bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermo-Economic Performance of an Organic Rankine Cycle System Recovering Waste Heat Onboard an Offshore Service Vessel
Authors: Ng ChunWee , Tam Ivan C. K. , Wu Dawei
Published: May 2020

Recent regulatory developments in the global maritime industry have signalled an increased emphasis on the improvement of energy efficiency onboard ships. Among the various efficiency enhancement options, recovering waste heat using the organic Rankine cycle (ORC) has been studied and identified as a promising one in many earlier studies. In this paper, a marine application of ORC for waste heat recovery will be discussed by performing the first law thermodynamic analysis based on the operating profile and machinery design data of an offshore service vessel (OSV) and defining four standard cycle configurations that include simple, recuperated, dual heat source, and with intermediate heating. The use of five hydrocarbon working fluids that are suitable for shipboard usage comprising cyclopentane, n-heptane, n-octane, methanol and ethanol are examined. The economic analysis found that annual fuel saving between 5% and 9% is possible and estimated a specific installation cost of $5000–8000 USD/kW. Among the various options, the methanol ORC in a simple cycle configuration is found to have the shortest payback time relatively balancing between annual fuel saving and total module cost. Finally, the simple cycle ORC running on methanol is further examined using the second law entropy generation analysis and it is found that the heat exchangers in the system accounted for nearly 95% of the overall entropy generation rate and further work is recommended to reduce this in the future.
Basidiospores from Wood-Decay Fungi Transform Laccase Substrates in the Absence of Glucose and Nitrogen Supplements
Authors: Gramss Gerhard , Voigt Klaus-Dieter
Published: May 2020

Preparations of bacterial endospores and fungal conidia are applied in biocontrols, biocatalyses, and lignocellulose fermentations. The biocatalytic abilities of basidiospores from mushrooms of the order Agaricales are unknown. To assess their potential in colonizing recalcitrant substrates solely with their inherent resources, spores of the white-rot fungi Stropharia rugoso-annulata (Stru) and Kuehneromyces mutabilis (Kmt, Strophariaceae) were analyzed for surface-bound and internal total carbohydrates, phenols, proteins, minerals, and oxidoreductases to estimate their chemistry and the preconditions to transform the laccase substrates guaiacol and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) independent of external glucose and nitrogen. Surfaces of Stru/Kmt spores released (mg kg−1) hexoses, 7300/9700; phenols, >62/220; proteins, 21/168; and laccases, 42/0–0.15 µmol ABTS•+ kg−1 min−1 that mimicked oxidative activities of the resting spores. Milled-spore extracts contained pentoses, 96,600/6750; hexoses, 160,000/15,130; phenols, 452/767; protein, 12,600/924; true laccase, 688/0.30; and enzyme-protein-activating transition metals such as Cu in concentrations typical of wheat grains. Independent of external N and C supply, spores (<1‰) germinated in bideionized water, supported by their surface resources. Kmt spores germinated, too, at comparable rates in N-free solutions of glucose and the not immediately metabolizable ABTS and guaiacol. The release of proteins and oxidoreductase(s) by Kmt spores starting upon germination was higher in guaiacol-incubated idiophase- than in glucose-incubated trophophase-spores and led to the 3–4-fold formation of guaiacol polymerizates and ABTS•+. Constitutive aromatic ring-cleaving dioxygenases in the dormant spore that could be involved in the intrinsic metabolization of guaiacol were not detected. It is concluded that intrinsic resources enable (germinating) spores to release the highly efficient laccases of basidiomycetes and to transform aromatic compounds in the absence of sugar amendments. Spores show therefore plant seed-like autonomy in nutrient modification and acquisition during the early stages of the colonization of inert substrates.
The CFTR Mutation c.3453G > C (D1152H) Confers an Anion Selectivity Defect in Primary Airway Tissue that Can be Rescued by Ivacaftor
Authors: Laselva Onofrio , Moraes Theo J. , He Gengming , Bartlett Claire , Szàrics Ida , Ouyang Hong , Gunawardena Tarini N. A. , Strug Lisa , Bear Christine E. , Gonska Tanja
Published: May 2020

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene variant, c.3453G > C (D1152H), is associated with mild Cystic Fibrosis (CF) disease, though there is considerable clinical variability ranging from no detectable symptoms to lung disease with early acquisition of Pseudomonas aeruginosa. The approval extension of ivacaftor, the first CFTR modulator drug approved, to include D1152H was based on a positive drug response of defective CFTR-D1152H chloride channel function when expressed in FRT cells. Functional analyses of primary human nasal epithelial cells (HNE) from an individual homozygous for D1152H now revealed that while CFTR-D1152H demonstrated normal, wild-type level chloride conductance, its bicarbonate-selective conductance was impaired. Treatment with ivacaftor increased this bicarbonate-selective conductance. Extensive genetic, protein and functional analysis of the nasal cells of this D1152H/D1152H patient revealed a 90% reduction of CFTR transcripts due to the homozygous presence of the 5T polymorphism in the poly-T tract forming a complex allele with D1152H. Thus, we confirm previous observation in patient-derived tissue that 10% normal CFTR transcripts confer normal, wild-type level chloride channel activity. Together, this study highlights the benefit of patient-derived tissues to study the functional expression and pharmacological modulation of CF-causing mutations, in order to understand pathogenesis and therapeutic responses.
Dynamics of Bose–Einstein Condensates Subject to the Pöschl–Teller Potential through Numerical and Variational Solutions of the Gross–Pitaevskii Equation
Authors: Pereira Lucas Carvalho , Nascimento Valter Aragão do
Published: May 2020

