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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]

The initial cracks and new cracks are primary factors on the mechanical properties of building materials. To quantitatively reveal the compaction effect on initial cracks and the "pseudo closure" phenomenon on new cracks, triaxial compression tests (TC) and cyclic triaxial complete loading and unloading tests (CTCLU) with real-time ultrasonic velocity monitoring were performed on siltstone under different confining pressure. The variation of volume compression strain and damage stress with confining pressure is significant, indicating the triaxial compression mechanical behavior of rocks shows strong compaction and damage effects. Under triaxial compression, the "pseudo closure" phenomenon of new cracks in the post-peak stage is the reason that ultrasound velocity does not decrease significantly. However, the real-time ultrasonic velocity law under CTCLU tests can truly reflect the compaction and damage behavior of materials. The test results indicate that the open and closure of initial cracks, new cracks, and pores occur at different loading and unloading stages of confining pressure and deviatoric stress, which determine the variation of real-time ultrasonic velocity under CTCLU tests. The ultrasonic velocity increment models for confining pressure and deviatoric stress loading and the velocity models after complete stress unloaded were established. In these models, initial crack plastic compaction limit, pore elastic compaction limit, and new crack damage limit were defined, to illustrate the changing characteristics of the micro structure on materials. The Raymer porosity inversion model was improved based on real-time ultrasonic velocity model, the calculation results show that the porosity of the initial cracks accounts for 30–40 % of the total porosity. Finally, based on the real-time porosity inversion results the effective compressibility coefficient of initial cracks and the cumulative crack density of new cracks were calculated, and the comparison coefficient and damage variable of rocks were established, respectively. • The cyclic triaxial complete loading and unloading tests with real-time velocity monitoring were performed on siltstone. • The relationship between real-time velocity and the open and closure of initial cracks, new cracks, and pores was revealed. • The improved real-time porosity inversion model was established. • The comparison coefficient of initial cracks and the damage variable of new cracks were proposed. [ABSTRACT FROM AUTHOR]

Precise control and accurate endpoint determination in the thawing of frozen beef are vital for maintaining its quality and safety in the food industry. Traditional thawing methods, which are time-controlled, often lead to inconsistencies like under or over-thawing, adversely affecting texture, color, nutritional value, and increasing the risk of microbial contamination. This study introduces a novel, non-destructive approach using ultrasonic signals and ultrasonic velocity for the quantification of beef thawing. It involves analyzing thermal images of beef cross-sections to assess thawing levels and gathering ultrasonic data at various thawing stages. Machine learning algorithms, including KNN, ANN, Extra-Trees, and LightGBM, were employed to develop prediction models that accurately identify the thawing endpoint. The models exhibit high accuracy, with R^2 values exceeding 0.9, some reaching as high as 0.986. This method represents a significant advancement in non-destructive quality control, enhancing safety and quality management in the beef processing sector. • Predicting the degree of beef thawing using ultrasound technology. • Proposed a method to quantify the degree of beef thawing. • The accuracy of the predictive model can reach up to 0.986. • The model can accurately determine the thawing endpoint. [ABSTRACT FROM AUTHOR]

In this present exploration, chitosan doped with different lanthanide oxides such as CeO 2 , Nd 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , Dy 2 O 3 and Ho 2 O 3 has been prepared and its optical and thermodynamical properties were studied as a function of the ion size of the lanthanide element and its atomic masses. From the refractive index measurement, the space-filling factor and polarizability have been obtained. The propagation of ultrasonic waves like ultrasonic velocity and its derived quantities such as relaxation strength (r s), adiabatic bulk modulus (K s), acoustic impedance (Z) and adiabatic compressibility (β) have been obtained for different Chitosan-Lanthanide oxides (Ch-LnO). FTIR studies confirm the formation of different Ch-LnO. The variation of all the said properties with ion size is opposite to that of atomic mass due to lanthanide contraction. The results are presented and discussed in a detailed manner. • For the first time, the effect of lanthanide contraction on the optical and thermodynamical properties has been investigated. • There is a competition between size and mass on the said properties has been observed. • All the measured optical and thermodynamical properties are varied with ion size which is in contradiction to atomic mass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introduction of defects in BaFe 12 O 19 through 200 MeV Ag16+ ion irradiation. • Significant shift in T C from 732 K to 540 K. • Decrease in M s and T C was observed with the defects. Sol-gel auto combustion method has been used to synthesize M−type barium hexagonal ferrite (BaFe 12 O 19). The defects were created in M−type BaFe 12 O 19 utilizing the 15UD Pelletron tandem accelerator. The synthesized BaFe 12 O 19 was exposed to 200 MeV Ag16+ ions radiation, and the shift in the phase transition of M−type BaFe 12 O 19 were explored through in-situ ultrasonic measurement. The defect-induced sample exhibits reduced magnetization compared to the pristine ferrite, attributed to ion-induced disorder and a decline in superexchange interactions. Further, the defect-induced sample experiences a decrease in coercivity owing to reduced crystallite and grain sizes caused by irradiation. The phase transition temperature shifts from 732 K in the pristine sample to 540 K in the defect-induced sample. [ABSTRACT FROM AUTHOR]

This study investigates the effects of La 2 O 3 on the mechanical, thermal, and physical characteristics and the ability of bismuth germinate glass with different compositions to protect against radiation. The glasses included ZnO, Na 2 O, Bi 2 O 3 , GeO 2 , and different concentrations of La 2 O 3 (between 0 and 20 mol%). The glass density substantially increased from 3428 kg/m³ to 4412 kg/m³ as the concentration of La 2 O 3 increased. This observation underscores the considerable influence of La 2 O 3 on densification, which can be attributed to its higher coordination number and molecular weight. In addition, bridging oxygen atoms reduced the molar volume from 60.2 to 57.8 × 10−6 m3. This decrease suggests the synthesis of oxygen atoms, which increase the glass transition temperature from 536 to 573 K, improving the glass's thermal properties under investigation. As the amount of La 2 O 3 increased, the ultrasonic velocity measurements indicated an increase in longitudinal and shear velocities from 3192 to 3611 m/s and 1884–2185 m/s, respectively. Longitudinal and shear ultrasonic velocity measurements can be utilized to determine the elastic moduli, Poisson's ratio, and Debye temperature. Correlations between these results and theoretical models highlighted the strengthening effect of La 2 O 3 on the glass structure. Another important study area was radiation shielding efficiency, which showed that higher La 2 O 3 content improved photon blocking. The study showed the potential of La 2 O 3 -enriched glasses in applications needing radiation protection by looking at the effective atomic number and neutron shielding. Overall, adding La 2 O 3 strengthens the characteristics of bismuth-germinate glasses, increasing their suitability for certain applications in radiation-exposed areas. • La2O3-doped bismuth-germanate glasses synthesized. • Improved mechanical and shielding properties. • Empirical and theoretical validations were conducted. • Outperforms heavy-weight concrete in shielding. [ABSTRACT FROM AUTHOR]

