bluuebunny/crossref_metadata_2025 huggingface dataset:
Management and Outcomes of Facial Nerve Hemangiomas: A Systematic Review of the Literature
Authors: Lesha Emal , Dugan John E. , Cecia Arba , Nichols C Stewart , Orr Taylor J. , Nezha Anxhela , Parikh Kara A. , Khan Nickalus R.
Published: April 2024

Objectives To conduct a systematic review of facial nerve hemangiomas (FNH), focusing on patient characteristics, management options, and treatment outcomes.

Design A systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, utilizing PubMed, EMBASE, Scopus, and Cochrane databases from inception to December 31, 2022.

Setting Literature sourced from various databases providing information on FNH cases.

Participants A total of 176 patients with FNH were included in the study, identified from 40 articles meeting inclusion criteria.

Main Outcome Measures Patient demographics, lesion characteristics, preoperative symptoms, surgical approaches, and postoperative outcomes, including House-Brackmann (HB) grades.

Results Among the 1,682 initially identified articles, 40 were included in the final review. From these, a total of 176 patients (mean age = 42.7 ± 12.8, 51.1% male) were included for analysis. Bivariate analysis showed that patients with longer preoperative symptom duration and facial nerve sacrifice had significantly greater postoperative HB Grades (p < 0.001). Additionally, a strong positive correlation was observed between pre- and postoperative HB Grades (Spearman's rho = 0.649). Multivariable linear regression analysis showed that both facial nerve sacrifice (β = 0.86, 95% confidence interval [CI]: 0.38–1.34; p < 0.001) and greater preoperative HB Grades (β = 0.36, 95% CI: 0.20–0.53; p < 0.001) were associated with significantly greater postoperative HB Grades, but preoperative symptom duration did not persist as a significant predictor of postoperative HB Grades.

Conclusions FNHs are rare lesions of the skull base affecting the temporal bone. Our findings highlight the role of preoperative facial nerve function and intraoperative preservation of the facial nerve in predicting postoperative outcomes. Timely resection of lesions that prioritizes facial nerve preservation is critical to achieving optimal patient outcomes.
The white ring sign is useful for differentiating between fundic gland polyps and gastric adenocarcinoma of the fundic gland type
Authors: Takahashi Keitaro , Sasaki Takahiro , Ueno Nobuhiro , Maguchi Haruka , Tachibana Shion , Hayashi Ryunosuke , Kobayashi Yu , Sugiyama Yuya , Sakatani Aki , Ando Katsuyoshi , Kashima Shin , Moriichi Kentaro , Tanabe Hiroki , Harada Kazumichi , Yuzawa Sayaka , Ichihara Shin , Okumura Toshikatsu , Fujiya Mikihiro
Published: April 2024

Background and study aims Gastric adenocarcinoma of the fundic gland type (GA-FG) is characterized by an elevated lesion with vessel dilation exhibiting branching architecture (DVBA). However, this feature is also found in fundic gland polyps (FGPs), posing a challenge in their differentiation. In this study, we aimed to investigate the clinicopathological features of gastric elevated lesions with DVBA and assess the efficacy of the white ring sign (WRS) as a novel marker for distinguishing between FGPs and GA-FGs.

Methods We analyzed 159 gastric elevated lesions without DVBA and 51 gastric elevated lesions with DVBA, further dividing the latter into 39 in the WRS-positive group and 12 in the WRS-negative group. The clinicopathological features, diagnostic accuracy, and inter-rater reliability were analyzed.

Results Univariate and multivariate analyses for gastric elevated lesions with DVBA identified the histological type consistent with FGPs and GA-FGs, along with the presence of round pits in the background gastric mucosa, as independent predictors. FGPs were present in 92.3% (36/39) of the WRS-positive group and GA-FGs were observed in 50.0% (6/12) of the WRS-negative group. WRS positivity and negativity exhibited high diagnostic accuracy, with 100% sensitivity, 80.0% specificity, and 94.1% accuracy for FGPs, and 100% sensitivity, 86.7% specificity, and 88.2% accuracy for GA-FGs. Kappa values for WRS between experts and nonexperts were 0.891 and 0.841, respectively, indicating excellent agreement.

Conclusions WRS positivity and negativity demonstrate high diagnostic accuracy and inter-rater reliability for FGPs and GA-FGs, respectively, suggesting that WRS is a useful novel marker for distinguishing between FGPs and GA-FGs.
Systematic Review: Success Rate of Endoscopic Endonasal versus Combined Endonasal and Transorbital Neuroendoscopic Approach for Nontraumatic Cerebrospinal Fluid Leak Repairs in the Lateral Recess of Sphenoid Sinus
Authors: Ahmed Umnia Nasir , Siddiqui Mohammed Saqlain , Iftikhar Haissan , Jolly Karan , Nieto Hannah , Muzaffar Jameel
Published: April 2024

Background Cerebrospinal fluid (CSF) leaks from the lateral recess of the sphenoid sinus (LRS) occur due to a skull base defect and are important to treat due to the associated morbidity, e.g., life-threatening meningitis. Nontraumatic CSF leaks have a predilection toward obesity which is a rising phenomenon. LRS is notoriously difficult to access because of its lateral location and its associated neurovascular complications. An alternative surgical corridor has been explored which is the transorbital neuroendoscopic (TONES) approach.

