Resumen: En este trabajo se realiza un estudio numérico del flujo de aire de un soplador para la selección de la papa amarilla Tumbay. Se aplica la técnica de volúmenes finitos para resolver las ecuaciones de continuidad, momento y energía. Se consideran el fluido con comportamiento de gas ideal con densidad variable y el modelo de turbulencia SST. La simulación tiene un flujo de entrada, a diferentes presiones, el cual impacta sobre la papa Tumbay cuando se identifica alguna anomalía. Los resultados muestran que un chorro de aire a través de un soplador tiene la fuerza de impacto suficiente para desviar la trayectoria deseada del tubérculo, separándolo del grupo de otra clase. Se concluye que la combinación de herramientas computacionales de método de elementos discretos y la dinámica de fluidos computacional (DEM-CFD) permite describir la iteración del flujo de aire impactando con la papa provocando un desvío en su trayectoria.

Abstract: In this research study, a numerical analysis of a blower’s airflow is conducted to sort Tumbay yellow potatoes. The finite volume technique is applied to solve the continuity, momentum, and energy equations. The analysis considers a fluid with ideal gas behavior and with variable density. The SST turbulence model is applied. The simulation has an inlet flow, at different pressures, that impacts a Tumbay yellow potato when any anomaly is identified. The results show that the air jet through a blower has sufficient impact force to deflect the trajectory of a tuber, successfully separating it from other class groups. It is concluded that the combination of computational tools with discrete element methods and computational fluid dynamics (DEM-CFD) allows to accurately describe the air flow’s impact on a potato and its and posterior deviation from its trajectory.

Abstract The tribological behavior of moving components and tooling in the automotive industry is a critical issue for improving tool life and increasing efficiency. This work discusses the effects of Zn and ZnO nanoparticle additives homogeneously dispersed within a metal-forming synthetic fluid at various filler fractions: 0.01, 0.05 and 0.10wt.%. Nanolubricants were evaluated under scuffing conditions at extreme pressures (EP) conditions using a four-ball tribotester in order to obtain the load-carrying capacity (pοz) behavior, and overall tribological characteristics. This method has shown, with great precision, the influence of the nanofillers on the EP behavior of conventional lubricants. Worn surfaces were characterized through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) to determine the tribological mechanisms of nanoparticles. An Alicona 3D surface measuring system was used for measuring the surface roughness of the wear scars. Both nanoparticles exhibited better friction-reducing and anti-wear properties compared to the base synthetic fluid. For Zn-based nanolubricants, an enhancement of ~180% in ροz was obtained with 0.10wt.%, showing the effect of the spherical nanostructures that were tribosintered onto the surface due to the EPs of the test. Furthermore, the highest enhancement in pοz (up to 250%) was achieved with incorporation of 0.10wt.% of ZnO demonstrating the potential of nanolubricants for improving the efficiency of mechanical components.

Soldagem de ligas ferrosas tem sido amplamente utilizada por muitos anos no México. Com o advento da indústria aeroespacial , novas ligas , os processos e os desafios também. Um exemplo disto é o material de soldadura TIG 6AL4V como titânio usados em peças de aeronaves . Neste trabalho, ensaios mecânicos e não destrutivos , a fim de testar os parâmetros fixos e móveis para a obtenção de determinados critérios de qualidade para o processo e fornecer dados da indústria que vão melhorar esses processos foram realizados e ser competitivo. Para isso três níveis de parâmetros de entrada e calores foram selecionados para esta variável está relacionada com as características metalúrgicas e até certo ponto com a cura. Baixos níveis de alta, média e foram testados através da variação da tensão , corrente e velocidade constatação de que os valores assumidos não cumpriu a Charpy entalhe tenacidade. A fim de otimizar e alcançar o valor-alvo, um desenho composto central foi realizada utilizando a médio e tratamentos de alta apresentou melhores propriedades encontrando cumprimento dos critérios e parâmetros de qualidade e fornecimento de calor adequada para resposta óptima. O experimento não conseguiu melhorar a tenacidade da solda até 12 Joules cumprindo a resistência à tração , limite de escoamento e alongamento mínimo especificado para o material de base.

Welding of ferrous alloys has been widely used for many years in Mexico. With the arrival of the Aerospace industry, new alloys, processes and challenges as well. An example of this is the GTAW welding materials such as Titanium 6AL4V, which is applied in the manufacturing of aeronautical components. In this work, mechanical and non-destructive tests were carried out, in order to get fixed and adjustable parameters for achieving a suitable quality in the welding process and to provide data to the industry with which improving in this process is attainable. In order to reach the goal of this work, three heat levels and parameters were chosen and the results were related to the metallurgical characteristics of the weldment, with which a smooth weld can be achieved. High, medium and low parameters in voltage, amperage and speed were tested. There was found that the assumed values for the titanium welding did not meet the Charpy notch toughness. To optimize and achieve the target value, there was a central design using medium and high treatments that yielded best properties. The results met the critical to quality parameters; and the heat input was suitable for an optimal response. The results achieved with the experiment were an improvement on the toughness up to12 Joules. The other properties like tensile strength, yield strength and elongation fulfil the base metal specification.

