282 research outputs found
BioCH4 from the Anaerobic co-Digestion of the Organic Fraction of Municipal Solid Waste and Maize Cob Wastes
Maize Cob Waste (MCW) is available in high amounts, as maize is the most
produced cereal in the world. MCW is generally left in the fields despite its
negligible impact in soil fertility. It can be used as substrate in Anaerobic co-Digestion
(AcoD) and as precursor to produce Activated Carbons (ACs). In this
context, a biorefinery concept was developed based on two purposes: 1) the pretreated
MCW can be valorised as co-substrate in the AcoD with Organic Fraction
of Municipal Solid Wastes (OFMSW), and 2) MCW can be used as a precursor of
ACs for biomethane (bioCH4) conditioning.
The AcoD of OFMSW with chemically pre-treated MCW in presence of
H2O2 at 23 ºC increased the biogas and CH4 yields by 65% and 48%, respectively,
when compared to AD of standalone OFMSW., providing higher biogas quality
and a more stable AcoD process than with non-pre-treated MCW.
Among the ACs produced, the physically MCW(PA)3h AC performed better
in H2S removal than commercial and impregnated by liquid digestate ACs.
Textural properties seemed to be more important than the mineral content for
H2S removal and the presence of O2 on MCW(PA)3h surface may have favoured
H2S catalytic oxidation.
The MCW(PA)3h AC was also the most suitable candidate for CO2 separation
due to its more favourable textural properties, sufficient selectivity and
higher working capacity than the others ACs produced. The adsorption equilibrium
measurements of CO2 and CH4 showed that the Sips isotherm model and
the Adsorption Potential Theory (APT) can be confidently employed to correlate
the experimental data, as well as the axial dispersed plug-flow and Linear Driving
Force (LDF) model is able to correlate the fixed bed experimental data.
The environmental Life Cycle Assessment of a biorefinery case study was
performed on the hypothesis of implementing, at an existing Portuguese
Anaerobic Digestion plant processing OFMSW, (i) an AcoD unit using MCW as
co-substrate; (ii) an H2S unit using MCW(PA)3h as adsorbent, and (iii) a Pressure
Swing Adsorption (PSA) upgrading unit. The cogeneration of the biogas produced
during AcoD with non-pre-treated MCW is more sustainable than with
pre-treated MCW. The environmental impacts associated with biogas upgrading
to bioCH4 at optimized H2S adsorption capacity of MCW(PA)3h, if fossil natural
gas used for the OFMSW transport is substituted by the produced bioCH4, decreased
significantly, giving lower impacts than cogeneration in five categories
Low-Floor Tanner Codes via Hamming-Node or RSCC-Node Doping
We study the design of structured Tanner codes with low error-rate floors on the AWGN channel. The design technique involves the “doping” of standard LDPC (proto-)graphs, by which we mean Hamming or recursive systematic convolutional (RSC) code constraints are used together with single-parity-check (SPC) constraints to construct a code’s protograph. We show that the doping of a “good” graph with Hamming or RSC codes is a pragmatic approach that frequently results in a code with a good threshold and very low error-rate floor. We focus on low-rate Tanner codes, in part because the design of low-rate, low-floor LDPC codes is particularly difficult. Lastly, we perform a simple complexity analysis of our Tanner codes and examine the performance of lower-complexity, suboptimal Hamming-node decoders
Design of a drainage system to improve the water regimen in Lanzhot (South Moravia)
El objetivo del proyecto es la elección y diseño de un sistema de drenaje para controlar el régimen hídrico en una región del sur de República Checa, característico por tener un suelo poco permeable
Opening the black box: How staff training and development may affect the innovation of enterprises
We describe a research on the interplay that appears to exist in companies between Human Resource Management and innovation. This complex, multicomponent, non-linear and dynamic interplay is often viewed as a "black box". To help open the black box, we outline both a theoretical framework and preliminary empirical data. We view innovation as an organization-level property, favored by the organization's self-perception as a knowledge engine. Therefore, we devised a protocol to study the companies' strategies for training and development and their innovation profile. The protocol consisted in a questionnaire with 100 closed questions, suitable for companies which rely mostly on an inner training and development service. The questionnaire was administered to a sample of Italian firms from the Food & beverages and Fashion markets. The results show that certain facets of training and development are indeed correlated to innovation. Finally, we discuss the results
Intervir para revitalizar o Centro Histórico de Estremoz
Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Urbanismo, apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.N/
Relación entre el nivel de grasa e ingestión y la excreción urinaria de nitrógeno y energía, en gazapos en crecimiento-cebo
Se determinó la excreción urinaria de nitrógeno (NU, %) y de energía (EU, kcal/100g), en la última semana de vida, de 36 conejos alimentados, desde el destete (a los 28 d) hasta el sacrificio a los dos meses de edad, con tres piensos conteniendo 0, 3 y 6 % de grasa añadida (G0, G3 y G6); y administrados a dos niveles de ingestión:
ad libitum (IL) y restringido (IR) al 70 % de IL. El NU y la EU estuvieron influidos positivamente tanto por el nivel de ingestión (P<0,001) como por el % de grasa ingerida (P<0,05). En estos resultados puede estar involucrado el metabolismo tan elevado de las lipoproteínas transportadoras de lípidos, implicadas en el metabolismo de las grasas, ya sean de origen alimentario o de la lipogénesis de novo. La relación entre la EU y el NU aporta valores muy superiores a los que podría corresponder a las materias orgánicas nitrogenadas, por lo que se podría
pensar, como posible causa, en la intervención de materia orgánica no nitrogenada. Asimismo, la cuantificación de la EM del pienso se ve afectada por el incremento del valor calórico de la orina, con el nivel de ingestión y/o el 6 % de grasa añadida. Con ello se evidencia la desigualdad entre ED y EM de la grasa en las raciones que las
incluya. Asimismo, el hecho de que la movilización grasa —bien sea de origen alimentario o de la lipogénesis— altere la excreción nitrogenada y/o energética a través de la orina, pone de manifiesto la importancia de su consideración, especialmente cuando dicha pérdida puede afectar a los rendimientos de algunas producciones animales.Energy (EU, kcal/100g) and nitrogen (NU, %) urinary excretion were determined, during the week prior to slaughter, in an experiment carried out with 36 rabbits fed from weaning (28 d of age) to two months of age.
Three diets were utilized consisting of: 0 %, 3 % and 6 % fat (G0, G3 and G6); and two levels of intake: ad libitum (IL) and restricted to 70 % of IL (IR). Both NU and EU were incremented by level of feed intake (P <
0.001) and fat level (P < 0.05) in the diet. These increment can be explained by the high metabolism of the remnant lipoprotein particles lipids transporters implied in the metabolism of the fats. The relationship between the EU and the NU contributes with high values to those that it could correspond to the nitrogen organic matters (NOM), that would be thought as a possible cause to the intervention of non NOM. Likewise, dietary metabolizable energy (ME) was affected by the increased caloric content in the urine, in the fattening diets, mainly in the
IL. Fat metabolism affected urinary excretion of N, thus suggesting that when fat is added to the diet, this effect should be taken into consideration
Dietary squalene increases high density lipoprotein-cholesterol and paraoxonase 1 and decreases oxidative stress in mice
Background and Purpose: Squalene, the main hydrocarbon in the unsaponifiable fraction of virgin olive oil, is involved in cholesterol synthesis and it has been reported to own antiatherosclerotic and antiesteatosic effects. However, the squalene’s role on lipid plasma parameters and the influence of genotype on this effect need to be addressed.
Experimental Approaches: Three male mouse models (wild-type, Apoa1- and Apoe- deficient) were fed chow semisynthetic diets enriched in squalene to provide a dose of 1 g/kg during 11 weeks. After this period, their plasma parameters and lipoprotein profiles were analyzed.
Key Results: Squalene administration at a dose of 1 g/kg showed decreased reactive oxygen species in lipoprotein fractions independently of the animal background and caused an specific increase in high density lipoprotein (HDL)-cholesterol levels, accompanied by an increase in phosphatidylcholine and paraoxonase 1 and no changes in apolipoproteins A1 and A4 in wild-type mice. In these mice, the cholesterol increase was due to its esterified form and associated with an increased hepatic expression of Lcat. These effects were not observed in absence of apolipoprotein A1. The increases in HDL- paraoxonase 1 were translated into decreased plasma malondialdehyde levels depending on the presence of Apolipoprotein A1.
Conclusions and Implications: Dietary squalene promotes changes in HDL- cholesterol and paraoxonase 1 and decreases reactive oxygen species in lipoproteins and plasma malondialdehyde levels, providing new benefits of its intake that might contribute to explain the properties of virgin olive oil, although the phenotype related to apolipoproteins A1 and E may be particularly relevant
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