Síntese, aplicação e avaliação do efeito do teor de fósforo da celulose fosfatada em argamassa de alvenaria com aditivo comercial a base de hidroxi-etil-metil celulose (HEMC)

Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength

Estudo do processo de combustão in-situ usando poços horizontais como produtores de óleo (Toe-to-Hell Air Injection)

The method "toe-to-heel air injection" (THAITM) is a process of enhanced oil recovery, which is the integration of in-situ combustion with technological advances in drilling horizontal wells. This method uses horizontal wells as producers of oil, keeping vertical injection wells to inject air. This process has not yet been applied in Brazil, making it necessary, evaluation of these new technologies applied to local realities, therefore, this study aimed to perform a parametric study of the combustion process with in-situ oil production in horizontal wells, using a semi synthetic reservoir, with characteristics of the Brazilian Northeast basin. The simulations were performed in a commercial software "STARS" (Steam, Thermal, and Advanced Processes Reservoir Simulator), from CMG (Computer Modelling Group). The following operating parameters were analyzed: air rate, configuration of producer wells and oxygen concentration. A sensitivity study on cumulative oil (Np) was performed with the technique of experimental design, with a mixed model of two and three levels (32x22), a total of 36 runs. Also, it was done a technical economic estimative for each model of fluid. The results showed that injection rate was the most influence parameter on oil recovery, for both studied models, well arrangement depends on fluid model, and oxygen concentration favors recovery oil. The process can be profitable depends on air rate

Estudo do processo de combustão in-situ em reservatórios maduros de óleos médios e leves (high pressure air injection)

Nearly 3 x 1011 m3 of medium and light oils will remain in reservoirs worldwide after conventional recovery methods have been exhausted and much of this volume would be recovered by Enhanced Oil Recovery (EOR) methods. The in-situ combustion (ISC) is an EOR method in which an oxygen-containing gas is injected into a reservoir where it reacts with the crude oil to create a high-temperature combustion front that is propagated through the reservoir. The High Pressure Air Injection (HPAI) method is a particular denomination of the air injection process applied in light oil reservoirs, for which the combustion reactions are dominant between 150 and 300°C and the generation of flue gas is the main factor to the oil displacement. A simulation model of a homogeneous reservoir was built to study, which was initially undergone to primary production, for 3 years, next by a waterflooding process for 21 more years. At this point, with the mature condition established into the reservoir, three variations of this model were selected, according to the recovery factors (RF) reached, for study the in-situ combustion (HPAI) technique. Next to this, a sensitivity analysis on the RF of characteristic operational parameters of the method was carried out: air injection rate per well, oxygen concentration into the injected gas, patterns of air injection and wells perforations configuration. This analysis, for 10 more years of production time, was performed with assistance of the central composite design. The reservoir behavior and the impacts of chemical reactions parameters and of reservoir particularities on the RF were also evaluated. An economic analysis and a study to maximize the RF of the process were also carried out. The simulation runs were performed in the simulator of thermal processes in reservoirs STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator) from CMG (Computer Modelling Group). The results showed the incremental RF were small and the net present value (NPV) is affected by high initial investments to compress the air. It was noticed that the adoption of high oxygen concentration into the injected gas and of the five spot pattern tends to improve the RF, and the wells perforations configuration has more influence with the increase of the oil thickness. Simulated cases relating to the reservoir particularities showed that smaller residual oil saturations to gas lead to greater RF and the presence of heterogeneities results in important variations on the RF and on the production curves

Air velocity and exposure time to ventilation affect body surface and rectal temperature of broiler chickens

