Generation loss contingencies in electric power systems result in a deviation of system frequency from nominal, a condition which must be corrected promptly in order to prevent further degradation of the power system. Automatic load-shedding using underfrequency relays is one of the techniques used to correct abnormal frequency deviations and prevent the risk of uncontrolled outages. If sufficient load is shed following a contingency to preserve interconnections and keep generators on-line, the system can be restored with relative speed and ease. On the other hand, if a declining frequency condition is not dealt with adequately, a cascading disconnection of generating units may develop, leading to a possible total system blackout. / This thesis develops and tests a new systematic method for setting underfrequency relays offering a number of advantages over conventional methods. A discretized swing equation model is used to evaluate the system frequency following a contingency, and the operational logic of an underfrequency relay is modeled using mixed integer linear programming (MILP) techniques. The proposed approach computes relay settings with respect to a subset of all plausible contingencies for a given system. A method for selecting the subset of contingencies for inclusion in the MILP is presented. The goal of this thesis is to demonstrate that given certain types of degrees of freedom in the relay setting problem, it is possible to obtain a set of relay settings that limits damage or disconnection of generating units for each and every possible generation loss outage in a given system, while attempting to shed the least amount of load for each contingency.

Abstract Background: The aging population is a rapidly growing demographic. Isolation and limited autonomy render many of the elderly vulnerable to abuse, neglect and exploitation. As the population grows, so does the need for Adult Protective Services (APS). This study was conducted to examine current knowledge of Georgia older adult protection laws and to identify training opportunities to better prepare the APS workforce in cases detection and intervention. Methods: A primary survey was developed in partnership with the Georgia Division of Aging Services’ leadership to identify key training priority issues APS caseworkers and investigators. A 47-item, electronic questionnaire was delivered (using Psychdata) to all APS employees via work- issued email accounts. Descriptive analyses, t-tests, and chi-square analyses were used to determine APS employees’ baseline knowledge of Georgia’s elder abuse policies, laws, and practices as well as examine associations of age, ethnicity, and formal education level with knowledge. A p-value of <0 >.05 and 95% confidence intervals were used to determine statistical significance of the analyses performed. Results: In total, 92 out of 175 APS staff responded to the survey (53% response rate). The majority of respondents were Caucasian (56%) women (92%). For over half the survey items, a paired sample t-tests revealed significant differences between what APS staff reported as known and what APS staff members indicated they needed to know more about in terms of elder abuse and current policies. Chi-square tests revealed that non-Caucasians significantly preferred video conferencing as a training format (44% compared to 18%), [χ2 (1) = 7.102, p < .008] whereas Caucasians preferred asynchronous online learning formats (55% compared to 28%) [χ2 (1) =5.951, p < .015]. Conclusions: Results from this study provides the Georgia Division of Aging with insights into specific content areas that can be emphasized in future trainings. Soliciting input from intended trainees allows public health educators to tailor and improve training sessions. Trainee input may result in optimization of attendance, knowledge acquisition, and intervention practices regarding APS service delivery. This in turn can enhance APS staff efficiency and response to cases of violence against older adults.

Consequences of refusing to participate in the criminal investigation or protective measures A quantitative study within a group of women assessed for risk of future intimate partner violence victimization Josefin Niit and Lisa Norrbin Abstract Intimate partner violence [IPV] is a global issue and IPV towards women have received increased attention during the last decades. The police perform a vital task in supporting victims of IPV and providing protective measures to prevent further violence. Some victims refuse to participate in the criminal investigation or protective measures, which can have consequences for the judicial process or the risk of future victimization. The aim of the present study was to investigate the consequences of refusing to participate in the criminal investigation or protective measures within a group of women assessed for risk of future IPV victimization. A quantitative approach was applied to compare women who refused to participate against women who participated. The sample consisted of 207 cases which were assessed with SARA:SV in the police county of Södertörn. The results demonstrated that when women refused to participate in the criminal investigation the cases were 6.2 times less likely prosecuted. Women who refused to participate in the protective measures were repeatedly victimized to the same amount, even though they in comparison were a lower risk group. However, these women were 4 times more likely victims of assault when repeatedly victimized. Findings from the current study provide useful knowledge about consequences for women who refuse to participate in the criminal investigation or protective measures and enables practical solutions for agents of the judicial system to further help these women. Keywords: Intimate partner violence, participation, criminal investigation, protective measures, SARA:SV / <p>2013-06-11</p>

