4 resultados para General allocation model

em Universidade Federal do Rio Grande do Norte(UFRN)


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The present work presents the study and implementation of an adaptive bilinear compensated generalized predictive controller. This work uses conventional techniques of predictive control and includes techniques of adaptive control for better results. In order to solve control problems frequently found in the chemical industry, bilinear models are considered to represent the dynamics of the studied systems. Bilinear models are simpler than general nonlinear model, however it can to represent the intrinsic not-linearities of industrial processes. The linearization of the model, by the approach to time step quasilinear , is used to allow the application of the equations of the generalized predictive controller (GPC). Such linearization, however, generates an error of prediction, which is minimized through a compensation term. The term in study is implemented in an adaptive form, due to the nonlinear relationship between the input signal and the prediction error.Simulation results show the efficiency of adaptive predictive bilinear controller in comparison with the conventional.

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Expanded Bed Adsorption (EBA) is an integrative process that combines concepts of chromatography and fluidization of solids. The many parameters involved and their synergistic effects complicate the optimization of the process. Fortunately, some mathematical tools have been developed in order to guide the investigation of the EBA system. In this work the application of experimental design, phenomenological modeling and artificial neural networks (ANN) in understanding chitosanases adsorption on ion exchange resin Streamline® DEAE have been investigated. The strain Paenibacillus ehimensis NRRL B-23118 was used for chitosanase production. EBA experiments were carried out using a column of 2.6 cm inner diameter with 30.0 cm in height that was coupled to a peristaltic pump. At the bottom of the column there was a distributor of glass beads having a height of 3.0 cm. Assays for residence time distribution (RTD) revelead a high degree of mixing, however, the Richardson-Zaki coefficients showed that the column was on the threshold of stability. Isotherm models fitted the adsorption equilibrium data in the presence of lyotropic salts. The results of experiment design indicated that the ionic strength and superficial velocity are important to the recovery and purity of chitosanases. The molecular mass of the two chitosanases were approximately 23 kDa and 52 kDa as estimated by SDS-PAGE. The phenomenological modeling was aimed to describe the operations in batch and column chromatography. The simulations were performed in Microsoft Visual Studio. The kinetic rate constant model set to kinetic curves efficiently under conditions of initial enzyme activity 0.232, 0.142 e 0.079 UA/mL. The simulated breakthrough curves showed some differences with experimental data, especially regarding the slope. Sensitivity tests of the model on the surface velocity, axial dispersion and initial concentration showed agreement with the literature. The neural network was constructed in MATLAB and Neural Network Toolbox. The cross-validation was used to improve the ability of generalization. The parameters of ANN were improved to obtain the settings 6-6 (enzyme activity) and 9-6 (total protein), as well as tansig transfer function and Levenberg-Marquardt training algorithm. The neural Carlos Eduardo de Araújo Padilha dezembro/2013 9 networks simulations, including all the steps of cycle, showed good agreement with experimental data, with a correlation coefficient of approximately 0.974. The effects of input variables on profiles of the stages of loading, washing and elution were consistent with the literature

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Fibromyalgia (FM) is a non-inflammatory rheumatic syndrome of unknown etiology, with symptoms of diffuse musculoskeletal pain and presence of specific anatomic sites called tender points. The symptoms are often associated with fatigue, sleep disturbances, morning stiffness, alterations in pain perception, anxiety and depression. Fibromyalgia exhibits a correlation between physical and behavioral symptoms, which have a negative influence on the quality of life of patients. Emotional skills are important factors since they are related to subjective well-being, personal productivity, social interaction and interpersonal relationships. We aim to describe the physical and psychosocial interactions in women with FM, showing the association between perceived social support and affect with symptoms of pain, functionality and mood. We will also describe a body representation of pain in women with FM. Data were collected over 3 years and the sample size ranged between studies. This is an exploratory cross-sectional study conducted with a convenience sample of 63 women with FM and 42 healthy women as a control group (CT), aged 20-76 years, recruited through spontaneous demand at Onofre Lopes University Hospital (HUOL) and the Clinical School of Physiotherapy of Universidade Potiguar (UNP). The Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory (BDI), Social Support Scale (MOS), Hamilton Anxiety Scale and Scale of Positive and Negative Affect Schedule (PANAS), in addition to pressure algometry were used. For data analysis, we used parametric and non-parametric tests and a general linear model with adjustment variables and analysis of variance. A significant difference was found between pain threshold and tolerance, functionality, depression, anxiety, social support, and positive and negative affect between the groups. Affective states and social support were associated with anxiety, depression and functionality. A body was drawn representing pain with higher incidences in trapeze, supraspinatus and second ribs. The reason for studying sensory aspects, affective behavior and social support in FM patients opens perspectives for scientific and clinical research of this syndrome. Women with chronic pain such as FM appear to have altered mood states, less social support and affective dysfunctions, influencing the other symptoms of the syndrome

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Introduction: Population aging in Brazil underscores the need to discuss the proper management of the budget allocated in health field, especially in the sectors of high complexity, where coexist costly procedures, limited resources and the need for cost containment. In the other hand, demand is growing in a way directly proportional to the increase in the number of elderly in country. Objective: In this way, this research had as main objective to analyze the costs resulting from the admission of elderly in intensive care units (ICU) and its associated factors. Methods: This is a cross-sectional study with a quantitative approach and featured as a descriptive and exploratory research. Data were collected from medical records of elderly hospitalized in ICU from a brazilian city called Natal-RN, between november first, 2013 and january, 31 of 2014. The variables collected relate to the socio demographic profile, morbidity framework and characterization of hospitalization. The dependent variable was categorized by quartile 75 in high and low expense of hospitalization and submitted to chi-square test with the independent variables of the survey. Associations with p value <0.20 in the bivariate analysis were submitted to the technique of multiple logistic regression. We opted for the construction of three regression models from the above algorithm: general regression model, composed by all 493 hospitalizations in the study, other made with 181 individuals admitted in health public system (SUS) and a third one related to 312 cases from private service in health area. Results: In the general regression model, the variables respiratory diseases, hospitalizations in the private system, disoriented patient and previous stroke were associated with greater probability of high spending in the ICU. In the other hand, in SUS kind of hospitalizations, this probability was associated with disoriented patient, 80 years old or more, sepsis and admission for clinical reason. In the cases from the private network health, the high expenditure was associated with respiratory disease, mechanical ventilation, hospitalization for clinical reason and disoriented patients. Conclusion: The increased expenditure on hospitalization of elderly in intensive care depends on the clinical conditions of individuals. This highlights the importance of avoiding hospitalizations due to diseases sensitive to primary care by health preventive actions and providing comprehensive care to the elderly. In addition, obtaining different explanatory models, according to kind hospital funding, demonstrates the importance of the organization in health services related to composition of costs of hospitalization among the elderly. Another question founded was the need that to improve the funding, we must use rationally the available resources by avoiding unnecessary hospitalizations of elderly people in the extremes of severity. On this kind of precarious funding, ICU hospitalization of elderly non-critical or in a terminal state can compromise the quality of services provided to those who really need intensive care.