19 resultados para Column connection solution

em Brock University, Canada


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The value of career education is measured by the extent to which it enhances students' decision making skills regarding career planning. This is referred to as "career maturity". The purpose of this study was to examine what connections could be found between career education and career maturity within one career planning course. A senior level career planning class was studied in depth for one semester and five senior students participated in the study. The five students were interviewed three times during the semester to determine whether, and to what extent, students feel more prepared personally to make decisions as a result of a guided course of instruction. The current trend in education shows an increased emphasis on career education. The government mandates career education, students are in need of career planning courses, and parents want students to learn how to effectively make decisions concerning their future. With this increased emphasis comes the need to evaluate current career education programs which is why this study is significant and useful. The central findings were as follows: first, as a result of taking a career planning course students did increase their career maturity. Second, current career education planning curriculum was similar to the proposed course of study for career planning which comes into effect in September 1999. Current curriculum does help to prepare students to make informed educational and career decisions, a chief aim of the proposed curriculum. Knowing that this outcome is currently achieved will help when the course is being organized to fit the new curriculum.

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A study has been conducted focusing on how the phosphorus renrx)val efficiency of a constructed wetland (CW) can be optimized through the selective enrichment of the substratum. Activated alumina and powdered iron were examined as possible enrichment compounds. Using packed glass column trials it was found that alumina was not suitable for the renx)val of ortho-phosphate from solution, while mixtures of powdered iron and quartz sand proved to be very efficient. The evaluation of iron/sand mixtures in CWs planted with cattails was performed in three stages; first using an indoor lab scale wetland, then an outdoor lab scale wetland, and finally in a small scale pilot project. For the lab scale tests, three basic configurations were evaluated: using the iron/sand as a pre-filter, in the root bed. and as a post filter. Primary lagoon effluent was applied to the test cells to simulate actual CW conditions, and the total phosphorus and iron concentrations of the influent and effluent were nfK)nitored. The pilot scale trials were limited to using only a post filter design, due to in-progress research at the pilot site. The lab scale tests achieved average renrK>val efficiencies greater than 91% for all indoor configurations, and greater than 97% for all outdoor configurations. The pilot scale tests had an average renK)val efficiency of 60%. This relatively low efficiency in the pilot scale can be attributed to the post filters being only one tenth the size of the lab scale test in terms of hydraulic loading (6 cm/day vs. 60 cm/day).

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Parenting goals are the behavioral, cognitive, and affective outcomes that parents implicitly or explicitly strive to achieve during specific interactions with their children. In the present study, intergenerational parenting practices and goals in Italian-Canadian and Anglo-Canadian families were examined. The association between parenting goals, parents' socialization practices, and the quality of relationship between parent and child were investigated. Participants included individuals ranging in age from 1 8-26 years and their mothers from Anglo-Canadian (n= 31) and Italian-Canadian families (n= 50). The young adults and their mothers were asked to imagine how their respective parents would have reacted to five hypothetical vignettes depicting difficult parent-child interactions. Young adults and their mothers were also asked to rate the importance of parenting goals within these parent-child situations. In addition, young adults assessed the perceived quality of their present relationships with each parent. Cultural differences were revealed such that Italian-Canadian parents endorsed more authoritarian parenting strategies and relationship-centered goals than Anglo-Canadian parents. However, Italian-Canadian and Anglo-Canadian parents were not found to differ on their endorsement of parent-centered goals. Italian-Canadian parents' who did use authoritarian strategies were found to have young-adult children who perceived their relationship with their parents as less satisfying, intimate, affectionate and having relatively high levels of conflict than parents who did not use authoritarian strategies. Anglo-Canadian parents' authoritative strategies were correlated with a better perceived relationship quality by young-adult children.

