bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing the Leaching of Chalcopyrite Using Acidithiobacillus ferrooxidans under the Induction of Surfactant Triton X-100
Authors: Zhang Ruiyang , Sun Chunbao , Kou Jue , Zhao Hongyu , Wei Dezhou , Xing Yi
Published: December 2018

Chalcopyrite is the richest copper sulfide mineral in the world, but it is also the most resistant to biohydrometallurgical processing. To promote the bioleaching of chalcopyrite, a nonionic surfactant, t-octyl phenoxy polyethoxy ethanol (Triton X-100), was employed in this paper. Action of Triton X-100 in chalcopyrite leaching using Acidithiobacillus ferrooxidans was explored in shake flasks. Results showed that 30 mg·L−1 of Triton X-100 increased the bioleaching yield of copper by 42.21% compared to the process without additive after 24 days. Under the stress of Triton X-100, the bioleaching efficiency of chalcopyrite slightly dropped at an early stage, but remarkably increased afterwards. XRD and XPS analysis of the leach residues demonstrated that potassium jarosite and elemental sulfur resulted in surface leaching passivation. Surfactant Triton X-100 appeared to induce the oxidation of elemental sulfur by bacteria owing to the increase in the sulfur surface hydrophobicity. These results suggest that Triton X-100 itself has no ability to leach chalcopyrite, but under its induction, the bioleaching of chalcopyrite can be enhanced due to the removal of the passivation layer.
A Mechanism for the Adsorption of 2-(Hexadecanoylamino)Acetic Acid by Smithsonite: Surface Spectroscopy and Microflotation Experiments
Authors: Luo Bin , Liu Junbo , Liu Quanjun , Song Chao , Yu Li , Li Shimei , Lai Hao
Published: December 2018

Zinc is mostly extracted from oxidized zinc and zinc sulfide minerals, and this process involves flotation as a key step. While it is easier to float the sulfide mineral, its consumption and depletion has led to an increased reliance on oxidized zinc minerals, including smithsonite. Hence, the development of efficient ways of collecting smithsonite by flotation is an important objective. Herein, we describe the use of 2-(hexadecanoylamino)acetic acid (HAA), a novel surfactant, as a collector during smithsonite flotation. The mechanism and flotation performance of HAA during smithsonite flotation was investigated by total organic carbon (TOC) content studies, zeta potential measurements, Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses, combined with microflotation experiments. The flotation results revealed that HAA was an excellent collector in pulp over a wide pH range (9–12) and at a relatively low concentration (2 × 10−4 mol/L), at which a recovery of close to 90% of the smithsonite mineral was obtained. TOC content studies revealed that the good flotation recovery was ascribable to large amounts of collector molecule adsorbed on the smithsonite surface, while zeta potential measurements showed that the HAA was chemically adsorbed onto the smithsonite. FTIR and XPS analyses revealed that the HAA collector molecules adsorbed onto the smithsonite surface as zinc–HAA complexes involving carboxylate moieties and Zn sites on the smithsonite surface in alkaline solution.
Thermo-Elasticity of Materials from Quasi-Harmonic Calculations
Authors: Destefanis Maurizio , Ravoux Corentin , Cossard Alessandro , Erba Alessandro
Published: December 2018

An effective algorithm for the quasi-harmonic calculation of thermo-elastic stiffness constants of materials is discussed and implemented into the Crystal program for quantum-mechanical simulations of extended systems. Two different approaches of increasing complexity and accuracy are presented. The first one is a quasi-static approximation where the thermal dependence of elastic constants is assumed to be due only to the thermal expansion of the system. The second one is fully quasi-harmonic, takes into account thermal expansion, and explicitly computes Helmholtz free energy derivatives with respect to strain. The conversion of isothermal into adiabatic thermo-elastic constants is also addressed. The algorithm is formally presented and applied to the description of the thermo-elastic response of the forsterite mineral.
Simultaneous Determination of Five Phenolic Acids and Four Flavonoid Glycosides in Rat Plasma Using HPLC-MS/MS and Its Application to a Pharmacokinetic Study after a Single Intravenous Administration of Kudiezi Injection
Authors: Shi Peiying , Yang Chunlei , Su Ya , Huang Liying , Lin Xinhua , Yao Hong
Published: December 2018

This study has developed a reliable and precise high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of five phenolic acids and four flavonoid glycosides in rat plasma after a single intravenous administration of Kudiezi injection (KI). Chromatographic separation was carried out on an Ultimate®XB-C18 column (4.6 × 100 mm, 3.5 μm) using a gradient elution program with a mobile phase consisting of water containing 0.5% acetic acid and acetonitrile at a flow rate of 0.6 mL/min. Detection was performed on a triple-quadrupole tandem mass spectrometry using multiple reaction monitoring in negative electrospray ionization mode. The calibration curves of all analytes showed good linearity (R2 > 0.990). The results of selectivity, intra-day and inter-day precisions, extraction recoveries, matrix effects and stability were satisfactory. Pharmacokinetic parameters showed that luteolin-7-O-β-d-gentiobioside, luteolin-7-O-β-d-glucuronide, luteolin-7-O-β-d-glucoside and apigenin-7-O-β-d-glucuronide were eliminated quickly (0.07 h < t1/2 < 0.66 h), whereas 5-caffeoylquinic acid, caftaric acid, chlorogenic acid, 4-caffeoylquinic acid and caffeic acid were eliminated relatively slowly (2.22 h < t1/2 < 6.09 h) in rat blood. The pharmacokinetic results would be valuable to identify bioactive constituents, elucidate mechanisms of pharmacological actions or adverse drug reactions and guide the rational clinical use of KI.
Neo-5,22E-Cholestadienol Derivatives from Buthus martensii Karsch and Targeted Bactericidal Action Mechanisms
Authors: Lv Biyu , Yin Weiping , Gao Jiayu , Liu Huaqing , Liu Kun , Bai Jie , Yang Qiangqiang
Published: December 2018

