bluuebunny/crossref_metadata_2025 huggingface dataset:
Influencing Mechanisms of a Crosswind on the Thermo-Hydraulic Characteristics of a Large-Scale Air-Cooled Heat Exchanger
Authors: Kong Yanqiang , Wang Weijia , Zuo Zhitao , Yang Lijun , Du Xiaoze , Xu Chao , Yang Yongping
Published: March 2019

For the large scale air-cooled heat exchanger of a natural draft dry cooling system (NDDCS) in power plants, its thermo-flow characteristics are basically dominated by crosswinds. Unfortunately however, the detailed mechanisms of the crosswind effects have yet to be fully uncovered. Therefore, in this research, the local flow and heat transfer performances of the cooling deltas, which are also termed as the fundamental cells of the large-scale air-cooled heat exchanger, are specifically investigated with full consideration for the cell structure and the water-side temperature distribution at various wind speeds. A 3D CFD method with a realizable k-ε turbulence model, heat exchanger model, and porous media model is developed, and the accuracy and credibility of the numerical model are experimentally validated. With the numerical simulation, the overall 3D outlet air temperature of the large-scale air-cooled heat exchanger, and the corresponding local air velocity and temperature fields of the cooling deltas are qualitatively analyzed. Furthermore, the air-mass flow rate and heat rejection are also quantitatively studied at both the global and local views. The results depict that with an increase in the wind speed, the air mass flow rate and heat rejection will increase greatly for the frontal deltas; however, they will drop dramatically for the middle-front deltas. As for the middle- as well as the middle-rear deltas, the thermo-flow performances vary markedly at various wind speeds, which behave in the most deteriorated manner at a wind speed of 12 m/s. The rear deltas show the best thermo-flow performances at a wind speed of 12 m/s, but the worst at 16 m/s. A detailed analysis of the variable fields for each cooling delta may contribute to the performance improvement of the large-scale air-cooled heat exchanger of NDDCS.
Techno-Economic Assessment of Bio-Energy with Carbon Capture and Storage Systems in a Typical Sugarcane Mill in Brazil
Authors: Restrepo-Valencia Sara , Walter Arnaldo
Published: March 2019

For significantly reducing greenhouse gas emissions, those from electricity generation should be negative by the end of the century. In this sense, bio-energy with carbon capture and storage (BECCS) technology in sugarcane mills could be crucial. This paper presents a technical and economic assessment of BECCS systems in a typical Brazilian sugarcane mill, considering the adoption of advanced—although commercial—steam cogeneration systems. The technical results are based on computational simulations, considering CO2 capture both from fermentation (released during ethanol production) and due to biomass combustion. The post combustion capture technology based on amine was considered integrated to the mill and to the cogeneration system. A range of energy requirements and costs were taken from the literature, and different milling capacities and capturing rates were considered. Results show that CO2 capture from both flows is technically feasible. Capturing CO2 from fermentation is the alternative that should be prioritized as energy requirements for capturing from combustion are meaningful, with high impacts on surplus electricity. In the reference case, the cost of avoided CO2 emissions was estimated at 62 €/t CO2, and this can be reduced to 59 €/t CO2 in case of more efficient technologies, or even to 48 €/t CO2 in case of larger plants.
Utilization of an Air-PCM Heat Exchanger in Passive Cooling of Buildings: A Simulation Study on the Energy Saving Potential in Different European Climates
Authors: Charvát Pavel , Klimeš Lubomír , Zálešák Martin
Published: March 2019

The energy saving potential (ESP) of passive cooling of buildings with the use of an air-PCMheat exchanger (cold storage unit) was investigated through numerical simulations. One of the goals of the study was to identify the phase change temperature of a PCM that would provide the highest energy saving potential under the specific climate and operating conditions. The considered air-PCM heat exchanger contained 100 aluminum panels filled with a PCM. The PCM had a thermal storage capacity of 200 kJ/kg in the phase change temperature range of 4 ∘ C. The air-PCM heat exchanger was used to cool down the outdoor air supplied to a building during the day, and the heat accumulated in the PCM was rejected to the outdoors at night. The simulations were conducted for 16 locations in Europe with the investigated time period from 1 May–30 September. The outdoor temperature set point of 20 ∘ C was used for the utilization of stored cold. In the case of the location with the highest ESP, the scenarios with the temperature set point and without the set point (which provides maximum theoretical ESP) were compared under various air flow rates. The average utilization rate of the heat of fusion did not exceed 50% in any of the investigated scenarios.
An Expeditious Methodology to Assess the Effects of Intermittent Generation on Power Systems
Authors: Rosas Gracita Batista , Lourenço Elizete Maria , Falcão Djalma Mosqueira , Fernandes Thelma Solange Piazza
Published: March 2019

