The luminescent decay of pure potassium iodide has been measured under various conditions of temperature, annealing and x-irradiation time. The decay curves are found to be approximately of the form I(t) = [formula omitted] where I(t) is the luminescent intensity at the time t. Using a method that has been developed for the analysis of decay curves, numerical values for the decay constants, λi , and the trap populations Pi, have been estimated. The decay constants are found to be simple temperature functions of the form λi = [formula omitted] with the activation energies, Ei, lying between 0.4 and 0.8 ev and escape probabilities, Si, between 10⁴ and 10⁸ sec.⁻¹. The temperature dependence of the Pi is complicated and indicates that radiationless transitions strongly contribute to the emptying of traps at high temperatures. An irreversible increase in luminescent output produced by repeated x-irradiation without intermediate annealing is discovered; it points to considerable deviation from a first order decay mechanism in the case of slowly decaying traps. The mechanism of the irreversible effect is discussed on a semi-quantitative basis. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The mechanism of oxidation of Potassium iodide by Chlorine and Fluorine gas has been studied using powdered KI, pressed pellets and single crystals (pressed pellets only in the case of Fluorine). The electrical conductivity of a KI pellet has also been determined as a function of temperature. The major part of the experimental work concerns changes in D.C. electrical conductivity during reaction. The main conclusions are as follows: (a) The room temperature conductivity of KI is always higher than that obtained by extrapolating the impurity-range, and the activation energy below about 92° C. is very small; this is tentatively attributed to a space-charge effect. (b) In the KI/CI₂ reaction, the products are invariably KCl and I₂ in various forms (including V-Centres), although poly-halides are thermodynamically more stable. Thus the reduction of Chlorine occurs in a manner which does not allow reorganization to ICI₂-. (c) In pressed pellets, the conductivity always increases at the start of oxidation, but the enhanced conductivity may be ionic or electronic in different circumstances, and the initial increase may be followed by several alternative processes which are structure-sensitive. There is an inverse correlation between initial conductance and reactivity which is interpreted in terms of competition between (i) trapping of positive holes at isolated cation vacancies and (ii) nucleation of solid Iodine at grain boundaries. (d) Unpressed powders show no increase in conductance during reaction; this is attributed to preferential oxidation of bound surface states. / Science, Faculty of / Chemistry, Department of / Graduate

The electrical conductivity of pure KI and CdI₂-doped KI has been studied in the temperature range 200 to 23°C. Two regions A and B (corresponding to different activation energy of conductivity) are identified. The region A can be given a conventional interpretation in terms of migration of cation vacancies in the bulk, their concentration being determined by impurities. U (the energy for migration of cation vacancies) amounts to 0.96 ± 0.02 eV. Observed activation energies higher than this value are accounted for by association and precipitation effects. Association energy of cation vacancies with impurities (0.48 eV. for Cd⁺₂) and heat of solution (0.25 eV. for CdI₂) obtained here are comparable with known values for other alkali halides. Region B found in this work represents unusual behaviour and has not previously been observed in any alkali halides. The activation energy of conductivity is considerably less than the energy needed for the migration of cation vacancies in the bulk. The activation energy E(formula omitted) (for region B) is about 0.57 eV. in a single crystal and 0.38 eV. in a pure KI pellet. Such low activation energies cannot be given a similar interpretation as for region A. It is suggested that the cation vacancies are in regions of unusually high mobility such as dislocations and grain boundaries. This effect may arise partly from a lower activation energy for motion of vacancies in these regions and partly from a vacancy concentration in these regions which increases with decreasing temperature, under the control of "space- charge" effects. The value 0.57 eV. appears to refer to isolated dislocations or low angle boundaries, while the value of 0.38 eV. refers to large angle intercrystalline boundaries in a pellet. A strong piece of evidence for this suggestion comes from the conductivity runs on single crystals. In an untreated single crystal, just as in pure pellets, two regions A and B are identified but region B disappears in crystals annealed overnight and reappears in a mechanically strained crystal. Moreover, region A remains almost undisturbed in each case. This means that the conduction process in region B is governed by dislocations and grain boundaries whereas region A is governed by motion of cation vacancies in the bulk. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

No description available.

