bluuebunny/crossref_metadata_2025 huggingface dataset:
Irrigation Water Quality and Soil Structural Stability: A Perspective with Some New Insights
Authors: Rengasamy Pichu
Published: May 2018

The sustainability of irrigated agriculture depends on the quality of irrigation water used. The electrolyte concentration (EC) of irrigation water may lead to the accumulation of salts in the root zone layers and affect the physiological functions of the crop by osmotic and ion toxicity effects. Further, the cationic and anionic composition of the water may alter the exchangeable cation composition of the soil as well as its pH. Because of the dominance of sodium salts in many sources of irrigation water, parameters related to sodium such as exchangeable sodium percentage (ESP) of soils and sodium adsorption ratio (SAR) of soil solutions have been commonly used to study the effects of sodium in irrigation water on soil structural stability. Quirk and Schofield’s concept of ‘threshold electrolyte concentration’ (TEC) has shown the importance of electrolytes in preventing the effects of sodium on soil structure. Based on this concept, several models have been proposed to relate ESP or SAR with EC to predict the possible impacts of irrigation water on soil structural stability. However, many research reports indicate that this relationship varies with soils, and a given model is not suitable for all types of soils. Further, the effects of potassium and magnesium in the processes leading to clay dispersion are disregarded in these models. This essay analyses all the factors involved in the structural failure of soils with different cationic composition, identifies the defects in these TEC models, and re-defines TEC on the basis of new insights on dispersive and flocculating charges of soils. This review does not deal with EC effects on crops nor the role of contaminant ions not involved with soil structural stability.
Selenium-Dependent Antioxidant Enzymes: Actions and Properties of Selenoproteins
Authors: Zoidis Evangelos , Seremelis Isidoros , Kontopoulos Nikolaos , Danezis Georgios
Published: May 2018

Unlike other essential trace elements that interact with proteins in the form of cofactors, selenium (Se) becomes co-translationally incorporated into the polypeptide chain as part of 21st naturally occurring amino acid, selenocysteine (Sec), encoded by the UGA codon. Any protein that includes Sec in its polypeptide chain is defined as selenoprotein. Members of the selenoproteins family exert various functions and their synthesis depends on specific cofactors and on dietary Se. The Se intake in productive animals such as chickens affect nutrient utilization, production performances, antioxidative status and responses of the immune system. Although several functions of selenoproteins are unknown, many disorders are related to alterations in selenoprotein expression or activity. Selenium insufficiency and polymorphisms or mutations in selenoproteins’ genes and synthesis cofactors are involved in the pathophysiology of many diseases, including cardiovascular disorders, immune dysfunctions, cancer, muscle and bone disorders, endocrine functions and neurological disorders. Finally, heavy metal poisoning decreases mRNA levels of selenoproteins and increases mRNA levels of inflammatory factors, underlying the antagonistic effect of Se. This review is an update on Se dependent antioxidant enzymes, presenting the current state of the art and is focusing on results obtained mainly in chicken.
Similarity Estimation for Large-Scale Human Action Video Data on Spark
Authors: Xu Weihua , Uddin Md , Dolgorsuren Batjargal , Akhond Mostafijur , Khan Kifayat , Hossain Md , Lee Young-Koo
Published: May 2018

The amount of human action video data is increasing rapidly due to the growth of multimedia data, which increases the problem of how to process the large number of human action videos efficiently. Therefore, we devise a novel approach for human action similarity estimation in the distributed environment. The efficiency of human action similarity estimation depends on feature descriptors. Existing feature descriptors such as Local Binary Pattern and Local Ternary Pattern can only extract texture information but cannot obtain the object shape information. To resolve this, we introduce a new feature descriptor, namely Edge based Local Pattern descriptor (ELP). ELP can extract object shape information besides texture information and ELP can also deal with intensity fluctuations. Moreover, we explore Apache Spark to perform feature extraction in the distributed environment. Finally, we present an empirical scalability evaluation of the task of extracting features from video datasets.
Evaluation of the Change in Undrained Shear Strength in Cohesive Soils due to Principal Stress Rotation Using an Artificial Neural Network
Authors: Wrzesiński Grzegorz , Sulewska Maria , Lechowicz Zbigniew
Published: May 2018

This paper presents a method describing the application of artificial neural networks to evaluate the change in undrained shear strength in cohesive soils due to principal stress rotation. For analysis, the results of torsional shear hollow cylinder (TSHC) tests were used. An artificial neural network with an architecture of 7–6–1 was able to predict the real value of normalized undrained shear strength, τfu/σ’v, based on soil type, over-consolidation ratio (OCR), plasticity index, IP, and the angle of principal stress rotation, α, with an average relative error of around ±3%, and a single maximum value of relative error around 6%.
Empirical Evaluation of Rock Mass Rating and Tunneling Quality Index System for Tunnel Support Design
Authors: Rehman Hafeezur , Naji Abdul , Kim Jung-joo , Yoo Han-Kyu
Published: May 2018

