Co2 Emission And Carbon Capture For Coal Fired Power Plants In Malaysia And Indonesia.

Coal consumption in Malaysia and Indonesia is growing at the rate of 9.7 and 4.7% per year since 2002, respectively. The increase in coal utilization usually tallies fairly well with the increase in CO2 emission. The present study attempts at predicting the emissions of CO2 from coal fired power plants from 2005 until 2020

CARACTERIZAÇÃO GEOLÓGICA E GEOTÉCNICA DE SOLOS RESIDUAIS TROPICAIS DA REGIÃO CENTRAL DE ANGOLA

Poucos são os trabalhos científicos existentes que contemplem a composição química, mineralógica e textural de solos residuais tropicais de Angola, sendo que os mais comuns têm sido focados para a caracterização pedológica, fundamentalmente para fins agrícolas [Castanheira, 1998], ou baseiam-se em classificações cujas realidades não se enquadram com as de Angola, tanto pela ausência de bibliografia, como pela complexidade que os mesmos apresentam. Em resultado disso, a aplicação destes solos para fins de engenharia traz, muitas das vezes, consequências nefastas que podem ser imprevisíveis e irreversíveis, do ponto de vista da funcionalidade e segurança das obras de engenharia. Assim, o presente trabalho tem como objectivo determinar características geológicas e geotécnicas dos solos residuais da Região Central de Angola (Huambo, Kwanza-Sul e Kwanza-Norte), ilustrados na Figura 1, assim como identificar os principais factores que determinam a formação dos mesmos. Dado que a composição mineralógica e textural de um solo residual, é resultado principalmente da história geológica herdada da rocha-mãe, do clima predominante e das condições geomorfológicas, não se pode caracterizar os solos residuais sem antes conhecer a composição química e mineralógica da rocha-mãe em questão [Duarte, 2002]. Sendo assim, a caracterização mineralógica foi efetuada mediante a aplicação das técnicas de análise mineralógica por difracção de raios-X (DRX) e a análise química por espectrometria de fluorescência de raios-X (FRX), a fim de se identificar os principais tipos de minerais, assim como os elementos químicos constituintes tanto da rocha-mãe, como do solo residual resultante. Os resultados de DRX revelam que as de rochas de origem são constituídas por quartzo muito abundante, presença de feldspatos potássicos (microclina e ortose) e plagioclases ricas em sódio (Albite) [Ferreira da Silva, 2009]. As micas estão presentes em todas as rochas, às vezes com a maior preponderância da biotite (amostras A e B), e noutros casos com o maior predomínio da moscovite/ilite (amostras C e F). Noutros casos (e.g. amostra de rocha F), constata-se que os seus minerais constituintes são o quartzo, a albite, a moscovite/ilite, a ortose e a braunite (óxido silicato de manganês). Esta constituição mineralógica é típica de rochas granitóides, precisamente granitos, e é confirmada pelos dados químicos obtidos por FRX que revelam que as rochas são constituídas por SiO2 (71%), Al2O3 (14%), K2O (4%), Fe3O2 (3%), Na2O (3%) e CaO (2%) [Duarte et al, 2013]. Com a atuação dos mecanismos de alteração, os minerais que se cristalizam em primeiro lugar, formados a temperaturas mais altas (e.g. as biotites) são menos estáveis quando submetidos as condições atmosféricas mais rigorosas (e.g. os solos do Huambo) dando lugar aos óxidos de ferro e de alumínio (hematite, goethite e a gibsite). Ao passo que os minerais que se cristalizam em último lugar, formados em temperaturas mais baixas e mais próximas às das condições superficiais (e.g. o quartzo), são mais estáveis. Os resultados da caracterização mineralógica são confirmados pela FRX que nos revelam que as perdas são muito acentuadas em regiões com taxas altas de precipitação, onde os elementos mais móveis (Na, K, Ca, Mg, etc.) quase desapareceram na totalidade, obtendo-se a composição de um solo rico em alumínio e ferro, com algum titânio. Noutras regiões (e.g. Cassenda, com menor taxa de precipitação), os elementos móveis mantém-se parcialmente nas amostras, o que denota menor disponibilidade de água para lixiviar tais elementos. Os dados obtidos a partir das análises mineralógicas e químicas efetuadas, permitem identificar os processos de alteração envolvidos nos solos em causa, e compreender os resultados experimentais relativos às propriedades físicas e mecânicas (composição textural, consistência, porosidade, peso volúmico seco máximo, teor em água ótimo, C.B.R., etc.), cuja determinação pode aferir acerca das áreas da engenharia geotécnica onde estes solos poderão ser aplicados [Duarte et al, 2011]

Studies On Adsorption/Desorption Of Carbon Dioxide With Respect To Thermal Regeneration Of Hydrotalcites.

