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TUNING MOLECULAR ARCHITECTURES AT THE LIQUID- SOLID INTERFACE BY CONTROLLING SOLVENT POLARITY AND CONCENTRATION OF MOLECULESNguyen, Thi Ngoc Ha 03 November 2014 (has links)
Das grundlegende Verständnis von Selbstorganisationsprozessen auf molekularem Niveau ist von entscheidender Bedeutung für den Fortschritt der Nanotechnologie. In diesem Zusammenhang werden hier Untersuchungen derartiger Prozesse an der Grenzfläche zwischen einer flüssigen Phase (z.B. einer Lösung) und einer kristallinen Festkörperoberfläche durchgeführt. Die Konzentration der Lösung und die Polarität des Lösungsmittels sind von entscheidender Bedeutung für die Kontrolle der durch Selbstorganisation gebildeten Strukturen von Molekülen an den flüssig-fest Grenzflächen zu einem Graphitsubstrat (HOPG). Im Mittelpunkt der vorliegenden Arbeit stehen die Einflüsse dieser beiden Parameter auf die Anordnung der Moleküle. Zunächst wird die Polarität der Lösungsmittel diskutiert. Lösungsmittel mit verschiedenen Polaritäten wie Phenyloctan (unpolar), Fettsäuren (moderat polar) und Fettalkohole (stark polar) wurden verwendet um Trimesinsäure (TMA) zu lösen. TMA bildet keine geordnete Struktur aus wenn es aus Phenyloctan (PO) abgeschieden wird. Ein poröses Muster ("Chicken-wire"-Struktur) entsteht aus der Lösung von TMA in Octansäure, wohingegen aus der Lösung von TMA in Undecanol ein Linienmuster durch Koadsorption von TMA und Undecanol Molekülen gebildet wird. Als nächstes werden die Auswirkungen der Ultraschallbehandlung der Lösungen zur Kontrolle der Konzentration der Lösung und die daraus resultierende unterschiedliche molekulare Packungsdichte und Strukturen beschrieben. Eine selbstassemblierte Struktur aus Zick-Zack-Dimerketten wird bei der TMA-PO Lösung nur beobachtet, wenn die Lösung für 5 Stunden Ultraschall ausgesetzt wurde. Die hoher Packungsdichte in Form der "Flower"-Struktur wird für Lösungen von TMA in Octansäure gefunden, nachdem diese für lange Zeit mit Ultraschall behandelt wurden. Ein weiterer Aspekt der vorliegenden Arbeit ist die entdeckte Veresterungsreaktion an der TMA-undecanol/HOPG Grenzfläche. 1-undecyl Monoester von TMA wurde überraschender Weise an dieser Grenzfläche gefunden, nachdem die TMA-Undecanol Lösungen, für lange Zeit Ultraschall ausgesetzt wurden. Diese Monoestermoleküle bilden sich an der flüssig-fest Grenzfläche allein auf Grund der erhöhten Konzentration von TMA (ohne jegliche externe Katalysatoren). Der physikalische Hintergrund der Prozesse des Lösens und der Ultraschallbehandlung sind der Gegenstand weiterer Untersuchungen. Selbstassemblierte Abscheidung tritt auch bei Verwendung nur der reinen Lösungsmittel (Octansäure beziehungsweise Undecanol) auf, was zu verschiedenen Mustern führt, welche ebenfalls durch Ultraschallbehandlung kontrolliert eingestellt werden können.:LIST OF ABBREVIATIONS 6
CHAPTER I: INTRODUCTION 7
CHAPTER II: BASIC PRINCIPLES 10
II.1. Principles of scanning tunneling microscopy (STM) 10
II.2. Scanning tunneling microscopy at the liquid-solid interface (LSI) 15
II.3.The interactions between solvent and solute molecules in the solution 18
II.4. The interactions between molecules and the substrate 21
II.5. Solvent effects on self-assembly at the liquid-solid interface 23
