Sonic Frequencies Research Articles

Hydraulic permeability prediction from attenuation in an oil well using the squirt flow model

A practical methodology is presented for estimating the hydraulic permeability from the wave attenuation at sonic frequencies using the poroelastic squirt flow model associated with the mechanism that encompasses the interaction between solid and fluid in an oil well. The methodology consists of four stages: a) the petrophysical evaluation, b) the static rock physics modeling that includes its diagnostics, c) the estimation of wave attenuations using an inversion scheme to optimize the Z critical parameter from the squirt flow model, d) the correlation between attenuations and the Z parameter with hydraulic permeabilities obtained by conventional well logs and available core analysis. The correlations are the means to establish the predicted hydraulic permeabilities from sonic and ultrasonic data. The obtained results suggest that the Z parameter is low while attenuations are high when the medium presents high porosity and permeability. In the methodology, the inversion scheme is proposed to find the Z parameter, the velocity dispersion, and attenuations in terms of the inverse quality factors, respectively for P-wave (QP –1) and S-wave S (QS –1) using a simulated annealing technique. The results from the application of the methodology are validated with core data (water saturation, porosity, and permeability) and mineralogical analysis from thin sections by the point counting technique. This methodology promises a means for predicting the hydraulic permeability from sonic and ultrasonic velocities in a well.

Artificial Intelligence in Metamaterial Informatics for Sonic Frequency Mechanical Identification Tags

AbstractDesigning mechanical metamaterials to control wave propagation often requires extensive finite element analysis and discrete Fourier transform simulations before fabricating 3D printed structures and conducting experiments. Here, an alternative approach is presented to developing a metamaterial informatics framework by integrating dataset collection with artificial intelligence (AI), which can significantly accelerate the advancement of phononic wave chip technologies based on the triply periodic minimal surface (TPMS). Visualized data analysis is performed to evaluate the sensitivity of phononic band frequency numbers (BNF). Subsequently, various machine learning algorithms are compared for the prediction of sonic BNFs to create a unique identificable encoded mechanical identification tag (EMIT) interacting with sound waves. Then, for the mechanical decoding part with the help of acoustic analogy, a novel concept technology is developed that integrates 3D‐printed EMITs with a deep‐learning audio classifier for the ownership identification of instruments. Underwater application is discussed further for civil accident investigations, such as echolocating missing aircraft, divers, sunken ships, and containers with valuable cargo. These TPMS‐based EMITs represent the first‐generation passive sonic frequency identification (SFID) transponder‐tags, marking the advent of SFID transponder systems.

Laboratory measurements of water saturation effects on the acoustic velocity and attenuation of sand packs in the 1–20 kHz frequency range

AbstractWe present novel experimental measurements of acoustic velocity and attenuation in unconsolidated sand with water saturation within the sonic (well‐log analogue) frequency range of 1–20 kHz. The measurements were conducted on jacketed sand packs with 0.5‐m length and 0.069‐m diameter using a bespoke acoustic pulse tube (a water‐filled, stainless steel, thick‐walled tube) under 10 MPa of hydrostatic confining pressure and 0.1 MPa of atmospheric pore pressure. We assess the fluid distribution effect on our measurements through an effective medium rock physics model, using uniform and patchy saturation approaches. Our velocity and attenuation (Q−1) are accurate to ±2.4% and ±5.8%, respectively, based on comparisons with a theoretical transmission coefficient model. Velocity decreases with increasing water saturation up to ∼75% and then increases up to the maximum saturation. The velocity profiles across all four samples show similar values with small differences observed around 70%–90% water saturation, then converging again at maximum saturation. In contrast, the attenuation increases at low saturation, followed by a slight decrease towards maximum saturation. Velocity increases with frequency across all samples, which contrasts with the complex frequency‐dependent pattern of attenuation. These results provide valuable insights into understanding elastic wave measurements over a broad frequency spectrum, particularly in the sonic range.

