Influence Of Physical Properties Research Articles

Influence of thermophysical and acoustic properties on temperature elevation at muscle/bone interface induced by ultrasound hyperthermia

Therapeutic ultrasound heating is a very common technique in the treatment of muscular and joints injuries. However, insufficient or excessive heating delivered to living tissues can be either innocuous or hazardous to the patient. The present work deals with the heat transfer process in living tissues, with particular concern on the behavior at the muscle-bone interface, when ultrasound irradiation is applied. Based on the Generalized Integral Transform Technique (GITT), a hybrid numerical-analytical solution of the Pennes’ equation using the open-source UNIT code (“UNified Integral Transforms”) is proposed, considering different boundary conditions. The influence of physical properties and parameters, such as beam incidence angle, acoustic attenuation coefficients for refracted longitudinal and shear waves in the bone, and blood perfusion in the muscle, were more closely analyzed. Numerical results of temperature profiles showing variations of up to 2 °C for different situations are presented, illustrating a marked dependence of heating patterns on the perfusion rates as well as on the effect of shear waves. The conclusions are that such type of more detailed analysis is essential for the accurate identification of physical properties in living tissues and phantoms and can contribute to the treatment planning for therapeutic ultrasound.

Influence of physical properties and chemical compositions of bitumen on foam characteristics

This study explores the influence of intrinsic bitumen properties on foam characteristics, considering physical properties (penetration, softening point, viscosity), chemical compositions (SARA components, FTIR indices), and physico-chemical characteristics [surface free energy (SFE)]. Ten distinct bitumen samples from two different sources were analyzed. The results reveal that physical properties alone do not sufficiently account for variations in foaming potential among bitumen types. However, chemical compositions and SFE proved to be more informative, explaining the differences in maximum expansion ratio and foam index, specifically for bitumen from the same source. In contrast, when bitumen originates from different sources, none of these intrinsic properties can clarify foaming potential. Notably, intrinsic bitumen properties fail to elucidate the variability in the half-life of foamed bitumen, even when the bitumen types share the same source. These findings underscore the significance of considering multiple factors when assessing bitumen's foam characteristics, particularly when evaluating materials from diverse sources.

Phases distribution in slurry bubble columns: Insights from single-source computed tomography and gas holdup measurements

In this study, a cylindrical stainless-steel column with dimensions of 250 cm in height and 16.2 cm in diameter was employed to investigate how fluid properties influence phase distribution within slurry bubble columns. The research focused on various superficial gas velocities and operating pressures. Data collection was carried out using single-source Computed Tomography and overall gas holdup. The gas holdup was found to be directly proportional to both the superficial gas velocity and the operating pressure. Results revealed that both liquid properties and operating pressure have a considerable impact on flow regime transition. Interestingly, when comparing water to Therminol LT, higher gas holdup measurements were observed when water was used, displaying a relative difference of approximately 29% in the bubbly flow regime under ambient conditions. The effect of liquid properties on holdup profiles became more pronounced at high pressures. For example, under higher pressure conditions, Therminol LT exhibited a higher gas holdup rate due to its lower viscosity and surface tension, leading to an increased rate of bubble breakup. While the influence of physical properties on the solids' holdup profile was relatively less significant, it remained noteworthy when compared to its impact on the gas holdup profile.

The Influence of Physical Properties on the Membrane Morphology Formation during the Nonisothermal Thermally Induced Phase Separation Process.

The physical properties of a polymer solution that are composition- and/or temperature-dependent are among the most influential parameters to impact the dynamics and thermodynamics of the phase separation process and, as a result, the morphology formation. In this study, the impact of composition- and temperature-dependent density, heat capacity, and heat conductivity on the membrane structure formation during the thermally induced phase separation process of a high-viscosity polymer solution was investigated via coupling the Cahn-Hilliard equation for phase separation with the Fourier heat transfer equation. The variations of each physical property were also investigated in terms of different boundary conditions and initial solvent volume fractions. It was determined that the physical properties of the polymer solution have a noteworthy impact on the membrane morphology in terms of shorter phase separation time and droplet size. In addition, the influence of enthalpy of demixing in this case is critical because each physical property showed a nonhomogeneous pattern owing to the heat generation during phase separation, which in turn influenced the membrane morphology. Accordingly, it was determined that investigating spinodal decomposition without including heat transfer and the impact of physical properties on the morphology formation would lead to an inadequate understanding of the process, specifically in high-viscosity polymer solutions.

