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This work considers the isothermal process of incompressible viscous fluid filtration in an oil-saturated, fractured-porous reservoir. A study of the pressure and water saturation distribution process is carried out for a case in which a production well is put into operation. For this problem, i.e., a mathematical model in a two-dimensional formulation, a numerical method and a parallel algorithm are proposed. The mathematical model of two-phase filtration is written in accordance with the classical laws of continuum mechanics and Darcy's law and also includes a function of fluid exchange between low-permeability pores and high-permeability natural fractures within the framework of the Warren–Root model. The numerical solution is based on the finite-difference method and a splitting scheme of physical processes and spatial coordinates. For a split system with respect to piezoconductivity, an implicit finite-difference scheme with fixed saturations is constructed, and with respect to saturation transfer, explicit and implicit difference schemes are constructed. For parallel implementation of the developed numerical approach, a method based on geometric parallelism is selected. Testing of the developed method is performed using the example of calculating liquid mass transfer for a wide range of parameters. To verify the model, the obtained calculated pressure curves are compared with field data recorded by a deep-well measuring device. The results allow for estimation of the distribution of reservoir pressure and water saturation depending on the permeability of the fracture set and the pore part. The obtained results allow for monitoring of well operations, reducing unexpected accident risks and optimizing the development system in order to increase oil production in fractured-porous reservoirs. Computational experiments confirm the efficiency of the developed numerical algorithm and its parallel implementation. [ABSTRACT FROM AUTHOR]

In this paper we investigate the Riemannian extensibility of saturation phenomena treated first in the Euclidean framework by Brandolini et al. [Sharp estimates and saturation phenomena for a nonlocal eigenvalue problem. Adv Math (N Y). 2011;228(4):2352–2365.]. The saturation problem is formulated in terms of the first eigenvalue of the perturbation of the Laplace-Beltrami operator by the integral of the unknown function: the first eigenvalue increases with the weight affecting the integral up to a finite critical value and then remains constant, i.e. it saturates. Given a Riemannian manifold with certain curvature constraints, by using symmetrization arguments and sharp isoperimetric inequalities, we reduce the general problem to a variational one, formulated on either positively or negatively curved Riemannian model spaces; in addition, the possible scenarios for the optimal domains turn to be either geodesic balls or the union of two disjoint geodesic balls. We then explicitly compute the eigenvalues and eigenfunctions in terms of the radii, curvature and weight. A sufficient condition (incompatibility of a system of nonlinear equations involving special functions) is given that implies similar saturation phenomena to the Euclidean case. Due to its highly nonlinear character of the reduced problem (arising from the presence of curvature and special functions), we provide only partial answers to the original problem. However, both analytical computations and numerical tests suggest that the required incompatibility always persists. In addition, in the limit cases when the curvature tends to zero (for both positive an negative curvature), our results reduce to the Euclidean version. [ABSTRACT FROM AUTHOR]

There has been a recent explosion of articles on minimum sample sizes needed for analyzing qualitative data. The purpose of this integrated review is to examine this literature for 10 types of qualitative data analysis (5 types of saturation and 5 common methods). Building on established reviews and expanding to new methods, our findings extract the following sample size guidelines: theme saturation (9 interviews; 4 focus groups), meaning saturation (24 interviews; 8 focus groups), theoretical saturation (20–30+ interviews), metatheme saturation (20–40 interviews per site), and saturation in salience (10 exhaustive free lists); two methods where power analysis determines sample size: classical content analysis (statistical power analysis) and qualitative content analysis (information power); and three methods with little or no sample size guidance: reflexive thematic analysis, schema analysis, and ethnography (current guidance indicates 50–81 data documents or 20–30 interviews may be adequate). Our review highlights areas in which the extant literature does not provide sufficient sample size guidance—not because it is epistemologically flawed, but because it is not yet comprehensive and nuanced enough. To address this, we conclude by proposing ways researchers can navigate and contribute to the complex literature on sample size estimates. [ABSTRACT FROM AUTHOR]

ABSTRACT This article studies the state and disturbance simultaneous estimation problem for a class of nonlinear descriptor systems with δQC$$ \delta \mathrm{QC} $$ using a dynamic event‐triggered mechanism. δQC$$ \delta \mathrm{QC} $$ refers to incremental quadratic constraints, which can provide a unified description of many types of common nonlinear functions. To reduce the negative impact of measurement outliers on the identification estimation, a stubborn state and disturbance observer co‐design scheme is proposed for the first time by embedding dynamic saturation output estimation errors. Meanwhile, a dynamic event‐triggered mechanism is introduced to avoid the need for continuously available output information, which can reduce the pressure on communication resources. By constructing a Lyapunov function, existence conditions of the stubborn state and disturbance observer are obtained in the form of a convex optimization problem so that the error estimation maintains an acceptable estimation performance. Finally, simulation examples illustrate the universality and stubbornness of the proposed observer. [ABSTRACT FROM AUTHOR]

Under the long-term influence of overburden load and water infiltration, coal undergoes creep damage, and the disturbance caused by mining activities can lead to sudden instability, triggering geological disasters such as mine flooding. Therefore, this study prepared four types of coal samples with different saturations under creep damage conditions and conventional coal samples. A comparative study was conducted using uniaxial compression tests to examine the deterioration characteristics of physical and mechanical parameters, failure modes, and energy evolution patterns in these two types of coal samples. Additionally, a microscopic deterioration model of coal samples under the combined influence of water and creep damage was constructed to elucidate the mechanism of creep damage on the deterioration of mechanical properties in water-containing coal samples. The research findings indicate that coal samples affected by creep damage and conventional coal samples exhibit significant consistency in mechanical parameters and energy evolution patterns. Specifically, an increase in saturation is positively correlated with peak stress, elastic modulus, and dissipated energy. Conversely, peak strain, total input energy, and elastic strain energy are negatively correlated with rising saturation levels. Under the same saturation conditions, the change in mechanical parameters and energy characteristics is more pronounced in creep-damaged coal samples. Furthermore, the stress-strain curves of both coal sample types exhibit prolonged compaction stages, shortened elastic stages, and more significant yield stages. Under equivalent saturation levels, the stress-strain trends in creep-damaged coal samples show more substantial variations. Upon loading and failure, the conventional coal sample transitions from single inclined plane shear failure to tension-shear mixed failure as the saturation increases. Conversely, the creep-damaged coal sample shifts from "X"-type conjugate shear failure and tension-shear mixed failure to tension failure, signifying a tendency toward more complex failure modes. In cases where the coal sample has a water saturation of 41%, the deterioration of its mechanical parameters is primarily attributed to creep damage. However, when the water saturation reaches 41–100%, water plays a dominant role in the deterioration of the coal sample's mechanical parameters. After experiencing creep damage, the internal micro-cracks of the coal sample are extensively developed, which is also the primary factor contributing to the deterioration of the coal sample's mechanical properties and an increased proportion of dissipated energy. [ABSTRACT FROM AUTHOR]