We present for the first time an approach about Bose–Einstein condensates made up of atoms with attractive interatomic interactions confined to the Pöschl–Teller hyperbolic potential. In this paper, we consider a Bose–Einstein condensate confined in a cigar-shaped, and it was modeled by the mean field equation known as the Gross–Pitaevskii equation. An analytical (variational method) and numerical (two-step Crank–Nicolson) approach is proposed to study the proposed model of interatomic interaction. The solutions of the one-dimensional Gross–Pitaevskii equation obtained in this paper confirmed, from a theoretical point of view, the possibility of the Pöschl–Teller potential to confine Bose–Einstein condensates. The chemical potential as a function of the depth of the Pöschl–Teller potential showed a behavior very similar to the cases of Bose–Einstein condensates and superfluid Fermi gases in optical lattices and optical superlattices. The results presented in this paper can open the way for several applications in atomic and molecular physics, solid state physics, condensed matter physics, and material sciences.
Correlation of Strain Path, Texture, Twinning, and Mechanical Properties in Twinning-Induced Plasticity Steel during Wire Drawing
Authors: Hwang Joong-Ki
Published: May 2020

The effect of changing the strain path on texture development, twin kinetics, and mechanical properties in twinning-induced plasticity steel was investigated to understand twinning behavior in more detail. Among the various plastic deformation processes, the wire drawing process was selected to achieve the aims of the study. Specimens of cold-drawn TWIP steel wire under the same effective strain but with different crystallographic textures were successfully fabricated using the effect of the wire drawing direction. Electron backscatter diffraction results showed that the drawn wires using both unidirectional (UD) and reverse-directional (RD) wire drawing processes were characterized as duplex fiber textures of major <111> and minor <100>. It was found that the RD wire had a higher fraction of <111> component at both the center and surface areas compared to the UD wire, because the metal flow of the RD wire was beneficial for the development of a <111> orientation. The pronounced <111> crystallographic orientation of the RD wire activated the twinning rate and geometrically necessary dislocation density, leading to an increase in strength but a decrease in ductility. The strain path is as important as the amount of strain for strengthening the materials, especially those that are deformed by twinning.
Refractive-Index Profile Reconstruction in Graded-Index Polymer Optical Fibers Using Raman Spectroscopy
Authors: Azkune Mikel , Ortega-Gomez Angel , Ayesta Igor , Zubia Joseba
Published: May 2020

This work reports a novel method to create a 3D map of the refractive index of different graded-index polymer optical fibers (GI-POF), measuring the Raman spectra at different points of their transverse sections. Raman fingerprints provide accurate molecular information of the sample with high spatial resolution. The refractive index of GI-POFs is modified by adding a dopant in the preform; therefore, by recording the intensities of the Raman peaks related to the dopant material, a 3D map of the refractive index is rendered. In order to demonstrate the usefulness of the method, three different GI-POFs were characterized and the obtained results were compared with the information provided by the manufacturers. The results show accurate 3D maps of the refractive index taken in the actual GI-POF end faces, showing different imperfections that manufacturers do not take into account, such as the slight deviations of the azimuthal symmetry. The simplicity and the feasibility of the technique mean this method has high potential for fiber characterization purposes.
Understanding the Detection Mechanisms and Ability of Molecular Hydrogen on Three-Dimensional Bicontinuous Nanoporous Reduced Graphene Oxide
Authors: Ito Yoshikazu , Kayanuma Megumi , Shigeta Yasuteru , Fujita Jun-ichi , Tanabe Yoichi
Published: May 2020

Environmental safety has become increasingly important with respect to hydrogen use in society. Monitoring techniques for explosive gaseous hydrogen are essential to ensure safety in sustainable hydrogen utilization. Here, we reveal molecular hydrogen detection mechanisms with monolithic three-dimensional nanoporous reduced graphene oxide under gaseous hydrogen flow and at room temperature. Nanoporous reduced graphene oxide significantly increased molecular hydrogen physisorption without the need to employ catalytic metals or heating. This can be explained by the significantly increased surface area in comparison to two-dimensional graphene sheets and conventional reduced graphene oxide flakes. Using this large surface area, molecular hydrogen adsorption behaviors were accurately observed. In particular, we found that the electrical resistance firstly decreased and then gradually increased with higher gaseous hydrogen concentrations. The resistance decrease was due to charge transfer from the molecular hydrogen to the reduced graphene oxide at adsorbed molecular hydrogen concentrations lower than 2.8 ppm; conversely, the resistance increase was a result of Coulomb scattering effects at adsorbed molecular hydrogen concentrations exceeding 5.0 ppm, as supported by density functional theory. These findings not only provide the detailed adsorption mechanisms of molecular hydrogen, but also advance the development of catalyst-free non-heated physisorption-type molecular detection devices.
Geometric Analysis of Type B Aortic Dissections Shows Aortic Remodeling After Intervention Using Multilayer Stents
Authors: Costache Victor S. , Meekel Jorn P. , Costache Andreea , Melnic Tatiana , Solomon Crina , Chitic Anca M. , Bucurenciu Cristian , Moldovan Horatiu , Antoniac Iulian , Candea Gabriela , Yeung Kak K.
Published: May 2020

