Performance and test section flow characteristics of the National Full-Scale Aerodynamics Complex 80- by 120-Foot Wind Tunnel

Results from the performance and test section flow calibration of the 80- by 120-Foot Wind Tunnel are presented. Measurements indicating the 80- by 120-ft test section flow quality were obtained throughout the tunnel operational envelope and for atmospheric wind speeds up to approximately 20 knots. Tunnel performance characteristics and a dynamic pressure system calibration were also documented during the process of mapping the test section flow field. Experimental results indicate that the test section flow quality is relatively insensitive to dynamic pressure and the level of atmospheric winds experienced during the calibration. The dynamic pressure variation in the test section is within +/-75 percent of the average. The axial turbulence intensity is less than 0.5 percent up to the maximum test section speed of 100 knots, and the vertical and lateral flow angle variations are within +/-5 deg and +/-7 deg, respectively. Atmospheric winds were found to affect the pressure distribution in the test section only at high ratios of wind speed to test section speed

Performance and test section flow characteristics of the National Full-Scale Aerodynamics Complex 40- by 80-foot wind tunnel

Results from the performance and test section flow calibration of the 40- by 80-Foot Wind Tunnel are presented. A flow calibration test was conducted in May and June 1987. The goal of the flow calibration test was to determine detailed spatial variations in the 40- by 80-ft test section flow quality throughout the tunnel operational envelope. Data were collected for test section speeds up to 300 knots and for air exchange rates of 0, 5, and 10 percent. The tunnel performance was also calibrated during the detailed mapping of the test section flow field. Experimental results presented indicate that the flow quality in the test section, with the exception of temperature, is relatively insensitive to the level of dynamic pressure and the air exchange rate. The dynamic pressure variation in the test section is within + or - 0.5 deg at all test section velocities. Cross-stream temperature gradients in the test section caused by the air exchange system were documented, and a correction method was established. Streamwise static pressure variation on the centerline is about 1 percent of test section dynamic pressure over 30 ft of the test section length

Aerodynamic surface distension system for high angle of attack forebody vortex control

A deployable system is introduced for assisting flight control under certain flight conditions, such as at high angles of attack, whereby two inflatable membranes are located on the forebody portion of an aircraft on opposite sides thereof. The members form control surfaces for effecting lateral control forces if one is inflated and longitudinal control forces if both are inflated

Flow direction measurement criteria and techniques planned for the 40- by 80-/80- x 120-foot wind tunnel integrated systems tests

A study was performed in order to develop the criteria for the selection of flow direction indicators for use in the Integrated Systems Tests (ISTs) of the 40 by 80/80 by 120 Foot Wind Tunnel System. The problems, requirements, and limitations of flow direction measurement in the wind tunnel were investigated. The locations and types of flow direction measurements planned in the facility were discussed. A review of current methods of flow direction measurement was made and the most suitable technique for each location was chosen. A flow direction vane for each location was chosen. A flow direction vane that employs a Hall Effect Transducer was then developed and evaluated for application during the ISTs

Topological complexity of the relative closure of a semi-Pfaffian couple

Gabrielov introduced the notion of relative closure of a Pfaffian couple as an alternative construction of the o-minimal structure generated by Khovanskii's Pfaffian functions. In this paper, use the notion of format (or complexity) of a Pfaffian couple to derive explicit upper-bounds for the homology of its relative closure. Keywords: Pfaffian functions, fewnomials, o-minimal structures, Betti numbers.Comment: 12 pages, 1 figure. v3: Proofs and bounds have been slightly improve

Exploring the functional domain and the target of the tetanus toxin light chain in neurohypophysial terminals

The tetanus toxin light chain blocks calcium induced vasopressin release from neurohypophysial nerve terminals. Here we show that histidine residue 233 within the putative zinc binding motif of the tetanus toxin light chain is essential for the inhibition of exocytosis, in the rat. The zinc chelating agent dipicolinic acid as well as captopril, an inhibitor of zinc-dependent peptidases, counteract the effect of the neurotoxin. Synthetic peptides, the sequences of which correspond to motifs present in the cytoplasmic domain of the synaptic vesicle membrane protein synaptobrevin 1 and 2, prevent the effect of the tetanus toxin light chain. Our results indicate that zinc bound to the zinc binding motif constitutes the active site of the tetanus toxin light chain. Moreover they suggest that cleavage of synaptobrevin by the neurotoxin causes the inhibition of exocytotic release of vasopressin from secretory granules

Efficient extraction of canonical spatial relationships using a recursive enumeration of k-subsets

The spatial arrangement of a chemical compound plays an important role regarding the related properties or activities. A straightforward approach to encode the geometry is to enumerate pairwise spatial relationships between k substructures, like functional groups or subgraphs. This leads to a combinatorial explosion with th

Exploratory study of the underutilization of CTSA module services

Background/Objective: The Clinical and Translational Science Award (CTSA) program aims to enhance the quality, efficiency, and impact of translation from discovery to interventions that improve human health. CTSA program hubs at medical research institutions across the United States develop and test innovative tools, methods, and processes, offering core resources and training for the clinical and translational research (CTR) workforce. Hubs have developed services across different domains, such as informatics and pilot studies, to provide ad hoc expertise and staffing for local research teams. Although these services can provide efficient, cost-effective ways to cover skills gaps and implement rigorous studies, three CTSAs of varying size found the majority of investigators were single domain service users, likely missing opportunities to further enhance their work. Methods: Through interviews with CTSA service users and a survey of CTSA service managers, this exploratory study aims to identify barriers to using services from multiple modules and solutions to overcome those barriers. Results: Barriers include challenges in finding information about services, unclear or unknown user needs, and users’ lack of funding to engage in services. More issues were identified for the largest CTSA. Conclusions: Although this study represents a small subset of CTSA hubs, we anticipate that our findings and proposed solutions will be relevant to the broader CTSA community. This study provides foundational information can use in their own efforts to increase service utilization and methods that can be used for more comprehensive studies that focus on explaining the relationship between CTSA features and rates of single versus cross-module service use.Peer Reviewe

Модификация оптических свойств двумерных материалов лазерной обработкой и плазмонными наночастицами

Практическая ценность исследований состоит в разработке масштабируемого и недорогого процесса обработки 2D материалов, который может применяться в разработке фотонных и электронных компонентовA practical value of the work is the development of a scalable and cheap processing method for 2D materials that can be applied in a production of photonic and electronic component