bluuebunny/crossref_metadata_2025 huggingface dataset:
Prosthetic Management of Flap-Related Complications Following Glossectomy in Locally Advanced Tongue Cancer
Authors: Jagtiani Kiran , Bhatia Prachi , Jain Radhika , Singh Gurkaran Preet , Gurav Sandeep
Published: September 2023

Total glossectomy defects resulting from postoncologic resection are commonly reconstructed with locoregional or free flaps. However, effectively managing complications that may arise after reconstruction can be a significant challenge. We present a unique case series describing prosthetic management of flap-related complications following glossectomy in patients treated for locally advanced tongue cancer. Three patients underwent total glossectomy, neck dissection, reconstruction using free flap, and tracheostomy. Two patients developed an intraoral fistula located in the anterior region of the floor of the mouth. The third patient developed a flap failure requiring a second procedure using a pectoralis major myocutaneous flap for correction of the orocutaneous fistula that ultimately did not heal. Mandibular obturator prostheses lined with a soft liner were fabricated for all the patients, which helped reduce salivary incontinence and improve swallowing and speech. This case series highlights that a collaborative interdisciplinary team approach is crucial for optimizing postoperative function and outcomes when managing complications from reconstructive procedures.
Arthroplasty-Related Pseudotumor of the Scapula: Case Report and Review of the Literature
Authors: Kapustina Irina , Ali Youssef , Kallen Michael E. , Hasan S. Ashfaq , Davis Derik L.
Published: September 2023

Arthroplasty-related pseudotumors are nonneoplastic and noninfectious inflammatory masses that are typically associated with adverse reaction to metal debris. Pseudotumors most commonly occur in the setting of metal-on-metal joint replacements at the hip. However, the presentation of pseudotumor at the shoulder is exceedingly rare. In this article, we reported a case of arthroplasty-related pseudotumor of the scapula. Clinical history, radiologic signs, and tissue analysis are described. Knowledge of this rare diagnosis will support clinical decision making for teams of radiologists, pathologists, oncologists, and orthopaedic surgeons who provide care for patients presenting with suspicious shoulder masses.
Evaluation of an Objective MRI-Based Tumor Regression Grade (mrTRG) Score and a Subjective Likert Score for Assessing Treatment Response in Locally Advanced Rectal Cancers—A Retrospective Study
Authors: Katdare Aparna N. , Baheti Akshay D. , Pangarkar Sayali Y. , Mistry Kunal A. , Ankathi Suman K. , Haria Purvi D. , Choudhari Amit J. , Guha Amrita , Gala Kunal , Shetty Nitin , Kulkarni Suyash , Ramadwar Mukta , Bal Munita
Published: September 2023

Purpose: Magnetic resonance imaging (MRI) with the help of MRI-based tumor regression grade (mrTRG) score has been used as a tool to predict pathological tumor regression grade (pTRG) in patients of rectal cancer post-neoadjuvant chemoradiation. Our study aims to evaluate the ability of MRI in assessing treatment response comparing an objective mrTRG score and a subjective Likert score, with a focus on the ability to predict pathologic complete response (pCR).

Methods: Post-treatment MRI studies were retrospectively reviewed for 170 consecutive cases of histopathologically proven rectal cancer after receiving neoadjuvant chemoradiation and prior to surgery by two oncoradiologists blinded to the eventual postoperative histopathology findings. An objective (mrTRG) and a subjective Likert score were assigned to all the cases. Receiver operating characteristic curves were constructed to determine the ability of Likert scale and mrTRG to predict pCR, with postoperative histopathology being the gold standard. The optimal cutoff points on the scale of 1 to 5 were obtained for mrTRG and Likert scale with the greatest sum of sensitivity and specificity using the Youden Index.

Results: The most accurate cutoff point for the mrTRG to predict complete response was 2.5 (using Youden index), with a sensitivity of 69.2%, specificity of 69.6%, positive predictive value (PPV) of 85.6%, negative predictive value (NPV) of 46.4%, and accuracy of 69.3%. The most accurate cutoff for the Likert scale to predict complete response was 3.5, with a sensitivity of 47.5%, specificity of 89.1%, PPV of 91.9%, NPV of 39.4%, and accuracy of 59%. mrTRG had a lower cutoff and was more accurate in predicting pCR compared to Likert score.

Conclusion: An objective mrTRG was more accurate than a subjective Likert scale to predict complete response in our study.
Quantification of the Field of View for Standard Lateral Arthroscopy of the Canine Shoulder
Authors: Holman Sarah N. , Schaefer Susan L.
Published: September 2023

Objective The aim of this study was to define the extent of the biceps tendon, subscapularis tendon, and cranial border of the medial glenohumeral ligament within the field of view during standard lateral shoulder arthroscopy in the dog. We also examine the effect of joint flexion on the field of view of the biceps tendon.

