bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Genome-to-Genome Comparison Approach for Large-Scale Revisiting of Current Microbial Taxonomy
Authors: Tsai Ming-Hsin , Liu Yen-Yi , Soo Von-Wun , Chen Chih-Chieh
Published: June 2019

Microbial diversity has always presented taxonomic challenges. With the popularity of next-generation sequencing technology, more unculturable bacteria have been sequenced, facilitating the discovery of additional new species and complicated current microbial classification. The major challenge is to assign appropriate taxonomic names. Hence, assessing the consistency between taxonomy and genomic relatedness is critical. We proposed and applied a genome comparison approach to a large-scale survey to investigate the distribution of genomic differences among microorganisms. The approach applies a genome-wide criterion, homologous coverage ratio (HCR), for describing the homology between species. The survey included 7861 microbial genomes that excluded plasmids, and 1220 pairs of genera exhibited ambiguous classification. In this study, we also compared the performance of HCR and average nucleotide identity (ANI). The results indicated that HCR and ANI analyses yield comparable results, but a few examples suggested that HCR has a superior clustering effect. In addition, we used the Genome Taxonomy Database (GTDB), the gold standard for taxonomy, to validate our analysis. The GTDB offers 120 ubiquitous single-copy proteins as marker genes for species classification. We determined that the analysis of the GTDB still results in classification boundary blur between some genera and that the marker gene-based approach has limitations. Although the choice of marker genes has been quite rigorous, the bias of marker gene selection remains unavoidable. Therefore, methods based on genomic alignment should be considered for use for species classification in order to avoid the bias of marker gene selection. On the basis of our observations of microbial diversity, microbial classification should be re-examined using genome-wide comparisons.
Geology and Genesis of Xianglushan Fe-Cu Orefield in Sichuan (SW China): Evidence from C-O-S-Pb Isotopes
Authors: Wang Tianguo , Lai Chunkit , Li Huan
Published: June 2019

The Proterozoic Xianglushan Fe-Cu orefield (western Sichuan) is located in the Huili–Dongchuan ore belt on the southwestern margin of the Yangtze Block in SW China. The orefield has experienced complex magmatotectonic activities, and hosts a wide variety of Fe oxide-(Cu-Au) deposits. At Xianglushan, the orebodies are made of stratabound magnetite–hematite orebodies superimposed by vein-type chalcopyrite mineralization. The stratabound Fe orebodies are hosted mainly in the Proterozoic volcanic-sedimentary rocks of the lower Yinmin Formation, whilst the Cu vein or stockwork ores were mainly emplaced into the upper part of the footwall volcanic rocks and the lower part of the Fe orebodies. We divided the alteration/mineralization and their fluid inclusions (FIs) into the (I) sodic-calcic alteration, (II) potassic-silicic-sericite alteration and Fe-(Cu) mineralization, and (III) carbonate alteration and Cu mineralization stages. Stage II FIs are mainly two-phase (vapor-liquid), and are featured by medium temperature (348 to 379 °C) and high salinity (21.8 to 22.9 wt % NaCl eqv). Their generally negative calcite δ13C (−4.1‰ to −3.1‰) and δ18OH2O (12.2‰ to 15.3‰) values reveal that the Stage II ore fluids have had a seawater-magmatic fluid mixed source. Late Stage II pyrite has δ34S (−3.3‰ to 13.7‰), 206Pb/204Pb (17.663 to 18.982), 207Pb/204Pb (15.498 to 15.824) and 208Pb/204Pb (37.784 to 38.985), suggesting that the ore-forming materials were derived from dominantly upper crustal source. Stage III FIs are also mainly two-phase (vapor-liquid), and are featured by lower temperature (206 to 267 °C) and salinity (19.0 to 22.5 wt % NaCl eqv) than their Stage II counterparts. The Stage III ore fluids were also likely derived from a meteoric–magmatic mixed source with greater magmatic influence, as indicated by the generally negative calcite δ13C (−6.9‰ to −4.6‰) and δ18OH2O (6.3‰ to 9.2‰) values. Similar to the late Stage II pyrite, the Stage III chalcopyrite δ34S (−4.6‰ to 5.2‰) and Pb isotopes (206Pb/204Pb = 18.198 to 18.987; 207Pb/204Pb = 15.534 to 15.876; and 208Pb/204Pb = 37.685 to 39.476) also suggest a crustal ore-forming material source. Therefore, we suggest that the Fe-(Cu) and Cu mineralization at Xianglushan had similar ore fluid and material sources, although the magmatic influence increased in the later stage. This resembles many Fe-(Cu) deposits in the Huili–Dongchuan ore belt. We conclude that the Xianglushan Fe-Cu deposits are both similar to and different from typical iron-oxide copper gold (IOCG) deposits in terms of alteration styles and hydrothermal mineral assemblages, and are thus best classified as IOCG-like deposits hosted in submarine volcanic-sedimentary rocks. Considering the Mesoproterozoic regional tectonics in the southwestern Yangtze Block, we propose that the Xianglushan ore formation occurred in an intra-/back-arc inversion setting, possibly related to the closure of the Anning ocean basin.
Subduction-Induced Fractionated Highly Siderophile Element Patterns in Forearc Mantle
Authors: Xu Yang , Liu Chuan-Zhou
Published: June 2019

