bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vivo Deformation and Strain Measurements in Human Bone Using Digital Volume Correlation (DVC) and 3T Clinical MRI
Authors: Tavana Saman , N. Clark Jeffrey , Newell Nicolas , Calder James D. , Hansen Ulrich
Published: November 2020

Strains within bone play an important role in the remodelling process and the mechanisms of fracture. The ability to assess these strains in vivo can provide clinically relevant information regarding bone health, injury risk, and can also be used to optimise treatments. In vivo bone strains have been investigated using multiple experimental techniques, but none have quantified 3D strains using non-invasive techniques. Digital volume correlation based on clinical MRI (DVC-MRI) is a non-invasive technique that has the potential to achieve this. However, before it can be implemented, uncertainties associated with the measurements must be quantified. Here, DVC-MRI was evaluated to assess its potential to measure in vivo strains in the talus. A zero-strain test (two repeated unloaded scans) was conducted using three MRI sequences, and three DVC approaches to quantify errors and to establish optimal settings. With optimal settings, strains could be measured with a precision of 200 με and accuracy of 480 με for a spatial resolution of 7.5 mm, and a precision of 133 με and accuracy of 251 με for a spatial resolution of 10 mm. These results demonstrate that this technique has the potential to measure relevant levels of in vivo bone strain and to be used for a range of clinical applications.
Influence of ns-Laser Cleaning Parameters on the Removal of the Painted Layer and Selected Properties of the Base Metal
Authors: Li Xinyan , Wang Dan , Gao Juming , Zhang Weiwei , Li Canyang , Wang Nianzheng , Lei Yucheng
Published: November 2020

The removal of the surface paint of Q345 (Gr·B) steel, as well as microstructure and hardness of the cleaned surface were investigated. The laser source used in this study is a nanosecond pulsed Gaussian light source. The surface morphology and microstructure were characterized by a scanning electron microscope and electron back-scattered diffraction. A hardness test was used for capturing variations of the parameter of the cleaned region in comparison to the base metal. The results show that when the X-scanning speed was 1500 mm/s and Y-moving speeds was 7 mm/s during ns-laser cleaning, respectively, the cleaned surface was relatively flat and there was only a few small residual paint. In addition, the contents of Fe and C elements on the cleaned surface reached to 89% and 9%, respectively. Moreover, the roughness was the lowest of 0.5 μm through the observation of the three-dimensional topography. In addition, a fine grain layer appeared on the cleaned surface after laser cleaning at the X-scanning speeds of 500 mm/s and 1000 mm/s. The maximum hardness of the fine grain layer was more than 400 HV, higher than the base metal.
A Study of Manufacturing Processes of Composite Form-Stable Phase Change Materials Based on Ca(NO3)2–NaNO3 and Expanded Graphite
Authors: Ren Yunxiu , Xu Chao , Wang Tieying , Tian Ziqian , Liao Zhirong
Published: November 2020

The fabrication of form-stable phase change materials (FS-PCMs) usually involves four manufacturing processes: mixing, immersion, stabilization, and sintering. In each process, the operation parameters could affect the performance of the fabricated PCM composite. To gain an efficient and low-cost method for large-scale production of the molten salts/expanded graphite (EG) composite FS-PCMs, the effects of different operating parameters were investigated, including the stirring speed, evaporation temperature, melt-impregnation, cold-pressing pressure, and sintering temperature on the densification, microstructure, and thermophysical properties of the composite FS-PCMs. It was found that the microstructure, the morphology and durability, and the thermophysical properties such as thermal conductivity and specific heat enthalpy depended highly on the operating parameters. The following optimal operating parameters of the Ca(NO3)2–NaNO3/EG composite FS-PCMs are suggested: the stirring speed of 20 rpm, the evaporation temperature of 98 °C, the melt-impregnation temperature of 280 °C, the cold-pressing pressure of 8 MPa, and the sintering temperature of 300 °C. The results of the present work can provide valuable insights for the large-scale production of the composite FS-PCMs.
Theoretical Investigation on Failure Behavior of Ogive-Nose Projectile Subjected to Impact Loading
Authors: Li Zhao , Xu Xiangzhao
Published: November 2020

Experimental and theoretical investigations on the failure behaviors of projectile during high-speed impact into concrete slabs were performed in this study. The ogive-nose projectiles after impact experiments were recovered and their microstructures were observed by scanning electron microscope and metallographic microscope. Mass abrasion and nose blunting are the typical failure models of steel projectile. Furthermore, thermal melting and cutting are the two main failure mechanisms. Based on the microscopic experimental results, a theoretical model of ogive-nose projectile subjected to impact loading considering the melting and cutting mechanisms was proposed. A modified cap model is introduced for describing the failure behavior of concrete targets, and then the dynamic cavity expansion theory is used to determine the resistance of projectiles during penetration. Besides, combining with the two-dimensional heat conduction equation and abrasive wear theory, the two main abrasion mechanisms of melting and cutting are included in the proposed model, which breaks through the framework of previous abrasion models with single abrasion mechanism. The predicted results of the present abrasion model are in good agreement with the experimental data, which indicates that the proposed model can effectively predict the failure behavior and penetration performance parameters of high-speed projectiles during penetration into concrete targets, such as mass loss, nose blunting, and depth of penetration.
Influence of Silver as a Catalyst on the Growth of β-Ga2O3 Nanowires on GaAs
Authors: Alhalaili Badriyah , Mao Howard , Dryden Daniel M. , Cansizoglu Hilal , Bunk Ryan James , Vidu Ruxandra , Woodall Jerry , Islam M. Saif
Published: November 2020

