Applied Sciences

18 pages, 5247 KiB

Open AccessFeature PaperArticle

A New Approach for Grid-Connected Hybrid Renewable Energy System Sizing Considering Harmonic Contents of Smart Home Appliances

by Ayşe Kübra Erenoğlu, Alper Çiçek, Oktay Arıkan, Ozan Erdinç and João P. S. Catalão

Appl. Sci. 2019, 9(18), 3941; https://doi.org/10.3390/app9183941 - 19 Sep 2019

Cited by 8 | Viewed by 3835

Abstract

Even renewable energy sources provide several advantages, especially from an environmental point of view, where the world has faced great challenges in the last few decades; several negative issues also exist regarding the integration of renewable resources-based power production units in electric power [...] Read more.

Even renewable energy sources provide several advantages, especially from an environmental point of view, where the world has faced great challenges in the last few decades; several negative issues also exist regarding the integration of renewable resources-based power production units in electric power systems. One of the main problems related to pivotal renewable energy resources such as solar, wind, etc., is their stochastic and uncontrollable nature in terms of power production. Therefore, this stochasticity in the supply side of the power system may pose many challenges for system operators. This issue is also problematic for smaller applications where the stochastic production by a main resource, such as a roof-top photovoltaic system, and load demand may not match perfectly at each time instant and therefore should be compensated by additional resources such as battery-based energy storage systems. Herein, the economic considerations to ensure minimum costs for such a hybrid system design are vital so as to increase the penetration of such systems. Therefore, the optimal sizing and planning of hybrid systems have recently gained increasing importance to enhance power system operation in the context of the smart grid paradigm. From a different perspective, harmonics are one of the most important power quality problems in system operations caused by widespread integration of power electronic loads with non-linear characteristics that should be considered. Thus, a new approach for grid-connected hybrid renewable energy system sizing is provided. In order to determine optimal capacities for photovoltaic (PV) and energy storage system (ESS) units for covering residential consumer demand, a mixed integer linear programming (MILP)-based formulation is presented. The main objective is minimizing total costs of the system consisting of investment, capital and maintenance cost functions. A daily power curve is created accurately with real measurements of non-linear loads considering harmonic contents of smart home appliances in Yildiz Technical University, Istanbul, Turkey. In addition, real radiation and temperature values are used in PV production as well as dynamic pricing schemes for realistic evaluations. Moreover, optimal sizing results are compared for both the harmonic-based power curve and rated power curve in terms of satisfying objective function. Full article

(This article belongs to the Special Issue Smart Home and Energy Management Systems 2019)

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15 pages, 3716 KiB

Open AccessArticle

Shipborne Acquisition, Tracking, and Pointing Experimental Verifications towards Satellite-to-Sea Laser Communication

by Dong He, Qiang Wang, Xiang Liu, Zhijun Song, Jianwei Zhou, Zhongke Wang, Chunyang Gao, Tong Zhang, Xiaoping Qi, Yi Tan, Ge Ren, Bo Qi, Jigang Ren, Yuan Cao and Yongmei Huang

Appl. Sci. 2019, 9(18), 3940; https://doi.org/10.3390/app9183940 - 19 Sep 2019

Cited by 14 | Viewed by 4950

Abstract

Acquisition, tracking, and pointing (ATP) is a key technology in free space laser communication that has a characteristically high precision. In this paper, we report the acquisition and tracking of low-Earth-orbit satellites using shipborne ATP and verify the feasibility of establishing optical links [...] Read more.

Acquisition, tracking, and pointing (ATP) is a key technology in free space laser communication that has a characteristically high precision. In this paper, we report the acquisition and tracking of low-Earth-orbit satellites using shipborne ATP and verify the feasibility of establishing optical links between laser communication satellites and ships in the future. In particular, we developed a shipborne ATP system for satellite-to-sea applications in laser communications. We also designed an acquisition strategy for satellite-to-sea laser communication. In addition, a method was proposed for improving shipborne ATP pointing error. We tracked some stars at sea, achieving a pointing accuracy of less than 180μrad.We then acquired and tracked some low-Earth-orbit satellites at sea, achieving a tracking accuracy of about 20μrad. The results achieved in this work experimentally demonstrate the feasibility of ATP in satellite-to-sea laser communications. Full article

(This article belongs to the Special Issue Optical Communications and Networking: Prospects in Industrial Applications)

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14 pages, 3293 KiB

Open AccessArticle

Effects of the Projectile Geometries on Normal and Oblique Penetration Using the Finite Cavity Pressure Method

by Yo-Han YOO, Jong-Bong KIM and Chang-Whan LEE

Appl. Sci. 2019, 9(18), 3939; https://doi.org/10.3390/app9183939 - 19 Sep 2019

Cited by 12 | Viewed by 3667

Abstract

In this work, the penetration depth of a projectile with various geometries was analyzed using the cavity pressure method. The finite cavity method combines an analytical method and the finite element method and considers the deformation of the projectile only. This simulation method [...] Read more.

In this work, the penetration depth of a projectile with various geometries was analyzed using the cavity pressure method. The finite cavity method combines an analytical method and the finite element method and considers the deformation of the projectile only. This simulation method was implemented to ABAQUS/Explicit using user subroutine VDLOAD. The target material was 6061-T6511 aluminum material, and the projectile material was vacuum-arc-remelted (VAR) 4340 steel. In the analysis, the normal impact and the oblique impact with the angle of 30° were studied. First, the developed simulation model was verified using the previous experiments. With the developed finite element analysis with the cavity pressure method, the effect of projectile shape on penetration was investigated. The target geometry maximizes penetration depth was discussed. The angle of the nose affects mainly on the penetration characteristics. The projectile having an ogive nose with high caliber-radius-head (CRH) value shows the best penetration depth and the least plastic deformation in both the normal impact and the oblique impact. Full article

(This article belongs to the Section Mechanical Engineering)

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15 pages, 4196 KiB

Open AccessArticle

Electrical Stimulation through Conductive Substrate to Enhance Osteo-Differentiation of Human Dental Pulp-Derived Stem Cells

by Yu-Che Cheng, Chien-Hsun Chen, Hong-Wei Kuo, Ting-Ling Yen, Ya-Yuan Mao and Wei-Wen Hu

Appl. Sci. 2019, 9(18), 3938; https://doi.org/10.3390/app9183938 - 19 Sep 2019

Cited by 18 | Viewed by 3914

Abstract

Human dental pulp-derived stem cells (hDPSCs) are promising cellular sources for bone healing. The acceleration of their differentiation should be beneficial to their clinical application. Therefore, a conductive polypyrrole (PPy)-made electrical stimulation (ES) device was fabricated to provide direct-current electric field (DCEF) treatment, [...] Read more.

