This program successfully indicates the most useful predictors of pressure loss in an Oil-Water pipeline flow for a given dataset under three comparison methods. For future work, we propose that a probabilistic predictor-performance map is developed to quantify the odds that a given predictor will yield the best performance for a new data point. In addition, it is suggested that the program is extended for the calculation of pressure gradient data for non-horizontal pipelines.
A probabilistic approach to two-phase liquid-liquid (oil-water) flow patterns is presented. An experimental dataset of 8073 points was compiled and processed in order to determine an acceptable data pool. The experimental data was then validated by means of OLGA Multiphase Toolkit and used to generate the probabilistic flow pattern maps. Considering that different dispersion patterns were taken into account, a probability surface was generated for each flow pattern, with the aim of simplifying the reading. Furthermore, a tool was developed to assist the recognition of probabilities.
The present work seeks to simulate the three dimensional oil-water turbulent flow and oil separation process on a traditional deoiling hydrocyclone using STAR-CCM+ CFD (Computational Fluid Dynamics) software. In order to evaluate the effect of the implementation of functionalized surfaces on the deoiling process, The Reynolds Stress model and the eulerian-eulerian model are combined to handle the complex anisotropic turbulent two-phase flow. Velocity and pressure profiles were obtained for a single phase simulation in order to evaluate the flow behavior on the hydrocyclone. Then, oil volume fraction, velocity, and pressure profiles were obtained for a multiphase simulation and the results were in agreement with previously reported data in the literature. At last, surface functionalization was implemented on the monophasic simulation due to convergence issues with the multiphase modified simulation. The results were not conclusive towards the effect of surface functionalization on separation performance but strongly showed the need of continuing this work into the multiphase simulation or experimental research.
Even if the best model for each pattern was identified, to obtain more precise results, the database could be extended. This taking into account, that all data must be experimental data reporting pressure gradients. Also, the use of high viscosity oils in the experiments, will be recommended, since this analysis would be nearer to the reality in the industry, where higher viscosity oils are used. In this terms, the analysis that was made just for horizontal pipes, should also be extended to inclined pipes. For the reason that in the industry oil-water flow transport pipes often have an inclination different from 0 or 90 (vertical pipes) degree . The next logical step for this study, could be making a fitting of the best combinations of models for each pattern with the experimental data, in order to obtain one new simpler model for the practice. Moreover, separating data in real oils and synthetic oils, could also be interesting since all of the pressure gradient models evaluated, assume perfect drops; a better response of the models will be expected for the synthetic ones.
SI.OilVolumeFraction vw_b "Water volume fraction of the bottom outlet"; SI.OilVolumeFraction vo_b "Oil volume fraction of the bottom outlet"; SI.OilVolumeFraction vo_t "Oil volume fraction of the top outlet"; SI.OilVolumeFraction vo_bn "Auxiliar value";
An emulsion can be described as system shaped for two immiscible liquids stabilized by the action of surface-active substances, that are capable to react with the oil-water interface reducing flocculation or coalescence of the droplets, both processes can lead to a layer separation and breakdown of the emulsions structure (Friberg et al. 1997; McClements 2005). Many products in the food industry are emulsion-based or contain emulsion. Some belong to oil in water emulsions such as milk, carbonated drinks and soup. Others belong to water in oil emulsion, like margarine and butter (Dalgleish 2006; McClements 2005). One of the most common preservation technology in food industry is freezing storage, which keeps microorganism in dormant state and extend the shelf life. Though freezing is widely used in long term storage and transport of food, it is detrimental to the stability of emulsions (Friberg et al. 1997; McClements 2005). Several physicochemical phenomenon occur when an emulsion system is submitted to a freeze-thaw treatment (FT). Due to nucleation and recrystallization of ice crystals and the high solute concentration, the growing ice modifies the interdroplet forces, leading to the separation of phases (Degner et al. 2014; Ghosh and Coupland 2008; Zhao et al. 2018). Different factors as lipid composition, sugar concentration, salt concentration or surfactant composition affect the FT stability of emulsions. Thus, with a better designing of emulsion, the quality of some foodstuff can be improved (Degner et al. 2014; Ghosh and Coupland 2008).
ing critique of international oil giants and pliant governments in Latin Ameri- ca in his widely read book, El Festin del Petróleo (1974), helped to win him two years in jail just as Ecuador was opening up its Amazonian region, once again, to oil development. Galarza painted a big- brush picture of rapacious transnational companies in the mid-early 20th cen- tury: his Seven Dinosaurs—Standard Oil of New Jersey, Shell, Mobil, Gulf, Texaco, BP, and Standard Oil of California—doing whatever they darn well please in weak countries. Transnational oil companies’ plunders are now tempered by stronger and more democratic governments and the existence of national oil companies across Latin America. While Galarza was later named Ecuador’s first Minister of the Environment, oil development for indigenous communities remains highly controversial and heavily disputed.