Recently, multilayer stents for type B aortic dissections (TBAD) have been proposed to decrease false lumen flow, increase and streamline true lumen flow, and retain branch vessel patency. We aimed to provide a protocol with standardized techniques to investigate aortic remodeling of TBAD by multilayer flow modulators (MFM) in static geometric and hemodynamic analyses. Combining existing literature and new insights, a standardized protocol was designed. Using pre- and postoperative CT scans, geometric models were constructed, lumen dimensions were calculated, computational fluid dynamics (CFD) models were composed, and velocity and pressures were calculated. Sixteen TBAD cases treated with MFM were included for analysis. For each case, aortic remodeling was analyzed using post-processing medical imaging software. After 3D models were created, geometrical anatomical measurements were performed, and meshes for finite element analysis were generated. MFM cases were compared pre- and postoperatively; true lumen volumes increased (p < 0.001), false lumen volumes decreased (p = 0.001), true lumen diameter at the plane of maximum compression (PMC) increased (p < 0.001), and false lumen index decreased (p = 0.008). True lumen flow was streamlined, and the overall fluid velocity and pressures decreased (p < 0.001 and p = 0.006, respectively). This protocol provided a standardized method to evaluate the effects of MFM treatments in TBAD on geometric analyses, PMC, and CFD outcomes.
Phase, Composition and Structure Changes of CoCrNi-Based Concentrated Alloys Resulting from High Temperature Oxidation
Authors: Vilémová Monika , Hadraba Hynek , Weiss Zdeněk , Lukáč František , Csáki Štefan , Chlup Zdeněk , Matějíček Jiří , Chráska Tomáš
Published: May 2020

In this work, CoCrNi, FeCoCrNi and CoCrFeMnNi concentrated alloys with a Y-Ti oxide particle dispersion were prepared by mechanical alloying and Spark Plasma Sintering. The alloy consists of an FCC Ni-based matrix with a Y-Ti oxide dispersion and additional phases of Cr23C6 and Cr2O3. The effect of Fe, Mn, and Y-Ti oxide particles on the formation of oxide scales and the composition of the adjacent CoCrNi and FeCoCrNi alloys was studied. It was found that alloys without Mn in their composition form a protective Cr2O3 scale. The Cr23C6 particles provide an alternative mechanism for balancing the chromium loss during the oxidation. Y and Ti from the oxide particles participate in the formation of the protective oxide scales. Fe promotes Y and especially Ti diffusion through the Cr2O3 scale, resulting in the formation of Ti-depleted regions in the alloy. The findings will serve for the further development of these new materials.
Research on Anisotropic Viscoelastic Constitutive Model of Compression Molding for CFRP
Authors: Xie Jiuming , Wang Shiyu , Cui Zhongbao , Wu Jin , Zhou Xuejun
Published: May 2020

The carbon-fiber-reinforced polymer (CFRP) is a mainstream material for lightweight products from the end of the 20th century to the present day. Its compression molding process has obvious advantages in mass production. This paper attempts to establish the constitutive models of compression molding of the CFRP materials and study their mechanism. Based on anisotropic linear elastic mechanics, viscoelastic mechanics, and thermodynamics, as well as the Maxwell viscoelastic constitutive model, we first establish the constitutive model of thermorheologically simple CFRP materials (TSMs). Then, considering the influence of temperature on the initial stiffness and equilibrium stiffness, the concept of temperature stiffness coefficient is introduced, and the Cartier coordinate system is converted into a cylindrical coordinate system, thereby establishing the constitutive model of thermorheologically complex materials (TCMs) using the tensor form. Finally, by comparing to the structure of the Zocher model, the two constitutive models established in this study are verified. The research findings have important theoretical research significance for studying the compression molding mechanism of carbon fiber and further improving the quality of product molding.
The Strength of Egg Trays under Compression: A Numerical and Experimental Study
Authors: Czechowski Leszek , Kmita-Fudalej Gabriela , Szewczyk Włodzimierz
Published: May 2020

This work concerns the analysis of egg packages subjected to compression. Experimental investigations were carried out to determine the curves of compression and maximum loads. To compare packages accessible on the market, several different shapes of egg packages were tested after being conditioned in air with a relative humidity of 50%. Several paper structures in stock were compressed. By validating the experiment results, numerical computations based on the finite element method (FEM) were executed. The estimations of a numerical model were performed with the use of the perfect plasticity of paper and with the assumption of large strains and deflections. Our own two structures of egg packaging were taken into account: basic and modified. The material of the packages was composed of 90% recovered paper and 10% coconut fibres. This paper involved the numerical modelling of such complex packaging. Moreover, our research showed that introducing several features into the structures of the packaging can improve the stiffness and raise the maximum load. Thanks to the application of ribs and grooves, the strength ratio and compression stiffness, in comparison to the basic tray, increased by approximately 23.4% and 36%, respectively. Moreover, the obtained indexes of modified trays were higher than the majority of the studied market trays.
Role of Natural Stone Wastes and Minerals in the Alkali Activation Process: A Review
Authors: Coppola Bartolomeo , Tulliani Jean-Marc , Antonaci Paola , Palmero Paola
Published: May 2020