The influence of physical properties on structured packing HETP correlations

This study focuses on the impact of physical properties on structured packing HETP correlations in the literature. A model derived from inadequate HETP data will not only cause inaccurate correlations but will also impact the relationship between specific physical properties and the model’s predicted HETP. The correlations included in this study were Gualito (1997), Billet and Schultes (1999), Aspen (2012), Delft (2014), and Song (2018). A sensitivity analysis was conducted to determine the effect of physical properties on the predicted HETP from the above models. Results indicated that the observed relationship between liquid viscosity and predicted HETP did not show expected trends in the Gualito and Billet and Schultes correlations. A Monte Carlo analysis was performed to quantify uncertainty in the HETP model predictions due to expected variability in physical property data. Experimental HETP data utilized for this study represented pressures ranging from 0.13 to 27.6 bara.

Effects of physical properties on the compression wave speed of seafloor sediment in the South China Sea: Comparisons between theoretical models and measured data

The compression wave speed and physical properties of seafloor sediments are significant in marine engineering and marine acoustics. Although most regression equations can be satisfactorily fitted to the data and provide a useful predictive method, there is little insight into the influence of physical properties on the compression wave speed of seafloor sediment in the South China Sea (SCS). To characterize the compression wave speed and physical properties of seafloor sediments, the compression wave speed, porosity, density, and mean grain size were measured and calculated for forty-two samples collected from the South China Sea. The results show that the RMS roughness of seafloor sediment in the South China Sea ranges from 0.2 to 15 μm, and the porosity and density are determined by the RMS roughness and mean grain size. The relationships between the compression wave speed and physical properties of seafloor sediments are consistent with the intergranular friction model. When we have the physical parameters but no compression wave speed, therefore, the intergranular friction model can be used to predict the compression wave speed of seafloor sediment. Compared with the Wood model curve, we also reveal that the intergranular friction of seafloor sediment is an important parameter in determining the compression wave speed.

Sodium diffusion in heterogeneous porous media: Connecting laboratory experiments and simulations

Sodium has been suggested as a tracer for brine in reservoir formations where a significant amount of sodium ion is found mainly in the aqueous phase. Fortunately, the most abundant sodium isotope, 23Na, is Nuclear Magnetic Resonance (NMR) active, making it possible to study the structure and dynamical properties of both bulk and pore confined fluid systems. We investigated the diffusion of key dissolved sodium species in bulk solution and porous media as a function of composition, ionic strength, and permeability of the carbonate samples using NMR relaxometry and pulsed-field gradient (PFG) NMR techniques. We use Indiana limestone as an example of natural porous media and water as a freely diffusible tracer and carrier. We demonstrate apparent diffusion measurement of sodium based on changes in spin–spin relaxation time (T2) signal in pore confinement. The diffusion rate of sodium decreases with increasing counter-ion size. This effect is greater at higher ionic strengths and lower chemical potentials in porous media. The reactive transport code, CrunchFlow, was used to complement the NMR experiments to simulate diffusion behavior in porous media. Combining these two methods provides a powerful approach to estimating effective diffusion coefficients in heterogeneous matrices. The modeling considers the influence of physical properties (porosity and tortuosity) and chemical properties (geochemical composition and chemical gradients). The results presented in this work highlight the advantage of measuring apparent diffusivity using NMR T2 relaxometry in conjunction with numerical simulation to derive effective diffusivity and the corresponding matrix properties (i.e., tortuosity) of the system.

Graphene variants and heteroatom doped nanocomposites as electrode material for symmetric supercapacitors

Composites of graphene variants are synthesised and their efficacy on electrochemical performance for supercapacitor is analysed systematically using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and impedance spectroscopy (EIS). The influence of physical properties on electrochemical performance is analysed and the results revealed that microstructures played an important role in electrochemical performance. Reduced graphene oxide (rGO) and its nanocomposites with carbon nanofiber (rGO/CNF) and carbon nanotube (rGO/CNT) are subjected to electrochemical studies. Further, nitrogen doped counterparts (NrGO, NrGO/CNF, NrGO/CNT) of the aforementioned nanocomposites are analysed and enhancement in conductivity and capacitive behaviour is observed. NrGO/CNT electrode material showed enhanced coulombic efficiency and capacity retention of 99% even after 10,000 cycles denoting good cyclability, which can be attributed to the balanced microporosity and mesoporosity of the electrode material.

The Influence of Physical Properties and Increasing Woven Fabric Layers on the Noise Absorption Capacity.

