Study of an Automatic System for Control of the Terminal Phase of Satellite Rendezvous

An analytical and simulation study has been conducted of an automatic system for control of the terminal phase of rendezvous between two space vehicles. The basic system employs switching and thrust orientation criteria based upon relative-motion parameters first to establish a collision course and then to reduce the range and range rate to zero, simultaneously. In addition, a technique has been devised by which the system effects control based upon the total amount of fuel available for this phase of the space mission. The onboard equipment assumed for the intercepting vehicle includes a special-purpose computer, an attitude-control system, a single main rocket engine with, multi-start capabilities, and sensors capable of measuring range, line-of sight angles, and the time derivatives of these quantities. Techniques are developed. for employing control with either modulated thrust or on-off thrust at a constant level. The results of an analog simulation study of the automatic control system in which a six-degree-of freedom vehicle is assumed are presented for various initial conditions at the beginning of the terminal phase. The results of the study indicate that the automatic system can effectively control the terminal phase of rendezvous over a wide range of initial conditions and control-system requirements and, in addition, can utilize the available fuel in a very efficient manner

Exploring the Impact of COVID-19 on Adults with Intellectual and Developmental Disabilities in the United States

Like most disasters, the COVID-19 pandemic has disproportionately impacted people from historically marginalized communities. People with intellectual and developmental disabilities (IDD) have faced higher rates of infection, hospitalization, and death compared to people without disabilities, as well as significant disruptions to the services that support them to participate in the community. A relative lack of research about the experiences of people with IDD may have contributed to this risk and continues to limit our understanding of the impacts of COVID-19. This three-paper dissertation is guided by the theory of epistemic injustice (Fricker, 2007) to understand the impacts of COVID-19 on people with IDD as they relate to broader questions about whether and to what degree people with IDD are included in research and policy. This dissertation supports prior literature that found that people with IDD have been uniquely and disproportionately impacted by the COVID-19 pandemic compared to people without disabilities and that epistemic injustice in research and policy may have contributed to these inequities. These findings suggest that future research at all levels must include people with IDD to ensure that they are considered in future public health emergencies

A study of swirling air flow in a converging nozzle

A study was conducted to determine the behavior of swirling air flow in a converging nozzle. Special instrumentation was constructed to obtain radial traverses of the flow at four axial positions. the data collected consisted of velocity, static pressure, and stagnation temperature. The flow pattern demonstrated the Ranque-Hilsh effect and reversed axial flow in the core region. As the flow entered the nozzle, it had the characteristics of a free vortex. At the exit plane the characteristics were those of a forced vortex. The converging nozzle caused an increase in the magnitude of the axial velocity component --Abstract, page ii

THE ROLE AND IMPACT OF SCHOOL NURSES AND INTENTIONS TO DELEGATE DIABETES-RELATED TASKS AMIDST BUDGET CUTS AND LEGISLATIVE CHANGES

As the percentage of school children with chronic conditions such as diabetes continues to rise, funding for school nurses to keep those students healthy and safe is decreasing. This dissertation includes three studies: (1) a systematic review of the literature on the role and impact of American elementary school nurses, (2) a focus group study that further examined the role of Kentucky school nurses and described their reaction to a new regulation that necessitates delegation of diabetes-related nursing tasks to unlicensed assistive personnel (UAP), and (3) a quantitative study that examined Kentucky school nurses’ past behaviors and future intentions regarding the delegation of diabetes-related tasks. A systematic review of the literature revealed that activities of school nurses can be conceptualized into four major areas: (a) health promotion and disease prevention; (b) triage and treatment of acute issues (e.g., injuries and infectious diseases); (c) management of chronic conditions; and (d) psychosocial support. School nursing activities are associated with increased attendance, higher quality schools, and cost savings. Focus groups in three regions of Kentucky found that Kentucky school nurses fulfill the same major roles as their counterparts across the nation, and face similar challenges such as lack of time, limited resources, language barriers, and communication issues with families. School nurse participants described their biggest impact on students as identifying and addressing students’ physical and psychosocial barriers to learning. While recent legislation was passed in Kentucky necessitating the delegation of insulin administration to UAP, school nurses had not experienced many changes at the time of the focus groups. However, some nurses said that their districts were not planning to delegate insulin administration and intended to keep a nurse in every school. Others appreciated the prospect of having more trained staff in schools to recognize signs of distress in chronically ill students. A statewide survey of 111 Kentucky school nurses indicated that nurses’ past delegation behaviors and future intentions related to delegation are rooted in the level of skilled decision-making that must occur and the risk to the student if the wrong decision is made. Unfortunately, school nurses’ intentions to delegate higher-stakes tasks (e.g. carbohydrate counting, insulin dose verification, and insulin administration) were significantly stronger than their support for (attitude related to) delegation of those tasks, which is disconcerting both for the safety of students as well as for the liability retained by delegating nurses. This disparity between support and intentions indicated that school nurses anticipate that they will have to delegate certain tasks to UAP despite their discomfort with delegating them, most likely due to high workload and lack of resources. Additional studies should be undertaken to determine the impact of legislative changes on the delivery of school health services in Kentucky and other states, particularly once school districts and nurses have had adequate time to adjust to new laws. Such studies should investigate to whom nurses are delegating health services, what tasks are being delegated, and the extent and process of training that UAP receive. Future surveys should utilize perceived behavioral control items that assess situational control (e.g. policy, workload) over delegation rather than, or in addition to, efficacy of individual skills required for delegation of nursing tasks. Researchers must further explore the discrepancies between attitude and intentions; that is, why are nurses planning to delegate tasks to UAP if they do not support the delegation of those tasks? Kentucky school nurses are champions of health promotion for children, not only in their provision of health services and health education, but also in the area of school health policy. School nurses should train UAP so that more school staff can recognize signs of distress in students with diabetes, but at the same time should continue to advocate and seek funding for a nurse in every school with the help of the Every Student Succeeds Act

Nebraska Forest Service: Your Christmas Tree

Trees are the centerpiece for many Christmas celebrations, but proper care is necessary to ensure the safety of your tree and other seasonal decorations. Keep the holidays merry by following some simple fire prevention tips to protect your family and home! Natural Trees; Artificial Trees; Lighting; Holiday Decoration