Human dental pulp-derived stem cells (hDPSCs) are promising cellular sources for bone healing. The acceleration of their differentiation should be beneficial to their clinical application. Therefore, a conductive polypyrrole (PPy)-made electrical stimulation (ES) device was fabricated to provide direct-current electric field (DCEF) treatment, and its effect on osteo-differentiation of hDPSCs was investigated in this study. To determine the optimal treating time, electrical field of 0.33 V/cm was applied to hDPSCs once for 4 h on different days after the osteo-induction. The alizarin red S staining results suggested that ES accelerated the mineralization rates of hDPSCs. The quantification analysis results revealed a nearly threefold enhancement in calcium deposition by ES at day 0, 2, and 4, whereas the promotion effect in later stages was in vain. To determine the ES-mediated signaling pathway, the expression of genes in the bone morphogenetic protein (BMP) family and related receptors were quantified using qPCR. In the early stages of osteo-differentiation, the mRNA levels of BMP2, BMP3, BMP4, and BMP5 were increased significantly in the ES groups, indicating that these genes were involved in the specific signaling routes induced by ES. We are the first using DCEF to improve the osteo-differentiation of hDPSCs, and our results promise the therapeutic applications of hDPSCs on cell-based bone tissue engineering. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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15 pages, 753 KiB

Open AccessArticle

Continuous-Variable Quantum Key Distribution Robust Against Polarization-Dependent Loss

by Ying Guo, Minglu Cai and Duan Huang

Appl. Sci. 2019, 9(18), 3937; https://doi.org/10.3390/app9183937 - 19 Sep 2019

Viewed by 3730

Abstract

Polarization is one of the physical characteristics of optical waves, and the polarization-division-multiplexing (PDM) scheme has gained much attraction thanks to its capability of achieving high transmission rate. In the PDM-based quantum key distribution (QKD), the key information could be encoded independently by [...] Read more.

Polarization is one of the physical characteristics of optical waves, and the polarization-division-multiplexing (PDM) scheme has gained much attraction thanks to its capability of achieving high transmission rate. In the PDM-based quantum key distribution (QKD), the key information could be encoded independently by the optical fields

E_{x}

and

E_{y}

, where the 2-dimensional modulation and orthogonal polarization multiplexing usually result in two-fold channel capacity. Unfortunately, the non-negligible polarization-dependent loss (PDL) caused by the crystal dichroism in optical devices may result in the signal distortion, leading to an imbalanced optical signal-to-noise ratio. Here, we present a polarization-pairwise coding (PPC) scheme for the PDM-based continuous-variable (CV) QKD systems to overcome the PDL problem. Numerical simulation results indicate that the PDL-induced performance degradation can be mitigated. In addition, the PPC scheme, tailored to be robust against a high level of PDL, offers a suitable solution to improve the performance of the PDM-based CVQKD in terms of the secret key rate and maximal transmission distance. Full article

(This article belongs to the Special Issue Quantum Communications and Quantum Networks)

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52 pages, 414 KiB

Open AccessArticle

A Model for Naturalistic Programming with Implementation

by Oscar Pulido-Prieto and Ulises Juárez-Martínez

Appl. Sci. 2019, 9(18), 3936; https://doi.org/10.3390/app9183936 - 19 Sep 2019

Cited by 4 | Viewed by 3137

Abstract

While the use of natural language for software development has been proposed since the 1960s, it was limited by the inherent ambiguity of natural languages, which people resolve using reasoning in a text or conversation. Programming languages are formal general-purpose or domain-specific alternatives [...] Read more.

While the use of natural language for software development has been proposed since the 1960s, it was limited by the inherent ambiguity of natural languages, which people resolve using reasoning in a text or conversation. Programming languages are formal general-purpose or domain-specific alternatives based on mathematical formalism and which are at a remove from natural language. Over the years, various authors have presented studies in which they attempted to use a subset of the English language for solving particular problems. Each author approached the problem by covering particular domains, rather than focusing on describing general elements that would help other authors develop general-purpose languages, instead focusing even more on domain-specific languages. The identification of common elements in these studies reveals characteristics that enable the design and implementation of general-purpose naturalistic languages, which requires the establishment of a programming model. This article presents a conceptual model which describes the elements required for designing general-purpose programming languages and which integrates abstraction, temporal elements and indirect references into its grammar. Moreover, as its grammar resembles natural language, thus reducing the gap between problem and solution domains, a naturalistic language prototype is presented, as are three test scenarios which demonstrate its characteristics. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

11 pages, 3089 KiB

Open AccessArticle

Vision-Based Classification of Mosquito Species: Comparison of Conventional and Deep Learning Methods

by Kazushige Okayasu, Kota Yoshida, Masataka Fuchida and Akio Nakamura

Appl. Sci. 2019, 9(18), 3935; https://doi.org/10.3390/app9183935 - 19 Sep 2019

Cited by 45 | Viewed by 7106

Abstract

This study aims to propose a vision-based method to classify mosquito species. To investigate the efficiency of the method, we compared two different classification methods: The handcraft feature-based conventional method and the convolutional neural network-based deep learning method. For the conventional method, 12 [...] Read more.

This study aims to propose a vision-based method to classify mosquito species. To investigate the efficiency of the method, we compared two different classification methods: The handcraft feature-based conventional method and the convolutional neural network-based deep learning method. For the conventional method, 12 types of features were adopted for handcraft feature extraction, while a support vector machine method was adopted for classification. For the deep learning method, three types of architectures were adopted for classification. We built a mosquito image dataset, which included 14,400 images with three types of mosquito species. The dataset comprised 12,000 images for training, 1500 images for testing, and 900 images for validating. Experimental results revealed that the accuracy of the conventional method using the scale-invariant feature transform algorithm was 82.4% at maximum, whereas the accuracy of the deep learning method was 95.5% in a residual network using data augmentation. From the experimental results, deep learning can be considered to be effective for classifying the mosquito species of the proposed dataset. Furthermore, data augmentation improves the accuracy of mosquito species’ classification. Full article

(This article belongs to the Special Issue Computer Vision and Pattern Recognition in the Era of Deep Learning)

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13 pages, 1179 KiB

Open AccessArticle

Application Research of Multi-Mode Relay in Future Heterogeneous Networks

by Wenle Bai, Yu Xiao, Danping Hu and Yongmei Zhang

Appl. Sci. 2019, 9(18), 3934; https://doi.org/10.3390/app9183934 - 19 Sep 2019

Cited by 1 | Viewed by 2592

Abstract

The fast increase of users in existing mobile networks requires more base stations (BSs) to bear more communication traffic. Future heterogeneous network is considered to be a promising candidate architecture to meet the demands of wireless networks under scarcity of radio frequency (RF) [...] Read more.

