bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aircraft Nose Landing Gear Shimmy with Nonlinear Tyre Models
Authors: guo xiangying , nan tian , chen yao , zhang weixing , cao Dongxing 
Published: November 2024

Abstract

In this study, an application of a nonlinear tyre model is considered in the analysis of aircraft nose landing gear shimmy. An aircraft single-wheel nose landing gear system is used to analyse the shimmy stability, where the tyre model is designed to account the nonlinear relaxation length by the two-degree-of-freedom model, as well as the nonlinearity of the tyre contact patch. This improvement takes into account the nonlinear relaxation length of the tyre and the time-varying changes in the tyre contact path due to large amplitude vibrations. The system is analysed using nonlinear bifurcation methods, and the results indicate that the nonlinear tyre model exhibits greater amplitude and extends the velocity range for shimmy occurrence. Simultaneously, the bistable region where coupled shimmy oscillations occur also shifts downwards, indicating a greater tendency for coupled oscillations involving lateral bending shimmy oscillations and torsional shimmy oscillations. Moreover, evaluate the differences between two tyre models and the results show that the new nonlinear tyre model can allow for better and more accurate predictions of shimmy behaviour and potential oscillation amplitude based on varying environmental factors. From the perspective of shimmy prediction and prevention, the application of this new model in shimmy analysis enhances aircraft safety redundancy and increases overall safety.
Structural and morphological analysis of lead oxide nanoflowers and nanorods prepared under different reaction times, pH, and simple method
Authors: Yazdani-Darki Sepideh , Eslami-Kalantari Mohammad , Zare Hakimeh 
Published: November 2024

Abstract

This study aims at the effects of pH variation and reaction time on the dimension and morphology of lead oxide (PbO) nanostructures grown through a simple low-temperature method without using any surfactants. It has been shown that the growth of PbO with different morphologies such as flowers and rods can be controlled by simply changing the reaction time and pH. During the growth process, the pH of the reaction gradually changed from 12 to 14. The prepared samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The growth process can be initiated in favorable conditions like a pH of 14 and reaction times of 5 and 7 hours, and the petal-like PbO nanostructures began to appear. It indicates that weak alkaline conditions are required to obtain nanorods with well-defined tetragonal or orthorhombic facets. The growth of PbO nanorods is greatly influenced by the competition between crystal growth and etching. It has been found that PbO nanoflowers contain many radial plates with a diameter of 32 µm and PbO nanorods contain many radial nanorods with a diameter of 157 nm and a length of 12 µm. The formation mechanism of flower and rods-like PbO nanostructures can be explained based on the common theory of crystal nucleation and crystal growth direction.
Sensitivity of quantum dot semiconductor lasers to optical feedback by open loop system.
Authors: Mahdi Mayyadah Qable , ghalib basim abdullattif , AL-mamoori Mohammed H. K. 
Published: November 2024

Abstract

This research shows that the line width enhancement factor in quantum dot lasers is affected by the time delay that is produced through optical feedback in the case of an open ring system for lasers and the length of the external cavity. It uses a model of the rate equation for semiconductor lasers, transmitter and receiver, and studies the dynamic characteristics of the laser output and the effect of each current. Injection, linewidth enhancement factor, delay time, and external cavity length, based on the results that appeared when choosing the value of the linewidth enhancement factor (α = 2), a time delay of (100–500) ps, a time difference of 10 ps, ​​and an injection current (1.5, 2.5, 4.5) multiplied by Threshold current and the study of the relationship between photon density and time and the relationship between photon density for both the transmitter and the receiver, in addition to the relationship between the occupation factor for both the transmitter and the receiver and its relationship with time and its effect on the output behavior of the quantum dot semiconductor laser in the transmitter and receiver lasers, where it is in several cases and may sometimes be Stable and may be periodic, semi-periodic, multi-periodic, or random (chaos).
Marriage Selection Criteria in Korea: What an economic shock reveals about the marriage selection criteria
Authors: Lee Jin Hyung , Kum Hyunsub 
Published: November 2024

