content of nano-Fe2O3 addition (x = 1.0 wt. %) enhanced ε\u27 and reduced tan D of (Cu0.5Tl0.5)-1223 phase, which is a desirable demand for practical applications

Proton conducting membrane by radiation-induced grafting of 1-vinylimidazole onto poly(ethylene-co-tetrafluoro ethylene) film and phosphoric acid doping

Phosphoric acid doped proton conducting membranes denoted as ETFE-g- P(1-VIm) for possible use in high temperature polymer electrolyte membrane fuel cell (PEMFC) were prepared by radiation induced graft polymerization of 1- vinylimidazole (1-VIm) onto poly(ethylene-co-tetrafluoroethylene) (ETFE) films followed by doping with phosphoric acid (PA). The ETFE films were irradiated by electron beam (EB) accelerator prior to grafting. The effect of the grafting parameters such as monomer concentration, absorbed dose, reaction time and medium temperature onto the degree of grafting (G%) were studied. The G% was found to be strongly dependent upon the investigated grafting parameters, which were optimized using response surface method (RSM) through the Box-Behnken design expert software. This led to the development of a quadratic model capable of predicting the degree of grafting. The validity of the statistical model was supported by the small deviation between the predicted (G = 61%) and experimental (G = 57%) values. The optimum conditions for achieving maximum G% were determined at: monomer concentration of 55 vol%, absorbed dose of 100 kGy, reaction time in the range of 14-20 h and medium temperature of 61°C. The effect of phosphoric acid doping parameters on the doping behaviour of the grafted ETFE films was also optimized using Taguchi method through implementing a Taguchi L9 (34) orthogonal array. The optimum parameters for achieving a maximum acid doping level (7.45 mmol/repeat polymer unit) were: G of 54%, acid concentration of 65%, temperature of 100oC and time of 5 days. The predicted doping value was deviated by 4.9% from the experimental one suggesting the validity of the model in prediction and optimization of acid doping reaction. The kinetics of phosphoric acid doping reaction was also investigated and two rate constants of 0.46 and 0.16 for PA doping reaction were graphically obtained suggesting a zeroth order reaction. The proton conductivity of the membranes was investigated using 4-probe conductivity cell attached to a direct current source meter in correlation with temperature and relative humidity. The proton conductivity was found to increase with the increase in doping level at constant temperature and relative humidity. Proton conductivity of 143 mS/cm at 20% relative humidity was achieved in the membranes having G of 38 and 54% suggesting a less water dependant conductivity. It can be concluded that the obtained membranes have very good combinations of physico-chemical and material properties suitable for possible application in PEMFC operating above 100 oC

Turbulent flow in an idealized wing-body junction

Imperial Users onl

Unequal citizens: Cairo between gated and informal

The conception of citizenship which accompanied the emergence of the nation-state, in essence, relates to ‘a territorially bounded population with a specific set of rights and duties.’ Such a conception of citizenship assumes that all the members of the nation have exactly the same set of rights and duties. I am interested in studying Cairo. Unfortunately, it is particularly far from this normative definition of citizenship, as its citizens are not equal. For that reason, I am keen on studying citizenship in practice, as a relation between citizens and state. I argue that state practices, represented in urban planning, are constructing distinct communities based on spatial segregation and inequality which constitute different citizenships within the same society. These different conceptions of citizenship imply that the citizens of the same nation have distinct visions on their roles as citizens and the role of the state towards them. Consequently, the state-society relations are framed differently by both the citizens and the state, based on the citizens’ discrete social, economic and political realities. I am specifically interested in answering the question of how does state-citizen relations differ from gated communities to informal areas? And what are the implications of these different conceptions of citizenship? In an attempt to answer this question, fieldwork has been conducted in two selected neighboring areas; Uptown Cairo representing a gated community and Manshīyat Nāṣir representing an informal area

The Role of Nutrient Supplementation to Prevent Perinatal Depression. A Narrative Review

