bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of cluster magnetorheological electro-Fenton composite polishing process for single-crystal GaN wafer based on BBD experimental method
Authors: Zheng Qiongbin , Wu Yusen , Pan Jisheng , Xiang Min , Wang Hao , Yan Qiusheng
Published: February 2024

A cluster magnetorheological (MR) electro-Fenton composite polishing technique was proposed in this work, which can realize high efficiency, ultra-smooth and damage-free of GaN wafer by the synergistic effect of electro-Fenton reaction and flexible mechanical removal of MR polishing. The key parameters of electro-Fenton were optimized through methyl orange degradation experiments based on BBD experimental method. The results showed that the decolorization rate had a strong dependence on H2O2 concentration, Fe–C concentration and pH value, where the decolorization rate had the maximum value when the H2O2 concentration of 5 wt%, Fe–C concentration of 3 wt% and pH value of 3. Compared with the Fenton reaction, the decolorization and REDOX potential of methyl orange solution were significantly improved in the electro-Fenton reaction. Furthermore, the process parameters of the cluster MR electro-Fenton composite polishing were optimized to obtain the best polishing result, which was realized under the conditions of 3 wt% diamond (grain size: 0.5 µm), a polishing gap of 0.9 mm and a polishing time of 60 min. The novel method achieved a material removal rate of 10.79 μm h−1, which was much higher than that of the conventional technique. In addition, an ultra-smooth and damage-free surface with a roughness of 1.29 nm Ra was obtained.
Active vibration control for thin curved structures using dielectric elastomer actuators
Authors: Hiruta Toshiki , Ishihara Hiroki , Hosoya Naoki , Maeda Shingo , Takagi Kentaro , Kajiwara Itsuro
Published: February 2024

This study proposes an active vibration control technique for pipe structures using dielectric elastomer actuators (DEAs). Vibrations in pipe structures must be eliminated to improve their mechanical reliability, and active vibration control techniques can be applied for effective vibration suppression. Soft actuators, which can completely fit pipe structures with complex-shaped surfaces, are required to transfer their vibration reduction forces to the target. DEA is suitable for this kind of target structure because DEA is characterized by high stretchability, flexibility, large deformation, and fast response. By applying the DEA, the effectiveness of vibration control for the pipe structure was experimentally demonstrated. A stacked DEA was fabricated and attached to the target structure. Its shape and placement were determined based on a modal analysis of the target structure. A control system, in which the controller for the active vibration control was designed based on

H
∞

control theory, was composed. The vibration control experiment was conducted using the controller with a digital control system, and the vibration reduction effect was evaluated based on the frequency response of the target pipe structure.
Design and implementation of the logic gates using electrically doped configurable polarity control double gate tunnel FET
Authors: Sharma Arun Kumar , Gopal Girdhar , Varma Tarun
Published: February 2024

This paper designs and implements the basic logic and universal gates based on the proposed electrically doped, configurable polarity control double gate tunnel FET (ED-CPC-DGTFET). In contrast to the CMOS and MOSFET, the primary concern of the proposed device is to overcome the transistor count needed to design logic gates. A few compact realizations of logic gates have been reported earlier using conventional double-gate TFETs. The main key to designing and implementing logic gates with the proposed structure is controlling the channel’s tunneling barrier height by altering the gate electrode work function. Additionally, abrupt interband tunneling of TFET by varying gate bias makes the device appropriate for implementing logic gates. The proposed device has a dynamic configuration that can change from n-type to p-type DGTFET by varying the bias at PG-1 and PG-2. Since lightly doped TFETs have a low ON-state current therefore, a high-k material (HfO

2
) is employed in place of SiO

2
on top of the source side to enhance the ON-state current. Using two-dimensional simulations, the device is designed to implement logic gates with gate lengths of 50 nm and silicon body thicknesses of 10 nm (t
si
). OR and AND logic gates are implemented using the n-type ED-CPC-DGTFET structure, and universal gates are implemented using the p-type variant of the proposed ED-CPC-DGTFET structure by independently biasing the top and bottom gates against various inputs.
Yield–stress shear thinning and shear thickening fluid flows in deformable channels
Authors: Garg Ashish , Prasad Pranjal
Published: February 2024

