bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior and susceptibility to stress corrosion cracking of a nickel‐based alloy in superheated steam and supercritical water
Authors: Khan Hasan Izhar , Zhang Naiqiang , Zhu Zhongliang , Jiang Dongfang , Asif Tahir , Xu Hong
Published: July 2018

Stress corrosion cracking (SCC) behavior of Alloy 617 was studied to evaluate its suitability for Generation IV supercritical water reactor concept. A series of slow strain rate tensile (SSRT) tests at a constant strain rate of 5 × 10−7 s−1 were carried out in superheated steam and supercritical water over a pressure range of 0.1–25 MPa at 650 °C. SSRT test in dry N2 gas was also performed to compare the results in non‐corrosive environment with corrosive medium environment. Intergranular cracks were observed for all specimens regardless of the test environment. Alloy 617 showed susceptibility to SCC at the tested experimental conditions. The dominance of intergranular SCC was observed on the gage surface and fracture surface by using scanning electron microscope analysis. The effect of varying environmental conditions on SCC susceptibility is further discussed.
Effect of titanium nitride (TiN) on the corrosion behavior of a supermartensitic stainless steel
Authors: Rodrigues César Augusto D. , Bandeira Rafael M. , Duarte Bárbara B. , Tremiliosi‐Filho Germano , Roche Virginie , Jorge Alberto M.
Published: July 2018

This study evaluates the effect of high N, Ni, and Ti contents on the microstructure and corrosion properties of a supermartensitic stainless steel when immersed in a 3.5% NaCl solution. Tempering procedure at several temperatures resulted in a martensitic microstructure composed of grains ranging from 60 to 70 μm, TiN microparticles, and austenite. The sample treated at 610 °C showed better corrosion resistance due to the lower current density of the anodic polarization curve and less negative pitting potential, which was thoroughly influenced by the content of austenite (6.2 vol%). Anodic curves presented current fluctuation attributed to the presence of passive film instability, due to micro‐galvanic corrosion between TiN particles and matrix. Impedance analysis on the sample tempered at 610 °C confirmed that 6.2 vol% of austenite assists the protective film by making it thicker and more protective in chloride media.
Influence of Fe3O4 particle size on corrosion of carbon steel under wet/dry cyclic conditions
Authors: Samusawa Itaru , Shiotani Kazuhiko
Published: July 2018

The influence of the particle size of Fe3O4 on the surface of steel on the corrosivity and electrochemical properties under wet/dry cyclic conditions was investigated. The results showed that Fe3O4 on the steel surface increases the cathodic current and corrosivity of the steel, but this effect is minor in the case of fine Fe3O4 particles. The diffusion mobility of cathodic reactants on the surface of fine Fe3O4 was evaluated by a molecular dynamics simulation, and the influence of the Fe3O4 rust particle size on the corrosion behavior of steel is discussed. It is probable that the diffusion mobility of cathodic reactants (H2O and O2) is low in between fine Fe3O4 particles, which significantly retards the cathodic reaction on Fe3O4 and the steel surface.
Coumarin‐Caged Polyphosphazenes with a Visible‐Light Driven On‐Demand Degradation
Authors: Iturmendi Aitziber , Theis Sabrina , Maderegger Dominik , Monkowius Uwe , Teasdale Ian
Published: July 2018

Polymers that, upon photochemical activation with visible light, undergo rapid degradation to small molecules are described. Through functionalization of a polyphosphazene backbone with pendant coumarin groups sensitive to light, polymers which are stable in the dark could be prepared. Upon irradiation, cleavage of the coumarin moieties exposes carboxylic acid moieties along the polymer backbone. The subsequent macromolecular photoacid is found to catalyze the rapid hydrolytic degradation of the polyphosphazene backbone. Water‐soluble and non‐water‐soluble polymers are reported, which due to their sensitivity toward light in the visible region could be significant as photocleavable materials in biological applications.
Abundance, rather than composition, of methane‐cycling microbes mainly affects methane emissions from different vegetation soils in the Zoige alpine wetland
Authors: Zhang Yanfen , Cui Mengmeng , Duan Jingbo , Zhuang Xuliang , Zhuang Guoqiang , Ma Anzhou
Published: July 2018

Methane fluxes, which are controlled by methanogens and methanotrophs, vary among wetland vegetation species. In this study, we investigated belowground methanogens and methanotrophs in two soils under two different dominant vegetation species with different methane fluxes in the Zoige wetland, which was slightly but significantly (p ≤ 0.05) higher in soils covered by Carex muliensis than that in soils covered by Eleocharis valleculosa. Real‐time quantitative PCR and Illumina MiSeq sequencing methods were used to elucidate the microbial communities based on the key genes involved in methane production and oxidation. The absolute abundances of methanogens and methanotrophs of samples from C. muliensis were 1.80 ± 0.07 × 106 and 4.03 ± 0.28 × 106 copies g‐soil−1, respectively, and which from E. valleculosa were 3.99 ± 0.19 × 105 and 2.53 ± 0.22 × 106 copies g‐soil−1 , respectively. The t‐test result showed that both the abundance of methanogens and methanotrophs from C. muliensis were significantly higher (p ≤ 0.05) than that of samples from E. valleculosa. However, the diversities and compositions of both methanogens and methanotrophs showed no significant differences (p ≥ 0.05) between vegetation species. The path analysis showed that the microbial abundance had a greater effect than the microbial diversity on methane production potentials and the regression analysis also showed that the methane emissions significantly (p ≤ 0.05) varied with the abundance of methane‐cycling microbes. These findings imply that abundance rather than diversity and composition of a methane‐cycling microbial community is the major contributor to the variations in methane emissions between vegetation types in the Zoige wetland.
Computation of eigenvalues and eigenfunctions of a Schrödinger‐type boundary‐value‐transmission problem with retarded argument
Authors: Şen Erdoğan
Published: July 2018