Background: Micronutrient supplements are widely available and can play a crucial role in the prevention of perinatal depression; however, their benefits are still not well studied.Objectives: The authors performed this literature review to assess the effectiveness of micronutrients to prevent perinatal depression.Method: The authors searched electronic databases (PubMed, Scopus, and USW Library) until May 1, 2023. The studies were included if they were evaluating the preventive effect of micronutrients on perinatal depression.Results: The authors identified 3218 articles, of which 14 were eligible to be included in the review (8 RCTs, 3 Cohort studies, and 3 cross-sectional studies). Results of the review illustrate some degree of effectiveness of vitamin D supplementation, calcium, selenium, manganese, and probiotics to provide preventive effects against perinatal depression, while there is no evidence of a significant preventive effect for PUFAS (fish oil) supplementation.Conclusion: Despite the popular information. PUFA supplements had no role in preventing perinatal depression. Other nutrients such as vitamin D, calcium, selenium, manganese, and probiotics showed some protective effects, which warranted more research in this area and preferably in women with a history of perinatal depression for a better understanding of their preventive effects

Nursing Students' Perception regarding Patients' Rights and Patients' Advocacy

Background: Advocacy (protection) is one  key concepts in nursing ethics  defined as the process of informing patients who seek health care and have efforts in creating a safe place and clean hospital for patients. An important tenet of nursing is respecting the human rights and dignity of all patients. The priority of healthcare organizations must be protection of patients’ rights. If the human rights and patients welfare be at risk, it is necessary that a person undertake their protection.  The patient's advocacy is vital for vulnerable groups such as elders, very young people, people who reside in institutions, prisoners and disabled group. Nursing profession is a job in which human rights and ethics are essential points and the distance between the ethical issues related to this profession and their application is also important. Aim: Assess the  nursing students' perceptions regarding patients' rights and patients' advocacy. Design: descriptive correlation design. Subjects: Convenient sample of nursing students (No. =143) in Faculty of Nursing at Port Said University/ Egypt. Tools: The data collected using two tools, the first one:  questionnaire which assesses the patients' rights. The second tool: The patients' advocacy questionnaire. Results: There was highly perception of nursing students regarding patients' rights and patients' advocacy. Recommendation: Further studies to assess the health care providers' awareness and application of patients' right and patients' advocacy needs to be conducted in Egypt. Key Words: Patients' Right, Patient Advocacy, Nursing Students' Perception

Women\u27s health: A global perspective

The purpose of this chapter is to discuss global issues related to women\u27s health. Several universal issues were selected for presentation to provide a context for understanding health care for women and to challenge readers to identify potential threats to quality care. In addition, principles that have been proposed for the development and implementation of a viable and comprehensive health care system for women are identified and discussed. The intent here is not to capture the situation and health experience of women in all parts of the world; nor is it possible to address all the contextual contingencies needed for addressing women\u27s health. Rather, the intent is to provide a framework for understanding the neglect that women have encountered in all aspects of their lives, including health care. Furthermore, our aim is to provide those who have been committed to health care for women with support in their attempt to provide quality health carefor other women. Finally,our goal is to raise the readers\u27 consciousness of women\u27s health needs beyond the United States. We fully realize that women\u27s health issues cannot be understood in isolation from the specific sociocultural context of their situations; however, by highlighting some universals, perhaps we can underscore the need for global cooperation in taking a more coherent and coordinated approach to providing affordable and quality health care for women

Effect of resistance and aerobic exercises on bone mineral density, muscle strength and functional ability in children with hemophilia

Background and purpose: Children with hemophilia are at risk for reduced bone mineral density (BMD), muscle strength and functional ability as a result of reduced leisure-time activity and less involvement in intense activities. So, the purpose of this study was to investigate the effect of resistance and aerobic exercise program on BMD, muscle strength and functional ability in children with hemophilia.Materials and methods: Thirty boys with hemophilia A ranging in age from 10 to 14 years had participated in this study. They were assigned randomly into two equal groups (control and study groups). Control group received a designed physical therapy program and aerobic exercise in the form of treadmill training, while the study group received the same program as the control group in addition to resistance training program in the form of bicycle ergometer training and weight resistance. Both groups received treatment sessions three times per week for three successive months. BMD, muscle strength of knee flexors and extensors and functional ability were evaluated before and after the 3 months of treatment program.Results: There was no significant difference between both groups in the pre-treatment mean values of all measured variables. Significant improvement was observed in BMD, knee extensors and flexors strength, and functional ability in the study group when comparing pre and post treatment measurements. There was a significant improvement in functional ability of the control group. Significant difference was also observed between both groups when comparing the post treatment measurements in favor of the study group.Conclusion: Based on obtained data, it can be concluded that, resistance and aerobic exercise training program is effective in increasing BMD, muscle strength and functional ability in children with hemophilia.Keywords: Hemophilia; Resistance; Aerobic exercise; Bone mineral density; Strength; Functional abilit