bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review and aerodynamic analysis of NACA 2415 morphing wing for variable span and scale morphing concepts using CFD analysis
Authors: Kabir A , Al-Obaidi A S M , Myan F W Y 
Published: July 2023

Abstract
Morphing wings made a significant advancement in aircraft engineering by improving aerodynamic performance for better fuel efficiency and are still under research. This paper reviewed and investigated some morphing wing types including the variable sweep, trailing edge, leading edge, variable span, variable chord, or scale, and airfoil morphing among others. Based on the review, two types of morphing wings were chosen for detailed investigation, and they were variable span and variable scale. Each morphing concept from the selected morphing wing types was implemented in airfoil wing configuration for aerodynamic performance analysis. Computational Fluid Dynamics (CFD) simulation is used to design and analyse morphing wing configurations of the chosen morphing concepts. In this research, two CFD analyses were investigated based on wing configuration; each consists of chosen morphing concept. Before the main CFD simulation of morphing wing analysis, CFD analysis of reference data of a typical NACA 2415 airfoil was verified. The lift coefficient of the morphing wing obtained from CFD analysis was compared with the unmorphed NACA airfoil wing to evaluate the morphing wing’s aerodynamic performance. It is concluded that there is an improvement in lift coefficients using the morphing concept cases, showing improved aerodynamic performance.
A preliminary study of chemical property and thermal stability of potassium chloride encapsulated in starch-alginate matrix
Authors: Chen Ying Si , Phang Siew Wei , Shuib Anis Suhaila 
Published: July 2023

Abstract
A potassium controlled-release fertilizer was fabricated in a starch-alginate matrix by using calcium chloride as a cross-linker. 16 formulas were designed with varying amounts of alginate and potassium chloride with the same amount of starch and calcium chloride, and most of the formulas can form beads successfully. High sodium alginate and low potassium chloride assembled better shape and higher encapsulation efficiency. The highest encapsulation efficiency ratio of starch, sodium alginate, and potassium chloride was 5:1:10 in the 16 formulas. The bonding of alginate and starch, and calcium chloride were evidenced by FTIR, and the study of TGA revealed good thermal stability and compatibility between the polymers and potassium chloride.
Integrated smart public parking system for Malaysia
Authors: Qi Low Zhi , Tien Douglas Tong Kum , King Phang Swee 
Published: July 2023

Abstract
Searching for unoccupied parking spots is a challenge in most modern cities. The increase in the number of vehicles, limited parking spaces and low-speed parking search exacerbated traffic congestion. Consequently, smart parking system solutions have grown in popularity. Smart parking systems were developed in the early 2000s and have advanced to help with parking issues in various countries. In Malaysia however, there is slow adoption of smart parking systems although the need is equally urgent. The aim of this study is to investigate the feasibility of applying a parking spot detection system using cameras installed on lampposts for outdoor public parking in Malaysia. This study aims to demonstrate that a system of lesser complexity can be useful. The proposed solution combined parking spot detection with timing of the parking duration to help drivers monitor their parking time. This can be achieved using image detection and applying filters to identify the occupancy of parking spots. Real-time occupancy data is then exported with an excel file and this data is saved for further study and application development.
Impact of camber angle on the tire tread behaviour in different road conditions
Authors: Djap S , Ku P X 
Published: July 2023

AbstractThe camber angle is one of the wheel alignment properties that is crucial as a slight change to the orientation of the camber angle determines the lifespan of a tire. The stress distribution on the innermost of a tire increase as the positive camber angle is increased, and vice versa, which causes the abnormal uneven premature wear of the tire. This research is done with the main objectives to simulate the performance of tires concerning the camber angle by using the finite element analysis method, and to study the influence of camber angle on different tire tread patterns under two different road conditions, i.e., smooth road and irregular road. Three tire models with different tire tread patterns and two different road conditions are developed using SolidWorks while the investigation of each tire performance is done through ANSYS under static condition in this research. Tire inflation analysis is performed using static structural analysis feature available in ANSYS where the total deformation and equivalent stress are determined based on the specific vertical load applied onto the tire, ignoring any damping effects and inertia. Boundary conditions and other relevant constraints are applied, and then mesh independent test is carried out to all tire models prior to performing the simulation. Based on the simulation results, the maximum total deformation increases as the camber angle increases in both road conditions, while the maximum equivalent stress does not show any trend. It is concluded that tire tread pattern influences the maximum equivalent stress experienced by the tire.
Mechanical Performance of 5-speed Manual Transmission Gearshift Bracket
Authors: Wong J Y , Abu Bakar N Z , Meera Hussain H 
Published: July 2023

