Síntese de amônia: modelagem e simulação do processo de conversão

Este trabalho tem como alvo a modelagem e a simulação do processo de síntese da amônia. Foram analisados os principais processos existentes, especialmente no tocante à etapa principal, que é o loop de conversão, e proposto um fluxograma com base nos principais processos comerciais para uma análise detalhada. Este processo consiste de dois conversores em série, com três leitos catalíticos e resfriamento intermediário, quatro trocadores de calor e um separador final do produto. Foram identificadas as correntes e as principais condições operacionais. Foi elaborado um programa em EXCEL/VBA, que permitiu executar o dimensionamento do processo bem como a sua simulação para diferentes condições operacionais. Os resultados obtidos foram comparados com dados de encontrados na literatura para três diferentes pressões de operação do processo, mostrando-se satisfatórios, validando os modelos e o algoritmo proposto

Performance of soybean plants subject to water deficit in different development stages

Soybean plants are constantly exposed to abiotic stresses that compromise production, among these, in areas of Brazilian Cerrado, mainly in the northeast region, periods of drought can occur due to irregular and summer rainfall. Thus, the objective of this work was to determine the physiological response of Monsoy 9350 soybean at different stages of development, when subjected to water stress. The experiment was conducted in a greenhouse, in the experimental area of the campus of the Universidade Federal do Piauí (UFPI) in Bom Jesus-PI, assembled in a 3x3 factorial scheme, with water in the soil at three levels (50% VTP; 75% VTP and 100% VTP) and three phenological phases, budding to bloom (BF); bloom to complete grain filling (FE) and budding to complete grain filling (BE), the experiment consisted of 9 treatments, in a randomized block design, containing 4 replications. The evaluation of the experiment was standardized according to the phenological stages and not according to the time. The following variables were evaluated: plant height, internode length, internode thickness, number of branches, chlorophyll index, number of flowers, insertion of the first pod and number of pods. According to the evaluated results, the water stress in soybean for cultivating Monsoy 9350 mainly affects the period from budding to bloom, interfering negatively in height, chlorophyll and number of pods

Conservation of heliconia inflorescences previously fertilized with increasing doses of nitrogen and potassium

A longevidade das hastes florais é um dos principais aspectos observados na produção de flores para corte, constituindo-se um pré-requisito para a qualidade do produto e sucesso da comercialização. Nesse sentido, objetivou-se avaliar a conservação de inflorescências de helicônias com ou sem renovação da água de manutenção, previamente adubadas com doses crescentes de nitrogênio e potássio. Foram utilizadas inflorescências de helicônias da espécie Heliconia psittacorum x H. spathocircinata cv. Golden Torch cultivadas a céu aberto no Setor de Floricultura da UFPI, Bom Jesus (PI), sob doses crescentes de adubação com N e K. O delineamento foi em blocos casualizados em esquema fatorial 4 x 4 x 2, correspondendo a: i) doses de N (0, 120, 180 e 240 g de N cova1); ii) doses de K (0, 120, 180 e 240 g de K2O cova-1); e iii) renovação da água de manutenção (sem e com renovação) com três repetições e três hastes cada uma. Fora realizado a avaliação de absorção de água pelas hastes florais, perda de massa fresca das hastes florais, massa seca das hastes florais e longevidade pós-colheita. A dose de 180 g cova-1 tanto de N quanto K proporcionou a maior longevidade das hastes florais com manutenção da qualidade. A absorção de água pelas hastes florais e sua massa seca após a colheita foram influenciadas pela adubação prévia de N e K. A renovação da água de manutenção também influenciou positivamente na longevidade das hastes florais, sendo um manejo indicado para manter a qualidade pós-colheita.The post-harvest of floral stems is one of the main features observed in the production of flowers for cutting, becoming a prerequisite for product quality and successful marketing. In this sense, the objective was to evaluate the conservation of heliconias inflorescences with or without renewal of the water maintenance, previously fertilized with increasing doses of nitrogen and potassium. Inflorescences of Heliconia psittacorum x H. spathocircinata cultivar Golden Torch were used and grown in open conditions in the Floriculture area at UFPI, city of Bom Jesus, Piauí State under increasing doses of fertilization with N and K. The stems were harvested in the morning, standardized and placed in containers with 500 mL of water. The design was a randomized block in factorial 4 x 4 x 2, corresponding to: i) N doses (0, 120, 180, and 240 g N hole-1), ii) K doses (0, 120, 180, and 240 g K2O hole-1), and iii) renewing the water maintenance in vase (with and without renewal) with three replicates of three stems each. Some evaluations were observed during the Study, such as: the water uptake by the flower stems; loss of fresh weight of the flower stems, dry weight of the flower stems and post-harvest longevity. The dose of 180 g hole-1 both as N and K provided the longevity of the flower stems with quality maintenance. The absorption of water by the flower stems and its dry mass after harvesting are influenced by previous fertilizer N and K. The renewal of the water maintenance also positively influence the longevity of flower stems and its a management indicated to maintain quality post-harvest

