CETA truck and EVA restraint system

The Crew Equipment Translation Aid (CETA) experiment is an extravehicular activity (EVA) Space Transportation System (STS) based flight experiment which will explore various modes of transporting astronauts and light equipment for Space Station Freedom (SSF). The basic elements of CETA are: (1) two 25 foot long sections of monorail, which will be EVA assembled in the STS cargo bay to become a single 50 ft. rail called the track; (2) a wheeled baseplate called the truck which rolls along the track and can accept three cart concepts; and (3) the three carts which are designated manual, electric, and mechanical. The three carts serve as the astronaut restraint and locomotive interfaces with the track. The manual cart is powered by the astronaut grasping the track's handrail and pulling himself along. The electric cart is operated by an astronaut turning a generator which powers the electric motor and drives the cart. The mechanical cart is driven by a Bendix type transmission and is similar in concept to a man-propelled railroad cart. During launch and landing, the truck is attached to the deployable track by means of EVA removable restraint bolts and held in position by a system of retractable shims. These shims are positioned on the exterior of the rail for launch and landing and rotate out of the way for the duration of the experiment. The shims are held in position by strips of Velcro nap, which rub against the sides of the shim and exert a tailored force. The amount of force required to rotate the shims was a major EVA concern, along with operational repeatability and extreme temperature effects. The restraint system was tested in a thermal-vac and vibration environment and was shown to meet all of the initial design requirements. Using design inputs from the astronauts who will perform the EVA, CETA evolved through an iterative design process and represented a cooperative effort

Study of the ionosphere layers in the infrared region of the spectrum

Infrared emission of ionospheric layer

RESULTS OF 1982 RODENTICIDE FIELD TESTS

A 2.0% zinc phosphide pellet and a 0.001% brodifacoum bait gave the lowest percentage post-treatment activity in a field test in which broadcast applications were followed shortly by rain. There was not a clear difference in performance between the single-feeding toxicants and the multiple-feeding anticoagulants in this experiment. A 0.075% cholecalciferol bait gave control comparable to some registered materials and shows promise for future development. A bait containing 0.0216% diphacinone gave significantly better control than one containing 0.005% diphacinone

RESULTS OF 1982 RODENTICIDE FIELD TESTS

A 2.0% zinc phosphide pellet and a 0.001% brodifacoum bait gave the lowest percentage post-treatment activity in a field test in which broadcast applications were followed shortly by rain. There was not a clear difference in performance between the single-feeding toxicants and the multiple-feeding anticoagulants in this experiment. A 0.075% cholecalciferol bait gave control comparable to some registered materials and shows promise for future development. A bait containing 0.0216% diphacinone gave significantly better control than one containing 0.005% diphacinone

The Effect of Gender, Ethnicity, and Income on College Students\u27 Use of Communication Technologies

Because campus officials are relying on personal communication technologies to communicate with students, a question arises about access and usage. Although communication technologies are popular among college students, some evidence suggests that differences exist in ownership and use. We examined patterns of student ownership and use of cell phones and use of instant messaging, focusing on three predictors of digital inequality: gender, ethnicity, and income. Logistic and hierarchical linear regression analyses were used to analyze results from 4,491 students. The odds that female and white students owned cell phones were more than twice as high as for men and African-American students. Students in the $100,000–$149,000 per year income bracket were more than three times as likely to own a cell phone than those from the median bracket. However, being female, African-American, and/or from the highest income brackets was positively predictive of the number of text messages sent and the amount of time spent talking on a cell phone per week. We found no differences between students on the use of instant messaging. Implications of these results, as well as areas for further research, are provided

The Effect of Gender, Ethnicity, and Income on College Students\u27 Use of Communication Technologies

Because campus officials are relying on personal communication technologies to communicate with students, a question arises about access and usage. Although communication technologies are popular among college students, some evidence suggests that differences exist in ownership and use. We examined patterns of student ownership and use of cell phones and use of instant messaging, focusing on three predictors of digital inequality: gender, ethnicity, and income. Logistic and hierarchical linear regression analyses were used to analyze results from 4,491 students. The odds that female and white students owned cell phones were more than twice as high as for men and African-American students. Students in the $100,000–$149,000 per year income bracket were more than three times as likely to own a cell phone than those from the median bracket. However, being female, African-American, and/or from the highest income brackets was positively predictive of the number of text messages sent and the amount of time spent talking on a cell phone per week. We found no differences between students on the use of instant messaging. Implications of these results, as well as areas for further research, are provided

