Search Results (18)

This study incorporates a nonlinear seepage relationship into Biot’s consolidation theory and simulates the consolidation of a single vertical drain under vacuum preloading using the finite element method. The model, simplified via the equal-strain assumption, is validated against theoretical predictions. Under the axisymmetric Biot’s framework, consolidation behavior is analyzed in detail. The results show that in the early stages of consolidation, excess pore water pressure in the vicinity of the prefabricated vertical drain (PVD) does not fully dissipate and may even increase, indicating the occurrence of the Mandel–Cryer effect. As the consolidation process advances, the consolidation front gradually extends outward, and the void ratio near the PVD decreases rapidly, leading to the formation of a clogging zone. In contrast, the reduction in the void ratio in the non-clogging region is relatively slow. The progressive development of the clogging zone significantly impedes the overall consolidation rate. Furthermore, this study explores the influence of key parameters—including the compression index, permeability coefficient, well diameter ratio, smear effect, and well resistance—on the formation of the clogging zone and the Mandel–Cryer effect. Full article

In the present scenario, coherent states of a quantum harmonic oscillator are generalized with positive Fox H auxiliary functions. The novel generalized coherent states provide canonical coherent states and Mittag-Leffler or Wright generalized coherent states, as particular cases, and resolve the identity operator, over the Fock space, with a weight function that is the product of a Fox H function and a Wright generalized hypergeometric function. The novel generalized coherent states, or the corresponding truncated generalized coherent states, are characterized by anomalous statistics for large values of the number of excitations: the corresponding decay laws exhibit, for determined values of the involved parameters, various behaviors that depart from exponential and inverse-power-law decays, or their product. The analysis of the Mandel Q factor shows that, for small values of the label, the statistics of the number of excitations becomes super-Poissonian, or sub-Poissonian, by simply choosing sufficiently large values of one of the involved parameters. The time evolution of a generalized coherent state interacting with a thermal reservoir and the purity are analyzed. Full article

A novel and general approach to the practical ROMP polymerization of cinchona alkaloid derivatives providing novel hybrid materials having quinine attached on a poly(norbornene-5,6-dicarboxyimide) matrix is presented. The concept involves an easy modification of quinine (in general, any cinchona alkaloid) toward clickable 9-azide that reacts with N-propargyl-cis-5-norbornene-exo-2,3-dicarboxylic imide in Cu(I)-catalyzed Huisgen cycloaddition (click chemistry). The resulting monomers undergo a controllable ROMP reaction that leads to novel polymers of a desired length and solubility. This sequence allows for the facile preparation of a regularly decorated polymeric material having one quinine moiety per single mer of the polymer chain inaccessible using typical immobilization methods. A poly(norbornene-5,6-dicarboxyimide) type of polymeric matrix was selected due to the high reactivity of the exo-norbornene motif in Ru(II)-catalyzed ROMP and its chemical and thermal stability as well as convenient, scalable access from inexpensive cis-5-norbornene-exo-2,3-dicarboxylic anhydride (‘one-pot’ Diels–Alder reaction of dicyclopentadiene and maleic anhydride). An appropriate combination of a Grubbs catalyst, Ru(II) (G1, G2), and ROMP conditions allowed for the efficient synthesis of well-defined soluble polymers with mass parameters in the range Mn = 2.24 × 10⁴ – 2.26 × 10⁴ g/mol and Mw = 2.90 × 10⁴–3.05 × 10⁴ g/mol with good polydispersity, Đ_M = 1.32–1.35, and excellent thermal stability (up to 309°C T_d10). Spectroscopic studies (NMR and electronic circular dichroism (ECD)) of these products revealed a linear structure with the slight advantage of a trans-configuration of an olefinic double bond. The resulting short-chain polymer discriminates mandelic acid enantiomers with a preference for the (R)-stereoisomer in spectrofluorimetric assays. This concept seems to be rather general with respect to other molecules dedicated to incorporation into the poly(norbornene-5,6-dicarboxyimide) chain. Full article

