Values Of Sound Velocity Research Articles

Molecular interactional study of SDS and CTAB in aqueous medium of anti-HIV drugs (Emtricitabine and Lamivudine) at different temperatures: A physicochemical investigation

The present study deals with the interactions of Emtricitabine and Lamivudine (anti-HIV drugs) with anionic surfactant sodium dodecylsulphate (SDS) and cationic surfactant cetyltrimethylammonium bromide (CTAB) at (298.15–313.15) K temperature range by volumetry, compressibility and viscometric approach. The experimental values of sound velocity and density are used to compute various parameters such as apparent molar volume (φv), isentropic compressibility (κs), and apparent molar adiabatic compression (φκ) by employing cosphere overlap model. Relative viscosity parameter (ηr) evaluated from viscosity data also helps to understand various interactions prevalent in surfactant-drug-water ternary system. This attempt of extracting information about various physicochemical interactions of anti-HIV drugs with surfactants can prove beneficial to develop novel anti-HIV agents with better viral resistance activity.

Physicochemical and molecular docking studies of tween 20 in the presence of NaX salts and hydrotropes in aqueous media

An investigation has been conducted on the interaction between the plasma protein bovine serum albumin (BSA) and the surfactant T20 using various hydrotropes of sodium salt (NaX, where X is Sal and Benz). The acquired results provide a practical and efficient means to comprehend the binding process of the micellar system T20 to BSA. The predominant forces involved are hydrophobic forces and hydrogen bonding. The further study intends to investigate the impact of NaX (here, X represents Cl, Br, NO3, Sal, and Benz), on the T20 solution using various techniques including density (ρ), viscosity (η), sound velocity (U), dynamic light scattering (Dh), FT-IR spectroscopy, and molecular docking at varying temperatures. The values of ρ, η, and U increase as the concentration of Na salt increases. Conversely, when the temperature increases, the values of ρ and η fall, while the value of U increases. NaSal exhibits higher viscosity compared to other substances. The phase separation model was employed to calculate the standard Gibbs free energy ( Δ G CP 0 ), enthalpy ( Δ H CP 0 ), and entropy ( Δ S CP 0 ). The NaBenz exhibits the highest values of sound velocity while examining at different temperatures. The structural identification was performed using FT-IR data, which revealed good agreement with the available literature.

Simple Experiment to Show Gravity Does Not Affect the Velocity of Sound

In the present work, we have designed an electronic setup to experimentally verify that gravity does not directly affect the velocity of sound as stated by Lord Rayleigh. For this purpose, we have designed a setup comprising of two sensors namely ultrasonic sensor and accelerometer and a microcontroller Raspberry Pi to determine the values of sound velocity and acceleration due to gravity. The setup was then carefully enclosed in a box with bubble pack and dropped from a height of [Formula: see text]. At this height, there is no variation in air pressure and density, thus, the only parameter which is being varied is acceleration due to gravity. Under the free fall condition, the Raspberry Pi was programmed to control the working of both the sensors and store their responses in the memory card. The results show that the acceleration due to gravity acting upon the setup becomes negligible soon after it is dropped but the velocity of sound remains unaffected.

Porosity dependence of sound velocities in partially sintered alumina, zirconia, ATZ, and mullite ceramics

AbstractYoung's modulus and sound velocities of partially sintered alumina, zirconia, ATZ, and mullite ceramics with a broad range of porosities determined via the impulse excitation technique (IET) and the ultrasonic wave propagation pulse‐echo technique (UPT) are found to be in good agreement and exhibit sigmoidal curves as a function of the sintering temperature. The porosity dependence of the relative values of Young's modulus and sound velocities is either close to or below (but never above) the prediction based on an exponential relation, and none of them is significantly below the prediction based on a percolation relation or a recently proposed numerical benchmark relation for overlapping monosized spheres. Values are lower when concave pores or irregular anisometric grains are dominating. The correlation of the normalized longitudinal wave velocities and relative transverse wave velocities, with VL/VT ratios ranging from 0.50 to 1.91, is well predicted by models for Poisson's ratios between 0.35 and 0.2.

