Strong Frequency Dependence Research Articles

A frequency-dependent model for bone remodeling using a micromorphic porous medium subjected to harmonic mechanical loading

In this paper, the bone tissue was modeled as a linear viscoelastic material saturated with interstitial fluid. We considered a specific case of harmonic loading and related the mechanical stimuli to the loading frequency. In this way, we could include the inertial effect in the model while not having to deal with the perturbation during each loading period. Two types of mechanical signals were considered: strain energy and dissipation energy. A parametric study revealed the dependency of the two signals on loading frequency and material property. The evolution of the apparent mass density supported the parametric study’s findings. Under the three different frequency loadings, the strain energy-stimulated samples experienced identical remodeling scenarios. The samples stimulated with dissipation energy, on the other hand, exhibited a strong frequency dependence. An additional study was performed to investigate the effect of long-term variations in the loading frequency on the remodeling process. This demonstrated the model’s capabilities in designing and evaluating load regimes for rehabilitation following a bone injury or bone reconstruction.

The Influence of Space Traffic on AIM/CIPS PMC Frequencies at 80°N

AbstractWe explore the effects of lower thermospheric water vapor deposited by launch vehicle plumes on polar mesospheric cloud (PMC) frequencies at 80°N. We use July‐averaged PMC frequencies from 2007 to 2022 from the Cloud Imaging and Particle Size (CIPS) instrument on NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite. Launch sites worldwide are typically located near northern mid‐latitudes. Using the orbital launch record for the same time period, we find that the number of launches correlates with PMC frequencies with a coefficient of r = 0.60, which increases to r = 0.75 when only selecting launches from 2.5 to 21.5 local time (LT), indicating a weak LT dependence on global‐scale transport to 80°N. To support our findings, we use meridional winds from the Michelson Interferometer for Global High‐resolution Imaging experiment on NASA's Ionospheric Connection Explorer satellite and winds from the Horizontal Wind Model climatology to interpret the northward motion of air parcels at 105 km. We find the launch LT window that maximizes the correlation coefficient to be consistent with the expected maximum northward motion from the diurnal variation of mid‐latitude meridional winds. Comparisons with Microwave Limb Sounder satellite observations of upper mesospheric temperature and water vapor reveal a strong dependence of cloud frequency on water vapor (r = 0.86) but not on temperature (r = −0.26), indicating that water vapor is the primary source of PMC variability for the bright PMCs at 80°N. We therefore find that launch vehicle plumes originating primarily from northern mid‐latitudes modulate PMC frequency at 80°N in July.

Investigation of Dynamic Viscoelastic Characteristics of Permeable Asphalt

In order to provide a basis for the structural analysis, design and maintenance of permeable asphalt pavements, and to promote their engineering promotion and application, this study investigated the dynamic viscoelastic properties of permeable asphalt mixtures (PAC-13) under complex stress states. A Simple Performance Tester (SPT) system was used to measure the dynamic modulus of the mix under complex stress states. The displacement factor and principal dynamic modulus curves were formed by fitting Sigmoidal functions and using 1stOpt (first optimization) software, the phase angle principal curves were further determined, and the dynamic modulus was predicted for the ambient phase (15–25 °C) using the Hirsch model. The results showed that the dynamic modulus of the mixtures decreases with an increasing temperature, and the maximum decrease in the dynamic modulus is 93% when the confining pressure is 100 kPa and the loading frequency is 10 Hz. The dynamic modulus increases with an increasing confining pressure and loading frequency, the maximum increase with an increasing confining pressure is 26.1% when the temperature is 25 °C and the loading frequency is 10 Hz, and the maximum increase with an increasing loading frequency is 411% when the temperature is 25 °C and the confining pressure is 100 Hz. The dynamic modulus has a strong frequency dependence at low temperatures, while it is stress-dependent at high temperatures. Meanwhile, based on the Hirsch model, a new modified prediction model was developed, which can well predict the dynamic modulus of permeable asphalt mixtures at room temperature.

