1,559 research outputs found
IDENTIFYING THE OPTIMUM PROCESS PARAMETERS OF PRECISION GLASS MOLDING FOR ASPHERICAL LENSES
The purpose of this research is to determine the optimum process parameters for the Precision Glass Molding (PGM) Process using Manufacturing Design, Design of Experiments and Metrology (for measuring the geometry of lenses). First, a custom machine is designed and manufactured which can carry out Precision Glass Lens Molding Experiments. This machine is then modified to improve temperature, position and force control. A literature review is performed to obtain data for process parameters that have been used in previous PGM studies. The collected data is then used in Design of Experiments to create twenty seven experiments that determine the optimum process parameters. The lenses produced from these experiments are measured for surface form and surface roughness. This research also addresses the issues with PGM which include wear of mold coating, sticking of glass on mold cavities and repeatability of form of the lenses produced. This project resulted in data that could be used in validating PGM finite element simulations and the PGM experiments are able to produce good quality lenses. Three experiments are chosen for optimum process parameters. One experiment has the optimum (minimum) cycle time for PGM, the second experiment has the optimum process repeatability and the third has optimum process parameters for reducing power error on the aspherical side of the lens
The impact of human capital on urban poverty: The case of Sargodha city
The positive relationship between human capital and income/wages has been supported by empirical research. Millennium Development Goals (MDGs) and the Poverty Reduction Strategy Paper (PRSP) enormously emphasize on human capital for curbing poverty. The economic development in East Asian countries is also linked with investment in education for the development of human capital. This study is designed to investigate the relationship of different levels of education and experience upon urban poverty at medium sized city in Pakistan such as Sargodha. A survey-based analysis was carried out on a sample of 330 households. Poverty status of the individual is defined by using adjusted official poverty line. Results show that education and experience is negatively related with the poverty status of individuals and this fact sustains even in separate gender estimates as well. This implies education of poor is necessary in breaking the vicious circle of poverty. Combined effort by public, private, community participation and NGO’s with special focus on elementary (Primary and middle) education is suggested for reducing poverty by increasing the productivity of the poor through education.Human Capital, Urban Poverty, Sargodha, Pakistan
Women's experiences of mistreatment during childbirth: A comparative view of home- and facility-based births in Pakistan.
INTRODUCTION: Respectful and dignified healthcare is a fundamental right for every woman. However, many women seeking childbirth services, especially those in low-income countries such as Pakistan, are mistreated by their birth attendants. The aim of this epidemiological study was to estimate the prevalence of mistreatment and types of mistreatment among women giving birth in facility- and home-based settings in Pakistan in order to address the lack of empirical evidence on this topic. The study also examined the association between demographics (socio-demographic, reproductive history and empowerment status) and mistreatment, both in general and according to birth setting (whether home- or facility-based). MATERIAL AND METHODS: In phase one, we identified 24 mistreatment indicators through an extensive literature review. We then pre-tested these indicators and classified them into seven behavioural types. During phase two, the survey was conducted (April-May 2013) in 14 districts across Pakistan. A total of 1,334 women who had given birth at home or in a healthcare facility over the past 12 months were interviewed. Linear regression analysis was employed for the full data set, and for facility- and home-based births separately, using Stata version 14.1. RESULTS: There were no significant differences in manifestations of mistreatment between facility- and home-based childbirths. Approximately 97% of women reported experiencing at least one disrespectful and abusive behaviour. Experiences of mistreatment by type were as follows: non-consented care (81%); right to information (72%); non-confidential care (69%); verbal abuse (35%); abandonment of care (32%); discriminatory care (15%); and physical abuse (15%). In overall analysis, experience of mistreatment was lower among women who were unemployed (β = -1.17, 95% CI -1.81, -0.53); and higher among less empowered women (β = 0.11, 95% CI 0.06, 0.16); and those assisted by a traditional birth attendant as opposed to a general physician (β = 0.94, 95% CI 0.13, 1.75). Sub-group analyses for home-based births identified the same significant associations with mistreatment, with ethnicity included. In facility-based births, there was a significant relationship between women's employment and empowerment status and mistreatment. Women with prior education on birth preparedness were less likely to experience mistreatment compared to those who had received no previous birth preparedness education. CONCLUSION: In order to promote care that is woman-centred and provided in a respectful and culturally appropriate manner, service providers should be cognisant of the current situation and ensure provision of quality antenatal care. At the community level, women should seek antenatal care for improved birth preparedness, while at the interpersonal level strategies should be devised to leverage women's ability to participate in key household decisions
Channel Impulse Response-based Distributed Physical Layer Authentication
In this preliminary work, we study the problem of {\it distributed}
authentication in wireless networks. Specifically, we consider a system where
multiple Bob (sensor) nodes listen to a channel and report their {\it
correlated} measurements to a Fusion Center (FC) which makes the ultimate
authentication decision. For the feature-based authentication at the FC,
channel impulse response has been utilized as the device fingerprint.
