bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Health Awareness and Oral Hygiene Practices among Married Women of Al-Ahsa, Saudi Arabia
Authors: Bokhari Syed Akhtar Hussain , Sanikommu Suresh , BuHulayqah Abdullah , Al-Momen Hussain , Al-Zuriq Abdullah , Khurshid Zohaib
Published: April 2024

Objective Awareness of mothers about oral health and their oral hygiene practices may benefit both maternal and infant oral health. This study assessed the oral health awareness and oral hygiene practices among married females.

Materials and Methods A cross-sectional study was conducted on 430 females using a self-administered close-ended questionnaire that was distributed through WhatsApp application. Chi-squared test and t-test were applied with significance level of p-value less than or equal to 0.05.

Results Three hundred and fifty-six females responded to the survey. Ninety percent women brushed their teeth daily, 52% used dental floss, and 58% used mouthwash. Seventy-nine percent patients visited a dentist when had a dental problem. Females more than or equal 75% think that dentist visit is important or consider it safe and 34% had visited the dentist during pregnancy. Sixty-eight percent women think that incidence of oral disease increases during pregnancy, and 42% agreed that oral disease affect the baby's oral health. Sixty-seven percent were aware that women could develop pregnancy gingivitis and 8% think that poor oral health can lead to birth of premature baby. Mothers with less than or equal to 10 years of married life have shown significantly (≤0.04) higher knowledge and good oral hygiene practices than other older mothers. Regression analysis showed a significant (p ≤ 0.035) relationship between incidence of oral disease in pregnancy with married life years; effect of oral disease on baby' health with age and occupation; use of dental floss with income and living area; knowledge of pregnancy gingivitis with number of children; effect of bad oral hygiene on pregnancy outcome with income; and dentist visit during pregnancy with married life years.

Conclusion Females with higher education, less years of married life, and higher number of children were better aware of oral health and oral hygiene practices and its effect on their baby's oral health.
Musculoskeletal Issues in Pediatric Burn Patients
Authors: Phillips William A.
Published: April 2024

A burn injury affects virtually every organ system. The purpose of this article is to review musculoskeletal issues in children with burn injuries. Both acute and long-term problems will be discussed. A low threshold to consult a pediatric orthopaedist is recommended.
Airway Management for Acute and Reconstructive Burns: Our 30-year Experience
Authors: Mittal Brita M. , McQuitty Robert A. , Talon Mark , McQuitty Alexis L.
Published: April 2024

Airway management in both acute and reconstructive burn patients can be a major challenge for evaluation, intubation, and securing the airway in the setting of altered airway structure. Airway evaluation in both acute and reconstructive patients includes examination for evidence of laryngeal and supraglottic edema and structural changes due to trauma and/or scarring that will impact the successful approach to acquiring an airway for surgical procedures and medical recovery. The approach to acquiring a successful airway is rarely standard laryngoscopy and often requires fiberoptic bronchoscopy and a variety of airway manipulation techniques. Tracheostomy should be reserved for those with classic requirements of ventilatory and/or mechanical failure or severe upper airway burns. Even securing an airway for surgical procedures, especially with patients suffering injuries involving the head and neck, can be nonstandard and requires creative and flexible approaches to be successful. After much trial and error over the past 30 years in a large burn center, our multidisciplinary team has learned many valuable lessons. This review will focus on our current approach to safe airway management in acute and reconstructive burn patients.
Modified Technique to Protect the Superior Sagittal Sinus in Cranial Vault Reconstruction for Scaphocephaly
Authors: Pereira Leopoldina Peixoto , Oliveira Joana , Santos Patrícia , Polónia Patrícia , Vaz Rui , Pereira Josué
Published: April 2024

Scaphocephaly remains the most prevalent form of isolated single-suture synostosis. In most Pediatric Neurosurgery Centers, the treatment consists of extensive calvarial reshaping operations which are performed in relatively late ages. We described a modified open technique of cranial vault reconstruction for scaphocephaly and we report the anesthetic approach and how it influences our results and enables the performance of this surgery at earlier ages. A total of 47 patients with an average age of 11 ± 2.72 months underwent to the same surgical technique. Blood transfusion during the surgical intervention was needed in 25 patients (53%), and 22 patients (46.8%) did not need blood transfusion. None of the 14 patients who used tranexamic acid (TXA) needed blood transfusions. We reported a statistically significant association between the use of TXA and blood transfusion (p < 0.0001), with a decreased need for blood transfusion with the use of TXA. Besides sagittal suturectomy, we create new parasagittal sutures by replacing the prematurely fused one, and 1.5 cm of the anterior segment of bone of those 2 rectangular structures are cut before fixation, to enable the immediate shortening of the anteroposterior (AP) diameter of the skull. Finally, we put a mesh plate (SonicWeld Rx, KLS Martin Group, Tuttlingen, Baden-Wuerttemberg, Germany) over the superior sagittal sinus (SSS), which is fixed anteriorly and posteriorly with pins (SonicPins Rx, KLS Martin Group). This procedure enables an immediate reduction of the AP diameter of the skull, with no further therapies needed, and promotes a wide decompression and remodeling of the skull. With an experienced surgical team and an anesthesiologic protocol, we were able to perform this surgery at early ages, requiring no blood transfusions.
Flexible piezoresistive pressure sensor based on a graphene-carbon nanotube-polydimethylsiloxane composite
Authors: Wei Huifen , Li Xiangmeng , Yao Fangping , Feng Xinyu , Zhu Xijing
Published: April 2024