Separation of source, attenuation and site parameters of 2 moderate earthquakes in France: an elastic radiative transfer approach

Summary An accurate magnitude estimation is necessary to properly evaluate seismic hazard, especially in low to moderate seismicity areas such as Metropolitan France. However, magnitudes of small earthquakes are subject to large uncertainties caused by major high-frequency propagation effects which are generally not properly considered. To address this issue, we developed a method to separate source, attenuation and site parameters from the elastic radiative transfer modeling of the full energy envelopes of seismograms. The key feature of our approach is the treatment of attenuation -both scattering and absorption- in a simple but realistic velocity model of the Earth’s lithosphere, including a velocity discontinuity at the Moho. To reach this goal, we developed a 2-step inversion procedure, allowing first to extract attenuation parameters for each source-station path from the whole observed energy envelope using the Levenberg-Marquardt and grid-search algorithms, then to determine site amplification and the source displacement spectrum from which the moment magnitude Mw is extracted. In the first step, we use the forward modeling procedure of Heller et al. (2022) in order to simulate energy envelopes by taking into account the full treatment of wave polarization, the focal mechanism of the source and the scattering anisotropy. The inversion procedure is then applied to the 2019 ML 5.2 Le Teil and 2014 ML 4.5 Lourdes earthquakes which both occurred in southern France. Data from 6 stations are selected for each event. The inversion results confirm a significant variability in the attenuation parameters (scattering and absorption) at regional scale and a strong frequency dependence. Scattering appears to be stronger towards the French Alps and Western Pyrenees. Absorption is stronger as frequency increases. Although not very resolvable, the mechanism of scattering appears to be forward or very forward. By inverting the source spectrum, we determine moment magnitudes Mw of 5.02 ± 0.17 for the Le Teil earthquake and 4.17 ± 0.15 for the Lourdes earthquake.

Impedance phase-dependent correction factor for a tonehole model

The upper and lower end corrections of an open tonehole in a woodwind instrument are often accommodated by adding them to the physical thickness of the wall to create an effective thickness used in calculating the impedance of the tonehole. A rough estimate of the correction often used is 1.5 time the tonehole radius (1.5b), while other more rigorous treatments yield values in this vicinity. These values are usually independent of frequency or are constrained to a range of geometric tonehole and bore dimensions. The data from this study showed a strong and significant frequency dependency that produced a large range of correction values between about 0.5b and 1.5b. This variation correlated with the phase of the impedance of the highest open tonehole, and generally increased with increasing sounding frequency. This paper will discuss the conditions under which the measurements were made and how the correction factors were obtained, and will propose how the observed frequency dependence can be incorporated into the correction factor through the phases of the impedances of the open toneholes.

Resonant generation of propagating second-harmonic spin waves in nano-waveguides

Generation of second-harmonic waves is one of the universal nonlinear phenomena that have found numerous technical applications in many modern technologies, in particular, in photonics. This phenomenon also has great potential in the field of magnonics, which considers the use of spin waves in magnetic nanostructures to implement wave-based signal processing and computing. However, due to the strong frequency dependence of the phase velocity of spin waves, resonant phase-matched generation of second-harmonic spin waves has not yet been achieved in practice. Here, we show experimentally that such a process can be realized using a combination of different modes of nano-sized spin-wave waveguides based on low-damping magnetic insulators. We demonstrate that our approach enables efficient spatially-extended energy transfer between interacting waves, which can be controlled by the intensity of the initial wave and the static magnetic field.