The purpose of this study is to investigate a Schrödinger type of boundary‐value‐transmission problem with retarded argument. By modifying some techniques of [S.B. Norkin, Differential equations of the second order with retarded argument, Translations of Mathematical Monographs, Vol. 31, AMS, Providence, RI, 1972] and suggesting own approaches, we find asymptotic formulas for the eigenvalues and eigenfunctions of the second‐order differential equation with retarded argument, which includes the eigenparameter as a quadratic function.
Uniqueness and decay in local thermal non‐equilibrium double porosity thermoelasticity
Authors: Franchi Franca , Lazzari Barbara , Nibbi Roberta , Straughan Brian
Published: July 2018

This paper studies a model for thermoelasticity where the body has a double porosity structure. There are the usual pores associated to a porous body, herein called macro pores. In addition, the solid skeleton contains cracks or fissures that give rise to a micro porosity. The fully anisotropic situation is analyzed. We firstly establish uniqueness of a solution to the boundary‐initial value problem when the elastic coefficients are sign indefinite and are required to satisfy only major symmetry. Furthermore, in the quasi‐equilibrium case, where the solid acceleration is neglected, we demonstrate that a solution to the boundary‐initial value problem with zero boundary conditions will decay to zero in a certain sense, under the assumption that there are no sources and external body force involved.
A finite‐strain gradient‐inelastic beam theory and a corresponding force‐based frame element formulation
Authors: Salehi Mohammad , Sideris Petros
Published: July 2018

This paper extends the gradient‐inelastic (GI) beam theory, introduced by the authors to simulate material softening phenomena, to further account for geometric nonlinearities and formulates a corresponding force‐based (FB) frame element computational formulation. Geometric nonlinearities are considered via a rigorously derived finite‐strain beam formulation, which is shown to coincide with Reissner's geometrically nonlinear beam formulation. The resulting finite‐strain GI beam theory: (i) accounts for large strains and rotations, unlike the majority of geometrically nonlinear beam formulations used in structural modeling that consider small strains and moderate rotations; (ii) ensures spatial continuity and boundedness of the finite section strain field during material softening via the gradient nonlocality relations, eliminating strain singularities in beams with softening materials; and (iii) decouples the gradient nonlocality relations from the constitutive relations, allowing use of any material model. On the basis of the proposed finite‐strain GI beam theory, an exact FB frame element formulation is derived, which is particularly novel in that it: (a) expresses the compatibility relations in terms of total strains/displacements, as opposed to strain/displacement rates that introduce accumulated computational error during their numerical time integration, and (b) directly integrates the strain‐displacement equations via a composite two‐point integration method derived from a cubic Hermite interpolating polynomial to calculate the displacement field over the element length and, thus, address the coupling between equilibrium and strain‐displacement equations. This approach achieves high accuracy and mesh convergence rate and avoids polynomial interpolations of individual section fields, which often lead to instabilities with mesh refinements. The FB formulation is then integrated into a corotational framework and is used to study the response of structures, simultaneously accounting for geometric nonlinearities and material softening. The FB formulation is further extended to capture member buckling triggered by minor perturbations/imperfections of the initial member geometry.
Unvealing GaN Polytypism in Distributed GaN/InAlN Bragg Reflectors Through HRTEM Image Simulation
Authors: López‐Conesa Lluís , Pérez‐Omil José Antonio , Gačević Žarko , Calleja Enrique , Estradé Sònia , Peiró Francesca
Published: July 2018

In this work, through high resolution transmission electron microscopy (HRTEM) and image simulation, the origins of the reduced reflectivity values measured for a nearly lattice‐matched GaN/InAlN distributed Bragg reflector (DBR) are investigated. HRTEM images reveal significant structural defects in the GaN semiperiods, such as coexistence of wurtzite and zinc blende phases and zinc‐blende twinned domains, which contribute to the experimentally observed decrease in reflectivity. Contact regions arising because of the superposition of both cubic and hexagonal GaN polytypes and/or cubic twinned domains are modeled and used to simulate HRTEM images that confirm the experimental phase contrast and hence the validity of the proposed models.
Graphite Microislands Prepared for Reliability Improvement of Amorphous Carbon Based Resistive Switching Memory
Authors: Ding Wentao , Tao Ye , Li Xuhong , Lin Ya , Wang Zhongqiang , Xu Haiyang , Zhao Xiaoning , Liu Weizhen , Ma Jiangang , Liu Yichun
Published: July 2018