II.5.1. Solvent co-adsorption effect 23
II.5.2. Solvent influences polymorphism 24
II.5.3. The influence of solvent functionality on self-assembled structures 25
II.6. Ultrasonic influences on concentration of solution 25
CHAPTER III: EXPERIMENTAL SECTION 28
III.1. Solute: Trimesic acid (TMA) (C6H3(COOH)3) 28
III.2. Solvents 28
III.2.1. Strong non-polar solvent: phenyloctane (octylbenzene) (C14H22) 29
III.2.2. Medium polar solvents: alkanoic acids (CnH2n+1COOH, n = 6, 7, 8) 29
III.2.3. Strong polar solvents: alkanoic alcohols (CnH2n+1OH, n = 10, 11) 30
III.3. Preparation of solutions 32
III.4. Substrates 33
III.5. Tip preparation 34
CHAPTER IV: SELF-ASSEMBLY OF TRIMESIC ACID (TMA) CONTROLLED BY SOLVENT POLARITY AND CONCENTRATION OF SOLUTION 36
IV.1. Trimesic acid (TMA) dissolved in a strong non-polar phenyloctane (PO) solvent 36
Results and discussion 37
Summary 46
IV.2. TMA dissolved in medium polar solvents, alkanoic acids 47
IV.2.1. TMA in octanoic acid at different sonication time 49
IV.2.2. TMA in heptanoic and nonanoic acids at different sonication time 56
Summary 57
IV.3. TMA dissolved in strong polar alkanoic alcohol solvents 58
IV.3.1. Linear pattern (LP) from non-sonicated solutions of TMA - undecanol 59
IV.3.2. High density linear pattern from 2 hours sonicated solutions of TMA - undecanol 61
IV.3.3. LP and ester formations from solutions of TMA in undecanol sonicated over extended time (4, 6, and 8 hours) 63
IV.3.4. Monoester at HOPG substrate-undecanol interface 65
IV.3.5. Linear pattern (LP) and ester formation from TMA-decanol solution 72
Summary 73
CHAPTER V: SELF-ASSEMBLY OF SOLVENT MOLECULES INFLUENCED BY SONICATION TIME 75
V.1. Self-assembly of octanoic acid on HOPG controlled by sonication time 75
V.1.1. Self-assembly of octanoic acid from 0-2 hours sonicated liquid on HOPG 76
V.1.2. Patterns deposited from 3 to 10 hours sonicated octanoic acid liquids 78
V.2. Self-assembly of undecanol on HOPG controlled by sonication time 79
V.2.1. Undecanol on HOPG at 0- 2 hours sonication 80
V.2.2. Undecanol on HOPG from 4- 6 hours sonicated liquids 82
CHAPTER VI: SUMMARY AND OUTLOOK 85
APPENDIX 89
REFERENCES 93
ERKLÄRUNG 108
CURRICULUM VITAE 109
ACKNOWLEDGEMENT 110
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The Mizoroki-Heck Reaction in Tunable Aryl Alkyl Ionic LiquidsLerch, Swantje, Fritsch, Stefan, Strassner, Thomas 19 March 2024 (has links)
We report the use of imidazolium based tunable aryl alkyl ionic liquids (TAAILs) as solvents in the Mizoroki–Heck reaction. Different commercially available palladium sources, inorganic bases, TAAILs and reaction conditions were tested for the synthesis of trans-stilbene using bromobenzene and styrene. A variety of different stilbene derivatives were synthesized with exclusive formation of the (E)-isomers and isolated yields up to 97%. We were able to optimize the reaction conditions using only 0.25 mol% of Pd(OAc)2 as the catalyst and a reaction time of 4 hours. No additional ligands or additives are used in the reaction. The catalytic system using TAAILs achieved higher yields than commercially available imidazolium and phosphonium ionic liquids, demonstrating the potential of tailored ionic liquids as a reaction medium for the Mizoroki– Heck reaction.
