Latest Articles

Open AccessFeature PaperArticle
Energy Efficiency Based Control Strategy of a Three-Level Interleaved DC-DC Buck Converter Supplying a Proton Exchange Membrane Electrolyzer
Electronics 2019, 8(9), 933; https://doi.org/10.3390/electronics8090933 (registering DOI) -
Abstract
To face the intensive use of natural gas and other fossil fuels to generate hydrogen, water electrolysis based on renewable energy sources (RES) seems to be a viable solution. Due to their fast response times, and high efficiency, proton exchange membrane electrolyzer (PEM [...] Read more.
To face the intensive use of natural gas and other fossil fuels to generate hydrogen, water electrolysis based on renewable energy sources (RES) seems to be a viable solution. Due to their fast response times, and high efficiency, proton exchange membrane electrolyzer (PEM EL) is the most suitable technology for long-term energy storage, combined with RES. Like fuel cells, the development of fit DC-DC converters is mandatory to interface the EL to the DC grid. Given that PEM EL operating voltages are quite low and to meet requirements in terms of output current ripples, new emerging interleaved DC-DC converter topologies seem to be the best candidates. In this work, a three-level interleaved DC-DC buck converter has been chosen to supply a PEM EL from a DC grid. Therefore, the main objective of this paper is to develop a suitable control strategy of this interleaved topology connected to a PEM EL emulator. To design the control strategy, investigations have been carried out on energy efficiency, hydrogen flow rate, and specific energy consumption. The obtained experimental results validate the performance of the converter in protecting the PEM EL during transient operations while guaranteeing correct specific energy consumption. Full article
Open AccessArticle
Chronic Pain Patients’ Gaze Patterns toward Pain-Related Information: Comparison between Pictorial and Linguistic Stimuli
Medicina 2019, 55(9), 530; https://doi.org/10.3390/medicina55090530 (registering DOI) -
Abstract
Background and Objectives: The attentional bias and information processing model explained that individuals who interpret pain stimuli as threatening may increase their attention toward pain-related information. Previous eye tracking studies found pain attentional bias among individuals with chronic pain; however, those studies investigated [...] Read more.
Background and Objectives: The attentional bias and information processing model explained that individuals who interpret pain stimuli as threatening may increase their attention toward pain-related information. Previous eye tracking studies found pain attentional bias among individuals with chronic pain; however, those studies investigated this phenomenon by using only one stimulus modality. Therefore, the present study investigated attentional engagement to pain-related information and the role of pain catastrophizing on pain attentional engagement to pain-related stimuli among chronic pain patients by utilizing both linguistic and visual stimulus. Materials and Methods: Forty chronic pain patients were recruited from the rehabilitation center, the back pain clinic, and the rheumatology department of Chung-Ang University Hospital in Seoul, Korea. Patients observed pictures of faces and words displaying pain, presented simultaneously with neutral expressions, while their eye movements were measured using the eye tracking system. A t-test and ANOVA were conducted to compare stimulus pairs for the total gaze duration. Results revealed that chronic pain patients demonstrated attentional preference toward pain words but not for pain faces. An ANOVA with bias scores was conducted to investigate the role of pain catastrophizing on attentional patterns. Results indicated that chronic pain patients with high pain catastrophizing scores gazed significantly longer at pain- and anger-related words than neutral words compared to those with low pain catastrophizing scores. The same patterns were not observed for the facial expression stimulus pairs. Conclusions: The results of the present study revealed attentional preference toward pain-related words and the significant role of pain catastrophizing on pain attentional engagement to pain-related words. However, different patterns were observed between linguistic and visual stimuli. Clinical implications related to use in pain treatment and future research suggestions are discussed. Full article
Open AccessArticle
Utilization of Traditional Chinese Medicine Practitioners in Later Life in Mainland China
