Vibration frequency analysis of three-layered cylinder shaped shell with effect of FGM central layer thickness.
ABSTRACT: In this research, vibration frequency analysis of three layered functionally graded material (FGM) cylinder-shaped shell is studied with FGM central layer and the internal and external layers are of homogenous material. Strain and curvature-displacement relations are taken from Sander's shell theory. The shell frequency equation is obtained by employing the Rayleigh Ritz method. Influence on natural frequencies (NFs) is observed for various thickness of the middle layer. The characteristics beam functions are used to estimate the dependence of axial modal. Results are obtained for thickness to radius ratios and length to radius ratios for different edge conditions. The validity of this method is checked for numerous results in the open literature.
Project description:A four-noded finite element of a moderately thick plate made of functionally graded material (FGM) is presented. The base element is rectangular and can be extended to any shape using a transformation based on NURBS functions. The proposed 2D shape functions are consistent with the physical interpretation and describe the states of element displacement caused by unit displacements of nodes. These functions depend on the FGM's material parameters and are called material-oriented. The shape function matrix is based on a superposition displacement field of two plate strips with 1D exact shape functions. A characteristic feature of the proposed formulation is full coupling of the membrane and bending states in the plate. The analytical form of the stiffness matrix and the nodal load vector was obtained, which leads to the numerical efficiency of the formulation. The element has been incorporated into Abaqus software with the use of Maple program. The finite element shows good convergence properties for different FGM models in the transverse direction to the middle plane of the plate. During derivation of the 2D plate element the formally exact 1D finite element for transverse nonhomogeneous FGM plate strip was developed.
Project description:This study aimed to develop series analytical solutions based on the Mindlin plate theory for the free vibrations of functionally graded material (FGM) rectangular plates. The material properties of FGM rectangular plates are assumed to vary along their thickness, and the volume fractions of the plate constituents are defined by a simple power-law function. The series solutions consist of the Fourier cosine series and auxiliary functions of polynomials. The series solutions were established by satisfying governing equations and boundary conditions in the expanded space of the Fourier cosine series. The proposed solutions were validated through comprehensive convergence studies on the first six vibration frequencies of square plates under four combinations of boundary conditions and through comparison of the obtained convergent results with those in the literature. The convergence studies indicated that the solutions obtained for different modes could converge from the upper or lower bounds to the exact values or in an oscillatory manner. The present solutions were further employed to determine the first six vibration frequencies of FGM rectangular plates with various aspect ratios, thickness-to-width ratios, distributions of material properties and combinations of boundary conditions.
Project description:In 2015, UN member states committed to eliminate female genital mutilation (FGM) by 2030 as part of the Sustainable Development Agenda. To reach this goal, interventions need to be targeted and guided by the best available evidence. To date, however, estimates of the number of girls and women affected by FGM and their trends over time and geographic space have been limited by the availability, specificity and quality of population-level data. We present new estimates based on all publicly available nationally representative surveys collected since the 1990s that contain both information on FGM status and on the age at which FGM occurred. Using survival analysis, we generate estimates of FGM risk by single year of age for all countries with available data, and for rural and urban areas separately. The likelihood of experiencing FGM has decreased at the global level, but progress has been starkly uneven between countries. The available data indicate no progress in reducing FGM risk in Gambia, Guinea-Bissau, Mali and Guinea. In addition, rural and urban areas have diverged over the last two decades, with FGM declining more rapidly in urban areas. We describe limitations in the availability and quality of data on FGM occurrence and age-at-FGM. Based on current trends, the SDG goal of eliminating FGM by 2030 is out of reach, and the pace at which the practice is being abandoned would need to accelerate to eliminate FGM by 2030. The heterogeneity in trends between countries and rural vs urban areas offers an opportunity to contrast countries where FGM is in rapid decline and explore potential policy lessons and programmatic implications for countries where the practice of FGM appears to remain entrenched.
Project description:BACKGROUND:Although Sudan has one of the highest prevalence of female genital mutilation or cutting (FGM/C), there have been shifts in e practice. These shifts include a reduction in the prevalence among younger age cohorts, changes in the types of FGM/C, an increase in medicalization, and changes in age of the practice. The drivers of these shifts are not well understood. METHOD:Qualitative data drawn from a larger study in Khartoum and Gedaref States, Family and Midwife individual interviews and focus group discussions. Analysis and categorization within a Social Norms theoretical framework. RESULTS:Major findings confirmed shifts in the type FGM/C (presumably from infibulation to non-infibulating types) and increasing medicalization in the studied communities. These shifts were reported to be driven by social, professional and religious norms. CONCLUSION:Changes in FGM practice in Sudan include drivers which will not facilitate abandonment of the practice instead lead to normalization of FGM/C. Yet professionalisation of Midwives including their oath to stop FGM/C has potential to facilitate abandonment rapidly if developed with other Sudan health professionals.