Fundamentos: A primeira escolha para o tratamento da esporotricose cutânea é o itraconazol oral, contudo o aumento de casos ocorridos numa epidemia de transmissão zoonótica fez com que se buscassem alternativas efetivas e seguras de tratamento. Objetivo: Avaliar uma nova posologia do iodeto de potássio (KI) como alternativa para o tratamento das formas cutâneas limitadas da esporotricose. Métodos: Foram incluídos 102 pacientes com esporotricose, diagnosticados através do isolamento do Sporothrix sp. e divididos em dois grupos que receberam doses diferentes de KI: grupo A recebeu a dose anterior (média 4,83g/dia) e grupo B, a dose reduzida (média 2,52g/dia). Os critérios de cura se basearam em dados clínicos e sorológicos. Resultados: Setenta e nove pacientes (77,4%) obtiveram cura clínica, 70,6 e 84,3% respectivamente nos grupos A e B. Dezesseis pacientes (15,6%) perderam o seguimento e sete trocaram de medicamento: cinco no grupo A e dois no grupo B. A incidência de eventos adversos foi a mesma nos dois grupos (64,7%) com predomínio do gosto metálico (44%), seguido por intolerância gastrointestinal leve e erupção acneiforme (10,7% cada). Nenhum evento adverso grave ocorreu e não houve recidivas. A análise dos desfechos não demonstrou diferença estatisticamente significativa entre os grupos (p=0,9255). A melhora dos títulos sorológicos foi significativa em ambos grupos. Conclusões: O iodeto de potássio, sob a forma de solução saturada, administrado em dose e frequência reduzidas, pode ser usado como alternativa efetiva e segura para o tratamento da esporotricose cutânea. Através de análises estatísticas, a posologia habitual não demonstrou ser superior à proposta por este estudo. A sorologia para esporotricose pode ser utilizada como ferramenta valiosa para acompanhamento clínico destes pacientes. / Background: The first therapeutic choice for the treatment of cutaneous sporotrichosis is oral itraconazole; however, the increase in cases of zoonotic transmission outbreak necessitates a search for effective and safe treatment alternatives. Objective: To evaluate a new posology using low doses of potassium iodide (KI) for limited cutaneous forms of sporotrichosis. Methods: One hundred and two patients with sporotrichosis diagnosed by isolation of Sporothrix sp. were included and were divided into two groups that received different doses of KI: group A received the previous dose (media 4,83g/day) and group B the reduced dose (media 2,52g/day). The cure criteria was based on clinical and serological data. Results: Seventy-nine patients (77.4 %) reached clinical cure: 70.6% and 84.3 % of groups A and B, respectively. Sixteen patients (15.6 %) were lost to followup and seven changed drug therapy: five in group A and two in group B. The incidence of adverse events was the same for both groups (64.7%): predominantly metallic taste (44 %), followed by mild gastrointestinal intolerance and acneiform eruption (10.7% each). No serious adverse events occurred, and there were no recurrences. Analysis of the results showed no statistically significant difference between groups (p = 0.9255). The improvement in serologic titres was significant in both treatment groups. Conclusion: Potassium iodide, as a saturated solution, prescribed in reduced dose and frequency, can be used as an effective and safe alternative for the treatment of cutaneous sporotrichosis. Through statistical analysis, the usual posology was not shown to be superior to the one proposed in this study. Serology for sporotrichosis may be used as a valuable tool in the clinical monitoring of these patients.

Fundamentos: A primeira escolha para o tratamento da esporotricose cutânea é o itraconazol oral, contudo o aumento de casos ocorridos numa epidemia de transmissão zoonótica fez com que se buscassem alternativas efetivas e seguras de tratamento. Objetivo: Avaliar uma nova posologia do iodeto de potássio (KI) como alternativa para o tratamento das formas cutâneas limitadas da esporotricose. Métodos: Foram incluídos 102 pacientes com esporotricose, diagnosticados através do isolamento do Sporothrix sp. e divididos em dois grupos que receberam doses diferentes de KI: grupo A recebeu a dose anterior (média 4,83g/dia) e grupo B, a dose reduzida (média 2,52g/dia). Os critérios de cura se basearam em dados clínicos e sorológicos. Resultados: Setenta e nove pacientes (77,4%) obtiveram cura clínica, 70,6 e 84,3% respectivamente nos grupos A e B. Dezesseis pacientes (15,6%) perderam o seguimento e sete trocaram de medicamento: cinco no grupo A e dois no grupo B. A incidência de eventos adversos foi a mesma nos dois grupos (64,7%) com predomínio do gosto metálico (44%), seguido por intolerância gastrointestinal leve e erupção acneiforme (10,7% cada). Nenhum evento adverso grave ocorreu e não houve recidivas. A análise dos desfechos não demonstrou diferença estatisticamente significativa entre os grupos (p=0,9255). A melhora dos títulos sorológicos foi significativa em ambos grupos. Conclusões: O iodeto de potássio, sob a forma de solução saturada, administrado em dose e frequência reduzidas, pode ser usado como alternativa efetiva e segura para o tratamento da esporotricose cutânea. Através de análises estatísticas, a posologia habitual não demonstrou ser superior à proposta por este estudo. A sorologia para esporotricose pode ser utilizada