Simulating squirt flow in realistic rock models using graphical processing units (GPUs)

SUMMARY Understanding the underlying mechanisms of seismic attenuation and moduli dispersion in fluid-saturated cracked porous rocks is of great importance for the development of non-invasive methods to characterize the subsurface. Wave-induced fluid flow at the pore scale, so-called squirt flow, is responsible for seismic attenuation and moduli dispersion at sonic and ultra-sonic frequencies and may be relevant at seismic frequencies. The squirt flow associated attenuation is usually quantified using analytical models. However, numerical experiments suggest that the squirt flow related dissipation is sensitive to fine details of the pore geometry, which can only be modelled numerically. Most of the existing numerical studies explore this phenomenon using simplified models, and there is a lack of numerical studies that model the physics in realistic pore geometries with sufficient numerical resolution. As a result, the impact of wave-induced fluid flow on the effective static and time-dependent mechanical characteristics in realistic settings is still poorly understood. I address these issues by developing a numerical method to model the effective mechanical properties of a hydromechanically coupled system at the pore scale suitable for graphical processing units. A numerical evaluation of attenuation and modulus dispersion due to squirt flow in models based on 3-D microtomography images of cracked Carrara marble is presented. It is shown that the local hydraulic conductivity can be quantitatively estimated from the numerically evaluated effective properties. The accuracy of the numerical results is carefully analysed. This study improves the understanding of the underlying mechanisms of attenuation and moduli dispersion in fluid-saturated cracked rocks. The new method can be applied to model squirt flow for entire laboratory samples in the centimetre scale which was not possible a decade ago.

Seismoelectric wave propagation through a fluid-saturated porous sandwiched interlayer

The seismoelectric waves generated in a fluid-saturated porous interlayer and the reflection/transmission characteristics at the interfaces of sandwiched structure are studied in this paper. Aiming to describe the strong attenuation and dispersion simultaneously at seismic and sonic frequencies, a new fractional viscoelastic model for the solid skeleton is introduced to the Pride's seismoelectric coupling theory. Using the interfacial continuity of stress, displacements, magnetic and electric fields, the reflection/transmission coefficients are determined. The numerical results are provided and shown graphically. The effects of seismoelectric coupling and the viscoelastic characteristics of solid skeleton on the reflection and transmission of seismoelectric waves are mainly studied. It is observed that the thickness, porosity and the viscoelastic characteristics of solid skeleton have evident effects not only on the electromagnetic waves but also on the seismic waves.

Laboratory experiments and theoretical study of pressure and fluid influences on acoustic response in tight rocks with pore microstructure

AbstractWave‐induced fluid flow is considered to be a major source of seismic attenuation and dispersion in porous rocks. From the physical description of partially saturated reservoirs, numerous analytical solutions based on upscaling homogenization theories have been employed to calculate equivalent frequency‐dependent poroelastic media. Nevertheless, dispersion and attenuation predictions are often not reasonably consistent with laboratory and field measurements in a broad frequency range, particularly due to influences of biphasic fluids and their distribution, presence of heterogeneities on various length scales, and pore microstructure. We investigate the role of pore microstructure on pressure and fluid saturation dependence of elastic velocities in tight sandstones. Previous work points out that differentiating the impacts of heterogeneities at various scales on dispersion within seismic exploration and sonic frequencies can be very difficult. In practice, this is because fluid‐related dispersion mechanisms are impossible to be independent. Thus, it is important for a theoretical and more quantitative analysis of the relative contribution of interrelated energy dissipation processes through a better understanding of combined influences due to the presence of microscopic and mesoscopic heterogeneities. Based on microscopic squirt flow and mesoscopic flow in a partially saturated medium, we develop a poroelastic model that allows evaluating the overall frequency‐dependent dispersion via considering a random distribution of fluid heterogeneities as well as the broadly distributed aspect ratio of compliant pores. Experimental validation of the model is accomplished via a comprehensive comparison of predictions with measurements of partially saturated velocities versus pressure and fluid for sandstones with specific pore microstructures.

Experimental Study of Seismic Wave Attenuation in Carbonate Rocks

Summary Seismic wave attenuation has a great potential for studying saturated and fractured media, due to its high sensitivity to the physical properties of geological media. However, accurately estimating this parameter can be challenging due to its sensitivity to signal noise, particularly in heterogeneous media such as carbonate rocks. This explains the paucity of attenuation studies carried out in carbonate rocks compared with sandstones, and the ambiguity around its mechanisms and its relationship with petrophysical properties. To investigate further, we conducted an experimental study of ultrasonic waveform signals (0.5–3 MHz) reordered under dry and fully saturation conditions in 13 samples covering a wide range of petrophysical values and subjected them to differential pressure reaching reservoir pressure. The resulting increase in attenuation magnitudes and their variation with pressure due to brine saturation were more pronounced than in velocity magnitudes, confirming the higher sensitivity of attenuation to fluid content. However, understanding the relationship between attenuation and petrophysical properties required a careful examination of the results and more elucidation about attenuation mechanisms. We suggested that multiple attenuation mechanisms coexist, including scattering, cracks slipping, solid frictional relative motion, and global and squirt flow. This explains the frequency dependence of attenuation, with higher magnitudes at sonic frequencies, where the squirt flow mechanism may be dominant. In contrast to sandstone, the magnitude of compressional to shear attenuation ratio (QP−1/QS−1) was found to be greater than unity in both dry and brine fully saturated carbonate samples at ultrasonic frequencies. This result may be due to the complex porosity structure of carbonate rocks, which makes it not appropriate to the sandstone rock physics models.

