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Appl. Sci., Volume 12, Issue 12 (June-2 2022) – 529 articles

Cover Story (view full-size image): Molecular simulations using coarse-grained models allow the structure, dynamics, and mechanics of DNA origamis to be comprehensively characterized. Here, we focus on the free-energy landscape of a jointed DNA origami that has been designed to exhibit two mechanically stable states and for which a bistable landscape has been inferred from ensembles of structures visualized by electron microscopy. Surprisingly, simulations using the oxDNA model predict that the defect-free origami has a single free-energy minimum. The expected second state is not stable because the hinge joints do not simply allow free angular motion but instead lead to increasing free-energetic penalties as the joint angles relevant to the second state are approached. This raises interesting questions about the cause of this difference between the simulations and experiment. View this paper
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19 pages, 2502 KiB  
Article
Characterization of 75 Cultivars of Four Capsicum Species in Terms of Fruit Morphology, Capsaicinoids, Fatty Acids, and Pigments
by Pingping Li, Xiang Zhang, Yuting Liu, Zhihe Xie, Ruihao Zhang, Kai Zhao, Junheng Lv, Jinfen Wen and Minghua Deng
Appl. Sci. 2022, 12(12), 6292; https://doi.org/10.3390/app12126292 - 20 Jun 2022
Cited by 2 | Viewed by 1920
Abstract
Fruit quality has long been well known as an important prerequisite for evaluating pepper resources. In the study, 75 cultivars belonging to four Capsicum species were investigated on the bases of fruit morphology and concentrations of fruit secondary metabolites. The results showed that [...] Read more.
Fruit quality has long been well known as an important prerequisite for evaluating pepper resources. In the study, 75 cultivars belonging to four Capsicum species were investigated on the bases of fruit morphology and concentrations of fruit secondary metabolites. The results showed that C. annuum had a greater variation than C. chinense and C. frutescens in terms of fruit weight, size and contents of carotenoids, anthocyanidins, and capsaicinoids. Moreover, there were significant differences in the concentrations of total phenol, total soluble sugar, total soluble solids, titratable acid, and total soluble protein of all samples. Capsaicin and dihydrocapsaicin were the most important capsaicinoids components in pepper fruits, of which C. chinense both had the highest levels, whereas some accessions of C. annuum were not detected. Eighteen fatty acids were detected in pepper fruits, and the dominant member was linoleic acid (a polyunsaturated fatty acid) therein. We integrated a set of methods for metabolites, and the results indicated that there was a positive correlation between concentrations of capsaicinoids and fatty acids. Four accessions had the highest contents of quality-related compounds, two of which belonged to C. chinense (S23 and S24) and possessed high levels of capsaicin. However, S67 had a high level of β-carotene and S68 contained higher contents of total fatty acid and ascorbic acid, and both of them belonged to C. annuum. This work could provide a valid experimental basis for the potential application value of the four accessions mentioned above. Full article
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19 pages, 2724 KiB  
Article
Extraction of Catastrophe Boundary and Evolution of Expressway Traffic Flow State
by Dayi Qu, Haomin Liu, Hui Song and Yiming Meng
Appl. Sci. 2022, 12(12), 6291; https://doi.org/10.3390/app12126291 - 20 Jun 2022
Cited by 3 | Viewed by 1711
Abstract
As the main road type in an urban traffic system, the increasingly severe congestion of the expressway restricts social and economic development. It is essential to explore the evolution law of congestion and dissipation to ensure the efficient operation of the expressway. In [...] Read more.
As the main road type in an urban traffic system, the increasingly severe congestion of the expressway restricts social and economic development. It is essential to explore the evolution law of congestion and dissipation to ensure the efficient operation of the expressway. In order to accurately grasp the evolution law of the expressway traffic flow state, this paper selects the expressway weaving section, which is a traffic flow frequency-changing area, to study the traffic operation state, change process, and evolution law, and determine the traffic state discrimination standard. The simulation analysis was carried out using the traffic simulation platform, Vissim software. The simulation results showed an apparent catastrophe phenomenon in the mutual transformation between free and congestion flow. The spectral clustering analysis algorithm was used to accurately extract the boundary of traffic state mutation, combined with the cusp catastrophe theory, to study and analyze the traffic flow state at different times and positions, thus completely displaying the evolution characteristics of traffic flow state. The research results provide an essential theoretical basis for formulating control measures of expressway traffic flow and strategies for traffic congestion dissipation. Full article
(This article belongs to the Section Transportation and Future Mobility)
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16 pages, 2015 KiB  
Article
Artificial Neural Networks for Predicting Food Antiradical Potential
by Victor Gorbachev, Marina Nikitina, Daria Velina, Sherzodkhon Mutallibzoda, Vladimir Nosov, Galina Korneva, Anna Terekhova, Elena Artemova, Bella Khashir, Igor Sokolov, Svetlana Dimitrieva and Igor Nikitin
Appl. Sci. 2022, 12(12), 6290; https://doi.org/10.3390/app12126290 - 20 Jun 2022
Cited by 7 | Viewed by 4901
Abstract
Using an artificial neural network (ANN), the values of the antiradical potential of 1315 items of food and agricultural raw materials were calculated. We used an ANN with the structure of a “multilayer perceptron” (MLP) and with the hyberbolic tangent (Tanh) as an [...] Read more.
Using an artificial neural network (ANN), the values of the antiradical potential of 1315 items of food and agricultural raw materials were calculated. We used an ANN with the structure of a “multilayer perceptron” (MLP) and with the hyberbolic tangent (Tanh) as an activation function. Values reported in the United States Food and Nutrient Database for Dietary Studies (FNDDS) were taken as input to the analysis. When training the ANN, 60 parameters were used, such as the content of plastic substances, food calories, the amount of mineral components, vitamins, the composition of fatty acids and additional substances presented in this database. The analysis revealed correlations, namely, a direct relationship between the value of the antiradical potential (ARP) of food and the concentration of dietary fiber (r = 0.539) and a negative correlation between the value of ARP and the total calorie content of food (r = −0.432) at a significance level of p < 0.001 for both values. The average ARP value for 10 product groups within the 95% CI (confidence interval) was ≈23–28 equivalents (in terms of ascorbic acid) per 1 g of dry matter. The study also evaluated the range of average values of the daily recommended intake of food components (according to Food and Agriculture Organization—FAO, World Health Organization—WHO, Russia and the USA), which within the 95% CI, amounted to 23.41–28.98 equivalents per 1 g of dry weight. Based on the results of the study, it was found that the predicted ARP values depend not only on the type of raw materials and the method of their processing, but also on a number of other environmental and technological factors that make it difficult to obtain accurate values. Full article
(This article belongs to the Special Issue Advances in Agricultural Food and Pharmaceutical Analysis)
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10 pages, 1185 KiB  
Article
A Comparative Study of Two Martensitic Alloy Systems in Endodontic Files Carried out by Unskilled Hands
by Juan Algar, Alejandra Loring-Castillo, Ruth Pérez-Alfayate, Carmen Martín Carreras-Presas and Ana Suárez
Appl. Sci. 2022, 12(12), 6289; https://doi.org/10.3390/app12126289 - 20 Jun 2022
Viewed by 1767
Abstract
The aim of this study was to compare the behavior of two heat-treated file systems on resin blocks in unskilled hands. For this purpose, an in vitro, randomized, cross-sectional study was conducted to compare ProTaper Gold (PTG) with BlueShaper (BS) files. A total [...] Read more.
