Electrospinning, an economical technique, is widely used for biomedical scaffold fabrication, crucial in tissue and organ regeneration, particularly with biomaterials. Polymers, either pure or reinforced with ceramics, aid in cell proliferation and tissue formation. Polyhydroxybutyrate (PHB) is a promising biopolymer for tissue engineering, offering biocompatibility comparable to petroleum-derived polymers. Combining PHB with hydroxyapatite (HAp) enhances mechanical strength and osteoconductivity. This study aims to produce electrospun PHB microfibrous webs reinforced with HAp for scaffold fabrication. Morphological variations are analyzed through manipulation of electrospinning parameters. The study observed microfibrous webs with diameters ranging from 2 to 9 µm. Mechanical and microstructural evaluations demonstrate superior strength of PHB/HAp microfibrous webs compared to pure PHB, 1.23 MPa and 0.58 MPa respectively, demonstrating the efficacy of HAp reinforcement. These findings highlight the potential of PHB/HAp microfibrous webs in bone tissue engineering. Electrospinning technique fabrication regeneration biomaterials Polymers ceramics formation (PHB engineering petroleumderived petroleum derived polymers (HAp osteoconductivity parameters µm PHBHAp 123 1 23 1.2 058 0 58 0.5 respectively reinforcement 12 1. 05 5 0.

O Brasil é um dos maiores produtores de manga e o Vale do São Francisco corresponde por cerca de 87% das exportações brasileiras deste produto para o mercado europeu. O objetivo deste estudo foi caracterizar o comportamento mecânico dos frutos de acordo com os estádios de maturação, a fim de evitar danos físicos causados pelo manejo inadequado do fruto durante a colheita, armazenamento, processamento e transporte. Os testes de compressão foram realizados nas cultivares de manga (Mangifera indica L.) Keitt e Tommy Atkins em diferentes estádios de maturação para caracterizar o módulo elástico interno e determinar o estresse máximo até a ruptura da manga. Os frutos mostraram diminuição das propriedades mecânicas correlacionadas com o aumento do estádio de maturação, para ambos os cultivares. A variedade Tommy Atkins mostrou melhores propriedades mecânicas, provavelmente relacionadas a uma maior concentração de fibras na polpa, o que resulta em melhor estabilização mecânica.

Brazil is one of the largest producers of mangoes, and the São Francisco Valley accounts for about 87 % of Brazilian exports of this product to the European market. This study aimed to characterize the mechanical behavior of the fruits according to the maturation stages, in order to prevent physical damage caused by improper handling of the fruit during harvest, storage, processing and transportation. The compression tests were performed on the mango cultivars (Mangifera indica L.) Keitt and Tommy Atkins at different maturation stages in order to characterize the internal elastic modulus and determine the maximum stress until rupture of the sleeve. The fruits showed a decrease in mechanical properties correlated with the increase of maturation stage, for both cutivars. The Tommy Atkins variety showed better mechanical properties probably related to a higher concentration of fibers in the pulp which yields better mechanical stabilization.

Prototypes of porous hydroxyapatite (HAp) were produced from Gypsum/PVA composite, using a mass proportion of 15% polymer. The material was obtained by means of chemical conversion in (NH4)2HPO4 0.5 mol.L-1 solution and NH4OH 6.0 mol.L-1 alkaline medium for pH control, maintained between 6.0 and 9.0. The reaction occurred at a temperature of 100ºC at different test times. The obtained HAp was characterized by several techniques, such as FTIR, which identified the SO4(2-) groups characteristic for the Gypsum block, and the PO4(3-) groups that are attributed to the biomaterial HAp, besides XRD and SEM, which made it possible to confirm a successful conversion of the material. Tests for mechanical resistance to compression (σc) were carried out for both materials as well.

Durante as operações de manuseio, podem ocorrer vários problemas que reduzem a qualidade das hortaliças. As injúrias mecânicas são a causa principal de perdas pós-colheita, para as abóboras, e podem ocorrer em qualquer ponto da cadeia de produção. Objetivou-se, com o presente trabalho, estudar o comportamento de frutos de abóbora, durante os estádios de maturação, nos valores da força máxima de compressão para deformações fixas, e determinar o módulo proporcional de deformidade desta hortaliça submetida a compressão, em posição de repouso. Os frutos foram colhidos aos 15, 30, 40, 50 e 60 dias após a fecundação e comprimidos uniaxicialmente, entre duas placas paralelas. A partir dos resultados obtidos, concluiu-se que tanto a força de compressão necessária, como o módulo proporcional de deformidade, aumentaram com a maturação, atingindo força máxima de 1.778 N e módulo de deformidade máxima de 164 MPa, após 30 dias. Após este período, tanto os valores da força máxima, quanto os valores do módulo, decresceram, chegando a 1.514,8 N de força máxima e módulo de 132,09 MPa, após 60 dias de maturação. Com o aumento do tempo de maturação, ocorreu aumento na rigidez dos frutos, com consequente aumento na carga máxima para atingir maiores deformações. O tempo ideal para colheita e transporte dos frutos da abóbora 'Jacarezinho' foi de 30 a 40 dias após a antese.

During handling operations, many problems that reduce the quality of vegetables may occur. Mechanical injuries are the leading cause of postharvest losses for the pumpkin, and can take place at any point of the production chain. This study aimed at evaluating the pumpkin fruits behavior, during their ripening stages, on the values of maximum compression force for fixed deformations, and determining the proportional deformability modulus of the fruits under compression at the repose position. Fruits were harvested at 15, 30, 40, 50 and 60 days after flowering and uniaxially compressed between two parallel plates. The results allowed to conclude that both the required compression force and the proportional deformability modulus increased during the maturation course, reaching a maximum force of 1,778 N and a maximum deformation modulus of 164 MPa, after 30 days. After this period, both the maximum force and the modulus values decreased, reaching 1,514.8 N of maximum force and a modulus of 132.09 MPa, after 60 days of ripening. Over the course of a longer maturation time, the fruit firmness increased, therefore requiring an increase in the maximum load to achieve greater deformation. The ideal period for harvest and transport of 'Jacarezinho' pumpkin fruits was set from 30 to 40 days after anthesis.