Noise pollution from the environment may wreak havoc on a person’s wellbeing. Numerous sound-absorbing materials are employed to address these issues, one of which is textile-woven fabrics. In this study, 12 woven textiles with four different weave structures (plain, rib, sateen, and twill) and those formed from three distinct polyester yarns were evaluated for their sound absorption properties using an impedance tube. The study was conducted within the range of 80–5000 (Hz) frequency. Part of the investigation was measuring different layers of woven fabrics under three different measuring conditions. Firstly, only woven fabrics were evaluated. Following that, woven and nonwoven textiles were measured. The third variant, in addition to the woven fabrics, included an air gap. In addition, this study includes tests and analyses of the effect of roughness and porosity of the fabric structure on the effectiveness of noise reduction by woven fabrics. The absorption capacity of plain fabric is higher at lower frequencies than other woven fabrics. Other weave structures noise reduction efficiency is higher as the frequency range increases. The absorption efficiency of plain fabric decreases with fabric layering. Utilizing woven fabric combined with nonwoven fabric reduces noise more effectively than the air gap variant. Low surface roughness and a highly porous surface of the fabric indicate a high noise reduction coefficient (NRC).

Numerical Simulation of Nanosilica Sol Grouting for Deep Tunnels Based on the Multifield Coupling Mechanism

Grouting is an effective technical way for the construction of deep tunnels in unfavorable geological conditions. The fluid-solid-chemical coupling mechanism of grouting process is analyzed from the following three aspects: influence of physical properties of silica sol on permeability coefficient, dynamic changes of porosity and permeability of geotechnical media with seepage pressure, and governing equations for flow and mass transfer characteristics. A dynamically changing model for nanosilica sol grouting in deep tunnels is established, considering the changing physical properties of grout and surrounding rock. Based on the Xianglushan Tunnel of Yunnan Water Diversion Project, the temporal and spatial evolution of silica sol grout is studied. The effect characteristics of grouting pressure and initial permeability are clarified. The rationality of this model is verified by classical Newtonian fluid grouting theory. The main conclusions: with the molar concentration as the index, the grout range can be divided into the raw grout region and the transition region; with the decrease of the grouting pressure, the growth rate of the normal grouting radius and the axial grouting radius will gradually decrease; due to the mechanical dispersion and molecular diffusion, the range of the transition region will gradually increase with time. The ratio of the transition region to grouting radius fluctuates slightly with time under the initial permeability of 5 D. The fluctuation increases with the decrease of initial permeability, and the average ratio increases with the decrease of grouting pressure. This study can provide theoretical guidance for grouting design of deep tunnel engineering.

Effects of physical and chemical properties on the dissolution of sea salt

Salt plays a crucial role in human health. However, excess use of NaCl in food products can be harmful to health. One suggestion for this problem is optimization salt dissolution to increase the content of salt ions in the mouth. For this purpose, it is important to understand the solubility properties of salt crystals in saliva. The dissolving process is not only affected by the physical properties but also by the chemical composition of the salt. This study compared the solubility of four commercial grain salts in four regions in Vietnam (Bac Lieu, Thanh Hoa, Sa Huynh, Vung Tau), one flower salt in Sa Huynh and a control sample with two particle sizes 1 - 2 mm and 2 - 3 mm in a Saliva Artificial Gal – Fovet solution (SAGF). Dissolution was determined by analyzing microscopic images taken by the time and analysis by Bayesian and Partial Least Squared methods. The research evaluated the influence of physical properties (area, Feret's diameter, circularity, aspect ratio and solidity) and chemical compositions (sodium, potassium, magnesium, calcium and moisture content) on the dissolving process. Salt samples showed significant differences in physical and chemical properties by region. Morphological parameters are affected by conditions of salt crystallization that indicated through region of origin. Dissolution is evaluated through solubility coefficient, Sa Huynh flower salt and control salt have the highest solubility coefficient, simultaneously, it is also the smallest value of roundness and surface index. The projected area, magnesium and sodium content are the factors which strongly affecting on dissolution of salt samples. These results demonstrated the possibility to exploit these factors to adjust the solubility of salt as well as the perceived salinity over time.