Project description:Background: Female genital mutilation (FGM) occurs mainly in Africa, parts of the Arabian Peninsula and parts of Asia. It is commonly associated with acute complications as well as diverse late/delayed complications. One of the most common of these late complications is progressively enlarging painless cysts of the vulva. Case Report: An 8-year-old girl from Eritrea presented to our paediatric emergency department with a progressively enlarging mass of the vulva. She had undergone a clitoridectomy and partial removal of the labia minora as an infant in Eritrea. We performed surgical excision of the cyst and reconstruction of the labia. Histology showed a traumatic squamous epithelial inclusion cyst of the vulva. Conclusion: Epithelial or dermoid cysts of the vulva following FGM are extremely rare. Symptoms often require surgical intervention. Through increasing migration, more girls and female youths with FGM are likely to present to practices and hospitals in Germany. Thus increased knowledge and awareness of the medical complications of FGM and their treatment will be necessary in years to come.
Project description:The large bulk bandgap (1.35 eV) and Bohr radius (~10 nm) of InP semiconductor nanocrystals provides bandgap tunability over a wide spectral range, providing superior color tuning compared to that of CdSe quantum dots. In this paper, the dependence of the bandgap, photoluminescence emission, and exciton radiative lifetime of core/shell quantum dot heterostructures has been investigated using colloidal InP core nanocrystals with multiple diameters (1.5, 2.5, and 3.7 nm). The shell thickness and composition dependence of the bandgap for type-I and type-II heterostructures was observed by coating the InP core with ZnS, ZnSe, CdS, or CdSe through one to ten iterations of a successive ion layer adsorption and reaction (SILAR)-based shell deposition. The empirical results are compared to bandgap energy predictions made with effective mass modeling. Photoluminescence emission colors have been successfully tuned throughout the visible and into the near infrared (NIR) wavelength ranges for type-I and type-II heterostructures, respectively. Based on sizing data from transmission electron microscopy (TEM), it is observed that at the same particle diameter, average radiative lifetimes can differ as much as 20-fold across different shell compositions due to the relative positions of valence and conduction bands. In this direct comparison of InP/ZnS, InP/ZnSe, InP/CdS, and InP/CdSe core/shell heterostructures, we clearly delineate the impact of core size, shell composition, and shell thickness on the resulting optical properties. Specifically, Zn-based shells yield type-I structures that are color tuned through core size, while the Cd-based shells yield type-II particles that emit in the NIR regardless of the starting core size if several layers of CdS(e) have been successfully deposited. Particles with thicker CdS(e) shells exhibit longer photoluminescence lifetimes, while little shell-thickness dependence is observed for the Zn-based shells. Taken together, these InP-based heterostructures demonstrate the extent to which we are able to precisely tailor the material properties of core/shell particles using core/shell dimensions and composition as variables.
Project description:INTRODUCTION:Female genital mutilation (FGM) is a significant global health concern and is likely to become an increasingly important healthcare challenge in destination countries such as the UK owing to rising levels of migration from FGM-affected countries. Currently, there is no consensus on the optimal timing of deinfibulation (opening) surgery for women who have experienced type 3 FGM and care provision remains suboptimal in the UK. This qualitative study aims to explore the views of survivors, male partners and healthcare professionals (HCPs) on the timing of deinfibulation and delivery of NHS FGM services. METHODS AND ANALYSIS:A qualitative study, informed by the Sound of Silence conceptual framework, will be undertaken via two work packages (WPs). WP1 will explore views on timing preferences for deinfibulation and NHS FGM services through interviews and discussion groups with FGM survivors (n~50), male partners (n~10) and HCPs (n~50). WP2 will use established techniques via two workshops (community (n~20-25 participants) and national stakeholder (n~30-35 participants)) to synthesise qualitative research findings and inform best practice and policy recommendations around the timing of deinfibulation and NHS FGM care provision. Supported by trained interpreters, data collection will be audio recorded and transcribed. Data will be analysed using the framework method to facilitate a systematic mapping and exploration of qualitative data from multiple sources. ETHICS AND DISSEMINATION:The study has received ethical approval from the North West Greater Manchester East Research Ethics Committee (18/NW/0498). The outputs for this study will be recommendations for best practice and policy around FGM care provision that reflects the views and preferences of key stakeholders. The findings will be disseminated via conference presentations, peer-reviewed publications, patient groups, third sector organisations and social media. TRIAL REGISTRATION NUMBER:ISRCTN 14710507.
