Wind Tunnel Results of the Aerodynamic Performance of a 1/8-Scale Model of a Twin-Engine Transport with Multi-Element Wing

A wind tunnel investigation was performed in the 14- by 22-Foot Subsonic Tunnel on a pressure instrumented 1/8-scale twin-engine subsonic transport to better understand the flow physics on a multi-element wing section. The wing consisted of a part-span, triple-slotted trailing edge flap, inboard leading-edge Krueger flap and an outboard leading-edge slat. The model was instrumented with flush pressure ports at the fuselage centerline and seven spanwise wing locations. The model was tested in cruise, take-off and landing configurations at dynamic pressures and Mach numbers from 10 lbf/ft(exp 2) to 50 lbf/ft(exp 2) and 0.08 to 0.17, respectively. This resulted in corresponding Reynolds numbers of 0.8 x 10(exp 5) to 1.8 x 10(exp 6). Pressure data were collected using electronically scanned pressure devices and force and moment data were collected with a six component strain gauge balance. Results are presented for various control surface deflections over an angle-of-attack range from -4 degrees to 16 degrees and sideslip angle range from -10 degrees to 10 degrees. Longitudinal and lateral directional aerodynamic data are presented as well as chordwise pressure distributions at the seven spanwise wing locations and the fuselage centerline

Subsonic aerodynamic characteristic of semispan commercial transport model with wing-mounted advanced ducted propeller operating in reverse thrust

A test was conducted in the Langley 14 by 22 Foot Subsonic Tunnel to determine the effect of the reverse-thrust flow field of a wing-mounted advanced ducted propeller on the aerodynamic characteristics of a semispan subsonic high-lift transport model. The advanced ducted propeller (ADP) model was mounted separately in position alongside the wing so that only the aerodynamic interference of the propeller and nacelle affected the aerodynamic performance of the transport model. Mach numbers ranged from 0.14 to 0.26; corresponding Reynolds numbers ranged from 2.2 to 3.9 x 10(exp 6). The reverse-thrust flow field of the ADP shielded a portion of the wing from the free-stream airflow and reduced both lift and drag. The reduction in lift and drag was a function of ADP rotational speed and free-stream velocity. Test results included ground effects data for the transport model and ADP configuration. The ground plane caused a beneficial increase in drag and an undesirable slight increase in lift. The ADP and transport model performance in ground effect was similar to performance trends observed for out of ground effect. The test results form a comprehensive data set that supports the application of the ADP engine and airplane concept on the next generation of advanced subsonic transports. Before this investigation, the engine application was predicted to have detrimental ground effect characteristics. Ground effect test measurements indicated no critical problems and were the first step in proving the viability of this engine and airplane configuration

Effect of a Pre-Dinner Walnut Snack on Nutrient Intake Among University Students

https://openriver.winona.edu/urc2018/1021/thumbnail.jp

An examination of protist diversity in serpentinization-hosted ecosystems of the Samail Ophiolite of Oman

In the Samail Ophiolite of Oman, the geological process of serpentinization produces reduced, hydrogen rich, hyperalkaline (pH > 11) fluids. These fluids are generated through water reacting with ultramafic rock from the upper mantle in the subsurface. On Earth’s continents, serpentinized fluids can be expressed at the surface where they can mix with circumneutral surface water and subsequently generate a pH gradient (∼pH 8 to pH > 11) in addition to variations in other chemical parameters such as dissolved CO2, O2, and H2. Globally, archaeal and bacterial community diversity has been shown to reflect geochemical gradients established by the process of serpentinization. It is unknown if the same is true for microorganisms of the domain Eukarya (eukaryotes). In this study, using 18S rRNA gene amplicon sequencing, we explore the diversity of microbial eukaryotes called protists in sediments of serpentinized fluids in Oman. We demonstrate that protist community composition and diversity correlate significantly with variations in pH, with protist richness being significantly lower in sediments of hyperalkaline fluids. In addition to pH, the availability of CO2 to phototrophic protists, the composition of potential food sources (prokaryotes) for heterotrophic protists and the concentration of O2 for anaerobic protists are factors that likely shape overall protist community composition and diversity along the geochemical gradient. The taxonomy of the protist 18S rRNA gene sequences indicates the presence of protists that are involved in carbon cycling in serpentinized fluids of Oman. Therefore, as we evaluate the applicability of serpentinization for carbon sequestration, the presence and diversity of protists should be considered