The primary output of the rock mass rating (RMR) and tunneling quality index (Q) system is a preliminary tunnel support design, as these methods are empirically developed and updated for this purpose. In this study, these internationally accepted design tools are evaluated to improve results for tunnel support design. The rating system is simplified and improved for some parameters through the use of equations to replace the discrete/lump characterization with a continuous rating. Recent developments in characterization and support are used in proposing the back analysis approach of rock mass quality calculation from tunnel span and installed support. This approach is used for two tunnel projects which experience high stresses. Approximately 90% of the tunnel sections show that actual supports have rock bolt spacing and shotcrete thickness which are heavier than those indicated by RMR89, indicating a system limitation. Another assessment using RMR14 indicates that its rating is higher than that of RMR89. A strong correlation exists between them, as supported by the literature and data from analyses of 462 tunnel sections. Despite its new version, RMR89 still preserves its importance. Evaluating the different correlations between RMR and Q through published data indicates that the rock mass fabric index gives comparatively better results.
A New Approach to Privacy-Preserving Multiple Independent Data Publishing
Authors: Hasan A S M Touhidul , Jiang Qingshan , Chen Hui , Wang Shengrui
Published: May 2018

We study the problem of privacy preservation in multiple independent data publishing. An attack on personal privacy which uses independent datasets is called a composition attack. For example, a patient might have visited two hospitals for the same disease, and his information is independently anonymized and distributed by the two hospitals. Much of the published work makes use of techniques that reduce data utility as the price of preventing composition attacks on published datasets. In this paper, we propose an innovative approach to protecting published datasets from composition attack. Our cell generalization approach increases both protection of individual privacy from composition attack and data utility. Experimental results show that our approach can preserve more data utility than the existing methods.
Generation of Ultrashort Optical Pulses in the Deep-Ultraviolet Region Based on Four-Wave Raman Mixing
Authors: Mori Yoshifumi , Imasaka Totaro
Published: May 2018

A two-color pump beam (800 and 1200 nm) was introduced into hydrogen for molecular phase modulation, and a probe beam (267 nm) to generate Raman sidebands, by coherent frequency modulation based on four-wave Raman mixing. The phase and temporal profile were evaluated by means of a self-diffraction frequency resolved optical gating (SD FROG) system. The relative phases among the Raman sidebands were controlled by changing the angle of a thin CaF2-plate inserted into the 267-nm beam path, suggesting that a train of 2.6-fs pulses was generated in the deep-ultraviolet region.
Efficiently Answering Reachability Queries for Tree-Structured Data in Repetitive Prime Number Labeling Schemes
Authors: Ahn Jinhyun , Lee Taewhi , Im Dong-Hyuk
Published: May 2018

Reachability queries plays a crucial role in accessing relationships between nodes in tree-structured data. Previous studies have proposed prime number labeling schemes that answer reachability queries using arithmetic operations. However, the prime numbers in these schemes can become very large when a tree contains a considerable number of nodes; thus, it is not scalable. Recently, a repetitive prime number labeling scheme that reduces space requirements was proposed. Unfortunately, it suffers from slow query processing, owing to the complexity of its reachability test. In this paper, we propose a more efficient method for answering reachability queries in a repetitive prime number labeling scheme. The results of experiments using real-world XML datasets show that our approach reduces reachability query processing times.
Nanostructured Composites of Sodium Montmorillonite Clay and PEO Used in Dissolution Improvement of Aprepitant Drug by Melt Mixing
Authors: Pappa Christina , Nanaki Stavroula , Giliopoulos Dimitrios , Triantafyllidis Konstantinos , Kostoglou Margaritis , Avgeropoulos Apostolos , Bikiaris Dimitrios
Published: May 2018

In this work, aprepitant (APR) was loaded in a high-molecular-weight poly(ethylene oxide) (PEO) and PEO/clay nanocomposites via the melt-mixing process in order to investigate the combined effect of the PEO and PEO/clay phases on the dissolution profile of APR. Various drug (5, 10, 20 wt %) and Cloisite-Na+ microgranuled nanoclay (5 and 10 wt %) loadings were used for the preparation of the solid dispersions using a twin screw melt mixer at temperatures below the drug’s melting point. X-ray diffraction (XRD) and infrared (FTIR) data of the prepared formulations confirmed that the semicrystalline structure of the PEO and the structure of APR have remained intact. The PEO chain intercalation in the intragallery space between the clay nanolayers was also confirmed by XRD, especially in the APR/PEO formulations containing 5 wt % microgranuled nanoclay. The in vitro release study demonstrated that in all formulations, the dissolution rate of APR was substantially enhanced compared to neat drug. Immediate release formulations have been prepared, and the combination of PEO/5 wt % clay nanocomposite phase with 5 or 10 wt % drug loading gives much higher maximum dissolution (reaching 98 and 85%, respectively) compared to the neat drug (40%). This improved performance was attributed to the highly intercalated/exfoliated state of clay nanolayers in the APR/PEO/5 wt % clay formulations. A model was also investigated to explain the physical mechanism of drug release in all formulations.
Inherent Properties of Smart Tensegrity Structures
Authors: Al Sabouni-Zawadzka Anna , Gilewski Wojciech
Published: May 2018