This review aims to provide a comprehensive assessment concerning alkali activation of natural stone wastes and minerals. In particular, the structure of the review is divided into two main sections in which the works dealing with alumino-silicate and carbonatic stones are discussed, respectively. Alumino-silicate stones are generally composed of quartz and feldspars, while carbonatic stones are mainly made of calcite and dolomite. The role of these minerals in the alkali activation process is discussed, attesting their influence in the development of the final product properties. In most of the works, authors use mineral additions only as fillers or aggregates and, in some cases, as a partial substitution of more traditional raw powders, such as metakaolin, fly ash, and granulated blast furnace slag. However, a few works in which alumino-silicate and carbonatic stone wastes are used as the main active components are discussed as well. Not only the raw materials, but also the entire alkali activation process and the curing conditions adopted in the literature studies here reviewed are systematically analyzed to improve the understanding of their effect on the physical, mechanical, and durability properties of the final products and to eventually foster the reuse of natural stone wastes for the purposes of sustainability in different applications.
Discrete Element Simulation of the Effect of Roller-Spreading Parameters on Powder-Bed Density in Additive Manufacturing
Authors: Zhang Jiangtao , Tan Yuanqiang , Bao Tao , Xu Yangli , Xiao Xiangwu , Jiang Shengqiang
Published: May 2020

The powder-bed with uniform and high density that determined by the spreading process parameters is the key factor for fabricating high performance parts in Additive Manufacturing (AM) process. In this work, Discrete Element Method (DEM) was deployed in order to simulate Al2O3 ceramic powder roller-spreading. The effects of roller-spreading parameters include translational velocity Vs, roller’s rotational speed ω, roller’s diameter D, and powder layer thickness H on powder-bed density were analyzed. The results show that the increased translational velocity of roller leads to poor powder-bed density. However, the larger roller’s diameter will improve powder-bed density. Moreover, the roller’s rotational speed has little effect on powder-bed density. Layer thickness is the most significant influencing factor on powder-bed density. When layer thickness is 50 μm, most of particles are pushed out of the build platform forming a lot of voids. However, when the layer thickness is greater than 150 μm, the powder-bed becomes more uniform and denser. This work can provide a reliable basis for roller-spreading parameters optimization.
Decontamination of Titanium Surface Using Different Methods: An In Vitro Study
Authors: Yan Sifan , Li Min , Komasa Satoshi , Agariguchi Akinori , Yang Yuanyuan , Zeng Yuhao , Takao Seiji , Zhang Honghao , Tashiro Yuichiro , Kusumoto Tetsuji , Kobayashi Yasuyuki , Chen Liji , Kashiwagi Kosuke , Matsumoto Naoyuki , Okazaki Joji , Kawazoe Takayoshi
Published: May 2020

Contamination of implants is inevitable during different steps of production as well as during the clinical use. We devised a new implant cleaning strategy to restore the bioactivities on dental implant surfaces. We evaluated the efficiency of the Finevo cleaning system, and Ultraviolet and Plasma treatments to decontaminate hydrocarbon-contaminated titanium disks. The surfaces of the contaminated titanium disks cleaned using the Finevo cleaning system were similar to those of the uncontaminated titanium disks in scanning electron microscopy and X-ray photoelectron spectroscopy analysis, but no obvious change in the roughness was observed in the scanning probe microscopy analysis. The rat bone marrow mesenchymal stem cells (rBMMSCs) cultured on the treated titanium disks attached to and covered the surfaces of disks cleaned with the Finevo cleaning system. The alkaline phosphatase activity, calcium deposition, and osteogenesis-related gene expression in rBMMSCs on disks cleaned using the Finevo cleaning system were higher compared to those in the ultraviolet and plasma treatments, displaying better cell functionality. Thus, the Finevo cleaning system can enhance the attachment, differentiation, and mineralization of rBMMSCs on treated titanium disk surfaces. This research provides a new strategy for cleaning the surface of contaminated titanium dental implants and for restoration of their biological functions.
Hydrogen Trapping in bcc Iron
Authors: Kholtobina Anastasiia S. , Pippan Reinhard , Romaner Lorenz , Scheiber Daniel , Ecker Werner , Razumovskiy Vsevolod I.
Published: May 2020

Fundamental understanding of H localization in steel is an important step towards theoretical descriptions of hydrogen embrittlement mechanisms at the atomic level. In this paper, we investigate the interaction between atomic H and defects in ferromagnetic body-centered cubic (bcc) iron using density functional theory (DFT) calculations. Hydrogen trapping profiles in the bulk lattice, at vacancies, dislocations and grain boundaries (GBs) are calculated and used to evaluate the concentrations of H at these defects as a function of temperature. The results on H-trapping at GBs enable further investigating H-enhanced decohesion at GBs in Fe. A hierarchy map of trapping energies associated with the most common crystal lattice defects is presented and the most attractive H-trapping sites are identified.
A Proposition of an In Situ Production of a Blended Cement
Authors: Halbiniak Jacek , Katzer Jacek , Major Maciej , Major Izabela
Published: May 2020

