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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Chemical effects in x-ray emission spectra of transition metal compounds

MAZZILLI, BARBARA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:59Z (GMT). No. of bitstreams: 1 12889.pdf: 3125642 bytes, checksum: b56aa69cfba2da94049299248d6af43e (MD5) / Tese (Doutoramento) / IEA/T / University of London - Dept. of Chemistry
2

Chemical effects in x-ray emission spectra of transition metal compounds

MAZZILLI, BARBARA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:59Z (GMT). No. of bitstreams: 1 12889.pdf: 3125642 bytes, checksum: b56aa69cfba2da94049299248d6af43e (MD5) / Tese (Doutoramento) / IEA/T / University of London - Dept. of Chemistry
3

Beach burial of cetaceans: implications for conservation, and public health and safety

Bui, Ann January 2009 (has links)
Every year hundreds of cetaceans strand on New Zealand beaches. Options for dealing with disposal of their carcasses are few, creating significant problems for the Department of Conservation (DOC). More often than not their carcasses are buried in beaches at or just above high water mark, near where the animals have stranded. The primary objective of this thesis is to determine the effects of cetacean burial on beach sediments, and evaluate potential health and safety risks associated with this practice. A secondary objective of this thesis is to appraise the appropriateness of one location DOC has repeatedly transported cetacean carcasses to and buried within beach sediments, Motutapu Island in Waitemata Harbour. The chemical effects of cetacean burial over a six-month period are reported for two sites at which animals were buried in 2008, Muriwai and Pakiri beaches; the biological effects of this burial are reported for one of these sites, Muriwai Beach, 12 months post burial. Intertidal faunal and floral inventories are provided for six sites around Motutapu Island, and these then compared and contrasted with inventories compiled from an additional 290 intertidal sites between Whangarei Heads and Tauranga Harbour, North Island East Coast, to appraise the relative uniqueness of intertidal species diversity around Motutapu Island. At both Muriwai and Pakiri beaches, nitrogen and phosphate concentrations in surface sands changed considerably following cetacean burial, although over six months the effect was localized and elevated concentrations of these two chemicals that could be attributed to a buried carcass did not extend more than 40 m from the site of whale burial. Deep-core profiles revealed nitrogen and phosphate concentrations at and in the immediate vicinity of cetacean burial approximately six months after burial to be markedly elevated to the level of the water table, but elevated concentrations attributable to the buried carcass were not observed greater than 25 m from the site of burial. Elevated concentrations of nitrogen and phosphates in beaches persist in surface sediments for at least six months post burial. Twelve months post cetacean burial no significant difference in species richness or abundance were apparent in intertidal communities extending along transects proximal to and some distance from the Muriwai Beach carcass; there is no evidence for any significant short-term (to 12 months) biological effects of cetacean burial in beaches. Of those shores on Motutapu Island accessible by earth-moving equipment and large vessels capable of dealing with and transporting large cetacean carcasses, Station Bay appeared to be the most appropriate site for whale burial. However its small size and relatively high biological value (fairly high species richness for comparable shores between Whangarei Heads and Tauranga) renders it an inappropriate long-term option for whale burial. Other shores on Motutapu Island host some of the highest species richness of all shores surveyed between Whangarei Heads and Tauranga Harbour, rendering them entirely inappropriate locations for burying cetaceans, over and above other variables that may influence disposal location identification (such as archaeological sites, dwellings and accessibility). Motutapu Island is not considered an appropriate location for cetacean burial within beaches. Alternative disposal strategies need to be explored for dealing with cetaceans that strand on Auckland east coast beaches. Although burial is the most convenient and most economical strategy to dispose of cetacean carcass, especially in mass stranding events or when cetaceans are of large size, and the biological effects of this practice are not considered significant (for the one whale that could be studied), persistent enrichment of beach sediments with organic matter could result in prolonged persistence of pathogens in beaches, causing unforeseen risks to human health and safety. Recommendations are made to minimize possible threats to public following burial of cetaceans in beaches, until the potential health risks of burial are more fully understood.
4