The present paper discusses different aspects of the structural control of smart systems with a focus on tensegrity structures. Special attention is paid to unique features of tensegrity systems, referred to by the authors as inherent, which are induced by infinitesimal mechanisms that are balanced with self-stress states. The following inherent properties are defined: self-control, self-diagnosis, self-repair and self-adjustment (active control). All these features are thoroughly described and illustrated on a series of analyses performed on numerical models of various tensegrity systems. The presented examples of the analyses of different tensegrity modules and multi-module structures show that it is possible to control their properties by adjusting the pre-stressing forces. Moreover, it is proven that the adjustment of self-stress forces in a tensegrity system allows one to repair the damaged structure by compensating the damaged member.
CFD Simulations of Flows in a Wind Farm in Complex Terrain and Comparisons to Measurements
Authors: Sessarego Matias , Shen Wen Zhong , Van der Laan Maarten Paul , Hansen Kurt Schaldemose , Zhu Wei Jun
Published: May 2018

This article describes Computational Fluid Dynamics (CFD) simulations of flows in a wind farm in complex terrain in Shaanxi, China and the comparisons of the computational results with utility scale field measurements. The CFD simulations performed in the study are using either a Reynolds-Averaged Navier–Stokes (RANS) or Large-Eddy Simulation (LES) solver. The RANS method together with an Actuator Disc (AD) approach is employed to predict the performance of the 25 wind turbines in the farm, while the LES and Actuator Line (AL) technique is used to obtain a detailed description of the flow field around a specific wind turbine #14 near two met masts. The AD-RANS simulation results are compared with the mean values of power obtained from field measurements. Furthermore, the AL-LES results are compared with the mean values of power, rotor speed, and wind speed measured from the wind turbine and its nearby two masts. Results from the simulations indicate that both AD-RANS and AL-LES methods can reasonably predict the performance of the wind farm and wind turbine #14, respectively, in complex terrain in Shaanxi. The mean percent difference obtained for power in the AD-RANS simulations was approximately 20%. Percent differences obtained for power and rotor RPM in the AL-LES varied between 0.08% and 11.6%. The mean percent differences in the AL-LES for power and rotor RPM are approximately 7% and 1%, respectively.
Two-Stage Strategy for CO Removal from H2-Rich Streams over (Nano-) CuO/CeO2 Structured Catalyst at Low Temperature
Authors: Landi Gianluca , Di Benedetto Almerinda , Lisi Luciana
Published: May 2018

Proton exchange membrane (PEM) fuel cells represent one of the most interesting systems for converting hydrogen from fossil or renewable fuels into electric power at low temperature. To prevent poisoning of fuel cell anodes, CO concentration has to be reduced to 10–100 ppm. To this aim, the preliminary catalytic preferential oxidation of CO may be used, provided that the catalyst effectively oxidizes CO, limiting as much as possible the oxidation of H2. Presently, both high selectivity and CO conversion cannot be simultaneously achieved. In this work, a novel strategy for CO removal from H2-rich streams based on a CuO/CeO2 reactive trap is proposed, exploiting both catalytic and adsorption properties of this material. The process occurs in two stages. In the first stage, one reactor, fed with a CO-containing stream, works as a CO-reactive adsorber, providing a CO-free mixture. In the second stage, the adsorbed CO is converted to CO2 by O2. By this approach it is possible to simultaneously get CO lower than the limiting value and avoid any H2 oxidation with no O2 in the feed stream to PEM. Experimental tests allowed the evaluation of the kinetic parameters of all the reaction mechanism steps. Model simulations were performed at varying operating parameters, showing that the positive effect of high contact times and low CO inlet concentration is significantly affected by the non-linear behavior of the CO reactive adsorption.
Automatic Selection of Low-Permeability Sandstone Acoustic Emission Feature Parameters and Its Application in Moisture Identification
Authors: Tao Kai , Zheng Wei
Published: May 2018

Moisture is a vital factor in the structural stability of sandstone, which is the main component of low-permeability reservoir rocks. Hence, studies into moisture identification are crucial. Diverse information about rock, such as its structural and mechanical parameters, can be obtained from the acoustic emission (AE) signal. However, the types of AE parameters are varied, and the rock information that is represented by them is different. Traditional methods of parameter selection are mostly based on the correlation between parameters and the experience of researchers, which are not accurate when the correlation between parameters is fuzzy and does not meet automation requirements. In this study, a method of signal feature selection based on a data fluctuation rule and clustering analysis is proposed. This method takes the fluctuation law of the signal itself and the correlation degree of cluster labels as the basis, and the selection step is divided into two steps. An experimental platform is established, and uniaxial compression on sandstones with different moisture contents is carried out to verify the efficiency of this method. The selected feature parameters are used for moisture classification combined with a support vector machine (SVM) classifier, and the identification results verify the efficiency of energy security monitoring in low-permeability rocks.
Extreme Precipitation Events in Serbia: Defining the Threshold Criteria for Emergency Preparedness
Authors: Anđelković Goran , Jovanović Slavoljub , Manojlović Sanja , Samardžić Ivan , Živković Ljiljana , Šabić Dejan , Gatarić Dragica , Džinović Milanka
Published: May 2018