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Leaching of copper and gold concentrate in the presence of halidesTogtokhbaatar, Purev-Ochir 22 July 2024 (has links)
Ionometallurgy is a new trend to utilise ionic liquids as alternative green solvents for oxidic and sulfidic copper minerals. It has broad potential for traditional pyrometallurgy and hydrometallurgy. Ionometallurgy utilises ionic liquids (ILs), highly potent complexing ligands (chloride), to process oxide and copper sulfide minerals. This work focused on using the deep eutectic solvents (DES) of ionic liquids, which and provide alternative options for processing various metals, alloys, and concentrates.
For this job, various analytical methods were used to determine the copper concentrate and its residue after leaching (MLA-SEM and XRPD), quantify the elements in the solution (IC and ICP-OES/MS) and explain the oxidation behaviour (CV and UV-Vis spectroscopy). Combining the analytical and electrochemical methods to the leaching experiment provided the control to improve the results and understand its oxidation behaviour.
Chosen DES, Oxaline (ChCl + oxalic acid, 1:1), and Ethaline (ChCl + ethylene glycol, 1:2) were tested and enhanced on the actual copper concentrates with and without oxidative additives (FeCl3 and I2). Those oxidative additives are selected for leaching experiments by their redox potential in Ethaline.
However, there are many acceptable values; the most exciting result related to Ethaline plus iodine was the potential leaching system for chalcopyrite and copper-gold concentrates leaching. Because ion chromatography (IC) and UV-Vis’s analysis confirm iodine oxidizes the Cu+ species quickly in Ethaline. Whilst identical results and oxidation behaviour appeared in chalcocite (Cu2S), chalcopyrite (CuFeS2) and copper-gold concentrates leaching.
During the iodine reduction to iodide in the system, IC proved that chalcopyrite releases the Fe3+, oxidizing the chalcopyrite particles. Also, iodine oxidized the natural gold in copper-gold concentrate successfully, and gold concentration quantified ICP-MS and MLA-SEM proved there is no visible gold in the leaching residue.
Based on the optimal Ethaline + I2 leaching condition, the copper concentrate was carried out with the bottle roller leaching to represent the tank leaching. Thus, DES shows that it has a high potential to be continued to scale up the experiment. Also, water was given to the Ethaline leaching system, and water had a good influence on the leaching due to reducing the viscosity and saving the Ethaline amount. Hence Ethaline plus water is used for the copper ore leaching in the column, and it can be seen that Ethaline + I2 with water (up to 20%) has a high potential to process the low-grade copper sulfide ores.:Acknowledgements
Abstract
Abbreviations
TABLE OF CONTENTS
CHAPTER ONE – INTRODUCTION OF COPPER PROCESSING TECHNOLOGIES
1.1. Overview
1.2. Copper
1.3. Gold
1.4. Hydrometallurgy and pyrometallurgy of copper and gold
1.5. Current copper and gold concentrate processing methods
1.6. An alternative copper concentrate processing method
Summary of chapter 1
CHAPTER TWO – FUNDAMENTALS FOR PROCESS DEVELOPING
2.1. Introduction
2.2. Effect of temperature and stirring in leaching
2.3. Analytical methods and experimental
2.4. Experimental for leaching
2.5. Discussion of experimental errors
CHAPTER THREE: ANALYTICAL EXPERIMENTS FOR LEACHING
3.1. Introduction
3.2. Analysis of copper concentrate
3.3. Cyclic voltammetry
3.4. UV-Vis spectroscopy analysis of target metals
3.5. Metals solubility in DES
3.6. Summary and conclusions
CHAPTER FOUR: FUNDAMENTAL LEACHING EXPERIMENT AND INITIAL INVESTIGATION
4.1. Introduction
4.2. Initial study and fundamental leaching experiments
4.3. Study of mineral oxidation
4.4. Deep eutectic solvents leaching
4.5. Chapter summary and conclusion
CHAPTER FIVE: LEACHING OF MODEL SYSTEMS IN ETHALINE WITH OXIDATIVE ADDITIVES
5.1. Introduction
5.2. Iodine effect on Cu2S and CuS leaching in Ethaline
5.3. Ferric chloride effect on CuS and Cu2S leaching
5.4. Leaching of natural gold in Ethaline with the presence of iodine
5.5. Cyclic voltammetry investigation of Cu+/2+ sulfides in DES
5.6. Chapter summary and conclusion
CHAPTER SIX: LEACHING OF COPPER-GOLD CONCENTRATES IN DES AND WITH OXIDATIVE ADDITIVES
6.1. Introduction
6.2. Effect of ferric chloride (FeCl3)
6.3. Effect of iodine (I2)
6.4. Electrochemical and spectroscopic analysis of copper-gold concentrate leachates
6.6. Chapter summary and conclusion
CHAPTER SEVEN: OVERALL CONCLUSION AND FUTURE WORK
7.1. Overall conclusions
7.2. Recommendations for future research
CHAPTER EIGHT: APPENDIX
8.1. Chemicals and materials
8.2. Appendix
References
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Child Neurodevelopment following In Utero Exposure to Organic SolventsLaslo-Baker, Dionne 17 December 2012 (has links)
BACKGROUND: Many women of reproductive age are employed in industries involving exposure to organic solvents. Animal toxicological studies and human case reports demonstrate that exposure to organic solvents can cause neuropsychological deficits in exposed offspring; however, there is limited data from prospective controlled human studies.
