Seismic behavior of steel tubular bridge columns equipped with low-yield-point steel plates in the root replaceable pier

To enable rapid recovery of a steel bridge column after an earthquake,a novel tubular-section steel bridge column equipped with low-yield-point(LYP)steel tubular plates in the root replaceable pier is proposed.For the purpose of discussing the seismic behavior of the novel steel bridge column,quasi-static tests and finite element simulation analyses of the specimens were carried out.The effects of parameters such as the axial compression ratio,eccentricity,and thickness and material strength of the tubular plate in the energy-dissipating zone are discussed.Experimental results from seven specimens that were subjected to four failure modes are presented.The damage to the quasi-static specimens is localized to the replaceable energy-dissipating pier.The seismic behavior of the novel steel bridge columns is significantly influenced by the axial compression ratio and eccentricity of specimens.Numerical results show that the high stress area of the specimens is mainly concentrated in the connection zone between the LYP steel tubular plate and the bottom steel plate,which is consistent with the position of the quasi-static specimen when it was prone to fracture.Finally,a calculation formula is proposed to facilitate the capacity prediction of this new steel tubular bridge column under repeated loading.

Recognition of Ethics and Sustainability:A Case Study of Coca-Cola

Corporate ethics and sustainable development are receiving increasing attention in today’s society.More and more companies are realizing that ethical and sustainable development is not only a requirement for fulfilling social responsibility but also a key factor for achieving long-term growth and sustainable competitive advantage.As a result,companies are integrating ethics and sustainability into their strategies,decisions,and operations to achieve both business success and social benefit.However,some companies shout sustainability and environmental protection slogans;the actual practice differs from the claim.This paper combined the planning and actual data of the Coca-Cola Company and found that the Coca-Cola Company was suspected of greenwashing.While Coca-Cola does contribute to the environment,there is a difference between what it does and what it says.As for the possibility of this problem,the article also makes a relative solution and assessment.

A Two-step Inverse Method for Quantitative Damage Evaluation of Plate-like Structures Using Vibration Approach

This study presents a novel two-step approach to assess plate-like structural laminar damages,particularly for delamination damage detection of composite structures.Firstly,a 2-D continuous wavelet transform is employed to identify the damage location and sizes from vibration curvature data.An inverse method is subsequently then used to determine the bending stiffness reduction ratio along a specified direction,enabling the quantification of the delamination severity.The method employed in this study is an extension of the one-dimensional inverse method developed in a previous work of the authors.The applicability of the two-step inverse approach is demonstrated in a simulation analysis and by an experimental study on a cantilever composite plate containing a single delamination.The inverse method is shown to have the capacity to reveal the detailed damage information of delamination within a constrained searching space and can be used to determine the effective flexural stiffness of composite plate structures,even in cases of complex delamination damage.

Numerical investigation into the effect of backfilling on coal pillar strength in highwall mining

This paper attempts to quantify the effect of backfilling on pillar strength in highwall mining using numerical modelling. Calibration against the new empirical strength formula for highwall mining was conducted to obtain the material parameters used in the numerical modelling. With the obtained coal strength parameters, three sets of backfill properties were investigated. The results reveal that the behavior of pillars varies with the type and amount of backfill as well as the pillar width to mining height ratio(w/h). In case of cohesive backfill, generally 75% backfill shows a significant increase in peak strength, and the increase in peak strength is more pronounced for the pillars having lower w/h ratios. In case of noncohesive backfill, the changes in both the peak and residual strengths with up to 92% backfill are negligible while the residual strength constantly increases after reaching the peak strength only when 100%backfill is placed. Based on the modelling results, different backfilling strategies should be considered on a case by case basis depending on the type of backfill available and desired pillar dimension.

A review on photo-thermal catalytic conversion of carbon dioxide

The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed.

The dynamic evolution of aggregated lithium dendrites in lithium metal batteries

Lithium(Li)metal anodes promise an ultrahigh theoretical energy density and low redox potential,thus being the critical energy material for next-generation batteries.Unfortunately,the formation of Li dendrites in Li metal anodes remarkably hinders the practical applications of Li metal anodes.Herein,the dynamic evolution of discrete Li dendrites and aggregated Li dendrites with increasing current densities is visualized by in-situ optical microscopy in conjunction with ex-situ scanning electron microscopy.As revealed by the phase field simulations,the formation of aggregated Li dendrites under high current density is attributed to the locally concentrated electric field rather than the depletion of Li ions.More specifically,the locally concentrated electric field stems from the spatial inhomogeneity on the Li metal surface and will be further enhanced with increasing current densities.Adjusting the above two factors with the help of the constructed phase field model is able to regulate the electrodeposited morphology from aggregated Li dendrites to discrete Li dendrites,and ultimately columnar Li morphology.The methodology and mechanistic understanding established herein give a significant step toward the practical applications of Li metal anodes.

