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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
681

THE INTERPLAY BETWEEN SOCIAL IDENTITY FORMATION AND SOCIAL MEDIA ADOPTION

Nzeribe, Eric John C. 05 1900 (has links)
The steady increase in social media use, combined with a new opportunity for individuals to express and/or redefine their social identity, has created many new platforms and forums. The global pandemic and the further digitization of communication and self-expression amplified the trend. As individuals shape their online identities, they receive feedback from their online networks (likes, comments, shares, etc.). The feedback can reinforce or challenge their identities, leading them to adapt their self-presentation accordingly. This research investigated the under-explored interplay between Social Identity (SI) formation and Social Media (SM) adoption. While the Unified Theory of Acceptance and Use of Technology (UTAUT) model has been practical, it has become crucial to enhance it based on the relationship/intersection of SI expression and SM use and its implications for social media companies, policymakers, individuals, businesses, and society, as a whole. The research employed inductive qualitative analysis on “public-primary posts of personal narratives from X platform and subreddit communities while preserving participant anonymity. Study 2 data corpus was 62,429 posts. There is a bi-directional influence on social identity formation and social media adoption. The limitations of this study include the subjective nature of qualitative research and the fact that the posts were not intended for academic study. Further, there were no follow-ups and member checking; thus, I could not validate the findings with participants. I also note that many people came to the subreddit platform with their problems, and the entries did not include the resolution of their issues. Only an interview would reveal the outcome, which was not carried out in this study. One recommendation is that social media providers install AI chatbots that scour their platforms for people needing help and render support to people who are vulnerable, especially those seeking mental health resources. Finally, this study’s proposition that when people are lonely, they seek support and comfort on social media needs more research. Further, in the advent of mainstream adoption of Artificial Intelligence (AI) in 2023, research will need to be conducted to ensure the safe and viable long-term use of social platforms for good, as opposed to evil. / Business Administration/Interdisciplinary
682

Towards a multidimensional approach to measure quality and safety of care in maternity units in Oman

Al Nadabi, Waleed K.A. January 2019 (has links)
Improving the quality and safety of maternity services is an international top agenda item. This thesis describes the progress towards the development of a multidimensional approach to measure the quality and safety of care in ten maternity units in Oman based on three of the five dimensional Patient Safety Measurement and Monitoring Framework (PSMMF) which include measuring "past harm" and "anticipation and preparedness”. The three monitoring approaches used in this research are: (1) measuring the patient safety culture (2) measuring patient satisfaction (3) and monitoring caesarean section rates. The specific objectives of the research are to (1) measure patient safety culture level, (2) examine the association between nurse’s nationality and patient safety culture, (3) validate an Arabic language survey to measure maternal satisfaction about the childbearing experience, (4) measure patient satisfaction about the childbearing experience, and (5) to examine caesarean section rates across maternity units using statistical process control charts. This thesis started with four systematic reviews that focused on (1) the use of patient safety culture for monitoring maternity units (2) the available interventions to improve patient safety culture (3) Arabic surveys available for measuring maternal satisfaction and (4) the use of statistical process control charts for monitoring performance indicators. The overall conclusion from these reviews that these approaches are being increasingly used in maternity, found feasible and useful, and there are areas that need attention for future work. Five field studies were conducted to address the research aim and objectives. Patient safety culture was measured by a cross-sectional survey of all staff in the ten maternity units. It was found that safety culture in Oman is below the target level and that there is wide variation in the safety scores across hospitals and across different categories of staff. Non-Omani nurses have a more positive perception of patient safety culture than Omani nurses in all domains except in respect of stress recognition and this difference need further investigation and needs to be considered by designers of interventions to enhance patient safety culture. Using two existing validated English surveys, an Arabic survey was developed, validated, and used to measure maternal satisfaction with childbirth services. It was found that the new survey has good psychometric properties and that in all the ten hospitals, mothers were satisfied with the care provided during child delivery but satisfaction score varied across hospitals and groups of participants. Caesarean section rate in the last 17 years was examined using statistical process control charts to understand the variation across the ten hospitals. It was found that caesarean section rate is above the rate recommended by the World Health Organisation. Special cause variations were detected that warrant further investigation. In conclusion, the field studies demonstrated that it is feasible to use the three approaches to monitor quality and safety in maternity units. However, further work is required to use these data to enhance the quality and safety of care. Additionally, future work is needed to cover the other three dimensions of the PSMMF. / Ministry of Health in Oman,
683

Idiosyncratic risk and the cross-section of stock returns: the role of mean-reverting idiosyncratic volatility

