Morgan A. Walker

ORCID: 0000-0003-0383-4230
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About
Contact & Profiles
Research Areas
  • Zoonotic diseases and public health
  • Bacillus and Francisella bacterial research
  • Gas Dynamics and Kinetic Theory
  • Computational Fluid Dynamics and Aerodynamics
  • Aerodynamics and Fluid Dynamics Research
  • Wind and Air Flow Studies
  • Yersinia bacterium, plague, ectoparasites research
  • Rocket and propulsion systems research
  • Wildlife Ecology and Conservation
  • Reservoir Engineering and Simulation Methods
  • Archaeology and Natural History
  • Spinal Cord Injury Research
  • Congenital heart defects research
  • Hematological disorders and diagnostics
  • Animal Behavior and Reproduction
  • Analytical Chemistry and Sensors
  • Planetary Science and Exploration
  • Tumors and Oncological Cases
  • Fluid Dynamics and Vibration Analysis
  • Oil and Gas Production Techniques
  • Orthopedic Infections and Treatments
  • Proteoglycans and glycosaminoglycans research
  • Rangeland and Wildlife Management
  • Livestock Farming and Management
  • Advanced Sensor Technologies Research

University of Florida
2019-2023

Langley Research Center
2022-2023

University of North Carolina Health Care
2022

National Institute Of Hygiene And Epidemiology
2022

University of Tampa
2019

Western University
2018

Bristol Royal Infirmary
1983

Abstract Scavenging of carrion shapes ecological landscapes by influencing scavenger population demography, increasing inter- and intra-specific interactions, generating ecosystem services such as nutrient cycling disease moderation. Previous research found the cues promoting, or constraints limiting, an individual’s propensity ability to scavenge vary widely, depending on anthropogenic environmental factors. Here we investigated differences in scavenging patterns a complex guild...

10.1038/s41598-021-83426-3 article EN cc-by Scientific Reports 2021-02-19

Anthrax is a serious zoonosis caused by Bacillus anthracis, which primarily affects wild herbivorous animals with spillover into humans. The disease occurs nearly worldwide but poorly reported in Southeast Asian countries. In Vietnam, anthrax underreported, and little known about its temporal spatial distributions. This paper examines the spatio-temporal distribution epidemiological characteristics of human livestock from Dien Bien province, Vietnam 2010 to 2019. We also aim define role...

10.1371/journal.pntd.0010942 article EN cc-by PLoS neglected tropical diseases 2022-12-20

ABSTRACT. Anthrax, caused by Bacillus anthracis, has a nearly global distribution but is understudied in Southeast Asia, including Vietnam. Here, we used historical data from 1999 to 2020 Ha Giang, province northern The objectives were describe the spatiotemporal patterns and epidemiology of human livestock anthrax compare vaccine coverage with incidence. Annual incidence rates (per 10,000) for humans, buffalo/cattle, goats explore comparison annual variations. A subset describes humans...

10.4269/ajtmh.22-0384 article EN cc-by American Journal of Tropical Medicine and Hygiene 2023-01-23

View Video Presentation: https://doi.org/10.2514/6.2023-0423.vid A wind tunnel test was conducted at the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel to evaluate liftoff and transition flow environment of Space Launch System Block 1B launch vehicles tower interference effects with newly designed Mo- bile Launcher 2. This leveraged several unique diagnostic capabilities, including eight distributed force moment measurements on tiers, new umbilical crew access arm...

10.2514/6.2023-0423 article EN AIAA SCITECH 2022 Forum 2023-01-19

Vertical distribution of static ground wind loads was directly measured on Mobile Launcher support hardware to the NASA Space Launch System (SLS) at 1.75% scale in Langley Research Center 14- by 22-Foot Subsonic Tunnel. Low-speed tunnel testing liftoff phase flight conducted for SLS Block 1B family rockets with their associated systems. Improved methods measuring and estimating launch tower assembly are introduced detail. A novel, distributed measurement technique is compared against...

10.2514/6.2023-0424 article EN AIAA SCITECH 2022 Forum 2023-01-19

View Video Presentation: https://doi.org/10.2514/6.2022-3666.vid In many aerodynamic measurement applications, the ability to make time-accurate measurements with pressure scanners provides practical advantages over making same directly using flush-mounted transducers. However, pneumatic distortion due tubing between sensing module and surface port limits usefulness of such averaged, steady data only. This issue has restricted application for unsteady in wind tunnel flight-testing...

10.2514/6.2022-3666 article EN AIAA Aviation 2019 Forum 2022-06-20

Transonic, high Reynolds number wind tunnel testing for the Space Launch System (SLS) ascent flight environment was conducted in National Transonic Facility (NTF) at NASA Langley Research Center from December 2019 to April 2021. The test sponsored by SLS Program and Engineering & Safety with objective of assessing characterizing effects on aerodynamics launch vehicle. cryogenic article a 1.75%-scale representation Block 1 Cargo configuration that fabricated mostly out stainless steel, but...

10.2514/6.2023-0425 article EN AIAA SCITECH 2022 Forum 2023-01-19

Loss of function after spinal cord injury (SCI) results from the primary that causes interruption axonal tracts, neuronal and glial cell death, secondary in which inflammation drives lesion expansion, further loss gray white matter. There are two main therapeutic strategies for treatment SCI: pro-reparative sprouting aim to promote functional recovery through enhancing plasticity spared axons neuroprotection/anti-inflammatory decrease injury. Chondroitin sulfate proteoglycans (CSPGs) matrix...

