826 research outputs found
Caddo Ceramics on the Red River in North Central Texas
Caddo ceramics manufactured after A.D. 900 were widely traded in Texas, being found in some quantity on North Central, East Central, Central, and inland Southeast Texas archeological sites. They were also traded with prehistoric peoples in the Midwest (as far north as Iowa and Illinois) and the Southeastern U.S. While archeologists have known this for some time, much of the ceramic evidence for prehistoric Caddoan trade and exchange with other Native Americans has not been systematically compiled and studied, as became apparent during a recent review of the prehistoric and historic aboriginal pottery in Texas. Consequently, Caddoan archeologists are not yet in the position to confidently discuss the scope, timing, or direction of trade/exchange between Caddoan groups and surrounding non-Caddoan communities, or explore changes in the nature of social and economic relationships between particular Caddo groups and other prehistoric peoples.
This paper represents part of our initial efforts to begin systematically compiling archeological information on the distribution and character of Caddo ceramic sherds and vessels outside what is considered the southern Caddoan archaeological area. In it, we report on Early and Late Caddo ceramics found by Dr. Ernest R. Martin at two sites along the Red River in North Central Texas, some 130 km or more west of the westernmost Caddo settlements on the Red River in Northeast Texas
Whatever Happened to the Principles of Management?
Earnest R. Archer is Professor of Management in the Department of Management, School of Business Administration at Winthrop College, Rock Hill, South Carolina
Attitudinal Differences Between Male And Female Auditors, With Special Emphasis On Turnover Trends
Liquid-phase mass transfer at low flow rates in a packed column
Liquid-phase mass transfer in a packed bed was investigated for flow conditions for which the effect of neglecting axial transfer in the prediction of concentration distributions would most likely be significant. The purpose of this study was twofold: 1) to obtain experimental concentration data suitable for comparison with future theoretical studies, and 2) to analyze these data in terms of calculated effective axial and radial diffusivities and Peclet numbers
Chemostratigraphy and depositional environment of an Ordovician sedimentary section across the Miramichi Group - Tetagouche Group contact, northeastern New Brunswick
A thick section of Ordovician sedimentary rocks underlies and overlies felsic to mafic volcanic rocks of the Tetagouche Group, Bathurst Mining Camp. The dark grey quartzose slates and siltstones of the Patrick Brook Formation (Miramichi Group) occur below the volcanic rocks, whereas the dark grey to black slates and siltstones of the Boucher Brook Formation (Tetagouche Group) are intercalated with the volcanic rocks and overlie the sequence. The Miramichi-Tctagouche contact represents the interpreted Gander-Dunnage boundary in northeastern New Brunswick. Distinguishing between these two simitar formations is important for stratigraphic and geo-tectonic interpretations of the Bathurst Mining Camp and for exploration in these sequences. The geochemical composition of a semi-con form able section of rocks from the Boucher Brook (Middle to Late? Ordovician) and Patrick Brook (Early to Middle Ordovician) formations was determined to identify geochemical chemostratigraphic discriminants, as well as to determine the depositional environment in which these were deposited.
The high AI2O3 and distinctly higher high-field-strength elements (LREE, Th, HREE, and Y) in the Patrick Brook rocks are characteristic of mature sedimentary rocks and indicate intense chemical weathering (tropical environment) in the source regions, which is consistent with their compositional similarity to Avalon-derived shales analogous to Gander Zone sedimentary rocks. The Boucher Brook slates and siltstones are immature sedimentary rocks based on the preservation of albite and the less coherent trace-element systematics to phyllosilicate indices (AI2O3 and K2O). The Boucher Brook Formation is probably derived from the associated volcanic rocks.
The higher Mn and Fe and positive Ce/Ce* anomaly in some Boucher Brook Formation compared to the Patrick Brook rocks indicate that the Boucher Brook rocks in this section were deposited in a transitional anoxic/ oxic environment. The Patrick Brook rocks that immediately precede felsic volcanism and formation of massive sulphide deposits are highly reduced based on C and S contents, which is consistent with the sulphur isotope data. Moderately heavy δ34S values are indicative of SO42- reduction to H2S under anoxic conditions, which is significant in the formation and preservation of massive sulphides in the basal Tetagouche sequence.
RÉSUMÉ
Une section épaisse de roches sédimentaires de l’Ordovicien est sus-jacente ct sous-jacente à des roches volcanomafiques à volcanofelsiques du groupe de Tetagouche, dans le Camp minier de Bathurst. Des siltstones et des schistes quartzeux gris foncé de la Formation de Patrick Brook (groupe de Miramichi) sont présents au-dessous des roches volcaniques, tandis que des schistes et des siltstones gris foncé à noirs de la formation de Boucher Brook (groupe de Tetagouche) sont intercales dans les roches volcaniques et recouvrent la séquence. La surface de contact de Miramichi-Tetagouche représente ce qu'on interprèts comme la limite de Gander-Dunnage dans le nord-est du Nouveau-Brunswick. Il est important d'établir une distinction entre ces deux formations semblables pour les interprétations stratigraphiques du Camp minier de Bathurst et pour l'exploration dans ces séquences. On a détermine la composition géochimique d'une section semi-concordante de roches de Boucher Brook (Ordovicien moyen à tardif?) et de Patrick Brook (Ordovicien inférieur à moyen) afin de repérer les discriminants chimiostratigraphiques géochimiques ainsi que pour définir le milieu sédimentaire dans lequel ceux-ci ont été deposes.