Beach burial of cetaceans: implications for conservation, and public health and safety

Bui, Ann January 2009 (has links)
Every year hundreds of cetaceans strand on New Zealand beaches. Options for dealing with disposal of their carcasses are few, creating significant problems for the Department of Conservation (DOC). More often than not their carcasses are buried in beaches at or just above high water mark, near where the animals have stranded. The primary objective of this thesis is to determine the effects of cetacean burial on beach sediments, and evaluate potential health and safety risks associated with this practice. A secondary objective of this thesis is to appraise the appropriateness of one location DOC has repeatedly transported cetacean carcasses to and buried within beach sediments, Motutapu Island in Waitemata Harbour. The chemical effects of cetacean burial over a six-month period are reported for two sites at which animals were buried in 2008, Muriwai and Pakiri beaches; the biological effects of this burial are reported for one of these sites, Muriwai Beach, 12 months post burial. Intertidal faunal and floral inventories are provided for six sites around Motutapu Island, and these then compared and contrasted with inventories compiled from an additional 290 intertidal sites between Whangarei Heads and Tauranga Harbour, North Island East Coast, to appraise the relative uniqueness of intertidal species diversity around Motutapu Island. At both Muriwai and Pakiri beaches, nitrogen and phosphate concentrations in surface sands changed considerably following cetacean burial, although over six months the effect was localized and elevated concentrations of these two chemicals that could be attributed to a buried carcass did not extend more than 40 m from the site of whale burial. Deep-core profiles revealed nitrogen and phosphate concentrations at and in the immediate vicinity of cetacean burial approximately six months after burial to be markedly elevated to the level of the water table, but elevated concentrations attributable to the buried carcass were not observed greater than 25 m from the site of burial. Elevated concentrations of nitrogen and phosphates in beaches persist in surface sediments for at least six months post burial. Twelve months post cetacean burial no significant difference in species richness or abundance were apparent in intertidal communities extending along transects proximal to and some distance from the Muriwai Beach carcass; there is no evidence for any significant short-term (to 12 months) biological effects of cetacean burial in beaches. Of those shores on Motutapu Island accessible by earth-moving equipment and large vessels capable of dealing with and transporting large cetacean carcasses, Station Bay appeared to be the most appropriate site for whale burial. However its small size and relatively high biological value (fairly high species richness for comparable shores between Whangarei Heads and Tauranga) renders it an inappropriate long-term option for whale burial. Other shores on Motutapu Island host some of the highest species richness of all shores surveyed between Whangarei Heads and Tauranga Harbour, rendering them entirely inappropriate locations for burying cetaceans, over and above other variables that may influence disposal location identification (such as archaeological sites, dwellings and accessibility). Motutapu Island is not considered an appropriate location for cetacean burial within beaches. Alternative disposal strategies need to be explored for dealing with cetaceans that strand on Auckland east coast beaches. Although burial is the most convenient and most economical strategy to dispose of cetacean carcass, especially in mass stranding events or when cetaceans are of large size, and the biological effects of this practice are not considered significant (for the one whale that could be studied), persistent enrichment of beach sediments with organic matter could result in prolonged persistence of pathogens in beaches, causing unforeseen risks to human health and safety. Recommendations are made to minimize possible threats to public following burial of cetaceans in beaches, until the potential health risks of burial are more fully understood.
5