The aim of this study was to compare the behavior of two heat-treated file systems on resin blocks in unskilled hands. For this purpose, an in vitro, randomized, cross-sectional study was conducted to compare ProTaper Gold (PTG) with BlueShaper (BS) files. A total of 81 resin blocks were used and analyzed photographically to assess the amount of material removed during instrumentation. PTG removed more material on the outside of the curve in the coronal and apical third, while BS removed more material on the inner part of the curve in the middle third. The procedural errors observed in the total sample were apical transportation (33.8%), blockages (4.9%), ledges (3.7%), and canal perforation. PTG produced more apical transportation, and there were no statistically significant differences between the groups in the formation of ledges, canal perforations, or blockages. No file fractures were recorded during the study. Within the limitations of this study, we can affirm that neither file excessively deformed the artificial canals, and the PTG file produced more apical transportation. Full article
(This article belongs to the Section Biomedical Engineering)
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12 pages, 5756 KiB  
Article
Analysis of Cavity Corner Geometry Effect on Recirculation Zone Structure
by Justas Šereika, Paulius Vilkinis and Nerijus Pedišius
Appl. Sci. 2022, 12(12), 6288; https://doi.org/10.3390/app12126288 - 20 Jun 2022
Cited by 4 | Viewed by 1600
Abstract
A numerical investigation of flow topology in open-type cavities with length-to-depth ratio L/h1 = 4 was performed in the Reynolds number range of 10–1000. Cavities with differently rounded corners were chosen for simulation. Three-dimensional numerical simulations were performed to analyse [...] Read more.
A numerical investigation of flow topology in open-type cavities with length-to-depth ratio L/h1 = 4 was performed in the Reynolds number range of 10–1000. Cavities with differently rounded corners were chosen for simulation. Three-dimensional numerical simulations were performed to analyse flow topology in different planes. A series of experiments was performed to ensure the validity of numerical simulations. Both numerical simulations and physical experiments were conducted with water as the working fluid. Since the results agreed acceptably, further simulations were performed. The main goal of this study was to investigate and highlight the influence of rounded cavity corners on the topology and stability of flow. Analysis revealed that fully rounded upper cavity corners decrease pressure loss compared to other investigated cases; therefore, the velocity of the main flow is increased. Additionally, fully rounded upper corners form a notably smaller recirculation zone compared to other investigated cases. Flow stability analysis showed that fully rounded cavity bottom corners negatively impact flow stability by increasing the intensity of turbulence. Full article
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25 pages, 4883 KiB  
Article
Thermal Evaluation of a Novel Integrated System Based on Solid Oxide Fuel Cells and Combined Heat and Power Production Using Ammonia as Fuel
by Phan Anh Duong, Borim Ryu, Jinwon Jung and Hokeun Kang
Appl. Sci. 2022, 12(12), 6287; https://doi.org/10.3390/app12126287 - 20 Jun 2022
Cited by 18 | Viewed by 2866
Abstract
A novel integrated system based on solid oxide fuel cells (SOFCs), a gas turbine (GT), the steam Rankine cycle (SRC), the Kalina cycle (KC), and the organic Rankine cycle (ORC) is proposed to achieve cascade energy utilization. Mathematical models are introduced and system [...] Read more.
A novel integrated system based on solid oxide fuel cells (SOFCs), a gas turbine (GT), the steam Rankine cycle (SRC), the Kalina cycle (KC), and the organic Rankine cycle (ORC) is proposed to achieve cascade energy utilization. Mathematical models are introduced and system performance is analyzed using energy and exergy methods. The first and second laws of thermodynamics are used to analyze the system thermodynamically. In addition, exergy destruction and losses of the various integrated subsystems are calculated. The energy and exergy efficiencies of the multigeneration system are estimated to be 60.4% and 57.3%, respectively. In addition, the hot water produced during the waste heat recovery process may also be used for accommodating seafarers on ships. Sequential optimization is developed to optimize the operating conditions of the integrated system to achieve the required power output. A comprehensive parametric study is conducted to investigate the effect of varying the current densities of the fuel cell and working fluid of the ORC on the overall performance of the combined system and subsystems. The working performance of five working fluids for the ORC as candidates—R134a, R600, R601, R152a, and R124—is compared. R152a, which provides 71.23 kW of power output, and energy and exergy efficiencies of 22.49% and 42.76%, respectively, is selected as the best thermodynamic performance for the ORC. Full article
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19 pages, 5376 KiB  
Article
Combining High-Resolution Hard X-ray Tomography and Histology for Stem Cell-Mediated Distraction Osteogenesis
by Griffin Rodgers, Guido R. Sigron, Christine Tanner, Simone E. Hieber, Felix Beckmann, Georg Schulz, Arnaud Scherberich, Claude Jaquiéry, Christoph Kunz and Bert Müller
Appl. Sci. 2022, 12(12), 6286; https://doi.org/10.3390/app12126286 - 20 Jun 2022
Cited by 2 | Viewed by 1884
Abstract
Distraction osteogenesis is a clinically established technique for lengthening, molding and shaping bone by new bone formation. The experimental evaluation of this expensive and time-consuming treatment is of high impact for better understanding of tissue engineering but mainly relies on a limited number [...] Read more.
Distraction osteogenesis is a clinically established technique for lengthening, molding and shaping bone by new bone formation. The experimental evaluation of this expensive and time-consuming treatment is of high impact for better understanding of tissue engineering but mainly relies on a limited number of histological slices. These tissue slices contain two-dimensional information comprising only about one percent of the volume of interest. In order to analyze the soft and hard tissues of the entire jaw of a single rat in a multimodal assessment, we combined micro computed tomography (µCT) with histology. The µCT data acquired before and after decalcification were registered to determine the impact of decalcification on local tissue shrinkage. Identification of the location of the H&E-stained specimen within the synchrotron radiation-based µCT data collected after decalcification was achieved via non-rigid slice-to-volume registration. The resulting bi- and tri-variate histograms were divided into clusters related to anatomical features from bone and soft tissues, which allowed for a comparison of the approaches and resulted in the hypothesis that the combination of laboratory-based µCT before decalcification, synchrotron radiation-based µCT after decalcification and histology with hematoxylin-and-eosin staining could be used to discriminate between different types of collagen, key components of new bone formation. Full article
(This article belongs to the Topic Medical Image Analysis)
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29 pages, 8995 KiB  
Article
Investigation of the Effect of Capillary Barrier on Water–Oil Movement in Water Flooding
by Bingtao Hu, Zhaolin Gu, Chenxing Zhou, Le Wang, Chuanqing Huang and Junwei Su
Appl. Sci. 2022, 12(12), 6285; https://doi.org/10.3390/app12126285 - 20 Jun 2022
Cited by 7 | Viewed by 2023
Abstract
Water flooding technology is widely used to improve oil recovery efficiency in oilfields. The capillary barrier effect induced by the complex pore structures in the reservoir rocks is a crucial reason for the trapping of a great deal of residual oil in oil [...] Read more.
