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

http://sistemas.eel.usp.br/docentes/arquivos/2166002/1234Nb/Geetha-review2009.pdf

Ti based biomaterials, the ultimate choice for orthopaedic implants – A review

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

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

The rate of removal of di-n-butyl phosphate (DBP) by sorption on activated alumina (AA) has been studied in batch conditions. The rate of adsorption of DBP is initially rapid for about 10–20 min and reaches a maximum in about two hours. The Langmuir and Freundlich isotherm equations have been used to describe the partitioning behavior of the system. Kinetic modeling analysis of the pseudo-first-order, pseudo-second-order, and pore diffusion model, coupled with the observed Langmuir or Freundlich isotherm equations showed that pseudo-second-order equation and pore diffusion model to be the most appropriate models for the description of transport of DBP within AA particles. The agreement between the model predictions and experimental data indicated that adsorption and diffusion of DBP can be simulated by the proposed models. From analysis of the experimental kinetic data, effective diffusivity has also been estimated and is found to be in the range of 10−9 cm2/s.

Adsorption of di-butyl phosphate on activated alumina: equilibrium and kinetics

The present work reports the effect of surface intermetallic layers formed by diffusion alloying, on the aqueous corrosion behavior of four different 316L stainless steels containing various nitrogen contents (0.015, 0.1,0.2 and 0.56 %N). Surface diffusion alloying have been carried out by three different annealing processes, namely by diffusing pre-deposited film of (i) Al at 1023 K, (ii) Ti at 1123 K and (iii) Ti/Al multilayer at 1123 K. X-ray diffraction patterns of surface modified specimens showed the presence of several intermetallic phases along with nitrides of type AlN, TiN and/or Ti 2 N depending on the particular process. Detailed characterization of the chemical distribution of various species after the surface diffusion alloying process, have been performed using Secondary Ion Mass Spectrometry (SIMS). With increase in the matrix nitrogen content, an enrichment of surface layer with nitrogen by SIMS, increased nitride precipitation by XRD and SEM and increase in case-hardness by microhardness measurements have been observed. The effect of matrix nitrogen content on the volume fractions of the intermetallic aluminides and nitride phases formed in composite surface layer, and their influence on the corrosion resistance of austenitic stainless steels in 0.5 M sulphuric acid is discussed in greater detail based on Open Circuit Potential (OCP)-time measurements, potentiodynamic polarisation studies and Electrochemical Impedance Spectroscopy (EIS) investigations.

Effect of matrix nitrogen content on the microstructure and corrosion behaviour of intermetallic diffusion coatings over nitrogen added type 316L stainless steels

Urea-adduct process is commercially used to selectively separate n-alkanes from industrial hydrocarbon mixtures. Authors have explored application of this method for recovery of n-alkane based diluents from spent PUREX/UREX solvent. Traditionally this separation is performed by vacuum distillation, an energy-intensive process. The proposed method is simple and does not involve either exotic chemicals or complex processing steps. Application of urea-adduct process for recovery of diluent from spent solvent is reported here possibly first time in literature. Physical properties such as densities, viscosities and vapour pressure for irradiated organic solutions were also measured and reported.

Development of a urea-adduct process for recovery of n-alkane based diluent from spent PUREX/UREX solvent

Pyrochemical reprocessing utilizing molten chloride salt medium has been considered as one of the best options for the reprocessing of spent metallic fuels from future fast breeder reactors. Purification of molten salt is an important step where chlorine gas is purged in molten LiCl-KCl eutectic salt at 873 K. Materials for manufacturing of vessels and components for salt purification system should possess high corrosion resistance under such a highly corrosive environment. The present paper discusses the corrosion behavior of INCONEL Alloys 600 (UNS N06600), 625 (UNS N06625), and 690 (UNS N06690) and their welds in molten LiCl-KCl eutectic salt at 873 K under Cl2 bubbling. Characterization of the exposed surfaces was performed by using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy, and glancing incidence x-ray diffraction. The results of the present study indicated that N06600 and N06690 offered better corrosion resistance compared to N06625. Surface morphology of the exposed b...

U. Kamachi Mudali

Papers

Adsorption of di-butyl phosphate on activated alumina: equilibrium and kinetics

Effect of matrix nitrogen content on the microstructure and corrosion behaviour of intermetallic diffusion coatings over nitrogen added type 316L stainless steels

Development of a urea-adduct process for recovery of n-alkane based diluent from spent PUREX/UREX solvent

Corrosion of Nickel Alloys in Molten LiCl-KCl Medium Under Cl2 Bubbling

Pitting induced failure of austenitic cryogenic condenser coil for acetone service