Saturation Method Research Articles

Optimal long-term planning of CCUS and carbon trading mechanism in offshore-onshore integrated energy system

The offshore-onshore integrated energy system (OOIES) interconnects the offshore oil extraction platforms, offshore wind farms (OWFs), onshore coal/gas-fired power plants and oil distillation factories, which has great potential in CO2 emission reduction. To investigate its long-term CO2 emission reduction and economic benefits in the subsequent operation, an optimal long-term planning (OLTP) model of carbon capture, utilization, and storage (CCUS) and carbon trading mechanism (CTM) in OOIES is proposed. In the model, a CCUS model using the geological reservoir model for CO2 enhanced oil recovery (CO2-EOR) is proposed, a price-based CTM with carbon emission allowance and Chinese certified emission reduction is included, multi-band intervals are used to describe the uncertain prices and OWF outputs, and GlueVaR is introduced to measure the risks caused by uncertainties for risk management. For the solution of the OLTP model, the geological reservoir model with partial differential equations is transformed into mix-integer linear constraints by using the implicit pressure explicit saturation method, the ReLU-based multi-layer perceptron method and the convex envelop relaxation technique. Moreover, by applying multi-band interval possibility degree and GlueVaR's coherence, the original uncertainty optimization model is transformed into a mixed-integer linear programming model. Case study on an actual OOIES on the east bank of the Pearl River estuary demonstrates the effectiveness of the proposed method. Compared to the optimal results without CCUS and CTM, the optimal results of the proposed method reduce the CO2 emission by 13.28 % and the expected value and GlueVaR of total cost by 2.381 % and 22.480 %, respectively.

SEISMIC WAVE PROPAGATION IN PARTIALLY SATURATED FRACTAL POROUS MEDIA

Wave-induced fluid flow, being widely accepted as a dominant loss mechanism of wave attenuation, can lead to significant seismic attenuation due to mesoscopic heterogeneities such as partial saturation. However, the dependence of fluid distribution on microstructure in partially saturated porous media remains unclear. To quantify the relationship between microstructure and fluid distribution, a saturation fractal dimension is applied on the assumption of pore fractal distribution and gas patch fractal distribution. By integrating the Biot-Rayleigh theory, a theoretical model of partially saturated fractal porous media is established. The results indicate that the scales of fluid flow and the magnitude of peak attenuation are significantly influenced by both the maximum gas patch size and the pore fractal dimension. The proposed model is further validated by comparing it with laboratory measurements. The findings indicate that the variations in the maximum gas patch size correspond to the variations in fluid distribution, and the peak attenuation will reach its maximum magnitude when the saturation fractal dimension equals the pore fractal dimension. The discrepancies between the measurements and modeling results are discussed, revealing that, in addition to microstructure, factors such as rock properties, boundary condition, and saturation methods significantly influence the fluid distribution, as well as velocity dispersion and attenuation. The proposed theory provides a reasonable explanation of dispersion and attenuation in fieldwork, thereby presenting a novel perspective for future endeavors in forward modeling and seismic inversion.

Non-classical effective methods for reduction of heteroaromatic compounds

The review summarizes the known data on various methods for saturation and dearomatization of heterocyclic moieties, forming diverse aromatic compounds. Since the classical hydrogenation of substrates with molecular hydrogen has a number of fundamental drawbacks that hinder both its use at the laboratory level and its widespread implementation in industrial production, the main attention is paid to non-classical methods described in the literature over the last 20-25 years. The methods of ammonia-free Birch reduction, transfer hydrogenation, reduction by Hantzsch esters and some other reactions involving heterocyclic compounds are summarized and systematized. It is shown that such methods of reduction or dearomatization of heterocycles can in some cases be more efficient than classical procedures.<br> The bibliography includes 173 references.

Enhanced and robust contrast in CEST MRI: Saturation pulse shape design via optimal control.