Water flooding technology is widely used to improve oil recovery efficiency in oilfields. The capillary barrier effect induced by the complex pore structures in the reservoir rocks is a crucial reason for the trapping of a great deal of residual oil in oil reservoirs after water flooding. However, the formation condition along with the effect on the recovery rate of the capillary barrier under different wettability conditions should be investigated further. To bridge the gap between the microscopic mechanism of the capillary barrier effect and the macroscopic mechanism of oil displacement efficiency, a simple conceptual capillary model is constructed to obtain the formation conditions of the capillary barrier using the analysis method, and its influence on macroscopic oil displacement efficiency in the porous media model with an opening angle of 45° is systematically investigated in this study using direct numerical simulations (DNS) coupled with the volume of fluid method. The results showed that the capillary barrier effect plays a significant role in the formation of the residual oil in the reservoir rock and the contact angle and the opening angle are the primary factors for the formation of the capillary barrier. The capillary force is the driving force when the oil–water interface advances in the throat channel under water-wet conditions, while the capillary force hinders the movement of oil–water movement when the liquid flows out of the throat channel and when θ + β > 90o. Furthermore, the highest oil displacement efficiency is achieved at the intermediate capillary number and in the case that the minimum conditions of occurrence of the capillary barrier phenomenon are satisfied. This is of great significance for controlling the optimized contact angle to further enhance the oil recovery rate of current oil reservoirs using waterflooding technology. Full article
(This article belongs to the Topic Enhanced Oil Recovery Technologies)
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17 pages, 2793 KiB  
Article
An Extended Functional Design Approach Based on Working Principle and Property and Its Application
by Song Li, Wenqiang Li and Yan Li
Appl. Sci. 2022, 12(12), 6284; https://doi.org/10.3390/app12126284 - 20 Jun 2022
Viewed by 1856
Abstract
(1) Background: Functional design is an activity that is part of conceptual design; it aims to clarify customer needs and develop the functional architecture and solution concepts for a product or system under development. The existing functional design approaches mainly focus on assisting [...] Read more.
(1) Background: Functional design is an activity that is part of conceptual design; it aims to clarify customer needs and develop the functional architecture and solution concepts for a product or system under development. The existing functional design approaches mainly focus on assisting designers in searching for design solutions to desired functions, which rely too much on established design knowledge. This type of approach is usually characterized by the relevant design analogy, especially case analogy, or structure analogy. However, this cannot help to generate new design solutions if there is little established design knowledge. (2) Methods: To overcome this limitation, working principle and property are designated as intermediate transformation variables. The corresponding mapping relationships, from function to working principle, and from working principle to property, are comprehensively discussed. Then, an extended functional design approach is proposed, which is characterized by the function (F)–working principle (WP)–property (P)–structure (S) mapping process. The conceptual design of a self-adaptive luggage transfer device is taken as an example to illustrate the proposed approach. (3) Conclusions: Based on the working principle and the desired property, how to generate a possible structure solution according to an expected function is clarified explicitly. The proposed approach could be regarded as a complement to the existing functional design approach. Full article
(This article belongs to the Section Mechanical Engineering)
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23 pages, 2927 KiB  
Review
Deep Learning for Video Application in Cooperative Vehicle-Infrastructure System: A Comprehensive Survey
by Beipo Su, Yongfeng Ju and Liang Dai
Appl. Sci. 2022, 12(12), 6283; https://doi.org/10.3390/app12126283 - 20 Jun 2022
Cited by 1 | Viewed by 2031
Abstract
Video application is a research hotspot in cooperative vehicle-infrastructure systems (CVIS) which is greatly related to traffic safety and the quality of user experience. Dealing with large datasets of feedback from complex environments is a challenge when using traditional video application approaches. However, [...] Read more.
Video application is a research hotspot in cooperative vehicle-infrastructure systems (CVIS) which is greatly related to traffic safety and the quality of user experience. Dealing with large datasets of feedback from complex environments is a challenge when using traditional video application approaches. However, the in-depth structure of deep learning has the ability to deal with high-dimensional data sets, which shows better performance in video application problems. Therefore, the research value and significance of video applications over CVIS can be better reflected through deep learning. Firstly, the research status of traditional video application methods and deep learning methods over CVIS were introduced; the existing video application methods based on deep learning were classified according to generative and discriminative deep architecture. Then, we summarized the main methods of deep learning and deep reinforcement learning algorithms for video applications over CVIS, and made a comparative study of their performances. Finally, the challenges and development trends of deep learning in the field were explored and discussed. Full article
(This article belongs to the Special Issue Computer Vision and Pattern Recognition Based on Deep Learning)
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22 pages, 5146 KiB  
Article
Load-Settlement Behaviour Analysis Based on the Characteristics of the Vertical Loads under a Pile Group
by Haijun Liu, Zhaoran Xiao and Kinman Lee
Appl. Sci. 2022, 12(12), 6282; https://doi.org/10.3390/app12126282 - 20 Jun 2022
Cited by 2 | Viewed by 3249
Abstract
The nonlinear load-settlement behaviours of vertically loaded pile groups containing various numbers of piles (up to a few hundred piles in a group) are analysed using the method proposed by Lee and Xiao. This back-analysis method assumes the “local shear displacement” of a [...] Read more.
The nonlinear load-settlement behaviours of vertically loaded pile groups containing various numbers of piles (up to a few hundred piles in a group) are analysed using the method proposed by Lee and Xiao. This back-analysis method assumes the “local shear displacement” of a thin layer of disturbed soil along the pile–soil interface and the soil outside the interface is assumed to be linear elastic. Parametric studies are conducted to examine the load-displacement behaviours of the rigidly capped pile groups. Factors such as the number of piles in a group, pile slenderness (L/D), and pile spacing (S/D) are examined to study the effects on the performance of pile groups up to the failure state. Some phenomenological features of large pile groups under nonlinear conditions, which are difficult to obtain through an elastic analysis, are revealed in the present analysis. Full article
(This article belongs to the Section Civil Engineering)
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15 pages, 3470 KiB  
Review
A Survey of Multi-Focus Image Fusion Methods
by Youyong Zhou, Lingjie Yu, Chao Zhi, Chuwen Huang, Shuai Wang, Mengqiu Zhu, Zhenxia Ke, Zhongyuan Gao, Yuming Zhang and Sida Fu
Appl. Sci. 2022, 12(12), 6281; https://doi.org/10.3390/app12126281 - 20 Jun 2022
Cited by 13 | Viewed by 3424
Abstract
As an important branch in the field of image fusion, the multi-focus image fusion technique can effectively solve the problem of optical lens depth of field, making two or more partially focused images fuse into a fully focused image. In this paper, the [...] Read more.
