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Article
A New Cross-Platform Instrument for Microstructure Turbulence Measurements
J. Mar. Sci. Eng. 2021, 9(10), 1051; https://doi.org/10.3390/jmse9101051 (registering DOI) - 24 Sep 2021
Abstract
This study developed a new cross-platform instrument for microstructure turbulence measurement (CPMTM) and evaluated its performance. The CPMTM is designed as an “all-in-one” payload that can be easily integrated with a variety of marine instrumentation platforms. The sensors in the CPMTM include two [...] Read more.
This study developed a new cross-platform instrument for microstructure turbulence measurement (CPMTM) and evaluated its performance. The CPMTM is designed as an “all-in-one” payload that can be easily integrated with a variety of marine instrumentation platforms. The sensors in the CPMTM include two shear probes, a fast-response temperature probe, and an accelerometer for monitoring vibrations. In addition, a custom-designed flexible connection vibration-damping device is used to isolate platform vibrations. To validate the CPMTM performance, a direct comparison was carried out with a reference acoustic Doppler velocimeter in a controlled flume for four background turbulence levels. The results of the comparison show that the velocity spectra measured by the CPMTM and ADV w components are in agreement, which demonstrates the ability of the CPMTM to acquire accurate turbulence data. Furthermore, the CPMTM was integrated into the long-range Sea-Whale 2000 AUV and tested in the northern South China Sea in September 2020. The data collected by the CPMTM show that the measured shear spectrum of the noise reduction agrees well with the empirical Nasmyth spectrum. Turbulent kinetic energy dissipation rates as low as 7 × 10−10 W kg−1 can be resolved. Laboratory and field experiments illustrate that the CPMTM has an extraordinarily low noise level and is validated for turbulence measurements. Full article
(This article belongs to the Section Ocean Engineering)
Article
Composites to Produce a Material with Zero Absolute Thermopower S = 0 or a Thermopower Switch between S = 0 and S ≠ 0
Materials 2021, 14(19), 5529; https://doi.org/10.3390/ma14195529 (registering DOI) - 24 Sep 2021
Abstract
From the theory of two-phase composites it is concluded that in the concentration dependence of the Seebeck coefficient S a kink can occur precisely at S=0 absolute if the two phases have different kinds of carriers, electrons and holes, and if [...] Read more.
From the theory of two-phase composites it is concluded that in the concentration dependence of the Seebeck coefficient S a kink can occur precisely at S=0 absolute if the two phases have different kinds of carriers, electrons and holes, and if the phase grains are spherical without preferred orientations and arranged in a symmetrical fashion. This feature, indeed found to be realized in amorphous Cr1xSix thin films deposited by ion beam sputtering from Cr-Si alloy targets, can be applied to make reference standards for S=0 at room temperature and even at higher temperatures. Additionally, it may be used to design a thermopower switch between S=0 and S0. It is also concluded that the structure realized in any alloy during solidification does not only depend on the diffusion mobility of the atoms and on the existence of a (relative) minimum in the Gibbs’ free energy. It depends also on the fact whether this structure is compatible with the demand that (spatial) continuity of the entropy and energy flux densities and their gradients is saved during the solidification process. Full article
(This article belongs to the Special Issue Advanced Materials and Modules for Thermoelectric Energy Conversion)
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Article
Series with Commuting Terms in Topologized Semigroups
Axioms 2021, 10(4), 237; https://doi.org/10.3390/axioms10040237 (registering DOI) - 24 Sep 2021
Abstract
We show that the following general version of the Riemann–Dirichlet theorem is true: if every rearrangement of a series with pairwise commuting terms in a Hausdorff topologized semigroup converges, then its sum range is a singleton. Full article
Article
The Impact of Calcitriol on Orthodontic Tooth Movement: A Cumulative Systematic Review and Meta-Analysis
Appl. Sci. 2021, 11(19), 8882; https://doi.org/10.3390/app11198882 (registering DOI) - 24 Sep 2021
Abstract
A cumulative review with a systematic approach aimed to provide a comparison of studies’ investigating the possible impact of the active form of vitamin D3, calcitriol (CTL), on the tooth movement caused by orthodontic forces (OTM) by evaluating the quality of [...] Read more.