Geriatrics 2019, 4(3), 49; https://doi.org/10.3390/geriatrics4030049 (registering DOI) -
Abstract
Mainland China is one of the world’s most rapidly aging countries, and yet there is very limited literature on traditional Chinese medicine (TCM) use in older individuals. This study aimed to determine the national and provincial prevalence of TCM practitioner utilization in later [...] Read more.
Mainland China is one of the world’s most rapidly aging countries, and yet there is very limited literature on traditional Chinese medicine (TCM) use in older individuals. This study aimed to determine the national and provincial prevalence of TCM practitioner utilization in later life and associated factors. We used World Health Organization China Study on Global Aging and Adult Health Wave 1 data to determine descriptive statistics of the study population of participants aged 50 years and over. Multivariate logistic regression was conducted controlling for sociodemographic and health factors. A total of 14% of participants utilized a TCM practitioner, and the prevalence of utilization varied significantly by locality. Utilization was more likely in participants living in rural areas [adjusted odds ratio (OR) = 12.96; p < 0.001], Hubei (OR = 7.17; p < 0.001), or Shandong provinces (OR = 4.21; p < 0.001) and being diagnosed with chronic lung disease (OR = 1.97; p = 0.005). Hence, rurality, provincial influence, and chronic lung diseases are significant factors associated with TCM practitioner utilization among older individuals in China. These findings may inform policy for preservation and development of TCM nationally as well as its sustainability in an increasingly aging society. Full article
Open AccessArticle
Highly Sensitive Signal Processing Devices for Capacitive Transducers of Micromechanical Accelerometers
Electronics 2019, 8(9), 932; https://doi.org/10.3390/electronics8090932 (registering DOI) -
Abstract
In this paper, the principles of the open-loop frequency-based signal processing devices for capacitive MEMS accelerometers are used to develop three CMOS IP-core (Intellectual Property core) projects of highly sensitive signal processing devices with frequency output. Signal processing devices designed in accordance with [...] Read more.
In this paper, the principles of the open-loop frequency-based signal processing devices for capacitive MEMS accelerometers are used to develop three CMOS IP-core (Intellectual Property core) projects of highly sensitive signal processing devices with frequency output. Signal processing devices designed in accordance with the considered method form an output of rectangular pulses whose frequencies equal a difference of signal frequencies from two identical generators with micromechanical accelerometer capacitive transducers in their frequency control circuits. First, the analog project scheme uses two harmonic LC oscillators and an analog mixer to form an output rectangular-shape differential-frequency signal, the frequency of which is dependent on the measured acceleration. Second, the digital project is fully scalable for various CMOS-technologies due to oscillators of rectangular pulses and a digital mixer. Third, the mixed-signal project combines the advantages of the analog and digital projects. The signal processing device projects were developed, modeled and compared to comprehensively solve the problems of increasing sensitivity, dynamic range, noise immunity and resistance to destabilizing factors (e.g., to temperature changes). Full article
Open AccessArticle
Water Pathways for the Hindu-Kush-Himalaya and an Analysis of Three Flood Events
Atmosphere 2019, 10(9), 489; https://doi.org/10.3390/atmos10090489 (registering DOI) -
Abstract
The climatology of major sources and pathways of moisture for three locales along the Hindu-Kush-Himalayan region are examined, by use of Lagrangian methods applied to the ERA-Interim dataset, over the period from 1980 to 2016 for both summer (JJA) and winter (NDJ) periods. [...] Read more.
