Analysis of process variables via CFD to evaluate the performance of a FCC riser

Feedstock conversion and yield products are studied through a 3D model simulating the main reactor of the fluid catalytic cracking (FCC) process. Computational fluid dynamic (CFD) is used with Eulerian-Eulerian approach to predict the fluid catalytic cracking behavior. The model considers 12 lumps with catalyst deactivation by coke and poisoning by alkaline nitrides and polycyclic aromatic adsorption to estimate the kinetic behavior which, starting from a given feedstock, produces several cracking products. Different feedstock compositions are considered. The model is compared with sampling data at industrial operation conditions. The simulation model is able to represent accurately the products behavior for the different operating conditions considered. All the conditions considered were solved using a solver ANSYS CFX 14.0. The different operation process variables and hydrodynamic effects of the industrial riser of a fluid catalytic cracking (FCC) are evaluated. Predictions from the model are shown and comparison with experimental conversion and yields products are presented; recommendations are drawn to establish the conditions to obtain higher product yields in the industrial process

Cyclic scheduling of pulp digesters with integrated heating tasks

This paper addresses a multistage batch plant scheduling problem under energy constraints. These reflect the limited availability of a thermal heating utility that is shared among parallel digesters of different capacities for the production of pulp. Depending on the processing sequence, more or less steam will be available for a given digester, which will affect the duration of its heating stage and the overall cycle time. Such integrated heating tasks resemble direct heat integration, which has been addressed through models based on generic frameworks for process representation (e.g., State-Task Network, Resource-Task Network, State-Sequence Network) and relying on a single time grid, either discrete or continuous. A new multiple time grid continuous-time model is now proposed where the complex energy constraints are derived from the higher level modeling framework that is Generalized Disjunctive Programming. The results show a considerable better performance compared to RTN discrete and continuous-time formulations, due to a substantially lower integrality gap and model size

Survival Probability in Patients with Sickle Cell Anemia Using the Competitive Risk Statistical Model.

The clinical picture of patients with sickle cell anemia (SCA) is associated with several complications some of which could be fatal. The objective of this study is to analyze the causes of death and the effect of sex and age on survival of Brazilian patients with SCA. Data of patients with SCA who were seen and followed at HEMORIO for 15 years were retrospectively collected and analyzed. Statistical modeling was performed using survival analysis in the presence of competing risks estimating the covariate effects on a sub-distribution hazard function. Eight models were implemented, one for each cause of death. The cause-specific cumulative incidence function was also estimated. Males were most vulnerable for death from chronic organ damage (p = 0.0005) while females were most vulnerable for infection (p=0.03). Age was significantly associated (p ≤ 0.05) with death due to acute chest syndrome (ACS), infection, and death during crisis. The lower survival was related to death from infection, followed by death due to ACS. The independent variables age and sex were significantly associated with ACS, infection, chronic organ damage and death during crisis. These data could help Brazilian authorities strengthen public policies to protect this vulnerable population

Influencia de la práctica del Yang Shi Taijiquan en mujeres mayores de 70 años

The research was carried out in order to evaluate the influence of the practice of Yang Shi Taijiquan in women over 70 years old. An intervention-action study, divided into four phases, was carried out where the Wai San She Fa alternative was applied. Eight women between 70 and 74 years old were chosen, recently incorporated into the “José María Queralt” grandparents club and without previous experiences of these practices. To evaluate functional physical condition were used the Senior Fitness Test (SFT), the Wilcoxon rank test, and the data were processed through the SPSS statistical package.La investigación se realizó con la finalidad de evaluar la influencia de la práctica del Yang Shi Taijiquan en mujeres mayores de 70 años. Se realizó un estudio de intervención-acción, dividido en cuatro fases, donde se aplicó la alternativa Wai San He Fa. Se escogieron 8 mujeres entre 70 y 74 años, recién incorporadas al club de abuelos “José María Queralt” y sin experiencias previas de estas prácticas. Para evaluar la condición física funcional se utilizó el Senior Fitness Test (SFT), la prueba de rangos de Wilcoxon y se procesaron los datos a través del paquete estadístico SPSS

Spectral solution for the air stripping pollutants removal dynamic model with non linear steady state conditions

This work deals with the numerical simulation of air stripping process for the pre-treatment of groundwater used in human consumption. The model established in steady state presents an exponential solution that is used, together with the Tau Method, to get a spectral approach of the solution of the system of partial differential equations associated to the model in transient state

AVALIAÇÃO ECONÔMICO-FINANCEIRA DA CULTURA DE CURAUÁ (Ananas comosus var. erectifolius (L. B. Smith) Coppus & Leal: UM ESTUDO DE CASO NO MUNICÍPIO DE SANTO ANTÔNIO DO TAUÁ, ESTADO DO PARÁ.

