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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.
71

Spolupráce rodiny a školy na počátku vzdělávání / Cooperation of family and school at the beginning of schooling

Dušková, Tereza January 2011 (has links)
Name: Cooperation of family and school at the beginning of schooling Author: Dušková, T. Supervisor: Mgr. Kargerová, J., Ph.D. The diploma thesis is focused on the cooperation of family and school at the beginning of schooling. The theoretical part describes the school and the family as the institutions that have an irreplaceable position in a life of child. It offers a view into the history and its forms of cooperation and aims which were reached in compare with today's understanding of the child and childhood. It deals with 1989 and its events which influenced the politic, economic and pedagogic situation - the child is in the middle of the family a school attention. The education is innovated, reformatted and new laws together with some new school programmes are issued. The theoretical background is finished by a description of Začít spolu program, its brief characteristic and concrete forms of cooperation with families. The empiric part surveys the situation in an ordinary school and the school worked according to the Začít spolu program. It compares their elementary and secondary levels and it offers some recommendations for better family-school cooperation.
72

Istanalyse C-Bindung Sachsen: Ermittlung der Kohlenstoffbindung von Treibhausgasspeichern und -senken in Sachsen

Grünwald, Thomas 28 August 2019 (has links)
Die Konzentrationen der Treibhausgase (THG) Kohlendioxid (CO2), Methan (CH4) und Lachgas (N2O) haben ein Niveau erreicht, welches mit sehr hoher Wahrscheinlichkeit seit 800.000 Jahren nicht vorgekommen ist (Stocker et al. 2013).
73

Role of deposition temperature and concentration on the self-assembly and reaction of organic molecules at the solution-graphite interface

