bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of an Active Leveling Scheme for a Short-Range Gravity Experiment
Authors: Johnson Alyssa , Rogers Claire , Dunkley Noah , Gengo Michael , Hoyle C.D.
Published: December 2023

At Cal Poly Humboldt, undergraduate researchers and faculty have constructed a torsion-pendulum experiment that seeks to measure gravitational interactions below test mass separations of 100 microns. The aim of this experiment is to look for deviations in the weak equivalence principle (WEP) and inverse-square law (ISL). The scale at which this experiment operates is within an untested range at the submillimeter scale. This apparatus’s torsion pendulum consists of equal masses with differing materials arranged as a composition dipole. The twist of this configuration is measured as an attractor mass oscillates in a parallel-plate arrangement nearby. The oscillation creates a time-dependent torque on the pendulum which can be studied for deviations in the WEP and ISL. At present, an active leveling scheme has been implemented to mediate the apparatus’s long-term tilt variations. This scheme has been optimized through the use of a power supply and proportional-integral-derivative (PID) loop that mitigates the variations in tilt by applying a voltage to a resistor attached to one of the apparatus legs. The applied voltage causes thermal expansion of the apparatus leg support structure, thus correcting and modulating the tilt of this experiment.
Temperature Dependence of the Static Friction Coefficient of Common Recyclable Polymers
Authors: Aduli Camran
Published: December 2023

According to the classical adhesion explanation for the phenomenon of friction, the friction coefficient between two surfaces is defined as the ratio between the horizontal friction force exerted on each surface and the perpendicular normal force between each surface. There is a paucity of published investigations into the relationship between the contact temperature of a polymer-nonpolymer physical interface and the resultant static friction coefficient at varying temperatures. This study investigates the relationship between temperature and the static friction coefficients of five recyclable thermoplastic polymers in polymer-aluminum interfaces across a range of temperatures. The results demonstrate a generalizable relationship between the static friction coefficient and the contact temperature of polymer-aluminum interfaces which corresponds to polymer-specific phase-change temperatures.
Measuring dn/dc for Polysaccharide Microgels of Varying Crosslinking Density
Authors: Herron Patrick , Streletzky Kiril A.
Published: December 2023

Static light scattering (SLS) is a powerful, noninvasive experimental method that yields the molecular weight (average molecular weight, Mw), the size (radius of gyration, Rg), and the interactions between the scatters (the second virial coefficient, A2). However, proper SLS measurements require determination of the specific refractive index increment (dn/dc) for the samples studied. While tables of dn/dc values are available for various substances, they are not generally available for microgel particles, which in our case are crosslinked chains of an amphiphilic polymer. This paper is focused on measuring dn/dc for microgel samples of varying crosslinking concentrations. Microgel dn/dc values were found to be different from the value of the parent polymer given in literature and found to have a temperature dependence as well as a crosslinker concentration dependence at higher crosslinker concentrations. Using the measured values of microgel dn/dc instead of tabulated parent polymer values on estimates of microgel Mw, Rg, and A2 highlights the importance of direct dn/dc measurements for samples studied by SLS.
Developing an Interactive Simulation for Noninertial Reference Frames
Authors: Mburu Ted K.
Published: December 2023

The forces involved in the motion of objects within noninertial reference frames are challenging concepts for introductory and advanced mechanics students. Furthermore, students often struggle to predict the trajectories of an object due to these fictitious forces. While most students encounter noninertial reference frames daily, students often spend most of their physics coursework analyzing situations in which the Coriolis and centrifugal forces are negligible. We developed an interactive and freely accessible simulation of a rotating turntable apparatus that aims to improve understanding of the motion of objects in noninertial reference frames.
Advances in separation of monochiral semiconducting carbon nanotubes and the application in electronics
Authors: Sun Yanan , Zhu Jiejie , Yi Wenhui , Wei Yuxiang , Zhou Xuejiao , Zhang Peng , Liu Yang , Li Peixian , Lei Yimin , Ma Xiaohua
Published: December 2023

For over half a century, traditional silicon-based integrated circuits (ICs) have been the basis of computational electronics and are widely used in computers, cell phones, and other fields. With the rapid development of human society, silicon-based semiconductor technology is approaching its physical and engineering limits. Our increasing diversity of non-traditional computing needs, such as ultra-small, ultra-fast, ultra-low-power wearables, and space radiation protection, is driving the search for new electronic materials. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have many excellent electrical properties, such as high carrier mobility and high ballistic transport, making them strong candidates for new semiconductor materials in the post-Moore era. Carbon-based electronic technology has been developed for over 20 years, and the fundamental issues such as the material purification of s-SWCNTs, preparation prospects of s-SWCNT-based field-effect transistors (CNT FETs), and device physics based on CNT FETs have been basically solved. However, the chiral diversity of s-SWCNTs may lead to problems such as fluctuations in the electrical performance of CNT FETs, limiting the application of s-SWCNTs in high-end ICs. Monochiral s-SWCNTs not only have excellent electrical properties but also have a controllable structure and uniformity, which are crucial for the high-end IC of CNTs. However, some problems exist in the purity and yield of monochiral s-SWCNT preparation and the optimization of monochiral CNT FETs. Therefore, the chiral sorting of CNTs is reviewed in this paper, and the progress of polymer reprocessing in chiral separation is highlighted. Then, the research progress of monochiral CNT FETs is introduced, and possible development directions are summarized and analyzed. Finally, the application prospects of chiral-enriched s-SWCNTs include challenges and future opportunities.
Realization-dependent model of hopping transport in disordered media
Authors: Thayil Abel , Filoche Marcel
Published: December 2023

