Compression Parameters Research Articles

Treelike process tensor contraction for automated compression of environments

The algorithm “automated compression of environments” (ACE) [M. Cygorek , ] provides a versatile way of simulating an extremely broad class of open quantum systems. This is achieved by encapsulating the influence of the environment, which is determined by the interaction Hamiltonian(s) and initial states, into compact process tensor matrix product operator (PT-MPO) representations. The generality of the ACE method comes at high numerical cost. Here, we demonstrate that orders-of-magnitude improvement of ACE is possible by changing the order of PT-MPO contraction from a sequential to a treelike scheme. The problem of combining two partial PT-MPOs with large inner bonds is solved by a preselection approach. The drawbacks of the preselection approach are that the MPO compression is suboptimal and that it is more prone to error accumulation than sequential combination and compression. We therefore also identify strategies to mitigate these disadvantages by fine-tuning compression parameters. This results in a scheme that is similar in compression efficiency and accuracy to the original ACE algorithm, yet is significantly faster. Our numerical experiments reach similar conclusions for bosonic and fermionic test cases, suggesting that our findings are characteristic of the combination of PT-MPOs more generally. Published by the American Physical Society 2024

Isotropization by shock waves generation in anisotropic hydrodynamics

Anisotropic hydrodynamics (aHydro) has proven successful in modeling the evolution of quark-gluon matter created in heavy-ion collisions. The hydrodynamic description of quark-gluon plasma has also been widely used to study sound phenomena, such as shock waves. It has recently been shown that initial fluctuations in energy density and supersonic partons can generate fairly strong shock waves. However, significant anisotropic properties of the system due to the rapid longitudinal expansion of matter have not been taken into account in such studies. Moreover, the process of isotropization and its characteristic time-scales were not considered along with the question of the shock waves formation. Previous studies on shock discontinuous solutions in anisotropic hydrodynamics assumed constant anisotropy, leading to flow refraction towards the anisotropy axis and flow acceleration, characteristics of rarefaction waves, indicating limitations in this approach. This paper investigates discontinuous solutions for normal shock waves without flow refraction, introducing two compression parameters for longitudinal and transverse pressures. The resulting analytical solutions, as well as numerical computations, provide an isotropization mechanism of the system.

Formulation and Evaluation of Mucoadhesive Buccal Tablets of Carvedilol

The aim of the study was to formulate and evaluate the carvedilol buccal tablets using HPMC K4M and xanthan gum as polymer. Buccal tablets of carvedilol were prepared by direct compression technique by using polymer in combination at different concentration. Drug excipient compatibility study indicates that there is no interaction between the excipient and the drug. Total seven batches were prepared and subjected to evaluation parameters. Pre-compression parameters for all batches showed excellent flow propertied of powder bled. Prepared buccal tablets were evaluated for various post compression parameters like hardness, thickness, weight variation, drug content, and friability, % swelling index, muco-adhesive strength and in vitro drug release. The harness of all batches was optimum showed good mechanical strength; thickness of tablets was uniform in all formulations the weight variation test of all the formulation was found to be within the limits of pharmacopoeial standard. % swelling index for all the batch formulation was optimum and seen to increase with increase in polymer concentration. Mucoadhesive strength was also showed acceptable results for all batch formulations which satisfy the need of mucoadhesive tablets. The in vitro dissolution profile of all the formulation showed sustained release of drug, for extended periods of time. The optimized formulation of F4 prepared with was consider as the optimized formulation with respect to drug content, % swelling index, Mucoadhesive strength and in vitro drug release pattern for 8 hrs. Formulation F4 showed highest 98.32±1.55 % drug release at the end of 8 hrs. Optimized formulation F4 was found to be stable during the stability studies for 3 month indicating good stability of the formulation. Keywords: carvedilol, Mucoadhesive strength, Optimized formulation, buccal tablets.