Yield stress shear thinning/thickening fluids flow through flexible channels, tubes are widespread in the natural world with many technological applications. In this paper, analytical formulae for the velocity profiles and flow rate are derived using the Herschel–Bulkley rheological model in both rigid and deformable shallow channels, employing the lubrication approximation. To account for deformable walls, the approach outlined by Gervais et al (2006, Lab on a Chip
6 500-7) and Christov et al (2018 J. Fluid Mech.
841 267-86) is utilized, applying small displacement structural mechanics and perturbation theory, respectively. The newly derived formulae also enable the analysis of flow dynamics in Newtonian fluids, power-law fluids, and Bingham fluids as their limiting cases, all of which have been previously described in the literature and also serves as the validation cases. It is observed that deformability increases the effective channel height and the flow rate within the channel. Multiple scaling relationships for the flow rate are identified under different applied pressure regimes and deformability parameters. Additionally, it is noted that increasing the yield stress results in decreased velocity in both the plug flow and non-plug flow regions. Higher yield stress also corresponds to an increase in the yield surface height and the solid plug within the central region, leading to a reduction in the flow rate. Furthermore, the shear thinning/thickening index is found to have no impact on plug height, although an increase in this index causes a reduction in the flow rate due to the corresponding increase in shear thickening of the material.
Quantum differential privacy under noise channels
Authors: Bai Ya-Ru , Tao Yuan-Hong , Wu Shu-Hui , Zhang Hui , Fei Shao-Ming
Published: February 2024

Quantum differential privacy is a way to protect privacy in quantum computing. It perturbs the final state of quantum computing by a specific quantum noise channel and makes the output useless to the attackers, so as to achieve privacy protection. In this paper, we study the quantum differential privacy under three channels: bit flip channel, phase flip channel and depolarizing channel. We calculate the privacy parameters for these three channels based on the proportional distance. We show the privacy protection capability by calculating the decay rates of the trace distances of two arbitrary quantum states before and after passing through the channels. Under the same privacy budget, we compare the fidelities, the trace distances between the real outputs and the outputs after entering the channels, and analyze the privacy protection performance of different quantum channels in detail.
MOND via Matrix Gravity
Authors: Avramidi Ivan , Niardi Roberto
Published: February 2024

MOND theory has arisen as a promising alternative to dark matter in explaining the collection of discrepancies that constitute the so-called missing mass problem. The MOND paradigm is briefly reviewed. It is shown that MOND theory can be incorporated in the framework of the recently proposed Matrix Gravity. In particular, we demonstrate that Matrix Gravity contains MOND as a particular case, which adds to the validity of Matrix Gravity and proves it is deserving of further inquiry.
News from the BIPM laboratories—2023
Authors: Stock Michael , Tavella Patrizia , Gressier Vincent , Wielgosz Robert , Milton Martin
Published: February 2024

In order to fulfil its mission to ensure and promote the global comparability of measurements, the BIPM operates laboratories in the fields of physical metrology, time, ionizing radiation and chemistry. These laboratories act as centres for scientific and technical collaboration between Member States providing capabilities for international measurement comparisons on a shared cost basis. They coordinate international comparisons of national measurement standards agreed to be of the highest priority, and they establish and maintain appropriate reference standards for use as the basis of key international comparisons at the highest level and provide selected calibrations from them. In the following sections, we provide highlights of the work the laboratories have undertaken during 2023.
TSA and FEM Analysis Applied to CAD/CAM Titanium All-on-Four Prosthesis
Authors: Zara Tommaso , Tribbiani Giulio , Ferranti Luca , Rossi Gianluca
Published: February 2024

Patient with fully edentulous maxillaries often suffer of several disease as an alteration of facial appearance, difficulties in eating, speech, and chews. Fixed and removable prosthesis can be a solution to rehabilitate this issue. The All-on-Four protocol is one of the possible treatment modalities for implant-supported prosthetics. It consists of placing four implants in an intermorainal position, two perpendicular to the occlusal plane and two tilted distally at a 45° angle. This paper aims to assess the stress distribution on an All-on-Four titanium prosthesis by means of a Thermoelastic Stress Analysis (TSA). This full-field non-contact measurement technique allows, through a thermal imaging camera, to observe how the surface temperature of an object changes under the effect of cyclic load. The principle on which thermoelastic analysis is based is the existence of a relationship between deformation, hence applied stress, and temperature change, called the thermoelastic effect. To perform the tests, the prosthesis was fixed to a resin jaw cast that has similar characteristics to the human bone, so that the same damping that would be present under normal working conditions could be accounted for. The distal artificial molar tooth was kept in contact to a narrow screw, which was attached to a Medium-Force (M-Series) Air-Cooled Shakers made by Santek. This shaker generates a sinusoidal load of 800N with a load cell at 10 Hz frequency, which can maintain the temperature variation of the prosthesis constant. A pre-load was applied before starting the tests. To see the change in temperature a Flir A6751SC thermal camera was used, and videos were acquired with a frame rate of 125 Hz and a resolution of 640x512 pixels. From the experimental TSA tests, the trend of the experimental stress concentration on the titanium specimen was detected. The outcomes of the experimental tests were compared to a 3D prosthesis model by Finite Element Analysis (FEM).
Application of Time Synchronous Averaging in Mitigating UAV Noise and Signal Loss for Continuous Scanning Laser Doppler Vibrometry
Authors: Mohammadi M , Oberst S , Halkon B J
Published: February 2024

