Applied Sciences

28 pages, 2033 KiB

Open AccessReview

Data Harmonization for Heterogeneous Datasets: A Systematic Literature Review

by Ganesh Kumar, Shuib Basri, Abdullahi Abubakar Imam, Sunder Ali Khowaja, Luiz Fernando Capretz and Abdullateef Oluwagbemiga Balogun

Appl. Sci. 2021, 11(17), 8275; https://doi.org/10.3390/app11178275 - 6 Sep 2021

Cited by 30 | Viewed by 10196

Abstract

As data size increases drastically, its variety also increases. Investigating such heterogeneous data is one of the most challenging tasks in information management and data analytics. The heterogeneity and decentralization of data sources affect data visualization and prediction, thereby influencing analytical results accordingly. [...] Read more.

As data size increases drastically, its variety also increases. Investigating such heterogeneous data is one of the most challenging tasks in information management and data analytics. The heterogeneity and decentralization of data sources affect data visualization and prediction, thereby influencing analytical results accordingly. Data harmonization (DH) corresponds to a field that unifies the representation of such a disparate nature of data. Over the years, multiple solutions have been developed to minimize the heterogeneity aspects and disparity in formats of big-data types. In this study, a systematic review of the literature was conducted to assess the state-of-the-art DH techniques. This study aimed to understand the issues faced due to heterogeneity, the need for DH and the techniques that deal with substantial heterogeneous textual datasets. The process produced 1355 articles, but among them, only 70 articles were found to be relevant through inclusion and exclusion criteria methods. The result shows that the heterogeneity of structured, semi-structured, and unstructured (SSU) data can be managed by using DH and its core techniques, such as text preprocessing, Natural Language Preprocessing (NLP), machine learning (ML), and deep learning (DL). These techniques are applied to many real-world applications centered on the information-retrieval domain. Several assessment criteria were implemented to measure the efficiency of these techniques, such as precision, recall, F-1, accuracy, and time. A detailed explanation of each research question, common techniques, and performance measures is also discussed. Lastly, we present readers with a detailed discussion of the existing work, contributions, and managerial and academic implications, along with the conclusion, limitations, and future research directions. Full article

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11 pages, 3122 KiB

Open AccessFeature PaperArticle

Effects of Glutathione Diminishment on the Immune Responses against Mycobacterium tuberculosis Infection

by Ruoqiong Cao, Afsal Kolloli, Ranjeet Kumar, James Owens, Kayvan Sasaninia, Charles Vaughn, Mohkam Singh, Edward Truong, Nala Kachour, Abrianna Beever, Wael Khamas, Selvakumar Subbian and Vishwanath Venketaraman

Appl. Sci. 2021, 11(17), 8274; https://doi.org/10.3390/app11178274 - 6 Sep 2021

Cited by 9 | Viewed by 4045

Abstract

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), continues to be a global health burden. We have reported that patients with marked deficiency in the production of glutathione (GSH) had impaired granulomatous effector responses against M. tb infection, which were [...] Read more.

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), continues to be a global health burden. We have reported that patients with marked deficiency in the production of glutathione (GSH) had impaired granulomatous effector responses against M. tb infection, which were restored when supplementing patients with liposomal GSH (lGSH). However, the effects of GSH deficiency in the lung parenchyma in altering granuloma formation and effector responses against M. tb infection remain unexplored. We aim to elucidate the effects of diethyl maleate (DEM)-induced GSH deficiency during an active M. tb infection in an in vivo mouse model. We assessed for total and reduced GSH levels, malondialdehyde (MDA) levels, cytokine profiles, granuloma formation and M. tb burden. DEM administration significantly diminished total and reduced GSH levels in the lungs and plasma and increased MDA levels in infected mice compared to sham-treated controls. DEM treatment was also associated with an increase in IL-6, TNF-α and ill-formed granulomas in infected mice. Furthermore, M. tb survival was significantly increased along with a higher pulmonary and extrapulmonary bacterial load following DEM treatment. Overall, GSH deficiency led to increased oxidative stress, impaired granuloma response, and increased M. tb survival in infected mice. These findings can provide insight into how GSH deficiency can interfere with the control of M. tb infection and avenues for novel therapeutic approaches. Full article

(This article belongs to the Special Issue Polydopamine Nanomaterials: Synthesis and Applications)

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Measurement of total and reduced forms of glutathione in the lung lysates and plasma of M. tb infected mice that were sham-treated or treated with DEM. Total glutathione was measured in the plasma and lung lysates of M. tb infected mice at 2 weeks (A,C) and 4 weeks (B,D) post-infection. Reduced form of glutathione was also measured in the lung lysates and plasma of M. tb infected mice at 2 weeks (E,F) and 4 weeks (G,H) post-infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported represent the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus untreated category. ** p-value < 0.005. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 1 Cont.
Measurement of total and reduced forms of glutathione in the lung lysates and plasma of M. tb infected mice that were sham-treated or treated with DEM. Total glutathione was measured in the plasma and lung lysates of M. tb infected mice at 2 weeks (A,C) and 4 weeks (B,D) post-infection. Reduced form of glutathione was also measured in the lung lysates and plasma of M. tb infected mice at 2 weeks (E,F) and 4 weeks (G,H) post-infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported represent the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus untreated category. ** p-value < 0.005. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 2
Measurement of IL-6 in the lung lysates and plasma of M. tb infected mice that were sham-treated or treated with DEM. IL-6 levels were measured in the lung lysates at 4 weeks (A) and 8 weeks (B) post-infection and in the plasma at 2 weeks (C), 4 weeks (D), and 8 weeks (E) post-M. tb infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported are representative of the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus the untreated category. ** p-value < 0.005. When three asterisks are represented (***), a p-value below 0.0001 is implied. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 3
Measurement of TNF-α in the lung lysates and plasma of M. tb infected mice that were sham-treated or treated with DEM. Levels of TNF-α were measured in the lung lysates at 8 weeks (A) post-infection and in the plasma at 4 weeks (B) and 8 weeks (C) post-M. tb infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported are representative of the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus the untreated category. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 4
Measurement of MDA in the lung lysates and plasma of M. tb infected mice that were sham-treated or treated with DEM. MDA levels were measured in the plasma at 4 weeks (A) and 8 weeks (B) post-M. tb infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported are representative of the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus the untreated category. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 5
Survival of M. tb in the lung and spleen of mice that were sham-treated or treated with DEM. Survival of M. tb was determined in the lung lysates at 2 weeks (A), 4 weeks (B) and 8 weeks (C) post-infection and in the spleen lysates at 2 weeks (D), 4 weeks (E) and 8 weeks (F) post-M. tb infection. Statistical analysis was performed using GraphPad Prism software. Unpaired t tests were performed using Welsch correction. All values reported are representative of the mean values for each respective category and a p-value of <0.05 was considered significant. Any placement of an asterisk (*) denotes a direct comparison of the DEM-treated versus the untreated category. ** p-value < 0.005. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">Figure 6
Morphometric analysis and hematoxylin and eosin staining of lung tissue sections of M. tb-infected mice that were sham-treated or treated with DEM. Morphometric analysis was performed in the mouse lung sections stained with hematoxylin and eosin at 4 weeks (A) and 8 weeks (B) post-M. tb infection. 10× (C,E,G,I) and 40× (D,F,H,J) images of hematoxylin and eosin-stained lung sections of mice at 4 weeks (C–F) and 8 weeks (G–J) post-M. tb infection are presented. The sample size (n) includes six mice each in the untreated and DEM-treated groups. Full article ">

18 pages, 7971 KiB

Open AccessFeature PaperArticle

Immunomodulatory Effects of Pentoxifylline: Profiling Data Based on RAW 264.7 Cellular Signaling

by Mi Hyun Seo, Mi Young Eo, Truc Thi Hoang Nguyen, Hoon Joo Yang and Soung Min Kim

Appl. Sci. 2021, 11(17), 8273; https://doi.org/10.3390/app11178273 - 6 Sep 2021

Cited by 2 | Viewed by 3125

Abstract

Pentoxifylline (PTX) is a methylxanthine derivative that has been developed as an immunomodulatory agent and an improvement of microcirculation. Osteoradionecrosis (ORN) is a serious complication of radiation therapy due to hypovascularity. Coronavirus disease 2019 (COVID-19) has spread globally. Symptoms for this disease include [...] Read more.