Background/Objectives: Mandelic acid as a chemical peel has been used in cosmetology for years and is being gradually exchanged for lactobionic acid. However, in the cosmetology literature, there is no information on the effectiveness of the aforementioned peels in terms of hydration and elasticity for women’s facial skin depending on their age. The effects of lactobionic and mandelic acid on the skin of women aged 30–40 and 50–60 years are assessed in terms of their moisturizing and elasticizing effects. Methods: The participants of this study were 180 women aged 30–40 and 50–60 years. The selection of the group was random. Contraindications to the examination were excluded in all participants. The level of hydration was assessed using Tewameter and the level of elasticity using a cutometric probe (Courage-Khazaka Multi Test Skin Center MC 1000, Kőln, Germany). The participants also used a moisturizer. Moreover, a series of five exfoliating treatments using 40% mandelic acid or 40% lactobionic acid were performed in 120 of the participants. After 14 days since the last treatment, the assessment of their facial skin’s hydration and elasticity was performed yet again. Results: In the case of women aged 30–40 years, the level of hydration and elasticity increased after using lactobionic and mandelic acid, as well as a moisturizer. In the group of older women aged 50–60 years, the level of elasticity increased after using both acids and moisturizer, but the hydration parameter increased only after the usage of lactobionic acid and moisturizer. Conclusions: In terms of age, lactobionic acid will be more suitable for people aged 50–60, while for women aged 30–40, lactobionic or mandelic acid can be used. Full article

Background: Skin is the largest organ in the human body. Some skin parameters like moisturization and sebum secretion play a vital role in the skin’s functioning. This study aims to assess the effects of topical chemical peels of different concentrations and pH, applied manually and with ultrasounds, on the level of hydration, erythema, pigmentation, and sebum secretion of the skin. Methods: The study involved 90 Caucasian females, aged 25 to 59, with dry, dehydrated skin, skin with erythema or pigmentation disorders. The patients were randomly divided into three equal groups. The subjects from Group A were applied 10% mandelic acid with 25% gluconolactone of pH 4.0 manually. In Group B, 40% mandelic acid of pH 1.5 was used. The subjects from Group C were applied 10% mandelic acid with 25% gluconolactone of pH 4.0 via sonophoresis. A series of six procedures in weekly intervals was performed. Skin functional parameters (skin hydration, erythema, and melanin indicators) were taken before the first procedure, after 14 days, 28 days, and 42 days. Results: In Group A, the level of moisturization of the skin increased statistically significantly (p = 0.0100) however, the sebum secretion and erythema did not change. In Group B, the level of moisturization improved statistically significantly, as well as erythema (p = 0.0001). Sebum secretion in the final measurement increased. The moisturization and erythema in Group C did not differ statistically significantly. On the other hand, the sebum secretion increased significantly. Conclusions: Very superficial chemical peels significantly alter selected skin parameters. AHAs and PHAs applied using the ultrasound method do not affect the level of hydration, erythema, or pigmentation of the skin. Full article

In the present article, we build the excitedcoherent states associated with deformed $su(1,1)$ algebra (DSUA), called photon-added deformed Perelomov coherent states (PA-DPCSs). The constructed coherent states are obtained by using an alterationof the Holstein–Primakoff realization (HPR) for DSUA. A general method to resolve of the problem of the unitary operator was developed for these kinds of quantum states. The Mandel parameter is considered to examine the statistical properties of PA-DPCSs. Furthermore, we offer a physical method to generate the PA-DPCSs in the framework of interaction among fields and atoms. Finally, we introduce the concept of entangled states for PA-DPCSs and examine the entanglement properties for entangled PA-DPCSs. Full article

A model of consolidation for a single-drain well under vacuum preloading, based on Biot’s axisymmetric theory and considering the “real strain” hypothesis, was established using the finite element method. Degenerating the consolidation equation of real strain yielded the Barron’s classical free strain and equal strain equations. The free strain and equal strain finite element models were derived by imposing boundary and constraint conditions on the real strain FEM model. The validation of the simulation process confirmed that the numerical model achieved consistent outcomes, with the theoretical values postulating its effectiveness. The real strain model revealed the Mandel–Cryer effect of soil near the vertical drain during the initial vacuum preloading consolidation process, causing the effective stress to increase more than the effective stress generated by the vacuum pressure and leading to a greater reduction in the void ratio. This phenomenon is one of the reasons for clogging during the vacuum preloading process. However, the free strain and equal strain models cannot produce this effect because they cannot describe the coupling between soil deformation and fluid flow. The parameter analysis of the real strain model showed that as Poisson’s ratio for soil decreased, the consolidation rate of soil also decreased, while the Mandel–Cryer effect of soil increased. Full article

