ABSTRACT The aim of this article was to study the impact of tax installment plans on the tax aggressiveness of Brazilian listed companies. Despite the relevance and timeliness of the topic, there are no studies that examine the use of special tax installment plans as a determinant of the tax aggressiveness of Brazilian listed companies. Tax installment plans have been used repeatedly by Brazilian companies and the number of adherents has grown significantly over time, where this resource can be understood by companies from the perspectives of tax regularization and tax savings. The research contributes to the scientific knowledge on the subject by providing evidence on the determinants of tax aggressiveness, and it is believed that the government can use the results to improve the offer of tax installment plans and the understanding of tax legislation, such as through the development of restrictions on access to installment plans, by allocating them to companies in real financial difficulties, as well as through improvements in its inspection process, considering that companies that pay taxes in installments are more tax aggressive. The data were obtained from explanatory notes, through the Ministry of the Economy’s access to information service, and from the Economatica® database. The Special Tax Regularization Program (PERT) 2017 was used as a reference for tax installment plans, and tax aggressiveness was measured using the effective tax rate (ETR), ETR Cash, and book tax difference (BTD). The period analyzed is from 2017 to 2020, and the statistical method applied was multiple linear regression for panel data with random effects. The results show that companies that choose to pay their taxes in installments tend to take a more aggressive tax position. The evidence contributes to extending the theory of the determinants of tax aggressiveness and can help the government in its inspections and in improving tax installment offers and tax benefits.

RESUMO O objetivo deste artigo foi verificar a influência do parcelamento tributário na agressividade fiscal de empresas brasileiras abertas. Apesar da relevância e atualidade do tema, não há estudos que tratam do uso do parcelamento tributário especial como determinante da agressividade fiscal de empresas brasileiras abertas. O parcelamento tributário tem sido utilizado de forma recorrente pelas empresas brasileiras e o número de adesões tem crescido significativamente ao longo do tempo, quando esse recurso pode ser compreendido pelas empresas sob as perspectivas de regularização fiscal e economia tributária. A pesquisa contribui para o conhecimento científico da temática ao disponibilizar evidências a respeito dos determinantes da agressividade fiscal, e acredita-se que o governo possa fazer uso dos resultados para aprimorar as ofertas de parcelamentos tributários e melhorias de entendimento na legislação tributária, como elaboração de restrições para acesso aos parcelamentos, ao destiná-los para empresas com reais dificuldades financeiras, assim como aperfeiçoamento de seu processo de fiscalização, considerando que as empresas que parcelam tributos são mais agressivas tributariamente. Os dados foram obtidos em notas explicativas, por meio do serviço de acesso à informação do Ministério da Economia e no banco de dados Economatica®. Utilizou-se do Programa Especial de Regularização Tributária (PERT) 2017 como referência ao parcelamento tributário, e a agressividade fiscal foi mensurada por meio da effective tax rate (ETR), ETR Cash e book tax difference (BTD). O período analisado refere-se a 2017 a 2020 e o método estatístico aplicado foi a regressão linear múltipla para dados em painel com efeitos aleatórios. Os resultados revelam que empresas que optam por parcelar seus tributos tendem a assumir uma posição mais agressiva tributariamente. As evidências contribuem para expansão da teoria de determinantes da agressividade fiscal e podem auxiliar o governo em suas fiscalizações e aprimoramento de ofertas de parcelamentos tributários e benefícios fiscais.

Resumo Células solares com emissor e face posterior passivada (PERC, passivated emitter and rear cell) vêm dominando o mercado fotovoltaico em razão de seu processo de fabricação ser compatível com as linhas industriais que vinham sendo utilizadas e pela produção de dispositivos de alta eficiência. Atualmente o silício tipo p é o mais utilizado pela indústria de células solares, mas o silício tipo n deve ganhar mercado nos próximos anos juntamente com o emprego de lâminas de espessura reduzida. O objetivo deste trabalho é apresentar uma revisão sistemática dos principais estudos na área de células solares base n, sendo elas do tipo PERC, PERT (passivated emitter-rear totally diffused) e TOPCon (tunnel oxide passivated contact), com ênfase para a abordagem de contatos seletivos, emissores seletivos e nos processos utilizados, bem como na análise de células solares de espessura reduzida em relação ao padrão da indústria atual.