Uniform graphite microislands (GMs) are prepared through catalytic graphitization of amorphous carbon (a‐C) thin film. Taking advantage of the specific structural feature of the GMs, we demonstrate an effective approach to improve the reliability of amorphous carbon based resistive random access memory devices. Through investigating the temperature dependence of the high/low resistance states (HRS/LRS), it is verified that the conductive filaments (CFs) prefer to grow along the GMs. The enhancement of local‐electric‐field around the GMs can not only induce a lower forming/set voltage to largely avoid CFs overgrowth, but also simplify the CFs morphology. As a result, the relative fluctuation of HRS/LRS resistance reduces from 82.8%/46.3% to 27.4%/18.8%, respectively. In addition, the memory devices with GMs structure exhibit a low cycling degradation and good retention (>104 s at 85 °C).
Optimized sampling design and rationale for verification and validation
Authors: Cheng S. , Kupfer K. , Dixon M. , Shammas S.
Published: July 2018

An optimized sampling design that meets customer, design, or process requirements, while balancing technology limitations, is still a common challenge to engineering communities. This is especially true in the medical device industry. Acceptance sampling plans for manufacturing are widely available, but the appropriate sampling plans for verification and validation (V&V) are less well known. This paper applies established statistical theory to derive sampling plans appropriate for estimating product reliability during V&V, where reliability must exceed an established threshold with an appropriate margin of statistical confidence. The paper provides insight on how to estimate parameters of interest and interpret acceptance criteria. Operating characteristic curves are used to examine if a design or process is capable of producing future product that meets design specifications and/or customer requirements in terms of confidence and reliability. The methodology is applied to both attribute and variable sampling plans, including examples showing how to achieve a high probability of passing the acceptance criteria. Formulas, sample size tables, and operating characteristic curves are provided for engineering practitioners to use. The paper aims at providing a practical quantitative approach and a valid statistical rationale to assess overall product quality during V&V.
Arm's‐length or give‐and‐take? Gender differences in the relational orientation of new ventures in Sub‐Saharan Africa
Authors: Uzuegbunam Anthonia O. , Uzuegbunam Ikenna
Published: July 2018

Research Summary

Women entrepreneurs in emerging economies face significant constraints in operating their businesses. Leveraging two samples of new ventures in Nigeria and Ghana, we explore gender differences in the relational orientation of entrepreneurs in their market interactions with customers. We observe that female entrepreneurs are more likely than their male counterparts to apply a relational approach in the receipt of payments for goods and services and in the structure of purchase contracts. These stylized findings are considered against the backdrop of existing literature and offer insight into the ways women entrepreneurs approach transactions with customers, especially in the context of emerging market ventures in Sub‐Saharan Africa.

Managerial Summary

Women entrepreneurs in emerging economies are confronted by significant resource challenges. But women entrepreneurs could also have an advantage in customer relationships. Our study uncovers two types of relational mechanisms that women entrepreneurs in emerging economies utilize in their engagement with customers. First, we find that female entrepreneurs are more likely than their male counterparts to utilize relational payments, in the form of prepayments or post payments from their customers. Second, female entrepreneurs are more likely to utilize relational contracts, in the form of unwitnessed oral purchase contracts with customers. Our study highlights the virtue of incorporating relational mechanisms in policies and practices aimed at fostering female entrepreneurship in emerging economies.
Binding Assessment of Monosaccharide–Boronic Acid Complexes via Tandem Mass Spectrometry
Authors: Kurogochi Masaki , Mizuno Mamoru , Matsuda Akio
Published: July 2018

Benzoxaborole and arylboronic acids bind to monosaccharides in water to form reversible boronic esters with multiple hydroxyl groups. When benzoxaborole binds with a diol or an arylboronic acid binds with a triol on a monosaccharide, a tetrahedral boron anion is formed at the boron atom. These boron anions can be detected as negative ions in mass spectrometry and tandem mass spectrometry, and profiling their fragment anions provides information on the stereo‐ and regiochemical configurations of the hydroxyl groups on the monosaccharides. Borate fragment anions derived from both benzoxaborole and arylboronic acids show differential connections with hydroxyl groups, which reflect the steric structure of the monosaccharide. As the result, we could distinguish monosaccharides by using the differences in the binding abilities of monosaccharide‐boronic acid complexes by means of mass spectrometric analysis.
Tuning the Crystal Phase and Morphology of the Photoluminescent Indium Sulphide Nanocrystals and Their Adsorption‐Based Catalytic and Photocatalytic Applications
Authors: Sharma Rahul Kumar , Chouryal Yogendra Nath , Nigam Sandeep , Saravanakumar Jeganathan , Barik Sunita , Ghosh Pushpal
Published: July 2018

Phase pure quantum confined In2S3 nanocrystals with high catalytic/photocatalytic efficiency are accessible solvothermally using task specific ionic liquid (IL) as structure directing agent and thiourea as sulphur source. Selective tuning of the shape, morphology and most importantly purity of the nanomaterials are controlled by changing the reaction time, IL and specially sulphur concentration. For instances, at 150oC, when IL is used cubic phase is obtained; however in absence of IL, tetragonal phase with bigger crystallite size appears. In most of the cases In(OH)3 is coming as an impurity; however pure In2S3 with highest catalytic efficiency and band gap of 2.23 eV is achieved when 18 times sulphur concentration is used keeping other reaction parameters same. Photoluminescence emission spectra show that quantum confined pure In2S3 nanoparticles are blue emitting material. Furthermore, pure In2S3 nanoparticles are used for degradation of both cationic [crystal violet, methylene blue, rhodamine B] and anionic organic dyes [methyl orange]. Rate and overall catalytic efficiency are found highest for crystal violet (91%) followed by methylene blue (77%), rhodamine B (44.7%) and least for methyl orange (15.29%). Analysis reveals that along with electrostatic interaction, molecular structures of dye molecules have also significant impact on adsorption capacity which finally governs the catalytic (even in the dark) and photocatalytic efficiency of nanocrystals.
N,O‐Codoped Hierarchically Porous Carbons Derived from Squid Pen for High‐Capacity Supercapacitors
Authors: Yin Jie , Fan Yueyue , Wu Jihuai , Xie Yiming
Published: July 2018