Objective To compare the success rate of the endoscopic endonasal with the TONES approaches.

Rationale This is the first systematic review on the endoscopic endonasal and combined transorbital approaches to treat CSF leaks from the LRS.

Method A PRISMA-concordant systematic review. PubMed, MEDLINE, EMBASE, Web of Science, and SCOPUS were searched. The studies underwent abstract and full-text screening by two reviewers. The data collected included patient demographic, surgical approach, reconstruction method, layers and materials, follow-up period, ROBINS-I bias, complications, and success rate.

Results In total, 26 of 4,385 studies were included for further synthesis. Of these studies, a total of 336 patients were identified from a cohort of 910 patients. The endoscopic endonasal approach showed a repair success rate of 95.24% and the combined TONES and endonasal approach showed a success rate of 100%.

Conclusion Both the endoscopic endonasal and transorbital approach provide a good success rate. However, due to the small TONES sample, large, randomized control trials are needed.
Conceptualising and measuring consumer perceptions of brand wastefulness
Authors: Gain Alexandria M. , Coote Leonard V. , Bonfrer André
Published: April 2024

Consumers consider the wastefulness of brands and are predisposed to exhibit aversion to those perceived as wasteful. However, there is a lack of consensus on how consumers associate wastefulness with brands and how this impacts downstream consumer brand responses. Integrating conceptualisations in the literature with original consumers’ insights, we conceptualise consumer perceived brand wastefulness (CPBW) as a multidimensional construct comprising perceptions of (1) unnecessary consumption, (2) inefficient utilisation, and (3) tangible waste. A multi-phase scale development process validated a CPBW scale measuring each dimension. The scale distinguished between consumer perceptions of more vs less wasteful brands and demonstrated CPBW as conceptually distinct from perceptions of brands’ environmental friendliness and corporate social responsibility (CSR). CPBW was related to unfavourable consumer brand responses, including a reduced purchase likelihood, lower willingness to pay a price premium, negative self-conscious emotions, and lower perceptions of brand quality and credibility. We discuss the theoretical and managerial implications and directions for future research.
High bunch charge low-energy electron streak diffraction
Authors: Lee Chiwon , Kassier Günther H. , Miller R. J. Dwayne
Published: April 2024

For time-resolved diffraction studies of irreversible structural dynamics upon photoexcitation, there are constraints on the number of perturbation cycles due to thermal effects and accumulated strain, which impact the degree of crystal order and spatial resolution. This problem is exasperated for surface studies that are more prone to disordering and defect formation. Ultrafast electron diffraction studies of these systems, with the conventional stroboscopic pump–probe protocol, require repetitive measurements on well-prepared diffraction samples to acquire and average signals above background in the dynamic range of interest from few tens to hundreds of picoseconds. Here, we present ultrafast streaked low-energy electron diffraction (LEED) that demands, in principle, only a single excitation per nominal data acquisition timeframe. By exploiting the space–time correlation characteristics of the streaking method and high-charge 2 keV electron bunches in the transmission geometry, we demonstrate about one order of magnitude reduction in the accumulated number of the excitation cycles and total electron dose, and 48% decrease in the root mean square error of the model fit residual compared to the conventional time-scanning measurement. We believe that our results demonstrate a viable alternative method with higher sensitivity to that of nanotip-based ultrafast LEED studies relying on a few electrons per a single excitation, to access to all classes of structural dynamics to provide an atomic level view of surface processes.
A spin-injected ferroelectric tunnel junction based on spin-dependent screening theory
Authors: Zheng Xingwen , Zuo Xi , Liu Yuzhen , Chen Chuanhui , Cui Bin , Xu Shusheng
Published: April 2024

In this work, spin transport in ferroelectric tunnel junctions with composite barriers and magnetic electrodes is investigated theoretically using spin-dependent screening theory. The shape of the insulator barrier and the electronic structure of the ferromagnetic electrode inevitably affect the spin transport properties. Interestingly, we find that when the Fermi level approaches the bottom of the minority-spin band of the electrode, an approximately ±100% bidirectional spin-filtering effect can be realized due to the included exchange potential with an appropriate electronic band structure of electrodes. Additionally, electrically induced magnetic reconstruction would occur on the electrode surface due to spin-dependent band bending. Our study significantly deepens the current understanding of spin-dependent screening on metal surfaces and at metal/ferroelectric interfaces and provides a feasible method for achieving the interface magnetoelectric effect.
Strain-induced high-Chern-number spin-unlocked edge states in monolayer MnAsO3 with intrinsic quantum anomalous Hall effect
Authors: Chen Hongxin , Lu Jiajun , Wang Naibin , Zhao Xiuwen , Hu Guichao , Yuan Xiaobo , Ren Junfeng
Published: April 2024