OBJECTIVE: To compare neuropsychological functioning between children whose mothers were occupationally exposed to organic solvents during pregnancy with a non-exposed matched comparison group.
METHODS: Participants were 48 women who had previously contacted the Motherisk Program in Toronto, Canada during pregnancy regarding occupational exposure to organic solvents and a matched comparison group of women with no known exposure to teratogens during pregnancy. Children (18 months to 8 years 11 months at time of study) were compared in areas of cognitive, language, motor, and behavioral functioning.
RESULTS: Children whose mothers were exposed to organic solvents during pregnancy displayed a lower level of functioning when compared with their matched peers in areas of cognitive, language, motor, and behavioral domains. Although the scores on measures of behavioral functioning were not in the clinical range, the mothers of exposed children reported more challenging behavioral problems.
In order to determine whether exposure predicted neuropsychological outcomes above and beyond maternal intellectual functioning, hierarchical regressions were run with maternal IQ and maternal education at Step 1and exposure status added at Step 2. In utero exposure to organic solvents predicted lower sores on global measures of Verbal IQ, receptive and expressive language scales above and beyond maternal intellectual functioning. Factors associated with higher levels of exposure (detecting odor, longer duration and total number of toxicity symptoms) was associated with poorer outcome on behavioral and motor functioning tests.
CONCLUSION: Despite the fact that the exposed mothers experienced minimal symptoms of toxicity, detrimental effects were still evident in their offspring. Current safety standards for exposure were designed for adults and need to be reevaluated. Further studies addressing exposure to specific organic solvents, dose, and gestational timing of exposure are warranted.
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Child Neurodevelopment following In Utero Exposure to Organic SolventsLaslo-Baker, Dionne 17 December 2012 (has links)
BACKGROUND: Many women of reproductive age are employed in industries involving exposure to organic solvents. Animal toxicological studies and human case reports demonstrate that exposure to organic solvents can cause neuropsychological deficits in exposed offspring; however, there is limited data from prospective controlled human studies.
OBJECTIVE: To compare neuropsychological functioning between children whose mothers were occupationally exposed to organic solvents during pregnancy with a non-exposed matched comparison group.
METHODS: Participants were 48 women who had previously contacted the Motherisk Program in Toronto, Canada during pregnancy regarding occupational exposure to organic solvents and a matched comparison group of women with no known exposure to teratogens during pregnancy. Children (18 months to 8 years 11 months at time of study) were compared in areas of cognitive, language, motor, and behavioral functioning.
RESULTS: Children whose mothers were exposed to organic solvents during pregnancy displayed a lower level of functioning when compared with their matched peers in areas of cognitive, language, motor, and behavioral domains. Although the scores on measures of behavioral functioning were not in the clinical range, the mothers of exposed children reported more challenging behavioral problems.