Abstract The PERC (passivated emitter and rear cell) solar cells have been dominating the competitive photovoltaic market due to their manufacturing process being compatible with the industrial lines that were being used and to produce high efficiency devices. Currently, p-type silicon is the most used by the solar cell industry, but n-type silicon should gain market in the coming years along with the use of thinner wafers. This work is a systematic review that aims to find the main recent studies in the field of n-type solar cells, like PERC, PERT (passivated emitter-rear totally diffused), and TOPCon (tunnel oxide passivated contact), with emphasis on the selective contacts and selective emitters and the processes to obtain them, as well as the analysis of solar cells of reduced thickness in relation to the current industrial standard.

Background: Alcohol and tobacco are important risk factors for chronic pancreatitis (CP). Aim: To analyze the effect of etiological factors such as tobacco and alcohol and pancreatic enzyme replacement therapy (PERT) in the progression of CP. Material and Methods: Patients with a diagnosis of CP were recruited and grouped according to variables such as tobacco, alcohol and PERT. They were followed for 18 months. Subsequently, different variables and analytical parameters involved in the progression of the disease were analyzed. Results: A total of 50 patients diagnosed with CP were included. Of these, 28 patients underwent PERT, 39 were smokers and 33 were alcohol users. Compared with patients without PERT, those with PERT had a higher proportion of diabetes (64 and 32%, respectively), had a higher need for endoscopic treatment (25 and 0%, respectively) and a normal body mass index (71 and 27.3%, respectively. The smokers had higher calcium levels and increased lymphocytosis and leukocytosis. The alcohol consumption group had a higher mean age (p = 0.04) Conclusions: PERT may improve the nutritional status but does not reduce the need for endoscopic or surgical treatment. Smoking and alcohol consumption favored the progression of CP. Also, smoking induced a pro-inflammatory state.

Abstract In this paper, a probabilistic methodology to estimate fundamental decision variables of the theory of seismic resilience of buildings is presented: repair costs, repair time, recovery time and number of workers needed to perform the rehabilitation works. The proposed evaluation scheme is based on the recursive PERT method and is consistent with the probabilistic methodology for evaluating performance proposed by PEER and with the concept of resilience developed by MCEER. To illustrate the methodology, the evaluation of a seven-story reinforced concrete building with unreinforced masonry infill walls and designed in accordance with the Complementary Technical Norms - Seismic Design (2020) is presented. This structural system is typical of office buildings. The proposed methodology can be used to increase the seismic resilience of buildings, and to establish mitigation and recovery strategies not only for individual buildings, but also for groups of buildings.

Resumen En este trabajo se presenta una metodología probabilista para estimar variables de decisión fundamentales de la teoría de la resiliencia sísmica de edificios: costos de reparación, tiempo de reparación, tiempo de recuperación y número de trabajadores necesarios para realizar los trabajos de rehabilitación. El esquema de evaluación propuesto está basado en el método recursivo PERT y es consistente con la metodología probabilista para evaluar el desempeño propuesta por el PEER y con el concepto de resiliencia desarrollado por el MCEER. Para ilustrar la metodología se presenta la evaluación de un edificio de concreto reforzado de siete niveles de altura diseñado de acuerdo con las Normas Técnicas Complementarias-Diseño por Sismo (2020) y en el que se consideran muros de mampostería no reforzada. Este sistema estructural es típico de los edificios para uso de oficinas. La metodología propuesta puede ser utilizada para incrementar la resiliencia sísmica de edificios, y para establecer estrategias de mitigación y recuperación no solo de edificios individuales, sino de conjuntos de edificios.

