Ibm fortran program for the calculation of cipw igneous rock norms

IBM Fortran program for calculation of normative composition of igneous rocks from chemical analyse

X-ray polarimetry with an active-matrix pixel proportional counter

We report the first results from an X-ray polarimeter with a micropattern gas proportional counter using an amorphous silicon active matrix readout. With 100% polarized X-rays at 4.5 keV, we obtain a modulation factor of 0.33 +/- 0.03, confirming previous reports of the high polarization sensitivity of a finely segmented pixel proportional counter. The detector described here has a geometry suitable for the focal plane of an astronomical X-ray telescope. Amorphous silicon readout technology will enable additional extensions and improvements.Comment: 4 pages, 4 figures, 1 tabl

In vitro transition of Schistocephalus solidus (Cestoda) from coracidium to procercoid and from procercoid to plerocercoid

With the present study, a culture system for successive life-cycle stages of the tapeworm Schistocephalus solidus was developed and this report documents for the first time, cultivation of the procercoid stage of S. solidus from eggs. Additionally we have transformed procercoids dissected from experimentally infected copepods and cultured procercoids into the early plerocercoid stage in vitro. Observations in the culture suggest that the coracidia can interact with their external environment and need no host specific stimuli, except for the components in the culture medium, for activation and hatching from the embryophore. Increasing the culture medium pH from 7.3 to 8.0 improved escape rates and frequencies of hook contractions, suggesting that the oncosphere may recognize and respond to environmental conditions along the host intestine. Procercoids in the culture did not stop growing indicating that conditions within the copepod may be important to limit growth and to induce transformation to plerocercoids. When procercoids are dissected from copepods and transferred to the culture, the outer tegument layers and cercomer starts to loosen. Comparison of the lectin staining of the loosened outer tegument layers and cercomer in procercoids dissected from copepods confirms that transitions of both, the oncosphere to procercoid and procercoid to plerocercoids, has taken place in the in vitro cultures

Charged particle production in the Pb+Pb system at 158 GeV/c per nucleon

Charged particle multiplicities from high multiplicity central interactions of 158 GeV/nucleon Pb ions with Pb target nuclei have been measured in the central and far forward projectile spectator regions using emulsion chambers. Multiplicities are significantly lower than predicted by Monte Carlo simulations. We examine the shape of the pseudorapidity distribution and its dependence on centrality in detail.Comment: 17 pages text plus 12 figures in postscript 12/23/99 -- Add TeX version of sourc

Automated track recognition and event reconstruction in nuclear emulsion

The major advantages of nuclear emulsion for detecting charged particles are its submicron position resolution and sensitivity to minimum ionizing particles. These must be balanced, however, against the difficult manual microscope measurement by skilled observers required for the analysis. We have developed an automated system to acquire and analyze the microscope images from emulsion chambers. Each emulsion plate is analyzed independently, allowing coincidence techniques to be used in order to reject background and estimate error rates. The system has been used to analyze a sample of high-multiplicity Pb-Pb interactions (charged particle multiplicities ∼1100) produced by the 158 GeV/c per nucleon 208Pb beam at CERN. Automatically measured events agree with our best manual measurements on 97% of all the tracks. We describe the image analysis and track reconstruction techniques, and discuss the measurement and reconstruction uncertainties

Surface roughness in rotary ultrasonic machining: hypotheses and their testing via experiments and simulations

Rotary ultrasonic machining (RUM) is a nontraditional drilling process. It has been used to drill not only brittle but also ductile materials. It was observed that the surface roughness of the drilled hole near the entrance side was better than that near the exit side. However, explanations about this observation could not be found in the literature. This paper aims to provide explanations about this observation. It presents three hypotheses and their testing via experiments and simulations

Diamondites: evidence for a distinct tectono-thermal diamond-forming event beneath the Kaapvaal craton

The petrogenesis and relationship of diamondite to well-studied monocrystalline and fibrous diamonds are poorly understood yet would potentially reveal new aspects of how diamond-forming fluids are transported through the lithosphere and equilibrate with surrounding silicates. Of 22 silicate- and oxide-bearing diamondites investigated, most yielded garnet intergrowths (n = 15) with major element geochemistry (i.e. Ca–Cr) classifying these samples as low-Ca websteritic or eclogitic. The garnet REE patterns fit an equilibrium model suggesting the diamond-forming fluid shares an affinity with high-density fluids (HDF) observed in fibrous diamonds, specifically on the join between the saline–carbonate end-members. The δ13C values for the diamonds range from − 5.27 to − 22.48‰ (V-PDB) with δ18O values for websteritic garnets ranging from + 7.6 to + 5.9‰ (V-SMOW). The combined C–O stable isotope data support a model for a hydrothermally altered and organic carbon-bearing subducted crustal source(s) for the diamond- and garnet-forming media. The nitrogen aggregation states of the diamonds require that diamondite-formation event(s) pre-dates fibrous diamond-formation and post-dates most of the gem monocrystalline diamond-formation events at Orapa. The modelled fluid compositions responsible for the precipitation of diamondites match the fluid-poor and fluid-rich (fibrous) monocrystalline diamonds, where all grow from HDFs within the saline-silicic-carbonatitic ternary system. However, while the nature of the parental fluid(s) share a common lithophile element geochemical affinity, the origin(s) of the saline, silicic, and/or carbonatitic components of these HDFs do not always share a common origin. Therefore, it is wholly conceivable that the diamondites are evidence of a distinct and temporally unconstrained tectono-thermal diamond-forming event beneath the Kaapvaal craton