Tank Tests of a Model of One Hull of the Savoia S-55-X Flying Boat N.A.C.A. Model 46

A model of one of the twin hulls of the Italian Savoia S-55-X flying boat (N.A.C.A. Model 46) was tested in the N.A.C.A. tank according to the general method. The data obtained from these tests cover a broad range of speeds, loads, and trims and are given in nondimensional form to facilitate their use in applying this form of hull to any other flying boat or comparing it's performance with the performance of any other hulls. The results show that the resistance characteristics at best trim of this model are excellent throughout the speed range. In order to compare the performance of the S-55-X hull with that of the 35, a pointed-step hull developed at the N.A.C.A. tank, the data are used in the computations of take-off example of a twin-hull, 23,500-pound flying boat. The calculations show that the S-55-X hull has better take-off performance

The Effect of the Angle of Afterbody Keel on the Water Performance of a Flying-Boat Hull Model

NACA model 11-C was tested according to the general method with the angle of afterbody keel set at five different angles from 2-1/2 degrees to 9 degrees, but without changing other features of the hull. The results of the tests are expressed in curves of test data and of non-dimensional coefficients. At the depth of step used in the tests, 3.3 percent beam, the smaller angles of afterbody keel give greater load-resistance ratios at the hump speed and smaller at high speed than the larger angles of afterbody keel. Comparisons are made of the load-resistance ratios at several other points in the speed range. The effect of variation of the angle of afterbody keel upon the take-off performance of a hypothetical flying boat of 15,000 pounds gross weight having a hull of model 11-C lines is calculated, and the calculations show that the craft with the largest of the angles of afterbody keel tested, 9 degrees, takes off in the least time and distance

Tanks Test of a Model of the Hull of the Navy PB-1 Flying Boat - N.A.C.A. Model 52

A model of the hull of the Navy PB-1 flying boat was tested in the N.A.C.A. tank as part of a program intended to provide information regarding the water performance of hulls of flying boats of earlier design for which hydrodynamic data have heretofore been unavailable. Tests were made according to the general method over the range of practical loadings with the model both fixed in trim and free to trim. A free-to-trim test according to the specific method was also made for the design load and take-off speed corresponding to those of the full-scale flying boat. The resistance obtained from the fixed-trim test was found to be about the same as that of the model of the NC flying-boat hull, and greater at the hump but smaller at high speeds than that of a model of the Sikorsky S-40 flying-boat hull

Quantum effects in the diffusion of hydrogen on Ru(0001)

An understanding of hydrogen diffusion on metal surfaces is important, not just for its role in heterogeneous catalysis and hydrogen fuel cell technology, but also because it provides model systems where tunneling can be studied under well-defined conditions. Here we report helium spin-echo measurements of the atomic-scale motion of hydrogen on the Ru(0001) surface between 75 and 250 K. Quantum effects are evident at temperatures as high as 200 K, while below 120 K we observe a tunneling-dominated temperature independent jump rate of 1.9$\times$10$^9$ s$^{-1}$, many orders of magnitude faster than previously seen. Quantum transition state theory calculations based on ab initio path-integral simulations reproduce the temperature dependence of the rate at higher temperatures and predict a crossover to tunneling-dominated diffusion at low temperatures, although the tunneling rate is under-estimated, highlighting the need for future experimental and theoretical studies of hydrogen diffusion on well-defined surfaces.Comment: 15 pages, 3 figure

Amphioxus (Branchiostoma floridae) has orthologs of vertebrate odorant receptors

<p>Abstract</p> <p>Background</p> <p>A common feature of chemosensory systems is the involvement of G protein-coupled receptors (GPCRs) in the detection of environmental stimuli. Several lineages of GPCRs are involved in vertebrate olfaction, including trace amine-associated receptors, type 1 and 2 vomeronasal receptors and odorant receptors (ORs). Gene duplication and gene loss in different vertebrate lineages have lead to an enormous amount of variation in OR gene repertoire among species; some fish have fewer than 100 OR genes, while some mammals possess more than 1000. Fascinating features of the vertebrate olfactory system include allelic exclusion, where each olfactory neuron expresses only a single OR gene, and axonal guidance where neurons expressing the same receptor project axons to common glomerulae. By identifying homologous ORs in vertebrate and in non-vertebrate chordates, we hope to expose ancestral features of the chordate olfactory system that will help us to better understand the evolution of the receptors themselves and of the cellular components of the olfactory system.</p> <p>Results</p> <p>We have identified 50 full-length and 11 partial ORs in <it>Branchiostoma floridae</it>. No ORs were identified in <it>Ciona intestinalis</it>. Phylogenetic analysis places the <it>B. floridae </it>OR genes in a monophyletic clade with the vertebrate ORs. The majority of OR genes in amphioxus are intronless and many are also tandemly arrayed in the genome. By exposing conserved amino acid motifs and testing the ability of those motifs to discriminate between ORs and non-OR GPCRs, we identified three OR-specific amino acid motifs common in cephalochordate, fish and mammalian and ORs.</p> <p>Conclusion</p> <p>Here, we show that amphioxus has orthologs of vertebrate ORs. This conclusion demonstrates that the receptors, and perhaps other components of vertebrate olfaction, evolved at least 550 million years ago. We have also identified highly conserved amino acid motifs that may be important for maintaining receptor conformation or regulating receptor activity. We anticipate that the identification of vertebrate OR orthologs in amphioxus will lead to an improved understanding of OR gene family evolution, OR gene function, and the mechanisms that control cell-specific expression, axonal guidance, signal transduction and signal integration.</p

Tank Tests of Models of Flying Boat Hulls Having Longitudinal Steps

Four models with longitudinal steps on the forebody were developed by modification of a model of a conventional hull and were tested in the National Advisory Committee for Aeronautics (NACA) tank. Models with longitudinal steps were found to have smaller resistance at high speed and greater resistance at low speed than the parent model that had the same afterbody but a conventional V-section forebody. The models with a single longitudinal step had better performance at hump speed and as low high-speed resistance except at very light loads. Spray strips at angles from 0 degrees to 45 degrees to the horizontal were fitted at the longitudinal steps and at the chine on one of the two step models having two longitudinal steps. The resistance and the height of the spray were less with each of the spray strips than without; the most favorable angle was found to lie between 15 degrees and 30 degrees

Fight On, Fight On for Ole Jax State: Houston Cole Library\u27s Historical Collections Highlight JSU\u27s Resiliency During Its First Pandemic

This document highlights some of the Houston Cole Library\u27s archival materials as they relate to the Jacksonville State Normal School during the Spanish Flu Pandemic of 1918-1919. The authors examine events in the greater context of Alabama and other institutions of higher education, and focus on how JSNS responded to its first pandemic.https://digitalcommons.jsu.edu/lib_ac_unihist_misc/1006/thumbnail.jp

Further Correlations of Cell Metabolism and Resistance to Tuberculosis: Studies on Mononuclear Peritoneal Exudate Cells from Mice and Guinea Pigs

The metabolic activity of mononuclear exudate cells from mice of different strains, and from the guinea pig, have been compared to the rabbit with the aim of relating metabolic activity of these cells to resistance of these species to tuberculosis. The presence of mast cells in the peritoneal exudates of mice was thought to interfere with the dehydrogenation of certain substrates due to the release of histamine. Some experimental evidence presented by the authors seems to support this thesis