The discovery and search for new antimicrobial molecules from insects and animals that live in polluted environments is a very important step in the scientific search for solutions to the current problem of antibiotic resistance. Previously, we have reported that the secondary metabolite with the antibacterial action discovered in scorpion. The current study further isolated three new compounds from Buthus martensii karsch, while compounds 1 and 2 possessed 5,22E-cholestadienol derivatives whose structure demonstrated broad spectrum bactericide activities. To explore the antibacterial properties of these new compounds, the result shows that compound 2 inhibited bacterial growth of both S. aureus and P. aeruginosa in a bactericidal rather than a bacteriostatic manner (MBC/MIC ratio ≤ 2). Similarly, with compound 1, a ratio of MBC/MIC ≤ 2 indicates bactericidal activity inhibited bacterial growth of P. aeruginosa. Remarkably, this suggests that two compounds can be classified as bactericidal agents against broad spectrum bactericide activities for 5,22E-cholestadienol derivatives from Buthus martensii karsch. The structures of compounds 1–3 were established by comprehensive spectra analysis including two-dimensional nuclear magnetic resonance (2D-NMR) and high-resolution electrospray ionization-mass spectrometry (HRESI-MS) spectra. The antibacterial mechanism is the specific binding (various of bonding forces between molecules) using compound 1 or 2 as a ligand based on the different receptor proteins’—2XRL or 1Q23—active sites from bacterial ribosome unit A, and thus prevent the synthesis of bacterial proteins. This unique mechanism avoids the cross-resistance issues of other antibacterial drugs.
Mass Transfer of Anthocyanins during Extraction from Pre-Fermentative Grape Solids under Simulated Fermentation Conditions: Effect of Convective Conditions
Authors: Setford Patrick C. , Jeffery David W. , Grbin Paul R. , Muhlack Richard A.
Published: December 2018

The colour of red wine is largely determined by the concentration of anthocyanins that are extracted from grape skins during fermentation. Because colour is a key parameter in determining the overall quality of the finished product, understanding the effect of processing variables on anthocyanin extraction is critical for producing a red wine with the desired sensorial characteristics. In this study, the effect of convective conditions (natural and forced) on the mass transfer properties of malvidin-3-glucoside (M3G) from pre-fermentative grape solids was explored at various liquid phase conditions representing stages of fermentation. A mathematical model that separates solid and liquid phase mass transfer parameters was applied to experimental extraction curves, and in all cases, provided a coefficient of determination exceeding 0.97. Calculated mass transfer coefficients indicated that under forced convective conditions, the extraction process was controlled by internal diffusion whereas under natural convection, both internal diffusion and liquid-phase mass transfer were relevant in determining the overall extraction rate. Predictive simulations of M3G extraction during active fermentation were accomplished by incorporating the current results with a previously developed fermentation model, providing insight into the effect of a dynamic liquid phase on anthocyanin extraction.
Physicochemical Properties and Storage Stability of Food Protein-Stabilized Nanoemulsions
Authors: Li Yangyang , Jin Hua , Sun Xiaotong , Sun Jingying , Liu Chang , Liu Chunhong , Xu Jing
Published: December 2018

This study investigated the preparation and properties of corn oil nanoemulsions stabilized by peanut protein isolate (PPI), rice bran protein isolate (RBPI), soybean protein isolate (SPI), and whey protein isolate (WPI). The mean droplet diameter of four protein-stabilized nanoemulsions prepared via ultrasound method was less than 245 nm. PPI-stabilized nanoemulsions showed better stability for 4 weeks, while the mean droplet diameter of RBPI-stabilized nanoemulsions had exceeded 1000 nm during the third week of storage. Fourier transform infrared and interfacial tension (IT) analysis showed that the higher level of disordered structure and lower IT of proteins made the stability of nanoemulsions better. Moreover, bivariate correlation analysis discovered that α-helix (p < 0.01) and β-turn (p < 0.05) of proteins were related to the mean droplet diameter of nanoemulsions, the random coil (p < 0.05) was related to the zeta potential of nanoemulsions. This study provided new idea for the relationship between the structure of protein and properties of protein-stabilized nanoemulsions.
Influence of Nanoparticle Pretreatment on the Thermal, Rheological and Mechanical Properties of PLA-PBSA Nanocomposites Incorporating Cellulose Nanocrystals or Montmorillonite
Authors: Abdallah Wissam , Mirzadeh Amin , Tan Victor , Kamal Musa R.
Published: December 2018

