bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of laser-generated ultrasonic waves in layered plates
Authors: Cheng A. , Murray T. W. , Achenbach J. D.
Published: July 2002

A model is presented for the pulsed laser generation of ultrasound in isotropic layered plates. The stresses and displacements of the plate have been formulated in the Hankel and Laplace transform domains using the Thompson transfer matrix approach. The time domain response has been obtained by numerically inverting the transforms. Several numerical results are presented showing the normal surface displacement in the following configurations: single-layer film on a semi-infinite substrate, two layers on a semi-infinite substrate, and three-layer plates. The model provides a useful tool for the determination of which modes are generated by a laser source in a layered system. It can also be used to determine how sensitive the modes are to small changes in density, thickness, or elastic properties of the layers and to help in the selection of experimental parameters (laser spot size, pulse length, and source to receiver distance) for optimal sensitivity.
A method to calculate the acoustic response of a thin, baffled, simply supported poroelastic plate
Authors: Horoshenkov K. V. , Sakagami K.
Published: July 2002

The Helmholtz integral equation formulation is used to produce the solution for the acoustic field reflected from a finite, thin, poroelastic plate in a rigid baffle with simply supported edges. The acoustic properties of the porous material are predicted using the effective fluid assumption. The solutions for the displacement of the plate and for the loading acoustic pressures are given in the form of the sine transform. The sine transform coefficients are obtained from the solution of a system of linear equations resulting from three integral Helmholtz formulations which relate the displacement of the plate and the acoustic pressures on the front and on the back of the plate. The effect of an air gap behind the plate in the front of a rigid wall is also considered. A parametric study is performed to predict the effect of variations in the parameters of the poroelastic plate. It is shown that thin, light, poroelastic plates can provide high values of the acoustic absorption even for low frequency sound. This effect can be exploited to design compact noise control systems with improved acoustic performance.
Distortion-product otoacoustic emissions measured at high frequencies in humans
Authors: Dreisbach Laura E. , Siegel Jonathan H.
Published: July 2002

Distortion-product otoacoustic emissions (DPOAEs) elicited with stimulus frequencies less than or equal to 8 kHz have been used in hearing clinics to assess whether the middle ear and cochlea are normal, but high-frequency hearing (>4 kHz) is most vulnerable to cochlear pathology. It might prove useful to measure DPOAEs with even higher frequency stimuli (>8 kHz), but there have been few reports of such studies in humans. DPOAEs have been measured in other mammals to the upper range of hearing sensitivity. The purpose of this study was to compare some characteristics of DPOAEs in human subjects elicited with high-frequency stimuli with those that have been extensively measured with lower-frequency stimuli. The primary goal was to establish if the same phenomenon responsible for the behavior of low-frequency DPOAEs is responsible for the behavior of high-frequency DPOAEs. Specifically, the DPOAE level with stimuli varied from 2 to 20 kHz, growth functions of DPOAEs, effects of varying the primary frequency ratio (f2/f1) on the DPOAE level, and DPOAE group delay were determined. Because the behaviors appeared to vary smoothly with stimulus frequency, the study suggests that emissions measured from 2 to 20 kHz were the product of the same biological process.
Optimal recovery of the elasticity tensor of general anisotropic materials from ultrasonic velocity data
Authors: Aristégui Christophe , Baste Stéphane
Published: July 2002

An ultrasonic wave approach is presented for the optimal identification of the 21 independent elasticity constants of the most general linear homogeneous anisotropic elastic solid from wave speed measurements of obliquely incident ultrasonic bulk waves. Since the symmetry of acquisition planes is not taken into account, this inversion process is generalized to materials that do not possess three mutually orthogonal planes of symmetry. Minimization of an overdetermined system of nonlinear algebraic equations is solved by a constrained optimization method. Various classes of symmetry are considered. Several critical factors (initial guesses, scatter in experimental data) which can influence the accuracy of the elastic property reconstruction algorithm have been investigated by means of numerical examples that simulate in the best way a typical experiment. The sensitivity of the reconstruction algorithm to each identified elasticity constant is detected a posteriori by means of the estimation of a confidence interval associated with each identified constant. The generalized reconstruction method is applied to the experimental data for materials with various symmetry classes.
Sonoluminescence: An alternative “electrohydrodynamic” hypothesis
Authors: Lepoint Thierry , De Pauw Damien , Lepoint-Mullie Françoise , Goldman Max , Goldman Alice
Published: July 2002