In order to determine whether exposure predicted neuropsychological outcomes above and beyond maternal intellectual functioning, hierarchical regressions were run with maternal IQ and maternal education at Step 1and exposure status added at Step 2. In utero exposure to organic solvents predicted lower sores on global measures of Verbal IQ, receptive and expressive language scales above and beyond maternal intellectual functioning. Factors associated with higher levels of exposure (detecting odor, longer duration and total number of toxicity symptoms) was associated with poorer outcome on behavioral and motor functioning tests.
CONCLUSION: Despite the fact that the exposed mothers experienced minimal symptoms of toxicity, detrimental effects were still evident in their offspring. Current safety standards for exposure were designed for adults and need to be reevaluated. Further studies addressing exposure to specific organic solvents, dose, and gestational timing of exposure are warranted.
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La dihydrofolate réductase R67, comme une cible d’antibiotiques et biocatalyseur potentielTimchenko, Natalia 12 1900 (has links)
La dihyrofolate réductase de type II R67 (DHFR R67) est une enzyme bactérienne encodée par un plasmide donc aisément transmissible. Elle catalyse la réaction de réduction du dihydrofolate (DHF) en tétrahydrofolate (THFA) essentiel pour la prolifération cellulaire. La DHFR R67 est une enzyme qui dépend du cofacteur NADPH. La DHFR R67 est différente, structurellement et génétiquement, de l’enzyme DHFR chromosomale présente chez tous les organismes et elle est résistante au triméthoprime (TMP) qui est largement utilisé dans les traitements antibactériens chez l’Homme. Aucun inhibiteur sélectif contre la DHFR R67 n’est actuellement répertorié.
Le but de cette étude a été d’identifier des molécules qui pourront inhiber la DHFR R67 sélectivement, sans affecter la DHFR humaine (DHFRh). La vérification de la qualité des essais enzymatiques en conditions déterminées pour le criblage d’inhibiteurs sur plusieurs lectrices à plaques a identifié des appareils appropriés pour l’analyse. L’étude de l’activité enzymatique de la DHFR R67 et de la DHFRh en présence des solvants organiques et liquides ioniques (LIs), comme des co-solvants pour le criblage rationnel d’inhibiteurs, a montré que certains LIs peuvent servir de milieu alternatif pour les essais enzymatiques. Le criblage rationnel basé sur l’approche du design d’un inhibiteur à partir de petites molécules, a révélé des molécules primaires qui inhibent la DHFR R67 de façon faible, mais sélective. Le test des composés biologiquement actifs qui comprennent des petits fragments, a montré l’augmentation de l’affinité entre la DHFR R67 et les composés testés. Trois composés ont été déterminés comme des inhibiteurs sélectifs prometteurs pour la DHFR R67. / Type II R-plasmid encoded dihyrofolate reductase (DHFR), R67 DHFR is a bacterial enzyme that catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THFA) which is essential for cell proliferation. R67 DHFR is an enzyme that depends on the cofactor NADPH as the hydride donor. R67 DHFR is distinct, structurally and genetically, from E. coli chromosomal DHFR (DHFR Ec) and it provides drug resistance to the widely-administered antibiotic trimethoprim (TMP). No selective inhibitor against R67 DHFR exists currently.
The goal of this study was to discover molecules that can selectively inhibit R67 DHFR, without affecting human DHFR (hDHFR). Verification of the quality of enzyme assays under defined conditions for inhibitor screening on plate readers found several appropriate instruments for analysis. The study of the enzymatic activity of R67 DHFR and hDHFR in the presence of organic solvents and ionic liquids (ILs), as co-solvents for rational screening of inhibitors, showed that ILs can provide alternative media for enzymatic assays. Rational screening based on the approach of fragment-based drug design, revealed primary molecules that inhibited DHFR R67 weakly, but selectively. The testing of more complex compounds with known biological activities gave ligands with increased affinity for R67 DHFR. Three compounds were identified as promising selective inhibitors for R67 DHFR.