Additionally, the {\it correlated} measurements by the Bob nodes allow us to
invoke Compressed sensing to significantly reduce the reporting overhead to the
FC. Numerical results show that: i) the detection performance of the FC is
superior to that of a single Bob-node, ii) compressed sensing leads to at least
overhead reduction on the reporting channel at the expense of a small
( dB) SNR margin to achieve the same detection performance.Comment: 6 pages, 5 figures, accepted for presentation at IEEE VTC 2017 Sprin
Are underprivileged and less empowered women deprived of respectful maternity care: Inequities in childbirth experiences in public health facilities in Pakistan
Background: Attainment of healthcare in respectful and dignified manner is a fundamental right for every woman regardless of the individual status. However, social exclusion, poor psychosocial support, and demeaning care during childbirth at health facilities are common worldwide, particularly in low- and middle-income countries. We concurrently examined how women with varying socio-demographic characteristics are treated during childbirth, the effect of women\u27s empowerment on mistreatment, and health services factors that contribute to mistreatment in secondary-level public health facilities in Pakistan.Methods: A cross-sectional survey was conducted during August-November 2016 among 783 women who gave birth in six secondary-care public health facilities across four contiguous districts of southern Sindh. Women were recruited in health facilities and later interviewed at home within 42 days of postpartum using a WHO\u27s framework-guided 43-item structured questionnaire. Means, standard deviation, and average were used to describe characteristics of the participants. Multivariable linear regression was applied using Stata 15.1.Results: Women experiencing at least one violation of their right to care by hospital staff during intrapartum care included: ineffective communication (100%); lack of supportive care (99.7%); loss of autonomy (97.5%); failure of meeting professional clinical standards (84.4%); lack of resources (76.3%); verbal abuse (15.2%); physical abuse (14.8%); and discrimination (3.2%). Risk factors of all three dimensions showed significant association with mistreatment: socio-demographic: primigravida and poorer were more mistreated; health services: lesser-education on birth preparedness and postnatal care leads to higher mistreatment; and in terms of women\u27s empowerment: women who were emotionally and physically abused by family, and those with lack of social support and lesser involvement in joint household decision making with husbands are more likely to be mistreated as compared to their counterparts. The magnitude of relationship between all significant risk factors and mistreatment, in the form of β coefficients, ranged from 0.2 to 5.5 with p-values less than 0.05.Conclusion: There are glaring inequalities in terms of the way women are treated during childbirth in public health facilities. Measures of socio-demographic, health services, and women\u27s empowerment showed a significant independent association with mistreatment during childbirth. At the health system level, there is a need for urgent solutions for more inclusive care to ensure that all women are treated with compassion and dignity, complemented by psychosocial support for those who are emotionally disturbed and lack social support
Development of a ceria-based catalyst prepared by the microemulsion method for highly selective CO2 conversion via reverse water gas shift
Reverse water gas shift (RWGS) is an emerging technology for CO2 utilization. The RWGS process catalytically converts CO2 to carbon monoxide (CO), producing syngas (a mixture of hydrogen (H2) and CO) which can be further used to produce higher hydrocarbons. Economically this route is more promising than the carbon capture technology because RWGS converts CO2 to valuable syngas that can offset the cost of CO2 capturing. The main challenge is selecting a suitable catalyst that must be highly active, selective, stable, and durable in converting CO2 to syngas.
