Ionospheric Electron Density During Solar Eclipse of 20 July 1963

Ionospheric electron density during solar eclips

Response of Ionospheric Electron Density to a Change of Electron Temperature

Spatial and temporal models used to study response of ionospheric electron density to change of electron temperatur

The geology and hydrocarbon potential of the Dawson Bay Formation carbonate unit (Middle Devonian), Williston Basin, North Dakota

The Middle Devonian Dawson Bay Formation carbonate unit is present in the subsurface of North Dakota except where truncated by post-depositional erosion. The carbonate unit thickens from the erosional limit to a maximum thickness of 47.5 m (156 ft.) in Renville County and reaches a maximum depth of 3798 m (12, 432 ft.) below the surface in McKenzie County. In North Dakota, a submarine hardground separates the carbonate unit from the underlying “Second Red Bed member” of the Dawson Bay Formation. The upper contact with the Souris River Formation is conformable except in those areas where the Dawson Bay Formation was exposed to subaerial erosion prior to deposition of the Souris River sediments. The Dawson Bay carbonate unit is predominantly dolomitic and fossiliferous limestone or fossiliferous dolostone. The carbonate unit can be subdivided into five lithofacies on the basis of characteristic fossil fauna, flora, and other lithologic features. In ascending order, the carbonate lithofacies are: lithofacies B (brachiopod-echinoderm wackestones and mudstones), lithofacies C (stromatoporoid boundstones, wackestones, and mudstones), lithofacies D (gastropod-ostracod-brachiopod-echinoderm wackestones and mudstones), and lithofacies F (cryptalgal boundstone and mudstones). Lithofacies analysis of the Dawson Bay carbonates suggests a shallowing-upward succession of depositional environments and associated energy zones as follows: shallow epieric sea (very low energy), stromatoporoid biostrome/bioherm (low energy), very shallow epeiric sea (very low energy), restricted shallow epeiric sea (extremely low energy), and shallow epeiric sea shoreline (variable energy). Eogenetic diagenesis includes: color-mottling, dolomitization of micrite to microcrystalline dolomite with penecontemporaneous anhydrite replacement of cryptalgal mudstones and boundstones, cementation by sparry calcite, and vuggy porosity development. Mesogenetic diagenesis includes: formation of mosaic dolomites; cementation by blocky equant calcite; neomorphism; pressure-solution; fracturing; halite cementation; and hydrocarbon emplacement. Late mesogenetic hydrocarbon generation occurred within basal Dawson Bay carbonates and/or was the result of migration into the formation. Middle to late mesogenetic anhydrite, halite, and calcite cementation partly limits reservoir potential. Hydrocarbon occurrence in the Dawson Bay carbonates is primarily associated with porosity within the stromatoporoid buildups, multiple fracturing events over topographic and structural highs, and multiple dolomitization events

Effect of Hydrostatic Compression on the Energy of the 14.4-kev Gamma Ray from Fe^(57) in Iron

The energy of the recoil-free fraction of they rays emitted by nuclei bound in solids1 has been found to be affected by temperature and by electronic configuration. The latter effect has been named the "isomeric" shift. Compression of a solid should influence the energy through both of these mechanisms. We have measured the effect of hydrostatic compression at 295°K on the energy hν of the recoil-free 14.4-kev γ rays emitted by 0.1-μsec Fe^(57) bound in metallic iron

A Retrospective Study on Pathologic Features and Racial Disparities in Prostate Cancer

We reviewed more than 3,000 pathology reports on prostate cancer-related surgical specimens and analyzed racial disparities in histological and clinical features at the time of initial biopsy, diagnosis of prostate cancer, and prostatectomy, as well as in characteristics of tumor evolution between African American and Caucasian patients. As compared to Caucasians, African American patients had younger age, higher cancer detection rate, higher Gleason score of prostate cancer, and more bilateral involvement of the prostate. African Americans also had larger prostates, greater volume of tumor, and more positive margins. The diagnosis of HGPIN or ASAP in prostate biopsies and African American race conferred an increased risk of diagnosis of prostate cancer. The interval between prior noncancerous biopsy and the subsequent biopsy with diagnosis of prostate cancer was shorter in men with HGPIN, with ASAP, or of African American race

Gravitational redshift of galaxies in clusters as predicted by general relativity

The theoretical framework of cosmology is mainly defined by gravity, of which general relativity is the current model. Recent tests of general relativity within the \Lambda Cold Dark Matter (CDM) model have found a concordance between predictions and the observations of the growth rate and clustering of the cosmic web. General relativity has not hitherto been tested on cosmological scales independent of the assumptions of the \Lambda CDM model. Here we report observation of the gravitational redshift of light coming from galaxies in clusters at the 99 per cent confidence level, based upon archival data. The measurement agrees with the predictions of general relativity and its modification created to explain cosmic acceleration without the need for dark energy (f(R) theory), but is inconsistent with alternative models designed to avoid the presence of dark matter.Comment: Published in Nature issued on 29 September 2011. This version includes the Letter published there as well as the Supplementary Information. 23 pages, 7 figure

The Greatness of Common Things

Many discoveries are lost through laziness, a fact of which we are well aware; or if every soldier carries a marshal's baton in his knapsack (as Napoleon thought), few soldiers take the trouble to unpack their kits. The atmosphere had been" investigated "for centuries, so that by 1890 surely we knew all about it; at that time Lord Rayleigh was determining with the greatest possible accuracy the densities of the common gases-oxygen, hydrogen and nitrogen. A waste of time. So most people would have thought then, even scientists and practical men : surely the properties of those gases were known accurately enough! But Rayleigh found out that nitrogen, prepared from ammonia, was lighter than " atmospheric nitrogen " by one-half per centum. The atmospheric nitrogen was " dry air minus oxygen," and at that time was thought to be a homogeneous substance and identical with chemically prepared nitrogen. Clearly, however, it was not! Then Lord Rayleigh and Sir William Ramsay proved that atmospheric nitrogen contained an inert gas, heavier than pure nitrogen, and this gas they called argon (argos, inactive, idle). Argon, indeed, constitutes one per centum of the atmosphere