bluuebunny/crossref_metadata_2025_split huggingface dataset:
Realtime 3D reconstruction algorithm based on improved AKAZE and multi-layer feature detection network
Authors: Pan Zihao , Hou Junyi , Su Yan , Lv Yong , Chen Zhong , Yu Lei 
Published: April 2024

Abstract
Simultaneous localization and mapping (SLAM) technology aims to solve the problem of how to determine the trajectory of robots by observing the environment and construct sparse spatial models. And the 3D reconstruction technology can further build dense spatial models based on the pose information. This paper proposes a dense 3D reconstruction algorithm based on improved accelerated-KAZE features and a multi-layer feature detection network. A multi-layer feature detection neural network is constructed to replace the bag-of-words model and optimize the loopback results, which improves the effect of pose estimation. The optimized algorithm improves the mapping effect and construct clear and robust indoor complex models. The pose estimation results show that the optimized algorithm improves the accuracy by 30% compared with ORB-SLAM2. Compared with the mapping effect of Kintinuous, ElasticFusion, ORB-SLAM2 and BundleFusion, the optimized models own the advantages of clearer details, richer information and no split layer.
A 3D printing assisted microfluidic absorbance-based measurement system for biological assay
Authors: Kumar Ankit , Nath Prathul , Das Neeladrisingha , Chatterjee Manisha , Roy Partha , Satapathi Soumitra 
Published: April 2024

Abstract
Development of rapid analytical systems utilizing 3D printing is an emerging area of interest with the potential to provide efficient solutions by integrating multidisciplinary technology without compromising the quality of the system. In this study we report the fabrication of a 3D printing assisted microfluidic based absorbance measurement system, leveraging 3D printing along with integrating miniature optical components for the accurate measurement of biological assays. The developed system is rapid, affordable, and compact, through set of computer-aided design models and fusion deposition modeling 3D printing along with relevant electronic circuitry involving optical components like surface mounting devices. The handheld device features a capacitive touchscreen display, programmed to seamlessly perform MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The device was employed for assessing the cell viability using Michigan cancer foundation-7 (MCF-7) cell lines over varying concentrations of tamoxifen, reciprocating the MTT assay analysis conducted by using spectrophotometer. The device achieved excellent results which upon comparison with the conventional spectrophotometer-based results have shown a correlation coefficient of 0.98. This compact and rapid absorbance measurement system holds significant potential for evaluating the cytotoxicity of drugs, and further development of innovative analytical devices.
Impact location of metal structures based on time–frequency image features and deep residual network
Authors: Zhang Yu , Zhou Zeye , Rui Xiaobo , Xu Lixin , Li Bin , Ma Chang , Qi Lei 
Published: April 2024

Abstract
Impact location detection plays an important role in the structural health monitoring of metal materials. However, the methods of metal material impact location detection based on physical analysis are often limited by the extraction accuracy of some parameters such as material and structure parameters and time difference calculation. Therefore, this paper develops a deep residual network method for impact location detection, time–frequency characteristic deep residual network (TF-DRN). This method takes the four-channel short-time Fourier transform time–frequency graph as input, uses the unique residual network architecture to automatically extract the advanced features, and then uses the global average pooling layer and the full connection layer to establish the mapping between the advanced features and the impact location, so as to detect the impact location. By introducing regularization and batch normalization, the problems of gradient disappearance and gradient explosion are alleviated, and the generalization and efficiency of impact location detection are further improved. The experimental results show that on an 800 mm × 800 mm × 2.5 mm aluminum plate, the average error of the validation set and the test set are 0.85 cm and 1.33 cm respectively, and the performance of the method is significantly better than that of CNN, ResNet18 and ResNet33 networks.
Modeling and simulation of grain growth for FGH96 superalloy using a developed cellular automaton model
Authors: Yang Yanhui , Zhang Boyan , Chen Xiuquan , Wang Xiaoxuan , Sun Jingshi 
Published: April 2024