Two-dimensional intrinsic magnetic topological materials that can realize device miniaturization have attracted significant attention recently based on their chiral dissipationless edge states. However, since the experimental observation of quantum anomalous Hall effect (QAHE) is still limited by low temperature, high operating temperature and large nontrivial gap are urgently needed. Here, monolayer MnAsO3 is predicted to be a room-temperature intrinsic magnetic topological material with high Chern number C = 3 based on first-principles calculations, which offers the possibility of achieving high-speed and low-energy-consumption electron transport in the future. Furthermore, the large and experimental feasible nontrivial gap up to 79.09 meV is obtained under compressive strain modulation. Moreover, the high-Chern-number topological phase transition and strain-induced spin-unlocked edge states are observed, indicating the possibility of tuning the electron transport of QAHE. All these findings suggest that monolayer MnAsO3 is a suitable and promising material for fabricating low-energy-consumption spintronics devices.
Global well-posedness of three-dimensional incompressible Boussinesq system with temperature-dependent viscosity
Authors: Niu Dongjuan , Wang Lu
Published: April 2024

In this paper, we focus on the global well-posedness of solutions to three-dimensional incompressible Boussinesq equations with temperature-dependent viscosity under the smallness assumption of initial velocity fields u0 in the critical space Ḃ3,10. The key ingredients here lie in the decomposition of the velocity fields and the regularity theory of the Stokes system, which are crucial to get rid of the smallness restricition of the initial temperature θ0. In addition, we mention that the improved decay estimates in time is also necessary.
Electron and ion temperature measurement with a new x-ray imaging crystal spectrometer on WEST
Authors: Da Ros A. , Vezinet D. , Colledani G. , Fenzi-Bonizec Christel , Moureau G. , Bertschinger G. ,   the WEST Team
Published: April 2024

A new x-ray imaging crystal spectrometer (XICS) has been installed, aligned, and used during experimental campaigns on the WEST tokamak. It has three interchangeable crystals for measuring the Ar XVII, Ar XVIII, and Fe XXV spectra, respectively. A patented rotating table holding the crystals is used to monitor the crystal facing the plasma remotely and without changing the position of the camera. Here, the focus is made on the Ar XVII spectrum, between 3.93 and 4.00 Å. The design of the diagnostic is presented, and a synthetic diagnostic, implemented with the Python library ToFu, is used to show the instrument’s operational performance and limits. The instrument function exhibits the following two main features: a distortion for the Ar XVII spectrum, presumably due to the crystal manufacturing in two parts, and the measurement of three W spectral lines on the Ar XVI spectrum. Line of sight-integrated profiles of the electron and ion temperatures are thus extracted from the Ar XVII spectrum from two distinct spectral line ratios and from the Doppler broadening, respectively. The bremsstrahlung emission and the W line measurements are the two main limitations to compute the electron temperature. Tomographic inversions are also implemented with the library ToFu and used in order to obtain the local electron and ion temperature profiles, which are compared to other measurements from the WEST ECE (electron cyclotron emission) diagnostic. It is shown that both the XICS line-integrated and ECE Te measurements are in better agreement. Systematic differences are shown between the electron temperature profiles calculated from the two available line ratios.
Study of the mechanism of single event burnout in lateral depletion-mode Ga2O3 MOSFET devices via TCAD simulation
Authors: Wang Kejia , Wang Zujun , Cao Rongxing , Liu Hanxun , Chang Wenjing , Zhao Lin , Mei Bo , Lv He , Zeng Xianghua , Xue Yuxiong
Published: April 2024

This study investigates the sensitive region and safe operation voltage of single-event burnout (SEB) in lateral depletion-mode Ga2O3 MOSFET devices via technology computer aided design simulation. Based on the distribution of the electric field, carrier concentration, and electron current density when SEB occurs, the radiation damage mechanism of SEB is proposed. The mechanism of SEB in Ga2O3 MOSFET was revealed to be the result of a unique structure without a PN junction within it, which possesses gate control ability and exerts a significant influence on the conduction of the depletion region.
Propagation of perfect vortex beam beyond the focal depth
Authors: Gangwar Swati , Jaiswal V. K. , Mehrotra Ranjana , Saha Shibu , Sharma Parag
Published: April 2024

Perfect vortex beam (PVB) has emerged as a promising candidate in the field of optical communication, which is currently limited due to its realization only at the focal depth of Fourier lens. The present letter reports devising of a unique technique for the propagation of PVB beyond this point and has been verified experimentally, inside laboratory, up to a distance of 5 m. The properties of PVBs, observed at the focus of the Fourier lens, were well preserved in the propagated beams. This proposed approach ensures preserving of the invariance of the annular radius of propagating PVBs, carrying different orbital angular momentum, which has emerged as a unique property for their potential application in the fields of communication, particle trapping, and micro-machining.
Irreducible modules over N = 2 superconformal algebras arising from algebraic D-modules
Authors: Chen Haibo , Dai Xiansheng , Liu Dong , Pei Yufeng
Published: April 2024

In this paper, we introduce a family of functors denoted as Fb, which act on algebraic D-modules and produce modules over N = 2 superconformal algebras. We demonstrate that these functors preserve irreducibility for all values of b, except for explicitly outlined cases. Moreover, we establish the necessary and sufficient conditions for determining the natural isomorphism between two such functors. Our constructed functors recover specific irreducible modules over N = 2 superconformal algebras, including intermediate series and U(h)-free modules. Additionally, we show that our constructed functors yield several new irreducible modules for N = 2 superconformal algebras.
A molecular dynamics simulation study of glycine/serine octapeptides labeled with 2,3-diazabicyclo[2.2.2]oct-2-ene fluorophore
Authors: Roccatano Danilo
Published: April 2024

