Lunar Clinopyroxenes: Chemical Composition, Structural State, and Texture

Single-crystal x-ray diffraction, microprobe, optical and electron optical examinations of clinopyroxenes from Apollo 11 lunar samples 10003, 10047, 10050, and 10084 show that generally the crystals are composed of (001) augitepigeonite intergrowths in varying ratios. Transmission electron micrographs reveal abundant exsolution lamellae, many only 60 A thick. In addition to the phase inhomogeneities, primary chemical inhomogeneities are clearly demonstrated. There are reciprocal relationships between calcium and iron and between Ti(4+) + 2Ai and 2Si. Our evidence suggests that a chemically inhomogeneous subcalcic C2/c augite was the only primary pyroxene from which pigeonite later exsolved.

The effect of a conventional versus a nonoccluding (cros-type) earmold upon the frequency response of a hearing aid

Sound-field Bekesy audiograms were obtained from one experienced hearing-impaired subject wearing an ear-level hearing aid with a conventional earmold and a nonoccluding CROS-type earmold. Comparisons were made to determine the effects of the two different types of earmolds as well as different tubing lengths for nonoccluding CROS-type earmolds. Findings indicate: (1) A nonoccluding CROS-type earmold alters the frequency response characteristics of a hearing aid by markedly reducing the amplification for the low frequencies. (2) The length of tubing has a minor effect compared with that caused by the nonoccluding CROS ear coupler. (3) Sound-field Bekesy audiometry is a reliable and valid tool for assessing changes in the amplifying characteristics of hearing aids.

Exsolution in Clinoamphiboles

Ten amphibole specimens from a variety of metamorphic rocks such as talc schists, eclogites, and metamorphosed iron formations contain lamellae of a second amphibole oriented parallel to ([unknown]101) or (100), or both, of the host. Tremolites, actinolites, and hornblendes commonly have lamellae of a calcium-poor clinoamphibole with P2(1)/m space-group symmetry, or lamellae of cummingtonite with C2/m space-group symmetry. Likewise cummingtonites and P2(1)/m clinoamphiboles commonly contain lamellae of calcium-rich C2/m amphiboles such as tremolite. Results of x-ray diffraction, electron-probe, and microscope studies indicate that most lamellae result from unmixing of a homogeneous amphibole. The P2(1)/m clinoamphibole is analogous to the clinopyroxene pigeonite in agreement with the results of M. G. Bown.

Mica Polytypes: Systematic Description and Identification

X-ray studies of mica specimens from a variety of geological localities show that biotite and certain lithium-rich mica samples are composed of a mixture of different polytypes. Many of the biotite structures are new complex polytypes not before reported. A new method of designating mica polytypes is proposed. Techniques are described for the systematic generation of all the possible layer-stacking sequences of mica polytypes and for the verification of the stacking sequences in newly discovered forms.

Quantitative Studies of the Precipitation and Agglutination Reactions between Serum of Patients with “Connective Tissue” Diseases and a Preparation (Cohn Fraction II) of Human Gamma Globulin

The formation of precipitates on the addition of γ globulin (Fraction II) to the serum of most patients with rheumatoid arthritis is in general correlated with the FII agglutination titer of the serum.

The quantitative precipitation curve of this reaction is dependent on the FII agglutination titer of the sera, the lot of Fraction II and the volume in which the reaction is performed.

It is likely that the rheumatoid factor and what has been termed the γ globulin factor coexist in serum. A simple precipitation method for the detection of large quantities of rheumatoid factor has been reported.