Pentoxifylline (PTX) is a methylxanthine derivative that has been developed as an immunomodulatory agent and an improvement of microcirculation. Osteoradionecrosis (ORN) is a serious complication of radiation therapy due to hypovascularity. Coronavirus disease 2019 (COVID-19) has spread globally. Symptoms for this disease include self-limiting respiratory tract illness to severe pneumonia and acute respiratory distress. In this study, the effects of PTX on RAW 264.7 cells were investigated to reveal the possibility of PTX as a therapeutic agent for ORN and COVID-19. To reveal PTX effects at the cellular level, protein expression profiles were analyzed in the PTX-treated RAW 264.7 cells by using immunoprecipitation high-performance liquid chromatography (IP-HPLC). PTX-treated RAW 264.7 cells showed increases in immunity- and osteogenesis-related proteins and concurrent decreases in proliferation-, matrix inflammation-, and cellular apoptosis-related proteins expressions. The IP-HPLC results indicate that PTX plays immunomodulatory roles in RAW 264.7 cells by regulating anti-inflammation-, proliferation-, immunity-, apoptosis-, and osteogenesis-related proteins. These results suggest that PTX may be used as supplement medications for ORN as well as for COVID-19. Full article

(This article belongs to the Special Issue COVID-19: Impact on Human Health and Behavior)

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Graphical abstract

15 pages, 4628 KiB

Open AccessArticle

A Hybrid Data-Fusion System by Integrating CFD and PNN for Structural Damage Identification

by Chun Fu and Shaofei Jiang

Appl. Sci. 2021, 11(17), 8272; https://doi.org/10.3390/app11178272 - 6 Sep 2021

Cited by 6 | Viewed by 2377

Abstract

Recently, a variety of intelligent structural damage identification algorithms have been developed and have obtained considerable attention worldwide due to the advantages of reliable analysis and high efficiency. However, the performances of existing intelligent damage identification methods are heavily dependent on the extracted [...] Read more.

Recently, a variety of intelligent structural damage identification algorithms have been developed and have obtained considerable attention worldwide due to the advantages of reliable analysis and high efficiency. However, the performances of existing intelligent damage identification methods are heavily dependent on the extracted signatures from raw signals. This will lead to the intelligent damage identification method becoming the optimal solution for actual application. Furthermore, the feature extraction and neural network training are time-consuming tasks, which affect the real-time performance in identification results directly. To address these problems, this paper proposes a new intelligent data fusion system for damage detection, combining the probabilistic neural network (PNN), data fusion technology with correlation fractal dimension (CFD). The intelligent system consists of three modules (models): the eigen-level fusion model, the decision-level fusion model and a PNN classifier model. The highlight points of this system are these three intelligent models specialized in certain situations. The eigen-level model is specialized in the case of measured data with enormous samples and uncertainties, and for the case of confidence level of each sensor is determined ahead, the decision-level model is the best choice. The single PNN model is considered only when the data collected is somehow limited, or few sensors have been installed. Numerical simulations of a two-span concrete-filled steel tubular arch bridge in service and a seven-storey steel frame in laboratory were used to validate the hybrid system by identifying both single- and multi-damage patterns. The results show that the hybrid data-fusion system has excellent performance of damage identification, and also has superior capability of anti-noise and robustness. Full article

(This article belongs to the Section Civil Engineering)

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14 pages, 3066 KiB

Open AccessFeature PaperArticle

Theoretical Evaluation of Microwave Ablation Applied on Muscle, Fat and Bone: A Numerical Study

by Cheng Chen, Ming-An Yu, Lin Qiu, Hong-Yu Chen, Zhen-Long Zhao, Jie Wu, Li-Li Peng, Zhi-Liang Wang and Ruo-Xiu Xiao

Appl. Sci. 2021, 11(17), 8271; https://doi.org/10.3390/app11178271 - 6 Sep 2021

Cited by 11 | Viewed by 2833

Abstract

(1) Background: Microwave ablation (MWA) is a common tumor ablation surgery. Because of the high temperature of the ablation antenna, it is strongly destructive to surrounding vital tissues, resulting in high professional requirements for clinicians. The method used to carry out temperature observation [...] Read more.

(1) Background: Microwave ablation (MWA) is a common tumor ablation surgery. Because of the high temperature of the ablation antenna, it is strongly destructive to surrounding vital tissues, resulting in high professional requirements for clinicians. The method used to carry out temperature observation and damage prediction in MWA is significant; (2) Methods: This work employs numerical study to explore temperature distribution of typical tissues in MWA. Firstly, clinical MWA based on isolated biological tissue is implemented. Then, the Pennes models and microwave radiation physics are established based on experimental parameters and existing related research. Initial values and boundary conditions are adjusted to better meet the real clinical materials and experimental conditions. Finally, clinical MWA data test this model. On the premise that the model is matched with clinical MWA, fat and bone are deduced for further heat transfer analysis. (3) Results: Numerical study obtains the temperature distribution of biological tissue in MWA. It observes the heat transfer law of ablation antenna in biological tissue. Additionally, combined with temperature threshold, it generates thermal damage of biological tissues and predicts the possible risks in MWA; (4) Conclusions: This work proposes a numerical study of typical biological tissues. It provides a new theoretical basis for clinically thermal ablation surgery. Full article

(This article belongs to the Special Issue Nano/Microscale Heat Transfer)

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Schematic diagram of biological tissue model. (a) Geometric structure and parameters of biological tissue model. (b) A free triangular grid in biological tissue model. Its cylindrical coordinate mainly analyzes d and z directions. Full article ">Figure 2
Temperature distribution at thermometric sequence near ablation antenna and MWA. Full article ">Figure 3
Temperature cloud map at 30 s, 60 s, 90 s, and 120 s. The 30 s and 60 s belong to the heating period, and 90 s and 120 s belong to the cooling period. (a) Temperature cloud map of muscle; (b) Temperature cloud map of fat; (c) Temperature cloud map of bone. Full article ">Figure 4
Temperature cloud map near ablation antenna. Full article ">Figure 5
Temperature distribution at the horizontal thermometric sequence of the highest temperature point near ablation antenna. (a) Temperature distribution from muscle; (b) Temperature distribution from fat; (c) Temperature distribution from the bone. Full article ">Figure 6
Damage fraction cloud map at 15 s, 30 s, 45 s, 60 s, 75 s. Damage fraction is calculated by temperature threshold. Its damage temperature <math display="inline"><semantics> <mrow> <msub> <mi>T</mi> <mi>d</mi> </msub> </mrow> </semantics></math> is set to 50 °C, and necrosis temperature <math display="inline"><semantics> <mrow> <msub> <mi>T</mi> <mi>n</mi> </msub> </mrow> </semantics></math> is set to 80 °C. Damage time is set to 15 s. (a) Damage fraction cloud map of muscle; (b) Damage fraction cloud map of fat; (c) Damage fraction cloud map of bone. Full article ">Figure 7
Damage fraction of three sequence points (z = 10 mm, z = 12 mm and z = 18 mm). All points recorded from 0 to 120 s are plotted. Bone damage fraction is additionally calculated at z = 5 mm. (a) Damage fraction from muscle; (b) Damage fraction from fat; (c) Damage fraction from bone. Full article ">

13 pages, 4878 KiB

Open AccessArticle

An Evaluation of the Demineralizing Effects of Various Acidic Solutions

by Agnes Kolumban, Marioara Moldovan, Ioan Andrei Țig, Ioana Chifor, Stanca Cuc, Marius Bud and Mindra Eugenia Badea

Appl. Sci. 2021, 11(17), 8270; https://doi.org/10.3390/app11178270 - 6 Sep 2021

Cited by 6 | Viewed by 4516

Abstract

The purpose of this study was to evaluate which of the techniques and acids included in this in vitro research can induce artificial caries lesions in the most natural way. White spot lesions were created using six different demineralizing solutions in liquid form [...] Read more.

The purpose of this study was to evaluate which of the techniques and acids included in this in vitro research can induce artificial caries lesions in the most natural way. White spot lesions were created using six different demineralizing solutions in liquid form (lactic acid; orthophosphoric acid; formic acid; and an acid solution that contains calcium chloride, sodium phosphate and acetic acid) and gel form (hydrochloric acid and orthophosphoric acid). Radiographs, photographs and readings with a DIAGNODent™ pen, VITA Easyshade and a scanning electron microscope (SEM) were made in the initial situation, after 30 min, 1 h, 24 h and 96 h of demineralization. The total color change (ΔE) values in most cases presented statistically significant differences. SEM images showed different aspects of the enamel surface for each type of acid. Only in the case of exposed dentine did the DIAGNODent™ pen record significant differences. There was no noticeable radio-translucency of the teeth treated for a short period of time, but after 24 h, the absence of enamel and major demineralization of dentine were visible. Acids in the liquid state can penetrate and demineralize dental structures deeper than those that are more viscous. This study should be repeated with a protocol that includes remineralization. Using weaker acids would be another direction that could lead to more interesting findings. Full article

(This article belongs to the Section Applied Dentistry and Oral Sciences)

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21 pages, 3571 KiB

Open AccessArticle

Can ISO GPS and ASME Tolerancing Systems Define the Same Functional Requirements?

by Zbigniew Humienny

Appl. Sci. 2021, 11(17), 8269; https://doi.org/10.3390/app11178269 - 6 Sep 2021

Cited by 6 | Viewed by 21888

Abstract

Geometrical tolerances are defined in the ISO Geometrical Product Specification system that is used worldwide, but on the other hand, the ASME Y14.5 standard is used in American companies to define how far actual parts may be away from their nominal geometry. This [...] Read more.