Molybdenum carbide clusters for thermal conversion of CO2 to CO via reverse water-gas shift reaction

Molybdenum carbides are highly active for CO2 conversion to CO via the reverse water-gas shift(RWGS)reaction, however the large grain size up to micrometers renders its relatively lower active sites utilization efficiency while generating CH4 as a by-product. In this work, a homogeneously dispersed molybdenum carbide hybrid catalyst with sub-nanosized cluster(the average size as small as 0.5 nm) is prepared via a facile carbothermal treatment for highly selective CO2-CO reduction. The partially disordered Mo2C clusters are characterized by synchrotron high-resolution XRD and atomic resolution HAADF-STEM analysis, for which the source cause of the disorder is pinpointed by XAFS analysis to be the nitrogen intercalants from the carbonaceous precursor. The partially disordered Mo2C clusters show a RWGS rate as high as 184.4 μmol gMo2C-1s-1 at 400 ℃ with a superior selectivity toward CO(> 99.5%). This work 2 highlights a facile strategy for fabricating highly dispersed and partially disordered Mo2C clusters at a sub-nano size with beneficial N-doping for delivering high catalytic activity and operational stability.

Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases

Inflammatory bowel diseases(IBD)are idiopathic chronic diseases of the gastrointestinal tract well known to be associated with both genetic and environmental risk factors.Permissive genotypes may manifest into clinical phenotypes under certain environmental influences and these may be best studied from migratory studies.Exploring differences between first and second generation migrants may further highlight the contribution of environmental factors towards the development of IBD.There are few opportunities that have been offered so far.We aim to review the available migration studies on IBD,evaluate the known environmental factors associated with IBD,and explore modern migration patterns to identify new opportunities and candidate migrant groups in IBD migration research.

The chemical origin of temperature-dependent lithium-ion concerted diffusion in sulfide solid electrolyte Li_(10)GeP_(2)S_(12)

Solid-state batteries have received increasing attention in scientific and industrial communities,which benefits from the intrinsically safe solid electrolytes(SEs).Although much effort has been devoted to designing SEs with high ionic conductivities,it is extremely difficult to fully understand the ionic diffusion mechanisms in SEs through conventional experimental and theoretical methods.Herein,the temperature-dependent concerted diffusion mechanism of ions in SEs is explored through machinelearning molecular dynamics,taking Li_(10)GeP_(2)S_(12) as a prototype.Weaker diffusion anisotropy,more disordered Li distributions,and shorter residence time are observed at a higher temperature.Arrhenius-type temperature dependence is maintained within a wide temperature range,which is attributed to the linear temperature dependence of jump frequencies of various concerted diffusion modes.These results provide a theoretical framework to understand the ionic diffusion mechanisms in SEs and deepen the understanding of the chemical origin of temperature-dependent concerted diffusions in SEs.

Harnessing the Beneficial Attributes of Ceria and Titania in a Mixed-Oxide Support for Nickel-Catalyzed Photothermal CO_2 Methanation

Solar-powered carbon dioxide （CO_2）-to-fuel conversion presents itself as an ideal solution for both CO_2 mit- igation and the rapidly growing world energy demand. In this work, the heating effect of light irradiation onto a bed of supported nickel （Ni） catalyst was utilized to facilitate CO_2 conversion. Ceria （CeO_2）-titania （TiO_2） oxide supports of different compositions were employed and their effects on photothermal CO_2 conver- sion examined, Two factors are shown to be crucial for instigating photothermal CO_2 methanation activity： ① Fine nickel deposits are required for both higher active catalyst area and greater light absorption capacity for the initial heating of the catalyst bed; and ② the presence of defect sites on the support are necessary to promote adsorption of C02 for its subsequent activation, Titania inclusion within the support plays a crucial role in maintaining the oxygen vacancy defect sites on the （titanium-doped） cerium oxide. The combination of elevated light absorption and stabilized reduced states for CO_2 adsorption subsequently invokes effective Dhotothermal CO_2 methanation when the ceria and titania are blended in the ideal ratio（s）.

Mitigating self-discharge of carbon-based electrochemical capacitors by modifying their electric-double layer to maximize energy efficiency

Self-discharge is a significant issue in electric double layer energy storage, which leads to a rapid voltage drop and low energy efficiency. Here, we attempt to solve this problem by changing the structure of the electric double layer into a de-solvated state, by constructing a nano-scale and ion-conductive solid electrolyte layer on the surface of a carbon electrode. The ion concentration gradient and potential field that drive the self-discharge are greatly restricted inside this electric double layer. Based on this understanding, a high-efficiency graphene-based lithium ion capacitor was built up, in which the self-discharge rate is reduced by 50% and the energy efficiency is doubled. The capacitor also has a high energy density, high power output and long life, and shows promise for practical applications.