This study reports on the development and validation of a HPTLC-derived database to identify phenolic compounds in honey. Two database sets are developed to contain the profiles of 107 standard compounds. Rich data in the form of Rf values, colour hues (H°) at 254 nm and 366 nm, at 366 nm after derivatising with natural product PEG reagent, and at 366 nm and white light after derivatising with vanillin–sulfuric acid reagent, λ max and λ min values in their fluorescence and λ max values in their UV-Vis spectra as well as λ max values in their fluorescence and UV-Vis spectra after derivatisation are used as filtering parameters to identify potential matches in a honey sample. A spectral overlay system is also developed to confirm these matches. The adopted filtering approach is used to validate the database application using positive and negative controls and also by comparing matches with those identified via HPLC-DAD. Manuka honey is used as the test honey and leptosperine, mandelic acid, kojic acid, lepteridine, gallic acid, epigallocatechin gallate, 2,3,4-trihydroxybenzoic acid, o-anisic acid and methyl syringate are identified in the honey using the HPTLC-derived database. Full article

Statistical and artificial neural network models are applied to forecast the quantum scheme of a three-level atomic system (3LAS) and field, initially following a photon added negative binomial distribution (PANBD). The Mandel parameter is used to detect the photon statistics of a radiation field. Explicit forms of the PANBD are given. The prediction of the Mandel parameter, atomic probability of the 3LAS in the upper state, and von Neumann entropy are obtained using time series and artificial neural network methods. The influence of probability success photons and the number of added photons to the NBD are examined. The total density matrix is used to compute and analyze the time evolution of the initial photonic negative binomial probability distribution that governs the 3LAS–field photon entanglement behavior. It is shown that the statistical quantities are strongly affected by probability success photons and the number of added photons to the NBD. Also, the prediction of quantum entropy is achieved by the time series and neural network. Full article

The scale dependence of the effective anti-plane shear modulus response in microstructures with statistical ergodicity and spatial wide-sense stationarity is investigated. In particular, Cauchy and Dagum autocorrelation functions which can decouple the fractal and the Hurst effects are used to describe the random shear modulus fields. The resulting stochastic boundary value problems (BVPs) are set up in line with the Hill–Mandel condition of elastostatics for different sizes of statistical volume elements (SVEs). These BVPs are solved using a physics-based cellular automaton (CA) method that is applicable for anti-plane elasticity to study the scaling of SVEs towards a representative volume element (RVE). This progression from SVE to RVE is described through a scaling function, which is best approximated by the same form as the Cauchy and Dagum autocorrelation functions. The scaling function is obtained by fitting the scaling data from simulations conducted over a large number of random field realizations. The numerical simulation results show that the scaling function is strongly dependent on the fractal dimension D, the Hurst parameter H, and the mesoscale $\delta$, and is weakly dependent on the autocorrelation function. Specifically, it is found that a larger D and a smaller H results in a higher rate of convergence towards an RVE with respect to $\delta$. Full article

The present research paper considers a three-level atom (3LA) that interacts with a field mode primarily in a photon-added coherent state of Morse potential (PACSMP). The dynamics of entanglement, the photon statistics, and the quantum Fisher information are investigated. The statistics of field photons are discussed by evaluating the Mandel parameter. We check the influence of the energy dissipation and intensity-dependent function. Finally, we detect the relationship between the entanglement, the field’s nonclassical characteristics, and atomic quantum Fisher information throughout the evolution of time. The findings illustrate the important role of the number of added photons and CSMP in affecting the entanglement’s time evolution, the quantum Fisher information, and the Mandel parameter. Based on the obtained results, we reached significant physical phenomena, including the sudden birth and death of the nonlocal correlation between atom-Morse potential field structures. Full article

