in iran, for column design, double i shape section is used due to lack of ipb profile. double i shape column performance is ambiguous in existing steel structures, especially when subjected to seismic loading. in this paper, double i shape column behavior is evaluated with 3d nonlinear analyses. monotonic behavior of 6 specimens and hysteretic behavior of other six specimens have been simulated...

It is of great significance to study the spatial-temporal variations thickness gas hydrate stability zone (GHSZ) understand decomposition, migration, accumulation and dissipation hydrate, corresponding relationship between bottom-simulating reflectors (BSRs) distribution heterogeneous hydrate. We selected Dongsha region in South China Sea (SCS) as research object calculate variation GHSZ since ...

A Bragg reflector consisting of a 25-period MnZnSSe/ZnSSE Bragg stack is reported. The II–VI semiconductor structure was grown by molecular beam epitaxy on a GaAs ~100! epilayer. Structural characterization of the Bragg reflector was performed with double crystal x-ray diffraction and transmission electron microscopy. These studies indicated that the epitaxial II–VI structure, whose total thick...

Thin oxide interlayers are commonly added to the back reflector of thin-film silicon solar cells to increase their current. To gain more insight in the enhancement mechanism, we tested different back reflector designs consisting of aluminium-doped zinc oxide (ZnO:Al) and/or hydrogenated silicon oxide (SiOx:H) interlayers with different metals (silver, aluminium, and chromium) in standard p-i-n ...

We report on a commercially reproducible silicon wafer with a high-reflectance buried distributed Bragg reflector (DBR). The substrate consists of a two-period DBR fabricated using a double silicon-on-insulator (SOI) process. The buried DBR provides a 90% reflecting surface. We have fabricated resonant cavity-enhanced Si photodetectors with 40% quantum efficiency at 860 nm and a full-width at h...

One form of Impulse Radiating Antenna (IRA) combines the technologies of the Balanced Transmission-line Wave (BTW) sensor with TEM-fed paraboloidal reflector antennas. The behavior of the IRA was calculated using a combination of the Method of Moments, using the NEC Code, and Geometrical Optics. The results of NEC compare favorably to both high and low frequency asymptotes. The frequency domain...

A solar cell is an electronic device which not only harvests photovoltaic effect but also transforms light energy into electricity. In photovoltaic phenomenon, a P-N junction is created to form an empty region.  The presented paper aims at proposing a new highly efficient InGaN/Si double-junction solar cell structure. This cell is designed to be used in a real environmental situation, so only s...

We report on the design, fabrication and performance of a matching integrated optical CDMA encoder-decoder pair based on holographic Bragg reflector technology. Simultaneous encoding/decoding operation of two multiple wavelength-hopping time-spreading codes was successfully demonstrated and shown to support two error-free OCDMA links at OC-24. A double-pass scheme was employed in the devices to...

This paper introduces a Design of dual reflector Cassegrain feed system antenna with suitable design aspects like smaller reflector and sub reflector diameter for higher sub reflector efficiency, lower Cassegrain blockage losses and desired illumination taper. Design parameters are computed from the simple and explicit analytical formulas. Design example is represented to differentiate the effi...