This paper proposes an expeditious methodology that provides hourly assessments of the effect of intermittent wind and solar power generation on the electrical quantities characterizing power systems. Currents are measured via circuit breakers to confirm the correct sizing of devices based on their rated currents. Nodal voltage magnitudes are assessed for compliance with limits imposed by regulatory authorities, whereas the active power produced by hydroelectrical generators is assessed for reserve energy. The proposed methodology leverages a fuzzy extended deterministic optimal power flow that uses in power balance equations the average hourly values of active power generated by wind and solar sources as well as hourly energy load. The power grid is modeled at the substation level to directly obtain power flow through circuit breakers. Uncertainties in power system electrical quantities are assessed for an optimal solution using a Taylor series associated with deviations from the average values of the active power produced by the wind and solar sources. These deviations are represented using a fuzzy triangular model reflecting the approximations of the probability density functions of these powers. The methodology takes into account a subjective investigation that focuses on the qualitative characteristic of these energy sources’ behaviors.
Identification Method for Voltage Sags Based on K-means-Singular Value Decomposition and Least Squares Support Vector Machine
Authors: Sha Haoyuan , Mei Fei , Zhang Chenyu , Pan Yi , Zheng Jianyong
Published: March 2019

Voltage sag is one of the most serious problems in power quality. The occurrence of voltage sag will lead to a huge loss in the social economy and have a serious effect on people’s daily life. The identification of sag types is the basis for solving the problem and ensuring the safe grid operation. Therefore, with the measured data uploaded by the sag monitoring system, this paper proposes a sag type identification algorithm based on K-means-Singular Value Decomposition (K-SVD) and Least Squares Support Vector Machine (LS-SVM). Firstly; each phase of the sag sample RMS data is sparsely coded by the K-SVD algorithm and the sparse coding information of each phase data is used as the feature matrix of the sag sample. Then the LS-SVM classifier is used to identify the sag type. This method not only works without any dependence on the sag data feature extraction by artificial ways, but can also judge the short-circuit fault phase, providing more effective information for the repair of grid faults. Finally, based on a comparison with existing methods, the accuracy advantages of the proposed algorithm with be presented.
Investigations on the Performance of a New Grounding Device with Spike Rods under High Magnitude Current Conditions
Authors: Abdul Ali Abdul Wali , Ahmad Nurul Nadia , Mohamad Nor Normiza , Reffin Muhd Shahirad , Amanina Syed Abdullah Syarifah
Published: March 2019

In many publications, the characteristics of practical earthing systems were investigated under conditions involving fast-impulse currents of different magnitudes by field measurements. However, as generally known, in practice the transient current can normally reach several tens of kiloamperes. This paper therefore aimed to investigate the characteristics of a new electrode for grounding systems under high current magnitude conditions, and compare it with steady-state test results. The earth electrodes were installed in low resistivity test media, so that high impulse current magnitudes can be achieved. The effects of impulse polarity and earth electrode’s geometry of a new earth electrode were also quantified under high impulse conditions, at high currents (up to 16 kA).
Efficiency Analysis of Low Electric Power Drives Employing Induction and Synchronous Reluctance Motors in Pump Applications
Authors: Kazakbaev Vadim , Prakht Vladimir , Dmitrievskii Vladimir , Ibrahim Mohamed N. , Oshurbekov Safarbek , Sarapulov Sergey
Published: March 2019

Due to the rapid increase in the number of variable speed AC drives, the analysis of their energy efficiency has become highly essential. However, such an analysis requires consideration of a wide variety of factors. This includes considering the energy loss in the frequency converter, depending on the motor type. In this article, a computational comparison of the energy properties of variable frequency pump drive employing two types of electric machines, i.e. an induction and a synchronous reluctance motor, is presented. The effect of the motor type on the losses in a low-voltage two-stage frequency converter using analytical and numerical models, with a further comparison, is investigated. Furthermore, an alternative approach to determine the current magnitude and power factor of the load of the converter is suggested. Eventually, this study provides a quantitative estimate of the increase in losses in the converter caused by using the two different motor types. Several experimental tests are conducted on induction and synchronous 1.1 kW reluctance motors.
Improved Perturb and Observation Method Based on Support Vector Regression
Authors: Tan Bicheng , Ke Xin , Tang Dachuan , Yin Sheng
Published: March 2019

Solar energy is the most valuable renewable energy source due to its abundant storage and is pollution-free. The output power of photovoltaic (PV) arrays will vary with external conditions, such as irradiance and temperature fluctuations. Therefore, an increase in the energy conversion rate is inseparable from maximum power point tracking (MPPT). The existing MPPT technology cannot either balance the tracking speed and tracking accuracy, or the implementation cost is too high due to the complexity of the calculation. In this paper, a new maximum power point tracking (MPPT) method was proposed. It improves the traditional perturb and observation (P&O) method by introducing the support vector regression (SVR) algorithm. In this method, the current maximum power point voltage is predicted by the trained model and compared with the current operating voltage to predict a reasonable step size. The boost DC/ DC (Direct current-Direct current converter) convert system applying the improved method and the traditional P&O was simulated in MATLAB-Simulink, respectively. The results of the simulation show that compared with the traditional P&O method, the proposed new method both improves the convergence time and tracking accuracy.
A Comprehensive VSM Control Strategy Designed for Unbalanced Grids
Authors: Miao Huiyu , Mei Fei , Yang Yun , Chen Hongfei , Zheng Jianyong
Published: March 2019