In this paper, we perceive boredom as a potential resource for creativity in qualitative research. We present three main arguments. First, boredom is often an inevitable stage on the way to research excitement and can even serve as an important clue leading to analytic surprises. Second, there is a methodological need to reflect on boredom in order to understand the researcher’s perception of meaningfulness and meaninglessness. Particularly, we show how the ‘interview society’, characterized by the dominance of the therapeutic discourse, shapes researchers’ expectations regarding what is considered ‘interesting’ or ‘boring.’ Finally, the researcher’s experience of boredom may provide insights into the very phenomenon under investigation. We flesh out these arguments by showing how the researcher’s boredom during interviews reflects the interviewees’ emotional style, expected of (women) managers in the neoliberal culture: emotional restraint and a façade of rationality and objectivity. [ABSTRACT FROM AUTHOR]

The increase in the use of molecular methodologies in systematics has driven the necessity for a comprehensive understanding of the limitations of different genetic markers. Not every marker is optimal for all species, which has led to multiple approaches in the study of the taxonomy and phylogeny of polyclad flatworms. The present study evaluates base-substitution rates of nuclear ribosomal (18S rDNA and 28S rDNA), mitochondrial ribosomal (16S rDNA), and protein-codifying (cytb , cox1) markers for this taxonomic group, with the main objective of assessing the robustness of these different markers for phylogenetic studies. Mutation rates and Ti/Tv ratios of the other markers were assessed for the first time. We estimated substitution rates and found cytb to be the most variable, while 18S rDNA was the least variable among them. On the other hand, the transition to transversion (Ti/Tv) ratio of the different genes revealed differences between the markers, with a higher number of transitions in the nuclear gene 28S and a higher number of transversions in the mitochondrial genes. Lastly, we identified that the third codon position of the studied protein-codifying genes was highly variable and that this position was saturated in the cox1 marker but not in cytb. We conclude that it is important to assess the markers employed for different phylogenetic levels for future studies, particularly in the order Polycladida. We encourage the use of mitochondrial genes cytb and 16S for phylogenetic studies at suborder, superfamily, and family levels and species delimitation in polyclads, in addition to the well-known 28S and cox1. [ABSTRACT FROM AUTHOR]

Suppose that is some nonempty set of finite groups. A group is saturated with groups from if each finite subgroup of lies in a subgroup isomorphic to an element of . We prove that a periodic group with locally finite centralizers of involutions which is saturated with simple unitary groups of degree 4 over finite fields of fixed odd characteristic is isomorphic to a simple unitary group of degree 4 over some locally finite field of characteristic . [ABSTRACT FROM AUTHOR]

In this article, I study Guy Debord's critical discourse, particularly his landmark essay The Society of the Spectacle. He underlines here the symbolic desert produced by modern societies. I stress the uniqueness of his perspective, to the extent that such desert stems from a situation of overabundance and excess, and not from a specific void or absence. This desert constitutes a space saturated with images and signs: it asserts the rule of the superfluous and the inconsequential. Moreover, this discourse was rooted in the Glorious Thirties, which were characterized by a strong economic growth. It must therefore be placed within a historical and social context that is quite different from twenty first Century French society. Contemporary France is marred by contrast by unemployment and precariousness as well as by huge socio-economic inequalities. The endless production of media images contradicts therefore the deep shortcomings of social reality. Finally, the concept of the Spectacle, for Debord, did not include yet the overwhelming power of new technologies. These technologies have greatly expanded the influence of images within the social and cultural sphere by making them instantaneous and readily available. The same process has also increased significantly the potential alienation and isolation of man. [ABSTRACT FROM AUTHOR]

All qualitative researchers are familiar with the idea of saturation: that researchers should continue to collect and/or analyze data until nothing new is being added to their arguments or conclusions. Saturation is, however, used and understood in a variety of ways, often appearing as an unevidenced and dogmatic statement seeking to justify that a piece of research is complete. This article explores the application of the idea of saturation in qualitative research, noting its association with grounded theory and the particular interest taken in it by health researchers. It concludes that it is both a misunderstood and an overworked concept. [ABSTRACT FROM AUTHOR]

In this paper, we introduce saturation and semisaturation functions of sequences, and we prove a number of fundamental results about these functions. Given a forbidden sequence u with r distinct letters, we say that a sequence s on a given alphabet is u -saturated if s is r -sparse, u -free, and adding any letter from the alphabet to an arbitrary position in s violates r -sparsity or induces a copy of u. We say that s is u -semisaturated if s is r -sparse and adding any letter from the alphabet to s violates r -sparsity or induces a new copy of u. Let the saturation function Sat (u , n) denote the minimum possible length of a u -saturated sequence on an alphabet of size n , and let the semisaturation function Ssat (u , n) denote the minimum possible length of a u -semisaturated sequence on an alphabet of size n. For alternating sequences, we determine both the saturation function and the semisaturation function up to a constant multiplicative factor. We show for every sequence that the semisaturation function is always either O (1) or Θ (n). For the saturation function, we show that every sequence u has either Sat (u , n) ≥ n or Sat (u , n) = O (1). For every sequence with 2 distinct letters, we show that the saturation function is always either O (1) or Θ (n). [ABSTRACT FROM AUTHOR]

Parametric resonance is a complicated phenomenon that manifests itself in many areas. When subjected to parametric resonance, the amplitude of the flexible manipulator will increase abruptly, resulting in the rapid deterioration of working performance. Most conventional control methods are ineffective when approaching resonance. Because of this, a new method for suppressing the parametric resonance of the flexible manipulator is proposed. A novel parametric resonance absorber, characterized by controllable vibration parameters and adjustable nonlinear coupling parameters, is designed to strengthen quadratic modal coupling with the flexible manipulator and to construct a transfer tunnel for exchanging and dissipating parametric resonance energy. Dynamics equations of the controlled flexible arm mode and the parametric resonance absorber mode are derived, and the corresponding steady-state solutions of parametric resonance are solved. The saturation principle is revealed and implemented based on the stability analysis of the steady-state response of parametric resonance. With the help of the saturation principle, the parametric resonance response of the flexible manipulator can be effectively suppressed to a small amplitude by the proposed parametric resonance absorber. A series of numerical simulations and experiments have verified the proposed method’s effectiveness in suppressing the flexible manipulator’s parametric resonance. [ABSTRACT FROM AUTHOR]

This study reports the room temperature testing of an InGaAs/InP photodetector, biased under linear sweep and/or parametric bias voltage for both modulated, and unmodulated 1550 nm wavelength illuminations. Charge transport of the photo-generated carriers is probed under absorber's electric field manipulations via parametric control of applied bias, readout element, and light intensity. The device exhibits three different illumination intensity dependent current signatures. Speed of the employed device is enhanced under relatively stronger electric fields ensuring higher drift, and reduced transit times. A three order reduction in the gain setting of the readout element results in ∼ 235 times large peak-current under 20 times smaller pulsed illumination of 0.2 μ W . This electric field enhancement decreases rise, and fall times under pulsed illumination from 225 ns to 115 ns , and 1.553 μ s to 1.143 μ s , respectively. But, the large photodetection plausibility, and reduced transit times ensuring relatively fast speed comes at the expense of ~ 5 order high noise activity in the device. It is also inferred that, overall noise spectrum of the device is not decided by simple generational processes in the absorber, but through the actual proportion of photo-generated carriers taking part in the real charge transport. [ABSTRACT FROM AUTHOR]