O objetivo do trabalho foi analisar a viabilidade econômico-financeira da produção de curauá, a partir de informações provenientes de áreas de produção localizadas no município de Santo Antônio do Tauá, no Estado do Pará. Como metodologia utilizou-se de avaliação: Valor Presente Líquido, Taxa Interno de Retorno, Relação Benefício-Custo e Ponto de Equilíbrio. Os resultados mostraram alta rentabilidade do curauá, dadas as condições de cultivo dos produtores de Tauá, superando de longe as principais culturas cultivadas pelos produtores do Estado. Concluiu-se que o curauá apresenta ampla capacidade de distribuir renda e gerar emprego nas áreas rurais do estado do Pará.----------The objective of this paper was analyze the economic and financial viability of curaua plantation, from primary information proceeding of production areas located in the city of Santo Antonio do Taua, in State of Para. The methodology was based in evaluation criteria: Present Liquid Value, Internal Tax of Return, Benefit-Cost Index and Break-Even Point. The results showed a high yield of the curaua, under the Taua producers’ cultures conditions, surpassing the principal cultures cultivated by State producers. It was concluded that the curaua plant shows a high capacity of get away income and create jobs in rural areas of the State of Para.Benefício-custo, Curauá, Estado do Pará, Cost-Benefit, curaua, State of Para, Crop Production/Industries,

Short-Term scheduling of a polymer compounding plant

This paper addresses the optimal short-term scheduling of a three parallel production line plymer compounding plant, whose equipments require cleaning between product changeovers. A very effective user-friendly software tool was developed, which consists of a general scheduling model coupled with capabilities of Microsoft Excel for data handling and analysis. The scheduling model is based on a Resource Task Network discrete time formulation and leads to Mixed Integer Linear Programming problems. As outputs the user can access the optimal schedules for a number of different objectives

Estudo Laboratorial Do Comportamento Mecânico De Duas Molas

A possibilidade de quantificação e controlo da proporção M/F no bracket são a solução para um movimento dentário previsível e controlado. O presente trabalho teve por objectivo determinar o sistema de forças em (força horizontal, proporção M/F, proporção C/D) de molas com geometria em T e em L, para uma mesma dimensão vertical (7 mm) e distância inter-bracket (13 mm), com cinco diferentes dobras de pré-activação e para duas ligas metálicas (aço inoxidável e TMA) de secção 0.017" x 0.025". Foram submetidas ao ensaio mecânico 200 molas - 10 molas por cada pré-activação (5), liga metálica (2) e geometria (2). A intensidade da força horizontal e do momento foram quantificadas utilizando-se um aparelho OrthoMeasure Moment/force, uma mesa de testes e um comparador digital. Os valores foram registados a cada 0,5 mm de activação, para uma activação inicial de 1 mm e final de 6 mm. Os dados foram analisados estatisticamente utilizando a metodologia ANOVA para um nível de significância de 5%.Os resultados permitiram concluir da existência de diferenças de médias estatisticamente significativas em função da pré-activação em todos os tipos de molas (TMA L e T, aço L eT) ao nível da força e proporção M/F. Em relação à força, as molas em L registaram valores superiores à mola em T e confirmou-se a influência da localização da pré-activação na força. Em relação à proporção M/F as molas T registaram valores superiores às molas em L. Na ausência de pré-activação as molas em TMA registaram valores superiores às molas em aço, com o valor máximo registado, inferior à dimensão vertical da mola. Nas molas sem pré-activação verificou-se um aumento da proporção M/F com o aumento da activação, e um efeito contrário foi aferido nas molas com pré-activação. Na maioria das activações com molas pré-activadas, as de aço apresentaram valores de proporção M/F superiores às de TMA. O aumento da proporção M/F verificado com a inserção de dobras de pré-activação foi superior no caso da distribuição das dobras ser parcial ou totalmente gengival.A mola com melhor compromisso entre a força e a proporção M/F foi a mola T em TMA com pré-activação de 40º, no intervalo de activação entre 1 mm e 4 mm.The possibility to quantify, as well as to control M/F ratios in the brackets are the key for a controlled and predictable dental movement. The present work has the purpose of determining the force systems in α (horizontal force, M/F ratios, C/D ratios) of the T and L shaped loops for the same vertical dimension (7mm), as well as for the same inter-bracket distance (13 mm). With five different pre-activation bends and two metallic alloys (stainless steel and titanium-molibdenum alloy - TMA) with a section of 0,017"x 0,025" Two hundred loops were submitted to the mechanical essay - for each pre-activation ten loops were used (5), metallic alloy (2) and geometry (2). The moment and horizontal force intensities were quantified using the OrthoMeasure Moment apparatus, the testing table and a digital comparator. The values were registered every 0,5 mm of activation, with an initial activation of 1 mm and a final activation of 6 mm. The data was statistically analysed using the ANOVA methodology for a significance level of 5%. The results allowed us to conclude that there are statistically significant average differences according to the pre-activation in all kinds of loops (TMA L, and T, steel L and T) at strength and ratio M/F levels. As to what concerns force, L loops registered higher values than T loops and the influence from pre-activation of force localization was confirmed. As to what concerns M/F ratios, T loops registered higher values than L loops. In the absence of pre-activations, the TMA loops presented higher values than steel loops, the maximum registered level being inferior to the vertical dimension of the loop. In the loops without pre-activation, an augmentation on the M/F ratio was demonstrated through an activation augmentation, an opposite was assessed in pre-activated loops. In most of the activations with pre-activated loops, the steel presented M/F ratio values higher than TMA. The increase in M/F ratio, assessed with the insertion of pre-activation bends, was higher when the bend distribution was partial or completely gingival. The loop presenting the best compromise between force and M/F ratio was the T loop in TMA, with a pre-activation of 40º, in the 1 mm to 4 mm activation interval