A virtual synchronous machine (VSM) is a converter which, compared to other types of converters, has more friendly interactions with the power grid because it is able to simulate the external characteristics of a synchronous machine, which can provide virtual inertia and damping. When the grid voltage is unbalanced, there will be negative sequence current and power oscillations. There will also be double-frequency ripples on the DC bus, which affect the normal operation of the DC power source or load. In order to solve these problems, a comprehensive control strategy is proposed in this paper. The principle of a VSM operated as a current source converter, also called VISMA, is used in the design. A complex coefficient filter is applied to separate the positive and negative sequence components of the grid voltage. By analyzing the reasons of power oscillations under unbalanced voltage, the electrical simulation part of the VSM is improved to achieve several objectives: to suppress negative sequence current and DC voltage ripples. Additionally, the rated voltage in the reactive control part is adaptively adjusted to stabilize the system. The validity of the proposed control strategy is verified by simulation and experiment.
Improvement in Energy Performance of Building Envelope Incorporating Electrochromic Windows (ECWs)
Authors: Park Bo Rang , Hong Jongin , Choi Eun Ji , Choi Young Jae , Lee Choonyeob , Moon Jin Woo
Published: March 2019

The present study sets out to review the thermal and optical properties of electrochromic windows (ECWs) through an analysis of the improvement in the energy performance of a building resulting from their application. The performance analysis was based on the change in the room temperature according to the solar transmittance and the orientation of the ECWs, the energy consumptions of the building’s heating/cooling systems, and that of the building’s lighting according to the visible light transmittance (VLT). To achieve this, the Quick Energy Simulation Tool (eQUEST), a building energy interpretation program, was used. The solar heat gain coefficient (SHGC) of the ECWs was found to be significantly reduced. This had the effect of lowering the room temperature in summer, such that the effect on the summer cooling energy consumption was also remarkable. However, with a reduction in the VLT, the lighting energy consumption increased. The net result of the changes in the heating/cooling and lighting energy consumptions was a reduction of about 11,207 kWh/yr (8.89%). The ECWs were found to realize a greater reduction in a building’s energy consumption than was possible with windows glazed with low-E coated glass.
Linking Terrestrial LiDAR Scanner and Conventional Forest Structure Measurements with Multi-Modal Satellite Data
Authors: Mulatu Kalkidan Ayele , Decuyper Mathieu , Brede Benjamin , Kooistra Lammert , Reiche Johannes , Mora Brice , Herold Martin
Published: March 2019

Obtaining information on vertical forest structure requires detailed data acquisition and analysis which is often performed at a plot level. With the growing availability of multi-modal satellite remote sensing (SRS) datasets, their usability towards forest structure estimation is increasing. We assessed the relationship of PlanetScope-, Sentinel-2-, and Landsat-7-derived vegetation indices (VIs), as well as ALOS-2 PALSAR-2- and Sentinel-1-derived backscatter intensities with a terrestrial laser scanner (TLS) and conventionally measured forest structure parameters acquired from 25 field plots in a tropical montane cloud forest in Kafa, Ethiopia. Results showed that canopy gap-related forest structure parameters had their highest correlation (|r| = 0.4 − 0.48) with optical sensor-derived VIs, while vegetation volume-related parameters were mainly correlated with red-edge- and short-wave infrared band-derived VIs (i.e., inverted red-edge chlorophyll index (IRECI), normalized difference moisture index), and synthetic aperture radar (SAR) backscatters (|r| = −0.57 − 0.49). Using stepwise multi-linear regression with the Akaike information criterion as evaluation parameter, we found that the fusion of different SRS-derived variables can improve the estimation of field-measured structural parameters. The combination of Sentinel-2 VIs and SAR backscatters was dominant in most of the predictive models, while IRECI was found to be the most common predictor for field-measured variables. The statistically significant regression models were able to estimate cumulative plant area volume density with an R2 of 0.58 and with the lowest relative root mean square error (RRMSE) value (0.23). Mean gap and number of gaps were also significantly estimated, but with higher RRMSE (R2 = 0.52, RRMSE = 1.4, R2 = 0.68, and RRMSE = 0.58, respectively). The models showed poor performance in predicting tree density and number of tree species (R2 = 0.28, RRMSE = 0.41, and R2 = 0.21, RRMSE = 0.39, respectively). This exploratory study demonstrated that SRS variables are sensitive to retrieve structural differences of tropical forests and have the potential to be used to upscale biodiversity relevant field-based forest structure estimates.
Influence of 3D Spruce Tree Representation on Accuracy of Airborne and Satellite Forest Reflectance Simulated in DART
Authors: Janoutová Růžena , Homolová Lucie , Malenovský Zbyněk , Hanuš Jan , Lauret Nicolas , Gastellu-Etchegorry Jean-Philippe
Published: March 2019

Advances in high-performance computer resources and exploitation of high-density terrestrial laser scanning (TLS) data allow for reconstruction of close-to-reality 3D forest scenes for use in canopy radiative transfer models. Consequently, our main objectives were (i) to reconstruct 3D representation of Norway spruce (Picea abies) trees by deriving distribution of woody and foliage elements from TLS and field structure data and (ii) to use the reconstructed 3D spruce representations for evaluation of the effects of canopy structure on forest reflectance simulated in the Discrete Anisotropic Radiative Transfer (DART) model. Data for this study were combined from two spruce research sites located in the mountainous areas of the Czech Republic. The canopy structure effects on simulated top-of-canopy reflectance were evaluated for four scenarios (10 × 10 m scenes with 10 trees), ranging from geometrically simple to highly detailed architectures. First scenario A used predefined simple tree crown shapes filled with a turbid medium with simplified trunks and branches. Other three scenarios used the reconstructed 3D spruce representations with B detailed needle shoots transformed into turbid medium, C with simplified shoots retained as facets, and D with detailed needle shoots retained as facets D. For the first time, we demonstrated the capability of the DART model to simulate reflectance of complex coniferous forest scenes up to the level of a single needle (scenario D). Simulated bidirectional reflectance factors extracted for each scenario were compared with actual airborne hyperspectral and space-borne Sentinel-2 MSI reflectance data. Scenario A yielded the largest differences from the remote sensing observations, mainly in the visible and NIR regions, whereas scenarios B, C, and D produced similar results revealing a good agreement with the remote sensing data. When judging the computational requirements for reflectance simulations in DART, scenario B can be considered as most operational spruce forest representation, because the transformation of 3D shoots in turbid medium reduces considerably the simulation time and hardware requirements.
Processing Iron Oxide Nanoparticle-Loaded Composite Carbon Fiber and the Photosensitivity Characterization
Authors: Gan Yong X. , Yu Christina , Panahi Niousha , Gan Jeremy B. , Cheng Wanli
Published: March 2019