Study Design This was a cadaveric study using 21 shoulders of large breed dogs. Each shoulder was explored with a 30-degree arthroscope using standard lateral ports. For each supporting structure, the margins within the arthroscopic field of view were marked with ink. In 11 shoulders, the distal margin of the biceps tendon was identified and marked first with the limb at a standing angle and then in flexion. The margins of the cranial border of the medial glenohumeral ligament were marked at the standing angle. In 10 additional shoulders, the margins of the subscapularis tendon were evaluated. Each joint was fully dissected and the portion of each stabilizing structure within the field of view was quantified.

Results Fifty-eight percent of the cranial border of the medial glenohumeral ligament was within the arthroscopic view. At a standing angle, 48% of the intra-articular length of the biceps tendon was within the arthroscopic view, compared to 63% with the limb flexed. Twenty percent of the subscapularis tendon was within the arthroscopic view.

Conclusion A significant portion of the biceps tendon and medial stabilizing structures of the canine shoulder are outside the field of view of arthroscopy through a standard lateral approach. The limitations of the arthroscopic field of view should be appreciated when evaluating the shoulder.
Electrical properties of hierarchical nitrogen-doped multi-walled carbon nanotubes obtained using cobalt nanoparticles
Authors: Lemesh N. V. , Rudenko R. M. , Voitsihovska O. O. , Poroshin V. N. , Nikolenko A. S. , Manoryk P. A.
Published: September 2023

In this work, for the first time, both initial and secondary branches of hierarchical nitrogen-doped multi-walled carbon nanotubes (h-N-MWCNTs) were obtained using chemical vapor deposition due to the decomposition of ace-tonitrile over Co-based nanoparticles. The results of a study of the electrical conductivity of h-N-MWCNTs for a wide temperature range of 300−4.2 K are presented. It was shown that fluctuation-assisted tunneling between delocalized states is the dominant conduction mechanism at temperatures above 50 K. An analysis of the temperature and electric field dependences of the resistance indicates that the transfer of electric charges below 50 K occurs due to hoppings between localized states located in the vicinity of the Fermi level. It was shown that the Coulomb interaction affects the charge carrier transport. The width of the Coulomb gap estimated from the temperature dependence of the resistance is 0.5 meV. The electrical conductivity of h-N-MWCNTs in the temperature range of 50−4.2 K occurs by the Efros–Shklovskii variable range hopping conduction mechanism. It was found that the charge localization length is ≈150 nm. Electrical property analysis indicates that the dielectric constant of the h-N-MWCNTs is ≈ 100.
Entropy of electron gas in semiconductor nanowires
Authors: Gulyamov G. , Davlatov A. B. , Urinboev D. R.
Published: September 2023

The thermodynamic potential and entropy of the electron gas of a semiconductor nanowire are obtained. When calculating the entropy of an electron gas with a nonparabolic energy dispersion, the Nelson method was used. The entropy of the electron gas with the value of the chemical potential of the smaller line, which is equal to or greater than the energy of an arbitrary discrete energy level, is studied. An analytical expression for the entropy is obtained in the case when the chemical potential of the electron gas is equal to the energy of the discrete level. The temperature dependences of the entropy of the electron gas of semiconductor nanowires on the degree of nonparabolicity of the energy dispersion law are found.
Conformational analysis of simple oxygenated hydrocarbons in a solid parahydrogen matrix
Authors: Yan Chloe , McKinnon Alexandra , Moore Brendan , Mahoney Kyle , Djuricanin Pavle , Momose Takamasa
Published: September 2023

Acetone, acetaldehyde, propylene oxide, propionaldehyde, and 2-propanol are all simple oxygen-containing organic molecules, and play an important role in combustion chemistry, atmospheric chemistry, and astrochemistry. These small molecules are often produced by chemical reactions or UV photolysis of larger molecules containing oxygen atoms. Thus, knowing the IR spectrum of these molecules is important for the identification of (photo)chemical processes of various molecules. In this study, the IR spectra of these five common organic molecules were studied using parahydrogen (pH2) matrix isolation with Fourier transform infrared spectroscopy. Conformational analysis of the IR spectra revealed two conformers of propionaldehyde and 2-propanol exist in the pH2 matrix at 3.8 K. This work will be useful for the identification of products in future pH2 photochemistry experiments.
Non-isothermal pyrolysis of Polyalthia longifolia using thermogravimetric analyzer: Kinetics and thermodynamics
Authors: Annapureddy Praveen Kumar Reddy , Kishore Nanda
Published: September 2023

Non-isothermal thermogravimetric experiments were carried out at four different heating rates to investigate thermal decomposition of Polyalthia longifolia leaves, with primary goals of determining kinetic triplets (activation energy, frequency factor, and reaction mechanism) and thermodynamic parameters. Kinetics investigation was conducted by utilizing five iso-conversional approaches, viz., Starink (STK), Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), differential Friedman method (DFM), and distributed activation energy model (DAEM). Results indicated that average activation energy (Eα) ranged between 211.57 and 231 kJ/mol. Average values of activation energy obtained by KAS (211.57 kJ/mol) were found to be in the neighborhood of that obtained by other three integral methods, i.e., OFW (210.80 kJ/mol), STK (211.80 kJ/mol), and DAEM (211.57 kJ/mol). Criado's master plots approach revealed that experimental data matches with none of the reaction model until conversion of 0.4 and thereafter follows D3 for conversion of 0.5–0.7, whereas master plots based on the integral form of data disclosed that this method is not appropriate for pyrolysis of the present biomass sample. Finally, pyrolysis of P. longifolia biomass to produce bioenergy is found to be feasible (Eα − ΔH = ∼5–6 kJ/mol).
Role reversal in a stage-structured prey–predator model with fear, delay, and carry-over effects
Authors: Gupta Ashvini , Dubey Balram
Published: September 2023