Development of Closed Organa Pipe Props as Learning Media to Determine the Speed of Sound Propagation in Air Assisted by Physics Toolbox Sensor Suite

Teaching aids can help students to gain an understanding of the concepts they learn. Based on the facts obtained at SMAN 1 Waru through teacher interviews and observations of the physics laboratory, the sound wave material of the sound source sub-chapter on organ pipes has never been practiced. The school needs more props to facilitate organ pipe practicum activities. This development's main objective is to create feasible closed organ pipe props in terms of accuracy and precision of sound propagation speed. The analysis stage is the initial stage in the ADDIE model development research. The ADDIE model development research carried out only until the Development stage, because the purpose of this research is only limited to developing and conducting trials in terms of accuracy and precision of the data obtained to produce a closed organa pipe props as a valid learning media to be implemented based on the validator's assessment. The speed of propagation of sound in air is obtained by multiplying the frequency value by the wavelength. The average value of the wavelength produced is (344.22 ± 0.034) m/s. The value of the sound propagation speed in the air produced using the developed closed organa pipe is not exactly the same as the theory but the value is almost close. The difference between the speed of propagation of sound in the air by experiment and theory is 1.22, so with a precision of 99.99% and the percentage of accuracy error is 99.65%, it is classified as a fairly high level of accuracy. Therefore, it can be concluded that the developed closed organa pipe props can be used as learning media to determine the value of sound propagation velocity.

Sound velocities in liquids near freezing: Dependence on the interaction potential and correlations with thermal conductivity

We present systematic investigation of sound velocities in various fluids at the fluid–solid phase transition. First, theoretical estimates indicating that quasi-universal values of sound velocities at freezing can be expected are presented. Then, this prediction is verified on three model systems with quite different interactions (inverse power law, screened Coulomb, and Lennard-Jones pairwise potentials) and 15 real atomic and molecular liquids. It is documented that the ratio of the sound velocity to the thermal velocity tends to a quasi-universal value (cs/vT∼10) in many systems considered, but exceptions also exist. In particular, extremely soft interactions can result in indefinitely large ratios cs/vT. Complex hydrocarbon liquids also demonstrate high ratios cs/vT. On the other hand, liquids composed of light elements, such as hydrogen and neon, demonstrate lower ratios cs/vT. For model systems, we discuss relations between the thermodynamic sound velocity and instantaneous longitudinal, transverse, and bulk sound velocities. It is found that these relations are greatly affected by the potential softness. Finally, correlations between the thermal conductivity coefficient and the sound velocity are briefly discussed in the context of Bridgman's formula.

Nano-SiO2 Recycled Concrete Anti-Sulfate Performance and Damage Mechanism Research

The use of construction waste for concrete is an effective way to reduce the environmental burden while improving the sustainability of construction materials. Nano-SiO2 (NS) has excellent volcanic ash activity, which can effectively improve the strength of concrete. In this study, the synergistic effects of NS and 30% recycled concrete aggregate (RCA) on the mass loss, compressive strength, ultrasonic sound velocity values and microstructure of RAC after 25, 50, 75 and 100 repetitions of a dry–wet cycle (DWC) of sulfuric acid were investigated. The results show that NS has a significant role in improving RAC performance. The RAC specimens showed the lowest mass loss rate, the highest compressive strength, the lowest ultrasonic velocity value and the best resistance to sulfate erosion when the NS doping was 4%. Meanwhile, under CT and SEM, RAC with NS has lower porosity and higher hydration, which can effectively inhibit the crack generation and has stable volume growth within 0–50 repetitions of DWC. In addition, the addition of NS improves not only the microstructure of the substrate but also the interfacial transition zone (ITZ). When 4% NS was added, the porosity was the lowest and the durability improvement was the best performance. This study not only improves the production performance of RAC but also provides a strong reference for the integrated application of nanomaterials in concrete.

Volumetric and Ultrasonic Studies of PEG200, PEG400, and Ethanol–Chlorhexidine Solutions at Various Temperatures

The density and sound velocity values for polyethylene glycols (PEGs) with molecular weights 200 and 400 in ethanol–chlorhexidine solutions were investigated at different temperatures, 288.15 to 318.15 K, and concentrations of 0.001, 0.003, and 0.005 mol·kg–1. The apparent molar properties and partial molar properties of ethanol–chlorhexidine solutions containing PEGs (200/400) were obtained using this experimental data. The thermodynamic parameters, such as apparent molar volume, (Vϕ), and limiting partial molar volume, (Vϕ0), are determined using density values obtained experimentally, whereas acoustic properties, such as apparent molar isentropic compression, (Kϕ, s), and limiting partial molar isentropic compression, (Kϕ, s0), are calculated using sound velocity values. These thermodynamic apparent and partial molar properties imply the occurrence of strong solute–solvent interactions. The temperature-dependent partial molar volume and partial molar expansibilities (Eϕ0) were also calculated. The presence of strong solute–solvent interactions has been discovered in the liquid mixtures.