The Gut Fungus Basidiobolus ranarum Has a Large Genome and Different Copy Numbers of Putatively Functionally Redundant Elongation Factor Genes

Fungal genomes range in size from 2.3 Mb for the microsporidian Encephalitozoon intestinalis up to 8000 Mb for Entomophaga aulicae, with a mean genome size of 37 Mb. Basidiobolus, a common inhabitant of vertebrate guts, is distantly related to all other fungi, and is unique in possessing both EF-1α and EFL genes. Using DNA sequencing and a quantitative PCR approach, we estimated a haploid genome size for Basidiobolus at 350 Mb. However, based on allelic variation, the nuclear genome is at least diploid, leading us to believe that the final genome size is at least 700 Mb. We also found that EFL was in three times the copy number of its putatively functionally overlapping paralog EF-1α. This suggests that gene or genome duplication may be an important feature of B. ranarum evolution, and also suggests that B. ranarum may have mechanisms in place that favor the preservation of functionally overlapping genes

Estimating Design Effect and Calculating Sample Size for Respondent-Driven Sampling Studies of Injection Drug Users in the United States

Respondent-driven sampling (RDS) has become increasingly popular for sampling hidden populations, including injecting drug users (IDU). However, RDS data are unique and require specialized analysis techniques, many of which remain underdeveloped. RDS sample size estimation requires knowing design effect (DE), which can only be calculated post hoc. Few studies have analyzed RDS DE using real world empirical data. We analyze estimated DE from 43 samples of IDU collected using a standardized protocol. We find the previous recommendation that sample size be at least doubled, consistent with DE = 2, underestimates true DE and recommend researchers use DE = 4 as an alternate estimate when calculating sample size. A formula for calculating sample size for RDS studies among IDU is presented. Researchers faced with limited resources may wish to accept slightly higher standard errors to keep sample size requirements low. Our results highlight dangers of ignoring sampling design in analysis

Distribution and Phylogeny of EFL and EF-1α in Euglenozoa Suggest Ancestral Co-Occurrence Followed by Differential Loss

BACKGROUND: The eukaryotic elongation factor EF-1alpha (also known as EF1A) catalyzes aminoacyl-tRNA binding by the ribosome during translation. Homologs of this essential protein occur in all domains of life, and it was previously thought to be ubiquitous in eukaryotes. Recently, however, a number of eukaryotes were found to lack EF-1alpha and instead encode a related protein called EFL (for EF-Like). EFL-encoding organisms are scattered widely across the tree of eukaryotes, and all have close relatives that encode EF-1alpha. This intriguingly complex distribution has been attributed to multiple lateral transfers because EFL's near mutual exclusivity with EF-1alpha makes an extended period of co-occurrence seem unlikely. However, differential loss may play a role in EFL evolution, and this possibility has been less widely discussed. METHODOLOGY/PRINCIPAL FINDINGS: We have undertaken an EST- and PCR-based survey to determine the distribution of these two proteins in a previously under-sampled group, the Euglenozoa. EF-1alpha was found to be widespread and monophyletic, suggesting it is ancestral in this group. EFL was found in some species belonging to each of the three euglenozoan lineages, diplonemids, kinetoplastids, and euglenids. CONCLUSIONS/SIGNIFICANCE: Interestingly, the kinetoplastid EFL sequences are specifically related despite the fact that the lineages in which they are found are not sisters to one another, suggesting that EFL and EF-1alpha co-occurred in an early ancestor of kinetoplastids. This represents the strongest phylogenetic evidence to date that differential loss has contributed to the complex distribution of EFL and EF-1alpha