Aplicação da programação linear para a minimização de custos em uma indústria de confecções de peças infantis/ Application of linear programming to minimize costs in a children's clothing industry

O crescimento de microempresas tem um papel importante na geração de emprego e renda para populações de áreas mais afastadas dos grandes centros de comércio. Nesse sentido, o presente artigo tem como objetivo minimizar custos de insumos para produção de materiais acabados em uma microempresa de confecções infantis, no município de Capanema, nordeste do Estado do Pará, através dos fundamentos da Pesquisa Operacional e Programação Linear. A metodologia deste Estudo de Caso seguiu três etapas: definição do problema e coleta de dados; formulação do modelo matemático e a obtenção da solução computacional do problema. O resultado da pesquisa mostrou que foi possível propor soluções significativas, como diminuir mão-de-obra e investir em marketing

Reaproveitamento do resíduo da indústria de carnaúba no substrato para produção de mudas de melancia

Os produtores de mudas de hortaliças estão sempre ávidos por novas tecnologias, especialmente quando se trata do insumo substrato para plantas. Neste sentido, objetivou-se avaliar o desenvolvimento de mudas de melancia cultivar Crimson Sweet, produzidas em diferentes proporções de resíduo de carnaúba para composição de substratos. O experimento foi conduzido em delineamento experimental inteiramente casualizado com cinco tratamentos com diferentes proporções de resíduo de carnaúba com casca de arroz (RCCA) e resíduo de carnaúba em pó (RCP): 1) 100 % RCCA; 2) 75 % RCCA + 25 % RCP; 3) 50 % RCCA + 50 % RCP; 4) 25 % RCCA + 75 % RCP; e 5) 100 % RCP com quatro repetições de 64 plântulas cada. Há influência do uso resíduo de cera de carnaúba como componente de substrato na formação de mudas de melancia cv. Crimson Sweet. O substrato 100% RCCA pode ser usado na produção de mudas de melancia de qualidade

Production performance of Hylocereus polyrhizus based on cladode size and position

The analysis of productive architecture of plants involves macroscopic observation of spatial distributions of different vegetative and reproductive organs. However, few studies have evaluated these aspects in dragon fruit plants for production purposes. The objective of this study was to evaluate vegetative, reproductive, and quality parameters of dragon fruit plants (Hylocereus polyrhizus; variety Cebra) based on the position and size of cladodes, considering morphological, production, and quality characteristics of the fruits. The experiment was conducted from September 2016 to May 2018, using a completely randomized design in a 3×4 factorial arrangement, consisted of three positions of cladode insertion in the plant (primary, secondary, and tertiary) and four different cladode sizes (≤ 20 cm; 21-40 cm; 41-60 cm, and 61-80 cm), with five replications and six cladodes per plot, totaling 360 evaluated cladodes. According to the results, vegetative and reproductive characteristics of dragon fruit plants variety Cebra were affected by the cladode position and size. Fruits developed on primary cladodes with sizes of 21 to 40 cm presented, in general, better-quality characteristics. All evaluated physical and physicochemical characteristics were affected by the cladode position and size, except for titratable acidity and soluble solids to titratable acidity ratio. Fruits developed on cladodes smaller than 20 cm had lower quality. Therefore, maintaining and promoting the growth of primary cladodes with sizes of 21 to 40 cm and removing those smaller than 20 cm is recommended.The analysis of productive architecture of plants involves macroscopic observation of spatial distributions of different vegetative and reproductive organs. However, few studies have evaluated these aspects in dragon fruit plants for production purposes. The objective of this study was to evaluate vegetative, reproductive, and quality parameters of dragon fruit plants (Hylocereus polyrhizus; variety Cebra) based on the position and size of cladodes, considering morphological, production, and quality characteristics of the fruits. The experiment was conducted from September 2016 to May 2018, using a completely randomized design in a 3×4 factorial arrangement, consisted of three positions of cladode insertion in the plant (primary, secondary, and tertiary) and four different cladode sizes (≤ 20 cm; 21-40 cm; 41-60 cm, and 61-80 cm), with five replications and six cladodes per plot, totaling 360 evaluated cladodes. According to the results, vegetative and reproductive characteristics of dragon fruit plants variety Cebra were affected by the cladode position and size. Fruits developed on primary cladodes with sizes of 21 to 40 cm presented, in general, better-quality characteristics. All evaluated physical and physicochemical characteristics were affected by the cladode position and size, except for titratable acidity and soluble solids to titratable acidity ratio. Fruits developed on cladodes smaller than 20 cm had lower quality. Therefore, maintaining and promoting the growth of primary cladodes with sizes of 21 to 40 cm and removing those smaller than 20 cm is recommended