This study used a sonochemical reactor to synthesize Co 0.50 Ni 0.50 La x Fe 2−x O 4 (0.00⩽x⩽0.2; step 0.05) spinel ferrites. X-ray diffraction spectra and scanning electron microscope (SEM) images were employed to verify and authenticate the physical characteristics, such as crystalline structure and morphology of the Co 0.50 Ni 0.50 La x Fe 2−x O 4 spinel ferrite particles. These structural analyses are targeted to confirm the singular-phase cubic Fd-3 m spinel ferrite nature. It has been noted from the SEM images that every particle resembles a sphere-like morphology. The real dielectric constants and dielectric loss of the prepared Co 0.50 Ni 0.50 La x Fe 2−x O 4 spinel ferrites were measured. The blocking (T B) and Curie (T C) temperatures of the spinel ferrites can also be explored and measured using temperature-dependent susceptibility and ultrasonic non-destructive techniques (NDT), respectively. The difference between the T B and T C is quite small. This observed difference implies that finding the phase transition temperature of spinel ferrites using ultrasonic NDT testing is a more flexible process than any other conventional technique. The room-temperature hysteresis shows that these La3+ doped Co 0.50 Ni 0.50 La x Fe 2−x O 4 ferrite samples might be more suitable for applications. • Influence of La3+ ions in Co 0.50 N i0.50 Fe 2 O 4 nanoferrite were explored. • Decrease in M s and T C was observed with increasing La3+ ions. • Phase transition explored through temperature-dependent susceptibility and ultrasonic measurement. [ABSTRACT FROM AUTHOR]

Ultrasound velocity was measured in hyaluronan solutions of various compositions at different temperatures. The velocity dependence on hyaluronan concentration at constant temperature (25 °C) was linear both in water and in 0.15 M NaCl regardless of hyaluronan molecular weight, confirming diluted-solution behavior. During cyclic heating and cooling, hysteresis on the temperature dependence of ultrasound velocity was observed in the range 30–55 °C in aqueous solutions for all molecular weights. In NaCl solutions, the hysteresis was suppressed and, in contrast to solutions in water where the velocity demonstrated a local maximum with temperature, the velocity decreased with increasing temperature. These findings were attributed to slow and hydration-linked hyaluronan conformation transitions during cooling in water, which were suppressed by the presence of salt, which makes hyaluronan's coiled conformation more compact. [ABSTRACT FROM AUTHOR]

Ultrasonic velocities, u , and densities, ρ , of binary liquid mixtures of dimethyl sulphoxide (DMSO) with ketones such as acetophenone (AP), cyclohexanone (CH), and 3-pentanone (3P), including pure liquids, over the entire composition range have been measured at 308.15 K. Using the experimental data, deviation in ultrasonic velocity, Δ u , deviation in isentropic compressibility, Δ k s , excess molar volume, V m E , excess intermolecular free length, L f E and excess acoustic impedance, ZE , partial molar volumes, V ‾ m , 1 , V ‾ m , 2 , and excess partial molar volumes, V ‾ m , 1 E , V ‾ m , 2 E have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess/deviation values of calculated properties and these properties have been fitted to Redlich–Kister type polynomial equation. The observed positive values of V m E , Δ k s , L f E and negative values of Δ u , ZE for all the binary liquid mixtures studied clearly indicate the presence of the dominance of weak physical interactions between the components of molecules. Further, FTIR spectra support the conclusions drawn from deviation/excess properties. Moreover, theoretical values of ultrasonic velocity in the mixtures have been evaluated using various theories and such values were compared with experimental velocities to verify the applicability of such theories to the systems investigated. [ABSTRACT FROM AUTHOR]

Improvement of elastic and optical properties of rare earth ions doped glasses via the amalgamation of synthetic glass formers with natural mineral modifier became a new strategy to achieve novel glass based optical devices. Inspired by this idea, we prepared some new types of CeO 2 doped boro-tellurite-dolomite (BTD) glasses of composition (35- x)B 2 O 3 –30TeO 2 -20Dp-15Dm- x CeO 2 (where 0 ≤ x ≤ 2.0 mol%, Dm: dolomite marble and Dp: dolomite pebble) by standard melt-quenching method and characterized. The role of changing CeO 2 concentration on the structural, elastic and optical traits of the proposed glasses was examined. Also, direct and indirect band gap energies, Urbach energies and refractive indices of glasses were evaluated using Tauc, absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Amorphous nature of the as-quenched samples was verified from XRD pattern and SEM image showed the homogeneous disordered surface. EDX spectra disclosed the right elemental traces in the prepared glasses. The N 4 ratio calculated from the FTIR spectra revealed that the inclusion of CeO 2 into the BTD network indeed favoured the conversion of BO 3 to BO 4 structural units. Besides, the ultrasonic velocities and elastic moduli were reduced with the increase in CeO 2 contents. Complete absence of any peak in the optical absorption spectra validated the existence of Ce4+ within glasses. Moreover, the absorption coefficient of prepared glasses was significantly enhanced and the absorption edge was red shifted (from 400 nm to 500 nm) with the increase in CeO 2 doping. Proposed glass compositions may be beneficial for future research and development on optical filter in photonic devices. [ABSTRACT FROM AUTHOR]

• Thermal cycling effect of LCO 2 cyclic injection on crack evolution was studied. • The relations among velocity, coal rank and injection cycles were studied. • The velocity ratio method was proposed to study the spatial variation of cracks. • A tridirectional velocity test method was developed to study velocity anisotropy. Enhanced coalbed methane (CBM) recovery by injecting liquid CO 2 (LCO 2) has been a promising research topic for decades. Although the phase-fracturing and blooding effect during injection have been studied, the non-isothermal impact of cryogenic fluids on the coal matrix, especially the effect of thermal cycling generated by the cyclic LCO 2 injection process, has not been studied in detail. This paper reports the development of a high-pressure and low-temperature reaction system, which can simulate the effect of thermal cycling on three different coals of different ranks, and the use of an ultrasonic device to study the P-wave velocity (Vp) in different directions before and after the influencing thermal cycling. The results show that all the cores subjected to different thermal cycling fractured to diverse degrees due to their initial texture and rank, and more cycles and lower rank increased the final fracture results. Influenced by thermal cycling, two endpoints of the Vp confidence interval (confidence level of 95%) of the coals decreased, and the velocity range of confidence interval all increased, the change of which might be attribute to the rank and the companying thermal cycling effect, resulting in the changes of crack structure and discrete degree of the velocity. The velocity anisotropy coefficient (k) value of the coal increased as the cycles increased, indicating that thermal cycling alters the coal structure randomly by means of fatigue accumulation and grain bond deterioration. The Vp z /Vp x and Vp z /Vp y value changes indicated that the internal cracks were not generated uniformly in all directions, and the presence of cracks helped the transfer of heat flux, which caused some thermal stress concentration areas to occur, further facilitating crack propagation at the crack tips. Meanwhile, the ΔVp% scatters of lignite, bituminite and anthracite cores were fitted as exponential, DoseResp and linear curves with cycles, respectively (R2 > 0.94). The mean fractal dimension D of the coals all increased with increasing cycles, and were negatively correlated with coal rank and ΔVp%, and positively correlated with Δk. The results provide some useful theoretical guidance for field application. [ABSTRACT FROM AUTHOR]

