Search

This work reports a simple bubble generator for the high-speed generation of microbubbles with constant cumulative production. To achieve this, a gas–liquid co-flowing microfluidic device with a tiny capillary orifice as small as 5 μm is fabricated to produce monodisperse microbubbles. The diameter of the microbubbles can be adjusted precisely by tuning the input gas pressure and flow rate of the continuous liquid phase. The co-flowing structure ensures the uniformity of the generated microbubbles, and the surfactant in the liquid phase prevents coalescence of the collected microbubbles. The diameter coefficient of variation (CV) of the generated microbubbles can reach a minimum of 1.3%. Additionally, the relationship between microbubble diameter and the gas channel orifice is studied using the low Capillary number (Ca) and Weber number (We) of the liquid phase. Moreover, by maintaining a consistent gas input pressure, the CV of the cumulative microbubble volume can reach 3.6% regardless of the flow rate of the liquid phase. This method not only facilitates the generation of microbubbles with morphologic stability under variable flow conditions, but also ensures that the cumulative microbubble production over a certain period of time remains constant, which is important for the volume-dominated application of chromatographic analysis and the component analysis of natural gas. [ABSTRACT FROM AUTHOR]

This work reports a simple bubble generator for the high-speed generation of microbubbles with constant cumulative production. To achieve this, a gas–liquid co-flowing microfluidic device with a tiny capillary orifice as small as 5 μm is fabricated to produce monodisperse microbubbles. The diameter of the microbubbles can be adjusted precisely by tuning the input gas pressure and flow rate of the continuous liquid phase. The co-flowing structure ensures the uniformity of the generated microbubbles, and the surfactant in the liquid phase prevents coalescence of the collected microbubbles. The diameter coefficient of variation (CV) of the generated microbubbles can reach a minimum of 1.3%. Additionally, the relationship between microbubble diameter and the gas channel orifice is studied using the low Capillary number (Ca) and Weber number (We) of the liquid phase. Moreover, by maintaining a consistent gas input pressure, the CV of the cumulative microbubble volume can reach 3.6% regardless of the flow rate of the liquid phase. This method not only facilitates the generation of microbubbles with morphologic stability under variable flow conditions, but also ensures that the cumulative microbubble production over a certain period of time remains constant, which is important for the volume-dominated application of chromatographic analysis and the component analysis of natural gas.

Together with lime, lemon is recognized as the third most extensively cultivated citrus species worldwide, trailing only behind orange and mandarin. The enhancement in the economic value of lemons as a valuable resource in Southern Italy depends by the competitiveness of local lemon production in both domestic and international markets. This necessitates conducting a comprehensive study that thoroughly explores the available indigenous germplasm at the local and national levels. This study aims to identify the most promising Sicilian and Campanian cultivars that are well suited for both fresh fruit consumption and the production of processed goods. This re-study assumes even greater importance considering the ongoing climate changes, as environmental stresses significantly impact the ripening process and the timing of fruit development. Our study has highlighted a notable diversity among the 18 investigated lemon cultivars, particularly highlighting specific cultivars that possess desirable attributes for fresh consumption. The cultivars that showed the greatest cumulative production over the 10 years of the study were Erice with 467.89 kg/tree and Femminello Siracusano 2KR with 408.44 kg. Notably, cultivars like Segesta, Erice, and Kamarina have exhibited higher percentages of juice content ranging from 27.30% to 31.08%. These cultivars show great potential for abundant juice content and optimal acidity levels for direct consumption. On the other hand, cultivars characterized by enhanced yield, such as Femminello Siracusano 2KR, Femminello Fior d'Arancio m79, and Erice, may prove to be particularly well suited to produce processed goods. Overall, our findings provide valuable insights into some qualitative parameters of lemon cultivars, important either for fresh consumption or for transformed products. [ABSTRACT FROM AUTHOR]

The flow regime is identified as a steady-state flow if the pressure at every location in the reservoir remains constant. In this work, we have determined the well production rate and cumulative production in a circular reservoir using the Finite Element Method for the condition of constant pressure outer boundary. The reservoir was divided into 4 smaller part known as finite element. These parts were analyzed and later assembled to form the domain of the reservoir. The analysis was done with the assumption that before the well begins production, there was uniform distribution of pressure all through the reservoir. The results obtained from the production rate analysis shows that the dimensionless production rate decreases significantly and later becomes uniform because the withdrawn fluid has been completely replaced. This condition remains throughout the entire life of the reservoir presumably. Also, the result shows that there is a uniform increase in the dimensionless cumulative production as time increases. The result obtained in this work was compared with the results obtained by previous researcher. The comparison shows a strong positive correlation between the two methods with a maximum percentage error of 0.1711 and 0.1864 and a minimum percentage error of 0.0001 and 0.0122 for dimensionless production rate and dimensionless cumulative production respectively. Also, result from previous researcher only state the production rate and cumulative production of the reservoir at a particular time but this work predicts the production rate and cumulative production in the entire reservoir at the same time.