At low injection or low temperatures, electron transport in disordered semiconductors is dominated by phonon-assisted hopping between localized states. A very popular approach to this hopping transport is the Miller–Abrahams model that requires a set of empirical parameters to define the hopping rates and the preferential paths between the states. We present here a transport model based on the localization landscape (LL) theory in which the location of the localized states, their energies, and the coupling between them are computed for any specific realization, accounting for its particular geometry and structure. This model unveils the transport network followed by the charge carriers that essentially consists in the geodesics of a metric deduced from the LL. The hopping rates and mobility are computed on a paradigmatic example of disordered semiconductor and compared with the prediction from the actual solution of the Schrödinger equation. We explore the temperature-dependency for various disorder strengths and demonstrate the applicability of the LL theory in efficiently modeling hopping transport in disordered systems.
Magnetic field induced instability pattern evolution in an immiscible alloy
Authors: Wei Chen , Wang Jun , He Yixuan , Yan Yujie , Beaugnon Eric , Li Jinshan
Published: December 2023

The magnetic field induced instability patterns have been observed in an undercooled immiscible Co–Cu alloy by an in situ magnetization measurement of the supercooled alloy melt. With the increase in magnetic field intensity and gradient, the undercooled immiscible melt experienced a transition from a core-shell structure to a layered structure at a lower field intensity and then a typical normal field instability pattern with the applied higher magnetic field gradient. Due to the different magnetic response ability of the separated phases in the presence of a magnetic field gradient, the transition of the morphology was complex, and its detailed investigations can provide important insight for better understanding of the ferrofluid and the creation of functional material. Furthermore, under an appropriate field gradient condition, it can achieve the subtle transitions between the diverse morphologies in an immiscible alloy.
Electrical single mode switching in coupled microcavity
Authors: Huang Chaoyang , Wang Xiaoxuan , Mao Lingfeng , Li Zhuxin , Zhang He , Cui Qiannan , Shi Zengliang , Xu Chunxiang
Published: December 2023

Flexible lasing mode regulation is significant for optoelectronic applications, such as on-chip communication and optoelectronic integration. However, reversible and dynamic single mode lasing output is still a challenge. Herein, reversible lasing modes tuning is demonstrated in whispering gallery mode microcavity controlled by bias voltages. Especially in coupled microcavity consisting of two microrods, applied electrical fields cause lasing modes shifting of one microrod, and the optical field coupling process with the other microrod occurs simultaneously to select distinct single mode lasing. Hence, the switchable single mode lasing can be achieved. The mechanisms of Vernier effect, electro-optic effect, and their synergy on lasing mode modulation are analyzed via experimental results and theoretical analysis. Synergistically running the two effects, the high quality factor of the single mode indicates an effective coupling process, providing an effective way for controllable lasers.
Drivers of the artiodactyl turnover in insular western Europe at the Eocene–Oligocene Transition
Authors: Weppe Romain , Condamine Fabien L. , Guinot Guillaume , Maugoust Jacob , Orliac Maëva J.
Published: December 2023

Simultaneously investigating the effects of abiotic and biotic factors on diversity dynamics is essential to understand the evolutionary history of clades. The Grande Coupure corresponds to a major faunal turnover at the Eocene–Oligocene transition (EOT) (~34.1 to 33.55 Mya) and is defined in western Europe as an extinction of insular European mammals coupled with the arrival of crown clades from Asia. Here, we focused on the species-rich group of endemic European artiodactyls to determine the drivers of the Grande Coupure during the major environmental disruptions at the EOT. Using Bayesian birth–death models, we analyzed an original high-resolution fossil dataset (90 species, >2,100 occurrences) from southwestern France (Quercy area) and estimated the regional diversification and diversity dynamics of endemic and immigrant artiodactyls. We show that the endemic artiodactyl radiation was mainly related to the Eocene tropical conditions, combined with biotic controls on speciation and clade-related diversity dependence. We further highlight that the major environmental changes at the transition (77% of species became extinct) and the concurrent increase in seasonality in Europe during the Oligocene were likely the main drivers of their decline. Surprisingly, our results do not support the widely-held hypothesis of active competition between endemic and immigrant artiodactyls but rather suggest a passive or opportunistic replacement by immigrants, which is further supported by morphological clustering of specific ecological traits across the Eocene-Oligocene transition. Our analyses provide insights into the evolutionary and ecological processes driving the diversification and decline of mammalian clades during a major biological and climatic crisis.
Coexistence within one cell of microvillous and ciliary phototransductions across M1- through M6-IpRGCs
Authors: Li Guang , Chen Lujing , Jiang Zheng , Yau King-Wai
Published: December 2023