A simple and inexpensive thermal oxidation process was performed to synthesize gallium oxide (Ga2O3) nanowires using Ag thin film as a catalyst at 800 °C and 1000 °C to understand the effect of the silver catalyst on the nanowire growth. The effect of doping and orientation of the substrates on the growth of Ga2O3 nanowires on single-crystal gallium arsenide (GaAs) wafers in atmosphere were investigated. A comprehensive study of the oxide film and nanowire growth was performed using various characterization techniques including XRD, SEM, EDS, focused ion beam (FIB), XPS and STEM. Based on the characterization results, we believe that Ag thin film produces Ag nanoparticles at high temperatures and enhances the reaction between oxygen and gallium, contributing to denser and longer Ga2O3 nanowires compared to those grown without silver catalyst. This process can be optimized for large-scale production of high-quality, dense, and long nanowires.
Influence of Hemp Shives Size on Hygro-Thermal and Mechanical Properties of a Hemp-Lime Composite
Authors: Brzyski Przemysław , Gładecki Mateusz , Rumińska Monika , Pietrak Karol , Kubiś Michał , Łapka Piotr
Published: November 2020

Different fractions of hemp shives are used in the mixtures of the hemp–lime composite. The market offers shives of different granulation. It depends on the type of industrial hemp and on the capabilities of decortication machines. The aim of the research presented in the article is to check differences in the mechanical and hygro-thermal properties of composites with different shives fractions. The research part of the paper presents the preparation method and investigation on hemp–lime composites. Apparent density, total porosity, thermal conductivity, capillary uptake, vapor permeability, specific heat, mass absorptivity, flexural and compressive strength were examined. The results confirm that the shives fraction influences the individual properties of the composites. Hemp–lime composites with fine shives are characterized by higher water absorption, thermal conductivity, mechanical strength, vapor permeability as well as lower capillary-lifting capacity and specific heat than composites with thick shives.
Sustainable Rabbit Skin Glue to Produce Bioactive Nanofibers for Nonactive Wound Dressings
Authors: Matei Ecaterina , Gaidau Carmen , Râpă Maria , Constantinescu Roxana , Savin Simona , Berechet Mariana Daniela , Predescu Andra Mihaela , Berbecaru Andrei Constantin , Coman George , Predescu Cristian
Published: November 2020

This paper assessed the collagen glue (Col) from rabbit skin for use as a raw material in combination with different water-based dispersants of antimicrobial agents such as ZnO NPs, TiO2 NPs doped with nitrogen and Ag NPs (TiO2-N-Ag NPs), and chitosan (CS) for the production of biocompatible and antimicrobial nanofibers. The electrospun nanofibers were investigated by scanning electron microscopy (SEM), attenuated total reflectance in conjunction with Fourier-transform infrared spectroscopy (ATR-FT-IR) analyses and antioxidant activity. The biocompatibility of electrospun nanofibers was investigated on cell lines of mouse fibroblast NCTC (clone L929) using MTT test assays. Antimicrobial activity was performed against Escherichia coli and Staphylococcus aureus bacteria and Candida albicans pathogenic fungus. Electrospun antimicrobial nanofibers based on collagen glue achieved reduction in the number of viable microorganisms against both fungi and bacteria and exhibited multiple inhibitory actions of fungal and bacterial strains. The electrospun nanofibers showed average dimension sizes in the range of 30–160 nm. The results indicated that both Col/TiO2-N-Ag NPs and Col/CS formulations are suitable for cell proliferation and may be useful for producing of nonactive wound dressings.
Thermochromism of Highly Luminescent Photopolymer Flexible Films Based On Eu (III) Salts Confined in Polysulfone
Authors: Outis Mani , Leal João Paulo , Casimiro Maria Helena , Monteiro Bernardo , Pereira Cláudia Cristina Lage
Published: November 2020

Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)4]− anion. The studied Eu(III) salts were [C16Pyr][Eu(fod)4] (1), and the previously reported [Chol][Eu(fod)4]. C16Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (ϕ) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)4] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)4/PSU presented a strong temperature dependence with a ratiometric thermal behavior.
Development of Eco-Sustainable PBAT-Based Blown Films and Performance Analysis for Food Packaging Applications
Authors: Pietrosanto Arianna , Scarfato Paola , Di Maio Luciano , Incarnato Loredana
Published: November 2020