Nanoparticles based on cellulose nanocrystals (CNC) and montmorillonite clay (MMT) were prepared using spray freeze-drying. The nanoparticles were then used as reinforcement to prepare nanocomposites with poly(lactic acid) (PLA) as the polymer matrix. The effect of spray freeze-dried CNC (SFD-CNC) and spray freeze-dried MMT (SFD-MMT) on the rheological and mechanical properties of PLA and its blends with poly[(butylene succinate)-co-adipate)] (PBSA) were investigated. An epoxy chain extender was used during preparation of the blends and nanocomposites to enhance the mechanical properties of the products. Different methods such as scanning electron microscopy, X-ray diffraction and adsorption/desorption analyses were used to characterize the prepared nanoparticles and their localization in the blends. Dynamic oscillatory shear behavior, elongational viscosity and mechanical characteristics of the nanocomposites of PLA and the blends were evaluated. The results obtained for nanocomposites filled with unmodified SFD-MMT were compared with those obtained when the filler was a commercial organically modified montmorillonite nanoclay (methyl-tallow-bis(2-hydroxyeethyl) quaternary ammonium chloride) (C30B), which was not spray freeze-dried.
Extracellular Vesicles as Conduits of Non-Coding RNA Emission and Intercellular Transfer in Brain Tumors
Authors: Spinelli Cristiana , Adnani Lata , Choi Dongsic , Rak Janusz
Published: December 2018

Non-coding RNA (ncRNA) species have emerged in as molecular fingerprints and regulators of brain tumor pathogenesis and progression. While changes in ncRNA levels have been traditionally regarded as cell intrinsic there is mounting evidence for their extracellular and paracrine function. One of the key mechanisms that enables ncRNA to exit from cells is their selective packaging into extracellular vesicles (EVs), and trafficking in the extracellular space and biofluids. Vesicular export processes reduce intracellular levels of specific ncRNA in EV donor cells while creating a pool of EV-associated ncRNA in the extracellular space and biofluids that enables their uptake by other recipient cells; both aspects have functional consequences. Cancer cells produce several EV subtypes (exosomes, ectosomes), which differ in their ncRNA composition, properties and function. Several RNA biotypes have been identified in the cargo of brain tumor EVs, of which microRNAs are the most studied, but other species (snRNA, YRNA, tRNA, and lncRNA) are often more abundant. Of particular interest is the link between transforming oncogenes and the biogenesis, cargo, uptake and function of tumor-derived EV, including EV content of oncogenic RNA. The ncRNA repertoire of EVs isolated from cerebrospinal fluid and serum is being developed as a liquid biopsy platform in brain tumors.
Tea Polyphenols in Promotion of Human Health
Authors: Khan Naghma , Mukhtar Hasan
Published: December 2018

Tea is the most widely used beverage worldwide. Japanese and Chinese people have been drinking tea for centuries and in Asia, it is the most consumed beverage besides water. It is a rich source of pharmacologically active molecules which have been implicated to provide diverse health benefits. The three major forms of tea are green, black and oolong tea based on the degree of fermentation. The composition of tea differs with the species, season, leaves, climate, and horticultural practices. Polyphenols are the major active compounds present in teas. The catechins are the major polyphenolic compounds in green tea, which include epigallocatechin-3-gallate (EGCG), epigallocatechin, epicatechin-3-gallate and epicatechin, gallocatechins and gallocatechin gallate. EGCG is the predominant and most studied catechin in green tea. There are numerous evidences from cell culture and animal studies that tea polyphenols have beneficial effects against several pathological diseases including cancer, diabetes and cardiovascular diseases. The polyphenolic compounds present in black tea include theaflavins and thearubigins. In this review article, we will summarize recent studies documenting the role of tea polyphenols in the prevention of cancer, diabetes, cardiovascular and neurological diseases.
Developing a Food Exchange System for Meal Planning in Vegan Children and Adolescents
Authors: Menal-Puey Susana , Martínez-Biarge Miriam , Marques-Lopes Iva
Published: December 2018

Vegan diets in children need to be adequately planned so they can safely meet children’s requirements for growth and development. Adequate and realistic meal planning guidelines should not be difficult to achieve, thanks to the increasing number and availability of natural and fortified vegan foods, which can help children to meet all their nutrients requirements. In order to ensure an adequate supply of key nutrients, families and health professionals need accurate, reliable, and easy-to-use meal planning tools. The aim of this article is to provide a practical approach system to meal planning, based on the same food exchange methodology that has been already published in adults. Daily portions of each food exchange group have been calculated so the resulting menu provides at least 90% of the Dietary Reference Intakes (DRIs) of protein, iron, zinc, calcium, and n-3 fatty acids for each age group, sex, and physical activity level. These diets do not provide enough vitamin B-12 and vitamin D. Although fortified plant drinks, breakfast cereals or plant protein-rich products could provide variable amounts of these two vitamins, B12 supplementation is always recommended and vitamin D supplementation should be considered whenever sun exposure is limited. This tool can be used to plan healthful and balanced vegan diets for children and adolescents.
Bow-Tie Cavity for Terahertz Radiation
Authors: Consolino Luigi , Campa Annamaria , Mazzotti Davide , Vitiello Miriam Serena , De Natale Paolo , Bartalini Saverio
Published: December 2018