Abstract
The main purposes of a gear shift bracket for manual transmission are to hold the gear shift cables and acts as pivot during the gear shifting process. During the gear shifting process, the bracket experiences push and pull reciprocating forces which applied by the driver while selecting or shifting gears. This study presents the development of a simulation model to analyze the mechanical performance of a specific manual transmission gearshift bracket. Based on the simulation results, an optimized bracket design was proposed. Commercial CAD software and Finite Element (FE) Method software were used to perform the simulation. Boundary and initial conditions were applied to the FE model which was based on the real-life mechanical movement of the bracket during gear shifting process. The boundary and initial conditions included fixed position, displacement and both select and shifting loads by following actual test requirements which replicated the movement of the actual model during gear shifting process. Specific mechanical ratio formula was used to obtain the magnitude of loads that was experienced by the gear shift bracket in both select and shifting gears action. The simulation of the gearshift bracket provided outcome parameters such as total deformation, maximum stress and safety factor value. Based on the safety factor value, the model was eligible for topology optimization process and it was modified to gain the optimized model. Then, the same simulation setup was used for the optimized model. The modified design bracket was able to provide a 7% reduction in mass, a 25.15% increase in maximum deformation, a 46,78% increase in maximum stress and, a 36.74% decrease in safety factor value by comparing it to the original model. Although the modified model has lower strength, but its safety factor value is still within the minimum requirements. This concludes that the simulation model allows the manufacturer to undertake design iteration and analyze its performance without producing any physical prototypes and conduct any actual test, thus saving development cost and time.
Study on the performance characteristics and failure analysis of exhaust valves
Authors: Yong M F , Ku P X 
Published: July 2023

Abstract
Exhaust valves are a type of valve that can commonly be found in the top section of the cylinder block in an engine. When failures occur on the exhaust valve, the engine has a high possibility to result engine failure or breakdown. This will affect the user where the user requires to spend a huge amount on repairing costs or engine replacement. Thus, this research aims to investigate the effect of the exhaust valve’s material on its performance and identify the appropriate material which could increase its fatigue life in a four-stroke internal combustion diesel engine. A three-dimension (3D) Computer-aided design model of the exhaust valve was generated by using SOLIDWORKS and undergo static structural analysis as well as thermal analysis. The measure variables are von-mises stress, total deformation, temperature, total heat flux and directional heat flux by using ANSYS Finite Element Analysis. Stainless steel 304 alloy and Aluminium-Silicon Carbide (Al-Sic) materials are the manipulated variable that was applied to the 3D CAD model exhaust valve to undergo all the analyses. Before performing all the analyses, the appropriate mesh method and mesh sizing was identified by referring to the mesh metrics spectrum and performing a mesh independence test. The results from the analysis were collected and tabulated for comparison and discussion purposes. From the analysis, the maximal thermal stress was determined in the valve stem region. By appointing Stainless Steel 304 alloy on the exhaust valve, the durability and the fatigue life are improved as the material can achieve a smaller value of temperature distribution, total heat flux, total deformation, and higher von-mises stress. This research provided a better understanding of the effect of an exhaust valve material on its performance characteristic.
Singularity resolving in solution of the boundary integral equation in two-dimensional vortex methods
Authors: Izmailova Yulia , Marchevsky Ilia , Sokol Kseniia 
Published: July 2023

