The effect of manipulated variables on the flotation response of run-of-mine coal supplied by Bullmoose Coal Mine (North East British Columbia) was studied in a pilot flotation column and a batch mechanical cell using experimental designs of the factorial class after the coal had been stage crushed and ground to about 96 percent minus 600 µm, the feed size to the flotation circuit at Bullmoose Coal Mine. The objective was to optimise statistically the two flotation units usings (1) screening designs, (2) the steepest ascent technique, and (3) central composite designs, and to compare cell performance. The efficiency index was employed as the primary optimisation criterion. The two cells yielded comparable efficiency indices, but the product ash content of clean coal from the flotation column was consistently lower. Evaluation of the efficiency indices of individual size fractions was also carried out at the optimum conditions of each cell. The approach taken was to separate the feed into individual size fractions, retain the fractions separately, and float them separately. The flotation column yielded higher efficiency indices and lower product ash content when a feed with 15 percent solids was floated. Results obtained by floating individual size fractions at 2 percent solids indicated that it is difficult to float sizes above 300 µm in both cells at such a low pulp density. Below 300 µm, the performance of both cells was comparable. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

Forensic toxicology is a branch of science that involves the analysis of drugs and other substances in biological fluids and tissues such as blood, urine, and oral fluid to aid medical or legal investigation of death, poisoning, and drug use. Due to the various components of different matrices, efficient and effective sample preparation techniques are necessary for reliable and accurate analysis. Following sample clean-up, a sensitive, specific, and robust method is ideal for consistent detection, identification, and quantitation of analytes. With the rise of drug abuse, there is a growing need to develop a single method that can target multiple classes of drugs quickly and effectively. This study validated two different sample preparation techniques for the detection and quantitation of six drug classes comprised of twenty-three drugs and metabolites in oral fluid. The drug classes were as follows: amphetamines, local anesthetics, opioids, hallucinogens, antidepressants, and novel psychoactive substances (NPS). Amphetamines used were amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), and 3,4-methylenedioxymethamphetamine (MDMA). Local anesthetics contained benzoylecgonine (BZE), cocaine, and lidocaine. Opioids included codeine, methadone, morphine, 6-monoacetylmorphine (6-MAM), fentanyl, and oxycodone. Hallucinogens included lysergic acid diethylamide (LSD) and phencyclidine (PCP). Antidepressants were amitriptyline, citalopram, fluoxetine, and trazodone. Lastly, NPS included ethylone, α-pyrrolidinopentiophenone (α-PVP), and 2,5-dimethoxy-4-iodophenethylamine N-(2-methoxybenzyl) (25I-NBOMe). Supported liquid extraction (SLE) and solid phase extraction (SPE) were assessed followed by confirmatory analysis by liquid chromatography (LC)-tandem mass spectrometry (MS/MS). Both methods were validated according to guidelines in the Standard Practices for Method Validation in Forensic Toxicology set by the American Academy of Forensic Science (AAFS) Standards Board (ASB). Parameters assessed include calibration model, bias, precision, limit of detection (LOD), limit of quantitation (LOQ), dilution integrity, ion suppression/enhancement, interference studies, and stability. Matrix recovery was added as another parameter. All calibration models were 0.99 or greater and all compounds were stable for at least 72 hours. Bias, precision, LOD, LOQ, dilution integrity, and interferences were similar between both methods. SLE yielded slightly better LOD and LOQ values. SLE had greater values of matrix recovery as well as lower levels of ionization suppression/enhancement. Overall, SLE was determined to be the better method of sample preparation for this panel of drugs in oral fluid. Not only did it yield higher values for several of the parameters assessed but it also was more efficient (1 hour versus 2 hours) while using less solvent.