Flexible sensors are used widely in wearable devices, specifically flexible piezoresistive sensors, which are common and easy to manipulate. However, fabricating such sensors is expensive and complex, so proposed here is a simple fabrication approach involving a sensor containing microstructures replicated from a sandpaper template onto which polydimethylsiloxane containing a mixture of graphene and carbon nanotubes is spin coated. The surface morphologies of three versions of the sensor made using different grades of sandpaper are observed, and the corresponding pressure sensitivities and linearity and hysteresis characteristics are assessed and analyzed. The results show that the sensor made using 80-mesh sandpaper has the best sensing performance. Its sensitivity is 0.341 kPa−1 in the loading range of 0–1.6 kPa, it responds to small external loading of 100 Pa with a resistance change of 10%, its loading and unloading response times are 0.126 and 0.2 s, respectively, and its hysteresis characteristic is ∼7%, indicating that the sensor has high sensitivity, fast response, and good stability. Thus, the presented piezoresistive sensor is promising for practical applications in flexible wearable electronics.
Type-II Dirac phonons in a two-dimensional phononic crystal
Authors: Xu Changqing , Mei Jun , Ma Guancong , Wu Ying
Published: April 2024

We explore the distinctive properties associated with a type-II Dirac point in a simply structured phononic crystal with a lattice deformation. This type-II Dirac point emerges at the Brillouin zone boundary, resulting from the lifting of two degenerate bands and featuring a conical-like Fermi surface in the equi-frequency curve. A practical implementation of such a phononic crystal is achieved with LEGO bricks. Upon introducing a periodic parity-time (PT) symmetric non-Hermitian perturbation, the phononic crystal undergoes a transition from PT-symmetric phase to PT-broken phase, causing the deformation of type-II Dirac point into an oval of exceptional points in the band structure. Based on the eigenmodes of the type-II Dirac point, a k⃗⋅p⃗ perturbation theory can be used to characterize these systems before and after the phase transition. Using a scattering matrix, we analyze the symmetric and broken phases and demonstrate that broadband unidirectional transparency and a coherent perfect absorber and laser can be realized with such a phononic crystal slab.
Accurate numerical analysis of resonances in random waveguides: Effects of the waveguide length
Authors: Katayama Kiyofumi , Tanaka Kazuo , Tanaka Masahiro
Published: April 2024

In this study, the transmission frequency dependence of the random waveguide, which is the waveguide having a randomly corrugated boundary, on waveguide length is investigated using an accurate numerical method. While resonances in the low-frequency region are caused by the interference among the dominant modes, those in the high-frequency region are caused by the mode conversion from the dominant mode to the second mode. Furthermore, their characteristics have not been investigated in detail. Numerical analysis shows that the resonant frequencies in the high-frequency region are nearly independent of the length of the random waveguide within the numerical error. It indicates that random waveguides can be regarded as a stack of independent resonators in high-frequency regions.
Tailoring intrinsic chiroptical responses via twisted bilayer α-MoO3 separated by a VO2 film
Authors: Lu Junjian , Sang Tian , Pian Chui , Ouyang Siyuan , Jing Ze
Published: April 2024

Flexible control of intrinsic chiroptical responses within compact nanostructures is crucial for flat optics, topological photonics, and chiroptics. However, previous approaches require complicated patterns with both in-plane and out-of-plane mirror symmetry breaking to achieve intrinsic chirality, and their chiroptical responses cannot be dynamically controlled as well. Herein, we demonstrated that near-perfect intrinsic circular dichroism (CD) can be achieved within a lithography-free structure consisting of the twisted bilayer α-MoO3 separated by a vanadium dioxide (VO2) film. By twisting the bilayer α-MoO3, dual-band intrinsic chiroptical responses can be realized due to the excitations of the hyperbolic phonon polaritons modes in the mid-infrared. It is the spin-selected average electric-field enhancement instead of the chiral absorption that is responsible for the intrinsic CD of the device. In addition, the chiroptical responses are insensitive to the variation of the thickness of the structure as well as the incident angle, and high contrast CD can be dynamically tuned by varying the volume fraction of VO2.
Conduction mechanism and shallow donor defects in Nb-doped β-Ga2O3 single crystals
Authors: Sai Qinglin , Cui Huiyuan , Xia Changtai , Qi Hongji , Pan Mingyan , Ahmed A. M. , Mohamed H. F.
Published: April 2024

Electrical properties, electronic defects, and photoluminescence (PL) of Nb-doped β-Ga2O3 crystals grown by the floating zone method have been studied in the temperature range from 10 to 350 K. The activation energies of shallow and deep traps were obtained and compared with their counterparts. The 0.25-Nb-doped Ga2O3 crystal has a metallic behavior at room temperature and a semiconducting behavior at low temperatures. This behavior was interpreted by the quantum corrections to the electrical resistivity resulting from the weak localization and Coulomb interaction. In addition, the 0.25-Nb-doped Ga2O3 crystal has a shallow donor ionization energy of 0.03 eV, indicating that it requires less energy to enable n-type conductivity. Hence, Nb is a good choice for improving the electrical conductivity of the β-Ga2O3 crystal. Three defect trap states were found at EC-0.81 eV, EC-0.49 eV, and EC-0.12 eV below the conduction band edge. The PL spectra of the undoped sample show two characteristic bands in the UV and blue regions under the excitation wavelength of 256 nm. On the other hand, in the Nb-doped β-Ga2O3 sample, a novel UV emission band with a shorter wavelength was observed.
Research on multi-UAV collaborative electronic countermeasures effectiveness method based on CRITIC weighting and improved gray correlation analysis
Authors: Liu Zhaozheng , Wang Xing , Kang Weijie , Chen You
Published: April 2024