Study of changes in the mechanical and acoustic properties of epoxy resins under long-time polymerization

Changes in the mechanical stress-strain curves and sound velocity of longitudinal waves for epoxy resin ED-20 with different content of polyethylene polyamine (PPA) hardener and diethylene glycol (DEG) plasticizer were studied for cure time from one to 30 days. The obtained dependences of the applied force on the absolute value of stretching for samples with different PPA content and different curing time make it possible to divide the sample state into three types: highly elastic; not fully cured; vitreous fully cured. The parameters characterizing each state are determined. The polymerization process continues with a curing time of 24 – 720 h for all samples. Acoustic measurements were carried out by the pulse method using an automated measuring system. The dependences of the longitudinal sound velocity on the curing time for samples with different contents of PPA and DEG plasticizer are presented. The sound velocity changed much less than the static Young’s modulus within the considered interval of the curing time. The presence of a «kink» in the interval from about 20 to 180 h is a feature of the dependences of the sound velocity on the curing time. The data obtained revealed that the section of rapid growth of the sound velocity corresponds to the transition from the highly elastic state to the glassy solid one. Experimental study of the physical properties of compositions based on ED20 resin with a concentration of the curing agent less than standard provides the possibility of detailed study of the dynamics of polymerization process after the transition from the gel state to the solid state at a long curing time. It is shown that the curing process continues for a rather long time in the solid state. The observed features on the dependences of the sound velocity on the curing time are attributed to the formation of the 3D structure during the transition from the highly elastic state to the solid glassy state. In this case, the value of the longitudinal sound velocity can be an indicator of the degree of completion of the polymerization process of finished products from composite materials based on epoxy resin, for which it may be difficult to measure the mechanical properties.

Evaluation of the effectiveness of treatment and monitoring of patients with systemic bone tissue disorders during dental implantation

The article presents a study of bone mineral density by DEXA and evaluated the effectiveness of correcting therapy using vitamin D by quantitative ultrasound densitometry to increase the effectiveness of the treatment of patients with dental defects in the background of systemic osteoporosis by dental implantation. Materials and methods: 619 people were examined by quantitative ultrasonic densitometry. The dynamics of changes in bone mineralization was studied with an interval of six months and 1 year. A comparative analysis of the average values of quantitative ultrasonic densitometry was carried out at various times after the installation of dental implants in the control and main groups. Results. Sound velocity values in patients with normal bone mass were (4203,3 ± 7,9). In patients with osteopenia, the rate of ultrasound in bone tissue was 3992,2 ± 3,6 (p < 0.001); in patients with osteoporosis 3802,7 ± 14,9 (p < 0.001). All these parameters were obtained after the use of corrective therapy with vitamin D3. Conclusions. The analysis of the results of quantitative ultrasound densitometry revealed that in the group of patients with osteoporosis, the indicators were reduced by an average of 9.5 % compared with patients with normal bone indicators (p < 0.001).

The Characterization of Hydrodynamic Flow Patterns in the Kawal River Estuary, Bintan Island, Indonesia

One of the pivotal oceanographic factors impacting the hydrodynamic attributes of the waters within the Kawal River Estuary is the prevailing current. This current pattern in the Kawal River estuary exhibits a dynamic nature, primarily under the influence of wind and tidal dynamics. The Kawal River Estuary, as a confluence zone of riverine and oceanic currents, manifests as a dynamically evolving aquatic environment. The investigation was conducted at the Kawal River Estuary in Bintan Regency during the months of September 2021 and January 2022. The research employed the MIKE 21 software, examining two distinct tidal states: high tide and low tide. In September, the sound velocity values averaged 1538.647 m/s at the water surface, 1539.984 m/s within the water column, and 1541.436 m/s at the seabed. In contrast, January recorded sound velocity values of 1534.517 m/s at the surface, 1535.613 m/s within the water column, and 1536.312 m/s at the seabed. Current velocities in September ranged between 0.02 m/s and 0.037 m/s, with a predominant southward direction, while in January, they varied from 0.02 m/s to 0.59 m/s, also exhibiting a southward trajectory. Notably, the swifter current velocities observed in January are attributed to the influence of the northern season.

Об учете вертикального распределения скорости звука при измерении глубины водоема

Investigates methods for taking into account the influence of the vertical distribution of sound velocity (VDSV) in determining of reservoir depth. Various algorithms for determining the depth of the reflecting object location are given, taking into account the changing of the sound velocity value, and an optimal algorithm in terms of the smallest error is proposed. Using the example of calculating the distance to the reflecting object in the conditions of winter hydrology of shallow northern seas and summer hydrology of deep seas of the North Pacific Ocean, a comparative analysis of the inaccuracy in measuring the depth of the reflecting object is performed.