To employ optimal control for the numerical design of Chemical Exchange Saturation Transfer (CEST) saturation pulses to maximize contrast and stability against inhomogeneities. We applied an optimal control framework for the design pulse shapes for CEST saturation pulse trains. The cost functional minimized both the pulse energy and the discrepancy between the corresponding CEST spectrum and the target spectrum based on a continuous radiofrequency (RF) pulse. The optimization is subject to hardware limitations. In measurements on a 7 T preclinical scanner, the optimal control pulses were compared to continuous-wave and Gaussian saturation methods. We conducted a comparison of the optimal control pulses with Gaussian, block pulse trains, and adiabatic spin-lock pulses. The optimal control pulse train demonstrated saturation levels comparable to continuous-wave saturation and surpassed Gaussian saturation by up to 50 % in phantom measurements. In phantom measurements at 3 T the optimized pulses not only showcased the highest CEST contrast, but also the highest stability against field inhomogeneities. In contrast, block pulse saturation resulted in severe artifacts. Dynamic Bloch-McConnell simulations were employed to identify the source of these artifacts, and underscore the robustness of the optimized pulses. In this work, it was shown that a substantial improvement in pulsed saturation CEST imaging can be achieved by using Optimal Control design principles. It is possible to overcome the sensitivity of saturation to B0 inhomogeneities while achieving CEST contrast close to continuous wave saturation.

Characterization and optimization of biodiesel production from corn oil using heterogeneous MoO3/MCM-41 catalysts

Different types of heterogeneous catalysts have been developed worldwide and tested for biodiesel production from corn oil as a feedstock via the transesterification and esterification reactions. In this study, varying contents of MoO3 were incorporated into the mesoporous molecular sieve MCM-41 using the pore saturation method to form heterogeneous catalysts (MoO3/MCM-41). Characterization results confirmed the formation of the MCM-41 structure and the mesoporous phase filling by molybdenum, along with different surface areas, volume, and pore diameters. The silanol groups impart acidity to the molecular sieve, and a molybdenum content above the optimum reduced the availability of acidic sites on the catalyst surface, filling the micro and mesoporous channels, resulting in lower acidity. Catalytic performance was evaluated using a 22 factorial design with three center points to optimize reaction parameters including MoO3content and temperature. The maximum yield was 87.87 %, achieved with a 3 % catalyst load containing 15 wt% MoO3, at an oil-to-alcohol molar ratio of 1:20 at 150 °C for 3 h. Temperature had the most significant influence on biodiesel yield.

A Study of Data Processing Methods for Non-Contact Multispectral Method of Blood Oxygen Saturation.

Regular monitoring of blood oxygenation is important for disease prevention and treatment. Image photoplethysmography (IPPG) technology is a non-contact physiological parameter detection technology, which has been widely used in blood oxygenation detection. However, traditional imaging devices still have issues such as low detection accuracy, narrower receiving spectral range. In this paper, we proposed two improved detection methods based on the dual-wavelength measurement principle, that is, dual-band IPPG signal ratio method and dual-band IPPG signal AC/DC method. To verify the effectiveness of the two methods, we used different heartbeat period IPPG signals as sample data sets, and combined PLS and RF algorithms for model training, thus obtaining the best data processing method. The experimental results showed that the dual-band IPPG signal AC/DC method can effectively reduce the model training time. This method meets the strong demand for non-contact blood oxygen measurement and provides a new measurement idea.

Study of the microhardness ensuring the contact endurance of structural materials

The strength of the working surfaces of gears depends on the mechanical properties of the material and the quality of parts. We present the results of studying the strength of materials and working surfaces of a gear mechanism due to structural changes attributed to chemical and thermal treatment. The surface strength of the gears of gas turbine engines was studied. Nitrocementation and ion nitriding were used for chemical and thermal treatment of the contacting surfaces of steel samples under study (20Kh3MVF-Sh, 16Kh3NVFMB-Sh, 18Kh2H4MA, and 12Kh2H4A). Changes in the microhardness of the component layers (diffusion, transition and basic) of the toothed crown were analyzed. Metallographic analysis of the structure of materials was carried out to describe the factors determining the surface strength of working surfaces. Systematized data on the change in the microhardness of materials obtained experimentally in conditions of mass production are presented. Presented experimental results on changes in the mechanical properties of materials are based on data on the microhardness and structural state of the surface layers of the working profiles of gears. A comparative assessment of the surface strength of the studied samples during contact interaction was performed. The dependence of the surface strength on the multifactorial volumetric structure and structure formation of the material in the process of operation is determined. It is shown that the method of surface saturation forms the structure of a material with different mechanical properties accompanied with the formation of a transition zone having characteristic distinctive values of the hardness. The results obtained can be used in the design of gears, taking into account changes in the mechanical properties and structure of materials to ensure the necessary operational requirements.