Considering recent weather events in Serbia (especially the floods in 2014), a need has arisen for research that would help in identifying extreme weather phenomena. Therefore, the aim of this paper is to determine the thresholds above which intense precipitation can be considered as extreme precipitation events in Serbia. In this study, we determined the frequency of precipitation occurring at an intensity above the threshold of an extreme phenomenon (1961–2015), as well as the frequency of precipitation occurring at or above the absolute daily maximum in the reference period (1961–1990). The study sample included daily rainfall observations from 28 stations from the national meteorological network in Serbia. Applying a decile method, all the stations recording precipitation above the threshold of dangerous phenomena on the same day are classified into the corresponding decile. The threshold value was determined as the average value of the extreme annual precipitation in the analyzed period. The cases that are due to the high prevalence listed in the last decile are considered extreme. The results showed that the critical number of observation points above which an event is considered extreme precipitation event is 6.21, and a warning of the danger could be ensured only in the case of neighboring stations in the network. The threshold of extreme precipitation events for the individual stations ranges up to 130 mm. The obtained results might be used to mitigate the effects of extreme precipitation events in Serbia in the future.
Decision-Making with Bipolar Neutrosophic TOPSIS and Bipolar Neutrosophic ELECTRE-I
Authors: Akram Muhammad , Shumaiza  , Smarandache Florentin
Published: May 2018

Technique for the order of preference by similarity to ideal solution (TOPSIS) and elimination and choice translating reality (ELECTRE) are widely used methods to solve multi-criteria decision making problems. In this research article, we present bipolar neutrosophic TOPSIS method and bipolar neutrosophic ELECTRE-I method to solve such problems. We use the revised closeness degree to rank the alternatives in our bipolar neutrosophic TOPSIS method. We describe bipolar neutrosophic TOPSIS method and bipolar neutrosophic ELECTRE-I method by flow charts. We solve numerical examples by proposed methods. We also give a comparison of these methods.
Hypoxia, Metabolism and Immune Cell Function
Authors: Krzywinska Ewelina , Stockmann Christian
Published: May 2018

Hypoxia is a hallmark of inflamed, infected or damaged tissue, and the adaptation to inadequate tissue oxygenation is regulated by hypoxia-inducible factors (HIFs). HIFs are key mediators of the cellular response to hypoxia, but they are also associated with pathological stress such as inflammation, bacteriological infection or cancer. In addition, HIFs are central regulators of many innate and adaptive immunological functions, including migration, antigen presentation, production of cytokines and antimicrobial peptides, phagocytosis as well as cellular metabolic reprogramming. A characteristic feature of immune cells is their ability to infiltrate and operate in tissues with low level of nutrients and oxygen. The objective of this article is to discuss the role of HIFs in the function of innate and adaptive immune cells in hypoxia, with a focus on how hypoxia modulates immunometabolism.
Nanocomposite-Based Aminated Polyethersulfone and Carboxylate Activated Carbon for Environmental Application. A Real Sample Analysis
Authors: Alenazi Noof , Hussein Mahmoud , Alamry Khalid , Asiri Abdullah
Published: May 2018

Aminated polyethersulfone (PES–NH2) has been synthesized and used with carboxylated activated carbon (AC–COOH) as an adsorbent using two different methods: in situ and ex situ techniques. The chemical modification of polyethersulfone (PES) to introduce –NH2 functions was used to overcome the hydrophobicity of PES which maximizes its use in water treatment applications whereas applying AC–COOH to this polymer provides a promising effective method as an adsorbent-separation technique to remove dye pollutants from wastewater. The structure and characterization of aminated polyethersulfone with carboxylated activated carbon (PES–NH2–AC–COOH) were identified using proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared (FT-IR spectroscopy), X-ray diffraction (XRD), thermal analysis (TA), and a scanning electron microscopy (SEM). The performance of PES–NH2 in situ and ex situ with AC–COOH was tested for the adsorption of cationic (methylene blue) and anionic (acid red 1) dyes from an aquatic environment. The results of the study showed a better thermal stability for the PES–NH2 with 20% AC–COOH with both in situ and ex situ techniques as well as an excellent adsorption performance in comparison with the bare PES–NH2. The resultant polymers displayed significantly high adsorption rates for the acid red dye (60% and 68%) and methylene blue dye (61% and 88%) by PES–NH2 with AC–COOH using in situ and ex situ techniques, respectively, in comparison with the control (PES–NH2) which showed lower adsorption rates for both dyes (21% for acid red and 33% for methylene blue). Lastly, the study experimental measurements found the most suitable model to describe the kinetic behavior of the acid red dye adsorption by our developed polymer (by PES–NH2 with AC–COOH) to be the pseudo-second-order kinetic model.
Total Synthesis and Biological Evaluation of Phaeosphaerides
Authors: Kobayashi Kenichi , Tanaka Kosaku , Kogen Hiroshi
Published: May 2018