Flower colour is an important mediator of plant–pollinator interactions. While the reflectance of light from the flower surface and background are governed by physical properties, the perceptual interpretation of such information is generated by complex multilayered visual processing. Should quantitative modelling of flower signals strive for repeatable consistency enabled by parameter simplification, or should modelling reflect the dynamic way in which bees are known to process signals? We discuss why colour is an interpretation of spectral information by the brain of an animal. Different species, or individuals within a species, may respond differently to colour signals depending on sensory apparatus and/or individual experience. Humans and bees have different spectral ranges, but colour theory is strongly rooted in human colour perception and many principles of colour vision appear to be common. We discuss bee colour perception based on physiological, neuroanatomical and behavioural evidence to provide a pathway for modelling flower colours. We examine whether flower petals and floral guides as viewed against spectrally different backgrounds should be considered as a simple colour contrast problem or require a more dynamic consideration of how bees make perceptual decisions. We discuss that plants such as deceptive orchids may present signals to exploit bee perception, whilst many plants do provide honest signalling where perceived saturation indicates the probability of collecting nutritional rewards towards the centre of a flower that then facilitates effective pollination. [ABSTRACT FROM AUTHOR]

Soil physical properties derived from phase relationships such as void ratio, degree of saturation, water content, and unit weight conventionally are formulated and calculated under the implicit assumption that the volumes of the three soil phases (i.e., solid, water, and air) are independent and unaffected by interactions among phases. However, significant variations do occur, including variation in the unit weight of soil water resulting from adsorptive soil–water interactions and variation in void volume resulting from bulk swelling or shrinking with changes in moisture. The importance of accounting for soil–water interactions in calculating soil physical properties was examined by introducing a new variable-volume soil phase diagram, and was illustrated using experimental data from consolidation and shrinkage tests for silts, nonswelling clays, and swelling clays. Errors in calculating void ratio and soil unit weight in saturated consolidation tests using conventional phase relationships can be significant—as high as 48% relative error in void ratio and as high as 16% relative error in soil unit weight. Errors in calculating moisture ratio and saturation in shrinkage tests can be as high as 53% relative error in moisture ratio and 42% in saturation. The occurrence of maximum error is highly correlated with soil water content corresponding to the maximum amount of adsorbed water. Liquid limit (LL) and specific surface area (SSA) were identified as index properties that can be used to account for volume variations in phase calculations. Examples are provided to illustrate the implementation of the proposed variable-volume soil phase formulation using LL or SSA in practical problems. Analysis showed that for fine-grained soils, it is practically necessary to use general variable-volume phase relationships to define basic soil properties in lieu of the conventional phase relationships. [ABSTRACT FROM AUTHOR]

Large-scale storage of 'green' hydrogen is essential in our quest to transition to renewable energy sources and achieve the net-zero emission targets. As such, Underground Hydrogen Storage (UHS) in geological porous media, such as in depleted oil and gas fields or saline aquifers, provides a cost-effective solution to store such large volumes of hydrogen (H 2) to buffer seasonal fluctuations in renewable energy supply and demand. Due to the novelty of the topic, many research gaps persist, but we focus on H 2 transport characteristics in the subsurface, hydrogen recoverability during cyclic operations, chemical interactions, and acoustic velocity as an indicator of H 2 saturation. In this study, we investigate UHS using a triaxial core-flooding experiment to address the above-mentioned research gaps by replicating field operations in the laboratory setup at representative subsurface conditions. Unstable displacement due to immiscible two-phase flow led to early H 2 breakthrough at 18% of H 2 saturation, ultimate H 2 saturation of 36% and withdrawal efficiency of 78% during the first cycle. However, cyclic charging and discharging led to an eventual H 2 withdrawal efficiency as high as 95%. Observed chemical interactions during our 3-day experiments were negligible, but our results also indicated a strong potential for evaporation-induced salt precipitation after injection of dry H 2 gas, leading to decreased reservoir porosity and permeability over time. Our ultrasonic measurements confirmed the sensitivity of P-wave velocity to H 2 saturation, which decreased by 3.5% when the H 2 saturation increased to 36%. This indicates that H 2 plume and leaks in UHS should be possible to monitor using 4D seismic surveys. Our results help to better understand H 2 flow, storage, and transport during cyclic UHS. The results indicate that H 2 withdrawal efficiency increases as the UHS reservoir matures and provides evidence of a dry near-well zone and evaporation induced salt precipitation in a UHS reservoir. [Display omitted] • Early breakthrough of H 2 at 18% H 2 saturation led to ultimate H 2 saturation of 36% after injecting 1.2 pore volumes of H 2. • H 2 withdrawal efficiency increased from 78% in the first cycle to 95% in the fourth cycle. • H 2 was produced at 90% purity with water vapor contamination indicating evaporation of liquid water into gaseous H 2. • 3.5% reduction in P-wave velocity when the H 2 saturation inside the specimen increased to 36%. • Evidence obtained for a dry near-well zone and evaporation induced salt precipitation during cyclic operations. [ABSTRACT FROM AUTHOR]

Forest biomass estimation is undoubtedly one of the most pressing research subjects at present. Combining multi-source remote sensing information can give full play to the advantages of different remote sensing technologies, providing more comprehensive and rich information for aboveground biomass (AGB) estimation research. Based on Landsat 8, Sentinel-2A, and ALOS2 PALSAR data, this paper takes the artificial coniferous forests in the Saihanba Forest of Hebei Province as the object of study, fully explores and establishes remote sensing factors and information related to forest structure, gives full play to the advantages of spectral signals in detecting the horizontal structure and multi-dimensional synthetic aperture radar (SAR) data in detecting the vertical structure, and combines environmental factors to carry out multivariate synergistic methods of estimating the AGB. This paper uses three variable selection methods (Pearson correlation coefficient, random forest significance, and the least absolute shrinkage and selection operator (LASSO)) to establish the variable sets, combining them with three typical non-parametric models to estimate AGB, namely, random forest (RF), support vector regression (SVR), and artificial neural network (ANN), to analyze the effect of forest structure on biomass estimation, explore the suitable AGB of artificial coniferous forests estimation of machine learning models, and develop the method of quantifying saturation value of the combined variables. The results show that the horizontal structure is more capable of explaining the AGB compared to the vertical structure information, and that combining the multi-structure information can improve the model results and the saturation value to a great extent. In this study, different sets of variables can produce relatively superior results in different models. The variable set selected using LASSO gives the best results in the SVR model, with an R 2 values of 0.9998 and 0.8792 for the training and the test set, respectively, and the highest saturation value obtained is 185.73 t/ha, which is beyond the range of the measured data. The problem of saturation in biomass estimation in boreal medium- and high-density forests was overcome to a certain extent, and the AGB of the Saihanba area was better estimated. [ABSTRACT FROM AUTHOR]