Extraction of Vitamin B12 from Aqueous Solution by using Solid- Liquid Extraction and Ultra Sonic Frequency

A new method to uptake vitamin B12 in aqueous solution as pharmaceutical preparations by adsorption on the solid phase surface by using a multi-layer graphene oxide derivative compounds while the ultrasonic frequency wave was used to increase the efficiency of the extraction of drug from aqueous solution. Interlayer drug extraction conditions were optimized by studying a number of conditions that affect the extraction rate, including pH, ultrasound frequency, residence time of the solution inside the ultrasound device, the effect of the amount of graphene oxide derivative, and vitamin B12 concentration. The effect of temperature was also studied and a number of thermodynamic factors were generated. From the results, it was found that the best weight for the economically useful graphene oxide derivative is 0.01 grams at a concentration of 20 ppm relative to the concentration of the vitamin using an acidic medium of 2.1. The best temperature is 40 0C and within 50 Hz of the frequencies of the ultrasound device during the incubation period of 50 minutes. The proposed method was also applied to pharmaceutical samples containing vitamin B12, and the extraction rate was 95.35 %, with a very small error rate of 0.0465.

A COMBINED ACTIVE (PIEZOS) AND PASSIVE (MICROSTRUCTURING) PARTIAL FLOW-BOILING APPROACH FOR STABLE HIGH HEAT-FLUX COOLING WITH DIELECTRIC FLUIDS

Controlled but explosive growth in vaporization rates is made feasible by ultrasonic acoustothermal heating of the microlayers associated with microscale nucleating bubbles within the microstructured boiling surface/region of a millimeter-scale heat exchanger (HX). The HX is 5 cm long and has a 1 cm × 5 mm rectangular cross section that uses saturated partial flow-boiling operations of HFE-7000. Experiments use layers of woven copper mesh to form a microstructured boiling surface/region and its nano/microscale amplitude ultrasonic (~1-6 MHz) and sonic (< 2 kHz, typically) vibrations induced by a pair of very thin ultrasonic piezoelectric-transducers (termed piezos) that are placed and actuated from outside the heat-sink. The ultrasonic frequencies are for substructural microvibrations whereas the lower sonic frequencies are for suitable resonant structural microvibrations that assist in bubble removal and liquid filling processes. The flow and the piezos' actuation control allow an approximately 5-fold increase in heat transfer coefficient value, going from about 9000 W/m<sup>2</sup>-°C associated with microstructured no-piezos cases to 50,000 W/ m<sup>2</sup>-°C at a representative heat flux of about 25 W/cm<sup>2</sup>. The partial boiling approach is enabled by one inlet and two exit ports. Further, significant increases to current critical heat flux values (~70 W/cm<sup>2</sup>) are possible and are being reported elsewhere. The electrical energy consumed (in W) for generating nano/micrometer amplitude vibrations is a small percentage (currently < 3%, eventually < 1% by design) of the total heat removed (in W), which is a heat removal rate of 125 W for the case reported here.

A simple and accurate model for attenuation and dispersion caused by squirt flow in isotropic porous rocks

Seismic waves propagating in fluid-saturated porous rocks exhibit attenuation and velocity dispersion in a broad range of frequencies. At sonic and ultrasonic frequencies, the attenuation is predominantly caused by fluid flow in cracks and grain contacts, so-called squirt flow. This physical mechanism for attenuation also may be relevant at seismic frequencies. We develop a simple and accurate analytical model for attenuation and dispersion caused by squirt flow in isotropic porous rocks. The input material properties for a specific rock model can be directly measured in a laboratory or calculated using analytical and numerical approaches. The results from our squirt flow model are compared with inherently accurate 3D numerical solutions for the same pore geometries. The analytical and numerical results are in good agreement. Furthermore, we observe that our analytical model is more accurate than the currently available analytical solution for squirt flow in isotropic porous rocks. MATLAB routines to reproduce the presented results are made available.