This research is focused on evaluation of conditions for thermal regeneration of hydrotalcite. In this study synthesized hydrotalcite prepared under reported optimum conditions namely calcination temperature (600oC) and Mg/Al mol ratio (3.0), and commercial hydrotalcite are compared for adsorption and desorption capacities

Evaluating a hybrid soil temperature model in a corn-soybean agroecosystem and a tallgrass prairie in the Great plains

Simulation models of soil-related biological processes usually require soil temperature data. Frequently these soil temperatures are simulated, and the soil temperature algorithms cannot be more complicated than the original process model. This situation has led to the use of semi-empirical-type relationships in these process models. The objective of this study was to evaluate a hybrid soil temperature model, which combines empirical and mechanistic approaches, in an agroecosystem and a tallgrass prairie in the Great Plains. The original hybrid soil temperature model was developed and verified for a temperate forest system. This model simulated soil temperatures on a daily basis from meteorological inputs (maximum and minimum air temperatures) and soil and plant properties. This model was modified using different extinction coefficients for the plant canopy and ground litter. The agroecosystem consisted of a no-till rotation system of corn (Zea mays L.) and soybeans (Glycine max [L.] Merr.). Soil temperatures were measured at different depths in multiple years (three years and two-and-a-half years in the agroecosystem and tallgrass prairie, respectively). In the agroecosystem, the root mean square error of the modified model simulation varied from 1.41º to 2.05ºC for the four depths (0.1, 0.2, 0.3, and 0.5 m). The mean absolute error varied from 1.06º to 1.53ºC. The root mean square error and mean absolute error of the modified model were about 0.1º–0.3ºC less than the original model at the 0.2–0.5 m depths. For the tallgrass prairie, the mean absolute errors of the simulated soil temperatures were slightly greater than the agroecosystem, varying from 1.48º to 1.7ºC for all years and from 1.09º to 1.37ºC during the active growing seasons for all years.EEA OliverosFil: Song, Feng. University of Nebraska–Lincoln. School of Natural Resources; Estados UnidosFil: Salvagiotti, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros. Departamento de Agronomía; ArgentinaFil: Schmer, M.R. University of Nebraska–Lincoln. Department of Agronomy and Horticulture; Estados UnidosFil: Wingeyer, Ana Beatriz. University of Nebraska–Lincoln. Department of Agronomy and Horticulture; Estados UnidosFil: Weiss, Albert. University of Nebraska–Lincoln. School of Natural Resources; Estados Unido

Entropy spectrum of a Kerr anti-de Sitter black hole

The entropy spectrum of a spherically symmetric black hole was derived without the quasinormal modes in the work of Majhi and Vagenas. Extending this work to rotating black holes, we quantize the entropy and the horizon area of a Kerr anti-de Sitter black hole by two methods. The spectra of entropy and area are obtained via the Bohr-Sommerfeld quantization rule and the adiabatic invariance in the first way. By addressing the wave function of emitted (absorbed) particles, the entropy and the area are quantized in the second one. Both results show that the entropy and the area spectra are equally spaced.Comment: Accepted for publication in The European Physical Journal C, Volume 72, Issue

Higher Dimensional Classical W-Algebras

Classical $W$-algebras in higher dimensions are constructed. This is achieved by generalizing the classical Gel'fand-Dickey brackets to the commutative limit of the ring of classical pseudodifferential operators in arbitrary dimension. These $W$-algebras are the Poisson structures associated with a higher dimensional version of the Khokhlov-Zabolotskaya hierarchy (dispersionless KP-hierarchy). The two dimensional case is worked out explicitly and it is shown that the role of Diff$S(1)$ is taken by the algebra of generators of local diffeomorphisms in two dimensions.Comment: 22 pages, Plain TeX, KUL-TF-92/19, US-FT/6-9

Coisotropic D8-branes and Model-building

Up to now chiral type IIA vacua have been mostly based on intersecting D6-branes wrapping special Lagrangian 3-cycles on a CY three-fold. We argue that there are additional BPS D-branes which have so far been neglected, and which seem to have interesting model-building features. They are coisotropic D8-branes, in the sense of Kapustin and Orlov. The D8-branes wrap 5-dimensional submanifolds of the CY which are trivial in homology, but contain a worldvolume flux that induces D6-brane charge on them. This induced D6-brane charge not only renders the D8-brane BPS, but also creates D=4 chirality when two D8-branes intersect. We discuss in detail the case of a type IIA Z2 x Z2 orientifold, where we provide explicit examples of coisotropic D8-branes. We study the chiral spectrum, SUSY conditions, and effective field theory of different systems of D8-branes in this orientifold, and show how the magnetic fluxes generate a superpotential for untwisted Kahler moduli. Finally, using both D6-branes and coisotropic D8-branes we construct new examples of MSSM-like type IIA vacua.Comment: 63 pages, 11 figures. Typos corrected and comments adde

Dietary supplementation of heat-treated Gracilaria and Ulva seaweeds enhanced acute hypoxia tolerance in gilthead sea bream (Sparus aurata)

