Blends of nylon-6 with polybutadiene were prepared with comparable morphology and different molecular weights of the matrix. These specimens were tested using the notched Izod impact test and the notched tensile impact test. An increase in molecular weight resulted in a shift of the brittle-to-tough transition temperature of 40°C to lower temperatures. In the notched tensile impact tests, espec...

Infrared imagers are important for reorganization and monitoring. This paper discusses the design of an infrared imager. Optical design in medium wavelength infrared (MWIR) and long wavelength infrared (LWIR) bands is different and needs distinct detectors and materials. Reflective systems are not suitable due to their small field of view (FOV) and vignetting. Refractive dual band optical syste...

In this research, residual strength and stress concentration factor of laminated composites with a circular open hole are studied analytically, numerically and experimentally. The numerical study was carried out using the finite element method. Moreover an analytical study was carried out with developing of point stress criterion. Mechanical testing was performed to determine the un-notched ten...

Since the 1970s, the remote sensing synthetic aperture radar (SAR) systems have been devel‐ oping increasingly. The SIR-C/X SAR mounted on the American Space Shuttle Endeavour firstly completed the high resolution 3D imaging all over the globe in Feb. 2000 [1]. It employs three dual-polarized sub-arrays operating at L-, Cand X-bands, respectively, as shown in Fig. 1[2]. The multi-band dual-pola...

Polyamide polymers have moderate mechanical properties, excellent wear resistant properties, and solvents. However, polyamides have some disadvantages such as notch sensitivity and high water absorption. Generally, polyamides are ductile in the un notched state but they show brittle behavior in the state of notched impact. Some disadvantages of polyamides can be improved by some fillers and add...

A dual-band circularly polarized antenna fed by four apertures that covers the bands of GPS, Galileo, is introduced. The ARSAs designed using FR4 substrates in the L and S bands have 3-dB axial-ratio bandwidths (ARBWs) of as large as 37% and 52%, respectively, whereas the one using an RT5880 substrate in the L band, 61%. In these 3-dB axial-ratio bands, impedance matching with VSWR<=1.8 is also...