Abstract
Through heat treatment experiments and numerical simulations, the effects of the heating temperature (1313–1423 K) and holding time (10–240 min) on the grain growth behavior of the extruded FGH96 alloy were investigated. A two-dimensional cellular automata (CA) model that considered the dissolution of the γ′ phase over time and the distribution characteristics with different sizes was developed to explore the grain growth behavior above the γ′ phase over-solution temperature (1423 K) and below the γ′ sub-solution temperature (1383 K), respectively. The results showed that the rate of grain growth of FGH96 alloy was obviously enhanced when the heating temperature exceeded 1363 K, which was mainly related to the dissolution of the γ′ phase, and the grain growth of FGH96 alloy mainly occurred during the initial stage of insulation. The grain growth model of the extruded FHG96 alloy could accurately predict the grain growth behavior, and the simulation results were in good agreement with the experimental results at over-solution temperature or sub-solution temperature. The effects of volume fraction and radius of γ′ phase on the grain growth behavior of FGH96 alloy were studied by simulating the grain growth behavior of FGH96 alloy under different sizes and volume fractions of γ′ phase. The results follow the Zener relation, and the coefficient n in the Zener relation was determined by fitting the simulation results.
Artificial neural network-based approach for prediction of nanomechanical properties of anodic coating on additively manufactured Al–10Si–Mg alloy
Authors: Ghosh Rahul , Sahu Bhavana , Dey Arjun , Thota Hari Krishna , Das Karabi 
Published: April 2024

Abstract
Nowadays, anodic coating on additively manufactured (AM) or 3D printed Al–10Si–Mg alloy are used for various components in spacecraft such as antenna feeds, wave guides, structural brackets, collimators, thermal radiators etc. In this study, artificial neural network (ANN) and power law-based models are developed from experimental nanoindentation data for predicting elastic modulus and hardness of anodized AM Al–10Si–Mg at any desired loads. Data from nanoindentation experiments conducted on plan- and cross-sections of anodized coating on AM Al–10Si–Mg alloy was considered for modeling. Apart from nanomechanical properties, load and displacement curves were predicted using Python software from ANN and the Power law model of nanoindentation. It is observed that the ANN model of 50 mN nanoindentation experimental data can accurately predict the loading pattern at any desired load below 50 mN. Elastic modulus and hardness of anodized AM Al–10Si–Mg computed from ANN and the power law model of the unloading curve are also comparable with the values obtained from Weibull distribution analysis reported elsewhere. The derived models were also used to predict nanomechanical properties at 25 and 35 mN, for which no experimental data was available. The computed hardness of plan section of the anodic coating is 3.99 and 4.02 GPa for 25 and 35 mN, respectively. The computed hardness of cross-section of the anodic coating of is 7.16 and 6.61 GPa for 25 and 35 mN, respectively. Thus, the ANN and Power law model of nanoindentation can predict elastic modulus and hardness at different loads by conducting the minimum number of experiments. The novel approach to predict nanomechanical properties using ANN resulted in determining realistic and design specific data on hardness and modulus of the anodized coating on AM Al–10Si–Mg alloy.
Colour and temperature of the stars: a demonstration using Arduino
Authors: Hahn Marcelo Dumas , Carvalho Paulo Simeão , Cruz Frederico Alan de Oliveira 
Published: April 2024

Abstract
Teaching the colour of stars is not as trivial as one might think. It can be challenging for students to grasp that the colour of stars follows a temperature sequence. This paper introduces a simple experimental setup for instructing the correlation between a star’s colour and its temperature. Furthermore, the experimental setup facilitates the exploration of the topic of colour addition, demonstrating to students how to replicate the colour of a star—a spectrum colour—by employing an RGB LED that emits only primary colours (red, green, and blue). The experiment utilised an Arduino microcontroller board in conjunction with RGB LEDs and an LCD display. The activity was conducted with 53 7th-grade students from a private school in Portugal results suggest a positive reception, indicating success in both motivational and cognitive aspects. The overall outcomes underscore the effectiveness of the activity in imparting new knowledge to students.
Dosimetric evaluation of different planning strategies for hypofractionated whole-breast irradiation technique
Authors: Tang Chunbo , Liu Biaoshui , Yuan Jun , He Ji , Xie Ruilian , Huang Minfeng , Niu Shanzhou , Liu Hongdong 
Published: April 2024