Analysis of stress-strain curve of POM fiber reinforced concrete

ABSTRACT As a new type of synthetic fiber, polyoxymethylene (POM) fiber has the advantages of high tensile strength, good dispersibility, and high bonding strength with cement interface. It has broad application prospects. However, there is limited research on POM fiber reinforced concrete. In order to provide scientific basis for promoting the application of POM fiber, this paper adopts a combination of indoor experiments and numerical simulations to obtain the axial stress-strain complete curves of POM fiber reinforced concrete with different volume dosages and studies the uniaxial compressive properties of POM fiber reinforced concrete. Finally, the constitutive equation parameters of POM fiber reinforced concrete were fitted using the Guo Zhenhai model, and the optimal fiber content was determined. The results indicate that at a POM fiber content of 1.5 kg/m3, the load-displacement curve exhibits optimal shape with the highest residual strength. With increasing fiber content, compressive stress-strain curve parameters initially increase and then decrease, peaking at 1.5 kg/m3, optimizing the mechanical properties of concrete. POM fiber has minimal impact on initial elastic modulus. Thus, optimal mechanical property enhancement is achieved with 1.5 kg/m3 POM fiber content.

Can We Differentiate Between Organic and Functional Bladder Outlet Obstruction in Males With Parkinson's Disease?

To determine the type of bladder outlet obstruction (BOO) in patients with Parkinson's disease (PD). A case-control study was carried out in 46 patients divided into two groups. Group 1 formed by 23 PD patients with BOO (a URA parameter ≥ 29 cm H2O). Group 2 formed by 23 patients with benign prostatic hyperplasia (BPH) and compressive obstruction (an opening pressure > 35 cm H2O) and URA parameter ≥ 29 cm H2O). Both groups underwent a pressure-flow study to calculate Dynamic Urethral Resistance Relationship (DURR) patterns. Based on previous research, we describe two types of DURR pattern. Pattern A typical of dynamic or functional obstruction and pattern B typical of static or organic obstruction. We found that PD patients had a significantly higher frequency of pattern A (70%) than BPH patients (4%). Other significant differences between groups were age (greater in PD group), bladder compliance (greater in PD group), maximum flow rate [Qmax (greater in BPH group)], maximum detrusor pressure [Pmax (greater in BPH group)], detrusor pressure at maximum flow rate [PQmax (greater in BPH group)], opening detrusor pressure (greater in BPH group), and the bladder contractility parameters BCI and Wmax (greater in BPH group). There were no significant differences in perineal voiding electromyography (EMG) activity between groups nor relationship between voiding EMG activity and the type of DURR pattern. Our results are consistent with the usefulness of the DURR pattern to differentiate between functional and organic BOO in PD patients. Most PD patients have functional obstruction although a minority has organic obstruction consistent with BPH.

Determination of the Hydraulic Conductivity Behavior of Seaweed Added Zeolite-Bentonite Mixtures in the Presence of Temperature with Empirical Relationships

The temperature factor is of great importance in areas that directly affect the environment and engineering parameters of liners, such as solid waste storage areas. It is known that the temperature value increases as a result of the degradation of waste in these areas, and temperature changes affect the engineering properties of the soils. Properties vary depending on the soil type, and additives that can be used to improve the engineering properties of soils come to the fore. One of the most important criteria is that the additive to be used is sustainable and environmentally friendly. Zostera marina, with its terminological name, or dried seaweed an aquatic plant and is a sustainable, low-cost material used in thermal insulation. In this study, dried seaweed additive was added to zeolite-bentonite mixtures and compression parameters were determined under room temperature and 40°C. Hydraulic conductivity values of seaweed-added mixtures were determined with the help of volumetric compression coefficient (mv) and consolidation coefficient (cv) parameters and empirical relationships obtained as a result of consolidation tests. Its potential to be used as a buffer material in the presence of temperature in solid waste storage areas evaluated. The tests results showed that the seaweed additive decreased the hydraulic conductivity values of zeolite-bentonite mixtures at room temperature and under 40°C.

