Made available in DSpace on 2015-04-14T14:27:13Z (GMT). No. of bitstreams: 1 392448.pdf: 1735159 bytes, checksum: 6361b502e56519ea6ae6f017aedda7ba (MD5) Previous issue date: 2007-05-17 / Esta disserta??o procura discutir a relev?ncia dos fundos de pens?o para o desenvolvimento econ?mico e social, concentrando-se nas restri??es as aloca??es dos recursos dessas entidades em projetos com preocupa??es socioambientais. Portanto, ? realizada uma revis?o da literatura econ?mica sobre os fundos de pens?o e discutida a sua rela??o com o crescimento e o desenvolvimento econ?micos. A partir de uma revis?o conceitual e hist?rica, utiliza-se a estrat?gia de pesquisa de estudo de caso, tendo como amostra do sistema de previd?ncia complementar os tr?s maiores fundos de pens?o do Brasil (Previ, Petros, Funcef), para, dentro do contexto real dessas entidades, analisar as suas pol?ticas de investimentos. A quase-totalidade dos investimentos dos fundos de pens?o est?o alocados nos segmentos de renda fixa e de renda vari?vel, sendo o mercado financeiro e o de capital os principais destinos dos ativos sob a gest?o das entidades, evidenciando as varia??es nas taxas de juros, nos pre?os das a??es e em outros ?ndices como os principais fatores de risco das opera??es de remunera??o dos recursos. As aloca??es de recursos em projetos com preocupa??es socioambientais possuem restri??es dos fundos de pens?o, que s?o: a l?gica do curto prazo conjugada aos juros altos, a regulamenta??o dos fundos de pens?o e a ?tica utilizada nas finan?as. Os dados apresentados pelos tr?s maiores fundos de pens?o brasileiros mostram uma pequena participa??o da carteira de aplica??es dessas entidades em projetos com preocupa??es socioambientais, mas as pol?ticas de investimentos tra?adas para o futuro apontam um aumento gradual e irrevers?vel de investimentos socialmente respons?veis. Os fundos de pens?o come?am a orientar as empresas nas quais participam a observarem um crescimento sustentado e uma postura socialmente respons?vel.

Made available in DSpace on 2015-12-03T18:35:01Z (GMT). No. of bitstreams: 1 Maria_Rosangela_da_Silva.pdf: 550901 bytes, checksum: 63eddfad275ad5beddca660f634f6b3e (MD5) Previous issue date: 2009-04-01 / The fundamental set of problems reviewed in this research resides in the fact that the accommodation sector demonstrates a lack about the management information to make available decisions by their managers. The research importance is to enhance since it's not possible to know at what point the accountants are acting attending to this demand, and how they have presented the necessary information to the hotel managers. Thus, the main purpose of this study is to identify the types of services required from the accounting offices by the hotels and bread-and-breakfast (B & B's) in Campos do Jord??o; another aim of the research is to identify the needs in term of information required by the hotels and B&B's managers related to the accountancy, that could be attended by the offices which supply services to them. Having how predominant methodological element the application of a questionnaire, the research performed is of an empirical theoretical nature and it was used a quantitative approach on an exploratory type. The interest population of the present study covers the hotels and B & B's located at the city of Campos do Jord??o, S??o Paulo state. The sampling wasn't probabilistic and to convenience based. Related to the results of the research, it was revealed that the services required by the managers are the ones related to fiscal nature information. It was identified that there is "space" to develop accounting services in the city object of study and if the accountants assume a posture of pro-activity there could be an adequacy of the accountant services on what the most recent literature indicates how the accountant future, what is, the consultant role. / A problem??tica desta pesquisa reside no fato de que o setor de hospedagem carece de informa????es gerenciais para tomada de decis??es por parte de seus gestores. A import??ncia da pesquisa ?? real??ada visto que n??o se sabe at?? que ponto os contadores est??o atuando em atendimento a esta demanda, e como t??m apresentado as informa????es necess??rias para os gestores hoteleiros. Desta forma, o objetivo principal deste estudo ?? identificar os tipos de servi??os requeridos dos escrit??rios de contabilidade pelos hot??is e pousadas de Campos do Jord??o; a pesquisa tamb??m tem o prop??sito de identificar as necessidades informativas que esses gestores de hot??is e pousadas t??m, relativamente ?? contabilidade, as quais poderiam ser atendidas pelos escrit??rios que lhes prestam servi??os. Tendo como elementos metodol??gicos predominantes a aplica????o de um question??rio, a pesquisa realizada ?? de natureza emp??rico-te??rica e utilizou-se uma abordagem quantitativa do tipo explorat??ria. A popula????o de interesse para o presente estudo compreende os hot??is e pousadas localizados na cidade de Campos do Jord??o, no estado de S??o Paulo. A amostragem foi n??o probabil??stica e por conveni??ncia. No que diz respeito aos resultados da pesquisa, ficou revelado que os servi??os requeridos pelos gestores s??o aqueles relacionados ?? informa????o de natureza fiscal. Foi identificado que h?? "espa??o" para o desenvolvimento de servi??os cont??beis na cidade estudada e que se houver uma postura de pr??-atividade dos contadores haveria a adequa????o dos servi??os cont??beis ao que a literatura mais recente indica como o futuro do contador, qual seja, o papel de consultor