Effects of Pore Geometry and Saturation on the Behavior of Multiscale Waves in Tight Sandstone Layers

AbstractGeometric heterogeneities in tight reservoir rocks saturated with a fluid mixture may exhibit different scale distribution characteristics. Conventional models of rock physics based on poroelasticity, which usually consider single‐scale pore structure and fluid patches, are inadequate for describing elastic wave responses. A major challenge is to establish the relationship between the wave response at different spatial scales and frequencies. To address this problem, three sets of observational data over a wide frequency range were obtained from a tight oil reservoir in the Ordos Basin, China. Ultrasonic measurements were made on eight sandstone samples at partial oil‐water saturation at 0.55 MHz. Data from six borehole measurements and seismic profiles were acquired and analyzed at about 10 kHz and 30 Hz, respectively. Analysis of the cast thin sections shows that dissolution pores and microcracks generally develop, with fractal dimensions of the pores ranging from 2.45 to 2.67 for the samples with porosities between 5.1% and 10.2%. Compressional wave velocity and attenuation were estimated from the observed data. The results show that the velocity dispersion from seismic to ultrasonic frequencies is 10.02%, mostly occurring between sonic and ultrasonic frequencies. The attenuation is stronger at higher oil saturation. The relationships between velocity, attenuation, and wavelength were established and can be used for further forward modeling and seismic interpretation studies. A partial saturation model has been derived based on effective differential medium theory and a double double‐porosity model, assuming that the medium contains fractal cracks and fluid patches. The effects of scale and saturation on wave responses are prevalent. Modeling results consistent with observed data show that the radii of cracks and fluid patches range from 0.1 μm to 2.8 mm, affecting ultrasonic, acoustic, and seismic attenuation. The multiscale data and proposed model quantify the relationship between fracture and fluid distributions and attenuation and could be useful for upscaling to the reservoir scale. The study helps improve the understanding of seismic wave propagation in partially saturated rocks, which has potential applications in seismic exploration, hydrocarbon production in reservoirs, and CO2 sequestration in aquifers.

Petrophysical parameters inversion for heavy oil reservoir based on a laboratory-calibrated frequency-variant rock-physics model

Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results for seismic inversion of heavy oil reservoir. To describe the viscoelastic behavior of heavy oil, we modeled the elastic properties of heavy oil with varying viscosity and frequency using the Cole-Cole-Maxwell (CCM) model. Then, we used a CCoherent Potential Approximation (CPA) instead of the Gassmann equations to account for the fluid effect, by extending the single-phase fluid condition to two-phase fluid (heavy oil and water) condition, so that partial saturation of heavy oil can be considered. This rock physics model establishes the relationship between the elastic modulus of reservoir rock and viscosity, frequency and saturation. The viscosity of the heavy oil and the elastic moduli and porosity of typical reservoir rock samples were measured in laboratory, which were used for calibration of the rock physics model. The well-calibrated frequency-variant CPA model was applied to the prediction of the P- and S-wave velocities in the seismic frequency range (1–100 Hz) and the inversion of petrophysical parameters for a heavy oil reservoir. The pre-stack inversion results of elastic parameters are improved compared with those results using the CPA model in the sonic logging frequency (∼10 kHz), or conventional rock physics model such as the Xu-Payne model. In addition, the inversion of the porosity of the reservoir was conducted with the simulated annealing method, and the result fits reasonably well with the logging curve and depicts the location of the heavy oil reservoir on the time slice. The application of the laboratory-calibrated CPA model provides better results with the velocity dispersion correction, suggesting the important role of accurate frequency dependent rock physics models in the seismic prediction of heavy oil reservoirs.

Attuning to In‐the‐Red Frequencies with/in Readers Workshop

AbstractIn this article, we ‘think with’ the theoretical concepts of flow, rupture, layering, and sampling to affectively attune to ‘in‐the‐red frequencies’ flowing across/with‐in a New York City primary classroom—that is, alternative sonic frequencies that trouble and refuse hegemonic literacy practices. These hip‐hop concepts theorise affect in relation to Black intellectual frameworks for moving, feeling, and sounding. Such frameworks honour philosophical practices emerging from Black people's lived experiences—practices that, historically, have been perceptually coded out of legibility by white supremacist institutions. Ultimately, we argue that thinking with flow↔rupture↔layering↔sampling enables more equitable practices that push literacies ‘into the red,’ namely, by respecting multiple perspectives, histories, and truths; accounting for power, privilege, positioning, and complicity; and highlighting ‘otherwise’ social worlds not predicated on hegemonic whiteness, anti‐blackness, and socio‐political violence.