Analysis of the efficacy of non-surgical treatment mainly focus on voice therapy and it's influencing factors in patients with unilateral vocal fold paralysis

Objective:Retrospective analysis of the efficacy and it's influencing factors of non-surgical treatment mainly focus on voice therapy for patients with unilateral vocal fold paralysis. Methods:The retrospective study includes 57 patients who were diagnosed with unilateral vocal fold paralysis and presented with hoarseness as their main complaint at the Department of Voice Medicine, Zhongshan Hospital of Xiamen University from August, 2021 to August, 2023. Judging the efficacy of non-surgical treatment mainly focus on voice therapy through changes in acoustic, aerodynamic, and laryngoscopic parameters; Analyze the relationship between patients' age, gender, duration of disease, cause of nerve injury, type of nerve injury, side of nerve injury and efficacy of non-surgical treatment. Results:After non-surgical treatment mainly focused on voice therapy, there were statistically significant differences（P<0.01） in the changes of vocal fold bow, glottal gap, glottal compression, loudness, Jitter, Shimmer, IC, and NC parameters. There is a statistically significant correlation between the duration of the disease and changes in glottal gap, Shimmer, and IC（P<0.05）, the side of nerve injury can affect changes of glottal gap and NC（P<0.05）. Conclusion:Non-surgical treatment mainly focused on voice therapy has a good efficacy on patients with unilateral vocal fold paralysis. The duration of the disease and the side of nerve injury may affect the efficacy.

Strong evidence for universality in homogeneous compressible turbulence

Quantifying the degree of universality in compressible turbulence is challenging due to the existence of different modes and their complex interactions. For a restricted family of flows, Donzis and John [Phys. Rev. Fluids 5, 084609 (2020)] showed that universal behavior is indeed observed in compressible turbulence if the ratio of dilatational to solenoidal root mean square (rms) velocities (δ=u′d/u′s) is incorporated as a scaling parameter along with the traditional turbulent Mach number (Mt=u′/〈c〉, where u′ is the rms velocity and 〈c〉 is the mean speed of sound). In this paper, we argue for the generality of those results by analyzing a wide range of compressible turbulent flows spanning a variety of flow configurations and setups to assess the degree of universal behavior. These include, among others, reacting flows, flows with solenoidal, thermal, and dilatational forcing, and flows with mean shear and bulk viscosity. We also performed new direct numerical simulations, which include turbulence in situations where vibrational modes of constitutive molecules are not in thermal equilibrium. Collectively, we offer the largest comparison across studies in the literature to date. We find that despite the wide range of forcing conditions and physical processes, universality holds across all these turbulent flows to a very satisfactory degree when both δ and Mt are considered as intrinsic compressibility parameters. The statistics investigated here—single-point statistics up to order four—are chosen such that they represent different ranges across the spectrum of dynamically relevant turbulence scales. We discuss the applicability of the purposed universal behavior for other key statistics in these turbulent flows, including two-point statistics and inhomogeneity effects, and the perspective it opens for modeling them.

Formulation and evaluation of novel orodispersible tablet by drug-drug solid dispersion of metoprolol tartrate and hydrochlorothiazide

This study investigates the effect of a novel drug-drug solid dispersion approach on the dissolution of hydrochlorothiazide in a fixed-dose combination with metoprolol tartrate. Solid dispersions of hydrochlorothiazide and metoprolol tartrate (12.5 mg: 25 mg) were prepared using the solvent evaporation technique. These dispersions were characterized by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR). The prepared solid dispersions, along with selected excipients, were compressed into orodispersible tablets and evaluated for precompression and post compression parameters. The solubility of hydrochlorothiazide was observed to increase with the concentration of metoprolol tartrate, as demonstrated by phase solubility studies and comparative solubility studies. Stability studies on the tablets indicated no significant changes in disintegration time, dissolution profile, or overall stability. The findings of this study suggest that the novel drug-drug solid dispersion approach is promising for enhancing the dissolution of poorly soluble drugs, when combined with soluble drugs in fixed-dose combinations.

Subgrain Size Modeling and Substructure Evolution in an AA1050 Aluminum Alloy during High-Temperature Compression.

For materials with high stacking fault energy (SFE), such as aluminum alloys, dynamic recovery (DRV) and dynamic recrystallization (DRX) are essential softening mechanisms during plastic deformation, which lead to the continuous generation and refinement of newborn subgrains (2° ˂ misorientation angle ˂ 15°). The present work investigates the influence of compression parameters on the evolution of the substructures for a 1050 aluminum alloy at elevated temperatures. The alloy microstructure was investigated under deformation temperatures ranging from 300 °C to 500 °C and strain rates from 0.01 to 0.1 s-1, respectively. A well-defined substructure and subsequent subgrain refinement provided indication of the evolution laws of the substructure under high-temperature compression. Corresponding experimental data on the average subgrain size under various compression conditions were obtained. Two different independent average subgrain size evolution models (empirical and substructure-based) were used and applied with several internal state variables. The substructure model employed physical variables to simulate subgrain refinement and thermal coarsening during deformation, incorporating a corresponding dislocation density evolution model. The correlation coefficient (R) and root mean square error (RMSE) of the substructure-based model were calculated to be 0.98 and 5.7%, respectively. These models can provide good estimates of the average subgrain size, with both predictions and experiments reproducing the expected subgrain size evolution using physically meaningful variables during continuous deformation.

