6 resultados para Data Acquisition Methods.

em Brock University, Canada


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Linear alkylbenzenes, LAB, formed by the Alel3 or HF catalyzed alkylation of benzene are common raw materials for surfactant manufacture. Normally they are sulphonated using S03 or oleum to give the corresponding linear alkylbenzene sulphonates In >95 % yield. As concern has grown about the environmental impact of surfactants,' questions have been raised about the trace levels of unreacted raw materials, linear alkylbenzenes and minor impurities present in them. With the advent of modem analytical instruments and techniques, namely GCIMS, the opportunity has arisen to identify the exact nature of these impurities and to determine the actual levels of them present in the commercial linear ,alkylbenzenes. The object of the proposed study was to separate, identify and quantify major and minor components (1-10%) in commercial linear alkylbenzenes. The focus of this study was on the structure elucidation and determination of impurities and on the qualitative determination of them in all analyzed linear alkylbenzene samples. A gas chromatography/mass spectrometry, (GCIMS) study was performed o~ five samples from the same manufacturer (different production dates) and then it was followed by the analyses of ten commercial linear alkylbenzenes from four different suppliers. All the major components, namely linear alkylbenzene isomers, followed the same elution pattern with the 2-phenyl isomer eluting last. The individual isomers were identified by interpretation of their electron impact and chemical ionization mass spectra. The percent isomer distribution was found to be different from sample to sample. Average molecular weights were calculated using two methods, GC and GCIMS, and compared with the results reported on the Certificate of Analyses (C.O.A.) provided by the manufacturers of commercial linear alkylbenzenes. The GC results in most cases agreed with the reported values, whereas GC/MS results were significantly lower, between 0.41 and 3.29 amu. The minor components, impurities such as branched alkylbenzenes and dialkyltetralins eluted according to their molecular weights. Their fragmentation patterns were studied using electron impact ionization mode and their molecular weight ions confirmed by a 'soft ionization technique', chemical ionization. The level of impurities present i~ the analyzed commercial linear alkylbenzenes was expressed as the percent of the total sample weight, as well as, in mg/g. The percent of impurities was observed to vary between 4.5 % and 16.8 % with the highest being in sample "I". Quantitation (mg/g) of impurities such as branched alkylbenzenes and dialkyltetralins was done using cis/trans-l,4,6,7-tetramethyltetralin as an internal standard. Samples were analyzed using .GC/MS system operating under full scan and single ion monitoring data acquisition modes. The latter data acquisition mode, which offers higher sensitivity, was used to analyze all samples under investigation for presence of linear dialkyltetralins. Dialkyltetralins were reported quantitatively, whereas branched alkylbenzenes were reported semi-qualitatively. The GC/MS method that was developed during the course of this study allowed identification of some other trace impurities present in commercial LABs. Compounds such as non-linear dialkyltetralins, dialkylindanes, diphenylalkanes and alkylnaphthalenes were identified but their detailed structure elucidation and the quantitation was beyond the scope of this study. However, further investigation of these compounds will be the subject of a future study.

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A simple, low-cost concentric capillary nebulizer (CCN) was developed and evaluated for ICP spectrometry. The CCN could be operated at sample uptake rates of 0.050-1.00 ml min'^ and under oscillating and non-oscillating conditions. Aerosol characteristics for the CCN were studied using a laser Fraunhofter diffraction analyzer. Solvent transport efficiencies and transport rates, detection limits, and short- and long-term stabilities were evaluated for the CCN with a modified cyclonic spray chamber at different sample uptake rates. The Mg II (280.2nm)/l\/lg 1(285.2nm) ratio was used for matrix effect studies. Results were compared to those with conventional nebulizers, a cross-flow nebulizer with a Scott-type spray chamber, a GemCone nebulizer with a cyclonic spray chamber, and a Meinhard TR-30-K3 concentric nebulizer with a cyclonic spray chamber. Transport efficiencies of up to 57% were obtained for the CCN. For the elements tested, short- and long-term precisions and detection limits obtained with the CCN at 0.050-0.500 ml min'^ are similar to, or better than, those obtained on the same instrument using the conventional nebulizers (at 1.0 ml min'^). The depressive and enhancement effects of easily ionizable element Na, sulfuric acid, and dodecylamine surfactant on analyte signals with the CCN are similar to, or better than, those obtained with the conventional nebulizers. However, capillary clog was observed when the sample solution with high dissolved solids was nebulized for more than 40 min. The effects of data acquisition and data processing on detection limits were studied using inductively coupled plasma-atomic emission spectrometry. The study examined the effects of different detection limit approaches, the effects of data integration modes, the effects of regression modes, the effects of the standard concentration range and the number of standards, the effects of sample uptake rate, and the effect of Integration time. All the experiments followed the same protocols. Three detection limit approaches were examined, lUPAC method, the residual standard deviation (RSD), and the signal-to-background ratio and relative standard deviation of the background (SBR-RSDB). The study demonstrated that the different approaches, the integration modes, the regression methods, and the sample uptake rates can have an effect on detection limits. The study also showed that the different approaches give different detection limits and some methods (for example, RSD) are susceptible to the quality of calibration curves. Multicomponents spectral fitting (MSF) gave the best results among these three integration modes, peak height, peak area, and MSF. Weighted least squares method showed the ability to obtain better quality calibration curves. Although an effect of the number of standards on detection limits was not observed, multiple standards are recommended because they provide more reliable calibration curves. An increase of sample uptake rate and integration time could improve detection limits. However, an improvement with increased integration time on detection limits was not observed because the auto integration mode was used.