The fast increase of users in existing mobile networks requires more base stations (BSs) to bear more communication traffic. Future heterogeneous network is considered to be a promising candidate architecture to meet the demands of wireless networks under scarcity of radio frequency (RF) resources. In this paper, we present a multi-mode relay (MMR) model based on two-way relay technology, which is applied to heterogeneous hierarchical wireless networks (HHWN), and set up a system model of HHWN with 3 tiers, 2 users between the macrocell, and the picocell as the multi-mode relay (MMR). Specifically, we consider the new system with unequal relay emission power situation, which is usually researched in the traditional literature with equal relay emission powers. Based on this idea, we define the two-way SINR ratio, derive the mathematical formulas of outage error probability with channel estimation errors, and verify theoretical expressions by data simulations. For further comparison, several experiments are implemented to illuminate the effect on outage probability among different levels of relay emission power, noise power, and signal power. Furthermore, several conclusions are obtained, which have some meanings for implementing MMR in future heterogeneous networks. Full article

(This article belongs to the Special Issue 5G Networks: Optimization, Machine Learning And Blockchain Technologies)

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18 pages, 1910 KiB

Open AccessArticle

Preparation and Characterization of Chitosan–Alginate Polyelectrolyte Complexes Loaded with Antibacterial Thyme Oil Nanoemulsions

by Hamid Hamedi, Sara Moradi, Alan E. Tonelli and Samuel M. Hudson

Appl. Sci. 2019, 9(18), 3933; https://doi.org/10.3390/app9183933 - 19 Sep 2019

Cited by 43 | Viewed by 6534

Abstract

Biomedical industries are attempting to utilize natural materials, as they are bio-compatible, non-toxic, and show bioactive properties, like antimicrobial activity. In this study, natural polyelectrolyte complexed chitosan/alginate films (PECs) were prepared via a casting/solvent evaporation technique, and their characteristics and drug release properties [...] Read more.

Biomedical industries are attempting to utilize natural materials, as they are bio-compatible, non-toxic, and show bioactive properties, like antimicrobial activity. In this study, natural polyelectrolyte complexed chitosan/alginate films (PECs) were prepared via a casting/solvent evaporation technique, and their characteristics and drug release properties were investigated. PEC films made with two different overall polymer contents, 0.4 and 1 w/v%, were loaded with thyme oil nanoemulsion as drug carrier. The structure of the films was studied by FTIR and optical and scanning electron microscopy. Prepared PEC films had good mechanical and water vapor permeability properties. Release of the thyme oil from the pH-sensitive PEC films (TM-PEC) was detected and followed by UV spectroscopy. The results indicated that the drug release rate of TM-PEC films was the fastest when the chitosan content was 1 %w/v, and various mathematical models were analyzed for investigating the drug release mechanism. Antibacterial tests were performed by counting the number of surviving gram-negative and gram-positive bacteria. The in vitro test indicated the limitation Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) growth in the presence of TM-PEC films. The MTT test showed more cell viability of the TM-PEC film in comparison with that of the PEC film without TM. Based on the measured physical and antibacterial properties, the chitosan–alginate PEC films loaded with antibacterial essential oils can be considered for biomedical applications, such as wound dressings or controlled release systems. Full article

(This article belongs to the Special Issue Smart Wound Dressings)

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Graphical abstract

23 pages, 13017 KiB

Open AccessArticle

Implementation of Lean Manufacturing to Reduce the Delivery Time of a Replacement Part to Dealers: A Case Study

by Carlos Eleazar Pérez-Pucheta, Elias Olivares-Benitez, Hertwin Minor-Popocatl, Prudencio Fidel Pacheco-García and Marcos Fernando Pérez-Pucheta

Appl. Sci. 2019, 9(18), 3932; https://doi.org/10.3390/app9183932 - 19 Sep 2019

Cited by 22 | Viewed by 7462

Abstract

In today’s automotive industry, Lean production systems are used successfully to reduce delivery times. The current case study addresses a problem that affects an automotive company, which is the excessive delivery time of a spare part to its both national and international authorized [...] Read more.

In today’s automotive industry, Lean production systems are used successfully to reduce delivery times. The current case study addresses a problem that affects an automotive company, which is the excessive delivery time of a spare part to its both national and international authorized dealers. In order to reduce the delivery time of this replacement part, the Lean Manufacturing methodology was used. For this purpose, the value stream mapping and the proposed A3 report are the tools used. With the use of these tools, activities that did not add any value are eliminated or modified; in addition, the logistical flow of the modules of the door-side trim panel delivery process is improved. As a result, added value is increased, the delivery time is reduced (for Mexico) and the number of product variants is reduced. Now, the painting process is done by the authorized dealers, and the number of pieces used for every spare part was estimated. The study demonstrates that the integration of value stream mapping administrative/productive in conjunction with the A3 report proposal allows to identify and eliminate waste in the delivery process. Full article

(This article belongs to the Special Issue Applied Engineering to Lean Manufacturing Production Systems)

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13 pages, 4187 KiB

Open AccessArticle

Mechanical Properties and Crack Classification of Basalt Fiber RPC Based on Acoustic Emission Parameters

by Hanbing Liu, Shiqi Liu, Peilei Zhou, Yuwei Zhang and Yubo Jiao

Appl. Sci. 2019, 9(18), 3931; https://doi.org/10.3390/app9183931 - 19 Sep 2019

Cited by 21 | Viewed by 2914

Abstract

The workability and mechanical properties of basalt fiber reactive powder concrete (BFRPC) were investigated by univariate analysis. The acoustic emission (AE) was used as a non-destructive technique to reveal the damage characterization of concrete samples of varying basalt fiber content. The fracture stages [...] Read more.

The workability and mechanical properties of basalt fiber reactive powder concrete (BFRPC) were investigated by univariate analysis. The acoustic emission (AE) was used as a non-destructive technique to reveal the damage characterization of concrete samples of varying basalt fiber content. The fracture stages and modes of specimens during flexural test were determined by AE parameters. The content of silica fume, quartz sand and basalt fiber of 0.4, 1.3 and 10 kg/m³, respectively, was found related to optimal improvements in mechanical strength. As for the characteristics of fracture, it was found that the fiber content was a significant determinant, and the key AE parameters, namely, hits, energy and amplitude, were found related to the damage stage of specimens. Furthermore, rise time (RA) and average frequency (AF) were found to have opposite trends during loading while their variation related to the fracture modes of BFRPC. Full article

(This article belongs to the Section Materials Science and Engineering)

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21 pages, 3507 KiB

Open AccessArticle

Indoor Localization Based on Wi-Fi Received Signal Strength Indicators: Feature Extraction, Mobile Fingerprinting, and Trajectory Learning

by Jaehyun Yoo and Jongho Park

Appl. Sci. 2019, 9(18), 3930; https://doi.org/10.3390/app9183930 - 19 Sep 2019

Cited by 15 | Viewed by 5037

Abstract

This paper studies the indoor localization based on Wi-Fi received signal strength indicator (RSSI). In addition to position estimation, this study examines the expansion of applications using Wi-Fi RSSI data sets in three areas: (i) feature extraction, (ii) mobile fingerprinting, and (iii) mapless [...] Read more.

