Disturbed State Research Articles

A theoretical model for the load-transfer analyses of load distributive compression anchor integrating DSC-based interface nonlinear model

An innovative anchorage technology named load distributive compression anchor (LDCA) has recently been employed in a multitude of geotechnical engineering. The anchoring structure comprises multiple anchor bodies, thereby overcoming the bearing defects associated with conventional load-concentrated anchors and providing superior bearing performance. The complex structural configuration of LDCA considerably complicates the process of load-transfer theoretical modeling. A lack of relevant studies from theoretical solution perspective is yet evident in previous works. In this paper, a theoretical model was proposed for the load-transfer analyses of LDCA, of which the soil-anchor interface mechanical behavior was specially characterized by a disturbed state concept (DSC)-based nonlinear model. The mechanical simulation for the connections in different anchor bodies was incorporated into the theoretical analysis framework through the utilization of finite difference method. Three groups of 3D finite element (FE) models were established to simulate the load-transfer behaviors of LDCAs with different numbers of anchor bodies. The theoretical calculations agree well with the FE numerical results and the in-situ pullout test data, thereby confirming the applicability of the load-transfer theoretical model. The axial force and interface shear stress distributions, as well as the bearing capacity for LDCAs, were discussed based on theoretical calculations and FE simulations. Sensitivity analysis of several key design parameters was conducted to investigate their effects on the bearing capacity of LDCAs. The findings achieved in this study can provide insights into the understanding of the load-transfer behaviors of LDCA, and contribute to the bearing performance evaluation.

Prosthetic Rehabilitation of a Hemi-mandibulectomy Patient with Interim Mandibular Guide Flange and Maxillary Twin Occlusion: A Case Report

ABSTRACT In hemi-mandibulectomy patients, the fabrication of a successful prosthesis is a challenging task. Segmental resection of the mandible causes deviation toward the resected side resulting in facial disfigurement, difficulty in speech, mastication, swallowing, respiration, and restricted mandibular movements. Such a condition affects the daily life of the patient and might also result in a disturbed psychological state. The primary goal of treating these patients was to achieve facial aesthetics and restore function and phonetics. Such a scenario can be tackled more efficiently with good patient cooperation and a well-fabricated prosthesis.

Response of piled raft foundations using the disturbed state concept theory: Analysis and interpretation

In nearshore and marine environments, challenges arise from loading conditions, subsoil profiles, and dynamic soil states influenced by continuous wave action. Piles in such settings face complex interactions due to soil vulnerability to loading and over-consolidation. Accurate estimation of pile shaft and base resistances, as well as raft-soil interface stiffness, is crucial. The paper introduces the disturbed state concept for analysing piled raft foundations under vertical loading. This theory assumes interface strength between piles and soil follows an exponential distribution, expressed through the Weibull function. Interaction between piles is established using a modified displacement factor, which is a modified form of Mindlin's solution. Raft-soil interaction is modelled with springs connected to the pile head. The load transfer model exhibits both softening and hardening responses. Validation against numerical and field experimental studies demonstrates close agreement within a 5%–15% error range. Parametric investigation analyses load-settlement response, percentage of load on pile base with settlement increase, and axial load transfer along pile length under varying conditions. The impact of limiting pile-soil relative movement on piled raft response is also explored.

An effective stress-based DSC model for predicting hydromechanical shear behavior of unsaturated collapsible soils subjected to initial shear stress

Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have encouraged several investigators to develop analytical, empirical, or semi-empirical models for predicting the shear behavior of unsaturated soils. However, most of the previously proposed models are for specimens subjected to the isotropic state of stress, without considering the effect of initial shear stress. In this study, a hydromechanical constitutive model is proposed for unsaturated collapsible soils during shearing, with consideration of the effect of the initial shear stress. The model implements an effective stress-based disturbed state concept (DSC) to predict the stress-strain behavior of the soil. Accordingly, material/state variables were defined for both the start of the shearing stage and the critical state of the soil. A series of laboratory tests was performed using a fully automated unsaturated triaxial device to verify the proposed model. The experimental program included 23 suction-controlled unsaturated triaxial shear tests on reconstituted specimens of Gorgan clayey loess wetted to different levels of suctions under both isotropic and anisotropic stress states. The results show excellent agreement between the prediction by the proposed model and the experimental results.

