bluuebunny/crossref_metadata_2025 huggingface dataset:
Management Transition to the Great Lakes Nearshore: Insights from Hydrodynamic Modeling
Authors: Huang Chenfu , Kuczynski Anika , Auer Martin T. , O’Donnell David M. , Xue Pengfei
Published: May 2019

The emerging shift in Great Lakes management from offshore to nearshore waters will require attention to complexities of coastal hydrodynamics and biogeochemical transformations. Emphasizing hydrodynamics, this work resolves transport processes in quantifying discharge plume and pollutant of concern (POC) footprint dimensions, the latter being the portion of the plume where water quality standards are not met. A generic approach, isolated from pollutant-specific biokinetics, provides first-approximation estimates of the footprint area. A high-resolution, linked hydrodynamic-tracer model is applied at a site in the Greater Toronto Area on Lake Ontario. Model results agree with observed meteorological and hydrodynamic conditions and satisfactorily simulate plume dimensions. Footprints are examined in the context of guidelines for regulatory mixing zone size and attendant loss of beneficial use. We demonstrate that the ratio of the water quality standard to the POC concentration at discharge is a key determinant of footprint dimensions. Footprint size for traditional pollutants (ammonia, total phosphorus) meets regulatory guidelines; however, that for soluble reactive phosphorus, a presently unattended pollutant, is ~1–2 orders of magnitude larger. This suggests that it may be necessary to upgrade treatment technologies to maintain consistency with regulatory guidelines and mitigate manifestations of the eutrophication-related soluble reactive phosphorus POC.
Case Study on Boil-Off Gas (BOG) Minimization for LNG Bunkering Vessel Using Energy Storage System (ESS)
Authors: Kim Kyunghwa , Park Kido , Roh Gilltae , Chun Kangwoo
Published: May 2019

Liquefied natural gas (LNG) is recognized as a preferable alternative fuel for ship owners, since it can substantially reduce harmful emissions to comply with stricter environmental regulations. The increasing number of LNG-fueled vessels has driven up the number of LNG bunkering vessels (LNGBVs) as well. A key issue of LNGBVs is boil-off gas (BOG) generation, especially the huge amount of BOG that is generated during loading and unloading (bunkering) processes. This study proposes a hybrid system that combines conventional onboard LNG-fueled generators with an energy storage system (ESS) to solve the BOG issue of LNGBVs. This hybrid system is targeted at an LNGBV with the cargo capacity of 5000 m3. The amount of BOG generation is calculated based on assumed operation modes, and the economic study and the environmental analysis are performed based on the results. By comparing the conventional system to the proposed ones, some benefits can be verified: about 46.2% BOG reduction, 66.0% fuel saving, a 7.6-year payback period, and 4.8 tons of greenhouse gas (GHG) reduction for one voyage in the best case, with some assumptions. This proposed hybrid system using the ESS could be an attractive green solution to LNGBV owners.
A Path-Planning Strategy for Unmanned Surface Vehicles Based on an Adaptive Hybrid Dynamic Stepsize and Target Attractive Force-RRT Algorithm
Authors: Zhang Zhen , Wu Defeng , Gu Jiadong , Li Fusheng
Published: May 2019

It is well known that path planning has always been an important study area for intelligent ships, especially for unmanned surface vehicles (USVs). Therefore, it is necessary to study the path-planning algorithm for USVs. As one of the basic algorithms for USV path planning, the rapidly-exploring random tree (RRT) is popular due to its simple structure, high speed and ease of modification. However, it also has some obvious drawbacks and problems. Designed to perfect defects of the basic RRT and improve the performance of USVs, an enhanced algorithm of path planning is proposed in this study, called the adaptive hybrid dynamic stepsize and target attractive force-RRT(AHDSTAF-RRT). The ability to pass through a narrow area and the forward speed in open areas of USVs are improved by adopting the AHDSTAF-RRT in comparison to the basic RRT algorithm. The improved algorithm is also applied to an actual gulf map for simulation experiments, and the experimental data is collected and organized. Simulation experiments show that the proposed AHDSTAF-RRT in this paper outperforms several existing RRT algorithms, both in terms of path length and calculating speed.
Numerical Analyses of Wave Generation and Vortex Formation under the Action of Viscous Fluid Flows over a Depression
Authors: Chang Chih-Hua
Published: May 2019

Transient free-surface deformations and evolving vortices due to the passage of flows over a submerged cavity are simulated. A two-dimensional stream function–vorticity formulation with a free-surface model is employed. Model results are validated against the limiting case of pure lid-driven cavity flow with comparisons of the vortical flow pattern and velocity profiles. The verification of the free-surface computations are also carried out by comparing results with published potential flow solutions for cases of flows over a depressed bottom topography. The agreements are generally good. Investigations are extended to other viscous flow conditions, where the cavity is set to have the normalized dimension of one by one when scaled by the still water depth. The free-surface elevations and streamline patterns for cases with Froude numbers ranging from 0.5 to 1.1 and different Reynolds numbers (Re = 5000 and 500) are calculated. At the condition of near-critical flow (Fr ≈ 1.0), the phenomenon of upstream advancing solitons is produced. Viscous effects on the free-surface profile reveal that at a lower value of Re (e.g., Re = 500) larger advancing solitary waves are generated. Vortical flow patterns in the cavity are examined for the cases with Fr = 1.0 and various values of Re. When Re = 5000, the vortex pattern includes a primary and a weak, but dominated secondary vortices at the time reaching a nearly quasi-steady motion. For the case of lower Re (e.g., Re = 500), a steady-state vortex pattern can be established with a clockwise primary vortex mostly occupied inside the cavity.
Direct-to-Consumer Genetic Testing Data Privacy: Key Concerns and Recommendations Based on Consumer Perspectives
Authors: Hendricks-Sturrup Rachele M. , Lu Christine Y.
Published: May 2019