Isolation of a New PAK1 Gene from Sea Cucumber(Apostichopus japonicus) and Its Expression Analysis and Function Characterization

The p21-activated kinase 1(PAK1)is a downstream serine/threonine kinase effector of Rac1/Cdc42 that regulates various biological processes including those associating with pathological inflammation.To investigate the function of PAK1 in echinoderms,we isolated a new PAK1 from sea cucumber Apostichopus japonicus(AjPAK1)by transcriptome database mining and with rapid amplification of cDNA ends(RACE).The full-length cDNA AjPAK1 was 2303 bp in length,containing a 1587 bp ORF encoding 528 amino acid residues.The deduced AjPAK1 contained a p21-Rho-binding domain(PBD)and a serine/threonine protein kinase catalytic domain(S_TKc),which was similar to the PAK1 of crown-of-thorns starfish Acanthaster planci and other eukaryotes.AjPAK1 expressed in all tissues of adult A.japonicus analyzed with the highest transcript anumdance detected in coelomocytes.Significant change in AjPAK1 abundance was observed at 4,24,48 and 72 h after Vibrio splendidus infection.Silencing AjPAK1 induced a significant reduction of lysozyme content in coelomic fluid and relative transcript abundances of AjRac1 and AjMKK3/6 in A.japonicus coelomocytes.These results should aid to characterize PAK1 of sea cucumber and decipher its immune function.

Transformation of methane to synthesis gas over metal oxides without using catalyst

This article reviews a new developing method in the field of metal oxide reduction in chemical and metallurgical processes, which uses methane as a reducing agent. Commonly, coal is used as the reducing agent in the reduction of metal oxide and other inorganic materials; Metal producing factories are among the most intensive and concentrated source of greenhouse gases and other pollutants such as heavy metals, sulfur dioxide and fly ash. Thermodynamically, methane has a great reducing capability and can be activated to produce synthesis gas over a metal oxide as an oxygen donor. Metal oxide reduction and methane activation, two concurrent thermochemical processes, can be combined as an efficient and energy-saving process; nowadays this kind of technologies is of great importance. This new reduction process could improve energy efficiencies and significantly decrease greenhouse gas emission compared to the conventional process; furthermore, the produced gases are synthesis gas that is more valuable than methane. In this paper, thermodynamic studies and advantages of this promising method were discussed. The major aim of this article is to introduce methane as a best and environmentally friendly reducing agent at low temperature.

Microstructure-based three-dimensional characterization of chip formation and surface generation in the machining of particulate-reinforced metal matrix composites

Particulate-reinforced metal matrix composites(PRMMCs)are difficult to machine due to the inclusion of hard,brittle reinforcing particles.Existing experimental investigations rarely reveal the complex material removal mechanisms(MRMs)involved in the machining of PRMMCs.This paper develops a three-dimensional(3D)microstructure-based model for investigating the MRM and surface integrity of machined PRMMCs.To accurately mimic the actual microstructure of a PRMMC,polyhedrons were randomly distributed inside the matrix to represent irregular SiC particles.Particle fracture and matrix deformation and failure were taken into account.For the model’s capability comparison,a two-dimensional(2D)analysis was also conducted.Relevant cutting experiments showed that the established 3D model accurately predicted the material removal,chip morphology,machined surface finish,and cutting forces.It was found that the matrix-particle-tool interactions led to particle fractures,mainly in the primary shear and secondary deformation zones along the cutting path and beneath the machined surface.Particle fracture and dilodegment greatly influences the quality of a machined surface.It was also found that although a 2D model can reflect certain material removal features,its ability to predict microstructural variation is limited.

Effect of Biscuit Baking Conditions on the Stability of Microencapsulated 5-Methyltetrahydrofolic Acid and Their Physical Properties

Among the folate compounds, 5-methyltetrahydrofolic acid (5-CH3THF) is regarded as one of the most bioactive forms of folate. It is regarded as the better source of folate to humans as compared to folic acid, a synthetic form of folate, which is used for fortifying foods to prevent the incidence of neural tube defects in the new born babies. The use of 5-CH3THF as an alternative fortificant, in place of folic acid, has been explored by various researchers. However, fortification of 5-CH3THF is problematic due to its lower stability. This study investigated the stability of microencapsulated 5-CH3THF in biscuits baked at various temperatures and times as well as changes in their physical properties. Microcapsule with pectin and alginate ratio of 80:20, prepared by spray drying, gave the highest retention (68.6%) of the 5-CH3THF, therefore, chosen for fortification. The encapsulated and unencapsulated 5-CH3THF were mixed separately with flour and biscuit ingredients and baked at 180℃, 200 and 220℃, each for 5, 9 and 12 min. The inclusion of encapsulated and unencapsulated 5-CH3THF in the biscuit formulation and subsequent baking at various temperatures and times resulted in retention of 5-CH3THF from 19.1% to 1.7%. Microencapsulation of 5-CH3THF slightly improved the retention of 5-CH3THF over unencapsuated biscuits at 180℃ for 5 min, but almost no such effect was achieved under baking temperatures of 200℃ and 220℃. Physical analysis showed darker colour, harder texture and lower moisture content for biscuits baked at higher test temperatures. It seems intense heating condition that caused “over baking” of the biscuit likely to be responsible for the loss of the vitamin as well as less desirable physical properties of the biscuits.