Abstract Multiwalled carbon nanotubes (MWCNTs) has been synthesized using chemical vapor deposition (CVD) method. Al – Layered Hydroxide (Al–LH) and MWCNTs nanocomposites; (1- x) Al–LH + (x) MWCNTs, 0.0 ≤ x ≤ 1; have been synthesized using citrate nitrate assisted hydrothermal technique. The crystal structure and the functional groups of the prepared samples were examined using X-ray diffraction (XRD) and Infrared spectroscopy (FTIR) respectively. The layered structure seemed under the high-resolution transmission electron microscopy (HRTEM), and the morphology was observed using field emission scanning electron microscopy (FESEM). Moreover, the synthesized nanocomposites were further characterized using Zeta potential, size analysis and Brunauer– Emmett–Teller (BET) surface area which showed their different characteristics as the MWCNTs content is changed. Thermal gravimetric analysis assured the thermal stability of the nanocomposites over the temperature from room up to 480 °C depending on the MWCNTs content. The obtained results revealed the improvement of all mechanical properties with the increase of MWCNTs content. Graphical abstract FESEM of nanocomposite with 5% MWCNT together with the compositional dependence of the Young and bulk modulus. Image 1 Highlights • Layered hydroxides/MWCNTs nanocomposites were successfully prepared by sonochemical method. • The largest surface area was achieved at 2.5 wt% MWCNTs. • Better thermal stability with increasing MWCNTs concentration were achieved at x = 5 and 7.5 wt%. • Improved young and bulk modulus were remarked at 2.5 wt%. [ABSTRACT FROM AUTHOR]

Abstract Calcium carbonate whisker (CW) can reinforce the flexural strength of cement paste and limit the development of micro-cracks at ambient temperature (25 ± 2 °C), but the effect of CW on mechanical properties of cement paste after exposure to high temperatures is still unknown. Therefore, mechanical properties, i.e. flexural strength, compressive strength and splitting tensile strength were measured using CW reinforced cement specimens before and after they were exposed to high temperatures. In addition, performance of CW reinforced cement paste after exposure to high temperatures was studied by ultrasonic test and mass loss test. At last, microstructural analysis (differential thermogravimetric analysis and scanning electron microscopy) were employed to study the deterioration mechanism of temperature and reinforcement mechanism of CW. These experimental results suggested that CW played a significant role in hindering the development of cracks before 600 °C. When temperatures increased up to 200 °C, the flexural strength decreased. However, the compressive strength and splitting tensile increased. When temperatures varied from 200 °C to 400 °C, the three strengths reacted differently to the elevated temperatures. Subsequently, the residual strength rapidly decreased up to 1000 °C. After that, the three strengths increased slightly. The residual strength, ultrasonic velocity and mass loss were related to the temperatures and CW content and quantitative measurement of these factors was also discussed. [ABSTRACT FROM AUTHOR]

• A new technique was developed for reproducible ultrasonic velocities measurements. • The microstructure of composite YBCO/Ni affects notably its mechanical properties. • Voids growing among YBCO grains influence the values of the ultrasonic velocities. • V S is much more sensitive than V L to connectivity among YBCO grains. • Calculations of ϴ D showed the effective role of Ni on the YBCO lattice vibrations. A series of superconducting composites (100-x) YBa 2 Cu 3 O 7-δ + x Ni metal (x = 0, 1, 2.5, 5, 7.5, 10 and 15 wt.%) was prepared by the solid state reaction method. Density and molar volume were determined using the immersion method. X-Rays-Diffraction (XRD) and Scanning Electron Microscope (SEM) characterizations were terminated for structural and microstructural analysis. The results showed the presence of orthorhombic peaks of YBa 2 Cu 3 O 7-δ (YBCO) in the whole composite samples with different lattice constants and how Ni addition affects the distortions in the orthorhombic unit cell of YBCO. A new technique has been used to measure the ultrasonic wave velocities, longitudinal (V L) and transverse or shear (V S), at 4 MHz ultrasonic frequency at room temperature. The mechanical parameters of the sintered superconductor samples including longitudinal modulus (L), shear modulus (G), Young's modulus (Y), Poisson's ratio (σ) and microhardness (H) were investigated from the view point of the porosity and the connectivity between the formed phases. Besides, the Debye temperature (ϴ D) was also determined as a function of Ni additions. The elastic moduli, H and ϴ D have been improved up to 2.5 wt.% Ni, then a decrease in all data observed with further addition of Ni content. Quantitative analysis has been implemented to obtain more details about the structure of the composite samples, based on orthorhombic phases, the oriented grain size, the porosity and the agglomeration between grains. [ABSTRACT FROM AUTHOR]

Highlights • Septonex properties compared to its structural relatives. • Four hyaluronan-Septonex interaction regions identified in water. • Only two regions found in the presence of NaCl. • Hyaluronan-Septonex aggregates less compressible than Septonex monomers or micelles. Abstract Interactions between hyaluronan and the cationic surfactant Septonex were studied using high resolution ultrasound spectroscopy. Four different interaction regions were identified in aqueous solution in a narrow interval of surfactant concentrations. In contrast, in 0.15 mol/L NaCl solution, essentially only two principal regions were observed. Hyaluronan-Septonex aggregates were generally less compressible than Septonex monomers or micelles and their formation in water was not appreciably affected by hyaluronan molecular weight. In the presence of NaCl, the effect of hyaluronan molecular weight was more profound, which can be ascribed to its conformational sensitivity to ionic strength combined with its role as a surfactant counterion. Hyaluronan-Septonex interactions were closer to interactions with CTAB than with TTAB. Differences in structure or Krafft temperature (solubility) between Septonex and CTAB were thus not significantly reflected in these interactions. The basic characteristics of Septonex surfactant were also determined. [ABSTRACT FROM AUTHOR]

Abstract Shale gas rocks are characterized as clastic sedimentary rocks, with features such as obvious bedding planes, presence of micro-cracks, and high clay and organic content. These rocks are anisotropic and inhomogeneous, exhibiting a nonlinear response under loading. In order to optimize the required energy for hydraulic fracturing operation and production in shale gas reservoirs, and for constitutive and numerical modeling, it is important to characterize these shale gas rocks. In this study, the hysteresis, elastic-plastic, viscoelastic, and strength properties of Marcellus Shale specimens, retrieved from a deep well located in West Virginia, were evaluated through performing a series of creep, cyclic, and triaxial multi-stage failure tests on these specimens. Both elastic moduli and plastic deformations show significant levels of pressure dependency. Moreover, higher creep compliance and lower Young's modulus values were observed for clay-rich specimens. Both Power-Law and Burgers' models were found to capture the creep response of these specimens reasonably well. The dynamic moduli estimated from the ultrasonic velocity measurements at different stress levels were found to be higher than static moduli estimations. In addition, the changes in the internal micro-structure of the specimens resulted from variations in the stress condition, were found to affect the ultrasonic velocity measurements. The strength properties of the calcite/quartz-rich specimen, using multi-stage triaxial failure test, were estimated through both Mohr-Coulomb and Hoek-Brown failure criteria. Highlights • Higher creep in the clay-rich specimen compared to calcite/quartz-rich specimen. • The measured P- and S-wave velocities during cyclic loading followed increase/decrease trend of applied differential stress. • Higher estimated static/dynamic moduli for calcite/quartz-rich specimen compared to clay-rich specimen. • Good agreement between experimental results and both Linearized Mohr-Coulomb and Hoek-Brown failure criteria. [ABSTRACT FROM AUTHOR]