Anahad Naad and Pictorial Resonance: The Halo and Sonic Vibration in Sikh Art

The halo is a familiar symbol across Buddhist, Christian, and Mughal art, but its role in Sikh visual media has yet to be acknowledged and examined. This article studies the Sikh halo in relation to key philosophical concepts of dasam dwar (the tenth door/opening, located at the crown of the head) and anahad naad (an embodied perception of an internally heard music). When viewed from a Sikh perspective, the halo emerges as an external marker of an internal attunement to the divine one. As spectators, we attune to the latent sonic frequencies of the halo, which reflect the spiritual attainment of Sikh Gurus and other holy figures. Sikh art allows the inner/outer dialectic of the halo to come into view: to our eyes, the halo signals spiritual realization, while to our ears, it invites us to contemplate the intensity of sonic vibration that resounds through and emits from the divine body in tandem with the expressive kirtan of Bhai Mardana and his rabab (a plucked chordophone). 
 
 Drawing on select artwork, I invite spectators to experience the sonic dimension through attention to the unique positioning of the halo in relation to the rabab. My critical focus on sonic vibration as suggested by a symbolic connection between the halo and anahad naad allows a concentration at the head to offer a new vantage point for understanding the iconographical presence of this symbol. This article centers Sikh art within the long history of the halo while highlighting how this symbol establishes a unique epistemological system of expressive meaning.

Introducing realistic distributions of gas bubble size and inclusion aspect ratio to model the coexistence of gas hydrate and free gas

The coexisting free gas within the hydrate stability zone is recognized by laboratory and field studies. The conventional resistivity method fails to obtain hydrate saturation in the sediment with gas hydrate and free gas because both of them are electrical insulators. Hydrate saturation can be obtained from a velocity log based on a certain rock physics model. However, few studies of rock physics have been conducted on gas and hydrate coexistence. In this study, a more realistic distribution of gas bubble size and inclusion aspect ratio was introduced into an effective medium model to elucidate how such coexistence affects velocity and attenuation at a broad-band frequency. The modeling results obtained indicate that such coexistence decreases P-wave velocity at low frequencies, while increases P- and S-wave velocities at high frequencies. The velocity decrease of P-wave at low frequencies is attributed to the overwhelming effect of gas bubble vibration, while it seems not to affect P-wave velocity at high frequencies significantly. Moreover, coexisting gas hydrate and free gas may strengthen P-wave attenuation at the broad-band frequency range. It is found that the damping of oscillating gas bubbles dominates P-wave attenuation at low frequencies, while squirt flow in the porous hydrate is more likely to contribute to P-wave attenuation at high frequencies. Hydrate morphology is also a significant factor affecting P-wave velocity and attenuation at high frequencies. This research reveals that rock physics modeling can provide insight into how to characterize the coexisting gas hydrate and free gas as referring to the acoustic velocity and attenuation at seismic, sonic, and ultrasonic frequencies.

Analytical simulation of the elastic moduli dispersion for an isotropic porous cylinder

There are extensive laboratory measurements of elastic moduli dispersion of porous materials, yet the mechanisms for the dispersion are not fully understood. Related analytical solutions are missing in the literature, potentially due to complex mathematical derivations. In this paper, we use Biot's theory of poroelastodynamics (PED) and present the first analytical solution for an isotropic fluid-saturated porous cylinder subject to a forced deformation test. This is done by introducing Helmholtz decomposition, two scalar potentials, and two vector potentials to decouple the original governing partial differential equations. The methods of matrix diagonalization and separation of variables are then used to solve the decoupled equations. The elastodynamics (ED) solution is also presented. We demonstrate the coupled responses of displacement, pore pressure, and stress and interpret systematically the mechanisms for the elastic moduli dispersion. Furthermore, we investigate comprehensively the effects of loading frequency, material's poromechanical characteristics, sample size, and boundary conditions on the elastic moduli dispersion. Finally, excellent matches are found between the analytical solution and published measurements of the dynamic Young's moduli and Poisson's ratios of a water-saturated clastic sediment rock and a glycerin-saturated limestone. The analytical solution captures the materials’ elastic moduli dispersion at both seismic and sonic frequencies. This work should be of interest to scientists and engineers who work on dynamics, vibration, and poromechanics.