A cumulative review with a systematic approach aimed to provide a comparison of studies’ investigating the possible impact of the active form of vitamin D3, calcitriol (CTL), on the tooth movement caused by orthodontic forces (OTM) by evaluating the quality of evidence, based on collating current data from animal model studies, in vivo cell culture studies, and human clinical trials. Methods: A strict systematic review protocol was applied following the application of the International Prospective Register of Systematic Reviews (PROSPERO). A structured search strategy, including main keywords, was defined during detailed search with the application of electronic database systems: Medline/Pubmed, EMBASE, Scopus, Web of Science, and PsycINFO. In addition, a search was carried out with the use of ClinicalTrials.gov search in order to include ongoing or recently completed trials. The Oxford Level of Evidence and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was utilized to critically evaluate the risk of bias and relative quality of studies included. Meta-analysis with the use of RevMan5 software, random effect, and inverted variable method allowed the quantification of cumulative results. Results: Twenty-seven studies were identified which fulfilled inclusion criteria, including two clinical studies. The assessed level of evidence was variable and inconsistent, predominantly being moderate or low due to a significant difference in study design, sample size, and study protocols. Data synthesis rendered from meta-analysis involving various CTL doses demonstrated slight discrepancies in tooth movement between control and experimental groups (mean difference = 0.27; 95% CI: 0.01–0.53, std mean difference = 0.49; 95% CI: 0.09–0.89), as well as relatively moderate heterogenicity. Conclusions: Although it has been suggested that CTL could accelerate OTM in animal studies and clinical context, these scarce data were supported by a low level of evidence and the studies were carried out using inadequate sample size. Well-powered RCT studies would help to overcome the lack of robustness of the research. Full article
(This article belongs to the Special Issue New Materials and Technologies in Orthodontics)
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Article
Field Quality Control of Spectral Solar Irradiance Measurements by Comparison with Broadband Measurements
Sustainability 2021, 13(19), 10585; https://doi.org/10.3390/su131910585 (registering DOI) - 24 Sep 2021
Abstract
Measurement of solar spectral irradiance is required in an increasingly wide variety of technical applications, such as atmospheric studies, health, and solar energy, among others. The solar spectral irradiance at ground level has a strong dependence on many atmospheric parameters. In addition, spectroradiometer [...] Read more.
Measurement of solar spectral irradiance is required in an increasingly wide variety of technical applications, such as atmospheric studies, health, and solar energy, among others. The solar spectral irradiance at ground level has a strong dependence on many atmospheric parameters. In addition, spectroradiometer optics and detectors have high sensitivity. Because of this, it is necessary to compare with a reference instrumentation or light source to verify the quality of measurements. A simple and realistic test for validating solar spectral irradiance measurements is presented in this study. This methodology is applicable for a specific spectral range inside the broadband range from 280 to 4000 nm under cloudless sky conditions. The method compares solar spectral irradiance measurements with both predictions of clear-sky solar spectral irradiance and measurements of broadband instruments such as pyrheliometers. For the spectral estimation, a free atmospheric transmittance simulation code with the air mass calculation as the mean parameter was used. The spectral direct normal irradiance (Gbλ) measurements of two different spectroradiometers were tested at Plataforma Solar de Almería, Spain. The results are presented in this article. Although only Gbλ measurements were considered in this study, the same methodology can be applied to the other solar irradiance components. Full article
(This article belongs to the Special Issue Concentrating Solar Power (CSP) Update)
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Article
UAV-Based Intelligent Transportation System for Emergency Reporting in Coverage Holes of Wireless Networks
Sensors 2021, 21(19), 6371; https://doi.org/10.3390/s21196371 (registering DOI) - 24 Sep 2021
Abstract
During critical moments, disaster and accident victims may not be able to request help from the emergency response center. This may happen when the victim’s vehicle is located within a coverage hole in a wireless network. In this paper, we adopt an unmanned [...] Read more.
During critical moments, disaster and accident victims may not be able to request help from the emergency response center. This may happen when the victim’s vehicle is located within a coverage hole in a wireless network. In this paper, we adopt an unmanned aerial vehicle (UAV) to work as an automatic emergency dispatcher for a user in a vehicle facing a critical condition. Given that the UAV is located within a coverage hole and a predetermined critical condition is detected, the UAV becomes airborne and dispatches distress messages to a communication network. We propose to use a path loss map for UAV trajectory design, and we formulate our problem mathematically as an Integer Linear Program (ILP). Our goals are to minimize the distress messages delivery time and the UAV’s mission completion time. Due to the difficulty of obtaining the optimal solution when the scale of the problem is large, we proposed an efficient algorithm that reduces the computational time significantly. We simulate our problem under different scenarios and settings, and study the performance of our proposed algorithm. Full article
(This article belongs to the Special Issue Connected Vehicles in Intelligent Transportation Systems (ITS))
Article
Adaptive Robust Motion Control of Quadrotor Systems Using Artificial Neural Networks and Particle Swarm Optimization
Mathematics 2021, 9(19), 2367; https://doi.org/10.3390/math9192367 (registering DOI) - 24 Sep 2021
Abstract
Most of the mechanical dynamic systems are subjected to parametric uncertainty, unmodeled dynamics, and undesired external vibrating disturbances while are motion controlled. In this regard, new adaptive and robust, advanced control theories have been developed to efficiently regulate the motion trajectories of these [...] Read more.