Intrinsically photosensitive retinal ganglion cells (ipRGCs) serve as primary photoceptors by expressing the photopigment, melanopsin, and also as retinal relay neurons for rod and cone signals en route to the brain, in both cases for the purpose of non-image vision as well as aspects of image vision. So far, six subtypes of ipRGCs (M1 through M6) have been characterized. Regarding their phototransduction mechanisms, we have previously found that, unconventionally, rhabdomeric (microvillous) and ciliary signaling motifs co-exist within a given M1-, M2-, and M4-ipRGC, with the first mechanism involving PLCβ4 and TRPC6,7 channels and the second involving cAMP and HCN channels. We have now examined M3-, M5-, and M6-cells and found that each cell likewise uses both signaling pathways for phototransduction, despite differences in the percentage representation by each pathway in a given ipRGC subtype for bright-flash responses (and saturated except for M6-cells). Generally, M3- and M5-cells show responses quite similar in kinetics to M2-responses, and M6-cell responses resemble broadly those of M1-cells although much lower in absolute sensitivity and amplitude. Therefore, similar to rod and cone subtypes in image vision, ipRGC subtypes possess the same phototransduction mechanism(s) even though they do not show microvilli or cilia morphologically.
Mechanism of eukaryotic origin unwinding is a dual helicase DNA shearing process
Authors: Langston Lance D. , Georgescu Roxana E. , O'Donnell Michael E.
Published: December 2023

DNA replication in all cells begins with the melting of base pairs at the duplex origin to allow access to single-stranded DNA templates which are replicated by DNA polymerases. In bacteria, origin DNA is presumed to be melted by accessory proteins that allow loading of two ring-shaped replicative helicases around single-strand DNA (ssDNA) for bidirectional unwinding and DNA replication. In eukaryotes, by contrast, two replicative CMG (Cdc45-Mcm2-7-GINS) helicases are initially loaded head to head around origin double-strand DNA (dsDNA), and there does not appear to be a separate origin unwinding factor. This led us to investigate whether head-to-head CMGs use their adenosine triphosphate (ATP)-driven motors to initiate duplex DNA unwinding at the origin. Here, we show that CMG tracks on one strand of the duplex while surrounding it, and this feature allows two head-to-head CMGs to unwind dsDNA by using their respective motors to pull on opposite strands of the duplex. We further show that while CMG is capable of limited duplex unwinding on its own, the extent of unwinding is greatly and rapidly stimulated by addition of the multifunctional CMG-binding protein Mcm10 that is critical for productive initiation of DNA replication in vivo. On the basis of these findings, we propose that Mcm10 is a processivity or positioning factor that helps translate the work performed by the dual CMG motors at the origin into productive unwinding that facilitates bidirectional DNA replication.
Negotiating leader identities through indirect mockery in talk about decision-making in a distributed
leadership context
Authors: Salomaa Elina , Van De Mieroop Dorien , Lehtinen Esa
Published: December 2023

In this article, we scrutinise how humour, and in particular, indirect mockery contributes to the construction of
leader identities in talk about decision-making in an organisation characterized by a distributed leadership
context. So rather than focusing on decision-making episodes themselves, we tease out an aspect of the goal achievement side of
the leadership influence process. Through multimodal discourse analysis, we focus on episodes in which the implementation side of
decisions is discussed and in which the head of the team initiates a humorous sequence, as this turned out to be an integral part
of talk about decision-making. We found that the humour was always oriented towards upper management and that it could serve
various functions. Overall, we argue that indirect mockery was a crucial means to navigate the tension that emerges from the team
head’s position within the complex leadership constellation, thus offering a critical perspective on distributed leadership.
Undertaking One Health Research with Australian Aboriginal and Torres Strait Islander Communities: Implications of a One Health Pilot Study
Authors: Riley Tamara , Meredith Anna , Anderson Neil E. , Cumming Bonny , Thandrayen Joanne , Lovett Raymond
Published: December 2023

This case study presents the research process and learnings from undertaking One Health research within Australian Aboriginal and Torres Strait Islander community settings. One Health is relevant to Australian Aboriginal and Torres Strait Islander communities where people and animals (commonly dogs and cats) live closely together and face health risks due to barriers in accessing animal health care. One Health is an appropriate approach to understanding and addressing health disparities as it aligns with community and cultural contexts that recognise the relationships between the health of people, animals and the shared environment. However, with minimal evidence in this space, the contribution of One Health to Aboriginal and Torres Strait Islander health is not well understood limiting the ability to implement One Health approaches and address the needs of communities, families, animals and the environment. This case study describes the research approach, methodology and implications from a pilot One Health study undertaken with Aboriginal and Torres Strait Islander communities that adopted Indigenous research methodologies within a One Health framework.