This article reviews studies regarding the total synthesis of phaeosphaerides A and B, nitrogen-containing bicyclic natural products isolated from an endophytic fungus. Numerous synthetic efforts and an X-ray crystal structure analysis of phaeosphaeride A have enabled revision of its originally proposed structure. In addition, a successful protic acid-mediated transformation of phaeosphaeride A to phaeosphaeride B revealed the hypothetical biosynthesis of phaeosphaeride B from phaeosphaeride A. Structure–activity relationship studies of phaeosphaeride derivatives are also discussed.
Improved CO-PROX Performance of CuO/CeO2 Catalysts by Using Nanometric Ceria as Support
Authors: Di Benedetto Almerinda , Landi Gianluca , Lisi Luciana
Published: May 2018

Despite of the huge number of papers about the catalytic preferential oxidation of CO (CO-PROX) for the purification of H2 streams, there is still a need for more effective catalysts in order to reduce the large required catalyst volume of CO-PROX unity. In this work, large surface area nanometric ceria was used as support for CuO/CeO2 catalysts with CuO load up to 10 wt % easily dispersed by wet impregnation. Catalysts were characterized by ICP-MS, XRD, SEM/EDS, N2 physisorption, H2 temperature programmed reduction (TPR), and CO2 temperature programmed desorption (TPD) and tested under different reaction conditions (including under feed containing inhibiting species such as CO2 and H2O). Catalytic tests revealed that our samples show high activity and selectivity even under stringent reaction conditions; moreover, they result among the most active catalysts when compared to those reported in the scientific literature. The high activity can be related to the enhanced amount of highly dispersed copper sites in strong interaction with ceria related to the nature of the nanometric support, as evidenced by the characterization techniques. Despite the high concentration of active copper sites, catalytic performance is limited by CO2 desorption from ceria in the neighborhood of copper sites, which prevents a further improvement. This suggests that new catalyst formulations should also provide a lower affinity towards CO2.
Influence of Lamellar Interface Morphology on Cracking Resistance of Plasma-Sprayed YSZ Coatings
Authors: Huang Jibo , Wang Weize , Lu Xiang , Liu Shaowu , Li Chaoxiong
Published: May 2018

Splat morphology is an important factor that influences the mechanical properties and durability of thermal barrier coatings (TBCs). In this study, yttria-stabilized zirconia (YSZ) coatings with different lamellar interface morphologies were deposited by atmospheric plasma spraying (APS) using feedstocks with different particle sizes. The influence of lamellar interface roughness on the cracking resistance of the coatings was investigated. Furthermore, the thermal shock and erosion resistance of coatings deposited by two different powders was evaluated. It was found that the particle size of the feedstock powder affects the stacking morphology of the splat that forms the coating. Coatings fabricated from coarse YSZ powders (45–60 μm) show a relatively rough inter-lamellar surface, with a roughness about 3 times greater than those faricated from fine powders (15–25 μm). Coatings prepared with fine powders tend to form large cracks parallel to the substrate direction under indentation, while no cracking phenomena were found in coatings prepared with coarse powders. Due to the higher cracking resistance, coatings prepared with coarse powders show better thermal shock and erosion resistances than those with fine powders. The results of this study provide a reference for the design and optimization of the microstructure of TBCs.
Hardware-Assisted Secure Communication in Embedded and Multi-Core Computing Systems
Authors: Saeed Ahmed , Ahmadinia Ali , Just Mike
Published: May 2018

With the sharp rise of functionalities and connectivities in multi-core embedded systems, these systems have become notably vulnerable to security attacks. Conventional software security mechanisms fail to deliver full safety and also affect the system performance significantly. In this paper, a hardware-based security procedure is proposed to handle critical information in real-time through comprehensive separation without needing any help from the software. To evaluate the proposed system, an authentication system based on an image procession solution has been implemented on a reconfigurable device. In addition, the proposed security mechanism is evaluated for the Networks-on-chips, where minimal area, power consumption and performance overheads are achieved.
Ants in Australia’s Monsoonal Tropics: CO1 Barcoding Reveals Extensive Unrecognised Diversity
Authors: Oberprieler Stefanie , Andersen Alan , Moritz Craig
Published: May 2018

The Australian monsoonal tropics (AMT) is a significant biodiversity hotspot, and recent genetic studies of several vertebrate groups have revealed its level of diversity is far higher than previously thought. However, the extent to which this applies to the AMT’s insect fauna, which represents most AMT faunal species, remains unknown. Here we examine the extent of unrecognised diversity in the AMT’s ecologically dominant insect group, ants. We used CO1 barcoding in combination with morphological variation and geographic distribution to explore diversity within seven taxa currently recognised as single species occurring throughout the AMT: one species of Papyrius Shattuck 1992, one of Iridomyrmex Mayr 1862, two from the Cardiocondyla nuda (Mayr 1866) group, and three from the Camponotus novaehollandiae (Mayr 1870) group. We found six of the seven target species each to represent several species, based on a combination of CO1 divergence (ranging up to 13%), morphological differentiation and geographic distribution. Our findings indicate that the levels of diversity and endemism of the AMT ant fauna are far higher than currently realised. We urge the need for further research in insect biodiversity in the AMT, both for a better understanding of the evolution of its remarkable biota, and as a basis for improved conservation planning.
Zika Virus and the Risk for Renter Households
Authors: Scarbrough Amanda , Rathnasekara Heranga , Holt Melinda , Hill Jack , Kafle Ram
Published: May 2018