La soldadura de aleaciones ferrosas ha sido ampliamente utilizada durante muchos años en México. Con la llegada de la industria Aeroespacial, nuevas aleaciones, procesos y retos también. Un ejemplo de esto es la soldadura GTAW en materiales como el Titanio 6Al4V utilizada en partes de los aviones. En este trabajo se realizaron pruebas mecánicas y no destructivas con la finalidad de probar parámetros fijos y móviles para la obtención de los criterios de calidad adecuadas al proceso y aportar a la industria datos que le permitan mejorar dichos procesos y ser competitiva. Para esto se seleccionaron tres niveles de parámetros y calores de aporte pues esta variable está relacionada con las características metalúrgicas y en cierto grado con la sanidad. Se probaron niveles altos, medios y bajos variando el voltaje, amperaje y la velocidad encontrando que los valores supuestos no cumplían la tenacidad a la entalla Charpy. Para optimizarlo y alcanzar el valor objetivo se realizó un diseño central compuesto utilizando los tratamientos medio y alto que arrojaron mejores propiedades encontrando el cumplimiento con las criterios de calidad y los parámetros, y el calor de aporte adecuados para tener una respuesta óptima. El experimento logró mejorar la tenacidad de la soldadura hasta 12 Joules cumpliendo con la resistencia a la tensión, esfuerzo de cedencia y elongación mínimo especificado para el material base.

Objetivo: O objetivo do trabalho é avaliar se a tenotomia de adutores e psoas é efetiva em controlar a luxação progressiva de pacientes tetraparéticos espásticos, nível motor V. Método: Foi feito um estudo retrospectivo de 26 pacientes operados na AACD-SP com a técnica cirúrgica de tenotomia de adutores e psoas em pacientes portadores de paralisia cerebral (PC) tetraparéticos espásticos, nível motor V. Avaliamos o índice de Reimers pré e pós-operatório e dividimos os pacientes em dois grupos: operados abaixo de cinco anos de idade e acima de cinco anos de idade. Os dados foram levados para análise estatística. Resultados: Com um seguimento de sete anos, os dois grupos tiveram, em sua maioria dos pacientes, o índice de Reimers diminuído quando comparados ao pré-operatório. Conclusão: A tenotomia dos adutores e psoas foi efetiva em evitar a progressão da luxação em pacientes com PC tetraparéticos, nível motor V. A idade do paciente na época da cirurgia não influenciou os resultados e sim o índice de Reimers elevado no pré-operatório e quadris assimétricos.

Objective: To assess if adductor and psoas release is effective in prevent hip displacement in quadriplegic Cerebral Palsy pacients, Gross motor V. Methods: A retrospective study with 26 patients who had psoas and adductor release was analyzed. Reimers Index before and after surgery was analysed. We divided the patients into two groups: surgery made in patients above five yars and after five years of age. Results: With a follow up of seven years, most of the patients of both groups had Reimers Index controlled by the surgery proposed. Conclusion: Adductor and psoas release was effective in controlled hip displacement in quadriplegic Cerebral Palsy patients, Gross Motor V. The age at the time of the surgery does not influence in the result.Reimers Index up to 70% and asymmetric hip not had good results.

A retrospective review of the clinical and demographic data was made in a teaching hospital of 950 beds. A consecutive sample of inpatients and outpatients with medical request of indirect immunofluorescence antinuclear antibodies test (IIF-ANA) in a period of 18 months was taken to define the positive predictive value (PPV) and the negative predictive value (NPP) of the IIF-ANA, anti-dsDNA antibodies, and anti-extractable nuclear antigens (anti-ENA) for the diagnosis of SLE and connectivopathies. The PPV and the NPP of the IIF-ANA for the detection of anti-DNA antibodies and anti-ENA were also calculated. It was found that 2 113 patients had been referred for the determination of IIF-ANA, of whom 273 were determined anti-doble strand DNA antibodies (anti-dsDNA) and 233 anti-extractable nuclear antigens (anti-ENA). 651 were registered with diagnosis of connective tissue disease (CTD), and 97 of them with systemic lupus erythematosus (SLE). The predicitive values of the positive results of IFI-ANA for the CTD and SLE were 59.8 and 22.8 %, respectively, whereas this same value of the anti-ENA for the CTD was 99.0 %, and that of the anti-dsDNA for the SLE was 97.3 %. The predictive values of the negative results of the IFI-ANA for the CTD and the SLE were 76.0 and 99.7 %, respectively. The predictive value of the negative results of the anti-ENA for the CTD was 28.4 % and that of the anti-dsDNA for the SLE was 87.9 %. It was concluded that most of the results of the IIF-ANA were negative and they were required for patients without connectivopathies, which gave rise to low predictive values and to a questionable clinical usefulness. These data suggest an inadequate overuse of the IIF-ANA test out of a logical clinical context. This situation may be corrected with a careful preselection of the patients based on the presence of various recognized clinical criteria of the connectivopathies.