Fabrication of multi‐heteroatom doped hierarchically porous carbon with a facile and environment procedure has been well investigated for supercapacitor industry. We put forward a time‐saving and environmentally friendly method for the manufacture of N,O‐codoped carbons by using direct carbonization of biomass squid pens. Under our facile procedure, the raw carbon materials have been transformed into hierarchical porous carbons, combined with high specific area surface (2540 cm2⋅g−1), micro/meso/macropore inside, and rich N (1.01‐7.44%) and O (17.00‐18.88%) content. It is a completely novel and green avenue for constructing hierarchical porous carbon materials from biomass, showing large commercial potential. Supercapacitors made from the resulting material possess very high specific capacitance (the highest up to 581 F⋅g−1), twice as much as commercial activated carbon (100‐250 F⋅g−1). In particular, it retains 336.6 F⋅g−1 of specific capacitance at a high current density of 10 A⋅g−1, which is a promising material for devices that require operation at high current densities. In addition, it also has a high cyclic stability (maintaining 90% capacitance after 10,000 cycle) and lower impedance. We believe that the hierarchically porous N,O‐codoped carbons derived from squid pens could be an ideal candidate for the energy storage and conversion devices.
Catalyst‐Free Selective Aza‐Michael Addition of 3‐Aminopyrazole to Nitroalkenes
Authors: Li Zheng , Song Wenli
Published: July 2018

Catalyst‐free N1 selective aza‐Michael addition of 3‐aminopyrazole to nitroalkenes is described. A series of 1‐(2‐nitro‐1‐arylethyl)‐1H‐pyrazol‐3‐amines were efficiently synthesized. The protocol has advantages of wide range of nitroalkene substrates, no catalyst, additives and bases, mild condition, high yield, and high selectivity. The method can also extend to gram scale.
Identification of a New Siderophore Acinetoamonabactin Produced by a Salt‐Tolerant Bacterium Acinetobacter Soli
Authors: Mudhulkar Raju , Rajapitamahuni Soundarya , Srivastava Sakshi , Bharadwaj Satyavolu V. Vamsi , Boricha Vinod P. , Mishra Sandhya , Chatterjee Pabitra B.
Published: July 2018

A halotolerant bacterium Acinetobacter soli (MTCC 5918), isolated from the salt farm of our institute, was found to secrete a novel siderophore under iron deprivation conditions. A combination of multinuclear one and two dimensional NMR spectroscopies in conjunction with mass technique revealed that the siderophore, we named acinetoamonabactin (1), is a triscatechol derivative of tris(aminomethyl)methylamine.
Sulfated β‐Cyclodextrin Templated Assembly and Disassembly of Acridine Orange: Unraveling Contrasting Binding Mechanisms and Light Off/On Switching
Authors: Sayed Mhejabeen , Panjwani Shirin , Pal Haridas
Published: July 2018

Present article reports the intriguing aggregation‐deaggregation behavior of acridine orange (AOH+), as induced by the water soluble macrocyclic host, sulfated β‐cyclodextrin (SCD), and the results are compared with those obtained earlier in the presence of sulfobutylether‐β‐cyclodextrin (SBEβCD) host. While monomeric form of AOH+ is widely investigated, the aggregation behavior of AOH+ still remains to be quite less explored, though dye aggregation has a great consequence for its uses as a fluorescence probe for various biological and other microheterogeneous systems. It is observed that aggregation/dimerization of AOH+ is highly assisted by SCD at lower host concentration, resulting a drastic fluorescence quenching for AOH+. In contrast, at higher SCD concentrations the host drives the initially formed AOH+ aggregates/dimers to convert into the monomeric AOH+‐SCD exo and inclusion complexes, ensuing a huge enhancement for AOH+ fluorescence. Though similar host assisted sequential fluorescence turn‐off and turn‐on for AOH+ was also observed earlier on using SBEβCD host (Phys. Chem. Chem. Phys. 2017, 19, 24166), in the present case the effect is exceptionally very large, suggesting the SCD to be a very efficient host to induce such a fluorescence Off‐On switching for the cationic dye AOH+, as explored elaborately in the present study following various photochemical and other complementary measurements.
Development of Synergistic, Dual Pd‐Cu@rGO Catalyst for Suzuki, Heck and Click Reactions: Facile Synthesis of Triazole or Tetrazole Containing Biaryls and Stilbenes
Authors: Gupta Ajay , Jamatia Ramen , Dam Binoyargha , Pal Amarta K.
Published: July 2018

