Acoustical modeling study of the open test section of the NASA Langley V/STOL wind tunnel

An acoustic model study was carried out to identify effective sound absorbing treatment of strategically located surfaces in an open wind tunnel test section. Also an aerodynamic study done concurrently, sought to find measures to control low frequency jet pulsations which occur when the tunnel is operated in its open test section configuration. The acoustical modeling study indicated that lining of the raised ceiling and the test section floor immediately below it, results in a substantial improvement. The aerodynamic model study indicated that: (1) the low frequency jet pulsations are most likely caused or maintained by coupling of aerodynamic and aeroacoustic phenomena in the closed tunnel circuit, (2) replacing the hard collector cowl with a geometrically identical but porous fiber metal surface of 100 mks rayls flow resistance does not result in any noticable reduction of the test section noise caused by the impingement of the turbulent flow on the cowl

Letter from D. L. Bliss to John Muir, 1899 Aug 29.

[1][letterhead]August 29th 1899John Muir EsqDear SirI am very anious to see you in regard to the Lake Tahoe Government Reservation and will be in San Francisco balance of this week. Will you be in the City between this time and Sunday or if not will you be at Martinez Sunday and can I see you there. Can arrange either way to [illegible] your convenience Will you kindly02612[2][letterhead]write me at #1208 Claus Spreckles Building and let me know where & when I can have an interview with you by so doing you will much obligedYours very trulyD.L. Bliss0261

Situational Leadership Styles in United States Air Force Air Traffic Control Towers

Leadership in air traffic control facilities is critical to the safe, orderly, and efficient flow of air traffic. The purpose of this qualitative study was to determine the preferred leadership style for United States Air Force air traffic control tower watch supervisors. A panel of 10 functional experts completed a 25 question scenario-based survey to establish a baseline for this study’s four research questions. A purposeful sample of eight control tower chief controllers representing the eight United States Air Force major commands were interviewed and their responses were compared to the mean of the experts panel. The data from the interviews was analyzed and in addition to the straight forward responses to the research questions two themes emerged: (1) the role of the monitor and (2) the apprentice controller’s role in emergency situations. The study discovered that United States Air Force control towers are fully implementing the fundamentals of situational leadership. The eight interviewees’ responses mirrored the expert panels’ answers. The results of this study provide control tower chief controllers, watch supervisors, and future watch supervisors a frame of reference on how situations are handled across the spectrum of facilities

Large area silicon sheet by EFG

Progress in a program to produce high speed, thin, wide silicon sheets for fabricating 10% efficient solar cells is reported. An EFG ribbon growth system was used to perform growth rate and ribbon thickness experiments. A new, wide ribbon growth system was developed. A theoretical study of stresses in ribbons was also conducted. The EFG ribbons were observed to exhibit a characteristic defect structure which is orientation dependent in the early stages of growth

High intensity X/ γ photon beams for nuclear physics and photonics

In this manuscript we review the challenges of Compton back-scattering sources in advancing photon beam performances in the1−20MeVenergy range, underlining the design criteria bringing tomaximum spectral luminosity and briefly describing the main achieve-ments in conceiving and developing new devices (multi-bunch RF cav-ities and Laser recirculators) for the case of ELI-NP Gamma BeamSystem (ELI-NP-GBS)

Creative and Stylistic Devices Employed by Children During a Storybook Narrative Task: A Cross-Cultural Study

Purpose: The purpose of this study was to analyze the effects of culture on the creative and stylistic features children employ when producing narratives based on wordless picture books. Method: Participants included 60 first- and second-grade African American, Latino American, and Caucasian children. A subset of narratives based on wordless picture books collected as part of a larger study was coded and analyzed for the following creative and stylistic conventions: organizational style (topic centered, linear, cyclical), dialogue (direct, indirect), reference to character relationships (nature, naming, conduct), embellishment (fantasy, suspense, conflict), and paralinguistic devices (expressive sounds, exclamatory utterances). Results: Many similarities and differences between ethnic groups were found. No significant differences were found between ethnic groups in organizational style or use of paralinguistic devices. African American children included more fantasy in their stories, Latino children named their characters more often, and Caucasian children made more references to the nature of character relationships. Conclusion: Even within the context of a highly structured narrative task based on wordless picture books, culture influences children’s production of narratives. Enhanced understanding of narrative structure, creativity, and style is necessary to provide ecologically valid narrative assessment and intervention for children from diverse cultural backgrounds

Delivery status of the ELI-NP gamma beam system

International audienceThe ELI-NP GBS is a high intensity and monochromatic gamma source under construction in Magurele (Romania). The design and construction of the Gamma Beam System complex as well as the integration of the technical plants and the commissioning of the overall facility, was awarded to the Eurogammas Consortium in March 2014. The delivery of the facility has been planned in for 4 stages and the first one was fulfilled in October 31st 2015. The engineering aspects related to the delivery stage 1 are presented