Resumo Os resíduos oriundos do processamento da madeira constituem uma oportunidade para o aproveitamento energético, sendo a briquetagem um processo eficiente para concentrar a energia disponível da biomassa florestal. Nesse sentido, este trabalho teve por objetivo avaliar diferentes composições de resíduos das madeiras de mogno-africano (Khaya ivorensis e Khaya senegalensis) e eucalipto (Eucalyptus grandis x Eucalyptus urophylla) para produção de briquetes. Para isso, cinco composições foram testadas com diferentes proporções de resíduos (100% eucalipto, 75% eucalipto + 25% mogno-africano, 50% eucalipto + 50% mogno-africano, 25% eucalipto + 75% mogno-africano e 100% mogno-africano) e submetidas às análises químicas e físicas (extrativos totais, ligninas totais, teor de cinzas, teor de umidade, poder calorífico e densidade a granel). Os briquetes foram produzidos à temperatura de 120°C, pressão de 100 kgf cm-2 e tempos de compactação e resfriamento de 5 e 7 minutos, respectivamente, sendo submetidos a ensaios físico-mecânicos (densidade relativa aparente e resistência à compressão axial). As composições com maiores porcentagens de mogno-africano tiveram maior teor de extrativos e cinzas, e maior poder calorífico superior. Para os briquetes oriundos das composições com maiores porcentagens de eucalipto, verificou-se menor densidade relativa aparente e menor resistência à compressão axial. Apesar disso, os resíduos dessas espécies possuem potencial para a geração de energia, sendo os briquetes produzidos com maior porcentagem de mogno-africano, os que apresentaram maior potencial energético e resistência mecânica.

Abstract The residues from wood processing are an opportunity for energy use, and the briquetting is an efficient process of concentrating the available energy from forest biomass. Therefore, this work aimed to evaluate different compositions of residues from African mahogany (Khaya ivorensis and Khaya senegalensis) and eucalypts (Eucalyptus grandis x Eucalyptus urophylla) woods for the production of briquettes. To do so, five composites were tested with different proportions of residues (100% eucalypts, 75% eucalypts + 25% African mahogany, 50% eucalypts + 50% African mahogany, 25% eucalypts + 75% African mahogany e 100% African mahogany) and submitted to analysis chemical and physical (total extracts, total lignin, ash content, moisture content, higher calorific value and bulk density). The briquettes were produced at a temperature of 120°C, pressure of 100 kgf cm-2 and compaction and cooling times of 5 and 7 minutes, respectively and were submitted to physical-mechanical analysis (apparent relative density and resistance to axial compression). The compositions with the highest percentage of African mahogany had higher extractives and ash content, and a greater calorific value. For the briquettes from compositions with higher percentages of eucalyptus, there was less apparent relative density and less resistance to axial compression. Despite this, the residues of these species have potential for energy generation. However, the briquettes with a higher percentage of African mahogany in the composition have greater energy potential and are, mechanically, more resistant.

ABSTRACT The objective of this study was to evaluate the effects of combining immunocastration and β-adrenergic agonists (β-AA) on blood metabolites and their correlations with performance and carcass traits of Nellore cattle. Ninety-six Nellore males were distributed in a randomized block design with a 2×3 factorial arrangement. The factors were two sexual conditions (immunocastrated and non-castrated), and three diets (control, with no inclusion of β-AA; RH, with 300 mg of ractopamine hydrochloride/d; and ZH, with 80 mg of zilpaterol hydrochloride/animal/d). The trial was conducted during 100 d, during which animals were fed ZH and RH for the last 30 and 33 d, respectively. Blood metabolites related to lipid and protein metabolism were assessed at the baseline (0 d of β-AA supplementation) and after 13 and 30 d of β-AA supplementation. No effect of sexual condition × β-AA supplementation × time on feed interaction was observed. Combining immunocastration with β-AA supplementation modified cholesterol and non-esterified fatty acids concentrations without affecting protein metabolism. Immunocastration enhances lipogenesis and reduces skeletal muscle accretion by increasing high-density lipoprotein and triglycerides concentrations and decreasing creatinine and creatine kinase concentrations, respectively. Zilpaterol hydrochloride enhances skeletal muscle accretion by decreasing urea and total protein concentrations and increases creatinine and creatine kinase concentrations without modifying lipid metabolism.

Resumo Novas formas de operação na distribuição de carga urbana podem levar a melhorias na eficiência das entregas de última milha, além de reduzir seu custo e seus impactos socioambientais. Entretanto, a viabilidade financeira dessas novas formas de operação pode ainda ser questionável por causa dos altos investimentos necessários e do elevado custo de mão de obra, especialmente em países em desenvolvimento. Portanto, este trabalho tem o objetivo de avaliar como essas novas modalidades podem ser adotadas no contexto de países em desenvolvimento, mais especificamente no Brasil, identificando os principais desafios, os benefícios e o impacto dessas práticas para as cidades, as quais, muitas vezes, já sofrem com outros problemas de infraestrutura de transportes.

Abstract New forms of operation in urban freight distribution can lead to improvements in the efficiency of last mile deliveries, besides contributing to reduce their costs and to reduce their socio-environmental impacts. However, the financial viability of such forms of operation may still be questionable due to the high investments required and the high labor cost involved, especially in developing countries. Therefore, this paper aims to assess how these new forms of operation can be implemented in the context of developing countries, identifying the main challenges, benefits and impact of these practices for the cities, which often suffer from other problems of transport infrastructure.