Sum-frequency triad interactions among surface waves propagating through an ice sheet

We study nonlinear resonant wave–wave interactions which occur when ocean waves propagate into a thin floating ice sheet. Using multiple-scale perturbation analysis, we obtain theoretical predictions of the wave amplitude evolution as a function of distance travelled past the ice edge for a semi-infinite ice sheet. The theoretical predictions are supported by a high-order spectral (HOS) method capable of simulating nonlinear interactions in both open water and the ice sheet. Using the HOS method, the amplitude evolution predictions are extended to multiple (coupled) triad interactions and a single ice sheet of finite length. We relate the amplitude evolution to mechanisms with strong frequency dependence – ice bending strain, related to ice breakup, as well as wave reflection and transmission. We show that, due to sum-frequency interactions, the maximum strain in the ice sheet can be more than twice that predicted by linearised theory. For an ice sheet of finite length, we show that nonlinear wave reflection and transmission coefficients depend on a parameter in terms of wave steepness and ice length, and can have values significantly different than those from linear theory. In particular, we show that nonlinear sum-frequency interactions can appreciably decrease the total wave energy transmitted past the ice sheet. This work has implications for understanding the occurrence of ice breakup, wave attenuation due to scattering in the marginal ice zone and the resulting ice floe size distribution.

Investigation of dielectric and electric modulus properties of Al/p-Si structures with pure, 3%, and 5% (graphene:PVA) by impedance spectroscopy

The Z–V measurements were performed in wide-range voltage (± 6 V), and then the real/imaginary parts of ε* (ε′, ε″), M* (M′, M″), Z* (Z′, Z″), tanδ, and σac values of the Al/p-Si structure with pure polyvinyl alcohol (PVA) (D1), 3% (D2), and 5% (D3) graphene-doped PVA interfacial-layer were calculated at four frequencies (1, 10, 100, and 1000 kHz). When the frequency in D2 and D3 structures was increased from 1 kHz to 1 MHz, the dielectric constant value changed from 32.47 to 5.12 and from 26.26 to 1.00, respectively. They have a strong frequency dependence due to the presence of interface traps (Nit), polarization types, and organic interlayers at low frequencies. The observed anomalous peak in the ε′ and ε″ versus voltage curves in the depletion zone is the result of re-structure/re-ordering molecules in these traps under voltage/electric-field, and Nit measured frequency (f = 1/T). As a result, the ε′ and ε″ will be given an excess value to their real-value at lower frequencies. Because Nit and dipoles do not have enough time to spin themselves in the direction of the electric field and follow the ac signal at high frequencies, they cannot contribute the true value of them. In general, series resistance (Rs) and the interfacial layer are effective in the accumulation zone, while Nit is effective in the depletion region. These findings demonstrate that pure and (Gr:PVA) polymer-films at the M/S interface can be employed successfully in place of standard oxide materials. According to the comparison of dielectric constants, electrical modulus, impedance, and ac conductivity of all three structures at 100 kHz and 1 MHz frequencies, 3% Gr doping to PVA increases interfacial characteristics.

Conductivity measurements in the 10–40 GHz band using Fabry–Pérot open resonator

In this paper we introduce a novel approach to measurement of electric conductivity of bulk, metallic samples. The method is based on a Fabry–Pérot Open Resonator operating in the plano-concave configuration. Because the resonator supports multiple TEM0,0,q modes, the proposed method provides properties of the sample-under-test at multiple frequencies in the band of 10 to 40 GHz with separation of ca. 1.5 GHz between consecutive frequency points. Contrary to other methods, it does not require that a sample is cut to any particular shape, as long as it is significantly larger than the TEM-mode beam waist and thicker that the penetration depth. It also provides high measurement accuracy that is comparable to alternative methods based on single-mode resonant setups and superior to the broadband transmission methods known in the literature. We demonstrate that the open resonator due to its relatively high Q-factor reaching 135000 can be successfully used in measurements of different samples of conductivity ranging from ca. 103 S/m (e.g. laminates based on carbon-fiber) up to the order of 107 S/m (e.g. aluminum alloys, copper). Using the measurement set-up we also demonstrate an interesting effect of strong frequency dependence of the effective conductivity of stainless steel. It is expected in all magnetic materials and results from large complex permeability of such samples. It is important to emphasize that no similar characterization campaigns are to be found in the literature.