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Several automated reversed-phase HPLC methods have been developed to determine trace concentrations of carbamate pesticides (which are of concern in Ontario environmental samples) in water by utilizing two solid sorbent extraction techniques. One of the methods is known as on-line pre-concentration'. This technique involves passing 100 milliliters of sample water through a 3 cm pre-column, packed with 5 micron ODS sorbent, at flow rates varying from 5-10 mUmin. By the use of a valve apparatus, the HPLC system is then switched to a gradient mobile phase program consisting of acetonitrile and water. The analytes, Propoxur, Carbofuran, Carbaryl, Propham, Captan, Chloropropham, Barban, and Butylate, which are pre-concentrated on the pre-column, are eluted and separated on a 25 cm C-8 analytical column and determined by UV absorption at 220 nm. The total analytical time is 60 minutes, and the pre-column can be used repeatedly for the analysis of as many as thirty samples. The method is highly sensitive as 100 percent of the analytes present in the sample can be injected into the HPLC. No breakthrough of any of the analytes was observed and the minimum detectable concentrations range from 10 to 480 ng/L. The developed method is totally automated for the analysis of one sample. When the above mobile phase is modified with a buffer solution, Aminocarb, Benomyl, and its degradation product, MBC, can also be detected along with the above pesticides with baseline resolution for all of the analytes. The method can also be easily modified to determine Benomyl and MBC both as solute and as particulate matter. By using a commercially available solid phase extraction cartridge, in lieu of a pre-column, for the extraction and concentration of analytes, a completely automated method has been developed with the aid of the Waters Millilab Workstation. Sample water is loaded at 10 mL/min through a cartridge and the concentrated analytes are eluted from the sorbent with acetonitrile. The resulting eluate is blown-down under nitrogen, made up to volume with water, and injected into the HPLC. The total analytical time is 90 minutes. Fifty percent of the analytes present in the sample can be injected into the HPLC, and recoveries for the above eight pesticides ranged from 84 to 93 percent. The minimum detectable concentrations range from 20 to 960 ng/L. The developed method is totally automated for the analysis of up to thirty consecutive samples. The method has proven to be applicable to both purer water samples as well as untreated lake water samples.

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The purpose of this study was to examine a model of personality and health. Specifically, this thesis examined perfectionism as a predictor of health status and health behaviours, as moderated by coping styles. A community sample of 813 young adults completed the Multidimensional Perfectionism Scale, the Coping Strategy Indicator, and measures of health symptoms, health care utilization, and various health behaviours. Multiple regression analyses revealed a number of significant findings. First, perfectionism and coping styles contributed significant main effects in predicting health status and health behaviours, although coping styles were not shown to moderate the perfectionism-health relationship. The data showed that perfectionism did constitute a health risk, both in terms of health status and health behaviours. Finally, an unexpected finding was that perfectionism also included adaptive features related to health. Specifically, some dimensions of perfectionism were also associated with reports of better health status and involvement in some positive health behaviours.