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Interactions peptides antibactériens - surfaces bactériennes : Etude de la carnobactériocine Cbn BM1, une bactériocine de classe IIa / Antimicrobial peptide - bacterial surfaces interactions : Study of the class IIa bacteriocin Cbn BM1Jacquet, Thibaut 23 November 2011 (has links)
Les bactériocines de classe IIa présentent une activité antimicrobienne résultant d'un mécanisme d'action ciblant les membranes des bactéries à Gram positif. Cette activité est modulée par différentes caractéristiques des surfaces bactériennes. Les propriétés physico-chimiques de surface de dix-huit souches bactériennes ont été déterminées afin d'étudier le lien entre ces propriétés et les phénotypes de résistance/sensibilité à Cbn BM1. Les résultats obtenus indiquent une grande diversité des propriétés physico-chimiques des surfaces analysées, sans cependant permettre d’établir un lien entre celles-ci et le phénotype de sensibilité/résistance à CbnBM1. Les mécanismes d'action de Cbn BM1 ont ensuite été étudiés sur Carnobacterium maltaromaticum DSM20730 et Listeria monocytogenes EGDe. L'atteinte de l'intégrité physique des membranes plasmiques par l'action de Cbn BM1 montre une hétérogénéité de réponse des populations bactériennes. Ce résultat a été confirmé par microscopie de force atomique in vivo à haute résolution. L'interaction de Cbn BM1 avec les membranes a été mise en évidence par mesure de l'anisotropie de fluorescence. Cette approche a révélé que Cbn BM1 présente des degrés de pénétration différents dans la membrane de C. maltaromaticum DSM20730 par rapport à L. monocytogenes EGDe. L'action de Cbn BM1 conduit cependant, pour les deux souches, à la modification de la force protomotrice membranaire. Ces différentes approches retenues pour l'étude des mécanismes d'action ont révélé que C. maltaromaticum DSM20730 et L. monocytogenes EGDe présentent une sensibilité à Cbn BM1 uniquement lorsque les cellules sont en phase exponentielle de croissance. / The antimicrobial activity of class IIa bacteriocins toward Gram positive bacteria relies on their membrane targeting mechanisms of action. These mechanisms are modulated by the bacterial surface properties. The physico-chemical surface properties of eighteen bacterial strains were determined to link these properties to the resistance/sensitivity to Cbn BM1 of the bacterial strains. In this way, two approaches were undertaken : the microbial adhesion to solvents and electrophoretic mobility measurements. The results show a large diversity of the determined properties among the strains but without establishing a direct link between the surface properties and the resistance/sensitivity phenotypes. Mechanisms of action of the bacteriocin Cbn BM1 on Carnobacterium maltaromaticum DSM20730 and Listeria monocytogenes EGDe were determined. Syto9® and propidium iodide allowed to show the heterogeneity of the bacterial populations toward the alteration of the membrane integrity. The interaction of Cbn BM1 with the bacterial membrane was studied by monitoring the fluorescence anisotropy of DPH and TMA-DPH. The results highlight a difference between the mechanism of action of Cbn BM1 on C. maltaromaticum DSM20730 and on L. monocytogenes EGDe. However, a treatment by Cbn BM1 leads to a perturbation of the component of the proton-motive force of the membrane for both strains. These approaches revealed that these bacterial strains exhibit a sensitivity to Cbn BM1 only when treated in log growth phase. Modification of nano-mechanical properties of C. maltaromaticum DSM20730 after a treatment by Cbn BM1 were assessed by an atomic force microscopy approach.