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Tidal effects in 4D-charged Einstein-Gauss-Bonnet gravity black hole
Authors: Asgher M , Abbas G
Published: December 2023

In this paper, we study the geodesic deviation between two nearby geodesics. For this process, we calculated the geodesic equation and radial motion of test particles. Also, the radial and angular tidal forces have been investigated using the curvature tensor in tetrad form. The radial tidal forces in 4D charged Einstein-Gauss-Bonnet gravity black hole show a tidal effect with a small value of radial coordinate r. The angular tidal forces show converse behavior as compared to the radial tidal forces at the short value of radial coordinate r. The radial and angular tidal forces have the same behavior at the immense value of radial coordinate r. The geodesic deviation paths depend on the charge Q parameter and Gauss-Bonnet parameter α of the black hole. We have compared our result with the 4D uncharged Einstein-Gauss-Bonnet gravity black hole and Reissner-Nordström with consideration of two kinds of initial conditions.
Comparison study of RF/analog and linearity performance of dual material gate graphene source vertical TFET (DMG-GR-VTFET) and single material gate GR-VTFET
Authors: Sharma Yakshraj , Vijay Lakshya , Kumari Archita , Muskan  , Tiwari Shreyas , Saha Rajesh
Published: December 2023

This paper investigates the comparative feature of Graphene Source Single Material Gate Vertical Tunnel FET (SMG-GR-VTFET) and Graphene Source Double Material Gate VTFET (DMG-GR-VTFET) on DC, analog/RF and linearity applications using Sentaurus TCAD simulator. The results show that both devices outperforms in DC characteristics, including ambipolar current, subthreshold swing (SS), ION/IOFF ratio etc The study focuses on important figures of merit (FOMs) such as transconductance (gm), output conductance (gd), cut-off frequency (ft), second-order transconductance (gm2), third-order transconductance (gm3), VIP2, and VIP3, which are all improved due to high mobility of graphene leads to improved band-to-band tunneling. The observed ION is 5.2 × 10−4 (1.1 × 10−3 A/μm), IOFF is 1.439 × 10−13 (2.28 × 10−16A/μm) and ION/IOFF ratio of 3.613 × 109 (4.824 × 1012) for SMG-GR-VTFET (DMG-GR-VTFET), respectively. It is seen that maximum gm is 2.96 × 10−3 (2.59 × 10−3 S μm−1) and cut-off frequency (ft) values of 1.1 × 1011 (1.85 × 1011 Hz) for SMG-GR-VTFET (DMG-GR-VTFET), respectively. Regarding the Linearity parameter VIP2 value is 2.71 V (0.99 V), respectively, for SMG-GR-VTFET (DMG-GR-VTFET). These results suggest that Graphene Source Vertical Tunnel FET is an excellent choice for analog and high-frequency applications.
Design and numerical optimisation of a CH3NH3SnI3−x
Br
x
/CI(G)S tandem solar cell with over 50% PCE
Authors: Uzagare Samuel , Chavan Kalyan B
Published: December 2023

This work proposes and numerically optimises a four terminal mechanically stacked tandem with CuI/CH3NH3SnI3−x
Br
x
/ZnO:Al/IZO as top subcell and IZO/GaSe/CI(G)S/CIGS-P+ as bottom subcell. The standalone optimised subcells exhibited power conversion efficiencies of 27.03% (CH3NH3SnI3 based cell) and 24.42% (CIGS based cell), with the tandem configuration showing a combined power conversion efficiency of 51.45%. Band gap optimisation of the CIGS based solar cell also revealed that its gallium content had to be nullified, which is a favourable outcome considering the high cost of gallium. Furthermore, the tandem device also exhibited excellent quantum efficiency while spanning the UV-Vis-NIR range of photon wavelength absorption, as a result of the CI(G)S based subcell complementing the top CH3NH3SnI3 based subcell.
Wavelet representation of hardcore bosons
Authors: Granet Etienne
Published: December 2023

We consider the one-dimensional Tonks–Girardeau gas with a space-dependent potential out of equilibrium. We derive the exact dynamics of the system when divided into n boxes and decomposed into energy eigenstates within each box. It is a representation of the wave function that is a mixture between real space and momentum space, with basis elements consisting of plane waves localized in a box, giving rise to the term ‘wavelet’. Using this representation, we derive the emergence of generalized hydrodynamics in appropriate limits without assuming local relaxation. We emphasize that a generalized hydrodynamic behaviour emerges in a high-momentum and short-time limit, in addition to the more common large-space and late-time limit, which is akin to a semi-classical expansion. In this limit, conserved charges do not require numerous particles to be described by generalized hydrodynamics. We also show that this wavelet representation provides an efficient numerical algorithm for a complete description of the out-of-equilibrium dynamics of hardcore bosons.
Improved mean-field dynamical equations are able to detect the two-step relaxation in glassy dynamics at low temperatures
Authors: Machado David , Mulet Roberto , Ricci-Tersenghi Federico
Published: December 2023