Geometrical tolerances are defined in the ISO Geometrical Product Specification system that is used worldwide, but on the other hand, the ASME Y14.5 standard is used in American companies to define how far actual parts may be away from their nominal geometry. This paper aimed to investigate whether specifications defining acceptable geometrical deviations in one system can be transformed to specifications in the other system. Twelve selected cases are discussed in the paper. Particularly, two cases of size tolerance, three cases of form tolerances, one case of orientation tolerance, four cases of position tolerance (including position tolerance with MMR for the pattern of five holes) and, finally, two cases of surface profile tolerance (unequally disposed tolerance zone and dynamic profile tolerance). The issue is not only in the several different symbols and a set of different defaults, but also in the different meanings and different application contexts of some symbols that have the same graphical form. The answer to the question raised in the paper title is yes for the majority of indications specified according to ASME Y14.5 when new tools from the 2017 edition of ISO 1101 are applied. Full article

(This article belongs to the Special Issue New Trends in Manufacturing Metrology)

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24 pages, 43617 KiB

Open AccessArticle

Characterization of Umami Dry-Cured Ham-Derived Dipeptide Interaction with Metabotropic Glutamate Receptor (mGluR) by Molecular Docking Simulation

by Alejandro Heres, Fidel Toldrá and Leticia Mora

Appl. Sci. 2021, 11(17), 8268; https://doi.org/10.3390/app11178268 - 6 Sep 2021

Cited by 9 | Viewed by 2671

Abstract

Dry-cured ham-derived dipeptides, generated along a dry-curing process, are of high importance since they play a role in flavor development of dry-cured ham. The objective of this study was to analyze the residues of the less-studied metabotropic glutamate receptor 1 (mGluR1) implicated in [...] Read more.

Dry-cured ham-derived dipeptides, generated along a dry-curing process, are of high importance since they play a role in flavor development of dry-cured ham. The objective of this study was to analyze the residues of the less-studied metabotropic glutamate receptor 1 (mGluR1) implicated in the recognition of umami dry-cured ham dipeptides by molecular docking simulation using the AutoDock Suite tool. AH, DA, DG, EE, ES, EV, and VG (and glutamate) were found to attach the enzyme with inhibition constants ranging from 12.32 µM (AH) to 875.75 µM (ES) in the case if Rattus norvegicus mGluR1 and 17.44 µM (VG) to 294.68 µM (DG) in the case of Homo sapiens, in the open–open conformations. Main interactions were done with key receptor residues Tyr74, Ser186, Glu292, and Lys409; and Ser165, Ser186, and Asp318, respectively, for the two receptors in the open–open conformations. However, more residues may be involved in the complex stabilization. Specifically, AH, EE and ES relatively established a higher number of H-bonds, but AH, EV, and VG presented relatively lower Ki values in all cases. The results obtained here could provide information about structure and taste relationships and constitute a theoretical reference for the interactions of novel umami food-derived peptides. Full article

(This article belongs to the Special Issue Role and Properties of Proteins and Peptides in Foods)

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15 pages, 10871 KiB

Open AccessArticle

Archaeological and Chemical Investigation on the High Imperial Mosaic Floor Mortars of the Domus Integrated in the Museum of Archaeology D. Diogo de Sousa, Braga, Portugal

by Ana Fragata, Jorge Ribeiro, Carla Candeias, Ana Velosa and Fernando Rocha

Appl. Sci. 2021, 11(17), 8267; https://doi.org/10.3390/app11178267 - 6 Sep 2021

Cited by 5 | Viewed by 3000

Abstract

This paper intends to characterize the floor mortar layers (nucleus, rudus and statumen) of the high imperial mosaics of the domus integrated in the Museum of Archeology D. Diogo de Sousa, the oldest roman housing testimonies known in Braga, Portugal. [...] Read more.

This paper intends to characterize the floor mortar layers (nucleus, rudus and statumen) of the high imperial mosaics of the domus integrated in the Museum of Archeology D. Diogo de Sousa, the oldest roman housing testimonies known in Braga, Portugal. It offers an important archaeological and historical contextualization and first chemical characterization attempt on the mortars. The study of 13 mortar samples was carried out at a chemical level through X-ray fluorescence spectroscopy (XRF). All samples presented low lime content when compared to similar studies. A high chemical similarity between nucleus mortars (opus signinum) and chemical composition differences between rudus and statumen mortars was determined, confirmed by statistical analyses. Their composition was distinctly related to the stratigraphic position of each floor mortar layer, following Vitruvius’ model, and to the external conditions and treatments (e.g., capillary rise with soluble salts and application of chemical treatments), to which they were submitted. Full article

(This article belongs to the Special Issue Contribution of X-ray Fluorescence Techniques in Cultural Heritage Materials Characterisation)

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12 pages, 1058 KiB

Open AccessArticle

A Statistical Procedure for Analyzing the Behavior of Air Pollutants during Temperature Extreme Events: The Case Study of Emilia-Romagna Region (Northern Italy)

by Maria Ragosta, Mariagrazia D’Emilio, Luciana Casaletto and Vito Telesca

Appl. Sci. 2021, 11(17), 8266; https://doi.org/10.3390/app11178266 - 6 Sep 2021

Cited by 1 | Viewed by 2214

Abstract

Meteorological conditions play a crucial role in air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. Extreme weather events can strongly affect surface air quality. Understanding relations between air pollutant concentrations and extreme weather events [...] Read more.

Meteorological conditions play a crucial role in air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. Extreme weather events can strongly affect surface air quality. Understanding relations between air pollutant concentrations and extreme weather events is a fundamental step toward improving the knowledge of how excessive heat impacts on air quality. In this work, we developed a statistical procedure for investigating the variations in the correlation structure of four air pollutants (NO_x, O₃, PM₁₀, PM_2.5) during extreme temperature events measured in monitoring sites located of Emilia Romagna region, Northern Italy, in summer (June–August) from 2015 to 2017. For the selected stations, Hot Days (HDs) and Heat Waves (HWs) were identified with respect to historical series of maximum temperature measured for a 30-year period (1971–2000). This method, based on multivariate techniques, allowed us to highlight the variations in air quality of study area due to the occurrence of HWs. The examined data, including PM concentrations, show higher values, whereas NO_x and O₃ concentrations seem to be not influenced by HWs. This operative procedure can be easily exported in other geographical areas for studying effects of climate change on a local scale. Full article

(This article belongs to the Special Issue New Trends in Air Quality and Climate Change Interlinks)

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12 pages, 2056 KiB

Open AccessArticle

Strain State in Metal Sheet Axisymmetric Stretching with Variable Initial Thickness: Numerical and Experimental Results

by Gillo Giuliano and Wilma Polini

Appl. Sci. 2021, 11(17), 8265; https://doi.org/10.3390/app11178265 - 6 Sep 2021

Cited by 2 | Viewed by 1943

Abstract

This work presents a finite element model to analyze the distribution of the strains due to an axisymmetric stretching of a metal sheet. The sheet is characterized by a variable initial thickness. The resulting strain state is compared with that of a sheet [...] Read more.

This work presents a finite element model to analyze the distribution of the strains due to an axisymmetric stretching of a metal sheet. The sheet is characterized by a variable initial thickness. The resulting strain state is compared with that of a sheet with a constant initial thickness. The results of the present study allow asserting that the distribution of strains in the sheet can be controlled by setting opportunely the trend of the sheet initial thickness. In this way, it is possible to see that, starting from a sheet with variable initial thickness, a lighter final product is obtained, whose final thickness distribution is more uniform than that of the product obtained from a classic stretching process that requires a sheet with constant initial thickness. Encouraging results from an experimental activity carried out on an AA6060 aluminum alloy sheet, whose trend of initial thicknesses was prepared by removing material from a commercial sheet with a constant thickness, allow us to note the good agreement with what was theoretically highlighted. Full article

(This article belongs to the Special Issue 10th Anniversary of Applied Sciences: Invited Papers in Mechanical Engineering Section)

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15 pages, 4988 KiB

Open AccessArticle

Effect of Urea Addition on Anatase Phase Enrichment and Nitrogen Doping of TiO₂ for Photocatalytic Abatement of Methylene Blue

by Maira Asif, Muhammad Zafar, Parveen Akhter, Murid Hussain, Adeel Umer, Abdul Razzaq and Woo-Young Kim

Appl. Sci. 2021, 11(17), 8264; https://doi.org/10.3390/app11178264 - 6 Sep 2021

Cited by 12 | Viewed by 3887

Abstract

TiO₂-based materials are commonly employed as photocatalysts for industrial wastewater treatment. The primary reasons of employing TiO₂ include cost effectiveness, ready availability, eco-friendliness, non-toxic behavior, and exceptional resistance towards photo-corrosion. However, the wider band gap of pure TiO₂ restricts [...] Read more.