A mechanism is proposed for the sonoluminescence (SL) arising from a single bubble maintained in levitation by an acoustic field. This proposal follows from a plasma diagnostic analysis which reveals that a single Ar bubble is characterized by a sparklike plasma (electron temperature and density: 20 000 K and 1025 m−3, respectively). The theoretical scenario (based on four hypotheses) is as follows. During its expansion and the major part of its collapse, a levitating bubble is governed by Rayleigh–Plesset dynamics. Several ns before maximum collapse the bubble interface becomes unstable and needlelike jets (the number of which is thought to be about 10) invade the bubble more or less symmetrically. Each jet (radius≈65 nm) reaches a distance equal to half of the radius of the bubble and releases a droplet (radius≈150 nm), so that an intracavity spray is released about 3 ns (perhaps less) before the time of collapse. It is implicitly proposed that the acoustic pressure at which inward jets (likely to disintegrate) may form constitutes the sonoluminescence threshold. Because of the serious distortion of the electrical double layer surrounding the bubble, both jets and droplets are electrically (but oppositely) charged. The electrical field is so high that electron emission occurs to such an extent that within 16 fs an enormous amount of energy (Joule effect) is released in the jet volume (4×1011 J m−3). The jets are ablated and a microplasma highly charged with energy (electronic temperature ⩾30 000 K; electronic density: 1026 m−3; lifetime <10 ps) expands at a velocity higher than 60 000 m s−1 so that a diverging shock wave is generated. An overpressure (higher than 1000 atm) accompanies the microplasma formation and is believed to induce strong deceleration in the bubble wall. The mechanism proposed is showed to apply to the case of bubbles in nonaqueous solvents, too. Some open questions are reported. Amongst them, (1) the possible role of the overpressure on Rayleigh–Plesset dynamics (particularly in the collapse zone) and on the aborted growth of the intracavity protuberances which might result from an incomplete ablation of the jets during the microplasma formation, (2) the effects of dissolved gases (air versus H2 or D2), (3) the effect of the liquid temperature, and (4) the role of small amounts of organic substances on SL intensity. Some experiments are suggested that may be capable of checking and distinguishing the present hypothesis from others.
Intermodulation components in inner hair cell and organ of Corti responses
Authors: Cheatham M. A. , Dallos P.
Published: July 2002

Two-tone responses are recorded from inner hair cells and from the organ of Corti fluid space in second and third turns of the guinea pig cochlea where best frequencies (BF) are approximately 4000 and 1000 Hz, respectively. This allows both ac and dc response components to be obtained and facilitates comparisons with psychophysical investigations that have traditionally been conducted at low and moderate frequencies. The measurements of ac responses in the organ of Corti fluid space also allow comparisons with mechanical results because the cochlear microphonic is proportional to basilar membrane displacement. By using a constant frequency ratio (f2/f1) of 1.4, local distortion products generated at the recording location are prominent when the two primaries are near the BF of the cell. However, when the primary pairs increase above BF, quadratic and cubic difference tones are recorded even when responses to the primaries are not measurable. The presence of these traveling distortion products is consistent with the idea that both f2−f1 and 2f1−f2 have their own traveling waves. Notches in the existence regions of quadratic and cubic difference tones were also observed and found to be influenced by mutual suppression between the two inputs.
Detection of temporal gaps in noise in dolphins: Evoked-potential study
Authors: Popov Vladimir V. , Supin Alexander Ya.
Published: July 2002

Temporal resolution of hearing was studied in bottlenosed dolphins by recording the auditory brain-stem response (ABR) evoked by gap in noise. Gaps shorter than 0.5 ms evoked a response combining both off- and on-components; longer gaps evoked separate off- and on-responses. Both the response to a short gap and on-response to the end of a long gap increased with increasing gap duration. On-response recovered completely at gap duration of 5–10 ms. Small but detectable response arose at gap duration as short as 0.1 ms. Contrary to the on-response after a long silence, the response to a short gap was less dependent on noise intensity. From these data, the temporal transfer function of the supposed integrator was derived assuming nonlinear transform of the integrator output to ABR amplitude. Equivalent rectangular duration of the found temporal transfer function was 0.27 ms.
Theory of acoustic attenuation, dispersion, and pulse propagation in unconsolidated granular materials including marine sediments
Authors: Buckingham Michael J.
Published: July 2002

A unified theory of sound propagation in saturated marine sediments is developed on the basis of a linear wave equation, which includes a new dissipation term representing internal losses arising from interparticle contacts. This loss mechanism, which shows a “memory” or hysteresis, is proposed as being responsible for the acoustic properties of sediments. To accommodate the memory, the loss term in the wave equation is formulated as a temporal convolution between the particle velocity and a material response function, h(t), which varies as t−n, where 0<n<1. The compressional wave that emerges from the analysis shows: (1) an attenuation that scales almost exactly as the first power of frequency (corresponding to a constant Q) over an unlimited number of decades; and (2) weak logarithmic dispersion. As well as being characteristic of the wave properties of actual marine sediments, the predicted attenuation and dispersion are consistent with the Kronig–Kramers relationships. The theory also leads to pulse propagation that is strictly causal, which, although a necessary requirement, is an issue that has been widely debated in the literature in the context of an attenuation that is proportional to frequency. Finally, the wave properties (phase speed and attenuation) are related to the mechanical properties (grain size, density, and porosity) of a sediment by combining the Hertz theory of particles in contact with a new, rough-surface, random-packing model of mineral grains in unconsolidated granular media. The resultant relationships between the acoustical and mechanical properties (e.g., sound speed and porosity) of marine sediments are shown to follow the trends of published experimental data sets very closely.
Diagnosis of periodic and chaotic responses in vibratory systems
Authors: Dai L. , Singh M. C.
Published: July 2002