We study the stochastic relaxation dynamics of the Ising p-spin model on a random graph, which is a well-known model with glassy dynamics at low temperatures. We introduce and discuss a new closure scheme for the master equation governing the continuous-time relaxation of the system, which translates into a set of differential equations for the evolution of local probabilities. The solution to these dynamical mean-field equations describes the out-of-equilibrium dynamics at high temperatures very well, notwithstanding the key observation that the off-equilibrium probability measure contains higher-order interaction terms not present in the equilibrium measure. In the low-temperature regime, the solution to the dynamical mean-field equations shows the correct two-step relaxation (a typical feature of glassy dynamics), but with a too-short relaxation timescale. We propose a solution to this problem by identifying the range of energies where entropic barriers play a key role and defining a renormalized microscopic timescale for the dynamical mean-field solution. The final result perfectly matches the complex out-of-equilibrium dynamics computed through extensive Monte Carlo simulations.
Design of Power Tower Climbing Robot
Authors: Cao Liwen , Zhang Shanlin
Published: December 2023

The maintenance of high-voltage transmission lines mainly relies on manual work. When workers climb power towers, tower climbing robots are needed to provide safety ropes. In this paper, a power tower climbing robot with a new structure is designed, and its three-dimensional model is created and simulated. Finally, combined with the motor selection in each robot component, the tower climbing robot prototype was made and tested. The designed climbing robot can complete the locking and crawl on the power tower.
Stability Analysis of Satellite Navigation and Positioning Reference Stations Considering Linear Motion
Authors: Huang Weizhao , Chen Yuan , Xin Tuo , Huang Linchao , Xu Shu
Published: December 2023

The coordinate frame is not only the foundation for depicting the shape and changes of the Earth and expressing geospatial information but also the crucial geospatial information infrastructure for expanding human activities and promoting social development. Research on satellite navigation and positioning reference stations considering linear motion will be of great significance for navigation and positioning. Therefore, this paper first deduces the transformation formula between different international terrestrial reference frames (ITRF) and the transformation relationship between different reference epochs. Second, a comparison experiment is conducted to analyze the influence of coordinates under different reference frames and epochs on the accuracy of the international GNSS service (IGS) baseline solution results. Finally, stability analysis is performed considering the effect of linear motion on the urban frame points. The results show that using the coordinates under the reference frame and epochs that best fit the measurement time for the baseline solution gives the most reliable results.
Modal Identification of Aircraft Time-varying Structure Based on Fiber Grating Measurement
Authors: Wang Yi , Yue Zhenjiang , Liu Li
Published: December 2023

To meet the increasing mission requirements, the time-varying characteristics of the aircraft structural system have been increasingly considered and utilized. Therefore, it is significant to obtain the structural modal parameters during the mission of the aircraft. However, the traditional electrical sensors have many limitations in the online measurement of spacecraft structure, and fiber grating sensors are expected to better adapt to the requirements. The online modal parameter identification methods of time-varying structures also lack sufficient research. The traditional modal parameter identification methods include non-parametric method and parametric method. However, the rapid development of neural networks in recent years makes them an effective tool for modal parameter identification. In this paper, a moving mass beam simulation model is established to simulate the time-varying characteristics of the structure, and the modal parameters of the dynamic strain signal are identified. The comparison results of three identification methods are obtained.
Bracket design and natural frequency analysis of civil aircraft inertial reference unit
Authors: Lan Xinghai , Liu Qiang
Published: December 2023

The Inertial Reference Unit (IRU) is an important and indispensable airborne equipment for civil aircraft, which is used to provide information on aircraft attitude, heading, acceleration and so on. The design of its bracket will directly affect the signal accuracy of the equipment. In order to ensure the accuracy of the information of the measuring equipment, the stiffness design of the support has strict requirements to avoid the impact of vibration and elastic deformation on the accuracy of the output signal. Through theoretical formula derivation and finite element analysis, this paper summarizes the influence of different bracket structure forms on the natural frequency and obtains the scheme to improve the natural frequency of the bracket. By increasing the flange height, adjusting the lightening hole on the plane mounting plate of the bracket and making the plane mounting plate, frame and skin form a box-shaped structure, the torsional stiffness of the bracket is enhanced. The results show that the improved bracket meets the requirements of natural frequency which is greater than 110 Hz, which can provide a reference for the design and strength analysis of similar aircraft airborne equipment.
Design and Implementation of Multiple Signal Demodulation Device Based on FPGA
Authors: Xie Jiang , Wang Kuan , Huang Ruchang
Published: December 2023

To meet the requirements of other aircraft flight test tasks for multiple types of engines and achieve a device matching multiple engine flight test tasks, a design scheme of a multi-signal demodulation device based on FPGA is proposed. This demodulation device collects and demodulates data such as throttle lever position signal, altitude speed, and switch value. It converts and analyzes the data in series and parallel through FPGA and forwards it to various interfaces such as the EEC interface and airborne testing system. According to the interface protocol requirements, it is converted into signals of types such as RS422, ARINC429, and Ethernet. This multi-signal demodulation device has broad application prospects.
Parameter Identification of KT Equation Based on Flight Test Data of Amphibious Aircraft
Authors: Shi Shengzhe , Wang Lili , Tang Bojian , Gao Xianjiao
Published: December 2023

