A new method for measuring slipperiness of airport runways and other paved surfaces

Aircraft stopping distances on wet runways are accurately predicted by measurements taken with a conventional automobile equipped with diagonal braking system and simple instrumentation for recording stopping distances

Ultra-high molecular sink vacuum chamber

Double-wall vacuum chamber can be separated from the remainder of the system and pumped by ultra-clean techniques. Ultrahigh vacuum is maintained by the cryogenic effect of a cold wall and titanium chemisorption

Friction evaluation of unpaved, gypsum-surface runways at Northrup Strip, White Sands Missile Range, in support of Space Shuttle Orbiter landing and retrieval operations

Friction measurement results obtained on the gypsum surface runways at Northrup Strip, White Sands Missile Range, N. M., using an instrumented tire test vehicle and a diagonal braked vehicle, are presented. These runways were prepared to serve as backup landing and retrieval sites to the primary sites located at Dryden Flight Research Center for shuttle orbiter during initial test flights. Similar friction data obtained on paved and other unpaved surfaces was shown for comparison and to indicate that the friction capability measured on the dry gypsum surface runways is sufficient for operations with the shuttle orbiter and the Boeing 747 aircraft. Based on these ground vehicle friction measurements, estimates of shuttle orbiter and aircraft tire friction performance are presented and discussed. General observations concerning the gypsum surface characteristics are also included and several recommendations are made for improving and maintaining adequate surface friction capabilities prior to the first shuttle orbiter landing

(SNP138) Mattie Yager: interviewed by Dorothy Noble Smith, transcribed by Sharon G. Marston

Records an interview with Mattie Yager, whose family lived near Old Rag Mountain in Madison County, Virginia. Describes daily life in the mountains, touching on the work of growing and preserving food, herbal remedies, courtship and holidays. Mrs. Woodward plays several old-time mountain tunes on her autoharp during the interview. Her son, Dennis Yager joins in at the end of the conversation. Dennis Yager and two other musicians give an impromptu concert of mountain music in SdArch no. SNP-137.https://commons.lib.jmu.edu/snp/1115/thumbnail.jp

Elastic precursor of the transformation from glycolipid-nanotube to -vesicle

By the combination of optical tweezer manipulation and digital video microscopy, the flexural rigidity of single glycolipid "nano" tubes has been measured below the transition temperature at which the lipid tubules are transformed into vesicles. Consequently, we have found a clear reduction of the rigidity obviously before the transition as temperature increasing. Further experiments of infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) have suggested a microscopic change of the tube walls, synchronizing with the precursory softening of the nanotubes.Comment: 9 pages, 6 figure

Preliminary test results of the joint FAA-USAF-NASA runway research program. Part 1: Traction measurements of several runways under wet and dry conditions with a Boeing 727, a diagonal-braked vehicle, and a mu-meter

The stopping distance, brake application velocity, and time of brake application were measured for two modern jet transports, along with the NASA diagonal-braked vehicle and the British Mu-Meter on several runways, which when wetted, cover the range of slipperiness likely to be encountered in the United States. Tests were designed to determine if correlation between the aircraft and friction measuring vehicles exists. The test procedure, data reduction techniques, and preliminary test results obtained with the Boeing 727, the Douglas DC-9, and the ground vehicles are given. Time histories of the aircraft test run parameters are included

Monobromoamine with Organomagnesium Halides

The reaction of monobromoamine with organomagnesium halides has been studied and compared with that of monochloroamine with the same reagents. The yields of primary amines obtained from monobromoamine are considerably smaller than those from monochloroamine. Otherwise the reactions are similar. On account of the instability of monobromoamine it was necessary to develop special methods of preparing, analyzing and working with solutions of this compound

Using the Data Modeling Worksheet to Improve Novice Data Modeler Performance

This research reports on use and evaluation of the data modeling worksheet as a pedagogical tool for improving a student\u27s ability to learn the extended entity-relationship data modeling methodology. A laboratory experiment using a modified posttest only, control group design compared the performance of two student subject groups. One group used the data modeling worksheet as an integral component of their instruction on database design. A second control group did not use the worksheet, but that group received comparable training in every other respect. Subjects were tasked to develop a data model that represented a textual description of a data modeling problem. The data analysis used a one-way ANOVA to evaluate eight hypotheses, each representing a facet of the data modeling methodology. The results indicate that the data modeling worksheet significantly improved student learning with regard to their ability to identify entities, entity identifier attributes, and ternary relationships

Anxious, Disconnected and ‘Missing Out’, but Oh So Convenient: Tertiary Students’ Perspectives of Remote Teaching and Learning with Covid-19

The higher education sector has learnt a great deal in the online delivery shift due to Covid-19, however, student voice has been underrepresented in literature. This paper reveals 15 student perspectives, including both international and domestic students, who were studying a Master of Teaching (Secondary) at one university in Melbourne, Australia, during heightened social distancing restrictions. The inductive thematic qualitative data analysis collected through semi-structured interviews showed opportunities and challenges of learning experiences. Emergent themes found affordances of convenience and challenges of relational and structural aspects of teaching and learning. Relational aspects of learning were more challenging, including peer collaboration, seeking informal advice and feedback from academics, and participation and engagement. We recommend the inclusion of student voice to guide post Covid-19 teacher education design recommend several areas of support to guide a humanising and personal connection into the remote learning environment