Compositions of highly siderophile elements (HSEs) in forearc mantle have been little studied and effects of slab dehydration on their abundances in forearc mantle remains unclear. This study reports two different kinds of HSE patterns for peridotites from a New Caledonia forearc ophiolite. The Group-I samples show relatively flat patterns of Ir-group-platinum-group elements (IPGEs) and enrichment of Pt over Pd. Such patterns imply that interstitial sulfides were significantly removed through melt extraction, whereas sulfides enclosed within silicates were mostly unaffected. Meanwhile, Pt-Fe alloys were generated, resulting in suprachondritic Pt/Pd ratios. In contrast, the Group-II samples display convex HSE patterns and are depleted in all HSEs except for Ru, yielding strongly positive Ru anomalies. This indicates that both enclosed and interstitial sulfides were substantially consumed, whereas chromite was generated to stabilize Ru. Compared to abyssal peridotites, subduction-related peridotites commonly have stronger fractionation in the HSEs. Therefore, the HSE data of mantle peridotites are potentially able to discriminate the tectonic settings of ophiolites.
Development of a Simulator for Random and Non-Random Breakage of Particles and Liberation of Grains Based on Voronoi Tessellation
Authors: Mirzaei Zeinab Sadat , Khalesi Mohammad Reza
Published: June 2019

In mineral processing, liberation of valuable mineral from gangue minerals is the most important stage before the concentration process. Comminution, which leads to liberation, includes two types of random and non-random breakages. The contribution of random and non-random breakage is very important in modelling the liberation phenomenon. In this paper, a simulator based on 2D Voronoi tessellation is introduced which can simulate random, preferential and detachment breakages of binary ores (valuable and gangue mineral). This simulator has been validated by image analysis of fragmented artificial ores which were made in different grades and comminuted in different energy levels by a drop weight device. The data obtained from images of comminuted particles were processed using the codes prepared in MATLAB®. Results showed that for the samples used in this study, the proportion of the intergranular breakage changes as the grade of the ore changes, with an agreement between simulations and experiments, independently from the energy level of comminution.
Preparation of a Stable Nanoscale Manganese Residue-Derived FeS@Starch-Derived Carbon Composite for the Adsorption of Safranine T
Authors: Hu Huayu , Lin Caiqiong , Zhang Yanjuan , Cai Xiunan , Huang Zuqiang , Chen Congjin , Qin Yuben , Liang Jing
Published: June 2019

To develop a novel, low-cost adsorbent with natural material and industrial waste as raw materials, nanoscale manganese residue-derived FeS@starch-derived carbon (MR–FeS@SC) composite was prepared by the carbonization of starch–manganese residue gel. Manganese residue-derived FeS (MR–FeS) and starch-derived carbon (SC) were also prepared as contrasts for comparative studies. The MR–FeS@SC nanocomposite exhibited relatively large specific surface area and micropore volume, appropriate pore size, abundant functional groups, strong interaction between the functional groups of SC and MR–FeS, and the immobilization and uniform distribution of MR–FeS nanoparticles onto SC support material, which contributed to better adsorption properties for the removal of Safranine T (ST) from the aqueous solution compared with those of MR–FeS and SC. The adsorption could be conducted at a wide range of pH and temperature to achieve a satisfy removal efficiency of ST with MR–FeS@SC nanocomposite as adsorbent. The adsorption kinetics well followed the pseudo-second-order model, and the dominant mechanism was chemisorption. The adsorption behavior was well described by the Langmuir isotherm model. Due to the strong interaction between MR–FeS nanoparticles and SC support, MR–FeS@SC nanocomposite exhibited better reusability and stability even after fifteen cycles. This study provides a facile method of preparing effective and stable adsorbents for the treatment of dye wastewater.
Preparation and Tribological Properties of WS2 Hexagonal Nanoplates and Nanoflowers
Authors: Zhang Xianghua , Wang Jiangtao , Xu Hongxiang , Tan Heng , Ye Xia
Published: June 2019

This paper presents the facile synthesis of two different morphologies of WS2 nanomaterials—WS2 hexagonal nanoplates and nanoflowers—by a sulfurization reaction. The phases and morphology of the samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The tribological performance of the two kinds of WS2 nanomaterials as additives in paraffin oil were measured using a UMT (Universal Mechanical Tester)-2 tribotester. The results demonstrated that the friction and wear performance of paraffin oil can be greatly improved with the addition of WS2 nanomaterials, and that the morphology and content of WS2 nanomaterials have a significant effect on the tribological properties of paraffin oil. The tribological performance of lubricating oil was best when the concentration of the WS2 nanomaterial additive was 0.5 wt %. Moreover, the paraffin oil with added WS2 nanoflowers exhibited better tribological properties than paraffin oil with added WS2 hexagonal nanoplates. The superior tribological properties of WS2 nanoflowers can be attributed to their special morphology, which contributes to the formation of a uniform tribo-film during the sliding process.
Aggregation, Sedimentation, and Dissolution of Copper Oxide Nanoparticles: Influence of Low-Molecular-Weight Organic Acids from Root Exudates
Authors: Peng Cheng , Tong Hong , Yuan Peng , Sun Lijuan , Jiang Lei , Shi Jiyan
Published: June 2019