In this work, iron oxide nanoparticle loaded carbon fibers were prepared by electrohydrodynamic co-casting a polymer and particle mixture followed by carbonization. The precursor used to generate carbon fibers was a linear molecular chain polymer: polyacrylonitrile (PAN). A solution containing iron (II, III) oxide (Fe3O4) particles and the PAN polymer dissolved in dimethylformamide (DMF) was electrohydrodynamically co-cast into fibers. The fibers were stabilized in air and carbonized in hydrogen at elevated temperatures. The microstructure and composition of the fibers were analyzed using scanning electron microscopy (SEM). A quantitative metallographic analysis method was used to determine the fiber size. It was found that the iron (II, III) oxide particles distributed uniformly within the carbonized fibers. Photosensitivity of the particle containing fibers was characterized through measuring the open circuit potential of the fiber samples under the visible light illumination. Potential applications of the fibers for photovoltaics and photonic sensing were discussed.
CHANG-ES: XVIII—The CHANG-ES Survey and Selected Results
Authors: Irwin Judith , Damas-Segovia Ancor , Krause Marita , Miskolczi Arpad , Li Jiangtao , Stein Yelena , English Jayanne , Henriksen Richard , Beck Rainer , Wiegert Theresa , Dettmar Ralf-Jürgen
Published: March 2019

The CHANG-ES (Continuum Halos in Nearby Galaxies) survey of 35 nearby edge-on galaxies is revealing new and sometimes unexpected and startling results in their radio continuum emission. The observations were in wide bandwidths centred at 1.6 and 6.0 GHz. Unique to this survey is full polarization data showing magnetic field structures in unprecedented detail, resolution and sensitivity for such a large sample. A wide range of new results are reported here, some never before seen in any galaxy. We see circular polarization and variability in active galactic nuclei (AGNs), in-disk discrete features, disk-halo structures sometimes only seen in polarization, and broad-scale halos with reversing magnetic fields, among others. This paper summarizes some of the CHANG-ES results seen thus far.
Estimation of Soil Erosion in Nepal Using a RUSLE Modeling and Geospatial Tool
Authors: Koirala Pooja , Thakuri Sudeep , Joshi Subesh , Chauhan Raju
Published: March 2019

Soil erosion is a major issue, causing the loss of topsoil and fertility in agricultural land in mountainous terrain. Estimation of soil erosion in Nepal is essential because of its agriculture-dependent economy (contributing 36% to national GDP) and for preparing erosion control plans. The present study, for the first time, attempts to estimate the soil loss of Nepal through the application of the Revised Universal Soil Loss Equation (RUSLE) model. In addition, it analyzes the effect of Land Use and Land Cover (LULC) and slope ( β ) exposition on soil erosion. Nation-wide mean annual soil loss of Nepal is estimated at 25 t ha−1 yr−1 with a total of 369 million tonnes (mT) of potential soil loss. Soil erosion based on the physiographic region of the country shows that the Middle Mountains, High Mountains, High Himal, Chure, and Terai have mean erosion rates of 38.0, 32.0, 28.0, 7.0, and 0.1 t ha−1 yr−1. The soil erosion rate by basins showed that the annual erosions of the Karnali, Gandaki, Koshi, and Mahakali River basins are 135, 96, 79, and 15 mT, respectively. The mean soil erosion rate was significantly high (34 t ha−1 yr−1) for steep slopes (β > 26.8%) and the low (3 t ha−1 yr−1) for gentle slopes (β < 5%). Based on LULC, the mean erosion rate for barren land was the highest (40 t ha−1 yr−1), followed by agricultural land (29 t ha−1 yr−1), shrubland (25 t ha−1 yr−1), grassland (23 t ha−1 yr−1), and forests (22 t ha−1 yr−1). The entire area had been categorized into 6 erosion classes based on the erosion severity, and 11% of the area was found to be under a very severe erosion risk (> 80 t ha−1 yr−1) that urgently required reducing the risk of erosion.
Digital Preservation of Indigenous Culture and Narratives from the Global South: In Search of an Approach
Authors: Dutta Uttaran
Published: March 2019