Abstract

This study investigates how marriage selection criteria such as education and family’s economic status have evolved according to economic surroundings in South Korea. We find from the examination of longitudinal data that when returns to investment in higher education diminish and economic hardship occurs, the social mix is prevalent with respect to the educational level as a marriage selection criterion but an alternative criterion such as family’s economic status is paid attention to.
JEL Classification: D31, J11, J12
Trends and Research Fields in Digitalization: A Bibliometric Review Approach
Authors: ALFAWAREH FARAJ , alfawareh Nawwaf , Fayad Abdallah F.S. , Domai Ammar 
Published: November 2024

Abstract

This study aims to highlight contemporary trends in existing literature on digitalization via bibliometric approach using the Scopus database. Digitalization research trends are investigated using bibliometric analysis via the Scopus database. Microsoft Excel is used to perform frequency analysis, VOSviewer is employed to conduct data visualization, whilst Harzing’s Publish or Perish is utilized to analyze the citation metrics. This study identifies the most popular publication trends, the most popular subject area, the most cited articles, the most active authors, the most prominent keyword analysis, the most active countries, the top document and the source type, the top source title, the most active funding institutions, and the most active institutions. Notably, the most active country producing digitalization research is Germany; the most active publishing institution in the digitalization field is Russia’s Peter the Great St. Peterburg Polytechnic University; and the most active author with 47 published papers on digitalization is Dumitrescu, R. These results indicate that digitalization is presently trending and is expected to continue so in the coming years. The study’s data collection depends on a single source, namely the Scopus database. But the results derived give a thorough understanding of digitalization and an overview of its research trends. This work can assist academic researchers, developers of digitalization, policymakers, and regulators in understanding more about this field on top of identifying areas for further examination. This paper sheds light on the current state of the field of digitalization, combining methodological approaches and valuable insights for future research. Furthermore, it serves as a starting point for professionals to fully understand the characteristics and potential of digitalization through a bibliometric approach.
Cohesive instability in elastomers: Insights from a crosslinked Van der Waals fluid model
Authors: Lamont Samuel C. , Vernerey Franck J. 
Published: November 2024

Abstract

The resistance to volumetric deformations displayed by polymer networks is largely due to secondary and tertiary interactions between neighboring polymer chains. These interactions are both entropic and enthalpic in nature but are fundamentally different from the entropic forces that resist shearing in these networks. In this paper, we introduce a new depiction of elastomers as a crosslinked Van der Waals fluid. Starting from first principles, we develop constitutive equations that are implemented in a continuum model as well as a discrete network model. Our models predict that the failure of polymer networks may be driven by an instability in the underlying polymer bulk 'fluid' or by the breaking of polymer chains, depending on the loading path taken. The results of this study indicate that material failure in elastomers exposed to a purely triaxial state, such as in a poker chip experiment, may be driven by an entirely different mode of instability than those deformed in pure shear, such as in a uniaxial tension experiment.
Multi-keyword Searchable Encryption Scheme with Policy Hiding Support for User Revocation in Cloud Environment
Authors: Zhang Xuan , Cao Suzhen , Liu Guorui , Han Lei , Zhang Tianhao 
Published: November 2024