As an important branch in the field of image fusion, the multi-focus image fusion technique can effectively solve the problem of optical lens depth of field, making two or more partially focused images fuse into a fully focused image. In this paper, the methods based on boundary segmentation was put forward as a group of image fusion method. Thus, a novel classification method of image fusion algorithms is proposed: transform domain methods, boundary segmentation methods, deep learning methods, and combination fusion methods. In addition, the subjective and objective evaluation standards are listed, and eight common objective evaluation indicators are described in detail. On the basis of lots of literature, this paper compares and summarizes various representative methods. At the end of this paper, some main limitations in current research are discussed, and the future development of multi-focus image fusion is prospected. Full article
(This article belongs to the Special Issue Intelligent Processing on Image and Optical Information, Volume III)
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15 pages, 1578 KiB  
Article
The Effect of Soil Amendments on Trace Elements’ Bioavailability and Toxicity to Earthworms in Contaminated Soils
by Aleksandra Ukalska-Jaruga, Grzegorz Siebielec, Sylwia Siebielec and Monika Pecio
Appl. Sci. 2022, 12(12), 6280; https://doi.org/10.3390/app12126280 - 20 Jun 2022
Cited by 7 | Viewed by 1992
Abstract
The aim of this study was to assess the impact of soil amendments, characterized by different sorption properties, on the effectiveness of trace elements’ (Cu, Zn, Pb, Cd, Ni, and Cr) stabilization and bioavailability to earthworms. The study was conducted as a microcosm [...] Read more.
The aim of this study was to assess the impact of soil amendments, characterized by different sorption properties, on the effectiveness of trace elements’ (Cu, Zn, Pb, Cd, Ni, and Cr) stabilization and bioavailability to earthworms. The study was conducted as a microcosm experiment using soil derived from a heavily contaminated post-industrial area. The Eisenia veneta earthworm was cultured for 4 weeks in soils amended with materials characterized by different properties, origins, and potential effects on limiting the availability of metals in soils: two type of compost (Zabrze compost-ZC; GWDA compost-GC), two types of biosolid (Bełchatów biosolids-BB, Grabów biosolids-GB), calcium phosphate (CP), iron oxide (IO), bentonite (BE), rock waste (RW), and limestone (CC). After the incubation, the biomass and survival numbers of the earthworm species decreased significantly (p < 0.05). The accumulation of metals in the earthworm tissues expressed by the bioaccumulation factor value (BSAF) were dependent on the type of amendment applied to the soil. The highest decrease in the earthworms’ weight and survival rate was caused by compost (72%) and bentonite (33%), while the lowest was caused by the rock waste (10%) and iron oxide (11%). The biosolids exhibited the greatest toxicity, causing the mortality of all the earthworms. The accumulation of metals in earthworm tissues and the BSAF value were dependent on the type of amendment applied to the soil. The BSAF for the contaminated soil by Cd decreased to the greatest extent after the addition of ZC (by 57%), GC (55%), CP (41%), and IO (37%). A similarly positive effect was noted for Pb after IO addition (45% decrease). The Zn, Cr, and Ni concentration in earthworms, contrary to other elements, increased, regardless of the amendment. The results showed that the applied soil amendments were characterized by varying potential for the reduction in the metal bioavailability in the soil, depending on their composition and physicochemical properties. Moreover, earthworms may exhibit a diversified response to soil amendments as a result of the impact of amendment on the metal forms in soils and their direct impact on organisms. Generally, the Cd was easily transferred from the soil into and accumulated in the earthworm tissues. Our study confirms that this element creates the highest risk for the trophic chain in soils affected by the Zn and Pb smelting industry. Moreover, greater Zn supply reduces the accumulation of Cd in animal bodies. This study provides valuable practical knowledge on the short-term biological effects of a range of soil amendments in metal-contaminated soils. Full article
(This article belongs to the Special Issue Pollution and Remediation of Groundwater and Soil Environment)
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17 pages, 4903 KiB  
Article
A Generalized Dynamic Model and Coupling Meshing Force Analysis for Planetary Gear Set Transmissions
by Haiwei Wang, Cheng Ji, Fengxia Lu, Cheng Wang and Xueyan Sun
Appl. Sci. 2022, 12(12), 6279; https://doi.org/10.3390/app12126279 - 20 Jun 2022
Viewed by 1836
Abstract
The dynamics analysis of a planetary gear set transmissions requires the creation of completely different models for different gears, which is very tedious. In this paper, a generalized dynamics modeling process is proposed for a three planetary gear set transmissions, and a generalized [...] Read more.
The dynamics analysis of a planetary gear set transmissions requires the creation of completely different models for different gears, which is very tedious. In this paper, a generalized dynamics modeling process is proposed for a three planetary gear set transmissions, and a generalized dynamic model for multiple gears is established by using the lumped mass method. The analysis of meshing force characteristics is carried out for the second gear position, and the meshing frequency coupling phenomenon between the meshing forces of the three planetary gear sets is investigated. The results show that, for the current gear set of meshing force, the meshing frequency components of other gear sets only appear in a part of the speed, and with the increase in speed, certain low-frequency components of other sets that exist at low speed will decrease or even disappear, and the coupling relationship between the meshing forces of different planetary gear sets is not symmetrical. Full article
(This article belongs to the Special Issue AI Applications in the Industrial Technologies)
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37 pages, 7770 KiB  
Article
Heuristic Approach for a Combined Transfer Line Balancing and Buffer Allocation Problem Considering Uncertain Demand
by Huan Shao, Giovanni Moroni, Aiping Li and Liyun Xu
Appl. Sci. 2022, 12(12), 6278; https://doi.org/10.3390/app12126278 - 20 Jun 2022
Cited by 2 | Viewed by 1542
Abstract
In this paper, we refer to a real case study of an industrial partner recently committed to its project on the design of a multi-unit and multi-product manufacturing system. Although the considered problem refers to an actual complex manufacturing system, it can be [...] Read more.
In this paper, we refer to a real case study of an industrial partner recently committed to its project on the design of a multi-unit and multi-product manufacturing system. Although the considered problem refers to an actual complex manufacturing system, it can be theoretically classified as a union of two key problems that need to be solved during the transfer line design stage: the transfer line balancing problem (TLBP) and the buffer allocation problem (BAP). As two closely related problems, TLBP and BAP usually have similar optimizing directions and share the same purpose: finding a balance between the performance of the transfer line system as well as minimizing investment costs. These problems are usually solved sequentially, but this leads to solutions close to a local optimum in the solution space and not to the global optimum of the overall problem. This paper presents a multi-objective optimization for concurrently solving transfer line balancing and buffer allocation problems. The new approach is based on a combination of evolutionary and heuristic-based algorithms and takes into account the uncertainty of market demand. To validate the proposed approach, an industrial case study in a multi-unit manufacturing system producing multiple products (four engine blocks) is discussed. Full article
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42 pages, 11173 KiB  
Article
Vanadium and Cobalt Occurrence in the Fe-Ti-V Oxide Deposits Related to Mesoproterozoic AMCG Complex in NE Poland
by Stanisław Z. Mikulski, Katarzyna Sadłowska, Janina Wiszniewska and Rafał Małek
Appl. Sci. 2022, 12(12), 6277; https://doi.org/10.3390/app12126277 - 20 Jun 2022
Cited by 3 | Viewed by 2674
Abstract
On the basis of geochemical whole-rock and mineralogical point analyses, the concentrations of V and Co were determined in magnetite-ilmenite oxide ores, associated with sulphides, at the Krzemianka and Udryn deposits in the Mesoproterozoic Suwałki Anorthosite Massif (SAM) in NE Poland. EPMA analyses [...] Read more.