This paper is devoted to the development of a new approach to distinguish between a chaotic and a periodic motion of a dynamical system. A criterion namely periodicity ratio is introduced to distinguish a periodic motion from a nonperiodic motion and differentiate chaos from a regular motion by a numerical procedure without plotting any figures. A Duffing’s equation and a nonlinear driven pendulum are analyzed by the periodicity ratio. Periodic–chaotic region diagrams are presented which allow a simultaneous comparison of periodic and chaotic behavior of a system with varying system parameters and a variety of initial conditions.
Suppression of distortion product otoacoustic emissions (DPOAE) near 2f1−f2 removes DP-gram fine structure—Evidence for a secondary generator
Authors: Heitmann Jürgen , Waldmann Bernd , Schnitzler Hans-Ulrich , Plinkert Peter K. , Zenner Hans-Peter
Published: July 2002

Since the discovery of distortion product otoacoustic emissions (DPOAE) there has been a controversial discussion about their cochlear generation sites. Suppression experiments suggest that the place near f2 is the main generation site. On the other hand, the fact that DPOAE can be perceived subjectively indicates that there is also a cochlear excitation at the place of 2f1−f2 resulting in a stimulus frequency otoacoustic emission (SFOAE). The contribution of this SFOAE to the overall emission is still unknown. Different studies showed contradictory results. We demonstrate a secondary generator by successive suppression of the SFOAE with a sine wave close to the frequency 2f1−f2. Suppression growth functions (SGF) showed a three-step behavior. For low suppressor levels, the emission either decreased or increased when increasing the suppressor. For intermediate suppressor levels, DP amplitude was constant and independant of suppressor level. For high suppressor levels, the emission always decreased with further increase of the suppressor. The behavior of the SGF in the first section depends on the fine structure of the DP-gram, which shows minima and maxima. Emissions at a maximum decreased while emissions at a minimum increased in the first section of the SGF. We conclude that the fine structure of the DP-gram is produced by alternate constructive and destructive interference of the two generators. By adding a third tone near 2f1−f2 the SFOAE and thus the interference are suppressed. The fine structure of the DP-gram vanishes and the resulting DP-gram should be more closely related to the cochlear status near f2.
Toward models for human production and perception of speech
Authors: Stevens Kenneth N.
Published: July 2002

Two of the goals of research in speech communication are to develop models of normal speech production and normal speech perception. Related objectives are to uncover the process by which children acquire the knowledge implicit in these models and to determine how the models are modified for disordered speech. Even partial achievement of these goals can have significant practical consequences, including machine recognition and synthesis of speech, and improved methods for diagnosis and remediation of speech disorders. In this paper, a current view of a framework for models of speech production and perception will be described, and some of the steps that have led to refinement of these models over the past 50-odd years will be described. Advances have been made in quantifying acoustic mechanisms of speech production and in specifying the nature of the discrete linguistic representation of an utterance in memory. From studies of speech perception and speech motor control, some understanding has been gained of how properties of the sound are related to the linguistic representation. There are large deficiencies, however, in our understanding of variability in speech due to speaker differences, speaking style, and context. [Work supported in part by NIH Grants DC00075 and DC02525.]
Acoustic thermometry of ocean climate: Comparison of acoustic, altimetric, and historical data
Authors: Spindel Robert C. ,   ATOC Group, Cornuelle B. D. , Dzieciuch M. , Munk W. H. , Worcester P. F. , Baggeroer A. B. , Menemenlis D. , Wunsch C. , Birdsall T. G. , Metzger K. , Clark C. , Colosi J. A. , Costa D. , Dushaw B. D. , Howe B. M. , Mercer J. A. , Spindel R. C. , Forbes A. M. G.
Published: July 2002

Approximately 15 months of data are now available from the 75-Hz ATOC transmissions from the Pioneer Seamount off Half Moon Bay, CA to horizontal arrays at 11 U.S. Navy horizontal arrays in the northeast Pacific, two vertical arrays, one near Hawaii and the other near Kiritimati (Christmas) Island. The data demonstrate that ocean basin temperatures can be determined with millidegree precision. Travel time variations at tidal frequencies agree well with predicted values. Low-frequency travel time variations provide range and depth averaged temperatures that are comparable to seasonal temperature variations derived from historical oceanography (Levitus94). They are also comparable (but not identical) to temperature variations derived from contemporaneous sea surface height variations measured by satellite altimetry. Preliminary results of combining the acoustic and altimetric data in a numerical general circulation model of the North Pacific are also available.
A viscous-elastic swimbladder model for describing enhanced-frequency resonance scattering from fish
Authors: Feuillade C. , Nero R. W.
Published: July 2002