To improve the turning efficiency of amphibious aircraft, the flight test of water surface rotation of amphibious aircraft was carried out. Referring to the KT equation of ship maneuverability, the paper established the maneuverability KT equation of the amphibious aircraft on the water surface, and the parameters in the KT equation of amphibious aircraft were identified by forward difference. The test results show that the average value of K value is -0.1095, and the average value of T value is 0.5490. The turning efficiency of amphibious aircraft is low, the maneuverability is insufficient, and the heading stability is good. At the same time, the steering response is fast and the delay is low.
Improved YOLOv7 Algorithm for Detecting Occluded Targets at Aircraft Turnaround Milestone
Authors: Liu Yuqi , Jiang Qirui , Dang Wanli , Luo Qian , Zheng Jiaoling
Published: December 2023

The aircraft and special vehicles in the aircraft turnaround milestone have the characteristics of large-scale difference, small spacing distance, etc., and many external interference factors result in many occlusion situations in the process of services. Aiming at the problem that existing airport detection algorithms are ineffective in detecting occluded targets in milestones, an improved YOLOv7 occluded target detection algorithm for aircraft turnaround milestones is proposed. The algorithm adds an efficient channel attention mechanism to the backbone network to suppress the interference information in the environment and improve the attention to the important channels and replaces the convolution in the feature fusion network with a double-pooled coordinate convolution, which is used to improve the model’s ability to extract the spatial information of the occluded target and the remaining features. The algorithm achieves an average detection precision of 89.7% and a recall rate of 88.3% on the aircraft turnaround milestone dataset covering numerous occlusion scenarios, which are 6.1% and 4.4% higher than the YOLOv7 algorithm, respectively. The experiments show that the algorithm can better cope with the task of occlusion target detection in aircraft turnaround milestones.
Bolt looseness identification using a knocking acoustic signal
Authors: Hao Bin , Su Yuelong , Yan XianFeng , Zhao Yitao
Published: December 2023

As a common failure form of the bolted joint, bolt looseness can lead to relative slip between the connected surfaces. Under the action of shear external forces, the bolt experiences fatigue failure and fracture, which can affect the service performance and connection strength of the equipment, and even cause major safety accidents. At present, good results have been achieved in detecting the tightness of bolt connections through Structural Health Monitoring (SHM) technology. However, most of them are still carried out under laboratory conditions and cannot be applied in engineering. Therefore, this article proposes looseness recognition of bolts by knocking acoustic signals. This method converts the acoustic time series signal into a Mel-Frequency Cepstral Coefficient (MFCC) frequency spectrum and then it recognizes the bolt looseness status through the Mobilenetv3 deep neural network. The results show this method can identify loose bolts. Meanwhile, it has a strong engineering application background.
Dynamic Stress Test of Aero-engine Compressor Rotor Blade
Authors: Chen Qinggui , Li Hongwei , Liang Zuotang , Song Hanqiang , Ma Zhongyuan , Sun Huguo
Published: December 2023

To evaluate the effect of the compressor rotor blade on compressor blade fatigue, a non-contact dynamic stress measurement scheme of one aero-engine eighth stage compressor rotor blade was designed, and the dynamic stress test was carried out. Meanwhile, modal analysis of the eighth stage compressor rotor blade was done by finite element analysis software. Results show that between the range of the idle speed and the highest speed, there is no resonance for the eighth stage compressor rotor blade and the maximum vibration amplitude is less than 65 μm, which cannot result in high cycle fatigue failure.
Application of Airborne Radar Variable Altitude Aerial Survey in High Precision Mapping of Mountainous Areas
Authors: Wu Qifan , Liu Ping’an , Dai Lei , Tang Yachong
Published: December 2023

This paper studies how to use UAV aerial survey equipment to carry laser radar and high-definition real-scene lenses to achieve high-precision mountain mapping. The study aims to solve the problems of complex terrain, difficulties in surveying, and controlling the accuracy of surveying and mapping in mountainous, canyon, and hilly areas. Firstly, the LK tea production area development project is selected as an example for example analysis. The aerial survey equipment and data acquisition equipment are selected according to the characteristics of the project. Secondly, aiming at the problem that the mountainous terrain undulates greatly and that the accuracy of ground object mapping is difficult to control, this paper puts forward the “variable height aerial survey” method. It collects aerial survey data according to the terrain characteristics. Finally, this paper proposes a “point cloud overlay” modeling method. It combines laser point cloud data with real 3D data to form a high-precision real 3D model point cloud reorganization and establish a high-precision real 3D model.
Experimental Study on Wave Motion Response Characteristics of Large Amphibious Aircraft
Authors: Wang Fan , Wu Bin , Jiao Jun , Shi Shengzhe , Jiang Ting
Published: December 2023