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The goal of this thesis was to study factors related to the development of Brassica juncea as a sustainable nematicide. Brassica juncea is characterized by the glycoside (glucosinolate) sinigrin. Various methods were developed for the determination of sinigrin in Brassica juncea tissue extracts. Sinigrin concentrations in plant tissues at various stages of growth were monitored. Sinigrin enzymatically breaks down into allylisothiocyanate (AITC). AITC is unstable in aqueous solution and degradation was studied in water and in soil. Finally, the toxicity of AITC against the root-lesion nematode (Pratylenchus penetrans) was determined. A method was developed to extract sinigrin from whole Brassica j uncea tissues. The optimal time of extraction wi th boiling phosphate buffer (0.7mM, pH=6.38) and methanol/water (70:30 v/v) solutions were both 25 minutes. Methanol/water extracted 13% greater amount of sinigrin than phosphate buffer solution. Degradation of sinigrin in boiling phosphate buffer solution (0.13%/minute) was similar to the loss of sinigrin during the extraction procedure. The loss of sinigrin from boiling methanol/water was estimated to be O.Ol%/minute. Brassica juncea extract clean up was accomplished by an ion-pair solid phase extraction (SPE) method. The recovery of sinigrin was 92.6% and coextractive impurities were not detected in the cleaned up extract. Several high performance liquid chromatography (HPLC) methods were developed for the determination of sinigrin. All the developed methods employed an isocratic mobile phase system wi th a low concentration of phosphate buffer solution, ammonium acetate solution or an ion-pair reagent solution. A step gradient system was also developed. The method involved preconditioning the analytical column with phosphate buffer solution and then switching the mobile phase to 100% water after sample injection.Sinigrin and benzyl-glucosinolate were both studied by HPLC particle beam negative chemical ionization mass spectrometry (HPLCPB- NCI-MS). Comparison of the mass spectra revealed the presence of fragments arising from the ~hioglucose moiety and glucosinolate side-chain. Variation in the slnlgrin concentration within Brassica juncea plants was studied (Domo and Cutlass cuItivars). The sinigrin concentration in the top three leaves was studied during growth of each cultivar. For Cutlass, the minimum (200~100~g/g) and maximum (1300~200~g/g) concentrations were observed at the third and seventh week after planting, respectively. For Domo, the minimum (190~70~g/g) and maximum (1100~400~g/g) concentrations were observed at the fourth and eighth week after planting, respectively. The highest sinigrin concentration was observed in flower tissues 2050±90~g/g and 2300±100~g/g for Cutlass and Domo cultivars, respectively. Physical properties of AITC were studied. The solubility of AITC in water was determined to be approximately 1290~g/ml at 24°C. An HPLC method was developed for the separation of degradation compounds from aqueous AITC sample solutions. Some of the degradation compounds identified have not been reported in the literature: allyl-thiourea, allyl-thiocyanate and diallyl-sulfide. In water, AITC degradation to' diallyl-thiourea was favored at basic pH (9.07) and degradation to diallyl-sulfide was favored at acidic pH (4 . 97). It wap necessary to amend the aqueous AITC sample solution with acetonitrile ?efore injection into the HPLC system. The acetonitrile amendment considerably improved AITC recovery and the reproducibility of the results. The half-life of aqueous AITC degradation at room temperature did not follow first-order kinetics. Beginning with a 1084~g/ml solution, the half-life was 633 hours. Wi th an ini tial AITC concentration of 335~g/ml the half-life was 865 hours. At 35°C the half-life AITC was 76+4 hours essentially independent of the iiisolution pH over the range of pH=4.97 to 9.07 (1000~g/ml). AITC degradation was also studied in soil at 35°C; after 24 hours approximately 75% of the initial AITC addition was unrecoverable by water extraction. The ECso of aqueous AITC against the root-lesion nematode (Pratylenchus penetrans) was determined to be approximately 20~g/ml at one hour exposure of the nematode to the test solution. The toxicological study was also performed with a myrosinase treated Brassica juncea extract. Myrosinase treatment of the Brassica juncea extract gave nearly quantitative conversion of sinigrin into AITC. The myrosinase treated extract was of the same efficacy as an aqueous AITC solution of equivalent concentration. The work of this thesis was focused upon understanding parameters relevant to the development of Brassica juncea as a sustainable nematicide. The broad range of experiments were undertaken in support of a research priority at Agriculture and Agri-Food Canada.

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A simple method was developed for treating corn seeds with oxamyl. It involved soaking the seeds to ensure oxamyl uptake, centrifugation to draw off excess solution, and drying under a stream of air to prevent the formation of fungus. The seeds were found to have an even distribution of oxamyl. Seeds remained fungus-free even 12 months after treatment. The highest nonphytotoxic treatment level was obtained by using a 4.00 mg/mL oxamyl solution. Extraction methods for the determination of oxamyl (methyl-N'N'-dimethyl-N-[(methylcarbamoyl)oxy]-l-thiooxamimidate), its oxime (methyl-N',N'-dimethyl-N-hydroxy-1-thiooxamimidate), and DMCF (N,N-dimethyl-1-cyanoformanade) in seed" root, and soil were developed. Seeds were processed by homogenizing, then shaking in methanol. Significantly more oxamyl was extracted from hydrated seeds as opposed to dry seeds. Soils were extracted by tumbling in methanol; recoveries range~ from 86 - 87% for oxamyl. Root was extracted to 93% efficiency for oxamyl by homogenizing the tissue in methanol. NucharAttaclay column cleanup afforded suitable extracts for analysis by RP-HPLC on a C18 column and UV detection at 254 nm. In the degradation study, oxamyl was found to dissipate from the seed down into the soil. It was also detected in the root. Oxime was detected in both the seed and soil, but not in the root. DMCF was detected in small amounts only in the seed.

