Calculation of Angular Deflection Limits of a Mobile Free-Space Optical Link Beam

The paper describes the effect of optical beam angular deflection on the power received by the receiver of a mobile free-space optical (FSO) link. Permissible fluctuations in the power received were studied on a steady model of the FSO link. It was assumed that these fluctuations were caused by oscillations of the optical beam across the receiver aperture. The formula for beam angular deflection limit was derived for two different types of optical intensity profile. The task was solved for two different types of atmosphere. The first type of atmosphere was considered a homogeneous and lossless environment. In the second type, atmospheric radiation attenuation was included in the calculations. Also, this article includes graphs of dependencies of the angular deflection limits upon the distance between the link stations

Exploiting multimode waveguides for pure fibre-based imaging

We acknowledge support from the UK Engineering and Physical Science Research CouncilThere has been an immense drive in modern microscopy towards miniaturisation and fibre based technology. This has been necessitated by the need to access hostile or diffcult environments in-situ and in-vivo. Strategies to date have included the use of specialist fibres and miniaturised scanning systems accompanied by ingenious microfabricated lenses. We present a novel approach for this field by utilising disordered light within a standard multimode optical fibre for lensless microscopy and optical mode conversion. We demonstrate the modalities of bright-field and dark-field imaging and scanning fluorescence microscopy at acquisition rates allowing observation of dynamic processes such as Brownian motion of mesoscopic particles. Furthermore, we show how such control can realise a new form of mode converter and generate various types of advanced light fields such as propagation-invariant beams and optical vortices. These may be useful for future fibre based implementations of super-resolution or light sheet microscopy.Publisher PDFPeer reviewe

Design and Modeling of the Properties of the Servomechanism for a Mobile Free Space Optical Link

The paper deals with the design of a tracking system determined for mobile free space optical link communication system. The paper also contains description of two-step method of the optical-axes pointing process, description of the basic properties of servomechanisms and results of the simple simulation of the tracking-system function model. The entire model consists of four partial models, i.e. of model of trajectory, model of uneven road surface, model of vehicle and model of horizontal and vertical servos. Results of these simulations will be used to give precision to the construction design of the mobile free space optical link station and its servomechanisms

An Evaluation of a School District’s Summer Library Program Designed to Prevent Summer Reading Loss

The purpose of this evaluation was to study the impact a school district’s summer library program had on summer reading loss. This study was conducted to analyze the design of the program and to determine what effect the program had on participants’ reading assessment scores as compared from spring (pre) to fall (post). Analysis of quantitative and qualitative data demonstrated the program was beneficial to students, parents, teachers, and school librarians. The findings show there is potential to use the summer library program to increase reading assessment scores; however, multiple doses of the program are necessary to achieve results. The findings also show school library programs must be intentionally integrated into the culture of a school district during the school year in order for a summer library program to succeed. A comprehensive change leadership plan for school library program advocacy and summer library program policy have been developed as a result of this study. Findings from this evaluation could also serve as a road map or lessons learned for school districts across the nation when implementing a summer library program

The 2022 midterms: Kentucky is shaping up to be one of the Democrats’ most uphill electoral battles this November

Following Kentucky’s primaries last month, Charles Booker will run for the Democratic Party against the incumbent Republican senator, Rand Paul. Despite Booker’s strong campaigning and given the likely Republican leaning national environment this year, Anne M. Cizmar argues that he and other Democrats are unlikely to fare well in the Bluegrass State in this year’s midterm elections

Advances in Modeling of Scanning Charged-Particle-Microscopy Images

Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM images of gold-on-carbon resolution sample for image-sharpness evaluation. Since then, the new improved version of the software was written in C++ programming language and is in the Public Domain. The current version of the software can generate arbitrary samples, any drift function, and many other features. This work describes scanning in charged-particle microscopes, which is applied both in the artificial image generator and the DCIC technique. As an example, the performance of the DCIC technique is demonstrated.Comment: 9 pages, 6 figure

The first Democratic debate: some unity, but significantdisagreements on policy

On Tuesday night, the five announced candidates for the Democratic presidential nomination debated for the first time. Anne Cizmar reviews the debate, writing that while there was unity among candidates compared with the Republican Party’s recent debates, issues such as gun control and foreign policy showed the divisions between the candidates. She argues that while Hillary Clinton, Bernie Sanders performed solidly, Martin O’Malley, Lincoln Chafee and Jim Webb did little to help their campaigns’ prospects

"Easy Issues" in American Politics

My dissertation explores Carmines' and Stimson's well-known and widely cited distinction between "easy" and "hard" issues as described in "The Two Faces of Issue Voting" (1980). They argue that some issues are inherently "easy," and are understood by the public at an emotional, "gut" level, while other issues are intrinsically "hard" and require greater political sophistication and interest to process. This theory is intuitively appealing and has been widely-accepted among political science scholars and pundits; however, many questions remain unanswered about this theory. In my dissertation I examine three primary questions---whether "easy" and "hard" issues exist, what are the sources of easiness, and how malleable is issue difficulty. I argue that economic and foreign policy issues, which are often regarded as "hard" are actually performance issues, and that issues are not inherently easy but are made so through political discourse. However, the ability to frame issues is not unlimited

Mitch McConnell looks poised to win a Senate race in Kentucky which may be the most expensive in U.S. history

Kentucky’s Senate race has so far been a hard fought one, with Democrat Alison Lundergan Grimes hoping to unseat the current Senate Minority Leader, Mitch McConnell. Despite McConnell’s relative low popularity ratings, Anne Cizmar argues that Grimes faces an uphill battle, having already had to distance herself from President Obama. She writes that barring a shake up to the campaign, McConnell looks on course to win a race which may see more than $100 million spent between the two candidates

Kentucky’s Republican primary moves to a ‘recanvass’ in the latest development in a noteworthy gubernatorial election

Republican voters in Kentucky went to the polls last week in a gubernatorial primary ahead of the general election in November. With the results of the primary on a knife edge of only 83 votes between the winner, Matt Bevin and the 2nd placed candidate, James Comer, the latter has requested a recanvas to contest the vote count. Anne Cizmar writes that the primary has been beset by allegations of domestic violence towards Comer and negative ads towards Bevin. Whoever wins the primary fight will face a tough battle to beat the Democratic nominee, Jack Conway, in a state which has tended to return Republicans to national office, but Democrats to the governor’s mansion