Intensive aquaculture practices involve rearing fish at high densities. In these conditions, fish may be exposed to suboptimal dissolved O2 levels with an increased formation of reactive O2 species (ROS) in tissues. Seaweeds (SW) contain biologically active substances with efficient antioxidant capacities. This study evaluated the effects of dietary supplementation of heat-treated SW (5% Gracilaria vermiculophylla or 5% Ulva lactuca) on stress bioindicators in sea bream subjected to a hypoxic challenge. 168 fish (104.5 g average weight) were distributed in 24 tanks, in which eight tanks were fed one of three experimental diets for 34 days: (i) a control diet without SW supplementation, (ii) a control diet supplemented with Ulva, or (iii) a control diet with Gracilaria. Thereafter, fish from 12 tanks (n=4 tanks/dietary treatment) were subjected to 24 h hypoxia (1.3 mg O2 l-1) and subsequent recovery normoxia (8.6 mg O2 l-1). Hypoxic fish showed an increase in hematocrit values regardless of dietary treatment. Dietary modulation of the O2-carrying capacity was conspicuous during recovery, as fish fed SW supplemented diets displayed significantly higher haemoglobin concentration than fish fed the control diet. After the challenge, survival rates in both groups of fish fed SW were higher, which was consistent with a decrease in hepatic lipid peroxidation in these groups. Furthermore, the hepatic antioxidant enzyme activities were modulated differently by changes in environmental O2 condition, particularly in sea bream fed the Gracilaria diet. After being subjected to hypoxia, the gene expression of antioxidant enzymes and molecular chaperones in liver and heart were down regulated in sea bream fed SW diets. This study suggests that the antioxidant properties of heat-treated SW may have a protective role against oxidative stress. The nature of these compounds and possible mechanisms implied are currently being investigated.Fil: Magnoni, Leonardo Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Universidad de Porto; PortugalFil: Martos Sitcha, Juan Antonio. Consejo Superior de Investigaciones Científicas; EspañaFil: Queiroz, Augusto. Universidad de Porto; PortugalFil: Calduch Giner, Josep Alvar. Consejo Superior de Investigaciones Científicas; EspañaFil: Magalhaes Gonçalves, Jose Fernando. Universidad de Porto; PortugalFil: Rocha, Cristina M.R.. Universidad de Porto; PortugalFil: Abreu, Helena T.. ALGAplus; PortugalFil: Schrama, Johan W.. Wageningen University; Países BajosFil: Ozorio, Rodrigo O.A.. Universidad de Porto; PortugalFil: Perez Sanchez, Jaume. Consejo Superior de Investigaciones Científicas; Españ

Assessing the Success of the Lunawa Restoration Project Six Years Post Restoration

The Lunawa lagoon, receives large amounts of untreated industrial effluents and domesticwaste water due to its industrialized and urbanized setting. As a result, the once pristinelagoon progressively deteriorated, ultimately becoming a health hazard to those living inclose proximity. Many restoration programmes, of differing magnitudes, were undertakenfrom time to time; the most recent being that by the Coast Conservation Department in 2007.The objective of the present study is to assess the status of the lagoon in terms of waterquality and avifaunal diversity six years after restoration.This study was conducted from April to July 2013 during which selected water qualityparameters in surface water were monitored at ten stations across the lagoon each month. Anavifaunal survey was also conducted along six transects twice a month over the four months.On each day birds were observed between 0700 and 1000 hrs at equally spaced points alongthese transects. The levels of many of the parameters were significantly different betweensites. The ranges recorded were pH: 7.0 - 10.4, salinity: 0.7-8.1 ppm, conductivity: 4.7 -4058.0 μS, turbidity: 4.29-69.32 NTU, dissolved oxygen (DO): 2.3 – 14.9 mgl-1, BiologicalOxygen Demand (BOD)5day: 7.9 - 23.2 mg l-1, nitrate: 1.4 - 8.4 mg l-1, phosphate: 0.0 - 4.9 mgl-1 and chloride: 461.5 - 2875.5 mg l-1. The mean values for conductivity and BOD weresignificantly lower (p< 0.05) and DO significantly higher (p< 0.05), than the values reportedfor the lagoon prior to restoration. Although recorded previously in lagoon water, the heavymetals, Cr, Pb, and Cu were not detected during the present study. Zn (0.31 mg l-1) was onlydetected from the eastern drainage basin. Thus the present status suggests gradualtransformation of the water quality in the lagoon since restoration. The avifaunal survey didnot show similarly positive trends. A total of 31 resident species of terrestrial and aquaticbirds were recorded during the present survey. The mean abundance of the birds on each daywas 57. Both these values were lower than that reported in previous surveys. It wasnoteworthy though is the re-colonization of some species such as the spot-billed pelican, piedking fisher, white ibis, and the grey heron. It is likely that the major reasons for the lowabundance of birds at present is the absence of riparian vegetation and trees along the banksof the lagoon, which were cleared (but replanted since) during the process of restoration.The improvement of the water quality of the lagoon over the six years post restorationindicates that these efforts have been successful. It appears that it is too premature to arrive atconclusions with regard to the bird community. But, with time, the re-establishment of thebank vegetation would very likely facilitate recolonization of a more diverse bioticcommunity