To master the motion response of an amphibious aircraft under regular waves of drifting and anchoring, a 1:8.5 scaled model test of an amphibious aircraft under regular waves was carried out, and the test device and acquisition method were designed. Through experiments, the wave response characteristics of the drifting and anchoring states were obtained, which provided technical support for the design of the IRS initial alignment algorithm for large amphibious aircraft.
A Follow-up Loading System during the Retraction and Extension Process of a Large Civil Aircraft
Authors: Liu Zhongping
Published: December 2023

This article introduces a design scheme for a distributed load follow-up loading system for large passenger aircraft flaps. The follow-up loading system includes tape lever components, follow-up pulley and drive components, force control actuators, fixed pulley and cable components, and support structures. At the same time, a loading control system was also designed. The dynamic loading system can simulate the deformation of flaps under distributed aerodynamic loads during the entire retraction and extension process, greatly improving the fidelity of the test environment and comprehensively assessing the interference between flaps and surrounding structures under all operating conditions.
Aerial refueling rendezvous routes for UAVs based on nonlinear guide laws
Authors: Wang Yipeng , Song Yujian , Zhang Deyue , Wang Guanglin
Published: December 2023

The route fusion rendezvous strategy is mostly used for air refueling within the safety zone, with fewer restrictions on the rendezvous airspace. There are fewer restrictions on the combined airspace. The refueling aircraft follows a set route, and the UAV gradually converges with the refueling aircraft by adjusting its own course. The UAVs gradually merge with the fueler’s route until they track the fueler to a certain distance behind the fueler and synchronize with the fueler’s status. The subsequent docking process is carried out.

The fused route design is analogous to the use of missiles to track and strike moving targets. The unmanned aircraft are treated as pursuers moving at high speed. The fueling aircraft are treated as targets moving in a fixed pattern to be returned. The main objective of the convergent route design is to draw on and select appropriate guidance laws to bring the unmanned aircraft close to the fuel tanker. The main objective of the route fusion design is to use and select a suitable guidance law that allows unmanned aircraft to approach the fueling aircraft and achieve autonomous rendezvous. The traditional navigation laws are Pure Pursuit (PP) and Proportional Navigation (PP). The basic idea is to change the speed vector of a drone by varying its size. The difference is that the pure tracking guidance law requires the speed vector of the drone to coincide with the line of sight. In contrast, the example guidance law starts from the fact that the angular rate of rotation of the drone’s speed vector and the ratio guiding law is to keep the angular rate of rotation of the speed vector of the drone and that of the target in a fixed proportion.
Performance Simulation of Thermodynamic Design for a New Turboshaft Engine
Authors: He Dongjing , Zhang Rui , Wen Cheng , Teng Jianliang
Published: December 2023

For a search and rescue (SAR) helicopter, the requirements of long-range and twin-engine are becoming increasingly important. In this paper, the overall performance of a new turboshaft engine for SAR helicopters is simulated. Firstly, the main performance parameters of competitor engines are collected and compared, and the thermodynamic cycle parameters of the new engine are proposed subsequently. Then, an engine model is created in Turbomatch and the overall performance of this model at the design point is calculated. Finally, the off-design performances at different conditions of output power, ambient temperature, altitudes and flight Mach numbers (Ma) are investigated. A strategy of variable stator vane (VSV) for the anti-surge control of the axial compressor is also introduced. The results of the performance simulation indicate that this engine is quite competitive with lower specific fuel consumption (SFC) and higher specific power (SP) compared to the current SAR helicopter engines.
Flow Characteristics of Gas-Liquid-Solid Three-Phase Flow in Civil Aircraft Waste System Study on Simulation Calculation
Authors: Zhang Yuying
Published: December 2023

The civil aircraft wastewater treatment system collects the aircraft toilet wastewater, hand washing grey water, and galley grey water into the waste water tank to solve the health and physiological needs of members on board. In this paper, taking the long branch of the waste system of civil aircraft as the research object, 1:1 modeling was carried out, and the multiphase flow of the long branch of the waste system was numerically simulated by using the CFD-DEM calculation model. The gas-liquid-solid three-phase flow form and flow characteristics of the long branch of the waste system were analyzed. The results show that under the conditions of a liquid-solid ratio of 2.5:1 and a system pressure difference of 55158 Pa, the total flow time of the solid phase is 1.6 s and the total flow time of the liquid phase is 1.95 s, which meets the design control time of 4 s for the long branch of the waste system. For the cross-sectional velocity of the pipeline, the gas velocity is greater than that of the liquid, and the liquid velocity is greater than that of the solid. The study on the flow performance of civil aircraft wastewater systems can provide theoretical support for the development of wastewater systems.
Research on Modal Test Method for Civil Aircraft Structure
Authors: Ni Junfei , Li Jun
Published: December 2023

In the process of civil aircraft development, it is of great significance to carry out a modal analysis of aircraft component structures and obtain modal parameters to verify whether the dynamic characteristics of aircraft structures meet the design requirements. This paper takes the structural modal of aircraft components as the research object and proposes the modal test method of aircraft structure, which provides effective modal test data support for the design and optimization of aircraft component structure.
Ppy-decorated graphene oxide: Synthesis and analysis of surface, structural and optical properties
Authors: Loyalka Swarnkesh , Dangi S. B. , Quraishi A. M. , Hashmi S. Z. , Singh Jasgurpreet , Singh A. K. , Alvi P. A.
Published: December 2023