Oil inventories percentage variation is a commonly used regressor in oil studies (Gorton et al. (2013); Melolinna (2011)) since it directly affects the supply of oil and therefore its price. The theoretical relationship between available stocks and risk premi- ums was first introduced by Kaldor (1939) in his Theory of Storage, in which he proposes the existence of a convenience yield to explain differences between current spot and fu- tures prices. Gorton et al. (2013) develop a model, based on Kaldor (1939)’s Theory of Storage, which under a few assumptions implies that a rise in inventories should lead to a decrease in the overall risk premiums, and they find empirical results supporting their model. Weekly US WTI inventories starting at 1983 are available from the EIA and their percentage differences were calculated in order to obtain a stationary time series.
performance. Surface tension is the tendency of the surface of a liquid to contract to the smallest possible area. The effect is similar to an elastic membrane or skin surrounding the body of liquid and pulling it into the shape, which will have the least amount of surface area. That shape is spherical. Surface tension tends to resist any effort to pull the liquid apart or to change its shape. Surface tension also pinches off droplets from the forward edge of the film of liquid as it stretches, forming the spray. Within the range of surface tensions normally found in fuel oils the effect of variations in surface tension may be considered to be very minor. The surface tension found with No. 2 fuel varies from approximately 29 dynes per centimeter to approximately 33 dynes per centimeter. That angle is very small as compared with the difference between fuel oil and water which has a surface tension of approximately 75 dynes per centimeter. Atomization of water produces sprays comparable to fuel oil sprays but it has been found that the spray angle with water is approximately 10° less than with No. 2 fuel oil at the same pressure.
(2005) compared bioremediation of diesel oil by natural attenuation, biostimulation and bioaugmentation. They concluded that the best approach for bioremediation of diesel oil was the bioaugmentation performed by inoculating microorganisms pre-selected from a contaminated site. Apparently, indigenous microbes (pre-selected for bioaugmentation) are more likely to survive and propagate when reintroduced into the site, as compared to transient or alien strains to such a habitat (Bento et al,. 2005; Thompson et al., 2005). On the contrary, there are reports of microcosm and field studies where inoculation with enriched cultures originating from the site itself did not affect hydrocarbon removal rates whereas stimulation was effective (Thomassin- Lacroix et al., 2002). Biostimulation can provide suitable nutrients and conditions for both indigenous and e xogenous microbes. Thus, biostimulation becomes a viable approach in those cases where microbial population gets acclimatized due to exposure to hydrocarbons at contaminated sites. Natural acclimatization by the indigenous microbial population often requires a longer time due to an extended lag phase leading to prolonged bioremediation processes (Lendvay et al., 2003).
1) Equipos modernos: al activar el modo 2 se inicia el prebarrido, donde la caja de control pone en funcionamiento a la bomba de gas-oil y al ventilador, de forma que se posibilita la circulación de gas-oil, evitando así, que a la hora de iniciarse la ignición no pueda realizarla por falta de
Nevertheless, and despite their advantages and long history in water lifting, HPP systems seem to be largely disregarded nowadays. On one hand, there are some contemporary studies [15–21] and literature reviews [4–6,22,23] on RE-based water pumping systems. However, none of them address hydropower as a sound source of energy. On the other hand, there are several old publications [14,24–31] that considered it to a bigger or lesser extent, though completely overlooking many other then-contemporary HPP technologies that were relevant—and, in some cases, even predominant—for other (non-Western) contexts. Therefore, and considering such knowledge fragmentation and consequent gap, this review constitutes the first worldwide-scale depiction of the past and present trends on the documented research, development, application, and commercialization of the HPP technologies. In turn, such information provides a general yet solid basis for scholars, (industry) researchers, managers, manufacturers, and users, with respect to the future uses these technologies (as well as new ones derived from them) might have under different sets of physical and social conditions.
The horizontal design makes them ideal in order to obtain larger fi ltering areas in the smallest possible space. They are calculated and designed specially for each application and features. These devices can be automated to meet the needs of each project and are the main applications in drinking water treatment plants, sewage treatment plants and desalination plants.
Barrantes Guevara Itala Roxana COMPETENCE CAPABILITY PERFORMANCE ORALTEXT Identify specífic Identify specific COMPREHENSION information from oral information from oral (listening) texts texts and crea[.]