26 resultados para Francisco J. C. Dantas

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

90.00% 90.00%

Publicador:

Resumo:

RESUMO: Objetivo: Avaliar as alterações histológicas, e o ganho de resistência em anastomoses duodenais tratadas com fator de crescimento de fibroblasto básico (FGFb). Métodos: Vinte ratos da raça Wistar foram submetidos a se§Ã£o transversal do duodeno, seguida de anastomose. Os animais foram divididos em 4 grupos de 5 animais cada: A1 e A2 (experimentais), nos quais foi aplicado FCFb sobre a anastomose logo após seu término; e B1 e B2 (controles), nos quais foi administrada solução salina sobre a zona de anastomose. Os roedores foram mortos com superdose de anestésico, sendo A1, B1 no 5º dia e A2, B2 no 7º dia de pós-operatório. Foi feita avaliação quanto à resistência das anastomoses à pressão e análise da densidade média dos achados histopatológicos com auxílio do sistema digitalizado Image proPlus. Resultados: No grupo A1 a pressão suportada pelas anastomoses foi de 52±14,4 mmHg e no grupo A2 140±34,8 mmHg. Em B1 a pressão atingiu 33,6±15,2 mmHg e as anastomoses do grupo B2 suportaram pressão 105±30,3. No grupo A1 a densidade média dos elementos histopatológicos foi de 93±9,3 e A2 atingiu 181,8±27,6. Nos grupos de controle B1 e B2 as densidades médias foram 67,6±16,7 e 101±12,9 respectivamente. A análise estatística revelou diferença significante entre nos dados dos grupos experimentais e controles (p<0,05).Conclusão: a aplicação tópica do FCFb foi capaz de aumentar a resistência das feridas do duodeno suturadas e observadas após 5 e 7 dias de evolução. Estimulou a neovascularização, a formação de fibroblastos e de fibras colágenas, melhorando os escores histológicos em relação ao controle.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

RESUMO: Objetivo: Avaliar as alterações histológicas, e o ganho de resistência em anastomoses duodenais tratadas com fator de crescimento de fibroblasto básico (FGFb). Métodos: Vinte ratos da raça Wistar foram submetidos a se§Ã£o transversal do duodeno, seguida de anastomose. Os animais foram divididos em 4 grupos de 5 animais cada: A1 e A2 (experimentais), nos quais foi aplicado FCFb sobre a anastomose logo após seu término; e B1 e B2 (controles), nos quais foi administrada solução salina sobre a zona de anastomose. Os roedores foram mortos com superdose de anestésico, sendo A1, B1 no 5º dia e A2, B2 no 7º dia de pós-operatório. Foi feita avaliação quanto à resistência das anastomoses à pressão e análise da densidade média dos achados histopatológicos com auxílio do sistema digitalizado Image proPlus. Resultados: No grupo A1 a pressão suportada pelas anastomoses foi de 52±14,4 mmHg e no grupo A2 140±34,8 mmHg. Em B1 a pressão atingiu 33,6±15,2 mmHg e as anastomoses do grupo B2 suportaram pressão 105±30,3. No grupo A1 a densidade média dos elementos histopatológicos foi de 93±9,3 e A2 atingiu 181,8±27,6. Nos grupos de controle B1 e B2 as densidades médias foram 67,6±16,7 e 101±12,9 respectivamente. A análise estatística revelou diferença significante entre nos dados dos grupos experimentais e controles (p<0,05).Conclusão: a aplicação tópica do FCFb foi capaz de aumentar a resistência das feridas do duodeno suturadas e observadas após 5 e 7 dias de evolução. Estimulou a neovascularização, a formação de fibroblastos e de fibras colágenas, melhorando os escores histológicos em relação ao controle.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This research presents a reading of the poetics of silence in the profile and actions of characters in Fogo morto, by Paraiba s novelist José Lins do Rego and Cartilha do silêncio, by Sergipe s writer José Francisco Costa Dantas. As a starting point, we intend to demonstrate, through analysis, how the traditional issue of patriarchy, installed in rural areas of Northeast Brazil, live their momentum of rise and decline in different social spaces within narratives. This article shows how man lives tensions caused by the socio-political changes that will gradually be deployed in their environment due to the process of transition from traditional to modern life. From this perspective, this reading encourages a critical reflection on the social space of the mills and farms at the time of their rise and decay, as well as the various gender relationships between the feminine and the masculine world. The analysis indicates that all the changes both in family and social space unfold a world of silent variants and this paper takes as its theoretical basis the concept of silence built from the reflections of Eni Puccinelli Orlandi (2002), Barros Lourival Holland (1990 ), Luiz Costa Lima (1974) and Marisa Simons (1999).