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This study explored motivations of mid-life women over 30 years old who had returned to school. It sought to fmd whether these women returned to solve a problem arising from life events, whether viewing a problem was related to internal or external motivation, whether this perception was related to having greater coping skills, and whether having greater coping was related to seeking support from internal or external sources. This study examined which emotions were most related to viewing a life event as a problem. Finally, it explored the results of previous research of mid-life women in their role as a student. Women (N==83) from three types of institutions volunteered for this study: a university (N==34), a college (N==28), and an adult education centre (N==21). Participants took home a questionnaire package - a I3-page questionnaire and consent form - that were completed and mailed back to the researcher in pre-paid envelopes. Results showed that women over 30 seek education as a solution to a life event problem. External motivation was related to a life event being a problem (p<.005). There was a significant difference in coping scores between institutions. Moods that were related to viewing a life event as problematic were: anger and depressive moods (p<. 001), fatigue and vigor (p<.O 1), and tension/anxiety (p<.05). Mid-life women students' satisfaction in this role was related to being externally motivated. These women sought support from both internal and external sources, rarely had social interactions with peers, and viewed this role as important, yet, temporary in that it will help them change their lives. Implications ofthe results suggest further exploration ofthe roles of anger and depression in motivating women over 30 to learn and finding ways of directing women to use their emotional intelligence to seek out learning.

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The Two-Connected Network with Bounded Ring (2CNBR) problem is a network design problem addressing the connection of servers to create a survivable network with limited redirections in the event of failures. Particle Swarm Optimization (PSO) is a stochastic population-based optimization technique modeled on the social behaviour of flocking birds or schooling fish. This thesis applies PSO to the 2CNBR problem. As PSO is originally designed to handle a continuous solution space, modification of the algorithm was necessary in order to adapt it for such a highly constrained discrete combinatorial optimization problem. Presented are an indirect transcription scheme for applying PSO to such discrete optimization problems and an oscillating mechanism for averting stagnation.

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Vitamin E is a well known fat soluble chain breaking antioxidant. It is a general tenn used to describe a family of eight stereoisomers of tocopherols. Selective retention of a-tocopherol in the human circulation system is regulated by the a -Tocopherol Transfer Protein (a-TIP). Using a fluorescently labelled a-tocopherol (NBD-a-Toc) synthesized in our laboratory, a fluorescence resonance energy transfer (FRET) assay was developed to monitor the kinetics of ligand transfer by a-hTTP in lipid vesicles. Preliminary results implied that NBD-a-Toe simply diffused from 6-His-a-hTTP to acceptor membranes since the kinetics of transfer were not responsive to a variety of conditions tested. After a series of trouble shooting experiments, we identified a minor contaminant, E coli. outer membrane porin F (OmpF) that co-purified with 6-His-a-hTTP from the metal affinity column as the source of the problem. In order to completely avoid OmpF contamination, a GST -a-hTTP fusion protein was purified from a glutathione agarose column followed by an on-column thrombin digestion to remove the GST tag. We then demonstrated that a-hTTP utilizes a collisional mechanism to deliver its ligand. Furthennore, a higher rate of a-tocopherol transfer to small unilamellar vesicles (SUV s) versus large unilamellar vesicles (LUV s) indicated that transfer is sensitive to membrane curvature. These findings suggest that ahTTP mediated a-Toc transfer is dominated by the hydrophobic nature of a-hTTP and the packing density of phospholipid head groups within acceptor membranes. Based on the calculated free energy change (dG) when a protein is transferred from water to the lipid bilayer, a model was generated to predict the orientation of a-hTTP when it interacts with lipid membranes. Guided by this model, several hydrophobic residues expected to penetrate deeply into the bilayer hydrophobic core, were mutated to either aspartate or alanine. Utilizing dual polarization interferometry and size exclusion vesicle binding assays, we identified the key residues for membrane binding to be F 165, F 169 and 1202. In addition, the rates of ligand transfer of the u-TTP mutants were directly correlated to their membrane binding capabilities, indicating that membrane binding was likely the rate limiting step in u-TTP mediated transfer of u-Toc. The propensity of u-TTP for highly curved membrane provides a connection to its colocalization with u-Toc in late endosomes.