This paper studies the indoor localization based on Wi-Fi received signal strength indicator (RSSI). In addition to position estimation, this study examines the expansion of applications using Wi-Fi RSSI data sets in three areas: (i) feature extraction, (ii) mobile fingerprinting, and (iii) mapless localization. First, the features of Wi-Fi RSSI observations are extracted with respect to different floor levels and designated landmarks. Second, the mobile fingerprinting method is proposed to allow a trainer to collect training data efficiently, which is faster and more efficient than the conventional static fingerprinting method. Third, in the case of the unknown-map situation, the trajectory learning method is suggested to learn map information using crowdsourced data. All of these parts are interconnected from the feature extraction and mobile fingerprinting to the map learning and the estimation. Based on the experimental results, we observed (i) clearly classified data points by the feature extraction method as regards the floors and landmarks, (ii) efficient mobile fingerprinting compared to conventional static fingerprinting, and (iii) improvement of the positioning accuracy owing to the trajectory learning. Full article

(This article belongs to the Special Issue Recent Advances in Indoor Localization Systems and Technologies)

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20 pages, 2579 KiB

Open AccessArticle

Research on Optimal Dispatching Strategy for Micro-Energy-Grid of Protected Agriculture

by Yuntao Ju, Mingxin Jin, Jiankai Wang, Jianhua Yang, Mingyu Dong, Dezhi Li, Kun Shi and Haibo Zhang

Appl. Sci. 2019, 9(18), 3929; https://doi.org/10.3390/app9183929 - 19 Sep 2019

Cited by 11 | Viewed by 2652

Abstract

With the growth in demand for energy and the boom in energy internet (EI) technologies, comes the multi-energy complementary system. In this paper, we first model the components of the micro-energy-grid for a greenhouse, and then analyzed two types of protected agriculture load: [...] Read more.

With the growth in demand for energy and the boom in energy internet (EI) technologies, comes the multi-energy complementary system. In this paper, we first model the components of the micro-energy-grid for a greenhouse, and then analyzed two types of protected agriculture load: time-shifting load and non-time-shifting load. Next, multi-scenario technology is directed against the uncertainty of photovoltaic (PV). Latin Hypercube Sampling (LHS) and the backward reduction algorithm are the two main methods we use to generate the representative scenarios and their probabilities, which are the basis for PV prediction in day-ahead scheduling. Third, besides the time of day (TOD) tariff, we present a model using real-time pricing of consumers’ electricity load, which is proposed to compare consumers’ demand response (DR). Finally, we establish a new optimization model of micro-energy-grid for greenhouses. By calculating the dispatch of electricity, heat, energy storage and time-shifting load under different conditions, the local consumption of PV and the comprehensive operational cost of micro-energy-grid can be analyzed. The results show that a storage device, time-shifting load and real-time pricing can bring more possibilities to the micro-energy-grid. By optimizing the time schedule of time-shifting load, the cost of the greenhouse is reduced. Full article

(This article belongs to the Special Issue Renewable Energy in Agriculture)

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23 pages, 6192 KiB

Open AccessArticle

Issues on the Vibration Analysis of In-Service Laminated Glass Structures: Analytical, Experimental and Numerical Investigations on Delaminated Beams

by Chiara Bedon

Appl. Sci. 2019, 9(18), 3928; https://doi.org/10.3390/app9183928 - 19 Sep 2019

Cited by 42 | Viewed by 4694

Abstract

Load-bearing laminated glass (LG) elements take the form of simple members in buildings (i.e., columns, beams, and plates) or realize stand-alone assemblies, where glass and other traditional constructional materials can interact. Among several relevant aspects, the dynamic response of LG structures requires dedicated [...] Read more.

Load-bearing laminated glass (LG) elements take the form of simple members in buildings (i.e., columns, beams, and plates) or realize stand-alone assemblies, where glass and other traditional constructional materials can interact. Among several relevant aspects, the dynamic response of LG structures requires dedicated methods of analysis, towards the fulfilment of safe design purposes. A combination of multiple aspects must be taken into account for dynamic calculations of even simple LG elements when compared to static conditions, first of all the sensitivity of common interlayers to the imposed vibration frequency. The challenge is even more complex for the vibration serviceability assessment of in-service LG structures, where the degradation of materials and possible delamination effects could manifest, hence resulting in structural performances that can markedly differ from early-design conditions. Major uncertainties can be associated to the actual mechanical characterization of materials in use (especially the viscoelastic interlayers), as well as the contribution of restraints (as compared to ideal boundaries) and the possible degradation of the bonding layers (i.e., delaminations). All of these aspects are examined in the paper, with the support of extended analytical calculations, on-site experimental measurements, and parametric Finite Element (FE) numerical analyses. When compared to literature efforts accounting for ideal boundaries only, an analytical formulation is proposed to include the effects of flexible restraints in the dynamic performance of general (double) LG beams. Special care is also spent for the presence of possible delaminations, including size and position effects. In the latter case, existing formulations for composite laminates are preliminarily adapted to LG beams. Their reliability and accuracy is assessed with the support of test predictions and parametric FE simulations. Full article

(This article belongs to the Special Issue Buildings and Structures under Extreme Loads)

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15 pages, 2821 KiB

Open AccessArticle

Experimental Verification of Yam (Dioscorea rotundata) Drying with Solar Adsorption Drying

by Emmanuel Amankwah, Gloria Kyere, Herbert Kyeremateng and Anton van Boxtel

Appl. Sci. 2019, 9(18), 3927; https://doi.org/10.3390/app9183927 - 19 Sep 2019

Cited by 10 | Viewed by 4230

Abstract

This work evaluates the yam (Dioscorea rotundata) drying performance of solar adsorption drying (SAD) compared to solar drying (SD) and open sun drying (OSD). The evaluation concerns the drying cycle for batches of yam, the effect on vitamin C, color and composition. [...] Read more.

This work evaluates the yam (Dioscorea rotundata) drying performance of solar adsorption drying (SAD) compared to solar drying (SD) and open sun drying (OSD). The evaluation concerns the drying cycle for batches of yam, the effect on vitamin C, color and composition. As SAD can be applied during the night, by using air dehumidified by passing through a bed of silica gel, the cycle time for drying batches of yam can be reduced over 20–25% compared to SD and halved compared to OSD. SAD is thereby most effective during the first nights of drying when the driving force is the highest. Composition was not affected by drying methods but did affect vitamin C content. Vitamin C retention is not significant different for SD and SAD, but with a slight preference for SD. For three yam cultivars (‘Pona’, ‘Lilii’ and ‘Dente’), ‘Lilii’ dried fastest and ‘Dente’ drying slowest. SAD maintained 16 the whitish color of yam better than the other drying methods. Full article

(This article belongs to the Special Issue Renewable Energy in Agriculture)

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12 pages, 2252 KiB

Open AccessArticle

Feasibility of the Detection of Carrageenan Adulteration in Chicken Meat Using Visible/Near-Infrared (Vis/NIR) Hyperspectral Imaging

by Yue Zhang, Hongzhe Jiang and Wei Wang

Appl. Sci. 2019, 9(18), 3926; https://doi.org/10.3390/app9183926 - 19 Sep 2019

Cited by 31 | Viewed by 3710

Abstract

The detection of carrageenan adulteration in chicken meat using a hyperspectral imaging (HSI) technique associated with three spectroscopic transforms was investigated. Minced chicken was adulterated with carrageenan solution (2% w/v) in the volume range of 0–5 mL at an increment of 1 mL. [...] Read more.