Bozhkov, S., Lee, H., Sivarajah, Uthayasankar, Despoudi, S., Nandy, M. 04 June 2018 (has links)
Yes / A key prediction of the Capital Asset Pricing Model (CAPM) is that idiosyncratic risk is not priced by investors because in the absence of frictions it can be fully diversified away. In the presence of constraints on diversification, refinements of the CAPM conclude that the part of idiosyncratic risk that is not diversified should be priced. Recent empirical studies yielded mixed evidence with some studies finding positive correlation between idiosyncratic risk and stock returns, while other studies reported none or even negative correlation. We revisit the problem whether idiosyncratic risk is priced by the stock market and what are the probable causes for the mixed evidence produced by other studies, using monthly data for the US market covering the period from 1980 until 2013. We find that one-period volatility forecasts are not significantly correlated with stock returns. The mean-reverting unconditional volatility, however, is a robust predictor of returns. Consistent with economic theory, the size of the premium depends on the degree of 'knowledge' of the security among market participants. In particular, the premium for Nasdaq-traded stocks is higher than that for NYSE and Amex stocks. We also find stronger correlation between idiosyncratic risk and returns during recessions, which may suggest interaction of risk premium with decreased risk tolerance or other investment considerations like flight to safety or liquidity requirements. The difference between the correlations of the idiosyncratic volatility estimators used by other studies and the true risk metric the mean-reverting volatility is the likely cause for the mixed evidence produced by other studies. Our results are robust with respect to liquidity, momentum, return reversals, unadjusted price, liquidity, credit quality, omitted factors, and hold at daily frequency. / National Research Foundation of Korea (2016S1A2A2912265)
684

Addressing and Assessing Lead Threats in Drinking Water: Non-Leaded Brass, Product Testing, Particulate Lead Occurrence and Effects of the Chloride to Sulfate Mass Ratio on Corrosion

Triantafyllidou, Simoni 10 November 2006 (has links)
Growing concern over adverse health effects from low level lead exposure motivated reassessment of lead occurrence in drinking water, from the perspective of 1) possibly eliminating lead from new brass materials, and 2) performance testing of existing products. During the course of this thesis work, it was discovered that several cases of childhood lead poisoning in North Carolina, South Carolina and Washington D.C. occurred from contaminated potable water. That disconcerting finding prompted additional work into 3) deficiencies in existing lead testing of drinking water samples, and 4) impacts of water treatment steps on lead leaching. Meters, components, and fittings manufactured from non-leaded brass (< 0.25 percent lead content) are increasingly specified for use in water distribution systems and premise plumbing, in response to California's Proposition 65 and the proposed Lead Free Drinking Water Act. An in-depth review of the available literature revealed that non-leaded brass releases minimal amounts of lead and other contaminants of concern to drinking water. There is legitimate concern about the corrosion resistance and longevity of these non-leaded alloys in the range of waters that will be encountered in practice. Nonetheless, when the potential impacts to manufacturers, utilities and consumers are considered, non-leaded brasses appear to be attractive albeit at slightly higher cost. For existing leaded brass products, concerns have been raised over potential limitations of performance standards used to certify the products as "safe" in the marketplace. The ANSI/NSF 61 Section 9 test is the industry standard, and its protocol is critically evaluated from the perspective of the leaching solution chemistry. Testing indicated that the protocol water is reasonably representative of a typical water supply. However, some lower pH and lower alkalinity waters can be much more aggressive than the existing section 9 water, and for potable water with these characteristics, problems with higher than desired lead leaching may occur. It may be desirable to tighten the standard's pass/fail lead criterion in order to account for this problem in practice. Several cases of childhood lead poisoning from water have been recently encountered, which prompted environmental assessments. It was visually obvious that some of the lead particles ingested by these children, present in water from the tap, were not completely dissolving in the standard method with weak acid recommended by the US EPA. A laboratory investigation proved that up to 80% particulate lead in water samples could be "missed" by the standard protocol. Unfortunately, tests with simulated gastric fluid revealed that much of this particulate lead would be bioavailable in the presence of chloride, warmer temperatures and lower pH inside the human stomach. It is recommended that water utilities be alert to this possible problem and that environmental assessments of lead poisoned children use stronger digestions to detect lead in water. Several of the lead poisoning instances occurred after the utility changed both disinfectant chemicals (from chlorine to chloramine) and coagulant types. Although authorities initially thought chloramine was the cause based on experiences in Washington D.C., bench scale studies in this work proved that a change in coagulant from aluminum sulfate to either ferric chloride or polyaluminum chloride was in fact the main reason of the lead spikes. The reduction in sulfate and increase in chloride increased the chloride to sulfate mass ratio of the water supply. A higher chloride to sulfate mass ratio triggered much higher (2.3-40 times more) lead leaching from solder connected to copper pipe. The adverse effects of the increase in the ratio could not be eliminated by adding a corrosion inhibitor. / Master of Science
685