Recent research on family income indicates that a lack of economic stability can affect healthy housing. Those with limited resources experience higher rates of inadequate and unstable housing many times forcing them to live in undesirable communities in which there can be several community-level health-related issues. One community-level health-related factor of concern has been the reemergence of Zika virus. Some research has indicated that a higher risk of catching Zika virus may exist in neighborhoods and areas with unhealthy housing. Therefore, this study sought to explore the existence of a relationship between rental housing and the Zika virus. Our findings indicated a significant correlation existed between renter occupied household units and the presence of Zika virus. This finding is notable as it indicates that renters have a higher chance of contracting Zika virus than non-renters. Future research should further examine the demographic and housing situation in other communities reporting cases of the Zika virus.
Adhesion Control Strategy Based on the Wheel-Rail Adhesion State Observation for High-Speed Trains
Authors: Fang Xiaochun , Lin Shuai , Yang Zhongping , Lin Fei , Sun Hu , Hu Liang
Published: May 2018

In this paper, an adhesion control strategy based on the wheel-rail adhesion state observation is proposed for high-speed trains. First, the high-speed train single axle dynamics model is established. Then, a modified adhesion control method is proposed. The scheme observes the tangential force coefficient between wheel and rail through full dimension observer and forecasts the slope of the adhesion-slip curve by the recursive least squares method with forgetting factor. Meanwhile, a feasibility analysis of the method and the control parameters tuning is conducted. Afterwards, the experimental study of the proposed adhesion control is carried out based on a 5.5 kW induction motor drag platform using dSPACE simulation technology. The experimental results confirm the feasibility of the adhesion control method proposed in this paper. Using the proposed adhesion control method can achieve high wheel-rail adhesion performance under variable complex road conditions.
Review on Health Management System for Lithium-Ion Batteries of Electric Vehicles
Authors: Omariba Zachary , Zhang Lijun , Sun Dongbai
Published: May 2018

The battery is the most ideal power source of the twenty-first century, and has a bright future in many applications, such as portable consumer electronics, electric vehicles (EVs), military and aerospace systems, and power storage for renewable energy sources, because of its many advantages that make it the most promising technology. EVs are viewed as one of the novel solutions to land transport systems, as they reduce overdependence on fossil energy. With the current growth of EVs, it calls for innovative ways of supplementing EVs power, as overdependence on electric power may add to expensive loads on the power grid. However lithium-ion batteries (LIBs) for EVs have high capacity, and large serial/parallel numbers, when coupled with problems like safety, durability, uniformity, and cost imposes limitations on the wide application of lithium-ion batteries in EVs. These LIBs face a major challenge of battery life, which research has shown can be extended by cell balancing. The common areas under which these batteries operate with safety and reliability require the effective control and management of battery health systems. A great deal of research is being carried out to see that this technology does not lead to failure in the applications, as its failure may lead to catastrophes or lessen performance. This paper, through an analytical review of the literature, gives a brief introduction to battery management system (BMS), opportunities, and challenges, and provides a future research agenda on battery health management. With issues raised in this review paper, further exploration is essential.
Nonlinear Modeling and Dynamic Analyses of the Hydro–Turbine Governing System in the Load Shedding Transient Regime
Authors: Yan Donglin , Wang Weiyu , Chen Qijuan
Published: May 2018

Load shedding processes are widespread in hydropower stations, which has great influence on the safe and stable operation of the hydro–turbine governing system. In order to study the dynamic characteristics of the hydro–turbine governing system during the load shedding process, a novel nonlinear mathematical model of the hydro–turbine governing system is established considering the hydro–turbine system, the generator system and the governor system. In particular, a novel nonlinear mathematical model of the six hydro–turbine transfer coefficients is presented based on the definitions and hydro–turbine internal characteristics. After that, from the viewpoint of nonlinear dynamics and the practical engineering, the dynamic characteristics of the hydro–turbine governing system are investigated utilizing bifurcation diagrams, time series, Poincare maps, power spectrums and phase planes. Some meaningful results are found. The advantages of the novel nonlinear mathematical model are illustrated and commented in detail in comparison with the previous model. Finally, these models and analysis results will provide some theoretical references for the operation of hydropower stations in the load shedding transient.
Ocean Wave Energy Converters: Status and Challenges
Authors: Aderinto Tunde , Li Hua
Published: May 2018

Wave energy is substantial as a resource, and its potential to significantly contribute to the existing energy mix has been identified. However, the commercial utilization of wave energy is still very low. This paper reviewed the background of wave energy harvesting technology, its evolution, and the present status of the industry. By covering the theoretical formulations, wave resource characterization methods, hydrodynamics of wave interaction with the wave energy converter, and the power take-off and electrical systems, different challenges were identified and discussed. Solutions were suggested while discussing the challenges in order to increase awareness and investment in wave energy industry as a whole.
Network Performance Optimization for Low-Voltage Power Line Communications
Authors: Cui Ying , Liu Xiaosheng , Cao Jian , Xu Dianguo
Published: May 2018

