A Variational Calculation of TE and TM Cutoff Wavenumbers in Circular Eccentric Guides by Conformal Mapping

The cutoff wavenumbers of higher order modes in circular eccentric guides are computed with the variational analysis combined with a conformal mapping. A conformal mapping is applied to the variational formulation, and the variational equation is solved by the finite-element method. Numerical results for TE and TM cutoff wavenumbers are presented for different distances between the centers and ratio of the radii. Comparisons with numerical results found in the literature validate the presented method

Compact Circular- Sided Microstrip Antenna for Circular Polarization

Development of a new compact circular-sided microstrip antenna is presented. This antenna offers considerable area re- TABLE 2. Variation of Resonant Frequencies duction compared to standard rectangular microstrip antenna designed for the same frequency. Typical antenna design and experimental results for circular polarization are also demonstrated. 77je antenna has a 3-dB axial ratio bandwidth of 1.5%

A New Broadband Circular Patch Antenna

A simple technique to improve the impedance bandwidth of a circular microstrip patch antenna using two sectorial slots is proposed. Using this design more than 5% impedance bandwidth is obtained. The added advantage of this new antenna is that it can be fed by a 50 microstrip line.

Compact dual band slot loaded circular microstrip antenna with a superstrate

Design of a compact dual frequency microstrip antenna is presented. The structure consists of a slotted circular patch with a dielectric superstrate. The superstrate,not only acts as a radome, but improves the bandwidth and lowers the resonant frequency also. The proposed design provides an overall size reduction of about 60% compared to an unslotted patch along with good efficiency,gain and bandwidth. The polarization planes at the two resonances are orthogonal and can be simultaneously excited using a coaxial feed. Parametric study of this configuration showed that the frequency ratio of the two resonances can be varied from 1.17 to 1.7 enabling its applications in the major wireless communication bands like AWS, DECT,PHS,Wi.Bro, ISM,and DMB. Design equations are also deduced for the proposed antenna and validated.

Circular microstrip antenna with a sector-slot for dual-port operation

Design of a dual-port circular patch antenna with a sector-slot for dual-frequency operation is presented. The antenna resonates at two distinct frequencies with orthogonal polarizations and broad radiation characteristics. Unlike the conventional circular patch, this antenna can be microstrip-fed to operate at either of the resonances. The two polarizations can be simultaneously excited using two electromagnetically coupled ports with an isolation better than −30 dB between the ports. This antenna has the added advantage of size reduction of 44% compared to the conventional circular patch without any reduction in gain.

Magnetism of isolated Mn12 single-molecule magnets detected by magnetic circular dichroism: Observation of spin tunneling with a magneto-optical technique

We report magnetic and magneto-optical measurements of two Mn12 single-molecule magnet derivatives isolated in organic glasses. Field-dependent magnetic circular dichroism (MCD) intensity curves (hysteresis cycles) are found to be essentially identical to superconducting quantum interference device magnetization results and provide experimental evidence for the potential of the optical technique for magnetic characterization. Optical observation of magnetic tunneling has been achieved by studying the decay of the MCD signal at weak applied magnetic field

A geometrical heuristic for drawing concept lattices

Concept lattices are used in formal concept analysis to represent data conceptually so that the original data are still recognizable. Their line diagrams should reflect the semantical relationships within the data. Up to now, no satisfactory automatic drawing programs for this task exist. The geometrical heuristic is the most successful tool for drawing concept lattices manually. It ueses a geometric representation as intermediate step between the list of upper covers and the line diagram of the lattice.

The circular economy and the water-food nexus

The global economy is based on a take-make-consume and dispose model where natural resources are turned into products and the waste disposed of instead of being reused as a resource. In the Asia-Pacific region climate change along with rapid population and economic growth is resulting in increased demand for water and food, potentially leading to economic and political instability. Europe has developed policy and technological innovations that can facilitate the transition towards a circular economy where waste becomes a resource. By using existing instruments Europe can transfer its circular economy knowledge and technology to the Asia-Pacific region to increase security of supply of scarce resources. This can help ensure global security, influence climate change negotiations and create jobs in Europe.

Educación vial : aprende a circular con nosotros.

Ejemplar editado en 2005 y reeditado en noviembre de 2007

Formative-3-Arranging-Drawing-Views - Storyline

Formative exercise on 3rd Angle Projection convention for FEEG1001 students.

La primera comunión en la escuela : circular de la Inspección de Enseñanza Primaria de Madrid.

Circular de la Inspección de Enseñanza Primaria de Madrid para informar de las celebraciones de las Primeras Comuniones en las escuelas de Madrid. En ella se asegura que estos actos se celebrarán en día festivo con el fin de que puedan acudir los familiares, que los niños estarán acompañados durante el acto de sus padres y familiares y que los niños deberán cantar himnos religiosos populares durante el acto de Comunión.

Información y educación sexuales : circular núm. 73-299, de 23 de julio de 1973.

Se transcribe el texto de una carta que se hizo llegar a los rectores, inspectores de departamento, directores de centros y directores de IDEN de Francia, en donde se exponían las razones por las que se imponía la necesidad de impartir una educación sexual desde la naturalidad y la responsabilidad, para que las familias en colaboración con la escuela, pudieran contribuir a prevenir a los jóvenes contra los problemas que pudiera acarrear la ignorancia en el terreno de la educación sexual. De este modo, se analiza la información que debían comunicar; la transmisión de la educación sexual y el inicio de la responsabilidad en este campo y la actitud que debiera adoptar el profesor ante las preguntas de sus alumnos.

El Real Decreto y la circular del Marqu??s de Orovio de 1875 : repercusiones en el claustro universitario y la prensa de Sevilla

Resumen basado en el de la publicaci??n

CARTA DO RESTAURO 1972, MINISTÉRIO DE INSTRUÇÃO PÚBLICA GOVERNO DA ITÁLIA, CIRCULAR Nº 117 DE 6 DE ABRIL DE 1972

Através da circular número 117, de 6 de Abril de 1972, o Ministério da Instrução Pública da Itália divulgou o Documento sobre Restauração de 1972 (Carta do Restauro, 1972) entre os directores e chefes de institutos autónomos, para que se atenham, escrupulosa e obrigatoriamente, em todas as intervenções de restauração em qualquer obra de arte, às normas por ela estabelecidas e às instruções anexas, aqui publicadas na íntegra.