Abstract

Purpose. The dose hotspot areas in hypofractionated whole-breast irradiation (WBI) greatly increase the risk of acute skin toxicity because of the anatomical peculiarities of the breast. In this study, we presented several novel planning strategies that integrate multiple sub-planning target volumes (sub-PTVs), field secondary placement, and RapidPlan models for right-sided hypofractionated WBI. Methods. A total of 35 cases of WBI with a dose of 42.5 Gy for PTVs using tangential intensity-modulated radiotherapy (IMRT) were selected. Both PTVs were planned for simultaneous treatment using the original manual multiple sub-PTV plan (OMMP) and the original manual single-PTV plan (OMSP). The manual field secondary placement multiple sub-PTV plan (m-FSMP) with multiple objects on the original PTV and the manual field secondary placement single-objective plan (m-FSSP) were initially planned, which were distribution-based of V105 (volume receiving 105% of the prescription dose). In addition, two RapidPlan-based plans were developed, including the RapidPlan-based multiple sub-PTVs plan (r-FSMP) and the RapidPlan-based single-PTV plan (r-FSSP). Dosimetric parameters of the plans were compared, and V105 was evaluated using multivariate analysis to determine how it was related to the volume of PTV and the interval of lateral beam angles (ILBA). Results. The lowest mean V105 (5.64 ± 6.5%) of PTV was observed in m-FSMP compared to other manual plans. Upon validation, r-FSSP demonstrated superior dosimetric quality for OAR compared to the two other manual planning methods, except for V5(the volume of ipsilateral lung receiving 5 Gy) of the ipsilateral lung. While r-FSMP showed no significant difference (p = 0.06) compared to r-FSSP, it achieved the lowest V105 value (4.3 ± 4.5%), albeit with a slight increase in the dose to some OARs. Multivariate GEE linear regression showed that V105 is significantly correlated with target volume and ILBA. Conclusions. m-FSMP and r-FSMP can substantially enhance the homogeneity index (HI) and reduce V105, thereby minimizing the risk of acute skin toxicities, even though there may be a slight dose compromise for certain OARs.
Brain elastography in aging relates to fluid/solid trendlines
Authors: Parker Kevin J , Kabir Irteza Enan , Doyley Marvin M , Faiyaz Abrar , Uddin Md Nasir , Flores Gilmer , Schifitto Giovanni 
Published: April 2024

Abstract
The relatively new tools of brain elastography have established a general trendline for healthy, aging adult humans, whereby the brain’s viscoelastic properties ‘soften’ over many decades. Earlier studies of the aging brain have demonstrated a wide spectrum of changes in morphology and composition towards the later decades of lifespan. This leads to a major question of causal mechanisms: of the many changes documented in structure and composition of the aging brain, which ones drive the long term trendline for viscoelastic properties of grey matter and white matter? The issue is important for illuminating which factors brain elastography is sensitive to, defining its unique role for study of the brain and clinical diagnoses of neurological disease and injury. We address these issues by examining trendlines in aging from our elastography data, also utilizing data from an earlier landmark study of brain composition, and from a biophysics model that captures the multiscale biphasic (fluid/solid) structure of the brain. Taken together, these imply that long term changes in extracellular water in the glymphatic system of the brain along with a decline in the extracellular matrix have a profound effect on the measured viscoelastic properties. Specifically, the trendlines indicate that water tends to replace solid fraction as a function of age, then grey matter stiffness decreases inversely as water fraction squared, whereas white matter stiffness declines inversely as water fraction to the 2/3 power, a behavior consistent with the cylindrical shape of the axons. These unique behaviors point to elastography of the brain as an important macroscopic measure of underlying microscopic structural change, with direct implications for clinical studies of aging, disease, and injury.
Contrast-enhanced photon-counting micro-CT of tumor xenograft models
Authors: Li Mengzhou , Guo Xiaodong , Verma Amit , Rudkouskaya Alena , McKenna Antigone M , Intes Xavier , Wang Ge , Barroso Margarida 
Published: April 2024