TiO₂-based materials are commonly employed as photocatalysts for industrial wastewater treatment. The primary reasons of employing TiO₂ include cost effectiveness, ready availability, eco-friendliness, non-toxic behavior, and exceptional resistance towards photo-corrosion. However, the wider band gap of pure TiO₂ restricts its performance because of its optical absorption of solar light to the ultraviolet (UV) region only, and to some extent of photo-excited charge recombination. In the present work an attempt is made to develop a facile synthesis approach by using urea, a cheap chemical precursor, to form nitrogen doped TiO₂ with the key objective of extended light absorption and thus enhanced photocatalytic performance. It was also observed that the urea-induced anatase phase enrichment of TiO₂ is another key factor in promoting the photocatalytic performance. The photocatalysts prepared by varying the amount of urea as a nitrogen dopant precursor, are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) to evaluate their crystallinity, morphology, functional groups, and charge separation properties, respectively. Moreover, the surface area was also estimated by physicochemical adsorption. The maximum nitrogen-doped sample yielded >99% photodegradation efficiency of methylene blue (MB) dye-simulated wastewater as compared to a pure TiO₂ sample which exhibited 6.46% efficiency. The results show that the simultaneous factors of nitrogen doping and anatase phase enhancement contributes significantly towards the improvement of photocatalytic performance. Full article

(This article belongs to the Special Issue Anatase Chemistry, Nanostructures and Functionalities‎)

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XRD patterns of pure TiO2, NT-1, NT-2 and NT-3, synthesized by using 0.0 g, 0.983 g, 1.965 g and 2.940 g of urea respectively (A: anatase phase, and R: rutile phase). Full article ">Figure 2
Raman spectra of pure TiO2, NT-1, NT-2 and NT-3, synthesized by using 0.0 g, 0.983 g, 1.965 g and 2.940 g of urea respectively. Full article ">Figure 3
SEM images of (a) Pure TiO2, (b) NT-1, (c) NT-2 and, (d) NT-3. Full article ">Figure 4
FTIR spectra of pure TiO2, NT-1, NT-2 and NT-3, synthesized by using 0.0 g, 0.983 g, 1.965 g and 2.940 g of urea respectively. (a) The complete spectrum; The enlarged view of regions between 750–2000 cm−1 (b), and 2000–4000 cm−1 (c). Full article ">Figure 5
TGA curves for pure TiO2, NT-1, NT-2 and NT-3, synthesized by using 0.0, 0.983, 1.965 and 2.940 g of urea, respectively. Full article ">Figure 6
(a) UV Vis DRS spectra, and (b) Band gap estimation of, Pure TiO2, NT-1, NT-2 and NT-3. Full article ">Figure 7
PL spectra of (a) Pure TiO2, (b) NT-1, (c) NT-2 and (d) NT-3. Full article ">Figure 8
High resolution XPS spectra with peak fittings for pure TiO2 sample showing: (a) Ti 2p, (b) O 1s, (c) N 1s, and (d) C 1s, regions. Full article ">Figure 9
High resolution XPS spectra with peak fittings for pure NT-3 sample showing: (a) Ti 2p, (b) O 1s, (c) N 1s, and (d) C 1s, regions. Full article ">Figure 10
Photocatalytic degradation of MB dye simulated wastewater by pure TiO2, NT-1, NT-2 and NT-3 samples. Full article ">Figure 11
Mechanistic overview for photocatalytic degradation of MB dye simulated wastewater by NT samples. Full article ">

8 pages, 1284 KiB

Open AccessArticle

The Performance of LiF:Mg-Ti for Proton Dosimetry within the Framework of the MoVe IT Project

by Vittoria D’Avino, Francesco Tommasino, Stefano Lorentini, Giuseppe La Verde and Mariagabriella Pugliese

Appl. Sci. 2021, 11(17), 8263; https://doi.org/10.3390/app11178263 - 6 Sep 2021

Cited by 3 | Viewed by 2807

Abstract

Proton therapy represents a technologically advanced method for delivery of radiation treatments to tumors. The determination of the biological effectiveness is one of the objectives of the MoVe IT (Modeling and Verification for Ion Beam Treatment Planning) project of the National Institute for [...] Read more.

Proton therapy represents a technologically advanced method for delivery of radiation treatments to tumors. The determination of the biological effectiveness is one of the objectives of the MoVe IT (Modeling and Verification for Ion Beam Treatment Planning) project of the National Institute for Nuclear Physics (INFN) CSN5. The aim of the present work, which is part of the project, was to evaluate the performance of the thermoluminescent dosimeters (TLDs-100) for dose verification in the proton beam line. Four irradiation experiments were performed in the experimental room at the Trento Proton Therapy Center, where a 150 MeV monoenergetic proton beam is available. A total of 80 TLDs were used. The TLDs were arranged in one or two rows and accommodated in a specially designed water-equivalent phantom. In the experimental setup, the beam enters orthogonally to the dosimeters and is distributed along the proton beam profile, while the irradiation delivers doses of 0.8 Gy or 1.5 Gy in the Bragg peak. For each irradiation stage, the depth–dose curve was determined by the TLD readings. The results showed the good performance of the TLDs-100, proving their reliability for dose recordings in future radiobiological experiments planned within the MoVe IT context. Full article

(This article belongs to the Special Issue Radiation Protection in Clinical and Environmental Setting)

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26 pages, 5621 KiB

Open AccessArticle

Monitoring of Heavy Metals and Nitrogen Concentrations in Mosses in the Vicinity of an Integrated Iron and Steel Plant: Case Study in Czechia

by Irena Pavlíková, Oldřich Motyka, Vítězslav Plášek and Jan Bitta

Appl. Sci. 2021, 11(17), 8262; https://doi.org/10.3390/app11178262 - 6 Sep 2021

Cited by 5 | Viewed by 3574

Abstract

A biomonitoring study using terrestrial mosses was performed in the vicinity of an Integrated Iron and Steel plant near the Czech–Polish border. Moss samples were collected in two seasons (June, October) in order to embrace the effect of the heating season on the [...] Read more.

A biomonitoring study using terrestrial mosses was performed in the vicinity of an Integrated Iron and Steel plant near the Czech–Polish border. Moss samples were collected in two seasons (June, October) in order to embrace the effect of the heating season on the pollution levels. The contents of metals (Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb, As, Sb and Hg) were determined using the Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Atomic Absorption Spectroscopy (AAS) and contents of N, C, H via elemental analysis. The influence of the proximity of the factory, the heating season and modelled concentrations of particulate matter <10 µm (PM₁₀) on determined concentrations of elements were studied via multivariate statistical methods using clr-transformed data. This approach led to the first-time demonstration that not only the distance from the industrial source but also the sampling season and PM₁₀ concentrations significantly affect the elemental content in mosses; the association of the emissions from the source and the determined concentrations of elements in moss samples were more evident outside the heating season (October). The analyses of transformed data revealed the association of Fe, Cr, V, As and Al with the coarse particles and their dominant spatial distribution depending on the prevailing wind directions. The spatial distribution of Mn, Zn and Cd, which are carried by fine particles, appears to depend more on atmospheric dispersion and long-range transport, and, thus, these metals should be considered weak markers of the pollution load in the close surroundings of an industrial source. Full article

(This article belongs to the Special Issue Monitoring and Analysis of Environmental Pollution)

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17 pages, 3473 KiB

Open AccessArticle

Using Statistical Modeling for Assessing Lettuce Crops Contaminated with Zn, Correlating Plants Growth Characteristics with the Soil Contamination Levels

by Petru Cardei, Florin Nenciu, Nicoleta Ungureanu, Mirabela Augustina Pruteanu, Valentin Vlăduț, Dan Cujbescu, Iuliana Găgeanu and Oana Diana Cristea

Appl. Sci. 2021, 11(17), 8261; https://doi.org/10.3390/app11178261 - 6 Sep 2021

Cited by 10 | Viewed by 2455

Abstract

The aim of the study was to identify new mathematical models and strategies that can characterize the behavior of pollutants accumulating in the soil over time, considering the special characteristics of these chemicals that cannot be degraded or destroyed easily. The paper proposes [...] Read more.

