5,640 research outputs found
High-strength large-diameter carbon-base fibers
Material is applicable as reinforcement for metal matrix composites. Composites with large diameter, carbon base monofilaments offer advantages of superior strength at high temperatures and low density and for high temperature equipment where component weight must be minimized
Improvement of chemical vapor deposition process for production of large diameter carbon base monofilaments
Research was conducted to develop large diameter carbon monofilament, containing 25 to 35 mole % element boron, in the 2.0 to 10.0 mil diameter range using the chemical vapor deposition process. The objective of the program was to gain an understanding of the critical process variables and their effect on fiber properties. Synthesis equipment was modified to allow these variables to be studied. Improved control of synthesis variables permitted reduction in scatter of properties of the monofilaments. Monofilaments have been synthesized in the 3.0 to nearly 6.0 mil diameter range having measured values up to 552,000 psi for ultimate tensile strength and up to 30 million psi for elastic modulus
Further development of chemical vapor deposition process for production of large diameter carbon-base monofilaments
The development of large diameter carbon-base monofilament in the 50 micron to 250 micron diameter range using the chemical vapor deposition process is described. The object of this program was to determine the critical process variables which control monofilament strength, monofilament modulus, and monofilament diameter. It was confirmed that wide scatter in the carbon substrate strength is primarily responsible for the scatter in the monofilament strength. It was also shown through etching experiments that defective substrate surface conditions which can induce low strength modular growth in the monofilament layers are best controlled by processing improvements during the synthesis of the substrate. Modulus was found to be linearily proportional to monofilament boron content. Filament modulus was increased to above 27.8MN/sq cm but only by a considerable increase in monofilament boron content to 60 wt. % or more. Monofilament diameter depended upon dwell time in the synthesis apparatus. A monofilament was prepared using these findings which had the combined properties of a mean U.T.S. of 398,000 N/sq cm, a modulus of 18.9 MN/sq cm (24,000,000 psi), and a diameter of 145 microns. Highest measured strength for this fiber was 451,000 N/sq cm (645,000 psi)
A proposal to extend our understanding of the global economy
Satellites acquire information on a global and repetitive basis. They are thus ideal tools for use when global scale and analysis over time is required. Data from satellites comes in digital form which means that it is ideally suited for incorporation in digital data bases and that it can be evaluated using automated techniques. The development of a global multi-source data set which integrates digital information is proposed regarding some 15,000 major industrial sites worldwide with remotely sensed images of the sites. The resulting data set would provide the basis for a wide variety of studies of the global economy. The preliminary results give promise of a new class of global policy model which is far more detailed and helpful to local policy makers than its predecessors. The central thesis of this proposal is that major industrial sites can be identified and their utilization can be tracked with the aid of satellite images
Researching trust in the police and trust in justice: a UK perspective
This paper describes the immediate and more distant origins of a programme of comparative research that is examining cross-national variations in public trust in justice and in the police. The programme is built around a module of the fifth European Social Survey, and evolved from a study funded by the European Commission. The paper describes the conceptual framework within which we are operating – developed in large measure from theories of procedural justice. It reviews some of the methodological issues raised by the use of sample surveys to research issues of public trust in the police, public perceptions of institutional legitimacy and compliance with the law. Finally it gives a flavour of some of the early findings emerging from the programme
The Beinecke Lesser Antilles Collection at Hamilton College: A Catalogue of Books, Manuscripts, Prints, Maps, and Drawings, 1521-1860
This distinguished catalogue of the Lesser Antilles provides extensive, precise descriptions of approximately one thousand printed books and one thousand manuscripts that Walter Beinecke, Jr., collected over several decades and donated to Hamilton College in Clinton, New York, where he was a trustee. The collection includes hundreds of rare original documents, fifty maps, plantation reports, correspondence, and oil paintings and watercolors.
The catalogue of the Walter Beinecke, Jr., Collection describes unique manuscript material and many rare books more fully than previously available in bibliographies. The Houghs have applied advanced bibliographical knowledge to this work and in some instances have added cogent historical annotation.
