Development and Implementation of Improved External Balance Load Measurements

The Texas A&M Oran W. Nicks Low Speed Wind Tunnel (LSWT) uses a large pyramidal-type external force balance to measure aerodynamic loads. This balance was designed and constructed in the 1940s and measures the six wind frame aerodynamic forces and moments through a system of levers and pushrods that terminate in six movable poise weights and individual analog controllers. These systems were updated in the mid 1970s to use vacuum tubes, double wound motors, rotary encoders, and analog linear potentiometers. Although antiquated, these analog components provide outstanding sensitivity and linearity. However, the fragility, tight tuning margins, and overall age of the system has proven troublesome for the LSWT. The objective of this thesis is to design, implement, and provide a preliminary calibration of new measurement electronics that improve sensor reaction time, robustness, and ease of use while taking advantage of existing mechanical structure. This updated system must meet certain minimum requirements, namely, it must be at least as accurate as the original system, it must react more quickly to disturbances, and it must enable straightforward future upgrades. To achieve these objectives, two different approaches were investigated. These were: first, a PID digital controller to act as a modernized version of the existing analog control system, and second, commercially available load cells placed in line within the pushrods directly connected to the balances. The commercial load cell approach was selected for implementation. This upgrade scheme resulted in an improvement on the accuracy, settling time, reliability, and serviceability of the existing system while eliminating one of its largest sources of hysteresis. Additionally, total reversion to the original analog system is still readily possible on short notice, should a problem with the new system arise

Incorporating science-based approaches into the rapid assessment of wetlands and streams : validation, restoration trajectory, and method development

Human alterations within wetlands and streams have resulted in a decrease in ecological functions and associated benefits to society. The scientific literature highlights the functional benefits provided by ecosystems including flood protection, nutrient cycling, and habitat maintenance. Additionally, legislation and regulatory policy require mitigation and restoration as compensation for declines in ecological functions. As a result, the need for practical, repeatable, and technically sound ecosystem assessment methods remains essential to natural resource management. However, few studies determine the validity of rapid assessment approaches by applying quantitative parameters, especially with respect to biogeochemical functions. We assessed biogeochemical functions applied to restored wetlands in the Mississippi River Valley, USA. Significantly higher rapid assessment outcomes were associated with increased ecosystem functionality (r=0.64-0.86). Findings suggest that rapid assessment tools serve as reliable proxies for measurements of nutrient and biogeochemical cycling. Further, a framework for identifying restoration trajectory metrics was established, with four rapid assessment variables yielded positive restoration trajectories within \u3c20 years (r = 0.59-0.89). Rapid assessment components were classified as rapid response, response, and stable variables categories and restoration milestones should focus on rapid response variables. In order to evaluate rapid ecological assessment in different environments, we examined proxy measures of biogeochemical function in headwater stream systems. Biogeochemical cycling proxies of C and N input and processing significantly, positively correlated with the results of a rapid assessment approach (r = 0.64-0.81). Also, stream loading equations demonstrate that N and P transport, sediment, conductivity, and temperature significantly, negatively correlated with rapid assessment scores (r = -0.56-0.81). Significant differences in nutrient processing, stream loading, water quality, and rapid xii assessment results were also observed between headwater streams located in recently altered (e.g., mined) and older second growth forested catchments (U = 0.01-0.24). Findings indicate that rapid assessment scores respond to a combination of alteration type and recovery time. An analysis examining the time and economic requirements of biogeochemical proxy measurements highlights the benefits of rapid assessment methods in evaluating biogeochemical functions. Based on these findings, a technical standard for rapid ecological assessment was developed. The technical standard establishes nine testable components that promote validity and defensibility in the development and application of rapid ecological assessment approaches

Defining Bone Health and Fracture Risk in West Virginia: The World Health Organization FRAX® Assessment Tool

This article highlights the expanding burden of osteoporosis in West Virginia. WV ranks second nationally in the percentage of its population that is ≥ 65 years of age. Our older population increases the risk of osteoporosis and fracture; the most recent data indicates that 77% of our women age 50 and older have osteoporosis or low bone mass. The lifetime risk of osteoporotic related fracture is alarming and occurs in 50% of females and 25% of males age 50 and older. The risk of osteoporosis related hip fracture in women is equal to the combined risk of breast, uterine or ovarian cancer with the annual risk of osteoporotic fracture greater than the combined risk of breast cancer, stroke and heart attack. Detecting individuals at risk for fracture has been aided by an internationally validated fracture prediction tool from the World Health Organization -- FRAX®. The FRAX® tool can be incorporated into protocols to help minimize barriers to effective osteoporosis screening and treatment in WV

