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Tänk efter före : en kvantitativ undersökning om informationskampanjers effekter på ungdomarNielsen, Maria, Sjödahl, Charlotta January 2005 (has links)
No description available.
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Tänk efter före : en kvantitativ undersökning om informationskampanjers effekter på ungdomarNielsen, Maria, Sjödahl, Charlotta January 2005 (has links)
No description available.
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Mineral Surface-Mediated Transformation of Insensitive Munition CompoundsKhatiwada, Raju, Khatiwada, Raju January 2016 (has links)
Abiotic transformation of compounds in the natural environment by metal oxides plays a significant a role in contaminant fate and behavior in soil. The ability of birnessite, ferrihydrite and green rust to abiotically transform insensitive munitions compounds (IMCs) parent (2,4 dinitroanisole [DNAN] and 3-nitro-1,2,4-triazol-5-one [NTO]), and daughter products (2-methoxy-5-nitro aniline [MENA], 2,4-diaminoanisole [DAAN]of DNAN; and 5-amino-1, 2, 4-triazol-3-one [ATO] of NTO) was studied in batch reactors under strictly controlled pH and ionic strength. The objectives of the study were to (i) assess the abiotic transformation potential of soluble DNAN, MENA, DAAN, NTO and ATO by birnessite, ferrihydrite and green rust, and (ii) identify inorganic reaction products. The study was carried out at metal oxide solid to IMC solution ratios (SSR) of 0.15, 1.5 and 15 g kg⁻¹ for birnessite and ferrihydrite and 10 g kg⁻¹ for green rust. Aqueous samples were collected at time intervals between 0 to 3 days after the reaction initiation and analyzed using HPLC with UV detection. Results indicated that DNAN was resistant to oxidation by birnessite and ferrihydrite at given solid to solution ratios. MENA was susceptible to rapid oxidation by birnessite (first order rate constant, 𝑘=1.36 h⁻¹ at 15 g kg⁻¹ SSR). The nitro groups from MENA largely mineralized to nitrite (NO₂⁻). In contrast, ferrihydrite did not oxidize MENA. DAAN was susceptible to oxidation by both birnessite and ferrihydrite, but about a six times higher oxidation rate was observed with birnessite (𝑘=1.18 h⁻¹) as compared to ferrihydrite (𝑘=0.22 h⁻¹) at an SSR of 1.5 g kg⁻¹. There was a complete loss of DAAN from solution after 5 min with birnessite at an SSR 15 g kg⁻¹ (𝑘≥90.5 h⁻¹). CO₂ evolution experiments indicate mineralization of 15 and 12 % of carbon associated with MENA and DAAN, respectively; under aerobic conditions with birnessite at an SSR of 15 g kg⁻¹. NTO was resistant to oxidation by birnessite and ferrihydrite at any SSR; however, there was slight initial loss from solution upon reaction with ferrihydrite at 0.15 and 1.5 g kg⁻¹ SSR and complete loss at 15 g kg⁻¹ SSR due to adsorption. ATO was susceptible to oxidation by birnessite and sorption by ferrihydrite. The first order rate constants (𝑘) for ATO with birnessite at 0.15 and 1.5 g kg⁻¹ SSR are 0.04 and 3.03 h⁻¹ respectively. There was complete loss of ATO from solution with birnessite at 15 g kg⁻¹ SSR (𝑘 ≥ 90.2 h⁻¹) within 5 min of reaction. Transformation products analysis revealed urea, CO₂ and N₂ as major reaction products with 44 % urea recovery and recovery of 51.5 % of ATO carbon as CO₂ and 47.8 % of ATO nitrogen as N₂ at 15 g kg⁻¹ SSR. The oxidation of ATO in the presence of birnessite was found to be independent of dissolved O₂. The results indicate that ATO, the major reductive (bio)transformation product of NTO, is readily oxidized by birnessite in soil. NTO was found strongly sorbed to ferrihydrite as compared to that of ATO. The results of the green rust experiment indicate rapid abiotic reduction of parent compounds NTO and DNAN to their reduced aminated daughter products. NTO was generally reductively transformed to 5-amino-1, 2, 4-triazol-3-one (ATO) within 10 min and completely reacted in 20 min. DNAN was rapidly transformed to its reduced daughter products MENA and 4-methoxy-5-nitroaniline (iMENA). The reduction occurred with a distinctive, staggered regioselectivity. Over the first 10 min, the para-nitro group of DNAN was selectively reduced, generating iMENA. Thereafter the ortho-nitro group was preferentially reduced, generating MENA. Both iMENA and MENA were subsequently transformed to the final reduction product DAAN within 1 day. X-ray absorption near edge spectroscopy data suggested oxidative transformation of green rust to lepidocrocite-like mineral forms, accounting for 94 % of the mineral products in the case of NTO reaction as compared to 62 % in the case of DNAN. The results taken as whole suggest that complete abiotic transformation of IMCs could be achieved by coupled stepwise green rust and birnessite treatments.