The compound 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) is a versatile fluorophore widely used in Förster resonance energy transfer (FRET) spectroscopy studies due to its remarkable sensitivity, enabling precise donor–acceptor distance measurements, even for short peptides. Integrating time-resolved and FRET spectroscopies with molecular dynamics simulations provides a robust approach to unravel the structure and dynamics of biopolymers in a solution. This study investigates the structural behavior of three octapeptide variants: Trp-(Gly-Ser)3-Dbo, Trp-(GlyGly)3-Dbo, and Trp-(SerSer)3-Dbo, where Dbo represents the DBO-containing modified aspartic acid, using molecular dynamics simulations. Glycine- and serine-rich amino acid fragments, common in flexible protein regions, play essential roles in functional properties. Results show excellent agreement between end-to-end distances, orientational factors from simulations, and the available experimental and theoretical data, validating the reliability of the GROMOS force field model. The end-to-end distribution, modeled using three Gaussian distributions, reveals a complex shape, confirmed by cluster analysis highlighting a limited number of significant conformations dominating the peptide landscape. All peptides predominantly adopt a disordered state in the solvent, yet exhibit a compact shape, aligning with the model of disordered polypeptide chains in poor solvents. Conformations show marginal dependence on chain composition, with Ser-only chains exhibiting slightly more elongation. This study enhances our understanding of peptide behavior, providing valuable insights into their structural dynamics in solution.
Momordica charantia leaf disease detection and treatment using agricultural mobile robot
Authors: Fusic S Julius , T Sugumari , Giri Jayant , Makki Emad , Sitharthan R. , Murugesan Shunmathi , Bhowmik Abhijit
Published: April 2024

Detecting diseases is a vital and crucial step in maintaining healthy, high-yielding plants. The challenge of manually identifying infections is arduous as well. The proposed work is to diagnose plant leaf diseases and discuss their origins and remedies. Image processing is used to discover the infected leaf and provide remedial measures through a mobile robot application. The use of machine learning techniques allows for the detection of leaf diseases using the support vector machine model, the K nearest neighbor model, and the Naïve Bayes classification to categorize the sample leaves. In this paper, the Momordica charantia leaf and the common four diseases dataset are developed, and a classification model is developed to identify and categorize leaf curl, downy mildew, powdery mildew, and angular leaf spot. Based on the disease classification, appropriate chemical pesticides are sprayed by controlling the servo actuated valve in the proposed agriculture robot, which is controlled and validated. The result reveals that the proposed approach has an average accuracy of 82% in identifying the disease type that remains more prevalent in Momordica charantia leaves than other compared classification algorithms.
Study on energy capture characteristics of piezoelectric stack energy harvester for railway track
Authors: Min Zhaowei , Sui Guangdong , Hou Chengwei , Zhang Xiaofan , Shan Xiaobiao , Xie Tao
Published: April 2024

Railway traffic plays a pivotal role within the current transportation system, with ensuring its safety being of paramount importance. Real-time monitoring of train track health through sensor technology has emerged as a significant approach for achieving this objective. However, a persistent challenge lies in providing cost-effective and stable power to sensors in remote areas. This paper proposes the utilization of a novel piezoelectric stack energy harvester in railway systems to address this issue. The substantial and consistent vibration energy produced by railway operations makes it an ideal source for energy harvesting, unaffected by environmental conditions. Through simulation analysis and experimental verification, this study explores the impact of load size, load frequency, and external resistance on the energy harvesting efficiency of the proposed piezoelectric stack energy harvester. The results indicate that the output power of the energy harvester increases with the load size. Furthermore, the frequency significantly influences the energy capture efficiency when below 8 Hz, with minimal impact on frequencies above 8 Hz. Interestingly, the load dramatically affects the energy capture efficiency, even at higher frequencies. With the external resistance set to 250 kΩ, the harvester achieves a maximum output power of 42.76 mW.
Thermal aging performance of soybean insulating oil mixed with glyceryl triacetate
Authors: Su Ziming , Zeng Zhenglin , Chen Rui , Wu Xinzhi , Tang Chao
Published: April 2024

A method of delaying the aging of natural ester oil-paper insulation systems by adding glyceryl triacetate is proposed in this work. A study was conducted on the thermal aging performance of soybean insulating oil mixed with glyceryl triacetate at a volume fraction of 7.5%. Through a 42-day accelerated thermal aging experiment, it was found that the addition of glyceryl triacetate effectively delayed the increase in kinematic viscosity of the insulating oil and reduced the generation of aging products such as moisture and acid. However, the polar compounds in glyceryl triacetate reduced the breakdown voltage of the mixed oil and made the dielectric loss factor higher than that of pure oil. In addition, tests were conducted on the insulating paper immersed in two types of oil, and it was found that the addition of glyceryl triacetate helps to distribute mixed oil molecules on the surface of insulating paper, which effectively helped absorb moisture from the paper, weakening the hydrolysis reaction of cellulose and delaying the aging of insulating paper. In addition, the insulating paper immersed in the mixed oil maintains good power frequency breakdown voltage and dielectric properties throughout the thermal aging experiment.
Transition metals of Pt and Pd on the surface of topological insulator Bi2Se3
Authors: Liu Lina , Miotkowski Ireneusz , Zemlyanov Dmitry , Chen Yong P.
Published: April 2024