Acoustic fields of acid suspensions containing cassava bagasse: Influence of physical properties on acoustic attenuation

The effects produced by high-intensity ultrasound application during the acid pretreatment of biomass can enhance its later conversion into bioethanol. Therefore, it is interesting to evaluate how residues, such as cassava bagasse (CB), affect the actual acoustic field applied and, thus, the magnitude of its effects. For this, calorimetric method was used to estimate acoustic energy and the efficiency of electric-acoustic energy conversion in acid suspensions containing different CB concentrations (2–10%). Tests were carried out under different input powers, from 160 to 400 W (24 kHz), at different distances (1.5–5.5 cm) from the sonotrode. Thus, the experimental acoustic intensity measured varied from 12.90 to 68.57 W·cm−2, the highest values being registered in the suspensions with the lowest CB content (65.55–36.81% of conversion yield close to the sonotrode). Attenuation was also addressed during sound wave propagation, finding a constant value of 0.021 cm−1. Polynomial models were well fitted to acoustic parameters and acoustic intensity exhibited a high correlation (r>0.87 and pvalue ≤ 0.05) with the experimental thermophysical properties of the suspensions.

Influence of physical properties on the taste and flavor of strawberry jam.

This study investigated the influence of the type and concentration of pectin on the sensory attributes and physical properties of a model strawberry jam. The methods used for the sensory evaluation and determination of physical characteristics that affect human taste and flavor perception are outlined. Increasing pectin concentration altered the solid (elastic) properties of the model strawberry jam. Each sensory attribute showed high correlation with various physical properties as determined by viscosity measurements. These results allowed us to predict the human oral cavity conditions during taste and flavor perception. From this study, it is clear that humans assess the physical properties of foods by the tongue movements and adjustments in the oral cavity conditions according to the taste and flavor characteristics.

Separation/connection procedures: From cleansing behavior to numerical cognition.

Lee and Schwarz (L&S) suggest that separation is the grounded procedure underlying cleansing effects in different psychological domains. Here, we interpret L&S's account from a hierarchical view of cognition that considers the influence of physical properties and sensorimotor constraints on mental representations. This approach allows theoretical integration and generalization of L&S's account to the domain of formal quantitative reasoning.

Influence of physical properties on boring operations of AISI 1050 steel bars

Abstract The main reason for vibration and tool deflection in boring processes are the geometrical, mechanical, and physical properties of the boring bar employed. The diameter of the boring bar is rather small when compared with its length due to the nature of the mechanism in the boring process., In the present study, the influence of the physical properties of boring bars on the deflection amplitudes, natural, and circular natural frequencies were investigated both theoretically and experimentally. For that purpose, seven kinds of boring bars were used. The influence of the characters of boring bars on the amplitudes of tool deflection was investigated both theoretically and experimentally. By contrast, this influence on the natural and the circular natural frequencies were investigated only theoretically. It was found that boring bars filled with rubber and silicon recorded the smallest deflection amplitudes. Particularly, bars filled with silicon manifested the lower tool deflection amplitudes under the selected conditions. It should be added that lower feed rates and cutting depths caused severe tool deflection amplitudes. Moreover, the optimum compatibility between the theoretical and experimental results of tool deflection amplitudes was observed in bars filled with silicon ∅ 16 mm.

Revisiting thermal penetration depth for caloric cooling system

Thermal penetration depth is a physical quantity identifying the distance that heat can diffuse through the domain material, which has been widely adopted for thermoacoustic cryocoolers in the past, where the diffusive thermal resistance is the only dominating factor for gaseous refrigerant. By ignoring the surface convection thermal resistance, we show that the conventional thermal penetration depth significantly overestimates the cooling performance of the caloric material. This paper modifies the conventional thermal penetration depth with the consideration of convection thermal resistance and applies this concept to caloric cooling devices. The modified thermal penetration depth can be computed by the approximate fitting formula, which is numerically validated by CFD simulation results. The influence of physical properties and geometric parameters of materials on thermal penetration depth is discussed. In addition, the modified thermal penetration depth can be visualized on Biot number and Fourier number chart, which can guide design of future caloric cooling systems. This design approach is supported by the experimental data from the literature.

The Influence of Physical properties on the Antibacterial Activity of Lysine Conjugated Chitosan Functionalized Silver Nanoparticles

