Elf: computer automation and error correction for a microwave network analyzer

A microwave measurement system has been developed that combines a personal computer (PC) and an conventional vector network analyzer to yield a full complex-error-corrected automatic network analyzer. The system consists of a Hewlett-Packard HP 8410C network analyzer, an HP 8350B sweep oscillator, and an IBM PC. A program called Elf runs on the PC, performing calibration and measurement algorithms and providing a flexible, menu-oriented user interface. The system, when calibrated, achieves a worst-case measurement error vector of magnitude ≤ 0.02 for transmission and reflection coefficient measurements over the 2-12.4-GHz frequency range and has a measurement speed of three frequency points/s. Elf provides an inexpensive method for upgrading the HP 8410 to achieve the high accuracy of an automatic network analyzer

Puff, an Interactive Microwave Computer Aided Design Program for Personal Computers

We will demonstrate a CAD program designed for the lay out and analysis of microstrip circuits. The program runs on the IBM PC or AT. Circuit elements are selected from a parts list and drawn on the screen using the cursor keys. The analysis may then be performed, directly from the screen drawing. Puff has been used by microwave students in classes at the California Institute of Technology and the University of California at Los Angeles

Exercise-induced tendon and bone injury in recreational runners: A test-retest reliability study

Background: Long-distance runners are prone to injuries including Achilles tendinopathy and medial tibial stress syndrome. We have developed an Internet comprehensive self-report questionnaire examining the medical history, injury history, and running habits of adult recreational runners. Objective: The objective of the study was to evaluate two alternative forms of test-retest reliability of a comprehensive self-report Internet questionnaire retrospectively examining the medical history, injury history, and running habits among a sample of adult recreational runners. This will contribute to the broad aims of a wider study investigating genetics and running injury. Methods: Invitations to complete an Internet questionnaire were sent by email to a convenience pilot population (test group 1). Inclusion criteria required participants to be a recreational runner age 18 or over, who ran over 15 km per week on a consistent basis. The survey questions addressed regular running habits and any injuries (including signs, symptoms, and diagnosis) of the lower limbs that resulted in discontinuation of running for a period of 2 consecutive weeks or more, within the last 2 years. Questions also addressed general health, age, sex, height, weight, and ethnic background. Participants were then asked to repeat the survey using the Internet platform again after 10-14 days. Following analysis of test group 1, we soft-launched the survey to a larger population (test group 2), through a local running club of 900 members via email platform. The same inclusion criteria applied, however, participants were asked to complete a repeat of the survey by telephone interview after 7-10 days. Selected key questions, important to clarify inclusion or exclusion from the wider genetics study, were selected to evaluate test-retest reliability. Reliability was quantified using the kappa coefficient for categorical data. Results: In response to the invitation, 28 participants accessed the survey from test group 1, 23 completed the Internet survey on the first occasion, and 20 completed the Internet retest within 10-21 days. Test-retest reliability scored moderate to almost perfect (kappa=.41 to .99) for 19/19 of the key questions analyzed. Following the invitation, 122 participants accessed the survey from test group 2, 101 completed the Internet survey on the first occasion, and 50 were randomly selected and contacted by email inviting them to repeat the survey by telephone interview. There were 33 participants that consented to the telephone interview and 30 completed the questionnaire within 7-10 days. Test-retest reliability scored moderate to almost perfect for 18/19 (kappa=.41 to .99) and slight for 1/19 of the key questions analyzed. Conclusions: We successfully developed a self-reported, retrospective questionnaire, delivered using Internet software, providing stable and reliable answers. We demonstrate that our survey provides a relatively quick, easy to complete, and cost effective method to collect epidemiological data from recreational runners and evaluate these participants for inclusion into a genetic study

Updated Distributional Records of Selected Kentucky Fishes

Distribution records for 15 fish species of conservation interest are included for Kentucky. Notropis dorsalis, previously undocumented in Kentucky, is reported for the first time (Mayfield Creek drainage). Also reported are state rediscoveries of three species thought to be extirpated from Kentucky: Ichthyomyzon gagei (Tennessee River drainage), Hemitremia flammea (Lower Cumberland and Green river drainages), and Hybopsis amnis (upper Cumberland River drainage). Unreported drainage records comprise nine species: Ichthyomyzon castaneus (Salt River drainage and Upper Green River drainage); Ichthyomyzon unicuspis (Salt River drainage and upper Big Sandy River drainage); Campostoma pullum (Tennessee River drainage); Umbra limi (Obion Creek drainage); Lepomis marginatus (Blood River system); Ammocrypta pellucida (Tygart’s Creek drainage); Nothonotus camurus (Kinniconick Creek drainage); Percina sciera (Salt River drainage); and Percina squamata (Laurel River system). Finally, we report range extensions of Notropis maculatus (Mayfield Creek drainage and Clarks River system) and Typhlichthys subterraneus (Cumberland River drainage). All but four species (I. unicuspis, C. pullum, N. camurus, and P. sciera) have a state conservation status designation because they are rare or have limited (e.g., peripheral) distributions in Kentucky

The Grizzly, October 26, 1993

Colvin, Reynolds to Serve on Captains\u27 Council • Verdict Returned in Reginald Denny Trial • Ursinus Loses Friend and Supporter • Student Apathy Strikes Again • Ursinus Students to Perform in State Choral Festival • Gaijin-Eyes Exhibit to Open • Literary Society • Self-Realization in the Big Apple: Wiggly Blocks and The Piano • Bears Win Homecoming • Phillies Lose World Serieshttps://digitalcommons.ursinus.edu/grizzlynews/1322/thumbnail.jp

Phase-Control of Photoabsorption in Optically Dense Media

We present a self-consistent theory, as well as an illustrative application to a realistic system, of phase control of photoabsorption in an optically dense medium. We demonstrate that, when propagation effects are taken into consideration, the impact on phase control is significant. Independently of the value of the initial phase difference between the two fields, over a short scaled distance of propagation, the medium tends to settle the relative phase so that it cancels the atomic excitation. In addition, we find some rather unusual behavior for an optically thin layer.Comment: 5 pages, 3 figures, submitted to PR

Photodetachment study of the 1s3s4s ^4S resonance in He^-

A Feshbach resonance associated with the 1s3s4s ^{4}S state of He^{-} has been observed in the He(1s2s ^{3}S) + e^- (\epsilon s) partial photodetachment cross section. The residual He(1s2s ^{3}S) atoms were resonantly ionized and the resulting He^+ ions were detected in the presence of a small background. A collinear laser-ion beam apparatus was used to attain both high resolution and sensitivity. We measured a resonance energy E_r = 2.959 255(7) eV and a width \Gamma = 0.19(3) meV, in agreement with a recent calculation.Comment: LaTeX article, 4 pages, 3 figures, 21 reference

The Grizzly, November 9, 1993

Whitman Elected Governor • Pysch Conference Held at U.C. • Novack Wins Award • Hubbard Presents Shooting Back • POW-Turned-Artist Featured in Berman Exhibit • The Blenders: A Review • Literary Society • Never Discuss Politics or Religion at the Dinner Table • How CAB Gets Their Acts Together • In Defense of Greek Life, Part One • Letter to the Editor • Ursinus Hosts First Centennial Conference Seminar • Bears Kicked Late by Mules • Indoor Volleyball and Intramural Sportshttps://digitalcommons.ursinus.edu/grizzlynews/1324/thumbnail.jp