We report on the development, testing, and performance analysis of a bow-tie resonant cavity for terahertz (THz) radiation, injected with a continuous-wave 2.55 THz quantum cascade laser. The bow-tie cavity employs a wire-grid polarizer as input/output coupler and a pair of copper spherical mirrors coated with an unprotected 500 nm thick gold layer. The improvements with respect to previous setups have led to a measured finesse value F = 123, and a quality factor Q = 5.1·105. The resonator performances and the relevant parameters are theoretically predicted and discussed, and a comparison among simulated and experimental spectra is given.
A Statistical Analysis on the Effect of Antioxidants on the Thermal-Oxidative Stability of Commercial Mass- and Emulsion-Polymerized ABS
Authors: Fiorio Rudinei , D’hooge Dagmar R. , Ragaert Kim , Cardon Ludwig
Published: December 2018

In the present work, statistical analysis (16 processing conditions and 2 virgin unmodified samples) is performed to study the influence of antioxidants (AOs) during acrylonitrile-butadiene-styrene terpolymer (ABS) melt-blending (220 °C) on the degradation of the polybutadiene (PB) rich phase, the oxidation onset temperature (OOT), the oxidation peak temperature (OP), and the yellowing index (YI). Predictive equations are constructed, with a focus on three commercial AOs (two primary: Irganox 1076 and 245; and one secondary: Irgafos 168) and two commercial ABS types (mass- and emulsion-polymerized). Fourier transform infrared spectroscopy (FTIR) results indicate that the nitrile absorption peak at 2237 cm−1 is recommended as reference peak to identify chemical changes in the PB content. The melt processing of unmodified ABSs promotes a reduction in OOT and OP, and promotes an increase in the YI. ABS obtained by mass polymerization shows a higher thermal-oxidative stability. The addition of a primary AO increases the thermal-oxidative stability, whereas the secondary AO only increases OP. The addition of the two primary AOs has a synergetic effect resulting in higher OOT and OP values. Statistical analysis shows that OP data are influenced by all three AO types, but 0.2 m% of Irganox 1076 displays high potential in an industrial context.
Functional Polyimide/Polyhedral Oligomeric Silsesquioxane Nanocomposites
Authors: Mohamed Mohamed Gamal , Kuo Shiao Wei
Published: December 2018

The preparation of hybrid nanocomposite materials derived from polyhedral oligomeric silsesquioxane (POSS) nanoparticles and polyimide (PI) has recently attracted much attention from both academia and industry, because such materials can display low water absorption, high thermal stability, good mechanical characteristics, low dielectric constant, flame retardance, chemical resistance, thermo-redox stability, surface hydrophobicity, and excellent electrical properties. Herein, we discussed the various methods that have been used to insert POSS nanoparticles into PI matrices, through covalent chemical bonding and physical blending, as well as the influence of the POSS units on the physical properties of the PIs.
Enzymes@ZIF-8 Nanocomposites with Protection Nanocoating: Stability and Acid-Resistant Evaluation
Authors: Feng Yuxiao , Zhong Le , Bilal Muhammad , Tan Zhilei , Hou Ying , Jia Shiru , Cui Jiandong
Published: December 2018

Zeolitic imidazole framework-8 (ZIF-8) with tunable pore sizes and high surface areas have recently emerged as a promising support for immobilizing enzymes. However, the instability in the aqueous acidic environment and difficulty of recovery has limited their practical applications in some cases. In this study, catalase/ZIF-8 composites with a protective nanocoating were prepared by the controlled self-assembly of silanes or coordination complexes (tannic acid (TA) and Fe3+). The properties of the catalase (CAT)/ZIF-8 composites with a protective nanocoating were also determined. The recovered activity of CAT/ZIF-8 and CAT/ZIF-8 with protective nanocoating was 70% and 65%, respectively. Compared with the conventional CAT/ZIF-8 composites, CAT/ZIF-8 with protective nanocoating exhibited excellent acid resistance. For example, after treatment for 60 min in phosphate buffer solution (pH 3.0), CAT/ZIF-8 composites only maintained 20% of their initial activity (about 12 U/mg). However, CAT/ZIF-8 with a protective nanocoating could still retain about 50% of its initial activity (about 10 U/mg). Meanwhile, the thermostability and storage stability of the CAT/ZIF-8 composites was enhanced significantly due to the presence of nanocoating compared with conventional CAT/ZIF-8. More importantly, the CAT/ZIF-8 with a protective nanocoating retained 40% of its initial activity after 7 cycles, whereas CAT/ZIF-8 only retained 8% of the initial activity. The approach in this study could be an efficient strategy to prepare enzyme/ZIF-8 composites with both high acid resistance and excellent recyclability.
Synthesis and Characterization of an Antioxidative Galactomannan–Iron(III) Complex from Sesbania Seed
Authors: Huang Caoxing , Tao Yuheng , Li Min , Zhang Weiyu , Fan Yimin , Yong Qiang
Published: December 2018

Galactomannan, a water-soluble polymer in the cell wall of leguminous plants, has been proven to possess anticancer and antioxidative activity. In this work, galactomannan with different molecular weights (GM-40 and GM-65) was obtained from Sesbania seeds and synthesized into galactomannan–iron(III) complexes, which are termed as GM-40-Fe and GM-65-Fe, respectively. These galactomannan–iron(III) complexes are intended to function as organic iron supplements to treat iron deficiency with the added benefit of antioxidative activity. The prepared galactomannan–iron(III) complexes were characterized for chemical composition, morphology, antioxidant capacity, and bioavailability in vitro. The results showed that galactomannan–iron(III) complexes could be produced with iron contents as high as 65.4 mg/g. Antioxidant assays indicated that both GM-40-Fe and GM-65-Fe exhibited antioxidant activities for scavenging radicals in vitro. The iron release/bioavailability assays showed that the iron was easily released into artificial gastric and intestinal juices, resulting in iron release rates of 88–94% over 300 min. These results suggest that galactomannan–iron(III) complexes synthesized from Sesbania seed polysaccharides are capable of being administered as organic iron supplements to patients with iron deficiency.
Effects of a Phosphorus Flame Retardant System on the Mechanical and Fire Behavior of Microcellular ABS
Authors: Realinho Vera , Arencón David , Antunes Marcelo , Velasco José Ignacio
Published: December 2018

