Groundwater balance estimation techniques, as important tools for dealing with many hydrological problems, are one of the main issues in water resources management. One of the critical challenges in ...estimating the groundwater balance components is the uncertainty in the proposed inflow and outflow rates. Groundwater recharge rate varies both spatially and temporally, making direct measurement difficult. In order to reliably estimate the groundwater recharge rate in the groundwater balance equations, the uncertainties in estimation of the other components such as evapotranspiration (ET) should be reduced by estimating them using more accurate techniques such as remote sensing-based methods. The present study applies the WetSpass-M distributed model to the Rafsanjan aquifer in Kerman, Iran. This model has been run for eight years (2009–2016) with monthly time steps. The recorded monthly surface flow data of the hydrometric station is used as the observed data for calibration and validation. ET is also calculated with satellite images of Landsat8 by using SSEB and SEBAL algorithms on a monthly scale in order to evaluate the reliability of the estimated ET by the model. The average rainfall rate during the simulation period is 297.1 MCM/year. The obtained results showed that the average ET and groundwater recharge from rainfall is 185.1 and 102.1 MCM/year, respectively. Although, considering the rainfall rate and irrigation, these numbers are estimated to be 552.3 and 417.2 MCM/year, respectively. Two components of recharge rate and ET constitute large portions of the groundwater balance.
In the treatment of peritoneal carcinomatosis, systemic chemotherapy is not quite effective due to the poor penetration of cytotoxic agents into the peritoneal cavity, whereas intraperitoneal ...administration of chemotherapeutic agents is generally accompanied by quick absorption of the free drug from the peritoneum. Local delivery of drugs with controlled-release delivery systems like liposomes could provide sustained, elevated drug levels and reduce local and systemic toxicity. In order to achieve an ameliorated liposomal formulation that results in higher peritoneal levels of the drug and retention, vesicles composed of different phospholipid compositions (distearoyl DSPC; dipalmitoyl DPPC; or dimiristoylphosphatidylcholine DMPC) and various charges (neutral; negative, containing distearoylphosphatidylglycerol DSPG; or positive, containing dioleyloxy trimethylammonium propane DOTAP) were prepared at two sizes of 100 and 1000
nm. The effect of surface hydrophilicity was also investigated by incorporating PEG into the DSPC-containing neutral and charged liposomes. Liposomes were labeled with
99mTc and injected into mouse peritoneum. Mice were then sacrificed at eight different time points, and the percentage of injected radiolabel in the peritoneal cavity and the tissue distribution in terms of the percent of the injected dose/gram of tissue (%ID/g) were obtained.
The ratio of the peritoneal AUC to the free label ranged from a minimum of 4.95 for DMPC/CHOL (cholesterol) 100
nm vesicles to a maximum of 24.99 for DSPC/CHOL/DOTAP 1000
nm (DOTAP 1000) vesicles. These last positively charged vesicles had the greatest peritoneal level; moreover, their level remained constant at approximately 25% of the injected dose from 2 to 48
h. Among the conventional (i.e., without PEG) 100
nm liposomes, the positively charged vesicles again showed the greatest retention. Incorporation of PEG at this size into the lipid structures augmented the peritoneal level, particularly for negatively charged liposomes. The positively charged PEGylated vesicles (DOTAP/PEG 100) had the second-greatest peritoneal level after DOTAP 1000; however, their peritoneal-to-blood AUC ratio was low (3.05).
Overall, among the different liposomal formulations, the positively charged conventional liposomes (100 and 1000
nm) provided greater peritoneal levels and retention. DOTAP/PEG100 may also be a more efficient formulation because this formulation can provide a high level of anticancer drug into the peritoneal cavity and also can passively target the primary tumor.
Peritoneal level and tissue distribution of classical and PEGylated liposomes with different phospholipid compositions and charges at two sizes (100
nm, A; and 1000
nm, B), were investigated after i.p. injection to mice. Positively charged conventional liposomes provided greater peritoneal levels and retention.
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•Based on pore-scale results, we conceptualize a phase diagram which links the transport regimes to the Péclet number and correlation length.
Transport in porous media is often characterized by the ...advection–dispersion equation, with the dispersion coefficient as the most important parameter that links the hydrodynamics to the transport processes. Morphological properties of any porous medium, such as pore size distribution, network topology, and correlation length control transport. In this study we explore the impact of correlation length on transport regime using pore-network modelling. Earlier direct simulation studies of dispersion in carbonate and sandstone rocks showed larger dispersion compared to granular homogenous sandpacks. However, in these studies, isolation of the impact of correlation length on transport regime was not possible due to the fundamentally different pore morphologies and pore-size distributions. Against this limitation, we simulate advection–dispersion transport for a wide range of Péclet numbers in unstructured irregular networks with “different” correlation lengths but “identical” pore size distributions and pore morphologies. Our simulation results show an increase in the magnitudes of the estimated dispersion coefficients in correlated networks compared to uncorrelated ones in the advection-controlled regime. The range of the Péclet numbers which dictate mixed advection–diffusion regime considerably reduces in the correlated networks. The findings emphasize the critical role of correlation length which is depicted in a conceptual transport phase diagram and the importance of accounting for the micro-scale correlation lengths into predictive stochastic pore-scale modelling.