Vegetation classification has always been the focus of remote sensing applications, especially for tropical regions with fragmented terrain, cloudy and rainy climates, and dense vegetation. How to effectively classify vegetation in tropical regions by using multi-spectral remote sensing with high resolution and red-edge spectrum needs to be further verified. Based on the experiment in Wenchang, Hainan, China, which is located in the tropical monsoon region, and combined with the ZY-1 02D 2.5 m fused images in January, March, July, and August, this paper discusses whether NDVI and four red-edge vegetation indices (VIs), CIre, NDVIre, MCARI, and TCARI, can promote vegetation classification and reduce the saturation. The results show that the schemes with the highest classification accuracies in all phases are those in which the red-edge VIs are involved, which suggests that the red-edge VIs can effectively contribute to the classification of vegetation. The maximum accuracy of the single phase is 86%, and the combined accuracy of the four phases can be improved to 92%. It has also been found that CIre and NDVIre do not reach saturation as easily as NDVI and MCARI in July and August, and their ability to enhance the separability between different vegetation types is superior to that of TCARI. In general, red-edge VIs can effectively promote vegetation classification in tropical monsoon regions, and red-edge VIs, such as CIre and NDVIre, have an anti-saturation performance, which can slow down the confusion between different vegetation types due to saturation. [ABSTRACT FROM AUTHOR]

This paper experimentally investigates the influence of saturation on dynamic behaviors of concrete under both tension and compression stress states. Two grades of concrete were saturated to 0%, 50%, and 100% by oven drying and water soaking procedures. Split Hopkinson pressure bar (SHPB) tests, reaching the highest strain rate of about 170 s−1 , were carried out for dynamic compression. Dynamic splitting tensile tests were carried out by an Instron high-speed test machine, achieving the highest strain rate of about 40 s−1. The test results show that concrete specimens with different saturation ratios are all strain rate-sensitive. Under tensile loading, the effect of free on viscosity is only found to affect concrete's behavior when the strain rate is not very high. The strain rate sensitivity increases with water content when the strain rate is lower than about 3 s−1. However, when the strain rate is greater than 3 s−1 , strain rate sensitivity of concretes with different saturations become similar. Under compressive loading, free water in pores reduces the rate effect because it increases the hydrostatic pressure inside the specimen and leads to hydraulic fracturing. The microcracks caused by the hydraulic fracturing effect in the specimen result in macroscopic strength degeneration. [ABSTRACT FROM AUTHOR]

Experiments on visually grounded, definite reference production often manipulate simple visual scenes in the form of grids filled with objects, for example, to test how speakers are affected by the number of objects that are visible. Regarding the latter, it was found that speech onset times increase along with domain size, at least when speakers refer to nonsalient target objects that do not pop out of the visual domain. This finding suggests that even in the case of many distractors, speakers perform object‐by‐object scans of the visual scene. The current study investigates whether this systematic processing strategy can be explained by the simplified nature of the scenes that were used, and if different strategies can be identified for photo‐realistic visual scenes. In doing so, we conducted a preregistered experiment that manipulated domain size and saturation; replicated the measures of speech onset times; and recorded eye movements to measure speakers' viewing strategies more directly. Using controlled photo‐realistic scenes, we find (1) that speech onset times increase linearly as more distractors are present; (2) that larger domains elicit relatively fewer fixation switches back and forth between the target and its distractors, mainly before speech onset; and (3) that speakers fixate the target relatively less often in larger domains, mainly after speech onset. We conclude that careful object‐by‐object scans remain the dominant strategy in our photo‐realistic scenes, to a limited extent combined with low‐level saliency mechanisms. A relevant direction for future research would be to employ less controlled photo‐realistic stimuli that do allow for interpretation based on context. [ABSTRACT FROM AUTHOR]

For field development and drilling decisions, production assets and reservoir engineers require dynamic reservoir properties, such as saturation and pressure changes of a reservoir from the pre‐production virgin state. To date, geophysicists have produced time‐lapse (4D) seismic attributes (mostly on stacked seismic data) rather than dynamic parameters directly. In this paper, we present a new method to estimate saturation and pressure properties from time‐lapse seismic data to provide to reservoir engineers. This new three‐step method is demonstrated over the Edvard Grieg field in the North Sea. We can realize this method thanks to advanced seismic multi‐component acquisition via PP and PS seismic data and processing that allows accurate estimation of amplitude‐variation‐with‐offset parameters P‐ and S‐impedances. With time‐lapse P‐ and S‐impedances optimally resolved, we estimate a stable set of axes identifying water saturation increase (water replacing oil), gas saturation increase (gas injection or gas out of solution), pressure increase (at injectors) and pressure decrease (at producers). Once these axes are obtained, we convert every 4D P‐ and S‐impedance data points into 4D pseudo‐saturation and pseudo‐pressure using a transformation of coordinates. We next use the rock physics relationships of this field to show that a linear relationship can be used to map any 4D change in the field from impedances to saturations and pressures. Key locations in the field with largest saturation and pressure changes are used to find calibration values at these extreme points. Next, from the pseudo‐seismic 4D data, a linear mapping is used to calculate actual reservoir property changes (fractions for saturation and bars for pressure). This allows us to obtain fieldwide dynamic values for water and gas saturations and injection and production related pressure changes. The results are shown, and dynamic changes are interpreted on the Edvard Grieg field data. [ABSTRACT FROM AUTHOR]

Using the concept of methodological congruence—where the different elements of a study 'fit' together—we explore both problematic and good practice in (reflexive) thematic analysis (TA) as reported in Health Promotion International (HPI). Aligning with the importance we place on 'owning your perspectives' we situate this exploration in relation to our understanding of the variation in approaches to TA and qualitative research more broadly. This contextualization is necessary for highlighting why we judge practices to be in/congruent, and to facilitate more knowing congruence in future research. We critically reviewed a 'sample' of 31 papers published in HPI between 2010 and 2023 citing Braun and Clarke as reference for TA. We overview a range of problematic and good features of the use of TA in HPI , before focusing on two domains that seemed to present key challenges: theory and themes. Methodological incongruence can occur when postpositivist values and practices unwittingly creep into ostensibly non-positivist TA; we encourage thoughtfully and what we term 'knowing' consideration of theory, and quality practices and criteria. Methodological incongruence can also occur through mismatched conceptualizations of themes—notably, the use of 'topic summaries' as themes for reflexive TA (and fragmented thematic structures with 'thin' themes). We provide examples from the reviewed papers to demonstrate good practice in researcher reflexivity, articulation of theoretical and methodological frameworks and congruent themes. However, mindful of power dynamics, we only discuss problematic practice in general terms, to protect author anonymity. To facilitate thoughtful, quality TA—of all kinds—we provide eight pointers for researchers (and reviewers) to guide quality practice, and facilitate the use of concepts, procedures and criteria that promote knowing methodological congruence. [ABSTRACT FROM AUTHOR]