This research seeks to digitally preserve cultural histories and artifacts, which are practiced/produced in the underserved indigenous spaces of rural eastern India. This paper is a case study of co-developing Sangraksha—a digital humanities application. The application seeks to facilitate the process of writing history from the below by underrepresented populations at the margins. The villages in this research were geographically remote and socio-economically underdeveloped. The research populations represented individuals who possessed low levels of literacy, limited language proficiency in English and mainstream Indic languages (e.g., Hindi and Bengali), as well as limited familiarity with computers and computing environments. Grounded in long-term ethnographic engagements in the remote Global South, this study explored a range of cultural, aesthetic, and contextual factors that were instrumental in shaping and co-generating digital humanities solutions for under-researched international populations. On one hand, the research initiative sought to co-create a culturally meaningful and welcoming digital environment to make the experience contextually appropriate and user-friendly. On the other hand, grounded in visual and sensory methodologies, this research used community generated imageries and multimedia (audio, photographs and audio-visual) to make the application inclusive and accessible. Moreover, the application-development attempt also paid close attention to intercultural, local-centric, community-driven co-design aspects to make the approach socially-embedded and sustainable in the long term.
Alarming and/or Alerting Device Effectiveness in Reducing Falls in Long-Term Care (LTC) Facilities? A Systematic Review
Authors: Mileski Michael , Brooks Matthew , Topinka Joseph Baar , Hamilton Guy , Land Cleatus , Mitchell Traci , Mosley Brandy , McClay Rebecca
Published: March 2019

Perceptions against the use of alarming devices persist in long-term care environments as they are seen as annoying, costly, and a waste of time to the staff involved. Ascertaining whether these perceptions are true or false via the literature was a focus of this study. Proper information to educate staff and to work past these perceptions can be a positive effector for resident safety. Many facilitators for the use of alarming devices were found, as well as many barriers to their use as well. New technology is changing the perceptions regarding these types of devices as time passes. Education is a key component for staff, residents, and families. There are “traditional” issues with the use of alarms such as alarm fatigue by caregivers, high costs of implementation, and issues with proper implementation of alarms. Alarms are perceived as intrusive and the noise from them can be a potential cause of falls. However, alarming devices can be a key intervention in the safety of those residents who are prone to falls. This requires proper implementation and education for all parties involved, and proper oversight surrounding use of the devices.
Characterization and Adsorption Behavior of Strontium from Aqueous Solutions onto Chitosan-Fuller’s Earth Beads
Authors: Hasan Shameem , Iasir A. Rafi M. , Ghosh Tushar K. , Sen Gupta Bhaskar , Prelas Mark A.
Published: March 2019

Fuller’s earth spherical beads using chitosan as a binder were prepared for the removal of strontium ions from aqueous solution. The adsorbents were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which revealed the porous nature of the beads. The Brunauer–Emmett–Teller (BET) surface area of the beads was found to be 48.5 m2/g. The adsorption capacities of the beads were evaluated under both batch and dynamic conditions. The adsorption capacity was found to be ~29 mg/g of adsorbent at 298 K when the equilibrium concentration of strontium in the solution was 925 mg/L at pH 6.5. The X-ray photoelectron spectroscopy (XPS) data suggest that strontium uptake by the beads occurs mainly through an ion-exchange process. Kinetic data indicate that the sorption of strontium onto the beads follows anomalous diffusion. Thermodynamic data suggest that the ion-exchange of Sr2+ on the bead surface was feasible, spontaneous and endothermic in nature.
Erosion Failure of a Soil Slope by Heavy Rain: Laboratory Investigation and Modified GA Model of Soil Slope Failure
Authors: Jing Xiaofei , Chen Yulong , Pan Changshu , Yin Tianwei , Wang Wensong , Fan Xiaohua
Published: March 2019

Rainfall has been identified as one of the main causes for slope failures in areas where high annual rainfall is experienced. The slope angle is important for its stability during rainfall. This paper aimed to determine the impact of the angle of soil slope on the migration of wetting front in rainfall. The results proved that under the same rainfall condition, more runoff was generated with the increase of slope angle, which resulted in more serious erosion of the soil and the ascent of wetting front. A modified Green-Ampt (GA) model of wetting front was also proposed considering the seepage in the saturated zone and the slope angle. These findings will provide insights into the rainfall-induced failure of soil slopes in terms of angle.
Fluoride Exposure Induces Inhibition of Sodium/Iodide Symporter (NIS) Contributing to Impaired Iodine Absorption and Iodine Deficiency: Molecular Mechanisms of Inhibition and Implications for Public Health
Authors: Waugh Declan Timothy
Published: March 2019