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En studie av IOGT-NTO:s strategier för att påverka politiska beslut 1990-2006Norfall, Malin January 2008 (has links)
Sammanfattning Jag har skrivit en uppsats om IOGT-NTO :s strategier för att påverka politiska beslut under tidsperioden 1990 till 2006. Jag utgår från frågorna; Hur har strategierna sett ut? I vad mån har de förändrats? För att försöka mäta vilka metoder organisationen använder sig av har jag kombinerat en teori av Michael Karlssons ”den nationella vägen eller brysselstrategin” med modellen över politiskt deltagande som finns i SOU 1999:121 Avkorporativisering och lobbyism. Jag letade sedan information i IOGT-NTO:s verksamhetsberättelser och delade sedan upp den efter tidsperioder och kategori. Jag tog de 6 resultaten i min modell: Parlamentarisk demokrati, Korporatism, Direkta aktioner, Direkta kontakter, Opinionsbildning, Mediakontakter. För att nå ett bättre resultat ansåg jag ändå att jag var tvungen att ytterligare komplettera med två kategorier: samarbete och prioriteringar eftersom detta är så viktigt för IOGT-NTO:s påverkansarbete. För att sammanfatta mina resultat har IOGT-NTO gått från en organisation med många frågor och endast samarbete med andra nykterhetsrörelser till att bli en organisation som koncentrerat sina frågor som det satsats på och istället jobbar organisationen i flera nätverk, både nationella men även internationella, och genom flera kanaler för att nå bättre resultat i att påverka politiska beslut. Organisationen har förhållit sig både till det svenska EU-medlemskapet och Internets utveckling och betydelse samt behovet att synas i media.
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Charge transfer states at polymer solar cell interfaces : Insights from atomic-scale modeling / Laddningsöverföringstillstånd vid polymersolcellsgränssnitt : Inblick från modellering i atomskalaSvensson, Rickard January 2022 (has links)
Organic solar cells (OSCs) based on non-fullerene acceptors (NFAs) have attracted a great deal of attention in recent years due to their rapidly increasing efficiency and enormous potential. In this work, the optical and electronic properties of systems containing the very promising non-fullerene acceptor PYT have been thoroughly studied with the use of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). By changing the electron linker from thiophene to furan and selenophene, respectively, the PYT was divided into three variants, each of which was studied independently. In addition, these three systems were combined with the donor PBDB-T to generate two distinct interface conformations. The properties studied in this work include the optimized geometries, HOMO-LUMO levels, UV-Vis spectra, frontier molecular orbitals (FMOs), natural transition orbitals (NTOs), density of states (DOS), dipole moments, open-circuit voltages, exciton binding energies, and local exciton (LE) and charge transfer (CT) energies. The calculations were performed in chlorobenzene solution utilizing the polarizable continuum model (PCM). It was discovered that PBDB-T/PY-Se exhibited remarkable flatness employing the π-π stacking conformation which corresponds well with the excellent D/A compatibility observed experimentally. All interfaces displayed appropriate positioning of the HOMO-LUMO levels, with the acceptor dominating the LUMO and the donor dominating the HOMO, with HOMO-LUMO gaps ranging between 1.34 and 1.38 eV. The differences in the interchanging of the electron linker were not that significant, and neither was the change in interface conformation in terms of the HOMO-LUMO levels. This may indicate that the system can be effective even without the presence of a π-π stacking conformation. The first excited states for all interface