Direct-to-consumer genetic testing (DTC-GT) companies are engaging health consumers in unprecedented ways and leveraging the genetic information they collect to further engage health companies. This has produced controversy about DTC-GT consumer expectations, standards, and perceptions of privacy. In this commentary, we highlight recent events involving DTC-GT companies and controversy about privacy that followed those events and discuss recent studies that have explored DTC-GT consumer concerns about privacy. We discuss DTC-GT company standards of upholding consumer privacy and the general accessibility of DTC-GT company terms of use agreements and privacy policies that are written at reading levels above that of many consumers. We conclude that broader discussions and more research are needed to identify DTC-GT consumer concerns about and expectations of privacy. We anticipate that our recommendations will advance discussions on consumer privacy expectations and protections in an era of increasing engagement in DTC-GT.
Money as an Institution: Rule versus Evolved Practice? Analysis of Multiple Currencies in Argentina
Authors: Gómez Georgina M.
Published: May 2019

Monetary policies and adjustments during a financial crisis depend on policy-makers’ conceptions on what money is and how it works. There is sufficient consensus among scholars that money is an institution created within the economic system and is in line with other institutions that regulate economic action. However, there are different understandings of what institutions are and how they operate, and these understandings imply differences in terms of monetary enforcement, resilience, responsiveness and stability. This paper discusses the two main approaches that conceptualise institutions as rules and as practices presenting an empirically informed discussion of money as an institution drawing on these insights. It grounds the analysis on the empirical case of Argentina as a monetary laboratory and the plurality of currencies that circulate in its economy. The study argues that while the official currency of Argentina corresponds to the institutions as rules approach, the adoption of the U.S. dollar into a bimonetary economy evolved as equilibrium. In between, the massive community currency systems that rose and declined during the economic meltdown between 1998 and 2002 were a hybrid institution that combined rules and practice. All three of them show various degrees of resilience and stability.
A Lightweight Localization Solution for Small, Low Resources WSNs
Authors: Xiong Hong , Sichitiu Mihail L.
Published: May 2019

The increasing demand for location-dependent services in wireless sensor networks (WSNs) calls for solutions capable of handling the diversified demands and the unique challenges presented in WSNs. In most applications, nodes need to determine their locations in a reliable manner while operating under stringent constraints in computation, communication, and energy resources. This paper offers a novel solution to bridge the gap between the high accuracy demand and low resources available for range-based localization. We propose KickLoc, a fully distributed scheme, which considers the uncertainty of the distance measurements to minimize localization errors introduced from the range measurement, and leverages information from all neighboring nodes for better position estimations. Our work is evaluated via extensive simulations, with comparisons to other well-known localization schemes, and the Cramér-Rao lower bound (CRLB). In addition, we implement and evaluate the proposed system on sensor platforms with different range measurement mechanisms. The results show that this localization solution outperforms existing methods in various scenarios, while remains lightweight and suitable for small, low resources WSNs.
Comparison of Cash Crop Suitability Assessment Using Parametric, AHP, and FAHP Methods
Authors: Rodcha Rujee , K. Tripathi Nitin , Prasad Shrestha Rajendra
Published: May 2019

Cash crops, which include eucalyptus, play an important role in Thailand in wood utilization. Consequently, cash crops have become a significant driving force in land use changes and low crop yield; thus, the development of an accurate cash crop suitability model is needed. The aim of this study is to evaluate the land suitability of cash crops, such as eucalyptus, which is based on Multi Criteria Decision Making (MCDM) in Nakhon Ratchasima Province in Thailand. Parametric, classical Analytical Hierarchy Process (AHP), and fuzzy AHP (FAHP) approaches integrated with Geographic Information Systems (GIS) are compared to accomplish this. Parametric approaches equally allocate importance to all factors. AHP assigns the distribution of important factors using expert opinions. FAHP accounts for the uncertainty in expert opinions, and the triangular (Tri) and trapezoidal (Tra) approaches are compared. The results demonstrated that Trapezoidal Fuzzy AHP (TraFAHP) could classify and map cash crop suitability with 90.16% accuracy, which is a higher overall accuracy than the other approaches that are based on reference map validation. Therefore, we recommend the TraFAHP method for accurately identifying cash crop suitability.
What Happened to the Forests of Sierra Leone?
Authors: Wadsworth Richard A. , Lebbie Aiah R.
Published: May 2019