The sodium iodide symporter (NIS) is the plasma membrane glycoprotein that mediates active iodide transport in the thyroid and other tissues, such as the salivary, gastric mucosa, rectal mucosa, bronchial mucosa, placenta and mammary glands. In the thyroid, NIS mediates the uptake and accumulation of iodine and its activity is crucial for the development of the central nervous system and disease prevention. Since the discovery of NIS in 1996, research has further shown that NIS functionality and iodine transport is dependent on the activity of the sodium potassium activated adenosine 5′-triphosphatase pump (Na+, K+-ATPase). In this article, I review the molecular mechanisms by which F inhibits NIS expression and functionality which in turn contributes to impaired iodide absorption, diminished iodide-concentrating ability and iodine deficiency disorders. I discuss how NIS expression and activity is inhibited by thyroglobulin (Tg), tumour necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), interleukin 6 (IL-6) and Interleukin 1 beta (IL-1β), interferon-γ (IFN-γ), insulin like growth factor 1 (IGF-1) and phosphoinositide 3-kinase (PI3K) and how fluoride upregulates expression and activity of these biomarkers. I further describe the crucial role of prolactin and megalin in regulation of NIS expression and iodine homeostasis and the effect of fluoride in down regulating prolactin and megalin expression. Among many other issues, I discuss the potential conflict between public health policies such as water fluoridation and its contribution to iodine deficiency, neurodevelopmental and pathological disorders. Further studies are warranted to examine these associations.
Correction: Akanda, M.R., et al., Anti-Inflammatory and Gastroprotective Roles of Rabdosia inflexa through Downregulation of Pro-Inflammatory Cytokines and MAPK/NF-κB Signaling Pathways. Int. J. Mol. Sci. 2018, 19, 584
Authors: Akanda Md , Kim In-Shik , Ahn Dongchoon , Tae Hyun-Jin , Nam Hyeon-Hwa , Choo Byung-Kil , Kim Kyunghwa , Park Byung-Yong
Published: March 2019

The authors wish to make the following corrections to this paper [...]
Development of a Soy Protein Hydrolysate with an Antihypertensive Effect
Authors: Daliri Eric Banan-Mwine , Ofosu Fred Kwame , Chelliah Ramachandran , Park Mi Houn , Kim Jong-Hak , Oh Deog-Hwan
Published: March 2019

In this study, we combined enzymatic hydrolysis and lactic acid fermentation to generate an antihypertensive product. Soybean protein isolates were first hydrolyzed by Prozyme and subsequently fermented with Lactobacillus rhamnosus EBD1. After fermentation, the in vitro angiotensin-converting enzyme (ACE) inhibitory activity of the product (P-SPI) increased from 60.8 ± 2.0% to 88.24 ± 3.2%, while captopril (a positive control) had an inhibitory activity of 94.20 ± 5.4%. Mass spectrometry revealed the presence of three potent and abundant ACE inhibitory peptides, PPNNNPASPSFSSSS, GPKALPII, and IIRCTGC in P-SPI. Hydrolyzing P-SPI with gastrointestinal proteases did not significantly affect its ACE inhibitory ability. Also, oral administration of P-SPI (200 mg/kg body weight) to spontaneous hypertensive rats (SHRs) for 6 weeks significantly lowered systolic blood pressure (−19 ± 4 mm Hg, p < 0.05) and controlled body weight gain relative to control SHRs that were fed with physiological saline. Overall, P-SPI could be used as an antihypertensive functional food.
Vitamin D Supplementation as Add-on Therapy in Multiple Sclerosis—Balance between Benefit and Risk?: A Commentary on Vitamin D Supplementation in Central Nervous System Demyelinating Disease—Enough Is Enough
Authors: Goischke Hans-Klaus
Published: March 2019

The excellent publication by Häusler and Weber [...]
Oral DhHP-6 for the Treatment of Type 2 Diabetes Mellitus
Authors: Wang Kai , Su Yu , Liang Yuting , Song Yanhui , Wang Liping
Published: March 2019

Type 2 diabetes mellitus (T2DM) is associated with pancreatic β-cell dysfunction which can be induced by oxidative stress. Deuterohemin-βAla-His-Thr-Val-Glu-Lys (DhHP-6) is a microperoxidase mimetic that can scavenge reactive oxygen species (ROS) in vivo. In our previous studies, we demonstrated an increased stability of linear peptides upon their covalent attachment to porphyrins. In this study, we assessed the utility of DhHP-6 as an oral anti-diabetic drug in vitro and in vivo. DhHP-6 showed high resistance to proteolytic degradation in vitro and in vivo. The degraded DhHP-6 product in gastrointestinal (GI) fluid retained the enzymatic activity of DhHP-6, but displayed a higher permeability coefficient. DhHP-6 protected against the cell damage induced by H2O2 and promoted insulin secretion in INS-1 cells. In the T2DM model, DhHP-6 reduced blood glucose levels and facilitated the recovery of blood lipid disorders. DhHP-6 also mitigated both insulin resistance and glucose tolerance. Most importantly, DhHP-6 promoted the recovery of damaged pancreas islets. These findings suggest that DhHP-6 in physiological environments has high stability against enzymatic degradation and maintains enzymatic activity. As DhHP-6 lowered the fasting blood glucose levels of T2DM mice, it thus represents a promising candidate for oral administration and clinical therapy.
Endothelin-1 Induces Mesothelial Mesenchymal Transition and Correlates with Pleural Fibrosis in Tuberculous Pleural Effusions
Authors: Wu Zhung-Han , Tsai Jie-Heng , Hsieh Cheng-Ying , Chen Wei-Lin , Chung Chi-Li
Published: March 2019