systems were shown to be pure CT transitions, and on average, 80% of the states exhibit CT character. The remaining contributions consisted of transitions within the pure materials, with a larger contribution within the acceptor. The theoretical results of this study indicate that systems containing the novel polymer acceptor PYT and its variants PY-O and PY-Se exhibit very intriguing properties, and further development of OSCs containing these polymers might further aid in the development of high-performance OSCs. / Organiska solceller (OSC) baserade på icke-fullerenacceptorer (NFA) har väckt stor uppmärksamhet de senaste åren på grund av dess snabbt ökande effektivitet och enorma potential. I detta arbete har de optiska och elektroniska egenskaperna hos system innehållande den mycket lovande icke-fullerenacceptorn PYT studerats grundligt med användning av täthetsfunktionalteorin (DFT) och den tidsberoende täthetsfunktionalteorin (TDDFT). Genom att ändra elektronförbindelsen från tiofen till furan respektive selenofen så delades PYT upp i tre varianter som var och en studerades oberoende av varandra. Dessutom kombinerades dessa tre system med donatorn PBDB-T för att generera två distinkta gränssnittskonformationer. Egenskaperna som studeras i detta arbete inkluderar optimerade geometrier, HOMO-LUMO-nivåer, UV-vis spektra, gränsmolekylära orbitaler (FMO), naturliga övergångsorbitaler (NTO), tillståndstäthet (DOS), dipolmoment, tomgångsspänning, excitonbindningsenergi samt lokal exciton (LE) och laddningsöverförings (CT) energier. Beräkningarna utfördes i klorbensenlösning med användning av den polariserbara kontinuummodellen (PCM). I resultatet uppvisade PBDB-T/PY-Se en anmärkningsvärd planhet med användning av π-π staplingskonformationen som överensstämmer väl med den utmärkta D/A-kompatibiliteten som observerats experimentellt. Alla gränssnitt visade lämplig positionering av HOMO-LUMO-nivåerna, med acceptorn som dominerade LUMO och donatorn som dominerade HOMO, med HOMO-LUMO-gap mellan 1.34 och 1.38 eV. Skillnaderna i utbytet av elektronförbindelsen visade sig inte vara signifikanta och inte heller skillnaden i gränssnittskonformation när det gäller HOMO-LUMO-nivåerna. Detta kan indikera att systemet kan vara effektivt även utan förekomst av π-π staplingskonformation. De första exciterade tillstånden för alla gränssnittssystem visade sig vara rena CT-övergångar och i genomsnitt uppvisade 80% av tillstånden CT-karaktär. Resterande andel bestod av övergångar inom de rena materialen med en större andel inom acceptorn. De teoretiska resultaten av denna studie indikerar att system innehållande den nya polymeracceptorn PYT och dess varianter PY-O och PY-Se uppvisar mycket spännande egenskaper samt att vidareutveckling av OSC:er som innehåller dessa polymerer ytterligare kan hjälpa till i utvecklingen av högpresterande OSC:er.
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Theoretical Investigation Of Tautomeric Equilibria In Certain Explosive MaterialsCelik Bayar, Caglar 01 December 2012 (has links) (PDF)
Explosive materials have always been attracting the attention of scientists. Various explosives either in pure bulk form or as admixtures are synthesized and investigated from different points of view. However, because of dangerous character of these materials, their syntheses and properties have to be forecasted by theoretical studies.
The new research trends of explosive materials generally include the designs of novel derivatives of well&ndash / known explosives to improve their detonation performances (heats of explosion, detonation velocities and detonation pressures) and thermal stabilities and decrease their sensitivities towards friction, electric spark, shock and impact either experimentally or theoretically.