Resonance ionization spectroscopy of neodymium for determining a highly efficient two-step ionization scheme

Two-color two-step resonance ionization spectroscopy of neodymium (Nd) was performed to identify more than 120 even-parity autoionizing levels and their candidate J-values. The analysis of the observed autoionizing Rydberg series yielded a value of 44,560.11 (43)stat (2)sys cm−1 as a more accurate ionization potential of Nd. The saturation method was used to measure the transition cross-sections for some intense ionization transitions. From the measured cross-sections, the ionization efficiencies of some two-step ionization schemes were evaluated using the scheme cross-section formula to obtain several promising schemes.

Assessing swelling-induced damage in shale samples during triaxial testing

In shale testing, understanding the impact of effective stress and saturation conditions is crucial for accurate material behaviour assessment and parameter determination. In some cases, saturation in triaxial testing starts at low effective stress before ramping up for shearing. However, when in contact with water (or saline water), shales are prone to swelling, particularly at low effective stress levels, which can induce fissures and alter material properties. This study investigates the influence of fluid saturation strategies and stress/pressure variations on the mechanical behaviour of shales, particularly under low effective confinement. Building upon the comprehensive testing campaign (>140 tests) in Crisci et al. (2024), additional tests were conducted on Opalinus Clay shale, focusing on sample saturation methods and loading histories before shearing. The conditions under which tested specimens experience damage were detected through diagnostic indicators such as differences in stress path and lower strength and stiffness compared to intact specimens with identical basic properties. Micro CT scanning confirms that damage is related to the development of fissures. The volumetric changes in specimens were quantified throughout the testing phases and thresholds for tolerable strains and effective stresses, specific to this material, were established. Comparative analysis with Opalinus Clay from shallower depths and other shales globally revealed consistent findings. Notably, it is shown that, for all shale types analyzed, a linear failure envelope emerges in the low to intermediate effective stress regime when filtering out "damaged" specimens. This suggests that non-linear failure envelopes observed in some cases may stem from exposing specimens to low effective stress before shearing.

The Role of Elements of Text Analysis in Consecutive Interpreting Performance: A Mixed-Methods Study

Despite the theoretical importance of text analysis in translation process, there is a paucity of experimental research into the role that the elements of the text can play in enhancing interpreting performance. The present study, adopting a mixed-methods design, aimed to investigate whether knowledge of text elements enhances consecutive interpreting performance. In so doing, a sample of 36 homogeneous undergraduate translation students participated in this study based on convenience sampling, and a pool of six students participated in the qualitative phase of the study based on purposive sampling, following the data saturation method. Following Nord’s guidelines for text analysis, the experimental group was exposed to the elements of text during the intervention. A validated assessment rubric was utilized to measure students’ interpreting performance, taking the inter-rater reliability of the scores also into consideration. The results of one-way ANOVA confirmed that there was a statistically significant difference between the control group and the experimental group; the experimental group outperformed the control group. Having calculated the inter-coder reliability of the responses emerged from the interviews, the number of common factors included six themes, namely unique, new information, message analysis, motivating, general lexis, and semiotics. In the end, some practical implications are offered for interpreting students and teachers.

Combined Physics- and Machine-Learning-Based Method to Identify Druggable Binding Sites Using SILCS-Hotspots.

