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Constructing hope in challenging spaces: narratives by health professionals on issues of solvent useDe Boer, Tracy 28 March 2013 (has links)
The process of recovery from addiction is a multifaceted process that involves the efforts of clients, professionals and the broader community. Additional challenges to recovery are present for individuals who use solvents. This study investigates how professionals, involved in the provision of services to clientele who use solvents, understand the process of healing in their collaborative work. Using a narrative methodology, semi-‐structured interviews were conducted with professionals employed in providing recovery-based services to individuals who use volatile solvents. The stories of these professionals demonstrate how they view their clients as “just like everyone else” despite what the dominant cultural story says about their possibilities for recovery. The professionals told stories which are in extreme opposition to the story of dominant culture and involved groupings of “us” (professionals) versus “them” (others). These stories, and how they were told, are discussed in relation to hope for professionals who provide health and housing services.
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Die effek van ototoksiese koolwaterstowwe op die gehoordrempels van werkers by 'n petrochemiese fabriek / Wilhelm JoubertJoubert, Wilhelm Hendrik January 2004 (has links)
The aim of this study was to determine in an empirical manner whether the
phenomenon of hearing loss due to the exposure to volatile organic solvents was
present in the gasification plants of a petrochemical factory.
The experimental groups included unexposed (N=20) workers, workers (N=20)
exposed to noise and workers (N=19) exposed to noise and volatile organic solvents.
The following assessments were made: diagnostic audiometry for the assessment of
hearing thresholds; biological monitoring of ortho-cresol and hippuric acid for the
biological markers of toluene; passive air sampling and noise measurements.
Questionnaires were completed by the three groups to collect information about age,
ethnicity, smoking habits, alcohol consumption and work history regarding the
exposure to ototoxic substances as well as the period of employment.
There were no statistically significant differences between the average ages of the
three groups, but more of the workers in the noise group were from a higher age
group. This age composition and the work history of the noise group were considered
as possible influences on the results of this hearing study. The results of the passive
air sampling show that the levels of volatile organic solvents were lower than the
occupational exposure limits on the day of sampling. The biological monitoring
shows that the markers, namely hippuric acid and o-cresol, were lower than the
biological exposure indices. The noise group was exposed to sound pressure levels of
79-90 dB(A) and the noise + hydrocarbon group to levels of 85-88 dB(A). The
average hearing thresholds of the noise group were at most of the frequencies (0.5-8
kHz) significantly higher (p≤0,05) than that of the noise + hydrocarbon group. The
average hearing thresholds of the control group were overall lower than the noise
group's hearing thresholds, but on average a little higher than the noise +
hydrocarbon group's hearing thresholds.
No relationship was found in this study between the exposure to volatile organic
solvents (for example toluene that was used as marker in this study) and the elevation
of hearing thresholds of workers at the gasification plants of the petrochemical
factory. / Thesis (M.Sc.)--North-West University, Potchefstroom Campus, 2004.
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Design and synthesis of volatile compounds for chemical vapor deposition of electronic materialsMatthews, Jason Shastri 05 1900 (has links)
No description available.
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Constructing hope in challenging spaces: narratives by health professionals on issues of solvent useDe Boer, Tracy 28 March 2013 (has links)
The process of recovery from addiction is a multifaceted process that involves the efforts of clients, professionals and the broader community. Additional challenges to recovery are present for individuals who use solvents. This study investigates how professionals, involved in the provision of services to clientele who use solvents, understand the process of healing in their collaborative work. Using a narrative methodology, semi-‐structured interviews were conducted with professionals employed in providing recovery-based services to individuals who use volatile solvents. The stories of these professionals demonstrate how they view their clients as “just like everyone else” despite what the dominant cultural story says about their possibilities for recovery. The professionals told stories which are in extreme opposition to the story of dominant culture and involved groupings of “us” (professionals) versus “them” (others). These stories, and how they were told, are discussed in relation to hope for professionals who provide health and housing services.