The last National Forest Inventory of Sierra Leone took place more than four decades ago in 1975. There appears to be no legal definition of “forest” in Sierra Leone and it is sometimes unclear whether reports are referring to the forest as a “land use” or a “land cover”. Estimates of forest loss in the Global Forest Resource Assessment Country Reports are based on the estimated rate during the period 1975 to 1986, and this has not been adjusted for the effects of the civil war, economic booms and busts, and the human population doubling (from about three million in 1975 to over seven million in 2018). Country estimates as part of the FAO (Food and Agriculture Organization of the United Nations) Global Forest Assessment for 2015 aggregate several classes that are not usually considered as “forest” in normal discourse in Sierra Leone (for example, mangrove swamps, rubber plantations and Raphia palm swamps). This paper makes use of maps from 1950, 1975, and 2000/2 to discuss the fate of forests in Sierra Leone. The widely accepted narrative on forest loss in Sierra Leone and generally in West Africa is that it is rapid, drastic and recent. We suggest that the validity of this narrative depends on how you define “forest”. This paper provides a detailed description of what has happened, and at the same time, offers a different view on the relationship between forests and people than the ideas put forward by James Fairhead and Melissa LeachIf we are going to progress the debate about forests in West Africa, up-to-date information and the involvement of all stakeholders are needed to contribute to the debate on what to measure. Otherwise, the decades-old assumption that the area of forest in Sierra Leone lies between less than 5% and more than 75%, provides an error margin that is not useful. This, therefore, necessitates a new forest inventory.
Developmental Biology in Cyanobacteria
Authors: Herrero Antonia , Flores Enrique
Published: May 2019

Filamentous, heterocyst-forming cyanobacteria are phototrophic multicellular organisms in which N2-fixing heterocysts and CO2-fixing vegetative cells exchange regulators and nutrients [...]
Post-FSW Cold-Rolling Simulation of ECAP Shear Deformation and Its Microstructure Role Combined to Annealing in a FSWed AA5754 Plate Joint
Authors: Cabibbo Marcello , Paoletti Chiara , Ghat Mohamed , Forcellese Archimede , Simoncini Michela
Published: May 2019

Friction stir welds are considered reliable joints for their lack of voids, cracks and distortions. When compared to the base material, friction stir welding (FSW) joints typically exhibit finer grain structured (especially at the nugget zone, NZ). Similarly, refined grain structure can also be obtained by severe plastic deformation (SPD) techniques, such as equal channel angular pressing (ECAP). In fact, the fine grain structures produced within the NZ of FSW or friction stir processed (FSP) materials are usually coarser than the ones achieved by ECAP. The former is characterized by lower dislocation density, higher high-angle boundary fraction and different mechanical strength, compared to what can be obtained by ECAP. In this study, a dedicated cold-rolling (CR) set-up, specifically designed to simulate an ECAP-equivalent shear deformation, was used to further refine the grain structure of FSW AA5754 sheets. The effect of ECAP-equivalent deformation induced by CR in a 2 mm-thick AA5754-H111 FSW joint was investigated. FSW was carried out at two different rotational (ω) and translational (v) welding speeds, 600 rpm, 200 mm/min and 1800 rpm, 75 mm/min, respectively. FSW sheets were then CR to obtain an equivalent shear strain of ε ~ 1.08, that is equivalent to 1-ECAP pass carried out with an internal die channels intersecting at an angle φ = 90° with a curvature extending over an angle Ψ = 20°. By CR, the sheet thickness reduced only by ~20%. The role of annealing on the FSW and CR plastically deformed AA5754 was also investigated. This was applied either prior or after FSW, and it resulted that whenever it follows the FSW, the mean volume fraction of dispersoids and Mg-rich particles is higher than the case of annealing preceding the FSW process. On the contrary, it was found that the annealing treatment had a minimal role on the dispersoids and particles mean size. The here reported post-FSW ECAP-simulated deformation, obtained by a customized CR process, showed sheet integrity and a significant concurrent grain size refinement.
Colorimetric Detection of Mercury Ions in Water with Capped Silver Nanoprisms
Authors: Tanvir Fouzia , Yaqub Atif , Tanvir Shazia , An Ran , Anderson William A.
Published: May 2019

The emission of mercury (II) from coal combustion and other industrial processes may have impacts on water resources, and the detection with sensitive but rapid testing methods is desirable for environmental screening. Towards this end, silver nanoprisms were chemically synthesized resulting in a blue reagent solution that transitioned towards red and yellow solutions when exposed to Hg2+ ions at concentrations from 0.5 to 100 µM. A galvanic reduction of Hg2+ onto the surfaces is apparently responsible for a change in nanoprism shape towards spherical nanoparticles, leading to the change in solution color. There were no interferences by other tested mono- and divalent metal cations in solution and pH had minimal influence in the range of 6.5 to 9.8. The silver nanoprism reagent provided a detection limit of approximately 1.5 µM (300 µg/L) for mercury (II), which compared reasonably well with other reported nanoparticle-based techniques. Further optimization may reduce this detection limit, but matrix effects in realistic water samples require further investigation and amelioration.
Study on Bainitic Transformation by Dilatometer and In Situ LSCM
Authors: Long Xiaoyan , Zhang Fucheng , Yang Zhinan , Zhang Ming
Published: May 2019

This study investigates the bainitic transformation kinetics of carbide-free bainitic steel with Si + Al and carbide-bearing bainitic steel without Si + Al, as well as the phase transformation and microstructure through in situ high-temperature laser scanning confocal microscopy. Results show that bainitic ferrite plates preferentially nucleate at the grain boundary. New plates nucleate on previously formed ones, including two dimensions which appear on a plane where a three-dimensional space of bainitic ferrite forms. Nucleation on the formed bainitic ferrite is faster than that at the grain boundary in some grains. The bainitic ferrite growth at the austenite grain boundary is longer and has a faster transformation rate. The bainitic ferrite growth on the formed bainitic ferrite plate is shorter and has a slower transformation rate. The location and number of nucleation sites influence the thickness of the bainitic ferrite. The higher the number of plates preferentially nucleating at the original austenite grain boundary, the greater the thickness of the bainitic ferrite.
Effect of Intermetallic Compounds on the Thermal and Mechanical Properties of Al–Cu Composite Materials Fabricated by Spark Plasma Sintering
Authors: Kim Kyungju , Kim Dasom , Park Kwangjae , Cho Myunghoon , Cho Seungchan , Kwon Hansang
Published: May 2019

