Characteristics of Heavy Accessory Minerals in a Pre-Cambrian Granite Gneiss

Heavy accessory minerals have been separated from specimens of granite gneiss taken in a traverse across the Beartooth Plateau. Prominent accessories are biotite, magnetite, ilmenite, zircon, apatite, epidote and titanite. Characteristics of zircon, apatite and titanite from these samples are described

Student Participation in Field Classes

Field work consisting of trips and excursions out from the class room plays a prominent part in instruction in many of the science courses throughout our educational system. Almost all courses in general or natural science in the secondary schools have it as an attachment of greater or less rating. So also do the technical or applied science courses in colleges. The materials and features with which the various branches of science deal are widely scattered over the earth\u27s surface. They cannot all be brought into the laboratory and dealt with indoors, nor adequately represented by illustrative materials of one sort or another. Photographs, lantern slides, models and the illustrations of textbooks serve some considerable purpose in this regard, but they fail to give an adequate conception of size, of texture and of space relationships. Thus from the very nature of the materials pertaining to a particular science it is only natural that field class work should have some part in the teaching of that science

Etched Boulder at Ames, Iowa (Abstract)

A large rounded granitic glacial erratic from the Iowa State College campus has several granitic dikes up to a few inches in width crisscrossing it. They project from the surface of the dike as much as three inches and have smooth surfaces. The surface of the granite country rock is pitted but quite sound. It is believed probably that the boulder has been etched by wind action

Structure of the Des Moines Series at Redfield, Iowa

In southwestern Dallas County, in the vicinity of Redfield and for several miles farther east along the Raccoon River, there are exposures of sandstones and shales of the Des Moines series. These were studied by Leonard who concluded that the strata were not flat lying nor with a gentle southwest dip, but assumed the form of an anticline of presumably north-south axis in the vicinity of Redfield. He based this conclusion upon an apparent rise of a prominent sandstone member along the Raccoon River west toward Redfield, upon the non-appearance, at Redfield, of beds found in sections east and west along the river, and upon the presence of fracture cleavage in one of the outcrops of the sandstone

Weathering of Sandstone in the Iowa State Capitol Building

Extreme weathering of some of the sandstone in the superstructure of the Iowa State Capitol at Des Moines has within recent years been a cause of considerable concern. The part of the building affected is that above the level of the basement story, and it is greatest toward the top of the building. Decorations, balustrades, cornices, architraves, pediments, hereafter to be referred to as trimmings and decorations, have been affected to the point where many pieces have fallen and crumbled away. The falling material is a source of danger, the appearance of the building is unfavorably affected, and the monetary damage to the structure is great. Considerable sums have already been spent in removing weakened stone, and in making replacements with cement or other materials, where possible. Certain parts of the exterior are however, apparently continuing to suffer progressive weathering which may be expected to persist and to be a cause of concern and expense. It will apparently be necessary to continue the work of removing weakened stone and of replacing and restoring the missing parts where it is thought to be desirable

Conservation of Geologic Features in Iowa

It is suggested that attention be given to the following geologic features as possible subjects for recognition or preservation or protection: glacial erratics unique for size, shape, or composition; type sections or localities in the bedrock; falls; springs; fossil or geode collecting areas; areas of natural outcrops of all bedrock formations of the state

Enhancing Egress Drills: Preparation and Assessment of Evacuee Performance

This article explores how egress drills-specifically those related to fire incidents-are currently used, their impact on safety levels, and the insights gained from them. It is suggested that neither the merits of egress drills are well understood, nor the impact on egress performance well characterized. In addition, the manner in which they are conducted varies both between and within regulatory jurisdictions. By investigating their strengths and limitations, this article suggests opportunities for their enhancement possibly through the use of other egress models to support and expand upon the benefits provided. It is by no means suggested that drills are not important to evacuation safety-only that their inconsistent use and the interpretation of the results produced may mean we (as researchers, practitioners, regulators, and stakeholders) are not getting the maximum benefit out of this important tool

Comparative Dosimetric Analysis and Normal Tissue Complication Probability Modelling of Four-Dimensional Computed Tomography Planning Scans Within the UK NeoSCOPE Trial

Aims: NeoSCOPE is a trial of two different neoadjuvant chemoradiotherapy regimens for resectable oesophageal cancer and was the first multicentre trial in the UK to incorporate four-dimensional computed tomography (4D-CT) into radiotherapy planning. Despite 4D-CT being increasingly accepted as a standard of care for lower third and junctional oesophageal tumours, there is limited evidence of its benefit over standard three-dimensional computed tomography (3D-CT). // Materials: Using NeoSCOPE 4D-CT cases, we undertook a dosimetric comparison study of 3D-CT versus 4D-CT plans comparing target volume coverage and dose to organs at risk. We used established normal tissue complication probability models to evaluate the potential toxicity reduction of using 4D-CT plans in oesophageal cancer. // Results: 4D-CT resulted in a smaller median absolute PTV volume and lower dose levels for all reported constraints with comparable target volume coverage. NTCP modelling suggests a significant relative risk reduction of cardiac and pulmonary toxicity endpoints with 4D-CT. // Conclusion: Our work shows that incorporating 4D-CT into treatment planning may significantly reduce the toxicity burden from this treatment