Identifying druggable binding sites on proteins is an important and challenging problem, particularly for cryptic, allosteric binding sites that may not be obvious from X-ray, cryo-EM, or predicted structures. The Site-Identification by Ligand Competitive Saturation (SILCS) method accounts for the flexibility of the target protein using all-atom molecular simulations that include various small molecule solutes in aqueous solution. During the simulations, the combination of protein flexibility and comprehensive sampling of the water and solute spatial distributions can identify buried binding pockets absent in experimentally determined structures. Previously, we reported a method for leveraging the information in the SILCS sampling to identify binding sites (termed Hotspots) of small mono- or bicyclic compounds, a subset of which coincide with known binding sites of drug-like molecules. Here, we build on that physics-based approach and present a ML model for ranking the Hotspots according to the likelihood they can accommodate drug-like molecules (e.g., molecular weight >200 Da). In the independent validation set, which includes various enzymes and receptors, our model recalls 67% and 89% of experimentally validated ligand binding sites in the top 10 and 20 ranked Hotspots, respectively. Furthermore, we show that the model's output Decision Function is a useful metric to predict binding sites and their potential druggability in new targets. Given the utility the SILCS method for ligand discovery and optimization, the tools presented represent an important advancement in the identification of orthosteric and allosteric binding sites and the discovery of drug-like molecules targeting those sites.

Comparison of Detection Methods for Lactoferrin Iron Saturation

Comparison of Detection Methods for Lactoferrin Iron Saturation

Super-resolution reconstruction of hydrate-bearing CT images for microscopic detection of pore

The pore structure of marine natural gas-hydrate-bearing sediments is a key factor related to the physical properties of reservoirs. However, the resolution of micro-computed tomography (micro-CT) images is unsuitable for the analysis of pore structures in fine-grained sediments. In this regard, super-resolution (SR) reconstruction technology is expected to improve the spatial resolution of micro-CT images. We present a self-supervised learning method that does not require high-resolution datasets as input images to complete the training and reconstruction processes. This method is an end-to-end network consisting of two subnetworks: an SR network and a downscaling network. We trained on a self-built dataset of hydrate samples from three different particle sizes. Compared with typical methods, the SR results indicate that our method provides high resolution while improving clarity. In addition, it has the highest consistency with the liquid saturation method with the subsequent calculation of porosity parameters. This study contributes to the investigation of seepage and energy transfer in sediments containing natural gas hydrates, which is particularly important for the exploration and development of marine natural gas hydrate resources.

Enhancing sand liquefaction resistance through microbial-induced partial saturation: An experimental study

The liquefaction potential of saturated sand can be significantly reduced by inducing partial saturation in the soil. Conventional soil liquefaction mitigation methods, namely soil densification, drainage, cementing, and groundwater lowering, pose environmental concerns and are challenging to apply to pre-existing structures. However, the microbially induced partial saturation (MIPS) method is emerging as a novel and eco-friendly approach to mitigate liquefaction. The MIPS method involves microbial denitrification, which produces nitrogen gas and results in a desaturating effect in the saturated soil. The current study conducted a series of stress-controlled undrained cyclic triaxial tests on saturated sandy soil and microbially-desaturated sandy soil under different relative densities and loading conditions. In addition, the study systematically analyzed the effects of temperature and pH on bacterial activity and the denitrification process. Batch experiments were conducted to establish a relationship between the initial nitrate concentration in the bacterial media and the resulting desaturation.Comprehensive analyses of cyclic resistance curves were performed to gain a thorough understanding. Additionally, the study conducts detailed analyses of the accumulation of excess pore pressure and the resulting axial strains and deformation patterns in both treated and untreated sand. This study demonstrates that the MIPS treatment considerably enhances the liquefaction resistance of treated sand.

Centrifuge modeling-of-models investigation on earthquake-induced excess pore pressure behavior of silty sand

Two centrifuge experiments conducted at Rensselaer Polytechnic Institute (RPI) aimed to evaluate the effectiveness of the used centrifuge scaling laws and validate results obtained within the project, related to the liquefaction behavior of silty sand soils under simulated field drainage conditions. These experiments, replicating a 5-m thick silty sand layer under 1 atm overburden pressure and featuring a double drainage condition, were performed at two different centrifugal accelerations. Due to the difficulties encountered in saturating silty sand, this paper presents a bottom-up saturation method, verified through assessments of remaining air volume after saturation. Despite differing g-levels, the tests consistently demonstrated similar behaviors in terms of acceleration, pore pressure buildup and dissipation, and stress-strain responses, validating the saturation and modeling technique for silty sand.