Acoustic scattering from many species of fish is strongly increased by the resonance response of the swimbladder. This gas-filled, elastic-walled internal sac may have several functions, including hearing and buoyancy. A complete physical description of the response must include the swimbladder wall, the surrounding flesh, and the gas enclosed. This work presents a new mathematical/physical model to describe resonance scattering from swimbladder fish. The model consists of a spherical air bubble enclosed, first, by an elastic shell (representing the swimbladder wall), and then by a viscous shell (representing the surrounding fish flesh). The rigidity of the inner shell increases the monopole resonance frequency of the bubble. The viscosity of the outer shell causes the resonance to be damped. By allowing these factors to vary within physically reasonable bounds, the new model has been used to explain the experimentally measured resonance frequencies and damping of swimbladder resonances in Atlantic cod. The model provides insights into the physiological mechanisms by which fish may actively control the resonance frequencies of their swimbladders to improve hearing, and how this control can be lost under varying water pressure conditions. The impact of this issue on fisheries survey procedures is discussed.
A spring model for the simulation of the propagation of ultrasonic pulses through imperfect contact interfaces
Authors: Delsanto P. P. , Scalerandi M.
Published: July 2002

A spring model for the simulation of the propagation of ultrasonic pulses in arbitrarily complex heterogeneous media is proposed in the framework of the local interaction simulation approach (LISA). The algorithm used allows us to include heuristically additional local interaction mechanisms. In particular, the problem of propagation of pulses across imperfect contact interfaces is considered. A contact quality tensor, which is expected to be connected, although not necessarily in a trivial way, to the bond quality, is introduced directly into the model in order to treat interface flaws, such as delaminations and/or slipping bonds. To demonstrate the applicability of the technique, which is particularly suitable for parallel processing, a few examples of numerical simulation of pulse propagation in media with various kinds of imperfections are presented.
Velocity shift using the Rytov approximation
Authors: Samuelides Y.
Published: July 2002

The high-frequency propagation of acoustic plane waves in a weakly heterogeneous random stationary 2-D medium is considered. The apparent velocity of the wave is larger than the velocity corresponding to the background homogeneous medium; the difference is called velocity shift. Both this shift and the variance of the apparent velocity are calculated using the Rytov approximation; explicit formulas are given when the covariance of the medium is Gaussian. This enables one to show several properties of the shift and the variance, which are illustrated by some numerical experiments on the wave equation.
Intrinsic envelope fluctuations and modulation-detection thresholds for narrow-band noise carriers
Authors: Dau Torsten , Verhey Jesko , Kohlrausch Armin
Published: July 2002

A model is presented which calculates the intrinsic envelope power of a bandpass noise carrier within the passband of a hypothetical modulation filter tuned to a specific modulation frequency. Model predictions are compared to experimentally obtained amplitude modulation (AM) detection thresholds. In experiment 1, thresholds for modulation rates of 5, 25, and 100 Hz imposed on a bandpass Gaussian noise carrier with a fixed upper cutoff frequency of 6 kHz and a bandwidth in the range from 1 to 6000 Hz were obtained. In experiment 2, three noises with different spectra of the intrinsic fluctuations served as the carrier: Gaussian noise, multiplied noise, and low-noise noise. In each case, the carrier was spectrally centered at 5 kHz and had a bandwidth of 50 Hz. The AM detection thresholds were obtained for modulation frequencies of 10, 20, 30, 50, 70, and 100 Hz. The intrinsic envelope power of the carrier at the output of the modulation filter tuned to the signal modulation frequency appears to provide a good estimate for AM detection threshold. The results are compared with predictions on the basis of the more complex auditory processing model by Dau et al. [J. Acoust. Soc. Am. 99, 3615–3622 (1997)].
Use of context by young and aged adults with normal hearing
Authors: Dubno Judy R. , Ahlstrom Jayne B. , Horwitz Amy R.
Published: July 2002

Word recognition in sentences with and without context was measured in young and aged subjects with normal but not identical audiograms. Benefit derived from context by older adults has been obscured, in part, by the confounding effect of even mildly elevated thresholds, especially as listening conditions vary in difficulty. This problem was addressed here by precisely controlling signal-to-noise ratio across conditions and by accounting for individual differences in signal-to-noise ratio. Pure-tone thresholds and word recognition were measured in quiet and threshold-shaped maskers that shifted quiet thresholds by 20 and 40 dB. Word recognition was measured at several speech levels in each condition. Threshold was defined as the speech level (or signal-to-noise ratio) corresponding to the 50 rau point on the psychometric function. As expected, thresholds and slopes of psychometric functions were different for sentences with context compared to those for sentences without context. These differences were equivalent for young and aged subjects. Individual differences in word recognition among all subjects, young and aged, were accounted for by individual differences in signal-to-noise ratio. With signal-to-noise ratio held constant, word recognition for all subjects remained constant or decreased only slightly as speech and noise levels increased. These results suggest that, given equivalent speech audibility, older and younger listeners derive equivalent benefit from context.
A Low‐Temperature Batch Process for the Deposition of High‐Quality Conformal Alumina Thin Films for Electronic Applications
Authors: Burwell Gregory , Rejnhard Klaudia , Evans Jon , Mitchell Jacob , Grimes Michael T. , Elwin Matt , Armin Ardalan , Meredith Paul
Published: April 2023