Here, we have syntheized Ppy (Polypyrrole) decorated GO (graphene oxide) and investigaed its morphological and optical characteristics. For fabrication of nanocomposites, in-situ polymerization technique was used. The crystalline size and strain of the synthesised sample were determined using an X-ray diffractometer (XRD). The surface morphology of the nanocomposites was investigated using field emission scanning electron microscopy (FESEM). The optical bandgap and PL spectra of the synthesised sample were examined using a photospectrometer and photoluminescence (PL) technique. The calculated crystalline size was ~ found as 5.91 nm with strain ~ 0.33907. In PL spectra, two peaks were found at ~ 430 nm and ~ 500 nm. The direct bandgap was calculated as~ 2.22 eV (visible region). Insights into their structural and optical characteristics are gained from the synthesis and characterization of PPy decorated GO nanocomposites, opening the door for further research and application in a variety of fields.
Electrical and gamma ray shielding properties of phospho-tellurite glasses doped with alkali and transition metal oxides
Authors: Pallavi J G , Sankarappa T , Amarkumar M , Ashwini D , Mohansingh H , Aravind D , Raghavendra B
Published: December 2023

This article presents investigated results on physical, electrical and gamma radiation shielding properties of glasses of composition, (P2O5)0.25-(TeO2)0.5-x-(Na2O)0.1- (ZnO)0.15-(CoO)x (x= 0.10, 0.15, 0.20, 0.25, 030 and 0.35) were synthesized by melt quenching procedure. After confirming non-crystallinity, density was measured and found it to be decreased with increase of CoO concentration in the range 4.0370 gm/cm3 - 3.5673 gm/cm3. Molar volume, mean distance between TMIs, small polaron radius, oxygen packing density and field strength were estimated. Conductivity was measured in the temperature range 303K -663K. High temperature conductivity is found to be varied as per Mott’s (SPH) model. High temperature activation energy is found to be increased with CoO content. Low temperature conductivity variation has been analyzed using Mott’s (VRH) model. Gamma ray shielding parameters were evaluated using Phy-X/PSD software for the energy range 0.005 MeV-15 MeV. The mass and linear attenuation coefficients were found to decrease with CoO content and photon energy. Half and tenth value layers increased with increase of mole fractions of CoO. All the observed shielding parameters are superior to those reported previously for other glasses. The glass with x=0.10 is best suited for the utility of gamma shielding at low energy.
Coupled plasmon-LO-phonon modes in the ground state of a GaAs-based electron-electron biwire system
Authors: Puttar Devi , Rani Preeti , Verma Vishal , Garg Vinayak
Published: December 2023

We study the coupled plasmon-longitudinal optical-phonon (pl-LO-ph) modes in a GaAs-based electron-electron (e-e) biwire system at absolute zero within the dynamic mean-field approximation of Singwi and others (popularly known as the qSTLS theory). Here, in addition to the standard electron-electron (e-e) interactions, we also take into account the electron-phonon (e-ph) coupling and calculate pl-LO-ph modes at some selected values of wire-width, inter-wire separation and electron number density. The coupled modes are found to resonantly split into eight branches, four of which lie outside and four inside the electron-hole (e-h) pair continuum. Out of four branches which exist above the e-h pair continuum, two are plasmon-like modes having energies below than that of transverse optical (TO) phonons, and the other two are phonon-like modes having energies above longitudinal optical (LO) phonons. Additionally, we compare the plasmon-like modes with true plasmons (resulting only from the typical e-e interactions) and note that the e-ph coupling softens the true plasmon modes.
Study of Superconductivity in Restricted Quantum Chromo-Dynamics in non-Abelian Gauge Theory
Authors: Preeti  , Samandeep  , Mahajan Neelu
Published: December 2023

An Abelian Higgs model with dual superconductivity and confinement has been constructed and its string representation is described in terms of the average of Wilson loops in this QCD Abelian projection. Investigations has been carried out on monopole condensation and chromo-magnetic superconductivity within the framework of restricted quantum chromodynamics in the SU(2) gauge theory.
Role of site symmetry in photoluminescence spectrum of Eu2+ doped phosphors - A review
Authors: Singh Pradyuman , Nagpure I. M.
Published: December 2023

The role of site symmetry is one of the important parameters in the emission spectrum of the phosphor. The emission from the phosphor can be tuned due to alteration in the site symmetry by selecting appropriate synthesis procedure. The spectral shift in the emission spectrum can be achieved by variation in the coordination number (CN) or by tuning symmetry in a coordination environment. Few reported phosphors such as Eu2+ doped Ca3Mg3(PO4)4, Ba2CaMg2Si6O17 and Ca3Al2O6 where the spectral shift is noted are used in this review for the analysis.