Quantifying the water saturation degree of cement-based materials by hydrogen nuclear magnetic resonance (1H NMR)

This study investigated the T2 spectrum of hydrogen nuclear magnetic resonance (1H NMR) signals in cement paste with water-to-cement ratios (w/c) of 0.2, 0.35, and 0.5 under three different saturation methods (natural soak, vacuum saturation, and vacuum saturation with high pressure). The saturation degree and pore structure of the cement paste under different saturation methods has been calculated through the linear relationship between water absorption and increment of NMR amplitude intensity. The results showed that the saturation degree of the cement paste increased progressively with the duration of saturation until it reached a state of equilibrium. It can increase saturation degree and reduce the saturation time by increasing the saturation pressure, and vacuum saturation with high pressure is necessary for cement paste with lower w/c. It is important to noted that conditions such as unsaturation, natural soak, and vacuum saturation may result in incomplete water saturation, leading to a partial loss of the 1H NMR signal amplitude intensity and underestimation of porosity measurements. Considering the duration of saturation and the degree of saturation, it is recommended a saturation duration of at least 4 h with a vacuum pressure of 8 MPa for cement paste with w/c ratio of 0.2 and 0.35. For cement paste with w/c of 0.5, a saturation duration of at least 0.5 h with a vacuum pressure of 8 MPa is suggested.

Novel eco-friendly spectrophotometric determination of lercanidipine hydrochloride in tablets using methyl red

The aim of the work was to develop a simple, eco-friendly, quick, affordable and alternative spectrophotometric procedure that uses the azodye methyl red (MR) for the determination of lercanidipine in its dosage form considering the “green” chemistry principles. Materials and methods. Analytical equipment: Shimadzu UV-1800 double beam UV-visible spectrophotometer (Japan) with included UV-Probe 2.70 software, RAD WAG AS 200/C precise analytical balance (Poland), Elmasonic EASY 40H ultrasonic bath. Lercanidipine hydrochloride (purity 99 %) was purchased from Jiyan Chemicals (India). Lercanidipine tablets 10 mg and 20 mg were used in our experiments. Results and discussion. To determine the amount of lercanidipine in tablets, a spectrophotometric method has been developed. To select the best dye for the method development, we tested a variety of dyes, including MR, bromocresol purple, bromophenol blue, cresol red, bromocresol green and bromothymol blue. We selected MR as the reagent based on the experimental studies' outcomes, and the solvent was an acetonitrile and ethanol mixture with a ratio of 95 to 5. The optimal parameters were determined for the quantitation of lercanidipine in tablets utilizing MR with 5×10-5 mol/L of dye concentration, 0.5 ml of MR solution, at a temperature of 25 °C without heating; detection wavelength was 498 nm and reaction time of 5 min. By using the molar ratios (saturation) method and Job's (continuous variations) approach, the stoichiometric coefficients of reacting components involving lercanidipine and dye were established to be 1:1. The proposed spectrophotometric procedure was linear within the concentration ranging from 6.48 – 32.41 μg/mL. Using the least squares method, a regression equation was generated: y = 0.0208x – 0.0318. The correlation coefficient was higher than 0.999, indicating that the analytical procedures' linearity is acceptable; the limit of detection and limit of quantitation were 1.19 μg/mL and 3.62 μg/mL, respectively. The robustness, accuracy and precision of the study results fell within acceptable limits. The proposed method was successfully applied to determine the content of lercanidipine in its tablet dosage forms. The analysis of the method's "greenness" using AGREE and GAPI tools yielded excellent results. Conclusions. The method that has been developed can serve as an alternative approach for the routine control of lercanidipine content in its tablets

Solubility measurement, calculation, solvent effect and preferential solvation of fenoxaprop-p-ethyl in four cosolvent mixtures at (278.15–323.15) K