The rhizosphere is an essential pathway for the uptake of metal-based nanoparticles (MNPs) by plant roots. However, the interaction between root exudates and MNPs is still unclear. In this study, we initially identified the major low-molecular-weight organic acids (LMWOAs) in the rice root exudates using hydroponics. Then, the individual LMWOAs were added to CuO nanoparticle suspensions to investigate their effects on the environmental behavior of the MNPs. The results showed that both the variety and the concentration of LMWOAs impacted the aggregation, sedimentation, and dissolution of CuO nanoparticles (NPs). Almost all LMWOAs except succinic acid inhibited the aggregation of CuO NPs by enhancing the electrostatic repulsive force between NPs. The presence of citric and oxalic acids rather than lactic acid greatly improved the stability of CuO NP suspensions, but other acids showed a low promoting and high inhibiting effect on NP sedimentation. Moreover, all the LMWOAs from root exudates facilitated the dissolution of CuO NPs with a positive dose-dependent correlation, especially formic acid. Notably, citric acid, as the most abundant LMWOAs in rice root exudates, largely determined the aggregation, sedimentation, and dissolution of CuO NPs. This study provides a better understanding on NP–plant interactions in the rhizosphere.
Regulation of Cu Species in CuO/SiO2 and Its Structural Evolution in Ethynylation Reaction
Authors: Li Haitao , Ban Lijun , Wang Zhipeng , Meng Pingfan , Zhang Yin , Wu Ruifang , Zhao Yongxiang
Published: June 2019

A Cu-based nano-catalyst has been widely used in the ethynylation of formaldehyde; however, the effects of the presence of Cu on the reaction have not yet been reported. CuO/SiO2 catalysts with different Cu species were prepared by impregnation (IM), deposition–precipitation (DP), and ammonia evaporation (AE). The structural evolution of the Cu species in different states of the ethynylation reaction and the structure–activity relationship between the existence state of the Cu species and the catalytic properties of the ethynylation reaction were studied. The results show that the Cu species in the CuO/SiO2 (IM), prepared using the impregnation method, are in the form of bulk CuO, with large particles and no interactions with the support. The bulk CuO species are transformed into Cu+ with a low exposure surface at the beginning of the reaction, which is easily lost. Thus, this approach shows the lowest initial activity and poor cycle stability. A high dispersion of CuO and copper phyllosilicate exists in CuO/SiO2 (DP). The former makes the catalyst have the best initial activity, while the latter slows release, maintaining the stability of the catalyst. There is mainly copper phyllosilicate in CuO/SiO2 (AE), which is slowly transformed into a highly dispersed and stable Cu+ center in the in situ reaction. Although the initial activity of the catalyst is not optimal, it has the optimal service stability.
The Relationships between Process Parameters and Polymeric Nanofibers Fabricated Using a Modified Coaxial Electrospinning
Authors: Zhou Honglei , Shi Zhaorong , Wan Xi , Fang Hualing , Yu Deng-Guang , Chen Xiaohong , Liu Ping
Published: June 2019

The concrete relationship between the process parameters and nanoproduct properties is an important challenge for applying nanotechnology to produce functional nanomaterials. In this study, the relationships between series of process parameters and the medicated nanofibers’ diameter were investigated. With an electrospinnable solution of hydroxypropyl methylcellulose (HPMC) and ketoprofen as the core fluid, four kinds of nanofibers were prepared with ethanol as a sheath fluid and under the variable applied voltages. Based on these nanofibers, a series of relationships between the process parameters and the nanofibers’ diameters (D) were disclosed, such as with the height of the Taylor cone (H, D = 125 + 363H), with the angle of the Taylor cone (α, D = 1576 − 19α), with the length of the straight fluid jet (L, D = 285 + 209L), and with the spreading angle of the instable region (θ, D = 2342 − 43θ). In vitro dissolution tests verified that the smaller the diameters, the faster ketoprofen (KET) was released from the HPMC nanofibers. These concrete process-property relationships should provide a way to achieve new knowledge about the electrostatic energy-fluid interactions, and to meanwhile improve researchers’ capability to optimize the coaxial process conditions to achieve the desired nanoproducts.
MoS2 Coexisting in 1T and 2H Phases Synthesized by Common Hydrothermal Method for Hydrogen Evolution Reaction
Authors: Yao Yixin , Ao Kelong , Lv Pengfei , Wei Qufu
Published: June 2019

Molybdenum disulfide has been one of the most studied hydrogen evolution catalyst materials in recent years, but its disadvantages, such as poor conductivity, hinder its further development. Here, we employ the common hydrothermal method, followed by an additional solvothermal method to construct an uncommon molybdenum disulfide with two crystal forms of 1T and 2H to improve catalytic properties. The low overpotential (180 mV) and small Tafel slope (88 mV/dec) all indicated that molybdenum disulfide had favorable catalytic performance for hydrogen evolution. Further conjunctions revealed that the improvement of performance was probably related to the structural changes brought about by the 1T phase and the resulting sulfur vacancies, which could be used as a reference for the further application of MoS2.
Effect of Sputtering Temperature on Fluorocarbon Films: Surface Nanostructure and Fluorine/Carbon Ratio
Authors: Zhao Qi , Wang Feipeng , Wang Kaizheng , Xie Guibai , Cui Wanzhao , Li Jian
Published: June 2019