The Noise Reduction Algorithm May Not Compensate for the Degradation in Output Signal-to-Noise Ratio Caused by Wide Dynamic Range Compression.

Most modern hearing aids (HAs) employ wide dynamic range compression (WDRC) and noise reduction (NR) algorithms. It is known that the nonlinear effects of WDRC and NR cause changes to the output signal-to-noise ratio (SNR) of an HA. However, the relative contributions of WDRC and NR to the nonlinear effects are not fully understood. The current study investigated (a) whether WDRC or NR dominates the nonlinear effects measured at the output of a digital HA and (b) whether the electroacoustic effectiveness of NR depends on WDRC parameters while input SNR and background noise are systematically varied. Test stimuli were Connected Speech Test sentences in multitalker babble noise (2- or 20-talker), presented at input SNRs ranging from -10 to +10 dB. The HA was programmed using multiband WDRC set according to the National Acoustic Laboratories for Nonlinear HA fitting formula 2 prescriptive fits for four standard audiograms and two compression speeds. The NR algorithm of the HA was switched on or off in separate conditions. Nonlinear electroacoustic effects from the WDRC and NR algorithms were assessed by measuring the output SNR of the HA using a phase-inversion technique. To investigate whether there are other factors that may be important besides the output SNR, the Hearing Aid Speech Intelligibility Index and the Hearing Aid Speech Quality Index were applied to the recordings to generate inferences on aided speech intelligibility and perceived speech quality. Results showed that WDRC dominated the net nonlinear effect at low-input SNRs, and the net nonlinear effect of WDRC and NR was reduced at high-input SNRs. Results also showed that the effectiveness of NR depended on compression parameters. The effectiveness of NR was partially explained by the trend of Hearing Aid Speech Intelligibility Index and Hearing Aid Speech Quality Index scores, potentially indicating that the Hearing Aid Speech Intelligibility Index and Hearing Aid Speech Quality Index scores may capture factors that cannot be captured by the output SNR metric. Results suggest that the individual signal-processing stages in an HA should not be considered as independent. Electroacoustic evaluation of WDRC and NR algorithms in isolation is not sufficient to capture the combined nonlinear effect of the two algorithms. https://doi.org/10.23641/asha.25962541.

Formulation and evaluation of extended-release floating tablets of labetalol hydrochloride 200 mg

The aim of present work is to formulate and evaluate extended-release floating tablets of Labetalol HCL to improve the bioavailability, Patient compliance and solubility on oral floating drug of Labetalol HCL. Labetalol HCL is mainly used in the treatment of hypertension, which is BCS Class Ⅰ drug i.e. Highly soluble and highly permeable. The tablets were prepared by wet granulation method by using different concentrations of HPMC polymer. The tablets were evaluated for Preformulation characteristics, Pre compression parameters and post compression parameters. In-vitro dissolution studies were performed for all prepared formulations by using dissolution test apparatus employing a paddle stirrer at 50 rpm and 37 ± 0.5°C, 0.1N HCL buffer was used as dissolution medium. Samples of 5ml each were withdrawn at different time intervals. Each sample withdrawn was replaced with an equal amount of fresh dissolution medium. Samples were diluted and assayed at 302 nm using Agilent UV Visible double beam spectrophotometer. The increased drug release is due to the presence of low concentration of HPMC K4 m. The drug release kinetics was calculated for all the formulations, among all the formulations F8 was taken as optimized formulation whose percentage drug release was found to be 96%. It indicates the release follows zero order and Hixon kinetics. Hence formulation F8 was Considered as the optimized batch and stability studies were conducted at 40oc±2oc/75±5%RH, Storage condition for 3 months and no change was observed.