The detection of carrageenan adulteration in chicken meat using a hyperspectral imaging (HSI) technique associated with three spectroscopic transforms was investigated. Minced chicken was adulterated with carrageenan solution (2% w/v) in the volume range of 0–5 mL at an increment of 1 mL. Hyperspectral images of prepared samples were captured in a reflectance mode in a Visible/Near-Infrared (Vis/NIR, 400–1000 nm) region. The reflectance (R) spectra were first extracted from regions of interest (ROIs) by applying a mask that was built using band math combined with thresholding and were then transformed into two other spectral units, absorbance (A) and Kubelka-Munck (KM). Partial least squares regression (PLSR) models based on full raw and preprocessed spectra in the three profiles were established and A spectra were found to perform best with R_p² = 0.92, root mean square error of prediction set (RMSEP) = 0.48, and residual predictive deviation (RPD) = 6.18. To simplify the models, several wavelengths were selected using regression coefficients (RC) based on all three spectral units, and 10 wavelengths selected from A spectra (409, 425, 444, 521, 582, 621, 763, 840, 893, and 939 nm) still performed best with the R_p², RMSEP, and RPD of 0.85, 0.93, and 3.20, respectively. Thus, the preferred simplified RC-A-PLSR model was selected and transferred into each pixel to obtain the distribution maps and finally, the general different adulteration levels of different samples were readily discernible. The overall results ascertained that the HSI technique demonstrated to be an effective tool for detecting and visualizing carrageenan adulteration in authentic chicken meat, especially in the absorbance mode. Full article

(This article belongs to the Special Issue Applications of Hyperspectral Imaging for Food and Agriculture II)

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9 pages, 532 KiB

Open AccessArticle

Effect of Sensory Loss on Improvements of Upper-Limb Paralysis Through Robot-Assisted Training: A Preliminary Case Series Study

by Hiroyuki Miyasaka, Kotaro Takeda, Hitoshi Ohnishi, Abbas Orand and Shigeru Sonoda

Appl. Sci. 2019, 9(18), 3925; https://doi.org/10.3390/app9183925 - 19 Sep 2019

Cited by 6 | Viewed by 3042

Abstract

Sensory disorder is a factor preventing recovery from motor paralysis after stroke. Although several robot-assisted exercises for the hemiplegic upper limb of stroke patients have been proposed, few studies have examined improvement in function in stroke patients with sensory disorder using robot-assisted training. [...] Read more.

Sensory disorder is a factor preventing recovery from motor paralysis after stroke. Although several robot-assisted exercises for the hemiplegic upper limb of stroke patients have been proposed, few studies have examined improvement in function in stroke patients with sensory disorder using robot-assisted training. In this study, the efficacies of robot training for the hemiplegic upper limb of three stroke patients with complete sensory loss were compared with those of 19 patients without complete sensory loss. Robot training to assist reach motion was performed in 10 sessions over a 2-week period for 5 days per week at 1 h per day. Before and after the training, the total Fugl–Meyer Assessment score excluding coordination and tendon reflex (FMA-total) and the FMA shoulder and elbow score excluding tendon reflex (FMA-S/E) were evaluated. Reach and path errors (RE and PE) during the reach motion were also evaluated by the arm-training robot. In most cases, both the FMA-total and the FMA-S/E scores improved. Cases with complete sensory loss showed worse RE and PE scores. Our results suggest that motor paralysis is improved by robot training. However, improvement may be varied according to the presence or absence of somatic sensory feedback. Full article

(This article belongs to the Special Issue Recent Advance and Future Trends in Rehabilitation and Nursing-Care Robots)

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28 pages, 3501 KiB

Open AccessArticle

Modular Diversity of the BLUF Proteins and Their Potential for the Development of Diverse Optogenetic Tools

by Manish Singh Kaushik, Ramandeep Sharma, Sindhu Kandoth Veetil, Sandeep Kumar Srivastava and Suneel Kateriya

Appl. Sci. 2019, 9(18), 3924; https://doi.org/10.3390/app9183924 - 19 Sep 2019

Cited by 6 | Viewed by 4604

Abstract

Organisms can respond to varying light conditions using a wide range of sensory photoreceptors. These photoreceptors can be standalone proteins or represent a module in multidomain proteins, where one or more modules sense light as an input signal which is converted into an [...] Read more.

Organisms can respond to varying light conditions using a wide range of sensory photoreceptors. These photoreceptors can be standalone proteins or represent a module in multidomain proteins, where one or more modules sense light as an input signal which is converted into an output response via structural rearrangements in these receptors. The output signals are utilized downstream by effector proteins or multiprotein clusters to modulate their activity, which could further affect specific interactions, gene regulation or enzymatic catalysis. The blue-light using flavin (BLUF) photosensory module is an autonomous unit that is naturally distributed among functionally distinct proteins. In this study, we identified 34 BLUF photoreceptors of prokaryotic and eukaryotic origin from available bioinformatics sequence databases. Interestingly, our analysis shows diverse BLUF-effector arrangements with a functional association that was previously unknown or thought to be rare among the BLUF class of sensory proteins, such as endonucleases, tet repressor family (tetR), regulators of G-protein signaling, GAL4 transcription family and several other previously unidentified effectors, such as RhoGEF, Phosphatidyl-Ethanolamine Binding protein (PBP), ankyrin and leucine-rich repeats. Interaction studies and the indexing of BLUF domains further show the diversity of BLUF-effector combinations. These diverse modular architectures highlight how the organism’s behaviour, cellular processes, and distinct cellular outputs are regulated by integrating BLUF sensing modules in combination with a plethora of diverse signatures. Our analysis highlights the modular diversity of BLUF containing proteins and opens the possibility of creating a rational design of novel functional chimeras using a BLUF architecture with relevant cellular effectors. Thus, the BLUF domain could be a potential candidate for the development of powerful novel optogenetic tools for its application in modulating diverse cell signaling. Full article

(This article belongs to the Special Issue The Advances and Applications of Optogenetics)

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7 pages, 2608 KiB

Open AccessArticle

A Pilot Study of Wet Lung Using Lung Ultrasound Surface Wave Elastography in an Ex Vivo Swine Lung Model

by Xiaoming Zhang, Boran Zhou and Alex X. Zhang

Appl. Sci. 2019, 9(18), 3923; https://doi.org/10.3390/app9183923 - 19 Sep 2019

Cited by 1 | Viewed by 2726

Abstract

Extravascular lung water (EVLW) is a basic symptom of congestive heart failure and other conditions. Computed tomography (CT) is standard method used to assess EVLW, but it requires ionizing radiation and radiology facilities. Lung ultrasound reverberation artifacts called B-lines have been used to [...] Read more.