Highlights • CO 2 hydrate distribution and morphology in sandstone was analysed. • CO 2 hydrate occurrence in sandstone is consistent with the free-floating model. • CO 2 -hydrate cluster size distributions and hydrate surface area-volume relationships follow power law relations. Abstract Carbon dioxide geo-sequestration (CGS) into sediments in the form of (gas) hydrates is one proposed method for reducing anthropogenic carbon dioxide emissions to the atmosphere and, thus reducing global warming and climate change. However, there is a serious lack of understanding of how such CO 2 hydrate forms and exists in sediments. We thus imaged CO 2 hydrate distribution in sandstone, and investigated the hydrate morphology and cluster characteristics via x-ray micro-computed tomography in 3D in-situ. A substantial amount of gas hydrate (∼17% saturation) was observed, and the stochastically distributed hydrate clusters followed power-law relations with respect to their size distributions and surface area-volume relationships. The layer-like hydrate configuration is expected to reduce CO 2 mobility in the reservoir, and the smaller than expected hydrate surface-area/volume ratio will reduce methane production and CO 2 storage capacities. These findings will aid large-scale implementation of industrial CGS projects via the hydrate route. [ABSTRACT FROM AUTHOR]

Schematic representation of ionic-hydrophilic and hydrophilic-hydrophilic interactions between streptomycin sulphate and citrate salts in an aqueous medium. [Display omitted] • (B/ V É ¸ 0) values(>3.72) shows that the drug streptomycin sulphate forms hydrated sphere. • Positive value of d B /d T indicates the structure-breaking nature of streptomycin sulphate. • The sign of Δ tr K ϕ , S 0 indicates the presence of ionic-hydrophilic interactions. • The presence of H-bond is confirmed from FTIR spectroscopic study. The effect of electrolyte on antibiotic drug streptomycin sulfate has been investigated at five temperatures (298.15–318.15) K and 0.1 MPa atmospheric pressure. The influence of concentrations and temperatures on the viscometric and ultrasonic properties of K 3 Cit and Na 3 Cit with water has been studied. The experimentally obtained data of ultrasonic speed (u) and viscosity (η) of the solutions have been used to evaluate different parameters at the studied temperatures. A, called the Falkenhagen coefficient, and B, is the Jones-Dole coefficient , transfer viscosity B -Coefficient, Δ tr B , at various temperatures (298.15–318.15) K were assessed by viscosity data. The ultrasonic data and the parameter for instance apparent molar isentropic compressibility, K ϕ , S , limiting apparent molar isentropic compressibility, K ϕ , S 0 , and limiting apparent molar isentropic compressibility of transfer, Δ tr K ϕ , S 0 have been analysed to study the presence of molecular interactions at different temperatures. The spectroscopic data have been used to know the existence of Hydrogen-bonding and other types of solute and solvent interactions in the solution. All these parameters have been taken to observe the different forces of attraction, association, dissociation, and structure-making/breaking properties of the drug streptomycin sulphate in the K 3 Cit + Water and Na 3 Cit + Water solutions at said temperatures. [ABSTRACT FROM AUTHOR]

[Display omitted] • The combined effect of pH and Xylitol on the solvation profile of Ovalbumin is discussed. • The preferential hydration of Ovalbumin is confirmed by ultrasonic and Molecular Dynamics simulations. • The existence of non–covalent interactions is confirmed by theoretical and computational studies. • The presence of dipole–dipole interactions is noticed in both pH extremities but differ in their magnitude. • Oxygen atoms are preferentially oriented on Ovalbumin surface in acidic model whereas hydrogen atoms in alkaline model. Artificial sweetener-protein interactions are playing a major role in enhancing the functional properties of protein-based food and pharmaceutical products. This article discusses the molecular details of ovalbumin (OA) solvation in an aqueous solution of xylitol (XY) in different pH environments. This task can be accomplished by both Ultrasonic and Molecular Simulation studies. In ultrasonic studies, density, ultrasound velocity, viscosity, and surface tension have been measured for OA in various pH of phosphate buffer with and without XY. Further, some of the calculated parameters such as adiabatic compressibility, intermolecular free length, free volume, etc have been worked out. From ultrasonic results, pH dependent preferential hydration of OA was noticed in the presence of XY in an aqueous environment. In Molecular Dynamics Simulation (MDS) studies, water and XY accumulation to OA surface for different pH models were analyzed. The different states of protonation of the OA surface promote two distinct effects on the solvent and cosolvent orientation. [ABSTRACT FROM AUTHOR]

Abstract High clay and organic content, irregular voids, presence of micro-cracks, and obvious bedding planes are among features of shale gas rocks that affect their mechanical response. These sedimentary rocks exhibit substantial degree of anisotropy and inhomogeneity, with non-linear response when subjected to axial loading. The laboratory characterization of these rocks is necessary to design an optimized hydraulic fracturing programme, and for reliable constitutive and numerical modeling of these formations. In this study, a series of triaxial multi-stage elastic and cyclic tests were performed on Marcellus Shale specimens, retrieved from a deep well (~2270 m deep) located in West Virginia, to characterize their elastic-plastic and hysteresis response subjected to loading/unloading cycles. The experimental results indicated a nonlinear response, particularly at low differential stress levels. In addition, the specimens with higher clay content exhibited a softer response with lower estimated static and dynamic moduli at different stress levels compared to those of specimens with higher calcite/quartz content. The ultrasonic P- and S-wave velocity measurements were found to be sensitive to the changes in the micro-structure of the rock caused by variation in stress condition. In general, the estimated Young's modulus during unloading was found to be higher than loading. The plastic deformations were pronounced in the first cycle of loading, followed by a decreasing trend in the subsequent cycles. [ABSTRACT FROM AUTHOR]

The nondestructive assessment of concrete strength in existing structures is a real and complex challenge. Recent research advances have been done, like the idea of conditional coring or the development of a bi-objective approach for assessing concrete variability. It will be shown here how, through the use of synthetic simulations and the analysis of uncertainty propagation in the investigation and assessment process, it is possible to (a) confirm the interest of these research results, (b) develop a consistent approach for an efficient and reliable assessment of concrete strength in existing structures. This work will be based on the definition of prescribed targets in terms of uncertainty of assessment and on the concept of risk, i.e. probability of missing the targets. [ABSTRACT FROM AUTHOR]

The elastic and ultrasonic properties of the hexagonal intermetallic CeCuGe ternary compound have been evaluated along unique axis at room temperature. Higher order elastic constants have been calculated for CeCuGe compound using Lennard–Jones interaction potential model. The ultrasonic velocity, Debye average velocity, thermal relaxation time and acoustic coupling constant are evaluated along unique axis of the crystal and the temperature dependent ultrasonic velocities are evaluated along different angles with unique axis of the crystal. Finally temperature dependent ultrasonic attenuation is evaluated to extract important information about the material. [ABSTRACT FROM AUTHOR]