The aim of the study was to identify new mathematical models and strategies that can characterize the behavior of pollutants accumulating in the soil over time, considering the special characteristics of these chemicals that cannot be degraded or destroyed easily. The paper proposes a statistical model for assessing the accumulation of Zn in the lettuce (Lactuca sativa L.), based on three indicators that characterize the development of lettuce plants over time. The experimental data can be used to obtain interpolated variations of the mass increase functions and to determine several functions that express the time dependence of heavy metal accumulation in the plant. The resulting interpolation functions have multiple applications, being useful in generating predictions for plant growth parameters when they are grown in contaminated environments, determining whether pollutant concentrations may be hazardous for human health, and may be used to verify and validate dynamic mathematical contamination models. Full article

(This article belongs to the Topic New Research on Detection and Removal of Emerging Pollutants)

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8 pages, 3602 KiB

Open AccessCommunication

Definition of a Protocol to Manage and Officially Confirm SHB Presence in Sentinel Honeybee Colonies

by Giovanni Formato, Giovanni Federico, Camilla Di Ruggiero, Marco Pietropaoli, Marcella Milito and Franco Mutinelli

Appl. Sci. 2021, 11(17), 8260; https://doi.org/10.3390/app11178260 - 6 Sep 2021

Cited by 3 | Viewed by 2225

Abstract

Given the consolidated circulation of Aethina tumida (SHB) in Reggio Calabria and Vibo Valentia provinces of Calabria region (Southern Italy), the need for a more effective and less time-consuming approach to SHB surveillance emerged. Accordingly, honeybee sentinel colonies were established in the infested [...] Read more.

Given the consolidated circulation of Aethina tumida (SHB) in Reggio Calabria and Vibo Valentia provinces of Calabria region (Southern Italy), the need for a more effective and less time-consuming approach to SHB surveillance emerged. Accordingly, honeybee sentinel colonies were established in the infested areas under the supervision and management of the Veterinary Services of the Local Health Unit. In this short communication, we present the protocol adopted in the Calabria region to manage the SHB positive sentinel honeybee colonies. The procedures for safely packing and transport the SHB infested sentinel honeybee colonies from the field to the official laboratory and the subsequent procedure for their careful inspection in the laboratory are illustrated. Full article

(This article belongs to the Special Issue Frontier Research in Apiculture (Diagnosis and Control of Bee Diseases, Bee Products, Environmental Monitoring))

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12 pages, 2424 KiB

Open AccessArticle

Fast Stepwise Inertial Control Scheme of a DFIG for Reducing Second Frequency Drop

by Yien Xu, Dejian Yang, Jiejie Huang, Xinsong Zhang and Liang Hua

Appl. Sci. 2021, 11(17), 8259; https://doi.org/10.3390/app11178259 - 6 Sep 2021

Cited by 4 | Viewed by 2232

Abstract

With the fast growth in the penetration of wind power, doubly fed induction generators (DFIGs) are recommended for their ability to enforce grid codes that provide inertial control services by releasing rotational energy. However, after supporting the system frequency, a second frequency drop [...] Read more.

With the fast growth in the penetration of wind power, doubly fed induction generators (DFIGs) are recommended for their ability to enforce grid codes that provide inertial control services by releasing rotational energy. However, after supporting the system frequency, a second frequency drop (SFD) is prone to occurring to regain the rotor speed caused by the sudden reduction in output. In this article, we propose a torque limit-based fast stepwise inertial control scheme of a DFIG using a piecewise reference function for reducing the SFD while preserving the frequency nadir (FN) with less rotor energy released. To achieve the first objective, the power reference increases to the torque limit and then decays with the rotor speed toward the preset operating point. To achieve the second objective, the power reference smoothly lessens over time based on the exponential function. The performance of the proposed stepwise inertial control strategy was studied under various scenarios, including constant wind speed and ramp down wind speed conditions. The test results demonstrated that the frequency stability is preserved during the frequency support phase, while the second frequency drop and mechanical stress on the wind turbine reduce during the rotor speed restoration phase when the DFIG implements the proposed stepwise inertial control scheme. Full article

(This article belongs to the Section Energy Science and Technology)

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Vector control of the rotor side converter. Full article ">Figure 2
Operational features of the conventional scheme. Full article ">Figure 3
Control concept of the proposed stepwise inertial control scheme. Full article ">Figure 4
Operational features of the proposed stepwise inertial control scheme. Full article ">Figure 5
Test system embedded with a DFIG. Full article ">Figure 6
Results for Case 1: (a) frequency, (b) output power, (c) rotor speed, and (d) torque difference. Full article ">Figure 7
Results for Case 2: (a) frequency, (b) output power, (c) rotor speed, and (d) torque difference. Full article ">Figure 8
Results for Case 3: (a) wind speed, (b) frequency, (c) output power, and (d) rotor speed. Full article ">

20 pages, 90783 KiB

Open AccessArticle

Multiple-Input Convolutional Neural Network Model for Large-Scale Seismic Damage Assessment of Reinforced Concrete Frame Buildings

by Chen Xiong, Jie Zheng, Liangjin Xu, Chengyu Cen, Ruihao Zheng and Yi Li

Appl. Sci. 2021, 11(17), 8258; https://doi.org/10.3390/app11178258 - 6 Sep 2021

Cited by 20 | Viewed by 3176

Abstract

This study introduces a multiple-input convolutional neural network (MI-CNN) model for the seismic damage assessment of regional buildings. First, ground motion sequences together with building attribute data are adopted as inputs of the proposed MI-CNN model. Second, the prediction accuracy of MI-CNN model [...] Read more.

This study introduces a multiple-input convolutional neural network (MI-CNN) model for the seismic damage assessment of regional buildings. First, ground motion sequences together with building attribute data are adopted as inputs of the proposed MI-CNN model. Second, the prediction accuracy of MI-CNN model is discussed comprehensively for different scenarios. The overall prediction accuracy is 79.7%, and the prediction accuracies for all scenarios are above 77%, indicating a good prediction performance of the proposed method. The computation efficiency of the proposed method is 340 times faster than that of the nonlinear multi-degree-of-freedom shear model using time history analysis. Third, a case study is conducted for reinforced concrete (RC) frame buildings in Shenzhen city, and two seismic scenarios (i.e., M6.5 and M7.5) are studied for the area. The simulation results of the area indicate a good agreement between the MI-CNN model and the benchmark model. The outcomes of this study are expected to provide a useful reference for timely emergency response and disaster relief after earthquakes. Full article

(This article belongs to the Special Issue Artificial Neural Networks Applied in Civil Engineering)

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12 pages, 2937 KiB

Open AccessArticle

Effects of a Dual-Purpose Inoculant on the Quality and Aerobic Stability of Corn Silage at the Laboratory and Field Scales

by Hsiu-Ming Weng, Li-Chen Kao, Shu-Min Wang, Chia-Sheng Chen, Ting-Yu Lee, Hsiao-Tung Chang, San-Land Young and Jin-Seng Lin

Appl. Sci. 2021, 11(17), 8257; https://doi.org/10.3390/app11178257 - 6 Sep 2021

Cited by 1 | Viewed by 2334

Abstract

This study investigated the effects of a dual-purpose inoculant (DPI) on the fermentation profile, nutritive value, and aerobic stability of silage. The inoculant effect was first examined with minisilos, and the results were later validated with 400-kg silo bales and a 40-t bunker [...] Read more.