Abstract
The problem of 2D incompressible flow simulation around airfoils with sharp edges and corner point is considered. The solution of the boundary integral equation with respect to vortex sheet intensity arising in Lagrangian vortex method has weak singularity that cannot be resolved correctly in the framework of the existing Galerkin-type numerical schemes. It is shown that for piecewise-smooth bounded solutions the known schemes allow for solution reconstruction with high quality and provide the 2-nd order of accuracy, while for singular solution their order of accuracy goes down to the 1-st. A numerical scheme is suggested that allows for solution singularity resolving and provides the 2-nd order of accuracy. As a model problem, the added mass tensor components computation is considered, since its exact value is known for the Joukowsky wing airfoil with sharp edge (cusp point).
Hybrid Barnes – Hut/Multipole algorithm application to vortex particles velocities calculation and integral equation solution
Authors: Kolganova Alexandra , Marchevsky Ilia , Ryatina Evgeniya 
Published: July 2023

Abstract
The approximate fast algorithm is developed that makes it possible to calculate velocities of the vortex particles in two-dimensional flow simulations by using vortex methods. It is adapted to efficient solution of the boundary integral equation arising at each time step of simulation. The proposed method can be considered as generalization of the classical Barnes – Hut method, taking into account some ideas of the Fast Multipole Method. Some model problems are considered that can be solved by using vortex methods, the developed fast algorithm is implemented for multi-cores CPUs and (with some modifications) for GPUs. The scalability of the code is rather high; the developed algorithms can run with millions of vortex particles taking only tens or hundreds of milliseconds per time step; linear systems with dimension of about 104 can be solved on multicore CPU in tens milliseconds.
Readout electronics for the CEPC vertex detector prototype and beam telescope
Authors: Yan Z. , Hu J. , Wu T. , Zhou J. , Li S. , Zhang X. , Huang X. , Hu Y. , Wang W. , Liang Z. , Wei W. , Zhang Y. , Wei X. , Zhang L. , Qi M. , Zeng H. , Jia X. , Zhou X. , Guimarães da Costa J. , Fu J. , Zhang H. , Li G. , Wu L. , Dong M. , Li X. , Casanova R. , Zhang L. , Dong J. , Wang J. , Zheng R. , Lu W. , Grinstein S. 
Published: July 2023

Abstract
The proposed Circular Electron Positron Collider (CEPC)
imposes unique requirements on the vertex detector. In response, the
MOST1 and MOST2 projects were launched with the aim of developing a
fully functional pixel sensor and implementing the prototype of the
inner tracking detector. To efficiently manage the data flow from
multiple sensors, specialized readout electronics are required. In
order to evaluate the MOST2 project indicators set for the vertex
detector prototype, a beam telescope was constructed using six
TaichuPix-3 sensor chips and applied in different experiments. The
experimental results demonstrate that the telescope functions
effectively and that the detector prototype meets the design
objectives of the MOST2 project. This project encompasses the design
of the readout electronics, the functionality of the readout system,
the architecture of the telescope, and the specifics of the
telescope experiments.
Highly dynamic X-ray image enhancement based on generative adversarial network
Authors: Yan Hongxu , Liu Yi , Ding Xiaxu , Zhang Haowen , Bai Qiang , Zhang Pengcheng , Gui Zhiguo 
Published: July 2023

Abstract
When using X-ray to detect industrial workpieces, the images
obtained frequently have low contrast, making it difficult to detect
defects. This paper proposes a GAN-based X-ray image enhancement
network to address this issue. In detail, the X-ray image is
concatenated with its antiphase image (as an exposure mask) as the
input image, and a trainable Sobel operator is used to extract the
edge features of the input image. The input image and edge features
are then concatenated and fed into the U-Net generator to be
enhanced. The spatial and channel attention models are used to
adjust feature weights in U-Net, and a detail extraction network is
designed to extract detail features from the input X-ray
image. Furthermore, the extracted detail features are fused with the
image by the generator after contrast stretching to produce the
final enhanced image. Finally, a global-local discriminator is used
to discriminate the authenticity of the image so that the contrast
of the final obtained image is improved and the details are
highlighted. Following experimental validation, the method proposed
in this paper has a significant enhancement effect on industrial
X-ray images and performs well in terms of enhancing image contrast
and highlighting image details.
Biomimetic models of fish gill rakers as lateral displacement arrays for particle separation
Authors: Witkop Erin M , Van Wassenbergh Sam , Heideman Paul D , Sanderson S Laurie 
Published: July 2023