Validity of the Contextual Competence Scale for Engineering Students

BackgroundEngineering educators and practitioners increasingly value contextual competence. A psychometrically sound, practical, and useful scale for assessing undergraduate engineering students' contextual competence is needed.Purpose/HypothesisThis article provides comprehensive evidence of the content, structural, discriminant, and criterion‐related validity of the contextual competence scale.Design/MethodThis study used student, alumni, and faculty survey data from a nationally representative sample of 120 U.S. engineering programs from 31 four‐year institutions. Validity evidence was obtained by expert review of questions, a pilot test, factor analyses, and several analyses utilizing t‐tests, correlations, and regression.ResultsExperts constructed the questions used in the scale (content validity). Those questions combined to measure a single concept (structural validity), the scale reliably measures (Cronbach's alpha = .91) that concept, and it focuses on contextual competence instead of other student outcomes (discriminant validity). The contextual competence scale varies according to students' characteristics and curricular experiences as well as similarities and differences in student and alumni levels of contextual competence in the same programs and institutions (criterion‐related validity). Finally, the scale may be a more accurate measure of contextual competence than faculty members' perceptions of students' ability.ConclusionsThe contextual competence scale allows engineering programs to meet ABET and other self‐study requirements or do large‐scale research with relative ease and little expense. The process described in this article can be used by other researchers in engineering education for their scale development efforts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110541/1/jee20062.pd

Microstructure, strength and fatigue of an ultrafine-grained Al-Cu-Mg alloy

© 2015, Institute of Problems of Mechanical Engineering. The impact of equal-channel angular pressing (ECAP) on the microstructure of an Al-Cu-Mg alloy has been investigated using transmission electron microscopy and electron backscatter diffraction. A combination of an ultrafine-grained and bimodal structure was observed in the alloy as a result of ECAP processing. The ECAP-processed samples after tensile tests and cyclic loads have demonstrated an enhanced ultimate tensile strength and fatigue endurance limit in comparison with the properties of the samples subjected to the standard T6 treatment

Computational Fluid Dynamics-Enabled Modelling and Optimisation of Coolant Flow through Helical Channels

Computational Fluid Dynamics (CFD) is used to investigate the effect of geometry and flow parameters on liquid flow in helical channels for conditions relevant to coolant flow in twist drilling applications. CFD predictions of pressure drop in circular and triangular channels are compared against three important experimental correlations and it is shown that the correlation due to Yamamoto et al. [1] is accurate for both circular and triangular channels. Numerical results show how pressure drop varies with pitch, torsion and arc length and how the regions of high velocity flow can be manipulated through helical orientation. A parametrisation of triangular channels is presented and a meta-model for pressure drop created which demonstrates clearly how this depends on corner radius and orientation. Results also show how the larger pressure drop associated with triangular channels, for a given target flow rate, can be reduced towards those for equivalent flows in circular channels by increasing cross-sectional area whilst reducing flow velocities accordingly

Reviews

The following publications have been reviewed by the mentioned authors;An Italic Calligraphy Handbook by Carolyn Knudsen Adams, reviewed by John LancasterDesign and British Industry by Richard Stewart, reviewed by John H. CarswellDesign Graphics by David Fair and Marilyn Kenny, reviewed by D. R. JonesGCSE Craft, Design and Technology by Richard Kimbell, John Plater and Tristram Shepard, reviewed by D. R. JonesProblem Solving in Science and Technology by David Rowlands, reviewed by Peter C. MillrayTechnical Drawing, An Usborne Guide by Susan Peach, reviewed by Keith VickersTVEI and Secondary Education: a critical appraisal by Denis Gleeson, reviewed by Martin MersonWorking in Design by the Careers and Occupational Information Centre, reviewed by S. J. Lodg