Many byproducts and waste materials with pozzolanic properties can substitute natural raw materials in cement production. Some of these waste materials like fly ash and blast furnace slag are commonly harnessed by cement industry. Others are of seldom use due to limitations of the very centralized cement production systems currently in use. In the authors opinion, it is necessary to change this system to enable efficient utilization of various waste materials that are available locally (e.g., white and red ceramics). In this study, a new partially centralized system of cement production is proposed. The adoption of a new system would significantly reduce the volume of long-distance transportation and enable utilization of numerous locally available waste materials that are currently dismissed. The last stage of production of the ready-to-use cement would take place in situ. The cement would be produced on demand and be immediately used for concrete production on-site. The research program was conducted considering the importance of the quality of cements obtained in the new way, substituting up to 12% of its mass by white ceramics. The research program was proof of concept of the proposed cement production system. It was shown that the quality of “in situ cement” does not differ from standard cements.
Investigations of New Phenothiazine-Based Compounds for Dye-Sensitized Solar Cells with Theoretical Insight
Authors: Slodek Aneta , Zych Dawid , Szafraniec-Gorol Grażyna , Gnida Paweł , Vasylieva Marharyta , Schab-Balcerzak Ewa
Published: May 2020

New D-π-D-π-A low-molecular-weight compounds, based on a phenothiazine scaffold linked via an acetylene unit with various donor moiety and cyanoacrylic acid anchoring groups, respectively, were successfully synthesized. The prepared phenothiazine dyes were entirely characterized using nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. The compounds were designed to study the relationship between end-capping donor groups’ structure on their optoelectronic and thermal properties as well as the dye-sensitized solar cells’ performance. The effect of π-conjugation enlargement by incorporation of different heterocyclic substituents possessing various electron–donor affinities was systematically experimentally and theoretically examined. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were implemented to determine the electronic properties of the novel molecules.
TheFinite Element Modeling and Experimental Study of Sandwich Plates with Frequency-Dependent Viscoelastic Material Model
Authors: Huang Zhicheng , Wang Xingguo , Wu Nanxing , Chu Fulei , Luo Jing
Published: May 2020

Athree-layer composite plate element is developed for finite element modeling and vibration analysis of sandwich plate with frequency-dependent viscoelastic material core. The plate element is quadrilateral element bounded by four-node with 7-degree-of-freedom per node. The frequency-dependent characteristics of viscoelastic material parameters are described using the Biot model. The method of identifying the parameters of the Biot model is given. By introducing auxiliary coordinates, the Biot model is combined with the finite element equation of the viscoelastic sandwich plate. Through a series of mathematical transformations, the equation is transformed into a standard second-order steady linear system equation form to simplify the solution process. Finally, the vibration characteristics of the viscoelastic sandwich plate are analyzed and experimentally studied. The results show that the method in this paper is correct and reliable, and it has certain reference and application value for solving similar engineering vibration problems.
Semi-Implicit and Semi-Explicit Adams-Bashforth-Moulton Methods
Authors: Tutueva Aleksandra , Karimov Timur , Butusov Denis
Published: May 2020

Multistep integration methods are widespread in the simulation of high-dimensional dynamical systems due to their low computational costs. However, the stability of these methods decreases with the increase of the accuracy order, so there is a known room for improvement. One of the possible ways to increase stability is implicit integration, but it consequently leads to sufficient growth in computational costs. Recently, the development of semi-implicit techniques achieved great success in the construction of highly efficient single-step ordinary differential equations (ODE) solvers. Thus, the development of multistep semi-implicit integration methods is of interest. In this paper, we propose the simple solution to increase the numerical efficiency of Adams-Bashforth-Moulton predictor-corrector methods using semi-implicit integration. We present a general description of the proposed methods and explicitly show the superiority of ODE solvers based on semi-implicit predictor-corrector methods over their explicit and implicit counterparts. To validate this, performance plots are given for simulation of the van der Pol oscillator and the Rossler chaotic system with fixed and variable stepsize. The obtained results can be applied in the development of advanced simulation software.
Quantum Codes from Constacyclic Codes over the Ring Fq[u1,u2]/〈

u
1
2

-u1,

u
2
2

-u2,u1u2-u2u1〉
Authors: Alkenani Ahmad N. , Ashraf Mohammad , Mohammad Ghulam
Published: May 2020

In this paper, we study the structural properties of ( α + u 1 β + u 2 γ + u 1 u 2 δ ) -constacyclic codes over R = F q [ u 1 , u 2 ] / ⟨ u 1 2 − u 1 , u 2 2 − u 2 , u 1 u 2 − u 2 u 1 ⟩ where q = p m for odd prime p and m ≥ 1 . We derive the generators of constacyclic and dual constacyclic codes. We have shown that Gray image of a constacyclic code of length n is a quasi constacyclic code of length 4 n . Also we have classified all possible self dual linear codes over this ring R . We have given the applications by computing non-binary quantum codes over this ring R .
Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function: Reply to the Discussion by Majid Niazkar
Authors: Praks Pavel , Brkić Dejan
Published: May 2020

In this reply, we present updated approximations to the Colebrook equation for flow friction. The equations are equally computational simple, but with increased accuracy thanks to the optimization procedure, which was proposed by the discusser, Dr. Majid Niazkar. Our large-scale quasi-Monte Carlo verifications confirm that the here presented novel optimized numerical parameters further significantly increase accuracy of the estimated flow friction factor.
A Multi-Criteria Reference Point Based Approach for Assessing Regional Innovation Performance in Spain
Authors: Garcia-Bernabeu Ana , Cabello José Manuel , Ruiz Francisco
Published: May 2020