Most of the mechanical dynamic systems are subjected to parametric uncertainty, unmodeled dynamics, and undesired external vibrating disturbances while are motion controlled. In this regard, new adaptive and robust, advanced control theories have been developed to efficiently regulate the motion trajectories of these dynamic systems while dealing with several kinds of variable disturbances. In this work, a novel adaptive robust neural control design approach for efficient motion trajectory tracking control tasks for a considerably disturbed non-linear under-actuated quadrotor system is introduced. Self-adaptive disturbance signal modeling based on Taylor-series expansions to handle dynamic uncertainty is adopted. Dynamic compensators of planned motion tracking errors are then used for designing a baseline controller with adaptive capabilities provided by three layers B-spline artificial neural networks (Bs-ANN). In the presented adaptive robust control scheme, measurements of position signals are only required. Moreover, real-time accurate estimation of time-varying disturbances and time derivatives of error signals are unnecessary. Integral reconstructors of velocity error signals are properly integrated in the output error signal feedback control scheme. In addition, the appropriate combination of several mathematical tools, such as particle swarm optimization (PSO), Bézier polynomials, artificial neural networks, and Taylor-series expansions, are advantageously exploited in the proposed control design perspective. In this fashion, the present contribution introduces a new adaptive desired motion tracking control solution based on B-spline neural networks, along with dynamic tracking error compensators for quadrotor non-linear systems. Several numeric experiments were performed to assess and highlight the effectiveness of the adaptive robust motion tracking control for a quadrotor unmanned aerial vehicle while subjected to undesired vibrating disturbances. Experiments include important scenarios that commonly face the quadrotors as path and trajectory tracking, take-off and landing, variations of the quadrotor nominal mass and basic navigation. Obtained results evidence a satisfactory quadrotor motion control while acceptable attenuation levels of vibrating disturbances are exhibited. Full article
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Communication
Early-Season Mapping of Winter Crops Using Sentinel-2 Optical Imagery
Remote Sens. 2021, 13(19), 3822; https://doi.org/10.3390/rs13193822 (registering DOI) - 24 Sep 2021
Abstract
Sentinel-2 imagery is an unprecedented data source with high spatial, spectral and temporal resolution in addition to free access. The objective of this paper was to evaluate the potential of using Sentinel-2 data to map winter crops in the early growth stage. Analysis [...] Read more.
Sentinel-2 imagery is an unprecedented data source with high spatial, spectral and temporal resolution in addition to free access. The objective of this paper was to evaluate the potential of using Sentinel-2 data to map winter crops in the early growth stage. Analysis of three winter crop types—winter garlic, winter canola and winter wheat—was carried out in two agricultural regions of China. We analysed the spectral characteristics and vegetation index profiles of these crops in the early growth stage and other land cover types based on Sentinel-2 images. A decision tree classification model was built to distinguish the crops based on these data. The results demonstrate that winter garlic and winter wheat can be distinguished four months before harvest, while winter canola can be distinguished two months before harvest. The overall classification accuracy was 96.62% with a kappa coefficient of 0.95. Therefore, Sentinel-2 images can be used to accurately identify these winter crops in the early growth stage, making them an important data source in the field of agricultural remote sensing. Full article
Article
Against the Odds: Hybrid Zones between Mangrove Killifish Species with Different Mating Systems
Genes 2021, 12(10), 1486; https://doi.org/10.3390/genes12101486 (registering DOI) - 24 Sep 2021
Abstract
Different mating systems are expected to affect the extent and direction of hybridization. Due to the different levels of sexual conflict, the weak inbreeder/strong outbreeder (WISO) hypothesis predicts that gametes from self-incompatible (SI) species should outcompete gametes from self-compatible (SC) ones. However, other [...] Read more.