Data science as a flourishing interdisciplinary domain of computer and mathematical sciences is playing an important role in guiding the porous material research streams. In the present narrative ...review, we have examined recent trends and issues in data‐driven methods used in the image‐based porous material research studies relevant to water resources researchers and scientists. Initially, the recent trends in porous material data‐related issues have been investigated through search engine queries in terms of data source, data storage hub, programing languages, and software packages. Subsequent to a diligent analysis of the existing trends, a review of the common concepts of porous material research and data science are presented through six categories comprising big data, data regression, classification, image segmentation, geometry reconstruction, and image data resolution. We provide: (a) a focus on image‐based and pore scale methods which has not been presented previously, (b) a detailed search engine research for trend investigation, and (c) practical examples and comparison of data storage in porous media image‐based research. By reading this review article, an overall image of the active and popular interdisciplinary research domains can be obtained. Readers will also be informed of the latest data‐driven efforts and recommended research directions for tackling the image‐based porous material problems relevant to water resources research. We concluded that porous material image reconstruction and resolution improvement techniques are unique means to reveal unprecedented details of micro‐structures that may have been missed in a medium quality tomography image.
Key Points
The porous material data‐science concepts are portrayed and categorized into six subdomains
Image‐based deep learning is becoming a unique tool to characterize, simulate, and classify porous materials
Machine learning in porous material research studies is still dominated by MATLAB, however, Python developments are becoming a trend
Salt precipitation within pores of the reservoir is an important phenomenon occurring during CO2 injection into saline aquifers. The phenomenon results in permeability reduction and injectivity ...impairment. Salt precipitation mainly happens because of water vaporization inside the CO2‐saturated (dry‐out) region. For water‐wet systems, the capillary pressure acts toward the lower water saturation regions in the reservoir, thereby displacing a film of brine backward to the dry‐out region. This results in more precipitation. Overlooking this phenomenon, referred to as capillary‐driven backflow, results in over‐estimations of injectivity in the dried region. Here, we have developed an analytical solution based on fractional flow theory and shock waves for CO2‐brine systems considering the effect of capillary pressure. The validity of the solution is verified by comparing the outputs of our model with those of numerical results from a commercial numerical simulator for a hypothetical reservoir. An equation is derived to calculate the distance at which capillary pressure is most influential, and also the injectivity impairment at injection well due to salt precipitation was reasonably accurately estimated. The results emphasize that effects of capillary pressure should not be ignored.
Key Points
Effects of capillary pressure were included in an analytical solution of CO2 injection into saline aquifers
Capillary backflow induced salt precipitation affects injectivity of the wells in the aquifer
The area that is mostly affected by salt precipitation, near the injection, can be estimated through mass balance
This article reports on the synthesis and full characterization of innovative silica-based nanoparticle composed of fumed silica as a core decorated with polyethylenimine (PEI) with different ...molecular weights (25, 10 and 1.8 kDa). Wide range of analytical, spectroscopic, and microscopic methods (TEM, DLS, ζ potential, elemental analysis (EA), TNBS and FTIR) were used to characterize the nanoparticles. Furthermore, transfection efficiency of these nanoparticles as non-viral vector was examined. The silica-PEI conjugates retained both the ability of PEI to fully condense plasmid DNA at low N/P ratios and suitable buffering capacity at the endosomal pH range. PEI-functionalized silica remarkably enhanced EGFP-N1 gene expression in murine neuroblastoma (Neuro-2A) cells up to 38 folds compared to PEI 25 kDa. Meanwhile the results of the cytotoxicity assays indicated that these silica-PEI conjugates have acceptable level of viability.
In this paper, the improved particle swarm optimization (IPSO) algorithm is used to solve large scale reservoir operation optimization problem proposing unconstrained and two constrained versions of ...this algorithm. In the two constrained versions proposed for the IPSO algorithm, named PCIPSO and FCIPSO, each particle may be forced to satisfy problem constraints during solution building. By considering water releases or storage volumes at each operation time period as decision variable of the problem, here, two formulations are proposed for each version. In the second proposed constrained version algorithm (FCIPSO), at first, the water storage volume bounds are modified in order to recognize the infeasible components of the search space and exclude from the search process before the main search starts. This mechanism leads to smaller search space size for the problem and finally better results. The simple and hydropower operation problems of “Dez” reservoir in the southern Iran over 60, 240 and 480 monthly operations time periods are solved here using both proposed formulations of theses algorithms and the results are presented and compared with other available results. The results show the capability of the proposed algorithms and especially the second constrained version of the IPSO algorithm, FCIPSO, to optimally solve the reservoir operation optimization problem. In other words, the results of both formulations of constrained IPSO and especially FCIPSO algorithm are improved significantly in comparison with unconstrained IPSO algorithm over all operations time periods of simple and hydropower operation of the reservoir.
In this paper, the rolling contact fatigue crack growth in the presence of multiple cracks and their interactions is studied. The proposed formulation is based on linear elastic fracture mechanics ...and singular integral equations. The body under the rolling contact is modeled by a half-plane weakened by a set of surface, subsurface and surface–subsurface cracks. Rolling contact is simulated by translational motion of an elliptically distributed force along the half-plane boundary. Several parameters, such as the distance between cracks, the value of initial crack lengths, the value of the friction coefficient, and the initial angle between cracks and the boundary of the half-plane are studied. Results obtained from this investigation are in good agreement in a special case with those reported in the literature. It is observed that in the system of two parallel surface and subsurface cracks with equal lengths, changing the distance between the cracks changes the growth paths, and when this distance increases to a critical value, the cracks grow independently. In addition, in the case of two parallel surface cracks when the left crack is shorter, the cracks have a stronger tendency to join together, which leads to pitting phenomena on the contact surface. Furthermore, in the system of two parallel subsurface cracks, it is seen that fast fracture occurs sooner when the initial angle of the cracks increases. In the system of parallel surface and subsurface cracks, the dominant failure mode is spalling.
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