Combined effect of electric field and surface modification on pool boiling of R-123

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The effect of surface modification and high intensity electric field (uniform and non – uniform) acting separately or in combination on pool boiling of R-123 is presented in this thesis. The effect of surface modification was investigated on saturated pool boiling of R-123 for five horizontal copper surfaces modified by different treatments, namely: an emery polished surface, a fine sandblasted surface, a rough sandblasted surface, an electron beam (EB) enhanced surface and a sintered surface. Each 40 mm diameter heating surface formed the upper face of an oxygen-free copper block, electrically heated by embedded cartridge heaters. The experiments were performed from the convective heat transfer regime to the critical heat flux, with both increasing and decreasing heat flux, at 1.01 bar, and additionally at 2 bar and 4 bar for the emery polished surface. Significant enhancement of heat transfer with increasing surface modification was demonstrated, particularly for the EB enhanced and sintered surfaces. The emery polished and sandblasted surface results are compared with nucleate boiling correlations and other published data. The effect of uniform and non-uniform electric fields on saturated pool boiling of R-123 at 1.01 bar pressure was also examined. This method of heat transfer enhancement is known as electrohydrodynamic abbreviated as EHD-enhancement. A high voltage potential was applied at the electrode located above the heating surface, which was earthed. The voltage was varied from 0 to 30 kV. The uniform electric field was provided through a 40 mm diameter circular electrode of stainless steel 304 wire mesh having an aperture of 5.1 mm, while the non-uniform electric field was obtained by using a 40 mm diameter circular rod electrode with rods 5 and 8 mm apart. The effect of uniform electric field was investigated using all five modified surfaces, i.e. emery polished, fine sandblasted, rough sandblasted, EB enhanced and sintered surfaces, while non – uniform electric field was tested using the emery polished, fine sandblasted, EB enhanced and sintered surfaces. The effect of pressure on EHD enhancement was also examined using emery polished surface at saturation pressure of 2 and 4 bars while the electric field was fix at 20 kV corresponding to 2 MV/m. Further, the bubble dynamics is presented for the emery polished surface obtained using a high-speed high – resolution camera.The Government of Pakista

Influence of Social Exchange Relationship and Work Engagement on Creative Work Involvement: Mediation of Individual Innovative Behavior

The study probed the effect of social exchange relationship and work engagement on creative work involved with the assistance of mediation of individual innovative behavior of employees on work. Responses to a survey of 450 employees from the different service sector were used to the study hypotheses. Correlation and regression were done to see the impact of work engagement on employees’ creativity and individual innovative behavior with the assistance of social exchange relationship. This study shows the significant relation between social exchange relationship and creative work involvement. It also shows that employees should be provided with the resources so that they can perform well and also to be appreciated for their novel ideas which help the organization to progress. Individual innovative behavior also mediates connection among leader-member exchange and creative work involvement

Influence of Social Exchange Relationship and Work Engagement on Creative Work Involvement: Mediation of Individual Innovative Behavior

The study probed the effect of social exchange relationship and work engagement on creative work involved with the assistance of mediation of individual innovative behavior of employees on work. Responses to a survey of 450 employees from the different service sector were used to the study hypotheses. Correlation and regression were done to see the impact of work engagement on employees’ creativity and individual innovative behavior with the assistance of social exchange relationship. This study shows the significant relation between social exchange relationship and creative work involvement. It also shows that employees should be provided with the resources so that they can perform well and also to be appreciated for their novel ideas which help the organization to progress. Individual innovative behavior also mediates connection among leader-member exchange and creative work involvement

Geoelectrical Survey for the Exploration of Ground Water using Vertical Electrical Sounding: A Case Study of Androt District Rawlakot, Azad Jammu & Kashmir

Vertical Electrical Sounding (VES) method has been widely used to depict the subsurface lithology, thickness and structure based on resistivity of layered media with the ultimate objective of evaluating groundwater potential. In this investigation, VES was used to outline subsurface geology to produce a 2D subsurface resistivity model based on the resistivity contrast of layered rocks, for evaluating the accessibility of groundwater in the Siwaliks group of Androt District Rawlakot, Azad Jammu and Kashmir (AJ&K). The Schlumberger electrode configuration was used with spacing arrangement of current electrode (AB/2) going from 1.5 to 250 meters and potential electrode (MN) 1 to 50 meters. The VES data was qualitatively analyzed by using iteration software (IPI2win) which showed that the area is composed of clay, shale, fractured sandstone with intercalation of clay based on resistivity contrast. At depth of 40m-100m along VES indicates good prospects for ground water potential, associated with sandstone beds of Siwaliks group. The resistivity depth section maps at potential depth of 30m, 40m, 60m and 80m are prepared for the demarcation of potential reservoir beds at various depth. The interpreted sounding curves are interpreted qualitatively and pseudo section, Resistivity section and geological log are prepared based on resistivity contrast which shows agreement with geology and hydrological condition of the area. The favorable reservoir rock as an aquifer demarcated in the study area is fractured sandstone with intercalation of clay beds, with apparent resistivity range of 80Ωm to 100Ωm and thickness of 20m to 50m at different sites. The apparent resistivity sections revealed that the North East (NE) and North West (NW) regions are comparatively good potential reservoir for ground water

Seismic Interpretation and Reservoir Evaluation Utilizing 2-D Seismic Data and Wireline Logs of Bijnot-01 Well, Fort Abbas Field, Central Indus Basin, Pakistan