Multi-UAV cluster technology is a hot topic in modern electronic countermeasures research. Based on the “OODA loop” theory of electronic countermeasures, this paper analyzes the effectiveness evaluation method of multi-UAV collaborative electronic countermeasures. We establish an electronic countermeasures correlation state analysis model based on CRITIC weighting and improved gray correlation theory. This method combines multi-UAV collaborative scene examples and use the gray state correlation analysis method based on the dynamic resolution coefficient. We simulate the effects of electronic countermeasures and various influencing factors on the expected task objectives and verify the effectiveness of the proposed method. The results show that this method can better adapt to the dynamic electronic countermeasures scenarios of multi-UAV clusters and has certain participation value for comprehensively and systematically improving the effectiveness evaluation of electronic countermeasures.
Study on characteristics of gas–liquid two-phase flow in pump as turbine using multiple-size group model
Authors: Yang Hui , Ying Junhui , Lu Tianyu , Li Linmin , Li Xiaojun , Wei Yikun , Zhu Zuchao
Published: April 2024

The multi-size group (MUSIG) model is employed in this paper to simulate the gas–liquid two-phase flow in pump as turbine (PAT) since the traditional Eulerian–Eulerian two-fluid model is unable to take into account the phenomena of breakup and coalescence of bubbles. First, the simulation of gas–liquid two-phase flow in a square column is compared with the experiment to verify the accuracy of the MUSIG model. Then, the results of gas–liquid two-phase flow in PAT simulated by the MUSIG model are compared with those by the conventional uniform bubble (UB) model and find that the MUSIG model is more favorable to capture the flow pattern at high gas content compared to the UB model. Based on the MUSIG model, the internal flow characteristics, pressure fluctuation, and bubble size distribution of the PAT are analyzed. The rotation of the blades breaks a part of big bubbles into small bubbles in the volute, resulting in a smaller diameter of the bubbles entering the impeller. As the gas content increases, the number and size of vortices in the impeller flow channel increase. The vortex is formed at locations where the gas phase distribution in the impeller flow channel is concentrated. The outlet of the impeller is more prone to bubble consolidation under high gas content conditions. In conclusion, the MUSIG model can well predict the complex flow characteristics of gas–liquid two-phase inside the PAT and identify the key influencing factors of energy acquisition, which can provide support for improving the performance of the PAT design.
Prediction of particle-reinforced composite material properties based on an improved Halpin–Tsai model
Authors: Zhu Shuiwen , Wu Shunxin , Fu Yu , Guo Shuangxi
Published: April 2024

This paper introduces an improved Halpin–Tsai model to predict the mechanical, thermal, and electrical properties of silicon-carbide-reinforced polypropylene composites. The model considers the influence of porosity and corresponding silicon-carbide volume fractions and derives relationships between material property shape factors and the aspect ratio, silicon-carbide volume fraction, and porosity. The improved model’s predictions exhibit errors of 4.00% for mechanical properties, 2.13% for thermal properties, and 2.24% for electrical properties when compared to finite element analysis. This study demonstrates that the improved Halpin–Tsai model can effectively predict the properties of silicon-carbide-reinforced polypropylene composites, aiding in the design and optimization of these materials.
Mapping chemical reaction pathways in discharge plasmas: An approach based on force-directed layout
Authors: Zhan Haoyu , Chen Xiaoyue , Zhang Yanze , Qin Pengcheng , Luo Qinyi , Lan Lei
Published: April 2024

In the exploration of humid air discharges at atmospheric pressure using chemical kinetics, the mapping of chemical reaction pathways emerges as a crucial instrument for deciphering the underlying mechanisms of the reaction system. In this study, we employed a force-directed layout method to create diagrams of chemical reaction pathways based on simulation results from a global model of humid air discharges at atmospheric pressure. This innovative approach aids in addressing the challenges traditionally associated with mapping these pathways, notably the difficulty in balancing intuitiveness with the precise representation of physical data. In our method, the mass of each node in the diagram is determined by the species density, and the natural length between nodes is defined according to reaction rates, with the forces acting upon the nodes dictated by the variance between the actual distance and this natural length. The final arrangement of the nodes is established upon reaching a stable equilibrium after undergoing damped motion in response to these forces. This methodology not only provides a tangible and intuitive visualization of the complex interactions within discharge plasmas but also enables a detailed sensitivity analysis to assess the significance of various reactions.
Structural rearrangements in the nucleus localize latent HIV proviruses to a perinucleolar compartment supportive of reactivation
Authors: Kizito Fredrick , Nguyen Kien , Mbonye Uri , Shukla Meenakshi , Luttge Benjamin , Checkley Mary Ann , Agaponova Anna , Leskov Konstantin , Karn Jonathan
Published: April 2024

