Article
Materials Science, Coatings & Films
Jonathan A. Johnson, Jonathan L. Priedeman, Gregory B. Thompson
Summary: Agitation is necessary for producing conformal coatings onto powders using line-of-sight deposition. This study used a piston-crank agitation system to deposit W coatings onto different powder beds with varying levels of agitation. Based on the visual characteristics of the agitated powder charge, agitation can be categorized as limited, partial, or full. Limited agitation was insufficient for providing conformal coatings, while partial and full agitation allowed for complete coverage. The maximum acceleration required for full agitation varied depending on the material type.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Construction & Building Technology
Aws M. Nejres, Yasser Fakri Mustafa, Hasan S. Aldewachi
Summary: The chemical composition of natural asphalt and its rheological properties were analyzed in this study. It was found that the addition of additives improved the flow characteristics of the asphalt. Furthermore, the study highlighted the importance of the chemical composition of asphalt in determining its quality and application performance.
INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING
(2022)
Article
Chemistry, Physical
Seung T. Lee, Woo Y. Yoon
Summary: By using a Li-powder anode instead of a Li-foil anode, the capacity of Li-graphite and Li-O-2 cells can be increased, with Li-O-2 cells showing an enhancement of approximately 20%. The Li powder led to an increase in the exchange current density, enhancing the Li-ion concentration gradient at the cathode surface, which in turn increased the cell capacity.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Energy & Fuels
Shicheng Wang, Xiaolei Guo, Haifeng Lu, Haifeng Liu
Summary: The pressurized pneumatic conveying of biomass powder is a critical technical challenge for the entrained-flow gasification process. In this study, the dynamic compression characteristics of rice husk powder at different heights under gas pressurization were experimentally investigated. The rice husk powder column exhibited high compressibility, and the gas easily permeated through it. The agglomeration effect of the powder increased the void fraction and decreased the packing density. Additionally, the compressibility of the powder column increased with height, likely due to the particle movement distance and gas pressure drop. A model for the pressure-height relationship was proposed based on the Sone model, with an error of +/- 1%.
Article
Environmental Sciences
Guangmei Wu, Guitao Shi, Chuanjin Li, Ye Hu, Hongmei Ma, Zhenlou Chen
Summary: During the 2015-2016 Chinese Antarctic Research Expedition, a study was conducted on Particulate-bound mercury (PBM) in the boundary layer. The study found a significant latitudinal gradient in PBM, with higher levels over the Northern Hemisphere influenced by both continental and oceanic sources. Over the Southern Ocean, PBM levels were extremely low, while elevated PBM was observed across the Antarctic Ice Sheet, particularly at Dome A. The study also revealed the role of inland Antarctic snow in influencing atmospheric PBM concentrations over the Antarctic coastal seas.
ATMOSPHERIC ENVIRONMENT
(2023)
Article
Engineering, Chemical
Haifeng Lu, Hu Ruan, Massimo Poletto, Xiaolei Guo, Haifeng Liu
Summary: This paper explores the reliable method of using inserts in the hopper to improve the flow of powder. Glass beads, fluidized catalytic cracking catalyst (FCC), lignite and polyvinyl chloride (PVC) were used as experimental materials to characterize the flow properties of powders. Discharge experiments were conducted on a Perspex hopper at a laboratory scale, comparing the flow characteristics of fine powders discharged from a plain hopper and from hoppers modified with different geometrical inserts. The effects of inserts and powder properties on powder flow rate were discussed, and a mechanism model was developed to describe the hindering effect on discharge caused by the powder expansion at the hopper outlet. Mechanisms of insert on powder flow were analyzed, and it was demonstrated that the higher flow rates of hoppers with solid inserts were due to the anticipated expansion of the material generated by the presence of the insert.
Article
Environmental Sciences
Nore Praet, Tim Collart, Anouk Ollevier, Marc Roche, Koen Degrendele, Maarten De Rijcke, Peter Urban, Thomas Vandorpe
Summary: Monitoring turbidity is crucial for sustainable coastal management due to its negative impact on water clarity and ecological systems. Current monitoring techniques focus mainly on the surface layer, but a 3D monitoring approach is needed for coastal areas due to the dynamic nature of suspended particulate matter. Multibeam echosounders show promise as a tool for 3D turbidity and SPM monitoring.