Abstract
Ram suspension-feeding fish, such as herring, use gill rakers to separate small food particles from large water volumes while swimming forward with an open mouth. The fish gill raker function was tested using 3D-printed conical models and computational fluid dynamics simulations over a range of slot aspect ratios. Our hypothesis predicting the exit of particles based on mass flow rates, dividing streamlines (i.e. stagnation streamlines) at the slots between gill rakers, and particle size was supported by the results of experiments with physical models in a recirculating flume. Particle movement in suspension-feeding fish gill raker models was consistent with the physical principles of lateral displacement arrays (‘bump arrays’) for microfluidic and mesofluidic separation of particles by size. Although the particles were smaller than the slots between the rakers, the particles skipped over the vortical region that was generated downstream from each raker. The particles ‘bumped’ on anterior raker surfaces during posterior transport. Experiments in a recirculating flume demonstrate that the shortest distance between the dividing streamline and the raker surface preceding the slot predicts the maximum radius of a particle that will exit the model by passing through the slot. This theoretical maximum radius is analogous to the critical separation radius identified with reference to the stagnation streamlines in microfluidic and mesofluidic devices that use deterministic lateral displacement and sieve-based lateral displacement. These conclusions provide new perspectives and metrics for analyzing cross-flow and cross-step filtration in fish with applications to filtration engineering.
The effect of eliminating sintering during the synthesis of 3D scaffolds using the gel-casting method on their biological characteristics: in vivo and in vitro evaluations
Authors: Seyedmajidi Seyedali , Pourbagher Roghayeh , Seyedmajidi Maryam 
Published: July 2023

Abstract
The possibility of making shapeable three-dimensional scaffolds along with suitable mechanical properties is one of the most challenging points in tissue engineering. This study investigated the effect of the eliminating sintering during the synthesis of Hydroxyapatite/Agarose nanocomposite foam produced by gel-casting method, as bone tissue cellular scaffold, on its biological characteristics. The Hydroxyapatite/Agarose nanocomposite foam was synthesized by gel-casting, and samples were divided into two groups: group S, in which half of the samples were sintered, and group C, which the other half of the samples were left unsintered. To assess in vitro cytotoxicity, the supernatant culture medium was extracted from 100 mg ml−1 foam suspension in complete culture medium after 72 h incubation and diluted into various concentrations. SaOs-II cells were incubated with extracts of each scaffold at different concentrations and analyzed using the MTT assay. Additionally, in vivo characteristics were evaluated by implanting the scaffolds in rat tibia. Overall, the number of living cells was higher in group S than in group C, except for concentrations of 25% and 75% after 24 and 48 h of incubation, respectively. MTT assay results indicated that concentrations below 50% for group S and 25% for group C could be considered non-toxic. All in vivo variables exhibited significant changes over time, with most changes occurring faster in group S than in group C. There was a statistically significant difference between the two groups in terms of inflammation rate, osteocyte, osteoblast, and osteoclast count, as well as remaining biomaterial percentage only on day 30. Despite the delay in the tissue regeneration process observed by eliminating sintering during the gel-casting method, it is recommended as a means of producing reversible polymeric scaffolds with proper handling, cutting, and shaping capabilities that can be easily applied by clinicians during surgery according to the specific defect site.
Effect of immune responses on breath methane dynamics
Authors: Polag Daniela , Keppler Frank 
Published: July 2023