Project description:<h4>Background</h4>Female genital mutilation/cutting (FGM/C) is a common practice in developing countries, including the UAE, and presents a major health problem.<h4>Methods</h4>A questionnaire-based cross-sectional study was conducted among 1035 participants: 831 (80.3%) females and 204 (19.7%) males.<h4>Results</h4>The number of women with FGM/C was 344; hence the prevalence of FGM/C in our study was 41.4%. Type I was the most prevalent (62.8%), followed by Type II (16.6%) and Type III (5%). FGM/C was less prevalent among educated and employed women (p-value <?0.001) and was mostly performed during infancy and childhood. Among the participants, 13.7% reported that their daughters had undergone FGM/C, with Type I being the most common, and 25% of them planned to have their future daughters undergo Type I FGM/C. While FGM/C was mostly performed by ritual circumcisers (74.4%), in 25 and 36.7% of the cases, it was performed by health professionals and in the clinic setting, respectively. About 69% of the participants considered FGM/C a custom, 72.8% were against the practice, and only 17.4% believed in its legality. Complications occurred in 30% of cases. The type of FGM/C was associated with the occurrence of complications: bleeding, difficulties in sexual life, and delivery-related problems (p-value <?0.05). One-fifth of the male participants expressed plans to circumcise future daughters (p-value <?0.001).<h4>Conclusion</h4>FGM/C remains a prevalent practice in the UAE and has a negative association with the general health of Emirati women. The lack of clear legislation to criminalize this practice is a problem to be addressed. In this context, national-level educational and legal strategies should be a priority.
Project description:A theoretical analysis and computational study of biomaterial sample detection with surface plasmon resonance (SPR) phenomenon spectroscopy are presented in this work with the objective of achieving more sensitive detection. In this paper, a Fe?O?@Au core-shell, a nanocomposite spherical nanoparticle consisting of a spherical Fe?O? core covered by an Au shell, was used as an active material for biomaterial sample detection, such as for blood plasma, haemoglobin (Hb) cytoplasm and lecithin, with a wavelength of 632.8 nm. We present the detection amplification technique through an attenuated total reflection (ATR) spectrum in the Kretschmann configuration. The system consists of a four-layer material, i.e., prism/Ag/Fe?O?@Au + biomaterial sample/air. The effective permittivity determination of the core-shell nanoparticle (Fe?O?@Au) and the composite (Fe?O?@Au + biomaterial sample) was done by applying the effective medium theory approximation, and the calculation of the reflectivity was carried out by varying the size of the core-shell, volume fraction and biomaterial sample. In this model, the refractive index (RI) of the BK7 prism is 1.51; the RI of the Ag thin film is 0.13455 + 3.98651i with a thickness of 40 nm; and the RI of the composite is varied depending on the size of the nanoparticle core-shell and the RI of the biomaterial samples. Our results show that by varying the sizes of the core-shell, volume fraction and the RIs of the biomaterial samples, the dip in the reflectivity (ATR) spectrum is shifted to the larger angle of incident light, and the addition of a core-shell in the conventional SPR-based biosensor leads to the enhancement of the SPR biosensor sensitivity. For a core-shell with a radius a = 2.5 nm, the sensitivity increased by 10% for blood plasma detection, 47.72% for Hb cytoplasm detection and by 22.08% for lecithin detection compared to the sensitivity of the conventional SPR-based biosensor without core-shell addition.
Project description:INTRODUCTION:Female genital mutilation (FGM) is an issue of global concern. High levels of migration mean that healthcare systems in higher-income western countries are increasingly being challenged to respond to the care needs of affected communities. Research has identified significant challenges in the provision of, and access to, FGM-related healthcare. There is a lack of confidence and competence among health professionals in providing appropriate care, suggesting an urgent need for evidence-based service development in this area. This study will involve two systematic reviews of qualitative evidence to explore the experiences, needs, barriers and facilitators to seeking and providing FGM-related healthcare in high-income (Organisation for Economic Cooperation and Development) countries, from the perspectives of: (1) women and girls who have undergone FGM and (2) health professionals. REVIEW METHODS:Twelve databases including MEDLINE, EMBASE, PsycINFO, ASSIA, Web of Science, ERIC, CINAHL, and POPLINE will be searched with no limits on publication year. Relevant grey literature will be identified from digital sources and professional networks.Two reviewers will independently screen, select and critically appraise the studies. Study quality will be assessed using the Joanna Briggs Institute Qualitative Assessment and Review Instrument appraisal tool. Findings will be extracted into NVivo software. Synthesis will involve inductive thematic analysis, including in-depth reading, line by line coding of the findings, development of descriptive themes and re-coding to higher level analytical themes. Confidence in the review findings will be assessed using the CERQual approach. Findings will be integrated into a comprehensive set of recommendations for research, policy and practice. DISSEMINATION:The syntheses will be reported as per the Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) statement. Two reviews will be published in peer-reviewed journals and an integrated report disseminated at stakeholder engagement events. PROSPEROREGISTRATION NUMBER:CRD42015030001: 2015 and CRD42015030004: 2015.