A dual synergistic Pd−Cu@rGO catalyst was synthesized and characterized by various analytical techniques. From powder X‐ray diffraction, Raman, FT‐IR and X‐ray photoelectron spectroscopy analysis it was evident that graphite oxide was reduced during decoration with metal nanoparticles on its surface. The percentages of Cu and Pd in the catalyst was also evident from inductive coupled plasma‐atomic emission spectroscopy analysis. After the preparation and characterization of the catalyst, it was employed in Suzuki and Heck reactions. It was also established that the catalyst was efficient in tetrazole and triazoles synthesis (Click reaction). Further, the present catalyst was effective in furnishing the biaryls/stilbenes and tetrazoles/triazoles skeletons in the same organic compound via step wise reactions. The catalyst also showed good catalytic activity in gram scale reaction. The catalyst could be recycled and reused up to seven consecutive runs without not much loss in its catalytic activity. It was evident from TEM, SEM, EDX and FT‐IR analysis that the general morphology and characteristic of reused Pd−Cu@rGO remained almost unchanged.
Design of Cone‐Shaped Hole Transporting Material Organic Structures for Perovskite Solar Cells Applications
Authors: Sivanadanam Jagadeeswari , Mandal Sudip , Aidhen Indrapal Singh , Ramanujam Kothandaraman
Published: July 2018

This study reports design and synthesis of cone shaped hole transporting materials (HTM, i. e., H1 and H2). They are based on triphenylamine (TPA) and phenothiazine donors attached with two TPA moiety via electron rich π‐spacer (phenyl acrylonitrile). π‐spacers are proven to enhance the power conversion efficiency (PCE) of perovskite solar cells (PSCs) in the literature. Due to the electron withdrawing nature of the π‐spacer and the extended conjugation present in the HTMs proposed, a gradient for charge flow within the molecule is expected. This property is essential to transfer the electron from the HOMO of HTMs to the valence band of the perovskite via the arms of the HTMs. These HTMs do not show strong absorption in the visible region, exhibit high stokes shift and have their HOMO positioned above the perovskite's valence band. HTM layer of the PSCs were fabricated by a solution process method, at ambient conditions. A PCE of ∼1.9% at 1 sun condition was obtained, while under similar conditions the standard HTM (S‐OMeTAD) exhibited a PCE of 1.3%.
In Situ CVD Derived Co–N–C Composite as Highly Efficient Cathode for Flexible Li–O2 Batteries
Authors: Yang Zhen‐Dong , Yang Xiao‐Yang , Liu Tong , Chang Zhi‐Wen , Yin Yan‐Bin , Zhang Xin‐Bo , Yan Jun‐Min , Jiang Qing
Published: July 2018

To promote the development of high energy Li–O2 batteries, it is important to design and construct a suitable and effective oxygen‐breathing cathode. Herein, activated cobalt‐nitrogen‐doped carbon nanotube/carbon nanofiber composites (Co‐N‐CNT/CNF) as the effective cathodes for Li–O2 batteries are prepared by in situ chemical vapor deposition (CVD). The unique architecture of these electrodes facilitates the rapid oxygen diffusion and electrolyte penetration. Meanwhile, the nitrogen‐doped carbon nanotube/carbon nanofiber (N‐CNT/CNF) and Co/CoNx serve as reaction sites to promote the formation/decomposition of discharge product. Li–O2 batteries with Co‐N‐CNT/CNF cathodes exhibit superior electrochemical performance in terms of a positive discharge plateau (2.81 V) and a low charge overpotential (0.61 V). Besides, Li–O2 batteries also present a high discharge capacity (11512.4 mAh g−1 at 100 mA g−1), and a long cycle life (130 cycles). Meanwhile, the Co‐N‐CNT/CNF cathode also has an excellent flexibility, thus the assembled flexible battery with Co‐N‐CNT/CNF can work normally and hold a wonderful capacity rate under various bending conditions.
Controlling Nucleation in Lithium Metal Anodes
Authors: Guan Xuze , Wang Aoxuan , Liu Shan , Li Guojie , Liang Feng , Yang Ying‐Wei , Liu Xingjiang , Luo Jiayan
Published: July 2018

Rechargeable batteries are regarded as the most promising candidates for practical applications in portable electronic devices and electric vehicles. In recent decades, lithium metal batteries (LMBs) have been extensively studied due to their ultrahigh energy densities. However, short lifespan and poor safety caused by uncontrollable dendrite growth hinder their commercial applications. Besides, a clear understanding of Li nucleation and growth has not yet been obtained. In this Review, the failure mechanisms of Li metal anodes are ascribed to high reactivity of lithium, virtually infinite volume changes, and notorious dendrite growth. The principles of Li deposition nucleation and early dendrite growth are discussed and summarized. Correspondingly, four rational strategies of controlling nucleation are proposed to guide Li nucleation and growth. Finally, perspectives for understanding the Li metal deposition process and realizing safe and high‐energy rechargeable LMBs are given.
A Hierarchical 3D Nanostructured Microfluidic Device for Sensitive Detection of Pathogenic Bacteria
Authors: Jalali Mahsa , AbdelFatah Tamer , Mahshid Sahar Sadat , Labib Mahmoud , Sudalaiyadum Perumal Ayyappasamy , Mahshid Sara
Published: July 2018