Different mating systems are expected to affect the extent and direction of hybridization. Due to the different levels of sexual conflict, the weak inbreeder/strong outbreeder (WISO) hypothesis predicts that gametes from self-incompatible (SI) species should outcompete gametes from self-compatible (SC) ones. However, other factors such as timing of selfing and unilateral incompatibilities may also play a role on the direction of hybridization. In addition, differential mating opportunities provided by different mating systems are also expected to affect the direction of introgression in hybrid zones involving outcrossers and selfers. Here, we explored these hypotheses with a unique case of recent hybridization between two mangrove killifish species with different mating systems, Kryptolebias ocellatus (obligately outcrossing) and K. hermaphroditus (predominantly self-fertilizing) in two hybrid zones in southeast Brazil. Hybridization rates were relatively high (~20%), representing the first example of natural hybridization between species with different mating systems in vertebrates. All F1 individuals were sired by the selfing species. Backcrossing was small, but mostly asymmetrical with the SI parental species, suggesting pattern commonly observed in plant hybrid zones with different mating systems. Our findings shed light on how contrasting mating systems may affect the direction and extent of gene flow between sympatric species, ultimately affecting the evolution and maintenance of hybrid zones. Full article
(This article belongs to the Special Issue Evolutionary Consequences of Hybridisation in Eukaryotes)
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Review
Polyphenolic Flavonoid Compound Quercetin Effects in the Treatment of Acute Myeloid Leukemia and Myelodysplastic Syndromes
Molecules 2021, 26(19), 5781; https://doi.org/10.3390/molecules26195781 (registering DOI) - 24 Sep 2021
Abstract
Flavonoids are ubiquitous groups of polyphenolic compounds present in most natural products and plants. These substances have been shown to have promising chemopreventive and chemotherapeutic properties with multiple target interactions and multiple pathway regulations against various human cancers. Polyphenolic flavonoid compounds can block [...] Read more.
Flavonoids are ubiquitous groups of polyphenolic compounds present in most natural products and plants. These substances have been shown to have promising chemopreventive and chemotherapeutic properties with multiple target interactions and multiple pathway regulations against various human cancers. Polyphenolic flavonoid compounds can block the initiation or reverse the promotion stage of multistep carcinogenesis. Quercetin is one of the most abundant flavonoids found in fruits and vegetables and has been shown to have multiple properties capable of reducing cell growth in cancer cells. Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) therapy remains a challenge for hematologists worldwide, and the outcomes for patients with both disorders continue to be poor. This scenario indicates the increasing demand for innovative drugs and rational combinative therapies. Herein, we discuss the multitarget effects of the flavonoid quercetin, a naturally occurring flavonol, on AML and MDS. Full article
Article
Can Face- and Smartphone-Touching Behaviors Be Altered with Personal Hygiene Reminders during the COVID-19 Pandemic Period? An Observational Study
Int. J. Environ. Res. Public Health 2021, 18(19), 10038; https://doi.org/10.3390/ijerph181910038 (registering DOI) - 24 Sep 2021
Abstract
As part of the new measures to prevent the spread of the 2019 coronavirus disease (COVID-19), medical students were advised to wear a mask in class and avoid touching their faces. Few studies have analyzed the influence of health education on the frequency [...] Read more.
As part of the new measures to prevent the spread of the 2019 coronavirus disease (COVID-19), medical students were advised to wear a mask in class and avoid touching their faces. Few studies have analyzed the influence of health education on the frequency of face- and smartphone-touching behaviors during the COVID-19 pandemic. This research compared the frequency of in-class face- and smartphone-touching behaviors of medical students before and after the delivery of personal hygiene education during the COVID-19 pandemic. A behavioral observational study was conducted involving medical students at Taipei Medical University. Eighty medical students were recruited during a lecture on otorhinolaryngology. All medical students were required to wear a mask. Their face- and smartphone-touching behavior was observed by viewing the 4k resolution video tape recorded in class. The recording lasted for 2 h, comprising 1 h prior to the health educational reminder and 1 h afterwards. The frequencies of hand-to-face contact and hand-to-smartphone contact were analyzed before and after the delivery of health education emphasizing personal hygiene. Comprehensive health education and reminders effectively reduce the rate of face- and smartphone-touching behaviors. Full article
(This article belongs to the Special Issue The Role of Behavioural Science during COVID-19)
Article
Optimization of Electric Vehicles Based on Frank-Copula-GlueCVaR Combined Wind and Photovoltaic Output Scheduling Research
Energies 2021, 14(19), 6080; https://doi.org/10.3390/en14196080 (registering DOI) - 24 Sep 2021
Abstract
Improving the efficiency of renewable energy and electricity utilization is an urgent problem for China under the objectives of carbon peaking and carbon neutralization. This paper proposes an optimization scheduling method of electric vehicles (EV) combined with wind and photovoltaic power based on [...] Read more.