We study the question of finite generation of saturated multi-Rees algebras and investigate the asymptotic behaviour of related length functions. In the setup of excellent local domains, we show that the saturated multi-Rees algebra of a finite collection of ideals is finitely generated when the analytic spread is not maximal and the associated length function eventually agrees with a polynomial. Similar results are obtained when we restrict to two-dimensional local UFDs with no restrictions on the analytic spread. We further prove that the saturated multi-Rees algebra of finitely many monomial ideals in a polynomial ring modulo an irreducible monomial ideal, is always finitely generated. In this case, the corresponding length function is shown to exhibit piecewise quasi-polynomial behaviour. We also produce multi-ideal versions of a theorem of Amao. [ABSTRACT FROM AUTHOR]

We report a new low-affinity hemoglobinopathy (Hemoglobin Oviedo) in a family with isolated low oxygen saturation (89–92%) caused by a previously undescribed variant (NM_000518.5: c.115A > G;p.Thr39Ala) in the hemoglobin subunit β encoding gene (HBB gene) located on chromosome 11. [ABSTRACT FROM AUTHOR]

Using a randomized controlled trial, we investigated changes in both sexual harassment (SH) perpetration and victimization of 2104 middle school students in New York City who received divergent saturation and dosage levels of Shifting Boundaries, an SH prevention program, which was represented by the length of the program. We assessed the saturation effect of the program by comparing the outcomes across respondents from 26 schools in which there were varying percentages of students enrolled in the program. The data suggested that, overall, the program was effective in reducing sexual harassment victimization but achieved a null effect against respondents' SH perpetration and that neither the length nor the school-saturation level of the program exerted a significant effect on SH perpetration. Although the data indicated a significant difference in SH victimization between the treatment and control group, when comparing subgroups who received treatment with divergent saturation and dosage levels, no statistically significant difference was identified. Our results suggested that the program effect was not contingent on the portion of students in a school who enrolled in the program, nor was it contingent on the dosage. [ABSTRACT FROM AUTHOR]

This article addresses the event‐triggered adaptive consensus control of nonlinear multi‐agent systems with unknown control direction and actuator saturation. A new robust adaptive control algorithm based on an event‐triggered mechanism is designed. The smooth Lipschitz function approximates the saturated nonlinear function, while the Nussbaum function handles unknown control directions and residual terms. The event‐triggered mechanism is designed to determine the time of communication, significantly reducing the communication burden. An additional estimator is utilized to deal with unknown parameters involved in neighbor dynamics and prevent information exchange to consistency errors between connected subsystems. The results show that all the signals of the closed‐loop system are uniformly bounded, and the consensus tracking error converges to a bounded set. Meanwhile, Zeno's behavior is eliminated. Simulation results confirm the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

Transient absorption, or pump–probe microscopy is an absorption-based technique that can explore samples ultrafast dynamic properties and provide fluorescence-free contrast mechanisms. When applied to graphene and its derivatives, this technique exploits the graphene transient response caused by the ultrafast interband transition as the imaging contrast mechanism. The saturation of this transition is fundamental to allow for super-resolution optical far-field imaging, following the reversible saturable optical fluorescence transitions (RESOLFT) concept, although not involving fluorescence. With this aim, we propose a model to numerically compute the temporal evolution under saturation conditions of the single-layer graphene molecular states, which are involved in the transient absorption. Exploiting an algorithm based on the fourth order Runge–Kutta (RK4) method, and the density matrix approach, we numerically demonstrate that the transient absorption signal of single-layer graphene varies linearly as a function of excitation intensity until it reaches saturation. We experimentally verify this model using a custom pump–probe super-resolution microscope. The results define the intensities necessary to achieve super-resolution in a pump–probe nanoscope while studying graphene-based materials and open the possibility of predicting such a saturation process in other light-matter interactions that undergo the same transition. [ABSTRACT FROM AUTHOR]

Given a graph H, we say that an edge-colored graph G is H-rainbow saturated if it does not contain a rainbow copy of H, but the addition of any nonedge in any color creates a rainbow copy of H. The rainbow saturation number rsat(n, H) is the minimum number of edges among all H-rainbow saturated edge-colored graphs on n vertices. We prove that for any nonempty graph H, the rainbow saturation number is linear in n, thus proving a conjecture of Girã, Lewis, and Popielarz. In addition, we give an improved upper bound on the rainbow saturation number of the complete graph, disproving a second conjecture of Girão, Lewis, and Popielarz. [ABSTRACT FROM AUTHOR]

In the cultivation of maize, the leaf area index (LAI) serves as an important metric to determine the development of the plant. Unmanned aerial vehicles (UAVs) that capture RGB images, along with random forest regression (RFR), can be used to indirectly measure LAI through vegetative indices. Research using these techniques is at an early stage, especially in the context of maize for silage. Therefore, this study aimed to evaluate which vegetative indices have the strongest correlations with maize LAI and to compare two regression methods. RFR, ridge regression (RR), support vector machine (SVM), and multiple linear regression (MLR) regressions were performed in Python for comparison using images obtained in an area cultivated with maize for silage. The results showed that the RGB spectral indices showed saturation when the LAI reached 3 m2 m−2, with the VEG (vegetable index), COM (combination), ExGR (red–green excess), and TGI (triangular greenness index) indices selected for modeling. In terms of regression, RFR showed superior performance with an R2 value of 0.981 and a root mean square error (RMSE) of 0.138 m2 m−2. Therefore, it can be concluded that RFR using RGB indices is a good way to indirectly obtain the LAI. [ABSTRACT FROM AUTHOR]

This work compares three nonlinear solution methods for the performance of an induction motor’s magnetic equivalent circuit model with magnetic saturation. The interrelation between magnetic flux density and permeability introduces nonlinearities in the differential system of equations. Three popular nonlinear solution methods are selected for comparison, namely (i) the Gauss–Seidel method, (ii) the Newton–Raphson method and (iii) the inverse Broyden’s method. While all three methods have been applied in this context before, no comparison study has been published to the authors’ best knowledge. The study finds that the inverse Broyden’s method is most performant in terms of the number of required iterations, the computation time per iteration and the resulting total computation time. However, for substantial saturation levels, the authors recommend a hybrid implementation of multiple solution methods to obtain robust and reliable convergence. [ABSTRACT FROM AUTHOR]

The enzymology of the key steps in the archaeal phospholipid biosynthetic pathway has been elucidated in recent years. In contrast, the complete biosynthetic pathways for proposed membrane regulators consisting of polyterpenes, such as carotenoids, respiratory quinones, and polyprenols remain unknown. Notably, the multiplicity of geranylgeranyl reductases (GGRs) in archaeal genomes has been correlated with the saturation of polyterpenes. Although GGRs, which are responsible for saturation of the isoprene chains of phospholipids, have been identified and studied in detail, there is little information regarding the structure and function of the paralogs. Here, we discuss the diversity of archaeal membrane-associated polyterpenes which is correlated with the genomic loci, structural and sequence-based analyses of GGR paralogs. [ABSTRACT FROM AUTHOR]