Using an immunofluorescence assay based on CRISPR-dCas9-gRNA complexes that selectively bind to the HIV LTR (HIV Cas-FISH), we traced changes in HIV DNA localization in primary effector T cells from early infection until the cells become quiescent as they transition to memory cells. Unintegrated HIV DNA colocalized with CPSF6 and HIV capsid (CA, p24) was found in the cytoplasm and nuclear periphery at days 1 and 3 post infection. From days 3 to 7, most HIV DNA was distributed primarily in the nuclear intermediate euchromatic compartment and was transcribed. By day 21, the cells had entered quiescence, and HIV DNA accumulated in the perinucleolar compartment (PNC). The localization of proviruses to the PNC was blocked by integrase inhibitor Raltegravir, suggesting it was due to chromosomal rearrangements. During the reactivation of latently infected cells through the T cell receptor (TCR), nascent viral mRNA transcripts associated with HIV DNA in the PNC were detected. The viral trans-activator Tat and its regulatory partners, P-TEFb and 7SK snRNA, assembled in large interchromatin granule clusters near the provirus within 2 h of TCR activation. As T cell activation progressed, the HIV DNA shifted away from the PNC. HIV DNA in latently infected memory T cells from patients also accumulated in the PNC and showed identical patterns of nuclear rearrangements after cellular reactivation. Thus, in contrast to transformed cells where proviruses are found primarily at the nuclear periphery, in primary memory T cells, the nuclear architecture undergoes rearrangements that shape the transcriptional silencing and reactivation of proviral HIV.
Core planar cell polarity genes
VANGL1
and
VANGL2
in predisposition to congenital vertebral malformations
Authors: Feng Xin , Ye Yongyu , Zhang Jianan , Zhang Yuanqiang , Zhao Sen , Mak Judith C. W. , Otomo Nao , Zhao Zhengye , Niu Yuchen , Yonezawa Yoshiro , Li Guozhuang , Lin Mao , Li Xiaoxin , Cheung Prudence Wing Hang , Xu Kexin , Takeda Kazuki , Wang Shengru , Xie Junjie , Kotani Toshiaki , Choi Vanessa N. T. , Song You-Qiang , Yang Yang , Luk Keith Dip Kei , Lee Kin Shing , Li Ziquan , Li Pik Shan , Leung Connie Y. H. , Lin Xiaochen , Wang Xiaolu , Qiu Guixing ,   DISCO (Deciphering disorders Involving Scoliosis and COmorbidities) study group, Watanabe Kota ,   Japanese Early Onset Scoliosis Research Group, Wu Zhihong , Posey Jennifer E. , Ikegawa Shiro , Lupski James R. , Cheung Jason Pui Yin , Zhang Terry Jianguo , Gao Bo , Wu Nan , Qiu Guixing , Wu Nan , Zhang Jianguo , Wu Zhihong , Wang Shengru , Liu Sen , Li Ziquan , Yang Yang , Zhao Zhengye , Chen Guilin , Li Guozhuang , Zhu Yuanpeng , Cai Jihao , Liu Di , Xu Kexin , Yang Jianle , Maheshati Aoran , Li Qing , Xie Jingyi , Yin Xiangjie , Wang Jie , Li Zihua , Zheng Zhifa , Fang Kun , Nie Xiangyu , Cheng Xi , Wen Wen , Yang Xinyu , Zhang Yuanqiang , Liu Lian , Wang Lianlei , Chen Na , Lin Jiachen , Lin Mao , Zhao Lina , Liu Fei , Niu Yuchen , Liu Qing , Gao Guangxi , Li Shuai , Bai Yueyan , Zhao Sen , Ye Yongyu , Zhao Hengqiang , Chen Zefu , Liu Jiaqi , Yan Zihui , Yu Chenxi , Shao Jiashen , Otomo Nao , Yonezawa Yoshiro , Takeda Kazuki , Ogura Yoji , Kawakami Noriaki , Koatani Toshiaki , Suzuki Teppei , Uno Koki , Sudo Hideki , Inami Satoshi , Taneichi Hiroshi , Shigematsu Hideki , Watanabe Kei , Sugawara Ryo , Taniguchi Yuki , Minami Shohei , Nakamura Masaya , Matsumoto Morio , Ikegawa Shiro , Watanabe Kota
Published: April 2024

Congenital scoliosis (CS), affecting approximately 0.5 to 1 in 1,000 live births, is commonly caused by congenital vertebral malformations (CVMs) arising from aberrant somitogenesis or somite differentiation. While Wnt/ß-catenin signaling has been implicated in somite development, the function of Wnt/planar cell polarity (Wnt/PCP) signaling in this process remains unclear. Here, we investigated the role of
Vangl1
and
Vangl2
in vertebral development and found that their deletion causes vertebral anomalies resembling human CVMs. Analysis of exome sequencing data from multiethnic CS patients revealed a number of rare and deleterious variants in
VANGL1
and
VANGL2
, many of which exhibited loss-of-function and dominant-negative effects. Zebrafish models confirmed the pathogenicity of these variants. Furthermore, we found that
Vangl1
knock-in (p.R258H) mice exhibited vertebral malformations in a
Vangl
gene dose- and environment-dependent manner. Our findings highlight critical roles for PCP signaling in vertebral development and predisposition to CVMs in CS patients, providing insights into the molecular mechanisms underlying this disorder.
Limits of economy and fidelity for programmable assembly of size-controlled triply periodic polyhedra
Authors: Duque Carlos M. , Hall Douglas M. , Tyukodi Botond , Hagan Michael F. , Santangelo Christian D. , Grason Gregory M.
Published: April 2024

We propose and investigate an extension of the Caspar–Klug symmetry principles for viral capsid assembly to the programmable assembly of size-controlled triply periodic polyhedra, discrete variants of the Primitive, Diamond, and Gyroid cubic minimal surfaces. Inspired by a recent class of programmable DNA origami colloids, we demonstrate that the economy of design in these crystalline assemblies—in terms of the growth of the number of distinct particle species required with the increased size-scale (e.g., periodicity)—is comparable to viral shells. We further test the role of geometric specificity in these assemblies via dynamical assembly simulations, which show that conditions for simultaneously efficient and high-fidelity assembly require an intermediate degree of flexibility of local angles and lengths in programmed assembly. Off-target misassembly occurs via incorporation of a variant of disclination defects, generalized to the case of hyperbolic crystals. The possibility of these topological defects is a direct consequence of the very same symmetry principles that underlie the economical design, exposing a basic tradeoff between design economy and fidelity of programmable, size controlled assembly.
Response particles in Mandarin conversation
Authors: Wang Wei
Published: April 2024

This study examines three major response particles, o/ou, en, and a in Mandarin
conversation. Using the framework of interactional linguistics, this study examines the actions implemented by these particles and
their associated prosodic patterns. It discovers that, while these three particles have shared functions, they show interactional
nuances that allow for more fine-grained actions. It also reveals that different particles tend to have a similar prosodic design
when they implement the same action. This study sheds light on the detailed workings of these particles both prosodically and
interactionally in Mandarin speakers’ everyday conversation, contributing a specific case to further cross-linguistic
comparison.
On the frequency dependence of the PDIV in twisted pair magnet wire analogy in humid air
Authors: Šefl O , Färber R , Franck C M
Published: April 2024

The partial discharge inception voltage (PDIV) of low-voltage induction motor turn-turn insulation analogy is investigated for variable relative humidity (RH) of the surrounding air (temperature and pressure are kept constant close to their ambient values). Three materials, perfluoralkoxy alkane, sealed and unsealed alumina (UA), are employed as the dielectric coating (insulation) of test samples. Each material’s dielectric properties change differently with RH—of these, relative permittivity is regarded as the most crucial, as it was previously proven to be, along with the coating’s thickness, the key factor in determining the PDIV in dry air conditions. To further vary the value of permittivity and thus provide larger data sets for the verification study, the frequency of the excitation voltage is also varied between 1 Hz and 50 kHz. The obtained experimental data are compared against the PDIV predictions obtained by a breakdown model based on the reduced thickness of the coating (ratio of the coating thickness to its relative permittivity). Satisfying agreement between the measured and predicted PDIV are obtained for the first two materials, whereas significant discrepancies are seen for the UA material. For this case, surface conductivity is introduced into the prediction model and much better fits to the experimental data are obtained for a suitable value of surface resistance. It is hence demonstrated that the model is able to satisfactorily predict the PDIV for three substantially different materials when the RH of the surrounding air is varied between

10

%

–

80

%

.
The type-I, III nodal ring, type-I, III quadratic nodal point, and Dirac valley phonons in 2D kagome lattices M2C3 (M = As, Bi, Cd, Hg, P, Sb, Zn)
Authors: Liu Qing-Bo , Guo Zhi-Dong , Du Fan-Fan , Feng De-Ming , Tan Xing-Yi , Yu Ziyang , Xiong Lun
Published: April 2024

Topological phases in kagome systems have garnered considerable interest since the introduction of the colloidal kagome lattice. Our study employs first-principle calculations and symmetry analysis to predict the existence of ideal type-I, III nodal rings (NRs), type-I, III quadratic nodal points (QNPs), and Dirac valley phonons (DVPs) in a collection of two-dimensional (2D) kagome lattices M2C3 (M = As, Bi, Cd, Hg, P, Sb, Zn). Specifically, the Dirac valley points (DVPs) can be observed at two inequivalent valleys with Berry phases of +π and

−
π

, connected by edge arcs along the zigzag and armchair directions. Additionally, the QNP is pinned at the Γ point, and two edge states emerge from its projections. Notably, these kagome lattices also exhibit ideal type-I and III nodal rings protected by time inversion and spatial inversion symmetries. Our work examines the various categories of nodal points and nodal ring phonons within the 2D kagome systems and presents a selection of ideal candidates for investigating topological phonons in bosonic systems.
Hybrid-DFT study of halide perovskites, an energy-efficient material under compressive pressure for piezoelectric applications
Authors: Celestine L , Zosiamliana R , Kima Lalrin , Chettri Bhanu , Singh Y T , Gurung Shivraj , Surajkumar Singh N , Laref A , Rai D P
Published: April 2024

Recent studies have reported that lead-halide perovskites are the most efficient energy-harvesting materials. Regardless of their high-output energy and structural stability, lead-based products have risk factors due to their toxicity. Therefore, lead-free perovskites that offer green energy are the expected alternatives. We have taken CsGeX3 (X = Cl, Br, and I) as lead-free halide perovskites despite knowing the low power conversion rate. Herein, we have tried to study the mechanisms of enhancement of energy-harvesting capabilities involving an interplay between structure and electronic properties. A density functional theory simulation of these materials shows a decrease in the band gaps, lattice parameters, and volumes with increasing applied pressure. We report the high piezoelectric responses and high electro-mechanical conversion rates, which are intriguing for generating electricity through mechanical stress.
Evidences for local non-centrosymmetricity and strong phonon anomaly in EuCu2As2: a Raman spectroscopy and lattice dynamics study
Authors: Swain Debasmita , Dey Sarkar Mainak , Ptok Andrzej , Vaitheeswaran G , Roy Anushree , D Das Sitikantha
Published: April 2024

Phonon modes and their association with the electronic states have been investigated for the metallic EuCu2As2 system. In this work, we present the Raman spectra of this pnictide system which clearly shows the presence of seven well defined peaks above 100 cm−1 that is consistent with the locally non-centrosymmetric P4/nmm crystal structure, contrary to that what is expected from the accepted symmorphic I4/mmm structure. Lattice dynamics calculations using the P4/nmm symmetry attest that there is a commendable agreement between the calculated phonon spectra at the Γ point and the observed Raman mode frequencies, with the most intense peak at

∼

232

 cm−1 being ascribed to the A

1
g

mode. Temperature dependent Raman measurements show that there is a significant deviation from the expected anharmonic behaviour around 165 K for the A

1
g

mode, with anomalies being observed for several other modes as well, although to a lesser extent. Attempts are made to rationalize the observed anomalous behavior related to the hardening of the phonon modes, with parallels being drawn from metal dichalcogenide and allied systems. Similarities in the evolution of the Raman peak frequencies with temperature seem to suggest a strong signature of a subtle electronic density wave instability below 165 K in this compound.
Calibration of absorption coefficients of liquid solutions for measuring liquid film thickness by absorptiometry
Authors: Zhao Yu , Xu Haitao
Published: April 2024

Infrared absorptiometry is a widely used non-intrusive method for measuring the thickness of liquid films. The accuracy of that measurement depends crucially on having high-accuracy data of the absorption coefficient of the laser light used, which is, however, not easily available, especially for the wavelength range where the absorption is strong. Here we propose a method to calibrate the absorption coefficients in such cases. By measuring the light intensity reduction while scanning through a liquid film formed in a wedge, whose angle can be adjusted and determined a priori from interferometry, the absorption coefficient of the liquid can be accurately obtained without the need to create a flat liquid film with exact known thickness. The method is verified by calibrating the absorption coefficient of pure water at an infrared wavelength and the result agrees very well with the values found in the literature. As a demonstration of the application of the method, the absorption coefficients of soap solutions with different compositions were calibrated and used to measure the thicknesses of draining soap films. The results from the absorptiometry are in good agreement with the film thickness measured simultaneously from interferometry.
A new teaching-learning sequence to promote secondary school students’ learning of quantum physics using Dirac notation
Authors: Hennig Fabian , Tóth Kristóf , Förster Moritz , Bitzenbauer Philipp
Published: April 2024

This paper describes the design of a new teaching-learning sequence on quantum physics aimed at upper secondary school students. In this teaching-learning sequence, GeoGebra simulations and interactive screen experiments are used to investigate the behaviour of a single photon at beam splitter and single photon interference in a Michelson interferometer. We propose a minimal formalism using Dirac notation, which avoids complex numbers and elaborate vector calculus, to make a quantitative description of the quantum optics experiments accessible to secondary school students. With this new educational pathway, we take into account findings from physics education research, which suggest that the introduction of a mathematical formalism tailored to students’ abilities might help them to overcome naive-realist views of quanta or space-time descriptions of quantum phenomena, while at the same time facilitating a transition to a functional understanding of quantum models.
The driven unicycle
Authors: Mungan Carl E , Kabutz Heiko
Published: April 2024

The free-body diagram of a unicycle pedalled across level ground is analysed, showing that riders must tilt their bodies into the direction of the acceleration. A comparison is made with an unpowered round object rolling without slipping up or down an inclined plane. A Newtonian analysis predicts an acceleration of the unicycle as a function of the tilt angle that is in good agreement with measurements of an actual unicycle using a smartphone.
Illuminating dark matter: I. A guide for physics teachers
Authors: Pinochet Jorge
Published: April 2024

One of the great mysteries of contemporary science is dark matter, an exotic substance of unknown nature that, in theory, makes up about 27% of the total mass-energy density of the Universe, and which does not appear to emit, absorb, or reflect any kind of light, meaning that it is invisible and can only be detected through its gravitational effects on objects around it. Dark matter is a frontier topic, involving highly complex subjects that usually exceed the training of a physics teacher. Given this difficulty, the aim of this paper is to shed some light on dark matter, and to offer a broad, up-to-date introduction that is mainly directed at physics teachers in training and in practice. Due to the breadth of the subject, the article has been divided into two parts. In Part I, we deal with general concepts, which serve as an introduction to the more specific topics analysed in Part II.
ChatGPT as a tool for honing teachers’ Socratic dialogue skills
Authors: Gregorcic Bor , Polverini Giulia , Sarlah Andreja
Published: April 2024

In this proof-of-concept paper, we propose a specific kind of pedagogical use of ChatGPT—to help teachers practice their Socratic dialogue skills. We follow up on the previously published paper ‘ChatGPT and the frustrated Socrates’ by re-examining ChatGPT’s ability to engage in Socratic dialogue in the role of a physics student. While in late 2022 its ability to engage in such dialogue was poor, we see significant advancements in the chatbot’s ability to respond to leading questions asked by a human teacher. We suggest that ChatGPT now has the potential to be used in teacher training to help pre- or in-service physics teachers hone their Socratic dialogue skills. In the paper and its supplemental material, we provide illustrative examples of Socratic dialogues with ChatGPT and present a report on a pilot activity involving pre-service physics and mathematics teachers conversing with it in a Socratic fashion.
The internal resistance of a non-ideal inductor in an RLC series circuit at resonance
Authors: Torriente-García Ives , Muñoz-Pérez Francisco M , Castro-Palacio Juan C , Monsoriu Juan A
Published: April 2024

The measured voltage at the inductor in an RLC series circuit connected to a sinusoidal electromotive force depends on the current and the impedance. The latter does not only include the inductive reactance only but also the ohmic resistance of the inductor. This fact has a clear consequence on the result of the measurement as the measured voltage at the inductor is not in counterphase with the measured voltage at the capacitance as shown in theory where ideal inductors are usually considered. In this work, the resistance of a coil in an RLC circuit is obtained from the direct measurements of the phase of the voltage at the coil at resonance and the resonant frequency for different values of capacitance. This value is compared with the resistance of the coil determined directly with an ohmmeter. The agreement between both values is very good. The conventional signal generator has been replaced by a smartphone which is a very familiar device for the students. The smartphone can provide the necessary voltage supply for the experiment to be carried out successfully.
Penalty weight tuning in high dose rate brachytherapy using multi-objective Bayesian optimization
Authors: Jafarzadeh Hossein , Antaki Majd , Mao Ximeng , Duclos Marie , Maleki Farhard , Enger Shirin A
Published: April 2024

Objective. Treatment plan optimization in high dose rate brachytherapy often requires manual fine-tuning of penalty weights for each objective, which can be time-consuming and dependent on the planner's experience. To automate this process, this study used a multi-criteria approach called multi-objective Bayesian optimization with q-noisy expected hypervolume improvement as its acquisition function (MOBO-qNEHVI). Approach. The treatment plans of 13 prostate cancer patients were retrospectively imported to a research treatment planning system, RapidBrachyMTPS, where fast mixed integer optimization (FMIO) performs dwell time optimization given a set of penalty weights to deliver 15 Gy to the target volume. MOBO-qNEHVI was used to find patient-specific Pareto optimal penalty weight vectors that yield clinically acceptable dose volume histogram metrics. The relationship between the number of MOBO-qNEHVI iterations and the number of clinically acceptable plans per patient (acceptance rate) was investigated. The performance time was obtained for various parameter configurations. Main results. MOBO-qNEHVI found clinically acceptable treatment plans for all patients. With increasing the number of MOBO-qNEHVI iterations, the acceptance rate grew logarithmically while the performance time grew exponentially. Fixing the penalty weight of the tumour volume to maximum value, adding the target dose as a parameter, initiating MOBO-qNEHVI with 25 parallel sampling of FMIO, and running 6 MOBO-qNEHVI iterations found solutions that delivered 15 Gy to the hottest 95% of the clinical target volume while respecting the dose constraints to the organs at risk. The average acceptance rate for each patient was 89.74% ± 8.11%, and performance time was 66.6 ± 12.6 s. The initiation took 22.47 ± 7.57 s, and each iteration took 7.35 ± 2.45 s to find one Pareto solution.Significance. MOBO-qNEHVI combined with FMIO can automatically explore the trade-offs between treatment plan objectives in a patient specific manner within a minute. This approach can reduce the dependency of plan quality on planner’s experience and reduce dose to the organs at risk.
Optimizing control for strike point sweeping using lower divertor coil in EAST
Authors: Qiu Qinglai , Zhang Yang , Zhang Xiaodong , Yuan Qiping , Luo Zhengping , Wang Zhaoliang , Wu Yibing , Qian Jing , Guo Bin , Liang Ruirong , Wang Yuehang , Chen Jianjun , Huang Yao , Xiao Bingjia , Meng Lingyi ,   the East Team
Published: April 2024

In 2021, EAST was equipped with a full-ring divertor coil to facilitate research on the fish tail divertor concept. Initially, it was observed that the coil current had a negligible ability to sweep the strike point. Conversely, when the amplitude and frequency of the alternating current were marginally increased, there was a significant interruption to plasma control. This perturbation was attributed to the poloidal control field’s limited response rate to the coil’s fluctuations. To address this issue, novel control methodologies were devised to ensure stable and effective sweeping of the strike point using the divertor coil. The devised methods are twofold: For high-frequency strike point control, a low-pass filter decoupling technique based on ISOFLUX control strategy enabled achieving a sweeping frequency of 100 Hz. This strategy allowed for consistent plasma management without compromising average stored energy or density regulation. Resulting from this proficient manipulation of the strike point, a reduction in the peak temperature of the divertor plate was observed. For low-frequency sweeping, a static multi-input multi-output decoupling approach was developed, facilitating concurrent sweeping of both the outer and inner strike points.
Suprathermal-ion-driven fusion chain reactions in the pure deuterium system
Authors: Robinson A P L
Published: April 2024

It is argued that fusion chain reactions in the D-D system is feasible with supra-thermal deuterons in the MeV regime, with new generations of deuterons being generated either via neutron–deuteron or proton–deuteron collisions. The propagation of supra-thermal deuterons in an infinite, hot, dense deuterium target was studied using a Monte Carlo method that includes multiple nuclear reactions, electron and ion stopping, along with neutron and proton knock-ons. Over a wide range of densities we observed significant, albeit sub-critical chain reactions in the multi-keV temperature regime. At very high densities (over 1000 gcm−3) and temperatures (over 40 keV) we observed chain reactions that reached criticality. These results suggest that there is a case to re-assess the potential of inertial confinement fusion based on deuterium-heavy targets.
Auxetic fixation devices can achieve superior pullout performances compared to standard fixation concepts
Authors: Barnett Elinor , Fletcher James , Gill Harinderjit S , Pegg Elise C , Loukaides Evripides G
Published: April 2024

Despite bone screws being the most commonly inserted implant in orthopaedic surgery, 10% of fracture fixation failure is a result of screw migration or pullout. In this study, the effect of four auxetic structures on the pullout performance of a novel unthreaded bone fastener was investigated through experiments and numerical simulations. The auxetic fasteners included the re-entrant, rotating squares, missing rib, and tetrachiral structures. Parametric CAD models were developed for each, and polymer samples manufactured using a stereolithography process. Pullout testing using bone analogue material found the rotating squares fastener to achieve superior pullout resistance 2.5 times that of the non-auxetic control sample. With a pullout to push-in force ratio of 33.7, this fastener achieved high pullout resistance with a low insertion force improving ease of installation. The Poisson’s ratio of the structure was determined using image analysis to be −1.31, similar to the missing rib and re-entrant types. The low axial stiffness of 12.1 N mm−1 for the rotating squares fastener was the reason for superior performance, allowing axial and resulting transverse strain to be initiated at relatively low load. The effect of increased diametral interference was investigated, and the re-entrant structure found to be superior with pullout resistance improved by 342%. This work provides a foundation for further development of unthreaded auxetic bone fasteners, which have the potential to replace screws for some orthopaedic applications and significantly reduce the prevalence of pullout as a failure mode.
Synchrotron x-ray spectra characterisation for radiation therapy applications at the ESRF - ID17 biomedical beamline
Authors: Di Manici Ilaria , Reyes-Herrera Juan , Day Liam , Sánchez Del Río Manuel , Krisch Michael , Pellicioli Paolo
Published: April 2024

Objective. Radiation therapy requires reliable dosimetry protocols to deliver successful treatments with high accuracy and precision. In this context, accurate knowledge of the beam’s energy spectra is mandatory. The goal of this study was to validate the synchrotron x-ray spectrum of the ID17 beamline at the European Synchrotron Radiation Facility (ESRF). The modification of the synchrotron storage ring and beamline in recent years necessitates a new characterisation of the radiation spectra of the ID17 beamline. The validated spectra will be a starting point for possible future clinical applications. Approach. The half value layer method was used to measure the attenuation of the x-ray spectrum in Al and Cu. Experimental data was validated against theoretical data produced using OASYS; an in-house developed software for calculating beamline spectra. Two different spectral configurations, ‘conventional’ and ‘clinical’, were investigated. The characterised spectra were used to perform dosimetric validation of depth dose profiles measured in a water-equivalent phantom. The dose profile was measured using two different detectors and compared with calculations generated using two different Monte Carlo algorithms. Main results. The results showed good agreement between measured and predicted half value layers, with differences of less than 1% in most cases. Excellent dosimetric agreement to within 3% was obtained, an agreement that satisfies the requirements in conventional radiotherapy for approvable treatment planning. Significance. Accurate spectra have been defined and validated for the ESRF—ID17 Biomedical beamline. The validated spectra can be used as input for future dosimetric studies and treatment planning systems in the context of preclinical studies and possible future clinical trials.
Effect of instrumental polarization with a half-wave plate on the B-mode signal: prediction and correction
Authors: Patanchon Guillaume , Imada Hiroaki , Ishino Hirokazu , Matsumura Tomotake
Published: April 2024

We study the effect of incident unpolarized signal converted to polarized light produced by a realistic half-wave plate (HWP) and evaluate the impact of the effect in the measurement of Cosmic Microwave Background (CMB) B-mode polarization signal targeting to probe the tensor-to-scalar ratio r.
The HWP is modeled with the Mueller formalism, and coefficients are decomposed for any incident angle into harmonics of the HWP rotation frequency due to azimuthal angle dependence. Although we use a general formalism, band-averaged matrix coefficients are calculated as an example for a 9-layer sapphire HWP using EM propagation simulations. We perform simulations of multi-detector observations in a band centered at 140 GHz using LiteBIRD instrumental configuration. We show both theoretically and with the simulations that most of the artefacts on Stokes parameter maps are produced by the dipole leakage on B-modes induced by the fourth harmonics MQI

(4f) and MUI

(4f). The resulting effect is strongly linked to the spin-2 focal plane scanning cross linking parameters. We develop a maximum likelihood-based method to correct the IP leakage by joint fitting of the Mueller matrix coefficients as well as the Stokes parameter maps.
We show that the residual leakage after correction leads to an additional noise limited uncertainty on r of the order of 10-7, independently of the value of the Mueller matrix coefficients. We discuss the impact of the monopole signal and the potential coupling with other systematic effects such as gain variations and detector nonlinearities.