Increasing air movement over poultry by using fans (ventilation) has become an accepted means of reducing environmental heat stress over the last several years. The purpose of this study was to evaluate the effect of air velocity and exposure time to ventilation on body surface and rectal temperature of broiler chickens. Male broiler chickens aged 36-42 days were placed in individual wire cages and exposed to five different air velocities (5.7, 4.2, 3.1, 2.4, or 1.8 m/sec). Throughout the experiment head, back, leg, and rectal temperatures were monitored every 10 min during a 30-min period for each air velocity. The data showed that exposure time to the wind affected (P<.05) leg and body temperature, with a rapid reduction being observed during the first 10 min. There was a reduction in leg temperature with air velocity of 2 m/sec; however, air velocity lower than 4.5 m/sec was not effective in decreasing head and back temperature. The results suggest that air velocity of 2 m/sec, in air temperature of 29 degrees C, improves heat loss in the birds. The data also indicate that exposure time to ventilation seems to be a critical point in the maintenance of bird thermal homeostasis.

Soil CO2 emission as related to incorporation of sugarcane crop residues and aggregate breaking after rotary tiller

O preparo do solo é um dos processos que aceleram a decomposição da matéria orgânica, transferindo carbono para atmosfera, principalmente na forma de CO2. Neste trabalho, investigou-se o efeito do preparo com enxada rotativa sobre as emissões de CO2 do solo durante 02 semanas após o preparo do solo, incluindo-se a presença de resíduos vegetais sobre a superfície. As emissões foram avaliadas por 15 dias após preparo em 3 parcelas: 1) sem preparo e sem palha superficial (SPs); 2) preparo com enxada rotativa sem a presença de palha na superfície (ERs), e 3) preparo com enxada rotativa com a presença de palha superficial (ERc). As emissões provenientes da ERc foram superiores às demais (0,777 g CO2 m-2 h-1), sendo as menores emissões registradas na parcela SPs (0,414 g CO2 m-2 h-1). As emissões totais indicaram que a diferença de C-CO2 emitida à atmosfera corresponde a 3% do total de carbono adicional presente na palha, na parcela ERc, quando comparado à parcela ERs. O aumento da emissão da parcela SPs para ERs foi acompanhado de uma modificação na distribuição do tamanho de agregados, especialmente aqueles com diâmetro médio inferior a 2 mm. O aumento da emissão da parcela ERs para ERc esteve relacionado a uma diminuição da massa de palha na superfície, com fragmentação e incorporação da mesma no interior do solo. Quando se analisa a correlação linear entre emissão de CO2 versus temperatura e umidade do solo, somente a emissão da ERc foi significativamente correlacionada (p<0,05) à umidade do solo.

Mutagenic activity of airborne particulate matter (PM10) in a sugarcane farming area (Araraquara city, southeast Brazil)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Stress responses in juvenile pacu (Piaractus mesopotamicus) submitted to repeated air exposure.

Pacu juveniles (5.2 [plus or minus] 1.5 g) were submitted to two one-minute air exposures in a 24h interval, and sampled before the exposure (control) and 5, 15, 30 and 60 min., 24 and 48h afterwards for whole-body cortisol, sodium, potassium and calcium ion concentrations. For the first air exposure, there was a trend of increased cortisol concentration after 15 min., whereas in the second air exposure, the cortisol concentration increased significantly within 5 min. after stress was induced. Sodium ion concentration increased significantly 24h after both air exposures. Potassium concentration presented fluctuations over the experimental period. Calcium ion concentration increased progressively from 5 to 30 min., in both air exposures. The repeated air exposures exacerbated the cortisol response, but they did not affect the recovery ability of pacu over the experimental period. Additionally, the whole-body cortisol measurement might be a reliable indicator of stress, when sampled fish are smaller and blood volumes are very low, making samples inadequate for analysis.