Investigating micelle formation in systems with benzethonium chloride and n-lauroyl sarcosine sodium salt: The impact of thermal effects and ethyl lactate concentration using volumetric, statistical, acoustic, and molecular dynamic methods

Surface active agents (SAAs) are versatile molecules that possess the ability to serve as multifunctional ingredients in a wide range of consumer products across various industrial sectors. These molecules can act as wetting and dispersion agents, emulsifiers, foaming and anti-foaming agents, lubricants, and more. The objective of this study was to evaluate the effect of temperature, and ethyl lactate concentration on micelle formation in systems containing benzethonium chloride (BC) and N-lauroyl sarcosine sodium salt (NLSS). The experimental measurements were conducted at three equidistant temperatures i.e., 298.15 K to 318.15 K and pressure, P=0.1 MPa. Several volumetric as well as compressibility parameters including apparent molar properties (Vϕ,Kϕ,S), partial molar properties (Vϕ°,Kϕ,S°), transport properties (ΔtrVϕ°,ΔtrKϕ,S°), hydration number, etc. have been evaluated. A Bayesian two-factor design with uninformative priors was used to analyze the values of Vϕ°,and Kϕ,S°. It was possible to determine that the temperature factors, and the ethyl lactate (EL) addition significantly influence the results for Vϕ° while for Kϕ,S°it is not appreciable at 5 and 10 % in EL concentration when BC and NLSS systems is compared. The simulations of the micellization process show the impact of temperature, particularly in the presence of ethyl lactate, is evident in the structural and dynamic changes observed in the micelles. Specifically, as the temperature rises from 298.15 K to 318.15 K, the self-assembly process becomes more spontaneous and accelerated, leading to larger and more spherical micelles. These alterations in micelle size, shape, and orientation enhance their capacity to effectively solubilize hydrophobic substances. The computational simulations demonstrated that BC molecules exhibit spontaneous aggregation at the interface of polar-nonpolar systems, resulting in the formation of a monolayer. In this monolayer, the heads of the molecules are oriented towards the polar phase, while the hydrophobic tails are in the nonpolar phase. Similarly, the NLSS system exhibits a continuous and gradual process of self-organization over a period of 120 ns, where NLSS molecules naturally come together to create a single layer arrangement at the zigzag-shaped boundary.

Evaluation on different volume of fluid methods in unstructured solver under the optimized condition

We compared the accuracy of volume of fluid (VOF) methods in unstructured solvers using the following five different methods: 1 - the algebraically compressive VOF method, 2 – simple coupled VOF method with Level Set (S-CLSVOF) method, 3 - interface-compressing VOF method incorporated with Laplacian filter (VOFL), 4 - isoAdvector method, and 5 - isoAdvector method incorporated with Laplacian filter (isoAdvectorL) by incorporating them into OpenFOAM®, an open-source software. To evaluate these methods under proper conditions, we compared the calculation accuracy using the optimized parameters, which are explored by Bayesian optimization. The test cases for advection accuracy of volume fraction and for imbalance of surface tension force in static multiphase fluid fields were considered. In this study, we found that the compression parameters and maximum Courant number should be adjusted to obtain high accuracy simulation according to the simulation condition in VOF and S-CLSVOF method. In VOFL and isoAdvectorL methods, the spurious current can be extremely reduced, which means that these methods are suitable for slow flow with higher Laplace number conditions.

Radiation pressure-driven Rayleigh–Taylor instability in compressible strongly magnetized ultra-relativistic degenerate plasmas

The radiation pressure and strong magnetic fields are prominent in the structures of Rayleigh–Taylor (R–T) instability in the interior of white dwarfs. This paper investigates the radiation pressure-driven R–T instability in a compressible and magnetized ultra-relativistic degenerate strongly coupled plasma. The equation of state has been derived for such systems incorporating ultra-relativistic degenerate electrons with their radiation pressure and ion gas compressibility. The dispersion relation of the density gradients driven R–T instability is analyzed using the generalized hydrodynamic fluid model in the strongly coupled and weakly coupled limits. It is observed that the R–T instability criterion has been modified significantly due to radiation pressure, ion gas compressibility and degeneracy parameters. In the kinetic limit, the instability region is shorter than the hydrodynamic limit due to the dominance of plasma frequency over the viscoelastic relaxation frequency. The outcomes are explored in analyzing the development of R–T instability in the strongly magnetized carbon–oxygen white dwarfs. The radiation pressure, electron temperature and ion density strongly suppress the growth rate of the R–T instability in the interior of white dwarfs. The strong magnetic fields introduce asymmetry to the system by destabilizing the R–T unstable modes. The present results are also useful for understanding the R–T instability in the star formation and dense plasmas in inertial confinement fusion in some limiting cases.