Stress and frequency dependence of wave velocities in saturated rocks based on acoustoelasticity with squirt-flow dissipation

SUMMARY We perform seismic and ultrasonic measurements in carbonate and shaley sandstone samples as a function of differential pressure. The velocities show a strong frequency and pressure dependence. The dispersion disappears with increasing pressure and the squirt flow in turn inhibits the pressure dependence. To model these effects, we combine the Gurevich's squirt-flow model with the Mori–Tanaka scheme and the David Zimmerman model, and extend it with third-order elastic constants, to obtain a frequency-dependent acoustoelasticity model. Comparisons between measurements from this study and literature and modelling results show that the P-wave velocity increases non-linearly first and then nearly linearly, dominated by crack closure and acoustoelasticity, respectively. The pressure dependence of wave velocities is reduced by liquid substitution and further by the squirt-flow mechanism. The effects of fluid properties and crack closure on P-wave velocity decrease with differential pressure. The results will feed a new model and help better understanding the wave propagation in pre-stressed rocks at different scales.

Dynamic spin reordering in a hybrid layered ferrimagnet with intercalated biferrocenium radicals.

Molecule-based hybrid layered magnets provide an ideal platform for investigating the long-range spin-ordering process in low-dimensional magnetic systems. Within this context, a promising area of research is spin-sandwiched hybrid layered magnets. These materials offer the potential to explore how the spin, which is sandwiched between magnetic layers, is influenced by the internal magnetic fields generated by the magnetic layers. Herein, we report a layered ferrimagnet with intercalated biferrocenium ([bifc]+) radicals, [bifc][{Ru2(2,3,5,6-F4ArCO2)4}2(TCNQF2)] (1, TCNQF2 = 2,5-difluorotetracyano-p-quinodimethane). The [{Ru2(2,3,5,6-F4ArCO2)4}2(TCNQF2)]- moiety acts as a ferrimagnetic layer with S T = 3/2, composed of a paddlewheel [Ru2 II,II(2,3,5,6-F4ArCO2)4] (2,3,5,6-F4ArCO2 - = 2,3,5,6-tetrafluorobenzoate) with S = 1 and 2,5-difluoro-7,7,8,8-tetracyanoquinodimethanate (TCNQF2˙-) units with S = 1/2 in a 2 : 1 ratio. The isostructural paramagnetic compound [bifc][{Rh2(2,3,5,6-F4ArCO2)4}2(TCNQF2)] (2) consisting of diamagnetic [Rh2 II,II(2,3,5,6-F4ArCO2)4] components was also synthesized. An investigation of the properties of 2 revealed minimal magnetic interaction between the [bifc]+ and TCNQF2˙- components. Compound 1 displayed long-range ferrimagnetic ordering at the Curie temperature of 105 K without any frequency dependence on alternating current (AC) susceptibility, due to the combination of predominant ferrimagnetic ordering within the layer and interlayer ferromagnetic dipole interactions. However, subsequent stepwise magnetic ordering involving a strong AC frequency dependence was observed upon further cooling. These dynamic behaviors are associated with the ordering of two types of anisotropic [bifc]+ spins between the ferrimagnetic layers, indicating that [bifc]+ spin ordering is sensitive to anisotropic internal magnetic fields generated by the ferrimagnetic layers.

Voltage and frequency reliant interface traps and their lifetimes of the MPS structures interlayered with CdTe:PVA via the admittance method

In this work, to gain detailed information about the electrical characteristics, interface traps (Dit), and their lifetimes (τ) of the metal-polymer-semiconductor (MPS) type structures, admittance measurements performed in wide frequency and voltage ranges have been utilized. At the outset, the intercept, and slope of the 1/C2 vs V curve were used to unveil the density of acceptor-atoms (NA), depletion-layer width (WD), and barrier-height (ΦB). All these parameters show strong frequency dependence with the effect of the Dit, interlayer, interface, and dipole polarization, especially at low and moderate frequencies. Therefore, Dit and τ were determined from the admittance method. The measured C -G/ω vs V curves were adjusted for higher frequencies taking into account the series-resistance effect. Experimental results indicate the strong effect of the Rs value on the capacitance and conductance values only at the accumulation-regime for higher-frequencies whereas the Dit effect in both inversion and depletion regimes for lower-frequencies.