In this work, eco-sustainable blown films with improved performance, suitable for flexible packaging applications requiring high ductility, were developed and characterized. Films were made by blending two bioplastics with complementary properties—the ductile and flexible poly(butylene-adipate-co-terephthalate) (PBAT) and the rigid and brittle poly(lactic acid) (PLA)—at a 60/40 mass ratio. With the aim of improving the blends’ performance, the effects of two types of PLA, differing for viscosity and stereoregularity, and the addition of a commercial polymer chain extender (Joncryl®), were analyzed. The use of the PLA with a viscosity ratio closer to PBAT and lower stereoregularity led to a finer morphology and better interfacial adhesion between the phases, and the addition of the chain extender further reduced the size of the dispersed phase domains, with beneficial effects on the mechanical response of the produced films. The best system composition, made by the blend of PBAT, amorphous PLA, and the compatibilizer, proved to have improved mechanical properties, with a good balance between stiffness and ductility and also good transparency and sealability, which are desirable features for flexible packaging applications.
Determination of Tractor Engine Oil Change Interval Based on Material Properties
Authors: Hönig Vladimír , Procházka Petr , Obergruber Michal , Kučerová Viera , Mejstřík Pavel , Macků Jan , Bouček Jiří
Published: November 2020

This article focuses on the issue of motor oils used in the engines of non-road mobile machinery (NRMM), more specifically tractors. The primary goal of the paper is to determine the appropriate replacement interval for these oils. The physical properties of the examined samples were first determined by conventional instruments. Furthermore, the concentrations of abrasive metals, contaminants, and additive elements were measured using an optical emission spectrometer. Lastly, the content of water, fuel, and glycol and the products of oxidation, nitration, and sulfation were determined by using infrared spectrometry. The measured values were compared to the limit values. Based on the processing and evaluation of these analyses, the overall condition of the oils was assessed and subsequently the optimal exchange interval of the examined oils was determined. In addition, a risk analysis of the outage was performed. Due to the high yields of crops, farmers can lose a significant amount of product when a tractor is not functioning during the harvest period. This loss is calculated in the paper.
Factorization and Malleability of RSA Moduli, and Counting Points on Elliptic Curves Modulo N
Authors: Dieulefait Luis V. , Urroz Jorge
Published: November 2020

In this paper we address two different problems related with the factorization of an RSA (Rivest–Shamir–Adleman cryptosystem) modulus N. First we show that factoring is equivalent, in deterministic polynomial time, to counting points on a pair of twisted Elliptic curves modulo N. The second problem is related with malleability. This notion was introduced in 2006 by Pailler and Villar, and deals with the question of whether or not the factorization of a given number N becomes substantially easier when knowing the factorization of another one N′ relatively prime to N. Despite the efforts done up to now, a complete answer to this question was unknown. Here we settle the problem affirmatively. To construct a particular N′ that helps the factorization of N, we use the number of points of a single elliptic curve modulo N. Coppersmith’s algorithm allows us to go from the factors of N′ to the factors of N in polynomial time.
Sargassum horneri as a Functional Food Ameliorated IgE/BSA-Induced Mast Cell Activation and Passive Cutaneous Anaphylaxis in Mice
Authors: Han Eui Jeong , Kim Hyun-Soo , Sanjeewa Kalu Kapuge Asanka , Jung Kyungsook , Jee Youngheun , Jeon You-Jin , Fernando Ilekuttige Priyan Shanura , Ahn Ginnae
Published: November 2020

Sargassum horneri (S. horneri), an edible brown alga, has been proposed as a functional food with an improvement effect on abnormal skin immune responses. The present study investigates the anti-allergic effect of an ethanol extract from S. horneri (SHE) on immunoglobulin E (IgE)/bovine serum albumin (BSA)-mediated activation in bone marrow-derived cultured-mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) reaction in mice. SHE markedly and dose-dependently suppressed the degranulation of BMCMCs by reducing the β-hexosaminidase and histamine release without cytotoxicity. In addition, SHE significantly decreased the FcεRI expression on the surface of BMCMCs and its IgE binding. Moreover, SHE reduced the mRNA expression and the production of allergic cytokines; interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-10, IL-13; interferon (IFN)-γ and/or tumor necrosis factor (TNF)-α; and a chemokine, thymus and activation-regulated chemokine (TARC), by suppressing the activation of Src-family kinases and nuclear factor (NF)-κB signaling. In further study, the application of SHE reduced the PCA reaction in an IgE/BSA-induced type I allergic mice model. Taken together, we suggest that SHE has an anti-allergic effect in type I allergic responses.
Early vs. Delayed Feeding after Endoscopic Submucosal Dissection for Gastric Cancer: A Systematic Review and Meta-Analysis
Authors: Watanabe Jun , Watanabe Joji , Kotani Kazuhiko
Published: November 2020