Abstract

Objective. Photon-counting micro-computed tomography (micro-CT) is a major advance in small animal preclinical imaging. Small molecule- and nanoparticle-based contrast agents have been widely used to enable the differentiation of liver tumors from surrounding tissues using photon-counting micro-CT. However, there is a notable gap in the application of these market-available agents to the imaging of breast and ovarian tumors using photon-counting micro-CT. Herein, we have used photon-counting micro-CT to determine the effectiveness of these contrast agents in differentiating ovarian and breast tumor xenografts in live, intact mice. Approach. Nude mice carrying different types of breast and ovarian tumor xenografts (AU565, MDA-MB-231 and SKOV-3 human cancer cells) were injected with ISOVUE-370 (a small molecule-based agent) or Exitron Nano 12000 (a nanoparticle-based agent) and subjected to photon-counting micro-CT. To improve tumor visualization using photon-counting micro-CT, we developed a novel color visualization method, which changes color tones to highlight contrast media distribution, offering a robust alternative to traditional material decomposition methods with less computational demand. Main results. Our in vivo experiments confirm the effectiveness of this color visualization approach, showing distinct enhancement characteristics for each contrast agent. Qualitative and quantitative analyses suggest that Exitron Nano 12000 provides superior vasculature enhancement and better quantitative consistency across scans, while ISOVUE-370 delivers a more comprehensive tumor enhancement but with significant variance between scans due to its short blood half-time. Further, a paired t-test on mean and standard deviation values within tumor volumes showed significant differences between the AU565 and SKOV-3 tumor models with the nanoparticle-based contrast agent (p-values < 0.02), attributable to their distinct vascularity, as confirmed by immunohistochemical analysis. Significance. These findings underscore the utility of photon-counting micro-CT in non-invasively assessing the morphology and anatomy of different tumor xenografts, which is crucial for tumor characterization and longitudinal monitoring of tumor progression and response to treatments.
Suppression of equilibrium magnetic islands by density profile effect in quasi-axisymmetric stellarator plasmas
Authors: Fu T , Wang X Q , Su X , Xu Y , Okamura S , Shimizu A , Isobe M , Cheng J , Liu H F , Huang J , Zhang X , Liu H , Tang C J 
Published: April 2024

Abstract
In a quasi-axisymmetric stellarator, a significant bootstrap current will result in the generation of low-order rational surfaces and three-dimensional (3D) magnetic islands. In this paper, the influence of plasma density profiles on the equilibrium magnetic islands for the Chinese first quasi-axisymmetric stellarator (CFQS) is investigated using the HINT code. It is found that the flattening of the core plasma density profile leads to a significant suppression of magnetic islands. When the peaking factor of plasma density is 1.19, complete suppression of magnetic islands occurs while maintaining excellent integrity of the magnetic surface even with the volume-averaged plasma beta <β> increase up to 2%. On the other hand, during the transition of a plasma density profile from flat to hollow, there is a reversal in the core bootstrap current, resulting in reduction of rotational transform values to pass through the rational surface. Hence, formation of magnetic islands in the core region. Therefore, effective inhibition of CFQS’s magnetic islands can be achieved by appropriately controlling density profiles through methods like gas injection.
Plasma dynamics of individual HiPIMS pulses: imaging study using high-frame-rate camera
Authors: Panjan Matjaž 
Published: April 2024

