Base metals and other minor elements in the manganese deposits of west-central Arkansas

Manganese oxides from deposits in west-central Arkansas were analyzed by X-ray diffraction for mineralogy and by atomic absorption spectroscopy for Mn, Fe, Co, Cu, Ni, Zn, V, Al, Li, Na, K, Mg, Ca, Sr and Ba. We report on 42 samples from 25 sites with more than 25 wt.% Mn and less than 7 wt.% Fe. Most samples were mixtures of two or more of the following minerals, many with concentric deposition: cryptomelane, lithiophorite, psilomelane and pyrolusite. In the purer samples of single minerals, lithiophorite contained the higher concentrations of total base metals (Co + Cu + Ni + Zn) than other minerals. In atom % of Mn these concentrations were: 9.51% in lithiophorite; 0.432% in psilomelane; and 0.275% in cryptomelane. The relative concentration of base metals in the pure minerals, proceeding from highest to lowest concentration, were: lithiophorite (Co = Cu > Ni > Zn); psilomelane (Co > Cu > Zn > Ni) and cryptomelane (Zn > Co = Cu > Ni).The concentration of Li correlates with the metals Al, Co, Cu, Ni and Zn, in the mineral samples containing measurable Li. Correlation coefficients (?) for Li with the various metals and sum of the base metals were: Al (? = 0.976); Co (? = 0.44); Ni (? = 0.954); Cu (? = 0.918); Zn (? = 0.875); and (Co + Cu + Ni + Zn) (? = 0.979). Li is believed to be a measure of lithiophorite. Correlation was found between Al content and base metal contents for all samples: Co (? = 0.354); Ni (? = 0.749); Cu (? = 0.808); Zn (? = 0.632); and (Co + Cu + Ni + Zn) (? = 0.884). The Al correlation extended to published values for these and the minerals hollandite and todorokite, except for Zn. Zn correlated with K in published analyses and in the eastern half of the study area where cryptomelane predominated.A mechanism is proposed to explain the enhancement by Al of base metal incorporation into manganese oxide minerals. The mechanism involves the isomorphous substitution of Al³⁺ for Mn⁴⁺ with charge neutralization by bivalent base metal ions.     

UBV photometry of clusters in M31

A critical review is given of all published photoelectricUBV photometry of star clusters in the Andromeda Nebula. Observations by Sharovet al. are shown to exhibit rather large random errors, but no systematic deviations from theUBV system.     

Oscillator strengths for resonance lines of some silicon and sulfur ions

Oscillator strengths are calculated for resonance lines of some silicon and sulfur ions, which are present in the solar spectrum from about 160 Å to 380 Å. Spin-spin and spin-other orbit interactions are included. A comparison is made with Garstang's results for Six; agreement is good.     

Comparison of the thermal and nonthermal radiation characteristics of Jupiter at 6, 11, and 21 cm with model calculations

Four different data sets on Jupiter, one at 6, one at 11, and two at 21 cm, are compared to each other and with the synchrotron radiation model of the magnetosphere developed by I. de Pater (1981, J. Geophys. Res., 86, 3397–3422, 3423–3429). The model agrees with all these data sets, and hence was used to derive and interpret the characteristics of the thermal radiation component at all three wavelengths. The disk temperatures are 233 ± 17, 280 ±20, and 340 ± 26°K at 6, 11, and 21 cm, respectively. A comparison of the data with atmospheric model calculations strongly suggests that the disk is uniform at λ6 and λ11 cm near the center of the disk, where μ > 0.6?0.7. This may indicate a nonuniform distribution of ammonia at layers at and above the visible cloud layers.     

Propaganda and pretext

This Viewpoint describes and analyses the history and current features of the strategy of the Government of Japan, and the associated Institute for Cetacean Research in Tokyo, to regain control of the International Whaling Commission (IWC), to legitimise renewed unsustainable commercial whaling and to dismantle conservation measures taken by the IWC over the past three decades. A key element in that strategy now is to promote and nourish the false idea that the present crisis in world fisheries is significantly caused by the consumption of valuable fish by increasing whale populations.