In this patent review the progress in technology and prospects of bulk ternary LRE-Ba2Cu3Oy “LRE-123” (LRE=light rare earth, Nd, Eu, Sm, Gd) superconductors are presented. Number of experiments has proven that ternary LRE-123 melt processed materials exhibit excellent properties appropriate for development of bulk high-field high-Tc superconducting magnets. The key prerequisite for success in controlling flux pinning in these materials at high magnetic fields is creation of pinning defects with distinct superconducting properties compared to the superconducting matrix. In (Nd,Eu,Gd)-123 critical current density achieved the level of 105A/cm2 at 65K in self-field and 5T and the irreversibility field Birr (the field limit above which the superconductor looses its ability to carry electric current) approached 15T at 77K. The high critical current density at low and intermediate fields, persisting up to the boiling point of liquid oxygen (90.2K), close to Tc, is mainly due to size reduction of normal-conducting or insulating pinning defects up to nanoscale level. Such pinning sites are e.g. nanoscale secondary phase particles, Zr-, Nb-, Mo-, or Ti- oxides. In some particular (Nd,Eu,Gd)-123 compositions Birr increased twice due to a nanoscale planar substructure correlated with the regular twin structure.
For many years calcium phosphate based materials have been used to create bone substitutes as alternatives to human transplant. Most calcium phosphate biomaterials are characterized by high biocompatibility and excellent ability to undergo varying degrees of resorbability. Numerous investigations have been made to study calcium phosphate ceramic materials as bone substitutes. This patent review however, focuses on metal-doped calcium phosphates produced by various methods for clinical applications. A variety of synthesis methods have been employed to produce metal-doped calcium phosphates and different methods may produce different final products and characteristics in terms of crystallinity, morphology and stoichiometry. There are many metal ions such as magnesium (Mg), strontium (Sr), manganese (Mn), iron (Fe), zinc (Zn) and silver (Ag) that have been doped successfully into calcium phosphates to enhance their mechanical and biological properties. These biomaterials can be served as scaffold for bone regeneration with adequate mechanical properties to restore bone defects and facilitate healing process. The significant improvement in certain metal-doped calcium phosphates in terms of physico-chemical, biological and mechanical properties has shown the relevance in the development of metal-doped HA for biomedical applications. This paper provides a review of doping of the most common metals into calcium phosphate phase in order to optimize its performance as bone substitute materials. Some recent patents related to metal doped calcium phosphate ceramics are also reviewed.
The increasing use of composites in the transport industry and specifically in the aerospace field calls for nondestructive evaluation techniques for quality control during manufacturing and in service. Therefore, the availability of techniques which are effective to assess a material is free of slag inclusions, delamination and porosity is a crucial point. Of course, no technique is exhaustive alone; some are more effective for detection of surface discontinuities, others for outlining of buried shallow defects and others for detection of deeper anomalies. Then, an integration of two, or more, techniques may be the optimal solution especially for nondestructive evaluation of aerospace parts. The attention of this review is focused on two techniques: ultrasonic testing, which is commonly used, and infrared thermography, which was recently recognized amongst standards, for nondestructive testing and evaluation of composite materials in the aeronautical industry. For each of the two techniques, historical steps are traced with particular attention to the patents produced. In particular, the advantages coming from an integration of infrared thermography with ultrasonics and some other techniques are also discussed.
Extraction of Cu2+ , Co2+ and Ni2+ ions from aqueous solutions of bromide ion using 1-phenyl-3-methyl-4- trichloroacetylpyrazolone-5 (HTcP) in benzene and hexane organic medium has been studied. From the results, extraction of Co2+ and Ni2+ ions was masked by anionic complexes of the bromide ions throughout the pH range of 0 - 6. Cu2+ ions were quantitatively extracted from aqueous solutions of bromide ions, thereby presenting a technique for the efficient separation of Cu2+ ions from Co2+ and Ni2+ ions. Increase in bromide ion concentration from 0.05 to 0.3M had a salting out effect on the extraction of Cu2+ ions from 97.44% to 98.79% in benzene/HTcP medium and 97.13% to 98.33% in hexane/ HTcP. On application of statistical treatment using slope analysis, the values of pH1/2, log Kex and log Kd have been calculated and presented. Hence, the complex formed is Cu(TcP)2. Generally, extraction of Cu2+ ions was found to be more efficient in hexane/HTcP at relatively lower pH value in comparison to extraction into benzene/HTcP, while optimal percentage yield was slightly higher in benzene/HTcP than hexane/HTcP solution. This can be attributed to the lower dielectric constants of hexane (2.02) and lower dipole moment in comparison to that of benzene (2.28). Finally, molecular modeling shows that the stable structure of the ligand derivative (HTcP) was quite different in orientation from the parent ligand (1-phenyl-3-methyl-4-acetylpyrazolone-5 HPMAP) and has been attributed to the bulky nature of the trichloro unit. This has been discussed in line with relevant patents.
This article first gives a brief patent review of recent trends of steel alloys used in the manufacturing of highpressure gas containers. 4130 steel is among such alloys and has been extensively used in natural gas cylinders that are manufactured through the hot deformation processes. Due to the importance of process parameters such as temperature and strain rate on the ensuing microstructure, primarily grain size, and mechanical properties of the cylinder, the dynamic recrystallization characteristics of 4130 steel are investigated in the second part of this article. Hot compression tests on 4130 steel specimens have been performed at a temperature range of 900-1100°C, strain rate range of 0.001-0.1s-¹ and the strain of 0.9. The resulting flow stress curves show the occurrence of dynamic recrystallization with single or multiple peaks, before reaching the steady state flow at different temperatures and strain rates. The effect of various processing parameters on the microstructure of the alloy is identified by microstructural examination focusing on revealing primary austenite grains using special etchant solutions. It is found that the average grains size of the deformed 4130 steel increases with an increase of the forming temperature and a decrease in the strain rate. The grain size is decreased with an increase of the steady state stress.