In this work, fluorocarbon film was deposited on silicon (P/100) substrate using polytetrafluoroethylene (PTFE) as target material at elevated sputtering temperature. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed to investigate the surface morphology as well as structural and chemical compositions of the deposited film. The surface energy, as well as the polar and dispersion components, were determined by water contact angle (WCA) measurement. The experimental results indicated that increasing sputtering temperature effectively led to higher deposition rate, surface roughness and WCA of the film. It was found that the elevated temperature contributed to increasing saturated components (e.g., C–F2 and C–F3) and decreasing unsaturated components (e.g., C–C and C–CF), thus enhancing the fluorine-to-carbon (F/C) ratio. The results are expected aid in tailoring the design of fluorocarbon films for physicochemical properties.
A Tunable Graphene 0–90° Polarization Rotator Achieved by Sine Equation Voltage Adjustment
Authors: Dai Jinsong , Wei Zhongchao , Zhao Lin , Lin Qiyuan , Lou Yuyao
Published: June 2019

Polarization Manipulation has been widely used and plays a key role in wave propagation and information processing. Here, we introduce a polarization rotator in the terahertz range with a polarization conversion ratio up to 99.98% at 4.51 terahertz. It has a single graphene layer on top of the structure patterned by 45° tilted space elliptical rings. By changing the Fermi level from 0.3 ev to 0.7 ev of the graphene, we can turn the reflective light polarization direction between 0° to 90° with nearly unique magnitude. Surface currents theories and graphene characteristics clarify the relationship between polarization angle and Fermi level to be a sine equation adjusted voltage. We firstly put forward an equation to thetunable graphene changing the reflective light polarization angle. It can be widely used in measurement, optic communication, and biology. Besides, with nearly the unique reflective light in different directions, the rotator is designed into a novel radially polarization converter. The latter can be switched from radially polarized light to linearly polarized light, and vice versa, in the terahertz region.
Slowing Down Ageing: The Role of Nutrients and Microbiota in Modulation of the Epigenome
Authors: Gadecka Agnieszka , Bielak-Zmijewska Anna
Published: June 2019

The human population is getting ageing. Both ageing and age-related diseases are correlated with an increased number of senescent cells in the organism. Senescent cells do not divide but are metabolically active and influence their environment by secreting many proteins due to a phenomenon known as senescence associated secretory phenotype (SASP). Senescent cells differ from young cells by several features. They possess more damaged DNA, more impaired mitochondria and an increased level of free radicals that cause the oxidation of macromolecules. However, not only biochemical and structural changes are related to senescence. Senescent cells have an altered chromatin structure, and in consequence, altered gene expression. With age, the level of heterochromatin decreases, and less condensed chromatin is more prone to DNA damage. On the one hand, some gene promoters are easily available for the transcriptional machinery; on the other hand, some genes are more protected (locally increased level of heterochromatin). The structure of chromatin is precisely regulated by the epigenetic modification of DNA and posttranslational modification of histones. The methylation of DNA inhibits transcription, histone methylation mostly leads to a more condensed chromatin structure (with some exceptions) and acetylation plays an opposing role. The modification of both DNA and histones is regulated by factors present in the diet. This means that compounds contained in daily food can alter gene expression and protect cells from senescence, and therefore protect the organism from ageing. An opinion prevailed for some time that compounds from the diet do not act through direct regulation of the processes in the organism but through modification of the physiology of the microbiome. In this review we try to explain the role of some food compounds, which by acting on the epigenetic level might protect the organism from age-related diseases and slow down ageing. We also try to shed some light on the role of microbiome in this process.
Preparation and Thermal Evaluation of Novel Polyimide Protective Coatings for Quartz Capillary Chromatographic Columns Operated over 320 °C for High-Temperature Gas Chromatography Analysis
Authors: Huangfu Meng-ge , Zhang Yan , Zhang Xin-ling , Liu Jin-gang , Liu Ying-cong , Guo Yi-dan , Huang Qing-yuan , Zhang Xiu-min
Published: June 2019

Protection of intrinsically brittle quartz chromatographic columns (CCs) from breakage or property deterioration in gas chromatography (GC) analysis has become an important research topic regarding high-temperature GC techniques. Polyimide (PI) has proved to be the most suitable protective coating for quartz CCs. In the current research, a series of novel high-temperature-resistant PI coatings for quartz CCs operated over 320 °C have been successfully prepared. For this purpose, the aromatic diamine with a rigid skeleton structure 2-(4-aminophenyl)-5-aminobenzimidazole (APBI) was copolymerized with two aromatic dianhydrides—3,3’,4,4’-benzophenotetracarboxylic acid dianhydride (BTDA) and 4,4’-oxydiphthalic anhydride (ODPA)—and an aromatic diamine with flexible ether linkages—4,4’-oxydianiline (ODA)—by a two-step polymerization procedure via soluble poly(amic acid) (PAA) precursors, followed by thermal imidization at elevated temperatures. The developed PI coatings exhibited good comprehensive properties, including glass transition temperatures (Tg) as high as 346.9 °C, measured by dynamic mechanical analysis (DMA), and coefficients of linear thermal expansion (CTEs) as low as 24.6 × 10−6/K in the range of 50–300 °C. In addition, the PI coatings exhibited good adhesion to the fused quartz capillary columns. No cracking, delamination, warpage, or other failures occurred during the 100-cycle thermal shock test in the range of 25–320 °C.
Degradation of Metal-Organic Framework Materials as Controlled-Release Fertilizers in Crop Fields
Authors: Wu Ke , Du Changwen , Ma Fei , Shen Yazhen , Liang Dong , Zhou Jianmin
Published: June 2019