Toxoplasma gondii: isolation of tachyzoites rhoptries and incorporation into Iscom

Rhoptries have been isolated from Toxoplasma gondii tachyzoites by subcellular fractionation in isopynic density sucrose gradient. Five bands were observed, and transmission electron microscopy of these indicated that rhoptries were in band 3. This band had a density of 1.17g/cm(3). Fraction 1 had membrane structures of the parasite. Fraction 2 contained membranes and mitochondria (Fig. 1 B). Fraction 4 had mostly conoid structure (Fig. 2B) and fraction 5 showed ghosts. The electrophoretic and Western blotting analysis of the fractions indicated the presence of a number of proteins. Iscoms were constructed from band 3, which contained the rhoptry structures. Iscom showed a only protein incorporated of 55 kDa. Isolation of the parasite organelles has got in this work is necessary to identification, characterization, and function elucidation of the organelle proteins. (C) 2004 Elsevier B.V. All rights reserved.

Indol-butyric acid levels on cashew cloning by air-layering process

Um estudo foi conduzido com a finalidade de determinar a possibilidade de clonagem do cajueiro (Anacardium occidentale) por alporquia e a influência do AIB (ácido indolbutírico) nesse processo. Adotou-se delineamento experimental inteiramente casualizado, com 4 tratamentos, 10 alporques por parcela, repetidos por 4 vezes, num total de 160 alporques. Os tratamentos constaram das concentrações de AIB: 0 (testemunha), 1.000, 3.000 e 5.000 mg.kg-1. Foram avaliadas as percentagens de sobrevivência, calejamento e enraizamento, bem como número e comprimento médio de raízes. A maior percentagem de sobrevivência (67,5%) foi observada para a testemunha e concentração de 1.000 mg.kg-1, enquanto a melhor percentagem de enraizamento (82%) foi relacionada com o nível de 1.000 mg.kg-1. Para o número e comprimento médio de raízes, os melhores resultados foram concernentes à dose de 5.000 mg.kg-1. Não houve influência do AIB na clonagem do cajueiro por alporquia.

Chemical properties and enzyme activity in a sewage sludge-treated soil

A soil sample was taken from the top 0-20cm at Jaboticabal county, São Paulo State, Brazil, air dried, sieved to 5mm, and placed into pots (2700g per pot). Sewage sludge was air-dried, ground to 2mm, and thoroughly mixed to the top 0-10cm soil of each pot, which were irrigated with distilled water in a total volume equivalent to the last 30years average rainfall in the region. Sorghum was sowed 120days after sewage sludge incorporation and then the irrigation was made according to the plants' requirement. When the plants were about 10 cm high, they were thinned to two per pot. Soil samples (0-10, 10-20, and 20-30 cm depth) were obtained immediately after the incorporation of sewage sludge and at 30, 60, 120, and 170 days after, air dried, sieved to 2 mm and analyzed for organic matter (OM), pH (0,01 mol L-1 CaCl2), extractable P (resin), potassium (K), calcium (Ca), and magnesium (Mg), amylase and cellulase activity. Sewage sludge increased soil OM, pH, extractable phosphorus (P), K. Ca. amylase and cellulase activity, especially at the rate 16 t ha(-1). Organic matter, extractable P, K, Ca, Mg. and amylase activity were higher in the top 0-10cm, while pH was higher in the 20-30cm layer. Amylase activity was not affected by sampling depth. Organic matter, pH, extractable P. K, Ca, and Mg decreased during the experimental period. Amylase activity decreased until sorghum was sowed and increased afterwards. Cellulase activity increased until 90 days after sewage sludge application and then decreased. Sewage sludge used in the experiment should already contain some amylase activity or a substance that was a soil enzyme activator and also a substance that was an inhibitor of soil cellulase inhibitor. Sonic of the plant nutrients contained in sewage sludge, mainly P, did not migrate down the soil column. an indication that sewage sludge should be incorporated into the soil to improve nutrient bioavailability. Sorghum roots increased amylase activity but did not affect cellulase activity.