On the basis of geochemical whole-rock and mineralogical point analyses, the concentrations of V and Co were determined in magnetite-ilmenite oxide ores, associated with sulphides, at the Krzemianka and Udryn deposits in the Mesoproterozoic Suwałki Anorthosite Massif (SAM) in NE Poland. EPMA analyses showed that the main carrier of vanadium was magnetite (mean = 0.42 wt%) and, to a lesser extent, ilmenite (mean = 0.14 wt%) and minor Al-spinels (mean = 0.04 wt%). In turn, cobalt was found mainly in the form of isomorphic substitutions in magmatic sulphides such as pentlandite (mean = 4.41 wt% Co), pyrrhotite (mean = 0.16 wt%), and chalcopyrite (mean = 0.11 wt%). Moreover, Co-enrichments were also recognized in the secondary sulphides, such as pyrite and bravoite, replacing pyrrhotite (means = 1.6 and 2.7 wt% Co, respectively), and in the form of different thiospinels ((Fe, Ni) (Co, Ni)2S4), mainly siegenite (mean = 22.0 wt% Co), replacing pyrrhotite and pentlandite. Vanadium cations were substituted in Fe, Ti oxide minerals in place of Fe+3 cations, and in the case of cobalt, Fe+2 cations were substituted in sulphides and thiospinels. Vanadium and cobalt showed high Person’s correlation coefficients (r = 0.70), indicating their close spatial coexistence and a common source, which was parental anorthosite-norite magma of the SAM suites. The common magma genesis of magnetite-ilmenite and sulphide mineralization was also confirmed by the very similar shapes of the curves of REE content in the oxide-sulphide ores in relation to chondrite, in which negative Eu anomalies and positive Sm anomalies are clearly visible. Although the average contents of vanadium and cobalt were low (arithmetic means = 960 ppm, and 122 ppm, respectively), the resources of these metals were estimated to be large due to the enormous reserves of magnetite-ilmenite ores hosted by the SAM. However, the Fe-Ti-V ores associated with Fe, Ni, Co, and Cu sulphides were considered to be sub-economic because of their depth of occurrence (mainly 1.0 km below the surface level); their metal contents, which were usually too low; and additionally the fact that the location is in a highly environmentally protected landscape and lake area. Full article
(This article belongs to the Special Issue Mineralogy of Critical Elements Deposits)
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16 pages, 29275 KiB  
Article
An Automatic Foreign Matter Detection and Sorting System for PVC Powder
by Ssu-Han Chen, Jer-Huan Jang, Yu-Ru Chang, Chih-Hsiang Kang, Hung-Yi Chen, Kevin Fong-Rey Liu, Fong-Lin Lee, Yang-Shen Hsueh and Meng-Jey Youh
Appl. Sci. 2022, 12(12), 6276; https://doi.org/10.3390/app12126276 - 20 Jun 2022
Cited by 2 | Viewed by 2713
Abstract
In the present study, an automatic defect detection system has been assembled and introduced for Polyvinyl chloride (PVC) powder. The average diameter for PVC powder is approximately 100 μm. The system hardware includes a powder delivery device, a sieving device, a circular platform, [...] Read more.
In the present study, an automatic defect detection system has been assembled and introduced for Polyvinyl chloride (PVC) powder. The average diameter for PVC powder is approximately 100 μm. The system hardware includes a powder delivery device, a sieving device, a circular platform, an image capture device, and a recycling device. A defect detection algorithm based on YOLOv4 was developed using CSPDarkNet53 as the backbone for feature extraction, spatial pyramid pooling (SPP) and path aggregation network (PAN) as the neck, and Yoloblock as the head. An auto-annotation algorithm was developed based on a digital image processing algorithm to save time in feature engineering. Several hyper-parameters have been employed to improve the efficiency of detection in the process of training YOLOv4. The Taguchi method was utilized to optimize the performance of detection, in which the mean average precision (mAP) is the response. Results show that our optimized YOLOv4 has a test mAP of 0.9385, compared to 0.8653 and 0.7999 for naïve YOLOv4 and Faster RCNN, respectively. Additionally, with the optimized YOLOv4, there is no false alarm for images without any foreign matter. Full article
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20 pages, 11719 KiB  
Article
Dynamic Analysis of the Musical Triangles—Experimental and Numerical Approaches
by Mariana Domnica Stanciu, Silviu Marian Nastac, Voichita Bucur, Mihai Trandafir, Gheorghe Dron and Alina Maria Nauncef
Appl. Sci. 2022, 12(12), 6275; https://doi.org/10.3390/app12126275 - 20 Jun 2022
Cited by 5 | Viewed by 2076
Abstract
This paper addresses the experimental and numerical dynamic analysis of curved bars used as percussion musical instruments. These structures are known as triangles, being made of various metal materials. The study was based on the experimental analysis of the dynamic response over time [...] Read more.
This paper addresses the experimental and numerical dynamic analysis of curved bars used as percussion musical instruments. These structures are known as triangles, being made of various metal materials. The study was based on the experimental analysis of the dynamic response over time and the frequency of three types of triangles, different in material and size. Subsequently, finite element analysis of the same structures modeled with the SimCenter 12 program was performed. The results were compared, highlighting the contribution of material type and geometry in obtaining vibration modes, frequency spectrum, and structural damping coefficient. Between the experimental and the numerical analysis, the obtained errors were below 2.2% in terms of their natural frequencies. The study also highlights the complementarity of the two methods in understanding the vibration modes of triangles. Full article
(This article belongs to the Special Issue Mechanics, Dynamics and Acoustics of Musical Instruments)
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15 pages, 4030 KiB  
Article
Two-Phase Anaerobic Digestion of Corn Steep Liquor in Pilot Scale Biogas Plant with Automatic Control System with Simultaneous Hydrogen and Methane Production
by Elena Chorukova, Venelin Hubenov, Yana Gocheva and Ivan Simeonov
Appl. Sci. 2022, 12(12), 6274; https://doi.org/10.3390/app12126274 - 20 Jun 2022
Cited by 12 | Viewed by 2048
Abstract
Experimental studies of two-phase anaerobic digestion of corn steep liquor in semi-continuous automatic and semi-automatic modes of operation of a cascade of two anaerobic bioreactors with monitoring and control systems were performed. Corn steep liquor—a waste product from the process of treating corn [...] Read more.