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To investigate the thennal effects of latent heat in hydrothennal settings, an extension was made to the existing finite-element numerical modelling software, Aquarius. The latent heat algorithm was validated using a series of column models, which analysed the effects of penneability (flow rate), thennal gradient, and position along the two-phase curve (pressure). Increasing the flow rate and pressure increases displacement of the liquid-steam boundary from an initial position detennined without accounting for latent heat while increasing the thennal gradient decreases that displacement. Application to a regional scale model of a caldera-hosted hydrothennal system based on a representative suite of calderas (e.g., Yellowstone, Creede, Valles Grande) led to oscillations in the model solution. Oscillations can be reduced or eliminated by mesh refinement, which requires greater computation effort. Results indicate that latent heat should be accounted for to accurately model phase change conditions in hydrothennal settings.

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The purpos e of this phenomenological research is to explore the meaning of a YMCA-sponsored after-school recreation program in the lives of four adolescent boys. Listening to youth voice is impor t ant to the ability of othe r s to design, implement and evaluate high-quality programs tha t facilitate learning opportunities tha t a r e meaningful to participants. Within the context of interviews, task-based activities we r e used to ga the r data. Guided by Creswell's analytic spiral (1998), data wa s analyzed according to van Manen's (1990) thematic analysis and Caeilli's (2000) creative narrative analysis. It wa s found tha t this after-school progr am provided the s e adolescents with the opportunity to escape from the i r monotonous after-school activities and the instability of the i r home and school environments. Also, they we r e connected wi th positive peers, caring adults and the wide r community, opportunities tha t we r e limited in othe r aspects of the i r lives. Methodological issues a r e also discussed.

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The goal of the four studies that comprised this dissertation was to examine how spirituality/religiosity (SIR), as both an institutional and personal phenomenon, developed over time, and how its institutional (i.e., religious activity involvement) and personal (i.e., sense of connection with the sacred) components were uniquely linked with psychosocial adjustment. In Study 1, the differential longitudinal correlates of religious service attendance, as compared to involvement in other clubs, were evaluated with a sample of adolescents (n=1050) who completed a survey in grades 9, 11 and 12. Religious attendance and involvement in non-religious clubs were uniquely associated with positive adjustment in terms of lower substance use and better academic marks, particularly when involvement was sustained over time. In Study 2, the direction of effects was tested for the association between religious versus non-religious activities and both substance use and academic marks. Participants (n= 3993) were surveyed in grades 9 through 12. Higher religious attendance (but not non-religious club involvement) in one grade predicted lower levels of substance use in the next grade. Higher levels of nonreligious club involvement (but not religious service attendance) in one grade predicted higher academic achievement in the next grade, and higher academic achievement in one grade predicted more frequent non-religious club involvement in the next grade. The results suggest that different assets may be fostered in religious as compared to nonreligious activities, and, specifically, religious activity involvement may be important for the avoidance of substance use. The goal of Study 3 was to assess the unique associations between the institutional versus personal dimensions of SIR and a wide range of domains of psychosocial adjustment (namely, intrapersonal well-being, substance use, risk attitudes, parental relationship quality, academic orientation, and club involvement), and to examine the direction of effects in these associations. Participants (n=756) completed a survey in grades 11 and 12. Personal and institutional dimensions of SIR were differentially associated with adjustment, but it may only be in the domain of risk-taking (Le., risk attitudes, substance use) that SIR may predict positive adjustment over time. Finally, in Study 4, the goal was to examine how institutional and personal aspects of SIR developed within individual adolescents. Configurations of mUltiple dimensions of spirituality/religiosity were identified across 2 time points with an empirical classification procedure (cluster analysis), and sample- and individual-level development in these configurations were assessed. A five cluster-solution was optimal at both grades. Clusters were identified as aspirituallirreligious, disconnected wonderers, high institutional and personal, primarily personal, and meditators. With the exception of the high institutional and personal cluster, the cluster structures were stable over time. There also was significant intraindividual stability in all clusters over time; however, a significant proportion of individuals classified as high institutional and personal in Grade 11 moved into the primarily personal cluster in Grade 12. This program of research represented an important step towards addressing some of the limitations within the body of literature; namely, the uniqueness of religious activity involvement as a structured club, the differential link between institutional versus personal SIR and psychosocial adjustment, the direction of effects in the associations between institutional versus personal SIR and adjustment, and the way in which different dimensions of SIR may be configured and develop within individual adolescents over time.