Improving the efficiency of renewable energy and electricity utilization is an urgent problem for China under the objectives of carbon peaking and carbon neutralization. This paper proposes an optimization scheduling method of electric vehicles (EV) combined with wind and photovoltaic power based on the Frank-Copula-GlueCVaR. First, a joint output model based on copula theory was built to describe the correlation between wind and photovoltaic power output. Second, the Frank-Copula-GlueCVaR index was introduced in a novel way. Operators can now predetermine the future wind–photovoltaic joint output range based on this index and according to their risk preferences. Third, an optimal scheduling model aimed at reducing the group charging cost of EVs was proposed, thereby encouraging EV owners to participate in the demand response. Fourth, this paper: proposes the application of a Variant Roth–Serve algorithm; regards the EV group as a multi-intelligent group; and finds the Pareto optimal strategy of the EV group through continuous learning. Finally, case study results are shown to effectively absorb more renewable energy, reduce the consumption cost of the EV group, and suppress the load fluctuation of the whole EV group, which has a practical significance and theoretical value. Full article
Article
The Dose-Effects of Caffeine on Lower Body Maximal Strength, Muscular Endurance, and Rating of Perceived Exertion in Strength-Trained Females
Nutrients 2021, 13(10), 3342; https://doi.org/10.3390/nu13103342 (registering DOI) - 24 Sep 2021
Abstract
Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained [...] Read more.
Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained females. In a double-blind, randomised, counterbalanced design, fourteen strength-trained females using hormonal contraception consumed either 3 or 6 mg·kg−1 BM of caffeine or placebo (PLA). Following supplementation, participants performed a one-repetition maximum (1RM) leg press and repetitions to failure (RF) at 60% of their 1RM. During the RF test, rating of perceived exertion (RPE) was recorded every five repetitions and total volume (TV) lifted was calculated. Repeated measures ANOVA revealed that RF (p = 0.010) and TV (p = 0.012) attained significance, with pairwise comparisons indicating a significant difference between 3 mg·kg−1 BM and placebo for RF (p = 0.014), with an effect size of 0.56, and for 6 mg·kg−1 BM (p = 0.036) compared to the placebo, with an effect size of 0.65. No further significance was observed for 1RM or for RPE, and no difference was observed between caffeine trials. Although no impact on lower body muscular strength was observed, doses of 3 and 6 mg·kg−1 BM of caffeine improved lower body muscular endurance in resistance-trained females, which may have a practical application for enhancing resistance training stimuli and improving competitive performance. Full article
(This article belongs to the Special Issue Coffee and Caffeine Consumption for Health and Performance)
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Review
Autologous Bone Grafting in Trauma and Orthopaedic Surgery: An Evidence-Based Narrative Review
J. Clin. Med. 2021, 10(19), 4347; https://doi.org/10.3390/jcm10194347 (registering DOI) - 24 Sep 2021
Abstract
Autologous bone grafting is common in trauma and orthopaedic surgery. Both the Reamer Irrigator Aspirator (RIA) and Iliac Crest Bone Graft (ICBG) aim to obtain autologous bone graft. Although the process of harvesting a bone graft is considered simple, complications may occur. This [...] Read more.
Autologous bone grafting is common in trauma and orthopaedic surgery. Both the Reamer Irrigator Aspirator (RIA) and Iliac Crest Bone Graft (ICBG) aim to obtain autologous bone graft. Although the process of harvesting a bone graft is considered simple, complications may occur. This study examined morbidity and pain at the donor site, blood loss, and iatrogenic fractures, comparing RIA and ICBG. The source of the autologous bone graft, the alternative graft sites, and the storage modalities of the harvested bone marrow were also evaluated. In May 2021, PubMed, Embase, Scopus, and Google Scholar were accessed, with no time constraints. RIA may produce greater blood loss, but with less morbidity and complications, making it a potential alternative source of bone grafting. Full article
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Case Report
Milwaukee Makes a Difference: Recognizing Gifted Students from Culturally and Linguistically Diverse Families
Educ. Sci. 2021, 11(10), 578; https://doi.org/10.3390/educsci11100578 (registering DOI) - 24 Sep 2021
Abstract
Gifted education today faces a significant challenge in reaching equity as well as excellence. This is reflected in the disproportionate underrepresentation of children from Black, Hispanic, Native, and low-income families. This pattern of underrepresentation within programs for students with gifts and talents is [...] Read more.