Made available in DSpace on 2015-12-03T18:35:29Z (GMT). No. of bitstreams: 1 Marcos_de_Mello_Liberato.pdf: 734486 bytes, checksum: cf5e35324052e71d3641a4810970e357 (MD5) Previous issue date: 2013-10-15 / Pension Funds in Brazil are presented as large institutional investors, moving a significant sum of money in the financial market. Investment decisions made by its managers should generate positive returns in order to ensure a dignified retirement to its participants and beneficiaries. The corporate governance structure of pension funds and their mechanisms are essential elements in the management of these entities, and the consequent impact exerted on their performance. The objective of this research is to study the relationship between structure and corporate governance mechanisms and performance of pension funds in Brazil. This is an empirical study, with quantitative treatment of the data by use of linear regression with panel data. The period of analysis included the years 2008 to 2012. The results were favorable to the affirmative conclusion regarding the existence of an associative relationship between corporate governance mechanisms and their performance / As Entidades Fechadas de Previd??ncia Complementar no Brasil, conhecidas como fundos de pens??o, apresentam-se como grandes investidores institucionais, movimentando uma significativa soma de dinheiro no mercado financeiro. As decis??es de investimento tomadas por seus gestores devem gerar retornos positivos, de forma a garantir uma aposentadoria digna a seus participantes e benefici??rios. A estrutura de governan??a corporativa dos fundos de pens??o, e seus mecanismos, constituem elementos fundamentais na gest??o dessas institui????es, e no consequente impacto exercido sobre seu desempenho. O objetivo desta pesquisa ?? analisar a rela????o entre a estrutura e os mecanismos de governan??a corporativa e o desempenho dos fundos de pens??o no Brasil. Este ?? um estudo emp??rico anal??tico, com tratamento quantitativo dos dados, pelo uso da t??cnica de regress??o linear com dados em painel, cujo per??odo de an??lise compreendeu os anos de 2008 a 2012. Os resultados obtidos foram favor??veis ?? conclus??o afirmativa a respeito da exist??ncia de uma rela????o associativa entre os mecanismos de governan??a corporativa e o desempenho dessas entidades

Made available in DSpace on 2015-12-04T11:45:14Z (GMT). No. of bitstreams: 1 Wanderlei_Bamman_de_Carvalho.pdf: 491243 bytes, checksum: 0bbaceae980d0478b0359948e5a27adf (MD5) Previous issue date: 2004-03-04 / This study intends to present a model of managerial support, either assisting investors either the administrators of the Condo-hotels sector, proposing the improvement and the adaptation of the SUCH - System Uniform of Accounting for Hotels, to the Condo-hotels sector. The importance of the Condo-hotels sector for the Brazilian economy was delineated by this study, as well as its accelerated growth in the course of these last years. It must be detached the competitive factors of the sector, in a better way to make possible the enterprise, intending to contribute to the professionals of the area. The reasons are the proper peculiarities of the Condo-hotels sector, such as the Pool in its composition, inhabitants - owners, amongst innumerable others, that becomes each enterprise differentiated in relation its pairs, and it will be object of analysis. / Este estudo busca apresentar um modelo de suporte gerencial, seja no auxilio aos investidores, seja no aux??lio aos administradores do setor flateleiro, propondo o aperfei??oamento e a adapta????o do SUCH - Sistema Uniforme de Contabilidade para Hot??is, ao setor flateleiro. Delineou-se com esse estudo a import??ncia do setor flateleiro para a economia brasileira, bem como o seu crescimento acelerado no decorrer desses ??ltimos anos. Importa destacar tamb??m os fatores concorrenciais do setor, na busca de melhor viabilizar o empreendimento e com o intuito de contribuir com os profissionais da ??rea. Isso porque, o setor flateleiro possui peculiaridades t??o pr??prias, tais como o Pool em sua forma????o, moradores - propriet??rios, dentre in??meras outras, que torna cada empreendimento diferenciado em rela????o aos seus pares, tal como ser?? objeto de an??lise.