Light curve analysis usually involves extracting manually designed features associated with physical parameters and visual inspection. The large amount of data collected nowadays in astronomy by different surveys represents a major challenge of characterizing these signals. Therefore, finding good informative representation for them is a key non-trivial task. Some studies have tried unsupervised machine learning approaches to generate this representation without much effectiveness. In this article, we show that variational auto-encoders can learn these representations by taking the difference between successive timestamps as an additional input. We present two versions of such auto-encoders: Variational Recurrent Auto-Encoder plus time (VRAE${}_t$) and re-Scaling Variational Recurrent Auto Encoder plus time (S-VRAE${}_t$). The objective is to achieve the most likely low-dimensional representation of the time series that matched latent variables and, in order to reconstruct it, should compactly contain the pattern information. In addition, the S-VRAE${}_t$ embeds the re-scaling preprocessing of the time series into the model in order to use the Flux standard deviation in the learning of the light curves structure. To assess our approach, we used the largest transit light curve dataset obtained during the 4 years of the Kepler mission and compared to similar techniques in signal processing and light curves. The results show that the proposed methods obtain improvements in terms of the quality of the deep representation of phase-folded transit light curves with respect to their deterministic counterparts. Specifically, they present a good balance between the reconstruction task and the smoothness of the curve, validated with the root mean squared error, mean absolute error, and auto-correlation metrics. Furthermore, there was a good disentanglement in the representation, as validated by the Pearson correlation and mutual information metrics. Finally, a useful representation to distinguish categories was validated with the $F_1$ score in the task of classifying exoplanets. Moreover, the S-VRAE${}_t$ model increases all the advantages of VRAE${}_t$, achieving a classification performance quite close to its maximum model capacity and generating light curves that are visually comparable to a Mandel–Agol fit. Thus, the proposed methods present a new way of analyzing and characterizing light curves. Full article

In this work, we introduce the standard Tavis-Cummings model to describe two-qubit system interacting with a single-mode field associated to power-law (PL) potentials. We explore the effect of the time-dependent interaction and the Kerr-like medium. We solve the Schrödinger equation to obtain the density operator that allows us to investigate the dynamical behaviour of some quantumness measures, such as von Neumann entropy, negativity and Mandel’s parameter. We provide how these entanglement measures depend on the system parameters, which paves the way towards better control of entanglement generation in two-qubit systems. We find that the enhancement and preservation of the atoms-field entanglement and atom-atom entanglement can be achieved by a proper choice of the initial parameters of the field in the absence and presence of the time-dependent interaction and Kerr medium. We examine the photons distribution of the field and determine the situations for which the field exhibits super-poissonian, poissonian or sub-poissonian distribution. Full article

In this work, we examine a nonlinear version of the Tavis–Cummings model for two two-level atoms interacting with a single-mode field within a cavity in the context of power-law potentials. We consider the effect of the particle position that depends on the velocity and acceleration, and the coupling parameter is supposed to be time-dependent. We examine the effect of velocity and acceleration on the dynamical behavior of some quantumness measures, namely as von Neumann entropy, concurrence and Mandel parameter. We have found that the entanglement of subsystem states and the photon statistics are largely dependent on the choice of the qubit motion and power-law exponent. The obtained results present potential applications for quantum information and optics with optimal conditions. Full article

A 1:1 salt of carvedilol (CVD), an anti-hypertensive drug, with DL-mandelic acid (DL-MA) was crystallized from ethanol and the structure was characterized by X-ray single-crystal diffraction, revealing salt formation by transfer of an acidic proton from the COOH group of MA to the aliphatic (acyclic) secondary amino NH group of CVD. The crystal structure is triclinic, with a P-1 space group and unit cell parameters a = 9.8416(5) Å, b = 11.4689(5) Å, c = 14.0746(7) Å, α = 108.595(8), β = 95.182(7), γ = 107.323(8), V = 1406.95(15) ų, and Z = 2. The asymmetric unit contained one protonated CVD and one MA anion, linked via an N⁺–H∙∙∙O¯ strong hydrogen bond and a ratio of 1:1. As previously reported, the thermal, spectroscopic, and powder X-ray diffraction properties of the salt of CVD with DL-MA (CVD_DL-MA) differed from CVD alone. The intrinsic dissolution rate of CVD_DL-MA was about 10.7 times faster than CVD alone in a pH 6.8 buffer. Full article