Resumo Introdução: Alterações causadas no metabolismo de quem pratica exercício físico constantemente geram benefícios à saúde. Em atletas, porém, causam danos musculares e por isso métodos de recuperação pós-esforço são de extrema importância para a manutenção fisiológica de atletas. Objetivo: Analisar a eficácia da técnica de contraste com recuperação pós-esforço segundo atletas profissionais. Métodos: Aplicou-se um questionário online que abordou o conhecimento técnico científico de atletas profissionais acima de 18 anos, de ambos os sexos, sobre técnicas de recuperação pós-esforço (TRPE), informações pessoais e questões éticas. Realizou-se análise estatística descritiva, onde os valores foram apresentados em percentuais, e associação através do teste qui-quadrado sobre o conhecimento das TRPE e demais variáveis independentes. Resultados: Responderam ao questionário online 63 atletas, 15 mulheres e 48 homens, sendo que 71,4% tinham entre 18 e 30 anos de idade. Estes eram nadadores, futebolistas e praticantes de atletismo; 85,7% possuíam experiência superior a três anos na modalidade e 57,1% competiam em nível internacional. Sobre as principais TRPE, 92,1% tinham conhecimento, 58,7% conheciam mais de quatro, 96,8% usavam com frequência ao menos uma TRPE e 65,1% utilizavam a mais de três anos. O conhecimento de TRPE está associado à idade (p = 0,001), escolaridade (p = 0,001), tempo de prática (p = 0,001), horas de treino diário (0,001) e nível competitivo (p = 0,03). Quanto ao uso da técnica de contraste, 36,5% dos respondentes já a haviam utilizado e, destes, 34,9% a consideram efetiva. Conclusão: Os atletas que utilizaram a técnica de contraste relataram boa percepção de recuperação.

Abstract Introduction: Alterations caused in the metabolism of those who practice physical exercise regularly generate health benefits, however, in athletes, these alterations can cause muscle damage, so post-recovery recovery methods are extremely important for their physiological maintenance. Objective: To analyze the effectiveness of the contrast therapy technique with post-exercise recovery according to professional athletes. Methods: A questionnaire was applied that addressed the technical scientific knowledge of professional athletes over 18 years of age, of both sexes, about post-exerciseffort recovery techniques (PERT), personal information, and ethical issues, on an online platform. Descriptive statistical analysis was performed, with values presented in percentages and an association through the Chi-Square test on the knowledge of PERT and other independent variables. Results: In total, 63 athletes, 15 women and 48 men, answered the online questionnaire, 71.4% were between 18 and 30 years old, including swimmers, footballers, and athletics practitioners, and 85.7% had more than three years' experience in the sport and 57.1% competed at an international level. Considering the main PERTs, 92.1% were aware, 58.7% knew more than four, 96.8% frequently used at least one PERT, and 65.1% had used it for more than three years. Knowledge of PERTs is associated with age (p = 0.001), education (p = 0.001), practice time (p = 0.001), hours of daily training (0.001), and competitive level (p = 0.03). With respect to the use of the contrast technique, 36.5% of the respondents had already used it, and 34.9% found it effective. Conclusion: The athletes who used the contrast technique reported a good perception of recovery.

Titanium dioxide was extensively used in solar cell industry and currently has been studied to produce passivated contacts in PERC/PERT and TOPCon solar cells. The aim of this paper was to analyze the impact of the thickness of TiO2 thin films deposited by electro-beam evaporation on the weighted reflectance and the surface passivation on silicon solar cells. Thin films with different thicknesses were deposited to produce PERT solar cells, varying from 50 to 90 nm. The surface passivation was enhanced as the thickness was increased. For instance, at 400 nm, the internal quantum efficiency increased from 71% to 76% when the thickness of the TiO2 was augmented from 50 nm to 90 nm. The lowest weighted reflectance was obtained in samples with 80 nm thick TiO2 films. Considering the compromise between antireflection properties and surface passivation, the highest efficiency solar cells were produced with 80 nm thick TiO2.