The behavior of a metal-organic framework (MOF) compound synthesized in hydrothermal reaction conditions and rich in N, P, and Fe nutrients was explored in the field. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and laser induced breakdown spectroscopy (LIBS) characterization results showed that the chemical structures changed during the degradation process in crop field soil. The scanning electron microscope images showed that the micro-rod of the MOF peeled off and degraded in layers. During the growth period of wheat, the MOF degraded by 50.9%, with the degradation rate being closely related to soil temperature. It was also found that the degradation rate increased with soil temperature. Moreover, the nutrient concentration of the soil indicated that the MOF had stable nutrients release efficiencies and could provide a continuous supply of nutrients throughout the wheat growth period, which showed a great alternative for MOF as a fertilizer both benefiting agricultural production and environmental protection.
Recent Trends of Foaming in Polymer Processing: A Review
Authors: Jin Fan-Long , Zhao Miao , Park Mira , Park Soo-Jin
Published: June 2019

Polymer foams have low density, good heat insulation, good sound insulation effects, high specific strength, and high corrosion resistance, and are widely used in civil and industrial applications. In this paper, the classification of polymer foams, principles of the foaming process, types of blowing agents, and raw materials of polymer foams are reviewed. The research progress of various foaming methods and the current problems and possible solutions are discussed in detail.
Conductive Bicomponent Fibers Containing Polyaniline Produced via Side-by-Side Electrospinning
Authors: Liu Wangcheng , Zhang Jinwen , Liu Hang
Published: June 2019

In this study, using a barbed Y-connector as the spinneret, camphoric acid (CSA) doped polyaniline (PANI) and polyethylene oxide (PEO) were electrospun into side-by-side bicomponent fibers. Fiber mats obtained from this side-by-side spinneret were compared with those mats electrospun from blended PEO and PANI in terms of fiber morphology, electrical conductivity, thermal stability, mechanical properties, and relative resistivity under tensile strain. The influence of different content ratio of insulating PEO (3/4/5 w/v% to solvent) and conductive PANI-CSA (1.5/2.5/3.5 w/v% to solvent) on the abovementioned properties was studied as well. Results showed that this side-by-side spinning was capable of overcoming the poor spinnability of PANI to produce fibers with PEO carrying PANI on the surface of the bicomponent fibers, which demonstrated higher electrical conductivity than blends. Although the addition of PANI deteriorated mechanical properties for both side-by-side and blended fibers when compared to the pure PEO fibers, the side-by-side fibers showed much better fiber strength and elongation than blends. In addition, the superior ductility and decent relative electrical resistivity of the side-by-side fibers imparted them great potential for flexible sensor applications.
Compressive Alginate Sponge Derived from Seaweed Biomass Resources for Methylene Blue Removal from Wastewater
Authors: Shen Xiaojun , Huang Panli , Li Fengfeng , Wang Xiluan , Yuan Tongqi , Sun Runcang
Published: June 2019

Low cost fabrication of water treatment polymer materials directly from biomass resources is urgently needed in recent days. Herein, a compressive alginate sponge (AS) is prepared from seaweed biomass resources through a green two-step lyophilization method. This material is much different from conventional oven-, air-, vacuum-dried alginate-based adsorbents, which show limitations of shrinkage, rigidness, tight nonporous structure and restricted ions diffusion, hindering its practical applications, and was used to efficiently remove methylene blue (MB), a main colorful contaminant in dye manufacturing, from wastewater. The batch adsorption studies are carried out to determine the impact of pH, contact time and concentration of dye on the adsorption process. The maximum adsorption capacity can be obtained at 1279 mg g−1, and the shape-moldable AS can be facilely utilized as a fixed-bed absorption column, providing an efficient approach for continuous removal of MB within a short time. It is also important that such a compressive AS can be regenerated by a simple squeezing method while retaining about 70% capacity for more than ten cycles, which is convenient to be reused in practical water treatment. Compressive AS demonstrates its merits of high capability, large efficiency and easy to recycle as well as low cost resources, indicating widespread potentials for application in dye contaminant control regarding environmental protection.
Molecular Dynamics Simulation of Improving the Physical Properties of Polytetrafluoroethylene Cable Insulation Materials by Boron Nitride Nanoparticle under Moisture-Temperature-Electric Fields Conditions
Authors: Hua Xu , Wang Li , Yang Shanshui
Published: June 2019

The physical properties in amorphous regions are important for the insulation aging assessment of polytetrafluoroethylene (PTFE) cable insulation materials. In order to study the effect of boron nitride (BN) nanoparticles on the physical properties of PTFE materials under moisture, temperature, and electric fields conditions at the molecular level, the amorphous region models of PTFE, BN/PTFE, water/PTFE, and water/BN/PTFE were respectively constructed by molecular dynamics (MD) simulation. The mechanical properties including Young’s modulus, Poisson’s ratio, bulk modulus, and shear modulus, along with glass transition temperature, thermal conductivity, relative dielectric constant, and breakdown strength of the four models have been simulated and calculated. The results show that the mechanical properties and the glass transition temperature of PTFE are reduced by the injection of water molecules, whereas the same, along with the thermal conductivity, are improved by incorporating BN nanoparticles. Moreover, thermal conductivity is further improved by the surface grafting of BN nanoparticles. With the increase of temperature, the mechanical properties and the breakdown strength of PTFE decrease gradually, whereas the thermal conductivity increases linearly. The injection of water molecules increases the water content in the PTFE materials, which causes a gradual increase in its relative dielectric constant. This work has shown that this effect is significantly reduced by incorporation of BN nanoparticles. The variation of physical properties for PTFE and its composites under the action of moisture, temperature, and electric fields is of great significance to the study of wet, thermal, and electrical aging tests as well as the life prediction of PTFE cable insulation materials.
Efficient Oil/Water Separation Membrane Derived from Super-Flexible and Superhydrophilic Core–Shell Organic/Inorganic Nanofibrous Architectures
Authors: Liu Zhi , Qin Detao , Zhao Jianghui , Feng Quan , Li Zhengtao , Bai Hongwei , Sun Darren Delai
Published: June 2019