Transition metal catalysts supported on topological insulators are predicted to show improved catalytic properties due to the presence of topological surface states, which may float up to the catalysts and provide robust electron transfer. However, experimental studies of surface structures and corresponding catalytic properties of transition metal/topological insulator heterostructures have not been demonstrated so far. Here, we report the structures, chemical states, and adsorption behaviors of two conventional transition metal catalysts, Pt and Pd, on the surface of Bi2Se3, a common topological insulator material. We reveal that Pt forms nanoparticles on the Bi2Se3 surface. Moreover, the interaction between Pt and surface Se is observed. Furthermore, thermal dosing of O2 onto the Pt/Bi2Se3 heterostructure leads to no oxygen adsorption. Detailed scanning tunneling microscopy study indicates that Pt transforms into PtSe2 after the thermal process, thus preventing O2 from adsorption. For another transition metal Pd, it exhibits approximate layer-island growth on Bi2Se3, and Pd–Se interaction is also observed. Our work provides significant insights into the behaviors of transition metals on top of a common topological insulator material and will assist in the future design of catalysts built with topological materials.
A next-generation light-emitting device: ZOGAN LED with a heterogeneous p-layer composed of oxide and nitride semiconductors
Authors: Ryu Yung Ryel , Hong Sung Ki , Schubert E. Fred , Jeon Dong-Min , Shin Dong-Soo , Shim Jong-In , Kim Sang-Mook , Baek Jong Hyeob
Published: April 2024

We have developed a light-emitting device, called the ZOGAN light-emitting diode (LED). The ZOGAN LED is formed with the p-layer composed of both ZnO-based oxide and GaN-based nitride semiconductors. The ZOGAN LED shows the characteristics of light-emitting devices required for ultra-high-resolution displays.
Analysis of coupling characteristics of clean heating systems based on complementary solar, geothermal, and wind energy
Authors: Geng Zhi , Chen Keyu , Li Junfen , Wang Jianli , Shi Tianqing , Gu Yujiong
Published: April 2024

In order to overcome the limitations of traditional clean energy utilization methods, this paper proposed an innovative technical solution for a combined heating system that cleverly integrated solar, wind, and geothermal energy to achieve complementarity and synergized among them, thereby ensuring stable and efficient energy utilization. First, a comprehensive mathematical model was developed for the entire heating system, encompassing solar thermal subsystem, geothermal subsystem, wind power generation subsystem, and a second-stage reheating subsystem. Subsequently, Ebsilon simulation software was utilized to cleverly couple these subsystems together, with corresponding boundary conditions set to ensure the overall efficiency and stability of the system. Based on meteorological data and geothermal resource parameters from a typical heating season in Zhengzhou, Henan Province, China, this paper thoroughly analyzed the variations in key performance indicators such as the photothermal conversion efficiency of solar thermal subsystem and the heating capacity of geothermal subsystem. This provided valuable insight for optimizing the design of heating system. The results indicated that during the daylight hours of the heating season, both the photothermal conversion efficiency and the heat supply from the solar thermal subsystem exhibited an increasing trend as solar radiation increased. Among them, the photothermal conversion efficiency peaked at 76.013%, while the maximum heat supply output reached 40.311 kW. When solar direct radiation was relatively weak, the system primarily relied on the heat release process of the thermal storage tank to maintain heating, with a minimum heat supply of 27.268 kW. During nighttime hours of the heating season, the geothermal subsystem dominated the heating process, with a maximum heat supply of 125.556 kW. Additionally, for every 5 °C increased in geothermal water temperature, the heat supply from the geothermal subsystem increased by an average of 6.553 kW, demonstrating excellent heating response performance. Therefore, the integrated clean heating system that combines solar, geothermal, and wind energy not only significantly improves the utilization efficiency of clean energy but also enhances the heating stability of the integrated clean energy coupling system to a certain extent. The clean heating technical solution proposed in the paper had a theoretical total heating capacity of 19 680 kW during the heating season. When converted, this equates to a substitution of 6.9 tons of standard coal, resulting in a reduction of carbon dioxide emissions by 17.94 tons. This demonstrates the considerable cleanliness and environmental benefits of the proposed heating system. This study provides a valuable reference for the engineering application of renewable energy in the field of clean heating.
Time-dependent density functional theory with the orthogonal projector augmented wave method
Authors: Nguyen Minh , Duong Tim , Neuhauser Daniel
Published: April 2024

