Rapid determination of desorption efficiency, and analysis of solvent mixtures for occupational exposure studies

An analytical procedure has been developed for simultaneous determination of solvent mixture vapors to enable evaluation of occupational exposure. To determine the desorption efficiency the volatile components of the solvent mixtures were generated from a glass tube filled with glass wool. This device is easy to prepare and use. These vapors were then collected in activated charcoal tubes and analyzed by capillary gas chromatography. The method was tested with a mixture of 22 solvents, including aliphatic and aromatic hydrocarbons, alcohols, ethers, esters, and ketones, oil at low concentrations. All the components were defected. When a 99: 1 mixture of carbon disulfide-dimethylformamide was used for desorption the efficiency was > 75% for most of the solvents.

Analysis of the efficiency of silicate clay on the control of Xanthomonas axonopodis PV. passiflorae in vitro and in seedlings of yellow passion fruit contaminated

The bacterial spot in yellow passion fruit plants, caused by the bacteria Xanthomonas axonopodis pv. passiflorae, occurs in all producing areas of the country, and is responsible for great economic losses in the culture of passion fruit. This study aimed to test the efficiency of the silicate clay in the inhibition of the bacteria Xanthomonas axonopodis pv. passiflorae in vitro, and in both preventive and curative control of the bacterial spot in seedlings of yellow passion fruit plants. The silicate clay was added to the growth medium at concentrations of. 0.5, 1.0, 1.5 and 2.0%, placed in Petri dishes. After the culture medium was cooler, the bacterial suspension was inoculates (10(7) UFC.mL(-1)) with a handle, and left incubating at 28 degrees C for three days, and then the bacterial growth was evaluated. Subsequently, the product at the same concentrations above was sprayed on seedlings of 'Afruvec' passion fruit, as preventive or curative. The inoculation of the bacteria was made by foliar spraying of bacterial suspension (10(7) ufc.mL(-1)), 24 hours before or after the curative and preventive treatments, respectively. The severity of the disease was measured comparing each four true leaves from bottom up, with a diagrammatic scale. In the concentrations evaluated, the silicate clay inhibited both bacteria in vitro and symptoms of bacterial spot in the curative treatment. In preventive treatment, significant results were obtained using more than 1.0% of clay silicates. Based on these results, the clay silicate can be recommended, the concentration of 1.0-2.0% for the control of bacterial spot of passion fruit plants, in foliar sprays.

Factors affecting nucleolytic efficiency of some ternary metal complexes with DNA binding and recognition domains. Crystal and molecular structure of Zn(phen)(edda)

The binding selectivity of the M(phen)(edda) (M = Cu, Co, Ni, Zn; phen = 1,10-phenanthroline, edda = ethylenediaminediacetic acid) complexes towards ds(CG)(6), ds(AT)(6) and ds(CGCGAATTCGCG) B-form oligonucleotide duplexes were studied by CD spectroscopy and molecular modeling. The binding mode is intercalation and there is selectivity towards AT-sequence and stacking preference for A/A parallel or diagonal adjacent base steps in their intercalation. The nucleolytic properties of these complexes were investigated and the factors affecting the extent of cleavage were determined to be: concentration of complex, the nature of metal(11) ion, type of buffer, pH of buffer, incubation time, incubation temperature, and the presence of hydrogen peroxide or ascorbic acid as exogenous reagents. The fluorescence property of these complexes and its origin were also investigated. The crystal structure of the Zn(phen)(edda) complex is reported in which the zinc atom displays a distorted trans-N4O2 octahedral geometry; the crystal packing features double layers of complex molecules held together by extensive hydrogen bonding that inter-digitate with adjacent double layers via pi...pi interactions between 1,10-phenanthroline residues. The structure is compared with that of the recently described copper(II) analogue and, with the latter, included in molecular modeling. (C) 2008 Elsevier B.V. All rights reserved.