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Systemic approach and decision process for sustainability in chemical engineering : Application to computer aided product design / Approche systémique et processus décisionnel pour le développement durable en génie des procédés : Application à la substitution de produits par formulation inverseHeintz, Juliette 23 October 2012 (has links)
Dans un contexte de prise en compte croissante des enjeux environnementaux, l'industrie de la chimie et des procédés se retrouve confrontée à des problématiques de substitution de molécules. Les méthodes de formulation inverse, qui consistent en la recherche assistée par ordinateur de molécules satisfaisant un ensemble de contraintes, répondent de manière efficace à ces problématiques. A partir de l'analyse systémique des usages et fonctionnalités nécessaires dans ce contexte, nous développons un outil logiciel de formulation inverse mettant en oeuvre un algorithme génétique. Celui-ci est capable d'explorer un espace de solutions plus vaste en considérant les mélanges et non les molécules seules. Par ailleurs, il propose une définition des problèmes très flexible qui permet la recherche efficiente de molécules issues de filières renouvelables. En s'appuyant sur l'ingénierie système et l'ingénierie d'entreprise, nous proposons un processus formel de prise de décision pour la substitution de produit dans un contexte industriel. Ce processus de décision multi-critères englobe les phases de définition des exigences, de génération de solutions alternatives, de sélection de la meilleure alternative et de mise en oeuvre du produit. Il utilise une approche dirigée par les modèles et des techniques de prises de décision qui garantissent un alignement opérationnel en complément de l'alignement stratégique. A travers un cas d'étude, nous montrons comment l'utilisation conjointe de notre outil de recherche par formulation inverse et de notre processus de décision permet une démarche environnementale de substitution de produit à la fois efficiente et conforme à la réalité de l'entreprise. / In a context where environmental issues are increasingly taken into account, the chemical related industry faces situations imposing a chemical product substitution. Computer aided molecular design methods, which consist in finding molecules satisfying a set of constraints, are well adapted to these situations. Using a systemic analysis of the needs and uses linked to this context, we develop a computer aided product design tool implementing a genetic algorithm. It is able to explore a wider solution space thanks to a flexible molecular framework. Besides, by allowing a very flexible setting of the problem to be solved, it enables the search of molecules sourced from renewable resources. Based on concepts from system and enterprise engineering, we formalize a decision making process dedicated to the product substitution in an industrial context. This multi-criteria decision process includes the phases of the requirements definition, of the generation of alternative solutions, of the selection of the best alternative and of the product application. It uses a model driven approach and decision making techniques that guaranty an operational alignment in addition to the strategic alignment across the chemical enterprise. Through a case study, we expose how the combination of our computer aided product design tool and our decision making process enables an environmentally compliant approach of product substitution which is both efficient and in adequacy with enterprise context.
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Plant systems integration using the SAMI model to achieve asset effectiveness in modern plantsJoubert, Andrè January 2008 (has links)
Thesis (D. Tech. (Electrical Engineering, Dept. of Process Control and Computer Systems))--Vaal University of Technology. / In recent years, industrial plant maintenance has changed dramatically. These changes are due to a considerable increase in the number and variety of physical plant assets, increased design complexity, new maintenance techniques and changing perspectives regarding on how to perform maintenance effectively. Managers at modern process plants are becoming increasingly aware of the extent to which equipment failure affects safety and the environment.
Process plant personnel are limited in their ability to accurately and consistently evaluate the health of plant assets. Due to poor record keeping, maintenance staff often has little defence against aging equipment and asset failures. As a result companies have undertaken to implement planned equipment maintenance schedules and install new technology to allow for efficient tracking and analysing of equipment health across the board.
The introduction of an integrated asset management solution is presented in this thesis. The integrated asset management solution will assist maintenance staff to cost-effectively predict the probability of asset failure prior to the occurrence of any actual plant incidents. The integrated solution documented in this thesis will be implemented at the Sasol Solvents site to enhance plant availability, maximum up time for all plant assets and plant safety.
Strategic Asset Management Inc. (SAMI) uses the Operational Reliability Maturity Continuum model to improve profitability, efficiency and equipment reliability. The SAMI empirical model employs various stages to address improved performance and asset management and was used as a guideline to develop an integrated solution to optimise plant performance and profits.
The integrated asset management solution, documented in this thesis, was developed with the intended function of bringing information from diverse plant based systems and field equipment to the maintenance personnel in an understandable interface so that the information can be used to improve the reliability and availability of all plant assets.
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フロン代替有機溶剤の生物学的モニタリング柴田, 英治, 竹内, 康浩, 市原, 学 03 1900 (has links)
科学研究費補助金 研究種目:基盤研究(C)(2) 課題番号:10670348 研究代表者:柴田 英治 研究期間:1998-1999年度
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