A plate periodically bonded with piezoelectric patches on its surfaces is considered. The differential quadrature element method is used to solve the wave motion equation for the two-dimensional periodic structure. The method is very simple and easy to implement. Based on the method, band structures for in-plane wave propagating in the periodic piezoelectric plate are studied, from which the fr...

li2ni8o10 and limn2o4 nanoparticles as cathode materials of lithium ion battery, were successfully synthesized using lithium acetate, nickel and manganese acetate as li, ni and mn sources and stearic acid as a complexing reagent. the structure of the obtained products were characterized by ft-ir and xrd. the shape, size and distribution of the li2ni8o10 and limn2o4 nanoparticles were observed b...

background spoilage of tea (camellia sinensis) is often accompanied by contamination and formation of mycotoxins, which are toxic secondary metabolites produced by specific tea-borne fungi. objectives the purposes of this study were to isolate aspergillus flora in the air from tea gardens and factories in gilan and mazandaran provinces, in northern iran, and to determine their protein patterns....

In this paper, an ultra-low-noise amplifier with frequency band switching capability is designed, simulated and fabricated. The two frequency ranges of this amplifier consist of the 2.4 to 2.5 GHz and 3.1 GHz to 3.15 GHz frequency bands. The designed amplifier has a noise figure of less than 1dB, a minimum gain of 23 dB and a VSWR of less than 2 in the whole frequency band. The design process s...

A new multi-layer substrate integrated waveguide (SIW) structure is developed to design dual-band evanescent-mode band-pass filters (BPFs). Two independent series LC circuits are implemented by incorporating metallic irises in the different layers of the structure. The combination of the metallic irises with capacitive-plates is embedded inside the SIW to independently excite two evane...

Longwall shearers’ haulage system of the Eicotrack type, used most often nowadays, is presented in this article. Its disadvantages, causing problems with a correct operation mechanized longwall shearer systems, are discussed. The concept innovative Flextrack, which should reduce occurrence disadvantages mentioned above, described. A course and research results, connected rig tests Flextrack fun...

Band-notch characteristic has been of great interest recently to overcome the electromagnetic interference of Ultra-wideband systems (UWB) with other existing ones. In this paper, we present a novel microstrip-fed antenna with band rejection property appropriate for UWB applications. Band-notch characteristic has been achieved by adding a rectangular resonant element to the ground section. A pr...

introduction: climate change is one of the most significant challenges in sustainable development that has negative effects on land and marine ecosystems. this phenomenon leads to imbalances that cause effects including hydrological changes, increased soil erosion, increased runoffs and reduced groundwater aquifer feeding, etc. effects of climate changes over the past decade have significantly ...