京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第22796号 / エネ博第410号 / 新制||エネ||78(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 坂口 浩司, 教授 佐川 尚, 准教授 高井 茂臣 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Nowadays, catalysis lies at the heart of economy growth mainly in the petroleum industry. Catalysis can offer real and potential solutions to the current challenges for a long-term sustainable energy, green chemistry, and environmental protection. In this context, one of the most important and future prosperity promising catalytic applications in the petrochemical field is hydrocarbons metathesis; it consists on the conversion of both renewable and non-petroleum fossil carbon sources to transportation fuels. Olefin metathesis has become one of the standard methodologies for constructing C-C bonds in many organic transformation reactions. This owed to the numerous types of metathesis reactions that have been developed, for example, enyne, ring-opening and closing, self and cross metathesis, etc. But the one step conversion of olefin to alkanes has not been studied much. Recently, only one such a work has been published for the hydro-metathesis of propylene by tantalum hydride supported on KCC-1 in dynamic reactor. With this knowledge, we thought to study the hydro-metathesis using liquid olefin (1-decene). Another aspect of using 1-decene comes from our previous experience on metathesis of n-decane where the first step is the conversion of decane to 1-decene and subsequently to different chain length alkanes with W-alkyl/alkylidene catalyst. In this way, it would be easy for us to use different catalysts and compare them with parent catalyst concerning TON. We found 100% conversion with TON of 1010 using supported WMe6 onto SiO2-700 [(≡Si-O-)WMe5] against the previous results for n-decane showing 20% conversion and TON of 153. In this work, we disclose the hydro-metathesis reaction of 1-decene using well-defined silica supported W(VI), Mo(VI) and Ta(V) alkyl catalysts in batch reactor condition. This work is divided into three major sections; first chapter contains an introduction to the field of catalysis and surface organometallic chemistry. In second chapter, we describe all the experimental procedures of the catalysts. The third chapter is devoted to the characterization and interpretation followed by catalytic reactions. Finally, a brief conclusion of the present study is given.

No description available.

PFAS (per- and polyfluoroalkyl substances) are a large group of substances that are used in a large variety of products because of their unique water and dirt repellent properties. The substances are extremely persistent and can spread over large distances in groundwater, surface water, and in the air, which makes them an environmental and a health concern. A significant pathway of PFAS into the environment is through wastewater, where the usage of consumer products containing PFAS contribute to the emissions. The project was performed by analysing data of PFAS concentrations in wastewater and sludge sampled continuously during 2022 at Uddebo wastewater treatment plant (WWTP) in Luleå municipality. The aim was to evaluate the composition of PFAS compounds and their concentrations in wastewater and sludge and compare with other municipalities, to analyse how PFAS concentrations change during the existing wastewater treatment process, and to suggest strategies for future treatment of PFAS in wastewater.  No significant change of the PFAS content in wastewater could be observed throughout the treatment process in Uddebo WWTP. Evaluation of the PFAS composition showed that PFOS was the most abundant substance in both water and sludge. Over the year some variations in the total PFAS concentration could be seen, which coincided with increased water flow during the snowmelt period and an operational disturbance at the treatment plant. The variations of the total PFAS concentrations in wastewater over the year were mainly caused by PFBA, PFOS and 6:2 FTS. Analysis of total oxidizable precursors in the wastewater showed that substances that can transform into more persistent PFAS are present in the incoming water to the plant to a large extent. The pilot plant designed for treatment of pharmaceuticals, including ozonation and a granular activated carbon filter, did not result in any separation of PFAS from the water. An assessment of the contribution of PFAS from landfill leachate showed that it constitutes a significant share of the total PFAS content in wastewater. Compared with the content of PFAS in other Swedish WWTPs the total concentrations in wastewater at Uddebo WWTP was among the highest of five compared municipalities, while Luleå had the lowest PFAS concentrations in sludge among two compared municipalities.  The comparison between municipalities was limited by large differences in sampling frequency and performed analyses between the municipalities. Standardised analyses, additional background information, and more detailed statistical analyses are necessary to be able to make this type of comparison more informative. The occurrence of PFOS, which have been globally banned since 2009, shows that restrictions of the usage of PFAS must be combined with treatment of contaminated media to reduce the concentrations of PFAS in the environment. Development of PFAS degradation techniques is vital to remove PFAS from circulation. The difficulties of treating large amounts of water with low concentrations motivates investigations concerning if treatment of smaller water flows with higher PFAS concentrations is a better alternative than implementing treatment of the total amount of water that reaches the WWTP.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2009. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri--Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves : 117-131). Also available on the Internet.