Ecological efficiency in thermoelectric power plants

This work evaluates the environmental impact resulting from the natural gas and diesel combustion in thermoelectric power plants that utilize the combined cycle technology (CC), as regarding to Brazilian conditions according to Thermopower Priority Plan JPP). In the regions where there are not natural gas the option has been the utilization of diesel and consequentily there are more emission of pollutants. The ecological efficiency concept, which evaluates by and large the environmental impact, caused by CO2, SO2, NOx and particulate matter (PM) emissions. The combustion gases of the thermoelectric power plants working with natural gas (less pollutant) and diesel (more pollutant) cause problems to the environment, for their components harm the human being life, animals and directly the plants. The resulting pollution from natural gas and diesel combustion is analyzed, considering separately the CO2, SO2, NO2 and particulate matter gas emission and comparing them with the in use international standards regarding the air quality. It can be concluded that it is possible to calculate thermoelectric power plant quantitative and qualitative environment factor, and on the ecological standpoint, for plant with total power of 41441 kW, being 27 170 kW for the gas turbine and 14271 kW for the steam turbine. The natural gas used as fuel is better than the diesel, presenting ecological efficiency of 0.944 versus 0.914 for the latter, considering a thermal efficiency of 54% for the combined cycle. (c) 2006 Elsevier Ltd. All rights reserved.

Combined cycle versus one thousand diesel power plants: pollutant emissions, ecological efficiency and economic analysis

The increase in the use of natural gas in Brazil has stimulated public and private sectors to analyse the possibility of using combined cycle systems for generation of electrical energy. Gas turbine combined cycle power plants are becoming increasingly common due to their high efficiency, short lead times, and ability to meet environmental standards. Power is produced in a generator linked directly to the gas turbine. The gas turbine exhaust gases are sent to a heat recovery steam generator to produce superheated steam that can be used in a steam turbine to produce additional power. In this paper a comparative study between a 1000 MW combined cycle power plant and 1000 kW diesel power plant is presented. In first step, the energetic situation in Brazil, the needs of the electric sector modification and the needs of demand management and integrated means planning are clarified. In another step the characteristics of large and small thermoelectric power plants that use natural gas and diesel fuel, respectively, are presented. The ecological efficiency levels of each type of power plant is considered in the discussion, presenting the emissions of particulate material, sulphur dioxide (SO2), carbon dioxide (CO2) and nitrogen oxides (NOx). (c) 2006 Elsevier Ltd. All rights reserved.

Ecological efficiency and thermoeconomic analysis of a cogeneration system at a hospital

This work aims with an approach for cogeneration plants evaluation based on thermoeconomic functional diagram analysis. The second law of thermodynamics is used to develop a methodology to analyse cogeneration systems, based on exergoeconomics evaluation. The thermoeconomic optimisation method developed is applied to allow a better configuration of the cogeneration plant associated to a university hospital. Also ecological efficiency is evaluated. The method was efficient and contributes for thermoeconomics modelling and analysis and can be applied to any sort of thermal system, especially those with combined heat and power in thermal parity. (C) 2012 Elsevier Ltd. All rights reserved.

Ecological efficiency in CHP: Biodiesel case

This paper evaluates and quantifies the environmental impact resulting from the combination of biodiesel fuel (pure or blended with diesel), and diesel combustion in thermoelectric power plants that utilize combined cycle technology (CC). In regions without natural gas, the option was to utilize diesel fuel; the consequence would be a greater emission of pollutants. Biodiesel is a renewable fuel which has been considerably interesting in Brazil power matrix in recent years. The concept of ecological efficiency, largely evaluates the environmental impact caused by CO(2), SO(2), NO(x) and particle matter (PM) emissions. The pollution resulting from biodiesel and diesel combustion is analyzed, separately considering CO(2), SO(2), NO(x) and particulate matter gas emissions, and comparing them international standards currently used regarding air quality. It can be concluded that it is possible to calculate the qualitative environmental factor, and the ecological effect, from a thermoelectric power plant utilizing central heat power (CHP) of combined cycle. The ecological efficiency for pure biodiesel fuel (B100) is 98.16%; for biodiesel blended with conventional diesel fuel, B20 (20% biodiesel and 80% diesel) is 93.19%. Finally, ecological efficiency for conventional diesel is 92.18%, as long as a thermal efficiency of 55% for thermoelectric power plants occurs. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Determination of ecological efficiency in internal combustion engines: The use of biodiesel