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This research explored the risk and protective factors associated with criminality among adults with Fetal Alcohol Spectrum Disorder (FASD). While previous research has focused on identifying the factors that contribute to legal issues, there is a paucity of research on the protective factors that may lead to more positive outcomes for adults with FASD. The first paper examined the methodological issues encountered while conducting a mixed methods study on the experience of offenders and non-offenders with FASD. Difficulties with participant recruitment, the sample size, the terminology employed, and the appropriateness of psychometric measures were significant challenges that emerged during the research project. The second paper was a qualitative study that investigated the experience of adults with prenatal alcohol exposure and their families to determine the risk and protective factors for criminality. Families reported that neurobehavioural impairments such as difficulty with self-regulation and social skills deficits, combined with environmental demands that exceeded the capabilities of the individual with FASD, were important contributors to criminality. However, structure and supervision, education and employment, social and financial support, and positive peer influence were found to mitigate the risk of criminal behavior among adults with FASD. The findings from this thesis highlight the importance of including families in the research process as well as the need to have more family-centered services.

The effects of irradiation dose (0, 0.5 and 1.0 kGy), various gas atmospheres and storage temperature (5, 15 and 25$ sp circ$C) on the physical, chemical, microbiological, and organoleptic changes in fresh pork were studied using factorial design experiments. The effects on toxin production by Clostridium botulinum were also investigated using challenge studies. Shelf life could be extended to 21 d when product was packaged in 0% O$ sb2$, irradiated at 1.0 kGy and stored at 5$ sp circ$C compared to 4 d for control samples. While the presence of O$ sb2$ in the package headspace enhanced the antimicrobial effects of low-dose irradiation, it adversely affected the organoleptic qualities of pork. Botulinum toxin was detected after only 2 d in all inoculated treatments stored at 25$ sp circ$C. At 15$ sp circ$C, toxin was produced faster when pork was initially packaged with O$ sb2$ or low levels of CO$ sb2$ (15-30%) as compared to 100% N$ sb2$. Higher levels of CO$ sb2$ (45-75%) delayed toxin production. In most treatments, spoilage preceded toxigenesis. Models were developed relating the above factors to the time until toxin production and to the probability of toxigenesis. Temperature, initial O$ sb2$ and irradiation were all significant factors.

Listeria monocytogenes is a pathogenic, psychrotrophic microorganism that is ubiquitous in nature. L. monocytogenes has been isolated from numerous meat products, both fresh and processed, the incidence of contamination varying greatly. The ability of Listeria to grow in meats depends on temperature, pH, water activity (a$ sb{ rm w}$), nutrients, species and numbers of competing microorganisms, gaseous conditions, and levels of additional barriers. Therefore, methods to control the growth of L.monocytogenes are of great importance to food processors since this organism can grow under a wide range of environmental and storage conditions. Two methods of control, in conjunction with temperature, were studied in this project: (i) modified atmosphere packaging (MAP) and (ii) chitosan, to determine the optimum levels of these "hurdles" needed to effectively control the outgrowth of L.monocytogenes in both model broth and agar systems and in fresh pork loin. On the basis of these preliminary studies, a combination of chitosan as a dipping solution and modified atmosphere packaging were investigated to control the growth of L.monocytogenes in fresh pork loin. Pork loin samples were dipped in a 0.2% chitosan solution for 60 seconds and packaged under various atmospheres in Cryovac bags and stored at 5, 10 and 15$ sp circ$C up to 28 days. Samples were monitored for physical, chemical and microbiological changes throughout the storage period. Optimum control over the growth of L. monocytogenes was achieved using a combination of 100%N$ sb2$ + an Ageless FX oxygen absorbent and dipping in a 0.2% chitosan solution. Based on these studies, a combination of 0.2% chitosan and MAP could be used to extend the shelf life of pork without adversely affecting color, odor and exudate loss while inhibiting the growth of the pathogenic microorganism, L.monocytogenes. (Abstract shortened by UMI.)