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In recent years, studies about the physicochemical properties of mixed oxides, call attention of the scientific community, properties like as piezoelectricity, photoluminescence, or applications as catalysts, arise in these compounds, when their chemical compositions are modified, in this context some routes are employed in the synthesis of these materials, among which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional routes or chemical routes. In this work were synthesized oxides with variable composition, from the thermal decomposition of titanium, cobalt, nickel and praseodymium nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR), Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy (FTIR). From FTIR data, it was demonstrated that the displacement of the band corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid (H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g). By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By fluorimetry was observed that the intensity of emission bands are directly proportional to the concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides, demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the complete decomposition of the nitrilotriacetates in oxides

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Orthoferrites AFeO3 (A = rare earth) are an important class of perovskite oxides that exhibit weak ferromagnetism. These materials find numerous applications as chemical sensors, cathodes for fuel cells and catalysis, which make them interesting from the standpoint of science and technology. Their structural, electrical and magnetic properties are dependent on many factors such as the preparation method, heat treatment conditions, chemical composition and replacement of cations in sites A and/or B. In this paper, LaFe1-xMnxO3 (0 ≤ x ≤ 1) orthoferrites-type was prepared by Pechini method and Microwave-assisted combustion reaction in order to evaluate the influence of synthesis route on the formation of oxide, as well as the effect of parcial replacement of iron by manganese and heat treatment on the magnetic properties. The precursor powders were calcined at 700°C, 900°C, 1100°C and 1300°C for 4 hours and they were characterized by the techniques: Thermogravimetric analysis (TGA), X ray diffraction (XRD), Refinement by Rietveld method, Scanning electron microscopy (SEM), Reduction temperature programmed (RTP) and Magnetic hysteresis measurements performed at room temperature. According to the XRD patterns, the formation of perovskite phase with orthorhombic structure was observed for the systems where 0 ≤ x ≤ 0.5 and rhombohedral for x = 1. The results also showed a decrease of lattice parameters with the parcial replacement of iron by manganese and consequently a reduction in cell volume. The hysteresis curves exhibited weak ferromagnetism for the systems prepared by both synthesis methods. However, a dependence of magnetization as a function of dopant content was observed for samples produced by Pechini method. As for the systems prepared by combustion reaction, it was found that the secondary phases exert a strong influence on the magnetic behavior

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This is a work involving fundamental studies of chemistry where the synthesis and structural characterization, as well as a possible future application of these new compounds as luminescent sensors or sunscreen agents, complexes with 4,4 diaminostilbene-2,2-disulfonic (DSD) and trivalent lanthanide ions La3+, Nd3+, Eu3+, Gd3+ and Yb3+, were synthesized in the ratio of 3 mmol: 1 mmol (DSD: lanthanides). The complexes obtained with these ions were present in powder form and were characterized by complexometric titration with EDTA CHN Elemental analysis, molecular absorption spectroscopy in the ultraviolet region, the absorption spectroscopy in the infrared, thermal analysis (TG / DTG), Nuclear Magnetic Resonance - NMR 1H and Luminescence Spectroscopy. The complexometric titration and CHN analysis, confirmed the TG / DTG which suggest that these complexes have the following general chemical formulas: [La2(C14H12S2O6N2)2(H2O)2Cl2].7H2O,[Nd2(C14H12S2O6N2)2(H2O)2Cl2].6H2O,[Eu2(C14 H12S2O6N2)2(H2O)2Cl2].7H2O,[Gd2(C14H12S2O6N2)2(H2O)2Cl2].4H2O e [Yb2(C14H12S2O6N2)2(H2O)2].6H2O. The disappearance of the bands in the infrared spectrum at 2921 cm-1 and 2623 cm-1 and the displacement of the bands in the spectra of the amine complex indicate that the lanthanide ion is coordinated to the oxygen atoms and the sulfonate groups of the nitrogens amines, suggesting the formation of the dimer. The disappearance of the signal and the displacement signal SO3H amines in the 1H NMR spectrum of this complex are also indicative coordination and dimer formation. The Thermogravimetry indicates that the DSD is thermally stable in the range of 40º to 385°C and their complexes with lanthanide ions exhibit weight loss between 4 and 5 stages. The Uv-visible spectra indicated that the DSD and complexes exhibit cis isomers. The analysis of luminescence indicates that the complexes do not exhibit emission in the region of the lanthanides but an intense emission part of the binder. This is related to the triplet states of the ligand, which are in the lowest energy state emitting lanthanide ions, and also the formation of the dimer that suppress the luminescence of ion Eu3+. The formation of dimer was also confirmed by calculating the europium complex structure using the model Hamiltonian PM6 and Sparkle