This paper evaluates and quantifies the environmental impact from the use of some renewable fuels and fossils fuels in internal combustion engines. The following fuels are evaluated: gasoline blended with anhydrous ethyl alcohol (anhydrous ethanol), conventional diesel fuel, biodiesel in pure form and blended with diesel fuel, and natural gas. For the case of biodiesel, its complete life cycle and the closed carbon cycle (photosynthesis) were considered. The ecological efficiency concept depends on the environmental impact caused by CO(2), SO(2), NO(x) and particulate material (PM) emissions. The exhaust gases from internal combustion engines, in the case of the gasoline (blended with alcohol), biodiesel and biodiesel blended with conventional diesel, are the less polluting; on the other hand, the most polluting are those related to conventional diesel. They can cause serious problems to the environment because of their dangerous components for the human, animal and vegetable life. The resultant pollution of each one of the mentioned fuels are analyzed, considering separately CO(2), SO(2), NO(x) and particulate material (PM) emissions. As conclusion, it is possible to calculate an environmental factor that represents, qualitatively and quantitative, the emissions in internal combustion engines that are mostly used in urban transport. Biodiesel in pure form (B100) and blended with conventional diesel as fuel for engines pollute less than conventional diesel fuel. The ecological efficiency for pure biodiesel (B100) is 86.75%: for biodiesel blended with conventional diesel fuel (B20, 20% biodiesel and 80% diesel), it is 78.79%. Finally, the ecological efficiency for conventional diesel, when used in engines, is 77.34%; for gasoline, it is 82.52%, and for natural gas, it is 91.95%. All these figures considered a thermal efficiency of 30% for the internal combustion engine. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.

Energetic efficiency programs and power quality

This paper presents the results of the investigations that were done to identify and to quantify the power quality problems resultant from the actions done to improve the efficiency on electric energy consumption. The efficiencies of several electric devices were evaluated, among them: fluorescent bulb, electronic ballast, soft-starter, temperature controller for showers, dimmer and others. This evaluation allowed to establish a cause/effect analysis of the power quality.

Cost assessment of efficiency losses in hydroelectric plants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dynamics of meso and thermo citrate synthases with implicit solvation

The dynamics of hydration of meso and thermo citrate synthases has been investigated using the EEF1 methodology implemented with the CHARNM program. The native enzymes are composed of two identical subunits, each divided into a small and large domain. The dynamics behavior of both enzymes at 30 degrees C and 60 degrees C has been compared. The results of simulations show that during the hydration process, each subunit follows a different pathway of hydration, in spite of the identical sequence. The hydrated structures were compared with the crystalline structure, and the root mean square deviation (RMSD) of each residue along the trajectory was calculated. The regions with larger and smaller mobility were identified. In particular, helices belonging to the small domain are more mobile than those of the large domain. In contrast, the residues that constitute the active site show a much lower displacement compared with the crystalline structure. Hydration free energy calculations point out that Thermoplasma acidophilum citrate synthase (TCS) is more stable than chicken citrate synthase (CCS), at high temperatures. Such result has been ascribed to the higher number of superficial charges in the thermophilic homologue, which stabilizes the enzyme, while the mesophilic homologue denatures. These results are in accord with the experimental found that TCS keeps activity at temperatures farther apart from the catalysis regular temperature than the CCS. (c) 2005 Wiley Periodicals, Inc.

Influence of processing parameters on nanomaterials synthesis efficiency by a carbothermal reduction process

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of carrion smell and rebaiting time on the efficiency of pitfall traps to dung beetle sampling

Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are very useful insects, as they improve the chemo-physical properties of soil, clean pastures from dung pads, and help control symbovine flies associated with bovine cattle. Their importance makes it fundamental to sample and survey them adequately. The objectives of the present study were to determine the influence of decaying insects trapped in pitfalls on the attractiveness of Moura pig Sus scrofa L. (Suidae) and collared peccary Tayassu tajacu (L.) (Tayassuidae) dung used as baits to lure dung beetles, and to establish how long these baits remain attractive to dung beetles when used in these traps. Some dung beetle species seemed to be able to discriminate against foul smell from decaying insects within the first 24 h, hence decreasing trap efficiency. This was more evident in peccary dung-baited traps, which proved to be the least attractive bait. Attractiveness lasted only 24 h for peccary dung, after which it became unattractive, whereas the pig dung bait was highly attractive for 48 h, after which its attractiveness diminished but was not completely lost.