como ferramenta valiosa para acompanhamento clínico destes pacientes. / Background: The first therapeutic choice for the treatment of cutaneous sporotrichosis is oral itraconazole; however, the increase in cases of zoonotic transmission outbreak necessitates a search for effective and safe treatment alternatives. Objective: To evaluate a new posology using low doses of potassium iodide (KI) for limited cutaneous forms of sporotrichosis. Methods: One hundred and two patients with sporotrichosis diagnosed by isolation of Sporothrix sp. were included and were divided into two groups that received different doses of KI: group A received the previous dose (media 4,83g/day) and group B the reduced dose (media 2,52g/day). The cure criteria was based on clinical and serological data. Results: Seventy-nine patients (77.4 %) reached clinical cure: 70.6% and 84.3 % of groups A and B, respectively. Sixteen patients (15.6 %) were lost to followup and seven changed drug therapy: five in group A and two in group B. The incidence of adverse events was the same for both groups (64.7%): predominantly metallic taste (44 %), followed by mild gastrointestinal intolerance and acneiform eruption (10.7% each). No serious adverse events occurred, and there were no recurrences. Analysis of the results showed no statistically significant difference between groups (p = 0.9255). The improvement in serologic titres was significant in both treatment groups. Conclusion: Potassium iodide, as a saturated solution, prescribed in reduced dose and frequency, can be used as an effective and safe alternative for the treatment of cutaneous sporotrichosis. Through statistical analysis, the usual posology was not shown to be superior to the one proposed in this study. Serology for sporotrichosis may be used as a valuable tool in the clinical monitoring of these patients.

<p>Chemicals in indoor air, either emitted from a source or from a reaction, have been suggested to cause ill health in buildings. However, no clear correlations between exposure and health effects have been made. </p><p>In this thesis we studied the reaction between monoterpenes, a group of biogenic unsaturated C10 hydrocarbons, and ozone. Ozonolysis of monoterpenes was used as model reactions for unsaturated compounds in ambient air. Also the products formed from these reactions have been suggested as important participants in the occurrence of discomfort and ill health in buildings.</p><p>To enable a reliable and sensitive measurement of ppb-ppt levels of monoterpenes and the formed products in the presence of ozone an evaluation of available scrubber materials was made. Potassium iodide was shown to remove ambient levels of ozone and have a recovery of >95% for all monoterpenes and formed products included in the investigation.</p><p>Experimental conditions showed to have a large impact on the initial steps of the ozonolysis, and also on the composition of the formed products. We showed that water plays an important and complex role both in the initial stage of ozonolysis of ∆³-carene and in the formation and composition of products from the ozonolysis of ∆-pinene. The use of experimental design facilitated the evaluation of the investigated reactions. We showed that the formation of OH radicals could be studied using multiple linear regression models and that the presence or absence of OH radicals had a profound impact on the formation of many of the formed products. We also made an observation of the lack of formed OH radicals in the ozonolysis of limonene and discussed probable causes of this observation.</p><p>Despite the short reaction times and the ambient levels of ozone and monoterpenes used in our experiments we showed that a number of oxidation products were formed, and that the reaction rate is significantly increased in a ventilation system. This formation is underestimated by theoretical calculations and leads to high amounts of known irritants in the indoor air. We showed that theoretical calculations underestimate the formation of these oxidation products 3-13 times, depending on ventilation system and monoterpene. </p>

Chemicals in indoor air, either emitted from a source or from a reaction, have been suggested to cause ill health in buildings. However, no clear correlations between exposure and health effects have been made. In this thesis we studied the reaction between monoterpenes, a group of biogenic unsaturated C10 hydrocarbons, and ozone. Ozonolysis of monoterpenes was used as model reactions for unsaturated compounds in ambient air. Also the products formed from these reactions have been suggested as important participants in the occurrence of discomfort and ill health in buildings. To enable a reliable and sensitive measurement of ppb-ppt levels of monoterpenes and the formed products in the presence of ozone an evaluation of available scrubber materials was made. Potassium iodide was shown to remove ambient levels of ozone and have a recovery of &gt;95% for all monoterpenes and formed products included in the investigation. Experimental conditions showed to have a large impact on the initial steps of the ozonolysis, and also on the composition of the formed products. We showed that water plays an important and complex role both in the initial stage of ozonolysis of ∆3-carene and in the formation and composition of products