The present work highlights the reverse side of the same ecological coin by considering the counter-attack of prey on immature predators. We assume that the birth rate of prey is affected by the fear of adult predators and its carry-over effects (COEs). Next, we introduce two discrete delays to show time lag due to COEs and fear-response. We observe that the existence of a positive equilibrium point and the stability of the prey-only state is independent of fear and COEs. Furthermore, the necessary condition for the co-existence of all three species is determined. Our system experiences several local and global bifurcations, like, Hopf, saddle-node, transcritical, and homoclinic bifurcation. The simultaneous variation in the attack rate of prey and predator results in the Bogdanov–Takens bifurcation. Our numerical results explain the paradox of enrichment, chaos, and bi-stability of node-focus and node-cycle types. The system, with and without delay, is analyzed theoretically and numerically. Using the normal form method and center manifold theorem, the conditions for stability and direction of Hopf-bifurcation are also derived. The cascade of predator attacks, prey counter-attacks, and predator defense exhibit intricate dynamics, which sheds light on ecological harmony.
The influence of pulse repetition frequency on reactive oxygen species production in pulsed He+H2O plasmas at atmospheric pressure
Authors: Harris B. , Wagenaars E.
Published: September 2023

Atmospheric pressure plasmas generated from a helium gas with admixtures of water vapor have numerous applications in biomedicine. It is important that the chemistry of such plasmas can be tightly controlled so that they may be tailored for their intended use. In this study, computational modeling is used to vary the pulse repetition frequency of a nanosecond-pulsed, pin-to-pin He + 0.25% H2O discharge in the range of 1–100 kHz to determine the influence of the pulse repetition frequency on the resulting densities of reactive oxygen species and the rates of dominant reaction pathways involving them. The plasma is simulated using the 0D plasma-chemical kinetics model GlobalKin. The pulse shape is kept constant. The afterglow duration is, therefore, dependent on the repetition frequency. Analysis of the bulk plasma chemistry after the plasma has reached equilibrium shows that the peak electron density is only weakly dependent on the pulse repetition frequency. Increasing the pulse repetition frequency is shown to increase the density of H, O, and OH radicals, while the relationship between the repetition frequency and the densities of species with longer lifetimes, namely, H2O2 and O3, is found to be more complex. These are formed throughout the afterglow, and their density depends on the availability of reactant species, the afterglow duration, and the background gas temperature. This work concludes that the pulse repetition frequency is not a simple control parameter, especially for species that are predominantly produced in the afterglow. Detailed modeling is required for accurate control of species densities using the pulse repetition frequency.
Parametric analysis of a two-body floating-point absorber wave energy converter
Authors: Xu Qianlong , Li Ye , Bennetts Luke G. , Wang Shangming , Zhang Lijun , Xu Hao , Narasimalu Srikanth
Published: September 2023

In the evolution of floating-point absorber wave energy conversion systems, multiple-body systems are gaining more attention than single-body systems. Meanwhile, the design and operation factors affecting the performance of multiple-body systems are much greater than those of single-body systems. However, no systematic study has yet been presented. In this article, a theoretical model is proposed by using a coupled oscillator system consisting of a damper-spring system to represent a two-body system (the floating body and the reacting body). Dimensionless expressions for the motion response and wave power absorption efficiency are derived. With the newly developed model, we prove that an appropriately tuned two-body system can obtain a limiting power absorption width of L/2π (L is the incident wavelength) as much as a single-body system. The generic case of a two-body system is presented with numerical simulations as an example. The results show that increasing the damping coefficient can reduce the wave frequency at which the peak of power absorption efficiency occurs. Increasing stiffness can make the wave frequencies for high power absorption efficiency move to a higher frequency region and can also make the spectrum bandwidth for high power absorption efficiency become narrower. Further, we show that the two-body system can absorb more wave energy at low wave frequencies than the single-body system.
Machine learning-based optimization of a pitching airfoil performance in dynamic stall conditions using a suction controller
Authors: Kasmaiee Sa. , Tadjfar M. , Kasmaiee Si.
Published: September 2023