This study investigated the effects of a dual-purpose inoculant (DPI) on the fermentation profile, nutritive value, and aerobic stability of silage. The inoculant effect was first examined with minisilos, and the results were later validated with 400-kg silo bales and a 40-t bunker silo. Briefly, whole-plant corn harvested at the one-half to two-thirds milk line stage was chopped and then treated with or without inoculant containing Lactobacillus plantarum LP1028 and Lactobacillus buchneri LBC1029 at application rates of 2.5 × 10⁵ cfu and 5.0 × 10⁵ cfu per gram of fresh forage, respectively. The results showed that applying DPI had no effect on the nutritive value in all trials. DPI inoculation also slowed yeast and mold growth in silage under aerobic exposure. Inoculation may double the aerobic stability time after 105 d of ensiling (53.25 vs. 113.20 h) in a bunker silo. This study successfully examined the effectiveness of DPI in minisilos, and the results were consistent when moving from the laboratory to the field. Applying DPI made the fermentation more heterolactic without compromising the silage nutritive value, and increasing acetic acid acted as an antifungal agent to inhibit spoilage microbial growth and improve silage aerobic stability. Full article

(This article belongs to the Section Applied Microbiology)

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Changes in (a) yeast and mold counts (YMC) and (b) pH of 105-d ensiled laboratory-scale forages during aerobic exposure. Corn silage was treated without ( <img alt="Applsci 11 08257 i001" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i001.png"/>, n = 3) or with ( <img alt="Applsci 11 08257 i002" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i002.png"/>, n = 3) DPI. Values with asterisk (*) within the same aerobic exposure time differed significantly (p < 0.05). Data were presented as mean ± SEM. Full article ">Figure 2
Changes in yeast and mold counts (YMC) of 90-d ensiled baled forages during aerobic exposure. Corn silage was treated without ( <img alt="Applsci 11 08257 i001" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i001.png"/>, n=3) or with ( <img alt="Applsci 11 08257 i002" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i002.png"/>, n=3) DPI. Data were presented as mean ± SEM. Full article ">Figure 3
Changes in (a) pH, and (b) lactic acid concentration of 105-d ensiled bunker forages during aerobic exposure. Corn silage was treated without ( <img alt="Applsci 11 08257 i001" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i001.png"/>, n = 3) or with ( <img alt="Applsci 11 08257 i002" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i002.png"/>, n = 3) DPI. Asterisk (*) indicated that the slopes of linear regression lines differed significantly (p < 0.05). Data were presented as mean ± SEM. SEYX: standard error of regression coefficient. Full article ">Figure 4
Changes in yeast and mold counts (YMC) of 105-d ensiled bunker forages during aerobic exposure. Corn silage was treated without ( <img alt="Applsci 11 08257 i001" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i001.png"/>, n = 3) or with ( <img alt="Applsci 11 08257 i002" src="/applsci/applsci-11-08257/article_deploy/html/images/applsci-11-08257-i002.png"/>, n = 3) DPI. Values with asterisk (*) within the same aerobic exposure time differed significantly (p < 0.05). Data were presented as mean ± SEM. Full article ">Figure 5
Thermogram of corn silage after 105-d storage. Corn silage was treated without (left-half) and with (right-half) DPI and the silo working face was exposed to air for 96 h. Color indicated different temperature from low (blue, 27.7 °C) to high temperature (red, 33.2 °C). Full article ">

22 pages, 7633 KiB

Open AccessArticle

Mechanical and Tribological Characterization of a Bioactive Composite Resin

by Elsa Reis Carneiro, Ana Sofia Coelho, Inês Amaro, Anabela Baptista Paula, Carlos Miguel Marto, José Saraiva, Manuel Marques Ferreira, Luís Vilhena, Amílcar Ramalho and Eunice Carrilho

Appl. Sci. 2021, 11(17), 8256; https://doi.org/10.3390/app11178256 - 6 Sep 2021

Cited by 7 | Viewed by 3461

Abstract

Despite developments and advances in dental materials which allow for greater restorative performance, there are still challenges and questions regarding the formulation of new compositions and chemical reactions of materials used in restorative dentistry. The aim of this study was to assess and [...] Read more.

Despite developments and advances in dental materials which allow for greater restorative performance, there are still challenges and questions regarding the formulation of new compositions and chemical reactions of materials used in restorative dentistry. The aim of this study was to assess and compare the mechanical and tribological characteristics of a bioactive resin, a composite resin, and a glass ionomer. Twenty specimens of each material were divided into two groups: one control group (n = 10), not subjected to thermocycling, and one test group (n = 10) submitted to thermocycling. The Vickers microhardness test was carried out and surface roughness was evaluated. The tribological sliding indentation test was chosen. The bioactive resin had the lowest hardness, followed by the composite resin, and the glass ionomer. The bioactive resin also showed greater resistance to fracture. For the tribological test, the wear rate was lower for the bioactive resin, followed by the composite resin, and the glass ionomer. The bioactive resin presented a smooth surface without visible cracks, while the other materials presented a brittle peeling of great portions of material. Thus, the bioactive resin performs better in relation to fracture toughness, wear rate and impact absorption than the composite resin and much better than the glass ionomer. Full article

(This article belongs to the Special Issue Recent Progress in Biotribology, Biomaterials and Related Mechanical Measurements)

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20 pages, 4360 KiB

Open AccessArticle

Real-Time Cloth Simulation Using Compute Shader in Unity3D for AR/VR Contents

by Hongly Va, Min-Hyung Choi and Min Hong

Appl. Sci. 2021, 11(17), 8255; https://doi.org/10.3390/app11178255 - 6 Sep 2021

Cited by 11 | Viewed by 9483

Abstract

While the cloth component in Unity engine has been used to represent the 3D cloth object for augmented reality (AR) and virtual reality (VR), it has several limitations in term of resolution and performance. The purpose of our research is to develop a [...] Read more.

While the cloth component in Unity engine has been used to represent the 3D cloth object for augmented reality (AR) and virtual reality (VR), it has several limitations in term of resolution and performance. The purpose of our research is to develop a stable cloth simulation based on a parallel algorithm. The method of a mass–spring system is applied to real-time cloth simulation with three types of springs. However, cloth simulation using the mass–spring system requires a small integration time-step to use a large stiffness coefficient. Furthermore, constraint enforcement is applied to obtain the stable behavior of the cloth model. To reduce the computational burden of constraint enforcement, the adaptive constraint activation and deactivation (ACAD) technique that includes the mass–spring system and constraint enforcement method is applied to prevent excessive elongation of the cloth. The proposed algorithm utilizes the graphics processing unit (GPU) parallel processing, and implements it in Compute Shader that executes in different pipelines to the rendering pipeline. In this paper, we investigate the performance and compare the behavior of the mass–spring system, constraint enforcement, and ACAD techniques using a GPU-based parallel method. Full article

(This article belongs to the Special Issue AR, VR: From Latest Technologies to Novel Applications)

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25 pages, 6729 KiB

Open AccessArticle

Fragility Curves and Probabilistic Seismic Demand Models on the Seismic Assessment of RC Frames Subjected to Structural Pounding

by Maria G. Flenga and Maria J. Favvata

Appl. Sci. 2021, 11(17), 8253; https://doi.org/10.3390/app11178253 - 6 Sep 2021

Cited by 24 | Viewed by 5290

Abstract

This study aims to evaluate five different methodologies reported in the literature for developing fragility curves to assess the seismic performance of RC structures subjected to structural pounding. In this context, displacement-based and curvature-based fragility curves are developed. The use of probabilistic seismic [...] Read more.

This study aims to evaluate five different methodologies reported in the literature for developing fragility curves to assess the seismic performance of RC structures subjected to structural pounding. In this context, displacement-based and curvature-based fragility curves are developed. The use of probabilistic seismic demand models (PSDMs) on the fragility assessment of the pounding risk is further estimated. Linear and bilinear PSDMs are developed, while the validity of the assumptions commonly used to produce a PSDM is examined. Finally, the influence of the PSDMs’ assumptions on the derivation of fragilities for the structural pounding effect is identified. The examined pounding cases involve the interaction between adjacent RC structures that have equal story heights (floor-to-floor interaction). Results indicate that the fragility assessment of the RC structure that suffers the pounding effect is not affected by the examined methodologies when the performance level that controls the seismic behavior is exceeded at low levels of IM. Thus, the more vulnerable the structure is due to the pounding effect, the more likely that disparities among the fragility curves of the examined methods are eliminated. The use of a linear PSDM fails to properly describe the local inelastic demands of the structural RC member that suffers the impact effect. The PSDM’s assumptions are not always satisfied for the examined engineering demand parameters of this study, and thus may induce errors when fragility curves are developed. Nevertheless, errors induced due to the power law model and the homoscedasticity assumptions of the PSDM can be reduced by using the bilinear regression model. Full article

(This article belongs to the Special Issue Seismic Assessment and Design of Structures)

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16 pages, 6813 KiB

Open AccessArticle

Insight into the Role of Cerium (III) Addition to a MgAl-LDH Coating on AA6082

by Michele Fedel and Michele Zampiccoli

Appl. Sci. 2021, 11(17), 8252; https://doi.org/10.3390/app11178252 - 6 Sep 2021

Cited by 8 | Viewed by 3131

Abstract

In this work, Ce doped MgAl-LDHs layers have been developed through an in-situ synthesis method on 6082 aluminum surface. The aim was to gain mechanistic insight into the role of Ce(III) as an active corrosion inhibitor embedded in the LDHs layer. The development [...] Read more.