Endothelin (ET)-1 is involved in various fibrotic diseases. However, its implication in pleural fibrosis remains unknown. We aimed to study the profibrotic role of ET-1 in tuberculous pleural effusion (TBPE). The pleural effusion ET-1 levels were measured among 68 patients including transudative pleural effusion (TPE, n = 12), parapneumonic pleural effusion (PPE, n = 20), and TBPE (n = 36) groups. Pleural fibrosis, defined as radiological residual pleural thickening (RPT) and shadowing, was measured at 12-month follow-up. Additionally, the effect of ET-1 on mesothelial mesenchymal transition (MMT) and extracellular matrix (ECM) producion in human pleural mesothelial cells (PMCs) was assessed. Our findings revealed that effusion ET-1 levels were significantly higher in TBPE than in TPE and PPE, and were markedly higher in TBPE patients with RPT >10 mm than those with RPT ≤10 mm. ET-1 levels correlated substantially with residual pleural shadowing and independently predicted RPT >10 mm in TBPE. In PMCs, ET-1 time-dependently induced MMT with upregulation of α-smooth muscle actin and downregulation of E-cadherin, and stimulated ECM production; furthermore, ET receptor antagonists effectively abrogated these effects. In conclusion, ET-1 induces MMT and ECM synthesis in human PMCs and correlates with pleural fibrosis in TBPE. This study confers a novel insight into the pathogenesis and potential therapies for fibrotic pleural diseases.
HAMS: A Frequency-Domain Preprocessor for Wave-Structure Interactions—Theory, Development, and Application
Authors: Liu Yingyi
Published: March 2019

This paper presents the theoretical background, the numerical implementation, and the applications of a new software that has been developed in recent years for the analysis of wave-structure interactions. The software is developed in the frequency domain, as a preprocessor of computing the wave excitation force, the added mass, and the wave radiation damping, for the input to a time-domain solver via the Fourier cosine and sine transforms. In addition, it can also predict the motion responses of a marine structure with sufficient accuracy, with or without the presence of a mooring system. Unlike other frequency-domain software, such as WAMIT® and Hydrostar®, the present software currently employs the least squares method in association with a partially extended boundary integral equation method to remove the so-called “irregular frequencies”. Calculation of the free-surface Green’s function employs a combination of fast-convergent series expansions in different parametric sub-regions. The solution of the resultant linear algebraic system employs the lower-upper (LU) decomposition method. Symmetry properties can be exploited, and the open multi-processing (OpenMP) parallelization technique can be applied to reduce the computation burden. The accuracy and the efficiency of the developed software are finally confirmed by numerical validations on three benchmark cases of a floating ellipsoid, a truncated circular cylinder and the OC4 DeepCwind semisubmersible floating wind turbine. A free executable version of the software is available to the research communities with a hope of facilitating the advancements in the researches that are relevant to ocean engineering and marine renewable energies.
Exploring the Nexus between Displacement and Land Administration: The Case of Rwanda
Authors: Todorovski Dimo , Potel Jossam
Published: March 2019

In conflict situations, many people are displaced because of hostility and arms in the area. Displaced people are forced to leave behind their properties, and this in turn interrupts the relationship between people and their land. The emergency period in particular has been identified as a weak point in the humanitarian response to land issues in post-conflict situations. In addition, during this period of response, most post-conflict governments do not prioritize land administration as an emergency issue due to other social, economic, security, and political challenges, which countries face in the immediate aftermath of the conflict. In the longer run, this results in post-conflict illegal land occupation, secondary occupation, numerous disputes and claims over land, and dysfunctional government institutions that legalize these illegal and secondary occupations. This research explores the nexus between displacement and land administration in a post-conflict context. It uses empirical data from fieldwork in Rwanda, and discusses how government interventions in land administration in emergency and early recovery periods of post-conflict situations affect future land administration during the reconstruction phase. The post-conflict Rwandan government envisaged proper land administration as a contributor to sustainable peace and security as it enhances social equity and prevents conflicts. Thus, it embarked on a nationwide systematic land registration program to register land all over the country with the aim of easing land administration practices and reducing successive land-related claims and disputes. However, the program faced many challenges, among which were continuous land claims and disputes. Our research anticipates these continued land claims and disputes are due to how land issues were handled in the emergency and early recovery period of the post-conflict Rwanda, especially during land sharing initiatives and Imidugudu (collective settlement policy).
Comparison between Effects of Retroactivity and Resource Competition upon Change in Downstream Reporter Genes of Synthetic Genetic Circuits
Authors: Moriya Takefumi , Yamaoka Tomohiro , Wakayama Yuki , Ayukawa Shotaro , Zhang Zicong , Yamamura Masayuki , Wakao Shinji , Kiga Daisuke
Published: March 2019

Reporter genes have contributed to advancements in molecular biology. Binding of an upstream regulatory protein to a downstream reporter promoter allows quantification of the activity of the upstream protein produced from the corresponding gene. In studies of synthetic biology, analyses of reporter gene activities ensure control of the cell with synthetic genetic circuits, as achieved using a combination of in silico and in vivo experiments. However, unexpected effects of downstream reporter genes on upstream regulatory genes may interfere with in vivo observations. This phenomenon is termed as retroactivity. Using in silico and in vivo experiments, we found that a different copy number of regulatory protein-binding sites in a downstream gene altered the upstream dynamics, suggesting retroactivity of reporters in this synthetic genetic oscillator. Furthermore, by separating the two sources of retroactivity (titration of the component and competition for degradation), we showed that, in the dual-feedback oscillator, the level of the fluorescent protein reporter competing for degradation with the circuits’ components is important for the stability of the oscillations. Altogether, our results indicate that the selection of reporter promoters using a combination of in silico and in vivo experiments is essential for the advanced design of genetic circuits.
Film Thickness and Shape Evaluation in a Cam-Follower Line Contact with Digital Image Processing
Authors: Ciulli Enrico , Pugliese Giovanni , Fazzolari Francesco
Published: March 2019