Nguyen, Doan Chau Yen 25 April 2017 (has links) (PDF)
Das Hauptthema dieser Dissertation ist die Untersuchung der Selbstorganisation organischer Moleküle an der Flüssig-Fest-Grenzfläche (LSI). Besondere Betonung liegt auf der Kontrolle der Selbstassemblierung durch geeignete Parameter: die Substrattemperatur während der Abscheidung, die Konzentration der gelösten Moleküle, und die chemische Natur der gelösten Stoffe und Lösungsmittel. Die Untersuchungen wurden unter Verwendung der Rastertunnelmikroskopie (STM) durchgeführt. Der erste Schwerpunkt dieser Arbeit ist die systematische Untersuchung der Auswirkung erhöhter Substrattemperatur während der Abscheidung aus der Lösung auf die Selbstorganisation komplexer molekularer Architekturen an der LSI. Diese Untersuchungen wurden mit dem planaren Molekül Trimesinsäure (TMA), sowie dem nicht-planaren Molekül Benzen-1,3,5-triphosphonsäure (BTP) durchgeführt. Es wird gezeigt, dass der Polymorphismus der Adsorbatstrukturen von TMA und BTP durch die Substrattemperatur während der Abscheidung der Moleküle aus der Lösung für verschiedene Lösungsmitteln unterschiedlicher Polarität, wie Phenyloctan, Octansäure und Undecanol, kontrolliert werden kann. Durch die Erhöhung der Temperatur des vorgeheiztem Graphitsubstrates kann die spezifische 2D supramolekulare Struktur and die entsprechende Packungsdichte der Moleküle in der Adsorbatschicht für jedes der untersuchten Lösungsmittel präzise eingestellt werden. Weiterhin wird der Einfluss der Konzentration auf die resultierende Anordnung der TMA Moleküle an der LSI durch ein weiteres Experiment abgeschätzt, bei welchem Rühren (von 0 h bis 40 h) der Lösungen mit verschiedenen Lösungsmitteln eingesetzt wurde. Diese Ergebnisse zeigen, dass die verschiedenen Präparationsmethoden (Erhöhung der Abscheidetemperatur oder Rühren) zu derselben Tendenz der Änderung der geordneten Strukturen sowie der Packungsdichte führt, weswegen man schlussfolgern kann, dass die Erhöhung der Konzentration an der LSI bei erhöhter Abscheidetemperatur ebenso der Hauptgrund für die beobachteten Änderungen ist. Der zweite Schwerpunkt dieser Dissertation ist die Untersuchung von chemischen Reaktionen der selbstassemblierenden Moleküle. Eine Veresterungsreaktion von TMA mit Undecanol wurde gefunden. Weiterhin wurde, als ein erster Schritt zur Untersuchung der Zwillingspolymerisation, die Oligomerisation des Zwillingsmonomers 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) mit STM an der Grenzfläche zwischen der SBS-Undecanol-Lösung und einer Graphitoberfläche untersucht. Erstens wurde durch Ultraschallbehandlung der SBS Lösung in Undecanol für verschieden lange Zeiten die Oligomerisation der SBS Monomere ohne einen Katalysator an der LSI beobachtet. Zweitens konnte die Oligomerisation auch durch Erhöhung der Substrattemperatur während der Abscheidung der Moleküle aus der Lösung initiiert werden. Durch die schrittweise Erhöhung der Temperatur des vorgeheizten Substrates konnten mehrere, verschiedene, periodische Anordnungen von Phenol‒Dimeren, ‒Trimeren, und –Pentameren u.s.w. gefunden werden. Weiterhin wird die Auswirkung der Abscheidetemperatur auf die Selbstorganisation an der LSI nur der Lösungsmittelmoleküle aus dem reinen Lösungsmittel beschrieben. Dies ist wichtig, da die Undecanol‒Moleküle stets mit den gelösten, in dieser Arbeit verwendeten Stoffen (TMA, BTP, SBS) koadsorbieren und lineare Muster bilden. / The main aim of this thesis is to study the self-assembly of organic molecules at the liquid-solid interface (LSI). Special emphasis is given to controlling the process of self-assembly via suitable parameters such as: the substrate temperature during the initial deposition, the concentration of dissolved molecules, or the chemical nature of solutes and solvents. The investigations are performed using scanning tunneling microscopy (STM). The first focus of this work is the systematic investigation of the effect of the substrate temperature during the deposition out of the solution on the self-assembly of complex molecular architectures at the LSI. These investigations have been done with the planar molecule trimesic acid (TMA), and the non-planar molecule benzene 1,3,5-triphosphonic acid (BTP). We show that the polymorphism of the adsorbate structures of TMA (also with BTP) can be controlled by the substrate temperature during the deposition of the molecules out of the solution for various solvents of different polarity such as phenyloctane, octanoic acid, and undecanol. By increasing the temperature of the pre-heated graphite substrate, the specific 2D supramolecular structure and the corresponding packing density in the adsorbate layer can be precisely tuned for each kind of the solvents studied. Furthermore, the influence of the concentration on the resulting self-assembly of TMA molecules at the LSI is estimated by another experiment using stirring (from 0 h to 40 h) of the solutions of different kinds of solvents. These results demonstrate that choosing different preparation methods (increasing deposition temperatures or stirring) lead to the same tendency in the change of the self-assembled structures as well as the tuning of the packing density from which it can also be concluded that the increase of the concentration at increased deposition temperatures is also the main reason for the observed changes. The second focus of this work is the investigation of chemical reactions of self-assembling molecules. The esterification of TMA with undecanol was observed. Moreover as a first step to study twin polymerization, the oligomerization of the twin monomer 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) was investigated by STM at the SBS-undecanol solution/graphite interface. Firstly, by ultrasonicating the solution of SBS in undecanol for different times the oligomerization of SBS monomer without any catalyst has been observed at the LSI. Secondly, the oligomerization of SBS monomer can also be initiated by the substrate temperature during the deposition of the molecules out of the solution. By stepwise increasing the temperature of the pre-heated substrate, various periodic assemblies of phenolic dimer, trimer, pentamer resin, and so on were observed. Furthermore, the effect of deposition temperature on the self-assembly of solely solvent molecules from the pure liquid at the LSI is described, which is important because the undecanol solvent molecules are always co-adsorbed with the solutes used in this work (TMA, BTP, SBS) to form linear patterns.
74

Role of deposition temperature and concentration on the self-assembly and reaction of organic molecules at the solution-graphite interface