Flow separation control on oscillating airfoils is crucial for enhancing the efficiency of turbine blades. In this study, a genetic algorithm was employed to optimize the configuration of a pure suction jet actuator on an oscillating airfoil at a Reynolds number of 1.35×105. Neural networks based on multilayer perceptrons were used to train the aerodynamic coefficients as functions of the control parameters and reduce the number of simulations. The objective function was the mean performance coefficient, defined as the ratio of the average lift to the average drag during an oscillation period. The control parameters were location, velocity, opening length, and suction jet angle relative to the airfoil surface. The optimal jet had the maximum velocity and opening length and was normal to the airfoil surface. The optimal jet location was near the leading edge vortex (LEV) (between 3% and 6% of the chord). The optimum jet can increase the average performance coefficient (average ratio of lift to drag during a period) by about 24 times. The major part of this improvement is related to reducing drag force. The average lift coefficient increases from about 0.58 to about 0.92 using this jet, while the average drag coefficient decreases from about 0.23 to about 0.02. The optimal jet suppressed the dynamic stall vortex, which resulted from the combination of two clockwise vortices: LEV and turbulent separation vortex. Suppressing this vortex prevented the counterclockwise trailing edge vortex from growing at the end of the airfoil.
Near trapping phenomena in arrays of porous vertical cylinders
Authors: Konispoliatis Dimitrios N.
Published: September 2023

The near trapping phenomena are associated with the wave trapping in arrays of large number of solid bodies, which experience increased amplitudes of free-surface elevation between adjacent bodies, and corresponding large wave loads on each array element. In relevant situations of infinite arrays, the wave energy is trapped within the array allowing only a small amount of energy to radiate to the far field, forming the so-called trapped mode phenomenon. The question which this paper tries to answer is whether trapped waves are simulated by arrays of porous vertical cylinders. To tackle this task, a solution method that solves the corresponding diffraction problem by the application of the multiple scattering approach, for the simulation of the hydrodynamic interactions between the waves and the elements of the array, is proposed. Numerical results for several geometrical configurations are presented and discussed, highlighting the effect of porous cylinders on the exerted hydrodynamic loads on the array.
A surface-piercing truncated cylindrical meta-structure operating as a wave energy converter
Authors: Huang J. , Porter R. , Zheng Siming
Published: September 2023

In this paper, we study the interaction of water waves with a surface-piercing truncated cylindrical meta-structure consisting of two overlapping arrays of closely spaced vertical thin plates. The fluid resonance promoted in the narrow vertical channels formed by the cylindrical meta-structure is exploited by a novel design concept of the wave power converter by covering the surface of the cylinder with an array of small cuboid buoys which float in the gaps between the intersecting plate arrays. Each buoy is attached to its own spring and power takeoff damping mechanism, and the vertical displacement of individual buoys is replaced by a continuous two-dimensional function of position which follows from homogenization of the plate/fluid structure of the cylinder. Effective medium equations and boundary conditions are derived under both full depth-dependent theory and shallow-water theory, allowing semi-analytical methods to be developed to investigate the wave scattering and wave energy absorption properties of this cylindrical meta-structure. Results illustrate that the internal resonance of the cylindrical meta-structure can lead to significant wave power capture across a broad range of frequencies.
Vacancy-ordered Te4+-doped Rb2ZrCl6 double perovskite microcrystals for solid-state lighting and non-contact optical thermometry
Authors: Liu Jing , Hu Qichuan , Xu Hanqi , Yu Hailong , Du Baoxiang , Han Qiuju , Wu Wenzhi
Published: September 2023

In this work, we prepared the highly efficient yellow light-emitting vacancy-ordered Te4+-doped Rb2ZrCl6 microcrystals (RZCTs) through a hydrothermal method. RZCT with a photoluminescence quantum yield of 34.6% was prepared at Te4+ feeding ratio of 5%. RZCT is used to fabricate high-efficiency white light-emitting diodes, and adjusting the current can realize the transition of cold and warm white light with CIE color coordinates of (0.31, 0.28) and (0.36, 0.37), respectively. It is also applied to non-contact thermometry using photoluminescence lifetime, of which maximum relative and absolute sensitivities were obtained as 0.89% and 4.76 × 10−3 K−1, respectively. The study shows that the lead-free Te4+-doped perovskite microcrystals exist great potential in next-generation solid-state lighting and non-contact optical thermometry.
Thickness and temperature-dependent damping in La0.67Sr0.33MnO3 epitaxial films
Authors: Wang Yifei , Fan Xinxin , Feng Xiaoyu , Gao Xiaohu , Ke Yunfei , Yao Jiguang , Guo Muhan , Wang Tao , Shen Lvkang , Liu Ming , Xue Desheng , Fan Xiaolong
Published: September 2023

Damping of La0.67Sr0.33MnO3 (LSMO) epitaxial films as a function of thickness at different temperatures was studied. The competition between two scattering types (ρ-like and σ-like) with entirely distinct thickness and temperature dependencies resulted in complicated damping behavior. The behavior of σ-like damping in LSMO films is consistent with the behavior in magnetic metal films. However, because ρ-like damping is sensitive to the fine electron structure near the Fermi surface, the distortion of the oxygen octahedra controlled by the film thickness is an important factor in controlling the damping. Our study demonstrates that the complexity of damping in LSMO epitaxial films is a consequence of strong-correlation effects, which are characteristics of complex transition-metal oxides.
Influence of trap-assisted and intrinsic Auger–Meitner recombination on efficiency droop in green InGaN/GaN LEDs
Authors: Li Xuefeng , DeJong Elizabeth , Armitage Rob , Armstrong Andrew M. , Feezell Daniel
Published: September 2023