The complex lithology, frequent interbedding and strong heterogeneity of the shale oil reservoir in Lucaogou Formation of the Middle Permian in Jimsar Sag lead to the complexity of litho‐electric parameters and the low accuracy of conventional reservoir saturation evaluation methods. Therefore, in this paper, automatic lithologic identification was firstly performed with the optimization inversion method of mineral components and K‐means clustering algorithm, and then, litho‐electric experiments were carried out to determine the litho‐electric parameters of different lithologies. Furthermore, the shale oil reservoir saturation calculation models of different lithologies were optimized and determined. Then, a composite water saturation model (Composite‐SW) based on complex lithology identification was constructed. Finally, the model was verified and analysed with the experimental results of water saturation. The coefficient of correlation between the calculation results of the Composite‐SW model and the core experiment results reached.88, indicating that the model was much better than conventional models. The model can be widely applied in logging evaluation of the continental mixed shale oil reservoir in the study area. The study provides a new idea for oil saturation evaluation of continental shale oil reservoirs and is significant for evaluating other types of shale oil reservoirs. [ABSTRACT FROM AUTHOR]

The temperature dependences of the thermoelectromotive force of chromium mono and disilicides in the temperature range 200℃÷+600℃ have been studied. For chromium disilicide, the dependence of the thermopower coefficient (α) on temperature (T) has three sections. Chromium monosilicide is characterized by a smooth increase in thermopower with increasing temperatures up to 200℃, and then its constancy. It was revealed that silicides rich in chromium atoms have lower thermopower values than silicides rich in silicon. The maximum thermo-EMF values of 110 μV/K and 190 μV/K were observed for chromium mono- and disilicides, respectively. It was revealed that for chromium silicides the dependence of the dimensionless parameter Q = Z∙T on temperature is linear. The possibility of predicting the technology of synthesis of semiconductor material with optimal thermoelectric properties using the dependence of thermopower on conductivity and the parameter Q on temperature is shown. [ABSTRACT FROM AUTHOR]

To study the effects of gas hydrates on the prevention and control of coal and gas protrusions, this paper reports the results of acoustic emission experiments on coal bodies containing gas hydrates with different saturation levels. The results showed that few acoustic emission events were generated in the elasticity stages of coal bodies containing gas hydrates, and the first sudden increase in the number of ringing counts generally occurred before and after the yielding point. Additionally, the acoustic emission events in the yielding stage were more active, and the cumulative number of ringing counts increased faster. The peak ringing counts appeared around the damage point, and a small number of acoustic emission events were still generated after destruction of the coal samples. The cumulative ringing counts decreased linearly with increasing saturation. The effect of saturation on the cumulative ringing counts in the elasticity stage of the gas hydrate-containing coal samples was small, but the difference between the cumulative ringing counts in the yielding stage and those in the destruction stage was larger. The total cumulative ringing counts and the cumulative ringing counts during each stage for the gas hydrate-containing coal samples decreased with increasing enclosure pressure. The energy and amplitude of the loading process were consistent with the trend for the ringing counts. The acoustic emission ringing counts of gas-containing coals were greater than those of gas hydrate-containing coals in the yielding and destructing stages. [ABSTRACT FROM AUTHOR]

The condensate gas reservoir with bottom water and oil-rim faces the invasion of oil-rim and bottom water in the process of depleted gas production. In order to explore the invasion mechanism and distribution of oil-rim for a better coping strategy, the long-core displacement apparatus was modified for X-CT scan withstanding high temperature and high pressure (HTHP). From 56.58 to 47 MPa, the oil-gas contact rose fast and gradually slowed down, and the corresponding invasion volume accounted for 82.98% of the total invasion volume. From 47 to 8.8 MPa, the watercut soared to 98% and the invasion rate tended to stagnate. Finally, oil-rim oil was left completely in the reservoir pores and the recovery of condensate oil was only 30.27%. The paper revealed the damage of excessive pressure drop to condensate and oil-rim, and discussed its influencing factors and various pressure control methods. The modified apparatus filled the gap of obtaining oil saturation by X-CT scan under stable HTHP, which had a general application prospect in subsequent optimization and core displacement experiments where oil distribution needed to be observed under HTHP. [ABSTRACT FROM AUTHOR]

The province of Chimborazo located in the northern Andes of Ecuador presents many intrinsic factors, which contribute to the occurrence of mass movements, leaving in many of the cases registered damages of materials and loss of life. The recent landslide of March 26, 2023, in the Alausí canton is an event of great interest due to the magnitude of the occurred destruction and the corresponding fatalities. Therefore, there are two predominant objectives of the current study, of which the first has been to determine the most relevant characteristics of this mass movement by identifying and analyzing the geomorphology of the recorded slope movement and the lithological units involved, by field work and through geophysical surveys. Secondly, we performed a preliminary study of the possible triggers of the movement by means of the historical analysis of the precipitations during the months of January to March of the last decade and the study of the recent seismic series. However, through the obtained analysis, it is determined that the study site is composed of three distinctive lithological units. The observed mass movement is of the rotational type, as result of the intense rainfall that occurred during the first quarter of 2023, being hereby the most probable triggering factor. This corresponds to a 600% increase in the average monthly rainfall compared to the period from 2010 to 2022. [ABSTRACT FROM AUTHOR]

This paper introduces an FPGA-based implementation of a smart switch designed to avoid inrush currents occurring during the connection of single-phase transformers utilized in grid-connected photovoltaic (PV) systems. The magnitude of inrush currents is notably impacted by the residual flux within the transformer core and the precise moment of energization relative to the wave cycle. Alternative methods frequently hinge on intricate procedures to estimate residual flux. This challenge is adeptly circumvented by the innovative smart control system proposed herein, rendering it a cost-effective solution for grid-connected PV systems. The proposed solution for mitigating inrush current remains effective, even in the face of challenges with current and voltage sensors. This resilience arises from the system's ability to learn and adapt by leveraging information acquired from the network. [ABSTRACT FROM AUTHOR]

The movement of dissolved salt in melting snow is considered based on the equations of non-isothermal two-phase filtration. The thermal conductivity of snow and the dependence of the water freezing point on salinity were verified using available experimental data. The influence of the presence of dissolved salt on the phase transition was evaluated by numerical experiments. [ABSTRACT FROM AUTHOR]

The concept of saturation in qualitative research is a widely debated topic. Saturation refers to the point at which no new data or themes are emerging from the data set, which indicates that the data have been fully explored. It is considered an important concept as it helps to ensure that the findings are robust and that the data are being used to their full potential to achieve the research aim. Saturation, or the point at which further observation of data will not lead to the discovery of more information related to the research questions, is an important aspect of qualitative research. However, there is some mystification and semantic debate surrounding the term saturation, and it is not always clear how many rounds of research are needed to reach saturation or what criteria are used to make that determination during the thematic analysis process. This paper focuses on the actualisation of saturation in the context of thematic analysis and develops a systematic approach to using data to justify the contribution of research. Consequently, we introduce a distinct model to help researchers reach saturation through refining or expanding existing quotations, codes, themes and concepts as necessary. [ABSTRACT FROM AUTHOR]