Formulation, Optimization, and Evaluation of Ezetimibe for Chronotherapeutic Drug Delivery using Compression-Coating Technology

Objectives: The purpose of the present study was to Formulation, optimization and evaluation of drug for chronotherapeutic drug delivery using compression coating technology for hypercholesterolemia. Material and Methods: The drug delivery system was designed to deliver the drug at a time when it could be needed for the most in the early morning (4 to 6 a.m.) for patients in case of hypercholesterolemia. The pulsatile concept was applied to the dosage form by having a lag phase followed by an immediate release. The prepared system consisted of two parts: a core tablet containing the active ingredient and fracture outer shell with delay-release polymer having diffusion characteristics. Solid dispersion was carried out by screening of betacyclodextrin, Polyvinyl pyrrolidone (PVP K30), and HPMC using three different drug complex ratios 1:1, 1:2, and 1:3 by a solvent evaporation method through spray dryer. The immediate-release core tablet (IRCT) was prepared by using a superdisintegrant with active ingredients. Screening of IRCT was carried out by pre and post compression parameters, disintegration time and an in-vitro dissolution study. The pulsatile release tablet (PRT) of optimized IRCT was made by Glyceryl Behenate and Dibasic Calcium Phosphate. Optimization of polymer concentration of PRT was carried out by pre and post-compression parameters, pulsatile lag time, and an in-vitro dissolution study. A 32 factorial design was employed to optimize the PRT. The design consisted of two dependent variables R1, and R2 independent variables X1 and X2. The two independent formulation variables selected for the study including Concentration of coating polymer and Concentration of lubricant. The dependent variables are Lag Time and Thickness. Results: XRD, DSC and FTIR spectra showed that solid dispersion was formed by the drug and PVP K30 complex. IRCT batch RR1 containing 22mg croscarmellose sodium to achieve good 30sec disintegration time and 98.34% drug release at the end of 20 minutes of Ezetimibe respectively. PRT formulation DR6 showed good pre and post-compression parameters with a satisfactory drug release of 98.34% for Ezetimibe respectively with a lag time of 6 hours. The 32 factorial design was used for the optimization of PRT parameters. A total of 9 experiments were performed for two factors at three levels each. The optimized batch showed 98.27% DR for Ezetimibe in 6.2 hrs (within 20 min after lag time) with pulsatile lag time up to 6.0 hrs and thickness of 5.10 kp. Conclusion: It was concluded that tablet within the tablet, pulsatile drug delivery of Ezetimibe (BCS class-II drugs) was successfully formulated with the advantage of enhanced solubility, and pulsatile release behavior and had an added benefit of suitable for chronopharmacotherapy of diseases that show circadian rhythms in their pathophysiology.

Detection and Evaluation for High-Quality CPR Based on Motion Capture Devices: A Preliminary Test.

High-quality cardiopulmonary resuscitation (CPR) is important for successful revival. This test aimed to accurately and effectively assess parameters in CPR operations, particularly focusing on the non-quantified arm posture, to assist instructors in guiding students to enhance the quality of their performance. We used motion capture system (Mars series, Nokov, China) to collect compression data from four trained students about five rounds of CPR, recording dynamic data of each marker in three-dimensional space following time. Using the processed data, we calculated compression depth, frequency, and arm angles. Their performance still needed improvement, and there were variations in data within individuals. This suggests that when instructors conduct assessments, they should focus on not only the overall performance but also each compression. This experiment provides a new perspective for quantifying compression parameters, and future efforts should continue to optimize and incorporate new parameters for assessment.