Softening-based interface model and nonlinear load-settlement response analysis of piles in saturated and unsaturated multi-layered soils

This work presents a simplified method for the nonlinear analysis of the load–displacement response of piles in multi-layered soils. As a starting step, a new interface model based on the disturbed state concept (DSC) is put forth to simulate the interface shear stress-displacement relationship by considering the nonlinear hardening–softening behaviour. In the new model, input parameters can be conveniently calibrated using conventional interface shear tests or on-site tests. The good agreement between predictions and experimental data from interface direct shear tests validated the performance of the proposed DSC model. The DSC model performed better in terms of predictions when compared to the hyperbolic one. Next, the soil-structure interface model and bearing capacity theory are coupled to provide a theoretical framework for the analysis of pile load-transfer in saturated and unsaturated multi-layered soils, where the DSC model is employed to represent base resistance as well as skin friction. This work also discusses the profile of steady-state in-situ matric suction, soil–water characteristic curve, and pore-water pressure of unsaturated soils. The proposed method has the advantage of being used in practice as it is simple to obtain input parameters from laboratory tests, as well as Standard Penetration or Cone Penetration Tests. The proposed framework is finally applied to the analysis of five well-documentedcase studies. The proposed approach and the static load test results from the field measurements are found to be in satisfactory agreement, indicating that the proposed method performs well. The proposed method is suggested to be utilised for preliminary analysis, planning a suitable programme of loading tests, as well as optimizing the pile design by back analysis ofthe load test results.

Revisiting the hydrological legacy of revegetation on China's Loess Plateau using Eagleson's ecohydrological perspective

Revegetation has resulted in a trend of increasing vegetation greenness on the Chinese Loess Plateau. However, it remains unclear whether the regional vegetation coverage exceeds hydroclimatic limitations in the context of revegetation, and the hydrological effects of greening are controversial. Eagleson's optimality hypothesis can explain some of the hydrological effects on the Loess Plateau. Here, building on previous research, the geospatial vegetation states were estimated for pre- and post-revegetation periods on the Loess Plateau from 1982 to 2015 using Eagleson's ecological optimality theory. Additionally, a drought composite analysis approach was utilized to investigate the hydrological effects related to drought (including sensitivity and partitioning) under various vegetation states. It was found that revegetation increased the proportion of catchments in the equilibrium state and decreased the proportion in the disturbed state, owing to a wetter climate compared with the pre-revegetation period. Root-zone soil drought, driven by precipitation (P) deficit, asymmetrically triggered hydrological effects for both the pre- and post-revegetation periods, with reduced runoff (Q) for both periods and a decrease in evapotranspiration (ET) during the pre-revegetation period but an increase in ET during the post-revegetation period. Moreover, catchments in an equilibrium state exhibited lower sensitivity between ET and P, and more stable partitioning of ET with regards to P, compared with those in a disturbed state. These results underscore the theoretical framework that an equilibrium state is crucial for maintaining ecosystem ET. Our results highlight the necessity of considering the hydrologic regulation of vegetation states when assessing the hydrological effects of vegetation change.

ASSESSMENT OF THE IMPACT OF RECREATIONAL ACTIVITIES ON THE NATURAL ENVIRONMENT OF THE KARKARALY STATE NATIONAL NATURE PARK OF THE REPUBLIC OF KAZAKHSTAN

The article considers the results of assessment of recreational impact on the natural environment within Karkaraly SNNP (State National Nature Park). The purpose of this study is to assess the impact of recreational activities on the natural environment of Karkaraly SNNP using remote sensing data. The proposed methodology for assessing the impact of recreational activities on the natural environment using remote sensing data includes several steps from the selection of indicators for assessing recreational load to obtaining the integral value of recreational load on the natural environment. The most visited recreational sites were selected as objects of the study. The study showed that the natural environment near the sanatorium "Sosnovy Bor" in the area with high attendance of vacationers is in a relatively disturbed state. The key site has a dense network of paths, the stand of trees is weakly closed, groups of trees are limited by paths, roads and glades.