The climatology of major sources and pathways of moisture for three locales along the Hindu-Kush-Himalayan region are examined, by use of Lagrangian methods applied to the ERA-Interim dataset, over the period from 1980 to 2016 for both summer (JJA) and winter (NDJ) periods. We also investigate the major flooding events of 2010, 2013, and 2017 in Pakistan, Uttarakhand, and Kathmandu, respectively, and analyse a subset of the climatology associated with the 20 most significant rainfall events over each region of interest. A comparison is made between the climatology and extreme events, in the three regions of interest, during the summer monsoon period. For Northern Pakistan and Uttarakhand, the Indus basin plays the largest role in moisture uptake. Moisture is also gathered from Eastern Europe and Russia. Extreme events display an increased influence of sub-tropical weather systems, which manifest themselves through low-level moisture transport; predominantly from the Arabian sea and along the Gangetic plain. In the Kathmandu region, it is found that the major moisture sources come from the Gangetic plain, Arabian Sea, Red Sea, Bay of Bengal, and the Indus basin. In this case, extreme event pathways largely match those of the climatology, although an increased number of parcels originate from the western end of the Gangetic plain. These results provide insights into the rather significant influence of mid-latitudinal weather systems, even during the monsoon season, in defining the climatology of the Hindu-Kush-Himalaya region, as well as how extreme precipitation events in this region represent atypical moisture pathways. We propose a detailed investigation of how such water pathways are represented in climate models for the present climate conditions and in future climate scenarios, as this may be extremely relevant for understanding the impacts of climate change on the cryosphere and hydrosphere of the region. Full article
Open AccessFeature PaperArticle
Canonical Divergence for Flat α-Connections: Classical and Quantum
Entropy 2019, 21(9), 831; https://doi.org/10.3390/e21090831 (registering DOI) -
Abstract
A recent canonical divergence, which is introduced on a smooth manifold M endowed with a general dualistic structure (g,,*), is considered for flat α-connections. In the classical setting, we compute such a canonical divergence [...] Read more.
A recent canonical divergence, which is introduced on a smooth manifold M endowed with a general dualistic structure (g,,*), is considered for flat α-connections. In the classical setting, we compute such a canonical divergence on the manifold of positive measures and prove that it coincides with the classical α-divergence. In the quantum framework, the recent canonical divergence is evaluated for the quantum α-connections on the manifold of all positive definite Hermitian operators. In this case as well, we obtain that the recent canonical divergence is the quantum α-divergence. Full article
Open AccessArticle
Coseismic Ground Deformation Reproduced through Numerical Modeling: A Parameter Sensitivity Analysis
Geosciences 2019, 9(9), 370; https://doi.org/10.3390/geosciences9090370 (registering DOI) -
Abstract
Coseismic ground displacements detected through remote sensing surveys are often used to invert the coseismic slip distribution on geologically reliable fault planes. We analyze a well-known case study (2009 L’Aquila earthquake) to investigate how three-dimensional (3D) slip configuration affects coseismic ground surface deformation. [...] Read more.
Coseismic ground displacements detected through remote sensing surveys are often used to invert the coseismic slip distribution on geologically reliable fault planes. We analyze a well-known case study (2009 L’Aquila earthquake) to investigate how three-dimensional (3D) slip configuration affects coseismic ground surface deformation. Different coseismic slip surface configurations reconstructed using aftershocks distribution and coseismic cracks, were tested using 3D boundary element method numerical models. The models include two with slip patches that reach the surface and three models of blind normal-slip surfaces with different configurations of slip along shallowly-dipping secondary faults. We test the sensitivity of surface deformation to variations in stress drop and rock stiffness. We compare numerical models’ results with line of sight (LOS) surface deformation detected from differential SAR (Synthetic Aperture Radar) interferometry (DInSAR). The variations in fault configuration, rock stiffness and stress drop associated with the earthquake considerably impact the pattern of surface subsidence. In particular, the models with a coseismic slip patch that does not reach the surface have a better match to the line of sight coseismic surface deformation, as well as better match to the aftershock pattern, than models with rupture that reaches the surface. The coseismic slip along shallowly dipping secondary faults seems to provide a minor contribution toward surface deformation. Full article
Open AccessFeature PaperReview
Multiscale Computational Fluid Dynamics
Energies 2019, 12(17), 3272; https://doi.org/10.3390/en12173272 (registering DOI) -
Abstract
