This study explores alternative alkaline agents other than sodium carbonate for ASP process on reactive and non-reactive crude oil recovery at 55oC and 100oC. The alkalis studied were sodium metaborate, pH of 10-10.5, and a sodium silicate/borax mixture, pH of 11. Sodium metaborate showed very optimistic results similar to sodium carbonate studies. Sodium metaborate ASP floods recovered 97-99% of residual oil after waterflood in Berea sandstone at 55oC. The oil saturation in the core after the chemical flood was between 0.5-2%. Sodium metaborate ASP floods recovered 96% of the tertiary oil with a residual oil saturation of 2.6% in Bentheimer sandstone at 100oC. More importantly, the retention of surfactant was very low with the use of metaborate in Berea, Bentheimer and high clay content reservoir cores. 0.18 mg/g rock (68%) and 0.07 mg/g rock (30%) of surfactant was retained in Berea and Bentheimer respectively with the use of sodium metaborate. Sodium metaborate ASP floods recovered 96% and 98% of residual oil with a final oil saturation of 4.8% and 0.56% at 100oC and 55oC respectively in reservoir rock. The retention in reservoir core was 0.13 mg/g (48%) and 0.29 mg/g (80%) at 100oC and 55oC respectively. Sodium borax/metasilicate had a lower tertiary oil recovery due to higher surfactant retention in Berea sandstone. The ASP flood recovered 81% and 86% of tertiary oil at 100oC and 55oC respectively. The retention was 0.326 mg/g (97%) and 0.267 mg/g (98%). The last section involves treatment and reduction of reservoir cores containing clays and iron minerals. Reservoirs exist as anaerobic and reduced environments and these conditions must be emulated in laboratory experiments. Exposure of reservoir cores to aerobic conditions causes an oxidizing environment in the core leading to higher surfactant retention in the laboratory than the field. Dithionite was used to reduce reservoir cores and produce lower surfactant retention closer to field tests. Proper reduced conditions also improved oil recovery. Dithionite must be buffered with sodium bicarbonate to maintain the reducing power of dithionite. Dithionite oxidation by ferric iron and water causes hydroxyl ion consumption and pH decrease. The EH and iron concentration of the effluents must be monitored to determine the success of the core reduction. Effluent EH matching injected values and iron concentration close to the mineral solubility in brine should be used as benchmark for the success of core reduction / text

This report gives an in-depth study of the relationship between effective school leadership and teacher retention. It reviews existing literature that establishes the connection between effective school leadership and lower rates of teacher turnover. The report then attempts to find the relationship among effective school leadership, teacher retention, and student achievement in New York City middle schools. The report also highlights the important processes and strategies that the New York City Department of Education employs in an effort to increase teacher retention. A closer look at The New Teacher Project’s 2012 Report, “The Irreplaceables,” redirects the report to recommend retention efforts that focus on retaining the city’s highest-performing teachers instead of using “blind” retention strategies. In the end, the report summarizes the political climate in New York City between the teachers’ union and the district and recommends four strategies that keep this relationship in mind. / text

The purpose of this study was to (1) examine the academic and demographic characteristics of 6th-grade instrumental music students attending selected public schools of contrasting socioeconomic backgrounds, (2) examine the retention patterns of students who were required to enroll in 6th-grade instrumental music compared to those who elected to do so, and (3) construct a predictive model of student retention in middle school instrumental music programs. Individual student data (N = 1052) were gathered from beginning instrumental 6th-grade programs at selected schools in a large, urban school district in Texas. Data included students’ 5th and 6th standardized test results, 7th-grade class schedules, and demographic information. Data were analyzed according to the 6th-grade campus the students attended (Title I/non-Title I) and the type of school (elementary school with required music programs or middle school with elective music programs) to identify demographic and academic factors associated with 6th-and 7th-grade music participation. I examined students’ schedules for retention patterns associated with individual school scheduling and academic remedial policies. I used logistic regression to develop predictive models of retention based on the following factors: gender, ethnicity, special education, at-risk, gifted, 5th and 6th-grade standardized test results, 5th-grade campus and pre-AP enrollment. Only the 6th-grade standardized tests, either math or reading, predicted retention in instrumental music in all of the school settings. Ethnicity, at-risk, and 5th-grade standardized tests did not predict retention in any school setting. Each school setting was unique in the factors that predicted instrumental music retention. For example, in the Title I setting, giftedness and 6th-grade reading test results predicted retention whereas in the non-Title I setting, gender, pre-AP enrollment and 6th-grade math results predicted retention. I also observed that 6th-grade required music programs were, by default, more inclusive than elective programs, and that the diversity in the student population of the 6th-grade required programs was maintained during the 7th-grade when music became elective. Results from this study suggest that offering only one elective choice per year may exclude access to music education for low academic achievers and reduce enrollment in music ensembles. / text

