Modelagem matemática para o transporte de partículas sujeitas a múltiplos mecanismos de retenção

Discrepancies between classical model predictions and experimental data for deep bed filtration have been reported by various authors. In order to understand these discrepancies, an analytic continuum model for deep bed filtration is proposed. In this model, a filter coefficient is attributed to each distinct retention mechanism (straining, diffusion, gravity interception, etc.). It was shown that these coefficients generally cannot be merged into an effective filter coefficient, as considered in the classical model. Furthermore, the derived analytic solutions for the proposed model were applied for fitting experimental data, and a very good agreement between experimental data and proposed model predictions were obtained. Comparison of the obtained results with empirical correlations allowed identifying the dominant retention mechanisms. In addition, it was shown that the larger the ratio of particle to pore sizes, the more intensive the straining mechanism and the larger the discrepancies between experimental data and classical model predictions. The classical model and proposed model were compared via statistical analysis. The obtained p values allow concluding that the proposed model should be preferred especially when straining plays an important role. In addition, deep bed filtration with finite retention capacity was studied. This work also involves the study of filtration of particles through porous media with a finite capacity of filtration. It was observed, in this case, that is necessary to consider changes in the boundary conditions through time evolution. It was obtained a solution for such a model using different functions of filtration coefficients. Besides that, it was shown how to build a solution for any filtration coefficient. It was seen that, even considering the same filtration coefficient, the classic model and the one here propposed, show different predictions for the concentration of particles retained in the porous media and for the suspended particles at the exit of the media

Estudo psicossocial das perdas dentárias na terceira idade

The present study seeks to understand tooth loss by investigating the social representations in the daily life of elderly individuals, thus characterizing itself as a comparative and analytic research. It is known that tooth loss is a common occurrence in elderly individuals, interfering at the psychosocial and biological levels, through its functional, esthetical and social implications. The area of oral health in Brazil is lacking studies on this topic, especially with respect to the psychosocial aspects of the elderly. The Theory of Social Representations and the Central Nucleus Theory were selected for theoretical-methodological support. The Free Association of Words Test was used, whose inducing stimulus were the words tooth loss , in which each subject was asked to associate 3 words, to respond to a questionnaire related to socio-economic conditions and containing an investigation of tooth loss, access to odontological services and the need for dental treatment, and to undergo a focus group interview. The study sample consisted of 120 individuals 60 years of age or over, resident in Natal, RN, Brazil and participants of the Live Together to Live Better group of the Basic Health Unit of Felipe Camarão Residential District and Unati (Open University of the Elderly); an interview was performed with 36 subjects. Data analysis was performed by Evoc 2000, SPSS/99, Graph Pad and Alceste softwares. The results demonstrate that the central nucleus of the social representations of tooth loss for the Live Together group emerged from the difficulty in eating categories, showing a relation between physiologic necessity, desire and pleasure from eating, not to mention the pain that resulted from justifying the tooth loss. Besides the central discourses, the following peripheral elements were gathered: difficulty in adapting to the prosthesis, treatment and difficulty in speaking. All of these categories, except the last, also comprised the class themes of the group interview. For the Unati group the central nucleus emerged from the socio-economic difficulties categories, demonstrating a narrow relation between poverty, access to health and education and esthetics, confirming in the discourse of common sense, the association between tooth loss and aging. At the margin of the central discourses was collected the peripheral element difficulty in adapting to the prosthesis, found both in the Live Together and Unati groups, which expresses the resistance of the subject to this new situation and the failure of the rehabilitation treatment in the sense of reviving the memory of their natural teeth. All of these categories also constitute the class themes of the of the group interview. Thus, through the study of the social representations, we can reveal a reality in the perspective of the social subjects, contemplating the multiple facets of the social-cultural reality experienced by these individuals

Estimativa da área foliar e capacidade de retenção de calda fitossanitária em cafeeiro