To address the worldwide oil and water separation issue, a novel approach was inspired by natural phenomena to synthesize superhydrophilic and underwater superoleophobic organic/inorganic nanofibrous membranes via a scale up fabrication approach. The synthesized membranes possess a delicate organic core of PVDF-HFP and an inorganic shell of a CuO nanosheet structure, which endows super-flexible properties owing to the merits of PVDF-HFP backbones, and superhydrophilic functions contributed by the extremely rough surface of a CuO nanosheet anchored on flexible PVDF-HFP. Such an organic core and inorganic shell architecture not only functionalizes membrane performance in terms of antifouling, high flux, and low energy consumption, but also extends the lifespan by enhancing its mechanical strength and alkaline resistance to broaden its applicability. The resultant membrane exhibits good oil/water separation efficiency higher than 99.7%, as well as excellent anti-fouling properties for various oil/water mixtures. Considering the intrinsic structural innovation and its integrated advantages, this core–shell nanofibrous membrane is believed to be promising for oil/water separation, and this facile approach is also easy for scaled up manufacturing of functional organic/inorganic nanofibrous membranes with insightful benefits for industrial wastewater treatment, sensors, energy production, and many other related areas.
Molecular Dynamics Simulation and Experimental Studies on the Thermomechanical Properties of Epoxy Resin with Different Anhydride Curing Agents
Authors: Fu Kexin , Xie Qing , LÜ Fangcheng , Duan Qijun , Wang Xinjie , Zhu Quansheng , Huang Zhengyong
Published: June 2019

An investigation of the relationship between the microstructure parameters and thermomechanical properties of epoxy resin can provide a scientific basis for the optimization of epoxy systems. In this paper, the thermomechanical properties of diglycidyl ether of bisphenol A (DGEBA)/methyl tetrahydrophthalic anhydride (MTHPA) and DGEBA/nadic anhydride (NA) were calculated and tested by the method of molecular dynamics (MD) simulation combined with experimental verification. The effects of anhydride curing agents on the thermomechanical properties of epoxy resin were investigated. The results of the simulation and experiment showed that the thermomechanical parameters (glass transition temperature (Tg) and Young’s modulus) of the DGEBA/NA system were higher than those of the DGEBA/MTHPA system. The simulation results had a good agreement with the experimental data, which verified the accuracy of the crosslinking model of epoxy resin cured with anhydride curing agents. The microstructure parameters of the anhydride-epoxy system were analyzed by MD simulation, including bond-length distribution, synergy rotational energy barrier, cohesive energy density (CED) and fraction free volume (FFV). The results indicated that the bond-length distribution of the MTHPA and NA was the same except for C–C bonds. Compared with the DGEBA/MTHPA system, the DGEBA/NA system had a higher synergy rotational energy barrier and CED, and lower FFV. It can be seen that the slight change of curing agent structure has a significant effect on the synergy rotational energy barrier, CED and FFV, thus affecting the Tg and modulus of the system.
Functionalization of MXene Nanosheets for Polystyrene towards High Thermal Stability and Flame Retardant Properties
Authors: Si Jing-Yu , Tawiah Benjamin , Sun Wei-Long , Lin Bo , Wang Cheng , Yuen Anthony , Yu Bin , Li Ao , Yang Wei , Lu Hong-Dian , Chan Qing , Yeoh Guan
Published: June 2019

Fabricating high-performance MXene-based polymer nanocomposites is a huge challenge because of the poor dispersion and interfacial interaction of MXene nanosheets in the polymer matrix. To address the issue, MXene nanosheets were successfully exfoliated and subsequently modified by long-chain cationic agents with different chain lengths, i.e., decyltrimethylammonium bromide (DTAB), octadecyltrimethylammonium bromide (OTAB), and dihexadecyldimethylammonium bromide (DDAB). With the long-chain groups on their surface, modified Ti3C2 (MXene) nanosheets were well dispersed in N,N-dimethylformamide (DMF), resulting in the formation of uniform dispersion and strong interfacial adhesion within a polystyrene (PS) matrix. The thermal stability properties of cationic modified Ti3C2/PS nanocomposites were improved considerably with the temperatures at 5% weight loss increasing by 20 °C for DTAB-Ti3C2/PS, 25 °C for OTAB-Ti3C2/PS and 23 °C for DDAB-Ti3C2/PS, respectively. The modified MXene nanosheets also enhanced the flame-retardant properties of PS. Compared to neat PS, the peak heat release rate (PHRR) was reduced by approximately 26.4%, 21.5% and 20.8% for PS/OTAB-Ti3C2, PS/DDAB-Ti3C2 and PS/DTAB-Ti3C2, respectively. Significant reductions in CO and CO2 productions were also obtained in the cone calorimeter test and generally lower pyrolysis volatile products were recorded by PS/OTAB-Ti3C2 compared to pristine PS. These property enhancements of PS nanocomposites are attributed to the superior dispersion, catalytic and barrier effects of Ti3C2 nanosheets.
Low-Temperature Processed TiOx/Zn1−xCdxS Nanocomposite for Efficient MAPbIxCl1−x Perovskite and PCDTBT:PC70BM Polymer Solar Cells
Authors: Duong Binh , Lohawet Khathawut , Muangnapoh Tanyakorn , Nakajima Hideki , Chanlek Narong , Sharma Anirudh , Lewis David A. , Kumnorkaew Pisist
Published: June 2019