We study the impact of deep-level defects on trap-assisted Auger–Meitner recombination in c-plane InGaN/GaN LEDs using a small-signal electroluminescence (SSEL) method and deep-level optical spectroscopy (DLOS). Carrier dynamics information, including carrier lifetime, recombination rate, and carrier density, is obtained from SSEL, while DLOS is used to obtain the deep-level defect density. Through fitting the nonradiative recombination rates of wafers with different deep-level defect densities, we obtain the Shockley–Read–Hall (SRH) and trap-assisted Auger–Meitner recombination (TAAR) coefficients. We show that defect-related nonradiative recombination, including both SRH and TAAR, accounts for a relatively small fraction of the total nonradiative recombination, which is dominated by intrinsic Auger–Meitner recombination. The interplay between carrier localization and Coulomb enhancement has a different impact on radiative and intrinsic Auger–Meitner recombination. Evidence is presented that the imbalance between the change of radiative and intrinsic Auger–Meitner recombination is the primary cause of the efficiency droop at high carrier densities in the samples studied.
Effect of size of multiwalled carbon nanotubes on thermal conductivity and viscosity of ethylene glycol-based nanofluids for solar thermal applications
Authors: Dosodia Abhishek , Vadapalli Srinivas , Jain Amitabh Kumar , Sanduru Bhanuteja , Mukkamala Saratchandra Babu
Published: September 2023

The paper investigates the influence of the length of multi-walled carbon nanotubes (MWCNTs) dispersed as an additive in solar thermic fluids to enhance thermal conductivity. Here, pure ethylene glycol was chosen as solar thermic fluid due to its low viscosity, high boiling point, excellent chemical stability, and compatibility with the materials used in solar thermal systems. Pristine multi-walled carbon nanotubes are ball milled for 5, 10, and 20 h to reduce the length due to attrition. The effect of ball milling duration on the defect formation and damage to the tubular structure is assessed using Raman spectroscopy. Furthermore, the ball-milled MWCNTs were oxidized to separate amorphous carbon produced during ball milling, increasing their purity. The pristine long nanotubes and ball-milled nanotubes are mixed in pure ethylene glycol in 0.25 wt. %, and the stability of liquids is estimated using Ultraviolet–Visual (UV-Vis) spectroscopy for two months. The stability of the fluids and thermal conductivity have considerably enhanced with the dispersion of shortened MWCNTs. The dispersion of short MWCNTs in ethylene glycol resulted in a 20%–30% increase in thermal conductivity compared to pure ethylene glycol. It was also found that higher ball milling times resulted in ultra-high stability but the properties deteriorated due to the destruction of the MWCNTs' tubular structure, making them useless.
Swedish immersion in Finland and Swedish as a second-language subject in Sweden
Authors: Hedman Christina , Magnusson Ulrika
Published: September 2023

Based on fieldwork and interviews, we explore five teachers’ views about their teaching of Swedish as a second language in an early immersion school in Finland (Larch) and a linguistically heterogeneous primary school in Sweden (Chestnut). Drawing from ecological perspectives, we aim to contribute new knowledge on how second language teachers express their goals, teacher experiences and expertise depending on language and education policy as discursive-material reality. We discuss how societal, discursive and material differences were entangled with the teachers’ discourses, for example, the fact that Swedish immersion at Larch enjoyed a higher social status than Swedish as a second language at Chestnut. Concomitantly, the teachers adhered to pedagogical principles and the value of students’ linguistic and cultural repertoires in similar ways. We specifically discuss teacher autonomy as entwined with prevailing discursive-material realities, including distinct language education policies.
The realization of the speech acts of complaint and responding to complaint in Vodafone Egypt versus Vodafone
UK
Authors: El-Dakhs Dina Abdel Salam , Ibrahim Nermine Galal
Published: September 2023

The current study aims to compare the complaints/responses to complaints on the Facebook pages of Vodafone UK
versus Vodafone Egypt. 200 complaints and 200 responses to these complaints were collected from the Facebook pages of the two
companies in September 2022. The analysis results showed that the UK customers produced significantly more expressions of
disapproval, particularly ill consequences and annoyance, than their Egyptian counterparts. The Egyptian customers produced
significantly more blame and requests than the UK customers. In terms of responses to complaints, the UK responses were dominated
by acceptance strategies, particularly in the form of offers of repair, while the Egyptian responses came mainly in the form of
partial acceptance, particularly in the form of seeking further information.
A course of free voluntary reading on linguistic principles for average to below-average writers in university
Authors: Huck Geoffrey J.
Published: September 2023

This article describes an experiment in pedagogy for general writing improvement at the university level
consisting of a course of Free Voluntary Reading (FVR), which can be offered either independently of or together with standard
courses on writing. Evidence so far supporting the efficacy of FVR in helping students to improve their writing skills has largely
come from the K-12 grades and university-age foreign language students, so whether it would prove useful for university students
in general is open to question. A linguistic perspective is adopted, which entails a methodology for the experiment that differs
in major respects from that which is typical in composition studies. The results of the experiment showed that a course of FVR,
independently of instruction in writing, may be effective in improving university students’ grammatical fluency in writing.
Comment on ‘Thermodynamics of a particle in square well potential’
Authors: Fernández Francisco M
Published: September 2023