This work aimed to study the influence of the coffee tree leave's sizes, cv. Mundo Novo, on the evaluation of the leaf area and its spray retention capacity. Leaf mirroring on paper, leaf digitalization and imagine analyzes (QUANT) and rectangle circumscribed to the leaf methods were compared with LiCor area meter, model 3000. The spray retention capacity was evaluated with and without adjuvant addition at 0.1 and 0.2%. There weren't influence of the leave's size on the leaf area determination's methods. The leaves spray retention capacity was altered in function of the leaf size and of the adjuvant presence or not. The bigger spray retention capacity was observed at 7.7, 13.8 and 32 cm(2) leaves area. The spray without adjuvant exhibited biggest spray retention, with 77.1 mL m(-2). The spray additions of the 0.1 and 0.2% of adjuvant reduced in 64.8 and 67.3%, respectively, the spray retention capacity.

Efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros

A adição de óleos à calda de pulverização, muitas vezes, é utilizada a campo sem o adequado conhecimento sobre a absorção do produto fitossanitário pelo alvo, retenção de calda e até mesmo sobre a praga e a cultura. O objetivo do trabalho foi avaliar o efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros. Avaliou-se a mortalidade de ácaros, utilizando-se de frutos de laranja com uma arena circundada com cola entomológica para confinar os ácaros. Adotou-se o delineamento inteiramente casualizado, em esquema fatorial, constituído pelos fatores: duas formulações de cyhexatin (WG e SC), dois tipos de óleo (mineral e vegetal) e duas concentrações dos óleos (0,5 e 1,0%), e mais dois tratamentos adicionais (acaricidas não adicionados de óleo) e uma testemunha sem aplicação. A aplicação dos produtos foi realizada sobre frutos de laranja até além do ponto de escorrimento. Logo após a aplicação, transferiram-se 10 ácaros B. phoenicis para cada fruto.A contagem dos ácaros vivos, mortos e retidos na barreira adesiva foi realizada um dia após a aplicação. Para a determinação da quantidade de calda retida, utilizaram-se folhas de laranjeira, que foram pulverizadas até além do ponto de escorrimento, adotando-se os mesmos tratamentos e o delineamento estatístico mencionados para a avaliação da mortalidade de ácaros, com exceção da testemunha sem aplicação. Determinou-se a massa de líquido retido após a aplicação dos produtos por folha, com auxílio de balança de precisão. Verificou-se que um dia após a aplicação dos produtos, todos os tratamentos apresentaram mortalidade de B. phoenicis acima de 99%. Dessa forma, a adição de óleo, seja mineral, seja vegetal, ao acaricida cyhexatin não afetou a eficácia biológica deste acaricida nas formulações SC e WG. A maior fuga de B. phoenicis para a barreira de cola foi verificada nos tratamentos com adição de óleos, em comparação ao cyhexatin aplicado isoladamente. A adição de óleo, seja mineral, seja vegetal, ao cyhexatin na calda de pulverização reduziu a quantidade máxima de líquido retido pelas folhas de citros, podendo contribuir para a redução da quantidade de calda necessária para uma boa cobertura da planta.

Biodigestão anaeróbia de dejetos de bovinos leiteiros submetidos a diferentes tempos de retenção hidráulica

Utilizando-se biodigestores contínuos, abastecidos com dejetos de bovinos leiteiros e operados sob três tempos de retenção hidráulica, avaliou-se o efeito do processo de digestão anaeróbia sobre o número de microrganismos indicadores de poluição fecal, sobre a ocorrência de ovos e larvas de helmintos parasitas de ruminantes, analisando-se também os teores de sólidos totais e voláteis do afluente e dos efluentes, bem como a produção e a qualidade do biogás produzido. Verificou-se que vinte dias de retenção hidráulica foram suficientes para reduzir significativamente o número de microorganismos indicadores de poluição fecal e a quantidade de ovos de helmintos parasitas de ruminantes. Os resultados obtidos nas análises de sólidos totais e voláteis, bem como a produção de biogás (m³/dia), permitem concluir que o biodigestor modelo Chinês operado com 20 dias de tempo de retenção hidráulica, apresentou mais eficiência. Vale ressaltar que vinte dias de retenção foram insuficientes para impedir a sobrevivência de larvas de helmintos parasitas de ruminantes.