The present work deals with the study of phosphorus flame retardant microcellular acrylonitrile–butadiene–styrene (ABS) parts and the effects of weight reduction on the fire and mechanical performance. Phosphorus-based flame retardant additives (PFR), aluminum diethylphosphinate and ammonium polyphosphate, were used as a more environmentally friendly alternative to halogenated flame retardants. A 25 wt % of such PFR system was added to the polymer using a co-rotating twin-screw extruder. Subsequently, microcellular parts with 10, 15, and 20% of nominal weight reduction were prepared using a MuCell® injection-molding process. The results indicate that the presence of PFR particles increased the storage modulus and decreased the impact energy determined by means of dynamic-mechanical-thermal analysis and falling weight impact tests respectively. Nevertheless, the reduction of impact energy was found to be lower in ABS/PFR samples than in neat ABS with increasing weight reduction. This effect was attributed to the lower cell sizes and higher cell densities of the microcellular core of ABS/PFR parts. All ABS/PFR foams showed a self-extinguishing behavior under UL-94 burning vertical tests, independently of the weight reduction. Gradual decreases of the second peak of heat release rate and time of combustion with similar intumescent effect were observed with increasing weight reduction under cone calorimeter tests.
Simultaneous Assimilation of Remotely Sensed Soil Moisture and FAPAR for Improving Terrestrial Carbon Fluxes at Multiple Sites Using CCDAS
Authors: Wu Mousong , Scholze Marko , Voßbeck Michael , Kaminski Thomas , Hoffmann Georg
Published: December 2018

The carbon cycle of the terrestrial biosphere plays a vital role in controlling the global carbon balance and, consequently, climate change. Reliably modeled CO2 fluxes between the terrestrial biosphere and the atmosphere are necessary in projections of policy strategies aiming at constraining carbon emissions and of future climate change. In this study, SMOS (Soil Moisture and Ocean Salinity) L3 soil moisture and JRC-TIP FAPAR (Joint Research Centre—Two-stream Inversion Package Fraction of Absorbed Photosynthetically Active Radiation) data with respective original resolutions at 10 sites were used to constrain the process-based terrestrial biosphere model, BETHY (Biosphere, Energy Transfer and Hydrology), using the carbon cycle data assimilation system (CCDAS). We find that simultaneous assimilation of these two datasets jointly at all 10 sites yields a set of model parameters that achieve the best model performance in terms of independent observations of carbon fluxes as well as soil moisture. Assimilation in a single-site mode or using only a single dataset tends to over-adjust related parameters and deteriorates the model performance of a number of processes. The optimized parameter set derived from multi-site assimilation with soil moisture and FAPAR also improves, when applied at global scale simulations, the model-data fit against atmospheric CO2. This study demonstrates the potential of satellite-derived soil moisture and FAPAR when assimilated simultaneously in a model of the terrestrial carbon cycle to constrain terrestrial carbon fluxes. It furthermore shows that assimilation of soil moisture data helps to identity structural problems in the underlying model, i.e., missing management processes at sites covered by crops and grasslands.
Improving the Informational Value of MODIS Fractional Snow Cover Area Using Fuzzy Logic Based Ensemble Smoother Data Assimilation Frameworks
Authors: Teweldebrhan Aynom T. , Burkhart John F. , Schuler Thomas V. , Xu Chong-Yu
Published: December 2018

Remote sensing fractional snow cover area (fSCA) has been increasingly used to get an improved estimate of the spatiotemporal distribution of snow water equivalent (SWE) through reanalysis using different data assimilation (DA) schemes. Although the effective assimilation period of fSCA is well recognized in previous studies, little attention has been given to explicitly account for the relative significance of measurements in constraining model parameters and states. Timing of the more informative period varies both spatially and temporally in response to various climatic and physiographic factors. Here we use an automatic detection approach to locate the critical points in the time axis where the mean snow cover changes and where the melt-out period starts. The assimilation period was partitioned into three timing windows based on these critical points. A fuzzy coefficient was introduced in two ensemble-based DA schemes to take into account for the variability in informational value of fSCA observations with time. One of the DA schemes used in this study was the particle batch smoother (Pbs). The main challenge in Pbs and other Bayesian-based DA schemes is, that most of the weights are carried by few ensemble members. Thus, we also considered an alternative DA scheme based on the limits of acceptability concept (LoA) and certain hydrologic signatures and it has yielded an encouraging result. An improved estimate of SWE was also obtained in most of the analysis years as a result of introducing the fuzzy coefficients in both DA schemes. The most significant improvement was obtained in the correlation coefficient between the predicted and observed SWE values (site-averaged); with an increase by 8% and 16% after introducing the fuzzy coefficient in Pbs and LoA, respectively.
Laplacian Regularized Spatial-Aware Collaborative Graph for Discriminant Analysis of Hyperspectral Imagery
Authors: Jiang Xinwei , Song Xin , Zhang Yongshan , Jiang Junjun , Gao Junbin , Cai Zhihua
Published: December 2018