Abstract

In the current cloud computing environment, attribute-based access control must ensure that only authorized users can access specific sensitive data. However, the access control policies of existing solutions usually exist in plaintext form, which carries the risk of information leakage. In addition, in scenarios that require dealing with complex attack environments, its security may also be insufficient. To address these issues, we propose a dual system based multi keyword searchable encryption scheme that supports policy hiding and user revocation. In order to achieve partial concealment of access policies, user attribute values are encrypted and attribute names are attached to the ciphertext uploaded to the cloud service provider. The cloud service provider can see the names but cannot access the attribute values, effectively concealing sensitive information of access policies. The user's attributes and version number are verified by a third-party audit server. Ensure its legal authorization, only audited users can obtain the necessary ciphertext for decryption, which not only enables user revocation but also effectively prevents collusion attacks between users. Security analysis shows that this scheme utilizes a dual system encryption scheme under a fully secure model and has been proven to effectively resist keyword guessing attacks and user collusion attacks based on deterministic assumptions. According to security analysis and experimental results, the proposed solution achieves flexible cloud data storage and access while also improving security, meeting the requirements of complex cloud environments.
Crime analysis Addis Ababa sub-cities, reflecting the impact of policing efforts, and community involvement in crime prevention
Authors: Alehegn Derese , Ramasay Karunakaran , Engeda Banteyrgu 
Published: November 2024

Abstract

This research analyzes crime trends across sub-cities in Addis Ababa over the years 2018–2022, focusing on how policing strategies and community involvement have influenced crime patterns. The study identifies fluctuations in crime rates, highlighting the impact of, post-pandemic challenges, and ongoing security efforts. Kirkos, Addis Ketema, and Arada display distinct trends that reflect localized policing efforts and varying levels of community participation. Findings indicate that while certain efforts have been effective, there is a need for improved community engagement and real-time monitoring to ensure sustainable crime reduction. Recommendations include refining targeted interventions and strengthening partnerships between law enforcement and residents.
Research on the Prediction Model of Material Removal Rate in the Magnetic Abrasive Finishing Process
Authors: Liu Bingyang , Ding Yunlong , Yan Yuhang , Han Bing , Chen Yan 
Published: November 2024

Abstract

As an advanced precision machining process, magnetic abrasive finishing (MAF) technology can be applied to grind complex workpieces. However, it’s not conducive to formulate an appropriate processing that MAF processing on tubular workpiece has a severe lack of well defined material removal model. In order to solve this problem, the contact form between magnetic abrasive and workpiece surface was simplified, and the force analysis of magnetic abrasive in the magnetic field was performed. Furthermore, an ideal predictive model on material removal rate was proposed, which was based on both the quantity of active abrasives in the processing area and the depth at which magnetic abrasive was pressed into the workpiece. The correction factor 'k' was determined based on the comparison and analysis of experimental results and theoretical predictions. What’s more, the accuracy of the revised model on material removal rate was confirmed. The surface roughness of workpiece was reduced from 0.213 µm to 0.058 µm after undergoing 19 cycles of processing under the conditions of spindle speed of 1000 rad/min, abrasive mass of 3.5 g, machining gap of 2 mm, and a feed rate of 3 mm/s. The material removal rate was 0.140 µm/min, which exhibits an absolute error of 7.675% in comparison to the predicted value of 0.152 µm/min. The results indicate that the model can meet the prediction requirements of material removal rate in MAF process, and MAF technology can effectively achieve finishing on the inner surface of pipes.
Compact Metasurface-Based Circularly Polarized Reconfigurable Antenna
Authors: Nguyen-Dinh Thai , Le-Tuan Tu , Nguyen-Quoc Dinh , Tran-Huy Hung 
Published: November 2024

Abstract

A circularly polarized (CP) reconfigurable antenna with a compact size is presented in this paper. The proposed antenna can produce a unidirectional beam whose polarization is switchable between left-hand CP and right-hand CP. The proposed design consists of 2 × 2 unit cells as a primary radiating aperture and a switchable CP source. The polarization reconfigurability is achieved by turning ON/OFF two pin diodes. It is noted that the biasing wire and the diodes are positioned in the switchable feeding network rather than the radiating element to avoid unwanted radiation, which might cause negative effects on the antenna's radiation performance. Measured results show identical operation characteristics for both polarization states. The common operating bandwidth between RHCP and LHCP states is from 2.44 to 2.47 GHz. The measured broadside gain is about 4.6 dBic. Compared with other related works, the proposed antenna can provide dual CP with the smallest number of pin diodes and the most compact dimensions.
Perceptions and attitudes regarding robotic total hip arthroplasty: a patient stakeholder survey
Authors: MD Hassaan Abdel Khalikm , Selznick Asher , Bali MBBS FRCSC MSc MS Kamal , Amini Yasaman , Tate MSc Isabelle , Wood MD MSc F Thomas J 
Published: November 2024