The collection\u27s content addresses issues of broad international significance. Full understanding of the early history of the United States can best be achieved by studying interaction among the European states and the Antilles, as well as the commercial connection between the continental colonies and the Antilles. During the century and a half represented in this collection, England grew from a northern European power to a dominant world power, its growth largely funded by wealth provided from the Indies.
This work will be invaluable to libraries with holdings in Caribbean material, slave and slave trade material, economic history, American cartography, early American history, and general American travel books. It will be useful to all historians writing on the history of the region or on the history of colonialism and the slave trade generally.
414 pages : illustrations ; 29 cmhttps://digitalcommons.hamilton.edu/books/1063/thumbnail.jp
Estimating past exposure to arsenic from drinking water from both residential and occupational sources
Direct introduction of cloned DNA into the sea urchin zygote nucleus, and fate of injected DNA
A method is described for microinjection of cloned DNA into the zygote nucleus of Lytechinus variegatus. Eggs of this species are unusually transparent, facilitating visual monitoring of the injection process. The initial fate of injected DNA fragments appears similar to that observed earlier for exogenous DNA injected into unfertilized egg cytoplasm. Thus after end-to-end ligation, it is replicated after a lag of several hours to an extent indicating that it probably participates in most of the later rounds of DNA synthesis undergone by the host cell genomes during cleavage. The different consequences of nuclear versus cytoplasmic injection are evident at advanced larval stages. Larvae descendant from eggs in which exogenous DNA was injected into the nuclei are four times more likely (32% versus 8%) to retain this DNA in cell lineages that replicate very extensively during larval growth, i.e. the lineages contributing to the imaginal rudiment, and thus to display greatly enhanced contents of the exogenous DNA. Similarly, 36% of postmetamorphic juveniles from a nuclear injection sample retained the exogenous DNA sequences, compared to 12% of juveniles from a cytoplasmic injection sample. However, the number of copies of the exogenous DNA sequences retained per average genome in postmetamorphic juveniles was usually less than 0.1 (range 0.05-50), and genome blot hybridizations indicate that these sequences are organized as integrated, randomly oriented, end-to-end molecular concatenates. It follows that only a small fraction of the cells of the average juvenile usually retains the exogenous sequences. Thus, even when introduced by nuclear microinjection, the stable incorporation of exogenous DNA in the embryo occurs in a mosaic fashion, although in many recipients the DNA enters a wider range of cell lineages than is typical after cytoplasmic injection. Nuclear injection would probably be the route of choice for studies of exogenous DNA function in the postembryonic larval rudiment
A Curriculum Response to Budgetary and Marketing Pressures on a Two-Year Community College Engineering Technology Program (Microprecision Technology)
The process described is a program level response to institutional-wide budgetary restraints. The program in question is a two-year engineering technology associate degree program (Microprecision Technology). The major focus deals with:
1. reducing unit cost
2. improving marketability (recruiting)
3. improving transferability (as it relates to recruiting
The reductions in cost center around the ratio of contact hours to credit hours in the specialty courses as well as a reduction in the number of such courses. Issues dealing with marketability are directly related to the unique nature of the program and the difficulties involved in the public presentation of such a program. Increasing the transferability of this “nontransfer” program is seen as a method of focusing the attention of the growing number of entering students who wish to keep the transfer option open to them.
The above mentioned concerns necessitated the curriculum revisions described and included in this document
Passive and active seismic isolation for gravitational radiation detectors and other instruments
Some new passive and active methods for reducing the effects of seismic disturbances on suspended masses are described, with special reference to gravitational radiation detectors in which differential horizontal motions of two or more suspended test masses are monitored. In these methods it is important to be able to determine horizontal seismic accelerations independent of tilts of the ground. Measurement of changes in inclination of the suspension wire of a test mass, relative to a direction defined by a reference arm of long period of oscillation, makes it possible to carry this out over the frequency range of interest for earth-based gravitational radiation detectors. The signal obtained can then be used to compensate for the effects of seismic disturbances on the test mass if necessary. Alternatively the signal corresponding to horizontal acceleration can be used to move the point from which the test mass is suspended in such a way as to reduce the effect of the seismic disturbance and also damp pendulum motions of the suspended test mass. Experimental work with an active anti-seismic system of this type is described
- …