Dimensionality Reduction (DR) models are of significance to extract low-dimensional features for Hyperspectral Images (HSIs) data analysis where there exist lots of noisy and redundant spectral features. Among many DR techniques, the Graph-Embedding Discriminant Analysis framework has demonstrated its effectiveness for HSI feature reduction. Based on this framework, many representation based models are developed to learn the similarity graphs, but most of these methods ignore the spatial information, resulting in unsatisfactory performance of DR models. In this paper, we firstly propose a novel supervised DR algorithm termed Spatial-aware Collaborative Graph for Discriminant Analysis (SaCGDA) by introducing a simple but efficient spatial constraint into Collaborative Graph-based Discriminate Analysis (CGDA) which is inspired by recently developed Spatial-aware Collaborative Representation (SaCR). In order to make the representation of samples on the data manifold smoother, i.e., similar pixels share similar representations, we further add the spectral Laplacian regularization and propose the Laplacian regularized SaCGDA (LapSaCGDA), where the two spectral and spatial constraints can exploit the intrinsic geometric structures embedded in HSIs efficiently. Experiments on three HSIs data sets verify that the proposed SaCGDA and LapSaCGDA outperform other state-of-the-art methods.
Penetration Analysis of SAR Signals in the C and L Bands for Wheat, Maize, and Grasslands
Authors: El Hajj Mohammad , Baghdadi Nicolas , Bazzi Hassan , Zribi Mehrez
Published: December 2018

This paper assesses the potential of Synthetic Aperture Radar (SAR) in the C and L bands to penetrate into the canopy cover of wheat, maize and grasslands. For wheat and grasslands, the sensitivity of the C and L bands to in situ surface soil moisture (SSM) was first studied according to three levels of the Normalized Difference Vegetation Index (NDVI < 0.4, 0.4 < NDVI < 0.7, and NDVI > 0.7). Next, the temporal evolution of the SAR signal in the C and L bands was analyzed according to SSM and the NDVI. For wheat and grasslands, the results showed that the L-band in HH polarization penetrates the canopy even when the canopy is well-developed (NDVI > 0.7), whereas the penetration of the C-band into the canopy is limited for an NDVI < 0.7. For an NDVI less than 0.7, the sensitivity of the radar signal to SSM is approximately 0.27 dB/vol.% for the L-band in HH polarization and approximately 0.12 dB/vol.% for the C-band (in both VV and VH polarizations). For highly developed wheat and grassland cover (NDVI > 0.7), the sensitivity of the L-band in HH polarization to SSM is approximately 0.19 dB/vol.%, whereas as the C-band is insensitive to SSM. For maize, only the temporal evolution of the C-band according to SSM and the NDVI was studied because the swath of SAR images in the L-band did not cover the maize plots. The results showed that the C-band in VV polarization is able to penetrate the maize canopy even when the canopy is well developed (NDVI > 0.7) due to high-order scattering along the soil-vegetation pathway that contains a soil contribution. According to results obtained in this paper, the L-band would penetrate a well-developed maize cover since the penetration depth of the L-band is greater than that of the C-band.
ENSO and Teleconnections Observed Using MISR Cloud Height Anomalies
Authors: Davies Roger
Published: December 2018

Cloud-top height is an important climate variable due to its greenhouse effect, as well as being a useful indicator of circulation patterns. We use effective height anomalies from stereo retrievals at a horizontal resolution of 1.1 km after subtracting regional and seasonal mean values. After 18 years, any trend in the global average height anomaly remains hidden by the stronger influence of intermittent El Niño–Southern Oscillation (ENSO) events. However, interesting teleconnections and oscillatory patterns in regional cloud heights are starting to emerge. Different teleconnection patterns are now evident during the El Niño and La Niña phases giving rise to high values of the correlation coefficient between many global regions and the Central Pacific, which shows the greatest connection to ENSO. Cloud heights over the Central Pacific and Maritime Continent oscillate out of phase with each other and have nearly synchronous zero anomalies with a mean separation of about 1.8 years. These are lagged by one month from similar zero values in the Southern Oscillation Index. Surface zonal wind anomalies for these two regions also oscillate out of phase with each other, and are highly correlated with the height anomalies, leading them by one month.
Improving the GNSS-R Specular Reflection Point Positioning Accuracy Using the Gravity Field Normal Projection Reflection Reference Surface Combination Correction Method
Authors: Wu Fan , Zheng Wei , Li Zhaowei , Liu Zongqiang
Published: December 2018