The majority of high-performance perovskite and polymer solar cells consist of a TiO2 electron transport layer (ETL) processed at a high temperature (>450 °C). Here, we demonstrate that low-temperature (80 °C) ETL thin film of TiOx:Zn1−xCdxS can be used as an effective ETL and its band energy can be tuned by varying the TiOx:Zn1−xCdxS ratio. At the optimal ratio of 50:50 (vol%), the MAPbIxCl1−x perovskite and PCBTBT:PC70BM polymer solar cells achieved 9.79% and 4.95%, respectively. Morphological and optoelectronic analyses showed that tailoring band edges and homogeneous distribution of the local surface charges could improve the solar cells efficiency by more than 2%. We proposed a plausible mechanism to rationalize the variation in morphology and band energy of the ETL.
Measuring Energy Efficiency and Environmental Performance: A Case of South Asia
Authors: Hou Yumei , Iqbal Wasim , Muhammad Shaikh Ghulam , Iqbal Nadeem , Ahmad Solangi Yasir , Fatima Arooj
Published: June 2019

When assessing energy efficiency, most studies have frequently ignored environmental aspects even though the concept has been widely used in the past. This study evaluates the energy efficiency and environmental performance of South Asia by using DEA (data envelopment analysis) like mathematical composite indicator. We construct a comprehensive set of indicators, including an energy self-sufficiency ratio, energy production over consumption ratio, energy imports, diversification index of energy imports, energy reserve ratio, GDP productivity, energy intensity, per capita energy consumption index, carbon emission index, carbon emission index per unit of energy consumption and share of renewable energy in order to develop an energy efficiency and environmental performance index. Unlike other studies, this study first examines each indicator and then estimates a combined score for each country. The results reveal that Bhutan as a more secure country and Pakistan showed a decreasing trend, while Sri Lanka and India performed satisfactorily. Remarkably, Bangladesh, Nepal and Afghanistan showed a decreasing trend. This study proposes a policy that increases the cross-border trade of renewable energy for long term energy efficiency and environmental performance.
Numerical Study on the Gas-Water Two-Phase Flow in the Self-Priming Process of Self-Priming Centrifugal Pump
Authors: Wang Chuan , Hu Bo , Zhu Yong , Wang Xiuli , Luo Can , Cheng Li
Published: June 2019

A self-priming centrifugal pump can be used in various areas such as agricultural irrigation, urban greening, and building water-supply. In order to simulate the gas-water two-phase flow in the self-priming process of a self-priming centrifugal pump, the unsteady numerical calculation of a typical self-priming centrifugal pump was performed using the ANSYS Computational Fluid X (ANSYS CFX) software. It was found that the whole self-priming process of a self-priming pump can be divided into three stages: the initial self-priming stage, the middle self-priming stage, and the final self-priming stage. Moreover, the self-priming time of the initial and final self-priming stages accounts for a small percentage of the whole self-priming process, while the middle self-priming stage is the main stage in the self-priming process and further determines the length of the self-priming time.
Electrolyte Effects on Poly (Acrylic Acid)-Based Aircraft De-icing Fluids
Authors: Wang Yuchen , Hudson Nicholas , Pethrick Richard , Schaschke Carl
Published: June 2019

Poly (acrylic acid) [PAA]-based aircraft de-icing fluids are widely used commercially but are known to be subject to the formation of insoluble gel particles within wing structures. In this study, the rheological effects of the sodium chloride, potassium formate, and calcium acetate with commercially used PAA-based fluids are reported across the temperature range of −15 to 15 °C. Calcium ions have the potential to create gel particles, reflected in the shifts in the viscosity–temperature profile, while PAA aggregation is influenced by the concentrations and compositions of sodium and potassium salts in the water used for dilution. From the data presented, it is possible to create de-icing fluid formulations with the necessary rheological characteristics from stock solutions by dilution using available water sources, providing that the ion concentration is known.
Advancements in Canadian Biomaterials Research in Neurotraumatic Diagnosis and Therapies
Authors: Chen Suzan , Auriat Angela , Li Tongda , Stumpf Taisa , Wylie Ryan , Chen Xiongbiao , Willerth Stephanie , DeRosa Maria , Tarizian Maryam , Cao Xudong , Tsai Eve
Published: June 2019

Development of biomaterials for the diagnosis and treatment of neurotraumatic ailments has been significantly advanced with our deepened knowledge of the pathophysiology of neurotrauma. Canadian research in the fields of biomaterial-based contrast agents, non-invasive axonal tracing, non-invasive scaffold imaging, scaffold patterning, 3D printed scaffolds, and drug delivery are conquering barriers to patient diagnosis and treatment for traumatic injuries to the nervous system. This review highlights some of the highly interdisciplinary Canadian research in biomaterials with a focus on neurotrauma applications.
Prediction of Personality Profiles in the Pakistan Software Industry–A Study
Authors: Hasan Ali , Moin Sana , Pasha Maruf
Published: June 2019