Nguyen, Doan Chau Yen 17 January 2017 (has links)
Das Hauptthema dieser Dissertation ist die Untersuchung der Selbstorganisation organischer Moleküle an der Flüssig-Fest-Grenzfläche (LSI). Besondere Betonung liegt auf der Kontrolle der Selbstassemblierung durch geeignete Parameter: die Substrattemperatur während der Abscheidung, die Konzentration der gelösten Moleküle, und die chemische Natur der gelösten Stoffe und Lösungsmittel. Die Untersuchungen wurden unter Verwendung der Rastertunnelmikroskopie (STM) durchgeführt. Der erste Schwerpunkt dieser Arbeit ist die systematische Untersuchung der Auswirkung erhöhter Substrattemperatur während der Abscheidung aus der Lösung auf die Selbstorganisation komplexer molekularer Architekturen an der LSI. Diese Untersuchungen wurden mit dem planaren Molekül Trimesinsäure (TMA), sowie dem nicht-planaren Molekül Benzen-1,3,5-triphosphonsäure (BTP) durchgeführt. Es wird gezeigt, dass der Polymorphismus der Adsorbatstrukturen von TMA und BTP durch die Substrattemperatur während der Abscheidung der Moleküle aus der Lösung für verschiedene Lösungsmitteln unterschiedlicher Polarität, wie Phenyloctan, Octansäure und Undecanol, kontrolliert werden kann. Durch die Erhöhung der Temperatur des vorgeheiztem Graphitsubstrates kann die spezifische 2D supramolekulare Struktur and die entsprechende Packungsdichte der Moleküle in der Adsorbatschicht für jedes der untersuchten Lösungsmittel präzise eingestellt werden. Weiterhin wird der Einfluss der Konzentration auf die resultierende Anordnung der TMA Moleküle an der LSI durch ein weiteres Experiment abgeschätzt, bei welchem Rühren (von 0 h bis 40 h) der Lösungen mit verschiedenen Lösungsmitteln eingesetzt wurde. Diese Ergebnisse zeigen, dass die verschiedenen Präparationsmethoden (Erhöhung der Abscheidetemperatur oder Rühren) zu derselben Tendenz der Änderung der geordneten Strukturen sowie der Packungsdichte führt, weswegen man schlussfolgern kann, dass die Erhöhung der Konzentration an der LSI bei erhöhter Abscheidetemperatur ebenso der Hauptgrund für die beobachteten Änderungen ist. Der zweite Schwerpunkt dieser Dissertation ist die Untersuchung von chemischen Reaktionen der selbstassemblierenden Moleküle. Eine Veresterungsreaktion von TMA mit Undecanol wurde gefunden. Weiterhin wurde, als ein erster Schritt zur Untersuchung der Zwillingspolymerisation, die Oligomerisation des Zwillingsmonomers 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) mit STM an der Grenzfläche zwischen der SBS-Undecanol-Lösung und einer Graphitoberfläche untersucht. Erstens wurde durch Ultraschallbehandlung der SBS Lösung in Undecanol für verschieden lange Zeiten die Oligomerisation der SBS Monomere ohne einen Katalysator an der LSI beobachtet. Zweitens konnte die Oligomerisation auch durch Erhöhung der Substrattemperatur während der Abscheidung der Moleküle aus der Lösung initiiert werden. Durch die schrittweise Erhöhung der Temperatur des vorgeheizten Substrates konnten mehrere, verschiedene, periodische Anordnungen von Phenol‒Dimeren, ‒Trimeren, und –Pentameren u.s.w. gefunden werden. Weiterhin wird die Auswirkung der Abscheidetemperatur auf die Selbstorganisation an der LSI nur der Lösungsmittelmoleküle aus dem reinen Lösungsmittel beschrieben. Dies ist wichtig, da die Undecanol‒Moleküle stets mit den gelösten, in dieser Arbeit verwendeten Stoffen (TMA, BTP, SBS) koadsorbieren und lineare Muster bilden.:Chapter 1: Introduction Chapter 2: Basic principle 2.1 Principles of scanning tunneling microscopy (STM) 2.1.1 General working principle 2.1.2 Tunneling effect 2.1.3 Theory of STM 2.1.4 Contrast mechanism of molecular adsorbates 2.1.5 Modes of STM operation 2.2 STM at the liquid-solid interface (LSI) 2.3 Thermodynamics and kinetics 2.3.1 Equilibrium of the adsorption/desorption and initial agglomeration at the LSI 2.3.2 Kinetic and thermodynamic control over 2D molecular self-assembly 2.4 Experimental condition 2.4.1 Role of solvent 2.4.2 Role of concentration 2.4.3 Role of temperature References Chapter 3: Experimental section 3.1 Solutes 3.1.1 Trimesic acid (TMA) (1,3,5?C6H3(COOH)3) 3.1.2 Benzene 1.3.5-Triphosphonic acid (BTP) (1,3,5?C6H3(PO3H2)3) 3.1.3 Twin monomer 2,2’-spirobi[4H-1,3,2-benzo-dioxasiline] (SBS) 3.2 Solvents 3.3 