In this work, Ce doped MgAl-LDHs layers have been developed through an in-situ synthesis method on 6082 aluminum surface. The aim was to gain mechanistic insight into the role of Ce(III) as an active corrosion inhibitor embedded in the LDHs layer. The development of the LDH structure was verified by checking the presence of the characteristic XRD peaks, the platelet morphology (evaluated by SEM-EDXS) and the functional groups (by FTIR-ATR analyses). The same techniques were employed to assess the effect of a prolonged immersion time in 0.1 NaCl on the Ce doped MgAl-LDH coatings. Electrochemical impedance spectroscopy (EIS) was employed to monitor the evolution of the electrochemical properties of the coatings during prolonged immersion in saline solutions. The findings suggest a crystallization/dissolution/precipitation mechanism which implies: (i) the formation of crystalline cerium compounds, such as Ce(OH)₃, in the LDH structure during the synthesis; (ii) the dissolution upon exposure to the NaCl solution, thus leading to cerium ions release; (iii) the precipitation of amorphous Ce oxides/hydroxides at the cathodic sites when the metal starts to corrode; (iv), the consequent mitigation of the electrochemical activity of the metal and, thus, the reduction of the extent of corrosion. Full article

(This article belongs to the Special Issue Sustainable Surface Engineering for Functional Applications: Anti-corrosion and Tribological Systems, Responsive Interfaces, and Biomedical Devices)

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11 pages, 1394 KiB

Open AccessFeature PaperArticle

Influence of Pre-Etched Area and Functional Monomers on the Enamel Bond Strength of Orthodontic Adhesive Pastes

by Yuriko Tezuka, Yasuhiro Namura, Akihisa Utsu, Kiyotaka Wake, Yasuki Uchida, Mizuki Inaba, Toshiki Takamizawa and Mitsuru Motoyoshi

Appl. Sci. 2021, 11(17), 8251; https://doi.org/10.3390/app11178251 - 6 Sep 2021

Viewed by 2201

Abstract

This study was performed to investigate the influence of pre-etching area and functional monomers in orthodontic adhesive pastes on enamel bond strength. Bovine enamel was partially pre-etched with phosphoric acid for 30 s over areas with a diameter of 1.0, 2.0 or 3.0 [...] Read more.

This study was performed to investigate the influence of pre-etching area and functional monomers in orthodontic adhesive pastes on enamel bond strength. Bovine enamel was partially pre-etched with phosphoric acid for 30 s over areas with a diameter of 1.0, 2.0 or 3.0 mm, and metal brackets were then bonded with or without functional monomers in the orthodontic adhesive paste. For the baseline groups, the whole adherent area was pre-etched. The shear bond strength (SBS) and adhesive remnant index (ARI) were determined. The adhesive paste/enamel interfaces were observed by scanning electron microscopy (SEM). Although the adhesive paste with functional monomers showed higher SBS than the functional monomer-free adhesive paste in all groups, there were no significant differences in SBS between them regardless of the pre-etched area. The SBS increased with increasing pre-etched area in both orthodontic adhesive pastes. In SEM images of adhesive paste/enamel interfaces, although adhesive with functional monomers showed excellent adaptation, the functional monomer-free adhesive paste showed gap formation at the interface. These findings suggested that the pre-etching area greatly influenced bond strength, regardless of the presence or absence of the functional monomer in the orthodontic adhesive paste. Full article

(This article belongs to the Special Issue Current Techniques and Materials in Dentistry)

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17 pages, 5158 KiB

Open AccessArticle

Model-Based Analysis and Improvement of Vehicle Radiation Emissions at Low Frequency

by Feng Gao, Qing Wang and Yu Xiong

Appl. Sci. 2021, 11(17), 8250; https://doi.org/10.3390/app11178250 - 6 Sep 2021

Cited by 2 | Viewed by 2292

Abstract

With the development of electrification and intelligence, the electromagnetic environment of intelligent and electric vehicles becomes complicated and critical because of the high voltage/current of power components, the computation units with high frequency and the dense radio systems. These pose great challenges for [...] Read more.

With the development of electrification and intelligence, the electromagnetic environment of intelligent and electric vehicles becomes complicated and critical because of the high voltage/current of power components, the computation units with high frequency and the dense radio systems. These pose great challenges for the design of vehicle radiation emissions. To improve the development efficiency, a model-based analysis and improvement strategy is proposed. Firstly, a topological approach is presented to decouple and model the vehicle-level radiation problem. By this topological model, each technical factor is analyzed from both of its contribution and sensitivity to the radiation emission, which are further integrated together using the entropy weight method to generate the technical evaluation score. Then, other untechnical factors, i.e., the cost and application difficulty, are further combined with the technical evaluation results by the analytic hierarchy process to determine the final solution. This strategy has been applied to solve a radiation problem of an electric vehicle at low frequency to validate its effectiveness and show some application details. Full article

(This article belongs to the Special Issue Advanced Technologies in Electromagnetic Compatibility)

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16 pages, 2088 KiB

Open AccessArticle

A Study of the Behavior and Responsibility of Slovak Drivers, Especially in Case of Fatigue

by Adrian Hajducik, Stefan Medvecky, Slavomir Hrcek and Jaromir Klarak

Appl. Sci. 2021, 11(17), 8249; https://doi.org/10.3390/app11178249 - 6 Sep 2021

Cited by 4 | Viewed by 2650

Abstract

Driver fatigue can be manifested by various highly dangerous direct and indirect symptoms, for example, inattention or lack of concentration. The aim of the study was to compare the behavior of young drivers, older drivers and professional drivers, particularly in situations where they [...] Read more.

Driver fatigue can be manifested by various highly dangerous direct and indirect symptoms, for example, inattention or lack of concentration. The aim of the study was to compare the behavior of young drivers, older drivers and professional drivers, particularly in situations where they feel fatigued. In the online questionnaire, drivers answered various questions which analysed their responsibility of driving a car during fatigue, the optimum temperature in the car, or experience with microsleep. The sample of drivers consisted of 507 women and 951 men in Slovakia. Young drivers are more responsible when driving during fatigue, while professional drivers take risks, break the law, and drive tired more often. A total of 25% of all drivers experience fatigue more than once a week. Adverse results were found in connection with driving and fatigue, where more than 42% of respondents stated that their duties require them to drive even when they are tired. A total of 27% of drivers have had microsleep while driving. The survey showed that drivers are aware that thermoneutral temperature in a car interior can improve driving performance and a lower temperature can positively affect a person’s attention. The regulation of the temperature in the car was helpful for 75% of all drivers when they felt tired, and more than 97% of the drivers lowered the temperature in the interior of the vehicle in order to achieve a better concentration. In addition to standard statistical methods, a neural network was used for the evaluation of the questionnaire, which sought for individual connections and subsequent explanations for the hypotheses. The applied neural network was able to determine parameters such as the age of the driver and the annual raid as the riskiest and closely associated with the occurrence of microsleep between drivers. Full article

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14 pages, 1173 KiB

Open AccessArticle

Risk-Based Virtual Power Plant Implementation Strategy for Smart Energy Communities

by Eunsung Oh

Appl. Sci. 2021, 11(17), 8248; https://doi.org/10.3390/app11178248 - 6 Sep 2021

Cited by 7 | Viewed by 2391

Abstract

This paper focuses on a virtual power plant (VPP) implementation strategy for smart local energy communities (SECs) with energy service providers. It is difficult to balance energy in the implementation stage due to uncertainties in demand and resources. Therefore, VPP implementation was modeled [...] Read more.

This paper focuses on a virtual power plant (VPP) implementation strategy for smart local energy communities (SECs) with energy service providers. It is difficult to balance energy in the implementation stage due to uncertainties in demand and resources. Therefore, VPP implementation was modeled using the risk factor of energy balance. Using this risk factor, it was shown that the temporal correlation between demand and resources was the dominant factor involved in VPP implementation. Based on this, two risk-based VPP implementation strategies are proposed: an optimization-based strategy and a simple strategy that is solved in an iterative way. To minimize VPP implementation costs, the proposed strategies select the resources that have high correlation coefficients with demand and low correlation coefficients with other resources. Experimental results using real data sets show that the proposed strategies based on the risk factor are effective means of VPP implementation for commercial and residential SECs. The results imply that VPPs for commercial SECs are possible when PV is used as the main resource and is supplemented by wind, and it is effective to configure VPPs for residential SECs using wind according to the correlation between demand and resources. Full article

(This article belongs to the Special Issue Smart Solutions of Distributed Energy Systems: Design, Operation, and Application)

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10 pages, 5501 KiB

Open AccessFeature PaperArticle

Behavior of Generated Gas during Femtosecond Laser Lens Irradiation in Porcine Cadaver Eyes

by Yoichiro Masuda, Kotaro Oki, Akira Watanabe, Makiko Ohkido, Hisaharu Iwaki, Takuya Shiba and Tadashi Nakano

Appl. Sci. 2021, 11(17), 8247; https://doi.org/10.3390/app11178247 - 6 Sep 2021

Viewed by 1876

Abstract

(1) Background: We investigated the behavior of gas inside a lens and its influence on the lens capsule, which may cause complications by lens irradiation with a femtosecond laser cataract surgery device. (2) Methods: The crystalline lenses of 6-month-old porcine cadaver eyes were [...] Read more.