Made available in DSpace on 2015-12-04T11:45:37Z (GMT). No. of bitstreams: 1 Solange_Maria_da_Silva.pdf: 1098938 bytes, checksum: f4ddb860dac06301aaa61abc1950f791 (MD5) Previous issue date: 2005-06-27 / This study has as a purpose to contribute with the disclosure aspects in the lodging segment with a proposal of rendering of accounts for the investors. The study was based on the premise that the accounting information that adequately evidences the patrimonial situation, in a standardized way, allows the comparability among the means of accommodation, be them hotels, flats or similars, and contributes to a bigger transparency and improvement in the process of taking decisions by the investors. Starting from this, a bibliographic survey of relevant aspects of the accounting disclosure and a field research were carried out having as an objective to identify the reports and accounting needs of the asset management companies for the rendering of accounts to the investors, and to propose a sample in accordance with what is established in the Uniform System of Accounts for the Lodging Industry. The methodology adopted was data-collection, through a questionnaire to the companies of asset management located in Sao Paulo contracted to represent the investors in hotel industry properties. The results of the survey has demonstrated a gap between the reports that the companies of asset management receive from the hotel management companies to be sent to the investors and the minimum information disciplined in the Uniform System and required for a good practice of disclosure, proclaimed by national and international norm trends, a space filled by the object of the present work. A sample of rendering of accounts was formulated which contemplates Balance Sheet, Statement of Income, Statement of Cash Flow, Statement of Added Value, Budget and Explanation Notes, the minimum instruments necessary to enable the investors to take a quality decision. / Esse estudo tem por finalidade contribuir com os aspectos de evidencia????o nos meios de hospedagem com uma proposta de presta????o de contas para os investidores. O estudo baseou-se na premissa de que as informa????es cont??beis que evidenciam adequadamente a situa????o patrimonial, de forma padronizada permitem a comparabilidade entre os meios de hospedagem, sejam eles hot??is, flats ou similares, e contribuem para maior transpar??ncia e melhoria no processo de tomada de decis??o pelos investidores. A partir disso, realizou-se um levantamento bibliogr??fico dos aspectos relevantes da evidencia????o cont??bil, e pesquisa de campo com o objetivo de identificar as necessidades de relat??rios e informa????es cont??beis das empresas de asset management para presta????o de contas aos investidores, e propor um modelo, de acordo com o estabelecido no Uniform System of Accounts for the Lodging Industry. A metodologia adotada valeu-se de levantamento de dados por question??rio junto ??s empresas de asset management situadas em S??o Paulo, contratadas para representar os investidores de im??veis com base hoteleira. Os resultados da pesquisa demonstraram a exist??ncia de uma lacuna entre os relat??rios que as empresas de asset management recebem das administradoras hoteleiras para envio aos investidores e as informa????es m??nimas disciplinadas no Uniform System, e requeridas por uma boa pr??tica de evidencia????o, apregoada pelas tend??ncias de normas nacionais e internacionais; omiss??o essa preenchida pelo objeto do presente trabalho. Formulou-se um modelo de presta????o de contas que contempla: Balan??o Patrimonial, Demonstra????o de Resultados do Exerc??cio, Demonstra????o de Fluxo de Caixa, Demonstra????o do Valor Adicionado, Proje????es de Resultado e Notas Explicativas, instrumentos m??nimos necess??rios para munir os investidores para uma decis??o de qualidade.