Abstract
A high-frame-rate camera with microsecond-level time resolution was used to make systematic investigations of plasma self-organization and spoke dynamics during individual HiPIMS pulses. The plasma was imaged for a range of argon pressures (0.25–2 Pa) and peak discharge currents (10–400 A) using an Al target. The experiments revealed that plasma evolves through three characteristic stages as the discharge current increases. In stage I, which is present from the current onset and up to ∼25 A, spokes are azimuthally long and rotate in the −Ez
× B direction. The spoke behavior is similar to the one observed in DCMS discharges. The number of spokes depends on pressure and the current growth rate. At the lowest pressure (0.25 Pa) a single spoke is present in discharge, while at higher pressures (1–2 Pa) two spokes are most often observed. The spoke velocity depends on the number of spokes, current growth rate and pressure. A single spoke rotates with velocities in the 4–15 km s−1 range, while two spokes rotate in the 1–9 km s−1 range depending on the pressure and growth rate. Following stage I, the plasma undergoes a complex reorganization that is characterized by aperiodic spoke patterns and irregular dynamics. In stage II spokes are less localized, they merge, split and propagate either in the retrograde or prograde direction. After chaotic plasma reorganization, more ordered spoke patterns begin to form. Spokes in stage III are azimuthally shorter, typically exhibit a triangular shape and rotate in the Ez
× B direction. In general, the spoke dynamics is less complicated and is only influenced by the pressure. Spokes rotate faster at higher pressures than at lower ones; velocities range from 9 km s−1 at 0.25 Pa to 6 km s−1 at 2 Pa. The spoke velocity in stage III is largely unaffected by the discharge current or number of spokes. Stage III can be further divided into sub-stages, which are characterized by different current growth rates, spoke sizes and shapes. In general, the spoke evolution is highly reproducible for pulses with similar discharge current waveforms.
Rate-dependent energy dissipation of graded viscoelastic structures fabricated by grayscale vat photopolymerization
Authors: Valizadeh Iman , Weeger Oliver 
Published: April 2024

Abstract
A major benefit of additive manufacturing technologies is precise control over structural topologies and material properties, which allows to tailor, for instance, energy absorption and dissipation. While vat photopolymerization is generally restricted to a single material, grayscale masked stereolithography (gMSLA) allows to customize material behavior by grading the light intensity within a structure. This study investigates the impact and opportunities of grayscale grading strategies on the rate-dependent mechanical behavior of structures fabricated by gMSLA. Considering the viscoelastic nature of polymers, rate-dependent energy dissipation is explored, introducing a parametric linear viscoelastic constitutive model for varying grayscales. The investigation includes the comprehensive characterization of mechanical properties, numerical finite element simulation, validation through experimental procedures, and exploration of dissipation energy under different strain rates. In this way, a rational function successfully determines the critical strain rate at which the maximum dissipation occurs. Overall, the research offers a comprehensive investigation of the mechanical dissipation behavior of graded 3D printed structures, laying the foundation for further studies and advancements aimed at optimizing these structures for enhanced energy absorption capabilities.
A route to fabricate low resistance joints between Eu–Ba–Cu–O bulk, single grain superconductors
Authors: Congreve J V J , Shi Y , Tutt N C , Taylor R W , Bumby C , Dennis A R , Druiff H , Weerakonda Arachchilage D , Durrell J H , Cardwell D A 
Published: April 2024

Abstract
The fabrication of large (RE)–Ba–Cu–O single grains [(RE)BCO], where RE = Y, Gd, Eu or Sm, with the complex geometries required for many practical applications is currently limited by the time intensive, complex nature of the grain growth process. In addition, the shapes achievable using established melt processing techniques, such as top seeded melt growth, are constrained significantly by the limited number of post-processing techniques readily available. Machining of these materials is also difficult given their ceramic-like mechanical properties, which makes them both brittle and hard. A potential alternative to the slow and inflexible melt growth processes is to join many small, single grains to form one large composite grain, connected by electrically and mechanically high-performance joints. A reliable joining technique would also greatly reduce the need for post-growth machining processes. In this work we extend our previous investigation of the use of single grain YBCO-Ag as an intermediate joining material to achieve effective and reliable superconducting joints between EuBCO-Ag bulk, single grain superconductors. The technique reported in the earlier studies requires limited specialist equipment and does not require tight process parameter control, since there is no need to re-grow the joining material at the intergrain interface. This technique is of particular interest given that the difference between the peritectic temperatures of the bulk superconductor and the intermediate joining material is large. We report the properties of seven joints engineered at different joining temperatures. The trapped field properties of the resulting joined samples were measured and the microstructure at the position of the joint examined. We demonstrate that this simple and the rapid joining technique makes it possible to manufacture composite grains in an industrially important (RE)BCO bulk superconductor with comparable superconducting properties to those of a single grain of similar dimensions.