The laser Doppler vibrometer (LDV) has been shown to be effective for a wide application of vibration assessments that are well accepted. One of the new avenues for exploring alternative measurement scenarios, mounting LDVs on unmanned aerial vehicles (UAVs) is emerging as a potential avenue for remote and harsh environment measurements. Such configurations grapple with the challenge of the LDV sensor head being sensitive to UAV vibration during flight and signal loss due to tracking error. This study investigates the effectiveness of several Time Synchronous Averaging (TSA) techniques to circumvent these obstacles. Through comprehensive evaluations, all three TSA techniques under investigation demonstrated significant potential in suppressing UAV-induced noise and minimising the effects of signal dropout. Traditional TSA showcased a remarkable sixfold enhancement in signal quality when analysed via the mean square error. However, the study also highlighted that while TSA and Multi-Cycle Time Synchronous Average (MCTSA) elevated signal clarity, there is a trade-off between noise suppression and signal duration. Additionally, the findings emphasise the importance of synchronisation between scanning and target vibration. To achieve optimal results in Continuous Scanning Laser Doppler Vibrometer measurements, there is a need for advanced algorithms capable of estimating target vibration and synchronising scanning in real-time. As the study was rooted in steady-state vibrations, future research should explore transient vibration scenarios, thereby broadening the application scope of TSA techniques in UAV-mounted LDV systems.
A wavefront track approach to defect detection in composites by scanning laser Doppler vibrometry
Authors: Candelaresi D , Annessi A , Allevi G , Martarelli M , Castellini P
Published: February 2024

Composite laminates are becoming increasingly popular in a large variety of applications due to their favourable mechanical properties. However, laminates production processes can lead to various defects in the final material. The most common type is related to thickness variations, e.g. delaminations between layers, which can compromise the mechanical strength of the structure. Therefore, there is a great interest in developing non-destructive and non-contact quality control techniques for composite material assessment to minimize process costs. An interesting approach is the use of laser Doppler vibrometry combined with signal analysis based on Lamb waves propagation. In this work, we used an impulsive force given by a piezoelectric disk to the specimen and a laser Doppler vibrometer acquiring the points velocity over time along a scanning grid on the surface. The specimen is a fiberglass reinforced flat panel with seven different orientated layers which presents a delamination of about 22 mm. The maximum thickness-frequency product achieved in this analysis has been 0.2 MHz∙mm. In contrast to state-of-the-art methods for identifying thickness variation based on local estimation of the principal wave number, the proposed algorithm makes use of a tracking filter of the wave front of the propagating A0 mode waves, returning a final image in polar coordinates. The final information given by the algorithm provides the position of the delamination and, hence, can be used as a pass/failure test. State-of-the-art methods are also able to identify the shape of the defect but pay the price of a higher computational cost by using at least 4D matrix processing unlike our method which only uses 3D matrices.
On the prediction of the time-varying behaviour of dynamic systems by interpolating state-space models
Authors: Dias R S O , Martarelli M , Chiariotti P
Published: February 2024

In this article, a local Linear Parameter Varying (LPV) model identification approach is exploited to analyze the dynamic behaviour of a structure whose dynamics varies over time. This structure is composed by two aluminum crosses connected by a rubber mount. To observe time-dependent variations on the dynamics of this assembly, it is placed in a climate chamber and submitted to a six minute temperature run-up. During this run-up the structure is continuously excited by a shaker. The load provided by this device is measured by a load cell, while six accelerometers are measuring the responses of the system. The temperatures of the air inside the climate chamber and at the surface of the mount are also continuously measured. It is found that during the performed temperature run-up, the rubber mount temperature increased from, roughly, 14℃ to, approximately, 35.2℃. By using the measured load provided by the shaker and the measured accelerations, Frequency Response Functions (FRFs) at five different rubber mount temperatures are computed. From each of these sets of FRFs, state-space models are estimated. Afterwards, these models are used to define an interpolating LPV model, which enables the computation of interpolated state-space models representative of the dynamics of the system at each time sample. It is found that by feeding the interpolated state-space models with the measured load, an accurate simulation of the measured accelerations is obtained. Moreover, by exploiting a joint input-state estimation algorithm with the interpolated state-space models and with the measured accelerations, a very good prediction of the applied load can be obtained. It is also shown that if the time dependency of the dynamics of the system is ignored, the results are less accurate.
The influence of material’s surface modification on the structure’s dynamics-initial test results
Authors: Goszczak J , Mitukiewicz G , Batory D
Published: February 2024

Laser Doppler Vibrometry (LDV) is a still inexhaustible source of research knowledge. Continuous development of the hardware and software makes it possible to employ this technique to new applications. Among plenty of LDV research ideas, the analysis of the influence of material’s surface modification on the structure’s dynamics is not widely investigated. The aim of the paper is to verify a research hypothesis, which assumes that by applying a thin layer of material (coating) to an existing structure or by physical modification of structure’s surface, it is possible to measurably change the dynamics features of the analysed structure in terms of values of natural frequencies and oscillations amplitudes. To perform the assumed research and measurement of vibration a doppler laser vibrometer Polytec PSV-500 was used. Measurement outcomes for different titanium alloy plates surface modifications are depicted. In article’s summary research-based conclusions are formulated.
Updates on the measurement of the speed of gravity using LDVs and MEMS resonators
Authors: Cagnani Ivan
Published: February 2024