This study analyzed the memory retention of University of Kentucky Dietetic and Hospitality students as it relates to food safety and sanitation knowledge originally presented on the ServSafe® certification exam. Dietetic and hospitality students take the ServSafe® certification course during the sophomore year of their degree program, but they are responsible for the sanitation and food safety information throughout their entire program of undergraduate study. The final sample consisted of 25 participants, with 84% (n=21) in the Dietetics program and 16% (n=4) in the Hospitality, Management and Tourism program. The mean difference in total score, domain one, domain two, domain three, domain four and domain five were statistically significant with a p-value <0.05. Domain three was the domain students recalled the most with a difference of 16.52%. Domains four and five were recalled least by students with a difference of 35.8% and 35.65%. The information found in this study can be used in the Department of Dietetic and Human Nutrition (DHN) and the Department of Hospitality, Management and Tourism (HMT) to enhance the food sanitation knowledge of students throughout their courses.

Paper presented at the 15th LIASA Conference. 8-11 October 2013, Cape Town

M. Tech. Business Administration / The focus of this study is to understand and examine the challenges of knowledge retention as it relates to knowledge management, types of knowledge, present labour market, workforce crisis, behavioural factors, personality traits and culture. The purpose of this dissertation is to understand the challenges of knowledge retention in start-up, small or medium enterprises, using Machite Engineering Pty Ltd as a case study. The difficulties of retaining knowledge are faced by organizations of all sizes. Hence, this dissertation examines the knowledge retention factors in relation to employees' decisions to stay in an organization; the types of knowledge; the meaning of knowledge worker; the labour market most organizations operate in; work force crises; behavioural factors that influence knowledge retention; organizational structure; personality traits and lifestyle; culture; career development; labour turnover; and other variables that impact knowledge retention as identified in the literature review.

The study examined the removal mechanism of non-acclimated and acclimated aerobic activated sludge for 29 target organic micropollutants (OMPs) at low concentration. The selection of the target OMPs represents a wide range of physical-chemical properties such as hydrophobicity, charge state as well as a diverse range of classes, including pharmaceuticals, personal care products and household chemicals. The removal mechanisms of OMPs include adsorption, biodegradation, hydrolysis, and vaporization. Adsorption and biodegradation were found to be the main routes for OMPs removal for all target OMPs. Target OMPs responded to the two dominant removal routes in different ways: (1) complete adsorption, (2) strong biodegradation and weak adsorption, (3) medium biodegradation and adsorption, and (4) weak sorption and weak biodegradatio. Kinetic study showed that adsorption of atenolol, mathylparaben and propylparaben well followed first-order model (R2: 0.939 to 0.999) with the rate constants ranging from 0.519-7.092 h-1. For biodegradation kinetics, it was found that benzafibrate, bisphenol A, diclofenac, gemfibrozil, ibuprofen, caffeine and DEET followed zero-order model (K0:1.15E-4 to 0.0142 μg/Lh-1, R2: 0.991 to 0.999), while TCEP, naproxen, dipehydramine, oxybenzone and sulfamethoxazole followed first-order model (K1:1.96E-4 to 0.101 h-1, R2: 0.912 to 0.996). 4 Inhibition by sodium azide (NaN3)and high temperature sterilization was compared, and it was found that high temperature sterilization will damage cells and change the sludge charge state. For the OMPs adaptation removal study, it was found that some of OMPs effluent concentration decreased, which may be due to the slow adaptation of the sludge or the increase of certain bacteria culture; some increased due to chromic toxicity of the chemicals; most of the OMPs had stable effluent concentration trend, it was explained that some of the OMPs were too difficutl to remove while other showed strong quick adaptation. A new module combined of sequencing batch reactor (SBR) and nanofiltration membrane filtration (NF-MBR) was developed to further study the OMPs removal and to exam the concept of compounds (CRT). The NF-MBR was proved to be a promising bioreactor, as OMPs were rejected by NF membrane which leaded to a low OMPs concentration in permeate water, the apparent removal rate was over 80% for most of the OMPs.

