Tidal flat deposits of the Lower Proterozoic Campbell Group along the southwestern margin of the Kaapvaal Craton, Northern Cape Province, South Africa

Lower Proterozoic stromatolites and associated clastic carbonate deposits of the Campbell Group, from the southern margin (Prieska area) of the Kaapvaal Craton, northern Cape Province, are described. Contrary to previous interpretations (Beukes, 1978; 1980a) shallow subtidal to supratidal facies are recognised and discussed in regional context. An alternative model for the facies development of the Campbell Group is proposed

Barbarians at the British Museum: Anglo-Saxon Art, Race and Religion

A critical historiographical overview of art historical approaches to early medieval material culture, with a focus on the British Museum collections and their connections to religion

The depositional environment of some Middle Jurassic Ironshot Limestones of southern England.

Condensed beds in the Jurassic of northen Europe are usually characterized by limonite eoliths in a matrix of limestone, marl, or clay. Several of these beds have been studied in this country, particularly those in S.W, England; namely the Inferior Oolite and the Twinhoe Ironshot, (Upper Bathonian). The aim of this investigation was to determine the depositional environment of this facies. It is concluded that these ironshot limestones were deposited in very shallow water conditions, in areas of reduced sedimentation and reworking. In the case of the Inferior Oolite, areas of extreme condensation are separated by areas of less condensed deposits, suggesting the existence of several topographic highs on the sea floor on which the thinnest beds were laid down. Prom borehole data the Inferior Oolite of Dorset and Somerset has been found to lie on a wide shelf, on the western side of a large basin covering southern England. The Twinhoe Beds are considered to have been deposited in a transitional area, between the Fullers Earth Clay facies and the Great Oolite Limestone shelf facies; the Twinhoe Ironshot being formed during a period of reduced sedimentation. Both the Inferior Oolite and the Twinhoe Ironshot contain limonite ooliths, and these have been studied in order to decide whether the- ooliths were once chamosite. This was done means of x-ray diffraction and by electron microprobe analysis of individual ooliths and concretions. The results suggest that the limonite is a primary precipitate, which in the Middle Inferior Oolite has been found to pass eastwards into chamosite oolite, and finally into glauconitic limestones. The origin of the large limonitic conretions frequently found in condensed beds was also studied. It is considered that these are large oncolites on which limonite was precipitated, possibly due to selective adsorption by the algae themselves

The Real and the Sacred : Picturing Jesus in Nineteenth-Century Fiction

https://digitalcommons.montclair.edu/all_books/1162/thumbnail.jp

Alter Icons : The Russian Icon and Modernity

https://digitalcommons.montclair.edu/all_books/1354/thumbnail.jp

A Mobile Robot System for Ground Servicing Operations on the Space

A mobile system for space shuttle servicing, the Tessellator, has been configured, designed and is currently being built and integrated. Robot tasks include chemical injection and inspection of the shuttle’s thermal protection system. This paper outlines tasks, rationale, and facility requirements for the development of this system. A detailed look at the mobile system and manipulator follow with a look at mechanics, electronics, and software. Salient features of the mobile robot include omnidirectionality, high reach, high stiffness and accuracy with safety and self-reliance integral to all aspects of the design. The robot system is shown to meet task, facility, and NASA requirements in its design resulting in unprecedented specifications for a mobile-manipulation system. 1. Background Automation has historically not played a role in the ground processing operations of spacecraft and space systems. In part, this has been due to scepticism regarding the viability of robotics technologies and a strong concern for safety of flight hardware and personnel. The Robotics Institute at Carnegie Mellon University (CMU) and a committed group at NASA felt strongly that the time was right to investigate both applications and technologies for ground processing. In 1990 we investigated the automation of a variety of ground processing applications [NASA-TPS 90, NASA-PPS 90]. The studies not only concluded that there were tasks worth automating but that current robotic technologies made thi

A Mobile Robot System for Ground Servicing Operations on the Space Shuttle

A mobile system for space shuttle servicing, the Tessellator, has been configured, designed and is currently being built and integrated. Robot tasks include chemical injection and inspection of the shuttle's thermal protection system. This paper outlines tasks, rationale, and facility requirements for the development of this system. A detailed look at the mobile system and manipulator follow with a look at mechanics, electronics, and software. Salient features of the mobile robot include omnidirectionality, high reach, high stiffness and accuracy with safety and self-reliance integral to all aspects of the design. The robot system is shown to meet task, facility, and NASA requirements in its design resulting in unprecedented specifications for a mobile-manipulation system. 1. Background Automation has historically not played a role in the ground processing operations of spacecraft and space systems. In part, this has been due to scepticism regarding the viability of robotics technolo..