No description available.

In the preparation of tannin extract from chestnut wood chips there is present in the extract, along with the tannin, certain insoluble non-tannin constituents. If allowed to remain in the extract, these materials make the tanning solution unsuitable for use in the manufacture of leather. To accomplish the separation of the non-tannin constituents from the tannin, the Lead Corporation of Lynchburg, Virginia, now employs a process of concentration and mechanical settling. For the past twenty years the company has been engaged in research to develop a better process. The investigations have been concentrated mainly on the idea of varied forms of mechanical separation. So far no solution to the problem has been found, thereby giving rise to the opinion that perhaps mechanical separation is the wrong approach to the problem. In a preliminary study of this problem 6), research work has been done at V.P.I. using several new approaches, the most important of these being electrophoresis and adsorption. Of these two procedures, adsorption save indications of having the greater potentialities. The following thesis will deal with additional research work using coals of varying grades as an adsorbing medium. The American Viscose Company of Roanoke, Virginia has installed units for clarifying the spinning bath solutions. The units incorporate coal as an adsorbing medium. The process is extremely successful and therefore strengthens the belief that it may be applicable to the clarification of tannin extract solutions. Adsorption methods are often applied industrially to remove impurities, especially if they are present in low concentrations. Small amounts of impurities often interfere with processes such as crystallization, filtration, and distillation, but by the application of adsorption the impurities may be separated and the fault corrected. Often times adsorbents are used to recover valuable constituents, which otherwise would be lost completely or require for more costly processing. Separation by adsorption is made possible because of the fact that different materials differ in the degree to which they are adsorbed by a given adsorbent. The object of the research work is to investigate the possibility of developing an economically feasible process, based on adsorption, using coal as the adsorbent, for the separation of the insoluble non-tannin constituents present in a fresh tannin extract. / Master of Science

Ph.D. thesis is focused on the study of ecology and interactions among fungal disease horse chestnut leaf blotch, Guignardia aesculi, invasive pest horse chestnut leaf miner, Cameraria ohridella, and predatory mites of family Phytoseiidae. Ph.D. thesis consists of two main parts: 1) a detailed background research, and 2) six separate original published papers or manuscripts describing results of my own studies. The first study investigated spatial distribution of the first generation of C. ohridella in the urban environment in relation to the pest, the mortality of overwintering pupae at the end of vegetation season and the number of hatched C. ohridella and its parasitoids at the beginning of the following vegetation season. The second paper describes the interaction between C. ohridella and G. aesculi during vegetation season. The third and fourth papers deal with the effect of specific microctimatic conditions in site on the damage inflicted to horse chestnut leaves by G. aesculi. In addition, spatial distribution of G. aesculi in urban environment was studied. The fifth paper compared the species composition and the population density of Phytoseiidae between the Czech Republic and Greece. The sixth study described the species composition, abundance, population dynamics and sex ratio of phytoseiid mites inhabiting horse chestnut. The study also investigated, whether the abundance of predatory mites on horse chestnut leaves can be influenced by leaf damage caused by the horse chestnut leaf miner or G. aesculi during vegetation season.

No description available.

No description available.

Apesar da perda econômica, representada pela contaminação por fungos toxigênicos em castanhas-do-Brasil, um importante produto extrativista da região Norte do Brasil, estudos realizados ainda são incipientes quanto ao controle da contaminação por fungos aflatoxigênicos utilizando métodos como radiação gama (R.G) e, sobretudo, feixe de elétrons (F.E). Esses fatos motivaram a presente pesquisa teve como objetivo avaliar os efeitos da radiação gama e da aplicação de feixe de elétrons em amostras de castanha-do-Brasil inoculadas artificialmente com Aspergillus flavus. Para atingir tal objetivo, foram estudadas 50 amostras de castanha-do-Brasil, previamente, inoculadas com suspensão de esporos de A. flavus e, posteriormente, incubadas a 30 ºC em ambiente com umidade relativa controlada a 93 %. Após 15 dias de incubação, as amostras foram divididas em 5 grupos que receberam as seguintes doses de radiação: controle (0 kGy), 5 e 10 kGy F.E, 5 e 10 kGy R.G. A micobiota foi realizada através de diluição seriada, com semeadura em superfície utilizando ágar batata. Os resultados demonstraram que o tratamento com F.E utilizando a dose de 5 kGy e 10 kGy resultou na redução de crescimento de A. flavus em 74% (37/50) e 94% (47/50) das amostras. Quanto às amostras tratadas com R.G na dose de 5 kGy e 10 kGy não ocorreu crescimento fúngico em 92% (46/50) e 100% (50/50) delas. A pesquisa de aflatoxinas mostrou que doses de F.E de 5 kGy e 10 k Gy reduziram os níveis de AFB1 em 53,32% e 65,66%, respectivamente. Por sua vez, a aplicação de raios gama nas doses de 5 e 10 kGy reduziu os níveis das toxinas em 70,61% e 84,15 % respectivamente. Tal resultado pode ser atribuído a maior penetrabilidade da radiação gama. Análise sensorial demonstrou maior aceitação das amostras irradiadas com F.E e R.G na dose de 10 kGy. Concluímos que, apesar de a análise sensorial ter demonstrado perda de algumas características organolépticas, ambos os processos de radiação foram eficazes na redução da contagem de A. flavus e dos níveis de aflatoxinas. / Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded that although sensory analysis have demonstrated some loss of organoleptic characteristics, both processes of radiation were effective in reducing the count of A. flavus and aflatoxin contamination.

