Effect of the structure of commercial poly(ethylene oxide-b-propylene oxide) demulsifier bases on the demulsification of water-in-crude oil emulsions: elucidation of the demulsification mechanism

Water-in-crude oil emulsions are formed during petroleum production and asphaltenes play an important role in their stabilization. Demulsifiers are added to destabilize such emulsions,however the demulsification mechanism is not completely known. In this paper, the performances of commercial poly(ethylene oxide-b-propylene oxide) demulsifiers were studied using synthetic water-in-oil emulsions and model-systems (asphaltenes in organic solvent). No change in the asphaltene aggregate size induced by the demulsifier was observed. The demulsification performance decreased as the asphaltene aggregate size increased, so it can be suggested that the demulsification mechanism is correlated to the voids between the aggregates adsorbed on the water droplets surface.

Characterization of Lubricating Oil Using Ultrasound

This paper presents an ultrasonic method to measure small concentrations of water in lubricating oil. It uses an ultrasonic measurement cell composed by a piezoceramic emitter (5 and 10 MHz), and a large aperture PVDF receiver that eliminates diffraction effects. The propagation velocity, attenuation coefficient and density of several samples of water-in-oil emulsion were measured. The concentrations of water of the samples were in the range of 0 to 5% in volume, and the results showed that these low concentrations can be discriminated within a resolution of 0.2% in the studied range, using the measurement of the propagation velocity.

Two new serovars of Salmonella: S. Natal and S. potengi, isolated from fluvial water in Natal, Rio Grande do Norte State, Brazil

Two new serovars of Salmonella from estuary waters of potengi river in Natal, Rio Grande do Norte, were isolated. They were named S. natal (9,12: z4, z24:-) and S. potengi (18;z: -). Both types belong to the subgenus I, or subspecies 1, thought they showed atypical behaviour (KCN +).

Behavior of Biomphalaria glabrata, the intermediate host snail of Schistosoma mansoni, at different depths in water in laboratory conditions

Using three columns of different depths (1.10m, 8.40m and 10.40m), we investigated the possibility of Biomphalaria glabrata moving towards deep regions. In the 1.10m column, we noted that locomotion can occur in two manners: 1) when the foot is in contact with the substrate: a) sliding descent; b) sliding ascent; c) creeping descent; d) creeping ascent, 2) when the foot is not in contact with the substrate: a) sudden descent without emission of air bules; b) sudden descent with emission of air bules; c) sudden ascent. In the 8.40m column containing food on the bottom (experimental group), the snails remained longer at this depth when compared to those of the group which received no food (control). The sliding behavior was characteristic of locomotion occurring at 0 to 1m both in upward and downward directions. Creeping behavior was typical for the ascent of the snails that reached deeper levels. When the snails were creeping, the shell remained hanging as if it were heavier, a fact that may have been due to water entering the pulmonary chamber. In the 10.40m column, the snails slid downward to a depth of 4m or descended suddenly all the way to the bottom. Ascent occurred by creeping from the bottom to the surface. In the 8.40m and 10.40m columns, copulation, feeding and oviposition occurred at the deepest levels.

Pedotransfer functions to estimate retention and availability of water in soils of the state of Santa Catarina, Brazil

Studies on water retention and availability are scarce for subtropical or humid temperate climate regions of the southern hemisphere. The aims of this study were to evaluate the relations of the soil physical, chemical, and mineralogical properties with water retention and availability for the generation and validation of continuous point pedotransfer functions (PTFs) for soils of the State of Santa Catarina (SC) in the South of Brazil. Horizons of 44 profiles were sampled in areas under different cover crops and regions of SC, to determine: field capacity (FC, 10 kPa), permanent wilting point (PWP, 1,500 kPa), available water content (AW, by difference), saturated hydraulic conductivity, bulk density, aggregate stability, particle size distribution (seven classes), organic matter content, and particle density. Chemical and mineralogical properties were obtained from the literature. Spearman's rank correlation analysis and path analysis were used in the statistical analyses. The point PTFs for estimation of FC, PWP and AW were generated for the soil surface and subsurface through multiple regression analysis, followed by robust regression analysis, using two sets of predictive variables. Soils with finer texture and/or greater organic matter content retain more moisture, and organic matter is the property that mainly controls the water availability to plants in soil surface horizons. Path analysis was useful in understanding the relationships between soil properties for FC, PWP and AW. The predictive power of the generated PTFs to estimate FC and PWP was good for all horizons, while AW was best estimated by more complex models with better prediction for the surface horizons of soils in Santa Catarina.