Five years ago, at the XIII AIVELA conference, a project was presented by the author for the laboratory determination of the speed of propagation of the gravitational interaction using a vibrating tungsten disc as source of a local gravitational perturbation and a high-Q silicon resonator as gravitational antenna. Using laser Doppler vibrometers to track the vibrations of the transmitter and of the receivers, the speed of propagation of gravity would have been calculated from their measured phase difference. Numerous developments happened in the project since then, from the construction and acquirement of important components of the generator of dynamic Newtonian fields, to the experimental measurement of the speed of VHF radio waves in the near-field region as a preparatory technical test for handling and elaboration of the corresponding gravitational data. This latter experiment produced unexpected superluminal results, making it worthy of further study. The results of the test also broadened the scope of expectations and possible interpretations of the results of the gravitational experiment, including the additional role of an indirect assessment of the existence of gravitons.
Signal processing scheme for broadband heterodyne gigahertz interferometry with a broadband and a second low-noise photodetector with limited bandwidth
Authors: Schewe Marvin , Zhang Liding , Rembe Christian
Published: February 2024

There is a need for highly accurate vibration measurements in the gigahertz range. To measure these vibrations with heterodyne interferometers, methods in the state of the art require both high photodetector bandwidths and high carrier frequencies. However, conventional methods such as acousto-optic modulators rarely achieve frequency shifts above 500 MHz and are inefficient at higher frequencies. Additionally, detector bandwidths are limited, or the noise level of high bandwidth detectors is insufficient. In this paper, we propose a solution to these limitations by using a setup with two phase-locked lasers to create a beat frequency in combination with a signal processing scheme that utilizes a broadband and a second low-noise photodetector with a much smaller bandwidth and low noise. Our method could enable gigahertz heterodyne vibration measurements with high resolution. The novelty of our concept is that we only detect the lower sidebands and are still insensitive to AM. This is achieved by two consecutive measurements with frequency shifting of the lasers, effectively swapping the upper and lower sidebands.
Identification of damages in a concrete beam: a modal analysis based method
Authors: Cosoli G. , Martarelli M. , Mobili A. , Tittarelli F. , Revel G.M.
Published: February 2024

Structural Health monitoring (SHM) strategies can play a pivotal role in the perspective of enhancing structures and infrastructures life cycle and maintenance operations. A plethora of sensors and technologies can be employed in this field; in a seismic context, vibrational tests are particularly relevant, being able to give an insight on the dynamic characteristics of the structure itself. In particular, modal parameters can be considered in order to detect damages. A comparison between a certain test time and 0 test time (i.e., undamaged structure) is commonly performed; to this aim numerical models result particularly useful to provide baseline data (often unavailable in pre-existing structures), but they need to be validated before use. Non-contact techniques, like scanning laser Doppler vibrometry, can be exploited to do this. In this paper a numerical model of a scaled concrete beam is realized and validated through LDV data, then it is used to design load tests for progressive damages generation. Modal analysis is conducted after different load trials to evaluate changes of modal parameters in relation to the damage occurred; also, damage-related indices are proposed. The results confirmed the suitability of LDV for dynamic analyses of cement-based structures and this can be particularly useful when big structures (e.g., bridges) have to be monitored in-field. The numerical model was validated with acceptable absolute errors in terms of natural frequencies (between 26 Hz and 131 Hz) and high Modal Assurance Criterion (MAC) values (0.85-0.93). Moreover, the proposed methodology allows to detect damages also in a concise way through synthetic indices (with changes >50% in damaged vs undamaged conditions) and early warnings could be generated according to their values, hence supporting decision-making procedures in the building management scenario.
Highly-Linearized Heterodyne Self-Mixing Vibrometer
Authors: Cavedo Federico , Esmaili Parisa , Pesatori Alessandro , Norgia Michele
Published: February 2024

Vibration meters based on self-mixing interferometry are generally made in baseband, without modulations, because it is very difficult to obtain a linear modulation of the wavelength by controlling the supply current. In this paper, it is shown a multi-frequency modulation strategy for a heterodyne self-mixing vibrometer, which allows us to overcome the limits of frequency estimation algorithms and can work on a diffusing target up to a few meters away.
A Variable Carrier Generation for Heterodyne LDV with an Optical Phase-locked Loop
Authors: Gao Chunlin , Rembe Christian
Published: February 2024