Abstract

Purpose:
To describe the attitudes and preferences of patients pertaining to robotic-assisted total hip arthroplasty (RA-THA) with the long-term objective of designing a prospective randomized-controlled trial (RCT) to evaluate the efficacy of RA-THA compared to conventional technique.
Methods:
A cross-sectional survey of patients attending an outpatient high-volume academic arthroplasty clinic chosen was administered from December 2023 to May 2024. The survey was comprised of 31 items including patient demographic, patient reported factors of significance and perceptions surrounding RA-THA.
Results:
Ninety-seven patients completed the survey with a mean age of 67.5 ± 9.1 years and with 63% of patients being female. The majority of respondents were not at all familiar with RA-THA (69%). Common perceptions of RA-THA compared to conventional technique included a smaller incision (41%), lower chance of developing infection (47%), shorter length of surgery (41%), less blood loss (41%), lower cost (22%), shorter length of stay (30%), more precise implant positioning (46.8%), lower post-operative pain (29%), and lower post-operative complications (36%). Very important outcomes to be assessed in future investigations included post-operative range of motion (91%), implant longevity (91%), dislocation risk (90%), post-operative pain (89%), and infection risk (87%).
Conclusion:
Patient familiarity with robotic-assisted total hip arthroplasty is low. Patient perceptions regarding RA-THA compared to conventional technique are favorable, despite limited evidence to date. Important factors to be assessed in future RCTs include range of motion, implant longevity, dislocation risk and infection risk. Findings of this study can inform a clinically relevant RCT assessing RA-THA compared to conventional technique.
Study on the Surface Characteristics and Anti-icing Properties of PDMS Micro- and Nanostructres Imitating Bamboo Leaf Surface
Authors: Sun Hongwen , Wang Ruobing , Shen Jie , Gu Lijun 
Published: November 2024

Abstract

The formation of ice on solid surfaces can occasionally culminate in dire repercussions. Nature's own bamboo leaves present an excellent biomimetic blueprint for the conception of anti-icing micro- and nanostructured surfaces. This work leverages polydimethylsiloxane (PDMS) to emulate the intricate surface architecture of bamboo leaves. The surface morphology characteristics of both bamboo leaf mold and its replica were characterized using an Atomic Force Microscope (AFM). The AFM analysis revealed that the micro- and nanostructures adorning the replica surface were predominantly arranged in a needle-like fashion, with an average surface roughness of 46.4 nanometers. The freezing temperature of the PDMS surface was 2.8°C lower than that of an untreated planar surface. The textured surfaces demonstrated an increase of approximately 21% in the delayed freezing time compared to their non-textured counterpart. This research offers a novel approach to the research of anti-icing surface design.
Equation of State for Solid Argon Valid for Temperatures up to 760 K and Pressures up to 6300 MPa
Authors: Xiao Xiong , Sriskandaru Sakimsan , Maynard-Casely Helen E. , Thol Monika , Falloon Peter , Span Roland , May Eric F. 
Published: November 2024