Rational Design of Electrode–Electrolyte Interphase and Electrolytes for Rechargeable Proton Batteries

Rechargeable proton batteries have been regarded as a promising technology for next-generation energy storage devices,due to the smallest size,lightest weight,ultrafast diffusion kinetics and negligible cost of proton as charge carriers.Nevertheless,a proton battery possessing both high energy and power density is yet achieved.In addition,poor cycling stability is another major challenge making the lifespan of proton batteries unsatisfactory.These issues have motivated extensive research into electrode materials.Nonetheless,the design of electrode–electrolyte interphase and electrolytes is underdeveloped for solving the challenges.In this review,we summarize the development of interphase and electrolytes for proton batteries and elaborate on their importance in enhancing the energy density,power density and battery lifespan.The fundamental understanding of interphase is reviewed with respect to the desolvation process,interfacial reaction kinetics,solvent-electrode interactions,and analysis techniques.We categorize the currently used electrolytes according to their physicochemical properties and analyze their electrochemical potential window,solvent(e.g.,water)activities,ionic conductivity,thermal stability,and safety.Finally,we offer our views on the challenges and opportunities toward the future research for both interphase and electrolytes for achieving high-performance proton batteries for energy storage.

Ballistic impact response of flexible and rigid UHMWPE textile composites:Experiments and simulations

This study elaborates on the effects of matrix rigidity on the high-velocity impact behaviour of UHMWPE textile composites using experimental and numerical methods.Textile composite samples were manufactured of a plain-weave fabric(comprising Spectra?1000 fibres)and four different matrix materials.High-velocity impact tests were conducted by launching a spherical steel projectile to strike on the prepared samples via a gas gun.The experimental results showed that the textile composites gradually changed from a membrane stretching mode to a plate bending mode as the matrix rigidity and thickness increased.The composites deformed in the membrane stretching mode had higher impact resistance and energy absorption capacity,and it was found that the average energy absorption per ply was much higher in this mode,although the number of broken yarns was smaller in the perforated samples.Moreover,the flexible matrix composites always had higher perforation resistance but larger deformation than the rigid matrix counterparts in the tested thickness and velocity range.A novel numerical modelling approach with enhanced computational efficiency was proposed to simulate textile composites in mesoscale resolution.The simulation results revealed that stress and strain development in the more rigid matrix composite was localised in the vicinity of the impact location,leading to larger local deformation and inferior perforation resistance.

The evolution of clastic sedimentology

This valuable book was first published in Japanese in 2002, under the title Sedimentology： a way to the new discipline of earth sciences. Given the problems that nearly all non-Japanese people have in reading Japanese, its translation into English in an expanded form, accomplished with the help of Professor Kenyon-Smith, is exceedingly welcome, given that it is the first book to provide a history of sedimentology. I should say at the outset that the translation is firstrate, being a model of clarity that puts many modern English-language texts to shame. The book is also copiously illustrated, including many photo-portraits of persons previously only known to me by name or through their writings.

THE EFFECT OF, ABRASION ON LOW STRESS MECHANICAL PROPERTIES OF FABRIC

The low stress mechanical properties of a pure wool and a wool / polyester blend twill fab-rics which were abraded at various abrasion cycles were measured using the KES-F system andthe Instron tensile machine. The surface change of fabrics before and after abrasion was stu-died by means of scanning electron microscope. With the increasing number of cycles, the re-covery behavior of the fabrics studied in tensile, shear and bending deformation decrease, theantibuckling ability lowers, the friction coefficient increases. The geometric roughness de-creases during the first step of abrasion then enhances with further abrasion. The influence ofabrasion on mechanical properties of the pure wool fabric are larger than that of blend fabric.

The Rising Importance of Precision Engineering

Precision engineering is the discipline that encompasses the design,development,fabrication,and measurement of parts of a mechanical,optical,or electronic system,in software or in fixtures and other structures.For example,a precision instrument or machine should be able to function or perform at a high accuracy that is many orders of magnitude smaller than the size of the instrument or machine itself.It is critical that such accuracy and accurate performance are repeatable and stable over a designated period.Precision engineering also involves the generation of new knowledge-bases and creation of new technologies which will advance the innovation of such machines,instruments,or systems.