Psychology says not everyone is able to do all type of tasks assigned to them. This point is valid for people working in the software industries as well. Therefore, when assigning the most suitable tasks to people according to their personality type, a software development company’s succession rate can be proliferated to a remarkable level. In this manner, the main theme of this empirical research is to find relationships that establish links between personality type and their job designation preferences in the software industry. For this purpose, this study is comprised of 44 Pakistan developers, who are working in different software houses and are directly involved in developing software projects. In addition, an MBTI (Myers-Briggs Type Indicator) test indicator is used for the link establishment. With respect to the reported results, tester, team lead, and project manager are found to be ENFJs, which is the least common type in software developers. However, for web developers and software engineers, ISFJ is found to be the most preferable type, with an edge over ENFJ.
Experimental Setup of the Fast Current Controller for the Buenos Aires Heavy Ion Microbeam
Authors: Vega Nahuel Agustín , Müller Nahuel Agustín , de la Fourniére Emmanuel , Halac Emilia Beatriz , Debray Mario Ernesto
Published: June 2019

Recently we used the heavy ion microprobe of the Buenos Aires TANDAR Laboratory for Single Event Effects (SEE) and Total Dose (TD) experiments in electronics devices and components, requiring very low beam currents. The facility includes a fast beam switch that allows the control of the ion beam current and a mobile Si PIN (p-type, intrinsic, n-type) diode that directly measures the number of ions hitting the device. The fast beam deflector was used to reduce the current by producing a pulsed beam or generating a quasi-continuous (Poisson-like distributed) beam with currents ranging from tens to hundreds of ions/s. As an application for this current control method we present a single event effect (SEE) pulses map generated by a 32S8+ beam at 75 MeV on two 0.5 µm technology CMOS digital output buffers where the device was formed by cascading four CMOS inverters with increasing sizes from input to output to drive large loads. Using the same concept of pulse width modulated deflection, we developed a novel gradient scanning method. This system allows to produce in a single irradiation a distribution with a cumulative damage with a difference of two orders of magnitude at constant gradient. To demonstrate the method, we irradiated a lithium niobate monocrystal with 32S8+ beam at 75 MeV energy and later analyzed the produced damage by the micro-Raman technique and an optical profilometer.
“Ye Shall Know Them by Their Fruits”: Prosperity and Institutional Religion in Europe and the Americas
Authors: Garcia Portilla Jason
Published: June 2019

Low competitiveness is a common denominator of historically Roman Catholic countries. In contrast, historically Protestant countries generally perform better in education, social progress, and competitiveness. Jesus Christ described the true and false prophets coming on his behalf, as follows: “Ye shall know them by their fruits”. Inspired by this parable, this paper explores the relations between religious systems (‘prophets’) and social prosperity (‘fruits’). It asks how Protestantism influences prosperity as compared to Roman Catholicism in Europe and the Americas. Most empirical studies have hitherto disregarded the institutional influence of religion. Taking the work of Max Weber as their starting point, they have instead emphasised the cultural linkage between religious adherents and prosperity. This paper tests various correlational models and draws on a comprehensive conceptual framework to understand the institutional influence of religion on prosperity in Europe and the Americas. It argues that the uneven contributions of Roman Catholicism and Protestantism to prosperity are grounded in their different historical and institutional foundations and in the theologies that are pervasive in their countries of influence.
Both Like and Unlike: Rebirth, Olfaction, and the Transspecies Imagination in Modern Chinese Buddhism
Authors: Verchery Lina
Published: June 2019

This essay considers the importance of the transspecies imagination for moral cultivation in contemporary Chinese Buddhism. Drawing on scriptural, theoretical, and fieldwork-based ethnographic data, it argues that olfaction—often considered the most “animalistic” of the human senses—is uniquely efficacious for inspiring imaginative processes whereby Buddhists train themselves to inhabit the perspectives of non-human beings. In light of Buddhist theories of rebirth, this means extending human-like status to animals and recognizing the “animal” within the human as well. Responding to recent trends in the Humanities calling for an expanded notion of ontological continuity between the human and non-human—notably inspired by critical animal studies, post-humanism, the new materialism, and the “ontological turn”—this essay contends that Buddhist cosmological ideas, like those that demand the cultivation of the transspecies imagination, present resources for moral reflection that can challenge and enrich current mainstream thinking about humanity’s relation to the nonhuman world.
A General Framework for Portfolio Theory. Part III: Multi-Period Markets and Modular Approach
Authors: Maier-Paape Stanislaus , Platen Andreas , Zhu Qiji Jim
Published: June 2019

This is Part III of a series of papers which focus on a general framework for portfolio theory. Here, we extend a general framework for portfolio theory in a one-period financial market as introduced in Part I [Maier-Paape and Zhu, Risks 2018, 6(2), 53] to multi-period markets. This extension is reasonable for applications. More importantly, we take a new approach, the “modular portfolio theory”, which is built from the interaction among four related modules: (a) multi period market model; (b) trading strategies; (c) risk and utility functions (performance criteria); and (d) the optimization problem (efficient frontier and efficient portfolio). An important concept that allows dealing with the more general framework discussed here is a trading strategy generating function. This concept limits the discussion to a special class of manageable trading strategies, which is still wide enough to cover many frequently used trading strategies, for instance “constant weight” (fixed fraction). As application, we discuss the utility function of compounded return and the risk measure of relative log drawdowns.