Se hizo una revisión retrospectiva de datos clínicos y demográficos en un Hospital de Referencia Nacional de Salud de 950 camas. Se tomó una muestra consecutiva de pacientes hospitalizados y ambulatorios con solicitud médica de anticuerpos antinucleares por inmunofluorescencia indirecta (AAN-IFI) en un período de 18 meses para definir el valor predictivo positivo (VPP) y negativo (VPN) de los AAN-IFI, anticuerpos anti-DNA de doble cadena (anti-DNAdc) y anti-antígenos nucleares extraíbles (anti-ENA) para el diagnóstico del LES y de las conectivopatías, y el VPP y VPN de los AAN-IFI para la detección de los anticuerpos anti-DNAdc y anti-ENA. Se halló que 2 113 pacientes han sido referidos para la determinación de AAN-IFI, de los cuales a 273 se les determinó además anticuerpos anti-DNA de doble cadena (anti-DNAdc) y a 233 anti-antígenos nucleares extraíbles (anti-ENA); 651fueron registrados con el diagnóstico de enfermedad del tejido conectivo (ETC) y de estos, 97 con lupus eritematoso sistémico (LES). Los valores predictivos de los resultados positivos de AAN-IFI para las ETC y el LES fueron de 59,8 y 22,8 %, respectivamente, mientras que el de anti-ENA para las ETC fue 99,0 %, y el de anti-DNAdc para el LES fue 97,3 %. Los valores predictivos de los resultados negativos de AAN-IFI para las ETC y el LES fueron de 76,0 y 99,7 %, respectivamente, mientras que el de anti-ENA para las ETC fue 28,4 %, y el de anti-DNAdc para el LES fue 87,9 %. Se concluyó que la mayor parte de los resultados de AAN-IFI fueron negativos y solicitados en pacientes sin conectivopatías, lo que dio lugar a valores predictivos bajos y una utilidad clínica cuestionable. Estos datos sugieren una sobreutilización inadecuada de la prueba de AAN-IFI, fuera de un contexto clínico lógico. Esta situación puede corregirse con una esmerada preselección de los pacientes basada en la presencia de varios criterios clínicos reconocidos de las conectivopatías.

O objectivo fundamental desta revisão retrospectiva dos dados clínicos e do estudo do líquido céfalo-raquidiano (LCR) de 41 doentes com tumores intracranianos diagnosticados entre 197S e 1989 é analisar a importância do achado de células neoplásicas no LCR, principalmente quando o recurso à tomografia computorizada e ressonância magnética cerebrais era raro. Outro objectivo diz respeito ao estudo das alterações proteicas do LCR nos tumores cerebrais. A análise do LCR compreendeu a contagem celular, a observação dos quadros citomorfológicos obtidos após sedimentação, o doseamento das proteínas totais e a determinação dos perfis electroforéticos. Encontraram-se células tumorais em 12 doentes (29%): meduloblastomas - 6, meningites carcinomatosas - 3, glioblastoma multiforme - 1, ependimoma -1, metastases cerebrais -1; em 2 casos este achado foi inesperado. Na maior parte dos casos a localização do tumor perto do sistema ventricular favoreceu a exfoliação celular. Embora a pleocitose fosse rara e não se correlacionasse com a presença de células neoplásicas, verificámos que na maioria dos casos, incluindo todos aqueles com citologia "positiva", os quadros citomorfológicos eram patológicos. Os nossos resultados mostram que a pesquisa de células tumorais no LCR continua a ser util e o seu achado particularmente relevante quando inesperado.

The main objective of this retrospective review of clinical and cerebrospinal fluid (CSF) data from 41 patients with intracranial tumors diagnosed between 1975 and 1989, is to report the role that the finding of neoplastic cells in CSF plays, specially when cerebral CT-scanning and MRI were not currently done. Another objective is to study the CSF proteic abnormalities in cerebral tumors. CSF cell count, cytomorphologic pictures obtained after sedimentation and protein findings are described. Tumor cells were seen in 12 cases (29%): medulloblastomas - 6, meningeal carcinomatosis - 3, multiforme glioblastoma - 1, ependymoma -1, cerebral metastasis -1; in two cases it was an unexpected finding. We noticed that tumoral localization next to the ventricles favoured cell exfoliation. Although pleocytosis was rare and uncorrelated with the presence of neoplastic cells, pathological cytomorphologic pictures appeared in most of the cases including all "positive" ones. Our results stress that the appearance of neoplastic cells in CSF remains helpful specially when it is an unexpected finding.