ABSTRACT The aim of this study was to determine the prevalence of Cryptococcus neoformans in faeces of domestic pigeons (Columba livia) in public places in the city of Lima, Peru, in 2015-2016. Samples of dried faeces were collected from pigeon lofts from captive-bred racing pigeons and from public places for free-living pigeons. The samples were processed and cultured on Sabouraud dextrose agar and incubated at 37 °C up to 10 days. Colonies were identified through macroscopic evaluation, capsule visualization with Indian ink, urease test, sugar assimilation, rapid nitrate reduction, phenol oxidase test and growth on CGB agar. A frequency of 5.16% (16/310) of positive samples for C. neoformans in faeces of both types of pigeons was determined. In the faeces of homing pigeons was 8.89% (16/180), while there were no positive samples in the captive-bred racing pigeons. The stochastic Beta Pert simulation (@Risk 5.5(r)) a minimum and maximum prevalence for the study of 4.59 and 5.61%, respectively. Cryptococcus neoformans is present in the feces of homing pigeons in the city of Lima, Peru.

RESUMEN El objetivo del presente estudio fue determinar la prevalencia de Cryptococcus neoformans en heces de palomas domésticas (Columba livia) en lugares públicos de la ciudad de Lima, Perú, en 2015-2016. Se recolectaron muestras de heces secas en palomares de palomas mensajeras criadas en cautiverio y en ambientes públicos de palomas de Castilla. Las muestras fueron procesadas y sembradas en agar Sabouraud dextrosa, e incubadas a 37 °C hasta por 10 días. Las colonias fueron identificadas a través de la evaluación macroscópica, visualización de cápsula con tinta china, prueba de ureasa, asimilación de azúcares, reducción rápida de nitrato, prueba de fenoloxidasa y crecimiento en agar CGB. Se determinó una frecuencia de 5.16% (16/310) de muestras positivas a C. neoformans en heces de ambos tipos de palomas evaluadas. En las heces de palomas de Castilla fue de 8.89% (16/180), en tanto que no hubo muestras positivas en las palomas mensajeras. En la simulación estocástica Beta Pert (@Risk 5.5(r)) se determinó una prevalencia mínima y máxima para el estudio de 4.59 y 5.61%, respectivamente. Se concluye que Cryptococcus neoformans se encuentra presente en heces de palomas Castilla en la ciudad de Lima, Perú.

Abstract Background: Fast-track worldwide reperfusion programs improve outcomes in ST-elevation myocardial infarction and stroke. Similar programs called Program Evaluation and Review Technique (PERT) focus on submassive and massive pulmonary embolism (PE) excluding deep venous thrombosis (DVT). Methods: PREVENTION-team (Hospital Zambrano Hellion Venous Thromboembolism [VTE] Rapid Response). Primary objective: Fast-track stratification, diagnostics, and treatment (60-90 min) to improve proximal DVT and submassive and massive PE patients care. Secondary objectives: Increase diagnosis rate of low-risk PE and distal DVT; exploration of cause; long-term anticoagulation; identify high-risk profile for chronic complications; community-based support groups and patient education to extend the concept of the thrombosis-free hospital to thrombosis-free home. Structure and organization: The team includes cardiologists, vascular medicine, angiologist, echocardiographer, cardiovascular imaging, and interventional cardiologists. The team will be accessible 24 h a day, 7 days a week, 365 days a year, and base on previous national experience. The cardiology fellow on call will be responsible for activation and evaluation. We will design several tools to accelerate these processes. Risk stratification and therapeutic approach will be based on clinical presentation, echocardiogram, and biomarkers findings. According to PERT stratification based on resources and medical specialties, Hospital Zambrano Hellion has level 1 PERT. PREVENTION-team links physicians with different expertise, provide fast, efficient, and time-saving treatment, potentially saving lives and reducing bleeding and chronic complications in VTE patients. Finally, establishing a network in our hospital and health system to improve VTE patients care. To the best of our knowledge, this is the first rapid response team focused on VTE in Mexico.