Background: Endoscopic submucosal dissection (ESD) for gastric cancer is increasingly performed worldwide due to its efficacy and safety. This study aimed to assess the evidence of the impact of early vs. delayed feeding after ESD on quality of care, which remains to be fully determined. Methods: Electronic databases (PubMed, the Cochrane Central Register of Controlled Trials, EMBASE) and the trial registries (the World Health Organization International Clinical Trials Platform Search Portal and ClinicalTrials.gov) were searched for studies performed prior to September 2020. Study selection, data abstraction, and quality assessment were independently performed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Self-rated satisfaction and hospital stay were chiefly analyzed. Results: Two randomized controlled trials (239 patients) were included. The early and delayed post-ESD feeding groups had similar rates of post-ESD bleeding (risk ratio 1.90, 95% CI 0.42 to 8.63; I2 = 0%). Early post-ESD feeding resulted in increased patients’ satisfaction in comparison to delayed post-ESD feeding (standard mean difference (MD) 0.54, 95% CI 0.27 to 0.81; I2 = 0%) and reduced the length of hospital stay (MD −0.83, 95% CI −1.01 to −0.65; I2 = 0%). Conclusion: Early post-ESD feeding was associated with increased patients’ satisfaction and reduced hospital stay in comparison to delayed feeding, while the rate of complications did not differ to a statistically significant extent. As we must acknowledge the limited number of reviewed studies, various trials regarding the quality of care are further needed to determine the benefits of early feeding after ESD.
CO2 and H2S Degassing at Fangaia Mud Pool, Solfatara, Campi Flegrei (Italy): Origin and Dynamics of the Pool Basin
Authors: Rouwet Dmitri , Tamburello Giancarlo , Ricci Tullio , Sciarra Alessandra , Capecchiacci Francesco , Caliro Stefano
Published: November 2020

The Fangaia mud pool provides a “window” into the hydrothermal system underlying the degassing Solfatara crater, which is the most active volcanic centre inside the restless Campi Flegrei caldera, Southern Italy. The present study aimed at unravelling the degassing dynamics of CO2 and H2S flushing through the pH 1.2 steam-heated Fangaia mud pool, an ideal field laboratory as a proxy of an active crater lake. Our results from MultiGAS measurements above Fangaia’s surface show that H2S scrubbing, demonstrated by high CO2/H2S ratios, was most efficient in the portions of the basin affected by diffusive degassing. Convective bubbling degassing instead was the most effective mechanism to release gas in quantitative terms, with lower CO2/H2S ratios, similar to the Solfatara crater fumaroles, the high-T end member of the hydrothermal system. Unsurprisingly, total estimated CO2 and H2S fluxes from the small Fangaia pool (~184 m2 in June 2017) were at least two orders of magnitude lower (CO2 flux < 64 t/d, H2S flux < 0.5 t/d) than the total CO2 flux of the Campi Flegrei caldera (up to 3000 t/d for CO2), too low to affect the gas budget for the caldera, and hence volcano monitoring routines. Given the role of the rising gas as “sediment stirrer”, the physical and chemical processes behind gas migration through a mud pool are arguably the creating processes giving origin to Fangaia. Follow-up studies of this so far unique campaign will help to better understand the fast dynamics of this peculiar degassing feature.
Conceptual Design and Evaluation of Windshield Displays for Excavators
Authors: Sitompul Taufik Akbar , Wallmyr Markus , Lindell Rikard
Published: November 2020

This paper investigates the possible visualization using transparent displays, which could be placed on the excavator’s windshield. This way, the information could be presented closer to operators’ line of sight, without fully obstructing their view. Therefore, excavator operators could acquire the supportive information provided by the machine without diverting their attention from operational areas. To ensure that there is a match between the supportive information and operators’ contextual needs, we conducted four different activities as parts of our design process. Firstly, we looked at four relevant safety guidelines to determine which information is essential to perform safe operations. Secondly, we reviewed all commercially available technologies to discover their suitability in the excavator context. Thirdly, we conducted a design workshop to generate ideas on how the essential information should look like and behave based on the performed operation and the chosen available technology. Fourthly, we interviewed seven excavator operators to test their understanding and obtain their feedback on the proposed visualization concepts. The results indicated that four out of six visualization concepts that we proposed could be understood easily by the operators and we also revised them to better suit the operators’ way of thinking. All the operators also positively perceived this approach, since all of them included at least three visualization concepts to be presented on the windshield.
Current Evidence on the Protective Effects of Recombinant Human Erythropoietin and Its Molecular Variants against Pathological Hallmarks of Alzheimer’s Disease
Authors: Jarero-Basulto José J. , Rivera-Cervantes Martha C. , Gasca-Martínez Deisy , García-Sierra Francisco , Gasca-Martínez Yadira , Beas-Zárate Carlos
Published: November 2020

Substantial evidence in the literature demonstrates the pleiotropic effects of the administration of recombinant human erythropoietin (rhEPO) and its molecular variants in different tissues and organs, including the brain. Some of these reports suggest that the chemical properties of this molecule by itself or in combination with other agents (e.g., growth factors) could provide the necessary pharmacological characteristics to be considered a potential protective agent in neurological disorders such as Alzheimer’s disease (AD). AD is a degenerative disorder of the brain, characterized by an aberrant accumulation of amyloid β (Aβ) and hyperphosphorylated tau (tau-p) proteins in the extracellular and intracellular space, respectively, leading to inflammation, oxidative stress, excitotoxicity, and other neuronal alterations that compromise cell viability, causing neurodegeneration in the hippocampus and the cerebral cortex. Unfortunately, to date, it lacks an effective therapeutic strategy for its treatment. Therefore, in this review, we analyze the evidence regarding the effects of exogenous EPOs (rhEPO and its molecular variants) in several in vivo and in vitro Aβ and tau-p models of AD-type neurodegeneration, to be considered as an alternative protective treatment to this condition. Particularly, we focus on analyzing the differential effect of molecular variants of rhEPO when changes in doses, route of administration, duration of treatment or application times, are evaluated for the improved cellular alterations generated in this disease. This narrative review shows the evidence of the effectiveness of the exogenous EPOs as potential therapeutic molecules, focused on the mechanisms that establish cellular damage and clinical manifestation in the AD.
Design and Implementation of Fuzzy Compensation Scheme for Temperature and Solar Irradiance Wireless Sensor Network (WSN) on Solar Photovoltaic (PV) System
Authors: Pazikadin Abdul Rahim , Rifai Damhuji , Ali Kharudin , Mamat Nor Hana , Khamsah Noraznafulsima
Published: November 2020