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Studying positive adolescent development requires an examination of the mutually beneficial associations between youth and their environment. These youthcontext relations include both the contributions that youth make to others and society and the youth-context interactions that might predict positive youth outcomes. Community and youth-serving organizations, where youth may be involved in decision-making roles such as service delivery, advocacy, or on boards of directors, can provide one important context for youth contributions and for positive adolescent development. Research on the outcomes of youth involvement in organizational decision-making, however, is limited, and largely consists of exploratory qualitative studies. This dissertation is formatted as an integrated article dissertation. It begins with a review of the literature on contexts of structured youth activities and positive youth development. This review is intended to describe theory on development-context relations, in which development is considered an interactive process that occurs between individuals and their contexts, as it pertains the positive development of youth who are involved in various structured activities (e.g., volunteering). This description follows with a review of current research, and conclusions and rationale for the current studies. Following this theoretical and research background, the dissertation includes reports of two studies that were designed to address gaps in the research on youth involvement in organizational decision-making. The first was a qualitative research synthesis to elucidate and summarize the extant qualitative research on the outcomes of youth involvement in organizational decision making on adults and organizations. Results of this study suggested a number of outcomes for service provision, staff, and broader organizational functioning, including both benefits to organizations as well as some costs. The second study was a quantitative analysis of the associations among youth involvement, organizations' learning culture, and youth initiative, and relied on survey data gathered from adults and youth in community-based organizations with youth involvement. As expected, greater youth involvement in organizational decision making was associated with higher learning culture within the organization. Two dimensions of youth involvement, greater program engagement and relationships with adults, were related to greater youth initiative. A third dimension, sense of ownership, was not- .-.- associated with youth's level of initiative. Moreover, the association between relationships with adults and youth initiative was only significant in organizations with relatively low learning culture. Despite some limitations, these studies contribute to the research literature by providing some indication of the potential benefits and costs of youth involvement and by making an important contribution toward the early stages of context-level analyses of youth development. Findings have important implications for practitioners, funders, future research, and lifespan development theory.

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In this study of 109 adolescents from the eighth grade of seven public elementary schools in Ontario, the relationship among adolescents’ violent video game playing patterns, habits and attitudes, their levels of moral reasoning, and their attitudes towards violence in real life was investigated. In addition, gender differences were addressed. The mixed-methodology was employed combining qualitative and quantitative data. The research results confirmed that playing video games in general is a very popular activity among those adolescents. Significant negative relationship was found between adolescents’ amount of time playing violent video games during the day and their scores on The Sociomoral Reflection Measure. Significant difference was also found between adolescents who play violent video games and those who do not play violent video games on their scores on The Attitudes Towards Violence Scale. Boys and girls significantly differed in the amount of playing video games during the day, the reasons for playing video games, their favourite video game choices, and their favourite video game character choices. Boys and girls also significantly differed on their choices of personality traits of selected video game characters, the identification with video game characters, and their mood experiences while playing video games. The findings are put into the educational context and the context of normal development, and suggestions are given for parents, for educators, and for future violent video game research.