NTO (5&ndash / nitro&ndash / 2,4&ndash / dihydro&ndash / 3H&ndash / 1,2,4&ndash / triazol&ndash / 3&ndash / one) and PATO (3&ndash / picrylamino&ndash / 1,2,4&ndash / triazole) are very important secondary explosives that take place in the literature for many years in terms of their explosive properties. In this thesis study, new species of these explosives have been designed to enhance their detonation performances (ballistic properties) and to lower their sensitivities and reactivities computationally. Additionally, aromatic nitration reactions and their mechanisms for unprotonated and protonated PATO species have been analyzed. The ab initio quantum chemistry methods, Hartree&ndash / Fock (HF) and Density Functional Theory (DFT), have been used in the calculations with Pople basis sets.
Novel NTO and PATO tautomeric species have been designed and investigated to enlighten the effects of tautomerism on their quantum chemical properties and detonation performances in the gas phase.
Various aromatic nitration mechanisms (carbon and nitrogen mono&ndash / nitration mechanisms) of unprotonated tautomeric PATO species as well as PATO have been designed in gas phase and the reaction states (pre&ndash / transition states, transition states, intermediates and nitration products) have been detected belonging to these mechanisms. Nitrations in solution phase have also been analyzed. The reaction states have been detected for carbon and nitrogen mono&ndash / nitrations of protonated PATO species in the gas phase. The detonation performances of unnitrated and nitrated PATO products have been presented.
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Nitrogen Tetroxide to Mixed Oxides of Nitrogen: History, Usage, Synthesis, and Composition DeterminationAndrew W Head (11181636) 22 November 2021 (has links)
<div>Since as early as the 1920s, dinitrogen tetroxide (N2O4) has been regarded as a promising oxidizer in rocket propulsion systems. In more recent times, its predecessor, mixed oxides of nitrogen (MON), remains a top contender among oxidizers, due to its unique characteristics such as low freezing temperature and compatibility with common spacecraft materials. Today, these N2O4-based oxidizers are the preferred choice in many upper stages, launch escape systems, reaction control systems, liquid apogee engines, and in-space primary propulsion systems. N2O4-based oxidizers are a key factor in rocket propulsion, and thoroughly understanding their history, development, characteristics, synthesis, and composition analysis are crucial for space exploration today and into the future.<br><br></div><div>To fully understand and predict the physical properties of a MON sample, it is important to measure and quantify its chemical composition. The recommended method for MON composition analysis, as prescribed by the Department of Defense’s Defense Specification (MIL-SPEC) document on N2O4, involves the oxidation of NO and dinitrogen trioxide (N2O3) in the MON sample to determine their amounts. An equation unofficially called the “MIL-SPEC equation” is then used to determine the amount of NO needed to mix with N2O4 to synthesize that particular MON sample. However, no explanation is given as to how the equation was derived, or its significance.<br><br></div><div>This thesis aims to collect and organize key information on the synthesis, handling, and composition analysis of MON propellant. First, the history of development of N2O4-based oxidizers was researched, and current and future uses of N2O4 and MON propellants were identified. Then a method for synthesis and composition analysis was devised and tested. Water contamination was expected of skewing the results, so the process of water contamination was examined analytically. Then a detailed derivation of the MIL-SPEC equation was conducted, to fully understand its mechanics. An attempt was then made to reverse-engineer an unexplained numerical value in the equation, labeled by the author as the “solubility factor”. Several derivations were provided with varying degrees of complexity, producing alternative solubility factors of varying accuracies. Finally, experimental data was applied to these derived, hypothetical solubility factors and the MIL-SPEC solubility factor, with the intent of determining whether improvements could be made to the MON composition determination process.<br><br></div><div>The results suggest that the MIL-SPEC equation is sufficient for providing a relatively accurate measurement of the composition of a MON sample, while also being easy to implement, both in taking the necessary measurements and in conducting the numerical calculation. However, some minor adjustments to the equation could produce consistently more accurate composition measurements without adding any more difficulty or complication.</div>
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