The evaluation of regional innovation performance through composite innovation indices can serve as a valuable tool for policy-making. While discussion on the best methodology to construct composite innovation indices continues, we are interested in deepening the use of reference levels and the aggregation issue. So far, additive aggregation methods are, largely, the most widespread aggregation rule, thus allowing for full compensability among single indicators. In this paper, we present an integrated assessment methodology to evaluate regional innovation performance using the Multi-Reference Point based Weak and Strong Composite Indicator (MRP-WSCI) approach, which allows defining reference levels and different degrees of compensability. As an example of application to the Regional Innovation Scoreboard, the proposed technique is developed to measure the innovation performance of Spain’s regions taking into account Spanish and European reference levels. The main features of the proposed approach are: (i) absolute or relative reference levels could be previously defined by the decision maker; (ii) by establishing the reference levels, the resulting composite innovation index is an easy-to-interpret measure; and (iii) the non-compensatory strong composite indicator provides an additional layer of information for policy-making (iv) a visualization tool called Light-Diagram is proposed to track the specific strengths and weaknesses of the regions’ innovation performance.
Shape-Preserving Properties of a Relaxed Four-Point Interpolating Subdivision Scheme
Authors: Ashraf Pakeeza , Ghaffar Abdul , Baleanu Dumitru , Sehar Irem , Nisar Kottakkaran Sooppy , Khan Faheem
Published: May 2020

In this paper, we analyze shape-preserving behavior of a relaxed four-point binary interpolating subdivision scheme. These shape-preserving properties include positivity-preserving, monotonicity-preserving and convexity-preserving. We establish the conditions on the initial control points that allow the generation of shape-preserving limit curves by the four-point scheme. Some numerical examples are given to illustrate the graphical representation of shape-preserving properties of the relaxed scheme.
Bioactive Metabolites from the Mariana Trench Sediment-Derived Fungus Penicillium sp. SY2107
Authors: Kaleem Sidra , Qin Le , Yi Wenwen , Lian Xiao-Yuan , Zhang Zhizhen
Published: May 2020

Mariana Trench sediments are enriched in microorganisms, however, the structures and bioactivities of their secondary metabolites are not very known. In this study, a fungus Penicillium sp. SY2107 was isolated from a sample of Mariana Trench sediment collected at a depth of 11000 m and an extract prepared from the culture of this fungus in rice medium showed antimicrobial activities. Chemical investigation on this active extract led to the isolation of 16 compounds, including one novel meroterpenoid, named andrastone C. Structure of the new compound was elucidated based on high-resolution electrospray ionization mass spectroscopy (HRESIMS) data, extensive nuclear magnetic resonance (NMR) spectroscopic analyses and a single crystal X-ray diffraction. The crystal structure of a known meroterpenoid andrastone B was also reported in this study. Both andrastones B and C exhibited antimicrobial activities against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Candida albicans with minimum inhibitory concentration (MIC) values in a range from 6 to 13 μg/mL.
The Biotechnological Potential of the Marine Diatom Skeletonema dohrnii to the Elevated Temperature and pCO2
Authors: Thangaraj Satheeswaran , Sun Jun
Published: May 2020

Marine diatoms are promising candidates for biotechnological applications, since they contain high-value compounds, naturally. To facilitate the production of these compounds, stress conditions are often preferable; however, challenges remain with respect to maximizing a metabolic potential for the large-scale cultivation. Here, we sequenced the transcriptome of diatom Skeletonema dohrnii under the actual (21 °C, 400 ppm) and elevated (25 °C, 1000 ppm) temperature and pCO2 condition. Results indicated that cells grown at higher temperature and pCO2 showed increasing growth rate, pigment composition, and biochemical productivity as did the expression of chlorophyll, carotenoid and bioactive compound related genes or transcripts. Furthermore, performing de novo transcriptome, we identified 32,884 transcript clusters and found 10,974 of them were differentially expressed between these two conditions. Analyzing the functions of differentially expressed transcripts, we found many of them involved in core metabolic and biosynthesis pathways, including chlorophyll metabolism, carotenoid, phenylpropanoid, phenylalanine and tyrosine, and flavonoid biosynthesis was upregulated. Moreover, we here demonstrated that utilizing a unique bio-fixation ability, S. dohrnii is capable of suppressing central carbon metabolism to promote lipid productivity, fatty acid contents and other bioactive compounds under high temperature and pCO2 treatment. Our study suggests that this S. dohrnii species could be a potential candidate for wide-scale biotechnological applications under elevated temperature and CO2 conditions.
Development of Nanobainitic Microstructures in Carbo-Austempered Cast Steels: Heat Treatment, Microstructure and Properties
Authors: Ríos-Diez Oscar , Aristizábal-Sierra Ricardo , Serna-Giraldo Claudia , Jimenez Jose A. , Garcia-Mateo Carlos
Published: May 2020

Carburizing implies the existence of a carbon gradient from the surface to the core of the steel, which in turn will affect both the critical temperature for austenite formation and the kinetics of the bainitic transformation during the austempering treatment. Therefore, for future development of carbo-austempered steels with nanobainitic microstructures in the case, it is key to understand the effect of such carbon gradient has on the final microstructure and the mechanical properties reached by the heat treatments used. This work was divided into two parts, firstly two alloys with similar carbon content to those at the surface and center of the carburized steel were used to establish the optimal heat treatment parameters and to study bainite transformation kinetics by high resolution dilatometry. In a second step, a carburized alloy is produced and subjected to the designed heat treatments, in order to evaluate the microstructure and mechanical properties developed. Results thus obtained are compared with those obtained in the same carburized alloy after following the most common quench and temper treatment.
Probable Maximum Sizes of Inclusions Predicted by SEV and PSD for BH Steels of Automobile Exposed Panel with Different Sulfur Contents
Authors: Pan Xiaoqian , Yang Jian
Published: May 2020