In this study, cerium oxide (ceria) prepared through the reverse microemulsion (RME) process is used as a base catalytic material. An extensive investigation has been conducted to assess the potential of the RME-based bulk ceria and supported ceria on γ-alumina towards RWGS reaction, including reaction tests and several characterization techniques including X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transformed infrared spectroscopy (FTIR) to determine outlet gas composition, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) to determine the surface elemental composition, gas adsorption to determine the specific surface area (BET-SSA) and inductively coupled plasma optical emission spectroscopy (ICP-OES) to determine the bulk composition, TEM (transmission electron microscope) to look for the particle shape and find the crystalline planes, TPR (temperature-programmed reduction) to check the reducing abilities of the catalyst, CO2-TPD to find the relevant active site and in-situ FTIR studies to find the RWGS reaction mechanism.
First, RWGS reaction was studied over unsupported bulk ceria (CeO2) prepared by reverse microemulsion (RME) method and direct precipitated method. Using a unique microemulsion ratio, highly porous ceria nanoparticles (RME-ceria) with targeted exposed (111) facets and high specific surface area of 142 m2 gcat-1 were successfully synthesized compared to ceria nanoparticles prepare via direct precipitation method (DP-ceria) with specific surface area of 101 m2 gcat-1. Long term stability tests (almost 100 h on stream) showed well stable activity of RME-ceria towards the RWGS. At lower GHSV of 10,000 ml gcat-1 h-1, nearly equilibrium conversion (~ 62%) was observed which stabilizes after 70 h on stream to around 52%. However, DP-ceria showed significant decline in conversion from 53% to 24% in similar time span of 70 h. Compared to DP-ceria, RME-ceria showed excellent activity and stability at all conditions towards the RWGS reaction.
Second, the RWGS reaction was studied for the first time in the field on catalysis over ceria-supported γ-alumina prepared via reverse microemulsion method. Three catalysts were prepared at three different loadings of ceria (20 wt%, 30 wt% and 40 wt%). All the catalyst were test for the application of RWGS reaction. Results confirm that 40% wt ceria-supported γ-alumina (40%Ce/Al) showed similar activity and stability as of unsupported RME-ceria. 40% Ce/Al showed very high specific surface area of 292.06 m2 gcat-1, which is almost doubled compared to what we observe for the bulk RME-ceria. SEM results confirm the cluster like structure of the catalyst that leads to high porosity and high exposed surface area. Long term stability test at GHSV of 10,000 ml gcat-1 h-1 showed stable 55% CO2 conversion to CO with 100% selectivity. Finally, among all the Ce/Al catalyst formulations 40%Ce/Al catalyst appears as the optimum formulation for RWGS applications.
In the third part of this Ph.D. thesis, a thorough investigation was performed for the scope of stainless-steel reactors in the RWGS application. It was observed that at an operating temperature of above 550°C in a highly active carbonaceous environment of CO-H2-H2O stainless steel undergoes severe corrosion known as metal dusting. This disintegration leads to form nanometal particles that facilitate filamentous coke formation on the steel wall. Empty reactor test (without catalyst) confirms the fact that in the absence of CO, stainless steel showed stable behavior (no reactivity for the incoming gas mixture of H2-CO2 below 550°C and only 4% CO2 conversion to CO even after 90 h on stream).