Situational Awareness based Risk-Adapatable Access Control in Enterprise Networks

As the computing landscape evolves towards distributed architectures such as Internet of Things (IoT),enterprises are moving away from traditional perimeter based security models toward so called zero trust networking (ZTN) models that treat both the intranet and Internet as equally untrustworthy. Such security models incorporate risk arising from dynamic and situational factors, such as device location and security risk level risk, into the access control decision. Researchers have developed a number of risk models such as RAdAC (Risk Adaptable Access Control) to handle dynamic contexts and these have been applied to medical and other scenarios. In this position paper we describe our ongoing work to apply RAdAC to ZTN. We develop a policy management framework, FURZE, to facilitate fuzzy risk evaluation that also defines how to adapt to dynamically changing contexts. We also consider how enterprise security situational awareness (SSA) - which describes the potential impact to an organisations mission based on the current threats and the relative importance of the information asset under threat - can be incorporated into a RAdAC schemeComment: 6 page

Interference in White Bass Reproduction by Two Introduced Predators in Barren River Lake, Kentucky

White bass Morone chrysops are native to the Mississippi River and its tributaries. This range includes the Barren River in south central Kentucky. Over the last thirty years, the population of white bass in Barren River Lake, a reservoir of the Barren River, has been in decline. During that same time, two congeners of white bass have been introduced to the lake. Hybrid striped bass Morone chrysops × Morone saxatilis were introduced in 1979 and yellow bass Morone mississippiensis were first discovered in 2000. Due to the similar life histories and spawning strategies of all three Morone species, I hypothesized that the two introduced species are interfering with reproduction of the native white bass. In the springs of 2012 and 2013 I sampled fish from within a five kilometer stretch of Barren River upstream of the lake. I collected 144 white bass, 111 yellow bass and 29 hybrid striped bass. Detection of species at spawning sites was staggered with yellow bass and hybrid striped bass arriving after white bass but leading to a period of co-occurrence. White bass on the spawning sites appeared healthy: fecundity (75,200 to 741,150 eggs per female), mean gonadosomatic indices (peaked at 10.7% and 23.7% in sequential years), mean relative weight (93.8), and length at age (above the 50th percentile). Of the yellow bass stomachs examined, 21.6% contained fish eggs or larval fish. Based on arrival times and evidence of egg and larval fish predation, it is likely that yellow bass are directly impacting white bass spawning success through reproductive interference and the consumption of white bass offspring. Schoener’s index values revealed a significant degree of dietary overlap between white bass and yellow bass in larval fish, post larval fish, and arthropods (Cxy = 0.992,0.994, and 0.804, respectively), and between white bass and hybrid striped bass in arthropods (Cxy = 0.851). Information from this study may elucidate causes of the declining white bass population and aid in its management in Barren River Lake

Development and Implementation of Improved External Balance Load Measurements

The Texas A&M Oran W. Nicks Low Speed Wind Tunnel (LSWT) uses a large pyramidal-type external force balance to measure aerodynamic loads. This balance was designed and constructed in the 1940s and measures the six wind frame aerodynamic forces and moments through a system of levers and pushrods that terminate in six movable poise weights and individual analog controllers. These systems were updated in the mid 1970s to use vacuum tubes, double wound motors, rotary encoders, and analog linear potentiometers. Although antiquated, these analog components provide outstanding sensitivity and linearity. However, the fragility, tight tuning margins, and overall age of the system has proven troublesome for the LSWT. The objective of this thesis is to design, implement, and provide a preliminary calibration of new measurement electronics that improve sensor reaction time, robustness, and ease of use while taking advantage of existing mechanical structure. This updated system must meet certain minimum requirements, namely, it must be at least as accurate as the original system, it must react more quickly to disturbances, and it must enable straightforward future upgrades. To achieve these objectives, two different approaches were investigated. These were: first, a PID digital controller to act as a modernized version of the existing analog control system, and second, commercially available load cells placed in line within the pushrods directly connected to the balances. The commercial load cell approach was selected for implementation. This upgrade scheme resulted in an improvement on the accuracy, settling time, reliability, and serviceability of the existing system while eliminating one of its largest sources of hysteresis. Additionally, total reversion to the original analog system is still readily possible on short notice, should a problem with the new system arise

Robert F. Durden Correspondence

Entries include a handwritten letter on Duke University, Department of History, stationery