The projector augmented wave (PAW) method of Blöchl linearly maps smooth pseudo wavefunctions to the highly oscillatory all-electron DFT orbitals. Compared to norm-conserving pseudopotentials (NCPP), PAW has the advantage of lower kinetic energy cutoffs and larger grid spacing at the cost of having to solve for non-orthogonal wavefunctions. We earlier developed orthogonal PAW (OPAW) to allow the use of PAW when orthogonal wavefunctions are required. In OPAW, the pseudo wavefunctions are transformed through the efficient application of powers of the PAW overlap operator with essentially no extra cost compared to NCPP methods. Previously, we applied OPAW to DFT. Here, we take the first step to make OPAW viable for post-DFT methods by implementing it in real-time time-dependent (TD) DFT. Using fourth-order Runge–Kutta for the time-propagation, we compare calculations of absorption spectra for various organic and biological molecules and show that very large grid spacings are sufficient, 0.6–0.7 bohr in OPAW-TDDFT rather than the 0.4–0.5 bohr used in traditional NCPP-TDDFT calculations. This reduces the memory and propagation costs by around a factor of 3. Our method would be directly applicable to any post-DFT methods that require time-dependent propagations such as the GW approximation and the Bethe–Salpeter equation.
Thermal flux manipulation on the silicon photonic chip to suppress the thermal crosstalk
Authors: Ning Nannan , Zhang Qiang , Huang Qikai , Wang Yuehai , Lv Bihu , Yin Kun , Yang Jianyi , Yu Hui
Published: April 2024

The integration density of silicon photonic integrated circuit (PIC) is ultimately constrained by various crosstalk mechanisms on the chip. Among them, the most prominent limiting factor is the thermal crosstalk due to the wide use of the thermo-optic effect. High-density silicon PICs strongly demand an advanced structure with better thermal crosstalk suppression ability than the traditional air isolation trench. Inspired by the thermal-metamaterial based on the scattering-cancellation method, we demonstrate a closed heat shield (CHS) structure on a silicon PIC chip, which can manipulate the thermal flux to bypass the temperature-sensitive silicon photonics components. The on-chip CHS structure is a bilayer cylindrical shell fabricated by the standard silicon photonics processing flow. Its outer and inner shell layers are formed by a 6-μm-wide interconnection metal and 4-μm-wide air trench, respectively. Plenty of temperature-sensitive micro-ring resonators inside the CHS are used to probe the temperature profile. The measurement results show that the CHS can reduce the local temperatures by 50%/44%/36% at the locations 29/41/83 μm away from the external heater. In contrast, the conventional air trench of the same dimension reduces the local temperatures by 32%/28%/21% at the same positions. In addition, the response time of the thermal field inside the CHS is around one-half of that in the conventional air trench. Furthermore, the simulation result indicates that if the outer shell of the CHS can contact with the silicon substrate by utilizing the through-silicon-via structure, the thermal crosstalk suppression ability can be improved significantly.
Excellent electrostatic control and gate reliability for breakdown enhanced AlGaN/GaN HEMTs with extreme permittivity BaTiO3
Authors: Hao Lin , Hu Tiancheng , Guo Hui , Pan Danfeng , Ye Jiandong , Zhou Yugang , Lu Hai , Zhang Rong , Zheng Youdou , Chen Dunjun
Published: April 2024

In this Letter, we investigated the electrostatic control capability and gate reliability of the BaTiO3 integrated AlGaN/GaN HEMTs. The fabricated HEMT exhibits a high peak maximum transconductance of 141 mS/mm, a large ON/OFF current ratio of 4.1 × 109, and a small subthreshold swing of 70.6 mV/dec, attributed to the gate leakage suppression and prominent gate coupling. These parameters demonstrate that the HEMT device with extreme permittivity BaTiO3 dielectric has the excellent electrostatic control capability. A high breakdown voltage of 1348 V was also achieved thanks to the screening of the negative gate image charges and the resulting improvement of electric field distribution by using double-layer BaTiO3 with the wrapped gate structure. Furthermore, gate bias step-stress and pulse I–V measurements show that the device exhibits a small VTH shift of 0.06 V at 2 V bias stress and a slight current collapse of ∼2.7% accompanied with a 6.0% RON increment at a quiescent drain bias VDSQ = 30 V, which benefits from the high quality of the dielectrics/AlGaN interface with Dit of 8.87 × 1012 eV−1/cm2. These findings elucidate the immense potential of extreme permittivity dielectrics engineering in achieving high-performance AlGaN/GaN power electronic devices.
Effect of the superthermal electrons on the heat flux through a magnetized sheath
Authors: Ou Jing , Long Jiamin , Yang Jinhong , Xi Xuyao
Published: April 2024

A one-dimensional model, in which the ionization and collision are omitted in the Debye sheath region, is applied to investigate the effect of the superthermal electrons on the heat flux through a magnetized sheath. For different temperatures and concentrations of the superthermal electron, and magnitudes and directions of the magnetic field, the profiles of plasma parameters including ion density and flow velocity perpendicular to the wall, the background and superthermal electron densities, and sheath potential in the presheath region are calculated. The variation of the plasma density and sheath potential drop at the Debye sheath entrance with the superthermal electrons and magnetic field modifies the particle and heat fluxes across the Debye sheath to the material surface. The sheath heat transmission coefficient can increase significantly even for a very small superthermal electron population. The dependence of the sheath heat transmission coefficient on the magnetic field angle decreases with the contribution of the superthermal electron in a strong magnetized sheath. When investigation of the heat flux including the superthermal electrons to a water-cooled W/Cu monoblack for the tokamak divertor, compared to the case of without superthermal electrons, it is found that the increase in both heat flux to the material surface and surface temperature of the material is mainly due to the enhancement of the sheath potential drop caused by the superthermal electrons, but the increase in the latter is not as pronounced as the former.
Manipulation of high-frequency spin waves in ferromagnetic thin films via magnetic torques induced by ultrafast demagnetization
Authors: Xia Tianhao , Chen Yanping , Zhang Jiayang , Wang Linzheng , Wang Chen , Qi Runze , Sheng Zhengming
Published: April 2024