INOVAÇÃO NA AGRICULTURA FAMILIAR COM A PRODUÇÃO INTEGRADA DE OLERÍCOLAS E PEIXES

The present study aimed to evaluate and develop a new technology for family farming, which integrates vegetable farming with the creation of guinea fowl in elevated geomembrane tanks with water recirculation. To this end, 240 fish with an average weight of 10.67g were randomly distributed in a geomembrane tank with a capacity of 30 m3 of water. Water quality was monitored by analyzing the variables water temperature using a thermometer, dissolved oxygen, pH, alkalinity, nitrite and ammonia using colorimetric kits. Feeding was carried out twice a day at 7:00 am and 7:00 pm with extruded feed containing 32% crude protein, over a period of 204 days. Biometrics were carried out monthly to correct the diet, analyze the average total weight, average total length, weight gain and feed conversion. The water quality during the experimental period did not present critical levels for fish production and at the end of the 204 days of creation the fish had an average final weight of 719.4g, average final length of 48.5cm, average final weight gain of 708.5g and average feed conversion of 1.59. Regarding the productivity of the olerícolas, it was found that the effluent water of the rearing system provided adequate amounts of nutrients necessary for the development of the plants. The results indicate that the pintado has the potential to be created in elevated geomembrane tanks with water recirculation system and the effluent of the system can be used as an alternative for the integrated production of fish and olerícolas.The present study aimed to evaluate and develop a new technology for family farming, which integrates vegetable farming with the creation of guinea fowl in elevated geomembrane tanks with water recirculation. To this end, 240 fish with an average weight of 10.67g were randomly distributed in a geomembrane tank with a capacity of 30 m3 of water. Water quality was monitored by analyzing the variables water temperature using a thermometer, dissolved oxygen, pH, alkalinity, nitrite and ammonia using colorimetric kits. Feeding was carried out twice a day at 7:00 am and 7:00 pm with extruded feed containing 32% crude protein, over a period of 204 days. Biometrics were carried out monthly to correct the diet, analyze the average total weight, average total length, weight gain and feed conversion. The water quality during the experimental period did not present critical levels for fish production and at the end of the 204 days of creation the fish had an average final weight of 719.4g, average final length of 48.5cm, average final weight gain of 708.5g and average feed conversion of 1.59. Regarding the productivity of the olerícolas, it was found that the effluent water of the rearing system provided adequate amounts of nutrients necessary for the development of the plants. The results indicate that the pintado has the potential to be created in elevated geomembrane tanks with water recirculation system and the effluent of the system can be used as an alternative for the integrated production of fish and olerícolas.O presente estudo teve como objetivo avaliar e desenvolver uma nova tecnologia para agricultura familiar, que integre a olericultura com a criação de pintados em tanques elevados de geomembrana com recirculação de água. Para tanto, foram distribuídos aleatoriamente 240 peixes com peso médio de 10,67g em um tanque de geomembrana com capacidade de 30 m3 de água. A qualidade da água foi monitorada analisando as variáveis temperatura da água por meio de um termômetro, oxigênio dissolvido, pH, alcalinidade, nitrito e amônia por meio de kits colorimétricos.  O arraçoamento foi realizado duas vezes ao dia às 07h00min e 19h00min com ração extrusada contendo 32% de proteína bruta, durante um período de 204 dias. Mensalmente foram realizadas biometrias para corrigir o arraçoamento, analisar o peso total médio, comprimento total médio, ganho de peso e conversão alimentar. A qualidade da água durante o período experimental não apresentou níveis críticos para a produção dos peixes e no final dos 204 dias de criação os peixes apresentaram peso final médio de 719,4g, comprimento final médio de 48,5cm, ganho de peso final médio de 708,5g e conversão alimentar média de 1,59. Quanto à produtividade das olerícolas, constatou-se que a água do efluente do sistema de criação forneceu quantidades adequadas de nutrientes necessários ao desenvolvimento das plantas. Os resultados indicam que o pintado tem potencial para ser criado em tanques elevados de geomembrana com sistema de recirculação de água e o efluente do sistema pode ser utilizado como uma alternativa para a produção integrada de peixes e olerícolas

