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This paper presents a design, mathematical modeling, simulation results and laboratory implementation of a 300W high gain dc-dc boost converter with a coupled inductor, to step up the 24V of a battery bank to 311Vdc, aiming to supply residential loads with dc voltage in an off-grid PV system. The converter can supply most of the residential ac loads which input stage is a single-phase rectifier. Laboratory tests with the 300W converter supplying electronic lights, mobile charger and audio-video system ac showed the viability of the proposed idea.

A family of double conversion three-phase uninterruptible power systems with power factor correction and high-frequency transformer (HFT) isolation topologies, are presented in this work. This might be a suitable alternative compared to large conventional UPS systems that are based upon bulky transformers that operate at the grid frequency. This system is commonly used to supply critical loads, but nowadays, due to the increasing interest in renewable energy integration and distributed generation (DG), it can be also be a suitable solution for energy storage in microgrids or renewable power conditioning interface applications. The three-phase HFT UPS used for further analysis is composed of single-phase chopper modules, one -three-phase boost module, and one three-phase inverter. The relevant features are soft commutation of the controlled switches in the chopper stage, simple control strategy that can be implemented with well-known integrated circuits (IC), and the use of a few batteries in series due to the same reference of the step-up stages. Principle of operation of the chosen system for experimental validation, implemented control strategy and experimental results obtained for a 15kVA prototype are presented.Index Terms-high-frequency transformer isolation, power factor correction (PFC), three-phase uninterruptible power supply, distributed generation (DG).

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A trial was conducted to evaluate quality of quail eggs from two companies (A and B) at two storage times (5 and 15 days after packing). A total of 480 eggs were kept at room temperature and distributed in a completely randomized design in 2x2factorial arrangement (companies and storage time). The results indicated that trays from company B presented higher weight, as well as mean egg weight. However, the eggs in trays from company A showed greater uniformity. Evaluating the external quality, we found that above 90% of eggshell were considered with total integrity, and no difference for this characteristic between companies was found. The eggs from company A presented lower average weight in comparison to those from company B, regarding storage time. No differences were observed between eggs from companies A and B for Haugh unit value. Storage time of 15 days after packing promoted reduction in Haugh unit value in comparison to those stored for 5 days. Quail eggs from company A presented lower variation in weight, although heavier eggs are produced by company B. Internal quality of quail eggs from both companies was similar. Storage time affected eggs quality.

Objetivou-se com esta pesquisa avaliar os efeitos dos níveis de fibra em detergente neutro (FDN) das rações oferecidas para as aves entre a 7ª e 17ª semanas de idade sobre o desempenho, o desenvolvimento dos sistemas digestório e reprodutor, bem como os efeitos na maturidade sexual, no desempenho e na qualidade dos ovos na fase de postura.Foram distribuídas 1.296 aves em delineamento inteiramente casualizado em esquema fatorial 3 × 2, composto de três níveis de FDN e duas linhagens, com quatro repetições de 54 aves. Foram testados os níveis de 14,5; 16,5; e 18,5% de FDN em aves leves e semipesadas. Ao final da fase de crescimento, as aves foram transferidas para o galpão de postura, mantendo o mesmo delineamento, composto por 14 aves por parcela. Não houve interação entre os níveis de FDN e as linhagens para as variáveis avaliadas. Na fase de crescimento, o aumento do nível de FDN reduziu o ganho de peso e o peso final, piorou a conversão alimentar e aumentou o peso dos intestinos. Na fase de postura, os níveis de FDN não influenciaram o desempenho das aves nem os constituintes e a qualidade dos ovos. Na fase de crescimento, as aves semipesadas apresentaram maior consumo, ganho de peso e peso final, melhor conversão alimentar, peso maior da moela e menor do fígado e do ovário. Na fase de postura, as aves leves foram mais precoces, apresentaram menor peso e massa de ovos, pior conversão alimentar, ovos com mais gema, menos albúmen, maior densidade específica e menores unidades Haugh. Independentemente da linhagem, o aumento do nível de FDN em rações para crescimento pode influenciar o desempenho das frangas, resultando em aves menos pesadas, sem influenciar a maturidade sexual, o desempenho e a qualidade dos ovos na fase de postura.

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