The purpose of this study was to investigate the relationships among selected personal and environmental variables and the quality of elementary principals' administrative internships. Two research questions were used to investigate the influence of the variables on the quality of the internships. Procedural and experiential internship characteristics as identified by previous research were used as the basis for the dependent variable. Personal and environmental variables were identified from a review of the literature and through anecdotal experiences. Surveys were sent to 400 elementary school principals across the United States. The dependent variable involvement was regressed on 17 personal and environmental independent variables using a stepwise regression procedure. Results of the stepwise multiple regression for total quality performed in this study indicated that 39% of the variation in overall internship quality was explained by the intern's belief that the internship was worthwhile, the intern's level of work-related responsibility, whether or not the intern was a part of a cohort during their principal preparation program, and the length of the administrative internship. This study should be beneficial to colleges, universities, and other entities and individuals who are interested in the development of effective administrative internships in principal preparation programs. / Ed. D.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this study was to demonstrate the clinical application of the television microscope for direct intraoral micromeasurement of cavity margin deterioration. Mesiocclusal alloy restorations were placed in fifty-one maxillary second deciduous molars. A cast gold overlay with two proximal margin observation holes, one hole in the occlusal one-third and one hole in the gingival one-third, was fabricated for each restored tooth. The mesiobuccal proximal margins of the restorations were observed by the television microscope, and the marginal deterioration was electronically measured at intervals of one week, two weeks, four weeks, 12 weeks, 24 weeks, and 36 weeks postoperatively. The average gingival marginal deterioration ranged from 4.9 microns at one week to 37.8 microns at 36 weeks; the average occlusal marginal deterioration ranged from 5. 4 microns at one week to 60.1 microns at 36 weeks. The data indicated that the gingival area of the proximal margin deteriorated at a faster rate during the first 12 weeks postoperatively, and the occlusal area of the gingival margin deteriorated at a faster rate during the last 24 weeks. Greater marginal alloy flash in the gingival area was believed to be responsible for the initial gingival deterioration, and repeated masticatory stresses was believed to be major causative factor for the occlusal deterioration during the last 24 weeks of the study.

Abstract Heavy metals are used in many industrial processes and their cations are either valuable or environmentally harmful to discharge in wastewater. Thus, it is necessary to separate heavy metals in wastewater treatment. Amongst several technical methods of separation, use of permeable membranes is an important one. For separation processes, membranes can be selective towards a target heavy metal cation either against mono-valent common cations or against other similar heavy metal cations. Synthesis of selective permeable membranes for separation purposes is an area of continuous research to meet specific needs in different applications. One of the common applications of selective separation by a permeable membrane is cation/anion separation processes using cation exchange and anion exchange membranes. Another application of selective permeable membranes is the separation of mono-valent cations from other higher valence cations. Some researchers have focused on specific selective separation of heavy metal cation from other heavy metal cations having the same valent charge. Some use chelating particulates dispersed in a neutral polymeric membrane matrix and others applied a thin chelating film on the surface of a commercial cation exchange membrane. In this work, the synthesis of novel permeable selective membranes and their use for selective separation between two di-valent heavy metal cations is presented. Three different sets of membranes were prepared in non-imprinted and imprinted forms. The ion imprinted membranes form is prepared by pre-reacting the target metal ion with the selective chelating monomer before applying in situ polymerization step, and in the non-imprinted membranes form this step is not considered. Their morphological and chemical structures were determined and their separation performances were investigated using a diffusion dialysis technique. The first membrane (non-imprinted polyvinylidene fluoride-divinylbenzyl-triethylenetetramine (PVDF/diVB-TETA) and Cu-imprinted PVDF/diVB-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer divinylbenzyl-triethylenetetramine diVB-TETA (or diVB-TETA-Cu) within a PVDF substrate, using a divinylbenzene cross-linker. Fourier transform infrared FT-IR spectroscopy showed the successful in situ polymerization of the chelating monomer within the PVDF texture. The permeation study showed that the ion-imprinted membrane has a Cu2+ selectivity factor of 3.78, while the non-imprinted membrane has a Cu2+ selectivity factor of 1.65. In addition the Cu2+ permeation flux in the imprinted membrane is 3.9 time that in the non-imprinted membrane For the second membrane, the synthesis is similar to the first membrane for both non-imprinted and imprinted forms (polyvinylidene fluoride-divinylbenzyl-triethylenetetramine-N,N'-methylenebis(acrylamide) (PVDF/diVB-TETA-N) and PVDF/diVB-TETA-N-Cu respectively), except that the used cross-linker was N,N'-methylenebis(acrylamide). In addition, sodium 4-vinylbenzyl sulfonate was added in selected percentages, (5-15% mol), to enhance the permeation flux. FT-IR spectroscopy analysis of the prepared membranes confirmed the chemical structure of diVB-TETA-N and sulfonate group into PVDF. Permeation and selective separation studies for the prepared membranes showed that the ion-imprinted membrane has a higher selectivity for copper permeation over the non-imprinted membrane. However imprinted membrane showed a lower flux for the permeated cations than that of the non-imprinted membranes The addition of the sulfonate groups to the prepared membranes enhanced the flux of the permeated cations, but the copper selective permeation decreased for both types (non-imprinted and ion-imprinted). Moreover, the ion-imprinted membrane PVDF/diVB-TETA-N-Cu showed a lower flux for the permeated cations than that of the non-imprinted membranes PVDF/diVB-TETA-N. Selective separation factors decreased to unity when the content of the sulfonate groups increased to 15% mol. Ion imprinted membrane prepared with 10% of sulfonate group showed optimum copper selectivity factor (α = 30304) and permeation flux for copper (0.4949 μmol cm‒2 h‒1) The third membrane (non-imprinted Selemion TM cation exchange membrane-divinylbenzyl-triethylenetetramine (CMV-S/diVB-TETA) and ion-imprinted CMV-S/diVb-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer, diVB-TETA (or diVB-TETA-Cu), on the surface of the commercial cation exchange membrane, Selemion, using divinylbenzene as cross-linker. FT-IR spectroscopy confirmed the chemical structure of the chelating polymer on the CMV-S membrane surface. Permeation study showed that ion-imprinted CMV-S/diVB-TETA-Cu membrane reached high separation factor (α = 17), yet the flux is low (0.0391 μmol cm‒2 h‒1). Non-imprinted CMV-S/diVB-TETA membrane of thickness (0.115±0.005 mm) using cross-linker (10% DVB) showed reasonable copper selectivity factor (α = 2.723) and permeation flux (0.433 μmol cm‒2 h‒1) / Thesis / Doctor of Philosophy (PhD)

