Considerations on the frequency resource of professional wireless microphone systems

This Paper presents the results of spectral observations in the UHF TV Bands IV and V from 470 MHz up to 862 MHz with focus on the TV-Channels 61 to 63 and 67 to 69. Concerning the discussions on citet{WRC} this frequency range is in great demand of several applications and is usually treated as a "white space" in the TV-Bands. According to typical scenarios, two different spectral loads will be presented considering the requirements of professional wireless microphone receivers with respect to in-band intermodulation

The County Historical Society: Financial and Reporting Issues

Jessie Star, a recent accounting graduate from State University, has just volunteered (at the urging of her boss) to be the treasurer for the local Historical Society.  The County Historical Society is a not-for-profit organization that operates a museum displaying historical artifacts and an archive library housing historical documents and photographs.  The Society also operates a gift shop in its museum and manages a historical home owned by the county government.  The museum, library, storage areas, and offices are located in a building rented from a local corporation.  The historical home is located just a few blocks away.  The Society has three employees on its payroll:  Robert James, the full-time Executive Director, Erika Lawson, the part-time Museum Assistant, and an Archive Librarian, John Nelson.  A volunteer Board of Trustees, consisting of twelve members from the community, directs the Society.  As Treasurer, Jessie is an officer and member of the Board of Trustees.  She has the primary responsibility for maintaining the Society’s books, making investment/financing recommendations to the Board, and assisting with the annual external audit of the financial statements. Jesse has been struggling to get up to speed with the Society’s accounting so that she’ll be ready for her first Board meeting.  She is not very familiar with Fund Accounting and has never been involved with this type of not-for-profit organization.  Jessie set up a meeting with the former treasurer, Al Gone, to help her get up to speed with the issues

Comparison of methods for broadband electromagnetic characterization of Molded Interconnect Device materials

Combining the Molded Interconnect Device technology with the Laser Direct Structuring technology exhibits the potential of designing electrical and mechanical components on three-dimensional surfaces to increase functionality, level of integration and to reduce costs. When taking advantage of this technology especially in the design of RF devices, a precise knowledge of the electromagnetic parameters of the MID material is required, as the complex permeability and permittivity strongly influence the device performance. At present time, these materials are not electromagnetically characterized in the RF frequency range. In this paper different methods are therefore presented and compared with respect to their potentials for broadband electromagnetic characterization of Molded Interconnect Device materials

Manipulating ionization path in a Stark map: Stringent schemes for the selective field ionization in highly excited Rb Rydberg atoms

We have developed a quite stringent method in selectivity to ionize the low angular- momentum ($\ell$) states which lie below and above the adjacent manifold in highly excited Rb Rydberg atoms. The method fully exploits the pulsed field-ionization characteristics of the manifold states in high slew-rate regime: Specifically the low $\ell$ state below (above) the adjacent manifold is firstly transferred to the lowest (highest) state in the manifold via the adiabatic transition at the first avoided crossing in low slew-rate regime, and then the atoms are driven to a high electric field for ionization in high slew-rate regime. These extreme states of the manifold are ionized at quite different fields due to the tunneling process, resulting in thus the stringent selectivity. Two manipulation schemes to realize this method actually are demonstrated here experimentally.Comment: 10 pages, 4 figure

Systematic observation of tunneling field-ionization in highly excited Rb Rydberg atoms

Pulsed field ionization of high-$n$ (90 $\leq n \leq$ 150) manifold states in Rb Rydberg atoms has been investigated in high slew-rate regime. Two peaks in the field ionization spectra were systematically observed for the investigated $n$ region, where the field values at the lower peak do not almost depend on the excitation energy in the manifold, while those at the higher peak increase with increasing excitation energy. The fraction of the higher peak component to the total ionization signals increases with increasing $n$, exceeding 80% at $n$ = 147. Characteristic behavior of the peak component and the comparison with theoretical predictions indicate that the higher peak component is due to the tunneling process. The obtained results show for the first time that the tunneling process plays increasingly the dominant role at such highly excited nonhydrogenic Rydberg atoms.Comment: 8 pages, 5 figure

Hyperfine Magnetic Field Measurement in Heusler Alloys by TDPAC Technique

This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

Acute physical exercise improves shifting in adolescents at school: evidence for a dopaminergic contribution

The executive function of shifting between mental sets demands cognitive flexibility. Based on evidence that physical exercise fostered cognition, we tested whether acute physical exercise can improve shifting in an unselected sample of adolescents. Genetic polymorphisms were analyzed to gain more insight into possibly contributing neurophysiological processes. We examined 297 students aged between 13 and 17 years in their schools. Physical exercise was manipulated by an intense incremental exercise condition using bicycle ergometers and a control condition which involved watching an infotainment cartoon while sitting calm. The order of conditions was counterbalanced between participants. Shifting was assessed by a switching task after both conditions. Acute intense physical exercise significantly improved shifting as indicated by reduced switch costs. Exercise-induced performance gains in switch costs were predicted by a single nucleotide polymorphism (SNP) targeting the Dopamine Transporter (DAT1/SLCA6A3) gene suggesting that the brain dopamine system contributed to the effect. The results demonstrate the potential of acute physical exercise to improve cognitive flexibility in adolescents. The field conditions of the present approach suggest applications in schools