La quantité prononcée d'Al2O3 et la présence distinctement supérieure d'éléments d'intensité de champ élevée (éléments de terres rares légers, Th, éléments de terres rares lourds et Y) dans les roches de Patrick Brook constituent des traits caractérstiques de roches sédimentaires matures; el les témoignent d'une altération climatique chimique intense (milieu tropical) dans les regions d'origine, ce qui est compatible avec la similarité de leur composition avec les schistes en provenance d'Avalon analogues aux roches sédimentaires de la zone de Gander. Les schistes et les siltstones de Boucher Brook sont des roches sédimentaires immatures basées sur la conservation d'albite et la corrélation d'éléments traces moins cohérents avec les indices de phyllosilicates (AI2O3). La Formation de Boucher Brook provient probabtement de roches volcaniques connexes.
La proportion supérieure de Mn et de Fe et l’anomalie positive de Ce/Ce* dans certaines parties de la Formation de Boucher Brook révèlcnt que les roches de Boucher Brook de cette section ont été déposées dans un milieu anoxique / oxique de transition. Les roches de Patrick Brook qui ont immédiatement précedé le volcanisme felsique et la formation de gitcs de sulfures massifs ont, à en juger par Icur teneur en C et en S, subi une réduction importante, ce qui correspond aux données isotopiques relatives au soufre. Les valeurs moyennement prononcées de δ34S temoignent d'une réduction du SO42- en H2S dans des conditions anoxiques, un phénomène déterminant dans la formation et la conservation des sulfures massifs dans la séquence basale de Tetagouche.
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Random access quantum information processors
Qubit connectivity is an important property of a quantum processor, with an
ideal processor having random access -- the ability of arbitrary qubit pairs to
interact directly. Here, we implement a random access superconducting quantum
information processor, demonstrating universal operations on a nine-bit quantum
memory, with a single transmon serving as the central processor. The quantum
memory uses the eigenmodes of a linear array of coupled superconducting
resonators. The memory bits are superpositions of vacuum and single-photon
states, controlled by a single superconducting transmon coupled to the edge of
the array. We selectively stimulate single-photon vacuum Rabi oscillations
between the transmon and individual eigenmodes through parametric flux
modulation of the transmon frequency, producing sidebands resonant with the
modes. Utilizing these oscillations for state transfer, we perform a universal
set of single- and two-qubit gates between arbitrary pairs of modes, using only
the charge and flux bias of the transmon. Further, we prepare multimode
entangled Bell and GHZ states of arbitrary modes. The fast and flexible
control, achieved with efficient use of cryogenic resources and control
electronics, in a scalable architecture compatible with state-of-the-art
quantum memories is promising for quantum computation and simulation.Comment: 7 pages, 5 figures, supplementary information ancillary file, 21
page
Cylindrical surface profile and diameter measuring tool and method
A tool is shown having a cross beam assembly made of beams joined by a center box structure. The assembly is adapted to be mounted by brackets to the outer end of a cylindrical case. The center box structure has a vertical shaft rotatably mounted therein and extending beneath the assembly. Secured to the vertical shaft is a radius arm which is adapted to rotate with the shaft. On the longer end of the radius arm is a measuring tip which contacts the cylindrical surface to be measured and which provides an electric signal representing the radius of the cylindrical surface from the center of rotation of the radius arm. An electric servomotor rotates the vertical shaft and an electronic resolver provides an electric signal representing the angle of rotation of the shaft. The electric signals are provided to a computer station which has software for its computer to calculate and print out the continuous circumference profile of the cylindrical surface, and give its true diameter and the deviations from the ideal circle
Averages of Fourier coefficients of Siegel modular forms and representation of binary quadratic forms by quadratic forms in four variables
Let be a a negative discriminant and let vary over a set of
representatives of the integral equivalence classes of integral binary
quadratic forms of discriminant . We prove an asymptotic formula for for the average over of the number of representations of by an
integral positive definite quaternary quadratic form and obtain results on
averages of Fourier coefficients of linear combinations of Siegel theta series.
We also find an asymptotic bound from below on the number of binary forms of
fixed discriminant which are represented by a given quaternary form. In
particular, we can show that for growing a positive proportion of the
binary quadratic forms of discriminant is represented by the given
quaternary quadratic form.Comment: v5: Some typos correcte
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