Thermal control for mobile packages in the dusty lunar environment

Dual surface configurations illustrating thermal protection concepts to improve performance of simple radiative surfaces in mobile, dusty, lunar environment

Flow losses in flexible hose, volume 1 Final report

Empirical method for predicting flow loss of gas or liquid in flexible hose

Opportunistic detection of atrial fibrillation using blood pressure monitors: a systematic review

Background: Atrial Fibrillation (AF) affects around 2% of the population and early detection is beneficial, allowing patients to begin potentially life-saving anticoagulant therapies. Blood pressure (BP) monitors may offer an opportunity to screen for AF. Aim: To identify and appraise studies which report the diagnostic accuracy of automated BP monitors used for opportunistic AF detection. Methods: A systematic search was performed of the Medline, Medline-in-process and Embase literature databases. Papers were eligible if they described primary studies of the evaluation of a BP device for AF detection, were published in a peer reviewed journal and reported values for the sensitivity and specificity. Included studies were appraised using the QUADAS-2 tool to assess their risk of bias and applicability to opportunistic AF detection. Values for the sensitivity and specificity of AF detection were extracted from each paper and compared. Results and Conclusion: We identified seven papers evaluating six devices from two manufacturers. Only one study scored low risk in all of the QUADAS-2 domains. All studies reported specificity greater than 85% and six reported sensitivity greater than 90%. The studies showed that blood pressure devices with embedded algorithms for detecting arrhythmias show promise as screening tools for AF, comparing favourably with manual pulse palpation. But the studies used different methodologies and many were subject to potential bias. More studies are needed to more precisely define the sensitivity and specificity of opportunistic screening for AF during blood pressure measurement before its clinical utility in the population of interest can be assessed fully

Accuracy of pulse interval timing in ambulatory blood pressure measurement

Blood pressure (BP) monitors rely on pulse detection. Some blood pressure monitors use pulse timings to analyse pulse interval variability for arrhythmia screening, but this assumes that the pulse interval timings detected from BP cuffs are accurate compared with RR intervals derived from ECG. In this study we compared the accuracy of pulse intervals detected using an ambulatory blood pressure monitor (ABPM) with single lead ECG. Twenty participants wore an ABPM for three hours and a data logger which synchronously measured cuff pressure and ECG. RR intervals were compared with corresponding intervals derived from the cuff pressure tracings using three different pulse landmarks. Linear mixed effects models were used to assess differences between ECG and cuff pressure timings and to investigate the effect of potential covariates. In addition, the maximum number of successive oscillometric beats detectable in a measurement was assessed. From 243 BP measurements, the foot landmark of the oscillometric pulse was found to be associated with fewest covariates and had a random error of 9.5 ms. 99% of the cuff pressure recordings had more than 10 successive detectable oscillometric beats. RR intervals can be accurately estimated using an ABPM

Study of an engine flow diverter system for a large scale ejector powered aircraft model

Requirements were established for a conceptual design study to analyze and design an engine flow diverter system and to include accommodations for an ejector system in an existing 3/4 scale fighter model equipped with YJ-79 engines. Model constraints were identified and cost-effective limited modification was proposed to accept the ejectors, ducting and flow diverter valves. Complete system performance was calculated and a versatile computer program capable of analyzing any ejector system was developed

The Biology of fun: Do birds just want to have a good time?

The intention of this research project was to delve into the ecological study of playfulness and what appears to be fun in a broad range of bird species. (1) Do all birds exhibit playfulness and use fun? And if so, (2) how have these behaviors contributed to their evolutionary success? Past research has already been underway to biological define what constitutes both “fun” and “play” in animal species. In the past the majority of all test subjects have been mammals, however in the past decade (and especially in the past five years) other vertebrate species such as birds are beginning to be observed as well. The research is still in progress but it seems very obvious from studies so far have concluded that various aviary species do in fact exhibit playful behavior and have fun. Recent hypotheses regarding play in birds, how common it is among various species, and what species have yet to be studied were topics covered in the research. In essence a variety of species of birds are already confirmed to exhibit play behaviors and are used primarily to establish social connects, social hierarchies, and hone predatory and other survival skills.https://scholarscompass.vcu.edu/uresposters/1195/thumbnail.jp

Substrate-Integrated Folded Waveguide Slot Antenna

In recent years a number of researchers have proposed novel techniques for fabricating rectangular waveguide using microwave integrated circuit techniques. These so-called substrate integrated guides have been fabricated using multilayer LTCC, multi- and single-layer microwave laminates and photoimageable thick films. All of these structures result in dielectric filled rectangular waveguide and as such have a width reduction of 1/square root of the relative permittivity over conventional waveguide. Furthermore, by their very nature they are easily integrated with planar transmission lines and circuits, allowing hybrid waveguide/microstrip systems to be fabricated on a single substrate. Several researchers have investigated slot antennas and arrays in substrate-integrated guide. In this paper we show a slot antenna in a folded substrate-integrated waveguide. These waveguides have half the width of the other types of substrate-integrated waveguide. As such the present structure allows arrays of slot antennas to be more highly integrated

Remote sensing applications in forestry - The development of an earth resources information system using aerial photographs and digital computers Annual progress report

Earth resources information system using aerial photographs and digital computer