Aluminium–copper composite materials were successfully fabricated using spark plasma sintering with Al and Cu powders as the raw materials. Al–Cu composite powders were fabricated through a ball milling process, and the effect of the Cu content was investigated. Composite materials composed of Al–20Cu, Al–50Cu, and Al–80Cu (vol.%) were sintered by a spark plasma sintering process, which was carried out at 520 °C and 50 MPa for 5 min. The phase analysis of the composite materials by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) indicated that intermetallic compounds (IC) such as CuAl2 and Cu9Al4 were formed through reactions between Cu and Al during the spark plasma sintering process. The mechanical properties of the composites were analysed using a Vickers hardness tester. The Al–50Cu composite had a hardness of approximately 151 HV, which is higher than that of the other composites. The thermal conductivity of the composite materials was measured by laser flash analysis, and the highest value was obtained for the Al–80Cu composite material. This suggests that the Cu content affects physical properties of the Al–Cu composite material as well as the amount of intermetallic compounds formed in the composite material.
Ethylene Glycol Dicyclopentenyl (Meth)Acrylate Homo and Block Copolymers via Nitroxide Mediated Polymerization
Authors: Maupu Alexandre , Kanawati Yara , Métafiot Adrien , Maric Milan
Published: May 2019

Nitroxide-mediated polymerization (NMP), (homo and block copolymerization with styrene (S) and butyl methacrylate/S) of ethylene glycol dicyclopentenyl ether (meth)acrylates (EGDEA and EGDEMA) was studied using BlocBuilder alkoxyamines. EGDEA homopolymerization was not well-controlled, independent of temperature (90–120 °C), or additional free nitroxide (0–10 mol%) used. Number average molecular weights (Mn) achieved for poly(EGDEA) were 4.0–9.5 kg mol−1 and were accompanied by high dispersity (Ð = Mw/Mn = 1.62–2.09). Re-initiation and chain extension of the poly(EGDEA) chains with styrene (S) indicated some block copolymer formation, but a high fraction of chains were terminated irreversibly. EGDEA-stat-S statistical copolymerizations with a low mol fraction S in initial feed, fS,0 = 0.05, were slightly better controlled compared to poly(EGDEA) homopolymerizations (Ð was reduced to 1.44 compared to 1.62 at similar conditions). EGDEMA, in contrast, was successfully polymerized using a small fraction of S (fS,0 ~ 10 mol%) to high conversion (72%) to form well-defined EGDEMA-rich random copolymer (molar composition = FEGDEMA = 0.87) of Mn = 14.3 kg mol−1 and Ð = 1.38. EGDEMA-rich compositions were also polymerized with the unimolecular succinimidyl ester form of BlocBuilder initiator, NHS-BlocBuilder with similar results, although Ðs were higher ~1.6. Chain extensions resulted in monomodal shifts to higher molecular weights, indicating good chain end fidelity.
Generalized Stacking Fault Energy of {10-11}<11-23> Slip System in Mg-Based Binary Alloys: A First Principles Study
Authors: Dou Yuchen , Luo Hong , Zhang Jing , Tang Xiaohua
Published: May 2019

In this work, the generalized stacking fault energies (GSFEs) of {10-11}<11-23> slip system in a wide range of Mg-X (X = Ag, Al, Bi, Ca, Dy, Er, Gd, Ho, Li, Lu, Mn, Nd, Pb, Sc, Sm, Sn, Y, Yb, Zn and Zr) binary alloys has been studied. The doping concentration in the doping plane and the Mg-X system is 12.5 at.% and 1.79 at.%, respectively. Two slip modes (slip mode I and II) were considered. For pure magnesium, these two slip modes are equivalent to each other. However, substituting a solute atom into the magnesium matrix will cause different effects on these two slip modes. Based on the calculated GSFEs, two design maps were constructed to predict solute effects on the behavior of the {10-11}<11-23> dislocations. The design maps suggest that the addition of Ag, Al, Ca, Dy, Er, Gd, Ho, Lu, Nd, Sm, Y, Yb and Zn could facilitate the {10-11}<11-23> dislocations.
Experimental Verification of Isotropic and Anisotropic Anhysteretic Magnetization Models
Authors: Nowicki Michał , Szewczyk Roman , Nowak Paweł
Published: May 2019