Low-voltage power line communication (LVPLC) medium access control protocols significantly affect home area networks performance. This study addresses poor network performance issues caused by asymmetric channels and noise interference by proposing the following: (i) an improved Q learning method for optimizing the improved artificial LVPLC cobweb, wherein the learning-based hybrid time-division-multiple-access (TDMA)/carrier-sense-multiple-access (CSMA) protocol, the asymmetrical network system, is modeled as a discrete Markov decision process, associates the station information using online trial-and-error learning, builds a routing table, periodically studies stations to choose a better forward path, and optimizes the shortest backbone cluster tree between the central coordinator and the stations, guaranteeing network stability; and (ii) an improved adaptive p-persistent CSMA game optimization method is proposed to optimize the improved artificial cobweb saturation throughput and access delay performance. The current state of the game (e.g., the number of competitive stations) for each station is estimated by the hidden Markov model. The station changes its equilibrium strategy based on the estimated number of active stations, which reduces the collision probability of data packets, optimizes channel transmission status, and increases performance by dynamically adjusting the probability p. An optimal saturation performance is achieved by finitely repeating the game. We present numerical results to validate our proposed approach.
Dynamic Modeling and Analysis of PCM-Controlled DCM-Operating Buck Converters—A Reexamination
Authors: Suntio Teuvo
Published: May 2018

Peak-current-mode (PCM) control was proposed in 1978. The observed peculiar behavior caused by the application of PCM-control in the behavior of a switched-mode converter, which operates in continuous conduction mode (CCM), has led to a multitude of attempts to capture the dynamics associated to it. Only a few similar models have been published for a PCM-controlled converter, which operates in discontinuous conduction mode (DCM). PCM modeling is actually an extension of the modeling of direct-duty-ratio (DDR) or voltage-mode (VM) control, where the perturbed duty ratio is replaced by proper duty-ratio constraints. The modeling technique, which produces accurate PCM models in DCM, is developed in early 2000s. The given small-signal models are, however, load-resistor affected, which hides the real dynamic behavior of the associated converter. The objectives of this paper are as follows: (i) proving the accuracy of the modeling method published in 2001, (ii) performing a comprehensive dynamic analysis in order to reveal the real dynamics of the buck converter under PCM control in DCM, (iii) providing a method to improve the high-frequency accuracy of the small-signal models, and (iv) developing control-engineering-type block diagrams to facilitate the development of generalized transfer functions, which are applicable for PCM-controlled DCM-operated buck, boost, and buck-boost converters.
Detecting and Attributing Drivers of Forest Disturbance in the Colombian Andes Using Landsat Time-Series
Authors: Murillo-Sandoval Paulo , Hilker Thomas , Krawchuk Meg , Van Den Hoek Jamon
Published: May 2018

The Colombian Andes foothills have seen an expansion of forest disturbance since the 1950s. While understanding the drivers of disturbance is important for quantifying the implications of land use change on regional biodiversity, methods for attributing disturbance to specific drivers of change at a high temporal and spatial resolution are still lacking in the Andes region, in part due to persistent cloud cover. Using 20 years of Landsat images (1996–2015) covering Picachos National Park in the Colombian Andes, we detected sub-annual forest cover disturbances using the Breaks For Additive Season and Trend (BFAST) Monitor algorithm; characterized different types of disturbance using spectral, spatial, and topographic indicators; and attributed causes of forest disturbance such as conversion to pasture, conversion to agriculture, and non-stand replacing disturbance (i.e., thinning) using a Random Forest (RF) classifier. Conversion to pasture has been the main driver of forest disturbance in Picachos, responsible for 11,395 ± 72 ha (17%) of forest cover loss, followed by non-stand replacing disturbance and conversion to agriculture. Disturbance detection had 96% overall agreement with validation data, although we had a high omission error of 21% primarily associated with forest to agriculture conversion. Other change drivers had a much more reliable attribution with forest to pasture conversion or non-stand-replacing disturbance, showing only 1–5% commission and 2–14% omission errors. Our results provide spatially-explicit information on sub-annual disturbances and associated drivers of change that are necessary for evaluating and improving domestic conservation efforts and establishing systematic ecological observations, which is currently absent from Colombia. While effective at revealing forest change dynamics in a geographically remote and socio-politically complex region like Picachos, our approach is highly automated and it can be easily extended to the rest of Andes-Amazon transition belt where low availability of remote sensing data and high cloud cover impede efforts at consistent monitoring of forest cover change dynamics and drivers.
Environmentally Sustainable Flame Retardant Surface Treatments for Textiles: The Potential of a Novel Atmospheric Plasma/UV Laser Technology
Authors: Horrocks A. , Eivazi Sara , Ayesh Maram , Kandola Baljinder
Published: May 2018