A novel risk assessment tool for postoperative delirium in vascular surgery: The stress model (Siena posTopeRative dElirium in vaScular Surgery).

Postoperative delirium (POD) is a common complication with a high health-related impact. The creation of a model (Siena posTopeRative dElirium in vaScular Surgery) to identify high-risk patients with consecutive prompt diagnosis and correct management. This is an observational retrospective study to evaluate POD incidence in patients who underwent elective vascular surgery procedures between 2018 and 2020. POD was detected using CAM and defined as the onset of an acute confusional state, clinically manifesting as a disturbed state of consciousness, cognitive dysfunction, or alteration in perception and behavior. The total population was divided in the development and validation subsamples. Multivariable logistic regression analysis was performed, identifying variables related to the occurrence of POD. An additive score was created and the STRESS score was internally validated using the Validation subgroup. A total of 1067 patients were enrolled. POD occurred in 111 cases (10.4%). Multivariable logistic regression analysis for POD occurrence revealed as significant predictors: age>75 years, CKD, dyslipidaemia, psychiatric disease, CAD, hospitalization in the previous month, preoperative NLR >3.59, preoperative Hb < 12g/dl, preoperative Barthel score <75, major amputation, CLTI revascularization, general anesthesia, and postoperative urinary catheter. These variables were used to create the STRESS score. The model was applied to both development and validation subgroups; AUC was respectively 0.7079 (p < .0001) and 0.7270 (p < .0001). The STRESS score has a good predictive potentiality for POD occurrence in elective vascular surgery procedures. However, implementation and external validation are needed to be correctly used in everyday clinical practice.

Діяльність психологічної служби в роботі благодійних та громадських організацій

The article examines the mechanism of responding to a request from a client and the organization of providing psychological services in the work of charitable and public organizations. The main tasks of a psychological service are diagnostics and normalization of mental state of the recipient of services; restoration of disturbed mental state to an optimal level of mental health; correction of the personality of the recipient of services to ensure his or her efficient functioning in society; formation and restoration of adaptive mechanisms; conducting psychoprophylaxis; formation of positive reactions, motivations, social attitudes towards life and cognitive activity; providing assistance in establishing or restoring constructive relations with the family and social environment. In particular, seven types of psychological services are distinguished: psychological diagnostics, crisis psychological counseling, psychological counseling, psychotherapy, psychological support and accompaniment, group work and psychological first aid. Based on the study of the work of several charitable and public organizations, the main requests for psychological services were identified to be family relations, sexual problems, contacts with peers, education and career guidance, gender-based violence, somatic and mental health, general and psychophysiological development. We achieved the set goal, which involved studying the system of psychological services in the structures of charitable and public organizations. In the article, we described the types and the procedures of providing psychological services and its documentation.

Математическое моделирование потокораспределения возмущенного состояния теплоэнергетической системы

The results of the development of a model for the analysis of the disturbed state of a thermal power hydraulic system on the example of a heat supply system are presented. The parameters of the operating mode of the thermal power hydraulic system after the influence of disturbing factors on it were evaluated. It is shown that the classification of stationary states of the studied fragment of the system with steady flow distribution is oriented to boundary conditions. The boundary conditions classified into four types are considered. It is noted that the choice of boundary conditions must be carried out taking into account the use of energy equivalence in the analysis of the perturbed state of the studied fragment of the hydraulic system. The developed model of steady-state flow distribution with a non-isothermal flow of a viscous medium is presented. It is concluded that the developed mathematical model represents a qualitatively new approach to formalizing the problems of flow distribution analysis in systems with adjustable parameters. The model can be considered as a generalized form of representation of particular flow distribution models when describing the object under study, which can be considered as a hydraulic circuit with adjustable parameters with a non-isothermal flow of a viscous medium. It is shown that this model can be used to analyze and describe the flows and properties of a viscous medium in such systems where it is possible to regulate the parameters, and non-isothermal flow is taken into account.