Abstract
Methane (CH4) which can be detected in human breath has long been exclusively associated with anaerobic microbial activity (methanogenesis) in the gastrointestinal tract. However, recent studies challenge this understanding by revealing that CH4 might also be produced endogenously in cells through oxidative–reductive stress reactions. Consequently, variations in breath CH4 levels compared to an individual’s baseline level might indicate enhanced oxidative stress levels, and, therefore, monitoring breath CH4 levels might offer great potential for ‘in vivo’ diagnostics such as disease diagnosis, monitoring the efficacy of treatments, or during the application of personalized medicine. To evaluate the effects from immune responses triggered by infections, inflammations, and induced perturbation by vaccination on CH4 dynamics in breath, two subjects were monitored over a period of almost 2 years. Breath CH4 levels were measured by gas chromatography equipped with a flame-ionization detector. Both subjects exhibited significant deviations (positive and negative, respectively) from their normal CH4 breath levels during periods of potential enhanced immune activity. Deviations from the ‘healthy state’ were indicated by the exceeding of individual CH4 ranges. Moreover, for the first time we could clearly prove CH4 degradation induced through vaccination by measuring stable carbon isotopes of CH4 using gas chromatograph–combustion–isotope ratio mass spectrometry. Hence, breath CH4 concentration and isotopic analyses may be used as a biomarker to evaluate specific immune responses and individual immune states.
Prognostic value of global myocardial flow reserve in patients with history of coronary artery bypass grafting
Authors: Al Rifai Mahmoud , Ahmed Ahmed Ibrahim , Saad Jean Michel , Alahdab Fares , Nabi Faisal , Al-Mallah Mouaz H 
Published: July 2023

Abstract

Aims
It is not well understood whether positron emission tomography (PET)-derived myocardial flow reserve (MFR) is prognostic among patients with prior coronary artery bypass grafting (CABG).

Methods and results
Consecutive patients with a clinical indication for PET were enrolled in the Houston Methodist DeBakey Heart and Vascular Center PET registry and followed prospectively for incident outcomes. The primary outcome was a composite of all-cause death, myocardial infarction (MI)/unplanned revascularization, and heart failure admissions. Cox proportional hazards models were used to study the association between MFR (&lt;2 vs. ≥2) and incident events adjusting for clinical and myocardial perfusion imaging variables. The study population consisted of 836 patients with prior CABG; mean (SD) age 68 (10) years, 53% females, 79% Caucasian, 36% non-Hispanic, and 66% with MFR &lt;2. Over a median (interquartile range [IQR]) follow-up time of 12 (4–24) months, there were 122 incident events (46 HF admissions, 28 all-cause deaths, 23 MI, 22 PCI/3 repeat CABG 90 days after imaging). In adjusted analyses, patients with impaired MFR had a higher risk of the primary outcome [hazard ratio (HR) 2.06; 95% CI 1.23–3.44]. Results were significant for admission for heart failure admissions (HR 2.92; 95% CI 1.11–7.67) but not for all-cause death (HR 2.01, 95% CI 0.85–4.79), or MI/UR (HR 1.93, 95% CI 0.92–4.05).

Conclusion
Among patients with a history of CABG, PET-derived global MFR &lt;2 may identify those with a high risk of subsequent cardiovascular events, especially heart failure, independent of cardiovascular risk factors and perfusion data.
Richard Champion and the Rockingham Whigs: The Aristocratic Politics of a Bristolian Quaker Merchant in the Age of the American Revolution
Authors: Skjönsberg Max 
Published: July 2023

Abstract
This article explores the political career and writings of Richard Champion (1743–1791), a Bristolian Quaker and merchant who acted as a local supporter and agent of the Rockingham Whigs. It aims to recover a forgotten aspect of Lewis Namier’s original ambition to understand eighteenth-century politics through the perspective of relatively ordinary people such as merchants and civil servants. However, against old Namierite assumptions, as well as much of the recent historiography on the post-1760 period in British politics which focuses on a dichotomous conflict between ‘radical Whigs’ and ‘new Tories’, this article restores the importance of the Rockingham Whigs. Importantly, it shows that a commercial Dissenter such as Champion could be fully attuned to the aristocratic and party-centred interpretation of British politics associated with the Rockinghamites and Edmund Burke, and thus encourages us to consider the idea of ‘aristocratic government’ in inclusive and eclectic ways. The case-study of Champion demonstrates that a close reading of political correspondence from the period can confirm, as well as destabilise, the Whig history of party.