On the engineering portion of a research program to develop a zero-g, drag-free satellite and to perform a gyro test of general relativity in a satellite Fourth semiannual status report

Zero gravity satellite concept feasibility and control system design evaluation using air cushion vehicl

Develop a zero-G drag-free satellite and perform a gyro test of general relativity in a satellite Semiannual status report, Nov. 1965 - Apr. 1966

Aeronomy experiment satellite polar orbit, control analysis, and control simulatio

On the engineering portion of a research program - To perform a gyro test of general relativity in a satellite and develop associated control technology

Satellite attitude control using gyro-telescope structure driven by superconducting actuato

Lesions mimicking lacrimal gland pleomorphic adenoma

Aim: To report a series of patients with lacrimal gland lesions simulating the clinicoradiological features of lacrimal gland pleomorphic adenoma (LGPA). Methods: Multicentre retrospective, interventional case series. Clinical records of all patients with lesions mimicking LGPA seen in five orbital units were reviewed. Results: The study included 14 patients (seven men and seven women) with a mean age of 50.9 years. The diagnosis of LGPA was made in all cases by experienced orbital surgeons, based on clinicoradiological features, and lacrimal gland excision was performed. Postoperative histology revealed lymphoma (four patients), chronic dacryoadenitis (three patients), adenoid cystic carcinoma (two patients), Sjogren's syndrome (two patients), cavernous haemangioma (one patient), benign lymphoid hyperplasia (one patient) and granulomatous dacryoadenitis (one patient). Comparison with the total number of histologically confirmed LGPA cases seen during the study period revealed that 22.6% of cases of suspected LGPA were misdiagnosed based on clinicoradiological criteria. Conclusions: Many different lesions may mimic the clinicoradiological features of LGPA. The accepted clinicoradiological criteria used for the diagnosis of LGPA have a high false-positive rate, even in experienced hands. Based on this study, the authors believe that fine-needle aspiration biopsy or intraoperative biopsy and frozen section diagnosis may help reduce unnecessary lacrimal gland excision.Venkatesh C Prabhakaran, Paul S Cannon, Alan McNab, Garry Davis, Brett O’Donnell, Peter J Dolman, Raf Ghabrial, Dinesh Selv

The S2 VLBI Correlator: A Correlator for Space VLBI and Geodetic Signal Processing

We describe the design of a correlator system for ground and space-based VLBI. The correlator contains unique signal processing functions: flexible LO frequency switching for bandwidth synthesis; 1 ms dump intervals, multi-rate digital signal-processing techniques to allow correlation of signals at different sample rates; and a digital filter for very high resolution cross-power spectra. It also includes autocorrelation, tone extraction, pulsar gating, signal-statistics accumulation.Comment: 44 pages, 13 figure

Fuselage shell and cavity response measurements on a DC-9 test section

A series of fuselage shell and cavity response measurements conducted on a DC-9 aircraft test section are described. The objectives of these measurements were to define the shell and cavity model characteristics of the fuselage, understand the structural-acoustic coupling characteristics of the fuselage, and measure the response of the fuselage to different types of acoustic and vibration excitation. The fuselage was excited with several combinations of acoustic and mechanical sources using interior and exterior loudspeakers and shakers, and the response to these inputs was measured with arrays of microphones and accelerometers. The data were analyzed to generate spatial plots of the shell acceleration and cabin acoustic pressure field, and corresponding acceleration and pressure wavenumber maps. Analysis and interpretation of the spatial plots and wavenumber maps provided the required information on modal characteristics, structural-acoustic coupling, and fuselage response

Agricultural Communications: A National Portrait of Undergraduate Courses

Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs

Agricultural Communications: A National Portrait of Undergraduate Courses

Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs

Agricultural Communications: A National Portrait of Undergraduate Courses

Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs

Mechanism of CDW-SDW Transition in One Dimension

The phase transition between charge- and spin-density-wave (CDW, SDW) phases is studied in the one-dimensional extended Hubbard model at half-filling. We discuss whether the transition can be described by the Gaussian and the spin-gap transitions under charge-spin separation, or by a direct CDW-SDW transition. We determine these phase boundaries by level crossings of excitation spectra which are identified according to discrete symmetries of wave functions. We conclude that the Gaussian and the spin-gap transitions take place separately from weak- to intermediate-coupling region. This means that the third phase exists between the CDW and the SDW states. Our results are also consistent with those of the strong-coupling perturbative expansion and of the direct evaluation of order parameters.Comment: 5 pages(REVTeX), 5 figures(EPS), 1 table, also available from http://wwwsoc.nacsis.ac.jp/jps/jpsj/1999/p68a/p68a42/p68a42h/p68a42h.htm