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Together with lime, lemon is recognized as the third most extensively cultivated citrus species worldwide, trailing only behind orange and mandarin. The enhancement in the economic value of lemons as a valuable resource in Southern Italy depends by the competitiveness of local lemon production in both domestic and international markets. This necessitates conducting a comprehensive study that thoroughly explores the available indigenous germplasm at the local and national levels. This study aims to identify the most promising Sicilian and Campanian cultivars that are well suited for both fresh fruit consumption and the production of processed goods. This re-study assumes even greater importance considering the ongoing climate changes, as environmental stresses significantly impact the ripening process and the timing of fruit development. Our study has highlighted a notable diversity among the 18 investigated lemon cultivars, particularly highlighting specific cultivars that possess desirable attributes for fresh consumption. The cultivars that showed the greatest cumulative production over the 10 years of the study were Erice with 467.89 kg/tree and Femminello Siracusano 2KR with 408.44 kg. Notably, cultivars like Segesta, Erice, and Kamarina have exhibited higher percentages of juice content ranging from 27.30% to 31.08%. These cultivars show great potential for abundant juice content and optimal acidity levels for direct consumption. On the other hand, cultivars characterized by enhanced yield, such as Femminello Siracusano 2KR, Femminello Fior d’Arancio m79, and Erice, may prove to be particularly well suited to produce processed goods. Overall, our findings provide valuable insights into some qualitative parameters of lemon cultivars, important either for fresh consumption or for transformed products.

Hydrocarbon can be naturally produced from underneath fractured sandstone when pressure can no longer force fluids to the surface facilities. A satisfactory recovery factor for this production was conducted through the cost-effective enhanced oil recovery (EOR) method. Water alternated gas (WAG) injection is a promising EOR technique that combines the advantages of waterflooding and gas injection to achieve better mobility control, improved sweep efficiency, and overall recovery from the given reservoir. Therefore, this study aims to investigate the relationship of a miscible WAG to a core flood model using numerical simulation techniques (Eclipse Reservoir Simulator – Black Oil Model Option). In this case, reservoir X consisting of three wells drilled 15 years after the initial forecast showed that production cannot be sustained by natural depletion. Furthermore, the optimal WAG ratio was selected with different simulation scenarios using oil recovery factors to perform 12 simulation runs and study the influence of the WAG cycle period. The most effective WAG cycle scenario was 90W-30G with an oil recovery factor of 0.54684 (54.68 %) and cumulative production of 14.987MMSTB. The 30W-90G produced the lowest oil recovery factor and cumulative production of 0.47468 (47.47%) and 12.996 MMSTB, respectively. Therefore, a higher water cycling period is required for better oil recovery. The recovery is also enhanced by lowering the rate of water to gas injection. The results showed that despite the predicted higher recovery factor, a lower WAG ratio indicated a potential of relatively low-pressure maintenance which can affect future recovery from the reservoir.

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To accurately predict the cumulative production in the oilfield development process, the Von Bertalanfyy mathematical model which has similar characteristics with the change of cumulative oil production with time is introduced. This paper established a new model for sandstone water flooding oilfield to predict the change of cumulative production with time. Based on the actual data of ... oilfield, the parameters of the established model were solved, and the correctness of the model was verified. The new model was applied to test and analyze for application effect of the Shinan 31 oilfield. The results show that the Von Bertalanffy mathematical model for predicting the cumulative production has got accurately prediction results, especially the accuracy is higher than that of Usher model, Logistic model and Gompertz model, when the oilfield development is to the midel or late stages. At the same time, the model has the advantages of simple calculation and good applicability, which can guide the development of oilfield. [ABSTRACT FROM AUTHOR]