Conventional flame retardant (FR) application processes for textiles involve aqueous processing which is resource-intensive in terms of energy and water usage. Recent research using sol-gel and layer-by-layer chemistries, while claimed to be based on more environmentally sustainable chemistry, still require aqueous media with the continuing problem of water management and drying processes being required. This paper outlines the initial forensic work to characterise commercially produced viscose/flax, cellulosic furnishing fabrics which have had conferred upon them durable flame retardant (FR) treatments using a novel, patented atmospheric plasma/Ultraviolet (UV) excimer laser facility for processing textiles with the formal name Multiplexed Laser Surface Enhancement (MLSE) system. This system (MTIX Ltd., Huddersfield, UK) is claimed to offer the means of directly bonding of flame retardant precursor species to the component fibres introduced either before plasma/UV exposure or into the plasma/UV reaction zone itself; thereby eliminating a number of wet processing cycles. Nine commercial fabrics, pre-impregnated with a semi-durable, proprietary FR finish and subjected to the MLSE process have been analysed for their flame retardant properties before and after a 40 °C 30 min water soak. For one fabric, the pre-impregnated fabric was subjected to a normal heat cure treatment which conferred the same level of durability as the plasma/UV-treated analogue. Thermogravimetric analysis (TGA) and limiting oxygen index (LOI) were used to further characterise their burning behaviour and the effect of the treatment on surface fibre morphologies were assessed. Scanning electron microscopy indicated that negligible changes had occurred to surface topography of the viscose fibres occurred during plasma/UV excimer processing.
Role of SdiA on Biofilm Formation by Atypical Enteropathogenic Escherichia coli
Authors: Culler Hebert , Couto Samuel , Higa Juliana , Ruiz Renato , Yang Min , Bueris Vanessa , Franzolin Marcia , Sircili Marcelo
Published: May 2018

Atypical enteropathogenic Escherichia coli are capable to form biofilm on biotic and abiotic surfaces, regardless of the adherence pattern displayed. Several E. coli mechanisms are regulated by Quorum sensing (QS), including virulence factors and biofilm formation. Quorum sensing is a signaling system that confers bacteria with the ability to respond to chemical molecules known as autoinducers. Suppressor of division inhibitor (SdiA) is a QS receptor present in atypical enteropathogenic E. coli (aEPEC) that detects acyl homoserine lactone (AHL) type autoinducers. However, these bacteria do not encode an AHL synthase, but they are capable of sensing AHL molecules produced by other species, establishing an inter-species bacterial communication. In this study, we performed experiments to evaluate pellicle, ring-like structure and biofilm formation on wild type, sdiA mutants and complemented strains. We also evaluated the transcription of genes involved in different stages of biofilm formation, such as bcsA, csgA, csgD, fliC and fimA. The sdiA mutants were capable of forming thicker biofilm structures and showed increased motility when compared to wild type and complemented strains. Moreover, they also showed denser pellicles and ring-like structures. Quantitative real-time PCR (qRT-PCR) analysis demonstrated increased csgA, csgD and fliC transcription on mutant strains. Biofilm formation, as well as csgD, csgA and fimA transcription decreased on wild type strains by the addition of AHL. These results indicate that SdiA participates on the regulation of these phenotypes in aEPEC and that AHL addition enhances the repressor effect of this receptor on the transcription of biofilm and motility related genes.
The Role of Transposable Elements in Speciation
Authors: Serrato-Capuchina Antonio , Matute Daniel
Published: May 2018

Understanding the phenotypic and molecular mechanisms that contribute to genetic diversity between and within species is fundamental in studying the evolution of species. In particular, identifying the interspecific differences that lead to the reduction or even cessation of gene flow between nascent species is one of the main goals of speciation genetic research. Transposable elements (TEs) are DNA sequences with the ability to move within genomes. TEs are ubiquitous throughout eukaryotic genomes and have been shown to alter regulatory networks, gene expression, and to rearrange genomes as a result of their transposition. However, no systematic effort has evaluated the role of TEs in speciation. We compiled the evidence for TEs as potential causes of reproductive isolation across a diversity of taxa. We find that TEs are often associated with hybrid defects that might preclude the fusion between species, but that the involvement of TEs in other barriers to gene flow different from postzygotic isolation is still relatively unknown. Finally, we list a series of guides and research avenues to disentangle the effects of TEs on the origin of new species.
Metadata Life Cycles, Use Cases and Hierarchies
Authors: Habermann Ted
Published: May 2018

The historic view of metadata as “data about data” is expanding to include data about other items that must be created, used, and understood throughout the data and project life cycles. In this context, metadata might better be defined as the structured and standard part of documentation, and the metadata life cycle can be described as the metadata content that is required for documentation in each phase of the project and data life cycles. This incremental approach to metadata creation is similar to the spiral model used in software development. Each phase also has distinct users and specific questions to which they need answers. In many cases, the metadata life cycle involves hierarchies where latter phases have increased numbers of items. The relationships between metadata in different phases can be captured through structure in the metadata standard, or through conventions for identifiers. Metadata creation and management can be streamlined and simplified by re-using metadata across many records. Many of these ideas have been developed to various degrees in several Geoscience disciplines and are being used in metadata for documenting the integrated life cycle of environmental research in the Arctic, including projects, collection sites, and datasets.