Tipo e freqüência de alterações dentárias e periodontais em cães na região de Jaboticabal, SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Número mínimo de tensões para determinação da curva característica de retenção de água de um latossolo vermelho eutrófico sob sistema de semeadura direta

Para o conhecimento do comportamento físico-hídrico do solo, é fundamental a determinação da curva de retenção de água (CRA). A aquisição de dados para obtenção da CRA envolve processos demorados e custos elevados. A hipótese deste estudo foi a de que é possível determinar a CRA com menor número de tensões, reduzindo seu tempo de obtenção, sem, contudo, comprometer a acurácia dos resultados. Assim, o objetivo deste trabalho foi determinar quais tensões podem ser utilizadas para determinação da CRA de Latossolo Vermelho eutrófico de maneira acurada e em menor tempo. Foram determinados os conteúdos de água retidos em amostras de um Latossolo Vermelho eutrófico sob sistema de semeadura direta (SSD). As tensões utilizadas na determinação dos conteúdos de água foram: 0, 10, 20, 40, 60, 80, 100, 200, 300, 500, 700, 1.000, 3.000, 5.000 e 15.000 hPa. Os dados foram combinados e determinaram-se 450 CRAs ajustadas pelo modelo de van Genuchten. Os parâmetros α, m, n e Ug res, gerados pelo modelo, foram submetidos à análise de variância (teste F) e as médias comparadas pelo teste de Scott-Knott (p = 0,05). A hipótese deste estudo foi confirmada, ou seja, é possível determinar a CRA com menor número de tensões, reduzindo seu tempo de obtenção em até cinco vezes, sem, contudo, comprometer a acurácia dos resultados. A tensão de 15.000 hPa deve estar contida na combinação de tensões a serem utilizadas para determinação da curva característica de retenção de água, quando se emprega o modelo matemático de van Genuchten para ajuste dos dados. As curvas características de retenção de água do solo, definidas com as combinações de tensões (0, 60, 700 e 15.000 hPa), (0, 80, 700 e 15.000 hPa), (0, 100, 1.000 e 15.000 hPa), (0, 20, 60, 100, 700 e 15.000 hPa), (0, 80, 300, 700 e 15.000 hPa) e (0, 100, 300, 1.000 e 15.000 hPa), sendo os dados ajustados ao modelo de van Genuchten, proporcionaram estimativas dos conteúdos de água, retidos no Latossolo Vermelho eutrófico sob sistema de semeadura direta, com a mesma acurácia, quando comparada à curva de referência partindo-se de um conjunto de 15 valores de tensões.

Utilização de modelos matemáticos para estimar a retenção de minerais em cabras durante a gestação

O trabalho foi realizado com o objetivo de estimar a retenção de elementos minerais durante a gestação de cabras com um ou dois fetos, utilizando-se diferentes modelos matemáticos. A estimativa de retenção foi baseada na diferença entre o total de cada mineral depositado no feto, útero, membranas, fluídos fetais e glândula mamária dos animais nas diferentes etapas da gestação e o total de cada mineral armazenado nas cabras vazias, utilizando-se os modelos de predição: ln Y = A - B e -C X ; Y = A e B X e ln Y = A + Bx + Cx², em que x = tempo de gestação. Comparando-se a estimativa com os valores reais obtidos, verificou-se que o modelo proposto ln = A+Bx+Cx², explicou com coerência e precisão o comportamento biológico da retenção de minerais durante todas as fases da gestação.