This study attempted to estimate the maximum size of inclusions in the ultra-low carbon Bake Hardening (BH) steels of automobile exposed panel. The Probable Maximum Sizes (PMS) of inclusions at the different steelmaking stages for BH steel with different sulfur contents were predicted by two methods of Statistics of Extreme Values (SEV) and Particle Size Distribution (PSD). The S content does not show a relationship with the PMS prediction of inclusions in the molten steel in which Al2O3 is the main inclusion, while the higher content of S leads to a larger PMS value in the slab, due to more number of large-sized Al2O3-MnS inclusions formed during solidification. The PMS value in the slab is greater than that in the molten steel for BH steel. Thus, the PMS of inclusions in the slab cannot be estimated from the molten steel samples. The SEV can be used to predict well the PMS values at different steelmaking stages for BH steels. However, the PSD of exponential function cannot predict well the PMS value in the slab for BH steel when considering all kinds of inclusions due to the large influence of small-sized MnS with high number density on the PSD of exponential function. When only considering Al2O3-MnS inclusions, the PSD of exponential function can make a reasonable PMS prediction in the slab, because the size distribution of Al2O3-MnS with large size can follow the exponential function.
Using Metabolomics to Identify Cell Line-Independent Indicators of Growth Inhibition for Chinese Hamster Ovary Cell-Based Bioprocesses
Authors: Alden Nicholas , Raju Ravali , McElearney Kyle , Lambropoulos James , Kshirsagar Rashmi , Gilbert Alan , Lee Kyongbum
Published: May 2020

Chinese hamster ovary (CHO) cells are widely used for the production of biopharmaceuticals. Efforts to improve productivity through medium design and feeding strategy optimization have focused on preventing the depletion of essential nutrients and managing the accumulation of lactate and ammonia. In addition to ammonia and lactate, many other metabolites accumulate in CHO cell cultures, although their effects remain largely unknown. Elucidating these effects has the potential to further improve the productivity of CHO cell-based bioprocesses. This study used untargeted metabolomics to identify metabolites that accumulate in fed-batch cultures of monoclonal antibody (mAb) producing CHO cells. The metabolomics experiments profiled six cell lines that are derived from two different hosts, produce different mAbs, and exhibit different growth profiles. Comparing the cell lines’ metabolite profiles at different growth stages, we found a strong negative correlation between peak viable cell density (VCD) and a tryptophan metabolite, putatively identified as 5-hydroxyindoleacetaldehyde (5-HIAAld). Amino acid supplementation experiments showed strong growth inhibition of all cell lines by excess tryptophan, which correlated with the accumulation of 5-HIAAld in the culture medium. Prospectively, the approach presented in this study could be used to identify cell line- and host-independent metabolite markers for clone selection and bioprocess development.
Thin-Film MEMS Resistors with Enhanced Lifetime for Thermal Inkjet
Authors: Bar-Levav Elkana , Witman Moshe , Einat Moshe
Published: May 2020

In this paper, the failure mechanisms of the thermal inkjet thin-film resistors are recognized. Additionally, designs of resistors to overcome these mechanisms are suggested and tested by simulation and experiment. The resulting resistors are shown to have improved lifetimes, spanning an order of magnitude up to 2 × 109 pulses. The thermal failure mechanisms were defined according to the electric field magnitude in three critical points—the resistor center, the resistor–conductor edge, and the resistor thermal “hot spots”. Lowering the thermal gradients between these points will lead to the improved lifetime of the resistors. Using MATLAB PDE simulations, various resistors shapes, with different electric field ratios in the hot spots, were designed and manufactured on an 8″ silicon wafer. A series of lifetime experiments were conducted on the resistors, and a strong relation between the shape and the lifetime of the resistor was found. These results have immediate ramifications regarding the different printing apparatuses which function with thermal inkjet technology, allowing the commercial production of larger thermal printheads with high MTBF rate. Such heads may fit fast and large 3D printers.
Microbial Community and Fermentation Dynamics of Corn Silage Prepared with Heat-Resistant Lactic Acid Bacteria in a Hot Environment
Authors: Guan Hao , Shuai Yang , Yan Yanhong , Ran Qifan , Wang Xia , Li Dandan , Cai Yimin , Zhang Xinquan
Published: May 2020

To develop a silage fermentation technique to adapt to global climate changes, the microbiome and fermentation dynamics of corn silage inoculated with heat-resistant lactic acid bacteria (LAB) under high-temperature conditions were studied. Corn was ensiled in laboratory silo, with and without two selected strains, Lactobacillus salivarius LS358 and L. rhamnosus LR753, two type strains L. salivarius ATCC 11741T and L. rhamnosus ATCC 7469T. The ensiling temperatures were designed at 30 °C and 45 °C, and the sampling took place after 0, 3, 7, 14, and 60 days of fermentation. The higher pH and dry matter losses were observed in the silages stored at 45 °C compared to those stored at 30 °C. Silages inoculated with strains LS358 and LR753 at 30 °C had a lower ratio of lactic acid/acetic acid. The dominant bacterial genera gradually changed from Pediococcus and Lactobacillus to Lactobacillus in silages during ensiling at 30 °C, while the bacterial community became more complex and fragmented after 7 d of ensiling at 45 °C. The high temperatures significantly led to a transformation of the LAB population from homo-fermentation to hetero-fermentation. This study is the first to describe microbial population dynamics response to high temperature during corn ensiling, and the results indicate that L. rhamnosus 753 shows potential ability to improve silage fermentation in tropics and subtropics.
Bacteriophage-Derived Endolysins Applied as Potent Biocontrol Agents to Enhance Food Safety
Authors: Chang Yoonjee
Published: May 2020

