1,033 research outputs found

    Failure of the Standard Coupled-Channels Method in Describing the Inelastic Reaction Data: On the Use of a New Shape for the Coupling Potential

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    We present the failure of the standard coupled-channels method in explaining the inelastic scattering together with other observables such as elastic scattering, excitation function and fusion data. We use both microscopic double-folding and phenomenological deep potentials with shallow imaginary components. We argue that the solution of the problems for the inelastic scattering data is not related to the central nuclear potential, but to the coupling potential between excited states. We present that these problems can be addressed in a systematic way by using a different shape for the coupling potential instead of the usual one based on Taylor expansion.Comment: 10 pages, 4 figures, 1 table, Latex:RevTex4 published in J. Phys. G: Nucl. Part. Phy

    Closed-Form Green's Function Representations for Mutual Coupling Calculations Between Apertures on a Perfect Electric Conductor Circular Cylinder Covered with Dielectric Layers

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    Cataloged from PDF version of article.Closed-form Green’s function (CFGF) representations are developed for tangential magnetic current sources to calculate the mutual coupling between apertures on perfectly conducting circular cylinders covered with dielectric layers. The new representations are obtained by first rewriting the corresponding spectral domain Green’s function representations in a different form (so that accurate results for electrically large cylinders, and along the axial line of a cylinder can be obtained). Then, the summation over the cylindrical eigenmodes is calculated efficiently. Finally, the resulting expressions are transformed to the spatial domain using a modified two-level generalized pencil of function method. Numerical results are presented showing good agreement when compared to CST Microwave Studio results

    BIOLOGY OF SILKWORM (BOMBYX MORI) IN TURKEY

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    According to oldest records the first time silkworm was cultivated and silk was obtained from cocoonat China. Silkworm eggs and mulberry seeds was brought to Istanbul illegally the year 552 at age of Byzantine Empire although China kept it as a secret. It started to spread Marmara regione specially Bursa and It’s neighbourhood. Then it was spreaded to allover the world. Sericulture have been economical, cultural and traditional cultivating sector at Turkey for 1500 years. Silkworm is cultivated at about 30 countries that include Turkey. Silk fiber is superior to other fibers in terms of stability, flexibility and brightness. Amount of need is approximately twice the amount of cultivating. In whole world Turkish silk fiber quality is at second rank after japanese silk. Silkworm is a general term that includes a range from worm to the butterfly. Silkworm is a kind of night butterflies. Butterflies are light cream colour have chubby bodies and have soft feathers. Wingspan is about 4-5 cm. Butterfly have lost flying ability because of domestication also have 2 or 3 days life and at that period doesn’t feed and doesn’t fly. Silkworm is fed with mulberry leaves. One cocoon is made from a single silk fiber it’s lenght is 800 meters. Real silkworm named “Bombyx Mori L” is bred at mulberry tree which is cultivated at China is white breed. Bombyx Mori L silkworm producesbest silk fiber amoung other genus and it is most special genus cultivated

    Analysis of slotted sectoral waveguide array antennas with multilayer radomes and nonzero metal thickness

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    Slotted waveguide array antennas offer low cross-polarization and high power handling capacity, and they are low-profile which enables them to be used in conformal and structurally-integrated antenna solutions. Hence, they are excellent candidates for phased array antennas in radar applications, especially in air platforms. Aerodynamics and radar cross section (RCS) for an air platform are critical design considerations for air platforms; therefore, conformal and structurally-integrated solutions with integrated multilayer (sandwich) radomes are desired. Although the accurate and efficient design and analysis of low-profile conformal slotted waveguide arrays is of great interest, available solution methods in the literature usually suffer in terms of efficiency and memory requirements. Among the available solution methods, one of the widely used solvers are integral equation (IE) based ones that utilize the method of moments (MoM). However, IE solvers suffer from long matrix fill times, especially when cylindrically stratified media are considered. © 2015 IEEE

    Derivation of Green's function representations for the analysis of sectoral waveguides embedded in cylindrically stratified media

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    The design and analysis of dielectric-covered slotted waveguide arrays are of great interest in many military and civil applications, because of their low-profile, high efficiency and high power handling capabilities. Regarding the efficient and accurate analysis of such antennas, integral equation (IE) based methods that utilize the method of moments (MoM) or a hybrid combination of MoM with an appropriate Green's function (referred to as MoM/Green's function technique) are widely used. For the hybrid MoM/Green's function technique, appropriate dyadic Green's function representations for the waveguide interior and the exterior stratified media are required. However, in the case of a cylindrically conformal dielectric-covered slotted waveguide array, which may be desired due to aerodynamic and/or radar cross section (RCS) concerns, the abovementioned IE-based analysis that utilize a hybrid MoM/Green's function technique becomes a greater challenge due to the difficulties in the evaluation of the entries of MoM impedance/admittance matrices, especially for the terms related to cylindrically stratified media. © 2013 IEEE

    Analysis of Slotted Sectoral Waveguide Arrays with Multilayered Radomes

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    A method of moments/Green's function (MoM/GF) technique in the space domain is used for the rigorous and fast analysis of cylindrically conformal slotted sectoral waveguide arrays (SSWGAs) in the presence of multilayered cylindrical dielectric radomes. Representing the slots by fictitious magnetic currents via the equivalence principle, the geometry is divided into two regions and separate GF representations for each region are developed to be used in conjunction with the MoM procedure. Particularly, in the region that constitutes the cylindrically stratified medium, the newly developed closed-form GF representations for magnetic currents are valid for all source and observation points, including the source region (where source and observation points are on the top of each other). Basic performance metrics of an SSWGA such as equivalent slot currents, S-parameters, radiation patterns in the presence of a multilayered cylindrical radome are presented to assess the accuracy and efficiency of the proposed technique. © 1963-2012 IEEE

    Analysis of slotted sectoral waveguides embedded in cylindrically stratified media using closed-form Green's function representations

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    Slotted waveguide antenna arrays with dielectric covers are widely used in both military and civil applications due to their low-profile, high power handling capacity, and the ability to conform to the host platform. Conformity is especially required for air platforms where aerodynamics and radar cross section (RCS) of the vehicle are of utmost importance. For an air platform, one or more dielectric layers (monolithic or sandwich radomes) can be used to protect the antenna from the extreme flight conditions. Although the accurate and efficient design and analysis of low-profile conformal slotted waveguide arrays is of great interest, available solution methods in the literature usually suffer in terms of efficiency and memory requirements. Among the available solution methods, one of the widely used solvers are integral equation (IE) based ones that utilize the method of moments (MoM). However, the IE solvers suffer from long matrix fill times, especially when cylindrically stratified media are considered. © 2013 IEEE
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