Cardiovascular changes under normoxic and hypoxic conditions in the air-breathing teleost Synbranchus marmoratus: importance of the venous system

Synbranchus marmoratus is a facultative air-breathing fish, which uses its buccal cavity as well as its gills for air-breathing. S. marmoratus shows a very pronounced tachycardia when it surfaces to air-breathe. An elevation of heart rate decreases cardiac filling time and therefore may cause a decline in stroke volume (VS), but this can be compensated for by an increase in venous tone to maintain stroke volume. Thus, the study on S. marmoratus was undertaken to investigate how stroke volume and venous function are affected during air-breathing. To this end we measured cardiac output (Q), heart rate (fH), central venous blood pressure (PCV), mean circulatory filling pressure (MCFP), and dorsal aortic blood pressures (PDA) in S. marmoratus. Measurements were performed in aerated water (P-O2 > 130 mmHg), when the fish alternated between gill ventilation and prolonged periods of apnoeas, as well as during hypoxia (P-O2 <= 50 mmHg), when the fish changed from gill ventilation to air-breathing. Q increased significantly during gill ventilation compared to apnoea in aerated water through a significant increase in both fH and VS. PCV and MCFP also increased significantly. During hypoxia, when the animals surface to ventilate air, we found a marked rise in fH, PCV, MCFP, Q and VS, whereas PDA decreased significantly. Simultaneous increases in PCV and MCFP in aerated, as well as in hypoxic water, suggests that the venous system plays an important regulatory role for cardiac filling and VS in this species. In addition, we investigated adrenergic regulation of the venous system through bolus infusions of adrenergic agonists (adrenaline, phenylephrine and isoproterenol; 2 mu g kg(-1)). Adrenaline and phenylephrine caused a marked rise in PCV and MCFP, whereas isoproterenol led to a marked decrease in PCV, and tended to decrease MCFP. Thus, it is evident that stimulation of both alpha- and beta-adrenoreceptors affects venous tone in S. marmoratus.

The autonomic control and functional significance of the changes in heart rate associated with air breathing in the jeju, Hoplerythrinus unitaeniatus

The jeju is a teleost fish with bimodal respiration that utilizes a modified swim bladder as an air-breathing organ (ABO). Like all air-breathing fish studied to date, jeju exhibit pronounced changes in heart rate (f(H)) during air-breathing events, and it is believed that these may facilitate oxygen uptake (M-O2) from the ABO. The current study employed power spectral analysis (PSA) of f(H) patterns, coupled with instantaneous respirometry, to investigate the autonomic control of these phenomena and their functional significance for the efficacy of air breathing. The jeju obtained less than 5% of total M-O2 (M-tO2) from air breathing in normoxia at 26 degrees C, and PSA of beat-to-beat variability in fH revealed a pattern similar to that of unimodal water-breathing fish. In deep aquatic hypoxia (water P-O2=1 kPa) the jeju increased the frequency of air breathing (f(AB)) tenfold and maintained M-tO2 unchanged from normoxia. This was associated with a significant increase in heart rate variability (HRV), each air breath (AB) being preceded by a brief bradycardia and then followed by a brief tachycardia. These f(H) changes are qualitatively similar to those associated with breathing in unimodal air-breathing vertebrates. Within 20 heartbeats after the AB, however, a beat-to-beat variability in f(H) typical of water-breathing fish was re-established. Pharmacological blockade revealed that both adrenergic and cholinergic tone increased simultaneously prior to each AB, and then decreased after it. However, modulation of inhibitory cholinergic tone was responsible for the major proportion of HRV, including the precise beat-to-beat modulation of f(H) around each AB. Pharmacological blockade of all variations in f(H) associated with air breathing in deep hypoxia did not, however, have a significant effect upon f(AB) or the regulation of M-tO2. Thus, the functional significance of the profound HRV during air breathing remains a mystery.

Ionized-air-treated curaua fibers as reinforcement for phenolic matrices

Curaua fibers were treated with ionized air to improve the fiber/phenolic matrix adhesion.The treatment with ionized air did not change the thermal stability of the fibers. The impact strength increased with increase in the fiber treatment time. SEM micrographs of the fibers showed that the ionized air treatment led to separation of the fiber bundles. Treatment for 12 h also caused a partial degradation of the fibers, which prompted the matrix to transfer the load to a poorer reinforcing agent during impact, thereby decreasing the impact strength of the related composite. The composites reinforced with fibers treated with ionized air absorbed less water than those reinforced with untreated fibers.