When care is moved from the hospital to the home the demands for high quality care still remain. For problems arising from the geographical separation of patients and professional caregivers, information and communication technology may offer important solutions. The overall aim of this thesis was to describe relevant requirements, to design and implement an IT-based system, and finally to evaluate the system’s influence on symptom control and support for both patients/next-of-kin and professional caregivers in advanced home healthcare. Of importance were needs in basic as well as advanced home healthcare, as were usability perspectives of both patients and professional caregivers. Requirement areas such as security, mobility, and responsibility, which should be considered when monitoring patients in the home, were identified. A prototype system for everyday assistance for diabetes patients was designed, and a system for frequent pain assessment for palliative home healthcare patients using a pain diary, digital pen and mobile Internet technology, was developed and evaluated through a qualitative content analysis approach. Twelve palliative cancer patients and six professional caregivers participated. The data collected included an ease-of-use questionnaire, and interviews with patients, spouses and professional caregivers. Patients expressed increased and improved contact with the caregivers, increased participation in their own care, a sense of increased security, and easiness in using the equipment in spite of severe illness and difficulties in comprehending the technology and system intervention. The professional caregivers showed a shifting outlook towards the pain assessment method; an initial cautious outlook due to low expectations of the patients’ abilities to use the pain assessment method and the caregivers’ own reluctance to use the system and change their way-of-working. Despite this, the professional caregivers experienced positive outcomes in terms of an increased awareness of pain, and positive patient influences including increased participation in their care, increased security and improved changes in pain treatment as a response to reported pain assessments. In conclusion, the networked digital pen system provided an effortless method for pain assessment and had positive influences on the care. The results imply that digital pen technology is suitable for the assessment of symptoms by palliative patients since these patients often have a limited capacity to handle technology due to their state of health. / On the day of the public defence date of the doctoral thesis the status of article III and IV was Submitted.

Listeria monocytogenes (L. monocytogenes) est un pathogène majeur en santé publique comme les épisodes de 2008 dans les fromages et les charcuteries l’ont démontré. Au Canada, il n’y a pas de surveillance règlementaire de ce microorganisme dans les étapes précédant la transformation de produits prêts-à-manger. Ainsi, la présence et la circulation de ce microorganisme dans ces environnements est peu documentée. Pour décrire ces phénomènes, nous avons effectué un échantillonnage dans une usine d’abattage et de découpe de porcs au Québec, principalement dans les parcs d’attente, et dans l’environnement de l’abattage et de découpe : les échantillonages ont été effectués après lavage et désinfection sur une période de 2 ans. Un nombre de 874 échantillons a été récoltés. Le protocole de détection utilisé était inspiré de la méthode MFHPB-30 de Santé Canada. Les sérotypes ont été obtenus par PCR et les isolats caractérisés par un génotypage RFLP-PFGE en utilisant les enzymes de restriction Apa1 et Asc1. Nous avons détecté la présence de Listeria monocytogemes dans toutes ces étapes de la production. De ces échantillons positifs, 4 sérotypes (principalement 1/2b) ont émergé. Les patrons PFGE ont démontré la présence d’une variété de génotypes dans les zones d’attente et d’abattage de l’usine et la présence d’un type majeur dans l’environnement de la zone de découpe (le type 1 représentant 96.1% des souches à cette étape). De plus, nous avons démontré des liens entre les souches retrouvés au début de la production, en attente, et les souches retrouvées dans la zone de découpe. Ces résultats suggèrent que Listeria monocytogenes entre dans l’usine avec les animaux, contamine les étapes suivantes de la production et que certaines souches peuvent être sélectionnées et leur croissance favorisé dans l’environnement, devenant majoritaires, persistantes et préoccupantes en regars de la santé publique. / Listeria monocytogenes (L. monocytogenes) is a major public health concern as it was illustrated by the 2008 