Endolysins, bacteriophage-encoded enzymes, have emerged as antibacterial agents that can be actively applied in food processing systems as food preservatives to control pathogens and ultimately enhance food safety. Endolysins break down bacterial peptidoglycan structures at the terminal step of the phage reproduction cycle to enable phage progeny release. In particular, endolysin treatment is a novel strategy for controlling antibiotic-resistant bacteria, which are a severe and increasingly frequent problem in the food industry. In addition, endolysins can eliminate biofilms on the surfaces of utensils. Furthermore, the cell wall-binding domain of endolysins can be used as a tool for rapidly detecting pathogens. Research to extend the use of endolysins toward Gram-negative bacteria is now being extensively conducted. This review summarizes the trends in endolysin research to date and discusses the future applications of these enzymes as novel food preservation tools in the field of food safety.
Sorghum Growth Promotion by Paraburkholderia tropica and Herbaspirillum frisingense: Putative Mechanisms Revealed by Genomics and Metagenomics
Authors: Kuramae Eiko E. , Derksen Stan , Schlemper Thiago R. , Dimitrov Maurício R. , Costa Ohana Y. A. , da Silveira Adriana P. D.
Published: May 2020

Bacteria from the genera Paraburkholderia and Herbaspirillum can promote the growth of Sorghum bicolor, but the underlying mechanisms are not yet known. In a pot experiment, sorghum plants grown on sterilized substrate were inoculated with Paraburkholderia tropica strain IAC/BECa 135 and Herbaspirillum frisingense strain IAC/BECa 152 under phosphate-deficient conditions. These strains significantly increased Sorghum bicolor cultivar SRN-39 root and shoot biomass. Shotgun metagenomic analysis of the rhizosphere revealed successful colonization by both strains; however, the incidence of colonization was higher in plants inoculated with P. tropica strain IAC/BECa 135 than in those inoculated with H. frisingense strain IAC/BECa 152. Conversely, plants inoculated with H. frisingense strain IAC/BECa 152 showed the highest increase in biomass. Genomic analysis of the two inoculants implied a high degree of rhizosphere fitness of P. tropica strain IAC/BECa 135 through environmental signal processing, biofilm formation, and nutrient acquisition. Both genomes contained genes related to plant growth-promoting bacterial (PGPB) traits, including genes related to indole-3-acetate (IAA) synthesis, nitrogen fixation, nodulation, siderophore production, and phosphate solubilization, although the P. tropica strain IAC/BECa 135 genome contained a slightly more extensive repertoire. This study provides evidence that complementary mechanisms of growth promotion in Sorghum might occur, i.e., that P. tropica strain IAC/BECa 135 acts in the rhizosphere and increases the availability of nutrients, while H. frisingense strain IAC/BECa 152 influences plant hormone signaling. While the functional and taxonomic profiles of the rhizobiomes were similar in all treatments, significant differences in plant biomass were observed, indicating that the rhizobiome and the endophytic microbial community may play equally important roles in the complicated plant-microbial interplay underlying increased host plant growth.
The Ability of Respiratory Commensal Bacteria to Beneficially Modulate the Lung Innate Immune Response Is a Strain Dependent Characteristic
Authors: Ortiz Moyano Ramiro , Raya Tonetti Fernanda , Tomokiyo Mikado , Kanmani Paulraj , Vizoso-Pinto María Guadalupe , Kim Hojun , Quilodrán-Vega Sandra , Melnikov Vyacheslav , Alvarez Susana , Takahashi Hideki , Kurata Shoichiro , Kitazawa Haruki , Villena Julio
Published: May 2020

We investigated whether the ability of commensal respiratory bacteria to modulate the innate immune response against bacterial and viral pathogens was a shared or strain-specific characteristic. Bacterial strains belonging to the Corynebacterium pseudodiphtheriticum and Dolosigranulum pigrum species were compared by studying their influence in the Toll-like receptor (TLR)-2- and TLR3-triggered immune responses in the respiratory tract, as well as in the resistance to Respiratory Syncytial Virus (RSV) and Streptococcus pneumoniae infections. We demonstrated that nasally administered C. pseudodiphteriticum 090104 or D. pigrum 040417 were able to modulate respiratory immunity and increase the resistance against pathogens, while other strains of the same species did not influence the respiratory immune responses, demonstrating a clear strain-dependent immunomodulatory effect of respiratory commensal bacteria. We also reported here that bacterium-like particles (BLP) and cell walls derived from immunomodulatory respiratory commensal bacteria are an interesting alternative for the modulation of the respiratory immune system. Our study is a step forward in the positioning of certain strains of respiratory commensal bacteria as next-generation probiotics for the respiratory tract.