Seed biometric parameters in oil palm accessions from a Brazilian germplasm bank

The objective of this work was to evaluate the morphological diversity of oil palm seeds and to cluster the accessions according to their morphological characteristics. Forty-one accessions from the oil palm germplasm bank of Embrapa Amazônia Ocidental were evaluated - 18 of Elaeis oleifera and 23 of E. guineensis. The groups were formed based on morphological characteristics, by principal component analysis. In E. oleifera, four groups were formed, tied to their region of origin, but with significant morphological differences between accessions from the same population. For tenera-type E. guineensis seeds, three widely divergent groups were formed, especially as to external parameters, which differentiated them from the other ones. The parameter endocarp thickness stood out in intra- and inter-population differentiation. For dura-type E. guineensis, three groups were formed, with larger seeds and thicker endocarps, which differed from all the other ones. The variability observed for seed characteristics in the analyzed accessions allows the establishment of different groups, to define strategies for genetic improvement.

Rational use of water in a poultry slaughterhouse in the state of Paraná, Brazil: a case study

Agroindustries are major consumers of water. However, to adapt to environmental trends and be competitive in the market, they have sought rational use of water through water management in their activities. Cleaner Production can result in economic, environmental and social benefits, and in actions that promote reduction in water consumption. This case study was conducted in a slaughterhouse and poultry cold storage processing plant and aimed to identify points of excessive water consumption, and to propose alternatives for managing water resources by reducing consumption. Consumption data are presented in relation to the processing stages with alternatives proposed for the rational use of water, such as closure of mains water during shift changes. Following the implementation of recommendations, a reduction in water consumption of approximately 11,137 m³ per month was obtained, which equates to a savings of US$ 99,672 per year. From this study, it was concluded that the company under review could develop various improvement actions and make an important contribution to the preservation of water resources in the region where it operates.

Distribution of water in sandy soil applied by drip

The search for the use of water with high levels of efficiency has motivated the use of drip irrigation in several agricultural systems. However, for the efficiency be ensured, it is necessary that the water distribution in the soil profile must to be known in more details. As it is a highly variable process, function of the local characteristics, is essential the study of each case. The objective of this research was evaluating the water distribution in the soil profile, from drippers installed in surface and 0.15 m below the soil surface. The experiment was realized in the Technical Center of Irrigation (TCI) of the State University of Maringá - PR. The water monitoring in the soil profile was done with TDR probes installed in a box containing sandy soil, at the depths from 0.05 to 0.80 m; and 0.05 to 0.35 m of lateral spacing, at intervals of 0.05 m, totalizing 30 probes. The treatments were differentiated in relation of the installation depth of the emitters (0.0 and 0.15 m) and flow (1, 2, 4, 6, and 8 L h-1). The irrigation time was 8 hours continuous with reading of the TDR probes each 30 minutes. The results allowed concluding that the wet area with the emitter positioned on the soil surface was directly proportional to the flow increase. For the underground dripper, this area was substantially smaller and the water losses by percolation were higher, mainly to the flows higher than 4 L h-1, which provided to unacceptable water losses that should be avoided.

Oral administration of L-arginine decreases blood pressure and increases renal excretion of sodium and water in renovascular hypertensive rats

The two-kidney, one-clip renovascular (2K1C) hypertension model is characterized by a reduction in renal flow on the clipped artery that activates the renin-angiotensin system. Endothelium dysfunction, including diminished nitric oxide production, is also believed to play a role in the pathophysiology of this model. Some studies have shown an effect of L-arginine (L-Arg, a nitric oxide precursor) on hypertension. In the present study we determined the ability of L-Arg (7 days of treatment) to reduce blood pressure and alter renal excretions of water, Na+ and K+ in a model of 2K1C-induced hypertension. Under ether anesthesia, male Wistar rats (150-170 g) had a silver clip (0.20 mm) placed around the left renal artery to produce the 2K1C renovascular hypertension model. In the experimental group, the drinking water was replaced with an L-Arg solution (10 mg/ml; average intake of 300 mg/day) from the 7th to the 14th day after surgery. Sham-operated rats were used as controls. At the end of the treatment period, mean blood pressure was measured in conscious animals. The animals were then killed and the kidneys were removed and weighed. There was a significant reduction of mean blood pressure in the L-Arg-treated group when compared to control (129 ± 7 vs 168 ± 6 mmHg, N = 8-10 per group; P<0.05). Concomitantly, a significant enhancement of water and Na+ excretion was observed in the 2K1C L-Arg-treated group when compared to control (water: 13.0 ± 0.7 vs 9.2 ± 0.5 ml/day, P<0.01; Na+: 1.1 ± 0.05 vs 0.8 ± 0.05 mEq/day, respectively, P<0.01). These results show that orally administered L-Arg acts on the kidney, possibly inducing changes in renal hemodynamics or tubular transport due to an increase in nitric oxide formation.