Density ( d ) and Ultrasonic velocity ( U )have been measured in aqueous paracetamol and paracetamol + aqueous Urea in five different concentrations ranging from 0.01 M to 0.09 M at 0.02 M interval. Densities of these solutions were measured over the temperature range 298.15 K to 313.15 K at 5 K interval. The ultrasonic velocities ( U ) have been measured at 298.15 K only. Experimental density data have been used to estimate various important parameters, such as apparent molar volume ( V ɸ ), limiting apparent molar volume ( V ɸ 0 ), apparent molar expansibility ( E ɸ ) and limiting apparent molar expansibility ( E ɸ 0 ). Further, from the ultrasonic data, different thermo-acoustical parameters, such as isentropic compressibility ( K s ), apparent molar isentropic compressibility ( K s , ɸ ), acoustic impedance ( Z ), molar compressibility ( W ), internal pressure ( π i ), free volume ( V f ), molar sound velocity ( R ), free length ( L f ), relaxation time ( τ ), absorption co-efficient ( α / f 2 ) and solvation number ( S n ) have been calculated and explained in the light of solute-solute and solute-solvent interactions. [ABSTRACT FROM AUTHOR]

In recent years, there is an increasing demand for more sensitive and high magnetoresistive materials in high-speed electronic and magnetic devices. La 1−x Ca x MnO 3 perovskites are chosen to be beneficial for the potential applications in solid oxide fuel cells, magnetic sensors/reading heads and frequency switching devices. La 0.3 Ca 0.7 MnO 3 perovskites were prepared and sintered at four different temperatures such as 1173, 1273, 1373 and 1473 K. X-ray powder diffraction pattern confirms the existence of orthorhombic structure with Pnma space group in the perovskites. Scanning electron microscopy images of the perovskites were used to determine the size of the particles. In situ measurement of ultrasonic longitudinal velocity was carried out over a wide range of temperature. The ultrasonic measurements have shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature is found to increase from 625 to 640 K with the increase of sintering temperature. [ABSTRACT FROM AUTHOR]

The Gadolinium substituted LaCrO 3 isovalent perovskite was investigated in the present study. The samples of La 1-x Gd x CrO 3 ( x = 0, 0.025, 0.05, 0.10, 0.15 and 0.20) were prepared employing solid state reaction method. The X-Ray Diffraction (XRD) patterns confirmed that the prepared samples have orthorhombic structure with pnma space group at room temperature. The crystalline size of the samples is 98, 89, 76, 72, 60 and 55 nm respectively for the composition x = 0, 0.025, 0.05, 0.10, 0.15 and 0.20 and the same is decreasing with an increase in substitution of Gd in the samples. The scanning electron microscope images of the samples have spherical like morphology with a particle size of 150, 131, 129, 120, 116 and 94 nm for the composition x = 0, 0.025, 0.05, 0.10, 0.15 and 0.20 respectively. In-situ ultrasonic measurements were made over a wide range of temperature from 300 to 700 K to determine structural transition. The measured temperature dependent ultrasonic parameters are used to explore the structural phase transition from orthorhombic to rhombohedral phase in the prepared sample at high temperatures. [ABSTRACT FROM AUTHOR]

The present paper deals with the non-destructive evaluation of stressed High Damping Rubber Bearings (HDRB) in civil engineering. Such bearings are commonly made with alternating thin horizontal layers of High Damping Rubber (HDR) bonded to steel laminates. The influence of uniaxial compressive loading on pressure waves' velocity and bulk modulus is investigated for two types of bearings (with and without laminates). In the presence of laminates, bulk modulus increases with the applied compressive loading (e.g. ΔK = 20% at a mean stress σ = 16 MPa). In the absence of laminates, slipping on walls is visually observed in spite of their roughness and is thus confirmed by limitation in the increase of sound velocity. The feasibility of stress measurements using ultrasonic methods in HDRB is proved. [ABSTRACT FROM AUTHOR]

In this investigation zinc oxide (ZnO) nanoparticles were synthesized by precipitation method using Zn(CH 3 COO) 2 as a starting material. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X- ray spectroscopy (EDX). These nanoparticles were dispersed in 10% aqueous solution of propylene glycol in various concentrations with the help of ultrasonicator to obtain nanofluids of different concentrations. Ultrasonic velocity ( u ), density ( ρ ) and viscosity ( η ) of these nanofluids were measured experimentally as a function of temperatures ( T = 303.15 K, 308.15 K and 313.15 K). Using these experimentally measured values various acoustic parameters such as adiabatic compressibility ( β ad ), intermolecular free length ( L f ), relaxation time ( τ ), acoustic impedance ( Z ), free volume ( V f ) and attenuation coefficient ( α/f 2 ) were evaluated with a view to investigate molecular interactions. [ABSTRACT FROM AUTHOR]

• Solvation behavior of artificial sweetener in aqueous choline chloride have been discussed. • Thermodynamic parameters and taste behavior have been explored. • Hydration Numbers have been determined. • Interpretation of structure making and breaking ability of co-solute has been done. Artificial sweeteners also called non-calorific sweeteners are gaining popularity due to their sweet taste and metabolically inert nature. A lot of chemically designed artificial sweeteners are available in food industry. A type of artificial sweeteners is sugar alcohol, which have been used various food items and hence occupying a large place in food sector as well as in pharmaceutical industries. Erythritol, a sugar alcohol has been used in the present study as one of the component of ternary mixture. Other important constituent of the study is choline chloride. Choline is a primary metabolite that provides methyl groups required for the process of metabolism. Choline is key component that is utilized in the synthesis of two vital cell membrane phospholipids: phosphatidylcholine and sphingomyelin. Being a neurotransmitter, it also play an important role in balancing mood, memory and intelligence. To study the solvation behavior and collecting information regarding chemoreception, measurement of volumetric and acoustic properties of erythritol with choline chloride have been reported in this paper. By using the raw data of density and ultrasonic velocity measured by DSA 5000 of sound, different apparent molar properties of an non calorific sweetener (erythritol) have been computed for binary mixtures of different concentrations with water and ternary mixtures with choline chloride at different temperatures. Furthermore, other useful parameters for solvation have also been calculated like limiting apparent molar expansion, E ϕ 0 , specific volume, v ϕ , hydration numbers etc. The obtained results have been discussed for interactional behavior related to structure changes in the studied systems. [ABSTRACT FROM AUTHOR]

A multidisciplinary methodology is presented to assess the mechanical behaviour of a marble statue with complex fracture plans and localized cracks. First, a 3D model is generated by photogrammetry. Its underlying geometrical data provide valuable insight for the physical characterisation and the numerical analysis. Indeed, the ultrasound analysis, which is usually impossible on such a complex shape, is achieved thanks to the accurate measures of distance between transmitter and receiver obtained from the 3D geometrical model. Finally, an innovative use of FEM/DEM analysis is proposed to evaluate the mechanical relevance of a non-destructive basing system. Reflecting the advances of this collective work, the resulting pedestal solution is non-conventional since it is safe, not invasive and totally reversible. A particular attention is paid to use mainly open-source numerical tools from 3D acquisition through mechanical analysis in order to enable the reproducibility of the process. [ABSTRACT FROM AUTHOR]

