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Gas breakthrough is one of the key characteristics for saturated geological materials with low permeability encountered in deep geological disposal of high-level radioactive waste, shale gas extraction and CO2 capture-geological s...
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Gas breakthrough is one of the key characteristics for saturated geological materials with low permeability encountered in deep geological disposal of high-level radioactive waste, shale gas extraction and CO2 capture-geological storage, etc. Although gas breakthrough phenomenon is widely investigated in previous researches, the essential mechanisms are still not clearly explained. In the present work, a new approach for determination of gas breakthrough mechanism was proposed and a series of gas injection tests were conducted for verification. According to the theoretical analysis, the capillary effect, mechanical effect, as well as the interfacial leakage can induce gas breakthrough. The capillary breakthrough indicates the displacement of liquid phase driven by the capillary effect to form continuous flow pathway across the specimen. The mechanical breakthrough indicates the mechanically induced dilatancy of flow pathways followed by a significant decrease of the capillary flow resistance in the specimen. The interfacial breakthrough indicates the failure of the sealing capacity of the lateral boundary during the gas injection test. Based on the inherent characteristics, deformation properties of the specimen, as well as the boundary conditions, relationships between the capillary/mechanical/interfacial breakthrough pressure and the confining pressure were established, which can be used to determine the triggering mechanism of the gas breakthrough. Constant-volume and constant-isotropic stress gas injection tests were subsequently conducted for verification of the proposed approach. Results showed that the mechanical breakthrough is the most likely mechanism for the low permeability specimens tested in the present work.
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Sir Martin Hairer KBE, from Imperial College London, is the 2021 recipient of the Breakthrough Prize for Math- ematics, for his transformative con- tributions to the theory of stochastic analysis, particularly the theory of regula...
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Sir Martin Hairer KBE, from Imperial College London, is the 2021 recipient of the Breakthrough Prize for Math- ematics, for his transformative con- tributions to the theory of stochastic analysis, particularly the theory of regularity structures in stochastic partial differential equations.
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A simple and cost-effective method for conducting adsorption breakthrough experiments in a microsize carbon column is proposed; it is much faster than the conventional methods. Relative to the existing micro-column rapid breakthro...
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A simple and cost-effective method for conducting adsorption breakthrough experiments in a microsize carbon column is proposed; it is much faster than the conventional methods. Relative to the existing micro-column rapid breakthrough (MCRB) methods, this method employs simplified procedure, low cost and readily available pump, sampler, and piping and fittings to allow its practice in an ordinary environmental laboratory. The efficient MCRB method may be employed to identify the best granular activated carbon, to verify its treatment effectiveness, and to estimate its capacity utilization rate and the adsorption treatment cost. The effects of particle size and empty bed contact time on MCRB test results were determined. The validity and benefits of this MCRB method were demonstrated by the adsorption breakthrough data for phenol, red dye X3B, tannic acid, MTBE, 2,4-dichrophenol, and the organic pollutants in a biologically treated coking plant effluent.
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Time is brain. This statement is engrained within the collective psyche of medical professionals. Promptly discerning patients presenting with stroke from those.
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In this paper, a reservoir simulation study was conducted for the characterization and prediction of gas breakthrough during the development of cyclic steam and gas stimulation (CSGS) for a horizontal well. A new concept named the...
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In this paper, a reservoir simulation study was conducted for the characterization and prediction of gas breakthrough during the development of cyclic steam and gas stimulation (CSGS) for a horizontal well. A new concept named the gas breakthrough coefficient (GBC) was proposed to characterize the gas breakthrough degree quantitatively, and a regression model and two calibration curves were established to predict the gas breakthrough degree. The method of foam plugging to inhibit gas breakthrough was also discussed. It was found that the gas breakthrough degree could be well characterized by the GBC and distinguished as four types: weak, moderate, strong, and severe. The regression model and calibration curves could also be used to predict the gas breakthrough degree under different reservoir and development conditions. Foam plugging was found to be effective to inhibit gas breakthrough when the gas breakthrough degree was moderate or strong.
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This article uses the characteristics of citation curves in emerging research topics (ERTs) and combines them with the ERTs' knowledge bases to draw conclusions by comparing their development patterns. The goal of this study is to...
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This article uses the characteristics of citation curves in emerging research topics (ERTs) and combines them with the ERTs' knowledge bases to draw conclusions by comparing their development patterns. The goal of this study is to enrich the toolset for predicting breakthroughs in scientific research. A set of multidimensional and practical bibliometric indicators is used to identify ERTs, to further identify the knowledge bases of ERTs and construct citation curves for both ERTs and their knowledge bases. The development trends of the citation curves of ERTs and their knowledge bases in different time periods are compared and analysed from two dimensions: knowledge transition and continuous growth. We use the field of stem cell research to test our method. Based on the outcome of the analysis, we can assess the breakthrough potential of ERTs. The stratification, transition and recent changes of the citation curve can be used as a basis for analysing and assessing the ERTs' breakthrough potential. The combination of different citation diffusion patterns of ERTs and their knowledge bases can improve the effectiveness of identifying ERTs that can become breakthrough innovations.