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An Investigation of Two Modes of Plant Protection by the Biocontrol Agent Trichoderma virensCrutcher, Frankie 2011 December 1900 (has links)
The biocontrol fungus Trichoderma virens is an avirulent symbiont with the ability to control plant disease by the production of antibiotic compounds, induction of plant resistance to pathogens, and mycoparasitism of other fungi. In this document, the analysis of a putative terpene biosynthesis gene cluster (vir cluster) in T. virens is described. The vir cluster contains genes coding for four putative cytochrome P450s, an oxidoreductase, MFS transporter, and a terpene cyclase. To determine the function of this cluster in secondary metabolism biosynthesis, a strain of T. virens with a deletion of the putative cyclase, vir4, was constructed. Deletion mutants were deficient in the synthesis of sesquiterpene volatiles and complementation of vir4 restored this loss in transformants, albeit at a lower level of production. An analysis of phenotypic characteristics between mutant and wild-type strains did not identify any differences when the strain interacted with other fungi, bacteria, or Arabidopsis seedlings.
Paralogs of the gene encoding the elicitor SM1 were examined as genetic sources for potential elicitors to induce systemic resistance in plants. A search of the T. virens genome revealed the presence of three paralogs of sm1. One paralog, sm3, was found to be expressed when grown in association with plant roots and in still-culture. The Pichia pastoris protein expression system was used to generate sufficient quantities of SM3 to allow characterization of its function. The purified protein from the yeast system (picSM3) was shown to be glycosylated and to increase expression of a plant defense gene in maize seedlings. Mutant strains in which sm3 was either deleted or over-expressed were constructed to further explore the potential of sm3 as an elicitor of ISR. The differential production of SM1 and SM3 by these strains suggested that SM1 and SM3 may be co-regulated and native SM3 may be glycosylated.
To further understand the role of a putative glycosylation site as a mechanism to prevent dimerization and subsequent elicitor activity, a point mutation was created in a sm1 deletion strain. Analysis of the behavior of the protein demonstrates that the putative glycosylation site is not involved in protein aggregation and deletion of this site does not prevent the protein from testing positive for glycosylation. We propose that SM1is not glycosylated but instead may interact with an oligosaccharide or other small molecule. However, the mechanism of dimerization in SM1 remains unknown.
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The use of naturally generated volatile fatty acids for pesticide removal during the denitrification processHe, Xuan (Sarah) January 2006 (has links)
The effect of naturally produced volatile fatty acids (VFAs) on the removal of 2, 4-D from a wastewater during the denitrification process was studied in this thesis. The VFAs were generated from an anaerobic digester using soya flour solution as a synthetic feed. The digester was operated at an SRT and HRT of 10 days. The pH (4.8 ± 0.2) and temperature (32 ± 3 ℃) of the digester were not controlled. A mean VFA concentration of 3153 ± 801 mg/L was achieved with acid speciation results of acetic (51.4 %), propionic (27.5 %), n-butyric (19.6 %) and iso-valeric (1.4 %). The specific VFA production rate was 0.014 mg VFA/mg VSS/day. The extent of the digestion process converting the substrate from a particulate to soluble form was evaluated as the specific TOC solubilization rate (0.007 mg TOC/mg VSS/day), soluble COD production rate (0.022 mg SCOD/mg VSS/day) and percent VSS reduction (14 %). The low solubilization rate is possibly due to high feed solids (3.4%) which led to a heavily overloaded bioreactor. It also suggests that the particulate substrate was not entirely amenable to solubilization. The acclimation of 2, 4-D degrading bacteria was developed successfully in an SBR fed with sewage and 2, 4-D (30-100 mg/L) as carbon and energy sources. A mean MLSS of 3653 ± 547 mg/L and an SRT of 20 ± 9 days were observed during the research period. The settleability of the SBR sludge was excellent evidenced by a low sludge volume index (SVI) of 101 ± 50 mL/g and less than 5 mg/L of effluent suspended solids. The specific 2, 4-D degradation rate was 0.046 ± 0.018 mg/mg MLSS/day. However, the removal of 2, 4-D during 60 minutes of non-aerated phase was negligible while more than 90 % of the 2, 4-D was removed within 240 minutes of the aerated phase. The successful degradation of 2, 4-D is related to the length of the acclimation period, as the acclimation period increased, the specific biodegradation rate increased. A biosorption study using ultrasound pre-treatment of the SBR acclimated biomass suggested that less than 10 % of the removal of 2, 4-D was due to biosorption, while more than 90 % removal of the 2, 4-D was likely due to biodegradation. Denitrification