Present study attempts to decipher the subsurface structure and reservoir characterization of Fort-Abbas field, located in Punjab platform, Central Indus Basin utilizing 2-D seismic and wireline logs data. Four seismic lines, 944-FABS-42, 944-FABS-43, 944-FABS-48, 944-FABS-49 and wireline logs of Bijnot-01 well have been used for this research work to delineate subsurface structures and demarcation of zone having fair potential of hydrocarbon accumulation. Formation evaluation for hydrocarbon potential using the reservoir properties is also the foremost objective of this research work. Based on the results of seismic data interpretation of Fort-Abbas field and integrating it with formation tops and wireline logs data, three prominent reflectors have been marked i.e. Eocene Sui Main Limestone, Cretaceous Lower Goru and Jurassic Chiltan Limestone. The structure of the area is interpreted as gently dipping monocline. Based on the breakup of reflectors on seismic section, one normal fault is marked. Time and depth contour maps are generated to demarcate lateral extension and closure of the reservoir. Based on interpretation of wireline logs, a zone has been marked from depth of 504 m to 594 m (Datta Formation) as a favorable zone having good potential for hydrocarbon accumulation. Saturation of hydrocarbon (Sh) in this zone is calculated as 57%

Image segmentation methods and edge detection: An application to knee joint articular cartilage edge detection

Image segmentation is the process of partitioning a digital image into multiple segments and regions for further processing. Edge detection methods are widely used in the area of image processing for feature detection and extraction. In this paper we use human’s Knee MRI (Magnetic resonance imaging) images of patients and applied various image segmentation and edge detection methods for knee cartilage visualization. Also this paper focuses on providing an overview of important concepts, methods and algorithms commonly used for image segmentation and edge detection with focus on knee joint articular cartilage image segmentation and visualizatio

Performance and measurement of a community-based distribution model of family planning services in Pakistan

Introduction: Community-based distribution (CBD) has been successfully applied to family planning (FP) services worldwide. It forms the basis for the large lady health worker (LHW) programme in Pakistan which serves a limited number of women with contraception services. Thus, the concept has seen limited application in Pakistan. We present the outcomes of a CBD model that was implemented in 49 districts across Pakistan by a non-government organization (NGO).Methods: The Marie Stopes Society (MSS) developed a CBD model around its fixed centres and reached around half a million married women of reproductive age (MWRA) with services. The services provided included outreach, counselling, condoms, pills, injections, and referrals for intrauterine contraceptive devices (IUCDs) and other reproductive health services. Services were provided in peri-urban locations for a subsidized fee using a businesslike target setting approach. The results of the programme were assessed by triangulating inception records against a cross-sectional end-of-project survey and service delivery records.Results: The contraceptive prevalence rate (CPR) had increased from 38% to 51% by project-end with modern method use increasing by 50-200% and traditional method use remaining unchanged. Unmet need and self-reported pregnancy rates fell correspondingly. Approximately 73,500 new users were added to the initial user registered numbers to a total of 132,300; MSS accounted for 53,000 per year at the end of the project, which matched the commodities supplied by the NGO.Conclusions: The MSS CBD model presents a viable option for scaling effective FP services that may be replicated and scaled up with either donor support or by contracting out by the government. Triangulation of multiple data sources can provide more in-depth assessment of service delivery programmes and provide inferences that can inform service delivery

Combined effect of electric field and surface modification on pool boiling of R-123

The effect of surface modification and high intensity electric field (uniform and non – uniform) acting separately or in combination on pool boiling of R-123 is presented in this thesis. The effect of surface modification was investigated on saturated pool boiling of R-123 for five horizontal copper surfaces modified by different treatments, namely: an emery polished surface, a fine sandblasted surface, a rough sandblasted surface, an electron beam (EB) enhanced surface and a sintered surface. Each 40 mm diameter heating surface formed the upper face of an oxygen-free copper block, electrically heated by embedded cartridge heaters. The experiments were performed from the convective heat transfer regime to the critical heat flux, with both increasing and decreasing heat flux, at 1.01 bar, and additionally at 2 bar and 4 bar for the emery polished surface. Significant enhancement of heat transfer with increasing surface modification was demonstrated, particularly for the EB enhanced and sintered surfaces. The emery polished and sandblasted surface results are compared with nucleate boiling correlations and other published data. The effect of uniform and non-uniform electric fields on saturated pool boiling of R-123 at 1.01 bar pressure was also examined. This method of heat transfer enhancement is known as electrohydrodynamic abbreviated as EHD-enhancement. A high voltage potential was applied at the electrode located above the heating surface, which was earthed. The voltage was varied from 0 to 30 kV. The uniform electric field was provided through a 40 mm diameter circular electrode of stainless steel 304 wire mesh having an aperture of 5.1 mm, while the non-uniform electric field was obtained by using a 40 mm diameter circular rod electrode with rods 5 and 8 mm apart. The effect of uniform electric field was investigated using all five modified surfaces, i.e. emery polished, fine sandblasted, rough sandblasted, EB enhanced and sintered surfaces, while non – uniform electric field was tested using the emery polished, fine sandblasted, EB enhanced and sintered surfaces. The effect of pressure on EHD enhancement was also examined using emery polished surface at saturation pressure of 2 and 4 bars while the electric field was fix at 20 kV corresponding to 2 MV/m. Further, the bubble dynamics is presented for the emery polished surface obtained using a high-speed high – resolution camera.EThOS - Electronic Theses Online ServiceGovernment of PakistanGBUnited Kingdo