episodes in cheese and ready-to-eat meat. In Canada, there is currently no surveillance policy of this microorganism in the production steps preceding transformation of ready-to-eat products. The presence and the circulation of this microorganism in these environments is not well documented either. To describe these parameters, we sampled a Quebec slaughtering and cutting plant in the lairage pens and on representative areas of the slaughter process and cutting rooms after washing and disinfection, during a two-year period. A total of 874 samples were collected. Listeria detection followed the MFHPB-30 Health Canada standard method, serotype confirmation was obtained by PCR and isolates were characterized by Apa1 and Asc1 RFLP-PFGE genotyping. We reported detection of Listeria monocytogenes in all stages of production. Among the positive samples, 4 different serovars (mainly 1/2b) emerged. PFGE patterns showed presence of a variety of different genotypes in the lairage and slaughtering areas of the plant and the presence of a major type in the environment of the cutting room (type 1 representing 96.1% of the strains at this step). Furthermore, strains found at the lairage pens were related to strains in the cutting room. These results suggest that Listeria monocytogenes can enter the plant with the animals, contaminate further production steps and that some strains can be selected and their growth promoted in the environment. Hence, becoming predominant, persistant and a food safety issue.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective, of this study, was evaluated, different individual spaces for steers feedlot finished in group pens and yours effects on patterns behavioral and performance. Forty eight steers, with average initial of twenty months and 243.4 kg, were used. Animals were feedlot, four for pen, allocated in treatments accorded the individual space, 2.5, 5.0 and 10 m2, with four pens for treatment. The animals were feedlot until reaching estimated cold carcass weight of 220 kg. The diet, with 115 g of crude protein and 705 g of total digestible nutrient by kg of diet in dry matter (DM), contained roughage: concentrate relation of 39:61 (DM basis). The complete randomized block experimental design was used. The dry matter intake, with intakes of 8.21; 8.29 and 8.41 kg, for steers with individual spaces of 2.5; 5.0 and 10 m2, respectively, as well the average daily gain was simulated between the different spaces, with means of 1.32; 1.41 and 1.47 kg, in the same order. The steers feed efficiency was not influenced by space allowance. The individual space not influenced the time spent to feeding, idle and rumination, which showed mean of 244.1; 790.3 and 405.6 minutes/day, respectively. Likewise, the number of times that animals showed each of the behaviours, as well the changes in posture during idle and rumination were similar between the different spaces evaluated. The total time that the animals remained standing or lying was not influenced by individual space, with average duration of 610.0 and 830.0 minutes/day, respectively, and the realization of activities in synchronism, not difference between the different spaces, the average time that the animals fed, standing or lay down in synchrony was 85.8, 308.0 and 468.4 minutes/ day, in the same order. The total number of disputes, with 21.9, 21.5 and 19.7 events between animals kept in spaces, 2.5, 5.0 and 10 m2, in the same order, and the number of non-agonistic interaction was not influenced by individual space available. Confined steers with 5.0 and 10 m2, extended their members 8.8 and 9.7 times per day, respectively, superior to animals maintained on individual spaces of 2.5 m2, this behavior made 4.3 times per day. The cleanliness differed between the spaces, with values of 3.2, 2.4 and 1.1 for steers with individual spaces of 2.5, 5.0 and 10 m2 respectively, as well as respiratory rate, with 27.1, 24.8 and 22.7 breaths / minute, in the same order. The hot and cold carcass weight, 226.0 and 222.0, respectively, and hot and cold carcass dressing, 58.5 and 57.0 kg/ 100 kg by live weight, in the same order, were not influenced by individual space. For all spaces evaluated, the carcass required minimum fat thickness, 3 mm. The weights and percentage of commercial cuts, also the weight and participation tissues in carcass were similar between different spaces. Color, texture, marbling, sensorial characteristics and shear force, were not influenced by individual space. / Objetivou-se, com este estudo, avaliar a disponibilidade de diferentes espaços individuais para novilhos confinados coletivamente em fase de terminação e seus reflexos sobre parâmetros