A heterodyne laser Doppler vibrometer (LDV) requires a frequency shifter to generate a carrier for the vibration information in the detector signal. The carrier frequency should be carefully selected in order to obtain the intended measurement range with a demodulation bandwidth that avoids existing noise sources. The traditional frequency shift in heterodyne LDV is realized with an acoustooptical modulator, which can only generate a fixed carrier frequency. In this paper, a variable carrier generation method based on an optical phase locked loop (OPLL) is demonstrated. Our setup implements a feedback loop to control the phase of the second laser to synchronize a reference laser. In lock-in status the carrier for the vibration information associated with a local oscillator signal. In this paper, we obtain the laser diode parameters relevant to performance and on the design of the photodetector and loop filter. Finally, the performance of the lock-in OPLL, variable carrier as well as velocity measurement is reported and the reliability of the proposed method is evaluated.
DIC technique for experimental validation of higher order numerical models
Authors: Priya Thatikonda Nandini , Baraldi Daniele , Boscato Giosuè , Cecchi Antonella
Published: February 2024

This paper presents an adaptation to the Digital Image Correlation (DIC) technique to aid and improve standard measurement methods in experimental mechanics. The practical application is demonstrated by the validation of the Cosserat Continuum model, using small-scale masonry specimens. Numerical models, such as the Cosserat continuum, play an important role in the identification and description of the mechanical behaviour of structures. Especially when it comes to anisotropic and quasi-brittle materials like masonry, these models are needed to evaluate significant aspects like performance, safety, or the effects of various strengthening interventions. The experimental investigation to validate a numerical model is not always straightforward and several of them remain theoretical. Addressing this, the experimentation presented in this paper evaluates the Cosserat identification in shear, where along with simple shear deformation, rigid rotations, micro rotations and micro couples are also exhibited. With such complex deformations, conventional techniques, such as strain gauges, or extensometers can no longer be adopted. The adapted DIC allows the quantification of these deformation data and validates the numerical model.
Measuring the motion of the eardrum using Digital Image Correlation
Authors: Livens Pieter , Ukshini Enis , Dirckx Joris J.J.
Published: February 2024

The human eardrum is a translucent curved membrane and is in direct contact with the middle ear bones. Studying this complicated biomechanical system remains challenging. Digital image correlation (DIC) is an optical technique that allows measuring the shape and displacement of curved surfaces in 3D. In this work, we discuss the advantages and disadvantages of using DIC to study the eardrum at frequencies around 1 kHz. Special attention is given to the application of speckle patterns required to perform DIC on the translucent eardrum. Additionally, we detail an alternative approach to high-speed cameras: phase-locked light pulses. Using light pulses synced to the phase of the sound, regular DIC cameras can be used at their full resolution. This enables a high spatial resolution to thoroughly investigate the motion of the eardrum at the relevant frequencies.
Evaluation of electric field distortion at the Gaisberg Tower for continuing current measurements in lightning discharges
Authors: Kalecz G , Kiss I , Nemeth B
Published: February 2024

Upward lightning requires a distinct approach compared to downward (cloud-to-ground) lightning. Some lightning strikes are triggered by objects on the ground itself. The occurrence of such strikes depends on various factors, including the object’s geometric dimensions, structure, relative location within its environment, as well as the distribution and location of electrical charges within the thundercloud. This phenomenon takes place more and more often due to the spread of wind farms and higher buildings. In this article, simulation and calculation is carried out regarding the Gaisberg Tower in Austria which is actively used as a measurement and research site for lightning purposes. A finite element simulation is carried out to assess the electric field characteristics in the geometry. The close electric field measurement instruments are located 170 m away from the tower on an enclosure which must be considered during data analysis. The result of the created model is validated by former measurement data which confirms the arrangement of the model and creates the opportunity to directly transform the values of the electric field from the field mill to the tower during appropriate conditions.
Hybrid electrostatic filtration systems for exhaust gas cleaning
Authors: Jaworek Anatol , Sobczyk Arkadiusz T , Marchewicz Artur , Krupa Andrzej , Czech Tadeusz , Śliwiński Łukasz
Published: February 2024

Emission of submicron and nanoparticles by industrial processes, like coal or biomass combustion, solid waste incineration, cement kiln heating, and glass production is a serious environmental problem. The application of most effective bag filters is limited due to very high temperature of the exhaust gases from most of these processes, sometimes >1000 K, which the filter material cannot resists. Cyclones, which could be resistant to these temperatures, are not effective for PM2.5 particles removal, which are the most abundant in these processes. Electrostatic precipitators remove dust from flue gases with high mass collection efficiency, but in submicron range (~100 nm to 1 μm) the so called “penetration window” occurs, in which the fractional collection efficiency decreases even below 50% at minimum. Hybrid electrostatic filtration systems, which combines various conventional gas-cleaning devices were therefore proposed and tested in several research papers, in order to improve the overall collection efficiency of the precipitation processes. The heart in all of these devices is an electrostatic particle charger, which can be a conventional electrostatic precipitator, a corona-discharge particle precharger, or electrostatic particle agglomerator. After charging and/or agglomeration, the particles can be further removed by other devices like cyclones, electrostatic precipitators, or bag filters (after gas cooling to an allowable temperature). The paper reviews specific problems encountered in exhaust gas cleaning from various industrial processes, and the most interesting constructions designed for this goal. In particular, an example of a system comprising a unipolar electrostatic agglomerator, which simultaneously charges the particles and agglomerates them in alternating electric field, for the formation of aggregates of finer particles (PM1) with larger species, which could be removed by any conventional gas cleaning device, with sufficiently high collection efficiency, has been discussed in details.
Analytical and numerical modelling of the electrostatic behaviour of highly insulating materials in the time domain
Authors: Molinié Philippe
Published: February 2024