High‐quality, alumina thin films are extensively used as dielectrics, passivation layers, and barrier layers in electronics and many other applications. However, to achieve optimum stoichiometry and thus performance, the layers are often grown at elevated temperatures (>200 °C) using techniques such as atomic layer deposition (ALD). This is problematic for substrates or structures with low thermal budgets. Herein, alumina thin films are grown on 200 mm silicon substrates employing a versatile deposition method known as MVD at low deposition temperatures (35–150 °C). The chemical composition of the resulting films is investigated postdeposition using X‐ray photoelectron spectroscopy (XPS) and variable angle spectroscopic ellipsometry, with fully stoichiometric Al2O3achieved at deposition temperatures as low as 100 °C. Dielectric measurements confirm outstanding dielectric properties compared to typical thermal ALD layers deposited at much higher temperatures. This low‐temperature deposition performance by considering the MVD reactor design and the “pump‐type” regime of precursor delivery versus the “flow‐type” regime of ALD is rationalized and understood. The results clearly demonstrate that alumina thin films grown with MVD are highly versatile for electronic applications and are of particular relevance and interest for the high‐volume processing of dielectric, passivation, and barrier layers at low temperatures.
Ultrafast, High‐Strain, and Strong Uniaxial Hydrogel Actuators from Recyclable Nanofibril Networks
Authors: Benselfelt Tobias , Rothemund Philipp , Lee Pooi See
Published: April 2023

Polymer hydrogels mimic biological tissues and are suitable for future lifelike machines. However, their actuation is isotropic, so they must be crosslinked or placed in a turgor membrane to achieve high actuation pressures, severely impeding their performance. Here, it is shown that organizing cellulose nanofibrils (CNFs) in anisotropic hydrogel sheets leads to mechanical in‐plane reinforcement that generates a uniaxial, out‐of‐plane strain with performance far surpassing polymer hydrogels. These fibrillar hydrogel actuators expand uniaxially by 250 times with an initial rate of 100–130% s−1, compared to <10 times and <1% s−1 in directional strain rate for isotropic hydrogels, respectively. The blocking pressure reaches 0.9 MPa, similar to turgor actuators, while the time to reach 90% of the maximum pressure is 1–2 min, compared to 10 min to hours for polymer hydrogel actuators. Uniaxial actuators that lift objects 120 000 times their weight and soft grippers are showcased. In addition, the hydrogels can be recycled without a loss in performance. The uniaxial swelling allows adding channels through the gel for local solvent delivery, further increasing the actuation rate and cyclability. Thus, fibrillar networks can overcome the major drawbacks of hydrogel actuators and is a significant advancement towards hydrogel‐based lifelike machines.
Iron(II)‐Catalyzed Cyanoalkylsulfonylation/Annulation Cascades toward Functionalized Sulfonylated Pyrrolidone Alkylnitriles
Authors: Huang Jiapian , Xu Shujuan , Zhu Jia , Chen Zhiyuan
Published: April 2023

Under heating conditions, an iron(II)‐catalyzed cascade cyanoalkylsulfonylation/cyclization reaction is developed to produce cyanoalkylsulfonylated pyrrolidones bearing with a free CN moiety. This alkyl radical disconnection and cascade annulation protocol enjoys chemo‐ and regioselectivity with the tolerance toward a range of functional groups. The reactive cyanoalkyl radical, which was originated from the ring‐opening reaction of a cyclic imine radical, was found to be capable of capturing the in‐situ generated “SO2” species from DABSO, thus leading to the production of a cyanoalkyl sulfonyl radical and the subsequent alkene annulation sequences.

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Mechanochemical Degradation and Recycling of Synthetic Polymers
Authors: Zhou Junfeng , Hsu Tze‐Gang , Wang Junpeng
Published: April 2023

The accumulation of plastic waste, due to lack of recycling, has led to serious environmental pollution. Although mechanical recycling can alleviate this issue, it inevitably reduces the molecular weight and weakens the mechanical properties of materials and is not suitable for mixed materials. Chemical recycling, on the other hand, breaks the polymer into monomers or small‐molecule constituents, allowing for the preparation of materials of quality comparable to that of the virgin polymers and can be applied to mixed materials. Mechanochemical degradation and recycling leverages the advantages of mechanical techniques, such as scalability and efficient energy use, to achieve chemical recycling. We summarize recent progress in mechanochemical degradation and recycling of synthetic polymers, including both commercial polymers and those designed for more efficient mechanochemical degradation. We also point out the limitations of mechanochemical degradation and present our perspectives on how the challenges can be mitigated for a circular polymer economy.
Paired Oxidative and Reductive Catalysis: Breaking the Potential Barrier of Electrochemical C(sp3)−H Alkenylation**
Authors: Zou Long , Wang Xiaofan , Xiang Siqi , Zheng Weipeng , Lu Qingquan
Published: April 2023