Finally, suggestions for future work include the study of 40%Ce/Al using more advanced techniques like XPS, TME, and Raman spectroscopy for the in-depth surface analysis that would help to significantly enhance the activity at higher space velocities. It was also proposed that the effect of promoters like Cu, Co, and Fe should be studied. Literature showed that these promoters significantly enhance catalyst activity at a lower temperature. Conclusively, All the catalysts (unsupported and supported) showed 100%CO selectivity and stable conversion with excellent coking resistance
Methylene Blue and Lugol’s Iodine as an Adjunctive Tool for Early Diagnosis of Premalignant Oral Lesions
Objective: To compare Methylene blue and Lugol’s Iodine as6an adjunctive tool6for early diagnosis of premalignant oral6lesions by taking histopathology as gold standard. Methods: In this cross-sectional study patients of oral0premalignant lesions were selected. Methylene blue and lugols iodine staining was used at lesion’s area. Mucosa0of target site was dried gently by gauze0and power0air0spray with triple syringe to make sure that the0lesion is not0being contaminated with0saliva. The dye was applied directly with a cotton0bud for 10-20 seconds and was decolorized. The dye retention pattern was evaluated by stain retention’s intensity on the lesion. Incisional biopsy was performed simultaneously from that site as gold standard. Results: Out of 60 cases, males were 81.6%. Majority (65.0%) had more than one addicting habit of mainpuri, gutka and supari. The commonest region of oral lesions was the buccal6mucosa (61.6%). According to the diagnostic accuracy of methylene blue the sensitivity was 89.4% and specificity was 66.6%. According to the Lugol’s Iodine sensitivity was 83.3% and specificity was 50%. Conclusion: Methylene blue and lugols iodine staining are an easy and non-invasive screening tools for the early diagnosis of malignancy
Efficacy of Oral Zinc Sulphate in the Treatment of Recalcitrant Common Warts
Background: To determine the efficacy of oral Zinc Sulphate in treatment of recalcitrant common warts.Methods: In this randomized control trial 90 patients with recalcitrant warts were randomly allocated to two groups by lottery method named Group A (Oral Zinc sulphate) and Group B (Placebo). Group A patients were given oral zinc sulphate in a dose of 10mg/kg to a maximum dose of 600mg/day for two months. Group B received glucose tablets as placeboResults: Out of 45 patients in oral zinc sulphate group, 28 (62.22%) patients had complete eradication or at least 75% reduction in number of warts noted at presentation. On the other hand in the placebo group only 2 (4.44%) patients had > 75% reduction in number of warts.In oral zinc sulphate group it was noted that only 6 (13.3%) patients had less than 50% reduction in no. of warts. 11 (24.4%) had 50-75% efficacy and majority 28 (62.2%) patients had > 75 % reduction in number of warts. In contrast, in the placebo group 33 patients (73.3%) had less than 50% reduction, followed by 10 (22.2%) patients having 50-75% reduction and only 2 (4.4%) patients had > 75% reduction in no. of wartsConclusion: Warts are common viral infection of skin caused by Human Papilloma Virus. Despite various treatment options available at times warts become recalcitrant. Oral zinc sulphate is an effective treatment option for recalcitrant multiple viral warts. Being oral therapy it is easy to take with less frequent follow up visits required
Synthesis, characterization and evaluation of biological activities of manganese-doped zinc oxide nanoparticles
Purpose: To synthesize, characterize and investigate the antimicrobial properties of pure and manganese-doped zinc oxide nanoparticles.Method: Un-doped and manganese-doped zinc oxide (Mn-doped ZnO) nanoparticles were prepared using co-precipitation method. The synthesized Mn-doped ZnO nanoparticles were characterized using energy-dispersive x-ray spectroscopy (EDX), scanning electron microscopy (SEM), and x-ray diffraction (XRD) spectroscopic techniques. Their band gap energies were measured with ultraviolet-visible (UVVis) spectroscopy, while their antioxidant properties were evaluated by ferric reducing antioxidant power (FRAP), DPPH radical-scavenging, ferric thiocyanate (FTC) and total phenolic content (TPC) assays. The antimicrobial activities of the nanoparticles against different bacterial strains were determined using agar diffusion method.Result: Results from XRD, SEM, EDX and UV-Vis analyses demonstrated successful synthesis of undoped and Mn-doped ZnO nanoparticles as seen in their hexagonal, wurtzite structures. The un-doped and Mn-doped ZnO nanoparticles had average grain sizes of 16.72 nm and 17.5 nm, and band gap energies of 3.585 eV and 2.737 eV, respectively. Significant antibacterial activity was manifested by Mndoped ZnO against E. coli, S. aureus, Klebsiella and B. subtilis, with zones of inhibition (ZOIs) of 13 ± 0.09 mm, 14 ± 0.01 mm, 18 ± 0.07 mm and 20 ± 0.10 mm, respectively. The Mn-doped ZnO nanoparticles also exhibited effective and significant antioxidant potential relative to butylated hydroxytoluene (BHT) and un-doped ZnO nanoparticles.Conclusion: Mn-doped ZnO nanoparticles demonstrate significant antimicrobial and antioxidant activities. Thus, the preparation is a good candidate for further development into therapeutic formulations.Keywords: Mn-doped ZnO, Nanoparticles, Properties, Antioxidant, Antibacteria
- …