The usual response of an insulator subjected to a voltage step involves time power laws. We present here mathematical tools allowing to calculate this time domain response in open circuit after an initial charge deposit, within the framework of linear systems theory, using linear fractional transfer functions. In the time domain, the inverse Laplace transform of the data taken from the frequency domain leads to Mittag-Leffler functions, generalizing the Debye exponential response to an extended fractional α-order response. The open-circuit boundary conditions are different from the closed-circuit ones. We nevertheless demonstrate that using a transfer function deduced from the Cole-Cole response in closed-circuit, a precise analytical formula of the potential decay after an initial charge deposit may be established, and a numerical computation of this decay may be performed using easily available software. Applying the superposition principle, the voltage return following a brief short circuit may also be deduced. Experimental results are presented and the limits of the superposition principle applied to real materials are discussed.
Lab-based Martian analogue experiments investigating electric and magnetic fields of dust devils
Authors: Reid D P , Aplin K L
Published: February 2024

Dust devils – rotating vortices of lofted particulates formed by convection from solar heating - are a prevalent aspect of Martian weather.Within a dust devil, particles become charged though triboelectrification, and observations of terrestrial dust devils have revealed electric and magnetic fields. Understanding the behaviour of these aeolian events is vital for mission planning and duration, for example, with the Insight lander as a prime example of a mission cut short due to obscuration of solar panels by lofted dust, which is highly likely to be charged. Charged dust devils on Mars strongly imply the existence of electric discharges due to the low breakdown field. The existence of discharges would in turn imply a global electric circuit on the planet – with implications for organic chemical formation and methane losses.

This work presents a laboratory-based experimental set up for investigation into both electric and magnetic fields and the feasibility of using Martian analogue dust as alternative to in-situ measurements. In a dust devil, there are two main driving motions – a vertical separation of small and large particles, and the characteristic tight spiralling motion. The experimental set-up splits these components, allowing investigation into each. It is made up of a carefully designed cylindrical tank into which dusts or powders can be dropped to allow triboelectric charging as they fall under gravity. The base of the tank has a Faraday cup for charge measurement and there is also a field mill looking into the tank from the top. The rotational component is achieved using a paddle arrangement for samples placed in the base of the tank. Electric and magnetic fields have successfully been detected from charged dust with this system.
A method of risk assessment for static ignitions
Authors: Ohsawa A
Published: February 2024

This paper presents a method of risk assessment for static ignitions that can be widely used overseas. It describes how the developed risk assessment method identifies static ignition hazards and analyses static ignition risks. This method has been developed on the basis of the flow of procedures in IEC/ISO Guide 51, lessons learned from incidents over 50 years and the survey of the situation of electrostatic risk assessment in Japanese industry, and has been maintained as an implementation guide to assist safety managers since 2008. The method includes a process/operation review; hazard identification for explosive atmosphere formation, charging, electrostatic induction and electrostatic discharges; static ignition risk estimation and evaluation; and risk reduction countermeasures. Tools are also provided to aid implementation: a risk assessment sheet to follow the method and record the results, and 30 check items to identify static ignition hazards. The method with the guide has been adopted by many safety managers in Japan.
Parameters Influencing Space Charge Density in Vessels by Spraying Water
Authors: Baumann F , Schierding C , Himstedt M , Möckel D , Beyer M
Published: February 2024

Spraying water in vessels generates electrostatically charged clouds of droplets. If the resulting space charge density is sufficiently high, brush discharges to conductive earthed parts may occur. In vessels where potentially explosive atmospheres might occur, the prevention of hazardous space charge density is required. This work gives an overview of all the relevant parameters that influence the space charge density. For this purpose, own measurements are presented and compared with knowledge from the literature. The measurements have been carried out with earthed vessels and nozzles built of conductive material. To take the state of the art into account, pump pressures of up to 2500 bar have been used. The result of this work provides support for dimensioning vessels and water spraying techniques to minimize the risk of ignition hazards due to brush discharges of the electrostatically charged clouds of droplets.
Effect of moisture content on the triboelectric charging of polymers
Authors: Dani Csaba , Zeghloul Thami , Lungu Mihai , Achouri Imed-Eddine , Aouimeur Djillali , Dascalescu Lucian
Published: February 2024