Substrate: Highly oriented pyrolytic graphite (HOPG (0001)) 3.4 Preparation of the STM tips 3.5 Experimental methods for sample preparation 3.5.1 Preparation of the solution 3.5.2 Heating of the substrate 3.5.3 Ultrasonication 3.5.4 Stirring 3.6 Computational details References Chapter 4: Deposition temperature? and solvent-dependent 2D supramolecular assemblies of trimesic acid at the liquid-graphite interface revealed by STM Results and discussion 4.1 Hydrogen bonding motifs of trimesic acid molecules 4.2 TMA deposited from solution in octanoic acid 4.3 TMA deposited from solution in phenyloctane 4.4 TMA deposited from solution in undecanol 4.6 Discussion of the solute–solvent interactions 4.5 Effect of the deposition substrate temperature on the formation of ester at the LSI of TMA in undecanol Conclusion References Chapter 5: Role of concentration on the self-assembly of TMA at the LSI influenced by stirring time Results and discussion 5.1 TMA in octanoic acid 5.2 TMA in phenyloctane 5.3 TMA in undecanol Conclusion References Chapter 6: Role of deposition temperature on the self-assembly of the non-planar molecule benzene- 1,3,5- triphosphonic acid (BTP) at the LSI Results and discussion 6.1 BTP in undecanol at room temperature 6.2 BTP in undecanol at high substrate temperature during deposition Conclusion References Chapter 7: Role of deposition temperature on the self-assembly of pure undecanol solvent at the LSI Results and discussion 7.1 Adsorption geometry of undecanol on HOPG 7.2 Herringbone structures of undecanol 7.3 Parallel structure of undecanol at high substrate temperature during deposition Conclusion References Chapter 8: A first step to microscopically study twinpolymerization: self-assembly of twin monomer 2,2’-Spirobi[4H-1,3,2-benzo-dioxasiline] (SBS) at the LSI influenced by ultrasonication and deposition substrate temperature 8.1 Coadsorption of SBS and undecanol without ultrasonication and at room temperature 8.2 SBS deposited from solution in undecanol in dependence on the duration of ultrasonication 8.3 SBS deposited from solution in undecanol at varied deposition temperature of the substrate 8.4 Discussion and open questions Appendix References CHAPTER 9: SUMMARY AND OUTLOOK ERKLÄRUNG CURRICULUM VITAE ACKNOWLEDGEMENT / The main aim of this thesis is to study the self-assembly of organic molecules at the liquid-solid interface (LSI). Special emphasis is given to controlling the process of self-assembly via suitable parameters such as: the substrate temperature during the initial deposition, the concentration of dissolved molecules, or the chemical nature of solutes and solvents. The investigations are performed using scanning tunneling microscopy (STM). The first focus of this work is the systematic investigation of the effect of the substrate temperature during the deposition out of the solution on the self-assembly of complex molecular architectures at the LSI. These investigations have been done with the planar molecule trimesic acid (TMA), and the non-planar molecule benzene 1,3,5-triphosphonic acid (BTP). We show that the polymorphism of the adsorbate structures of TMA (also with BTP) can be controlled by the substrate temperature during the deposition of the molecules out of the solution for various solvents of different polarity such as phenyloctane, octanoic acid, and undecanol. By increasing the temperature of the pre-heated graphite substrate, the specific 2D supramolecular structure and the corresponding packing density in the adsorbate layer can be precisely tuned for each kind of the solvents studied. Furthermore, the influence of the concentration on the resulting self-assembly of TMA molecules at the LSI is estimated by another experiment using stirring (from 0 h to 40 h) of the solutions of different kinds of solvents. These results demonstrate that choosing different preparation methods (increasing deposition temperatures or stirring) lead to the same tendency in the change of the self-assembled structures as well as the tuning of the packing density from which it can also be concluded that the increase of the concentration at increased deposition temperatures is also the main reason for the observed changes. The second focus of this work is the