In the present investigation, the effect of ion size on the thermodynamical properties such as ultrasonic velocity (U), adiabatic compressibility (β), acoustic impedance (Z), adiabatic bulk modulus (K s ), relaxation strength (r s ) have been obtained for the different salts of chitosan viz., formate (3.5 Å ), acetate (4.5 Å ), Succinate (5 Å ) and Adipate (6 Å ). To find the effect of ion size, the effect due to water has been removed by calculating the change in ultrasonic velocity (dU), change in adiabatic compressibility (dβ), in acoustic impedance (dZ), in adiabatic bulk modulus (dK s ), and in relaxation strength (dr s ). Space filling factor and polarizability has been obtained from the refractive index data through Lorentz-Lorentz relation. FTIR studies confirm the formation of different quaternary salts of chitosan and their size (mass) effects which has been verified with Hooke’s law. All the said properties vary both with ion size and concentration of different salts of chitosan. This investigation may throw some light on better usage of chitosan in biomedical applications. The detailed results are presented and discussed. [ABSTRACT FROM AUTHOR]

Solubility of drugs in aqueous media is a real issue for scientists and a lot of work is going on to resolve the issue. The same is the case for ibuprofen, which is a derivative of propionic acid and belongs to the NSAIDs family having low solubility in pure water. Therefore, its solubility has been investigated in the presence of hydrotropic agents like urea, sodium salicylate and nicotinamide at four different temperatures ranging from 298.15 K to 313.15 K at 5 K interval. The values of density ( d ) and sound velocity ( U ) have been measured in aqueous ibuprofen and ibuprofen + aqueous solution of urea, sodium salicylate and nicotinamide separately in five different concentrations. Densities of these solutions were measured at the above said four temperatures. The ultrasonic velocities ( U ) have been measured at 298.15 K only. Experimental density data have been used to estimate various important parameters, such as apparent molar volume( V ɸ ), limiting apparent molar volume V ɸ 0 , apparent molar expansibility ( E ɸ ) and limiting apparent molar expansibility ( E ɸ 0 ) . Further, from the ultrasonic data, different thermo-acoustical parameters, such as isentropic compressibility ( K S ), apparent molar isentropic compressibility ( K s , ɸ ) and acoustic impedance ( Z ), have been evaluated, and discussed in the light of solute-solute and solute-solvent interactions. Solubility parameters were found to be useful for selecting a suitable hydrotropic agent in drug dissolution. [ABSTRACT FROM AUTHOR]

Tectonically deformed coal (TDC) is defined as coal formed by various tectonic stresses. As one of the key concerns in the formation and recovery of coal bed methane (CBM) from the tectonic deformation coal seams, the texture and fractures of TDC present various features in different deformation environments and as a result the physical properties change. Therefore, the identification of TDC is significant and can be obtained from the physical properties. In this study, fourteen representative TDC and two undeformed coal samples from the Suzhou mining area in the east of north China plate were collected to investigate the geophysical recognition parameters of TDC by elastic properties, such as the velocities (P and S-waves), elastic parameters (V p /V s and Poisson's ratio) and velocity anisotropies. The results show that the elastic properties of undeformed coal and TDC samples from different deformation environments exhibit significant difference. Normally, the velocities and elastic parameters of undeformed coal have the highest values, while the velocity anisotropy has the lowest value. In brittle deformation environment, the velocity and elastic parameters decrease while the velocity anisotropy ascends with increased deformation extent. For the TDC samples from shear deformation environment, the velocity anisotropies present the significant high values among the selected TDC samples. In plastic deformation environment, the elastic parameters gradually decrease with the deformation extent ascending, while the velocity anisotropies are relatively high. Among the elastic properties, the V p /V s , Poisson's ratio and velocity anisotropy are sensitive to deformation type and extent of coal samples. Furthermore, the development characteristics of coal structural fractures have a significant impact on the elastic properties of measured coal samples from different deformation environments. In summary, the results may provide reference parameters for future studies in CBM rock physics from the tectonic deformation coal seams. [ABSTRACT FROM AUTHOR]

A series of ternary phosphate glasses in the form of (PbO)x(ZnO)60-x(P 2 O 5 )40 where x = 0–60 mol%, have been successfully prepared by conventional melt-quenching technique. The physical and elastic properties of the glasses have been investigated using pulse echo technique. The longitudinal and shear velocity of the glasses were measured using the MBS8000 ultrasonic data acquisition system at 10 MHz frequency in room temperature. The density, ultrasonic velocity and elastic moduli are found to be composition dependent and the correlation between the elastic moduli with the atomic packing density is discussed in detailed. The shielding parameters, mass attenuation coefficients, half value layers and exposure buildup factor (EBF) values have been computed using WinXCom program with the use of GP fitting method, and variation of shielding parameters are discussed for the effect of PbO addition into the glasses and photon energy. An increase in the density of the glasses results in a change in crosslink density. The sound velocity and elastic properties increased with PbO content and increase in Poisson's ratio trend suggests that the rigidity of the glasses has decreased. Besides, the replacement of ZnO by PbO causes an increase in mass attenuation coefficient, while the half value layer and the exposure buildup factor were decreased and these glasses has been potentially used as shielding material. [ABSTRACT FROM AUTHOR]

The paper describes the application of High-Resolution Ultrasonic Spectroscopy for real-time, non-destructive, precision monitoring of enzymatic hydrolysis of polysaccharides in aqueous solutions, represented by barley 1,3(4)-β-D-glucan. The technique provided time profiles of the concentration of glycosidic bonds hydrolyzed, degree of hydrolysis, average degree of polymerization, and molar mass of hydrolysates produced. The limiting precision of the technique in measurements of the concentration of glycosidic bonds hydrolyzed is at the level of 0.01 mmol kg−1. The Michaelis constant K m for the enzyme employed, endo-1,3(4)-β- d -glucanase from Talaromyces emersonii , calculated from the ultrasonic reaction profiles was 0.061 mol L−1 at 50 °C, in 0.1 mol L−1 NaOAc buffer, pH 5.0 at 50 °C. The Mark-Houwink parameter a of the polysaccharide hydrolysates, obtained from correlation of ultrasonically measured evolution of average molar mass and of viscosity, was 0.63. [Display omitted] • HR-US non-destructively monitors β-glucan molar mass during hydrolysis. • Precision of HR-US measurements of glycosidic bonds hydrolyzed is 0.01 mmol kg−1 • Effect of hydrolysis on ultrasonic velocity is determined by compressibility. • Mark-Houwink parameter, α , of β-glucan hydrolysates is 0.63 [ABSTRACT FROM AUTHOR]

During heating of ovalbumin, the major protein of chicken egg white, amyloid-like aggregates are formed. Process conditions, redox agents and the presence of other proteins affect the specific nature of amyloid formation. In this work, amyloid formation of ovalbumin was investigated using a combination of fluorescence measurements, dynamic light scattering and ultrasound measurements. Fluorescence measurements indicated more pronounced conformational changes upon heating (60–80 °C) in the presence of the reducing agent dithiothreitol, whereas the oxidizing agent potassium iodate had little to no effect. Also particle size after heating was larger when disulfide bonds were reduced. Large particles were formed when ovalbumin was heated in the presence of other egg white proteins and also the pattern of change in ultrasound properties of ovalbumin-egg white mixtures was affected by these other egg white proteins. Changes in ultrasonic velocity and attenuation showed that amyloid formation in ovalbumin depends on the molecule's disulfide bond, and it is postulated that the amyloid-like aggregates formed as a result of thermal treatment are composed of a compact core surrounded by loosely packed protein segments. [ABSTRACT FROM AUTHOR]