Experimental studies of two-phase anaerobic digestion of corn steep liquor in semi-continuous automatic and semi-automatic modes of operation of a cascade of two anaerobic bioreactors with monitoring and control systems were performed. Corn steep liquor—a waste product from the process of treating corn grain for starch extraction—was used as a substrate in the process of anaerobic digestion with simultaneous hydrogen and methane production. The daily yields of biohydrogen in bioreactor 1 of the cascade (with a working volume of 8 dm3) are variable. In good operation, they are in the range of 0.7 to 1.0 L of biogas from a 1 dm3 working volume of the bioreactor, and the optimal pH is in the range of 5.0–5.5. The concentration of hydrogen in the biogas from the hydrogen bioreactor 1 is in the range of 14–34.7%. The daily yields of biomethane in bioreactor 2 of the cascade (with a working volume of 80 dm3) vary in the range 0.4 to 0.85 L of biogas from a 1 dm3 working volume of the bioreactor, and the concentration of methane in the biogas from bioreactor 2 is high and remains practically constant (in the range 65–69%). At a dilution rate of 0.4 day−1 and an organic loading rate of 20 gL for bioreactor 1, respectively, and a dilution rate of 0.05 day−1 for bioreactor 2, the best results were obtained. The computer control system is presented. Some energetical considerations were discussed. Full article
(This article belongs to the Section Applied Biosciences and Bioengineering)
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13 pages, 4737 KiB  
Article
Application of Sensitivity Analysis to Progressive Collapse Resistance of Planar Truss Structures
by Changren Ke and Qian Liu
Appl. Sci. 2022, 12(12), 6273; https://doi.org/10.3390/app12126273 - 20 Jun 2022
Cited by 1 | Viewed by 1416
Abstract
The conventional sensitivity analysis method unanimously takes all remaining elements except the damaged ones as statistical objects, and element importance is evaluated by the mean value of the sensitive indices of statistical objects. However, from the perspective of resisting progressive collapse, the method [...] Read more.
The conventional sensitivity analysis method unanimously takes all remaining elements except the damaged ones as statistical objects, and element importance is evaluated by the mean value of the sensitive indices of statistical objects. However, from the perspective of resisting progressive collapse, the method is not sufficiently targeted, and the evaluation results have some mistakes. The shortcomings of the traditional sensitivity analysis method in element importance evaluation were analyzed and compared through finite element investigations of two types of planar trusses. Based on the anti-progressive collapse mechanism of the planar truss, the sensitivity analysis method with lower chords as statistical objects was proposed to evaluate the importance of planar truss structural elements. This method is conceptually straightforward, and the assessment results are beyond-compare regarding accuracy via comparison against the results of other evaluation methods. Furthermore, based on identifying important elements, the structure’s bearing capacity can be improved by targeted anti-progressive collapse design. Full article
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19 pages, 1813 KiB  
Article
Explanation of What Time in Kinematics Is and Dispelling Myths Allegedly Stemming from the Special Theory of Relativity
by Roman Szostek
Appl. Sci. 2022, 12(12), 6272; https://doi.org/10.3390/app12126272 - 20 Jun 2022
Cited by 4 | Viewed by 2632
Abstract
One of the biggest unsolved problems in physics is explaining what time is. The paper explains what time is in kinematics theories. It has been proved that in the kinematics of Special Theory of Relativity (STR) and Special Theory of Ether (STE) time [...] Read more.
One of the biggest unsolved problems in physics is explaining what time is. The paper explains what time is in kinematics theories. It has been proved that in the kinematics of Special Theory of Relativity (STR) and Special Theory of Ether (STE) time is measured by the light clock. Therefore, all properties of time in kinematics result from the properties of a signal clock. The paper explains the time dilation phenomenon on the basis of STE. The presented explanation is not only a classic description of time dilation but is based on the construction of an innovative technical model of this phenomenon. Time dilation is due to the properties of the light clock. It is a natural property of this clock. The article shows that the claim that the speed of light in a vacuum is the maximum speed in the real world has no theoretical basis. In modern physics, such a doctrine has been adopted as a result of an overinterpretation of the mathematics on which the Special Theory of Relativity is based. The presented model shows how, using atomic clocks, it may be possible to determine the movement in relation to the universal frame of reference in which electromagnetic signals propagate. This article contains only original research. Full article
(This article belongs to the Section Applied Physics General)
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21 pages, 2508 KiB  
Article
Designing Personalized Persuasive Game Elements for Older Adults in Health Apps
by Yongyan Guo, Tongyao Yuan and Siyu Yue
Appl. Sci. 2022, 12(12), 6271; https://doi.org/10.3390/app12126271 - 20 Jun 2022
Cited by 7 | Viewed by 3550
Abstract
The use of gamification elements in health apps has been shown to promote healthy behaviors. However, one-size-fits-all gamification strategy does not have the best persuasive effect. Therefore, the aim of this paper was to determine how to select personalized game elements for older [...] Read more.
The use of gamification elements in health apps has been shown to promote healthy behaviors. However, one-size-fits-all gamification strategy does not have the best persuasive effect. Therefore, the aim of this paper was to determine how to select personalized game elements for older adults and use them in health education app design. Firstly, based on the DMC model, the Kano model was used to identify the demand attributes of game mechanisms, and three gamification mechanisms (winning, feedback and reward) preferred by the elderly were selected. Secondly, the corresponding gamification elements were selected by the focus group method, and nine virtual products were generated. Thirdly, the virtual products were rated and conjointly analyzed to obtain the relative importance of gamification mechanisms and the utility values of gamification elements, and a comparative analysis was conducted on four characteristics of older adults: age, gender, personal income, and education. The results obtained the best combination of gamification elements chosen by the elderly under different classifications. Finally, design guidelines on persuasive gamification elements were developed based on the characteristics of older adults, and a modified gamification model was proposed. The results of this study provide suggestions and guidelines for the design of persuasive gamification in health education apps, which will help improve the satisfaction of older adults with health apps. Full article
(This article belongs to the Topic eHealth and mHealth: Challenges and Prospects)
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18 pages, 18313 KiB  
Article
Fuzzy Multi-Mode Time–Cost–Quality Trade-Off Optimization in Construction Management of Hydraulic Structure Projects
by Serges Mendomo Meye, Guowei Li, Zhenzhong Shen and Jingbin Zhang
Appl. Sci. 2022, 12(12), 6270; https://doi.org/10.3390/app12126270 - 20 Jun 2022
Cited by 3 | Viewed by 1714
Abstract
Along with the increased use of water resources, some large water conservancy projects began construction to address power supply shortages and control flooding and drainage. As investment grows, construction cycles lengthen, external environmental impacts become bigger, and civil engineering project management becomes more [...] Read more.