The triboelectrostatic separation allows the sorting of granular polymers according to their contact charging characteristics. It consists in the appropriate triboelectric charging of particles, followed by their selective sorting in an electrostatic field. Exposed to a humid atmosphere, the polymer granules adsorb water moisture onto their surfaces, which modifies their charging characteristics, by improving the contact between surfaces. The present work was aimed at studying the effect of storage environmental conditions on the triboelectric charging of granular polymers in vibratory-type devices. Four granular different plastic wastes were placed in a climatic chamber and kept for 96 hours under controlled humidity, RH = 82% ± 4%, at 19 °C ± 1 °C. The measurement of the water content of the polymer granules pointed out an increase of at least 10% after 96 h of exposure to high relative humidity ambient conditions. The granules were successively charged by triboelectric effect in a vibratory device equipped with recipients in two different materials, at ambient conditions. The tribocharging efficiency was analyzed by measuring the electric charge of the granules with a Faraday pail connected to an electrometer. The thin water layer formed at the surface of the particle can explain their modified triboelectric behavior. The difference between the triboelectric charging behavior of “humid” and “normal” polymer granules depended also on the nature of the recipient of the tribocharging device.
Effect of atmospheric dielectric barrier discharge treatment on the triboelectric charging properties of brominated Polyethylene granules
Authors: Labiod Siham , Zeghloul Thami , Ziari Zehira , Bendilmi Mohamed-Sofiane , Dascalescu Lucian
Published: February 2024

This paper aims to investigate the effect of dielectric barrier discharge (DBD) plasma treatment on the triboelectric charging properties of granular materials containing brominated flame retardants (BFRs). This work focuses on the impact of treatment time and the applied voltage frequency. Experiments were carried out on Polyethylene (PE) particles containing 40000 ppm of bromine (PE 4.6 % of Hexabromobenzene) and BFR-free PE. The DBD treated particles were then charged by triboelectric effect in a multi-cylinder device. The triboelectric charge acquired by each sample was quantified using a Faraday cage connected to an electrometer. The humidity of the ambient air ranged between 51 % and 60 % and the temperature varied from 16.5 °C to 19 °C during the experiments. Results show the significant influence of DBD treatment time on the triboelectric charging of brominated and non-brominated PE granules. In case of brominated PE, the particles acquire less charge than the non-brominated ones. Furthermore, it was found that the charge of DBD-treated particles is influenced by the applied voltage frequency. The observed variation in triboelectric behavior may be attributed to the changes in the roughness and wettability of the polymer surface caused by DBD.
The generalized spring-loaded inverted pendulum model for analysis of various planar reduced-order models and for optimal robot leg design
Authors: Lu Wei-Chun , Lin Pei-Chun
Published: February 2024

This paper proposes a generalized spring-loaded inverted pendulum (G-SLIP) model to explore various popular reduced-order dynamic models’ characteristics and suggest a better robot leg design under specified performance indices. The G-SLIP model’s composition can be varied by changing the model’s parameters, such as ground contacting type and spring property. It can be transformed into four widely used models: the spring-loaded inverted pendulum (SLIP) model, the two-segment leg model, the SLIP with rolling foot model, and the rolling SLIP model. The effects of rolling contact and spring configuration on the dynamic behavior and fixed-point distribution of the G-SLIP model were analyzed, and the basins of attraction of the four described models were studied. By varying the parameters of the G-SLIP model, the dynamic behavior of the model can be optimized. Optimized for general locomotion running at various speeds, the model provided leg design guidelines. The leg was empirically fabricated and installed on the hexapod for experimental evaluation. The results indicated that the robot with a designed leg runs faster and is more power-efficient.
Impact of anthropogenic warming on emergence of extreme precipitation over global land monsoon area
Authors: Moon Suyeon , Ha Kyung-Ja , Lee Sun-Seon
Published: February 2024

Human activities have led to a global temperature increase, and the primary objective of the Paris Agreement is to limit this rise to 1.5 °C of warming level. Understanding the impact of global warming beyond preindustrial conditions on precipitation intensity is crucial for devising effective adaptation and mitigation strategies, particularly in densely populated global land monsoon (GLM) regions. However, the time of emergence (ToE) of extreme summer monsoon precipitation and its dependency on global warming targets has rarely been investigated. Using large ensemble simulations forced by the SSP3–7.0 scenario, we reveal that the impacts of anthropogenic forcing on extreme precipitation intensity become evident in GLM regions before 2050, accompanied by a sudden expansion in areas where the ToE of extreme precipitation occurs. Furthermore, our study demonstrates that achieving the Paris Agreement goal at 1.5 °C of global warming level can prevent the ToE of extreme precipitation in Asian and African monsoon regions. This, in turn, has the potential to halve the number (over one billion) of individuals exposed to extreme precipitation. These findings highlight the urgent need for action to mitigate the risk associated with anthropogenic warming induced climate change.
New horizons in the diagnosis and management of Alzheimer’s Disease in older adults
Authors: Dolphin Helena , Dyer Adam H , Morrison Laura , Shenkin Susan D , Welsh Tomas , Kennelly Sean P
Published: February 2024