investigation of chemical reactions of self-assembling molecules. The esterification of TMA with undecanol was observed. Moreover as a first step to study twin polymerization, the oligomerization of the twin monomer 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) was investigated by STM at the SBS-undecanol solution/graphite interface. Firstly, by ultrasonicating the solution of SBS in undecanol for different times the oligomerization of SBS monomer without any catalyst has been observed at the LSI. Secondly, the oligomerization of SBS monomer can also be initiated by the substrate temperature during the deposition of the molecules out of the solution. By stepwise increasing the temperature of the pre-heated substrate, various periodic assemblies of phenolic dimer, trimer, pentamer resin, and so on were observed. Furthermore, the effect of deposition temperature on the self-assembly of solely solvent molecules from the pure liquid at the LSI is described, which is important because the undecanol solvent molecules are always co-adsorbed with the solutes used in this work (TMA, BTP, SBS) to form linear patterns.:Chapter 1: Introduction Chapter 2: Basic principle 2.1 Principles of scanning tunneling microscopy (STM) 2.1.1 General working principle 2.1.2 Tunneling effect 2.1.3 Theory of STM 2.1.4 Contrast mechanism of molecular adsorbates 2.1.5 Modes of STM operation 2.2 STM at the liquid-solid interface (LSI) 2.3 Thermodynamics and kinetics 2.3.1 Equilibrium of the adsorption/desorption and initial agglomeration at the LSI 2.3.2 Kinetic and thermodynamic control over 2D molecular self-assembly 2.4 Experimental condition 2.4.1 Role of solvent 2.4.2 Role of concentration 2.4.3 Role of temperature References Chapter 3: Experimental section 3.1 Solutes 3.1.1 Trimesic acid (TMA) (1,3,5?C6H3(COOH)3) 3.1.2 Benzene 1.3.5-Triphosphonic acid (BTP) (1,3,5?C6H3(PO3H2)3) 3.1.3 Twin monomer 2,2’-spirobi[4H-1,3,2-benzo-dioxasiline] (SBS) 3.2 Solvents 3.3 Substrate: Highly oriented pyrolytic graphite (HOPG (0001)) 3.4 Preparation of the STM tips 3.5 Experimental methods for sample preparation 3.5.1 Preparation of the solution 3.5.2 Heating of the substrate 3.5.3 Ultrasonication 3.5.4 Stirring 3.6 Computational details References Chapter 4: Deposition temperature? and solvent-dependent 2D supramolecular assemblies of trimesic acid at the liquid-graphite interface revealed by STM Results and discussion 4.1 Hydrogen bonding motifs of trimesic acid molecules 4.2 TMA deposited from solution in octanoic acid 4.3 TMA deposited from solution in phenyloctane 4.4 TMA deposited from solution in undecanol 4.6 Discussion of the solute–solvent interactions 4.5 Effect of the deposition substrate temperature on the formation of ester at the LSI of TMA in undecanol Conclusion References Chapter 5: Role of concentration on the self-assembly of TMA at the LSI influenced by stirring time Results and discussion 5.1 TMA in octanoic acid 5.2 TMA in phenyloctane 5.3 TMA in undecanol Conclusion References Chapter 6: Role of deposition temperature on the self-assembly of the non-planar molecule benzene- 1,3,5- triphosphonic acid (BTP) at the LSI Results and discussion 6.1 BTP in undecanol at room temperature 6.2 BTP in undecanol at high substrate temperature during deposition Conclusion References Chapter 7: Role of deposition temperature on the self-assembly of pure undecanol solvent at the LSI Results and discussion 7.1 Adsorption geometry of undecanol on HOPG 7.2 Herringbone structures of undecanol 7.3 Parallel structure of undecanol at high substrate temperature during deposition Conclusion References Chapter 8: A first step to microscopically study twinpolymerization: self-assembly of twin monomer 2,2’-Spirobi[4H-1,3,2-benzo-dioxasiline] (SBS) at the LSI influenced by ultrasonication and deposition substrate temperature 8.1 Coadsorption of SBS and undecanol without ultrasonication and at room temperature 8.2 SBS deposited from solution in undecanol in dependence on the duration of ultrasonication 8.3 SBS deposited from solution in undecanol at varied deposition temperature of the substrate 8.4 Discussion and open questions Appendix References CHAPTER 9: SUMMARY AND OUTLOOK ERKLÄRUNG CURRICULUM VITAE ACKNOWLEDGEMENT
75