comportamentais e produtivos. Foram utilizados 48 novilhos, com idade e pesos médios iniciais de 20 meses e 243,4 kg, respectivamente. Os animais foram mantidos em baias coletivas, com quatro animais cada, distribuídos nos tratamentos conforme o espaço individual disponível, 2,5; 5,0 ou 10 m2, sendo utilizadas quatro baias por tratamento. Os novilhos permaneceram confinados até atingir, por estimativa, peso de carcaça fria de 220 kg. A dieta, com 115 g de proteína bruta e 705 g de nutrientes digestíveis totais por kg de matéria seca (MS) da dieta, a qual continha relação volumoso concentrado de 39: 61 (base na MS). O delineamento experimental utilizado foi blocos ao acaso. O consumo diário de matéria seca, com ingestões de 8,21; 8,29 e 8,41 kg, para novilhos mantidos com espaços individuais de 2,5; 5,0 e 10 m2, foi similar entre os diferentes espaçamentos, assim como o ganho médio diário de peso, com valores de 1,32; 1,41 e 1,47 kg, citados na mesma ordem. As eficiências alimentares dos novilhos não foram influenciadas pelo espaçamento. O espaço individual não influenciou os tempos de alimentação, ócio e ruminação, os quais apresentaram valores médios de 244,1; 790,3 e 405,6 minutos/dia, respectivamente, e as mudanças de postura durante ócios e ruminações. O tempo total que os animais permaneceram em pé ou deitados ao longo do dia, médias de 610,0 e 830,0 minutos, respectivamente, e o tempo médio que os animais se alimentaram, permaneceram em pé ou deitaram-se sincronizadamente foi de 85,8; 308,0 e 468,4 minutos/dia, citados na mesma ordem, não foram influenciados pelo espaço disponível. O número total de disputas, com 21,9; 21,5 e 19,7 ocorrências diárias nos novilhos em espaços de 2,5; 5,0 e 10 m2, respectivamente, e o número de interação não-agonísticas foram similares entre os diferentes espaçamentos avaliados. Novilhos confinados com 5,0 e 10 m2 estenderam seus membros 8,8 e 9,7 vezes por dia, respectivamente, superiores aos animais mantidos com disponibilidade individual de 2,5 m2, que realizaram esse comportamento 4,3 vezes ao dia. O escore de limpeza diferiu entre os espaçamentos, com valores de 3,2; 2,4 e 1,1 para novilhos com espaços individuais de 2,5; 5,0 e 10 m2, respectivamente, assim como a frequência respiratória, com 27,1; 24,8 e 22,7 movimentos/ minuto, citados na mesma ordem. Os pesos de carcaça quente e fria, médias de 226,0 e 220,0 kg, respectivamente, bem como seus rendimentos, 58,5 e 57,0 kg/ por 100 kg de peso vivo, citados na mesma ordem, não foram influenciados pelo espaçamento, tendo as carcaças apresentado espessura de gordura mínima exigida, 3 mm. O peso e o rendimento dos cortes comerciais da carcaça, como também o peso absoluto e a participação dos tecidos que compõem a carcaça foram similares entre os diferentes espaçamentos. Cor, textura, marmoreio, características organolépticas e força de cisalhamento da carne não foram influenciadas pelos espaçamentos utilizados.

As principais propriedades físico-químicas da quitosana dependem da massa molar média, grau médio de acetilação (<span style=\"text-decoration: overline\">GA) e do parâmetro de acetilação (PA) que expressa o padrão de distribuição das unidades 2-acetamido-2-desoxi-D-glucopiranose (GlcNAc) e 2-amino-2-desoxi-D-glucopiranose ( GlcN) ao longo de suas cadeias. A distribuição alternada, randômica ou em blocos das unidades GlcN e GlcNAc ao longo das cadeias poliméricas está diretamente relacionada com as condições de preparação da quitosana, sendo que as reações executadas em condições homogêneas geram quitosanas em cujas cadeias há o predomínio da distribuição randômica, enquanto que nas quitosanas produzidas em condições heterogêneas a distribuição em blocos predomina. Neste trabalho &beta;-quitina extraída de gládios de lulas (Loligo sp) foi submetida a 3 etapas consecutivas do processo de desacetilação assistida por irradiação de ultrassom de alta intensidade (processo DAIUS), resultando em quitosana extensivamente desacetilada (<span style=\"text-decoration: overline\">GA &asymp; 2%) e de elevada massa molar média viscosimétrica (<span style=\"text-decoration: overline\">Mv &asymp; 354000 g/mol) comparada a quitosanas obtidas por outros métodos. Essa amostra, denominada amostra QSo, foi dissolvida em ácido acético aquoso e então submetida à reação de N-acetilação por 24 h à temperatura ambiente. A ocorrência de O-acetilação foi evitada pela adição de 1,2-propanodiol ao meio reacional e a variação da razão molar anidrido acético/grupos amino permitiu a obtenção de cinco amostras de quitosanas N-acetiladas, as quais foram caracterizadas por espectroscopia de RMN 1H, espectroscopia na região do infravermelho, difração de raios