Previous investigations comparing direct versus indirectly cued movements have consistently shown that indirectly cued movements take longer to prepare (Neely and Heath, 2010) and involve the recruitment of additional brain areas (Connolly et al., 2000). This increase in processing time has been associated with the additional cognitive transformations required of the task (Neely and Heath, 2010). In the present study we investigated whether differences between direct versus indirectly cued movements are also reflected in the time course of motor preparation. Participants performed a targeting task, moving directly to the location of a visual cue (i.e., directly cued movement) or to a location that differed by 60˚, 90˚, or 120˚ with respect to the visual cue provided (i.e., indirectly cued movements). Participants were instructed to initiate their movements concurrently with an anticipated go-signal. To examine the time course of motor preparation, a startling acoustic stimulus (SAS, 124dB) was randomly presented 150 ms, 500 ms, or 1000 ms prior to the go-signal. Results from the startle trials revealed that the time course of motor preparation was similar regardless of the angle of rotation required and hence whether it was a direct or indirectly cued trial. Specifically, motor preparation was delayed until less than 500 ms prior to movement initiation for both direct and indirectly cued movements. These findings indicate that similar motor preparation strategies are engaged for both types of cued movements, suggesting that the time to prepare a motor response may be similar regardless of whether a cognitive transformation is required.

Previous investigations comparing direct versus indirectly cued movements have consistently shown that indirectly cued movements take longer to prepare (Neely and Heath, 2010) and involve the recruitment of additional brain areas (Connolly et al., 2000). This increase in processing time has been associated with the additional cognitive transformations required of the task (Neely and Heath, 2010). In the present study we investigated whether differences between direct versus indirectly cued movements are also reflected in the time course of motor preparation. Participants performed a targeting task, moving directly to the location of a visual cue (i.e., directly cued movement) or to a location that differed by 60˚, 90˚, or 120˚ with respect to the visual cue provided (i.e., indirectly cued movements). Participants were instructed to initiate their movements concurrently with an anticipated go-signal. To examine the time course of motor preparation, a startling acoustic stimulus (SAS, 124dB) was randomly presented 150 ms, 500 ms, or 1000 ms prior to the go-signal. Results from the startle trials revealed that the time course of motor preparation was similar regardless of the angle of rotation required and hence whether it was a direct or indirectly cued trial. Specifically, motor preparation was delayed until less than 500 ms prior to movement initiation for both direct and indirectly cued movements. These findings indicate that similar motor preparation strategies are engaged for both types of cued movements, suggesting that the time to prepare a motor response may be similar regardless of whether a cognitive transformation is required.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1982.