ABSTRACT This thesis describes an investigation into the role of acetylenic and allenic precursors in the formation of the important aroma compound β-damascenone (1). Chapter 1 provides an introduction to the subject, beginning with a brief history of the Australian wine industry which began with the first fleet’s arrival in 1788. Many of the various volatile compounds found in wine are then discussed, with particular emphasis on β-damascenone (1). Some previous syntheses of 1 are summarised, as well as the in vivo generation of this compound, and also the role of glycoconjugation in nature. The chapter concludes with the aims of the present work. Chapter 2 covers the synthesis of the suspected acetylenic precursor 9-hydroxymegastigma-3,5-dien-7-yne (36), which was prepared by the addition of 3-butyn-2-ol to 2,6,6-trimethylcyclohex-2-en-1-one, followed by a conjugate dehydration reaction. The synthetic sample of 36 was shown to be identical to a compound previously observed in the hydrolysate of 3,5,9-trihydroxymegastigma-6,7-diene (31). Upon acid hydrolysis, 36 produced > 90% β-damascenone (1). Chapter 3 outlines the synthesis and hydrolysis of the C9 glycoside 43, which was prepared by a modified Koenigs-Knorr procedure on aglycone 36. Diastereomerically pure samples of each of the two possible glycosides were synthesised from corresponding enantiomerically pure samples of 36, which in turn were prepared by the use of either (R) or (S) 3-butyn-2-ol. Detailed hydrolytic studies (at 25 ºC) were conducted on both the aglycone and the two glycosides: the half lives of conversion of 36 into 1 were 40 hours and 65 hours at pH 3.0 and pH 3.2 respectively; the (9R) diastereomer of 43 had half-lives of 3 days and 6 days, respectively at the same pH values, whereas the (9S) diastereomer had half lives of 3.5 days and 6.5 days, respectively at the same pH values. The synthesis of the other suspected precursor, megastigma-4,6,7-triene-3,9-diol (35) is covered in Chapter 4. This allene was prepared by addition of 3-butyn-2-ol to phorenol, with the allene function generated by reaction with lithium aluminium hydride. By using (3S)-phorenol and both (R) and (S) 3-butyn-2-ol, four different diastereomers of 35 were prepared and characterised. The (3S, 6R, 9S)-isomer of 35 was also found to be identical to a compound previously observed in the hydrolysate of (31). A detailed hydrolytic study of the four synthetic isomers of 35 is contained within Chapter 5. This study revealed that each of the four isomers underwent rapid epimerisation at 25 ºC and pH 3.0. Careful analysis of the four product mixtures by chiral GC-MS revealed that this epimerisation was occurring exclusively at C3. The complete absence of 3-hydroxydamascone (2) from any of the hydrolysates required a re-appraisal of the mechanism of in vivo formation of β-damascenone (1), which forms the focus of the second half of this chapter. The experimental procedures (materials and methods) for all work covered in chapters 2-5 are located in Chapter 6.

In this thesis complexes of acylchalcogoureas with cadmium (II), lead (II) and nickel (II) have been synthesised and investigated as single source precursors for the formation of metal chalcogenide thin films viaaerosol assisted chemical vapour deposition (AACVD). Routes to binary thin films have been explored using homoleptic complexes of the general structure bis(N,N-diethyl-N'-naphthoylchalcogoureato)metal(II). Analysis of the thin films produced showed the successful deposition of the binary materials from the synthesised complexes when characterised by powder XRD, ICP-OES, SEM and EDX. Routes to ternary thin films with the general structure MExE'1-x, where M represents a metal (Cd, Ni and Pb); and E chalcogen (S or Se) have been investigated using heteroleptic metal complexes of cadmium, nickel or lead including different chalcogen containing N,N-diethyl-N'-naphthoylchalcogoureato ligands and diethyldithiocarbamate. The precursors were fully characterised and novel compounds had their crystal structures determined. The heteroleptic complexes were thermolysed by AACVD forming the MExE'1-x thin films. In the cases of lead, nickel and cadmium the thin films produced showed that the composition of the film tended heavily towards the metal selenide. Ternary films of type MS1-xSex was prepared by mixing their binary precursors of type bis(N,N-diethyl-N'-naphthoylselenoureato)metal(II) and bis(N,N-diethyl-N'-naphthoylthioureato)metal(II) [metal = Cd, Ni and Pb]. In the case of lead and cadmium chalcogenide films variation of the ratio of sulphur and selenium containing precursors allowed for the full transition in composition between metal sulphide and metal selenide. In the case of CdS1-xSexthe band gap of the films was determined from UV-visible spectroscopy to vary from 2.4 eV (CdS) to 1.7 eV(CdSe). In the case of NiS1-xSex the movement from sulphide to selenide was less simple with multiple phases of nickel chalcogenides produced.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri--Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 103-117). Also issued on the Internet.