METHODS AND MEANS OF INCREASING THE EFFICIENCY OF COMPOSITE MATERIALS FOR SHIELDING ELECTROMAGNETIC FIELDS

The main principles of increasing the shielding coefficients of electromagnetic fields by composite materials are considered. It is shown that the protective properties in the low-frequency and high-frequency regions of the electromagnetic spectrum are provided by different physical mechanisms. Therefore, to ensure acceptable protective properties, it is necessary to coordinate the ratio of electrophysical and magnetic properties of materials based on compromise solutions. The main condition in the process of designing materials is to take into account the strong frequency dependence of the dielectric and magnetic permeability of filler particles. To predict the required volume content of the shielding filler in the dielectric matrix, it is possible to use the Maxwell-Garnett, Odelevsky, and Lorentz formulas. At the same time, it should be taken into account that the differences between calculated and experimental results are at least 20 %. For simultaneous effective shielding of ultra-low-frequency and ultra-high-frequency electromagnetic fields, the material must have both sufficient magnetic properties and acceptable electrical conductivity. This can be achieved by treating the original mixture containing ferromagnetic particles with a constant magnetic field of 200–300 A/m. By arranging the arrangement of shielding particles in the body of the composite, conduction circles are formed. With a shielding material content of 12–16 % by volume, a percolation effect is achieved - a sharp increase in the electrical conductivity of the material and an increase in protective properties. The amount of filler depends not only on the total volume, but also on the size of individual particles. In this way, simultaneous shielding of both the magnetic component of the industrial frequency electromagnetic field and ultrahigh and higher frequency electromagnetic fields is achieved. It is shown that it is expedient to investigate the possibility of arranging non-magnetic particles in the body of the composite by treating the initial mixture with an electric field.

Clapping triboelectric nanogenerators as self-powered, frequency-insensitive and gravity-independent vibration sensors

Self-powered vibration sensors have the potential to greatly improve vibration monitoring of remote and hard-to-access structures by providing cost-effective and energy-efficient solutions. One promising type of sensors based on the triboelectric generator mechanism has shown significant advantages over other self-powered sensors, including better energy conversion efficiency and high output voltage. However, the majority of the recently reported triboelectric powered sensors exhibit strong frequency dependence, being mostly effective under low frequency vibrations. To address these issues, herein we present a novel design of self-powered vibration sensors based on the clapping mode of a triboelectric nanogenerator (TENG). The sensor, consisting of two tribo-layers made of regular copy paper and PTFE that are clamped together by springs, is able to achieve a high sensitivity of 10.8 mV/g and a broad frequency range from 50 to 8000 Hz with a flat frequency response of ±5 dB, regardless of the inclination angle between the contacting surfaces and gravity. The sensor exhibits high linearity (0.9999) and stability over six days and 400,000 cycles. Furthermore, computational modelling has been conducted to understand the nonlinear clapping phenomenon and the influence of clamping force, proof mass and spring stiffness on the sensor's performance. The potential of the clapping TENG sensor is demonstrated through two different applications such as music recording and diagnosis of the loosing of bolts in a rotating machine. Its superior performances, along with low cost, compact design, and electromagnetic shielding, make it a promising candidate for battery-free high-frequency vibration sensors in practical vibration measurement applications.

Characterization of Mechanical Oscillations in Bismuth Selenide Nanowires at Low Temperatures.

