Effects of bioaugmentation by an anaerobic lipolytic bacterium on anaerobic digestion of lipid-rich waste

The effect of bioaugmentation with an anaerobic lipolytic bacterial strain on the anaerobic digestion of restaurant lipid-rich waste was studied in batch experiments with a model waste containing 10% lipids (triolein) under two sets of experimental conditions: (A) methanogenic conditions, and (B) initially acidogenic conditions in the presence of only the lipolytic strain biomass (4 days), followed by methanogenic conditions. The bioaugmenting lipolytic strain, Clostridium lundense (DSM 17049T), was isolated from bovine rumen. The highest lipolytic activity was detected at the beginning of the experiments. A higher methane production rate, 27.7 cm3 CH4(STP) g-1 VSadded day-1 (VS, volatile solids) was observed in experiment A with the presence of the bioaugmenting lipolytic strain under methanogenic conditions. The highest initial oleate concentration, 99% of the total oleate contained in the substrate, was observed in the experiments with the bioaugmenting lipolytic strain under treatment A conditions; the levels of palmitate and stearate were also higher until day 15, indicating that the bioaugmentation strategy improved the hydrolysis of the lipid fraction. In general, the results indicated that degradation of the long chain fatty acids (LCFAs) controlled the digestion process.Swedish Energy Agency ; Fundação para a Ciência e a Tecnologia (FCT

Influence of lipid concentration on the hydrolysis and biomethanation of lipid rich wastes

The influence of lipid concentration on hydrolysis and biomethanation of an artificial lipid rich (triolein) waste was evaluated. No inhibition on methane production was observed for tests with 5, 10 and 18 % (w/w, based on COD) of lipid. For higher amounts of lipid (31, 40 and 47 %) inhibition was observed. However, the process was able to recover from the inhibition. When the effect of lipase addition on enzymatic hydrolysis of lipids was studied, results showed that the higher the enzyme concentration, the more accentuated was the inhibition of the methane production. The enzyme seems to enhance the hydrolysis and produced intermediates are causing inhibition of the later steps of the degradation process. Since the VFA profiles presented similar trends for the different lipid amounts tested, the major obstacle to methane production is believed to be the LCFA formed.Fundação para a Ciência e a Tecnologia (FCT).The Swedish Energy Agency

Provisioning Spot Market Cloud Resources to Create Cost-effective Virtual Clusters

Infrastructure-as-a-Service providers are offering their unused resources in the form of variable-priced virtual machines (VMs), known as "spot instances", at prices significantly lower than their standard fixed-priced resources. To lease spot instances, users specify a maximum price they are willing to pay per hour and VMs will run only when the current price is lower than the user's bid. This paper proposes a resource allocation policy that addresses the problem of running deadline-constrained compute-intensive jobs on a pool of composed solely of spot instances, while exploiting variations in price and performance to run applications in a fast and economical way. Our policy relies on job runtime estimations to decide what are the best types of VMs to run each job and when jobs should run. Several estimation methods are evaluated and compared, using trace-based simulations, which take real price variation traces obtained from Amazon Web Services as input, as well as an application trace from the Parallel Workload Archive. Results demonstrate the effectiveness of running computational jobs on spot instances, at a fraction (up to 60% lower) of the price that would normally cost on fixed priced resources.Comment: 14 pages, 4 figures, 11th International Conference on Algorithms and Architectures for Parallel Processing (ICA3PP-11); Lecture Notes in Computer Science, Vol. 7016, 201

Anaerobic digestion of lipid-rich waste : effects of lipid concentration

The influence of lipid concentration on hydrolysis and biomethanation of a lipid-rich (triolein) model waste was evaluated in batch. The effect of increasing the concentration of lipid from 5% to 47% (w/w), based on chemical oxygen demand (COD), was investigated. The methane recovery observed was above 93% for all tests. An initial lag phase of approximately 6–10 days was observed for all tests. The methane production rate observed was similar for tests with 5%, 10% and 18% lipid (w/w, COD basis). For higher amounts of lipid (31%, 40% and 47%), a stronger inhibition was observed. However, the process was able to recover from the inhibition. When the effect of addition of lipase on enzymatic hydrolysis of lipids was studied, the results showed that the higher the enzyme concentration, the more accentuated was the inhibition of methane production. The enzyme appears to enhance the hydrolysis but the intermediates produced caused inhibition of the later steps in the degradation process. Since the volatile fatty acid (VFA) profiles presented similar trends for the different concentrations of lipid tested, the major obstacle to methane production was the long-chain fatty acids (LCFA) formation.Swedish Energy AgencyFundação para a Ciência e a Tecnologia (FCT

Polyhydroxyalkanoate (PHA) production from sludge and municipal wastewater treatment

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Qualidade da carne de cordeiros: genótipo e manejo nutricional.

Made available in DSpace on 2017-08-25T19:10:02Z (GMT). No. of bitstreams: 1 Qualidade.pdf: 414477 bytes, checksum: 8b4219f4b55df5a06623a29e39eaac8e (MD5) Previous issue date: 2017-08-2

Características morfométricas e da carcaça de tambaqui abatidos com diferentes pesos.

Peixe de destaque na piscicultura nacional, o tambaqui é a espécie nativa mais cultivada no Brasil em virtude da sua facilidade de produção e boa aceitação no mercado. Neste contexto, a pesquisa teve como objetivo avaliar as características morfométricas e da carcaça de tambaqui abatidos com diferentes pesos. Foram utilizados vinte e quatro tambaquis, em que os tratamentos (T) foram em função do peso vivo dos animais constituídos por T1: tambaquis entre 1 e 1,5 kg, T2: entre 2 e 2,5 kg e T3: entre 3 e 3,5 kg, distribuídos em um delineamento inteiramente casualizado. Todas as medidas morfométricas aumentaram (P<0,01) à medida que se elevou o peso ao abate dos animais. As razões morfométricas comprimento da cabeça/comprimento padrão (CC/CP), largura do tronco/comprimento do tronco (LT/CT), altura do tronco/comprimento do tronco (AT/CT) e altura do tronco/comprimento padrão (AT/CP) reduziram (P<0,01) com o aumento do peso. O peso de carcaça com e sem cabeça e de tronco limpo, assim como os dos componentes não-carcaça também aumentou (P<0,01), com exceção do rendimento do peixe eviscerado que foi maior (P<0,01) e do rendimento das vísceras que foi menor (P<0,05) nos animais abatidos entre 2,0 e 2,5 kg. Tambaquis abatidos com peso vivo entre 2,0 e 2,5 kg apresentam maior rendimento de carcaça e menor rendimento de vísceras

Feeding behavior of lambs fed diets containing old man saltbush hay.

This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate