bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of Undergraduate Students' Language Sample Analysis in Online and Face-to-Face Courses
Authors: Bitetti Dana
Published: October 2023

Purpose:

Language sample analysis (LSA) is an essential part of evaluations for young children, but few studies have investigated whether instructional methods for teaching LSA are effective based on student outcomes. Furthermore, with the growth of online coursework, there is a need to understand whether student outcomes differ depending on instructional modality. This study examined the results of an LSA project from two classes, online and face to face. Research questions addressed whether the measures calculated by the students differed significantly from the values derived by the instructor and whether the results of each language sample measure differed between the two classes.

Method:

There were 39 total participants: eight online students and 31 face-to-face students. Students transcribed an audio sample of a mother conversing with her 3-year-old son. Students calculated the number of complete and intelligible utterances, mean length of utterance in words (MLU-w), MLU in morphemes (MLU-m), number of total words (NTW), number of different words (NDW), and type–token ratio (TTR).

Results:

When compared to the instructor's values, students' results were significantly different for measures that involved totals (complete and intelligible utterances, NTW, NDW). However, the students used these values to calculate MLU-w, MLU-m, and TTR numbers that were not significantly different from those of the instructor. Results also indicated that there were no differences between the class calculations for most measures.

Conclusion:

Results are discussed considering how they inform the evidence-based teaching practices of instructors who are teaching undergraduate courses in communication sciences and disorders.
OTA testing of near‐field and far‐field communication links
Authors: Korunur Engiz B. , Lodro M. , Greedy S. , Thomas D.W.P.
Published: October 2023

In this work, near‐field and far‐field link measurement in metal enclosure environment is performed. The performance of near‐field and far‐field links are assessed using key performance indicators such as error vector magnitude, bit error rate, and signal‐to‐noise ratio. The metal enclosure is placed in an anechoic chamber, ensuring a stationary measurement environment. There are no external interference sources and the results are a function of near‐field and far‐field scenarios and hardware impairments. In measurements, software‐defined radios used for the transmission and reception of image data using the long‐term evolution‐advanced physical layer. Based on the results of the study, an optimum gain region can be determined where better key performance indicators are achieved. Furthermore, the frequency selectivity of the channel is reduced within the determined optimum gain region, leading to an improvement in the system's performance.
Robust positive control of tumour growth using angiogenic inhibition
Authors: Homayounzade Mohamadreza , Homayounzadeh Maryam , Khooban Mohammad Hassan
Published: October 2023

In practice, many physical systems, including physiological ones, can be considered whose input can take only positive quantities. However, most of the conventional control methods do not support the positivity of the main input data to the system. Furthermore, the parameters of these systems, similar to other non‐linear systems, are either not accurately identified or may change over time. Therefore, it is reasonable to design a controller that is robust against system uncertainties. A robust positive‐input control method is proposed for the automatic treatment of targeted anti‐angiogenic therapy implementing a recently published tumour growth model based on experiments conducted on mouse models. The backstepping (BS) approach is applied to design the positive input controller using sensory data of tumour volume as feedback. Unlike previous studies, the proposed controller only requires the measurement of tumour volume and does not require the measurement of inhibitor level. The exponential stability of the controlled system is proved mathematically using the Lyapunov theorem. As a result, the convergence rate of the tumour volume can be controlled, which is an important issue in cancer treatment. Moreover, the robustness of the system against parametric uncertainties is verified mathematically using the Lyapunov theorem. The real‐time simulation results‐based (OPAL‐RT) and comparisons with previous studies confirm the theoretical findings and effectiveness of the proposed method.
Kinetics of static recrystallization in Sn-added Fe-Si alloys
Authors: Dumont Myriam , Mavrikakis Nikolas , Saikaly Wahib , Mangelinck Dominique
Published: October 2023

Segregated solute atoms play an important role in grain boundary migration phenomena, which are critical for understanding the microstructure evolution in metals. Recrystallization kinetics of Fe-Si-Sn alloys were experimentally studied during static recrystallization. An established physical model that couples recovery and recrystallization was implemented to describe the experimental observations. The model was extended to include microstructural input, while taking into account the solute drag effect. The model is able to predict both the evolution of the recrystallized fraction and hardness after annealing in the temperature range [773K;1023K] for binary (Fe-5.8at. %Si) and ternary (Fe-5.8at. %Si-0.045at. % Sn) alloys.
Postdischarge Opioid Prescription after Cesarean: A Quality Improvement Initiative
Authors: Pellino Katherine T. , Kershner Alexandra , Peterson Erika L.
Published: October 2023

Objective This study aims to determine if adoption of a user-friendly algorithm for individualized opioid prescribing at discharge would decrease the number of opioids prescribed after cesarean delivery.

Study Design As part of a quality initiative, we developed and implemented an algorithm for opioid prescribing at discharge for patients after cesarean delivery. The intervention group comprised patients delivering by cesarean in the 6 months following initiation of the intervention. The intervention group was divided into three groups based on inpatient opioid needs 24 to 48 hours after delivery. Oxycodone tablets were prescribed at discharge based on inpatient group. The control group comprised patients delivering at the same institution in the 6 months prior to initiation of the intervention. The primary outcome was number of oxycodone tablets prescribed at discharge. The secondary outcome was the proportion of patients with a pain-related encounter or additional oxycodone prescription up to 6 weeks after delivery.

Results From July to December 2020, a total of 382 subjects met criteria for the intervention. The comparison group consisted of 391 subjects discharged from January to June 30, 2020, after cesarean. Baseline characteristics and inpatient opioid use 24 to 48 hours after delivery did not differ between the groups. Compared with the control group, subjects in the intervention group had fewer oxycodone tablets prescribed at discharge (11.1 vs. 15.8, p < 0.001). The number of pain-related encounters within 6 weeks of delivery did not differ between the intervention and comparison groups (10.5 vs. 10.3%, p = 0.82). There was no increase in the additional number of oxycodone prescriptions after discharge (4.7% in the intervention group vs. 4.3% in the control group, p = 0.81).

Conclusion Discharge opioid prescribing based on inpatient use after cesarean reduces the number of opioids prescribed without increasing the number of pain-related encounters after discharge. A simple algorithm may ensure compliance from prescribers.

Key Points
Nurse Practitioner Students' Knowledge Assessment and Perceived Preparedness to Triage Ophthalmology Complaints in a Primary Care Setting: An Educational Intervention
Authors: Reilly Grace R. , Russell Nancy G. , McIltrot Kimberly , Sisson Stephen D. , Scott Adrienne W.
Published: October 2023

Purpose In this proof-of-concept pilot study, we aimed to increase nurse practitioner (NP) student knowledge of ophthalmology to prepare NPs for encounters in primary care settings. The Association of University Professors of Ophthalmology (AUPO) and the American Academy of Ophthalmology (AAO) endorse core knowledge that medical students should achieve. We assess the effectiveness of an innovative ophthalmologist-led curriculum based on these competencies tailored to issues NPs encounter in primary care.

Methods Johns Hopkins University NP students enrolled in a pre–post-cohort study and educational intervention. The didactic program was developed according to AUPO and AAO core ophthalmology content for medical students and was taught in-person by an ophthalmologist. Pre–post-assessments evaluated students' perceived readiness to encounter ophthalmic issues in the clinic and baseline knowledge of core competencies of ophthalmology.

Results A total of 42 NP students were included in the analysis. NP students improved in core knowledge and readiness to encounter ophthalmology issues. After the educational event, there was a statistically significant improvement in students' ratings of preparedness to obtain a focused history, exam, perform initial management and decide the urgency of a referral for acute painless vision loss (p < 0.001), chronic vision loss (p < 0.001), or a patient with a red/painful eye (p < 0.001). Students showed a statistically significant improvement in postdidactic event core ophthalmology knowledge assessment scores (p = 0.002).

Conclusion Primary care NPs are increasingly the initial point of contact for patients with ophthalmic complaints, and thus, high-quality and thorough education regarding ophthalmology triage and referral for NPs is necessary. NP student comfort with and knowledge of ophthalmic complaints and triage may be improved by a brief educational intervention taught by an ophthalmologist early in the NP curriculum.
Management of Bilateral Foreign Objects in Immature Permanent Maxillary Central Incisors: A Case Report
Authors: Chourasia Hemant Ramesh
Published: October 2023

Traumatic dental injuries are more commonly seen in children and it often results in a complicated crown fracture. This case is unique as foreign objects in the form of hand-sewing needles were accidentally lodged bilaterally in both maxillary central incisors. A 13-year-old patient was referred to the Dental Clinics at the College of Dentistry, Jazan University with a complaint of broken needles in her front teeth and a history of trauma 3 years ago. Although the patient had the habit of using a hand-sewing needle to remove the lodged food particles from the open pulp chamber, she was not able to recollect the incidence of needle separations. Radiographic examination revealed radiopaque objects in the middle third of the right maxillary central incisor (#11) and in the apical third of the left maxillary central incisor (#21). Tooth #11 was clinically diagnosed as pulp necrosis with chronic apical abscess and tooth #21 as pulp necrosis with asymptomatic apical periodontitis. The micro tweezer from the broken instrument removal kit (Zumax Medical Co.,Ltd., Jiangsu, China) was used to retrieve the separated needle pieces under the operating microscope. The open apices were managed by the formation of mineral trioxide aggregate apical plug, and the procedure of root reinforcement was achieved by bonded resin cement and fiber resin posts. Finally, teeth were restored with dual cure core build-up composite material and direct composite veneers. Recommendations are made to treat complicated crown fractures, especially in children on priority to minimize the risk of foreign object impaction.
A Pilot Standardized Simulation-Based Mechanical Ventilation Curriculum Targeting Pulmonary and Critical Care Medicine and Critical Care Medicine Fellows
Authors: Pervaiz Amina , Daoud Asil , Alchakaki Abdulrazak , Ganti Shyam , Venkat Divya , Lee Sarah , Sankari Abdulghani
Published: October 2023

Introduction The mastery of mechanical ventilation (MV) management is challenging, as it requires the integration of physiological and technological knowledge with critical thinking. Our aim was to create a standardized curriculum with assessment tools based on evidence-based practices to identify the skill deficit and improve knowledge in MV management.

Methods For 3 years, 3 hours of standardized curriculum for each first-year pulmonary critical care medicine (PCCM) and critical care medicine (CCM) fellows was integrated into the orientation (chronologically): (1) a baseline knowledge pretest; (2) a 1-hour one-on-one case-based simulation session with debriefing. A 34-item competency checklist was used to assess critically thinking and skills and guide the debriefing; (3) a 1-hour group didactic on respiratory mechanics and physiology; (4) a 45-minute hands-on session in small groups of one to three fellows for basic knobology, waveforms, and various modes of mechanical ventilators; (5) a 15-minute group bedside teaching of vented patients covering topics such as techniques to alleviate dyssynchrony and advanced ventilator modes; (6) a one-on-one simulation reassessment session; (7) a knowledge posttest. Fellows' performances at baseline, 1-month posttest, and end-of-first year post-test were compared.

Results Fellows (n = 24) demonstrated significant improvement at 1-month posttest in knowledge (54.2% ± 11.0 vs. 76.6 ± 11.7%, p < 0.001) and MV competency (40.7 ± 11.0% vs. 69.7 ± 9.3%, p < 0.001), compared with pretest. These improvements were retained at the end-of-year reassessments (knowledge 75.1 ± 14.5% and MV competency 85.5 ± 8.7%; p < 0.001).

Conclusion Standardized simulation-based MV curriculum may improve the medical knowledge competency, and confidence of first-year PCCM and CCM fellows toward MV management before encountering actual ventilated patients.
A Rare Occurrence of Solid Gynecological Malignancy Synchronous with Hematological Malignancy: Rare Case and Review of Literature
Authors: Gupta Rubi , Dave Pariseema , Patel Bijal , Shukur Remi Abdul
Published: October 2023

A synchronous solid and hematological malignancy is an uncommon condition in which a patient develops two or more primary cancers, one of which is a solid malignancy and the other one is a hematological malignancy, within 6 months of primary cancer diagnosis. The most common histology in solid malignancies is gastrointestinal adenocarcinoma, which coexists with the lymphoma subtype diffuse large B-cell lymphoma (DLBCL). Here, we report an extremely rare combination of serous carcinoma of the ovary synchronous with lymphoma of DLBCL subtype. A woman aged 52 years presented with an abdominal mass and abdominal pain for a short duration of 15 days. She was evaluated using clinical, radiological, and biochemical parameters. She was diagnosed with non-Hodgkin lymphoma by tru-cut biopsy from a bony lytic lesion and ovarian cancer by staging laparotomy. R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisolone) chemotherapy for lymphoma and staging laparotomy for persistent adnexal mass resulted in complete remission of both ovarian cancer and lymphoma. She received paclitaxel and carboplatin-based postoperative chemotherapy as an adjuvant for ovarian cancer.
Functional MRI for Acute Covert Consciousness: Emerging Data and Implementation Case Series
Authors: Boerwinkle Varina L. , Gillette Kirsten , Rubinos Clio A. , Broman-Fulks Jordan , Aseem Fazila , DeHoff Grace K. , Arhin Martin , Cediel Emilio , Strohm Tamara
Published: October 2023

Although research studies have begun to demonstrate relationships between disorders of consciousness and brain network biomarkers, there are limited data on the practical aspects of obtaining such network biomarkers to potentially guide care. As the state of knowledge continues to evolve, guidelines from professional societies such as the American and European Academies of Neurology and many experts have advocated that the risk–benefit ratio for the assessment of network biomarkers has begun to favor their application toward potentially detecting covert consciousness. Given the lack of detailed operationalization guidance and the context of the ethical implications, herein we offer a roadmap based on local institutional experience with the implementation of functional MRI in the neonatal, pediatric, and adult intensive care units of our local government-supported health system. We provide a case-based demonstrative approach intended to review the current literature and to assist with the initiation of such services at other facilities.
RF acceleration of ultracold electron bunches
Authors: Nijhof D. F. J. , de Raadt T. C. H. , Huijts J. V. , Franssen J. G. H. , Mutsaers P. H. A. , Luiten O. J.
Published: October 2023

The ultrafast and ultracold electron source, based on laser cooling and trapping of atomic gas and its subsequent near-threshold two-step photoionization, is capable of generating electron bunches with a high transverse brightness at energies of roughly 10 keV. This paper investigates the possibility of increasing the range of applications of this source by accelerating the bunch using radio frequency electromagnetic fields. Bunch energies up to 35 keV are measured by analyzing the diffraction patterns generated from a mono-crystalline gold sample. It is found that the normalized transverse emittance is largely preserved during acceleration.
A theory of pitch for the hydrodynamic properties of molecules, helices, and achiral swimmers at low Reynolds number
Authors: Duraes Anderson D. S. , Gezelter J. Daniel
Published: October 2023

We present a theory for pitch, a matrix property that is linked to the coupling of rotational and translational motion of rigid bodies at low Reynolds numbers. The pitch matrix is a geometric property of objects in contact with a surrounding fluid, and it can be decomposed into three principal axes of pitch and their associated moments of pitch. The moments of pitch predict the translational motion in a direction parallel to each pitch axis when the object is rotated around that axis and can be used to explain translational drift, particularly for rotating helices. We also provide a symmetrized boundary element model for blocks of the resistance tensor, allowing calculation of the pitch matrix for arbitrary rigid bodies. We analyze a range of chiral objects, including chiral molecules and helices. Chiral objects with a Cn symmetry axis with n > 2 show additional symmetries in their pitch matrices. We also show that some achiral objects have non-vanishing pitch matrices, and we use this result to explain recent observations of achiral microswimmers. We also discuss the small but non-zero pitch of Lord Kelvin’s isotropic helicoid.
Optimizing pump–probe reflectivity measurements of ultrafast photoacoustics with modulated asynchronous optical sampling
Authors: Velsink M. C. , Illienko M. , Sudera P. , Witte S.
Published: October 2023

Time-resolved optical pump–probe experiments enable the study of complex light–matter interactions on ultrafast timescales, provided that they reach sufficient sensitivity. For instance, with pump-induced ultrafast photoacoustics, probing the typically small changes in optical properties requires a high signal-to-noise ratio. Asynchronous optical sampling (ASOPS), using two separate pulsed lasers at slightly different repetition rates, can be effective at removing noise by averaging many rapidly acquired traces. However, the pump–probe delay scan with ASOPS is always as long as the pump pulse interval, which is inefficient if the delay-time range of interest is shorter. Here, we demonstrate two modified ASOPS schemes that optimize measurement efficiency by only scanning the range of interest. The modification based on frequency modulated ASOPS (MASOPS) is most efficient, especially in the presence of low-frequency flicker noise. We provide a proof-of-concept measurement of ultrafast photoacoustics in which we use MASOPS to scan a time delay of 1/20 of the pump pulse interval. The resulting noise floor is 20 times lower compared to conventional ASOPS, allowing for 20 times faster measurements. Furthermore, we show that by taking experimental noise characteristics into account, more traditional pump–probe methods can also be optimized.
Interface instability of the thermal plasma jet
Authors: Xue Xiaochun , Huang Lei , Yu Yonggang , Liu Yi
Published: October 2023

This work is first focused to experimentally study the interface instability and expansion mechanism of thermal plasma jet and provide a better understanding of the complex fluid-dynamic interactions occurring on the surface of the plasma bubble due to the Kelvin–Helmholtz effect. The experimental techniques used include a plasma generator, a pulse-forming network based on the capacitive energy storage, pressure measurement system along the capillary tube, and high-speed camera system to trace the development processes of the plasma interface. Results indicate that the plasmas jet has a better advantage of radial expansion with a high light at the beginning. However, the axial expansion velocity is larger than the radial one with time going on; thus, a torch-shaped jet body occurs under the Rayleigh–Taylor effect and can be divided into two parts including a plasma head and tail. With a dissipation of the initial energy and turbulent mixing between the plasmas and the gas, the jet boundary is broken and even the local rupture phenomena occur on the plasma jet surface. The turbulent dissipation is also very violent when the discharge voltage increases to 3000 V; thus, the turbulent mixing layer between the plasma jet and the gas is quite thicker and the plasma jet boundary is also fuzzy resulting in that the fold surfaces with much larger degree exist earlier. These experimental phenomena are also explained further from the mechanism by deriving the momentum equations of the interface of the plasma jet into the gas. Finally, a fitting formula of the surface area as an important factor in the expansion process of the plasma is obtained to analyze the interface characteristic of the plasma jet.
Energy transfer assisted plasmonic random laser emission from polymer optical fiber
Authors: Anugop B. , Nampoori V. P. N. , Kailasnath M.
Published: October 2023

Here, we analyzed the effect of a donor molecule (Rh6G) on the random laser emission of an acceptor molecule (Rh640 perchlorate) coated on the surface of a polymer optical fiber. Due to the energy transfer mechanism, the random lasing threshold of Rh640 perchlorate was found to be reduced in the presence of Rh6G. Also, the emission spectrum of Rh640 perchlorate was blue-shifted with the addition of Rh6G. Meanwhile, there is an enhancement in the lasing threshold of Rh6G in the presence of Rh640 perchlorate. The present study demonstrates that by properly adjusting the concentrations of both donor and acceptor molecules, we can obtain a dual-color random laser emission from polymer optical fiber.
High-selectivity terahertz metamaterial nitric oxide sensor based on ZnTiO3 perovskite membrane
Authors: Wu Pei-Jung , Hung Jing-Ting , Hsieh Cho-Fan , Yang Chii-Rong , Yang Chan-Shan
Published: October 2023

Human exhaled gases contain a wide range of volatile organic compounds, offering the potential for detecting physiological, cardiovascular, and endocrine disorders. For instance, nitric oxide (NO) concentration can be indicative of chronic obstructive pulmonary disease. Analyzing exhaled gases provides a noninvasive approach to disease detection without posing any risks to individuals. While electronic sensors have been developed over the past two decades for NO detection at high temperatures, few studies have explored optical detection in the ultraviolet to visible light range, which may have adverse effects on the skin. In this study, we designed a split-ring resonator metamaterial tailored for operation within the terahertz (THz) frequency range. Specifically, the metamaterial was designed to resonate at the NO frequency of 0.257 THz. To enhance gas absorption capacity, we incorporated a composite film layer consisting of ZnTiO3 and reduced graphene oxide onto the metamaterial. By sintering ZnTiO3 powder at different temperatures, we achieved an increase in component sensitivity (ΔT/T) from 2% to 16.4%. Overall, the proposed metamaterial holds promise for both physical monitoring applications and the development of wearable electronic devices.
Research on simulation method for nonlinear effects of airborne SAR electromagnetic interference
Authors: Shen Yan , Wang Yu-Ming , Ma Li-Yun , Chen Ya-Zhou
Published: October 2023

In order to simulate the nonlinear interference effect of high-power electromagnetic signals on airborne Synthetic Aperture Radar (SAR) imaging, the walk–stop geometric modeling of airborne SAR was established, and the range time-domain pulse coherence method was used to simulate SAR echo. By establishing a SAR receiver RF channel model, the interference mechanism of high-power electromagnetic signals is combined on RF front-end devices, the nonlinear effects on the echo signal when high-power electromagnetic signals enter the receiver are simulated, and finally the range Doppler algorithm is used to image the echo signal and the interference signal. A method for evaluating the interference effect of high-power electromagnetic signals on airborne SAR imaging using the correlation coefficient of images was proposed. The results showed that the change in the correlation coefficient of images before and after interference relative to the interference signal ratio was consistent with the image interference effect. The correlation coefficient showed a stepped trend with the change in the interference signal ratio, and there was a saturation effect after the interference effect reached a certain level.
Prediction of the performance of the pressure-regulating valve in a large high-speed jet wind tunnel
Authors: Luo Taiyuan , Huang Zhiqiang , Lin Xuedong , Yin Jiang , Bai Benqi , Chen Ningli
Published: October 2023

Prediction of the performance of the pressure-regulating valves in a large high-speed jet wind tunnel is important for obtaining and adjusting a high-quality flow field in the test section. In this work, we proposed a prediction method that corrects the theoretical characteristics of the pressure-regulation of the valve based on the experimental testing data of the ratio between the high- and low-pressure of the valve. The current method was validated for a given Mach number of 0.8, and the results showed that compared with the theoretical characteristics, the displacement deviation of the spool was reduced by 9.84%, and the total pressure deviation of the settling chamber was reduced by 43.61%. The results also show that compared with the single low-pressure ratio correction characteristic, the displacement deviation of the spool was reduced by 0.94%, and the total pressure deviation of the settling chamber was reduced by 3.4%. This method can consider the variation of the pressure loss for different pressure ratios and improve the pressure prediction of the valve.
A flexible gyro-fluid system of equations
Authors: Staebler G. M. , Belli E. A. , Candy J.
Published: October 2023

Gyro-fluid equations are velocity space moments of the gyrokinetic equations. Special gyro-Landau-fluid closures have been developed that include the damping due to kinetic resonances by fitting to the collisionless local plasma response functions. This damping allows for accurate linear eigenmodes to be computed with a relatively low number of velocity space moments compared to the number of velocity quadrature points in gyrokinetic codes. However, none of the published gyro-Landau-fluid closure schemes considers the Onsager symmetries of the resulting quasi-linear fluxes as a constraint. Onsager symmetry guarantees that the matrix of diffusivities is positive definite, an important property for the numerical stability of a transport solver. A two parameter real closure for improving the accuracy of low resolution gyro-fluid equations, which preserves the Onsager symmetry and allows higher velocity space moments, is presented in this paper. The new linear gyro-fluid system (GFS) is used to extend the TGLF quasi-linear transport model so that it can compute the energy and momentum fluxes due to parallel magnetic fluctuations, completing the transport matrix. The GFS equations do not use a bounce average approximation. The GFS equations are fully electromagnetic with general flux surface magnetic geometry, pitch angle scattering for electron collisions, and subsonic equilibrium toroidal rotation. Using GFS eigenmodes in the quasi-linear TGLF model will be shown to yield a more accurate match to fluxes computed by CGYRO turbulence simulations. Prospects for future applications of a quasi-linear theory to new plasma transport regimes and magnetic confinement devices in addition to tokamaks are opened by the flexibility of the GFS eigensolver.
The Markovian Multiagent Monte-Carlo method as a differential evolution approach to the SCF problem for restricted and unrestricted Hartree–Fock and Kohn-Sham-DFT
Authors: Dittmer Linus Bjarne , Dreuw Andreas
Published: October 2023

In this paper we present the Markovian Multiagent Monte-Carlo Second Order Self-Consistent Field Algorithm (M3-SOSCF). This algorithm provides a highly reliable methodology for converging SCF calculations in single-reference methods using a modified differential evolution approach. Additionally, M3 is embarrassingly parallel and modular in regards to Newton–Raphson subroutines. We show that M3 is able to surpass contemporary SOSCFs in reliability, which is illustrated by a benchmark employing poor initial guesses and a second benchmark with SCF calculations which face difficulties using standard SCF algorithms. Furthermore, we analyse inherent properties of M3 and show that in addition to its robustness and efficiency, it is more user-friendly than current SOSCFs.
380-keV Ar+-irradiation effects on optical phonons in graphite studied with transient reflection measurement
Authors: Kimata Tetsuya , Kato Taichi , Takagi Itsuki , Konno Yuma , Okazaki Hiroyuki , Yamamoto Shunya , Yamaki Tetsuya , Nakamura Kazutaka G.
Published: October 2023

In this work, we performed transient reflection measurements using the pump–probe protocol to investigate the influence of lattice defects induced by 380 keV argon (Ar) ions on the phonon dynamics of interlayer shearing (E2g1) and in-plane carbon stretching (E2g2) modes in highly oriented pyrolytic graphite (HOPG). The frequency and decay rate of E2g1- and E2g2-mode phonons were changed significantly at the fluence of 1×1014 ions/cm2. This indicated that significant structural changes in HOPG due to 380 keV Ar-ion irradiation were expressed as changes in the frequency and decay rate of phonons. In HOPG irradiated with 380 keV Ar+ at the fluence of 1×1014 ions/cm2, our measurement results indicated that compressive and tensile stresses contributed to in-plane and interlayer graphite structures, respectively.
Influence of nanopore coating patterns on the translocation dynamics of polyelectrolytes
Authors: Datar Adwait , Tanyhin Bohdan , Melchionna Simone , Fyta Maria
Published: October 2023

Polyelectrolytes can electrophoretically be driven through nanopores in order to be detected. The respective translocation events are often very fast and the process needs to be controlled to promote efficient detection. To this end, we attempt to control the translocation dynamics by coating the inner surface of a nanopore. For this, different charge distributions are chosen that result in substantial variations of the pore–polymer interactions. In addition and in view of the existing detection modalities, experimental settings, and nanopore materials, different types of sensors inside the nanopore have been considered to probe the translocation process and its temporal spread. The respective transport of polyelectrolytes through the coated nanopores is modeled through a multi-physics computational scheme that incorporates a mesoscopic/electrokinetic description for the solvent and particle-based scheme for the polymer. This investigation could underline the interplay between sensing modality, nanopore material, and detection accuracy. The electro-osmotic flow and electrophoretic motion in a pore are analyzed together with the polymeric temporal and spatial fluctuations unraveling their correlations and pathways to optimize the translocation speed and dynamics. Accordingly, this work sketches pathways in order to tune the pore–polymer interactions in order to control the translocation dynamics and, in the long run, errors in their measurements.
Effect analysis of spatial discrepancy of secondary emission yield on multipactor formation
Authors: Lin Shu , Zhong Huan , Chen Cheng , Cao Meng , Li Yongdong , Zhai Yonggui , Wong Patrick Y. , Zhang Peng , Verboncoeur John P.
Published: October 2023

Spatial discrepancy of secondary emission yield (SEY) is probably exacerbated by unexpected surface contamination or imperfect surface treatments for SEY suppression, which accordingly provokes increased multipactor risk in microwave devices. In this paper, an improved 2D2V nonstationary statistical modeling for multipactor of parallel plates capable of regarding all electron impacts and electron exchange at the periodic boundaries is developed to investigate the effect of this spatial SEY discrepancy on multipactor formation in microwave devices. The comparison with the 1D2V statistical modeling results, which is valid for the parallel-plate multipactor, proves the accuracy of this improved 2D2V statistical modeling and the necessity of appropriate boundary setting in multipactor analysis with spatial SEY variation. The modeling results also reveal that the multipactor establishment is dominated by the electron multiplication and the electron overflow in the high-SEY region, thus making the multipactor threshold strongly dependent on both the SEY property and the dimension of the region. Electron multiplication can be fully sustained in the high-SEY region when its size exceeds a critical dimension, which satisfies a scaling law (the sustaining dimension is proportional to the gap with the product of the RF frequency and the gap kept constant) and varies with the involved multipactor mode. This research will help in evaluating accidental multipactor risk caused by the surface contamination and the efficiency of multipactor prevention via applying surface treatments for SEY suppression to accessible regions.
Impact of nanosecond laser annealing on vacancies in electroplated Cu films studied by monoenergetic positron beams
Authors: Uedono Akira , Nogami Takeshi , Gluschenkov Oleg , Sulehria Yasir , Liu Junjun , Tabata Toshiyuki , Lu Lu , Mitsuda Katsuhiro , Brown Ian , Okuno Yasutoshi
Published: October 2023

Positron annihilation was used to probe vacancy-type defects in electrodeposited Cu films after nanosecond pulse laser annealing. For the as-deposited Cu film, we identified the coexistence of two different vacancy-type defects, vacancy clusters (such as V16) and monovacancy-type defects, coupled with impurities. An enlargement in the vacancy size was observed after the laser annealing process. The size of these defects was estimated to be close to V30, and such defects could not be formed by conventional furnace annealing. After furnace annealing at 400 °C, the size of the larger vacancy clusters decreased, but that of the smaller vacancies increased. The observed change in the sizes of vacancies is considered to be related to interactions between vacancies and impurities. The depth profile of the defects varied by changing the laser energy density and the number of laser shots. The impact of laser annealing on the vacancy-type defects was observed even after furnace annealing at 800 °C. Because the presence of point defects in electroplated Cu directly correlates with electromigration and grain growth, the ability of laser annealing to introduce large vacancy clusters in the localized region shows the potential of nanosecond laser annealing as a low-thermal budget process tool for back-end-of-line materials.
Effects of the misalignment and axial gap on performance of a cover-plate pre-swirl system with impellers for gas turbine cooling
Authors: Liu Yuxin , Lu Bingyun , Kong Xiaozhi , Chen Hua
Published: October 2023

Impellers are designed and used in the cover-plate cavity of the pre-swirl system of modern gas turbines to keep the circumferential velocity of the airflow consistent with the local velocity of the rotor. This reduces the aerodynamic loss of the pre-swirl air delivery system for turbine cooling and further improves pre-swirl system performance. However, in practical applications, the cover-plate disk with impellers is usually installed and fixed to the turbine disk by buckles, which leads to the possibility of the circumferential position of impellers deviating from the design intention during installation and a certain axial gap between impellers and the turbine disk, resulting in deviations in cooling performance. In this work, low-radius cover-plate pre-swirl systems with and without impellers are compared through numerical simulations, and the effects of the impeller circumferential displacement angle (θ) in the range of −0.5° to 0.5° and the axial gap (Δ) in the range of 0%–25% of the cover-plate cavity width are investigated on the flow characteristics and system cooling performance. Results indicate that the impellers are sensitive to the manufacturing and installation deviations. The non-designed circumferential displacement of the impeller will misalign it with the rotating receiver holes and supply holes, hindering the airflow movement in the radial direction and increasing the back pressure of the impeller. Consequently, the severe vortices on the suction side downstream of the impeller leading edge can occur and the entropy production can increase. Numerical results show that when the impeller is displaced by 0.5° circumferentially, the temperature drop effectiveness decreases significantly, and is about 21% lower than that at the designed condition. Moreover, while the axial gap is small, the overall flow pattern and system temperature drop are only slightly affected. As the axial gap increases, there are more cooling airs flowing through the axial gap and not subject to the work of the impeller. Therefore, the temperature drop starts to fall and the swirl ratio declines. For the system studied, the temperature drop effectiveness decreases by around 7.8% when the axial gap reaches 25% of the cover-plate cavity width.
Integrative generalized master equation: A method to study long-timescale biomolecular dynamics via the integrals of memory kernels
Authors: Cao Siqin , Qiu Yunrui , Kalin Michael L. , Huang Xuhui
Published: October 2023

The generalized master equation (GME) provides a powerful approach to study biomolecular dynamics via non-Markovian dynamic models built from molecular dynamics (MD) simulations. Previously, we have implemented the GME, namely the quasi Markov State Model (qMSM), where we explicitly calculate the memory kernel and propagate dynamics using a discretized GME. qMSM can be constructed with much shorter MD trajectories than the MSM. However, since qMSM needs to explicitly compute the time-dependent memory kernels, it is heavily affected by the numerical fluctuations of simulation data when applied to study biomolecular conformational changes. This can lead to numerical instability of predicted long-time dynamics, greatly limiting the applicability of qMSM in complicated biomolecules. We present a new method, the Integrative GME (IGME), in which we analytically solve the GME under the condition when the memory kernels have decayed to zero. Our IGME overcomes the challenges of the qMSM by using the time integrations of memory kernels, thereby avoiding the numerical instability caused by explicit computation of time-dependent memory kernels. Using our solutions of the GME, we have developed a new approach to compute long-time dynamics based on MD simulations in a numerically stable, accurate and efficient way. To demonstrate its effectiveness, we have applied the IGME in three biomolecules: the alanine dipeptide, FIP35 WW-domain, and Taq RNA polymerase. In each system, the IGME achieves significantly smaller fluctuations for both memory kernels and long-time dynamics compared to the qMSM. We anticipate that the IGME can be widely applied to investigate biomolecular conformational changes.
Single spin magnetometry and relaxometry applied to antiferromagnetic materials
Authors: Finco Aurore , Jacques Vincent
Published: October 2023

Despite the considerable interest for antiferromagnets that appeared with the perspective of using them for spintronics, their experimental study, including the imaging of antiferromagnetic textures, remains a challenge. To address this issue, quantum sensors, and, in particular, the nitrogen-vacancy (NV) defects in diamond have become a widespread technical solution. We review here the recent applications of single NV centers to study a large variety of antiferromagnetic materials, from quantitative imaging of antiferromagnetic domains and non-collinear states, to the detection of spin waves confined in antiferromagnetic textures and the non-perturbative measurement of spin transport properties. We conclude with recent developments improving further the magnetic sensitivity of scanning NV microscopy, opening the way to detailed investigations of the internal texture of antiferromagnetic objects.
Improved efficiency with concave cavities on S3 surface of a rim-driven thruster
Authors: Li Peng , Yao Hua-Dong , Wang Chao , Weng Kaiqiang
Published: October 2023