Ultrasonic velocities, densities and viscosities have been measured in two binary liquid mixtures of quinoline with alkanols (ethanol and 1-propanol) over the entire molefraction range of quinoline at temperatures T = (303.15, 308.15, 313.15 and 318.15)K. From the experimentally measured data, excess thermo-acoustical parameters such as excess intermolecular freelength (L f E ), excess adiabatic compressibility (β E ), excess free volume (V f E ), excess internal pressure (π E ),excess enthalpy (H E ) and excess Gibb's free energy of activation function (G ⁎E ) have been calculated. These results are fitted to the Redlich-Kister polynomial equation and have been explained on the basis of intermolecular interactions present between the component molecules of the liquid mixtures. [ABSTRACT FROM AUTHOR]

In this paper a methodology for the quality control of the curing process in precast concrete plants is presented by non-destructive testing techniques. This methodology consists on a remote monitoring system and a method to estimate the strength gain of the precast elements during the curing process. The remote monitoring system is based on Wireless Sensor Networks (WSN) provided with temperature, humidity and ultrasonic sensors. The compressive strength is estimated using two different procedures, one based on temperature and the other one on ultrasonic velocity measurements. Comparing the compressive strength estimations obtained using temperature and ultrasonic velocity measurements, the concrete quality during early ages of curing can be controlled, and arising problems can immediately be detected. This methodology was tested in three different precast concrete plants in Spain. [ABSTRACT FROM AUTHOR]

Ultrasonic velocity ( U ), density ( ρ ) and viscosity ( η ) measurements have been carried out in three ternary mixtures of glucose, fructose and galactose with amylase in aqueous medium at 298.15 K. The experimental data have been used to calculate the further thermo acoustical parameters such as adiabatic compressibility ( β ), free length ( L f ), free volume ( V f ), internal pressure ( π i ), acoustical impedance ( Z ), relative association ( Ra ), molar sound velocity ( R ) and molar compressibility ( W ) with Gibb's energy (Δ G E ) of activation. The excess values are evaluated and discussed in the light of molecular interactions existing in the mixture. The above said derived and excess parameters are computed with excel environment. And the experimental and calculated derived and excess parameters are used to study the nature of molecular interaction and other behavior between the mixture components. The chances for change in structure, splitting and catalytic activity for three proportions are discussed for the above said bio molecules. [ABSTRACT FROM AUTHOR]

The present experimental investigation was carried out in order to explore the possible molecular inter-ionic interactions of saccharides namely, d -glucose, sucrose and maltose in aqueous solutions of α-amino acid such as l -arginine and l -lysine monohydrochloride at 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15 K. Experimental values of ultrasonic speed (U) and density (ρ) were carried out on the liquid ternary mixtures of l -arginine + saccharides + water. These measured experimental data have been used to calculate parameters such as isentropic compressibility (K s ), change in isentropic compressibility (∆ K s ), relative change in isentropic compressibility (∆ K r ), relative association (RA), specific acoustic impedance (Z), and apparent molal isentropic compressibility (ϕ ks ). The negative values of apparent molal isentropic compressibility indicates that the water molecules in the bulk solution are more compressible than the water around ionic charges of l -arginine and l -lysine monohydrochloride respectively. The present work revealed the possible molecular associations such as solute-solute and solute-solvent etc. and eventually discussed about the behaviour of solute (saccharides) in the given system. In these systems, strong solute-solvent interactions are observed and found to increase with an increase in temperature. [ABSTRACT FROM AUTHOR]

Ultrasonic investigations have been carried on the solutions of silicone rubber (SR) - nano hydroxyl apatite (n-HA) systems at an operating frequency of 2 MHz. Ultrasonic velocity (v), density (ρ) and refractive index (n) have been examined for the solutions of SR (average molecular weight = 1, 28,000 g/mol) and those of SR- n HA in toluene and xylene. The ‘v’ value has been found to be increased with increase in concentration of SR in the solvents. For a given SR content, the ‘v’ value has been observed to be higher for toluene than xylene. The results have been interpreted in terms of closer solubility parameter values. With the addition of n-HA, the ‘v’ increases for a given SR content and solvent. This has been accounted in terms of better molecular interaction being developed in the medium with the incorporation of n-HA. Various acoustical parameters such as adiabatic compressibility, acoustic impedance, Rao's constant, van der Waals constant and space filling factor have been computed to complement the observations. The observations on SR/n-HA systems is proposed for utilization in the encapsulation of drugs, for controlled release, under ultrasound stimulation. [ABSTRACT FROM AUTHOR]

Densities, ultrasonic velocities and viscosities have been measured in binary liquid mixtures of quinoline with arenes(benzene and toluene)at temperatures T = (303.15, 308.15, 313.15 and 318.15)K over the entire molefraction range of quinoline. From the experimentally measured data, excess thermo-acoustical parameters such as excess intermolecular freelength (L f E ), excess adiabatic compressibility (β E ), excess free volume (V f E ), excess internal pressure (π E ),excess enthalpy (H E ) and excess Gibb's free energy of activation function (G* E ) have been calculated. These results are fitted to the Redlich–Kister polynomial equation. These results have been explained on the basis of intermolecular interactions present between the component molecules of the liquid mixtures. [ABSTRACT FROM AUTHOR]

Ultrasonic refers to study of sound waves, which are higher frequency than the human audible range. It is widely used in many applications viz. medical, underwater, food and oil technology etc. The Intermolecular interaction plays an important role in the development of molecular science. Substituted benzothiazole plays a vital role in the biological field such as anti-allergic, anti- inflammatory analgesic, and fungicidal activity. Therefore, present work is carried out to study the substituted benzothiazole with different concentrations at 298.15K with 2 MHz. The acoustical parameters; adiabatic compressibility, linear free length, acoustic impedance, relative association etc evaluated with experimental values of density and ultrasonic velocity. It is observed that the density and ultrasonic velocity increases with increase the concentration of solute while adiabatic compressibility and linear free length deceases. The intermolecular interactions have been observed at molar concentrations, which suggest the solute-solvent interaction. [ABSTRACT FROM AUTHOR]

Uniaxial Compressive Strength (UCS) and Modulus of elasticity ( E ) of carbonate rocks are very critical properties in petroleum, mining and civil industries. UCS is the measure of the strength of the rock and E depicts the stiffness, together they control the deformational behavior. But the heterogeneity introduced as a result of fractures, dissolution and dependency on pH and temperature makes them a difficult material to study. Complex diagenesis and resulting pore system makes the job even more daunting. So, an attempt is made to predict these properties using simple index parameters such as Porosity, Density, P-wave velocity, Poisson’s ratio and Point load index. Multiple Linear Regression Analysis (MVRA) and Artificial Neural Networking (ANN) have been used for predicting the two properties and the accuracy is tested by root mean square error. The results show that ANN has a better predictive efficiency than MVRA and they can be applied for predicting UCS and Young’s modulus of carbonate rocks with reasonable confidence. [ABSTRACT FROM AUTHOR]

