다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

IN view of the interest attaching to the vaporisation and diffusion of solids, the following observations may be worthy of record.

The Diffusion of Solids

A review on the production of metal matrix composites through stir casting – Furnace design, properties, challenges, and research opportunities

Carbon-based composites have gained extensive attention as microwave absorbing materials due to the lighter weight compared with other materials. In this work, Co/C nanocomposites with Co nanoparticles uniformly distributed in amorphous carbon sheets are prepared by a freezing dry and carbothermic reduction process. Hierarchical porous microstructures (micropores, mesopores, macropores) are achieved by ice template and huge amounts of gas during carbothermal reduction. Excellent absorption performance is achieved at a very low Co/C content (10% and 15%), which is a great success to design ultralight absorbers. At 10% content level, the effective absorption bandwidth is 5.0 GHz with a thin thickness of 1.8 mm, while the absorption bandwidth is 4.7 GHz with a thin thickness of 1.5 mm at 15% Co/C content level. The excellent absorption performance is attributed to excellent impedance matching resulting from synergy of cobalt and carbon and strong interfacial polarization induced by the hierarchical porous microstructures. This work provides a new pathway of designing ultralight absorbers with the advantage of thin thickness and wide bandwidth. Excellent absorption performance is achieved at only 10% Co/C content level, a success to design ultralight absorbers.

Hierarchically porous Co/C nanocomposites for ultralight high-performance microwave absorption

a b s t r a c t Instrumented sharp indentation experiments using both conical and Vickers diamond pyramidal indenters were carried out to study deformation characteristics of Zr55Cu30Al10Ni5 bulk metallic glass. Finite element simulations of instrumented indentation were also performed to formulate an overall constitutive response. Comparing the experimentally obtained results with the finite element predictions, it can be stated that mechanical deformation of the bulk metallic glass can be described well by both Mohr–Coulomb and Drucker–Prager constitutive criteria. Using these criteria, the extent of material pile-up observed around the indenter was also estimated very well.

/pdf/materials-science-and-engineering-a-4dg6ampbu7.pdf

Materials Science and Engineering A

Formation mechanism of nano titanium carbide on multi-walled carbon nanotube and influence of the nanocarbides on the load-bearing contribution of the nanotubes inner-walls in aluminum-matrix composites

Establishing a correlation between interfacial microstructures and corrosion initiation sites in Al/Cu joints by SEM–EDS and AFM–SKPFM

In this study, the effect of various feed speeds on microstructure and mechanical properties of friction stir welded Cu–30Zn brass alloy is investigated. Rotation speed was fixed at 950rpm and feed speed varied in the range of 190–375mm/min. Examination of the microstructure showed very fine grains with some deformed grains in the stirred zone and some coarser grains in the thermo-mechanically affected zone and base metal. A unique deformation pattern, namely “stir band” in the stirred zone region was identified and its density increased by increase in feed speed. Results showed that the grain size profile was independent of feed speed and the hardness values decreased by increase in feed speed. Increase in feed speed led to a slight improvement of yield strength and ultimate tensile strength, associated to continuous spring-like morphology of stir bands acting as a strengthening structure. However, ductility reduces considerably from 57 to 27%. Moreover, it is observed that during tensile test, fracture cracks originate exactly adjacent to the stir bands.

Microstructural and mechanical properties of friction stir welded Cu–30Zn brass alloy at various feed speeds: Influence of stir bands

https://profdoc.um.ac.ir/articles/a/1021715.pdf

M. Haddad-Sabzevar

Papers

Materials Science and Engineering A

Formation mechanism of nano titanium carbide on multi-walled carbon nanotube and influence of the nanocarbides on the load-bearing contribution of the nanotubes inner-walls in aluminum-matrix composites

Establishing a correlation between interfacial microstructures and corrosion initiation sites in Al/Cu joints by SEM–EDS and AFM–SKPFM

Microstructural and mechanical properties of friction stir welded Cu–30Zn brass alloy at various feed speeds: Influence of stir bands

Microstructural and mechanical properties of friction stir welded Cu–30Zn brass alloy at various feed speeds: Influence of stir bands