Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The family of 2D transition metal carbides, carbonitrides and nitrides (collectively referred to as MXenes) has expanded rapidly since the discovery of Ti3C2 in 2011. The materials reported so far always have surface terminations, such as hydroxyl, oxygen or fluorine, which impart hydrophilicity to their surfaces. About 20 different MXenes have been synthesized, and the structures and properties of dozens more have been theoretically predicted. The availability of solid solutions, the control of surface terminations and a recent discovery of multi-transition-metal layered MXenes offer the potential for synthesis of many new structures. The versatile chemistry of MXenes allows the tuning of properties for applications including energy storage, electromagnetic interference shielding, reinforcement for composites, water purification, gas- and biosensors, lubrication, and photo-, electro- and chemical catalysis. Attractive electronic, optical, plasmonic and thermoelectric properties have also been shown. In this Review, we present the synthesis, structure and properties of MXenes, as well as their energy storage and related applications, and an outlook for future research. More than twenty 2D carbides, nitrides and carbonitrides of transition metals (MXenes) have been synthesized and studied, and dozens more predicted to exist. Highly electrically conductive MXenes show promise in electrical energy storage, electromagnetic interference shielding, electrocatalysis, plasmonics and other applications.

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2D metal carbides and nitrides (MXenes) for energy storage

This article presents an overview of the developments in stainless steels made since the 1990s. Some of the new applications that involve the use of stainless steel are also introduced. A brief introduction to the various classes of stainless steels, their precipitate phases and the status quo of their production around the globe is given first. The advances in a variety of subject areas that have been made recently will then be presented. These recent advances include (1) new findings on the various precipitate phases (the new J phase, new orientation relationships, new phase diagram for the Fe–Cr system, etc.); (2) new suggestions for the prevention/mitigation of the different problems and new methods for their detection/measurement and (3) new techniques for surface/bulk property enhancement (such as laser shot peening, grain boundary engineering and grain refinement). Recent developments in topics like phase prediction, stacking fault energy, superplasticity, metadynamic recrystallisation and the calculation of mechanical properties are introduced, too. In the end of this article, several new applications that involve the use of stainless steels are presented. Some of these are the use of austenitic stainless steels for signature authentication (magnetic recording), the utilisation of the cryogenic magnetic transition of the sigma phase for hot spot detection (the Sigmaplugs), the new Pt-enhanced radiopaque stainless steel (PERSS) coronary stents and stainless steel stents that may be used for magnetic drug targeting. Besides recent developments in conventional stainless steels, those in the high-nitrogen, low-Ni (or Ni-free) varieties are also introduced. These recent developments include new methods for attaining very high nitrogen contents, new guidelines for alloy design, the merits/demerits associated with high nitrogen contents, etc.

Recent developments in stainless steels

Density functional theory (DFT) computations were performed to investigate the electronic properties and Li storage capability of Ti3C2, one representative MXene (M represents transition metals, and X is either C or/and N) material, and its fluorinated and hydroxylated derivatives. The Ti3C2 monolayer acts as a magnetic metal, while its derived Ti3C2F2 and Ti3C2(OH)2 in their stable conformations are semiconductors with small band gaps. Li adsorption forms a strong Coulomb interaction with Ti3C2-based hosts but well preserves its structural integrity. The bare Ti3C2 monolayer exhibits a low barrier for Li diffusion and high Li storage capacity (up to Ti3C2Li2 stoichiometry). The surface functionalization of F and OH blocks Li transport and decreases Li storage capacity, which should be avoided in experiments. The exceptional properties, including good electronic conductivity, fast Li diffusion, low operating voltage, and high theoretical Li storage capacity, make Ti3C2 MXene a promising anode material for...

Are MXenes Promising Anode Materials for Li Ion Batteries? Computational Studies on Electronic Properties and Li Storage Capability of Ti3C2 and Ti3C2X2 (X = F, OH) Monolayer

A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ∼1 nm, the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interface...