Resumen Antecedentes: Programas de reperfusión mejoraron la evolución en infarto con elevación del ST y accidente cerebrovascular embólico. Programas similares llamados PERT para TEP masiva o submasiva excluyen TVP. Métodos: Equipo PREVENTION (Hospital Zambrano Hellion Venous Thromboembolism Rapid Response). Objetivo primario: Estratificación, diagnóstico y tratamiento acelerado (60-90 minutos) para mejorar atención del TVP proximal y TEP masiva o submasiva. Objetivos secundarios: Incrementar diagnóstico de TEP de riesgo bajo y TVP distal; explorar causa; anticoagulación a largo plazo; perfil de riesgo alto para complicaciones crónicas; grupos de soporte en la comunidad y educación para pacientes, y extender el concepto de hospital libre de trombosis a hogar libre de trombosis. Estructura y organización: Incluye cardiólogos, medicina vascular, angiólogo, ecocardiografistas, imagen cardiovascular. Basado en experiencia nacional, el equipo estará accesible 24 horas del día, siete días de la semana, 365 días del año. El residente de cardiología realizará la activación y estratificación. Diseñamos herramientas para acelerar el proceso. La estratificación de riesgo y el abordaje terapéutico se basará en presentación clínica, hallazgos ecocardiograficos y biomarcadores. El Hospital Zambrano Hellion tiene nivel PERT 1 de acuerdo a la estratificación PERT basada en recursos y especialidades. Equipo-PREVENTION en TEV vincula médicos con diferentes capacidades, ofrece rápido y eficiente tratamiento para preservar vidas y reducir complicaciones hemorrágicas y crónicas. En nuestro hospital y sistema de salud establecer una sólida red de trabajo para mejorar la atención. Hasta nuestro conocimiento, en México este podría ser el primer equipo de respuesta rápida enfocado en TEV.

En la industria de la construcción, planificar y controlar el cronograma de obra son importantes, debido a que se cometen errores al realizar la programación inicial del proyecto, ya que durante la ejecución de la obra se generan retrasos entre actividades al usar métodos convencionales como CPM y PERT por una ineficiente gestión del tiempo. Este trabajo de investigación determina los beneficios en la gestión del tiempo al aplicar la programación por Líneas de Balance (LDB), en la construcción de muros anclados del tercer anillo de una edificación, dado que este método facilita la visualización de actividades en el cronograma, lo que ayuda a identificar los conflictos entre las tareas antes de que estos se realicen. Se analiza las velocidades y rendimientos, de datos obtenidos de los cronogramas real y meta llevados a cabo con el método de LDB, para analizar la diferencia de velocidades representándolo en porcentajes, donde se evalúa aquellos sectores y partidas que generan retrasos o adelantos en el cronograma. Con base en los resultados obtenidos, el método LDB mejora la gestión del tiempo en 3.57% con relación a las velocidades de avance, empleando mejoras en el ratio y mano de obra a través del control del cronograma por porcentajes de avance de las actividades relativo a lo planificado. Además, se implementa un diagrama de flujo para una mejor aplicación de las LDB, en el control del proceso de las actividades de muros anclados, esto a diferencia de otros estudios previos realizados.

In the construction industry, planning and controlling the construction schedule are important, because mistakes are made in the initial scheduling of the project, as during the execution of the work delays are generated between activities using conventional methods such as CPM and PERT by inefficient time management. In this research work, the benefits in time management were determined by applying the programming by Balance Lines (LOB), in the construction of anchored walls of the third ring of a building, given that this method facilitates the visualization of activities in the schedule, which helps to identify conflicts between tasks before they are performed. We analyzed the velocities and yields of data obtained from the real and target schedules carried out with the LOB method, to analyze the difference in velocities representing it in percentages, where we evaluated those sectors and activities that generate delays or advances in the schedule. Based on the results obtained, the LOB method improved time management by 3.57% in relation to velocities, employing improvements in the ratio and labor through the control of the schedule by percentages of progress of the activities relative to what was planned. In addition, a flow chart was implemented for a better application of the LOB, in the control of the process of the activities of anchored walls, this unlike previous studies.