from the ozonolysis of ∆-pinene. The use of experimental design facilitated the evaluation of the investigated reactions. We showed that the formation of OH radicals could be studied using multiple linear regression models and that the presence or absence of OH radicals had a profound impact on the formation of many of the formed products. We also made an observation of the lack of formed OH radicals in the ozonolysis of limonene and discussed probable causes of this observation. Despite the short reaction times and the ambient levels of ozone and monoterpenes used in our experiments we showed that a number of oxidation products were formed, and that the reaction rate is significantly increased in a ventilation system. This formation is underestimated by theoretical calculations and leads to high amounts of known irritants in the indoor air. We showed that theoretical calculations underestimate the formation of these oxidation products 3-13 times, depending on ventilation system and monoterpene.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-09-20T13:24:55Z No. of bitstreams: 1 2011 - Priscila das merces de sena.pdf: 7709054 bytes, checksum: f76077cb7fca550b09f80cf277852e82 (MD5) / Made available in DSpace on 2016-09-20T13:24:55Z (GMT). No. of bitstreams: 1 2011 - Priscila das merces de sena.pdf: 7709054 bytes, checksum: f76077cb7fca550b09f80cf277852e82 (MD5) Previous issue date: 2011-05-31 / The Spotrhrix schenckii is widely dispersed in nature, especially in temperate and tropical climates. Sporotrichosis is the most common human subcutaneousmycosis in Latin America. In domestic feline, tissues can be found with a abundance of this parasite, fact that it is not usual in other species, so becoming a significantzoonoticagent. The objective in this study was to evaluate the regressiontimeoftheclinical disease, the side effects with Potassium Iodide (KI) administration, in dosis of 10 and 20mg/kg of weight, also evaluation the total T4 hormone concentrations, as well as the possible alterations of hemogram, and renal and hepatic serum biochemistrybyusingthismedication. Were used in this experimentation 14 domestic cats (Felis catusdomesticus), 11 males and three females, with indefinite race, and a mean age of 3.7 years old and average weight of 3.9 kg, with the disease sporotrichosis, all from Rio de Janeiro city. The animal selection was done through the confirmation of the sporotrichosis disease, by collecting material and conducting to mycological culture procedure. The animals were divided into two groups randomly: group I (10 mg of KI/ kg of weight), and group II (20 mg of KI/ kg of weight). Clinical and laboratory evaluations were performed in all cats in the study. Besides the total T4, the following laboratory tests were performed: hemogram, urea, creatinine, alkaline phosphatase, alanine-aminotransferase, gamma-glutamyltransferase, aspartate-aminotransferase. All tests were repeated every 15 days, and clinical evaluation was performed daily. This study concluded after comparison between the two groups that weren?t significant alterations in time regression of disease, as well as in that laboratorial analysis, but there were differences in side effects, so, dosis of 10 mg / kg of weight, once daily was the most right treatment of feline sporotrichosis / O Spotrhrix schenckii, agente etiol?gico da esporotricose,? amplamente disperso na natureza, especialmente em ambientes de climas temperados e tropicais. A esporotricose ? a micose subcut?nea humana mais comum na Am?rica Latina, e o felino tem potencial zoon?tico significativo. O objetivo deste trabalho foi avaliar o tempo de regress?o da doen?a cl?nica e as fun??es hep?tica, renal e tiroideana, com uso do iodeto de pot?ssio (IK) nas doses de 10 ou 20 mg/kg de peso, para tratamento da micose. Foram utilizados 14 felinos dom?sticos (Felis catus domesticus), sendo 11 machos e tr?s f?meas, ra?a indefinida, com idade m?dia de 3,7 anos e peso m?dio 3,9 kg, portadores da doen?a e provenientes do Munic?pio do Rio de Janeiro. A sele??o dos animais foi realizada atrav?s da confirma??o da doen?a, por meio da coleta de material e realiza??o de cultura micol?gica. Os animais foram divididos em dois grupos, de forma aleat?ria: grupo I (dose de 10 mg de IK/kg de peso) e grupo II (dose de 20 mg de IK/kg de peso), com m?dia do tempo de tratamento de 63 dias. Avalia??o cl?nica e laboratorial foi realizada em todos os gatos do estudo. Al?m do T4 total, os seguintes exames laboratoriais foram realizados: hemograma, ur?ia, creatinina, fosfatase alcalina, alanina-aminotransferase, gama-glutamiltransferase, aspartato-aminotransferase. Todos os exames foram repetidos a cada 15 dias, do in?cio ao final dotratamento e avalia??o cl?nica foi realizada diariamente. Este estudo concluiu, comparando-se os dois grupos, que n?o houve diferen?a estatisticamente significativa no tempo de regress?o da doen?a, mas houve diferen?as nos efeitos colaterais. Os animais do grupo I que apresentaram v?mitos e diarr?ia foram em n?mero de dois e os animais do grupo II apresentaram efeits colaterais cmo v?mitos, diarr?ia, prostra??o, anorexia, desidrata??o, febre, saliva??o, pelagem seca.Sendo a dose de 10 mg/kg, uma vez ao dia, a mais adequada para o tratamento de esporotircose felina, pois n?o provocou altera??es cl?nicas, laboratoriais e hormonais significativas