Alternative measures to evaluate the accuracy and bias of genomic predictions with censored records

This study aimed to propose and compare metrics of accuracy and bias of genomic prediction of breeding values for traits with censored data. Genotypic and censored-phenotypic information were simulated for four traits with QTL heritability and polygenic heritability, respectively: C1: 0.07-0.07, C2: 0.07-0.00, C3: 0.27-0.27, and C4: 0.27-0.00. Genomic breeding values were predicted using the Mixed Cox and Truncated Normal models. The accuracy of the models was estimated based on the Pearson (PC), maximal (MC), and Pearson correlation for censored data (PCC) while the genomic bias was calculated via simple linear regression (SLR) and Tobit (TB). MC and PCC were statistically superior to PC for the trait C3 with 10 and 40% censored information, for 70% censorship, PCC yielded better results than MC and PC. For the other traits, the proposed measures were superior or statistically equal to the PC. The coefficients associated with the marginal effects (TB) presented estimates close to those obtained for the SLR method, while the coefficient related to the latent variable showed almost unchanged pattern with the increase in censorship in most cases. From a statistical point of view, the use of methodologies for censored data should be prioritized, even for low censoring percentages

TEMPO DE ARMAZENAMENTO E TEMPERATURA NO COMPORTAMENTO GERMINATIVO DE Schinopsis brasiliensis ENGLER

A temperatura atua intimamente sobre a velocidade de absorção de água e igualmente sobre as reações bioquímicas que determinam tanto a velocidade e uniformidade de germinação. Por conseguinte, a viabilidade das sementes após períodos de armazenamento também pode ser um fator limitante no processo germinativo, minimizando o vigor. Diante disso, o presente trabalho teve como objetivo avaliar distintos períodos de armazenamento e temperaturas no comportamento germinativo de sementes de Schinopsis brasiliensis. O delineamento experimental adotado foi inteiramente casualizado, distribuídos em esquema fatorial 5x5, referentes a cinco tempos de armazenamento de sementes de S. brasiliensis armazenados em períodos distintos e cinco temperaturas constantes. Foram utilizados lotes de baraúna com período de armazenamento de 0, 12, 60, 72 e 84 meses, com quatro repetições. Calculou-se a percentagem de germinação, tempo médio de germinação, índice de velocidade de germinação, velocidade média de germinação e índice de Timson. Todos os parâmetros germinativos avaliados foram afetados significativamente. A viabilidade de sementes de S. brasiliensis é decrescida consideravelmente a partir de 12 meses de armazenamento. A temperatura e o tempo de armazenamento são fatores que influenciam diretamente o desenvolvimento inicial de sementes de S. brasiliensis. Palavras-chave: Anacardiaceae; germinação; espécies nativas; viabilidade; Caatinga.   STORAGE TEMPERATURE TIME IN GERMINAL BEHAVIOR Schinopsis brasiliensis ENGLER   ABSTRACT:  The temperature acts closely on the speed of water absorption and also on the biochemical reactions that determine both the speed and uniformity of germination. Therefore, the viability of the seeds after storage periods can also be a limiting factor in the germination process, minimizing vigour. Therefore, this study aimed to evaluate different storage periods and temperatures in the germination behavior of seeds of Schinopsis brasiliensis. The experimental design adopted was entirely randomized, distributed in a 5x5 factorial scheme, referring to five lots of S. brasiliensis seeds stored in different periods and five constant temperatures. Barauna batches with storage periods of 0, 12, 60, 72 and 84 months were used, with four repetitions. The germination percentage, mean germination time, germination speed index and Timson index were calculated. All germination parameters evaluated were significantly affected. The viability of S. brasiliensis seeds is considerably decreased from 12 months of storage. Temperature and storage time are factors that directly influence the initial development of S. brasiliensis seeds. Keywords: Anacardiaceae; germination; native species; viability; Caatinga