Abstract: Objective: To determine the degree of correlation in the radiological bone age assessment using the Greulich and Pyle method versus automated assessment through BoneXpert® software between 2013 and 2016. Material and Method: Correlation study of diagnostic techniques of 1500 carpal X-rays to assess bone age in patients under 16 years of age from Clínica Alemana de Santiago. X-rays with bone age assessment using the Atlas of Greulich and Pyle (GP) by 1 out of 7 pediatric radiologists, were analyzed using the BoneXpert (BE) software for automated bone age assessment. 100 cases were taken at random for analysis/re-analysis using the BoneXpert method to determine its accuracy. The level of correlation of the measurements was analyzed using the correlation coefficient (Pearson’s r) and the variability of the measurements using the Bland-Altman analysis. Results: 1493 cases were assessed, seven were excluded due to failure in the X-ray technique, 922 females (61.8%), with a median chronological age of 9.96 years and 11.12 years for males (p 0.001). The correlation between manual bone age (GP) and automated bone age using BoneXpert method among radiologists ran ged from 0.91 to 0.93. The Bland-Altman analysis indicated an average difference between manual bone age and bone age using the BoneXpert method of 0.19 years (CI 0.13 to 0.25). In the analysis/ re-analysis of 100 random cases using the BoneXpert software, the correlation was 1.00 (100% accu racy). Conclusion: The automated analysis using BoneXpert allows for standardized, low-variability, and high-concordance assessment.

Resumen: Objetivo: Determinar el grado de correlación en la valoración de la edad ósea radiológica mediante el método de Greulich y Pyle versus la evaluación automatizada por el programa computacional BoneXpert® entre los años 2013-2016. Material y Método: Estudio de correlación de técnicas diag nósticas de 1500 radiografías de carpo para evaluar la edad ósea, en pacientes menores de 16 años pertenecientes a Clínica Alemana de Santiago. Las radiografías con evaluación de la edad ósea por el Atlas de Greulich y Pyle (GP) por 1 de 7 radiólogos pediatras fueron sometidas al programa BoneX pert (BE) para la evaluación automatizada de la edad ósea. Se tomó 100 casos al azar para un análisis/ re-análisis del método BE, para conocer su precisión. Se analizó el nivel de correlación de las medicio nes por coeficiente de correlación (r de Pearson) y la variabilidad de las mediciones mediante análisis de Bland-Altman. Resultados: Se incluyeron 1.493 casos, se excluyeron 7 por falla en técnica de la radiografía, 922 de sexo femenino (61.8%), mediana de edad cronológica 9.96 años y 11.12 años para los varones (p 0,001). La correlación entre la edad ósea manual GP y la edad ósea automatizada BE entre los lectores varió entre 0,91 y 0,93. El análisis de Bland-Altman indicó una diferencia promedio entre la edad ósea manual y la edad ósea BE de 0,19 años (IC 0,13 a 0,25). En el análisis/re-análisis de 100 casos al azar mediante BoneXpert, la correlación fue de 1,0. Conclusión: El análisis automatizado mediante BoneXpert permite una evaluación estandarizada, de baja variabilidad, y alta concordancia.

Objectives: Pancreatic enzyme replacement therapy (PERT) remains a backbone in the nutritional treatment of cystic fibrosis. Currently, there is a lack of an evidence-based tool that allows dose adjustment. To date, no studies have found an association between PERT dose and fat absorption. Therefore, the aim of the study was to assess the influence of both the PERT dose and the variability in this dose on the coefficient of fat absorption (CFA). Methods: This is a retrospective longitudinal study of 16 pediatric patients (192 food records) with three consecutive visits to the hospital over a twelve-month period. Dietary fat intake and PERT were assessed via a four-day food record and fat content in stools was determined by means of a three-day stool sample collection. A beta regression model was built to explain the association between the CFA and the interaction between the PERT dose (lipase units [LU]/g dietary fat) and the variability in the PERT dose (standard deviation [SD]). Results: The coefficient of fat absorption increased with the PERT dose when the variability in the dose was low. In contrast, even at the highest PERT dose values, the CFA decreased when the variability was high. The confidence interval suggested an association, although the analysis was not statistically significant. Conclusion: The variability in the PERT dose adjustment should be taken into consideration when performing studies on PERT efficiency. A clinical goal should be the maintenance of a constant PERT dose rather than trying to obtain an optimal value.