batch tests (using SBR-acclimated biomass) demonstrated that the addition of a digester effluent rich in naturally-produced VFAs increased both the 2 specific denitrification rate and the 2, 4-D degradation efficiency, as compared to that using 2, 4-D as a sole carbon source. In particular, the specific denitrification rates increased from 0.0119 ± 0.0039 to 0.0192 ± 0.0079 to 0.024 ± 0.003 g NO₃-N/g VSS per day, when using 2, 4-D alone, 2, 4-D plus natural VFAs and natural VFAs alone as carbon sources. The percent 2, 4-D removal increased from 28.33 ± 11.88 using 2, 4-D alone as a carbon source to 54.17 ± 21.89 using 2, 4-D plus natural VFAs as carbon sources. The specific 2, 4-D degradation rate and 2, 4-D removal efficiency of unacclimated biomass were 2.0 to 2.5 times less than those of the acclimated biomass. Natural VFAs and synthetic VFAs were found to be identical in denitrification batch tests in terms of their use as a carbon source. The mean specific denitrification and VFA-C consumption rates as well as the mean specific 2, 4-D degradation rate derived from experiments using natural VFAs and 2, 4-D as carbon sources were close to the valuess from experiments using synthetic VFAs and 2, 4-D as carbon sources. Further exploration of 2, 4-D degradation behaviour with pulsed additions of NO₃-N did not find further significant 2, 4-D removal, although almost all of NO₃-N was used by the end of the experimental run due to endogenous carbon sources used for cell maintenance and growth. However, the higher the concentration of biomass used in the denitrification batch system, the larger the amount of 2, 4-D degraded and the faster the VFA-C and NO₃-N were consumed. Further research with respect to optimisation of the acid-phase anaerobic digestion process (e.g. to adjust SRT and HRT or to lower the solid content of synthetic feed) would improve the specific VFA production rate and the solubilization rate. More research on the SBR could be carried out to investigate its maximum 2, 4-D removal capability as well as the removal of other structurally related herbicides. Attempts could be made to stimulate the growth of denitrifiers in the SBR (e.g. to add certain amounts of NO₃-N according to proper C: N ratios or to increase the length of non-aerated time). More microbiological studies of 2, 4-D degrading bacteria may also be helpful to understand the combined SBR/denitrification and 2, 4-D degradation process. More theoretical aspects of modelling kinetics could be developed to apply the combined process in-situ at 2, 4-D contaminated sites.
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Die effek van ototoksiese koolwaterstowwe op die gehoordrempels van werkers by 'n petrochemiese fabriek / Wilhelm JoubertJoubert, Wilhelm Hendrik January 2004 (has links)
The aim of this study was to determine in an empirical manner whether the
phenomenon of hearing loss due to the exposure to volatile organic solvents was
present in the gasification plants of a petrochemical factory.
The experimental groups included unexposed (N=20) workers, workers (N=20)
exposed to noise and workers (N=19) exposed to noise and volatile organic solvents.
The following assessments were made: diagnostic audiometry for the assessment of
hearing thresholds; biological monitoring of ortho-cresol and hippuric acid for the
biological markers of toluene; passive air sampling and noise measurements.
Questionnaires were completed by the three groups to collect information about age,
ethnicity, smoking habits, alcohol consumption and work history regarding the
exposure to ototoxic substances as well as the period of employment.
There were no statistically significant differences between the average ages of the
three groups, but more of the workers in the noise group were from a higher age
group. This age composition and the work history of the noise group were considered
as possible influences on the results of this hearing study. The results of the passive
air sampling show that the levels of volatile organic solvents were lower than the
occupational exposure limits on the day of sampling. The biological monitoring
shows that the markers, namely hippuric acid and o-cresol, were lower than the
biological exposure indices. The noise group was exposed to sound pressure levels of
79-90 dB(A) and the noise + hydrocarbon group to levels of 85-88 dB(A). The
average hearing thresholds of the noise group were at most of the frequencies (0.5-8
kHz) significantly higher (p≤0,05) than that of the noise + hydrocarbon group. The
average hearing thresholds of the control group were overall lower than the noise
group's hearing thresholds, but on average a little higher than the noise +
hydrocarbon group's hearing thresholds.
No relationship was found in this study between the exposure to volatile organic
solvents (for example toluene that was used as marker in this study) and the elevation
of hearing thresholds of workers at the gasification plants of the petrochemical
factory. / Thesis (M.Sc.)--North-West University, Potchefstroom Campus, 2004.