Photovoltaic (PV) systems need measurements of incident solar irradiance and PV surface temperature for performance analysis and monitoring purposes. Ground-based network sensor measurement is preferred in many near real-time operations such as forecasting and photovoltaic (PV) performance evaluation on the ground. Hence, this study proposed a Fuzzy compensation scheme for temperature and solar irradiance wireless sensor network (WSN) measurement on stand-alone solar photovoltaic (PV) system to improve the sensor measurement. The WSN installation through an Internet of Things (IoT) platform for solar irradiance and PV surface temperature measurement was fabricated. The simulation for the solar irradiance Fuzzy Logic compensation (SIFLC) scheme and Temperature Fuzzy Logic compensation (TFLC) scheme was conducted using Matlab/Simulink. The simulation result identified that the scheme was used to compensate for the error temperature and solar irradiance sensor measurements over a variation temperature and solar irradiance range from 20 to 60 °C and from zero up to 2000 W/m2. The experimental results show that the Fuzzy Logic compensation scheme can reduce the sensor measurement error up to 17% and 20% for solar irradiance and PV temperature measurement.
All 3D Printed Stretchable Piezoelectric Nanogenerator for Self-Powered Sensor Application
Authors: Zhou Xinran , Parida Kaushik , Halevi Oded , Magdassi Shlomo , Lee Pooi See
Published: November 2020

With the rapid development of wearable electronic systems, the need for stretchable nanogenerators becomes increasingly important for autonomous applications such as the Internet-of-Things. Piezoelectric nanogenerators are of interest for their ability to harvest mechanical energy from the environment with its inherent polarization arising from crystal structures or molecular arrangements of the piezoelectric materials. In this work, 3D printing is used to fabricate a stretchable piezoelectric nanogenerator which can serve as a self-powered sensor based on synthesized oxide–polymer composites.
Classification of Watermelon Seeds Using Morphological Patterns of X-ray Imaging: A Comparison of Conventional Machine Learning and Deep Learning
Authors: Ahmed Mohammed Raju , Yasmin Jannat , Park Eunsung , Kim Geonwoo , Kim Moon S. , Wakholi Collins , Mo Changyeun , Cho Byoung-Kwan
Published: November 2020

In this study, conventional machine learning and deep leaning approaches were evaluated using X-ray imaging techniques for investigating the internal parameters (endosperm and air space) of three cultivars of watermelon seed. In the conventional machine learning, six types of image features were extracted after applying different types of image preprocessing, such as image intensity and contrast enhancement, and noise reduction. The sequential forward selection (SFS) method and Fisher objective function were used as the search strategy and feature optimization. Three classifiers were tested (linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and k-nearest neighbors algorithm (KNN)) to find the best performer. On the other hand, in the transfer learning (deep learning) approaches, simple ConvNet, AlexNet, VGG-19, ResNet-50, and ResNet-101 were used to train the dataset and class prediction of the seed. For the supervised model development (both conventional machine learning and deep learning), the germination test results of the samples were used where the seeds were divided into two classes: (1) normal viable seeds and (2) nonviable and abnormal viable seeds. In the conventional classification, 83.6% accuracy was obtained by LDA using 48 features. ResNet-50 performed better than other transfer learning architectures, with an 87.3% accuracy which was the highest accuracy in all classification models. The findings of this study manifested that transfer learning is a constructive strategy for classifying seeds by analyzing their morphology, where X-ray imaging can be adopted as a potential imaging technique.
Fast Sample Adaptive Offset Jointly Based on HOG Features and Depth Information for VVC in Visual Sensor Networks
Authors: Wang Ruyan , Tang Liuwei , Tang Tong
Published: November 2020

Visual sensor networks (VSNs) can be widely used in multimedia, security monitoring, network camera, industrial detection, and other fields. However, with the development of new communication technology and the increase of the number of camera nodes in VSN, transmitting and compressing the huge amounts of video and image data generated by video and image sensors has become a major challenge. The next-generation video coding standard—versatile video coding (VVC), can effectively compress the visual data, but the higher compression rate is at the cost of heavy computational complexity. Therefore, it is vital to reduce the coding complexity for the VVC encoder to be used in VSNs. In this paper, we propose a sample adaptive offset (SAO) acceleration method by jointly considering the histogram of oriented gradient (HOG) features and the depth information for VVC, which reduces the computational complexity in VSNs. Specifically, first, the offset mode selection (select band offset (BO) mode or edge offset (EO) mode) is simplified by utilizing the partition depth of coding tree unit (CTU). Then, for EO mode, the directional pattern selection is simplified by using HOG features and support vector machine (SVM). Finally, experimental results show that the proposed method averagely saves 67.79% of SAO encoding time only with 0.52% BD-rate degradation compared to the state-of-the-art method in VVC reference software (VTM 5.0) for VSNs.
Sensor Failure Detection in Ambient Assisted Living Using Association Rule Mining
Authors: ElHady Nancy E. , Jonas Stephan , Provost Julien , Senner Veit
Published: November 2020

