There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

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

http://digilib.its.ac.id/public/ITS-Undergraduate-10957-Paper.pdf

Carbon partitioning into austenite after martensite transformation

Effects of combined silicon and molybdenum alloying on the size and evolution of microalloy precipitates in HSLA steels containing niobium and titanium

Quantitative analysis of Nb in solution in a microalloyed carburizing steel by electrochemical etching

The present invention relates to the use of medium manganese steels for hot stamping to produce ultra high strength steel blanks with improved residual ductility of hot formed steels (as compared to boron-added steels such as 22MnB5 grade). The medium manganese steel sheets require much lower processing temperatures ( 900° C.) prior to forming operation, allowing reduction of energy consumption during manufacturing.

Ductile Ultra High Strength Medium Manganese Steel Produced Through Continuous Annealing and Hot Stamping

An embossed cold rolled metal (e.g. steel) sheet for use in manufacturing appliances and method of making same wherein the surface attributes of the embossed sheet are optimized to improve corrosion resistance of the painted product, promote uniform paint coverage of the sheet surface, reduce paint consumption, enable repainting without loss of pattern crispness, and provide consistent and aesthetically pleasing appearance of the painted sheet. The embossed sheet has a plurality of plateaus and impressions defined therein in a manner such that the arithmetic average surface roughness (Ra) of the plateaus is from about 50 to 100 microinches, the maximum impression depths over a given area are from about 0.0025 to 0.0032 inches, the impression walls define maximum slopes of from about 8-17 degrees, and there are no sharp corners or ridges at the transition points between plateaus and impressions.

John G. Speer

Papers

Effects of combined silicon and molybdenum alloying on the size and evolution of microalloy precipitates in HSLA steels containing niobium and titanium

Quantitative analysis of Nb in solution in a microalloyed carburizing steel by electrochemical etching

Ductile Ultra High Strength Medium Manganese Steel Produced Through Continuous Annealing and Hot Stamping

Method of determining slope angles of impression walls and depths of impressions on an embossed sheet surface

Comparison of Hole Expansion Properties of Quench & Partitioned, Quench & Tempered and Austempered Steels