Along with the increased use of water resources, some large water conservancy projects began construction to address power supply shortages and control flooding and drainage. As investment grows, construction cycles lengthen, external environmental impacts become bigger, and civil engineering project management becomes more complex. The real aim of the hydraulic-structure engineering project model is to manage ways of delivering the project on time while maintaining reasonable quality standards and building costs, to optimize project value. We note that the trade-off between conflicting objectives in a water conservancy project in an uncertain environment is a difficult task. To simulate the relationship between a project’s construction quality and its time limit, two new piecewise functions—a double exponential function and a quadratic function—were proposed, and then a fuzzy multi-mode discrete time–cost–quality trade-off concept for water-management projects was established. This model finds the best solution to an NP-hard problem using the particle-swarm optimization algorithm (PSO). A comparison of the calculations to previous studies validates the model and its computational approach. The optimized results of a water conservation project are provided as a conceptual framework for project planning and construction timeframes. Full article
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22 pages, 3830 KiB  
Article
A Novel CovidDetNet Deep Learning Model for Effective COVID-19 Infection Detection Using Chest Radiograph Images
by Naeem Ullah, Javed Ali Khan, Sultan Almakdi, Mohammad Sohail Khan, Mohammed Alshehri, Dabiah Alboaneen and Asaf Raza
Appl. Sci. 2022, 12(12), 6269; https://doi.org/10.3390/app12126269 - 20 Jun 2022
Cited by 27 | Viewed by 2810
Abstract
The suspected cases of COVID-19 must be detected quickly and accurately to avoid the transmission of COVID-19 on a large scale. Existing COVID-19 diagnostic tests are slow and take several hours to generate the required results. However, on the other hand, most X-rays [...] Read more.
The suspected cases of COVID-19 must be detected quickly and accurately to avoid the transmission of COVID-19 on a large scale. Existing COVID-19 diagnostic tests are slow and take several hours to generate the required results. However, on the other hand, most X-rays or chest radiographs only take less than 15 min to complete. Therefore, we can utilize chest radiographs to create a solution for early and accurate COVID-19 detection and diagnosis to reduce COVID-19 patient treatment problems and save time. For this purpose, CovidDetNet is proposed, which comprises ten learnable layers that are nine convolutional layers and one fully-connected layer. The architecture uses two activation functions: the ReLu activation function and the Leaky Relu activation function and two normalization operations that are batch normalization and cross channel normalization, making it a novel COVID-19 detection model. It is a novel deep learning-based approach that automatically and reliably detects COVID-19 using chest radiograph images. Towards this, a fine-grained COVID-19 classification experiment is conducted to identify and classify chest radiograph images into normal, COVID-19 positive, and pneumonia. In addition, the performance of the proposed novel CovidDetNet deep learning model is evaluated on a standard COVID-19 Radiography Database. Moreover, we compared the performance of our approach with hybrid approaches in which we used deep learning models as feature extractors and support vector machines (SVM) as a classifier. Experimental results on the dataset showed the superiority of the proposed CovidDetNet model over the existing methods. The proposed CovidDetNet outperformed the baseline hybrid deep learning-based models by achieving a high accuracy of 98.40%. Full article
(This article belongs to the Topic Machine Learning Techniques Driven Medicine Analysis)
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15 pages, 4909 KiB  
Article
Limited-Angle CT Reconstruction with Generative Adversarial Network Sinogram Inpainting and Unsupervised Artifact Removal
by En Xie, Peijun Ni, Rongfan Zhang and Xiongbing Li
Appl. Sci. 2022, 12(12), 6268; https://doi.org/10.3390/app12126268 - 20 Jun 2022
Cited by 5 | Viewed by 2205
Abstract
High-quality limited-angle computed tomography (CT) reconstruction is in high demand in the medical field. Being unlimited by the pairing of sinogram and the reconstructed image, unsupervised methods have attracted wide attention from researchers. The reconstruction limit of the existing unsupervised reconstruction methods, however, [...] Read more.
High-quality limited-angle computed tomography (CT) reconstruction is in high demand in the medical field. Being unlimited by the pairing of sinogram and the reconstructed image, unsupervised methods have attracted wide attention from researchers. The reconstruction limit of the existing unsupervised reconstruction methods, however, is to use [0°, 120°] of projection data, and the quality of the reconstruction still has room for improvement. In this paper, we propose a limited-angle CT reconstruction generative adversarial network based on sinogram inpainting and unsupervised artifact removal to further reduce the angle range limit and to improve the image quality. We collected a large number of CT lung and head images and Radon transformed them into missing sinograms. Sinogram inpainting network is developed to complete missing sinograms, based on which the filtered back projection algorithm can output images with most artifacts removed; then, these images are mapped to artifact-free images by using artifact removal network. Finally, we generated reconstruction results sized 512×512 that are comparable to full-scan reconstruction using only [0°, 90°] of limited sinogram projection data. Compared with the current unsupervised methods, the proposed method can reconstruct images of higher quality. Full article
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16 pages, 3115 KiB  
Article
Development of Novel Markers and Creation of Non-Anthocyanin and Anthocyanin-Rich Broccoli (Brassica oleracea var. italica) Cultivars
by Chunqing Liu, Xueqin Yao, Guangqing Li, Lei Huang, Chenghong Liu and Zhujie Xie
Appl. Sci. 2022, 12(12), 6267; https://doi.org/10.3390/app12126267 - 20 Jun 2022
Cited by 4 | Viewed by 1731
Abstract
In broccoli, anthocyanin pigments can be accumulated in the flower bud epidermis, resulting in a purple-green head. This study aimed to create non-anthocyanin green broccoli varieties and anthocyanin-rich purple broccoli varieties using new F3′H and Pur7.1-K1 molecular markers, respectively. The breeding program [...] Read more.
In broccoli, anthocyanin pigments can be accumulated in the flower bud epidermis, resulting in a purple-green head. This study aimed to create non-anthocyanin green broccoli varieties and anthocyanin-rich purple broccoli varieties using new F3′H and Pur7.1-K1 molecular markers, respectively. The breeding program started with crosses of the recipient (superior variety and line) LF02 line with the donor line SN60 carrying the recessive allele f3′h and the donor line BT126 carrying the dominant allele Pur7.1. The F1 hybrids were confirmed with molecular markers and backcrossed with the recurrent parent LF02, followed by cycles of foreground and background selection at each stage. A total of 161 green plants with the f3′hf3′h genotype and 152 purple plants with the Pur7.1Pur7.1 genotype were selected from the BC3F2 line. Among these, 34 green plants and 28 purple plants demonstrated >85% background recovery. The identified plants were selfed to obtain 301 green and 416 purple BC3F3 plants for assessment of major agronomic traits. After these investigations, two green broccoli lines without anthocyanin and three anthocyanin-rich purple lines with the best yield/quality characteristics were obtained. The development of these lines might help provide basic materials and the theoretical basis for breeding commercial broccoli varieties. Full article
(This article belongs to the Special Issue Genetics and Breeding of Broccoli)
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20 pages, 12735 KiB  
Article
Bolt Loosening Detection of Rocket Connection Structure Based on Variational Modal Decomposition and Support Vector Machines
by Weicheng Sun, Zhenqun Guan, Yan Zeng, Jiacheng Pan and Zhonghai Gao
Appl. Sci. 2022, 12(12), 6266; https://doi.org/10.3390/app12126266 - 20 Jun 2022
Cited by 2 | Viewed by 1726
Abstract
This paper designed a bolt-loosening Support Vector Machines’ conduct detection method with feature vectors comprising eigenvalue decomposition based on Variational Modal Decomposition (VMD) and Singular Value Decomposition (SVD), combined with permutation entropy. Particle Swarm Optimization-Support Vector Machines (PSO-SVMs) are used for small-sample machine [...] Read more.