Experimental study on the shear mechanical behavior of ice-rich debris–rock interface: effects of temperature, stress, and ice content

Glacier collapses can occur due to shear failure at the ice-rich debris–rock interface (IDRI). To examine the shear behavior of IDRI, shear tests were conducted on artificial IDRI specimens with varying ice contents (40%, 65%, and 90%), normal stresses (150, 250, 350, 450, and 550 kPa), and temperatures (−1, −3, −5, −7, and −9 °C). Our findings reveal that temperature has the most significant impact on both peak and residual shear strength, followed by normal stress and ice content. As the temperature increases from −9 to −1 °C, the peak and residual shear stress decreased by 62.5%–78%. Notably, for IDRI with the lowest ice content (40%), the residual shear stress is highly influenced by normal stress. We have developed an improved Mohr–Coulomb strength criterion of IDRI in which the cohesion and internal friction angle are determined by ice content and temperature. Furthermore, we propose a novel constitutive model, based on the disturbed state concept, to describe the shear behavior of IDRI. This model combines a spring model and a hyperbolic model. We also discuss the mechanisms through which ice content and temperature influence the shear deformation modes and shear strength of IDRI.

Coupled creep and nonlinear consolidation of soft soils in disturbed state concept framework

A simplified solution for coupled creep and nonlinear consolidation of soils has been presented based on the disturbed state concept (DSC). The nonlinearity of the problem due to the change of the material properties and thicknesses of the soil layer, and creep was considered in the proposed solution. The state of the soil before primary consolidation was considered as initially relatively intact, and after primary consolidation during the pure creep phase was considered as finally fully adjusted state. The state of the soil during the coupled creep and consolidation process was related to its relatively intact and fully adjusted states using two consolidation and creep state functions that have been derived based on the numerical solution of the problem. Using the consolidation state function, the solutions of Terzaghi’s theory of consolidation in two initial and end of the primary consolidation states were interpolated to achieve the solution of the nonlinear primary consolidation phase. The creep state function was used to implement the effect of the creep deformation during and after the primary consolidation in the settlement calculations. The result of the proposed method was verified by the results of the numerical and approximate methods along with laboratory data in the literature.

An in Vivo Evaluation of the Hepatoprotective Potential of Triphala in CCl4 Induced Hepatic Injured Rodent Model

Liver injury, also known as hepatotoxicity, is a serious health concern since it can irreversibly harm this significant organ's function, leading to life-threatening liver cirrhosis or liver failure. Natural medicinal plants have long been known to play essential roles in up-to-date medication discovery and they are considered as enormous sources of treatment now. Regarding the critical situation of hepatotoxic patients around the globe, among numerous plants with numerous potentials, “Triphala” is a popular and highly effective, strong Ayurvedic and Indian traditional medication with exclusive hepatoprotective and antioxidant properties. Triphala is a Sanskrit word that means three fruits and so, as the name, it is a mixture of an equal amount of the dried fruits of three plants: Emblica officinalis (Amalaki), Terminalia chebula (Haritaki) and Terminalia bellerica (Bibhitaki). In this experiment, carbon tetrachloride (CCl4) was used to induce hepatotoxicity and then the hepatoprotective activity of Triphala was assessed through determining the results of different parameters. Afterward observing the results, it was found that the plant can effectively reverse the disturbed pathological state toward healthy status to a different extent in a dependent manner. Here both medium dose and high dose can significantly reverse (p&lt;0.05) the disturbed pathological state towards a healthy pathological state. Moreover, any safety concern or possibility of side effects was not aroused throughout the investigation. Therefore, Triphala is considered to have a major aptitude towards hepatic protection and can be counted as an alternative to the marketed synthetic drug, silymarin, with more safety and quite equal efficacy. To conclude, more vigorous future study is needed so that this promising plant can be incorporated into the hepatotoxic treatment arena.

Investigation about the correlation between the severity of metabolic-associated fatty liver disease and adherence to the Mediterranean diet