The antibacterial activity of chitosan/lysine/silver (Cht/lys/Ag) on pathogens was influenced by physical properties and morphology to a higher degree compared with that of chitosan/silver (Cht/Ag). The antibacterial activity of Cht/Ag and Cht/lys/Ag were evaluated against pathogens Gram negative (E. coli and P. aeruginosa) and Gram positive bacteria (S. aureus and B. subtilis) by Kirby Bauer disk diffusion assay method. Crystallite size values of the synthesized system was calculated from XRD analysis to study their dependency on antibacterial activity. The FTIR spectral analysis shows the presence of -OH and COO- groups of Cht and lys and the variation in intensities confirmed the interaction with Ag nanoparticles which are stabilized. Moreover, UV–Vis results show that the Cht/lys/Ag composition enhanced the stability and induced the symmetry of Ag nanoparticles which were observed from surface plasmon resonance (SPR) effect of Cht/lys/Ag. In addition, the induced higher symmetry, low hydrodynamic diameter and higher diffusion coefficient from dynamic light scattering (DLS) measurement of Cht/lys/Ag were found to yield maximum bacterial inhibition than Cht/Ag which were due to lysine interaction. Obviously surface morphological changes in the composites are due to Ag and lysine interaction as seen from SEM micrographs. The synthesized NCs exhibit efficient antipathogens against Gram negative bacteria and are promising candidates in diverse applications in biomedical industries.

A biosensor with encapsuled bioreporters—optical fiber element for enhanced detectection of bioluminescence

It is proposed that a whole-cell optical fiber biosensor is used as an in situ first warning detector sensor for online monitoring of environmental pollution (e.g. waste water) in remote localities. The base requirement for this sensor is a very high sensitivity topollution. The work shows a simple way to increase sensor sensitivity, optimizing the shape of an optical fiber element (OFE) for more effective coupling of the low intensity light produced by bioluminescent bioreporters.Theoretical calculations of coupling efficiency showed that only 3.5% of photons produced by one bacterium placed on the front end of polymer-clad silica (PCS) fiber is guided to the detector. Our designed tapered OFEs with immobilized bioluminescent bioreporters Pseudomonas fluorescens HK44, with maximal transmittance, led to a sixfold increase in detected bioluminescence compared to that of the PCS fiber with the same active layer. It is shown that the shape of the OFE determines its transmission. The influences of physical properties and OFE geometry, cell immobilization into silica gel or bacterial plaque, on the intensity of detected light, were evaluated.

RESPONSE FUNCTION FOR THE SRELATIVE INDEX IN CAMBISOL TREATED WITH AND WITHOUT BOVINE LIQUID BIOFERTILIZER

ABSTRACT The present study aimed at assessing the influence of physical properties associated with soil structure on the Srelative index. Two soil conditions under Ficus carica L. cultivation were studied (with or without liquid bovine biofertilizer in the irrigation water), in the 0-0.1 m and 0-0.3 m layers. Disturbed and undisturbed soil samples were collected from the above-mentioned layers and physical analyzes, pertinent to the study objective, were performed. The response function model was applied to verify how the soil independent physical variables influence on the Srelative index in the 0-0.1 m and 0-0.3 m layers, with 0 and 60% biofertilizer, being combined two to two. Once the response functions were known, the slopes of both functions were compared, being represented by the coefficients β11-β12 and β21-β22. This comparison enabled verifying whether there was an effect of the treatments on the response variable. In addition, the standard error of the difference between coefficients was calculated, and the Student's t-test applied. The method of multiple regression was also used to confirm the effect of the variables on the Srelative index for the 0-0.3 m layer in both treatments. Then, the variables with greater weight were selected by a backward elimination method to estimate the Srelative. The results showed that the Srelative index is strongly influenced by properties of the porous fraction, with total porosity and continuity of pores being of significant influence. Management with liquid bovine biofertilizer results in improvement in the soil structure, with effects measured by the Srelative index.

Dynamics of Surface Soil Cover Temperature Fluctuations in the Arctic Region

Permafrost studies play important role in development and improvement of the geoecological predictive model of climate change and prediction of ecological situation development in the Arctic region. Data on the dynamics of surface soil cover temperature fluctuations are extremely crucial. Therefore, thermometers with automatic memory are necessary. This paper presents the results of daily measurements of soil cover temperature at different depths with a half-hour time interval of recording during the winter and spring periods. Also, characteristics of the studied soil cover, typical to tundra areas in the region of Nadym, are presented.A special multichannel thermometer with 21 temperature sensors is used to measure the temperature and produce the temperature data. Sensors on a probe are separated by the 5 cm distance which allows measuring the temperature of soil up to 1 m in depth. Temperature dynamics of freezing of snow and soil covers is studied. Acquired data is utilized to estimate the influence of physical properties of soil cover and ambient temperature on the prevailing geocryological situation. Freezing boundary formation is demonstrated, and specific “active temperature layer” as the layer of soil subjected to sharp daily temperature fluctuations is revealed.DOI 10.14258/izvasu(2018)1-03