This dissertation report began as an investigation into an overcurrent relay protection operation on a shunt capacitor bank (SCB) at ESKOM’s Westgate substation. Westgate substation has two SCBs, both of which were in service at the time of the 2007 incident. However, only the overcurrent protection scheme applied on SCB No.2 operated due to an external feeder fault on the Eltro feeder at Westgate substation. In 2004, SCB No.2 had tripped also on an overcurrent relay protection operation for an external fault. The difference identified in the otherwise identical SCBs was the relay technology employed by the overcurrent protection schemes i.e. electromechanical and electronic overcurrent relays were utilised. Therefore an investigation was initiated to determine any difference in the performance and reliability of overcurrent relay technologies in the SCB environment. The purpose of this work is to present the performance of the different technologies of overcurrent relays (electromechanical, electronic and digital) as applied to an ESKOM SCB during system disturbances and to compare their operation and behaviour. MatLAB and DigSILENT simulation packages were used to conduct preliminary fault studies to determine overcurrent relay performance, for a definite time overcurrent setting. These simulation results indicated that the simple electromechanical and electronic overcurrent relay could operate incorrectly in the SCB environment, during system disturbances. Practical laboratory tests were also conducted. This comprised of injecting DigSILENT simulations, comprising of system switching events and external faults, into three technologies of overcurrent relays. These Omicron injection tests found that the Westgate electronic relay would operate incorrectly for certain fault events in the SCB environment. Due to the results observed, further frequency response tests were conducted. These results suggested that the electronic and electromechanical overcurrent relays were susceptible to harmonics i.e. harmonics impact both the pick-up current setting and operating time of electronic and electromechanical overcurrent relays. The digital relay did not exhibit this vulnerability. Finally, recommendations were made to address the incorrect operation of the Westgate electronic relay in its SCB application. These recommendations could be applied in other ESKOM SCB overcurrent protection schemes, to prevent incorrect operation for system disturbances. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2009.

Rolling contact is experienced by a large number of components in mechanical designs. Examples include roller bearings and ink distribution rollers in the printing industry. Rolling contact results in surface wear. It is however possible to reduce rolling contact wear rates and surface fatigue by performing a surface modification such as powdered metal coating [35]. Powder coating methods such as Laser cladding and Plasma coating are two application processes that are completely different in method and therefore create different coating microstructures and bonding mechanisms between the coating and substrate. The aim of the research was to investigate the comparative rolling contact performance of two coating processes and two separate metal powder compositions. The coatings were applied to British standard En 9 steel test specimens. En 9 was selected due to its popular use in the manufacture of shafts, cylinders and rollers. Under rolling contact, material is removed from the surface as a result of wear and surface fatigue. Through testing and evaluation, the performance of the coating application processes were evaluated relative to one another and relative to the uncoated steel under rolling contact. The performance of the coating compositions were also evaluated against one another for a given coating application process. Results used to determine the performance of the coatings and coating processes were, the number of cycles to failure and the wear rates of the coated surface. Microstructure pictures of the coated surface were taken prior to testing and following testing. The pictures were used to qualitatively determine the effects of the rolling contact on the surfaces. Through the study of rolling contact, an explanation of the stresses induced in the contact area and the position of the maximum values were determined. The boundaries for the deformation regimes were identified through the understanding of the position of first yield and the shakedown limit under rolling contact. The theories of rolling contact fatigue are covered briefly as part of a better understanding of the failure mechanism however the experimentation is largely comparative based. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2008.

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