Metabolic-associated fatty liver disease (MAFLD) is defined by fatty liver combined with a disturbed metabolic state. Mediterranean diet (MedDiet) contains anti-inflammatory, anti-oxidative, and anti-fibrotic components and is seemingly beneficial in the management of MAFLD. We aimed to evaluate the correlation between adherence to MedDiet and the severity of MAFLD. Totally 101 adult patients diagnosed with MAFLD were enrolled in this cross-sectional study. Persian version of Mediterranean Diet Adherence Screener (MEDAS), demographics, clinical, laboratory, and FibroScan findings were collected. Correlation and regression analyses were performed. The mean of participants' age was 49.37±12.14 (51.48% male subjects). Six patients (5 diabetic and 1 pre-diabetic) had advanced fibrosis. Overall, 48.5% had good adherence to MedDiet [the least MEDAS-1 (15.8%) and the highest MEDAS-13 (99%)]. The adherence score was significantly higher in married, female, non-smoker, and diabetic subjects, and patients with hypertension. Adherence to MedDiet had insignificant correlations with hepatic fibrosis (P=0.888), steatosis (P=0.208), waist-to-height ratio (P=0.853), and FIB-4 score (P=0.919). Vitamin D level had just significant inverse associations with steatosis score (r=-0.21, P=0.037) and no significant association was found with fibrosis score (r=-0.036, P=0.717) and MedDiet adherence (r=0.055, P=0.581). According to the multiple regression analyses, less fruit intake, lower platelet count and DM had significant positive correlations with MAFLD severity (P<0.001). Adherence to Mediterranean diet, particularly a higher fruit intake, is associated with a lower severity of MAFLD. Dietary modification based on taste, economic state, and culture should be deliberated in different geographic areas along with nutritional education.

Ущерб окружающей среде в интерпретации российских судов

The article discusses the legal problems of compensation for environmental damage on the basis of judicial acts of the Supreme Court and the Constitutional Court of the Russian Federation, as well as the practice of arbitrazh courts. Trends such as the priority of monetary compensation for damage over recovery in kind and the lack of correlation between the amount of compensation and the costs of recultivation have been noted. Assessment of the damage using calculating methods, as well as the way of spending the amounts recovered, in the author’s opinion, deprives monetary redress of its compensatory nature. As a result, the civil law remedy performs an improper fiscal function and provides only general prevention, but not the restoration of the disturbed state of the environment. The author proposes to change approaches to environmental damage redress, taking into account the rules on “colouring” of environmental payments that have already entered into force.

Quantifying the behavioural consequences of shark ecotourism

Shark populations globally are facing catastrophic declines. Ecotourism has been posited as a potential solution to many of the issues facing shark conservation, yet increasingly studies suggest that such activity may negatively influence aspects of shark ecology and so further pressure declining populations. Here we combine UAV videography with deep learning algorithms, multivariate statistics and hidden Markov models (HMM) to quantitatively investigate the behavioural consequences of ecotourism in the whale shark (Rhincodon typus). We find that ecotourism increases the probability of sharks being in a disturbed behavioural state, likely increasing energetic expenditure and potentially leading to downstream ecological effects. These results are only recovered when fitting models that account for individual variation in behavioural responses and past behavioural history. Our results demonstrate that behavioural responses to ecotourism are context dependent, as the initial behavioural state is important in determining responses to human activity. We argue that models incorporating individuality and context-dependence should, wherever possible, be incorporated into future studies investigating the ecological impacts of shark ecotourism, which are only likely to increase in importance given the expansion of the industry and the dire conservation status of many shark species.

On the ductile damage progression in surface-damaged metallic strands: Towards a damage tolerance analysis

This paper reports a novel and straightforward numerical approach to perform a damage tolerance analysis for metallic strands. This methodology relies on the ductile damage evolution laws experienced by metallic wires and strands under tensile monotonic load. Regarding the wires, this new approach integrates both micromechanics–based and continuum damage mechanics-based approaches. Tensile capacity tests of high strength steel and aluminium alloy wires are simulated using 3-D nonlinear finite element models along with the Gurson-Tvegaard-Needleman constitutive plasticity-damage model (micromechanics–based approach) whose parameters are calibrated iteratively using the disturbed state concept. Numerical simulations reproduce the different phases of the ductile damage process which are then related to an isotropic damage index (continuum damage mechanics-based approach). Results show that the wires develop nonlinear ductile damage evolution laws well captured by the Bonorás model with critical damages ranging from 0.12 to 0.25. The existing gap between wires and strand damage evolutions is then filled by using proper kinematic assumptions for both intact and damaged strands along with a homogenization procedure. The latter have a prescribed number of surface wires, symmetrically and asymmetrically distributed, fully cut to simulate service damage. For validation purposes, strands with 1 × 7 construction typology are analyzed whose diameters range between [9.5–14.3] mm. One approach to assess strands structural integrity and safety conditions is to analyze the stability of damage states as the degradation process occurs. Using this metric for the 1 × 7 strands, reveals that two surface wires cut is the maximum acceptable surface damage which meets the criterion established in different international standards for this strand construction typology. Otherwise, the damage state progresses to either an unstable or inflection state that accelerates the reduction of the capacity of a damaged strand to withstand more damage.