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Studies of some volatile compounds of main group elementsAldridge, Simon January 1996 (has links)
Methylzinc tetrahydroborate, [MeZnBH<sub>4</sub>], has been prepared by two routes and the structure of the solid determined by X-ray crystallography to reveal helical polymers in which MeZn and BH<sub>4</sub> units alternate. The latter functions as a bidentate ligand with respect to each of the adjacent metal atoms. Investigation by mass spectrometry and matrix isolation shows that the vapour consists of an equilibrium mixture of monomeric and dimeric species. The pattern of infrared bands for the monomer is characteristic of a bidentate BH<sub>4</sub> group, a finding consistent with the results of DFT calculations. Disproportionation into [Me<sub>2</sub>Zn] and [Zn(BH<sub>4</sub>)<sub>2</sub>] is a common feature of the chemistry of methylzinc tetrahydroborate, although it has been possible to isolate and characterize the adduct [MeZnBH<sub>4</sub>.SMe<sub>2</sub>]. The reaction between [B<sub>4</sub>H<sub>10</sub> and [Me<sub>2</sub>Zn] in the gas phase affords colourless acicular crystals of [(MeZn)<sub>2</sub>B<sub>3</sub>H<sub>7</sub>] in yields of ca. 10%. This compound has been characterized by chemical analysis and by NMR and vibrational spectroscopy. X-ray crystallography reveals that the product is a dimer, [(MeZn)<sub>2</sub>B<sub>3</sub>H<sub>7</sub>]<sub>2</sub>, featuring two distinct zinc environments. Two B<sub>3</sub>H<sub>7</sub>ZnNe ligands, formally derived from B<sub>3</sub>H<sub>8</sub> by replacement of a µ<sub>2</sub>-H by a µ<sub>2</sub>-ZnMe unit, each function in a bis(bidentate) manner linking together two other MeZn centres through pairs of Zn-H-B bridges. The structures of several aluminium tetrahydroborates in the solid phase have been investigated by X-ray diffraction. The structure of dimethylaluminum tetrahydroborate has been shown to consist of helical polymeric chains in which Me<sub>2</sub>-Al and BH<sub>4</sub> units alternate. Here, too, the BH<sub>4</sub> groups exhibit bidentate ligation with respect to each of the adjacent metal atoms, although the degree of interaction between the metal centre and the BH<sub>4</sub> group is somewhat less than in [MeZnBH<sub>4</sub> ]. Solid aluminium tris(tetrahydroborate) exhibits two phases with a transition temperature in the range 180-195 K. Each phase is made up of discrete Al(BH <sub>4</sub> )<sub>3</sub> units, the principal differences relating to the packing of the individual molecules. In the a phase the Al(BH <sub>4</sub> )<sub>3</sub> molecules display an angle of 78.2° between the AlB<sub>3</sub> and Al(µ-H)<sub>2</sub> planes and are disposed about a 2<sub>1</sub> crystallographic screw axis; in the ß phase the molecular units conform to D<sub>3h</sub> symmetry. Dimethylindium octahydrotriborate, [Me<sub>2</sub> lnB<sub>3</sub> H<sub>8</sub> ], has been synthesized by the reaction between trimethylindium and tetraborane(10) and characterized by chemical analysis and by NMR and vibrational spectroscopy. X-ray diffraction of a single crystal reveals that the solid consists of [Me<sub>2</sub> lnB<sub>3</sub> H<sub>8</sub>] units, although there is evidence of charge separation in the sense [Me<sub>2</sub>ln]<sup>+</sup>[B<sub>3</sub> H<sub>8</sub> ]<sup>-</sup> and of secondary interaction between terminal hydrogen atoms and adjacent indium centres. The infrared spectrum of the matrix-isolated vapour is consistent with a monomeric structure similar to that of [Me<sub>2</sub> AlB<sub>3</sub> H<sub>8</sub>].
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Modelling radon-222 as a proxy for vapour phase transport in the unsaturated zoneGibbons, Deirdre January 2000 (has links)
No description available.
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Mathematical modelling of large low-rank coal particle devolatilization /Heidenreich, Craig. January 1999 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Chemical Engineering, 1999. / Includes bibliographical references (leaves 322-335).
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