Equilibrium solubility of fenoxaprop-p-ethyl in aqueous mixtures of ethanol/ isopropanol/acetonitrile/N,N-dimethylformamide (DMF) plus water was experimentally measured by isothermal saturation method at (278.15–323.15) K under 101.2 kPa. The order of solubility (mole fraction) of fenoxaprop-p-ethyl in pure solvents from high to low is 4.233 × 10−2 (DMF 323.15 K) > 2.044 × 10−2 (acetonitrile 323.15 K) > 7.727 × 10−3 (isopropanol 323.15 K) > 5.338 × 10−3 (ethanol 323.15 K) > 2.565 × 10−5 (water 323.15 K). Experimental results showed that temperature and type of solvent were decisive factors for the dissolution of fenoxaprop-p-ethyl. The content of fenoxaprop-p-ethyl in solution was analyzed by high-performance liquid chromatography (HPLC). Moreover, the solubility data of fenoxaprop-p-ethyl was correlated by Jouyban-Acree (J-A) model, van’t Hoff-Jouyban-Acree (V-J-A) model and Apelblat-Jouyban-Acree (A-J-A) model. The maximum of root-mean-square deviation (RMSD), relative average deviation (RAD) and standard deviation (SD) predicted via three thermodynamic models were 1.78 × 10−4 (DMF + water), 2.87 × 10−2 (acetonitrile + water) and 1.79 × 10−4 (DMF + water), respectively. In addition, the solvent effect between solute and solvent molecules was deduced by KAT-LSER model and the result showed that dipolarity/polarizability interactions between the solute and solvent molecules were dominant in the dissolution of fenoxaprop-p-ethyl. Finally, the preferential solvation parameter (δx1,3) of fenoxaprop-p-ethyl was obtained by the method of inverse Kirkwood–Buff integrals and the preferential dissolution behavior of each concentration range is explained by Lewis acid base theory. However, for acetonitrile + water, the change of δx1,3 may be due to the polarization effects and it is not suitable for Lewis acid base theory.

Localization and saturation of degradation space for weakly-supervised real-world super-resolution

Degradation in the real world is highly complex and random, making real super-resolution datasets expensive. A series of unsupervised methods attempt to model real degradations to address the lack of paired training data in real-world super-resolution tasks. However, these unsupervised methods cannot accurately locate the degradation space and the modeled degradation lacks diversity, making it unable to efficiently saturate the degradation space and leading to suboptimal solutions. In this study, we propose a novel degradation space localization and saturation (DSLS) method for weakly-supervised real-world SR, that can accurately localize the real degradation space to generate diverse degradation samples for training. Specifically, the proposed method uses a few paired data to locate the location of the real degradation space and unaligned data to further precisely locate the boundary of the real degradation space, thereby allowing the generated training samples to possess reasonable real degradation. Furthermore, we propose a degradation modulation mechanism to modulate the degradation strength and direction of the generated training samples, so that the generated training samples can efficiently and accurately saturate the real degradation space, making the trained super-resolution model more robust. Experimental results on real datasets demonstrate that our method can be plug-and-play embedded into the training phase of existing methods, while considerably improving the real super-resolution performance with a slight increase in training cost. We also conduct detailed ablation experiments to analyze and validate our contributions.

Additives Depletion by Water Contamination and Its Influences on Engine Oil Performance

Water enters engine oil in different ways and moves in the lubrication system causing an increase in wear, oil degradation and additives depletion. It has been proposed that water in the lubricants can transfer from dissolved to free phase leading to additives depletion in the oil. Different additives in the lubricants can easily latch to water molecules forming reverse micelles. The separation of reverse micelles from the oil causes additives depletion. This experimental and analytical study aims to investigate how the separation of free water above the saturation level can diminish the efficiency of additives in engine oils. The effect of varied levels of water on oil performance and its additives was investigated in this study. A new saturation method was used to determine the water saturation level in engine oil at different temperatures. The results reveal a decrease in additive concentration with increased separation of free water from the oil. Free water separation from engine oil is expected to reclaim the tribological performance, however, the results demonstrate that tribological performance after the separation of free water from the oil has been affected. The study showed not only does the removal of free water diminish the efficiency of additives due to additives depletion (≈ 10 wt%), but also the remaining dissolved water which is ≈ 2600 ppm can also affect wear and tribofilm chemistry. The results prove that two main mechanisms influence oil performance expressed as additives depletion by free water and remaining dissolved water.