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Discussions concerning the challenges of combining work and family are certainly not new, and still actively continue. There is, however, a silence in the related literature regarding a comprehensive description of integrating specifically university academic ~. work and family responsibilities. This silence is especially evident for men who are parents as well as academics. With the participation of 4 key informants, this qualitative research study gave voice to men and women who participate in the academic labour of a Canadian university as professors, and as graduate students, along with the parenting labour of at least 1 child under the age of7. Methodology was developed to reveal in-depth perspectives regarding the work practices employed by 4 key informants as they combined intellectual and child-care responsibilities. Multiple data collection methods included journal reflections, day time observation sessions, a focus group, and a final evaluation questionnaire. Using research findings, together with information extrapolated from Three Models of the Family (Eichler, 1997), this study also took steps toward developing a Proposed "Three Models of the University," to offer explanation for the work practices of the key informants as academics/parents, and also for future consideration in university policy formation.

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This action research assesses a framework that assists business educators in promoting leadership within a classroom. It is designed to better prepare students to assume leadership and fill the "leadership gap" in business. Two classes of 2nd-year community college business students participated in running and managing their own business community as teams of sales professionals by developing and practicing their own individual leadership for 28 weeks during their sales courses. The intent was to assess the development of leadership resulting from the implementation of the "Business Leadership in the Classroom" framework. This framework balances leadership principles to simulate a business environment with the practical elements of a learning community under the facilitation of an experienced business educator. The action research approach was used to assess and adjust approaches to business leadership on a continuous basis throughout the research. Data were collected from 61 students based on journals, surveys, peer group reviews, and my (facilitator) reflective journal.The findings reveal that both individual and collective business leadership views and practical skills developed over time. A business leadership mind-set evolved that ranged from a general awareness of the importance of leadership, to a conscious and deliberate use of individual leadership. Areas important in building a progression of leadership included: leadership teams, membership roles, weekly leadership teams, peer feedback, and activity-based learning. Emerging themes included leadership, leadership style, teamwork, as well as influence and motivation. The research framework was effective in supporting the development of business leadership but required some adjustments. These included increased structure and feedback mechanisms. Interpretation of the findings demonstrates the importance of real-world practical education in the classroom. Results show how focusing on a single mind-set such as business leadership, can result in enormous individual growth and development. When business students are encouraged to act as real businesspeople, managing their own learning, the results are effective in preparing them for the business world. All participants expressed their leadership in different ways based on personality and individual strengths. There was an overwhelming and, in some cases, passionate interest in leadership. The use of action research with a range of data collection methods provides a way to measure and track individual student learning and to generate adjustments to the research framework design and learning approaches. The findings generate implications and recommendations to continue this research further. Key recommendations center around how to ensure leadership development is sustained, including improved approaches to heighten the real-world feel of the classroom. Specifically, the use of leadership goals and action plans for each individual participant and an active use of outside business resource people as contacts for participants is recommended.

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This study examined the impact that collaborative learning had on the assessment and evaluation of writing practices of a group of teachers as they engaged in a community of learners. The study explored the development of teacher knowledge and perceptions as well as the implementation of effective assessment strategies in writing for students in grades 4 to 8 that could be achieved through collaboration. Teachers' perceptions of the value of collaboration were also embedded within the study. Multiple methods of data collection were used to gather rich and descriptive data. Those methods included interviews, observation, and documentation of meetings and of participants' perceptions of their assessment and evaluation practices. Five preexisting themes describing desired outcomes of change were used to analyze the data. These themes included: knowledge, attitude, skill, aspiration, and behaviour. While it was difficult to identify definitively the degree oflearning achieved by the participants, conclusions can be drawn that the participants experienced learning and some change in the areas of knowledge and skill, attitude, aspiration, and behaviour. What was notable was the continued belief on the part of the participants of the value of collaboration as a means of learning.

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The National Lacrosse League (NLL) is floundering. In an attempt to understand why NLL fans attend games and other sport fans do not, the NLL’s Edmonton Rush were studied. To best address the NLL’s attendance woes, two primary research questions were developed: 1) Why do fans of the Oilers and Oil Kings choose not to attend Edmonton Rush games? 2) Why do fans of the Edmonton Rush attend games? To answer these questions an online focus group along with a document analysis of Rush media, and a telephone interview were used to collect data. The data collection methods mentioned above assisted in answering the primary and secondary research questions, which allowed three major themes along with sub-themes to inductively emerge. The nonfans of the Rush do not attend Rush games because of the connection they have with hockey and the disconnection they have with lacrosse, some are simply not interested or were not entertained, as well as the lack of exposure the Rush receive. The Rush fan participants attend Rush games because of Edmonton community pride, the entertainment value they get out of attending a game, it is a great alternative new sport experience and it either is a substitute or a compliment to hockey. Both the nonfan and fan participants of this study believe that different marketing approaches can be utilized in order to attract nonfans to attend games.