Global Navigation Satellite System Reflectometry (GNSS-R) is of great significance for the extraction and research of precise information of sea surface topography. Improving measurement accuracy is necessary for realizing spaceborne GNSS-R sea surface altimetry application. The main error source of GNSS-R distance measurement is the error of the specular reflection point positioning, which directly affects the sea surface altimetry accuracy on the reference datum. There is an elevation error of several tens of meters between the reflection reference surface used by the existing specular reflection point geometric positioning methods and the sea surface elevation, which is importantly influenced by the earth’s gravity field. Therefore, the gravity field reflection reference surface correction is the key to improving the specular reflection point positioning accuracy. In this study, based on the correction of the GNSS-R reflection reference surface, research on improving the positioning accuracy of the specular reflection point is carried out. Firstly, in order to reduce the positioning error caused by the elevation difference between the reflection reference surface and the sea surface, the gravity field reflection reference surface correction method (GFRRSCM) which corrects the reflection reference surface from the WGS-84 ellipsoid to geoid is proposed, and the positioning accuracy is improved by 25.15 m. Secondly, the normal projection reflection reference surface correction method (NPRRSCM) is proposed to correct the specular reflection point determined by the GFRRSCM from the reflection reference plane of the radial to that of the normal. Additionally, in the process of solving the spatial geometric relationship of the reflection path, the approximate substitution error is reduced by directly solving the normal projection on the plane, and the positioning accuracy is further improved by 13.05 m towards the normal. Thirdly, based on the gravity field normal projection reflection reference surface combination correction method (GF-NPRRSCCM), the specular reflection point positioning accuracy is synthetically improved by 28.66 m.
Decreasing Rice Cropping Intensity in Southern China from 1990 to 2015
Authors: Jiang Min , Xin Liangjie , Li Xiubin , Tan Minghong , Wang Renjing
Published: December 2018

Assessing changes in rice cropping systems is essential for ensuring food security, greenhouse gas emissions, and sustainable water management. However, due to the insufficient availability of images with moderate to high spatial resolution, caused by frequent cloud cover and coarse temporal resolution, high-resolution maps of rice cropping systems at a large scale are relatively limited, especially in tropical and subtropical regions. This study combined the difference of Normalized Difference Vegetation Index (dNDVI) method and the Normalized Difference Vegetation Index (NDVI) threshold method to monitor changes in rice cropping systems of Southern China using Landsat images, based on the phenological differences between different rice cropping systems. From 1990–2015, the sown area of double cropping rice (DCR) in Southern China decreased by 61054.5 km2, the sown area of single cropping rice (SCR) increased by 20,110.7 km2, the index of multiple cropping decreased from 148.3% to 129.3%, and the proportion of DCR decreased by 20%. The rice cropping systems in Southern China showed a “double rice shrinking and single rice expanding” change pattern from north to south, and the most dramatic changes occurred in the Middle-Lower Yangtze Plain. This study provided an efficient strategy that can be applied to moderate to high resolution images with deficient data availability, and the resulting maps can be used as data support to adjust agricultural structures, formulate food security strategies, and compile a greenhouse gas emission inventory.
Wireless Network for Assessing Temperature Load of Large-Scale Structures Under Fire Hazards
Authors: Kim Robin E. , In Kiho , Yeo Inhwan
Published: December 2018

While the construction of high-rise buildings has become popular in big cities, an average of over 15,000 structure fires in those buildings are being reported in the United States. Especially because the fire in a building can result in a failure or even the collapse of the structure, assessing its integrity during and after the fire is of importance. Thus, in this paper, a framework with temperature sensors using wireless communication technology has been proposed. Associated hardware and software are carefully chosen and developed to provide an easy and effective solution for measuring fire load on large-scale structures during a fire. With an autonomous measurement system enabled, the key functions of the framework have been validated in a fire testing laboratory, using a real-scale steel column subject to standard fire. Unlike existing solutions of wireless temperature networks, the proposed solution can provide the user definable sampling frequencies based on the surface temperature and the means to assess the load redistribution of the structure due to fire loading in real-time. The results of the study show the great potential of using the developed framework for monitoring fire in a structure, allowing more accurate estimations of fire load in the design criteria, and advancing fire safety engineering.
Damping Force and Loading Position Dependence of Mass Sensitivity of Magnetoelastic Biosensors in Viscous Liquid
Authors: Zhang Kewei , Chen Zhe , Zhu Qianke , Jiang Yong , Liu Wenfeng , Wu Peixuan
Published: December 2018

We established the vibration governing equation for a magnetoelastic (ME) biosensor with target loading in liquid. Based on the equation, a numerical simulation approach was used to determine the effect of the target loading position and viscous damping coefficient on the node (“blind points”) and mass sensitivity (Sm) of an ME biosensor under different order resonances. The results indicate that viscous damping force causes the specific nodes shift but does not affect the overall variation trend of Sm as the change of target loading position and the effect on Sm gradually reduces when the target approaches to the node. In addition, Sm decreases with the increase of viscous damping coefficient but the tendency becomes weak at high-order resonance. Moreover, the effect of target loading position on Sm decreases with the increase of viscous damping coefficient. Finally, the results provide certain guidance on improving the mass sensitivity of an ME biosensor in liquid by controlling the target loading position.
A Generic Multi-Layer Architecture Based on ROS-JADE Integration for Autonomous Transport Vehicles
Authors: Martin Jon , Casquero Oskar , Fortes Brais , Marcos Marga
Published: December 2018

The design and operation of manufacturing systems is evolving to adapt to different challenges. One of the most important is the reconfiguration of the manufacturing process in response to context changes (e.g., faulty equipment or urgent orders, among others). In this sense, the Autonomous Transport Vehicle (ATV) plays a key role in building more flexible and decentralized manufacturing systems. Nowadays, robotic frameworks (RFs) are used for developing robotic systems such as ATVs, but they focus on the control of the robotic system itself. However, social abilities are required for performing intelligent interaction (peer-to-peer negotiation and decision-making) among the different and heterogeneous Cyber Physical Production Systems (such as machines, transport systems and other equipment present in the factory) to achieve manufacturing reconfiguration. This work contributes a generic multi-layer architecture that integrates a RF with a Multi-Agent System (MAS) to provide social abilities to ATVs. This architecture has been implemented on ROS and JADE, the most widespread RF and MAS framework, respectively. We believe this to be the first work that addresses the intelligent interaction of transportation systems for flexible manufacturing environments in a holistic form.
Object Tracking Algorithm Based on Dual Color Feature Fusion with Dimension Reduction
Authors: Hu Shuo , Ge Yanan , Han Jianglong , Zhang Xuguang
Published: December 2018