Tests on elliptical concrete filled steel tubular (CFST) beams and columns

Ren, Q-X., Han, L-H., Lam, Dennis, Li, W. 04 May 2014 (has links)
No / This paper presents a series of test results of elliptical concrete filled steel tubular (CFST) beams and columns to explore their performance under bending and compression. A total of twenty-six specimens were tested, including eight beams under pure bending and eighteen columns under the combination of bending and compression. The main parameters were the shear span to depth ratio for beams, the slenderness ratio and the load eccentricity for columns. The test results showed that the CFST beams and columns with elliptical sections behaved in ductile manners and were similar to the CFST members with circular sections. Finally, simplified models for predicting the bending strength, the initial and serviceability-level section bending stiffness of the elliptical CFST beams, as well as the axial and eccentric compressive strength of the composite columns were discussed.
686

Flexural behaviour of hybrid steel-GFRP reinforced concrete continuous T-beams

Almahmood, Hanady A.A., Ashour, Ashraf, Sheehan, Therese 10 August 2020 (has links)
Yes / This paper presents test results of six full scale reinforced concrete continuous T beams. One beam was reinforced with glass fibre reinforced polymer (GFRP) bars while the other five beams were reinforced with a different combination of GFRP and steel bars. The ratio of GFRP to steel reinforcement at both mid-span and middle-support sections was the main parameter investigated. The results showed that adding steel reinforcement to GFRP reinforced concrete T-beams improves the flexural stiffness, ductility and serviceability in terms of crack width and deflection control. However, the moment redistribution at failure was limited because of the early yielding of steel reinforcement at a beam section that does not reach its moment capacity and could still carry more loads due to the presence of FRP reinforcement. The experimental results were compared with the ultimate moment prediction of ACI 440.2R-17, and with the existing theoretical equations for deflection prediction. It was found that the ACI 440.2R-17 reasonably estimated the moment capacity of both mid-span and middle support sections. Conversely, the available theoretical deflection models underestimated the deflection of hybrid reinforced concrete T-beams at all load stages.
687

Portable wind tunnel design

Baydono, David, Sleiman, Salam January 2024 (has links)
Wind tunnels are important tools used in physics and engineering, with a wide range of usability and applications in industrial, research, and educational settings. A wind tunnel holds an object steady while generating airflow over it, often to study the interaction between the object and the airflow. The design of wind tunnels can be very costly, extensive, and difficult to implement. This paper analyzes literature on wind tunnels to compile a method for designing a portable wind tunnel suitable for educational and demonstrative purposes. The method includes design guidelines for each component, including the test section, contraction, settling chamber, honeycomb, diffuser, and fan section. A blueprint for a wind tunnel with specified dimensions is presented. The blueprint is designed to fit a Boeing 747-200 model, scaled at 1:390, and therefore have a 40 cm long test section with a 20x20 cm square cross-section. The designed wind tunnel achieves a velocity of 5 m/s in the test section. Emphasizing portability, simplicity, and functionality, this wind tunnel design enhances educational experiences, making complex fluid dynamics concepts accessible and engaging for students.
688

Portable wind tunnel design​

Baydono, David, Sleiman, Salam January 2024 (has links)
Wind tunnels are important tools used in physics and engineering, with a wide range of usability and applications in industrial, research, and educational settings. A wind tunnel holds an object steady while generating airflow over it, often to study the interaction between the object and the airflow. The design of wind tunnels can be very costly, extensive, and difficult to implement. This paper analyzes literature on wind tunnels to compile a method for designing a portable wind tunnel suitable for educational and demonstrative purposes. The method includes design guidelines for each component, including the test section, contraction, settling chamber, honeycomb, diffuser, and fan section. A blueprint for a wind tunnel with specified dimensions is presented. The blueprint is designed to fit a Boeing 747-200 model, scaled at 1:390, and therefore have a 40 cm long test section with a 20x20 cm square cross-section. The designed wind tunnel achieves a velocity of 5 m/s in the test section. Emphasizing portability, simplicity, and functionality, this wind tunnel design enhances educational experiences, making complex fluid dynamics concepts accessible and engaging for students.
689

Experimental Determination of the Scattering Cross-section of Ogives and Prolate Spheroids at Microwave Frequencies

Rhoads, Wayne C. 01 1900 (has links)
Because of the great difficulty of obtaining exact numerical values of cross-section, and because of the inherent uncertainties in interpreting and evaluating the approximate methods, accurate experimental cross-section data would be extremely useful to the radar engineer. It was with this purpose in mind that the present long-range research program in microwave scattering was undertaken. Of immediate interest were the scattering properties of the prolate spheroid, the ogive (formed by rotating the minor segment of a circle around the chord), and, for comparison, the long cylinder.
690

The Use of the Golden Proportion in Paintings by Titian and Raphael

Hamilton, Barbara Ruth 08 1900 (has links)
Paintings of Raphael and Titian were chosen for study (1) to ascertain the extent to which they used geometry, and (2) to determine, if possible, the differences and likenesses in their underlying schemas, and (3) to determine how geometrical divisions, if used, affected the character of their paintings.

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