The present study investigated the accuracy of micro-scale finite element modeling for simulating broadband ultrasound propagation in water-saturated trabecular bone-mimicking phantoms. To this end, five commercially manufactured aluminum foam samples as trabecular bone-mimicking phantoms were utilized for ultrasonic immersion through-transmission experiments. Based on micro-computed tomography images of the same physical samples, three-dimensional high-resolution computational samples were generated to be implemented in the micro-scale finite element models. The finite element models employed the standard Galerkin finite element method (FEM) in time domain to simulate the ultrasonic experiments. The numerical simulations did not include energy dissipative mechanisms of ultrasonic attenuation; however, they expectedly simulated reflection, refraction, scattering, and wave mode conversion. The accuracy of the finite element simulations were evaluated by comparing the simulated ultrasonic attenuation and velocity with the experimental data. The maximum and the average relative errors between the experimental and simulated attenuation coefficients in the frequency range of 0.6−1.4 MHz were 17% and 6% respectively. Moreover, the simulations closely predicted the time-of-flight based velocities and the phase velocities of ultrasound with maximum relative errors of 20 m/s and 11 m/s respectively. The results of this study strongly suggest that micro-scale finite element modeling can effectively simulate broadband ultrasound propagation in water-saturated trabecular bone-mimicking structures. [ABSTRACT FROM AUTHOR]

A microstructural and mechanical properties study was conducted to investigate the effect of the curing conditions on the final properties of self-compacting concrete. Two different curing conditions were considered simulating the summer conditions in coastal (20 °C and 70% relative humidity, RH) and central (cycles of 40 °C) zones in Spain. Different microstructural and mechanical parameters were measured to study the hydration using different techniques: Micro-Raman spectroscopy, nuclear magnetic resonance, compressive strength and ultrasonic testing. After 7 days of hydration the central conditions produce samples with higher hydration degree than coastal conditions, but after 28 days of curing, the hydration degree was very similar in both curing conditions. This high hydration degree after 7 days conducted to a decline or stabilization in compressive strength at long curing times. The mean chain length of the C-S-H gel formed in the studied concrete was quite high comparing with other works since more Al was incorporated in the C-S-H gel. It was also obtained that for high temperatures after 7 days of curing all microstructural and mechanical parameters were quite stable meaning that high temperatures accelerate the hydration of the samples. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the potential of ultrasonic velocity as a rapid and nondestructive method to predict the dimensional stability of oak ( Quercus petraea (Mattuschka) Lieblein) and chestnut ( Castanea sativa Mill.) that are commonly used in flooring industry. Ultrasonic velocity, specific gravity, and radial, tangential and volumetric shrinkages were measured on seventy-four 20 × 20 × 30-mm 3 specimens obtained from freshly cut oak and chestnut stems. The ultrasonic velocities of the specimens decreased with increasing moisture content (MC). We found that specific gravity was not a good predictor of the transverse shrinkages as indicated by relatively weak correlations. Ultrasonic velocity, on the other hand, was found to be a significant predictor of the transverse shrinkages for both oak and chestnut. The best results for prediction of shrinkages of oak and chestnut were obtained when the ultrasonic velocity and specific gravity were used together. The multiple regression models we developed in this study explained 77% of volumetric shrinkages in oak and 72% of volumetric shrinkages in chestnut. It is concluded that ultrasonic velocity coupled with specific gravity can be employed as predicting parameters to evaluate the dimensional stability of oak and chestnut wood during manufacturing process. [ABSTRACT FROM AUTHOR]

The longitudinal ultrasonic attenuation in 20Li 2 O–(80-x) B 2 O 3 –xWO 3 (0 ≤ x ≤ 12.5) glass system, was measured using pulse echo technique at ultrasonic frequencies 2, 4, 6 and 14 MHz in the temperature range from 150 to 300 K. The absorption curves showed the presence of well-defined broad peaks at various temperatures depending upon the glass composition and operating frequency. The maximum peaks move to higher temperatures with the increase of operating frequency indicating the presence of some kind of relaxation process. This process has been described as a thermally activated relaxation process which occurs when ultrasonic waves disturb the equilibrium of an atom vibrating in a double-well potential in the glass network structure. Results proved that the average activation energy of the process is mainly depending on the modifier content. This dependence was analyzed in terms of the loss of standard linear solid type, with low dispersion and a broad distribution of Arrhenius type relaxation with temperature independent relaxation strength. The experimental acoustic activation energy has been quantitatively analyzed in terms of the number of loss centers (number of oxygen atoms that vibrate in the double well potential). [ABSTRACT FROM AUTHOR]

In this work, we synthesized the protic ionic liquid 2-hydroxy diethylammonium lactate (2-HDEAL), the volumetric and acoustic behavior into different hydroxilic media (water, methanol and ethanol) at the range of temperature 288.15–323.15 K and atmospheric pressure being studied. The corresponding apparent molar volume and apparent molar isentropic compressibility values have been evaluated from the experimental data and fitted to a temperature dependent Redlich–Mayer equation. Derived properties such as isobaric expansibility isothermal coefficient of pressure excess molar enthalpy and other acoustical parameters were computed due to their importance in the study of specific molecular interactions into this environment. The new experimental data were used to test the prediction capability of different models (Mchaweh–Nasrifar–Moshfeghian (MNM) model, the modified Heller temperature dependent equation (MHE) and the Collision Factor Theory (CFT)). The obtained results indicate that ionic liquid interactions in water are weaker than in the studied alcoholic solutions, in accordance with previous results. The excess molar volumes were negative throughout the composition range for all mixtures at any temperature condition. The observed inverse dependence on temperature for aqueous or alcoholic mixtures, points out the special trend of packing of this protic ionic liquid into hydroxilic solvents and its strong dependence on steric hindrance of aliphatic residues into anions and cations. [ABSTRACT FROM AUTHOR]

In this study, Ni 0.5 Cu 0.25 Zn 0.25 Fe 2- x La x O 4 (x = 0.000, 0.025, 0.050, 0.075 and 0.100) spinel ferrites were prepared using sonochemical reactor. X-ray diffraction spectra were used to authorize/confirm the cubic spinel ferrite single-phase crystalline nature of the sample. The morphology of the prepared Ni 0.5 Cu 0.25 Zn 0.25 Fe 2- x La x O 4 spinel ferrites was investigated by scanning electron microscope. It is observed that all the particles have devised spherical-like morphology. The ultrasonic non-destructive technique is also a versatile/flexible method/tool to explore/measure the Curie temperature (T C) in the spinel ferrites. In-situ ultrasonic velocity measurements in the range of temperature from 300 to 900 K were carried out. The detected anomalous characteristic/behavior in the ultrasonic velocity was used to explore the T C of the prepared sample. T C of Ni 0.5 Cu 0.25 Zn 0.25 Fe 2- x La x O 4 is 735, 705,690, 675 and 655 K for the different composition x = 0.000, 0.025, 0.050, 0.075 and 0.100 respectively. The value of T C decreases with increasing La3+ doping concentration. Because La3+ ions are strongly paramagnetic, their presence reduces T C , which increases the paramagnetic zone. The vibrating sample magnetometry and susceptibility measurements have been used to investigate the influence of La3+ substitution on magnetic characteristics for further validation. [ABSTRACT FROM AUTHOR]