CAD e engenharia reversa como ferramentas de auxílio na fabricação de cartuchos para próteses ortopédicas

The manufacturing of above and below-knee prosthesis starts by taking surfac measurements of the patient s residual limb. This demands the making of a cartridg with appropriate fitting and customized to the profile of each patient. The traditiona process in public hospitals in Brazil begins with the completion of a record file (according to law nº388, of July 28, 1999 by the ministry of the health) for obtaining o the prosthesis, where it is identified the amputation level, equipment type, fitting type material, measures etc. Nowadays, that work is covered by the Brazilian Nationa Health Service (SUS) and is accomplished in a manual way being used commo measuring tapes characterizing a quite rudimentary, handmade work and without an accuracy.In this dissertation it is presented the development of a computer integrate tool that it include CAD theory, for visualization of both above and below-knee prosthesis in 3D (i.e. OrtoCAD), as well as, the design and the construction a low cos electro-mechanic 3D scanner (EMS). This apparatus is capable to automatically obtain geometric information of the stump or of the healthy leg while ensuring smalle uncertainty degree for all measurements. The methodology is based on reverse engineering concepts so that the EMS output is fed into the above mentioned academi CAD software in charge of the 3D computer graphics reconstruction of the residualimb s negative plaster cast or even the healthy leg s mirror image. The obtained results demonstrate that the proposed model is valid, because it allows the structura analysis to be performed based on the requested loads, boundary conditions, material chosen and wall thickness. Furthermore it allows the manufacturing of a prosthesis cartridge meeting high accuracy engineering patterns with consequent improvement in the quality of the overall production process

Desenvolvimento de métodos construtivos e de novos materiais empregados na confecção de cartuchos de próteses de membros inferiores

The manufacture of prostheses for lower limb amputees (transfemural and transtibial) requires the preparation of a cartridge with appropriate and custom fit to the profile of each patient. The traditional process to the patients, mainly in public hospitals in Brazil, begins with the completion of a form where types of equipment, plugins, measures, levels of amputation etc. are identified. Currently, such work is carried out manually using a common metric tape and caliper of wood to take the measures of the stump, featuring a very rudimentary, and with a high degree of uncertainty geometry of the final product. To address this problem, it was necessary to act in two simultaneously and correlated directions. Originally, it was developed an integrated tool for viewing 3D CAD for transfemoral types of prostheses and transtibial called OrtoCAD I. At the same time, it was necessary to design and build a reader Mechanical equipment (sort of three-dimensional scanner simplified) able to obtain, automatically and with accuracy, the geometric information of either of the stump or the healthy leg. The methodology includes the application of concepts of reverse engineering to computationally generate the representation of the stump and/or the reverse image of the healthy member. The materials used in the manufacturing of prostheses nor always obey to a technical scientific criteria, because, if by one way it meets the criteria of resistance, by the other, it brings serious problems mainly due to excess of weight. This causes to the user various disorders due to lack of conformity. That problem was addressed with the creation of a hybrid composite material for the manufacture of cartridges of prostheses. Using the Reader Fitter and OrtoCAD, the new composite material, which aggregates the mechanical properties of strength and rigidity on important parameters such as low weight and low cost, it can be defined in its better way. Besides, it brings a reduction of up steps in the current processes of manufacturing or even the feasibility of using new processes, in the industries, in order to obtain the prostheses. In this sense, the hybridization of the composite with the combination of natural and synthetic fibers can be a viable solution to the challenges offered above

Degradação luminosa e retenção foliar dos corantes azul brilhante FDC-1 e amarelo tartrasina FDC-5 utilizados como traçadores em pulverizações