This study investigated the effects of color presence and saturation on the affective judgment of real-life images, as functions of the image's affective valence. In the first two experiments, participants observed and rated original color photos and their grayscale versions, presented in an interleaved order across two separate experimental sessions. Color photos were rated as more pleasant than grayscale photos when image valence was positive, and more unpleasant when image valence was negative. The third experiment consisted of the same original images and their versions with saturation reduced by 50%. Original photos were rated as more pleasant than saturation-reduced photos when image valence was positive, yet less unpleasant when image valence was negative, implying potentially separable mechanisms for processing color presence and saturation. Significant interactions were found between color or saturation mode and valence on affective judgment in all three experiments. The effects persisted after controlling for colorfulness and luminance between the color and grayscale (or de-saturated) conditions. [ABSTRACT FROM AUTHOR]

Background: Despite the high number of synthetic androgenic–anabolic steroids, testosterone is still misused for doping in amateur and professional sports. However, only few studies investigated the dose–response effects of testosterone beyond its physiological concentrations and in over 90 years of research, no saturation dosage has been experimentally described for exogenous testosterone administration. Objectives: We want to elucidate the physiological and pathophysiological effects of supra‐physiological testosterone application and close this gap in testosterone dose–response data. Materials and methods: Male orchiectomized rats were treated with different testosterone doses ranging from 0.1 to 50 mg/kg body weight for 3 weeks. Several physiological endpoints (e.g., body weight, organ and muscle weight, muscle strength, muscle fiber size) were examined during and after the termination of the treatment with an adjusted Hershberger assay, open‐field‐test, and (immuno‐)histologic. Results: The wet weights of androgen responsive organs (penis, prostate, seminal vesicle) showed a significant increase in a dose‐dependent manner. Histological evaluation of the prostate showed a significant higher percentage of KI67 positive prostate nuclei in the highest dosage group and an increasing hyperplasia with increasing testosterone administered. A significant anabolic effect was only observed in Levator ani wet weight, and to minor degree for the cardiac muscle. Regarding other skeletal muscles (Musculus soleus and Musculus gastrognemicus), no significant testosterone effects were observed. We showed a significant increasing dosage–response effect for testosterone in androgen responsive organs with saturation at the two highest concentration of 10 and 50 mg/kg body weight. Discussion and conclusion: The dose‐dependent androgenic effects of testosterone were well observable and the anabolic effects on muscle tissue were visible although to a lesser degree, without the support of aerobic exercise and a protein rich diet. Future studies should investigate a combinatorial effect of testosterone and training. Nevertheless, with the chosen range of applied testosterone, we showed a saturation of testosterone effects in prostate, seminal vesicle, penis, and Levator ani. [ABSTRACT FROM AUTHOR]

A solution of the nonlinear problem on the driving of the oil from an oil-bearing stratum of finite length by the filtrate of a drilling agent (flushing water) has been constructed with the use of the asymptotic method. On the basis of this solution, the saturation field of the stratum in the zone of penetration of the flushing water into it was investigated with regard for the process of opening of the stratum by drilling. The indicated solution defines the movement, along the thickness of the stratum, of the boundary, corresponding to the position of a drill bit, above which the saturation of the stratum with the filtrate of the flushing water and the velocity of filtering of this water are prescribed, and, below this boundary, the velocity of the water filtration flow and the stratum saturation are assumed to be equal to zero. It is shown that, within large times, the solution obtained conforms with the known Buckley–Leverett expression. On the basis of the computational experiments, spatial and time distributions of the stratum saturation in the zone of penetration of the flushing water into it have been constructed with regard for the process of opening of the stratum. [ABSTRACT FROM AUTHOR]

Background: Semi-structured interviews allow progressive interview refinements to gain an in-depth understanding of a research question, but interview refinements affect the stopping point. This paper aims to describe a method that provides transparency in interview refinements and helps researchers decide on a stopping point. Methods: We established systematic and practical methods to document interview refinements and visualize novel and duplicate interview codes. We illustrated the methods using a case study called the Mass Atrial Fibrillation Screening Study, a real-world clinical trial. Interviews were audio recorded and transcribed progressively. Two researchers established the initial coding into a predefined framework with reference to the Medical Research Council Guidance of Process Evaluation. Final codes were reached by discussion and consensus. NVivo v12 software was utilized to manage the qualitative data. Results: We developed an open-access software package for the 'R' statistical programming language called 'novelqualcodes' and a video demonstrating the application. Our package converts NVivo coding matrices into graphs of the trends of novel and duplicate codes. Our package also enables users to document interview refinements as fieldnotes, providing a visual guide to help researchers decide on a stopping point. In the case study, one researcher (KCW) conducted 48 one-to-one in-depth semi-structured interviews with participants from September 2021 to July 2022. Interview refinements were identified and reported to provide transparency to the readers. The novel code graphs and examination of the code sufficiency in the predefined framework demonstrated the stopping point at which we were satisfied with the richness and insights of the interviews in answering our research question. Conclusions: We illustrated a new paradigm of systematic and practical methods and shared an open-access software package and a video to describe, document and visualize the path to the stopping point. This approach can be applied in other qualitative research using different predefined frameworks. [ABSTRACT FROM AUTHOR]

Geometric heterogeneities in tight reservoir rocks saturated with a fluid mixture may exhibit different scale distribution characteristics. Conventional models of rock physics based on poroelasticity, which usually consider single‐scale pore structure and fluid patches, are inadequate for describing elastic wave responses. A major challenge is to establish the relationship between the wave response at different spatial scales and frequencies. To address this problem, three sets of observational data over a wide frequency range were obtained from a tight oil reservoir in the Ordos Basin, China. Ultrasonic measurements were made on eight sandstone samples at partial oil‐water saturation at 0.55 MHz. Data from six borehole measurements and seismic profiles were acquired and analyzed at about 10 kHz and 30 Hz, respectively. Analysis of the cast thin sections shows that dissolution pores and microcracks generally develop, with fractal dimensions of the pores ranging from 2.45 to 2.67 for the samples with porosities between 5.1% and 10.2%. Compressional wave velocity and attenuation were estimated from the observed data. The results show that the velocity dispersion from seismic to ultrasonic frequencies is 10.02%, mostly occurring between sonic and ultrasonic frequencies. The attenuation is stronger at higher oil saturation. The relationships between velocity, attenuation, and wavelength were established and can be used for further forward modeling and seismic interpretation studies. A partial saturation model has been derived based on effective differential medium theory and a double double‐porosity model, assuming that the medium contains fractal cracks and fluid patches. The effects of scale and saturation on wave responses are prevalent. Modeling results consistent with observed data show that the radii of cracks and fluid patches range from 0.1 μm to 2.8 mm, affecting ultrasonic, acoustic, and seismic attenuation. The multiscale data and proposed model quantify the relationship between fracture and fluid distributions and attenuation and could be useful for upscaling to the reservoir scale. The study helps improve the understanding of seismic wave propagation in partially saturated rocks, which has potential applications in seismic exploration, hydrocarbon production in reservoirs, and CO2 sequestration in aquifers. Plain Language Summary: The physical properties of the rock and fluid can be inferred from the measured elastic wave responses and energy dissipation characteristics. However, the effects of heterogeneities of different sizes and at different frequencies can hinder studies to quantify wave responses in a partially saturated porous medium, which are usually based on laboratory measurements. A major problem is the difference between observed frequencies and scales: megahertz in the laboratory, 10 of kilohertz in the borehole scale, and hertz in the seismic exploration scale. In this work, the frequency‐ and saturation‐dependent compressional velocity and attenuation are investigated using three geophysical data sets from the same tight reservoirs. A strong velocity dispersion over the measured frequency range is observed. The stronger attenuation at partial saturation may be caused by the multiscale heterogeneities of the pore structure and fluid patch distribution. A fractal poroelasticity model is developed by gradually inserting inclusions of different sizes with compliant pores and liquid patches into a homogeneous host skeleton. The wave responses are significantly affected by scale distribution and saturation. The proposed model, verified by the measured data, can be useful in interpreting the anelasticity of tight heterogeneous reservoirs in a broadband range. Key Points: We investigate how fluid saturation affects wave attenuation and dispersion over a wide frequency range in tight sandstone layersA partial saturation model describes the fractal properties of the layersThe size of the cracks and fluid patches are determined by applying the fractal model to the multiscale data [ABSTRACT FROM AUTHOR]