(1) Background: We investigated the behavior of gas inside a lens and its influence on the lens capsule, which may cause complications by lens irradiation with a femtosecond laser cataract surgery device. (2) Methods: The crystalline lenses of 6-month-old porcine cadaver eyes were observed during laser irradiation. An intraocular endoscope in the vitreous cavity was used to measure the posterior capsule position. Optical coherence tomography measurements of the anterior chamber depth before and after the laser irradiation, as well as measurements of the equatorial perimeter of the extracted lens, were compared with those of the controls. (3) Results: Femtosecond laser-generated gas in the porcine lens was dependent on laser irradiation energy. Increases in the amount of laser irradiation energy caused the generated gas to coalesce, move backwards beyond the laser irradiation site, and expand the lens capsule and posterior capsule. (4) Conclusions: The present results suggest that laser irradiation-induced gas moves in the direction of the posterior capsule beyond the lens irradiation site and expands the lens capsule, which may be involved in the development of capsular block syndrome. Full article

(This article belongs to the Special Issue Laser Technologies and Nonlinear Optics in Surface Sciences)

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Eyeballs were placed on custom-made stands in order to achieve an appropriate height and position for femtosecond laser system CATALYS for the purpose of connecting the liquid optic interface and endoscope to the porcine eye. Full article ">Figure 2
Although laser irradiation caused anterior chamber depth to become significantly shallower, there was no correlation with the amount of laser irradiation energy. (a) Box-plot diagram showing mean values of anterior chamber depth in the eye before and after laser irradiation. Boxes, interquartile range (difference between upper 75% and lower 25% quartiles); thick black lines, median; whiskers, highest and lowest values that were not outliers or extreme values. A significant difference was observed in ACD before and after laser irradiation (p = 0.042 < 0.05)). (b) There was no correlation between laser irradiation energy dose and ACD change ratio (p = 0.054 > 0.05). Full article ">Figure 3
Generated gas by laser irradiation coalesced and moved rearward and beyond the irradiation site, thereby causing the posterior capsule to expand. Excised lens that was irradiated by the laser was expanded as compared to the control lens. (a–d) Endoscopic image after laser irradiation in lens H. (a) Before laser irradiation. (b) At 2 s after laser irradiation. (c) After 10 s of laser irradiation. (d) At 44 s after laser irradiation. Yellow dotted line indicates the starting position of laser irradiation; white dotted line indicates the posterior capsule position before laser irradiation; white arrowheads indicate posterior capsule position after expansion. (e,f) Microscopic image of extracted lens. (e) Control lens Y. (f) Lens H after laser irradiation. Scale bar is 1 mm. Laser irradiation energy amount listed in parentheses. Full article ">Figure 4
The greater the laser irradiation energy was, the more gas was produced. If pressure exceeded maximal pressure levels of the capsule, it ruptured. (a–c) Endoscopic images of lens P during laser irradiation procedure. (a) Before laser irradiation. (b) Immediately before rupture by CBS during laser irradiation. (c) Immediately after rupture by CBS during laser irradiation. (d) Endoscopic images of lens P from the posterior pole of the eye after laser irradiation. White dotted line indicates capsule position before laser irradiation; white arrowheads indicate posterior position after expansion; yellow arrowheads indicate gas distribution after bursting into the vitreous cavity behind the ciliary body. (e,f) Microscopic image of extracted lens P. Error bar is 1 mm. Laser irradiation energy amount listed in parentheses. Full article ">Figure 5
Generated gas caused the crystalline lens to become buoyant and overcome the weight of the lens, thereby allowing for it to float in the saline. Laser irradiation energy amount listed in parentheses. Full article ">Figure 6
The PCP ratio correlated well with the laser irradiation time and laser energy amount. (a): The PCP ratio of 5 eyes (total laser energy amount 16.6–25 J, laser irradiation time 37.5–48.7 s). The coefficient of determination (R2) for each regression line was 0.938–0.981. The PCP ratio within this irradiation time correlated well with the laser irradiation time and laser energy amount. (b): The PCP ratio in lens P, which was irradiated for 261 s, linearly increased up to about 70 s (R2 = 0.981), with the slope then decreasing, followed by a burst at 240 s. Full article ">Figure 7
Although the laser irradiation caused significantly longer average equatorial perimeter, there was no correlation with the amount of laser irradiation energy. (a) Box-plot diagram showing mean values of equatorial perimeter length in control lens and laser-irradiated lens. Boxes, interquartile range (difference between upper 75% and lower 25% quartiles); thick black lines, median; whiskers, highest and lowest values that were not outliers or extreme values. There was significant difference between these two groups (p = 0.001 < 0.05). (b) No correlation was found between amount of laser irradiation energy and equatorial perimeter of laser-irradiated lens (p = 0.899 > 0.05). Full article ">

24 pages, 1119 KiB

Open AccessArticle

Optimal Generation Start-Up Methodology for Power System Restoration Considering Conventional and Non-Conventional Renewable Energy Sources

by Ricardo Andrés Pardo-Martínez, Jesús M. López-Lezama and Nicolás Muñoz-Galeano

Appl. Sci. 2021, 11(17), 8246; https://doi.org/10.3390/app11178246 - 6 Sep 2021

Cited by 1 | Viewed by 2584

Abstract

Power system restoration must be accomplished as soon as possible after a blackout. In this process, available black-start (BS) units are used to provide cranking power to non-black-start (NBS) units so as to maximize the overall power system generation capacity. This procedure is [...] Read more.

Power system restoration must be accomplished as soon as possible after a blackout. In this process, available black-start (BS) units are used to provide cranking power to non-black-start (NBS) units so as to maximize the overall power system generation capacity. This procedure is known as the generation start-up problem, which is intrinsically combinatorial with complex non-linear constraints. This paper presents a new mixed integer linear programming (MILP) formulation for the generation start-up problem that integrates non-conventional renewable energy sources (NCRES) and battery energy storage systems (BESS). The main objective consists of determining an initial starting sequence for both BS and NBS units that would maximize the generation capacity of the system while meeting the non-served demand of the network. The nature of the proposed model leads to global optimal solutions, clearly outperforming heuristic and enumerative approaches, since the latter may take higher computational time while the former do not guarantee global optimal solutions. Several tests were carried out on the IEEE 39-bus test system considering BESS as well as wind and solar generation. The results showed the positive impact of NCRES in the restoration processes and evidenced the effectiveness and applicability of the proposed approach. It was found that including NCRES and BESS in the restoration process allows a reduction of 24.4% of the objective function compared to the classical restoration without these technologies. Full article

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13 pages, 1214 KiB

Open AccessFeature PaperArticle

Effect of Plasma Surface Modification on Print Quality of Biodegradable PLA Films

by Joanna Izdebska-Podsiadły

Appl. Sci. 2021, 11(17), 8245; https://doi.org/10.3390/app11178245 - 6 Sep 2021

Cited by 18 | Viewed by 3859

Abstract

PLA films, as non-absorbent materials, require modification of the surface before the printing process in order to improve the wettability of the substrate and to obtain proper ink adhesion to the substrate. In this paper, the surfaces of two kinds of PLA films [...] Read more.

PLA films, as non-absorbent materials, require modification of the surface before the printing process in order to improve the wettability of the substrate and to obtain proper ink adhesion to the substrate. In this paper, the surfaces of two kinds of PLA films were modified using plasma activation with parameters enabling high surface free energy (SFE) values, and then the films were printed on using different kinds of flexographic inks. Two gases, oxygen and argon, were used for activation, as these make it possible to obtain good hydrophilicity and high SFE values while having different effects on the roughness, or the degree of surface etching. Plasma-activated films were subsequently subjected to the measurements of: contact angle with water, diiodomethane and three printing inks, roughness, weight change, strength properties, color and gloss change, and SFE was determined. Unmodified and activated films were flexographically printed in laboratory conditions and then the quality of obtained prints was analyzed. The results showed a strong effect of activation with both oxygen and argon plasma on the SFE value of the films and the contact angles of water and inks, with the gas used for plasma activation and the type of film significantly influencing the thickness of the fused ink layer and the resultant color. Moreover, plasma activation had a especially favorable and significant effect on the quality of prints made with water-based inks, while it had little effect when printing with solvent-based inks. Full article

(This article belongs to the Special Issue Advances in Surface Modification of the Materials)

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Appl. Sci., Volume 11, Issue 17 (September-1 2021) – 508 articles

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