Extravascular lung water (EVLW) is a basic symptom of congestive heart failure and other conditions. Computed tomography (CT) is standard method used to assess EVLW, but it requires ionizing radiation and radiology facilities. Lung ultrasound reverberation artifacts called B-lines have been used to assess EVLW. However, analysis of B-line artifacts depends on expert interpretation and is subjective. Lung ultrasound surface wave elastography (LUSWE) was developed to measure lung surface wave speed. This pilot study aimed at measureing lung surface wave speed due to lung water in an ex vivo swine lung model. The surface wave speeds of a fresh ex vivo swine lung were measured at 100 Hz, 200 Hz, 300 Hz, and 400 Hz. An amount of water was then filled into the lung through its trachea. Ultrasound imaging was used to guide the water filling until significant changes were visible on the imaging. The lung surface wave speeds were measured again. It was found that the lung surface wave speed increases with frequency and decreases with water volume. These findings are confirmed by experimental results on an additional ex vivo swine lung sample. Full article

(This article belongs to the Special Issue Signal Processing and Image Analysis Techniques for Lung Ultrasound Imaging)

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7 pages, 2372 KiB

Open AccessArticle

Enhanced Tensile Plasticity in Ultrafine Lamellar Eutectic Al-CuBased Composites with α-Al Dendrites Prepared by Progressive Solidification

by Jialin Cheng, Yeling Yun and Jiaxin Rui

Appl. Sci. 2019, 9(18), 3922; https://doi.org/10.3390/app9183922 - 19 Sep 2019

Cited by 6 | Viewed by 3463

Abstract

In this paper, a new class of Al-Cubased composites which combine the ultrafine lamellar eutectic matrix (α-Al + θ-Al₂Cu) and micron-sized primary α-Al dendrites was prepared by progressive solidification. By adjusting the alloy composition and solidification process, [...] Read more.

In this paper, a new class of Al-Cubased composites which combine the ultrafine lamellar eutectic matrix (α-Al + θ-Al₂Cu) and micron-sized primary α-Al dendrites was prepared by progressive solidification. By adjusting the alloy composition and solidification process, the formation of favorable microstructural and micromechanical features can be achieved. The ultrafine lamellar eutectic composite Al₉₄Cu₆ exhibits excellent mechanical properties with 472 MPa fracture strength and 7.4% tensile plastic strain. The plasticity of the ultrafine lamellar eutectic composite relies on the volume fraction and work hardening ability of micron-scale primary phase. The present results provide a new perspective for improving the plasticity of the ultrafine lamellar eutectic alloys. Full article

(This article belongs to the Special Issue Metal Matrix Composite)

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16 pages, 5221 KiB

Open AccessArticle

Spore Viability and Cell Wall Integrity of Cordyceps pruinosa Treated with an Electric Shock-Free, Atmospheric-Pressure Air Plasma Jet

by Hyeongjin Noh, Ji Eun Kim, Jun Young Kim, Seong Hwan Kim, Ihn Han, Jun Sup Lim, Se Hoon Ki, Eun Ha Choi and Geon Joon Lee

Appl. Sci. 2019, 9(18), 3921; https://doi.org/10.3390/app9183921 - 18 Sep 2019

Cited by 8 | Viewed by 3605

Abstract

Atmospheric-pressure

A r

plasma jets are known to be detrimental to Cordyceps pruinosa spores. However, it is not clear what kinds of reactive species are more effective with regard to fungal cell death. Herein, we study which reactive species plays pivotal roles in [...] Read more.

Atmospheric-pressure

A r

plasma jets are known to be detrimental to Cordyceps pruinosa spores. However, it is not clear what kinds of reactive species are more effective with regard to fungal cell death. Herein, we study which reactive species plays pivotal roles in the death of fungal spores using an electric shock-free, atmospheric-pressure air plasma jet, simply called soft plasma jet. Plasma treatment significantly reduced the spore viability and damaged fungal DNA. As observed from the circular dichroism spectra, scanning electron microscope images, and flow cytometric measurements, cell wall integrity was decreased by reactive oxygen and nitrogen species (RONS) from the plasma itself and the plasma-activated water. Consequently, degradation of the spore cell wall allows RONS from the plasma to reach the intracellular components. Such plasma-induced intracellular RONS can attack spore DNA and other intracellular components, as confirmed by electrophoresis analysis and phosphorylated histone measurement. In addition, weakening of the spore cell wall allowed for the loss of intracellular components, which can lead to cell death. Plasma radicals were investigated by measuring the optical emission spectrum of the soft plasma jet, and intracellular reactive oxygen species were confirmed by measuring the fluorescence of 2′, 7′-dichlorodihydrofluorescein-diacetate (

H_{2} D C F

-

D A

)-stained spores. The soft plasma jet generated considerable amounts of

H_{2} O_{2}

and

N O_{x}

but a very small number of

O H

radicals as compared to the atmospheric-pressure

A r

plasma jet; this indicates that plasma-induced long-lived reactive species (

H_{2} O_{2}

and

N O_{x}

) play an important role in the weakening of spore cell walls and cell death. Full article

(This article belongs to the Special Issue Plasma Medicine Technologies)

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14 pages, 423 KiB

Open AccessArticle

Upper Limb Robotics in Rehabilitation: An Approach to Select the Devices, Based on Rehabilitation Aims, and Their Evaluation in a Feasibility Study

by Irene Aprile, Arianna Cruciani, Marco Germanotta, Valerio Gower, Cristiano Pecchioli, Davide Cattaneo, Federica Vannetti, Luca Padua and Furio Gramatica

Appl. Sci. 2019, 9(18), 3920; https://doi.org/10.3390/app9183920 - 18 Sep 2019

Cited by 25 | Viewed by 6300

Abstract

Robot-mediated therapy is a viable approach for upper limb rehabilitation. The upper limb is a highly complex segment and the identification of the appropriate devices capable of rehabilitating it globally (from the shoulder to the hand) in clinical practice is crucial. In this [...] Read more.

Robot-mediated therapy is a viable approach for upper limb rehabilitation. The upper limb is a highly complex segment and the identification of the appropriate devices capable of rehabilitating it globally (from the shoulder to the hand) in clinical practice is crucial. In this work, we aimed: (i) to describe an approach used in identifying a set of technological and robotic devices to globally treat the upper limb, and (ii) to evaluate the feasibility of the identified set in clinical practice. Using an ad-hoc form, a multidisciplinary team identified a set of four robotic and sensor-based devices to treat globally the upper limb. Then, 30 stroke patients were enrolled and assigned to two groups: the robotic group (RG), where patients were treated with the robotic set, or the conventional group (CG). All patients were evaluated before and after the treatment. In the RG the patients used all the devices (one in each rehabilitation session); the treatment was well accepted, without drop-outs or adverse events. Using a multidisciplinary approach, we identified a set of technological and robotic devices to treat the upper limb globally, and then we experimented to ascertain its feasibility, in a pilot study. Robotics offers a considerable number of devices for rehabilitation that should be selected according to rehabilitation aims and feasibility in clinical practice. Full article

(This article belongs to the Special Issue Rehabilitation Robotics: Recent Advancements and New Perspectives about Training and Assessment of Sensorimotor Functions)

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16 pages, 4114 KiB

Open AccessArticle

Free Vibration of a Taut Cable with Two Discrete Inertial Mass Dampers

by Zhihao Wang, Fangfang Yue and Hui Gao

Appl. Sci. 2019, 9(18), 3919; https://doi.org/10.3390/app9183919 - 18 Sep 2019

Cited by 18 | Viewed by 3047

Abstract

Recently, inertial mass dampers (IMDs) have shown superior control performance over traditional viscous dampers (VDs) in vibration control of stay cables. However, a single IMD may be incapable of providing sufficient supplemental modal damping to a super-long cable, especially for the multimode cable [...] Read more.