Определение констант уравнения состояния для расчета упругих свойств различных моторных топлив и технических жидкостей

The creation of modern mathematical models of unsteady high-pressure fuel injection in engines requires the replacement of universal empirical equations for one of the elastic properties of fuel by a mathematically more correct equation of state. The necessity of the existence and use of convenient and simple forms of the equation of state, allowing the values of density, compressibility factor and sound velocity of traditional and alternative fuels for diesel engines to be determined quickly and with sufficient accuracy, has been substantiated. Modern approaches to the description of the state of droplet and two-phase liquids are analyzed. The absence of phase transitions in the process of fuel delivery under high pressures has allowed to substantiate the possibility of using the equation of state for the forward and backward account. An equation of state adequate to processes with high and ultrahigh pressures (up to 400 MPa) and moderately high temperatures (up to 460 K) has been proposed. The equipment used and the method of obtaining empirical information through determination of the current sound velocity are described. A method for calculating the values of constants of the chosen form of the equation of state in the form of expressions determining their dependence on temperature and an algorithm for calculating the constants of the equation of state in processing experimental data are presented. Based on literature data, as well as the results of studies conducted, sets of empirical equation of state constants for 49 diesel fuels, various test and technical fluids, and alternative motor fuels are obtained

Measuring material velocity and thickness mapping of flax fiber-reinforced plastic composites using automated ultrasonic rapid motion scanner

The interest in using sustainable materials was a part of the Sustainable Development Goals by the United Nations in 2015, its mission aims to eradicate poverty and conserve the environment by the year 2023. The use of engineered bio-fiber has the potential to replace the usage of synthetic fibers. However, the diversification of the application is limitless. The intended paper investigates the detection of impurities of cured pre-impregnated bio-composite using C-scan ultrasound. The Flax Fiber-Reinforced Plastic Composites were fabricated and cured with heat-assisted curing. The panels were inspected by an automatic ultrasonic rapid motion scanner to measure the material sound velocity of the Flax panel. As a result, the test obtained a reference value of Flax Fiber-Reinforced Plastic Composite material sound velocity of 3.17 (31700 mm/s) for thickness mapping. The obtain sound velocity value can be used as a future reference for inspecting any type of flax material specimen by using the rapid motion scanner from Eddyfi Technologies.

İKİ FARKLI POMZA AGREGASI İÇEREN CAM TOZU KATKILI BETONLARIN FİZİKSEL VE MEKANİK ÖZELLİKLERİNİN İNCELENMESİ

In this study, the physical and mechanical properties of concretes produced using basaltic and acidic pumice at different rates were investigated. Pumice aggregates have been replaced by 50% and 100% of normal-weight aggregates. In addition, in order to produce a more environmentally friendly concrete, 5 different mixtures were produced by replacing waste glass powder from cement at the rate of 10%. Unit volume weight, water absorption, porosity, ultrasonic pulse velocity and compressive strength tests were applied to the produced samples. As a result of the study, while the 100% substituted acidic pumice aggregate gave the lowest density, ultrasonic sound transmission velocity and compressive strength values, the water absorption and porosity values were the highest. Except for the concrete mixture containing 100% acidic pumice aggregate, all of the other lightweight concrete mixtures have higher compressive strength values than the compressive strength value of the structural light-weight concrete (17,2 MPa) specified in the TS 2511 standard.

Investigation on beamforming solution for multi-receiver synthetic aperture sonar using CW pulse with sound velocity profiles in Vietnam’s sea

This paper proposes a novel beamforming solution for multi-receiver synthetic aperture sonar (SAS), which uses gated continuous-wave (CW) pulses, based on the average value of equivalent sound velocity (ESV) when considering the change of the sound velocity with depth. The main beam can be steered to desirable positions with the proposed solution. Besides, the computation time for the phase distribution from the proposed solution reduces compared with the conventional solution by dividing the propagation trajectory into straight lines, where the sound velocity is unchanged. The effectiveness of the proposed solution is validated and evaluated by the results of the beam pattern and the time for determining the phase distribution with the sound velocity profiles (SVPs) in Vietnam’s sea.

Density and Ultrasonic Study of Benzene Sulphonyl Chloride with Hydrocarbon at 303.15 K.