A single transistor preamplifier circuit was designed to facilitate electrical detection of mechanical oscillations in nanoelectromechanical systems (NEMSs) at low temperatures. The amplifier was integrated in the close vicinity of the nanowire inside the cryostat to minimize cabling load and interference. The function of the circuit was impedance conversion for current flow measurements in NEMSs with a high internal resistance. The circuit was tested to operate at temperatures as low as 5 K and demonstrated the ability to detect oscillations in double-clamped bismuth selenide nanowires upon excitation by a 0.1 MHz-10 MHz AC signal applied to a mechanically separated gate electrode. A strong resonance frequency dependency on temperature was observed. A relatively weak shift in the oscillation amplitude and resonance frequency was measured when a DC bias voltage was applied to the gate electrode at a constant temperature.

Time, frequency, and quantile-based impacts of disaggregated electricity generation on carbon neutrality: evidence from leading European Union countries

ABSTRACT Due to increasing geopolitical tensions and disruption of gas supplies, European countries have been looking for alternatives for electricity generation (EG). As part of this process, one of the most important goals for long-term sustainability is to ensure carbon neutrality. Therefore, this study analyzes time, frequency, and quantile-based impacts of EG from different electricity generation sources (i.e., renewable, nuclear, and fossil fuels) on carbon neutrality, focusing on four leading European countries. The study applies the wavelet transform coherence (WC), quantile-on-quantile regression (QQ), and Granger causality in quantiles (GQ) to high-frequency daily data between January 2, 2019 and March 10, 2023. Results show that (i) there is a strong time and frequency dependence between EG and CO2 emissions across countries, while results vary by EG sources and countries; (ii) renewable EG dampens CO2 emissions. At higher quantiles, a higher share of renewable EG lowers CO2 emissions in Germany and Spain, while they increase in France; (iii) nuclear EG is beneficial only for the United Kingdom. (iv) Fossil EG increases CO2 emissions in all countries. Excessive fossil EG leads to more CO2 emissions at higher quantiles; (v) the impacts of EG on CO2 emissions have a time-, frequency-, quantile-, country-, and EG source-dependent structure. The outcomes of the study demonstrates that the ideal EG source for countries is mainly renewable EG, while in the case of the United Kingdom, nuclear EG could be an alternative for improving the environment while reducing fossil fuels.

Factors influencing the induced primary emission and induced secondary emission in the frequency range of 2 to 150 kHz

The induced primary emission leads to changes in the primary emission of a device and the induced secondary emission leads to changes in the propagation of supraharmonics in the adjacent phase due to the connection of single-phase loads spread over three phases in an installation. The induced primary emission and induced secondary emission are shown to give a significant contribution to the total emission measured at a given point in an installation. The induction of the emission is caused by the inductive and capacitive coupling among the conductors within the cables. This paper presents an analysis of four parameters that impact the magnitude of the induced emissions. Simulations carried out in COMSOL, show that the type of cable used impacts the induced emission and studies show that shielded cable with a stranded conductor with the shield grounded will lead to a reduction in the induced emissions. Among the other parameters, i.e., the load and transformer impedance and the length of the cable, the length of the cable is dominating in deciding the magnitude of the induced emissions. Analysis is carried out using Monte Carlo simulation and varying parameters stochastically. For all investigated parameters there is a strong frequency dependency. The stochastic variation of the load impedance in one phase causes a variation of 5% whereas the change in length of the cable leads to a maximum 40% variation in the considered frequency range for induced primary emission. Measurement results are presented to validate the results.

The nature of the frequency dependence of the adiabatic temperature change in Ni50Mn28Ga22-x(Cu, Zn)x Heusler alloys in cyclic magnetic fields

