Refractory Iron Research Articles

α-Thalassemia Phenotype Induced by the New IVS-II-2 (T→A) Splice Donor Site Mutation on the α2-Globin Gene

We present a family of North European extraction referred for a refractory non iron depleted microcytic anemia. The proband, a 36-year-old male, presented with chronic borderline anemia and microcytic hypochromic parameters. No abnormal hemoglobin (Hb) fractions were observed on high performance liquid chromatography (HPLC) or on alkaline electrophoresis. Gap-polymerase chain reaction (gap-PCR) excluded the seven common α-thalassemia (thal) deletion defects. However, the β/α-globin chain synthesis ratio measured in vitro was unbalanced, indicating a reduced expression of the α-globin genes. Direct sequencing of the α-globin genes revealed heterozygosity for a T→A transversion at the IVS-II-2 position of the α2 gene. This is the first IVS-II splice donor site mutation described on the α2-globin gene.

Beneficiation tests on an Indian bauxite incorporating magnetic separation

Indian bauxite ores are generally rich in goethite, hematite and titanium oxide, although their mineralogy differs.1 To meet refractory specification iron and titanium oxide must be removed. The use of gravity and magnetic separations to enrich the Al2O3 content has been reported in the past.2–4 Previous workers have shown that Arkansas bauxite containing 11.3% Fe2O3 and up to 2% TiO2 could be beneficiated to less than 1.2% Fe2O3 and less than 0.7% TiO2 by wet, high-intensity magnetic separation.2 Elsewhere Balkany has reported that bauxite can be upgraded by selective crushing, scrubbing and attrition, flotation and wet high-intensity magnetic separation.5 The Indian Bureau of Mines has successfully applied various beneficiation techniques, such as tabling, magnetic separation, acid leaching, reduction roasting and high-intensity magnetic separation, to some Indian bauxite ores, mainly to reduce the iron and silica contents.2 Tests of the removal of Fe2O3 and TiO 2 were conducted on a typical bauxite from Maharashtra State, India, with the aim of meeting refractory specification.

Spectra of the \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\frac{1}{4}$ \end{document} keV X‐Ray Diffuse Background from the Diffuse X‐Ray Spectrometer Experiment

The Diffuse X-ray Spectrometer (DXS) flew as an attached payload on the STS-54 mission of the space shuttle Endeavour in 1993 January and obtained spectra of the soft X-ray diffuse background in the 148-284 eV (84-44 ?) band using a Bragg-crystal spectrometer. The spectra show strong emission lines, indicating that the emission is primarily thermal. Since the observations were made at low Galactic latitude, this thermal emission must arise from a nearby hot component of the interstellar medium, most likely the Local Hot Bubble, a region within ~100 pc of the Sun characterized by an absence of dense neutral gas. The DXS spectrum of the hot interstellar medium is not consistent with either collisional equilibrium models or with nonequilibrium ionization models of the X-ray emission from astrophysical plasmas. Models of X-ray emission processes appear not yet adequate for detailed interpretation of these data. The DXS data are most nearly consistent with models of thermal emission from a plasma with a temperature of 106.1 K and depletions of refractory elements magnesium, silicon, and iron to levels ~30% of solar.

Refractory ceramics and iron smelting in East Africa

Over the last twenty years, there has been a discernible increase in the number of scholars who have focused their research on metal production, working and use in antiquity, a field of study which has come to be known as archaeometallurgy. Materials scientists and conservators have worked primarily in the laboratory while archaeologists have conducted fieldwork geared to the study of metal technology in a cultural context with laboratory analysis as one portion of the interpretive program.

Iron overload complicating sideroblastic anemia—Is the gene for hemochromatosis responsible?

Idiopathic hemochromatosis is a hereditary disease that is associated with human leucocytic antigens A3, B7, and B14. A genetic association between human leucocytic antigen-linked hemochromatosis and idiopathic refractory sideroblastic anemia has been suggested that may predispose some patients with idiopathic refractory sideroblastic anemia to develop gross iron overload. Study of the family of a patient with idiopathic refractory sideroblastic anemia and hemochromatosis revealed that 2 of 5 first-degree relatives had significant elevations of serum ferritin, and a shared human leucocytic antigen haplotype, supporting the concept that patients with idiopathic refractory sideroblastic anemia and significant iron overload have at least one allele for hemochromatosis.

Mass loss from the proto-sun - Formation and evolution of the solar nebula

We consider the formation and evolution of the solar nebula in the light of observations of T Tauri stars, oxygen-isotopic anomalies in meteorites, and the mass and angular momentum distribution in the present solar system. It is argued that the solar nebula formed from the mass lost by the proto-Sun. The outflow of initially partially ionized material in the presence of a strong proto-solar magnetic field would lead to the transfer of angular momentum from the central Sun to the outflowing matter. This explains the present angular momentum distribution between the Sun and the planetary system. When the outflowing matter cooled sufficiently, to less than 2000 K, approx. l0/sup 12/ cm from the Sun, the material would neutralize, and the magnetic field would then decouple from the outflowing matter. Further motion would be governed by the gravitational field of the proto-Sun, the gas pressure, and the centrifugal force. When these forces balance, the radial flow would stop, and a rotating solar nebula would form. Chemical condensation would occur in the outflowing matter when suitable pressure-temperature conditions would develop. The condensation of the refractory mineral Al/sub 2/O/sub 3/ would start at a distance of approx.2 x l0/sup 12/ cm from themore » Sun, where the pressure would be approx. 3 x l0 /sup 8/ atm, and temperature approx. l450 K. The condensation sequence of other lower temperature minerals would follow this. All the refractory minerals and iron would condense within the orbit of the planet Mercury. All the volatiles would condense before the outflowing matter crossed the asteroid region. The grains would move to the outer part of the nebula along with the outflowing gas.« less