Search results for "Coal"
showing 10 items of 354 documents
Forward and backward diffusion approximations for haploid exchangeable population models
2001
Abstract The class of haploid population models with non-overlapping generations and fixed population size N is considered such that the family sizes ν1,…,νN within a generation are exchangeable random variables. A criterion for weak convergence in the Skorohod sense is established for a properly time- and space-scaled process counting the number of descendants forward in time. The generator A of the limit process X is constructed using the joint moments of the offspring variables ν1,…,νN. In particular, the Wright–Fisher diffusion with generator Af(x)= 1 2 x(1−x)f″(x) appears in the limit as the population size N tends to infinity if and only if the condition lim N→∞ E((ν 1 −1) 3 )/(N Var …
Dynamic simulation model of a coal thermoelectric plant with a flue gas desulphurisation system
2006
Abstract In this paper a Dynamic Simulation Model has been used to present the likely responses of the electricity industries’ latest perturbations such as: changes in environmental regulations, international fuel market evolution, restriction on fuel supply and increase on fuel prices, liberalisation of the European Electricity Market, and the results of applying energy policies and official tools such as taxes and emission allowances. The case under study refers to the Teruel Power Plant, built after the 1970s oil crisis to ensure national electricity supply; burning domestically produced coal in order to ensure local mining activity. The Teruel Power Plant has made relevant investments i…
Conversion of peat and coal nitrogen through HCN and NH3 to nitrogen oxides at 800 °C
1993
The conversion of fuel nitrogen through HCN and NH3 to nitrogen oxides (N2O, NO and NO2) was studied using an entrained-flow reactor at 800 °C with one coal and four peats at 5 and 1% O2. The ON ratios of the fuels were between 7 and 20. A clear dependence was found between the HCNNH3 ratio measured just after the vigorous pyrolysis step and the N2ONO ratio in the flue gas when these were plotted as a function of the initial ON ratio of the fuel.
Macrobotanical evidence (wood charcoal and seeds) from the Middle Palaeolithic site of El Salt, Eastern Iberia: Palaeoenvironmental data and plant re…
2018
Despite the current growing number of studies that focus on macrobotanical remains from Middle Palaeolithiccontexts, plant use among hunter-gatherer societies remains unknown in many regions of Europe. Large-scaleflotation of archaeological sediments has made it possible to recover a large amount of plant remains (fruits,seeds and wood) from units VIII, IX, Xa and Xb at El Salt, Eastern Iberia (49.2–52.3 ka BP). The combination ofanthracological and carpological analyses has provided a more accurate picture of the Middle Palaeolithiclandscape in the Serpis valley, as well as significant information about other possible uses of plants, not only asfuel, but for woodworking or food, for instan…
Ancient DNA reveals prehistoric gene-flow from Siberia in the complex human population history of North East Europe.
2013
North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Ru…
THE SHAPLEY-SOLIDARITY VALUE FOR GAMES WITH A COALITION STRUCTURE
2013
A value for games with a coalition structure is introduced, where the rules guiding cooperation among the members of the same coalition are different from the interaction rules among coalitions. In particular, players inside a coalition exhibit a greater degree of solidarity than they are willing to use with players outside their coalition. The Shapley value is therefore used to compute the aggregate payoffs for the coalitions, and the solidarity value to obtain the payoffs for the players inside each coalition.
Phylogeographic patterns in Drosophila montana
2006
The Drosophila virilis species group offers valuable opportunities for studying the roles of chromosomal re-arrangements and mating signals in speciation. The 13 species are divided into two subgroups, the montana and virilis 'phylads'. There is greater differentiation among species within the montana phylad in both karyotype and acoustic signals than exists among members of the virilis phylad. Drosophila montana is a divergent species which is included in the montana phylad. Here, we analyse the phylogeography of D. montana to provide a framework for understanding divergence of acoustic signals among populations. We analysed mitochondrial sequences corresponding to the cytochrome oxidase I…
Efficient Removal of Methyl Red Dye by Using Bark of Hopbush
2022
Methyl red (MR) dye, one of the azo dyes, is mutagenic and its persistence has negative effects on the environment and people’s health. The current work is the first to demonstrate that methyl red dye can be removed effectively and sustainably, utilizing biomass derived from the bark of the Dodonaea viscosa (Hopbush) plant. The Hopbush bark shows effective adsorption of MR, upto 73%, under optimized conditions in an aqueous medium. The experimental conditions were optimized by examining the effect of time, initial dye concentration, pH and ionic strength on the adsorption process in an aqueous medium. Maximum (i.e., 73%) adsorption of MR removal (500 ppm) was observed in highly acidic…
Identification of carbonaceous geosorbents for PAHs by organic petrography in river floodplain soils.
2007
Organic petrographic analysis was applied to provide direct information on carbonaceous geosorbents for PAHs in river floodplain soils. The anthropogenic OM group (primarily coal and coal-derived particles) displayed large volume amounts for all the soil samples. Distinct PAH concentrations with similar PAH distribution patterns were determined in grain size and density fractions for each sample. Two-ring PAHs had stronger correlation to organic carbon (OC) than black carbon (BC) contents, while heavier PAHs showed correlation to BC, rather than OC. In this study, we combined grain size and density separation, PAH determinations, TOC and BC measurements, and organic petrographic identificat…
Effects of Activated Carbon on PCB Bioaccumulation and Biological Responses of Chironomus riparius in Full Life Cycle Test
2016
The nonbiting midge Chironomus riparius was used to study the remediation potential and secondary effects of activated carbon (AC, ø 63-200 μm) in PCB contaminated sediments. AC amendments efficiently reduced PCB bioavailability determined by Chironomus riparius bioaccumulation tests and passive samplers. PCBs were shown to transfer from larvae to adults. Lower PCB concentrations were observed in adult midges emerging from AC amended compared to unamended sediments. Increased reproduction, survival, larval growth and gut wall microvilli length were observed with low AC dose (0.5% sediment dw) compared to unamended sediment, indicating an improved success of larvae in the sediment with low o…