Efficient capture and rapid detection of pathogenic bacteria from body fluids lead to early diagnostics of bacterial infections and significantly enhance the survival rate. We propose a universal nano/microfluidic device integrated with a 3D nanostructured detection platform for sensitive and quantifiable detection of pathogenic bacteria. Surface characterization of the nanostructured detection platform confirms a uniform distribution of hierarchical 3D nano‐/microisland (NMI) structures with spatial orientation and nanorough protrusions. The hierarchical 3D NMI is the unique characteristic of the integrated device, which enables enhanced capture and quantifiable detection of bacteria via both a probe‐free and immunoaffinity detection method. As a proof of principle, we demonstrate probe‐free capture of pathogenic Escherichia coli (E. coli) and immunocapture of methicillin‐resistant‐Staphylococcus aureus (MRSA). Our device demonstrates a linear range between 50 and 104 CFU mL−1, with average efficiency of 93% and 85% for probe‐free detection of E. coli and immunoaffinity detection of MRSA, respectively. It is successfully demonstrated that the spatial orientation of 3D NMIs contributes in quantifiable detection of fluorescently labeled bacteria, while the nanorough protrusions contribute in probe‐free capture of bacteria. The ease of fabrication, integration, and implementation can inspire future point‐of‐care devices based on nanomaterial interfaces for sensitive and high‐throughput optical detection.
Aggregated inference
Authors: Huo Xiaoming , Cao Shanshan
Published: July 2018

Aggregated inference on distributed data becomes more and more important due to the larger size of data collected in different industries. Modeling and inference are needed in the case where data cannot be obtained at a central location; aggregated statistical inference is a major tool to solve the aforementioned problems. In the literature, problems under the setting of regression model (more generally, M‐estimator) are extensively studied. There are at least two popular techniques for distributed estimation: (a) averaging estimators from local locations and (b) the one‐step approach, which combines the simple averaging estimator with a classical Newton's method (using the local Hessian matrices) to generate a “one‐step” estimator. It is proved that under certain assumptions, the above constructed estimators enjoy the same asymptotic properties as the centralized estimator, which is obtained as if all data were available at a central location. We review the aforementioned two major estimations. It can be seen that, in Big‐Data problems, dividing the data to multiple machines and then using the aggregation technique to solve the estimation problem in parallel can speed up the computation with little compromise of the quality of the estimators. We discuss potential extensions to other models, such as support vector machine, principle component analysis, and so on. Numerical examples are omitted due to the space limitation; they can be easily found in the literature.

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Knowledge Discovery

Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods

Statistical Models > Fitting Models

Statistical and Graphical Methods of Data Analysis > Modeling Methods and Algorithms
Eyebrow semantic description via clustering based on Axiomatic Fuzzy Set
Authors: Li Danyang , Ren Yan , Du Tao , Liu Wanquan
Published: July 2018

In this paper, we aim to extract the eyebrow semantic descriptors based on the Axiomatic Fuzzy Set (AFS) theory. First, we normalize the image of the eyebrows and automatically mark it by using a recently proposed facial landmarks detector. Second, a recent clustering algorithm based on AFS theory for eyes semantics abstraction is used to cluster these detected eyebrow landmarks and give semantic descriptors for each eyebrow. Finally, BU‐4DFE and Multi‐PIE databases are used to validate the effectiveness of the proposed approach. Furthermore, the eyebrow descriptions with different expressions and similar expressions are investigated and we show that the semantic descriptors are closely related to expressions. The experimental results show that the eyebrow semantic concepts obtained by the AFS clustering algorithm are better than the results produced by the traditional clustering methods (k‐means and FCM) in terms of consistency for different expressions.

This article is categorized under:

Fundamental Concepts of Data and Knowledge > Knowledge Representation

Algorithmic Development > Biological Data Mining
Effect of Processing Parameters and Shape of Blade on the Solidification of Single-Crystal CMSX-4 Ni-Based Superalloy
Authors: Szeliga Dariusz
Published: July 2018

The effect of mold withdrawal velocity, heater and pouring temperatures and the thickness of blade root on the solidification parameters and shape of the liquidus isotherm as well as microstructure of single-crystal CMSX-4 nickel-based superalloy, manufactured by the Bridgman method, has been analyzed in the article. The temperature gradient G, solidification rate v and location of the liquidus isotherm were determined in relation to the radiation baffle on the basis of temperature measurements conducted in nine test points along the height of castings (140 mm) with different thicknesses of root (27, 15 and 7 mm) and withdrawal velocities of 3 and 5 mm/min. The increase of root thickness, relative to the airfoil, resulted in the rise of inhomogeneity of solidification parameters as well as the primary dendrite arm spacing and unsteady state solidification along the whole blade height. However, in the case of blade with constant thickness, the steady-state solidification was created at the distance of 65 to 130 mm from its base. The increase of mold withdrawal velocity caused the decrease of temperature gradient. However, the solidification rate was different from the mold withdrawal velocity, especially in the root and middle part of the airfoil. The increase of heater temperature resulted in a rise of temperature gradient and reduction of the curvature of the liquidus isotherm, whereas the pouring temperature did not affect the solidification parameters in the blade. Particularly unfavorable conditions of the solidification process could occur in the middle part of the airfoil and root because of the lowest value of G/v and the largest primary dendrite arm spacing.
Comprehensive simulation of metagenomic sequencing data with non‐uniform sampling distribution
Authors: Liu Shansong , Hua Kui , Chen Sijie , Zhang Xuegong
Published: July 2018

Background

Metagenomic sequencing is a complex sampling procedure from unknown mixtures of many genomes. Having metagenome data with known genome compositions is essential for both benchmarking bioinformatics software and for investigating influences of various factors on the data. Compared to data from real microbiome samples or from defined microbial mock community, simulated data with proper computational models are better for the purpose as they provide more flexibility for controlling multiple factors.