A castanha-do-brasil é uma planta de grande importância econômica na região da Amazônia. Os baixos níveis tecnológicos característicos de sua cadeia produtiva e as condições inadequadas de manejo da matéria prima, favorecem o aparecimento de contaminação por fungos produtores de micotoxinas. A fumonisinas B2 (FB2) é uma micotoxina produzida por espécies de Fusarium e Aspergillus section Nigri, e é motivo de preocupação para a saúde humana e de animais. O objetivo do presente trabalho foi verificar o potêncial toxigênico quanto à produção de fumonisina B2 das cepas de A. section Nigri isolados de castanha-do-brasil e verificar a contaminação desse alimento por essa micotoxina. De um total de 200 cepas de A. section Nigri testadas quanto à capacidade de produção de fumonisina B2, apenas 39 cepas (19,5 %) produziram FB2, cento e trinta e oito (69 %) não foram produtoras de fumonisina B2 e 23 cepas (11,5 %) apresentaram picos menores que o limite de detecção. Das 100 amostras de castanha-do-brasil analisadas, nenhuma estava contaminada por fumonisina B2. / Brazil nut is a plant with vast economic importance in the Amazon region and is an important product exported by Brazil. However, low levels of technology, and inadequate management of raw material favor the appearance of contamination by fungi that produce toxic metabolites called mycotoxins. Fumonisin B2 (FB2) is a mycotoxin produced by Fusarium species and Aspergillus section Nigri, and is of concern for human health. The aim of this study was to assess the toxigenic potential for fumonisin B2 production by Aspergillus section Nigri strain isolated from brazil nut and check the contamination of food by this mycotoxin. From a total of 200 strains of Aspergillus section Nigri tested for the ability to produce fumonisin B2, only 39 strains (19.5 %) were producing FB2, 138 (69 %) were not producing fumonisin B2, and 23 strains (11.5 %) showed peaks less than the detection limit. Of the 100 samples of brazil nuts analyzed, none were contaminated with fumonisin B2.

O Brasil é o país que possui o maior rebanho bovino comercial do mundo, e o balanço de exportações de couro vem demonstrando ascensão no número de metros quadrados de couros exportados. No processo produtivo, a etapa de curtimento é de extrema importância para transformar a pele bovina em couros, tornando-a resistente ao ataque de microorganismos, além de conferir enchimento e garantir maior estabilidade hidrotérmica do material. O crescente apelo ambiental pela utilização de materiais renováveis na indústria levou aos taninos vegetais desempenharem papéis importantes como compostos curtentes na indústria coureira. Os taninos são estruturas fenólicas complexas, existindo uma quantidade considerável de parâmetros químicos que podem ser mensurados através de diversas técnicas analíticas. Por outro lado, para os couros, também existem ensaios empregados no produto final, cujo desempenho pode depender do material curtente utilizado. No presente estudo, foram empregados cinco tipos de taninos de maior uso na indústria coureira para avaliação de parâmetros químicos e posterior associação com propriedades nos couros: tanino de acácia, quebracho, castanheiro, mirabolano e tara. Inicialmente, foi realizada uma revisão bibliográfica, a fim de determinar propriedades químicas de maior relevância a serem mensuradas nos taninos no contexto de sua utilização como agentes curtentes. Nesse sentido, elencaram-se os ensaios de determinação de tanantes totais, não-tanantes, sólidos insolúveis, sólidos solúveis, sólidos totais, fenóis totais e massa molecular média para os taninos. Os parâmetros de percentual de sólidos insolúveis, sólidos solúveis não-tanantes e tanantes totais distinguiram bem os grupos de taninos que atravessaram dos que não atravessaram o couro. Assim, pela análise de insolúveis ser a mais simples e direta delas, recomendar-se-ia o seu uso para definir uma faixa de corte para distinguir o desempenho dos taninos no curtimento. A análise de FTIR-UATR foi útil na caracterização e distinção dos taninos nas famílias dos hidrolisáveis e condensados. Os ensaios de temperatura de retração e distensão da flor nos couros também mostraram associação com o atravessamento dos taninos nas peles durante o curtimento. Por fim, a diferença total de cor após exposição à luz UV também foi avaliada para os couros curtidos com os taninos vegetais, sendo que os taninos hidrolisáveis apresentaram uma menor diferença de cor em relação aos condensados. / Brazil is the country with the largest commercial cattle herd in the world, and the balance of exports of leather has shown a rise in the number of square meters of exported leather. In the production process, the tanning step is extremely important to transform the skin into leather, making it resistant to the attack by microorganisms, as well as providing filling and assuring greater hydrothermal stability of the material. The increasing environmental approach for the use of renewable materials in the industry has led to vegetable tannins an important role as tanning compounds in the leather industry. Tannins are complex phenolic structures and there are a considerable amount of chemical parameters that can be measured through various analytical techniques to characterize them. On the other hand, for hides, there are also tests used in the final product, whose performance may depend on the tanning material used. In the present study, five types of tannins highly used in the tanning industry were used for the evaluation of their chemical parameters and later correlation with properties in hides: Black Wattle (Acacia mearnsii), Quebracho (Schinopsis lorentzii), Chestnut (Castanea sativa), Tara (Caesalpinia spinosa) and myrabolan (Terminalia chebula). Initially, a bibliographical review was carried out to determine the most relevant chemical properties to be measured in the tannins in the context of their use as tanning agents. In this context, the assays for the determination of total tannin polyphenols, non-tannin polyphenols, insoluble solids, soluble solids, total solids, total phenols and average molecular weight for tannins were performed. FTIR-UATR analysis was useful in characterizing and distinguishing tannins in their families of hydrolysates and condensates. The Mann-Whitney-U test showed that the insoluble solids, non-tannin polyphenols, soluble solids and total tannin polyphenols percentage distinguished well the groups of tannins that crossed the hide from those that didn´t. Hence, once the analysis of insoluble solids is the simplest and the most direct of them, it would be recommended to use this parameter to define a cutting range to distinguish the performance of tannins in leather tanning. The shrinkage temperature and distension tests in the leather also showed association with the leather cross-sectional results during tanning baths. Finally, the total color difference after exposure to UV light was also evaluated for the tanned hides with the vegetable tannins, and the hydrolysable tannins presented a smaller color difference or greater light fastness in comparison to the condensates.