Due to the intrinsic inertness of alkanes, strong oxidative conditions are typically required to enable their C(sp3)−H functionalization. Herein, a paired electrocatalysis strategy was developed by integrating oxidative catalysis with reductive catalysis in one cell without interference, in which earth‐abundant iron and nickel are employed as the anodic and cathodic catalysts, respectively. This approach lowers the previously high oxidation potential required for alkane activation, enabling electrochemical alkane functionalization at the ultra‐low oxidation potential of ≈0.25 V vs. Ag/AgCl under mild conditions. Structurally diverse alkenes, including challenging all‐carbon tetrasubstituted olefins, can be accessed using readily available alkenyl electrophiles.
Chemical‐Mechanical Robustness of Single‐Crystalline Ni‐Rich Cathode Enabled by Surface Atomic Arrangement Control
Authors: Meng Xin‐Hai , Zhang Xu‐Dong , Sheng Hang , Fan Min , Lin Ting , Xiao Dongdong , Tian Jianxin , Wen Rui , Liu Wen‐Zhe , Shi Ji‐Lei , Wan Li‐Jun , Guo Yu‐Guo
Published: April 2023

Layered transition metal oxide cathodes have been one of the dominant cathodes for lithium‐ion batteries with efficient Li+ intercalation chemistry. However, limited by the weak layered interaction and unstable surface, mechanical and chemical failure plagues their electrochemical performance, especially for Ni‐rich cathodes. Here, adopting a simultaneous elemental‐structural atomic arrangement control based on the intrinsic Ni−Co−Mn system, the surface role is intensively investigated. Within the invariant oxygen sublattice of the crystal, a robust surface with the synergistic concentration gradient and layered‐spinel intertwined structure is constructed on the model single‐crystalline Ni‐rich cathode. With mechanical strain dissipation and chemical erosion suppression, the cathode exhibits an impressive capacity retention of 82 % even at the harsh 60 °C after 150 cycles at 1 C. This work highlights the coupling effect of structure and composition on the chemical‐mechanical properties, and the concept will spur more researches on the cathodes that share the same sublattice.
Evaluation of Exposure to Radiofrequency Electromagnetic Fields from Smart Utility Meters operating at 868 MHz
Authors: Addison Darren , Calderon Carolina , Peyman Azadeh
Published: April 2023

Power density and duty factor values were measured around smart utility meters operating at 868 MHz under laboratory‐controlled conditions. The maximum 6‐min averaged exposure recorded was 0.1 mWm−2, which is less than 0.0024% of the corresponding 1998 ICNIRP general public reference level. Duty factors measured were less than 2.8%. This study found that the exposure contribution from Zigbee smart meter devices operating at 868 MHz is generally lower than, if not similar to, those operating at 2.4 GHz. © 2023 Crown copyright. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society.
Validation of an LC–MS/MS method for assessment of fenbendazole sulfone drug residue in northern bobwhite liver
Authors: Henry Brett J. , Patel Dhavalkumar , Henry Cassandra , Brym Matthew Z. , Kendall Ronald J.
Published: April 2023

The Northern Bobwhite (Colinus virginianus) is an economically important game bird within the Rolling Plains Ecoregion. Within this region, bobwhite is experiencing extreme cyclic population fluctuations which are resulting in a net decline in total population. It is suspected that within this region two helminth parasites, an eyeworm (Oxyspirura petrowi) and a cecal worm (Aulonocephalus pennula), are contributing to this phenomenon. However, this has been difficult to study as the primary mode of investigation would be the deployment of anthelmintic treatment. Unfortunately, no registered treatments for wild bobwhite currently exist. Thus, utilizing an anthelmintictreatment for wild bobwhite would require registration of that treatment with the U.S. Food and Drug Administration (FDA). As bobwhite are game birds that are hunted, they are considered food‐producing animals to the FDA, and as such require the assessment for the withdrawal of the drug residues to be assessed for human food safety. In this study, we optimized and validated a bioanalytical method for the quantification of fenbendazole sulfone in bobwhite following the U.S. FDA Center for Veterinary Medicine Guidance for Industry #208 [VICH GL 49 (R)] for assessment of fenbendazole sulfone drug residue in Northern bobwhite liver. The official method for quantifying fenbendazole sulfone in domestic chicken (Gallus gallus) was adapted for use in bobwhite. The validated method quantitation range is 2.5–30 ng/mL for fenbendazole with an average recovery of 89.9% in bobwhite liver.
Hard to decide? The effect of imagery perspective and construal level on decision difficulty
Authors: Chang Chia‐Jung , Lan Shin , Huang Yu‐Wen
Published: April 2023

This research designed three experiments to investigate the mechanism of how imagery perspective influences decision difficulty, which increases consumers' willingness to postpone making choices based on the construal level. Studies 1, 2, and 3 demonstrated that imagining from the actor's perspective lowers one's construal level, and thus leads to greater decision difficulty and willingness to postpone making choices. In comparison, those taking the observer perspective represent things at higher construal levels and have less difficulty making decisions or willingness to postpone making choices. Moreover, the derived results showed the need for cognition to moderate the relationship between imagery perspective and construal level. The findings herein extended the physical buying situation to online consumption, providing implications for marketers to further explore consumer behavior.
A brain flatmap data visualization tool for mouse, rat, and human
Authors: Hahn Joel D. , Duckworth Chloe
Published: April 2023