Ambient Assisted Living (AAL) is becoming crucial to help governments face the consequences of the emerging ageing population. It aims to motivate independent living of older adults at their place of residence by monitoring their activities in an unobtrusive way. However, challenges are still faced to develop a practical AAL system. One of those challenges is detecting failures in non-intrusive sensors in the presence of the non-deterministic human behaviour. This paper proposes sensor failure detection and isolation system in the AAL environments equipped with event-driven, ambient binary sensors. Association Rule mining is used to extract fault-free correlations between sensors during the nominal behaviour of the resident. Pruning is then applied to obtain a non-redundant set of rules that captures the strongest correlations between sensors. The pruned rules are then monitored in real-time to update the health status of each sensor according to the satisfaction and/or unsatisfaction of rules. A sensor is flagged as faulty when its health status falls below a certain threshold. The results show that detection and isolation of sensors using the proposed method could be achieved using unlabelled datasets and without prior knowledge of the sensors’ topology.
An Analysis Review of Detection Coronavirus Disease 2019 (COVID-19) Based on Biosensor Application
Authors: Taha Bakr Ahmed , Al Mashhadany Yousif , Hafiz Mokhtar Mohd Hadri , Dzulkefly Bin Zan Mohd Saiful , Arsad Norhana
Published: November 2020

Timely detection and diagnosis are essentially needed to guide outbreak measures and infection control. It is vital to improve healthcare quality in public places, markets, schools and airports and provide useful insights into the technological environment and help researchers acknowledge the choices and gaps available in this field. In this narrative review, the detection of coronavirus disease 2019 (COVID-19) technologies is summarized and discussed with a comparison between them from several aspects to arrive at an accurate decision on the feasibility of applying the best of these techniques in the biosensors that operate using laser detection technology. The collection of data in this analysis was done by using six reliable academic databases, namely, Science Direct, IEEE Xplore, Scopus, Web of Science, Google Scholar and PubMed. This review includes an analysis review of three highlights: evaluating the hazard of pandemic COVID-19 transmission styles and comparing them with Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) to identify the main causes of the virus spreading, a critical analysis to diagnose coronavirus disease 2019 (COVID-19) based on artificial intelligence using CT scans and CXR images and types of biosensors. Finally, we select the best methods that can potentially stop the propagation of the coronavirus pandemic.
All-Optical Planar Polymer Waveguide-Based Biosensor Chip Designed for Smartphone-Assisted Detection of Vitamin D
Authors: Walter Johanna-Gabriela , Alwis Lourdes S. M. , Roth Bernhard , Bremer Kort
Published: November 2020

An all-optical plasmonic sensor platform designed for smartphones based on planar-optical waveguide structures integrated in a polymer chip is reported for the first time. To demonstrate the applicability of the sensor system for biosensing purposes, the detection of 25-hydroxyvitamin D (25OHD) in human serum samples using an AuNP-enhanced aptamer-based assay was demonstrated. With the aid of the developed assay sensitivity of 0.752 pixel/nM was achieved for 25OHD concentrations ranging from 0–100 nM. The waveguide structure of the sensor enables miniaturisation and parallelisation, thus, demonstrates the potential for simultaneous detection of various analytes including biomarkers. The entire optical arrangement can be integrated into a single polymer chip which allows for large scale and cost-efficient sensor fabrication. The broad utilization and access of smartphone electronics make the proposed design most attractive for its wider use in lab-on-chip applications.
Comparison of Wearable and Clinical Devices for Acquisition of Peripheral Nervous System Signals
Authors: Bizzego Andrea , Gabrieli Giulio , Furlanello Cesare , Esposito Gianluca
Published: November 2020

A key access point to the functioning of the autonomic nervous system is the investigation of peripheral signals. Wearable devices (WDs) enable the acquisition and quantification of peripheral signals in a wide range of contexts, from personal uses to scientific research. WDs have lower costs and higher portability than medical-grade devices. However, the achievable data quality can be lower, and data are subject to artifacts due to body movements and data losses. It is therefore crucial to evaluate the reliability and validity of WDs before their use in research. In this study, we introduce a data analysis procedure for the assessment of WDs for multivariate physiological signals. The quality of cardiac and electrodermal activity signals is validated with a standard set of signal quality indicators. The pipeline is available as a collection of open source Python scripts based on the pyphysio package. We apply the indicators for the analysis of signal quality on data simultaneously recorded from a clinical-grade device and two WDs. The dataset provides signals of six different physiological measures collected from 18 subjects with WDs. This study indicates the need to validate the use of WDs in experimental settings for research and the importance of both technological and signal processing aspects to obtain reliable signals and reproducible results.
Motion-Aware Interplay between WiGig and WiFi for Wireless Virtual Reality
Authors: Kim Sanghyun , Yun Ji-Hoon
Published: November 2020