Manifestações urinárias e sexuais em pacientes infectados pelo HTLV-I

HTLV-I is considered to be a virus of low morbidity, since the principal diseases associated with this viral infection, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia/lymphoma (ATLL), are observed in less than 5% of infected individuals. Urinary symptoms are frequent in patients with myelopathy and consist principally of nocturia, frequency, urgency, and urinary incontinence; however, the importance of these dysfunctions and their correlation with myelopathy is still to be fully clarified. This review gives particular emphasis to the high frequency of urinary and sexual complaints not only in patients with myelopathy but also in individuals considered to be HTLV-I carriers. Detrusor overactivity and bladder-sphincter dyssynergia are the most common urodynamic findings. The fact that urinary complaints and urodynamic parameters reported in individuals considered to be carriers are similar to those detected in patients with myelopathy supports the hypothesis that urinary disorders may represent an oligosymptomatic form of HAM/TSP. Erectile dysfunction is frequently observed in HTLV-I-infected patients with or without myelopathy. Urinary tract infections are also highly prevalent in these patients. Despite the lack of an effective treatment for myelopathy, the use of anticholinergic drugs and phosphodiesterase type 5 (PDE5) inhibitors may improve urinary complaints and erectile dysfunction in these patients.O HTLV-1 é considerado um vírus de baixa morbidade sendo a mielopatia associada ao HTLV-1 (HAM/TSP) e a leucemia / linfoma de células T do adulto (ATL) as principais doenças associadas à infecção viral, observados em menos de 5% dos indivíduos infectados. Manifestações urinárias são freqüentes em pacientes com mielopatia, e representadas principalmente por noctúria, polaciúria, urgência e incontinência urinária, embora a importância destas alterações, e a correlação com a patologia medular não tem sido devidamente estudada. Nesta revisão enfatizamos a elevada freqüência de queixas urinárias e sexuais em pacientes, não apenas os portadores de mielopatias, mas também em indivíduos considerados como portadores assintomáticos do HTLV-I. Hiperatividade detrusora e dissinergia vesico-esfincteriana são as manifestações urodinâmicas mais freqüentes. A documentação de queixas urinárias e os achados urodinâmicos observados em indivíduos considerados portadores assintomáticos são semelhantes aos detectados em pacientes com mielopatia dão suporte à hipótese que alterações urinárias possam representar uma forma oligossintomática da HAM/TSP. Disfunção eréctil é freqüentemente observada em pacientes infectados pelo HTLV-1, com ou sem mielopatia. Infecção do trato urinário também tem elevada prevalência nestes pacientes. A despeito da ausência de um tratamento efetivo da mielopatia, o uso de anticolinérgicos e de inibidores da fosfodiesterase tipo 5 podem melhorar as queixas urinárias e a disfunção eréctil destes pacientes