Oxidation of terpenes in indoor environments : A study of influencing factors

Pommer, Linda January 2003 (has links)
In this thesis the oxidation of monoterpenes by O3 and NO2 and factors that influenced the oxidation were studied. In the environment both ozone (O3) and nitrogen dioxide (NO2) are present as oxidising gases, which causes sampling artefacts when using Tenax TA as an adsorbent to sample organic compounds in the air. A scrubber was developed to remove O3 and NO2 prior to the sampling tube, and artefacts during sampling were minimised when using the scrubber. The main organic compounds sampled in this thesis were two monoterpenes, alfa-pinene and delta-3-carene, due to their presence in both indoor and outdoor air. The recovery of the monoterpenes through the scrubber varied between 75-97% at relative humidities of 15-75%. The reactions of alfa-pinene and delta-3-carene with O 3, NO2 and nitric oxide (NO) at different relative humidities (RHs) and reaction times were studied in a dark reaction chamber. The experiments were planned and performed according to an experimental design were the factors influencing the reaction (O3, NO2, NO, RH and reaction times) were varied between high and low levels. In the experiments up to 13% of the monoterpenes reacted when O3, NO2, and reaction time were at high levels, and NO, and RH were at low levels. In the evaluation eight and seven factors (including both single and interaction factors) were found to influence the amount of alfa-pinene and delta-3-carene reacted, respectively. The three most influencing factors for both of the monoterpenes were the O 3 level, the reaction time, and the RH. Increased O3 level and reaction time increased the amount of monoterpene reacted, and increased RH decreased the amount reacted. A theoretical model of the reactions occurring in the reaction chamber was created. The amount of monoterpene reacted at different initial settings of O3, NO2, and NO were calculated, as well as the influence of different reaction pathways, and the concentrations of O3 and NO2, and NO at specific reaction times. The results of the theoretical model were that the reactivity of the gas mixture towards alfa-pinene and delta-3-carene was underestimated. But, the calculated concentrations of O3, NO2, and NO in the theoretical model were found to correspond to a high degree with experimental results performed under similar conditions. The possible associations between organic compounds in indoor air, building variables and the presence of sick building syndrome were studied using principal component analysis. The most complex model was able to separate 71% of the “sick” buildings from the “healthy” buildings. The most important variables that separated the “sick” buildings from the “healthy” buildings were a more frequent occurrence or a higher concentration of compounds with shorter retention times in the “sick” buildings. The outcome of this thesis could be summarised as follows; - - - -
76

Charge into the Future Grid : Optimizing Batteries to Support the Future Low-Voltage Electrical Grid