Wireless virtual reality (VR) is a promising direction for future VR systems that offloads heavy computation to a remote processing entity and wirelessly receives high-quality streams. WiGig and WiFi are representative solutions to implement wireless VR; however, they differ in communication bandwidth and reliability. Our testbed experiments show that the performance of WiGig and VR traffic generation strongly correlates with and consequently can be predicted from a user’s motion. Based on this observation, we develop a wireless VR system that exploits the benefits of both links by switching between them and controlling the VR frame encoding for latency regulation and image quality enhancement. The proposed system predicts the performance of the links and selects the one with a higher capacity in an opportunistic manner. It adjusts the encoding rate of the host based on the motion-aware prediction of the frame size and estimated latency of the selected link. By evaluating the testbed data, we demonstrate that the proposed system outperforms a WiGig-only system with a fixed encoding rate in terms of latency regulation and image quality.
On the Challenges and Potential of Using Barometric Sensors to Track Human Activity
Authors: Manivannan Ajaykumar , Chin Wei Chien Benny , Barrat Alain , Bouffanais Roland
Published: November 2020

Barometers are among the oldest engineered sensors. Historically, they have been primarily used either as environmental sensors to measure the atmospheric pressure for weather forecasts or as altimeters for aircrafts. With the advent of microelectromechanical system (MEMS)-based barometers and their systematic embedding in smartphones and wearable devices, a vast breadth of new applications for the use of barometers has emerged. For instance, it is now possible to use barometers in conjunction with other sensors to track and identify a wide range of human activity classes. However, the effectiveness of barometers in the growing field of human activity recognition critically hinges on our understanding of the numerous factors affecting the atmospheric pressure, as well as on the properties of the sensor itself—sensitivity, accuracy, variability, etc. This review article thoroughly details all these factors and presents a comprehensive report of the numerous studies dealing with one or more of these factors in the particular framework of human activity tracking and recognition. In addition, we specifically collected some experimental data to illustrate the effects of these factors, which we observed to be in good agreement with the findings in the literature. We conclude this review with some suggestions on some possible future uses of barometric sensors for the specific purpose of tracking human activities.
Predictive Maintenance Scheduling with Failure Rate Described by Truncated Normal Distribution
Authors: Paprocka Iwona , Kempa Wojciech M. , Ćwikła Grzegorz
Published: November 2020

The method of risk assessment and planning of technical inspections of machines and optimization of production tasks is the main focus of this study. Any unpredicted failure resulted in the production plans no longer being valid, production processes needing to be rescheduled, costs of unused machine production capacity and losses due to the production of poor-quality products increase, as well as additional costs of human resources, equipment, and materials used during the maintenance. The method reflects the operation of the production system and the nature of the disturbances, allowing for the estimation of unknown parameters related to machine reliability. The machine failure frequency was described with the normal distribution truncated to the positive half of the axis. In production practice, this distribution is commonly used to describe the phenomenon of irregularities. The presented method was an extension of the Six Sigma concept for monitoring and continuous control in order to eliminate and prevent various inconsistencies in processes and resulting products. Reliability characteristics were used to develop predictive schedules. Schedules were assessed using the criteria of solution and quality robustness. Estimation methods of parameters describing disturbances were compared for different job shop scheduling problems. The estimation method based on a maximum likelihood approach allowed for more accurate prediction of scheduling problems. The paper presents a practical example of the application of the proposed method for electric steering gears.
Guided-Mode Resonance-Based Relative Humidity Sensing Employing a Planar Waveguide Structure
Authors: Urbancova Petra , Chylek Jakub , Hlubina Petr , Pudis Dusan
Published: November 2020

In this paper, we present a new type of guided-mode resonance (GMR)-based sensor that utilizes a planar waveguide structure (PWS). We employed a PWS with an asymmetric three-layer waveguide structure consisting of substrate/Au/photoresist. The ellipsometric characterization of the structure layers, the simulated reflectance spectra, and optical field distributions under GMR conditions showed that multiple waveguide modes can be excited in the PWS. These modes can be used for refractive index sensing, and the theoretical analysis of the designed PWS showed a sensitivity to the refractive index up to 6600 nm per refractive index unit (RIU) and a figure of merit (FOM) up to 224 RIU−1. In response to these promising theoretical results, the PWS was used to measure the relative humidity (RH) of moist air with a sensitivity up to 0.141 nm/%RH and a FOM reaching 3.7 × 10−3%RH−1. The results demonstrate that this highly-sensitive and hysteresis-free sensor based on GMR has the potential to be used in a wide range of applications.
Design of Tunable Holographic Liquid Crystalline Diffraction Gratings
Authors: Rutkowska Katarzyna A. , Kozanecka-Szmigiel Anna
Published: November 2020