Here we provide open‐access brain data flatmap visualization and analysis tools for the mouse, rat, and human. The present work stems from a previous JCN Toolbox article that introduced a novel flatmap of the mouse brain and substantially enhanced flatmaps of the rat and human brain. These brain flatmap data visualization tools enable computer‐generated graphical flatmap representation of tabulated user‐entered data. For mouse and rat, they are designed to accommodate data resolved spatially up to the level of gray matter regions, supported by parcellation and nomenclature defined in current brain reference atlases. For human, Brodmann cerebral cortical parcellation is emphasized, and all other major brain divisions are represented. A comprehensive user guide is included along with several use examples. These brain data visualization tools enable the tabulation and automatic graphical flatmap representation of any type of mouse, rat, or human brain data that is spatially localized. The formalized presentation afforded by these graphical tools facilitates comparative analysis between data sets within or between the represented species.
Stackedmulti‐layersecurity for Hadoop distributed file system usingHSCTsteganography
Authors: Suganya S. , Selvamuthukumaran S.
Published: April 2023

Big data needs to have scalable storage platforms as well as parallel processing environments. Hadoop is preferable because it is an open‐source software which works in a distributed, parallel processing environment and no need of any special hardware. In recent developments of Hadoop, security was introduced as optional. A symmetric block cipher advanced encryption standard (AES) is used for encryption. A 128 MB block of data needs 8 million encryptions. A better way of hiding the data from unauthorized access is preferable. Steganography, a more contemporary security technology than cryptography, is the art and science of hiding subconscious information in hidden item while exposing opponents their existence. The cover is an image, and the secret information may be a photo, music, video, or text. A double layer hexcode substituted–color space transformed (HSCT) steganography with 3 band splitting of data ensures confidentiality of the data and one time pad key generated with client's ID provides authentication also. Considering the volume of data, steganography concept is much faster than AES or any other cipher. Hiding the data inside the random images will indulge in fast reconstruction of data when needed for processing using either MapReduce or tools like spark.
Role of Hydrogen Bond Defects for Cluster Formation and Distribution in Ionic Liquids by Means of Neutron Diffraction and Molecular Dynamics Simulations
Authors: Busch Johanna , Niemann Thomas , Neumann Jan , Stange Peter , Gärtner Sabrina , Youngs Tristan , Youngs Sarah , Paschek Dietmar , Ludwig Ralf
Published: April 2023

Defects fundamentally govern the properties of all real materials. Correlating molecular defects to macroscopic quantities remains a challenge, particularly in the liquid phase. Herein, we report the influence of hydrogen bonds (HB) acting as defects in mixtures of non‐hydroxyl‐functionalized ionic liquids (ILs) with an increasing concentration of hydroxyl‐functionalized ILs. We observed two types of HB defects: The conventional HBs between cation and anion (c–a), and the elusive HBs between cations (c–c) despite the repulsive Coulomb forces. We use neutron diffraction with isotopic substitution in combination with molecular dynamics simulations for measuring the geometry, strength, and distribution of mobile OH defects in the IL mixtures. In principle, this procedure allows relating the number and stability of defects to macroscopic properties such as diffusion, viscosity, and conductivity, which are of utmost importance for the performance of electrolytes in batteries and other electrical devices.
Modeling of the effectiveness of novel edge seal designs for fast, low‐Cap‐Ex manufacturing
Authors: Kempe Michael D. , Watts Alliston , Shimpi Tushar , Ellis Samuel , Barth Kurt
Published: April 2023

In the manufacturing of photovoltaic (PV) modules, the lamination process can take up to 20 min to complete. In this work, new lamination processes are being developed, and have been prototyped, which hope to be able to cut this time down to as little as 30 s. This could provide significant savings in the cost of lamination equipment, floor space, and energy. PV modules are expected to have a lifespan exceeding 20 to 30 years. For moisture‐sensitive PV technologies, the edge seal between the two layers of glass can be the weakest point of its reliability. There is an inherent challenge when evaluating edge seal materials due to their low permeation rates. As part of Colorado State University's Photovoltaic Research and Development 2, work at the National Renewable Energy Laboratory has developed models to evaluate edge seal configurations in glass‐glass PV modules. Here, this new manufacturing process is evaluated for long‐term moisture durability. Different edge seal design options within glass–glass PV modules are explored. Most of these designs are targeting a superstrate on glass configuration, e.g CdTe, but some designs could be used on conventional crystalline Si cells. Using COMSOL finite element simulation software, we investigated the edge seal and interlayer design configurations containing silicone perimeter edge adhesive, desiccated polyisobutylene‐based edge seal, air, and polyolefin while integrating climate conditions equivalent to a hot and humid environment such as Miami, Florida. We found optimized configurations that will allow the module to prevent moisture ingress over 50 years minimizing the amount of time and material used while utilizing polymers that are easily dispensed.
Structural control on drainage pattern development of the western Taiwan orogenic wedge
Authors: Chen Cheng‐Hung , Shyu J. Bruce H. , Willett Sean D. , Chen Chia‐Yu
Published: April 2023