The freezing and thawing processes in sandstones under unsaturated conditions are methodically explored via the low-field nuclear magnetic resonance (NMR) technique. To precisely monitor the water content and distribution during the freezing and thawing processes, a special Carr–Purcell–Meiboom–Gill (CPMG) pulse sequence is proposed, leading pulse-induced temperature perturbations to be minimized. The results exhibit totally dissimilar water distributions in the two processes even under the same saturation: the freezing process retains more water in large pores, while the thawing process contains less water in large pores. This observation is primarily attributed to the ink-bottle effect occurring during the freezing: large pores with narrow entrances do not freeze until the entrance freezes. In addition, phase transition duration depends on the initial water saturation, for instance, the duration of the thawing process increases from 7 to 12 min as the initial water saturation varies from 40% to 80%. Through NMR observation, this phenomenon is associated with the variation of surface-to-volume ratio: high saturation is associated with the presence of water in large pores; the latter owns a small surface-to-volume ratio and accordingly involves a longer phase transition duration. After the assessment of surface-to-volume ratio, the intrinsic kinetic rate coefficient is further estimated to be 4.6 × 10–12 mol cm−2 s−1 ℃−1 for the ice thawing process in the studied rock. This value is five orders of magnitude lower than that found in the literature for the thawing process in bulk condition, i.e., 7.5 × 10–7 mol cm−2 s−1 ℃−1. We suggest that the small intrinsic kinetic rate coefficient addressed in the present work could be related to the constrained effect in rocks. Highlights: A special pulse sequence with minimized temperature perturbation is developed to perform the freezing/thawing experiment. The difference in water distribution is attributed to the effect of ink-bottle pores in the freezing and thawing processes. Phase transition time increases with initial water saturation, which is lucidly explained by the nuclear magnetic resonance measurement that directly gives rise to information about the surface-to-volume ratio. The intrinsic kinetic rate coefficient for ice melting within sandstones is estimated. [ABSTRACT FROM AUTHOR]

The present work details the development of a compositional model to replicate the heavy hydrocarbon flow in porous reservoir systems under non-isothermal conditions. The mathematical model considers mass and energy conservation equations describing the reactive of natural variables distributed in a multiphase hydrocarbon system. Such natural variable based compositional models better suit fully implicit numerical schemes with inexpensive Jacobian matrix computations. Further, the model accommodates a switch of primary variables for the disappearance and reappearance of a phase. The resulting nonlinear conservation equations are numerically discretized using a block-centered finite-difference scheme and solved with a quasi-Newton based implicit iterative solver. The present model is validated with the thermal profiles presented in the literature for the multiphase flow during the combustion of heavy crude oil in petroleum reservoir system with performance coefficient (R2), mean absolute error (MBE), and maximum absolute percentage error (MAPE) of about 0.954, 0.37, and 0.01 respectively. The developed compositional model projected 26 and 72 % of light and heavy oil recoveries respectively in about 160 days with a maximum or peak temperature of about 798 K. Further, the thermal and production profiles projected by the sensitivity analysis on various operating parameters are presented. It is noteworthy that the present works aid in providing an economical numerical based tool in evaluating the flow and transport during underground or in-situ combustion process for efficient energy exploration. [ABSTRACT FROM AUTHOR]

This paper discusses the Topp-Leone-G power series class of distributions. The greatest attention is paid to the investigation of intrinsic characteristic "saturation" to the horizontal asymptote in the Hausdorff sense. Some estimates for the value of the Hausdorff distance are obtained. We present a new family of recurrence generated adaptive functions with corresponding applications. The usefulness of the obtained results is demonstrated in a simulation study of some real data sets from the medical sector and insurance. Some suitable software modules within the programming environment CAS MATHEMATICA are proposed. [ABSTRACT FROM AUTHOR]

Background: The perception of the quality of care provided by the medical institution to patients is directly affected by the job satisfaction of nurses. The feeling of job satisfaction is caused besides other things by the subjective expectations of employees about what their work should provide them with in return. The aim of the study is to evaluate and compare job satisfaction of hospital nurses in the Czech Republic in 2011 and 2021 by identifying differences between their personal preferences and perceived saturation. Methods: The respondents are hospital nurses in the Czech Republic in 2011 and 2021. A developed questionnaire was used to determine the job satisfaction factors. The order of factors of personal preferences, perceived saturation and differences between them was compiled. For evaluation was used the Euclidean distance model that enables to capture the order and determine the significance given by the distance in which the factors are located. Results: At the top of personal preferences of hospital nurses, the factors salary and patient care are in the first two places with a similar distance. The salary factor is the most preferred by hospital nurses in both evaluated periods, and at the same time there is the greatest discrepancy between personal preferences and perceived saturation. By contrast, image of profession and working conditions were sufficiently saturated by the employer in both periods, but nurses do not significantly prefer these factors. Conclusions: The salary and patient care (i.e. the mission of the nurse's work itself) are at the top of personal preferences of hospital nurses, with an exclusive position among other factors. We consider it important that the hospital management emphasizes them in the management of hospital nurses. At the same time, the patient care is perceived by the hospital nurses as one of the most saturated factors - in contrast to salary, which is located at the complete opposite pole as the least saturated factor and therefore emerges from the mutual comparison as the factor with the greatest degree of divergence. The stated conclusions are valid for both compared periods. New method of data evaluation was successfully tested. [ABSTRACT FROM AUTHOR]

The influence of a capillary pressure jump in a porous medium on the equilibrium between its liquid and gas phases, defined by the Peng–Robinson equation of state, was investigated. A numerical analysis of the phase diagrams of a gas–condensate mixture, constructed in gas-pressure and liquid-pressure coordinates for different capillary pressure jumps in the mixture, has been performed. The boundary of the two-phase region of such a mixture was determined as a domain of its existence in the two-phase state. The calculations were not associated with a concrete porous medium, and they were based on the condition of phase equilibrium of such a medium at different capillary pressure jumps in it. [ABSTRACT FROM AUTHOR]