We argue that the approximate analytical expression for the canonical partition function for a particle in a box proposed recently was derived earlier by other authors in a more straightforward and efficient way. We also show that the canonical partition function for the particle in a finite box derived by the same authors is incorrect because they overlooked the contribution of the continuum spectrum.
Reply to the comment on ‘Thermodynamics of a particle in square well potential’
Authors: Bhattacharyya Satadal , Mitra Joydip
Published: September 2023

We clarify two comments made by Francisco M Fernández on our paper Bhattacharyya and Mitra (2022 Eur. J. Phys.
44 015101). The first one is regarding the calculation of the approximate partition function for a particle in a box that was derived earlier by others, and the second one is about the omission of the contribution to the continuous energy spectrum in the partition function calculation for a particle in a finite well.
Enhancing fog collection by optimizing wettability combination and fork-row collector arrangement: light and heavy fog
Authors: Zhang Ming , Xiao Menghan , Li Chuan , Li Dingchen , Li Jiawei , Yu Kexun , Pan Yuan
Published: September 2023

Fog collection is essential to alleviate water scarcity in arid areas. However, the vast majority of existing fog collectors only work effectively in heavy fog. To broaden the fog concentration range for efficient work, an optimization strategy based on wettability combination and fork-row arrangement is proposed in this work. Single-layer experiment results show that a hydrophilic (HL) surface with high deposition capacity collects droplets at a faster rate in light fog (25–80 g h−1), while the collection rate of a hydrophobic (HB) surface with high drainage capacity is higher in heavy fog (220–500 g h−1). Double-layer experiment results show that in light fog, the best combination of double-layer collection electrodes is HL–HL, while HB–HL performs best in heavy fog. A 35% improvement in collection rate can be obtained simply by changing the arrangement from smooth-row (S) to fork-row (F), which is attributed to the increased effective collision area of droplets. In our series of experiments, at 50 g h−1, the collection rate of double-layer combination HL–HL(F) is 56.7% higher than that of single-layer HL. In particular, the collection rate of HB–HL(F) reaches 1434.7 mg cm−2 h−1 at 500 g h−1. Such a good performance is attributed to the force imbalance of hanging droplets caused by wettability differences, which tends to transport small droplets on HB towards HL directionally, resulting in a rapid droplet slippage. Therefore, the HB–HL accelerates drainage and refreshes capture points. Furthermore, fog collection performance is also influenced by layer spacing, which has an optimal distance. These findings provide a promising method for practical applications of fog collectors in a wide range of fog flow quantities, enhancing adaptability to variable environments.
Enhancing BDS-3 PPP-AR with observable-specific signal biases
Authors: Galatiya Suya Robert , Chen Yung-Tsang , Kwong Chiew Foong , Zhang Penghe
Published: September 2023

In global navigation satellite system (GNSS) data processing, precise point positioning (PPP) with ambiguity resolution (PPP-AR) is a versatile technique that aims to achieve centimetre-level accuracy by resolving integer ambiguities in carrier phase observations. However, the inherent errors and biases in the satellite signals can degrade the performance of PPP-AR solutions. To mitigate such errors, this research proposed to argument PPP-AR using third-generation BeiDou Navigation Satellite System (BDS-3) multi-frequency observations and the observable-specific signal biases (OSBs) generated at the Centre National D’Etudes Spatiales (CNES). To test the proposed technique, both BDS-3 and Galileo observations from the multi-GNSS experiment network were used, in consideration that the latter also transmits multi-frequency signals. Before demonstrating the impact of CNES bias products on PPP-AR, the quality of BDS-3 and Galileo signals was assessed. The results indicated that the modernised frequencies had the best signal strength. The mean standard deviations for the estimated OSB for different receivers were close to each other in both constellations. Besides, the positioning results in different processing schemes unveiled a comparable positioning accuracy, and slightly better in the quad-PPP strategy using the Galileo constellation in both static and kinematic modes. Galileo also attained better ambiguity fixing rates and convergence time than BDS-3. Finally, there were slight differences in the magnitude of the estimated phase residuals for distinct frequency signals between BDS-3 and Galileo, including the interoperable and compatible signals.
Effect of magnetic field on voltammetric sensor for electrolytic concentration measurement and electrode–electrolyte interface model based on a novel geometry
Authors: Ranasingh Soumyaranjan , Pradhan Tapan , Dhenuvakonda Koteswara Raju
Published: September 2023