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Squamous cell carcinoma of the lower lip is among the most common malignant tumors of the oral and maxillofacial region, with good prognosis in more than 90% of patients with 5-year survival. In these carcinomas, the development of lymph node metastasis decreases the prognosis and it has been associated with the formation of new lymphatic vessels. It has been suggested the important role of vascular endothelial growth factor-C (VEGF-C), the receptor type 3 VEGF (VEGFR-3) and hypoxia-induced factor 1 (HIF-1) in this process. The aim of this study was to evaluate the immunoexpression of VEGF-C, VEGFR-3 and HIF-1α and correlate with intra and peritumoral lymphatic density in squamous cell carcinomas of the lower lip metastatic and non-metastatic. The sample consisted of 50 cases of squamous cell carcinoma of lower lip, of which 25 had regional lymph node metastasis and 25, absence of metastasis. The percentages of cells immunostained for VEGF-C, VEGFR-3 and HIF-1α in front of tumor invasion and in the center of tumor were evaluated. Microvessel density lymphatic (MDL) was determined by the counting of lymph microvessels immunostained by the anti-D2-40 in five fields (200×), in an area of evaluation with 0.7386 mm2. The invasion of the lymph vessels by malignant cells was also evaluated. Immunostaining was correlated with the presence and absence of metastasis, TNM clinical stage, local recurrence, disease outcome (remission of injury or patient death) and histological grading. The analysis of intra and peritumoral lymphatic density showed no significant association with clinicopathological parameters and immunoexpressions of VEGF-C, VEGFR-3 and HIF-1α (p > 0,05). There was a weak positive correlation, significant, between intra and peritumoral lymphatic density (r = 0,405; p = 0,004). VEGF-C showed no significant association with clinicopathological and prognosis parameters (p > 0,05). For VEGFR-3, there was scarce membrane staining and intense and homogenous cytoplasmic staining in neoplastic cells. Percentage of positive cytoplasmic VEGFR-3 in center of tumor, exhibited a statistically significant association with metastasis (p = 0,009), patient death (p = 0,008) and histological grades of malignancy proposed by Bryne et al. (1992) (p = 0,002) and World Health Organization (p = 0,003). A low positive correlation was statistically significant between the immunoreactivity of VEGFC and VEGFR-3 cytoplasmic (r = 0,358; p = 0,011) and between the percentage of positive cytoplasmic VEGFR-3 in front of tumor invasion and in the center of the tumor (r = 0,387; p = 0,005) was also demonstrated. There was no association between HIF-1α, clinicopathological and prognosis parameters, and VEGF-C and VEGFR-3. The percentage of nuclear positivity for HIF-1α was significantly higher in cases without invasion of peritumoral lymphatic (p = 0,040). Based on the results we can conclude that most cytoplasmic expression of VEGFR-3 in center of tumor in metastatic cases, high degree of malignancy and poorly differentiated, contributes to poor outcome of squamous cell carcinoma of the lower lip, including patient death. Intra and peritumoral lymphatic density seems to be not associated with lymph node metastasis in these carcinomas

Relevância:

30.00% 30.00%

Publicador:

Resumo:

RESUMO: Objetivo: Tem sido demonstrado que a icterícia obstrutiva provoca depressão do sistema imunológico, mudança no padrão de colonização bacteriana dos intestinos e passagem de bactérias da luz intestinal para a circulação porta e sistêmica. Estudo experimental em ratos procurou observar a possibilidade de translocação bacteriana para os pulmões após a ligadura do colédoco. Método: Foram utilizados 20 ratos Wistar pesando de 178 a 215g, separados aleatoriamente em dois grupos iguais. Nos ratos do grupo I foi feita a ligadura do colédoco e nos do grupo II apenas a manipulação do colédoco com pinça atraumática (sham operation). No sétimo dia de observação os animais foram mortos com superdose de anestésico, sangue foi colhido para dosagem de bilirrubinas e os pulmões ressecados sob condições assépticas. Metade de cada pulmão foi homogeneizada e semeada em meios de cultura ágar McConkey e ágar sangue. A outra metade serviu para exame histopatológico –coloração hematoxilina e eosina. Os dados foram analisados pelo teste t, com signifi¢ncia 0,05. Resultados: revelaram bilirrubina total em média 18,7±3,6 no grupo I e 0,7±0,2 no grupo II. No grupo I foram isoladas colônias de Klebsiela sp nos pulmões de 30% dos animais e E. coli em 20%, e os escores histopatológicos atingiram a média 6,2±2,08. No grupo II não foram detectadas bactérias nos pulmões e os escores do exame histopatológico atingiram 1,8±1,16. A diferença dos dados analisados mostrou-se significativa (p<0,05). Conclusões: Concluiu-se que a icterícia obstrutiva por ligadura do colédoco em ratos provocou translocação de germes Gram-negativos para os pulmões e resultou em alterações histopatológicas significativas.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A duração das operações pode representar um fator importante para uma série de complicações pós-operatórias, especialmente para os indivíduos idosos. Objetivo: estudar a repercussão nos pulmões, de operações de diferentes tempos de duração. Métodos: Vinte ratos idosos (18 meses) e 20 jovens (3 meses) foram separados aleatoriamente em grupos A e B respectivamente. Os grupos foram divididos em A1, A2, A3, A4, B1, B2, B3 and B4, com cinco ratos cada. Os animais foram anestesiados com pentobarbital (20mg/Kg) intraperitoneal. No subgrupo A1 e B1 foi feita operação com duração de 30 minutos, nos grupos A2 and B2 60 minutos, em A3 and B3 a operação foi feita em 120 minuto e os animais A4 e B4 (controle) não foram operados. O procedimento consistiu de laparotomia xifopubiana que foi aberta e fechada tantas vezes quanto necessário para atingir os tempos estipulados. Após o quinto dia pós-operatório os animais foram mortos com superdose de anestésico e biópsias de ambos os pulmões foram realizadas. Os achados histopatológicos foram transformados em escores. Resultados: os grupos de ratos jovens atingiram os escores: A1= escore 6, A2=11; A3=28; A4=5. Os ratos idosos tiveram os escores: B1=12; B2=34; B3=51 e B4=6. A análise estatística revelou diferenças significantes entre os escores dos grupos A e B. Conclusões: O tempo prolongado nas operações realizadas em ratos idosos contribuiu para o aparecimento de alterações pulmonares de modo significante. Quanto maior o tempo operatório, mais intensas e mais freqüentes as complicações pulmonares

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Analisar fatores intercorrentes e a incidência da infe§Ã£o em pacientes operados no Hospital Universitário da UFRN. Métodos: Foram estudados, através de protocolo previamente estabelecido, 3.120 pacientes internados que se submeteram a procedimentos cirúrgicos no período de janeiro de 1999 a outubro de 2002. Resultados: O índice de infe§Ã£o hospitalar foi de 5,9%, e a topografia de maior incidência foi a ferida operatória (3,7%). Infe§Ã£o respiratória ocorreu em 1,2%, urinária em 0,6% e bacteremia em 0,1%. O índice de infe§Ã£o comunitária foi de 9,2%, predominando infe§Ã£o urinária (5%) e respiratória (2,1%). Quanto ao grau de contaminação das feridas operatórias, as feridas limpas (1479) apresentaram infe§Ã£o em 2,9%, as feridas limpascontaminadas (1277) em 6,0% dos casos, as feridas contaminadas (270) em 15,1%, e as ferida infectadas (94) resultaram em infe§Ã£o em 30,75% dos casos. Conclusão: Concluiu-se que a incidência de infe§Ã£o cirúrgica foi compatível com os índices na literatura mundial. A partir desses dados, ratifica-se a importância de medidas de controle de infe§Ã£o hospitalar de forma sistemática, como vem sendo realizado no hospital onde o estudo foi realizado