Article
Engineering, Manufacturing
Tan-Phuc Le, Xiaogang Wang, Karl Peter Davidson, Jude Emil Fronda, Matteo Seita
Summary: This study presents a method to assess powder bed quality using particle-level resolution images provided by powder bed scanner technology. Three new metrics were defined to evaluate powder bed quality, showing differences in layers due to variations in powder conditions and recoating strategies. The results demonstrate how powders with different particle characteristics respond to various recoating conditions, leading to layers of different quality.
ADDITIVE MANUFACTURING
(2021)
Article
Chemistry, Multidisciplinary
Elena Pavoni, Efren Garcia-Ordiales, Stefano Covelli, Pablo Cienfuegos, Nieves Roqueni
Summary: At the Nalon River estuary in Northern Spain, the distribution and partitioning behavior of Hg and MeHg in the water column were studied, showing the influence of river discharge and tidal currents on the prevalence of dissolved and particulate Hg under different seasonal conditions. Particulate MeHg was found to prevail when river flow was low, especially at the estuary mouth, possibly due to resuspension of fine particles caused by strong tidal currents. Compared to total Hg concentration, extremely low amounts of dissolved and particulate MeHg were observed, with strong interactions between MeHg and organic carbon indicating a minimal risk of increased mobility and potential bioaccumulation of MeHg.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Minoru Maeda, Akiyoshi Matsumoto, Gen Nishijima, Yoon-Uk Heo, Seungyong Hahn, Sangjin Lee, Seyong Choi, Jung Ho Kim
Summary: In this study, the researchers proposed a method of regulating porous properties using magnesium powder blending. Through a detailed investigation, they found a significant correlation between various particle parameters, impurities, superconducting transition temperature, and current carrying capacity, with the porous properties. The blending of raw powders with spherical shape allowed for tuning of morphological structures and crystallinities inside the cores of the MgB2 superconducting wires, resulting in superior superconducting properties. This finding provides valuable insights for the widespread use and application of superconducting materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
Ming Li, Guanxiong Miao, Mohammadamin Moghadasi, Zhijian Pei, Chao Ma
Summary: In ceramic binder jetting additive manufacturing, there is a relationship between powder properties and feed region density, as well as powder bed density. The apparent density is a stronger predictor for powder bed density compared to tap density and Hausner ratio.
CERAMICS INTERNATIONAL
(2021)
Article
Engineering, Manufacturing
Francesco Sillani, Eric MacDonald, Janely Villela, Manfred Schmid, Konrad Wegener
Summary: Process monitoring with a laser profilometer integrated in a commercial polymer laser sintering machine allows for part qualification and process improvement. The study found that powder layer quality is influenced by recoating speed, preheating temperature, and particle shape, and that curling increases with decreasing preheating temperature.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Chemical
Wenchao Du, Ming Li, Zhijian Pei, Chao Ma
Summary: For the first time, different linear packing models (de Larrard's, Kwan's, and Yu's) were compared for their ability to predict packing density and optimal mixing fraction of mixtures of micropowders. The results showed that Kwan's model outperformed the other two models in predicting both packing density and optimal mixing fraction.
Article
Optics
Robin Kromer, Cyril Gorny, Elise Gruhier, Emilie Le Guen, Corinne Arvieu, Eric Lacoste
Summary: The effective absorptivity of IR laser light for different powder beds was studied. Reflectivity of aluminum, titanium, stainless steel, and copper alloys was measured, showing that the absorptivity of the powder bed was significantly higher than that of a uniform surface due to multiple scattering. The substrate also had an impact on the powder bed absorption. The inhomogeneity of the powder bed strongly modified the laser absorption for a small spot size, and the absorption fluctuated during the transition from the powder state to the molten pool state.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Kial D. Stewart, Callum J. Shakespeare, Yvan Dossmann, Andrew McC. Hogg
Summary: Laboratory experiments are crucial for studying stratified fluid dynamics, but visualizing the physics involved can be challenging. The hot double-bucket method simplifies visualization and generates double-diffusive layers that can be observed in real time. This technique provides a global shadowgraph view of isopycnal surfaces, demonstrating the propagation of small-amplitude internal waves and comparing observations with theoretical dispersion relations.