Gifted education today faces a significant challenge in reaching equity as well as excellence. This is reflected in the disproportionate underrepresentation of children from Black, Hispanic, Native, and low-income families. This pattern of underrepresentation within programs for students with gifts and talents is pervasive and pernicious and impacts gifted education programming across all 50 states in the United States of America. This article describes the efforts of Milwaukee Public Schools, a large urban school district in Wisconsin, to address the need for both equity and excellence within their gifted education programming. The U~STRARS~PLUS model formed the foundation for changing the culture of the schools from “at risk” to “at potential”. Dedicated leadership and the combination of securing external support, developing internal trust, and building capacity across the district were critical to creating a strength-based focus within the schools. While the journey is not over, the authors hope that others can learn from Milwaukee’s experiences. Full article
(This article belongs to the Special Issue Early Childhood Gifted Education: Pathways to Equity)
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Article
Decision-Making within Smart City: Waste Sorting
Sustainability 2021, 13(19), 10586; https://doi.org/10.3390/su131910586 (registering DOI) - 24 Sep 2021
Abstract
The concept of the Smart City is the answer for the majority of the challenges of an increased rate of urbanization. However, the implementation of the ideas of the Smart City faces some difficulties. It is a necessity to correspond to the sustainability [...] Read more.
The concept of the Smart City is the answer for the majority of the challenges of an increased rate of urbanization. However, the implementation of the ideas of the Smart City faces some difficulties. It is a necessity to correspond to the sustainability pillars and the decisive role of the population in all processes, and correspondently the necessity to comprehend what factors influence the decision-making process. The research goal of this paper is to analyze the factors determining the decision of the population of multi- and one-family houses to sort waste. The data were collected via population survey of the Vidusdaugavas region of Latvia and semi-structured interviews of municipal councils’ representatives. Both parties—population and authorities—have mentioned the existence of more negative factors of waste sorting in their life than positive ones. For authorities, the most important externalities of waste sorting have an economic nature, while, for citizens, the factors of convenience are not less important than costs. The problem was considered from the position of municipal authorities and the local population, and the identification of problems and misunderstanding is a possibility to start effective communication between the two parties. Moreover, the analysis of the literature has shown that Scandinavian countries and west European countries, which started their way towards implementing smart sustainable cities significantly earlier than Latvia, had the same stages. The most important factor for constructing a smart sustainable city is the changing the way of thinking of population. Full article
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Article
Evaluation of Goethite as a Catalyst for the Thermal Stage of the Westinghouse Process for Hydrogen Production
Catalysts 2021, 11(10), 1145; https://doi.org/10.3390/catal11101145 (registering DOI) - 24 Sep 2021
Abstract
This work focuses on the evaluation of goethite as a catalyst for the transformation of sulfuric acid into sulfur dioxide, a reaction with great interest for the hybrid electrochemical-thermoelectrochemical Westinghouse cycle for hydrogen production. A comparison of the performance of goethite with that [...] Read more.
This work focuses on the evaluation of goethite as a catalyst for the transformation of sulfuric acid into sulfur dioxide, a reaction with great interest for the hybrid electrochemical-thermoelectrochemical Westinghouse cycle for hydrogen production. A comparison of the performance of goethite with that of CuO, Fe2O3, and SiC has been carried out. Moreover, a mixture of those catalysts was evaluated. The results demonstrate that goethite can be used as a catalyst for the thermal decomposition of sulfuric acid in the Westinghouse cycle, with an activity higher than that of SiC but lower than that of Fe2O3 and CuO. However, it does not undergo sintering during its use, but just produces small particles in its surface, which remain after the treatment. Mixtures of Fe2O3 with SiC or goethite do not produce synergism, thus operating each catalyst in an independent way. Full article
Article
Danofloxacin Treatment Alters the Diversity and Resistome Profile of Gut Microbiota in Calves
Microorganisms 2021, 9(10), 2023; https://doi.org/10.3390/microorganisms9102023 (registering DOI) - 24 Sep 2021
Abstract
Fluoroquinolones, such as danofloxacin, are used to control bovine respiratory disease complex in beef cattle; however, little is known about their effects on gut microbiota and resistome. The objectives were to evaluate the effect of subcutaneously administered danofloxacin on gut microbiota and resistome, [...] Read more.