Spin-based technologies demand the effective excitation and control of high-frequency spin waves in order to increase the operational speed of magnonic logic circuits. An available option for the high-frequency spin wave is the perpendicular standing spin waves (PSSWs) in ferromagnetic thin films. However, the practical utilization of a PSSW is still challenging due to a few unsolved critical issues such as its relatively low amplitude and simultaneous excitation of other PSSW modes. Here, efficient excitation and control of a first-order PSSW mode are demonstrated in Ni80Fe20 thin films using a double-laser-pulse scheme. Based upon our experimental and theoretical investigations, it is found that the precession amplitudes of the Kittel and PSSW modes show strong dependence on equivalent torques (i.e., the averaged torques during fast relaxation process after the second pulse excitation) applied to these two modes. Thus, selective excitation and amplification of the first-order PSSW mode can be realized by manipulating the equivalent torque, i.e., introducing a second laser pulse with an appropriate arrival time and laser fluence. Moreover, the spectral tuning of this single PSSW mode can be achieved by proportionately adjusting the laser fluence of two pump pulses. These findings may pave the way for the realization and construction of future high-performance spintronic devices.
Multifactor response-based optimization for enhancing cavitation performance of short injection self-priming pumps
Authors: Yang Yang , Chen Xionghuan , Wang Hui , Wu Shaohui , Jiao Weixuan , Ji Leilei , Shi Weidong , He Zhaoming , Agarwal Ramesh K. , Wang Chuan
Published: April 2024

As the heart of the water supply systems, the energy conversion efficiency of the self-priming pumps with built-in injection system under overload conditions is extremely affected by cavitation problems. This study focuses on a typical short-type injection self-priming pump devoted to improve the pump performance, especially to solve the cavitation problem under overload conditions. Through a two-factor, five-level orthogonal test that combines numerical simulation and experimental validation, the influence of key structural parameters within the ejector on cavitation performance and energy characteristics are analyzed. The results demonstrate the high level accuracy of numerical simulation, as indicated by the consistency and small error between the numerical results and the experimental results for head, efficiency, and power under full flow conditions. Regression analysis based on the orthogonal test results reveals significant correlations between the hydraulic performance of the pump and the nozzle throat diameter and nozzle outlet diameter. Under overload conditions, the high-speed jet generated by the injector induces a negative pressure at the effuser and nozzle, leading to cavitation at the effuser throat and nozzle outlet. Employing appropriate structural parameters, particularly the effuser throat diameter and nozzle outlet diameter, proves effective in increasing the operating flow range. This in turn improves the energy characteristics of the entire hydraulic system. The optimal combination identified for the ejector's structural parameters in this study is a nozzle outlet diameter of 8.2 mm and a throat diameter of 18 mm. This provides theoretical insights for the optimal design of short-type jet self-priming pumps, holding practical significance in engineering applications.
Sliding ferroelectricity in kagome-B2X3 (X = S, Se, Te) bilayers
Authors: Guo Yan-Dong , Meng Rui-Jie , Hu Xue-Qin , Lin Li-Yan , Jiang Yue , Yang Ming-Yu , You Yun , Zhang Lan-Qi , Xu Yi-Long , Yan Xiao-Hong
Published: April 2024

Different from the honeycomb monolayer (like graphene), the single-layer boron chalcogenide B2X3 (X = S, Se, Te) exhibits a kagome lattice. Using the first-principles calculations, the existence of sliding ferroelectricity in van der Waals kagome-B2X3 bilayers is demonstrated. The sliding ferroelectricity results from the breaking of the inversion symmetry by interlayer sliding. In addition, there are multiple stable states in a unit cell for kagome-lattice bilayers. The bandgap is found to vary with sliding distance. By choosing specific pathways, not only the out-of-plane polarization but also the in-plane polarization can be reversed by interlayer sliding. Such a simultaneous reversal for both in-plane and out-of-plane polarizations by sliding would be useful for applications in various devices. These behaviors are found in all the three configurations (X = S, Se, Te), suggesting they are the intrinsic features of such systems and may throw light on the development of future devices.
Insight into blade tip vibration and deformation characteristics of boiler circulation pumps induced by tip leakage vortex under different tip clearances
Authors: Lv Hao , Guo Lei , Zhao Kun , Dai Jiahui , Li Yishan , Chen Songying
Published: April 2024

For circulating pumps in large power plant boilers, tip leakage flow is the main cause of blade fatigue. To investigate the correlation between tip leakage vortex and blade fatigue, in this paper, the bidirectional fluid structure coupling method is used to simulate the full flow field of the boiler circulating pump under different tip clearance sizes. The accuracy of the delayed detached vortex simulation method is verified by combining the external characteristics and vibration characteristics of the pump. It is obtained that tip leakage vortex is the main cause of blade tip vibration and deformation. Under deep stall conditions, the increase in tip clearance size suppresses the vibration displacement of the blade leading edge, while the opposite is true under optimal conditions. After decomposing tip leakage vortex, it is found that the compression–expansion term played a major role in the deformation of the blade tip, while the viscous dissipation term and the stretching term mainly affected the vibration frequency. At optimal working conditions, the main frequency of blade vibration is basically consistent with the main frequency of vortex generation. In deep stall condition, as the tip clearance size increases, the amplitude of the vibration main frequency decreases and the number of harmonic frequencies decreases, while the optimal condition is the opposite.
Analysis and modeling of the influence of gate leakage current on threshold voltage and subthreshold swing in p-GaN gate AlGaN/GaN high electron mobility transistors
Authors: Liu Kai , Wang Chong , Zhang Kuo , Ma Xiaohua , Bai Junchun , Zheng Xuefeng , Li Ang , Hao Yue
Published: April 2024