Rim-driven thrusters (RDT) are of great interest for the development of integrated electric motors for underwater vehicles. Gap flow is one of the most prominent flow characteristics and plays an important role in the hydrodynamic performance of RDT. In this study, the rim in a carefully designed RDT was modified with several concave cavities defined by four parameters, and their influence on hydrodynamics was carefully calculated and analyzed. The simulations were performed using the k-ω shear stress transport turbulence model by solving the unsteady Reynolds-averaged Navier–Stokes equations. The numerical method was verified using a popular combination. The numerical results showed that the concave cavities on the rim improve the propulsive efficiency of RDT by a maximum of 3.52%. The increase in the propulsive efficiency is directly associated with the parameters of the concave cavities. Nevertheless, the flow in the gap has a negligible effect on the main flow field through the RDT. According to the numerical analysis, the different pressure integrals at the front and back surfaces of the concave cavities are the main reason for the improvement of the propulsive efficiency. The modification of the rim is helpful and practical for the hydrodynamic optimization of the RDT.
Mechanisms of chiral plasmonics—Scattering, absorption, and photoluminescence
Authors: Cheng Yuqing , Sun Mengtao
Published: October 2023

Chirality is a concept that one object is not superimposable on its mirror image by translation and rotation. In particular, chiral plasmonics have been widely investigated due to their excellent optical chiral properties, and have led to numerous applications such as optical polarizing element etc. In this study, we develop a model based on the concept of the interaction between harmonic oscillators to investigate and explain the optical chiral mechanisms of strongly coupled metal nanoparticles (MNPs). The chirality of the scattering, absorption, and photoluminescence spectra are carefully discussed in detail. The results show that the chirality of the system originates not only from the orientations of the MNPs, but also from the different eigen parameters between them. Specifically, the derived three factors contribute to the chirality: the symmetry, the coupling strength, and the coherent superposition of the emitted electric field. This work provides a deeper understanding on the chiral plasmonics and may guide relevant applications in theory.
Corrigendum to: The role of grass-tree Xanthorrhoea semiplana (Asphodelaceae) canopies in temperature regulation and waterproofing for ground-dwelling wildlife
Authors: Petit Sophie , Frazer Deborah S.
Published: October 2023

 Context Birds appear to be better suited than mammals or reptiles to adapt to fast-changing landscapes because of their greater mobility; however, the behavioural effects of urbanisation on birds in Australia remain broadly unexplored.

 Aims This study aimed to investigate the effects of urbanisation on behavioural responses exhibited by a common and widespread meliphagid, the bandiny or New Holland honeyeater (Phylidonyris novaehollandiae) while undergoing standard bird banding processes.

 Methods Five non-invasive techniques (alarm calling, wriggling, biting, breathing rate, and tonic immobility) were explored for efficacy in identifying underlying differences in distress arising from mist-netting at urban and exurban localities in southwestern Western Australia.

 Key results Breathing rate was the most important variable for identifying differences in post-capture distress response. The breathing rate of urban bandiny following capture was lower than those of exurban areas. All other parameters proved suboptimal for detecting differential behavioural responses to handling between urban and exurban populations, despite having been successfully used in other international studies.

 Conclusions We suggest that urban honeyeaters exhibit lower mean breathing rates due to chronic overstimulation in response to urban lifestyles and are not able to further elevate this behaviour in response to stressful stimuli. The failure of other approaches explored highlights the need to apply ecosystem-appropriate methods for investigating urbanisation within an Australian context.

 Implications Our results suggest that behavioural approaches to quantifying avian stress developed internationally require additional consideration when applied to the ecosystems of Australia, whose birds are evolved to accommodate a different regime of seasonality that has shaped them behaviourally and morphologically.
Efficient automatic design of robots
Authors: Matthews David , Spielberg Andrew , Rus Daniela , Kriegman Sam , Bongard Josh
Published: October 2023

Robots are notoriously difficult to design because of complex interdependencies between their physical structure, sensory and motor layouts, and behavior. Despite this, almost every detail of every robot built to date has been manually determined by a human designer after several months or years of iterative ideation, prototyping, and testing. Inspired by evolutionary design in nature, the automated design of robots using evolutionary algorithms has been attempted for two decades, but it too remains inefficient: days of supercomputing are required to design robots in simulation that, when manufactured, exhibit desired behavior. Here we show de novo optimization of a robot’s structure to exhibit a desired behavior, within seconds on a single consumer-grade computer, and the manufactured robot’s retention of that behavior. Unlike other gradient-based robot design methods, this algorithm does not presuppose any particular anatomical form; starting instead from a randomly-generated apodous body plan, it consistently discovers legged locomotion, the most efficient known form of terrestrial movement. If combined with automated fabrication and scaled up to more challenging tasks, this advance promises near-instantaneous design, manufacture, and deployment of unique and useful machines for medical, environmental, vehicular, and space-based tasks.