Thermal effects on the strain rate-dependent behavior of highly compacted GMZ01 bentonite

Investigation of thermal effects on the strain rate-dependent properties of compacted bentonite is crucial for the long-term safety assessment of deep geological repository for disposal of high-level radioactive waste. In the present work, cylindrical GMZ01 bentonite specimens were compacted with suction-controlled by the vapor equilibrium technique. Then, a series of temperature- and suction-controlled stepwise constant rate strain (CRS) tests was performed and the rate-dependent compressibility behavior of the highly compacted GMZ01 bentonite was investigated. The plastic compressibility parameter λ, the elastic compressibility parameter κ, the yield stress p0, as well as the viscous parameter α were determined. Results indicate that λ, κ and α decrease and p0 increases as suction increases. Upon heating, parameters λ, α and p0 decrease. It is also found that p0 increases linearly with increasing CRS in a double-logarithm coordinate. Based on the experimental results, a viscosity parameter α(s, T) was fitted to capture the effects of suction s and temperature T on the relationship between yield stress and strain rate. Then, an elastic-thermo-viscoplastic model for unsaturated soils was developed to describe the thermal effects on the rate-dependent behavior of highly compacted GMZ01 bentonite. Validation showed that the calculated results agreed well to the measured ones.

DEVELOPMENT OF AEROSPACE IMAGES PRELIMINARY PROCESSING METHOD FOR SUBSEQUENT RECOGNITION AND IDENTIFICATION OF VARIOUS OBJECTS

Nowadays, the application of hyperspectral images is vital for every section of the humanity life such as agrotechnical research for the field condition state and water security. This article presents a new lossless data compression algorithm focused on the processing of hyperspectral aerospace images. The algorithm takes into account inter-band correlation and difference transformations to effectively reduce the range of initial values. correlation allows you to find the best reference channel that defines the sequence of operations in the algorithm, which contributes to a significant increase in the compression ratio while maintaining high data quality. The practical implementation of the algorithm lies in the process of the transfer the lower size file with high efficiency for unmanned aerial vehicle and satellites to save more computational resources. This method demonstrates high computational efficiency and can be applied to various tasks that require efficient storage and transmission of hyperspectral images. The importance of processing hyperspectral data and the problems associated with their volume and complexity of analysis were described. Current approaches to data compression are considered and their limitations are identified, which justifies the need to develop new methods. The relevance and necessity of effective compression algorithms for aerospace applications is emphasized. An analysis of existing methods and algorithms for compressing hyperspectral data was carried out. Particular attention is paid to approaches that use cross-channel correlation and difference transformations. The effectiveness of current methods is evaluated and their shortcomings are identified, which serves as a justification for the development of a new algorithm. A developed lossless data compression algorithm based on the use of inter-band correlation and difference transformations was described. The stages of forming groups of channels and the selection of optimal compression parameters are considered in detail. The method of determining the reference channel, which sets the sequence of operations in the algorithm, which provides more efficient data compression, is especially noted. The advantages and possible limitations of the new approach, as well as its potential for practical use, are discussed. It was noted that the developed method successfully solves the problems associated with the volume of hyperspectral data, providing a high compression ratio without quality loss. The prospects for further development of the algorithm and its application in various fields of science and technology are discussed.

Efficient machine learning model for settlement prediction of large diameter helical pile in c—Φ soil

Machine learning is frequently used in various geotechnical applications nowadays. This study presents a statistics and machine learning model for settlement prediction of helical piles that relates compressive service load and soil parameters as a group with the pile parameters. Machine learning algorithms such as Decision Trees, Random Forests, AdaBoost, and Artificial Neural Networks (ANN) were used to develop the predictive models. The models were validated using cross-validation techniques and tested on an independent dataset to assess their accuracy and generalizability. Numerical investigation is used here to supplement the field data by simulating various soil conditions and pile geometries that have not been tested in the field. This study compiled numerical results of 3600 models. As the models are well-calibrated and validated, the data from these models can be reasonably assumed to simulate the ground situation. At the end of this study, a comparative analysis of statistic learning and machine learning (ML) was done using the field axial load tests database and numerical investigation on helical piles. It is observed that ML models like Decision Trees and Random Forests provided the better model with R-squared values of 0.92 and 0.96, respectively, for large diameters. The authors believe this study will permit engineers and state agencies to understand this prediction model's efficacy better, resulting in a more resilient approach to designing large-diameter helical piles for the compressive load.