Modulation Effects on Organic Electronics

Chen, Hang 30 November 2005 (has links)
A high aspect ratio epoxy mask has been built with Taiyo PSR4000BN on chemical sensing array chip. Thickness up to 200 and #61549;m and aspect ratio up to 16:1 have been achieved with this material. It is demonstrated that this material satisfies the mechanical and chemical requirements. A three-electrode system has been designed and built for electrochemistry in micro-cell on chip. Tests with poly(phenylenesulfide-phenyleneamine) (PPSA) demonstrates that it is possible to precisely tune the properties (Work function and resistance) of conducting polymer that has been cast on chip surface. A new test platform GT03 has been fabricated and used to characterize the chemical effects on organic electronics. It is demonstrated that the chemical species in ambient environment can affect organic electronics properties on bulk, interface and electric contact. The contact resistance in organic field-effect transistors (OFETs) has been characterized with modified interdigitated structure (IDS). It is demonstrated that drain and source contact resistances can be calculated separately with modified four-point-probe measurements, and contact resistance and material bulk resistance are actually modulated by the gate electric field. Furthermore, the influence from oxygen doping in poly(3-hexylthiophene) (P3HT) based OFETs has been investigated. A new model of oxygen doping has been suggested and it is demonstrated that oxygen doping can affect all the resistance components in P3HT OFETs.
6

One year monitoring of potency change in commercial ibuprofen products stored in a household setting exposed to normal day-to-day temperature and humidity fluctuations

Archibald, Timothy, Brown, Stacy 12 April 2019 (has links)
Introduction.Most over the counter (OTC) medications are labeled for storage in a room temperature environment (68 – 77oF) under dry conditions, i.e. kept away from moisture. Despite this, many households store medications in the bathroom, where both temperature and humidity extremes may be experienced during the course of the day. In this project, we sought to investigate the effect that long-term storage in a household bathroom had on potency of OTC ibuprofen (IBU) products. One degradation product, 4-isobutylacetophenone (4-IBP), has been shown to possess toxic properties. As such, the emergence of this breakdown product was also monitored. Methods. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the quantitative determination of IBU and 4-IBP in aqueous samples. The assay utilized a UCT C18 column (2.1 x 100 mm; 1.8 micron) with acetonitrile as the organic phase and water as the aqueous phase, run in isocratic mode (15% A: 85% B). Ibuprofen was ionized in negative electrospray mode (-ESI) using m/z 205.09 and 4-IBU in +ESI mode at m/z 177.15. Calibration curves were created in the ranges of 0.1 – 2 mg/mL (IBU) and 2 – 100 mg/mL. Three brands each of IBU tablets (200mg) and suspensions (100mg/5mL) were purchased and assayed for IBU concentration at the initiation of the study. The samples were stored in a household bathroom, while temperature and humidity were continuously recorded using Extech Instruments RHT10 data-logger. Three tablets were removed from each bottle, and three 5-mL aliquots were removed from each suspension, for analysis each month. The samples were digested in 0.1M HCl for 1hr using sonication, and diluted to assay concentration (2 mg/mL for tablets; 0.2 mg/mL for suspensions) using acetonitrile. Each sample was assayed in triplicate and percent recovery was calculated against freshly prepared standards of IBU. Results. Acceptable potency range was defined as 90 – 110% of the labeled concentration. All tablets maintained acceptable average strength through three months, and a statistically significant change from initial concentration (as determined by a 2-way ANOVA, p = 0.05) was detected after 6 – 7 months. After ten months of storage, the average tablet strength was 74% of initial potency. All suspensions maintained acceptable average strength through five months, with statistically significant changes from initial concentration emerging after seven months storage. After 10 months of storage, the average suspension strength was 84% of initial potency. During the duration of the study, the average storage temperature was (20.9° C) and the average relative humidity was (65.7). The 4-IBU was not detected in any of the product samples during the duration of the study. Conclusions.These data indicate that, while the toxic degradation product, 4-IBU, has not been detected following bathroom storage of commercial IBU products, significant changes in product potency can negatively affect product efficacy. The container-closure systems used in OTC ibuprofen products do not protect against the effects of ongoing fluctuations in environmental temperature and humidity. Data indicate that suspension products are more resistant to temperature and humidity fluctuations, at least to the degree that would be present in a household bathroom.
7

X線分光における微小ピークの高感度検出法及び基礎原子過程に関する研究

中江, 保一 26 March 2012 (has links)
著者名別形の記述を修正(2022-04-21) / 京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第16850号 / 工博第3571号 / 新制||工||1540(附属図書館) / 29525 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 河合 潤, 教授 酒井 明, 教授 大塚 浩二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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