Abstract To evaluate the effect of oilfield development measures quantitatively, based on the theory of Arps production decline, this study deduced a linear relation between the product of cumulative production with production time (N p t) and production time (t), and established the cumulative production curve method for quantitative evaluation on the effect of development measures. The nitrogen injection pilot in Yanling oilfield was taken as an example to calculate the recoverable reserves before and after the nitrogen injection, and through the variation of recoverable reserves, the effect of the nitrogen injection on actual production was quantitatively evaluated. Similarity analysis of decline curve shape in the late period shows that the method is not restricted by decline types and the relationship curve between N p t and t in the late development is always tending to a straight line. The cumulative production curve method is not only suitable for single wells but also not restricted by reservoir types. Combined with derivative curve in diagnosis, it reflects the microscopic variations of the slope in the straight line segment and the variations of recoverable reserves and the process of reserve producing. The single wells in the Yanbei nitrogen injection pilot were evaluated quantitatively using the cumulative production curve method, the results show that: the nitrogen injection causes obvious productivity increase of the oil wells in the hillside of the buried hill, productivity decrease of the oil wells at the top of buried hill, and little influence on the productivity of oil wells in the margins of burial hill. [ABSTRACT FROM AUTHOR]

• Emergent marine ecosystem properties are well captured via cumulative trophic curves. • A relatively simple equation has very high explanatory power for marine ecosystem dynamics. • The cumulative tropic theory has robust predictive power and high potential utility for marine ecosystem applications. Examining marine ecosystems in a distinct way can produce new ecological, theoretical and applied insights. The common "S" and "hockey stick" -shaped curves, which result from examining the cumulative biomass and trophic level and the cumulative production and cumulative biomass curves of marine ecosystems, have strong potential to elucidate the mechanisms of marine food webs. These curves are based on the cumulative trophic theory, which can be summarized as the integration of biomass and production across trophic level that results from the relatively simple trophic transfer equation. Here we test the behavior of this theory via modeled simulations of the transfer equation under a variety of common mechanisms that can influence marine ecosystems. The simulated scenarios we present and evaluate here explore bottom-up driven changes (production, growth), internal dynamics (transfer efficiency) or top-down driven changes (mortality, selectivity), as well as multi-mechanism scenarios (overfishing and eutrophication) that are commonly experienced in marine ecosystems. We explore these scenarios at high, medium or low levels of change for each feature to ascertain how they can result in major changes to the realized trophodynamics of a marine ecosystem. Our results lend credence to the generality of the cumulative trophic theory by predicting the empirically observed "S" and "hockey stick" -shaped curves under a wide range of possible mechanisms. Given that common, repeatable and predictable dynamics is a key hallmark of increasingly robust theories, the application of cumulative trophic theory in managing marine ecosystems enables more repeatable and predictable responses across a wide range of conditions. [ABSTRACT FROM AUTHOR]

An evaluation of a new maternal line (LP) of rabbits was carried out. This new line was founded following a scheme similar to that applied in the selection for hyperprolificacy in rabbits or pigs. In this case, the selection criteria were hyperlongevity and an independent culling level near the average for prolificacy. Evaluation was carried out by comparison of the reproductive and longevity performance of the LP line with another maternal line recognized for good reproductive performance and standard longevity (V line). The results indicate that the LP line could be a valuable resource for inclusion in the current 3-way cross schema used in rabbit production, because females showed better survival ability and nearly the same prolificacy as the well-reputed V line. A V doe was 1.3 times more likely to leave the herd than an LP doe, and the probability of the differences in prolificacy between lines being greater than 0 was not extreme (no more than 0.22). Differences in relative performance of the lines were observed across farms for prolificacy, longevity, cumulative production, and fertility; however, based on deviance information criterion results, the data supported the hypothesis of only these differences being generated under a genotype x environment interaction for prolificacy traits. The longer productive life of LP females could partially be understood as an indication of success of the selection procedure during the foundation of this line. [ABSTRACT FROM AUTHOR]

The variability factor, (i.e., the variance) of the cumulative production, /spl Sigma/(t), delivered by a line composed of failure prone machines is studied in the fluid modeling approach. In this context, the evolution of /spl Sigma/(t) is described by a stochastic differential equation in which the noise source describes the random failures of the machines. We calculate the fluctuations of the production for three different situations, namely for a single nonMarkovian machine, for unbuffered networks of Markovian machines and for production dipoles composed of two machines separated by one buffer. The dynamics of the production dipole is approached via the introduction of a random environment model. Thanks to this new model, we can explicitly take into account the buffer induced correlations phenomena which directly influence the variability of /spl Sigma/(t). The probabilistic properties of the random time needed to complete a batch of fixed size are also explicitly derived. [ABSTRACT FROM PUBLISHER]