In this paper, the p-GaN gate AlGaN/GaN high electron mobility transistors (HEMTs) with varying combinations of gate metal work function and gate geometry are fabricated and investigate the influence of gate leakage current (IGS) on the threshold voltage (VTH) and subthreshold swing (SS). The unique dependence of VTH and SS on gate geometry for different metals is observed, which is different from traditional field-effect transistors. A novel hybrid physics model, consisting of the traditional capacitance divider model and hole injection model, is proposed to explain this phenomenon, and the results exhibit an excellent agreement with the experimental data. The holes traverse the gate/p-GaN Schottky barrier by thermal emission or tunneling and inject into the p-GaN layer, generating the IGS. Expanding upon the traditional capacitance divider model, a portion of the injected holes accumulate at the p-GaN/AlGaN interface and induce the corresponding electrons at the AlGaN/GaN heterojunction, which promotes channel conduction. Hence, the transfer curves display the correlation between IGS and VTH as well as SS. The results show that high IGS can alleviate the instability of VTH caused by the lithographic overlay error, and simultaneously optimize SS. This work offers a novel perspective for examining the turn-on mechanism of p-GaN HEMTs, thereby contributing to device design.
Study of phase transition and local order in equiatomic and nonequiatomic mixtures of HfNbTaTi under uniaxial loading from molecular dynamics simulations
Authors: Protim Hazarika Manash , Tripathi Ajay , Nath Chakraborty Somendra
Published: April 2024

We simulate an alloy of HfNbTaTi mixed in six different proportions and also of the equiatomic system under uniaxial tensile loading at 300 K. Molecular dynamics simulation trajectories are analyzed using radial distribution functions, OVITO, bond-orientational order parameters, and coordination numbers. Equiatomic and the two other alloys (Hf0.31Nb0.23Ta0.23Ti0.23 and Hf0.23Nb0.31Ta0.23Ti0.23) containing comparable fraction of elements deform similarly through the formation of an amorphous state. Two alloys rich in Nb (Hf0.17Nb0.50Ta0.16Ti0.17) and Ta (Hf0.17Nb0.16Ta0.50Ti0.17) deform similarly resulting in the formation of bcc atoms, which transform to fcc at higher loading. Finally, alloys rich in Hf (Hf0.50Nb0.16Ta0.17Ti0.17) and Ti (Hf0.17Nb0.16Ta0.17Ti0.50) deform resulting in high dislocation densities and hcp atoms. These two hcp-rich alloys also undergo strain hardening. In each mixture during loading, local orientational order of all the different elements changes similarly. Atoms prefer to pair with other atoms than to themselves during tensile loading.
Recent advances in 3D printing for in vitro cancer models
Authors: Zhang Bin , Morgan Meagan , Teoh Xin Yi , Mackay Ruth , Ermler Sibylle , Narayan Roger
Published: April 2024

3D printing techniques allow for the precise placement of living cells, biological substances, and biochemical components, establishing themselves as a promising approach in bioengineering. Recently, 3D printing has been applied to develop human-relevant in vitro cancer models with highly controlled complexity and as a potential method for drug screening and disease modeling. Compared to 2D culture, 3D-printed in vitro cancer models more closely replicate the in vivo microenvironment. Additionally, they offer a reduction in the complexity and ethical issues associated with using in vivo animal models. This focused review discusses the relevance of 3D printing technologies and the applied cells and materials used in cutting-edge in vitro cancer models and microfluidic device systems. Future prospective solutions were discussed to establish 3D-printed in vitro models as reliable tools for drug screening and understanding cancer disease mechanisms.
Statistical inference of unified hybrid censoring scheme for generalized inverted exponential distribution with application to COVID-19 data
Authors: Hasaballah Mustafa M. , Tashkandy Yusra A. , Balogun Oluwafemi Samson , Bakr M. E.
Published: April 2024

Using a unified hybrid censoring scheme, this study explores statistical inferences for products with lifetimes following the generalized inverted exponential distribution. The model’s parameters are estimated using the maximum likelihood approach. In addition, likelihood functions and asymptotic theories are employed to generate approximate confidence intervals. Moreover, Bayesian estimates based on classical likelihood functions are investigated, considering both asymmetric and symmetric loss functions with prior information. It is recommended to approximate the Bayes estimates using Gibbs sampling, which utilizes the Markov chain Monte Carlo technique to establish credible intervals for the parameters. A numerical example is provided to demonstrate the effectiveness of the proposed methods. Furthermore, a simulation study is conducted to illustrate the confidence intervals and the statistical characteristics of the parameters.