Apesar da perda econômica, representada pela contaminação por fungos toxigênicos em castanhas-do-Brasil, um importante produto extrativista da região Norte do Brasil, estudos realizados ainda são incipientes quanto ao controle da contaminação por fungos aflatoxigênicos utilizando métodos como radiação gama (R.G) e, sobretudo, feixe de elétrons (F.E). Esses fatos motivaram a presente pesquisa teve como objetivo avaliar os efeitos da radiação gama e da aplicação de feixe de elétrons em amostras de castanha-do-Brasil inoculadas artificialmente com Aspergillus flavus. Para atingir tal objetivo, foram estudadas 50 amostras de castanha-do-Brasil, previamente, inoculadas com suspensão de esporos de A. flavus e, posteriormente, incubadas a 30 ºC em ambiente com umidade relativa controlada a 93 %. Após 15 dias de incubação, as amostras foram divididas em 5 grupos que receberam as seguintes doses de radiação: controle (0 kGy), 5 e 10 kGy F.E, 5 e 10 kGy R.G. A micobiota foi realizada através de diluição seriada, com semeadura em superfície utilizando ágar batata. Os resultados demonstraram que o tratamento com F.E utilizando a dose de 5 kGy e 10 kGy resultou na redução de crescimento de A. flavus em 74% (37/50) e 94% (47/50) das amostras. Quanto às amostras tratadas com R.G na dose de 5 kGy e 10 kGy não ocorreu crescimento fúngico em 92% (46/50) e 100% (50/50) delas. A pesquisa de aflatoxinas mostrou que doses de F.E de 5 kGy e 10 k Gy reduziram os níveis de AFB1 em 53,32% e 65,66%, respectivamente. Por sua vez, a aplicação de raios gama nas doses de 5 e 10 kGy reduziu os níveis das toxinas em 70,61% e 84,15 % respectivamente. Tal resultado pode ser atribuído a maior penetrabilidade da radiação gama. Análise sensorial demonstrou maior aceitação das amostras irradiadas com F.E e R.G na dose de 10 kGy. Concluímos que, apesar de a análise sensorial ter demonstrado perda de algumas características organolépticas, ambos os processos de radiação foram eficazes na redução da contagem de A. flavus e dos níveis de aflatoxinas. / Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded that although sensory analysis have demonstrated some loss of organoleptic characteristics, both processes of radiation were effective in reducing the count of A. flavus and aflatoxin contamination.

I investigated the effect of energy sector development and introduced crested wheatgrass (Agropyron cristatum) on grassland birds on Canadian Forces Base Suffield. I conducted point counts and mapped breeding territories in 2007 and 2008 for Savannah sparrows (Passerculus sandwichensis), chestnut-collared longspurs (Calcarius ornatus), and Spragues pipits (Anthus spragueii). I found that Savannah sparrows favored areas with taller vegetation, human disturbances and crested wheatgrass in both years. Longspurs used shorter vegetation and in were tolerant of disturbance. Crested wheatgrass was avoided by longspurs in both years. Pipit territories contained similar vegetation to longspurs, were sensitive to disturbance, and avoided placing territories in areas containing crested wheatgrass or trails in both years. Well sites, pipelines and junctions were not avoided by the three species. My research suggests that reducing the number of trails and the spread of crested wheatgrass will increase habitat availability for sensitive species of grassland birds. / Ecology