Study of Constitutive Models of Reconstituted Clay with High Initial Water Content

The compression and shear behavior of reconstituted clay are closely related to the initial water content of the reconstituted soil. It is difficult to obtain the compression and shear test data of clay with a high initial water content. This study aims to propose a model to predict the compression deformation and strength characteristics of reconstituted clay prepared with any initial water content using less data. Based on the concept of the disturbed state, this paper establishes a mathematical model that can simulate the compression and triaxial shear characteristics of reconstituted clay with different initial water contents. This model uses three compression curves of reconstituted clay with different initial water contents to calibrate the model parameters, and can predict the compression deformation characteristics of reconstituted clay prepared with any initial water content. The model can simulate the consolidated undrained shear behavior of clay reconstituted with different initial water contents. Comparing the measured data shows that the model is in good agreement with the measured compression curve and the triaxial stress–strain curve. The error of the predicted pore ratio and test pore ratio before yield is within 5%, and the error of the predicted pore ratio and test pore ratio after yield is within 10%. The stress–strain relationship of clay hardening with different water contents can be captured. The model can provide a preliminary prediction for the mechanical properties of clay with a high initial water content.

Специализированная топографическая карта природоохранного назначения: концепция и система содержания (на примере болотных массивов)

The type of specialized topographical map for environmental protection, developed on the example of wetlands’ image, is substantiated. Such areas are protected by a number of international organizations and conventions. The requirements for them from a number of related areas of the economy, scientific research, for arrangement of rational environmental management, using specialized maps and protection of natural resources are determined. The concept of the map is formulated, in accordance with which the sections of its content are developed; they characterize the natural, disturbed state, and environmental protection of wetlands. The program of geographical characteristics is presented as an addition to the original map. Samples of images of bog complexes are proposed, showing the physiognomic varieties of swamps in various latitudinal zones. The general system and structure of the map content, conventional signs, samples of bog complexes are illustrated

Study on Soil Parameter Evolution during Ultra-Large Caisson Sinking Based on Artificial Neural Network Back Analysis

The determination of soil parameters in geotechnical engineering and their variations during the construction process have long been a focal point for engineering designers. While the artificial neural network (ANN) has been employed for back analysis of soil parameters, its application to caisson sinking processes remains limited. This study focuses on the Nanjing Longtan Yangtze River Bridge project, specifically the south anchoring of an ultra-large rectangular caisson. A comprehensive analysis of the sinking process was conducted using 400 finite element method (FEM) models to obtain the structural stress and earth pressure at key locations. Multiple combinations of soil parameters were considered, resulting in a diverse set of simulation results. These results were then utilized as training samples to develop a back-propagating artificial neural network (BP ANN), which utilized the structural stress and earth pressure as input sets and the soil parameters as output sets. The BP ANN was individually trained for each stage of the sinking process. Subsequently, the trained ANN was employed to predict the soil parameters under different working conditions based on actual monitoring data from engineering projects. The obtained soil parameter variations were further analyzed, leading to the following conclusions: (1) The soil parameters estimated by the ANN exhibited strong agreement with the original values from the geological survey report, validating their reliability; (2) The surrounding soil during the caisson sinking exhibited three distinct states: a stable state prior to the arrival of the cutting edges, a strengthened state upon the arrival of the cutting edges, and a disturbed state after the passage of the cutting edges; (3) In the stable state, the soil parameters closely resembled the original values, whereas in the strengthened state, the soil strength and stiffness significantly increased, while the Poisson’s ratio decreased. In the disturbed state, the soil strength and stiffness were slightly lower than the original values. This study represents a valuable exploration of back analysis for caisson engineering. The findings provide important insights for similar engineering design and construction projects.