Computational Fluid Dynamics (CFD) has numerous applications in the field of energy research, in modelling the basic physics of combustion, multiphase flow and heat transfer; and in the simulation of mechanical devices such as turbines, wind wave and tidal devices, and other devices [...] Read more.
Computational Fluid Dynamics (CFD) has numerous applications in the field of energy research, in modelling the basic physics of combustion, multiphase flow and heat transfer; and in the simulation of mechanical devices such as turbines, wind wave and tidal devices, and other devices for energy generation. With the constant increase in available computing power, the fidelity and accuracy of CFD simulations have constantly improved, and the technique is now an integral part of research and development. In the past few years, the development of multiscale methods has emerged as a topic of intensive research. The variable scales may be associated with scales of turbulence, or other physical processes which operate across a range of different scales, and often lead to spatial and temporal scales crossing the boundaries of continuum and molecular mechanics. In this paper, we present a short review of multiscale CFD frameworks with potential applications to energy problems. Full article
Open AccessArticle
Romanian Wormwood (Artemisia absinthium L.): Physicochemical and Nutraceutical Screening
Molecules 2019, 24(17), 3087; https://doi.org/10.3390/molecules24173087 (registering DOI) -
Abstract
Artemisia species are used worldwide for their antioxidant, antimicrobial and anti-inflammatory properties. This research was designed to investigate the phytochemical profile of two ethanolic extracts obtained from leaves and stems of A. absinthium L. as well as the biological potential (antioxidant activity, cytotoxic, [...] Read more.
Artemisia species are used worldwide for their antioxidant, antimicrobial and anti-inflammatory properties. This research was designed to investigate the phytochemical profile of two ethanolic extracts obtained from leaves and stems of A. absinthium L. as well as the biological potential (antioxidant activity, cytotoxic, anti-migratory and anti-inflammatory properties). Both plant materials showed quite similar thermogravimetric, FT-IR phenolic profile (high chlorogenic acid) with mild antioxidant capacity [ascorbic acid (0.02–0.1) > leaves (0.1–2.0) > stem (0.1–2.0)]. Alcoholic extracts from these plant materials showed a cytotoxic effect against A375 (melanoma) and MCF7 (breast adenocarcinoma) and affected less the non-malignant HaCaT cells (human keratinocytes) at 72 h post-stimulation and this same trend was observed in the anti-migratory (A375, MCF7 > HaCat) assay. Lastly, extracts ameliorated the pro-inflammatory effect of TPA (12-o-tetradecanoylphorbol-13-acetate) in mice ears, characterized by a diffuse neutrophil distribution with no exocytosis or micro-abscesses. Full article
Open AccessArticle
Synthesis and Characterization of FITC Labelled Ruthenium Dendrimer as a Prospective Anticancer Drug
Biomolecules 2019, 9(9), 411; https://doi.org/10.3390/biom9090411 (registering DOI) -
Abstract
Metallodendrimers—dendrimers with included metals—are widely investigated as biocompatible equivalents to metal nanoparticles. Applications can be expected in the fields of catalysis, as chemical sensors in molecular recognition and as anticancer drugs. Metallodendrimers can also mimic certain biomolecules, for example, haemoprotein in the case [...] Read more.
Metallodendrimers—dendrimers with included metals—are widely investigated as biocompatible equivalents to metal nanoparticles. Applications can be expected in the fields of catalysis, as chemical sensors in molecular recognition and as anticancer drugs. Metallodendrimers can also mimic certain biomolecules, for example, haemoprotein in the case of using a dendrimer with a porphyrin core. In previous papers, we showed the promising anticancer effects of carbosilane ruthenium dendrimers. The present paper is devoted to studying biocompatibility and the cytotoxic effect on normal and cancer cells of carbosilane ruthenium dendrimers labelled with fluorescent probe fluorescein isothiocyanate (FITC). The addition of fluorescent probe allowed tracking the metallodendrimer in both normal and cancer cells. It was found that carbosilane ruthenium dendrimer labelled with FITC in concentration up to 10 µmol/L was more cytotoxic for cancer cells than for normal cells. Thus, FITC labelled carbosilane ruthenium dendrimer is a good candidate for diagnostic imaging and studying anticancer effects of metallodendrimers in cancer therapy. Full article
Figures