EXPERIMENTS IN FLUIDS
(2021)
Article
Engineering, Multidisciplinary
Sicheng Jiao, Shixiang Wang, Minge Gao, Min Xu
Summary: This paper presents a non-contact method of thickness measurement for thin-walled rotary shell parts based on a chromatic confocal sensor. The method involves using a flip method to obtain surface profiles from both sides of the workpiece, measuring the decentration and tilt errors of the workpiece using a centering system, establishing a unified reference coordinate system, reconstructing the external and internal surface profiles, and calculating the thickness. Experimental results show that the method can accurately measure the thickness of a sapphire spherical shell workpiece and is consistent with measurements of other materials.
Article
Engineering, Multidisciplinary
Rajeev Kumar, Sajal Agarwal, Sarika Pal, Alka Verma, Yogendra Kumar Prajapati
Summary: This study evaluated the performance of a CaF2-Ag-MXene-based surface plasmon resonance (SPR) sensor at different wavelengths. The results showed that the sensor achieved the maximum sensitivity at a wavelength of 532 nm, and higher sensitivities were obtained at shorter wavelengths at the expense of detection accuracy.
Article
Engineering, Multidisciplinary
Attilio Di Nisio, Gregorio Andria, Francesco Adamo, Daniel Lotano, Filippo Attivissimo
Summary: Capacitive sensing is a widely used technique for a variety of applications, including avionics. However, current industry standard Capacitive Level Sensors (CLSs) used in helicopters perform poorly in terms of sensitivity and dynamic characteristics. In this study, novel geometries were explored and three prototypes were built and tested. Experimental validation showed that the new design featuring a helicoidal slit along the external electrode of the cylindrical probe improved sensitivity, response time, and linearity.
Article
Engineering, Multidisciplinary
Kai Yang, Huiqin Wang, Ke Wang, Fengchen Chen
Summary: This paper proposes an effective measurement method for dynamic compaction construction based on time series model, which enables real-time monitoring and measurement of anomalies and important construction parameters through simulating motion state transformation and running time estimation.
Article
Engineering, Multidisciplinary
Hui Fu, Qinghua Song, Jixiang Gong, Liping Jiang, Zhanqiang Liu, Qiang Luan, Hongsheng Wang
Summary: An automatic detection and pixel-level quantification model based on joint Mask R-CNN and TransUNet is developed to accurately evaluate microcrack damage on the grinding surfaces of engineering ceramics. The model is effectively trained on actual micrograph image dataset using a joint training strategy. The proposed model achieves reliable automatic detection and fine segmentation of microcracks, and a skeleton-based quantification model is also proposed to provide comprehensive and precise measurements of microcrack size.
Review
Engineering, Multidisciplinary
Sang Yeob Kim, Da Yun Kwon, Arum Jang, Young K. Ju, Jong-Sub Lee, Seungkwan Hong
Summary: This paper reviews the categorization and applications of UAV sensors in forensic engineering, with a focus on geotechnical, structural, and water infrastructure fields. It discusses the advantages and disadvantages of sensors with different wavelengths and addresses the challenges of current UAV technology and recommendations for further research in forensic engineering.
Article
Engineering, Multidisciplinary
Anton Nunez-Seoane, Joaquin Martinez-Sanchez, Erik Rua, Pedro Arias
Summary: This article compares the use of Mobile Laser Scanners (MLS) and Aerial Laser Scanners (ALS) for digitizing the road environment and detecting road slopes. The study found that ALS data and its corresponding algorithm achieved better detection and delimitation results compared to MLS. Measuring the road from a terrestrial perspective negatively impacted the detection process, while an aerial perspective allowed for scanning of the entire slope structure.