This study presents the results of direct measurements of the adiabatic temperature change (∆Tad) in Ni50Mn28Ga22−x(Cu, Zn)x (x = 0; 1,5) alloys in cyclic magnetic fields of 0.62 and 1.2 T at frequencies f= 1, 5, 10, and 20 Hz. The substitution of zinc and copper for the initial composition resulted in a decrease in ∆Tad and a stronger frequency dependence. The strong frequency dependence of ∆Tad near TC in the Ni50Mn28Ga22−x(Cu, Zn)x system is due to the inhomogeneous microstructure and the coexistence of martensite-austenite phases, which give rise to two simultaneously acting mechanisms. Firstly, the addition of Zn and Cu increases the coercive force HC, resulting in an increase in the viscosity coefficient. Secondly, an increase in the frequency of the cyclic magnetic field (i.e., an increase in the field sweep rate) leads to the same effect, increasing the viscosity coefficient. Which, in our opinion, is the reason for the frequency dependences of ∆Tad near TC. The study found that the specific cooling power (SCP) for the Ni50Mn28Ga22 sample in a cyclic magnetic field of 1.2 T increased with frequency, reaching 4.75 W/g at 20 Hz, which is 14.1 times greater than at 1 Hz. This suggests that, under conditions of sufficient heat exchange, the cooling efficiency of a magnetic refrigerator can be greatly improved by increasing the operating frequency.

Compensating for Nonlinear Distortions in Controlled Quantum Systems

Predictive design and optimization methods for controlled quantum systems depend on the accuracy of the system model. Any distortion of the input fields in an experimental platform alters the model accuracy and eventually disturbs the predicted dynamics. These distortions can be nonlinear with a strong frequency dependence so that the field interacting with the microscopic quantum system has limited resemblance to the input signal. We present an effective method for estimating these distortions, which is suitable for nonlinear transfer functions of arbitrary lengths and magnitudes provided the available training data has enough spectral components. Using a quadratic estimation, we have successfully tested our approach for a numerical example of a single Rydberg atom system. The transfer function estimated from the presented method is incorporated into an open-loop control optimization algorithm allowing for high-fidelity operations in quantum experiments.

Mysteries of Water and Other Anomalous Liquids: “Slow” Sound and Relaxing Compressibility and Heat Capacity (Brief Review)

Reasons for the existence of “fast” sound at terahertz frequencies in various liquids have been analyzed. It has been shown that the fast sound speed is described well by the conventional formula from the theory of elasticity, where ρ is the density of a liquid andandare the bulk and shear moduli at the frequency ω, respectively. The excess of the speed of fast sound over the speed of normal sound in “normal” liquids is 10–20% and is almost completely determined by the contribution of the shear modulusat high frequencies, and vanishes on the Frenkel line. At the same time, the huge excess (50–120%) of the fast speed of sound over the speed of normal sound in some liquids (called “anomalous”), such as water and tellurium melt, is due mainly to the strong frequency dependence of the bulk modulus. Anomalously low relaxing bulk moduli were studied in our previous works for many oxide and chalcogenide glasses near smeared pressure-induced phase transitions. In anomalous liquids, smeared phase transitions also occur in a wide temperature and pressure region, which sharply reduces the bulk moduli and speeds of sound. Thus, the record large difference between speeds of fast and normal sound in anomalous liquids is due not to anomalously fast sound but to the fact that normal sound in such liquids is anomalously “slow” and bulk moduli are anomalously low. Ultrasonic studies of low- and high-density amorphous water ices show that their bulk moduli are indeed a factor of 4–5 higher than the bulk modulus of water. In addition, because of smeared phase transitions, the heat capacities of water and tellurium melt are a factor of 1.5–2 higher than those for normal liquids; i.e., anomalous liquids are characterized not only by an anomalous (nonmonotonic) behavior but also by anomalous magnitudes of physical quantities for most of the available measurement methods. A similar anomalous increase in the compressibility and heat capacity is observed for all fluids in the close vicinity of the liquid–gas critical point. In this case, anomalously fast sound is observed at terahertz frequencies, which is also due to a sharp increase in the bulk modulusat high frequencies. At the same time, high compressibility and heat capacity, as well as a large excess of the speed of fast sound over the speed of normal sound, for anomalous liquids and glasses near smeared phase transitions are not necessarily due to the proximity of critical points and occur in any scenario of the smeared phase transition.