10.1089/neu.2018.5928 article EN Journal of Neurotrauma 2018-08-03

Landing on an aircraft carrier is a difficult maneuver involving aircraft, moving deck, and complex arresting system that stops the plane in less than four seconds. Furthermore, modeling of landing gear due to interactions between many complicated, nonlinear subsystems. Capturing these essential providing realistic simulation can be used for pilot training detailed design analysis. SDI Engineering has developed GearSim, software tool, recently adapted it simulations. This program contains...

10.2514/6.2020-1138 article EN AIAA SCITECH 2022 Forum 2020-01-05

Anthrax is a priority zoonosis for control in Vietnam. The geographic distribution of anthrax remains to be defined, challenging our ability target areas control. We analyzed human cases Vietnam obtain incidence at the national and provincial level. Nationally, trendline remained ≈61 cases/year throughout 26 years available data, indicating efforts are not effectively reducing disease burden over time. Most occurred Northern Midlands Mountainous regions, provinces Lai Chau, Dien Bien, Lao...

10.3201/eid2811.212584 article EN cc-by Emerging infectious diseases 2022-10-26

Environmentally mediated indirect pathogen transmission is linked to host movement and foraging in areas where pathogens are maintained the environment. In case of anthrax, spores causative bacterium Bacillus anthracis released into environment following death create locally infectious zones (LIZs) around carcass sites; by grazing at LIZs, herbivores potentially exposed spores. Here, we used camera traps assess how ungulate species use sites southwestern Montana evaluated these behaviours...

10.1098/rsos.200246 article EN cc-by Royal Society Open Science 2020-10-01

View Video Presentation: https://doi.org/10.2514/6.2023-0426.vid A high Reynolds number test of the Space Launch System was performed at NASA Langley National Transonic Facility (NTF). The objective to use cryogenic testing capabilities NTF acquire data over largest range numbers possible with a specific focus on closest flight conditions. Mach from 0.50 0.95, which corresponds ascent portion for SLS vehicle. Force and moment showed that pitching yawing moments were sensitive effects full...

10.2514/6.2023-0426 article EN AIAA SCITECH 2022 Forum 2023-01-19

View Video Presentation: https://doi.org/10.2514/6.2022-3665.vid Time-averaged global force and moment measurements in wind tunnel tests can obscure complex flow dynamics, including bistability phenomena. This paper presents a detailed analysis into the potential cause of previously unobserved discrepancies among repeat runs during 2021 14- by 22-Foot Subsonic Tunnel test Space Launch System. During test, it was observed that liftoff configuration repeatability not as strong expected when...

10.2514/6.2022-3665 article EN AIAA Aviation 2019 Forum 2022-06-20

(1) Background: Burkholderia pseudomallei is an environmentally mediated saprophytic pathogen that can cause severe disease in humans. It well known B. survives tropical moist soil environments worldwide, but melioidosis gaining recognition as a public and veterinary health issue Vietnam. The contribution of animals to human unknown, necessitating further investigation. (2) Methods: Swine sera were collected from two populations, one grazing commercially farmed, three provinces ELISAs...

10.3390/ijerph17145203 article EN International Journal of Environmental Research and Public Health 2020-07-18

Common practice in the Mid-Continent until recently was to prolong thenatural flow of oil wells as long possible by agitation and then swab for ashort period well put on pump. Comparatively thegas-lift has superseded swabbing agitating some casesencroached natural flowing life, particularly where it evident thatthe potential capacity greater than gas supply, orlifting medium. The majority are finished with either 61/4, 6 5/8 or 81/4-in. casingand connected a separator through line which is...

10.2118/930233-g article EN Transactions of the AIME 1930-12-01

This paper presents a new workflow for comparing experimental pressure-sensitive paint (PSP) data to computational fluid dynamic (CFD) simulations by way of mapping from corresponding surface grids utilizing interpolation methods. In addition generating quantitative and qualitative point-to-point comparisons between PSP CFD data, this extracts sectional loading both generates lineload comparison charts runs. Experimental presented in were 2016 test the NASA Space Launch System 11- 11-Foot...

10.2514/6.2022-0431 article EN AIAA SCITECH 2022 Forum 2022-01-03

View Video Presentation: https://doi.org/10.2514/6.2022-3667.vid A 1.75%-scale model of the NASA Space Launch System Block 1B Cargo vehicle was tested at Langley Research Center 14- by 22-Foot Subsonic Tunnel. These experiments provided a test bed for validating unsteady surface pressure measurements acquired via lengths tubing and an ESP scanner. Pressure measured using azimuthal array taps located on nose vehicle. Unique flow physics were observed in wind tunnel test, especially...

10.2514/6.2022-3667 article EN AIAA Aviation 2019 Forum 2022-06-20

During development of an aerodynamic database to cover ground wind loads, uncertainty quantification account for the Coandă effect forced a closer look into how this phenomenon manifests on Space Launch System. Aerodynamic data collected across life program are explored trends and ability characterize not just bounds forces moments but also better understand their distributions. Experimental in NASA Langley 14- by 22-Foot Subsonic Tunnel used explore integrated moments. This is followed up...

10.2514/6.2023-0648 article EN AIAA SCITECH 2022 Forum 2023-01-19
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