Methods

We developed a non‐uniform metagenomic sequencing simulation system (nuMetaSim) that is capable of mimicking various factors in real metagenomic sequencing to reflect multiple properties of real data with customizable parameter settings.

Results

We generated 9 comprehensive metagenomic datasets with different composition complexity from of 203 bacterial genomes and 2 archaeal genomes related with human intestine system.

Conclusion

The data can serve as benchmarks for comparing performance of different methods at different situations, and the software package allows users to generate simulation data that can better reflect the specific properties in their scenarios.
Segmentation based traversing-agent approach for road width extraction from satellite images using volunteered geographic information
Authors: Manandhar Prajowal , Marpu Prashanth Reddy , Aung Zeyar
Published: July 2018

We make use of the Volunteered Geographic Information (VGI) data to extract the total extent of the roads using remote sensing images. VGI data is often provided only as vector data represented by lines and not as full extent. Also, high geolocation accuracy is not guaranteed and it is common to observe misalignment with the target road segments by several pixels on the images. In this work, we use the prior information provided by the VGI and extract the full road extent even if there is significant mis-registration between the VGI and the image. The method consists of image segmentation and traversal of multiple agents along available VGI information. First, we perform image segmentation, and then we traverse through the fragmented road segments using autonomous agents to obtain a complete road map in a semi-automatic way once the seed-points are defined. The road center-line in the VGI guides the process and allows us to discover and extract the full extent of the road network based on the image data. The results demonstrate the validity and good performance of the proposed method for road extraction that reflects the actual road width despite the presence of disturbances such as shadows, cars and trees which shows the efficiency of the fusion of the VGI and satellite images.
The 2018 Revision to the Process of Care Model for Management of Erectile Dysfunction
Authors: Mulhall John P. , Giraldi Annamaria , Hackett Geoff , Hellstrom Wayne J.G. , Jannini Emmanuele A. , Rubio-Aurioles Eusebio , Trost Landon , Hassan Tarek A.
Published: July 2018

Introduction

Erectile dysfunction (ED) is a common condition the treatment of which over the years has expanded from specialty care settings to various other clinical settings. A Process of Care Model was developed in 1999 to provide primary care physicians with guidance in the diagnosis and management of ED.

Aim

This update to the Process of Care Model aims to reflect current ED management practices, because the study of ED has changed since 1999.

Methods

Updates to the Process of Care Model were developed during a meeting of international experts from diverse disciplines. The updated model is data-driven, evidence-based, and relevant to a wide range of healthcare providers.

Main Outcome Measures

This article summarizes the results of the expert meeting and focuses on ED management. The evaluation of ED is discussed in a separate article.

Results

The updated model presents modification of risk factors and correction of comorbidities frequently associated with ED as critical parts of patient management. Patients should be encouraged to make positive lifestyle changes such as improving diet and increasing physical exercise. Lifestyle changes may be accompanied by the first-line medical therapies of sexual counseling and therapy, which takes into consideration patient sexual dynamics and pharmacotherapy with phosphodiesterase 5 inhibitors (PDE5Is).

Clinical Implications

The updated model provides guidance regarding risk factors associated with ED, their modification, sexual counseling, and PDE5I selection, dosing, and patient education.

Strengths and Limitations

This update leverages the extensive clinical expertise and experience of the authors to provide updated, comprehensive guidance for ED management. The model reflects the views and experiences of a limited number of contributors; however, these authors draw upon a diverse array of clinical specialties and are regarded as experts in their fields. Additionally, no meta-analyses were performed to further support the ED evaluation guidelines presented.

Conclusion

Effective management of ED may be achieved through a combination of patient risk factor modification and first-line therapy, taking into consideration any patient comorbidities known to be associated with ED. Treatment goals should be individualized to restore sexual satisfaction to the patient and/or couple and improve quality of life based on the patient’s expressed needs and desires.
Extracorporeal Transseptal Penile Prosthesis Implantation for Extreme Cases of Corporeal Fibrosis: Shaeer Implantation Technique
Authors: Shaeer Osama , Shaeer Kamal
Published: July 2018

Background

Penile prosthesis implantation into scarred corporeal bodies is one of the most challenging procedures in prosthetic urologic surgery, especially following infection and extrusion of a penile implant. Several instruments and techniques have been used for making dilatation of scarred corporeal bodies easier and safer in expert hands. Nevertheless, in some cases, implantation is not possible.

Aim

This work presents extracorporeal transseptal implantation as a last resort in such cases.

Methods

In 39 patients with extensive corporeal fibrosis, penile prosthesis implantation is attempted. After failure of alternative techniques, extracorporeal implantation is resorted to in 10 patients. The corpus spongiosum is identified and protected. Diathermy knife is used to cut a longitudinal window into 1 corpus cavernosum, through the septum and into the contralateral corpus cavernosum. A single semirigid implant rod is inserted through the window at the base of the penis, halfway through. The 2 limbs of the rod are bent upward toward the glans, to assume a U shape. The limbs of the U are brought together at midshaft by a gathering suture passed through the corpora cavernosa and septum. The tips of the U are anchored under the glans.