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of this study was to follow the daily routine of elderly individuals residing at the Vila Vicentina ºlia Freire (VVJF) nursing home in João Pessoa, Brazil, observing and analyzing as much as possible, the way in which they live in a group and how they deal, through personal experiences, with their own body image and with that of others. The results were obtained from information considered relevant, according to the perspectives of the residents themselves, contained in narratives of their history and related to their quality of life. Our interest lays in how they coped with changes in their bodies at old age and adapted to the challenges of this new phase. To obtain this information, with significant expressions, we used the Narrative Interview (NI) as a research tool in order to redeem their life experience and develop an understanding of their impressions about the life experience at the current nursing home. We selected, among the housed, ten subjects - actors - to appear as a sample of the group together. The design of our sample had a hybrid model, combining two types: random sample (probability) and an intentional sample (not probability). After recording transcripts and ensuring that all the subjects showed common interests that were relevant to the group, we chose three categories for analysis as follows: a. the elderly as seen by themselves and by others; b. religiosity as a moral factor; c. intimacy and relationships. Our choice was based on the importance of the theme as a multidisciplinary topic in the quality of life of populations. The subjects, chosen as spokespersons for the VVJF, spoke, among other things, about the way in which they viewed the world, their own body and how they experienced the environment and their fellow residents, in an attitude of reflection and criticism that confirms the lucidity of an old age conditioned to an elderly institution. The method allowed us to investigate our subjects from a multidisciplinary point of view. We suggest other studies in assorted areas of the human sciences, having as principle, man at the center of all our scientific questionings. The paradigm that the elder is, necessarily, unhappy in his sheltered has been, in this job, broken through the testimonies collected, establishing multiple perspectives of the analyzed subjects by their respective narrative records. Involving the participation of researchers with major in Administration, Communication and Law, this study filled, in this aspect, the requirements of the multidisciplinarity of the Program of Pos-Graduation in Health Science

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In The paradoxical happiness , Gilles Lipovetsky elects five major paradigmatic models that command the pleasure and happiness in our societies. Starting with the paradigmatic models of penia (where it is emphasized the existential dissatisfaction supplied by the consumption and where advertising has a special place, bombarding consumers and creating consumer needs, in addition to selling a lifestyle rather than the products themselves), and narcissus (model constructed on the basis of self-exaltation and abdication of the social and political) intends to examine the relationship between the consumption exercised by young people and the advertising displayed on social networking sites, focusing on the social media Facebook, observing the virtual fan pages of the following brands: Coca-Cola; Pepsi; BlackBerry, Nokia, Riachuelo and C&A and their relationships with their consumers