Graphical abstract

Open AccessArticle
Extending the View on Project Performance
Adm. Sci. 2019, 9(3), 65; https://doi.org/10.3390/admsci9030065 (registering DOI) -
Abstract
The main aim of this study is to gain insights into project management professionals’ perception of how project success can be achieved. The Q-methodology was followed in this research. Based on an extensive literature review and validation through expert judgment, a framework consisting [...] Read more.
The main aim of this study is to gain insights into project management professionals’ perception of how project success can be achieved. The Q-methodology was followed in this research. Based on an extensive literature review and validation through expert judgment, a framework consisting of 33 factors increasing the likelihood of success was developed. A total of 34 practitioners in three different sectors (real estate, urban development, and infrastructure) in the Netherlands were asked to rank the statements contributing to the success of their projects. Four different perspectives of how project success can be achieved were distinguished in this study: “seeking the best match”, “being adaptive and open”, “keeping the team focused”, and “preparing for opportunities”. The perception of different practitioners of how success can be obtained may stem from factors of project context rather than sector and complexity. This highlights further research opportunities in taking a contingent approach when investigating project performance. The study helps to grasp the subjectivity of practitioners’ viewpoints regarding the potential ways to enhance project performance by understanding the similarity and differences of these viewpoints. Full article
Figures

Figure 1

Open AccessArticle
Mobility-Enabled Edge Server Selection for Multi-User Composite Services
Future Internet 2019, 11(9), 184; https://doi.org/10.3390/fi11090184 (registering DOI) -
Abstract
In mobile edge computing, a set of edge servers is geographically deployed near the mobile users such that accessible computing capacities and services can be provided to users with low latency. Due to user’s mobility, one fundamental and critical problem in mobile edge [...] Read more.
In mobile edge computing, a set of edge servers is geographically deployed near the mobile users such that accessible computing capacities and services can be provided to users with low latency. Due to user’s mobility, one fundamental and critical problem in mobile edge computing is how to select edge servers for many mobile users so that the total waiting time is minimized. In this paper, we propose a multi-user waiting time computation model about composite services and show the resource contention of the edge server among mobile users. Then, we introduce a novel and optimal Multi-user Edge server Selection method based on Particle swarm optimization (MESP) in mobile edge computing, which selects edge servers for mobile uses in advance within polynomial time. Extensive simulations on a real-world data-trace show that the MESP algorithm can effectively reduce the total waiting time compared with traditional approaches. Full article
Figures

Figure 1

Open AccessArticle
Washing Durability and Photo-Stability of NanoTiO2-SiO2 Coatings Exhausted onto Cotton and Cotton/Polyester Fabrics
Coatings 2019, 9(9), 545; https://doi.org/10.3390/coatings9090545 (registering DOI) -
Abstract
The purpose of this study was to assess and compare the durability of TiO2-SiO2 coatings applied in three concentrations onto two lightweight cellulose-based fabrics diverse in the composition against two external factors, repeated washings and prolonged intensive UV irradiation, by [...] Read more.
The purpose of this study was to assess and compare the durability of TiO2-SiO2 coatings applied in three concentrations onto two lightweight cellulose-based fabrics diverse in the composition against two external factors, repeated washings and prolonged intensive UV irradiation, by observing the changes in surface morphology, investigation of optical properties, and identification of specific molecular vibrations. The scanning electron microscopy (SEM) micrographs, diffuse reflectance spectroscopy (DRS) profiles and fourier transform-infrared (FT-IR) spectra implied equal distribution of TiO2-SiO2 nanoparticles over the surfaces of both fabrics after exhaustion procedures, regarding the concentration of colloidal paste and the type of material used, followed by a slight reduction of nanoparticles after twenty washing cycles. Moreover, the newly gained, good to very good UV protective functionality proved the suitability of the employed procedure and the sufficient durability of the selected coatings. Additionally, UV irradiation mainly caused damages to the cotton. Cotton/polyester became yellower under UV, although the application of TiO2-SiO2 protected the material against yellowness. Full article
Figures

Figure 1

Institutional Open Access Program (IOAP)

IOAP participants benefit from discounts and convenient payment options.

Feedback

We are keen to hear what you think about MDPI. To leave us your feedback, suggestions or questions please click here.

See what our authors and guest editors say about us.

About MDPI

MDPI.com is a platform for peer-reviewed, scientific open-access journals operated by MDPI, based in Basel, Switzerland. Additional offices are located in Beijing and Wuhan (China) as well as in Barcelona (Spain).

Back to Top