Voltammetric sensor models are widely used in electrolytic applications in industry and the laboratory. Research in these domains is enriched with data analytics tools and electrode design, which need to be revised to improve the sensitivity near the Nernst limit. Therefore, an intense demand exists for enhancing the sensitivity of conventional voltammetric sensor models with minimum alteration of design parameters. This research article focuses on the possible impact of a magnetic field in a conventional voltammetric sensor for electrolytic concentration measurement. The experimental results show a 45% increase in sensitivity with a 3%–43% increment in signal attenuation due to the magnetic field. Apart from analysing the impact of a magnetic field, this research also investigates sensors with different electrode materials and input excitation. Among different electrode materials, a sensor with Iron-Niobium is found to have maximum electrolytic sensitivity of 15.78 V mol−1 l−1 while measuring the electrolytic concentration of oxalic acid in the range of 0.001–0.01 mol l−1. Similarly, the proposed voltammetric sensor with Iron-Niobium electrodes is implemented to measure the concentration of other electrolytes with 10–130 V mol−1 l−1 sensitivity to enhance applicability. A modified electrical equivalent model with an additional inductive component is also proposed in this research work that explains the waveform dip followed by a peak overshoot due to the influence of the magnetic field. The proposed electrical equivalent model of electrode–electrolyte interface is compatible with a conventional model, which is confirmed based on the experimental observations and mathematical analysis.
Attention mechanism-guided residual convolution variational autoencoder for bearing fault diagnosis under noisy environments
Authors: Yan Xiaoan , Lu Yanyu , Liu Ying , Jia Minping
Published: September 2023

Due to rolling bearings usually operate under fluctuating working conditions in practical engineering, the raw vibration signals generated by bearing faults have nonlinear and non-stationary characteristics. Additionally, there is a lot of noise interference in the collected bearing vibration signal, which indicates that it is difficult to extract bearing fault information and obtain a satisfactory diagnosis accuracy via using traditional method. Deep learning provides a shining road to address this issue. Nevertheless, traditional deep network model has the shortcomings of poor generalization performance and weak robustness in the feature learning. To improve fault recognition accuracy and obtain a favorable anti-noise robustness, this paper proposes a novel bearing fault diagnosis approach based on attention mechanism-guided residual convolutional variational autoencoder (AM-RCVAE). Firstly, the improved residual module is constructed to overcome the convergence difficulty problem caused by network degradation and promote the model generalization performance by replacing the batch normalization (BN) layer in the traditional residual module with the adaptive BN layer. Subsequently, by incorporating the convolutional block attention module and the improved residual module into convolutional variational autoencoder, a deep network model termed as AM-RCVAE is presented to automatically learn fault features from the original data and perform fault diagnosis tasks. The effectiveness of the proposed approach is verified via two experimental cases. Moreover, the recognition accuracy and diagnostic performance of the proposed approach have been certain improved compared with several representative methods.
Mechanical and thermodynamic properties of γ-TiAl using first-principles calculations
Authors: Alam Mahfooz , Gandi Appala Naidu
Published: September 2023

Temperature dependence of structural, mechanical, and thermodynamic properties of γ-TiAl is modeled using an extended quasi-harmonic approximation and first-principles calculations. In the first step, the volumes are estimated as a function of temperature following the quasi-harmonic approximation. The lattice parameters are further optimized at fixed volumes in the second step. Modeled mechanical properties (bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and hardness) agree with the experimentally reported mechanical properties. Similarly, the modeled thermodynamic properties (entropy, heat capacity at constant pressure, Gibbs free energy) are in good agreement with the thermodynamic properties reported from experiments and CALculation of PHAse Diagrams approaches. This study suggests that further optimization of the degree of freedom in the unit cell improves the model accuracy of properties estimated following the quasi-harmonic approximation.
A shear modified GTN model based on stress degradation method for predicting ductile fracture
Authors: Min Fanlei , Gao Kunyuan , Zhang Xiaojun , Wei Wu , Qi Peng , Wu Xiaolan , Wen Shengping , Huang Hui , Nie Zuoren , Zhou Dejing
Published: September 2023

The Gurson–Tvergaard–Needleman (GTN) model has provided a powerful description of the nucleation growth and coalescence of micro voids, but it has limitations in simulating shear fracture due to the absence of a description of shear localization behavior. A shear improvement method is proposed for simulating the ductile fracture of materials under different stress states. The modified model not only allows for strain hardening of the matrix material, but also accounts for the stress degradation caused by shear. The strength equation of the material is described by both the shear stress state function and a decay function, making it easier for materials under shear stress state to experience material softening and further inducing shear fracture. The modified GTN model is developed by incorporating the shear stress degradation factor into the yield function, while taking into account both void growth and shear failure mechanisms. By carefully calibrating the model’s parameters, the deformation and fracture processes of tensile, plane strain, notch tensile, and compression specimens in the 7A52 aluminum alloy are simulated. The damage evolution behavior of the material under different stress states is analyzed. The results indicate that the damage include void growth mechanism and void shear mechanism. The proportions of these two mechanisms vary under different levels of stress triaxiality. Upon localizing material deformation, the shear stress state intensifies, and the shear damage mechanism assumes a critical role in fracture. The modified GTN model accurately predicts the load-displacement response and fracture path of the 7A52 aluminum alloy under a wide range of stress states.
Ahead of the Fisher–KPP front
Authors: Brunet Éric
Published: September 2023