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Venous ulcers (VU), recurrent chronic wounds resulting from Chronic Venous Insufficiency (CVI), affect different age groups and would severely affect ambulation of patients. The lesions require treatment lasting and complex and are responsible for significant morbidity and mortality. Thus, this study aims to identify the important aspects covered in the scientific literature protocol for assisting patients with venous ulcers, identifying the issues to be proposed by the judges of the study (nurses, doctors and physiotherapists) to the protocol of care provided to patients venous ulcers and present the structure of protocol proposed by the judges of the study to assist patients with venous ulcers treated at a referral hospital of Rio Grande do Norte. This is a descriptive study using a quantitative approach, carried out at the dressings, located in the outpatient surgical clinic of the Hospital University Onofre Lopes (HUOL), located in East Sanitary District, Natal-RN. The sample consisted of 39 professionals, 30 nurses, seven doctors and two physical therapists, team members HUOL surgical clinic and other public and private institutions of Rio Grande do Norte and Jequié/Bahia. These professionals were the judges responsible for selecting the guidelines already proposed in the literature on VU protocols. Approved by the Ethics in Research HUOL (Report n.o 081/07), began the first stage of the study which consisted of reviewing the scientific literature about the relevant aspects to be included in a protocol for assisting patients with VU. These aspects were organized into a proposed questionnaire to the judges of the study. Following examination, held on the content validation with application of the Kappa (K), accepting a score higher than 0.80 and the Likert Scale, whereas rates from 4.0 to 5.0. The data collected were organized in Microsoft Excel and exported into Statistical Package for Social Sciences (SPSS) 15.0. The literature review included national and international scientific articles, thesis, dissertation and institutional protocols. Regarding the characterization of professional nurses predominated (76.1%), between 34 and 45 years (41.0%), female (79.5%), married/consensual union (46.2%), with specialization in VU care (61.5%), working in the hospital network (46.1%), with up to 5 years experience in VU (69.2%) and claiming to feel prepared to care for these injuries (92.3 %). With regard to aspects that had very good agreement (K ≥ 0.81), remained the items found in the literature with some modifications. In the analysis of the proposed evaluation items had very important, ranging from 4.1 (drug treatment) to 4.9 (patient assessment and care of the injury and the injured and perilesional skin). The proposition of the protocol is arranged in eleven items: A) Evaluation of patient and lesion, B) Registration and documentation, C) the wound and perilesional skin, D) an indication of coverage, E) Use of antibiotic and pain treatment, F) Surgical treatment of CVI, G) Drug treatment, H) Improving venous return and prevetion of recurrence, I) Referral of patients, J) Training and K) Reference and counter reference

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The waste in the industries of escargot processing is very big. This is composed basically of escargot meat out of the commercialization patterns and the visceras. In this context, there is a need to take advantage to the use of these sub-products. A possibility should be drying them and transforming them in a certain form to be reused. Than, the present work has the objective of studying the reutilization of the sub-products of the escargot industrialization for by means of drying process. The samples were transformed in pastes, through a domestic processor for approximately 1 minute and compacted in trays of aluminum without perforations with three different heights (5 mm, 10 mm and 15 mm). The drying was accomplished in a tray dryer with air circulation and transverse flow at a speed of 0,2 m/s and three temperature levels (70°C, 80°C and 90ºC). A drying kinetics study was accomplished for the obtained curves and for the heat and mass transfer coefficients using experimental procedures based in an experimental planning of 22 factorial type. Microbiological and physiochemical analysis were also accomplished for the in nature and the dehydrated sub-products. In the drying process, it was observed the great importance of the external resistances to the mass transfer and heat in the period of constant tax influenced by the temperature. The evaporation taxes indicated a mixed control of the mass transfer for the case of the thickest layers. As already expected, the drying constant behavior was influenced by the temperature and thickness of the medium, increasing and decreasing. The statistical analysis of the results, in agreement with the factorial planning 22, showed that the fissures, the shrinking of the transfer area and the formation of a crust on the surface might have contributed to the differences between the practical results and the linear model proposed. The temperature and the thickness influenced significantly in the answers of the studied variables: evaporation tax and drying constant. They were obtained significant statistical models and predictive ones for evaporation tax for the meat as well as for the visceras

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The objective of this study was to evaluate the displacement of petroleum/diesel solutions, at different concentrations, observing the effect of ultrasonic vibrations in fluids present in porous media to obtain an increase in oil production. The bubbles produced by ultrasound implode asymmetrically in the rock, generating liquid jets with high speed, displacing the oil present in porous media. The oil/diesel solutions were prepared with concentrations ranging from 20 g/L to 720 g/L in oil in relation to diesel and its viscosities were obtained in a Brookfield Rheometer RS2000, with temperature ranging from 25 to 55 °C. After, calculations were performed to obtain the activation energy data for oil/diesel solutions. For oil recovery experiments, cylindrical samples of porous rock (core samples), with resin around the perimeter and its two circular bases free to allow the passage of fluids, were first saturated with 2% KCl solution and after with oil solutions. The results of oil extraction were satisfactory for all studied solutions, being obtained up to 68% partial displacement with saline solution injection. The ultrasound system was used after saline injection, increasing oil displacement, with oil extractions ranging from 63% to 79%. During the experiments, it was observed the warming of core samples, helping to reduce the viscosity of more concentrated systems, and consequently enhancing the percentage of advanced recovery for all studied solutions