1,682 research outputs found
Alien Registration- Levesque, Adolph J. (Millinocket, Penobscot County)
https://digitalmaine.com/alien_docs/8052/thumbnail.jp
An Exploratory Study of Forces and Frictions affecting Large-Scale Model-Driven Development
In this paper, we investigate model-driven engineering, reporting on an
exploratory case-study conducted at a large automotive company. The study
consisted of interviews with 20 engineers and managers working in different
roles. We found that, in the context of a large organization, contextual forces
dominate the cognitive issues of using model-driven technology. The four forces
we identified that are likely independent of the particular abstractions chosen
as the basis of software development are the need for diffing in software
product lines, the needs for problem-specific languages and types, the need for
live modeling in exploratory activities, and the need for point-to-point
traceability between artifacts. We also identified triggers of accidental
complexity, which we refer to as points of friction introduced by languages and
tools. Examples of the friction points identified are insufficient support for
model diffing, point-to-point traceability, and model changes at runtime.Comment: To appear in proceedings of MODELS 2012, LNCS Springe
The Strengths of Phenolic Ketimines and Their Methyl Ethers as Bases
The ionization constants of the monohydroxy-diphenyl ketimines and their methyl ethers are calculated from measurements of the hydrogen ion concentration of aqueous solutions of their hydrochlorides through the use of the quinhydrone electrode. This data has been collected as a part of the information expected to throw light on the varied stability toward hydrolysis shown by different ketimines
Simulated Altitude Investigation of Stewart-Warner Model 906-B Combustion Heater
An investigation has been conducted to determine thermal and pressure-drop performance and the operational characteristics of a Stewart-Warner model 906-B combustion heater. The performance tests covered a range of ventilating-air flows from 500 to 3185 pounds per hour, combustion-air pressure drops from 5 to 35 inches of water, and pressure altitudes from sea level to 41,000 feet. The operational characteristics investigated were the combustion-air flows for sustained combustion and for consistent ignition covering fuel-air ratios ranging from 0.033 to 0.10 and pressure altitudes from sea level to 45,000 feet. Rated heat output of 50,000 Btu per hour was obtained at pressure altitudes up to 27,000 feet for ventilating-air flows greater than 800 pounds per hour; rated output was not obtained at ventilating-air flow below 800 pounds per hour at any altitude. The maximum heater efficiency was found to be 60.7 percent at a fuel-air ratio of 0.050, a sea-level pressure altitude, a ventilating-air temperature of 0 F, combustion-air temperature of 14 F, a ventilating-air flow of 690 pounds per hour, and a combustion-air flow of 72.7 pounds per hour. The minimum combustion-air flow for sustained combustion at a pressure altitude of 25,000 feet was about 9 pounds per hour for fuel-air ratios between 0.037 and 0.099 and at a pressure altitude of 45,000 feet increased to 18 pounds per hour at a fuel-air ratio of 0.099 and 55 pounds per hour at a fuel-air ratio of 0.036. Combustion could be sustained at combustion-air flows above values of practical interest. The maximum flow was limited, however, by excessively high exhaust-gas temperature or high pressure drop. Both maximum and minimum combustion-air flows for consistent ignition decrease with increasing pressure altitude and the two curves intersect at a pressure altitude of approximately 25,000 feet and a combustion-air flow of approximately 28 pounds per hour
Analytical and Experimental Studies of a Divided-flow Ram-jet Combustor
Results of a theoretical and experimental study of the total pressure losses and combustion efficiencies associated with the divided-flow combustor are presented and comparisons made with the nondivided-flow combustor. The theoretical treatment indicated the range of primary-zone size, primary-zone air flow, and flame-holder pressure-loss coefficients over which the total-pressure loss through the divided-flow combustor was less than that through the nondivided-flow combustor. The experimental work indicated the range of fuel-air ratios, for a given size primary zone, over which the combustion efficiency in the divided-flow combustor was higher than that in the nondivided-flow combustor
Learning by doing: Action performance facilitates affordance perception
AbstractWe investigated the effect of action performance on perceptual judgments by evaluating accuracy in judging whether doorways allowed passage. Participants made judgments either before or after walking through doorways of varying widths. Participants in the action-first group benefited from action feedback and made more accurate judgments compared to a perception-first group that judged doorways before walking through them. Action feedback aided perceptual judgments by facilitating scaling to body dimensions: Judgments in the action-first group were strongly related to height, weight, and torso size, whereas judgments in the perception-first group were not
Effect of 5′-methylthioadenosine on gene action during heat shock in Drosophila melanogaster
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