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The modelling of breakthrough curves obtained in the adsorption of propene as a model compound onto different inorganic solids is described. All the runs were performed in a fixed bed at atmospheric pressure, employing a process t...
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The modelling of breakthrough curves obtained in the adsorption of propene as a model compound onto different inorganic solids is described. All the runs were performed in a fixed bed at atmospheric pressure, employing a process temperature of 30℃ and propene concentrations in the range 0.0022–0.0222 mol/Nm~3. The experimental conditions were therefore similar to those observed in the initial flue gases of cold start engines. The work described was mainly focused on the study of the influence of the adsorbent characteristics (composition, porous structure and surface area) on the kinetics of the adsorption process. The equilibrium adsorption values were initially determined from the breakthrough curves and satisfactorily fitted by the Langmuir isotherm model. These values were then used together with experimental breakthrough curves to analyse the kinetic expressions obtained applying the Linear Driving Force (LDF) model to the dynamic adsorption process. Values of the masstransfer coefficient, surfac and effective diffusion coefficients of propene have been calculated and are reported.
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Breakthrough cancer pain (btcp) represents an important element in the spectrum of cancer pain management. Because most btcp episodes peak in intensity within a few minutes, speed of medication onset is crucial for proper control....
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Breakthrough cancer pain (btcp) represents an important element in the spectrum of cancer pain management. Because most btcp episodes peak in intensity within a few minutes, speed of medication onset is crucial for proper control. In Canada, several current provincial guidelines for the management of cancer pain include a brief discussion about the treatment of btcp; however, there are no uniform national recommendations for the management of btcp. That lack, accompanied by unequal access to pain medication across the country, contributes to both regional and provincial variability in the management of btcp. Currently, immediate-release oral opioids are the treatment of choice for btcp. This approach might not always offer optimal speed for onset of action and duration to match the rapid nature of an episode of btcp. Novel transmucosal fentanyl formulations might be more appropriate for some types of btcp, but limited access to such drugs hinders their use. In addition, the recognition of btcp and its proper assessment, which are crucial steps toward appropriate treatment selection, remain challenging for many health care professionals. To facilitate appropriate management of btcp, a group of prominent Canadian specialists in palliative care, oncology, and anesthesiology convened to develop a set of recommendations and suggestions to assist Canadian health care providers in the treatment of btcp and the alleviation of the suffering and discomfort experienced by adult cancer patients.
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The recently introduced method of wide-azimuth data acquisitionoffers better illumination, noise attenuation, and lowerfrequencies to more accurately determine a velocity field forimaging. For the field data experiment to demonstr...
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The recently introduced method of wide-azimuth data acquisitionoffers better illumination, noise attenuation, and lowerfrequencies to more accurately determine a velocity field forimaging. For the field data experiment to demonstrate the technologies,we used a Gulf of Mexico (GOM) wide-azimuth dataset that allows us to take advantage of possible low frequencies,relatively large crossline offsets, and increased illumination. Theinput data was processed through true 3D azimuthal surfacerelatedmultiple elimination (SRME) with zero-phasing anddebubble. Eliminating the surface-related multiples aids thevelocity determination and helps uncover the subsalt sedimentsat the final imaging stage. After the initial velocity derivation,which was constrained to wells and geology, full-waveforminversion (FWI) was used to further update the velocity fieldto achieve an enhanced image. The methodology used followsthe top-down approach where suprasalt sediment model isdeveloped followed by the top of salt, salt flanks, base of salt,and finished with a limited subsalt update. To approximate theobserved data by using an acoustic inversion procedure, thepropagator includes effects of attenuation, anisotropy, acquisitionsource, and receiver depth. The geological environment issalt related, which implies that the observed data is highlyelastic, even though it is input to an acoustic full waveforminversion. To use the proper constraints for the inversion,layer-stripping method is used to develop the high-resolutionvelocity field. The inversion stages were carefully quality controlledthrough gather displays to ensure the kinematics werehonored. We then demonstrated the benefit of the FWI velocityfield by comparing the images derived with the traditionalray-based tomographic velocity field versus the velocity fieldderived by FWI performing reverse time migration to producethese images. Finally, the images were compared at key welllocations to evaluate the robustness of the workflow.
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Interval analysis, when applied to the so called problem of experi-mental data fitting, appears to be still in its infancy. Sometimes, partly becauseof the unrivaled reliability of interval methods, we do not obtain any results at...
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Interval analysis, when applied to the so called problem of experi-mental data fitting, appears to be still in its infancy. Sometimes, partly becauseof the unrivaled reliability of interval methods, we do not obtain any results atall. Worse yet, if this happens, then we are left in the state of complete ignoranceconcerning the unknown parameters of interest. This is in sharp contrast withwidespread statistical methods of data analysis. In this paper I show the connec-tions between those two approaches: how to process experimental data rigorously,using interval methods, and present the final results either as intervals (guaran-teed, rigorous results) or in a more familiar probabilistic form: as a mean valueand its standard deviation.
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