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Nanoscale thermal transport. II. 2003–2012

Ti3AlC2 has low density, high elastic modulus, quasi-ductility, and excellent oxidation resistance. However, its relatively low strength needs to be improved. In this study, dense Ti3AlC2-Y4Al2O9 composites (containing 2.5, 5, and 7.5 wt% Y4Al2O9) were synthesized by hot pressing/solid-liquid reaction using Ti, Al, C, and Y2O3 as initial materials. We investigated the in situ formation process of Y4Al2O9, and studied the change of microstructure and optimization of mechanical properties of the Ti3AlC2-Y4Al2O9 composites. The grain size and aspect ratio of Ti3AlC2 grains are significantly reduced in Ti3AlC2Y4Al2O9 composites, which is the source of higher strength from room temperature to elevated temperatures. The Ti3AlC2-5 wt%Y4Al2O9 composite shows better optimization in its mechanical properties than other studied composites. In addition, there is an improvement in strength without debit in toughness of the composite.

Strengthening Ti3AlC2 by In Situ Synthesizing Ti3AlC2–Y4Al2O9 Composites

Developments in Strategic Ceramic Materials: A Collection of Papers Presented at the 39th International Conference on Advanced Ceramics and Composites

The elastic stiffness and shear deformation mode of Al(3)BC(3), a metal borocarbide containing linear C-B-C units, are studied based on the first-principles total energy calculations. The predominant effect of C-B-C units on mechanical properties is reported by leading to low shear modulus. The low shear-strain resistance originates from the deformation mode as follows: the rigid linear C-B-C units tilt with respect to the c direction easily, and the corner-sharing Al(5)C bipyramid slabs simultaneously slide along the basal plane with low resistance. The proposed deformation mode may be universal for the ternary metal borocarbides family containing short linear C-B-C units. (c) 2006 American Institute of Physics.

First-principles prediction of low shear-strain resistance of Al(3)BC(3): A metal borocarbide containing short linear BC(2) units

In this paper, we predicted the possible mechanical properties and presented the electronic structure of Zr 3 AL 3 C 5 by means of first-principles pseudopotential total energy method. The equation of state, elastic parameters (including the full set of second order elastic coefficients, bulk and shear moduli, Young's moduli, and Poisson's ratio), and ideal tensile and shear strengths are reported and compared with those of the binary compound ZrC. Furthermore, the bond relaxation and bond breaking under tensile and shear deformation from elasticity to structural instability are illustrated. Because shear induced bond breaking occurs inside the NaCl-type ZrC x slabs, the ternary carbide is expected to have high hardness and strength, which are related to structural instability under shear deformation, similar to the binary carbide. In addition, mechanical properties are interpreted by analyzing the electronic structure and chemical bonding characteristics accompanying deformation paths. Based on the present results, Zr 3 AL 3 C 5 is predicted to be useful as a hard ceramic for high temperature applications.

First-principles prediction of the mechanical properties and electronic structure of ternary aluminum carbide Zr3Al3C5

By using high-energy shot peening (HESP) techniques, nano-structured surface layers were successfully created on some metallic materials. The distribution of defects in the surface layer was studied by means of positron lifetime spectroscopy for samples treated with different processing times. We determined the positron lifetime characteristics as a function of depth from the top surface. The results showed two microstructure regions on the surface layer: an ultra-fine grain region and a sequential transition region.

Jingyang Wang

Papers

Strengthening Ti3AlC2 by In Situ Synthesizing Ti3AlC2–Y4Al2O9 Composites

Developments in Strategic Ceramic Materials: A Collection of Papers Presented at the 39th International Conference on Advanced Ceramics and Composites

First-principles prediction of low shear-strain resistance of Al(3)BC(3): A metal borocarbide containing short linear BC(2) units

First-principles prediction of the mechanical properties and electronic structure of ternary aluminum carbide Zr3Al3C5

Defect Characteristics in the Surface Nanocrystallined Material Treated by High-Energy Shot Peening