Article
Engineering, Multidisciplinary
Nur Luqman Saleh, Aduwati Sali, Raja Syamsul Azmir Raja Abdullah, Sharifah M. Syed Ahmad, Jiun Terng Liew, Fazirulhisyam Hashim, Fairuz Abdullah, Nur Emileen Abdul Rashid
Summary: This study introduces an enhanced signal processing scheme for detecting mouth-click signals used by blind individuals. By utilizing additional band-pass filtering and other steps, the detection accuracy is improved. Experimental results using artificial signal data showed a 100% success rate in detecting obstacles. The emerging concepts in this research are expected to benefit radar and sonar system applications.
Article
Engineering, Multidisciplinary
Jiqiang Tang, Shengjie Qiu, Lu Zhang, Jinji Sun, Xinxiu Zhou
Summary: This paper studies the magnetic noise level of a compact high-performance magnetically shielded room (MSR) under different operational conditions and establishes a quantitative model for magnetic noise calculation. Verification experiments show the effectiveness of the proposed method.
Review
Engineering, Multidisciplinary
Krzysztof Bartnik, Marcin Koba, Mateusz Smietana
Summary: The demand for miniaturized sensors in the biomedical industry is increasing, and optical fiber sensors (OFSs) are gaining popularity due to their small size, flexibility, and biocompatibility. This study reviews various OFS designs tested in vivo and identifies future perspectives and challenges for OFS technology development from a user perspective.
Article
Engineering, Multidisciplinary
Yue Wang, Lei Zhou, Zihao Li, Jun Wang, Xuangou Wu, Xiangjun Wang, Lei Hu
Summary: This paper presents a 3-D reconstruction method for dynamic stereo vision of metal surface based on line structured light, overcoming the limitation of the measurement range of static stereo vision. The proposed method uses joint calibration and global optimization to accurately reconstruct the 3-D coordinates of the line structured light fringe, improving the reconstruction accuracy.
Article
Engineering, Multidisciplinary
Jaafar Alsalaet
Summary: Order tracking analysis is an effective tool for machinery fault diagnosis and operational modal analysis. This study presents a new formulation for the data equation of the second-generation Vold-Kalman filter, using separated cosine and sine kernels to minimize error and provide smoother envelopes. The proposed method achieves high accuracy even with small weighting factors.
Article
Engineering, Multidisciplinary
Tonglei Cao, Kechen Song, Likun Xu, Hu Feng, Yunhui Yan, Jingbo Guo
Summary: This study constructs a high-resolution dataset for surface defects in ceramic tiles and addresses the scale and quantity differences in defect distribution. An improved approach is proposed by introducing a content-aware feature recombination method and a dynamic attention mechanism. Experimental results demonstrate the superior accuracy and efficiency of the proposed method.
Article
Engineering, Multidisciplinary
Qinghong Fu, Yunxi Lou, Jianghui Deng, Xin Qiu, Xianhua Chen
Summary: Measurement and quantitative characterization of aging-induced gradient properties is crucial for accurate analysis and design of asphalt pavement. This research proposes the composite specimen method to obtain asphalt binders at different depths within the mixture and uses dynamic shear rheometer tests to measure aging-induced gradient properties and reveal internal mechanisms. G* master curves are constructed to investigate gradient aging effects in a wide range. The study finds that the composite specimen method can effectively restore the boundary conditions and that it is feasible to study gradient aging characteristics within the asphalt mixture. The study also observes variations in G* and delta values and the depth range of gradient aging effects for different aging levels.
Article
Engineering, Multidisciplinary
Min Li, Kai Wei, Tianhe Xu, Yali Shi, Dixing Wang
Summary: Due to the limitations of ground monitoring stations in China for the BDS, the accuracy of BDS Medium Earth Orbit (MEO) satellite orbits can be influenced. To overcome this, low Earth orbit (LEO) satellites can be used as additional monitoring stations. In this study, data from two LEO satellites were collected to improve the precise orbit determination of the BDS. By comparing the results with GPS and BDS-2/3 solutions, it was found that including the LEO satellites significantly improved the accuracy of GPS and BDS-2/3 orbits.