Recombinant E2 glycoprotein of bovine viral diarrhea virus induces a solid humoral neutralizing immune response but fails to confer total protection in cattle

Two recombinant baculoviruses were produced in order to obtain a bovine viral diarrhea virus (BVDV) immunogen: AcNPV/E2 expressing E2 glycoprotein, and AcNPV/E0E1E2 expressing the polyprotein region coding for the three structural proteins of BVDV (E0, E1, and E2). Mice were immunized with Sf9 cells infected with the recombinant baculoviruses in a water in oil formulation and the production of neutralizing antibodies was evaluated. Since E2 elicited higher neutralizing antibody titers than E0-E1-E2 polyprotein, it was selected to immunize cattle. Calves received two doses of recombinant E2 vaccine and were challenged with homologous BVDV 37 days later. The recombinant immunogen induced neutralizing titers which showed a mean value of 1.5 ± 0.27 on the day of challenge and reached a top value of 3.36 ± 0.36, 47 days later (84 days post-vaccination). On the other hand, sera from animals which received mock-infected Sf9 cells did not show neutralizing activity until 25 days post-challenge (62 days post-vaccination), suggesting that these antibodies were produced as a consequence of BVDV challenge. Even when no total protection was observed in cattle, in vitro viral neutralization assays revealed that the recombinant immunogen was able to induce neutralizing antibody synthesis against the homologous strain as well as against heterologous strains in a very efficient way.

Gastric emptying of water in children with severe functional fecal retention

The objective of this study was to evaluate gastric emptying (GE) in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention and fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years) were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3 min) was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE1), and when they achieved regular bowel movements (GE2), 12 ± 5 weeks after GE1. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges) for GE1 and GE2 were not significantly different [27.0 (16) and 27.5 (21) min, respectively (P = 0.10)]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

Effects of intracutaneous injections of sterile water in patients with acute low back pain: a randomized, controlled, clinical trial

Intracutaneous sterile water injection (ISWI) is used for relief of low back pain during labor, acute attacks of urolithiasis, chronic neck and shoulder pain following whiplash injuries, and chronic myofascial pain syndrome. We conducted a randomized, double-blinded, placebo-controlled trial to evaluate the effect of ISWI for relief of acute low back pain (aLBP). A total of 68 patients (41 females and 27 males) between 18 and 55 years old experiencing aLBP with moderate to severe pain (scores ≥5 on an 11-point visual analogue scale [VAS]) were recruited and randomly assigned to receive either ISWIs (n=34) or intracutaneous isotonic saline injections (placebo treatment; n=34). The primary outcome was improvement in pain intensity using the VAS at 10, 45, and 90 min and 1 day after treatment. The secondary outcome was functional improvement, which was assessed using the Patient-Specific Functional Scale (PSFS) 1 day after treatment. The mean VAS score was significantly lower in the ISWI group than in the control group at 10, 45, and 90 min, and 1 day after injection (P<0.05, t-test). The mean increment in PSFS score of the ISWI group was 2.9±2.2 1 day after treatment, while that in the control group was 0.9±2.2. Our study showed that ISWI was effective for relieving pain and improving function in aLBP patients at short-term follow-up. ISWI might be an alternative treatment for aLBP patients, especially in areas where medications are not available, as well as in specific patients (e.g., those who are pregnant or have asthma), who are unable to receive medications or other forms of analgesia because of side effects.

Hidrogeles microestructurados de acrilamida y determinación de su capacidad de absorber agua y etanol

This paper reports the synthesis of nanostructured hydrogels of acrylamide by a two-step polymerisation process. The first step is performed by inverse microemulsion polymerization (water-in-oil) of N-isopropylacrylamide (NIPA), with these particles then added to aqueous solutions of acrylamide (AM), adding a crosslinking agent. The polymerization reaction is then initiated, thereby producing nanostructured hydrogels. We determined the capacity to absorb water, water and / or ethanol when nanostructured hydrogels were immersed in aqueous solutions with different concentrations of ethanol. It was found that the hydrogels were selective in absorbing water in all cases increasing with the ethanol concentration of the solutions.

COMPARISON BETWEEN ASPHALTENES (SUB)FRACTIONS EXTRACTED FROM TWO DIFFERENT ASPHALTIC RESIDUES: CHEMICAL CHARACTERIZATION AND PHASE BEHAVIOR

Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Many studies have been conducted to characterize chemical structures of asphaltenes and assess their phase behavior in crude oil or in model-systems of asphaltenes extracted from oil or asphaltic residues from refineries. However, due to the diversity and complexity of these structures, there is still much to be investigated. In this study, asphaltene (sub)fractions were extracted from an asphaltic residue (AR02), characterized by NMR, elemental analysis, X-ray fluorescence and MS-TOF, and compared to asphaltene subfractions obtained from another asphaltic residue (AR01) described in a previous article. The (sub)fractions obtained from the two residues were used to prepare model-systems containing 1 wt% of asphaltenes in toluene and their phase behavior was evaluated by measuring asphaltene precipitation onset using optical microscopy. The results obtained indicated minor differences between the asphaltene fractions obtained from the asphaltic residues of distinct origins, with respect to aromaticity, elemental composition (CHN), presence and content of heteroelements and average molar mass. Regarding stability, minor differences in molecule polarity appear to promote major differences in the phase behavior of each of the asphaltene fractions isolated.