Outcomes

Achievement of acceptable coital relationship.

Results

The procedure allowed acceptable coital relationship and concealment in 9/10 cases. In 1 case, infection occurred. Reimplantation with the same method was performed 6 months later, and the implant survived adequately. Perforation, migration, and urethral injury were not encountered.

Clinical Implications

This technique may help salvage abandoned cases with corporal fibrosis, particularly when the necessary expertise for alternative techniques is unavailable or when such techniques fail.

Strengths & Limitations

The technique presented is fairly straightforward and safe. However, the number of cases and duration of follow-up are limited.

Conclusion

Extracorporeal transseptal penile prosthesis implantation can salvage cases with severe corporeal fibrosis when all alternatives fail.
Impact of apolipoprotein E genotypes on vitamin E and memantine treatment outcomes in Alzheimer's disease
Authors: Belitskaya‐Lévy Ilana , Dysken Maurice , Guarino Peter , Sano Mary , Asthana Sanjay , Vertrees Julia E. , Pallaki Muralidhar , Llorente Maria , Love Susan , Schellenberg Gerard
Published: July 2018

Introduction

Because apolipoprotein E (APOE) genotypes are known risk factors for Alzheimer's disease (AD), they have been measured in clinical trial participants to determine their effect on treatment outcome.

Methods

We determined APOE genotypes in a subset of subjects (N = 415) who participated in a randomized controlled trial of vitamin E and memantine in 613 veterans with mild‐to‐moderate AD.

Results

Similar to the primary study, substudy participants receiving vitamin E also had slower functional decline than those receiving placebo. Overall, there was no difference in the rate of functional decline between APOE ε4 allele carriers and noncarriers. A significant interaction was observed between treatment and the APOE genotype on AD progression: ε4 carriers declined faster than noncarriers in the vitamin E plus memantine treatment arm.

Discussion

APOE genotypes may modulate AD treatment response and should be included in the design of future randomized controlled trials.
“The God of Time is Heritage of Mine”
Authors: Ripanti Francesco , Mariotti Samanta
Published: July 2018

During the 2014 excavation campaign at Vignale an impressive late antique mosaic depicting Aion, the God of Time, was discovered. This artifact of 100 m2became a milestone for outreach activities; fund-raising, theatrical performances, and archaeological trekking sessions were tailored to this finding, in collaboration with local associations. The discovery of the mosaic consolidated the promotional lines followed for this project, on-site and off-site, capable of engaging different audiences. Taking into account the recent debate about emotion as an essential constituent of the heritage-making process, a preliminary analysis of these initiatives questions the existence and the development of an emotional connection between the public and the archaeological site. Since an emotional connection emerged, further analyses and studies need to specify the kinds of emotive connection that occur. Assessment of the emotional impact intrinsic to public outreach will provide clues to transforming the “intellectual” emotion of discovery into a shared and valuable emotion for the benefit of both the archaeological project and its stakeholders.
Why Are Heritage Interpreters Voiceless at the Trowel's Edge? A Plea for Rewriting the Archaeological Workflow
Authors: Perry Sara
Published: July 2018

“Heritage interpretation” is generally conceived as the development and presentation of knowledge about the past for public audiences. Most obviously evidenced in descriptive signs, guides, and related media installed on archaeological and cultural sites, heritage interpretation has more than a half century of theory and applied practice behind it, yet it continues to sit uncomfortably within the typical archaeological workflow. While the concept can be criticized on many fronts, of concern is the lack of recognition that it is of equal relevance to both nonexpert and expert audiences (as opposed to nonexpert audiences alone). Our profession appears to rest on an assumption that archaeologists do their own kind of interpretation—and, separately, nonexperts require a special approach that heritage interpreters must facilitate but that field specialists have no need for—or from which little obvious expert benefit can be derived. For this reason, it is rare to find heritage interpreters embedded in primary fieldwork teams. Here I call for a rethinking of the traditional workflow, with a view to integrating the heritage interpretation tool kit and heritage interpreters themselves into our basic field methodologies. Their direct involvement in disciplinary process from the outset has the potential to transform archaeological interpretation overall.
Stochastic nonzero-sum games: a new connection between singular control and optimal stopping
Authors: De Angelis Tiziano , Ferrari Giorgio
Published: July 2018

In this paper we establish a new connection between a class of two-player nonzero-sum games of optimal stopping and certain two-player nonzero-sum games of singular control. We show that whenever a Nash equilibrium in the game of stopping is attained by hitting times at two separate boundaries, then such boundaries also trigger a Nash equilibrium in the game of singular control. Moreover, a differential link between the players' value functions holds across the two games.
Kesten's bound for subexponential densities on the real line and its multi-dimensional analogues
Authors: Finkelshtein Dmitri , Tkachov Pasha
Published: July 2018

We study the tail asymptotic of subexponential probability densities on the real line. Namely, we show that the n-fold convolution of a subexponential probability density on the real line is asymptotically equivalent to this density multiplied by n. We prove Kesten's bound, which gives a uniform in n estimate of the n-fold convolution by the tail of the density. We also introduce a class of regular subexponential functions and use it to find an analogue of Kesten's bound for functions on ℝd. The results are applied to the study of the fundamental solution to a nonlocal heat equation.