Recently, inertial mass dampers (IMDs) have shown superior control performance over traditional viscous dampers (VDs) in vibration control of stay cables. However, a single IMD may be incapable of providing sufficient supplemental modal damping to a super-long cable, especially for the multimode cable vibration mitigation. Inspired by the potential advantages of attaching two discrete VDs at different locations of the cable, arranging two external discrete IMDs, either at the opposite ends or the same end of the cable is proposed to further improve vibration mitigation performance of the cable in this study. Complex modal analysis based on the taut-string model was employed and extended to allow for the existence of two external discrete IMDs, resulting in a transcendental equation for complex wavenumbers. Both asymptotic and numerical solutions for the case of two opposite IMDs or the case of two IMDs at the same end of the cable were obtained. Subsequently, the applicability of asymptotic solutions was then evaluated. Finally, parametric studies were performed to investigate the effects of damper positions and damper properties on the control performance of a cable with two discrete IMDs. Results showed that two opposite IMDs can generally provide superior control performance to the cable over a single IMD or two IMDs at the same end. It was also observed that attaching two IMDs at the same end of the cable had the potential to achieve significant damping improvement when the inertial mass of the IMDs is appropriate, which seems to be more promising than two opposite IMDs for practical application. Full article

(This article belongs to the Special Issue Recent Advances in the Design of Structures with Passive Energy Dissipation Systems)

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35 pages, 3156 KiB

Open AccessArticle

Combined Model for IAQ Assessment: Part 1—Morphology of the Model and Selection of Substantial Air Quality Impact Sub-Models

by Michał Piasecki and Krystyna Barbara Kostyrko

Appl. Sci. 2019, 9(18), 3918; https://doi.org/10.3390/app9183918 - 18 Sep 2019

Cited by 19 | Viewed by 4324

Abstract

Indoor air quality (IAQ) is one of the most important elements affecting a building user’s comfort and satisfaction. Currently, many methods of assessing the quality of indoor air have been described in the literature. In the authors’ opinion, the methods presented have not [...] Read more.

Indoor air quality (IAQ) is one of the most important elements affecting a building user’s comfort and satisfaction. Currently, many methods of assessing the quality of indoor air have been described in the literature. In the authors’ opinion, the methods presented have not been collected, systematized, and organized into one multi-component model. The application purpose of the assessment is extremely important when choosing IAQ model. This article provides the state-of-the-art overview on IAQ methodology and attempts to systematize approach. Sub-models of the processes that impact indoor air quality, which can be distinguished as components of the IAQ model, are selected and presented based on sensory satisfaction functions. Subcomponents of three potential IAQ models were classified according to their application potential: IAQ quality index, IAQ comfort index, and an overall health and comfort index. The authors provide a method for using the combined IAQ index to determine the indoor environmental quality index, IEQ. In addition, the article presents a method for adjusting the weights of particular subcomponents and a practical case study which provides IAQ and IEQ model implementation for a large office building assessment (with a BREEAM rating of excellent). Full article

(This article belongs to the Special Issue Indoor Air Quality)

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23 pages, 9149 KiB

Open AccessArticle

Influence of Weld Parameters on the Fatigue Life of Deck-Rib Welding Details in Orthotropic Steel Decks Based on the Improved Stress Integration Approach

by Baoya Cao, Youliang Ding, Zhao Fang, Fangfang Geng and Yongsheng Song

Appl. Sci. 2019, 9(18), 3917; https://doi.org/10.3390/app9183917 - 18 Sep 2019

Cited by 7 | Viewed by 4509

Abstract

Fatigue cracks in orthotropic steel decks (OSDs) have been a serious problem of steel bridges for a long time. The structural stress approach is an important approach for fatigue life evaluation of welded structures. Firstly, two parameters and the mesh sensitivity of the [...] Read more.

Fatigue cracks in orthotropic steel decks (OSDs) have been a serious problem of steel bridges for a long time. The structural stress approach is an important approach for fatigue life evaluation of welded structures. Firstly, two parameters and the mesh sensitivity of the stress-based integration equivalent structural stress approach (stress integration approach for short) are analyzed in this paper. Then, the applicability of the master S-N curve is verified based on experimental data of the deck-rib welding details in OSDs. Finally, the multi-scale finite element model (FEM) of Jiangyin Bridge is established, and the bridge fatigue life calculation steps based on the stress integration approach are given. The influence of the slope of the master S-N curve at high cycles on the bridge fatigue life is discussed. Further, the weld parameter influences on the bridge fatigue life are analyzed, as including the following: (1) The determination of the influence of the weld size changes caused by weld manufacturing errors on the bridge fatigue life; (2) the proposal of a new grinding treatment type, and the analysis of influence of the grinding radius on fatigue life; and (3) a comparison of the fatigue life of the deck-rib welding details under 80% partial penetration and 100% full penetration. The results show that the structural stress calculated by the stress integration approach does not change significantly with the parameters of the isolation body width

w

and the distance

δ

between the crack propagation surface and the reference surface. To simplify the calculation,

δ

is set as 0, and

w

can be set as the mesh size along the weld length direction. The mesh size of the stress integration approach is recommended as 0.25 times the deck thickness. The slope of the master S-N curve at high cycles significantly affects the bridge fatigue life, and a slope of 5 is reasonable. The weld parameter studies for the deck-rib welding details in the OSD of Jiangyin Bridge show that the change of weld size caused by manufacturing errors can obviously affect the bridge fatigue life, and the fatigue life of five different weld types varies from 51 years to 113 years. The new grinding treatment type, without weakening the deck, is beneficial to improving the bridge fatigue life. The fatigue life increases by approximately 5% with an increase of the grinding radius of 2 mm. The fatigue life of 80% partial penetration is slightly higher than that of 100% full penetration. Full article

(This article belongs to the Special Issue Assessing and Extending the Service Life of Bridges)

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12 pages, 2404 KiB

Open AccessArticle

A Comparative Study of Regression Model and the Adaptive Neuro-Fuzzy Conjecture Systems for Predicting Energy Consumption for Jaw Crusher

by Khaled Ali Abuhasel

Appl. Sci. 2019, 9(18), 3916; https://doi.org/10.3390/app9183916 - 18 Sep 2019

Cited by 11 | Viewed by 3637

Abstract

Crushing is a vital process for different industrial applications where a significant portion of power is consumed to properly blast rocks into a predefined size of fragmented rock. An accurate prediction of the energy needed to control this process rarely exists in the [...] Read more.