Dushku, Mergim, Kokko Ekholm, Julius January 2019 (has links)
The increase in electric vehicles and photovoltaic power production may introduce problems to the low-voltage distribution grid. With a higher number of electric vehicles, their accumulated charging power might breach the lowest allowed voltage level of the grid. Photovoltaic-modules can on the other hand exceed the highest allowed voltage level, by producing high accumulated power when the solar irradiance is high. Normally, electric distribution companies in Sweden reinforce the existing grid with more resilient infrastructure, such as stronger and larger cables or transformer stations. This is however a costly and time-consuming solution, which could be solved by using alternative means such as already existing resources. This Master's Thesis investigates how smart charging of batteries can support the low-voltage electrical grid with the increase in electric vehicles and photovoltaic power production. To do this, an optimization tool has been developed in Matlab. An existing model of a low-voltage grid is combined with the developed tool, where controllable batteries and photovoltaic-modules can be placed at specific households in the grid. The controllable batteries belong to either electric vehicles or stationary battery systems, and are intended to support the grid by the means of either reducing peak load powers, voltage variations, or a trade-off between them. Furthermore, this thesis investigates the maximum electric vehicle capability for a specific low-voltage electrical grid in Sweden. From the results, it can be concluded that smart charging of batteries can reduce the peak loads as well as voltage variations. The reduction of voltage variations for the entire low-voltage grid is greatest during the summer, when photovoltaic production generally is at its highest. The results also show that a stationary battery system can reduce the voltage variations to a greater extent, compared to an electric vehicle. Also, the introduction of multiple controllable batteries allows further support of the low-voltage grid. Regarding the maximum electric vehicle capability, the results show that the placement of the vehicles and the charging power strongly affect the maximum number of electric vehicles the low-voltage grid can manage. / Ökningen av elbilar och elproduktion från solceller kan ge problem i lågspänningsnätet. Med ett ökat antal elbilar kan den sammanlagrade effekten vid laddning underskrida den minsta tillåtna spänningsnivån i nätet. Solpaneler kan däremot leda till att den högsta tillåtna spänningsnivån överskrids, genom att producera en hög sammanlagrad effekt när solstrålningen är som högst. Vanligtvis förstärker elnätsbolag i Sverige det befintliga nätet med motståndskraftigare infrastruktur, såsom kraftigare och större kablar eller transformatorstationer. Detta är dock en kostsam och tidskrävande lösning, som skulle kunna lösas med alternativa medel, till exempel redan existerande resurser. Detta examensarbete undersöker hur smart laddning av batterier kan ge stöd till lågspänningsnätet, med en ökning av elbilar samt solcellsproduktion. För att undersöka detta har ett optimeringsverktyg utvecklats i Matlab. En befintlig modell av ett lågspänningsnät har kombinerats med det utvecklade optimeringsverktyget, där styrbara batterier samt solcellsproduktion kan placeras vid specifika hushåll i elnätet. De styrbara batterierna är antingen elbilar eller stationära batterisystem, och är ämnade till att stödja lågspänningsnätet genom att antingen reducera effekttoppar, spänningsvariationer eller en kompromiss av båda. Vidare undersöker detta examensarbete det maximala antalet elbilar som ett specifikt lågspänningsnät i Sverige kan hantera. Resultaten visar att smart laddning av batterier kan reducera effekttoppar samt spänningsvariationer. Reduceringen av spänningsvariationerna för hela lågspänningsnätet visar sig vara högst under sommaren, vilket är då solcellsproduktionen generellt är som högst. Resultaten visar även att stationära batterisystem kan reducera spänningsvariationer ytterligare, jämfört med en elbil. Att introducera flera styrbara batterier tillåter ett ännu större stöd till lågspänningsnätet. Angående det maximala antalet av elbilar som ett lågspänningsnät kan hantera visade resultaten att placeringen av elbilarna samt laddningseffekten har en stor påverkan.
77

Oxidation of terpenes in indoor environments : A study of influencing factors

Pommer, Linda January 2003 (has links)
<p>In this thesis the oxidation of monoterpenes by O3 and NO2 and factors that influenced the oxidation were studied. In the environment both ozone (O3) and nitrogen dioxide (NO2) are present as oxidising gases, which causes sampling artefacts when using Tenax TA as an adsorbent to sample organic compounds in the air. A scrubber was developed to remove O3 and NO2 prior to the sampling tube, and artefacts during sampling were minimised when using the scrubber. The main organic compounds sampled in this thesis were two monoterpenes, alfa-pinene and delta-3-carene, due to their presence in both indoor and outdoor air. The recovery of the monoterpenes through the scrubber varied between 75-97% at relative humidities of 15-75%.</p><p>The reactions of alfa-pinene and delta-3-carene with O 3, NO2 and nitric oxide (NO) at different relative humidities (RHs) and reaction times were studied in a dark reaction chamber. The experiments were planned and performed according to an experimental design were the factors influencing the reaction (O3, NO2, NO, RH and reaction times) were varied between high and low levels. In the experiments up to 13% of the monoterpenes reacted when O3, NO2, and reaction time were at high levels, and NO, and RH were at low levels. In the evaluation eight and seven factors (including both single and interaction factors) were found to influence the amount of alfa-pinene and delta-3-carene reacted, respectively. The three most influencing factors for both of the monoterpenes were the O 3 level, the reaction time, and the RH. Increased O3 level and reaction time increased the amount of monoterpene reacted, and increased RH decreased the amount reacted.</p><p>A theoretical model of the reactions occurring in the reaction chamber was created. The amount of monoterpene reacted at different initial settings of O3, NO2, and NO were calculated, as well as the influence of different reaction pathways, and the concentrations of O3 and NO2, and NO at specific reaction times. The results of the theoretical model were that the reactivity of the gas mixture towards alfa-pinene and delta-3-carene was underestimated. But, the calculated concentrations of O3, NO2, and NO in the theoretical model were found to correspond to a high degree with experimental results performed under similar conditions. The possible associations between organic compounds in indoor air, building variables and the presence of sick building syndrome were studied using principal component analysis. The most complex model was able to separate 71% of the “sick” buildings from the “healthy” buildings. The most important variables that separated the “sick” buildings from the “healthy” buildings were a more frequent occurrence or a higher concentration of compounds with shorter retention times in the “sick” buildings.</p><p>The outcome of this thesis could be summarised as follows;</p><p>-</p><p>-</p><p>-</p><p>-</p>
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A Sociological Approach to Indoor Environment in Dwellings : Risk factors for Sick Building Syndrome (SBS) and Discomfort