Abstract

Thermodynamic property data for solid argon have been analysed to construct a new fundamental equation of state (EOS) based on the Helmholtz energy. This approach is based on methodologies previously applied to solid CO₂ and benzene [J. Phys. Chem. Ref. Data 40, 043105 (2011); 50, 043104 (2021)]. The EOS is capable of predicting thermodynamic properties of solid argon up to 760 K and 6300 MPa, using temperature and cell volume as independent variables. The model incorporates the quasi-harmonic approximation with a Debye oscillator framework for vibrons, along with an anharmonic term to address deviations near the triple point. In addition to literature data, the model was regressed to new measurements of argon’s solid cell volume conducted from (8 to 50) K using a high-intensity neutron diffractometer, the results of which are reported here. This new EOS achieves a high degree of accuracy in representing experimental data, with uncertainties (k = 1) estimated of 0.1%, 0.5%, and 0.5% for the cell volume along the sublimation curve, along the melting curve, and in the compressed solid phase, respectively; 2% to 10% for the heat capacity along the sublimation curve in different temperature regions; 1% to 10% for the thermal expansivity on the sublimation curve; 2% for the isothermal bulk modulus, 1% for the isentropic bulk modulus, 0.2% for the enthalpy of sublimation, 0.5% to 2% for the enthalpy of melting, 1% for the sublimation pressure (T > 50 K), and 2% to 5% for melting pressure. The EOS maintains physically realistic behaviour across the range of conditions from absolute zero to high-pressure.
Discovering Associations Among Technologies Using Modified TFIDF
Authors: Alaeiyan Mehdi , Salemi Abolfazl , Alaeiyan Mohammadhadi 
Published: November 2024

Abstract

In contemporary times, the genesis of new and efficient innovative ideas necessitates a comprehensive understandingof various technologies. Given the extensive data inherent in these technologies, it is imperative to employ automatedmethods to elucidate the interconnections among them. This article endeavors to delineate the associationsbetween disparate technologies within a specific industry. To uncover these associations, we have utilized a generalizedapproach to Term Frequency-Inverse Document Frequency (TFIDF) across a broad spectrum of textual data,such as scholarly articles. These associations are represented in the guise of a weighted graph, wherein the verticescorrespond to individual technologies, and the edge weights quantify the degree of association between pairs of technologiesin percentage terms. This graphical representation, known as the ’association tech-graph,’ is instrumentalin the analysis and advancement of technological innovation within the industrial sector. Our proposed model is parameterized,engendering a variety of graphs contingent upon the values assigned to these parameters. A meticulousevaluation of these parameters, while increasing computational complexity, enhances the precision and accuracy ofthe resultant graph.
High risk of short-term mortality and postoperative complications in patients with generalized peritonitis undergoing major emergency abdominal surgery - a cohort study
Authors: Olausson Maria , Tolver Mette A , Gögenur Ismail 
Published: November 2024

Abstract

Background
Secondary generalized peritonitis is a potentially life-threatening condition. The aim of this study was to investigate the association between secondary generalized peritonitis and short-term mortality and postoperative complications in patients undergoing major abdominal emergency surgery.
Methods
The study included patients with the age ≥ 18 years undergoing major emergency abdominal surgery in a University Hospital from 2017 to 2019 after the introduction of a perioperative bundle care program. The primary outcome measures were short-term mortality, defined as death within 30 and 90 days after surgery and postoperative complications within 30 days after surgery. Uni- and multivariable logistic regression analyses were performed to evaluate risk factors for 30- and 90-days mortality and 30-days postoperative complications.
Results
A total of 591 patients were included, of whom 21% (124/591) had generalized peritonitis. The overall 30 day-mortality rate was 12.5% (74/591). Patients with generalized peritonitis had a significantly higher 30-day mortality rate than patients with non-generalized peritonitis 18.5% (23/124) vs. 10.9% (51/467), P < 0.033. Generalized peritonitis was an independent risk factor for 30-day mortality. There was a significantly higher rate of admission to ICU for patients with generalized peritonitis 39.5% (49/124) vs. 12.6% (59/467), P < 0.001. Patients with generalized peritonitis were significantly more prone to get both a surgical and non-surgical complication compared to patients with non-generalized peritonitis 87.1% (108/124) vs. 65.7% (307/467), P < 0.001.
Conclusion
In a population undergoing major emergency abdominal surgery treated in a perioperative optimization protocol, generalized peritonitis was an independent risk factor for both 30- and 90-days mortality and postoperative complications.