Tunable diffraction gratings and phase filters are important functional devices in optical communication and sensing systems. Polarization gratings, in particular, capable of redirecting an incident light beam completely into the first diffraction orders may be successfully fabricated in liquid crystalline cells assembled from substrates coated with uniform transparent electrodes and orienting layers that force a specific molecular distribution. In this work, the diffraction properties of liquid crystal (LC) cells characterized by a continually rotating cycloidal director pattern at the cell substrates and in the bulk, are studied theoretically by solving a relevant set of the Euler-Lagrange equations. The electric tunability of the gratings is analyzed by estimating the changes in liquid crystalline molecular distribution and thus in effective birefringence, as a function of external voltage. To the best of our knowledge, such detailed numerical calculations have not been presented so far for liquid crystal polarization gratings showing a cycloidal director pattern. Our theoretical predictions may be easily achieved in experimental conditions when exploiting, for example, photo-orienting material, to induce a permanent LC alignment with high spatial resolution. The proposed design may be for example, used as a tunable passband filter with adjustable bandwidths, thus allowing for potential applications in optical spectroscopy, optical communication networks, remote sensing and beyond.
Anionic Polyelectrolyte Hydrogel as an Adjuvant for Vaccine Development
Authors: Kozak Mariya , Mitina Nataliya , Zaichenko Alexandr , Vlizlo Vasyl
Published: November 2020

Vaccination is one of the main methods for the specific prevention of infectious diseases. The disadvantage of vaccination is the use of pathogens (live or attenuated viruses and bacteria) that can lead to the development of a disease. Recombinant technologies are capable of producing specific DNA or protein molecules that possess antigenic properties and do not cause disease. However, individual antigen molecules are low-immunogenic, and therefore, require conjugation with a compound possessing stronger immunogenic properties. In this study, we examined the immunogenic properties of the new anionic copolymer consisting of glycidyl methacrylate, butyl acrylate, triethylene glycol dimethacrylate, and acrylic acid, in mice. The experimental polymer induced a stronger immunogenic response than aluminum hydroxide. The histological studies have established that immunization both with aluminum hydroxide and the polymer studied does not cause damage to the liver, kidneys, or the spleen. No negative side effects were observed. It has been concluded that the new synthetic anionic polyelectrolyte hydrogel (PHG) has a potential as an adjuvant for vaccine development.
Waste to Catalyst: Synthesis of Catalysts from Sewage Sludge of the Mining, Steel, and Petroleum Industries
Authors: Castro-León Gabriela , Baquero-Quinteros Erik , Loor Bryan G. , Alvear Jhoselin , Montesdeoca Espín Diego E. , De La Rosa Andrés , Montero-Calderón Carolina
Published: November 2020

The generation of sewage sludge presents a problem for several manufacturing companies as it results from industrial processes or effluent treatment systems. The treatment of this type of waste requires high economic investment, for this reason, it is necessary to find alternatives to recover the valuable materials of the sludges. In this study, metal catalysts were synthesized using waste sludge from the steel, mining, and hydrocarbon industries. The waste sludge was subjected to thermal treatments for the removal of organic content and the reduction of metals with hydrogen current to activate their catalytic properties. The sludge and synthesized catalysts were analyzed to determine their physical, chemical, thermoenergetic, and catalytic properties. Catalytic activity was evaluated using CO chemisorption and by thermal–catalytic decomposition of crude oil. The best conditions for synthesizing the catalysts were a calcination temperature between 300 and 500 °C and a reduction temperature between 300 and 900 °C. The catalysts presented a specific surface between 2.33 and 16.78 m2/g. The catalytic material had a heat capacity between 0.7 and 1.2 kJ/kg∙K. The synthesized materials presented catalytic activity comparable to that of commercial catalysts. With this recovery technique, the industrial waste can be valorized, obtaining catalyst derived from the sludges and promoting the circular economy of manufacturing companies.
Sustainability Potential Evaluation of Concrete with Steel Slag Aggregates by the LCA Method
Authors: Václavík Vojtěch , Ondová Marcela , Dvorský Tomáš , Eštoková Adriana , Fabiánová Martina , Gola Lukáš
Published: November 2020

Sustainability in the construction industry refers to all resource-efficient and environmentally responsible processes throughout the life cycle of a structure. Green buildings may incorporate reused, recycled, or recovered materials in their construction. Concrete is as an important building material. Due to the implementation of by-products and waste from various industries into its structure, concrete represents a significant sustainable material. Steel slag has great potential for its reuse in concrete production. Despite its volume changes over time, steel slag can be applied in concrete as a cement replacement (normally) or as a substitute for natural aggregates (rarely). This paper focused on an investigation of concrete with steel slag as a substitute of natural gravel aggregate. Testing physical and mechanical properties of nontraditional concrete with steel slag as a substitute for natural aggregates of 4/8 mm and 8/16 mm fractions confirmed the possibility of using slag as a partial replacement of natural aggregate. Several samples of concrete with steel slag achieved even better mechanical parameters (e.g., compressive strength, frost resistance) than samples with natural aggregate. Moreover, a life cycle assessment (LCA) was performed within the system boundaries cradle-to-gate. The LCA results showed that replacements of natural aggregates significantly affected the utilization rate of nonrenewable raw materials and reduced the overall negative impacts of concrete on the environment up to 7%. The sustainability indicators (SUI), which considered the LCA data together with the technical parameters of concrete, were set to evaluate sustainability of the analyzed concretes. Based on the SUI results, replacing only one fraction of natural gravel aggregate in concrete was a more sustainable solution than replacing both fractions at once. These results confirmed the benefits of using waste to produce sustainable materials in construction industry.