Frequency-dependent P-wave anelasticity due to multiscale (fractal) heterogeneities in rocks

Understanding the effect that multiscale heterogeneities have on the wave responses of rocks at different frequencies is essential in the interpretation of seismic data. In fact, the behaviors of ultrasonic and seismic waves differ because the experiments involve different spatial scales. Then, a solution is to apply a theory that establishes a relation between the wave properties at different frequency bands considering a size range of heterogeneities. To investigate this problem, we have measured the compressional wave (P-wave) anelasticity (velocity and attenuation) of tight reservoir rocks at ultrasonic, sonic and seismic frequencies. The wave behavior as a function of porosity or clay content shows a consistent trend. With increasing confining pressure, the effect of porosity on attenuation decreases, while that of clay content gradually becomes important. To interpret the data, we propose a double-fractal poroelasticity model by incorporating the self-similarity characteristics of cracks and clay minerals. The comparison between the experimental data and model results reveals the fractality of the clay inclusions and cracks, with radii range of [10−6, 10−1.5] m and [10−6, 10−3.1] m, respectively, which is responsible for the anelastic behavior of the waves on a wide frequency band.

Acoustic Dispersion in Low Permeability Unconventional Reservoir Rocks and Shales at In Situ Stress Conditions

Utilizing laboratory measurements on dry and fully brine-saturated well-lithified shale reservoir rocks and comparing them to log data and theoretical modeling, we find no statistically significant intrinsic dispersion from seismic to sonic and laboratory measurement frequencies due to fluid effects. Under in situ stress conditions, the Gassmann zero-frequency P-wave velocity prediction for a Permian basin sample was within 0.3% of the measured velocity on the brine-saturated sample at an ultrasonic frequency. At deviatoric stresses ranging from 1.7 to 70 MPa on the same sample, the percent error in the Gassmann P-wave velocity prediction ranges from 0.3 to 2.2%. These results are consistent with the lack of significant dispersion in the reported velocities and theoretical predictions in the Cotton Valley shale. Based on the Biot–Gassmann model, the characteristic frequency in both formations occurs at ~1010 Hz. Applying a squirt flow model also predicts transition to the high-frequency regime occurring at ~109 Hz for both formations. The comparison of the sonic log measurements for four different shale/tight rock formations to ultrasonic measurements taken from core samples under in situ stress conditions confirms these findings. To our knowledge, this is the first extensive comparison of the sonic log to ultrasonic core data measurements. For these rocks, there is no clearly observable or predicted significant dispersion due to fluid effects at in situ stress conditions within the frequency range for which measurements are made.

Reviving the sound of a 150-year-old insect: The bioacoustics of Prophalangopsis obscura (Ensifera: Hagloidea).

Determining the acoustic ecology of extinct or rare species is challenging due to the inability to record their acoustic signals or hearing thresholds. Katydids and their relatives (Orthoptera: Ensifera) offer a model for inferring acoustic ecology of extinct and rare species, due to allometric parameters of their sound production organs. Here, the bioacoustics of the orthopteran Prophalangopsis obscura are investigated. This species is one of only eight remaining members of an ancient family with over 90 extinct species that dominated the acoustic landscape of the Jurassic. The species is known from only a single confirmed specimen-the 150-year-old holotype material housed at the London Natural History Museum. Using Laser-Doppler Vibrometry, 3D surface scanning microscopy, and known scaling relationships, it is shown that P. obscura produces a pure-tone song at a frequency of ~4.7 kHz. This frequency range is distinct but comparable to the calls of Jurassic relatives, suggesting a limitation of early acoustic signals in insects to sonic frequencies (<20 kHz). The acoustic ecology and importance of this species in understanding ensiferan evolution, is discussed.

‘I want my [un]happy ending!’ Queering happily ever after with/in a primary classroom

ABSTRACT In this paper, I explore moments in past research when my sense-making faltered, my confusion/joy/longing proliferated, and my own feelings got the best of me. I discuss the generative potential of these ‘analytical conundrums’ via a queer map of messy ‘complaints’. Within/across these complaints, I playfully attune to the sonic frequencies of happily ever after with/in diverse, intersecting dimensionalities. As I imagine them here, complaint mappings are provocations that invite us to sense/queer/reimagine educational research/practices/pedagogies that encourage subjects to live in one world – where having ‘a life’ becomes synonymous with having the right kind of intimate life. Specifically, I map out how literacy events are more-than-human scenes of entanglement, wherein gender/sex/uality/desire do not reside within individuals or things, but rather emerge via complex, entangled, and ‘mobile’ processes of attaching↔relating. It is my hope that mapping these ‘complaints’ will help tell these moments otherwise by generating a kind of un/happiness that embraces relationality, chance, possibility and wonder.