Três estudos foram conduzidos no Núcleo de Pesquisas Avançadas em Matologia (NUPAM) pertencente à UNESP/FCA - campus de Botucatu-SP, com o objetivo de avaliar a estabilidade dos corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5 quanto a diferentes períodos de exposição à luz solar e contato com folhas de Eichhornia crassipes. No primeiro estudo, soluções de 0,3125, 0,625, 1,25, 2,5, 5, 10 e 20 ppm dos corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5 foram acondicionadas em tubos de quartzo hermeticamente fechados e submetidos a 0, 0,5, 1, 2, 4, 6 e 10 horas de exposição à luz solar e ao escuro. Ao final de cada período, amostras de 10 mL foram retiradas dos tubos e analisadas. No segundo estudo, os tratamentos foram dispostos no esquema fatorial 2x7: duas condições luminosas (escuro e pleno sol) e sete períodos de exposição (0, 0,5, 1, 2, 4, 6 e 10 horas), com seis repetições. Com o auxílio de micropipeta, oito gotas de 5 µL das soluções Azul Brilhante e Amarelo Tartrasina a 4.000 ppm foram depositadas em placas de Petri de vidro. Após o término dos períodos de exposição, as placas foram lavadas com 50 mL de água destilada, com o objetivo de extrair o corante depositado sobre elas. No terceiro estudo, adotaram-se os mesmos tratamentos do segundo experimento, com quatro repetições, porém as soluções foram depositadas sobre as folhas de plantas de Eichhornia crassipes. Foram adotados também os mesmos procedimentos de extração dos corantes após o término dos períodos de exposição. As soluções finais obtidas nos três estudos foram submetidas à leitura óptica de absorbância em espectrofotômetro UV-visível nos comprimentos de onda de 630 e 427 nm, para os corantes Azul Brilhante FDC-1 e Amarelo Tartrasina FDC-5, respectivamente. As várias concentrações das soluções de ambos os corantes não sofreram degradação pela luz solar quando submetidas aos vários períodos de incidência luminosa nos tubos de quartzo (ambiente fechado), visto que as curvas de recuperação apresentaram equações semelhantes àquelas concentrações que foram mantidas no escuro. A mesma estabilidade também foi observada quando os corantes foram submetidos à luz solar em ambiente aberto, ou seja, nas placas de Petri. O corante Amarelo Tartrasina também se apresentou muito estável quando depositado sobre as folhas de E. crassipes, independentemente da exposição ou não à luz solar. Para o corante Azul Brilhante, ocorreram significativas perdas de 7,8 e 18,6% quando esteve depositado na superfície da folha de aguapé pelo período de 10 horas sob condições de escuro e plena luz solar, respectivamente.

Avaliação da desadaptação das selas de próteses parciais removíveis após 1 a 5 anos de uso

The non-adaptation of the removable partial prosthesis (RPP) base to fibromucosal tissue is caused by resorption of residual ridges (RRR). The onset of bone resorption, which occurs after tooth extraction and continues throughout life, is accelerated by local or systemic factors. Aim: Assess the degree of non-adaptation of removable partial prosthesis saddles and the factors that influence it. Methodology: A sectional study was conducted with 81 patients using RPP who had their prostheses installed between 2003 and 2007 (1 to 5 years of use) at the Faculty of Dentistry of the Universidade Federal do Rio Grande do Norte (UFRN). After anamnese and clinical examination, a cast was made with polyether-based material, using the base of the prosthesis to make the impression. The base of the saddle was loaded with the casting material and positioned in the mouth, applying pressure on the supports. After polymerization, the material was removed from the saddle and measurements were taken at 3 different points using a pachymeter. Results: The non-adaptation of the saddle increased significantly with years of use (p = 0.005). The tooth-tissue supported prostheses obtained higher mean non-adaptation values than those of tooth supported prostheses (p < 0.001). Flaccid mucosa showed the worst non-adaptation results, which were statistically different from resilient mucosa (p < 0.001). The greater the extension of the saddle, the greater the non-adaptation (p < 0.001). The natural tooth antagonistic arch yielded better results than did RPP and total prosthesis (p < 0.001). Saddle non-adaptation at the free end was less near the pillar tooth and greater in the more posterior region (p < 0.001). When adaptation of the supports to the niches was poor, greater saddle non-adaptation occurred than when it was good or fair (p < 0.001). Saddles located in the posterior region of the arch had greater non-adaptation than those in the anterior region (p = 0.023). Conclusion: The mean non-adaptation of the saddle to the residual ridges was 0.27 mm. It can be concluded that, even with the use of RPP, bone height reduction was slight within the 1-5-year period of use. The following are factors that influence adaptation of the RPP saddle base: years of use, age, force transmission path to the alveolar bone, location of the toothless area, antagonistic arch, type of mucosa, adaptation of supports to the niche and extension of the saddle