Fluoroquinolones, such as danofloxacin, are used to control bovine respiratory disease complex in beef cattle; however, little is known about their effects on gut microbiota and resistome. The objectives were to evaluate the effect of subcutaneously administered danofloxacin on gut microbiota and resistome, and the composition of Campylobacter in calves. Twenty calves were injected with a single dose of danofloxacin, and ten calves were kept as a control. The effects of danofloxacin on microbiota and the resistome were assessed using 16S rRNA sequencing, quantitative real-time PCR, and metagenomic Hi-C ProxiMeta. Alpha and beta diversities were significantly different (p < 0.05) between pre-and post-treatment samples, and the compositions of several bacterial taxa shifted. The patterns of association between the compositions of Campylobacter and other genera were affected by danofloxacin. Antimicrobial resistance genes (ARGs) conferring resistance to five antibiotics were identified with their respective reservoirs. Following the treatment, some ARGs (e.g., ant9, tet40, tetW) increased in frequencies and host ranges, suggesting initiation of horizontal gene transfer, and new ARGs (aac6, ermF, tetL, tetX) were detected in the post-treatment samples. In conclusion, danofloxacin induced alterations of gut microbiota and selection and enrichment of resistance genes even against antibiotics that are unrelated to danofloxacin. Full article
(This article belongs to the Special Issue Antimicrobial Stewardship in Food-Producing Animals)
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Review
Surface Modified Nanocellulose and Its Reinforcement in Natural Rubber Matrix Nanocomposites: A Review
Polymers 2021, 13(19), 3241; https://doi.org/10.3390/polym13193241 (registering DOI) - 24 Sep 2021
Abstract
Natural rubber is of significant economic importance owing to its excellent resilience, elasticity, abrasion and impact resistance. Despite that, natural rubber has been identified with some drawbacks such as low modulus and strength and therefore opens up the opportunity for adding a reinforcing [...] Read more.
Natural rubber is of significant economic importance owing to its excellent resilience, elasticity, abrasion and impact resistance. Despite that, natural rubber has been identified with some drawbacks such as low modulus and strength and therefore opens up the opportunity for adding a reinforcing agent. Apart from the conventional fillers such as silica, carbon black and lignocellulosic fibers, nanocellulose is also one of the ideal candidates. Nanocellulose is a promising filler with many excellent properties such as renewability, biocompatibility, non-toxicity, reactive surface, low density, high specific surface area, high tensile and elastic modulus. However, it has some limitations in hydrophobicity, solubility and compatibility and therefore it is very difficult to achieve good dispersion and interfacial properties with the natural rubber matrix. Surface modification is often carried out to enhance the interfacial compatibilities between nanocellulose and natural rubber and to alleviate difficulties in dispersing them in polar solvents or polymers. This paper aims to highlight the different surface modification methods employed by several researchers in modifying nanocellulose and its reinforcement effects in the natural rubber matrix. The mechanism of the different surface medication methods has been discussed. The review also lists out the conventional filler that had been used as reinforcing agent for natural rubber. The challenges and future prospective has also been concluded in the last part of this review. Full article
(This article belongs to the Special Issue Functional Natural-Based Polymers)
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Article
A Path Integral Molecular Dynamics Simulation of a Harpoon-Type Redox Reaction in a Helium Nanodroplet
Molecules 2021, 26(19), 5783; https://doi.org/10.3390/molecules26195783 (registering DOI) - 24 Sep 2021
Abstract
We present path integral molecular dynamics (PIMD) calculations of an electron transfer from a heliophobic Cs2 dimer in its (3Σu) state, located on the surface of a He droplet, to a heliophilic, fully immersed C60 molecule. Supported [...] Read more.
We present path integral molecular dynamics (PIMD) calculations of an electron transfer from a heliophobic Cs2 dimer in its (3Σu) state, located on the surface of a He droplet, to a heliophilic, fully immersed C60 molecule. Supported by electron ionization mass spectroscopy measurements (Renzler et al., J. Chem. Phys.2016, 145, 181101), this spatially quenched reaction was characterized as a harpoon-type or long-range electron transfer in a previous high-level ab initio study (de Lara-Castells et al., J. Phys. Chem. Lett.2017, 8, 4284). To go beyond the static approach, classical and quantum PIMD simulations are performed at 2 K, slightly below the critical temperature for helium superfluidity (2.172 K). Calculations are executed in the NVT ensemble as well as the NVE ensemble to provide insights into real-time dynamics. A droplet size of 2090 atoms is assumed to study the impact of spatial hindrance on reactivity. By changing the number of beads in the PIMD simulations, the impact of quantization can be studied in greater detail and without an implicit assumption of superfluidity. We find that the reaction probability increases with higher levels of quantization. Our findings confirm earlier, static predictions of a rotational motion of the Cs2 dimer upon reacting with the fullerene, involving a substantial displacement of helium. However, it also raises the new question of whether the interacting species are driven out-of-equilibrium after impurity uptake, since reactivity is strongly quenched if a full thermal equilibration is assumed. More generally, our work points towards a novel mechanism for long-range electron transfer through an interplay between nuclear quantum delocalization within the confining medium and delocalized electronic dispersion forces acting on the two reactants. Full article
(This article belongs to the Special Issue Reactivity and Properties of Radicals and Radical Ions)
Article
THz-TDS Techniques of Thickness Measurements in Thin Shim Stock Films and Composite Materials
Appl. Sci. 2021, 11(19), 8889; https://doi.org/10.3390/app11198889 (registering DOI) - 24 Sep 2021
Abstract
Terahertz wave (T-ray) scanning applications are one of the most promising tools for nondestructive evaluation. T-ray scanning applications use a T-ray technique to measure the thickness of both thin Shim stock films and GFRP (glass fiber-reinforced plastics) composites, of which the samples were [...] Read more.