Abstract: It is a well-known argument that many of the technological innovations that we use daily have been invented for war. However, we know less about the impact of those developments on architecture. With Cold War as backdrop, this research shows how management tools developed during the postwar period had an impact on architecture’s work processes, making its fluent insertion among the logics of capitalism possible.

Resumen: Es conocido el argumento de que muchas de las innovaciones tecnológicas que habitualmente usamos tienen su origen en la guerra. Sin embargo, se ha dicho menos sobre cómo esos desarrollos han impactado en la arquitectura. Con la Guerra Fría como telón de fondo, esta investigación nos muestra cómo los instrumentos del management desarrollados en la posguerra, tuvieron un impacto en los procesos de trabajo de la arquitectura, posibilitando su inserción más fluida en las lógicas del capitalismo.

CPM and PERT are well established as the main tools to plan and control construction projects. However, the planning and control of construction field operations has to consider the minute-by-minute complexity of bringing multiple resources together to produce a work package. At this level, the quality of each resource has major effects on the productivity, quality or safety. The rapidly changing dynamic nature of the site and the shifting quality of critical factors requires a new model to achieve zero-process waste. This paper presents a new construction management model that embraces a waste-based feed-forward control methodology designed to eliminate process- or muda-waste rather than high productivity. It extends the concept of the seven mudas by Taiichi Ohno to include all construction specific wastes. Of special interest of the discussed work is the waste effect of poor communication along the supply chain. After discussing the rational of the model the paper highlights the results of field observations in the area of foundations and steel construction. Wireless cameras were used for continuous-time studies to measure productive and wasted labor-hours before and after changes in the material supply logistics were implemented.

Los métodos CPM y PERT se encuentran bien establecidos como la principal herramienta de planificación y control de proyectos de construcción. Sin embargo, la planificación y el control de operaciones de construcción en terreno tienen que considerar la complejidad del día a día de utilizar múltiples recursos al mismo tiempo para elaborar un paquete de trabajo. A este nivel, la calidad de cada recurso tiene grandes efectos en la productividad, calidad o seguridad. Los rápidos cambios debido a la naturaleza dinámica en terreno y los cambios de calidad de los factores críticos requieren de un nuevo modelo para conseguir procesos con cero pérdidas. Este documento presenta un nuevo modelo de gestión de construcción que aprovecha la metodología de control por prealimentación basado en el desperdicio, diseñado para eliminar pérdidas o muda en los procesos en vez de aumentar la productividad. Éste amplía el concepto de los siete mudas de Taiichi Ohno que incluye todos los desperdicios específicos del proceso de construcción. De especial interés en el trabajo es el efecto del desperdicio por una mala comunicación a lo largo de la cadena de suministro. Después de discutir la lógica del modelo, este estudio presenta los resultados a partir de observaciones en terreno de las fundaciones y la construcción en acero. Se instalaron cámaras inalámbricas para realizar un estudio de tiempo continuo a fin de medir productividad y pérdidas de horas de trabajo, antes y después de implementar los cambios en la logística de la cadena de suministro.