Satisfação dos usuários e qualidade dos tratamentos protéticos realizados nos centros de especialidades odontológicas da grande Natal RN

Aim: To evaluate user satisfaction and quality of prosthetic treatments performed in specialized dental clinics (CEOs) of Natal Metropolitan Region - RN. Methods: Cross-sectional study with subjects who underwent prosthetic CEOs in the cities of Natal, Macaíba, Parnamirim and Sao Goncalo do Amarante in the period 2007 to 2009. Data collection was performed by questionnaire, clinical examination of the oral cavity and examination of fabricated denture. This analysis involved the following aspects: retention, stability, aesthetics and prosthesis fixation. The variables are presented by means of absolute numbers and proportions. The determination of the association between the independent and dependent variables was conducted by the association of Chi-square test and Fisher exact test. Results: A total of 149 users, totaling 233 conventional dentures (148 upper and 85 lower). Most patients (56.4%) were rehabilitated with conventional complete dentures. The technical quality of the denture was regarded as satisfactory in the majority (52.7%), whereas the inferior dentures were rated as unsatisfactory in 90.5% of cases. Satisfaction with the prosthesis was 69.1% (N = 103). The average time to begin treatment was 3 months to receive while the prosthesis was 4 months old. The presence of injury from the upper prosthesis occurred in 21.5% of cases (N = 32), candidiasis being the most frequent (N = 18). The technical quality of the upper prosthesis (p=0,041), as well as retention (p=0,002) and stability (p<0,001) were significantly associated with user satisfaction. Conclusions: The specialized Dental clinics has been fulfilling its role of providing treatment of intermediate complexity for low-income population with the majority of satisfield patients, even when their dentures have problems of technical quality

Avaliação clínica longitudinal do periodonto de dentes pilares e não pilares de próteses parciais removíveis

The literature has shown a relation between periodontics and the removable partial denture (RPD), with progressive destruction observed in the support structures. The aim of this study was to clinically assess periodontal condition in users of removal partial denture (RPD), and compare right abutments teeth, indirect abutments and controls before installation and after 1 year, in addition to comparing tooth-supported and tooth mucosa-supported abutments. A total of 50 patients, 32 women and 18 men, mean age of 45 years, took part in the study. The patients were examined by a single examiner at prosthesis installation and after 3, 6, 9 and 12 months. The following were verified at each examination: Probe Depth (PD), Plaque Index (PI), Gingival Index (GI), the amount of Keratinized Mucosa (KM), Gingival Recession (GR) and Dental Mobility (DM); in addition patients received oral hygiene orientation, accompanied by prophylaxis, periodontal scaling and root planing (PSRP), when necessary. Analysis of Variance (ANOVA) with Tukey-Kramer post test was used to assess the dependent variables (PD, PI, KM, GR) of the three groups over time while Friedman s test was used for GI. To assess the outcomes of prosthesis type in the right abutment group, a confidence interval-based analysis was performed. The results showed that the control group was the least compromised in all the variables studied. With respect to development of the groups over time, it was verified that the measures for GR, PD, GI and KM increased from initial examination to 1 year of use in all the groups, but only PI showed a significant increase. There was a non-discriminatory low prevalence of dental mobility. The tooth mucosa-supported prosthesis had significantly higher values for GR, GI and PI and significantly lower ones for KM when compared to tooth-supported. Over time, both types of prostheses showed no significant differences from initial to final examination for the variables GR, PD, KM and GI, with PI significant only for tooth-supported. The results showed that the teeth most involved in RPD design had greater potential of periodontal damage, probably because of greater dental biofilm accumulation. Abutments elements adjacent to the free extremities had less favorable periodontal condition than those adjacent to interpolated spaces, but the use of RPD did not worsen the initial condition

Influência da compactação de um solo arenoso na infiltração e retenção de carga orgânica de chorume

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)