Terahertz wave (T-ray) scanning applications are one of the most promising tools for nondestructive evaluation. T-ray scanning applications use a T-ray technique to measure the thickness of both thin Shim stock films and GFRP (glass fiber-reinforced plastics) composites, of which the samples were selected because the T-ray method could penetrate the non-conducting samples. Notably, this method is nondestructive, making it useful for analyzing the characteristics of the materials. Thus, the T-ray thickness measurement can be found for both non-conducting Shim stock films and GFRP composites. In this work, a characterization procedure was conducted to analyze electromagnetic properties, such as the refractive index. The obtained estimates of the properties are in good agreement with the known data for poly methyl methacrylate (PMMA) for acquiring the refractive index. The T-ray technique was developed to measure the thickness of the thin Shim stock films and the GFRP composites. Our tests obtained good results on the thickness of the standard film samples, with the different thicknesses ranging from around 120 μm to 500 μm. In this study, the T-ray method was based on the reflection mode measurement, and the time-of-flight (TOF) and resonance frequencies were utilized to acquire the thickness measurements of the films and GFRP composites. The results showed that the thickness of the samples of frequency matched those obtained directly by time-of-flight (TOF) methods. Full article
(This article belongs to the Special Issue Novel Approaches for Nondestructive Testing and Evaluation)
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The Relationship of Glutathione-S-Transferase and Multi-Drug Resistance-Related Protein 1 in Nitric Oxide (NO) Transport and Storage
Molecules 2021, 26(19), 5784; https://doi.org/10.3390/molecules26195784 (registering DOI) - 24 Sep 2021
Abstract
Nitric oxide is a diatomic gas that has traditionally been viewed, particularly in the context of chemical fields, as a toxic, pungent gas that is the product of ammonia oxidation. However, nitric oxide has been associated with many biological roles including cell signaling, [...] Read more.
Nitric oxide is a diatomic gas that has traditionally been viewed, particularly in the context of chemical fields, as a toxic, pungent gas that is the product of ammonia oxidation. However, nitric oxide has been associated with many biological roles including cell signaling, macrophage cytotoxicity, and vasodilation. More recently, a model for nitric oxide trafficking has been proposed where nitric oxide is regulated in the form of dinitrosyl-dithiol-iron-complexes, which are much less toxic and have a significantly greater half-life than free nitric oxide. Our laboratory has previously examined this hypothesis in tumor cells and has demonstrated that dinitrosyl-dithiol-iron-complexes are transported and stored by multi-drug resistance-related protein 1 and glutathione-S-transferase P1. A crystal structure of a dinitrosyl-dithiol-iron complex with glutathione-S-transferase P1 has been solved that demonstrates that a tyrosine residue in glutathione-S-transferase P1 is responsible for binding dinitrosyl-dithiol-iron-complexes. Considering the roles of nitric oxide in vasodilation and many other processes, a physiological model of nitric oxide transport and storage would be valuable in understanding nitric oxide physiology and pathophysiology. Full article
(This article belongs to the Special Issue Proteomics and Protein Biochemistry in Diseases)
Article
Dynamic Nearest Neighbor: An Improved Machine Learning Classifier and Its Application in Finances
Appl. Sci. 2021, 11(19), 8884; https://doi.org/10.3390/app11198884 (registering DOI) - 24 Sep 2021
Abstract
The presence of machine learning, data mining and related disciplines is increasingly evident in everyday environments. The support for the applications of learning techniques in topics related to economic risk assessment, among other financial topics of interest, is relevant for us as human [...] Read more.
The presence of machine learning, data mining and related disciplines is increasingly evident in everyday environments. The support for the applications of learning techniques in topics related to economic risk assessment, among other financial topics of interest, is relevant for us as human beings. The content of this paper consists of a proposal of a new supervised learning algorithm and its application in real world datasets related to finance, called D1-NN (Dynamic 1-Nearest Neighbor). The D1-NN performance is competitive against the main state of the art algorithms in solving finance-related problems. The effectiveness of the new D1-NN classifier was compared against five supervised classifiers of the most important approaches (Bayes, nearest neighbors, support vector machines, classifier ensembles, and neural networks), with superior results overall. Full article
(This article belongs to the Special Issue Methods and Applications of Data Mining in Business Domains)

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