Aiming at the problem of poor robustness and the low effectiveness of target tracking in complex scenes by using single color features, an object-tracking algorithm based on dual color feature fusion via dimension reduction is proposed, according to the Correlation Filter (CF)-based tracking framework. First, Color Name (CN) feature and Color Histogram (CH) feature extraction are respectively performed on the input image, and then the template and the candidate region are correlated by the CF-based methods, and the CH response and CN response of the target region are obtained, respectively. A self-adaptive feature fusion strategy is proposed to linearly fuse the CH response and the CN response to obtain a dual color feature response with global color distribution information and main color information. Finally, the position of the target is estimated, based on the fused response map, with the maximum of the fused response map corresponding to the estimated target position. The proposed method is based on fusion in the framework of the Staple algorithm, and dimension reduction by Principal Component Analysis (PCA) on the scale; the complexity of the algorithm is reduced, and the tracking performance is further improved. Experimental results on quantitative and qualitative evaluations on challenging benchmark sequences show that the proposed algorithm has better tracking accuracy and robustness than other state-of-the-art tracking algorithms in complex scenarios.
Rejecting Chaotic Disturbances Using a Super-Exponential-Zeroing Neurodynamic Approach for Synchronization of Chaotic Sensor Systems
Authors: Chen Dechao , Li Shuai , Wu Qing
Published: December 2018

Due to the existence of time-varying chaotic disturbances in complex applications, the chaotic synchronization of sensor systems becomes a tough issue in industry electronics fields. To accelerate the synchronization process of chaotic sensor systems, this paper proposes a super-exponential-zeroing neurodynamic (SEZN) approach and its associated controller. Unlike the conventional zeroing neurodynamic (CZN) approach with exponential convergence property, the controller designed by the proposed SEZN approach inherently possesses the advantage of super-exponential convergence property, which makes the synchronization process faster and more accurate. Theoretical analyses on the stability and convergence advantages in terms of both faster convergence speed and lower error bound within the task duration are rigorously presented. Moreover, three synchronization examples substantiate the validity of the SEZN approach and the related controller for synchronization of chaotic sensor systems. Comparisons with other approaches such as the CZN approach, show the convergence superiority of the proposed SEZN approach. Finally, extensive tests further investigate the impact on convergence performance by choosing different values of design parameter and initial state.
Parental Communication and Feelings of Affiliation in Adolescent Aggressors and Victims of Cyberbullying
Authors: Ortega Barón Jessica , Postigo Javier , Iranzo Begoña , Buelga Sofía , Carrascosa Laura
Published: December 2018

Cyberbullying is an increasingly frequent problem among adolescents, and it produces considerable social concern. Using a cross-sectional and quantitative methodology, the main objective of this study was to analyze the differences among students involved in the perpetration and victimization of cyberbullying (non-involved, occasional, and severe), in their parental communication, and feelings of affiliation with classmates. The sample consisted of 849 adolescents (51.7% boys and 48.3% girls) from 12 to 18 years old (M = 14.5; SD = 1.62). Three comparison groups of aggressors and victims of cyberbullying were formed, depending on the intensity of the intimidation: non-involved, occasional, and severe. The results of the analysis of variance indicated that adolescents involved in cyberbullying as perpetrators or victims have less open and more avoidant communication with their parents than adolescents who are not involved in cyberbullying. Additionally, victims of cyberbullying perceive lower feelings of affiliation with their classmates, whereas cyberbullies show no differences between the groups on this variable. These new results provide insight into the important role of family and peers in the prevention and eradication of the growing problem of cyberbullying.
Analyzing and Forecasting Energy Consumption in China’s Manufacturing Industry and Its Subindustries
Authors: Sun Wei , Hou Yufei , Guo Lanjiang
Published: December 2018

In the context of new industrialization, the energy problem being experienced by the manufacturing industry has aroused social concerns. This paper focuses on the energy use of 27 subindustries in China’s manufacturing industry and it develops an energy consumption index for 1994–2015. Subsequently, the method of grey relational analysis is used, with the full period divided according to years in which change points occur. The empirical analysis indicates that the energy consumption indexes generally exhibit a declining trend. Using the grey model (GM (1,1)) to forecast the index indicates a continued downward trend up to 2025 for energy-intensive industries, which is a more optimistic scenario than the trend forecast for the whole manufacturing sector. Thus, these energy-intensive industries do not drag down the performance of the whole manufacturing industry in regard to energy intensity. In future, more attention should be paid to energy-saving efforts by nontraditional high-energy-consuming industries. Although the results show that energy efficiency is improving in China, total annual consumption is rising rapidly. Therefore, the industry needs to continue to strengthen independent innovation and improve the efficiency of new energy use. The Chinese government should formulate feasible long-term plans to encourage enterprises to save energy.