The anhysteretic magnetization curve is the key element of modeling magnetic hysteresis loops. Despite the fact that it is intensively exploited, known models of anhysteretic curve have not been verified experimentally. This paper presents the validation of four anhysteretic curve models considering four different materials, including isotropic, such as Mn-Zn soft ferrite, as well as anisotropic amorphous and nanocrystalline alloys. The presented results indicate that only the model that considers anisotropic energy is valid for a wide set of modern magnetic materials. The most suitable of the verified models is the anisotropic extension function-based model, which considers uniaxial anisotropy.
Ti–Zr–Si–Nb Nanocrystalline Alloys and Metallic Glasses: Assessment on the Structure, Thermal Stability, Corrosion and Mechanical Properties
Authors: Gabor Camelia , Cristea Daniel , Velicu Ioana-Laura , Bedo Tibor , Gatto Andrea , Bassoli Elena , Varga Bela , Pop Mihai Alin , Geanta Victor , Stefanoiu Radu , Codescu Mirela Maria , Manta Eugen , Patroi Delia , Florescu Monica , Munteanu Sorin Ion , Ghiuta Ioana , Lupu Nicoleta , Munteanu Daniel
Published: May 2019

The development of novel Ti-based amorphous or β-phase nanostructured metallic materials could have significant benefits for implant applications, due to improved corrosion and mechanical characteristics (lower Young’s modulus, better wear performance, improved fracture toughness) in comparison to the standardized α+β titanium alloys. Moreover, the devitrification phenomenon, occurring during heating, could contribute to lower input power during additive manufacturing technologies. Ti-based alloy ribbons were obtained by melt-spinning, considering the ultra-fast cooling rates this method can provide. The titanium alloys contain in various proportions Zr, Nb, and Si (Ti60Zr10Si15Nb15, Ti64Zr10Si15Nb11, Ti56Zr10Si15Nb19) in various proportions. These elements were chosen due to their reported biological safety, as in the case of Zr and Nb, and the metallic glass-forming ability and biocompatibility of Si. The morphology and chemical composition were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy, while the structural features (crystallinity, phase attribution after devitrification (after heat treatment)) were assessed by X-ray diffraction. Some of the mechanical properties (hardness, Young’s modulus) were assessed by instrumented indentation. The thermal stability and crystallization temperatures were measured by differential thermal analysis. High-intensity exothermal peaks were observed during heating of melt-spun ribbons. The corrosion behavior was assessed by electrocorrosion tests. The results show the potential of these alloys to be used as materials for biomedical applications.
Cavitation Wear of Basalt-Based Glass Ceramic
Authors: Pavlovic Marko , Dojcinovic Marina , Prokic-Cvetkovic Radica , Andric Ljubisa , Ceganjac Zoran , Trumbulovic Ljiljana
Published: May 2019

This paper examines the possibility of using basalt-based glass ceramics for construction of structural parts of equipment in metallurgy and mining. An ultrasonic vibration method with a stationary sample pursuant to the ASTM G32 standard was used to evaluate the possibility of the glass ceramic samples application in such operating conditions. As the starting material for synthesis of samples, olivine–pyroxene basalt from the locality Vrelo–Kopaonik Mountain (Serbia) was used. In order to obtain pre-determined structure and properties of basalt-based glass ceramics, raw material preparation methods through the sample crushing, grinding, and mechanical activation processes have been examined together with sample synthesis by means of melting, casting, and thermal treatment applied for the samples concerned. The mass loss of samples in function of the cavitation time was monitored. Sample surface degradation level was quantified using the image analysis. During the test, changes in sample morphology were monitored by means of the scanning electronic microscopy method. The results showed that basalt-based glass ceramics are highly resistant to cavitation wear and can be used in similar exploitation conditions as a substitute for other metal materials.
In Situ Surface-Enhanced Raman Spectroscopy of Cellular Components: Theory and Experimental Results
Authors: D’Acunto Mario
Published: May 2019

In the last decade, surface-enhanced Raman spectroscopy (SERS) met increasing interest in the detection of chemical and biological agents due to its rapid performance and ultra-sensitive features. Being SERS a combination of Raman spectroscopy and nanotechnology, it includes the advantages of Raman spectroscopy, providing rapid spectra collection, small sample sizes, characteristic spectral fingerprints for specific analytes. In addition, SERS overcomes low sensitivity or fluorescence interference that represents two major drawbacks of traditional Raman spectroscopy. Nanoscale roughened metal surfaces tremendously enhance the weak Raman signal due to electromagnetic field enhancement generated by localized surface plasmon resonances. In this paper, we detected label-free SERS signals for arbitrarily configurations of dimers, trimers, etc., composed of gold nanoshells (AuNSs) and applied to the mapping of osteosarcoma intracellular components. The experimental results combined to a theoretical model computation of SERS signal of specific AuNSs configurations, based on open cavity plasmonics, give the possibility to quantify SERS enhancement for overcoming spectral fluctuations. The results show that the Raman signal is locally enhanced inside the cell by AuNSs uptake and correspondent geometrical configuration generating dimers are able to enhance locally electromagnetic fields. The SERS signals inside such regions permit the unequivocal identification of cancer-specific biochemical components such as hydroxyapatite, phenylalanine, and protein denaturation due to disulfide bonds breaking between cysteine links or proline.
Effects of Citric Acid on Structures and Properties of Thermoplastic Hydroxypropyl Amylomaize Starch Films
Authors: Qin Yang , Wang Wentao , Zhang Hui , Dai Yangyong , Hou Hanxue , Dong Haizhou
Published: May 2019