X, viscosimetria capilar, microscopia eletrônica de varredura e análise termogravimétrica. O parâmetro de acetilação (PA) das quitosanas N-acetiladas foi determinado a partir dos espectros de RMN 1H de modo a permitir a avaliação do tipo de distribuição de unidades 2-acetamido-2-desoxi-D-glucopiranose (GlcNAc) e 2-amino-2-desoxi-D-glucopiranose (GlcN) predominante nos produtos. As reações de N-acetilação foram executadas em duplicata gerando as amostras dos conjuntos 1 e 2, as quais apresentaram <span style=\"text-decoration: overline\">GA variando no intervalo 25%&lt; <span style=\"text-decoration: overline\">GA &lt;55%, sendo constatada variação linear de <span style=\"text-decoration: overline\">GA com a razão molar anidrido acético/grupos amino. As quitosanas N-acetiladas apresentaram parâmetro de acetilação variando com 0,9&lt;PA&lt;1,5, indicando o predomínio da distribuição randômica das unidades GlcNAc e GlcN. As quitosanas N-acetiladas apresentaram maior estabilidade térmica em comparação com a quitosana de partida (amostra QSo), devido a porcentagem de unidades GlcNAc nas cadeias dos polímeros que provocaram alterações na sua estrutura cristalina. Os ângulos de Bragg característicos de &beta;-quitina (amostra QTo) extraída de gládios de lulas foram identificados nos difratogramas das quitosanas N-acetiladas com 30%&lt; <span style=\"text-decoration: overline\">GA &lt;55%, o que sugere que essas amostras adquiriram características semelhantes a da &beta;-quitina. Outra evidência desse fato foi comprovada através da análise das micrografias das amostras de quitosana N-acetiladas, que revelaram que as características das superfícies das partículas das amostras mais acetiladas são semelhantes a da &beta;-quitina. / The main physichochemical properties of chitosan rely on its average molar mass, average degree of acetylation (<span style=\"text-decoration: overline\">GA) and the parameter of acetylation (PA), which expresses the distribution pattern of 2-deoxy-2-acetamido-D-glucopyranose (GlcNAc) and 2-deoxy-2-amino-D-glucopyranose (GlcN) units along its chains. The occurrence of alternated, random or block-like distribution of GlcN and GlcNAc along the polymer chains is directly related to preparation conditions of chitosan. When homogeneous conditions are applied chitosan chains exhibiting random distribution are produced, while the chitosan generated from heterogeneous reactions presents block-like distribution. In this work, &beta;-chitin extracted from squid pens (Loligo sp.) was submitted to three consecutive steps of ultrasound-assisted deacetylation process (USAD process), resulting in an extensively deactylated chitosan (DA=2%) with high viscosity average molar mass (<span style=\"text-decoration: overline\">Mv= 354,000 g/mol) compared to chitosan obtained by other methods. This chitosan, named sample CSo, was dissolved in aqueous acetic acid and then it was submitted to N-acetylation reaction for 24 hours at room temperature. The occurrence of O-acetylation was prevented by adding 1,2-propanediol to the reaction nedium and the variation of the molar ratio acetic anhydride/amino groups allowed the preparation of five N-acetylated chitosans, named as samples RCSon, which were characterized by 1H NMR spectroscopy, infrared spectroscopy, X-ray diffraction, viscometry, scanning electron microscopy and thermogravimetric analysis. The parameter of acetylation (PA) of N-acetylated chitosans was determined from the 1H NMR spectra, allowing the assessment to the distribution pattern of GlcNAc and GlcN units. The N-acetylation reactions were carried out in duplicate, generating two independent sets of N-acetylated chitosans whose average degree of acetylation ranged as 25% &lt; DA &lt; 55%, a linear increase of DA with increasing molar ratio acetic anhydride/amino groups being observed. The N-acetylated chitosans presented parameter of acetylation ranging as 0,9 &lt; PA &lt; 1,5, indicating the predominance of random distribution of GlcNAc and GlcN units. The N-acetylated chitosans showed higher thermal stability as compared to the parent chitosan (CSo sample), probably due to the changes in the degree of order resulting from the higher content of GlcNAc units present in former samples. The Bragg angles characteristic of beta-chitin (CTo sample) were identified in the XRD patterns of N-acetylated chitosans, suggesting that these samples acquired similar characteristics as beta-chitin. Further evidence of this fact was observed through the SEM analyses, which revealed that the characteristics of particle\'s surfaces of N-acetylated chitosans are similar to those of beta-chitin.

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