Engvall, Karin January 2003 (has links)
<p>The principal aim was to study selected aspects of indoor environment in dwellings and their association with symptoms compatible with the sick building syndrome (SBS). A validated questionnaire was developed specifically for residential indoor investigations, using sociological principles and test procedures. The questionnaire was mailed to 14,243 multi-family dwellings in Stockholm, selected by stratified random sampling. Females, subjects with a history of atopy, those above 65 y, and those in new buildings reported more symptoms. Subjects owning their own dwelling had less symptoms. A multiple regression model was developed, to identify residential buildings with a higher than expected occurrence of SBS. In total, 28.5% reported at least one sign of building dampness in their home (condensation on windows, humidity in the bathroom, mouldy odour, water leakage). All indicators of dampness were related to symptoms, even when adjusting for demographic data, and other building characteristics (OR=2.9-6.0). Associations between symptoms and other building data was evaluated in older houses, built before 1961. Subjects in older buildings with a mechanical ventilation system had fewer symptoms. Heating by electric radiators, and wood heating was associated with an increase of most types of symptoms (OR=1.2-5.0). Multiple sealing measures (OR=1.3), and major reconstruction (OR=1.1-1.9), was associated with an increase of symptoms. The effect of seasonal adapted ventilation (SAV) was studied in a small experimental study. A 20% reduction of ventilation flow from 0.5-0.8 ac/h to 0.4-0.5 ACH during the heating season increased the perception of poor indoor air quality in the dwelling in general, and in the bedroom. In conclusion, low building age, and building dampness in the dwelling are associated with SBS. In older houses, mechanical ventilation is beneficial. The thesis did not support the view that energy saving measures in general is an important risk factor for SBS, but major reconstruction and multiple sealing measures can be risk factor for symptoms. Reducing the outdoor ventilation flow below the current Swedish ventilation standard (0.5 ACH) may increase the perception of impaired air quality. </p>
79

A Sociological Approach to Indoor Environment in Dwellings : Risk factors for Sick Building Syndrome (SBS) and Discomfort

Engvall, Karin January 2003 (has links)
The principal aim was to study selected aspects of indoor environment in dwellings and their association with symptoms compatible with the sick building syndrome (SBS). A validated questionnaire was developed specifically for residential indoor investigations, using sociological principles and test procedures. The questionnaire was mailed to 14,243 multi-family dwellings in Stockholm, selected by stratified random sampling. Females, subjects with a history of atopy, those above 65 y, and those in new buildings reported more symptoms. Subjects owning their own dwelling had less symptoms. A multiple regression model was developed, to identify residential buildings with a higher than expected occurrence of SBS. In total, 28.5% reported at least one sign of building dampness in their home (condensation on windows, humidity in the bathroom, mouldy odour, water leakage). All indicators of dampness were related to symptoms, even when adjusting for demographic data, and other building characteristics (OR=2.9-6.0). Associations between symptoms and other building data was evaluated in older houses, built before 1961. Subjects in older buildings with a mechanical ventilation system had fewer symptoms. Heating by electric radiators, and wood heating was associated with an increase of most types of symptoms (OR=1.2-5.0). Multiple sealing measures (OR=1.3), and major reconstruction (OR=1.1-1.9), was associated with an increase of symptoms. The effect of seasonal adapted ventilation (SAV) was studied in a small experimental study. A 20% reduction of ventilation flow from 0.5-0.8 ac/h to 0.4-0.5 ACH during the heating season increased the perception of poor indoor air quality in the dwelling in general, and in the bedroom. In conclusion, low building age, and building dampness in the dwelling are associated with SBS. In older houses, mechanical ventilation is beneficial. The thesis did not support the view that energy saving measures in general is an important risk factor for SBS, but major reconstruction and multiple sealing measures can be risk factor for symptoms. Reducing the outdoor ventilation flow below the current Swedish ventilation standard (0.5 ACH) may increase the perception of impaired air quality.
80

Faculty Senate Minutes March 3, 2014

University of Arizona Faculty Senate 08 April 2014 (has links)
This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

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