Experimental values of Ultrasonic velocity and density for the binary mixture of Benzene Sulphonyl Chloride with Hydrocarbons have been measured at 303.15 K over the entire mole fraction range, using these data the excess Adiabatic compressibility (βsE) and excess Free length (Lf E) have been calculated. These parameter were used to study the nature and extent of intermolecular interaction between component molecules, present in binary mixture. excess value of Adiabatic compressibility (βsE), sound velocity (UE ) and free length(Lf E) were plotted against the mole fraction of Benzene Sulphonyl Chloride over the whole composition range the value of βsE, UE, Lf E for these three binary mixture have been found to be negative, the non linear variation of these parameter show the presence of interaction and their excess value is indicative of interaction between the components molecule in all system.

Impact of Intermolecular Interaction In Binary Blends From Estimated Sound Velocity

Purpose: To understand the nature of liquids the need of physico-chemical behavior of liquid mixtures or in pure form Sound velocity, viscosity and density values have been calibrated in binary and ternary system of some of the Aniline+1-alkanols with benzene, toluene, and hexane at 303K. Several theoretical models have been applied to evaluate the sound velocity values for the binary and ternary systems compared with the experimental values. Method: The ultrasonic velocity, density and viscosity measured with ultrasonic interferometer, specific gravity bottle with Oswald’s viscometer respectively. The measured ultrasonic velocity compared with theoretical models to understand the existence of molecular interactions from models like Nomoto’ Relation, Free Length Theory, ideals mixture relation etc. Results: NR predictions provide better closeness with test values and FLT predictions are not completely acceptable. FLT prediction is found to fail even for pure liquids. IMR predictions are more acceptable than NR, only for aniline + 1-pentanol binary and NR seem to be the best of all other systems. In binary, IMR predicted values are always lower than test values, but NR predictions are, in most cases, higher than test values. In ternary systems, especially at high mole fractions of aniline, the predicted sound velocity values (NR & IMR) are always lower than the experimentally observed values. Among the many theories considered, NR gives the best prediction of sound speed. The sequence of qualifications for predicting sound speed decreases as NR and IMR and FLT are completely invalid for all considered systems. Conclusion: Strong molecular interaction with the structure formation increases with mole fractions. Azeotropic destruction has been found to be the most common of the compounds considered.

Развитие средств термодинамического расчета характеристик ракетного двигателя с использованием языка программирования Julia

The experience in developing an algorithm and a program for the thermal-chemical calculation of the characteristics of a rocket engine is presented. The program is written in Julia. To calculate the equilibrium composition of combustion products the freely distributed library Ipopt is used. The program is interfaced to the database on thermodynamic properties of individual substances IVTANTERMO. For the convenience of processing, the information on thermodynamic properties is stored in two text files of a special form. The program has been developed using the simplest working process model according to which the flow is one-dimensional, the product flow is adiabatic, there are no friction losses, the product flow is equilibrium, and the speed of condensed particles is equal to the gas flow speed. Ratios for calculating the derivatives of composition, as well as equilibrium values of heat capacity and sound velocity are given. The text of the program can be used in the study process and can easily be adapted to more complex models of the rocket engine workflow. The calculation results obtained using the developed program are in good agreement with the results of TERRA calculations. The execution time of one calculation for a four-element fuel, which includes the determination of the combustion products characteristics in the chamber, the critical cross section and at the nozzle cross section, varies in the range of 3--5 s

Sound velocities in shock-compressed soda lime glass: Melting and liquid-state response

Longitudinal sound velocities (and elastic moduli) were determined in soda lime glass (SLG) at peak shock stresses ranging between 40 and 90 GPa. Laser interferometry was used to obtain particle velocity histories and sound velocities by impacting SLG samples on lithium fluoride (LiF) optical windows. In all experiments, the SLG response consists of a sharp jump to a constant state followed by a release wave. The measured longitudinal sound velocities and moduli showed a marked decrease between 52 and 58 GPa, providing experimental evidence for the transformation from an amorphous solid to a liquid in shock-compressed SLG. The stress threshold (\ensuremath{\sim}55 GPa) for melting in SLG is considerably lower than the threshold reported in shock-compressed fused silica (\ensuremath{\sim}72 GPa), showing the effect of network-modifying cations on the onset of melting. The relative values of sound velocities, shock velocities, and the Hugoniot slopes---between 58 and 90 GPa---are fully consistent with the thermodynamic response of a shock-compressed liquid. Using the experimental results, the Gr\"uneisen parameter (\ensuremath{\Gamma}) values were determined for liquid SLG to 90 GPa and then used to provide the Mie-Gr\"uneisen equation of state for liquid SLG.