Caracterização macro, meso e microscópica das estruturas frágeis do corpo arenítico conglomerático da região de Santana do Acaraú (CE) e seu embasamento circundante

The structural framework of the sedimentary basins usually plays an important role in oil prospects and reservoirs. Geometry, interconectivity and density of the brittle features developed during basin evolution could change the permo-porous character of the rocks involved in generation, migration and entrapment of fluid flow. Once the structural characterization of the reservois using only sub-surface data is not an easy task, many studies are focused in analogous outcrops trying to understand the main processes by which brittle tectonic is archieved. In the Santana do Acaraú region (Ceará state, NE Brazil) a pack of conglomeratic sandstone (here named CAC) has its geometry controlled mainly by NE trending faults, interpreted as related to reactivation of a precambrian Sobral Pedro II Lineament (LSP-II). Geological mapping of the CAC showed a major NE-SW trending synform developed before its complete lithification during a dextral transpression. This region was then selected to be studied in details in order of constrain the cretaceous deformation and so help the understanding the deformation of the basins along the brazilian equatorial margin. In order to characterize the brittle deformation in different scales, I study some attributes of the fractures and faults such as orientation, density, kinematic, opening, etc., through scanlines in satellite images, outcrops and thin sections. The study of the satellite images showed three main directions of the macrostructures, N-S, NE-SW and E-W. Two of theses features (N-S and E-W) are in aggreement with previous geophysical data. A bimodal pattern of the lineaments in the CAC´s basement rocks has been evidenciated by the NE and NW sets of structures obtained in the meso and microscale data. Besides the main dextral transpression two others later events, developed when the sediments were complety lithified, were recognized in the area. The interplay among theses events is responsible for the compartimentation of the CAC in several blocks along within some structural elements display diferents orientations. Based on the variation in the S0 orientation, the CAC can be subdivided in several domains. Dispite of the variations in orientations of the fractures/faults in the diferents domains, theses features, in the meso and microscopic scale, are concentrated in two sets (based on their trend) in all domains which show similar orientation of the S0 surface. Thus the S0 orientation was used to group the domains in three major sets: i) The first one is that where S0 is E-W oriented: the fractures are oriented mainly NE with the development of a secondary NW trending; ii) S0 trending NE: the fractures are concentrated mainly along the trend NW with a secondary concentration along the NE trend; iii) The third set, where S0 is NS the main fractures are NE and the secondary concentration is NW. Another analized parameter was the fault/fracture length. This attribute was studied in diferent scales trying to detect the upscale relationship. A terrain digital model (TDM) was built with the brittlel elements supperposed. This model enhanced a 3D visualization of the area as well as the spatial distribution of the fault/fractures. Finally, I believe that a better undertanding of the brittle tectonic affecting both CAC and its nearby basement will help the future interpretations of the tectonic envolved in the development of the sedimentary basins of the brazilian equatorial margin and their oil reservoirs and prospects, as for instance the Xaréu field in the Ceará basin, which subsurface data could be correlated with the surface ones

Evolução estrutural e termocronológica meso-cenozóica da Zona de Cisalhamento Portalegre, Nordeste do Brasil

The Portalegre shear zone (ZCPa), which is located in the Rio Grande do Norte and Paraíba states (Northeastern Brazil), is na important right-lateral, northeast-trending lineament formed during the Brazilian Orogenic Cicle). The ZCPa experienced na important brittle reactivation from the Mesozoic until the present. This reactivation led to the formation of the Gangorra, Pau dos Ferros, Coronel João Pessoa, Icozinho and Rio do Peixe basins. The reactivation northern parto f the ZCPa that marks the boundary of the Potiguar Basin is denominated Carnaubais Fault. Several fracture patterns were mapped along the ZCPa. Samples were collected in Neoproterozoic granite outcrops, along the ZCPa. These samples yielded AFT ages from 86±13 to 376±57 Ma, and the mean track length from 10.9±0.8 to 12.9±1.5 mm. Samples from the East block yielded mean ages of 103 Ma, mean track lengtn 12,1mm, and mean altitude 250m, whereas samples from West block yielded mean ages of 150 Ma, which reach 345 Ma and 220 Ma in the Pau dos Ferros and Coronel João Pessoa basins, respectively. Thermal history models were sorted out for each crustal block. Samples from West block recorded a thermal history from Carboniferous Period until the Permiano, when the block experienced gradual uplift until the Cretaceous, when it underwent downfaulting and heating until the Tertiary, and it eventually experienced a rapid uplift movement until recent times. Samples from the East block presented the same cooling and heating events, but at they occurred different times. The East block thermal record started ~140 Ma, when this block experienced cooling until ~75 Ma. Both blocks show a denundacion/erosional history more similar in the Tertiary. The AFT data indicate an important tectonic event ~140 Ma, when the West block experienced downfaulting and the East block experienced uplift. This tectonic process led to the generation of several sedimentary basins in the region, including the Potiguar basin. This tectonic event is also interpreted as a rift process caused by an E-W-trending extension. It the Tertiary, some heating events can be tentatively attributed to the macau volcanic event