Hydroxypropyl amylomaize starch (HPAS) films were prepared by hot press. The effects of initial pH of HPAS on the mechanical properties, molecular interaction, structure, and cross-linking degree of the resultant films were investigated. A weak acidic condition was suitable for cross-linking of citric acid and HPAS by reactive extrusion. The film of HPAS with an initial pH of 5.66 had the maximum tensile strength of 7.20 MPa and elongation-at-break of 94.53%, and the weight average molecular weight of HPAS increased to 4.17 × 105 g/mol. An appropriate initial pH facilitated the formation of diester bonds between HPAS and citric acid during extrusion, but too low initial pH levels resulted in hydrolysis of starch molecules and reduced the mechanical properties.
Influence of Randomness in Rubber Materials Parameters on the Reliability of Rubber O-Ring Seal
Authors: Liang Banglong , Yang Xi , Wang Zili , Su Xing , Liao Baopeng , Ren Yi , Sun Bo
Published: May 2019

The properties of materials directly affect the performance of the sealing structures, among which the rubber O-ring seal is one of the most commonly used. In addition, the performance of the O-ring seal is often influenced by the randomness in structure and working conditions, which greatly reduce the reliability of the sealing structure. This paper proposes a reliability-based method to analyze the influence of the randomness in rubber material parameters on the sealing performance of the O-ring. Based on the failure mechanism of the O-ring seal, the stochastic characteristics of the parameters in O-rings are determined through experiments, and the influences of these parameters on the reliability are subsequently analyzed. Moreover, the working conditions are also taken into account to analyze their influence on the performance and reliability of the O-ring seal. The proposed method provides easy access to estimate the reliability of the rubber O-ring seal considering the uncertainty in structure and operational conditions. It is revealed that the material and geometric parameters had greater influence on the reliability of the rubber O-ring.
Improved Method for Measuring the Permeability of Nanoporous Material and Its Application to Shale Matrix with Ultra-Low Permeability
Authors: Lu Taojie , Xu Ruina , Zhou Bo , Wang Yichuan , Zhang Fuzhen , Jiang Peixue
Published: May 2019

Nanoporous materials have a wide range of applications in clean energy and environmental research. The permeability of nanoporous materials is low, which affects the fluid transport behavior inside the nanopores and thus also affects the performance of technologies based on such materials. For example, during the development of shale gas resources, the permeability of the shale matrix is normally lower than 10−3 mD and has an important influence on rock parameters. It is challenging to measure small pressure changes accurately under high pressure. Although the pressure decay method provides an effective means for the measurement of low permeability, most apparatuses and experiments have difficulty measuring permeability in high pressure conditions over 1.38 MPa. Here, we propose an improved experimental method for the measurement of low permeability. To overcome the challenge of measuring small changes in pressure at high pressure, a pressure difference sensor is used. By improving the constant temperature accuracy and reducing the helium leakage rate, we measure shale matrix permeabilities ranging from 0.05 to 2 nD at pore pressures of up to 8 MPa, with good repeatability and sample mass irrelevance. The results show that porosity, pore pressure, and moisture conditions influence the matrix permeability. The permeability of moist shale is lower than that of dry shale, since water blocks some of the nanopores.
RETRACTED: Conflicts of Interest and Misleading Statements in Official Reports about the Health Consequences of Radiofrequency Radiation and Some New Measurements of Exposure Levels
Authors: Pockett Susan
Published: May 2019

Official reports to governments throughout the Western world attempt to allay public concern about the increasing inescapability of the microwaves (also known as radiofrequency radiation or RF) emitted by “smart” technologies, by repeating the dogma that the only proven biological effect of RF is acute tissue heating, and assuring us that the levels of radiation to which the public are exposed are significantly less than those needed to cause acute tissue heating. The present paper first shows the origin of this “thermal-only” dogma in the military paranoia of the 1950s. It then reveals how financial conflict of interest and intentionally misleading statements have been powerful factors in preserving that dogma in the face of now overwhelming evidence that it is false, using one 2018 report to ministers of the New Zealand government as an example. Lastly, some new pilot measurements of ambient RF power densities in Auckland city are reported and compared with levels reported in other cities, various international exposure limits, and levels shown scientifically to cause biological harm. It is concluded that politicians in the Western world should stop accepting soothing reports from individuals with blatant conflicts of interest and start taking the health and safety of their communities seriously.
Characterizations of Regular Ordered Semigroups by (∈,∈∨(k∗,qk))-Fuzzy Quasi-Ideals
Authors: Mahboob Ahsan , Salam Abdus , Ali Md. Firoj , Khan Noor Mohammad
Published: May 2019

In this paper, some properties of the ( k ∗ , k ) -lower part of ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy quasi-ideals are obtained. Then, we characterize regular ordered semigroups in terms of its ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy quasi-ideals, ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy generalized bi-ideals, ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy left ideals and ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy right ideals, and an equivalent condition for ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy left (resp. right) ideals is obtained. Finally, the existence theorems for an ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy quasi-ideal as well as for the minimality of an ( ∈ , ∈ ∨ ( k ∗ , q k ) ) -fuzzy quasi-ideal of an ordered semigroup are provided.
Skew-Reflected-Gompertz Information Quantifiers with Application to Sea Surface Temperature Records
Authors: Contreras-Reyes Javier E. , Maleki Mohsen , Devia Cortés Daniel
Published: May 2019