Structural control on drainage patterns has long been suggested to play an important role in the development of fluvial systems, including their map pattern. Along the western Taiwan orogenic wedge, a prominent drainage pattern change is present, from predominantly orogen parallel drainages in the south to river systems that flow perpendicular to the long axis of the mountain belt in the north. Such change likely reflects the temporal evolutionary process as the Taiwan orogen propagates southward. We propose that the flow direction change of river systems is produced by the development of the fold‐and‐thrust belt on the pro‐wedge side of the mountain belt and is facilitated by drainage reorganization that includes abrupt drainage captures and more gradual divide movements, permitting drainage basins to attain a geometrically stable configuration with time. Our observations in Taiwan demonstrate not only how tectonic uplift is effective at modifying river patterns in the early stages of orogenic development but also how time and increased stream power encourage river networks to adjust to more effective patterns in mature mountain belts.
Recent advances in synthesis and properties of zirconium‐based MXenes for application in rechargeable batteries
Authors: Thomas Susmi Anna , Cherusseri Jayesh
Published: April 2023

Advancement in the field of nanoscience and nanotechnology has envisaged the development of novel materials for a better human life. Nanomaterials have attracted the scientific research for the past three decades and are widely explored for multifunctional applications. Research is ongoing to understand the properties of various emerging nanomaterials such as MXenes, MBenes, transition metal dichalcogenides, black phosphorous, and so forth to name a few. Among the various layered two‐dimensional (2D) materials, transition metal carbides/nitrides/carbonitrides (collectively known as MXenes) have received profound interest due to their exciting physical and chemical properties. Among the MXene family, titanium‐based MXenes have been explored the most. But the research on non‐titanium‐based MXenes are still in the developing stage. Zirconium (Zr)‐based MXenes are the emerging materials having peculiar characteristics. Herein, we discuss the syntheses, properties, and application of Zr‐based MXenes. Initially, the MAX phases of Zr‐based MXenes are discussed. Further, the synthesis of Zr‐based MXenes by various methods are included. Furthermore, the applications of Zr‐based MXenes in rechargeable batteries such as lithium‐ion batteries, sodium‐ion batteries, potassium‐ion batteries, and so forth are reviewed.
A novel role for MLC1 in regulating astrocyte–synapse interactions
Authors: Kater Mandy S. J. , Baumgart Katharina F. , Badia‐Soteras Aina , Heistek Tim S. , Carney Karen E. , Timmerman A. Jacob , van Weering Jan R. T. , Smit August B. , van der Knaap Marjo S. , Mansvelder Huibert D. , Verheijen Mark H. G. , Min Rogier
Published: April 2023

Loss of function of the astrocyte membrane protein MLC1 is the primary genetic cause of the rare white matter disease Megalencephalic Leukoencephalopathy with subcortical Cysts (MLC), which is characterized by disrupted brain ion and water homeostasis. MLC1 is prominently present around fluid barriers in the brain, such as in astrocyte endfeet contacting blood vessels and in processes contacting the meninges. Whether the protein plays a role in other astrocyte domains is unknown. Here, we show that MLC1 is present in distal astrocyte processes, also known as perisynaptic astrocyte processes (PAPs) or astrocyte leaflets, which closely interact with excitatory synapses in the CA1 region of the hippocampus. We find that the PAP tip extending toward excitatory synapses is shortened in Mlc1‐null mice. This affects glutamatergic synaptic transmission, resulting in a reduced rate of spontaneous release events and slower glutamate re‐uptake under challenging conditions. Moreover, while PAPs in wildtype mice retract from the synapse upon fear conditioning, we reveal that this structural plasticity is disturbed in Mlc1‐null mice, where PAPs are already shorter. Finally, Mlc1‐null mice show reduced contextual fear memory. In conclusion, our study uncovers an unexpected role for the astrocyte protein MLC1 in regulating the structure of PAPs. Loss of MLC1 alters excitatory synaptic transmission, prevents normal PAP remodeling induced by fear conditioning and disrupts contextual fear memory expression. Thus, MLC1 is a new player in the regulation of astrocyte‐synapse interactions.
Backlashes or boosts? The role of warmth and gender in relational uncertainty reductions
Authors: Mitchell Rebecca L. , Matusik James G. , Johnson Russell E.
Published: April 2023

Both men and women who violate gender stereotypes incur backlashes, or penalties, for these transgressions. However, men who engage in warm, communal behaviors occasionally receive a boost (or benefit) for this female‐stereotyped behavior. To understand how and why warmth and gender interact to predict backlashes or boosts, we integrate uncertainty reduction theory with the stereotype content model and examine warmth by gender interactions. In our first study (a field examination of job seekers), we find that men receive a boost in hireability (i.e., an increased likelihood of obtaining a job offer) for exhibiting gender incongruent (i.e., high) levels of warmth, but women do not receive a backlash in hireability for exhibiting gender incongruent (i.e., low) levels of warmth. In our second study (a laboratory experiment), we replicate and extend these findings by elucidating why they occur: warmth reduces relational uncertainty for male, but not female, applicants. In our third study (another laboratory experiment), we again replicate and extend our findings by identifying when these effects are stronger: in male‐dominated roles. Our investigation suggests that the valence of the gender stereotype violation matters when it comes to hiring decisions. Indeed, we find that displaying warmth appears to promote, rather than impede, career outcomes for men.