Air-assisted boom sprayer and spray deposition on bean plants

A possibilidade do desenvolvimento de técnicas de aplicação de produtos fitossanitários mais seguras, com menores volumes de calda, número de aplicações e deriva, aliados à necessidade de se obter melhores níveis de controle dos agentes nocivos às plantas cultivadas, justificam o uso da assistência de ar junto à barra de pulverização. Com o objetivo de avaliar a deposição da pulverização na cultura do feijoeiro (Phaseolus vulgaris), em presença e ausência da assistência de ar junto à barra de pulverização, com diferentes pontas de pulverização e volumes de calda, foi conduzido um experimento em delineamento inteiramente casualizado, utilizando-se como traçador o óxido cuproso. Alvos artificiais (papel filtro com 3 x 3 cm) foram afixados nas superfícies adaxial e abaxial de folíolos posicionados nos terços superior e inferior de plantas, selecionadas ao acaso, distribuídas perpendicularmente ao deslocamento do pulverizador. Após a aplicação do traçador os coletores foram lavados individualmente em solução extratora de ácido nítrico a 1,0 mol L-1. A determinação quantitativa dos depósitos foi realizada com o uso da espectrofotometria de absorção atômica. A assistência de ar junto à barra de pulverização não aumentou a deposição do traçador em folíolos de feijoeiro, aos 48 dias após a emergência da cultura.

Incorporação do resíduo oriundo do beneficiamento de caulim em concreto asfáltico

The municipal district of Equador-RN is located in an area of great amounts of ores, being your main economical activity the extraction and the kaolin improvement. The main originating from environmental problem that activity is the amount of generated residue, about 70% of the extracted kaolin. The residues are simply piled up in lands of the improvement companies, occupying like this a large area and causing impact in the existent flora. When dry, the residues transform powdered and for the action of the wind, they disperse, polluting the air. Being like this, the present work has as objective evaluates the incorporation of the great residue, originating from of the kaolin improvement, in partial substitution of all the employed aggregates in a conventional mixture of asphalt concrete, which was used in the paving of BR101/RN061 - passage between Ponta Negra and Ares. That evaluation was accomplished in three stages. The first refers to the evaluation of the physical, thermal and mineralogical characteristics of the residue with the intention of to classify it and to define your application as aggregate (small and great). The second refers to the physical characterization of the aggregates and of the asphalt material used in the conventional mixture. And the third, to the evaluation of the mixtures containing residue, which were elaborated starting from the conventional mixture with the gradual incorporation of the residue, from 5 to 40%, in substitution to the part of the conventional aggregates, in way to obtain similar particle size curves the one of the conventional mixture. That evaluation was accomplished through the comparison between the volumetric composition, the mechanical behavior and the susceptibility to the humidity of the mixtures containing residue with the one of the conventional mixture, and with the one of the DNIT specifications. The results show that the great residue originating from of the kaolin improvement has grains of the most varied size, being like this, it can substitute part of all the conventional aggregates and of the filler in an asphalt mixture. Besides, your mineralogical composition presented the same present minerals in the composition of conventional aggregates used in paving. The results evaluation of the volumetric composition of the mixtures containing residue indicates that it can use up to 30% of residue in substitution to the conventional aggregates. The evaluation of the mechanical behavior of those mixtures indicates that the residue increment in the studied mixtures caused an increase of the stability and a reduction of the resistance to the traction. The values obtained in the resistance to the traction meet below the minimum value specified by DNIT, but close to the value obtained in the conventional mixture. When taking in consideration the susceptibility of the same ones to the humidity, the results indicate that she can use up to 25% of residue