This work aims at to characterize the mechanical behavior of the mango fruits in function of the problems found during the stages of production and commercialization. Problems like physical damages are caused by the inadequate handing of the fruits during harvest, storage, processing or transport. These problems are caused by information deficit about the mechanical behavior of the fruits and the maximum strength necessary o start internal degradation or external damages, that it harms yours commercialization. Compression tests were carried out in the specimens of the mangos (Mangifera Indica) the variety “Keitt” and “Tommy Atkins”, in repose position, to determination of the elasticity modulus and maximum strength up to rupture as a function the maturation phases 1, 2 and 3. The elasticity modulus decreases with advancement of the maturation stage, reaching values for the “Keitt” variety of 2,065 MPa, 1,734 MPa and 1,381 MPa for the maturation stage 1,2 and 3 respectively. The “Tommy Atkins” variety reached an elasticity modulus of 1,698 MPa, 1,657 MPa e 1,518 MPa for the maturation stage 1,2 and 3, respectively. The maximum compressive strength, that causes rupture in the fruits, for the variety “Tommy Atkins” were higher than those for “Keitt”. This fact is associated with the different structural composition of the fruits, because the "Tommy Atkins" variety has a fiber content greater than the "Keitt" variety.

En este trabajo se caracteriza la respuesta mecánica del mango en función de los problemas encontrados durante las etapas de producción y comercialización. Problemas como daños físicos provocados por la manipulación inadecuada de la fruta, sea en el momento de la cosecha, almacenamiento, procesamiento o transporte. Los problemas señalados son característicos de la falta de información sobre el máximo esfuerzo que el fruto puede soportar sin que el mismo sufra daño interno o rotura externa que comprometa su comercialización. Fueron realizados ensayos de compresión en mangos (Mangifera Indica) de las variedades “Keitt” y “Tommy Atkins”, en la posición natural de reposo, lo que posibilitó la determinación del módulo de elasticidad y la fuerza máxima soportada en función de las fases 1, 2 y 3 de maduración. El módulo de elasticidad se reduce con el avance de la fase de maduración, obteniéndose valores para la variedad “Keitt” de 2,065 MPa, 1,734 MPa y 1,381 MPa para las fases de maduración 1, 2 y 3 respectivamente, y para la variedad “Tommy Atkins” de 1,698 MPa, 1, 657 MPa y 1,518 para las mismas fases de maduración. Las medidas de las fuerzas máximas, que antecede la rotura de la fruta, soportadas por la variedad “Tommy Atkins” fueron superiores a las soportadas por la “Keitt”. Este hecho está relacionado con la diferente organización estructural de estas dos variedades, en la que la variedad “Tommy Atkins” presenta un porciento de fibra superior a la variedad “Keitt”.

O ruído das máquinas agrícolas, com o passar do tempo, pode provocar problemas auditivos em seus operadores. O objetivo deste trabalho foi avaliar o nível de potência sonora emitido por trator agrícola, em condições estáticas e dinâmicas, comparando-o às normas IEC651 e IEC61672. O trabalho foi realizado na Universidade Federal do Vale do São Francisco, Petrolina (PE), em 2009, utilizando-se um trator Valtra, modelo 785 TDA sem cabine, e medidores do nível de potência sonora. As medições foram: estática (posições anterior, posterior, direita e esquerda do assento do operador a cada metro, até a distância máxima de 10 m, e diferentes rotações do motor, com dois equipamentos de medição) e dinâmica (cinco velocidades de deslocamento, em pista de concreto e terra batida, utilizando-se dois equipamentos de medição). Para os equipamentos que atendem às normas IEC651 e IEC61672, o segundo sempre apresentou maiores valores do nível de potência sonora, devido ao primeiro ser utilizado com protetor de vento. Em todas as condições, o nível de potência sonora foi maior do que o permitido pela legislação. À medida que se aumenta a rotação do motor, ocorre incremento no nível de potência sonora. Verificou-se que as pistas de terra batida e concreto podem ser utilizadas para análise do nível de potência sonora, devido aos resultados similares apresentados. A velocidade de deslocamento do trator influenciou no nível de potência sonora, sendo que as marchas mais longas apresentaram maiores valores.

The noise produced by farm machinery may cause hearing problems to its operators along the time. The objective of this study was to evaluate the sound power level emitted by agricultural tractor under static and dynamic conditions, in relation to the IEC651 and IEC61672 norms. It was conducted at the Universidade Federal do Vale do São Francisco, in Petrolina, Pernambuco State, Brazil, in 2009, by using a Valtra 785 TDA tractor without cabin and equipment to measure its sound power level. The measurements were: static (anterior, posterior, right, and left positions, in relation to the operator’s seat, for each meter along the maximum distance of 10 m, and different engine rotation speeds, with two measuring devices) and dynamic (five speeds on concrete and soil test tracks, with two devices). Two measurement devices were used to evaluate the sound power level. For the devices in accordance with the IEC651 and IEC62672 norms, the second one always presented higher sound power levels, due to the fact that the first one was equipped with a wind protector. In all positions, the sound power level was higher than allowed by law. As the engine rotation speed increases, the sound power level also increases. It was noticed that both test tracks can be used for sound power level analysis, due to their similar results. The tractor speed affected its sound power level, with higher values for longer gears.