This paper designed a bolt-loosening Support Vector Machines’ conduct detection method with feature vectors comprising eigenvalue decomposition based on Variational Modal Decomposition (VMD) and Singular Value Decomposition (SVD), combined with permutation entropy. Particle Swarm Optimization-Support Vector Machines (PSO-SVMs) are used for small-sample machine learning and can effectively identify and judge the state of bolt preload. The effectiveness of the proposed method is verified in a typical example of a connection structure under random-amplitude impulse loads and Gaussian white noise with different signal-to-noise ratios. The effect of other bolt numbers being arranged is also discussed in the results. This method’s bolt-loosening identification rate is close to 90% under both equal-amplitude and variable-amplitude loads. Following the interference, with a signal-to-noise ratio of 20 dB, the method also has a recognition rate higher than 70% under various working conditions and bolt equipment schemes. The effectiveness of the method was verified by experiments. Full article
(This article belongs to the Section Mechanical Engineering)
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18 pages, 35535 KiB  
Article
Numerical Simulation of the Kelvin Wake Patterns
by Xiaofeng Sun, Miaoyu Cai, Jingkui Wang and Chunlei Liu
Appl. Sci. 2022, 12(12), 6265; https://doi.org/10.3390/app12126265 - 20 Jun 2022
Cited by 7 | Viewed by 2879
Abstract
The ship wave is of great interest for wave drag and coastal erosion. This paper proposes a mechanism of ship wave transformation to explore the effects of ship speed and ship size on the waveform. Firstly, based on the theory of potential flow, [...] Read more.
The ship wave is of great interest for wave drag and coastal erosion. This paper proposes a mechanism of ship wave transformation to explore the effects of ship speed and ship size on the waveform. Firstly, based on the theory of potential flow, the boundary integral equations for the Kelvin ship waves are obtained by deploying the different Kelvin sources or Rankine sources. Then, these integral equations are numerically discretized to a set of nonlinear equations. Finally, the Jacobian−free Newton–Krylov method with a preconditioner is adopted to solve the nonlinear equations. Though imitating plenty of different Kelvin wave patterns, the mechanism of ship wave transformation is proposed to conveniently generate the polymorphic Kelvin wake patterns. The above numerical simulation scheme is verified by comparing simulation results with real ship waves. After that, the wake angle is discussed with the effects of Froude number, source strength and source type by following the mechanism of ship wave transformation. The results show that the wake angle tends to decrease with ship speed but increase with ship size. In addition, for high ship speeds, the effect on the wake angle can be more dramatic. Full article
(This article belongs to the Section Marine Science and Engineering)
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21 pages, 3643 KiB  
Article
Morphometric-hydro Characterization of the Coastal Line between El-Qussier and Marsa-Alam, Egypt: Preliminary Flood Risk Signatures
by Abdelrahman Khalifa, Bashar Bashir, Abdullah Alsalman and Hussein Bachir
Appl. Sci. 2022, 12(12), 6264; https://doi.org/10.3390/app12126264 - 20 Jun 2022
Cited by 8 | Viewed by 2132
Abstract
Egypt is highly exposed to flash flood hazards, particularly in Sinai Peninsula and along the Red Sea coast, causing sudden and huge damages to constructions and huge losses in human lives during a very short time. This paper investigates the dominant characterization of [...] Read more.
Egypt is highly exposed to flash flood hazards, particularly in Sinai Peninsula and along the Red Sea coast, causing sudden and huge damages to constructions and huge losses in human lives during a very short time. This paper investigates the dominant characterization of morphometrical features and their relationships with the hydrological behaviors along an important strip of the western Red Sea coast. The study focuses on analyzing the October 2009 and 2019 storm events along the coastal area between EL-Qussier and Marsa Alam in order to intiate a preliminary flood risk assessment model. Morphometric features along the entire study zone provide a complete scenario of the nature of the catchments and sub-catchments development. Numerous morphometric indexes such as catchments geometry, areal indexes, linear indexes, and relief indexes were examined through processing different sets of data. Modern techniques such as remote sensing and geospatial analysis were applied to process different spatial and spectral data. The hydrological model (HEC-HMS) in the WMS software was run to delineate the catchments and sub-catchments and extract the peak flow hydrograph curves for the main catchments. The results of the water amounts and peak flow were calculated using the SCS unit hydrograph approach. The hydrological characteristics of the major catchments reveal conditions for moderate levels of flash flooding. The study ended with a number of recommendations that could minimize the negative effects of the flash flood hazards. Full article
(This article belongs to the Special Issue Natural Hazards and Geomorphology)
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11 pages, 1169 KiB  
Article
Assessment of Communication Quality through Work Authorization between Dentists and Dental Technicians in Fixed and Removable Prosthodontics
by Hadiqa Afzal, Naseer Ahmed, Abhishek Lal, Khulud A. Al-Aali, Mohammed Alrabiah, Mai M. Alhamdan, Ahmed Albahaqi, Abdulaziz Sharaf, Fahim Vohra and Tariq Abduljabbar
Appl. Sci. 2022, 12(12), 6263; https://doi.org/10.3390/app12126263 - 20 Jun 2022
Cited by 4 | Viewed by 3175
Abstract
Fabrication of a clinically successful dental prosthesis requires clear and effective communication between dentists and dental technicians. Adequate completion of work authorization by dentists provides a means for increased professional quality assurance and satisfaction in dental prosthesis. The aim of this study was [...] Read more.
Fabrication of a clinically successful dental prosthesis requires clear and effective communication between dentists and dental technicians. Adequate completion of work authorization by dentists provides a means for increased professional quality assurance and satisfaction in dental prosthesis. The aim of this study was to evaluate the quality of communication between dentists and dental technicians via work authorization for fixed and removable dental prosthesis in Pakistan. This cross-sectional study was conducted for a period of 6 months to assess the quality of communication between dentists and dental technicians. A well-constructed questionnaire regarding work authorization of removable and fixed prostheses was used as a tool to collect data from 453 dentists. A linear regression analysis was performed to evaluate the relationship of the independent and dependent variables. A p value of ≤0.05 was considered statistically significant. It was observed that 92.1% of the dentists leave removable partial denture design to the dental technicians. About 56.5% of the dentists indicated information about base retention of partial dentures in work authorization. The majority of the dentists (56.5%) mentioned the material to be used for the construction of casting partial dentures. Nearly 66% of the dentists indicated the design of margins, and 44.6% of the dentists did not select the shade for fixed prostheses. Nearly 43% of the dentists did not draw the design of restoration, 21.9% chose to draw the design on paper, and 32.2% of the dentists drew the design on the cast. Meanwhile, 76.8% of the participants chose to directly communicate with their dental technicians personally. Nearly 41% of the dentists were satisfied with the restoration design, and 13.5% of the participants were not satisfied with the designs. Poor communication between dentists and technicians was observed, as the majority of the design decisions were left to the dental technicians. Therefore, communication between dentists and dental technicians should be improved by conducting combined workshops for the successful construction of dental prostheses. Full article
(This article belongs to the Special Issue Advances in Dental Materials: A Look inside Digital Workflows)
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