The Skew-Reflected-Gompertz (SRG) distribution, introduced by Hosseinzadeh et al. (J. Comput. Appl. Math. (2019) 349, 132–141), produces two-piece asymmetric behavior of the Gompertz (GZ) distribution, which extends the positive to a whole dominion by an extra parameter. The SRG distribution also permits a better fit than its well-known classical competitors, namely the skew-normal and epsilon-skew-normal distributions, for data with a high presence of skewness. In this paper, we study information quantifiers such as Shannon and Rényi entropies, and Kullback–Leibler divergence in terms of exact expressions of GZ information measures. We find the asymptotic test useful to compare two SRG-distributed samples. Finally, as a real-world data example, we apply these results to South Pacific sea surface temperature records.
Adaptive Pinning Synchronization of Fractional Complex Networks with Impulses and Reaction–Diffusion Terms
Authors: Hai Xudong , Ren Guojian , Yu Yongguang , Xu Conghui
Published: May 2019

In this paper, a class of fractional complex networks with impulses and reaction–diffusion terms is introduced and studied. Meanwhile, a class of more general network structures is considered, which consists of an instant communication topology and a delayed communication topology. Based on the Lyapunov method and linear matrix inequality techniques, some sufficient criteria are obtained, ensuring adaptive pinning synchronization of the network under a designed adaptive control strategy. In addition, a pinning scheme is proposed, which shows that the nodes with delayed communication are good candidates for applying controllers. Finally, a numerical example is given to verify the validity of the main results.
Logarithmic Coefficients for Univalent Functions Defined by Subordination
Authors: Adegani Ebrahim Analouei , Cho Nak Eun , Jafari Mostafa
Published: May 2019

In this work, the bounds for the logarithmic coefficients γ n of the general classes S * ( φ ) and K ( φ ) were estimated. It is worthwhile mentioning that the given bounds would generalize some of the previous papers. Some consequences of the main results are also presented, noting that our method is more general than those used by others.
Subordination Approach to Space-Time Fractional Diffusion
Authors: Bazhlekova Emilia , Bazhlekov Ivan
Published: May 2019

The fundamental solution to the multi-dimensional space-time fractional diffusion equation is studied by applying the subordination principle, which provides a relation to the classical Gaussian function. Integral representations in terms of Mittag-Leffler functions are derived for the fundamental solution and the subordination kernel. The obtained integral representations are used for numerical evaluation of the fundamental solution for different values of the parameters.
A Study of Third Hankel Determinant Problem for Certain Subfamilies of Analytic Functions Involving Cardioid Domain
Authors: Shi Lei , Ali Izaz , Arif Muhammad , Cho Nak Eun , Hussain Shehzad , Khan Hassan
Published: May 2019

In the present article, we consider certain subfamilies of analytic functions connected with the cardioid domain in the region of the unit disk. The purpose of this article is to investigate the estimates of the third Hankel determinant for these families. Further, the same bounds have been investigated for two-fold and three-fold symmetric functions.
Memes Evolution in a Memetic Variant of Particle Swarm Optimization
Authors: Bartoccini Umberto , Carpi Arturo , Poggioni Valentina , Santucci Valentino
Published: May 2019

In this work, a coevolving memetic particle swarm optimization (CoMPSO) algorithm is presented. CoMPSO introduces the memetic evolution of local search operators in particle swarm optimization (PSO) continuous/discrete hybrid search spaces. The proposed solution allows one to overcome the rigidity of uniform local search strategies when applied to PSO. The key contribution is that memes provides each particle of a PSO scheme with the ability to adapt its exploration dynamics to the local characteristics of the search space landscape. The objective is obtained by an original hybrid continuous/discrete meme representation and a probabilistic co-evolving PSO scheme for discrete, continuous, or hybrid spaces. The coevolving memetic PSO evolves both the solutions and their associated memes, i.e. the local search operators. The proposed CoMPSO approach has been experimented on a standard suite of numerical optimization benchmark problems. Preliminary experimental results show that CoMPSO is competitive with respect to standard PSO and other memetic PSO schemes in literature, and its a promising starting point for further research in adaptive PSO local search operators.
Strong Convergence Theorems for Variational Inequalities and Common Fixed-Point Problems Using Relaxed Mann Implicit Iteration Methods
Authors: Ceng Lu-Chuan , Shang Meijuan
Published: May 2019

Mann-like iteration methods are significant to deal with convex feasibility problems in Banach spaces. We focus on a relaxed Mann implicit iteration method to solve a general system of accretive variational inequalities with an asymptotically nonexpansive mapping in the intermediate sense and a countable family of uniformly Lipschitzian pseudocontractive mappings. More convergence theorems are proved under some suitable weak condition in both 2-uniformly smooth and uniformly convex Banach spaces.
Solution of Ambartsumian Delay Differential Equation with Conformable Derivative
Authors: Khaled Sayed M. , El-Zahar Essam R. , Ebaid Abdelhalim
Published: May 2019

This paper addresses the modelling of Ambartsumian equation using the conformable derivative as an application of the theory of surface brightness in astronomy. The homotopy perturbationmethod is applied to solve this model, where the approximate solution is given in terms of the conformable derivative order and the exponential functions. The present solution reduces to the corresponding one in the relevant literature as a special case. Moreover, a rapid rate of convergence has been achieved for the obtained approximate solutions. Furthermore, the accuracy of the obtained numerical results is validated via calculating the residual against the impeded parameters. It is shown graphically that the obtained residual approaches zero in various cases, which proves the efficiency of the current analysis.
A Unified Generalization of the Catalan, Fuss, and Fuss—Catalan Numbers
Authors: Qi Feng , Shi Xiao-Ting , Cerone Pietro
Published: May 2019