The solution h to the Fisher–KPP equation with a steep enough initial condition develops into a front moving at velocity 2, with logarithmic corrections to its position. In this paper we investigate the value

h
(
c
t
,
t
)

of the solution ahead of the front, at time t and position ct, with c > 2. That value goes to zero exponentially fast with time, with a well-known rate, but the prefactor depends in a non-trivial way of c, the initial condition and the nonlinearity in the equation. We compute an asymptotic expansion of that prefactor for velocities c close to 2. The expansion is surprisingly explicit and irregular. The main tool of this paper is the so-called ‘magical expression’ which relates the position of the front, the initial condition, and the quantity we investigate.
Lyapunov irregular set of Banach cocycles
Authors: Chen Yexing , Zang Yuntao , Zou Rui
Published: September 2023

Let

(

Σ

M

,
f
)

be a topologically mixing subshift of finite type and let

be a Hölder continuous map where

B

×

is the set of invertible elements of a Banach ring B. We prove that either all ergodic measures have the same maximal Lyapunov exponent, or the irregular set

is residual in

Σ

M

and has full upper capacity topological entropy of

Σ

M

. We also prove for generic fiber-bunched cocycles, similar statements can be strengthened by considering the Bowen topological entropy.
Semi-TMS: an efficient regularization-oriented triple-teacher semi-supervised medical image segmentation model
Authors: Chen Weihong , Zhou Shangbo , Liu Xiaojuan , Chen Yijia
Published: September 2023

Objective. Although convolutional neural networks (CNN) and Transformers have performed well in many medical image segmentation tasks, they rely on large amounts of labeled data for training. The annotation of medical image data is expensive and time-consuming, so it is common to use semi-supervised learning methods that use a small amount of labeled data and a large amount of unlabeled data to improve the performance of medical imaging segmentation. Approach. This work aims to enhance the segmentation performance of medical images using a triple-teacher cross-learning semi-supervised medical image segmentation with shape perception and multi-scale consistency regularization. To effectively leverage the information from unlabeled data, we design a multi-scale semi-supervised method for three-teacher cross-learning based on shape perception, called Semi-TMS. The three teacher models engage in cross-learning with each other, where Teacher A and Teacher C utilize a CNN architecture, while Teacher B employs a transformer model. The cross-learning module consisting of Teacher A and Teacher C captures local and global information, generates pseudo-labels, and performs cross-learning using prediction results. Multi-scale consistency regularization is applied separately to the CNN and Transformer to improve accuracy. Furthermore, the low uncertainty output probabilities from Teacher A or Teacher C are utilized as input to Teacher B, enhancing the utilization of prior knowledge and overall segmentation robustness. Main results. Experimental evaluations on two public datasets demonstrate that the proposed method outperforms some existing semi-segmentation models, implicitly capturing shape information and effectively improving the utilization and accuracy of unlabeled data through multi-scale consistency. Significance. With the widespread utilization of medical imaging in clinical diagnosis, our method is expected to be a potential auxiliary tool, assisting clinicians and medical researchers in their diagnoses.
Experimental validation of an innovative approach in biokinetics study for personalised dosimetry of molecular radiation therapy treatments
Authors: Mancini-Terracciano C , Ambrosino A , Campana L , Cassano B , Collamati F , Faccini R , Iaccarino G , Mirabelli R , Morganti S , Nicolanti F , Pacilio M , Soriani A , Solfaroli Camillocci E
Published: September 2023

One of today’s main challenges in molecular radiation therapy is to assess an individual dosimetry that allows treatment to be tailored to the specific patient, in accordance with the current paradigm of ‘personalized medicine’. The evaluation of the absorbed doses for tumor and organs at risk in molecular radiotherapy is typically based on MIRD schema acquiring few experimental points for the assessement of biokinetic parameters. WIDMApp, the wearable individual dose monitoring apparatus, is an innovative approach for internal dosimetry based on a wearable radiation detecting system for individual biokinetics sampling, a Monte Carlo simulation for particle interaction, and an unfolding algorithm for data analysis and integrated activity determination at organ level. A prototype of a WIDMApp detector element was used to record the photon emissions in a body phantom containing 3 spheres with liquid sources (18F, 64Cu and 99m
Tc) to simulate organs having different washout. Modelling the phantom geometry on the basis of a CT scan imaging, the Monte Carlo simulation computed the contribution of each emitting sphere to the signal detected in 3 positions on the phantoms surface. Combining the simulated results with the data acquired for 120 h, the unfolding algorithm deconvolved the detected signal and assessed the decay half-life (T
1/2) and initial activity values (A(0)) that best reproduces the observed exponential decays. A 3%–18% level of agreement is found between the actual A(0) and T
1/2 values and those obtained by means of the minimization procedure based on the Monte Carlo simulation. That resulted in an estimation of the cumulated activity <15%. Moreover, WIDMApp data redundancy has been used to mitigate some experimental occurrences that happened during data taking. A first experimental test of the WIDMApp approach to internal radiation dosimetry is presented. Studies with patients are foreseen to validate the technique in a real environment.