En este artículo se aborda el problema de Planeamiento de la Expansión de la Red de Transmisión (PERT). El PERT consiste en determinar el conjunto de nuevos circuitos necesarios en un sistema de potencia, para atender una demanda futura. En su versión clásica, el PERT considera como candidatos de solución únicamente la adición de nuevas líneas y transformadores. La principal contribución de este artículo consiste en la inclusión de candidatos de solución no convencionales en el PERT. Dichos candidatos de solución son la repotenciación de circuitos existentes y la ubicación de bancos de capacitores. Para tener en cuenta estos últimos, se considera un modelo AC de la red de transmisión. La solución al modelo propuesto es llevada a cabo mediante un Algoritmo Genético Híbrido. Los resultados obtenidos son contrastados y validados con publicaciones previas de la literatura técnica. Los sistemas de prueba utilizados son el sistema Garver y el sistema IEEE de 24 barras. Los resultados obtenidos en ambos sistemas muestran que la inclusión de los candidatos no convencionales propuestos en este artículo permite disminuir los costos de la expansión de la red. Este hecho puede servir como indicador para que el planeador del sistema contemple nuevas posibilidades en los estudios de expansión.

This paper deals with the Transmission Network Expansion Planning (TNEP) problem. The TNEP consists of finding a set of new circuits on a power system, which is needed to attend a future demand. In its classical version, the TNEP only considers as solution candidates the addition of new lines and transformers. The main contribution of this paper consists in the inclusion of non-conventional solution candidates, namely the repowering of existing circuits and the location of capacitor banks. To take into account these last ones an AC model of the transmission network is considered. The solution of the proposed model is carried out using a Hybrid Genetic Algorithm. Results are compared and validated with previous works in the technical literature. The test systems used are the Garver system and IEEE 24 bus system. The results obtained in both systems showed that the inclusion of the non-conventional candidates, proposed in this paper, allows to reduce the cost of network expansion. This fact may be useful as an indicator for the system planner to consider new possibilities in the expansion studies.

ResumenSe evaluaron características de calidad y componentes de rendimiento en una progenie de 837 híbridos F1de papa, del cruce entre genotipos seleccionados por sus características de resistencia, producción y calidad del tubérculo. Las semillas sexuales se cultivaron bajo condiciones de invernadero y al momento de la cosecha se evaluó, para cada híbrido, las características de los tubérculos: color de piel y pulpa, profundidad de los ojos y número y masa total por planta. Posteriormente, los híbridos se sembraron durante 3 generaciones clonales en el campo. En cada ciclo se realizó una selección basada en su resistencia al tizón tardío (Phytophthora infestans (Mont.) de Bary) y al minador de la hoja (Liriomyzahuidobrensis Blanchard) y se descartaron aquellos con características no deseables en los tubérculos. En la tercera generación clonal en el campo se evaluaron, además, los componentes de rendimiento de cada híbrido y variables de calidad del tubérculo. Como resultado de estas evaluaciones se seleccionaron 19 híbridos al final de los 3 ciclos de evaluación en el campo. Los híbridos seleccionados presentan en su mayoría pulpa color crema, forma ovalada, piel lisa y ojos superficiales. Además, una producción media de un kilogramo por planta y altos contenidos de almidón y sólidos totales.

AbstractQuality characteristics and yield components were evaluated in an F1 progeny of 837 hybrids from a cross between potato genotypes selected for their characteristics of resistance, tuber yield and tuber quality. Sexual seed were grown under greenhouse conditions and tuber characteristics as skin and pulp color, eye depth, tuber number and total weight pert plant were assessed for each hybrid at harvest time. Thereafter, the hybrids were planted in the field through 3 clonal generations. In each cycle a selection based on resistance to late blight (Phytophthora infestans (Mont.) de Bary) and leafminer (Liriomyza huidobrensis Blanchard) was performed and those hybrids with undesirable characteristics in the tubers were also discarded. At harvest of the third clonal generation in the field, yield components and tuber quality of each hybrid were also recorded. As a result, 19 hybrids were selected at the end of the 3 cycles of field evaluation. Most of these hybrids show cream-colored flesh, oval shape, smooth skin and shallow eyes. Additionally, the hybrids yielded an average of one kilogram per plant, plus high contents of starch and total solids.