In the paper, the authors introduce a unified generalization of the Catalan numbers, the Fuss numbers, the Fuss–Catalan numbers, and the Catalan–Qi function, and discover some properties of the unified generalization, including a product-ratio expression of the unified generalization in terms of the Catalan–Qi functions, three integral representations of the unified generalization, and the logarithmically complete monotonicity of the second order for a special case of the unified generalization.
Hypolipidemic Effect of Arthrospira (Spirulina) maxima Supplementation and a Systematic Physical Exercise Program in Overweight and Obese Men: A Double-Blind, Randomized, and Crossover Controlled Trial
Authors: Hernández-Lepe Marco Antonio , Wall-Medrano Abraham , López-Díaz José Alberto , Juárez-Oropeza Marco Antonio , Luqueño-Bocardo Oscar Iván , Hernández-Torres Rosa Patricia , Ramos-Jiménez Arnulfo
Published: May 2019

Low-fat diets, lipid-modifying nutraceuticals and a higher level of physical activity are often recommended to reduce dyslipidemia. A double-blind, randomized, crossover, controlled trial was designed to evaluate the independent and synergistic effects of Arthrospira (Spirulina) maxima supplementation (4.5 g·day−1) with or without performing a physical exercise program (PEP: aerobic exercise (3 days·week−1) + high-intensity interval training (2 days·week−1)) on blood lipids and BMI of 52 sedentary men with excess body weight. During six weeks, all participants were assigned to four intervention treatments (Spirulina maxima with PEP (SE), placebo with PEP (Ex), Spirulina maxima without PEP (Sm), placebo without PEP (C; control)) and plasma lipids were evaluated spectrophotometrically pre- vs. post intervention in stratified subgroups (overweight, obese and dyslipidemic subjects). Pre/post comparisons showed significant reductions in all plasma lipids in the SE group, particularly in those with dyslipidemia (p ≤ 0.043). Comparing the final vs. the initial values, BMI, total cholesterol, triglycerides and low-density lipoprotein cholesterol were decreased. High-density lipoprotein cholesterol increased in all treatment groups compared to C. Changes were observed mostly in SE interventions, particularly in dyslipidemic subjects (p < 0.05). Spirulina maxima supplementation enhances the hypolipidemic effect of a systematic PEP in men with excess body weight and dyslipidemia.
Chemical Investigation of the Indonesian Tunicate Polycarpa aurata and Evaluation of the Effects Against Schistosoma mansoni of the Novel Alkaloids Polyaurines A and B
Authors: Casertano Marcello , Imperatore Concetta , Luciano Paolo , Aiello Anna , Putra Masteria Yunovilsa , Gimmelli Roberto , Ruberti Giovina , Menna Marialuisa
Published: May 2019

A deep study of the metabolic content of the tunicate Polycarpa aurata, collected from Indonesian coast, afforded the isolation of two novel alkaloids, polyaurines A (1) and B (2), along with two new p-substituted benzoyl derivatives (3 and 4) and four known compounds (5–8). The structural elucidation of the new secondary metabolites was assigned by 1D, 2D NMR, and HRESIMS techniques. Computational studies resulted a useful tool to unambiguously determine in polyaurine B the presence of rarely found 1,2,4-thiadiazole ring. The effects of polyaurines A and B on mammalian cells growth and on the viability of different blood-dwelling Schistosoma mansoni (phylum: Platyhelminthes) stages, as well as egg production, were evaluated. Both compounds resulted not cytotoxic; interestingly some of the eggs produced by polyaurine A-treated adult pairs in vitro are smaller, deformed, and/or fragmented; therefore, polyaurine A could represent an interesting bioactive natural molecule to be further investigated.
Identification of Cyanobacterial Strains with Potential for the Treatment of Obesity-Related Co-Morbidities by Bioactivity, Toxicity Evaluation and Metabolite Profiling
Authors: Costa Margarida , Rosa Filipa , Ribeiro Tiago , Hernandez-Bautista Rene , Bonaldo Marco , Gonçalves Silva Natália , Eiríksson Finnur , Thorsteinsdóttir Margrét , Ussar Siegfried , Urbatzka Ralph
Published: May 2019

Obesity is a complex disease resulting in several metabolic co-morbidities and is increasing at epidemic rates. The marine environment is an interesting resource of novel compounds and in particular cyanobacteria are well known for their capacity to produce novel secondary metabolites. In this work, we explored the potential of cyanobacteria for the production of compounds with relevant activities towards metabolic diseases using a blend of target-based, phenotypic and zebrafish assays as whole small animal models. A total of 46 cyanobacterial strains were grown and biomass fractionated, yielding in total 263 fractions. Bioactivities related to metabolic function were tested in different in vitro and in vivo models. Studying adipogenic and thermogenic gene expression in brown adipocytes, lipid metabolism and glucose uptake in hepatocytes, as well as lipid metabolism in zebrafish larvae, we identified 66 (25%) active fractions. This together with metabolite profiling and the evaluation of toxicity allowed the identification of 18 (7%) fractions with promising bioactivity towards different aspects of metabolic disease. Among those, we identified several known compounds, such as eryloside T, leptosin F, pheophorbide A, phaeophytin A, chlorophyll A, present as minor peaks. Those compounds were previously not described to have bioactivities in metabolic regulation, and both known or unknown compounds could be responsible for such effects. In summary, we find that cyanobacteria hold a huge repertoire of molecules with specific bioactivities towards metabolic diseases, which needs to be explored in the future.