Film thickness is the most important parameter of a lubricated contact. Its evaluation in a cam-follower contact is not easy due to the continuous variations of speed, load and geometry during the camshaft rotation. In this work, experimental apparatus with a system for film thickness and shape estimation using optical interferometry, is described. The basic principles of the interferometric techniques and the color spaces used to describe the color components of the fringes of the interference images are reported. Programs for calibration and image analysis, previously developed for point contacts, have been improved and specifically modified for line contacts. The essential steps of the calibration procedure are illustrated. Some experimental interference images obtained with both Hertzian and elastohydrodynamic lubricated cam-follower line contacts are analyzed. The results show program is capable of being used in very different conditions. The methodology developed seems to be promising for a quasi-automatic analysis of large numbers of interference images recorded during camshaft rotation.
Corrosion Resistance of Stainless Steels Intended to Come into Direct or Prolonged Contact with the Skin
Authors: Ziegenhagen Rene , Reclaru Lucien , Ardelean Lavinia Cosmina , Grecu Alexandru Florian
Published: March 2019

The biocompatibility of materials in contact with a living tissue becomes a puzzle in the overall picture of assessing the toxic effects of chemicals that come into contact with us. Allergic reactions to substances are a significant and growing health problem affecting large parts of the population in Europe. Wristwatches are objects worn in prolonged contact with the skin, being subject to localized corrosion, especially pitting and crevice types, in sulfide-chloride medium, and high wear in the bracelets joints. Watches of medium quality are usually made of stainless steels. The X2 CrNiMo 17-12-2 316L grade as well as X1 CrNiMo 20-25-5 Cu 1 or 904L are commonly used, having good resistance to generalized corrosion. The passive layer is nevertheless insufficient to ensure complete immunity in all cases of localized corrosion encountered during wear. For this reason, a high-corrosion-resistant steel: X1 CrNiMo 18-15-4 N 0.15 or 317LMN, from three different suppliers was evaluated. Metallographic characterization was carried out. The corrosion behavior evaluation was performed for the generalized corrosion, pitting and crevice corrosion and galvanic corrosion. Galvanic couples steel 317LMN-gold 18K alloy 3N and gold 18K 5M were used. The results of the generalized and pitting corrosion test indicated three basic groups. All of the 317LMNs were similar. The 316L variants tested noticeably worse. The 904Ls were difficult to discern, but certainly easier than the 316Ls and, possibly, at least comparable to the 317LMNs.
Self-Flushing in EDM Drilling of Ti6Al4V Using Rotating Shaped Electrodes
Authors: Goiogana Manu , Elkaseer Ahmed
Published: March 2019

This article reports an experimental investigation of the efficacy of self-flushing in the Electrical Discharge Machining (EDM) process in terms of tool wear rate (TWR), hole taper angle and material removal rate (MRR). In addition to a plain cylindrical shape, electrodes of different cross sections (slotted cylindrical, sharp-cornered triangular, round-cornered triangular, sharp-cornered square, round-cornered square, sharp-cornered hexagonal and round-cornered hexagonal) were designed as a means of inducing debris egress and then fabricated in graphite. EDM drilling trials using the rotating shaped electrodes were carried out on a Ti6Al4V workpiece. The results revealed that, although a low TWR and minimum hole taper angle were achieved using a plain cylindrical electrode, the usage of rotating shaped electrodes provided self-flushing of the dielectric fluid during the EDM process, which led to an improvement in MRR compared to that achieved with a plain cylindrical electrode. Besides, in general, the electrodes with rounded corners are associated with a lower TWR, a lower hole taper angle and a higher MRR when compared to the electrodes with sharp corners. Considering these results, it was concluded that different process attributes, i.e., TWR, hole taper angle and MRR, are all greatly affected by the electrode shape, and thus, the proper selection of the electrode shape is a precondition to attain a specific response from the EDM process.
Thermal, Mechanical, Viscoelastic and Morphological Properties of Poly(lactic acid) based Biocomposites with Potato Pulp Powder Treated with Waxes
Authors: Righetti Maria Cristina , Cinelli Patrizia , Mallegni Norma , Massa Carlo Andrea , Aliotta Laura , Lazzeri Andrea
Published: March 2019

The thermal, mechanical and viscoelastic properties of biocomposites of poly(lactic acid) (PLA) with 20 wt.% of potato pulp powder were investigated. The potato pulp powder utilized is a byproduct from the production and extraction of starch. The results showed that the potato pulp powder does not act as reinforcement, but as filler for PLA, due to an unfavorable aspect ratio and the irregular shape of the particles. In order to improve the mechanical response of the PLA/potato pulp powder biocomposites, surface treatment of the potato pulp particles with bio-based and petroleum-based waxes was investigated. This treatment was found to improve the properties of the biocomposites, enhancing the adhesion between the PLA based polymeric matrix and the potato pulp fibers. The best result is obtained with a petroleum-based wax, but also the bio-based waxes lead to good mechanical properties of the biocomposite. Thus, the addition to PLA of potato pulp powder, treated with waxes, appears a method able to (i) utilize and valorize an abundant agro-food biomass such as potato pulp, according to the principles of circular economy, (ii) favor the production of articles with properties valuable for practical applications, and (iii) reduce the cost of the final products, considering the relatively high cost of PLA.