Alzheimer’s Disease (ad) is the most common cause of dementia, and in addition to cognitive decline, it directly contributes to physical frailty, falls, incontinence, institutionalisation and polypharmacy in older adults. Increasing availability of clinically validated biomarkers including cerebrospinal fluid and positron emission tomography to assess both amyloid and tau pathology has led to a reconceptualisation of ad as a clinical–biological diagnosis, rather than one based purely on clinical phenotype. However, co-pathology is frequent in older adults which influence the accuracy of biomarker interpretation. Importantly, some older adults with positive amyloid or tau pathological biomarkers may never experience cognitive impairment or dementia. These strides towards achieving an accurate clinical–biological diagnosis are occurring alongside recent positive phase 3 trial results reporting statistically significant effects of anti-amyloid Disease-Modifying Therapies (DMTs) on disease severity in early ad. However, the real-world clinical benefit of these DMTs is not clear and concerns remain regarding how trial results will translate to real-world clinical populations, potential adverse effects (including amyloid-related imaging abnormalities), which can be severe and healthcare systems readiness to afford and deliver potential DMTs to appropriate populations. Here, we review recent advances in both clinical–biological diagnostic classification and future treatment in older adults living with ad. Advocating for access to both more accurate clinical–biological diagnosis and potential DMTs must be done so in a holistic and gerontologically attuned fashion, with geriatricians advocating for enhanced multi-component and multi-disciplinary care for all older adults with ad. This includes those across the ad severity spectrum including older adults potentially ineligible for emerging DMTs.
Veterinary systems biology for bridging the phenotype–genotype gap via computational modeling for disease epidemiology and animal welfare
Authors: Pathak Rajesh Kumar , Kim Jun-Mo
Published: February 2024

Veterinary systems biology is an innovative approach that integrates biological data at the molecular and cellular levels, allowing for a more extensive understanding of the interactions and functions of complex biological systems in livestock and veterinary science. It has tremendous potential to integrate multi-omics data with the support of vetinformatics resources for bridging the phenotype–genotype gap via computational modeling. To understand the dynamic behaviors of complex systems, computational models are frequently used. It facilitates a comprehensive understanding of how a host system defends itself against a pathogen attack or operates when the pathogen compromises the host’s immune system. In this context, various approaches, such as systems immunology, network pharmacology, vaccinology and immunoinformatics, can be employed to effectively investigate vaccines and drugs. By utilizing this approach, we can ensure the health of livestock. This is beneficial not only for animal welfare but also for human health and environmental well-being. Therefore, the current review offers a detailed summary of systems biology advancements utilized in veterinary sciences, demonstrating the potential of the holistic approach in disease epidemiology, animal welfare and productivity.
Learning by Stealth: Newly Qualified Social Workers’ Experiences of Navigating Health and Hospital Social Work
Authors: Davidson Danielle , Darracott Rosalyn
Published: February 2024

Hospitals are known to be fast paced, multidisciplinary environments, which can be experienced as both challenging and fulfilling workplaces by social workers. Newly qualified social workers (NQSWs) are still learning how to be social work professionals through their engagement in and delivery of practice. Drawing on a larger pilot study conducted in Brisbane, Queensland, this article reports findings from a cohort of NQSW hospital social workers’ conceptualisation and responses to complexity. Findings indicate that within a hospital context, NQSWs learn how to be professional social workers through stealth due to the broader organisational factors surrounding their role. Whilst these organisational factors present challenges, participants enacted several adaptive strategies to manage their work. Yet, these strategies are not without their limitations. Implications are raised in terms of the need for more purposeful support and socialisation of NQSWs within hospital contexts.
Ready, Willing and Able? Local Perspectives on Implementing Prevention in Social Care in England
Authors: Marczak Joanna , Wistow Gerald , Fernandez Jose-Luis
Published: February 2024

There is a growing emphasis on prevention to reconcile demographic pressures, resource scarcity and expectations of better quality care and support. The Care Act 2014 placed a statutory duty on English local authorities to prevent and delay the development of needs for care and support. However, evidence suggests that the prevention approach has secured less impact than intended. Given that existing approaches have achieved such limited results, new ways of addressing this apparently intractable challenge should be considered. We argue here that theory-based models that support the understanding of, and responses to, implementation barriers and facilitators can provide tools to support the development of more successful implementation. Drawing on in-depth interviews (n = 20) in selected English councils and analyses of their policy documents, we explore the ‘Ready, Willing and Able’ (RWA) model, which posits that those three preconditions must be satisfied before new practices can be implemented sustainably. We argue that RWA can provide a straightforward and parsimonious framework for identifying implementation barriers and facilitators. Using the model to identify potential bottlenecks prior to the implementation can help local actors clarify baseline barriers to progress. RWA could help to inform opportunities to target identified problems, by reinforcing facilitators and moderating barriers.