This study sought to provide empirical evidence regarding the use of spatial analysis in enrollment management to predict persistence and graduation. The research utilized data from the 2000 U.S. Census and applicant records from The University of Arizona to study the spatial distributions of enrollments. Based on the initial results, stepwise logistic regression was used to identify spatially associated student and neighborhood characteristics predicting persistence and graduation.The findings of this research indicate spatial analysis can be used as a valuable resource for enrollment management. Using a theoretical framework of the forms of capital and social reproduction, cultural and social capital characteristics were found to influence persistence at statistically significant levels. Most notably, the social capital proxy of neighborhood education levels, and the cultural capital proxies of the number of standardized tests a student has taken, and when the application for admission is submitted all significantly influenced a student's probability to persistence and graduate. When disaggregating by race and ethnicity, resident Hispanic students from highly Hispanic neighborhoods were found to persist at higher levels in the first year of college attendance. Also, resident Native Americans were found to have a higher probability to persist when evidencing cultural capital characteristics. Since spatially based student and neighborhood characteristics can be quantified and mapped, target populations can be identified and subsequently recruited, resulting in retention-focused admissions.

Retention of key employees is becoming an increasingly important challenge faced by many organisations. With every employee that leaves the company, cost of recruitment and appointment, as well as training and development cost subsequent to that, are lost. The situation is aggravated by the fact that it is usually the higher performing employee who is more mobile from a career point of view, or the employee who has completed his/her training and who is more marketable, that is lost to the organisation. To effectively retain workers, employers must know which factors motivate their employees to stay on and which factors cause them to leave. The general research objective was to determine variables that influence the retention of designated employees within a platinum mine. A qualitative research design was used. Twenty four designated employees were selected randomly from the following occupations in the mining career path, namely Crew Captain in training, Crew Captain, Learner Official and Shift Supervisor. A qualitative measuring instrument, based on the phenomenological paradigm, was used to determine employees' perceptions of retention of designated employees. Content analysis was used to analyse, quantify, and interpret the research data. The results indicated that designated employees are poached by competitor companies; that designated employees leave for better payment or benefits; that they value opportunities for growth and development; that the Crew Captain title, job content and job category cause employees to be unhappy; that designated employees leave after receiving training and development; that they do not feel valued or listened to; that they are unhappy with accommodation benefits and the bonus system; that they are managed by fear; that job security makes designated employees to stay; that they leave due to poor benefits; that they are in general dissatisfied with the company; that work and safety conditions are good; that designated employees experience a lot of work pressure; that they value family responsibility; that designated employees with limited education stay; and that they experience racial discrimination. Recommendations for future research are also made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2005.

In this thesis, the effectiveness of microparticle retention aid systems comprising of different cationic starches (tapioca and waxy maize), cationic flocculants (flocculant 1, linear with low charge density and flocculant 2, branched with medium charge density polyacrylamides) and anionic colloidal silica in improving retention and drainage of thermomechanical pulp (TMP) suspensions loaded with precipitated calcium carbonate (PCC) is studied. While starch is primarily added as dry strength agent in PCC-filled TMP suspensions, it also has a significant role in improving retention and drainage. Tapioca starch, which has both amylose and amylopectin, is found to be a better retention and drainage aid than waxy maize starch, which only contains amylopectin. In the absence of starch, both flocculants are ineffective in improving retention and drainage. With starch, both flocculant and silica are significant in enhancing retention and drainage further. Increasing the dosage of either flocculant or silica generally increases retention as well as drainage. Flocculant 2 is found to give slightly worse total and filler retention but better drainage compared to flocculant 1. The dosage of flocculant 2 is only half that of flocculant 1 though – for this reason overall flocculant 2 is deemed more effective in improving retention and drainage than flocculant 1. Split starch addition, where a portion of the starch is premixed with PCC and the rest added to the pulp, causes a slight decrease in both retention and drainage. Therefore, should the papermaker decide to use this approach, the starch should be split in a 25:75 ratio between PCC and the pulp to minimize the negative effects. Due to the cost benefits of using increased amounts of PCC, it is desirable to increase PCC content beyond the standard currently used (250 kg/t OD pulp for communications-grade paper). However, at very high dosages of PCC (500 kg/t OD pulp), the best combination identified in this work (tapioca starch, flocculant 2 and silica) is unable to maintain good retention and drainage. Increasing retention aid dosages may help retain more PCC, however this tactic can rapidly become uneconomical. A new approach is thus needed to achieve such highly-filled papers.