Crushing is a vital process for different industrial applications where a significant portion of power is consumed to properly blast rocks into a predefined size of fragmented rock. An accurate prediction of the energy needed to control this process rarely exists in the literature, hence there have been limited efforts to optimize the power consumption at the crushing stage by a jaw crusher; which is the most widely used type of crusher. The existence of accurate power prediction as well as optimizing the steps for primary crushing will offer vital tools in selecting a suitable crusher for a specific application. In this work, the specific power consumption of a jaw crusher is predicted with the help of the adaptive neuro-fuzzy interference system (ANFIS). The investigation included, aside from the power required for rock comminution, an optimization of the crushing process to reduce this estimated power. Results revealed the success of the model to accurately predict comminution power with an accuracy of more than 96% in comparison with the corresponding real data. The obtained results introduce good knowledge that may be used in future academic and industrial research. Full article

(This article belongs to the Section Mechanical Engineering)

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16 pages, 3553 KiB

Open AccessArticle

Automatic Object-Detection of School Building Elements in Visual Data: A Gray-Level Histogram Statistical Feature-Based Method

by Zhenyu Zhang, Hsi-Hsien Wei, Sang Guk Yum and Jieh-Haur Chen

Appl. Sci. 2019, 9(18), 3915; https://doi.org/10.3390/app9183915 - 18 Sep 2019

Cited by 2 | Viewed by 2685

Abstract

Automatic object-detection technique can improve the efficiency of building data collection for semi-empirical methods to assess the seismic vulnerability of buildings at a regional scale. However, current structural element detection methods rely on color, texture and/or shape information of the object to be [...] Read more.

Automatic object-detection technique can improve the efficiency of building data collection for semi-empirical methods to assess the seismic vulnerability of buildings at a regional scale. However, current structural element detection methods rely on color, texture and/or shape information of the object to be detected and are less flexible and reliable to detect columns or walls with unknown surface materials or deformed shapes in images. To overcome these limitations, this paper presents an innovative gray-level histogram (GLH) statistical feature-based object-detection method for automatically identifying structural elements, including columns and walls, in an image. This method starts with converting an RGB image (i.e. the image colors being a mix of red, green and blue light) into a grayscale image, followed by detecting vertical boundary lines using the Prewitt operator and the Hough transform. The detected lines divide the image into several sub-regions. Then, three GLH statistical parameters (variance, skewness, and kurtosis) of each sub-region are calculated. Finally, a column or a wall in a sub-region is recognized if these features of the sub-region satisfy the predefined criteria. This method was validated by testing the detection precision and recall for column and wall images. The results indicated the high accuracy of the proposed method in detecting structural elements with various surface treatments or deflected shapes. The proposed structural element detection method can be extended to detecting more structural characteristics and retrieving structural deficiencies from digital images in the future, promoting the automation in building data collection. Full article

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11 pages, 1461 KiB

Open AccessFeature PaperArticle

Ground-State and Thermodynamical Properties of Uranium Mononitride from Anharmonic First-Principles Theory

by Per Söderlind, Alexander Landa, Aurélien Perron, Babak Sadigh and Tae Wook Heo

Appl. Sci. 2019, 9(18), 3914; https://doi.org/10.3390/app9183914 - 18 Sep 2019

Cited by 15 | Viewed by 4411

Abstract

We report on an advanced density-functional theory (DFT) approach for investigating the ground-state and thermodynamical properties of uranium mononitride (UN). The electronic structure for UN at zero temperature is obtained from DFT that utilizes the generalized gradient approximation (GGA) for the electron exchange [...] Read more.

We report on an advanced density-functional theory (DFT) approach for investigating the ground-state and thermodynamical properties of uranium mononitride (UN). The electronic structure for UN at zero temperature is obtained from DFT that utilizes the generalized gradient approximation (GGA) for the electron exchange and correlation functional and includes spin-orbit interaction and an extension with orbital polarization. Thermodynamical properties are computed within the quasi-harmonic approximation in the Debye–Grüneisen model while anharmonicity is captured in the self-consistent ab initio lattice dynamics (SCAILD) scheme. Anharmonic phonons have heretofore never been modeled from first-principles for UN but they turn out to be important. The computed free energy compares well with that of a CALPHAD (CALculation of PHAse Diagrams) assessment of available experimental data. Full article

(This article belongs to the Special Issue Experimental and Theoretical Studies on the Physical Properties of Actinides and Their Oxides)

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23 pages, 1014 KiB

Open AccessArticle

The Identification and Assessment of Rail Corrugation Based on Computer Vision

by Dehua Wei, Xiukun Wei, Yuxin Liu, Limin Jia and Wenqiang Zhang

Appl. Sci. 2019, 9(18), 3913; https://doi.org/10.3390/app9183913 - 18 Sep 2019

Cited by 16 | Viewed by 2869

Abstract

The identification and assessment of rail corrugation are two of the essential tasks of daily railway inspection to guarantee the safety of train operation and promote the development of an efficient maintenance strategy. In view of the requirements for automatic identification and smart [...] Read more.

The identification and assessment of rail corrugation are two of the essential tasks of daily railway inspection to guarantee the safety of train operation and promote the development of an efficient maintenance strategy. In view of the requirements for automatic identification and smart decision-making, computer vision-based rail corrugation identification and assessment methods are presented in this paper. Firstly, an improved Spatial Pyramid Matching (SPM) model, integrating multi-features and locality-constrained linear coding (IMFLLC), is proposed for rail corrugation identification. After that, an innovative period estimation method for rail corrugation is proposed based on the frequency domain analysis of each column in the corrugation region. Finally, the severity of the rail corrugation is assessed with the help of the wear saliency calculation and fuzzy theory. The experiment results demonstrate that the proposed corrugation identification method achieves a higher precision rate and recall rate than those of traditional methods, reaching 99.67% and 98.34%, respectively. Besides, the validity and feasibility of the proposed methods for the rail corrugation period estimation and severity assessment are also investigated. Full article

(This article belongs to the Section Applied Industrial Technologies)

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26 pages, 7655 KiB

Open AccessArticle

An Intelligent Milling Tool Wear Monitoring Methodology Based on Convolutional Neural Network with Derived Wavelet Frames Coefficient

by Xincheng Cao, Binqiang Chen, Bin Yao and Shiqiang Zhuang

Appl. Sci. 2019, 9(18), 3912; https://doi.org/10.3390/app9183912 - 18 Sep 2019

Cited by 32 | Viewed by 4475

Abstract

Tool wear and breakage are inevitable due to the severe stress and high temperature in the cutting zone. A highly reliable tool condition monitoring system is necessary to increase productivity and quality, reduce tool costs and equipment downtime. Although many studies have been [...] Read more.

Tool wear and breakage are inevitable due to the severe stress and high temperature in the cutting zone. A highly reliable tool condition monitoring system is necessary to increase productivity and quality, reduce tool costs and equipment downtime. Although many studies have been conducted, most of them focused on single-step process or continuous cutting. In this paper, a high robust milling tool wear monitoring methodology based on 2-D convolutional neural network (CNN) and derived wavelet frames (DWFs) is presented. The frequency band of high signal-to-noise ratio is extracted via derived wavelet frames, and the spectrum is further folded into a 2-D matrix to train 2-D CNN. The feature extraction ability of the 2-D CNN is fully utilized, bypassing the complex and low-portability feature engineering. The full life test of the end mill was carried out with S45C steel work piece and multiple sets of cutting conditions. The recognition accuracy of the proposed methodology reaches 98.5%, and the performance of 1-D CNN as well as the beneficial effects of the DWFs are verified. Full article

(This article belongs to the Special Issue Machine Fault Diagnostics and Prognostics)

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