In this paper a design of triple band one turn helical antenna without ground plain for center frequency of 2.4 GHz, 3.6 GHz, and 5.4 GHz is discuss. These frequencies are selected such that the antenna radiate for continuous band of 2 GHz to 6.8 GHz frequency with variable gain. The purpose of this novel design is to enhance the gain as well as bandwidth. The triple band is achieved by three c...

objective: importance of management of gardens weeds is an issue that unfortunately has less been investigated by weeds researchers of country. one of the most important restrictive agents of cultivated surface and producing crops of citrus orchards are weeds. methods: to achieve this purpose, a research was performed in plot of valencia orange trees of citrus fruits of dezful in 2013. this pro...

Consistently classified among the references for calcite simple prisms, the microstructural units that form the outer layer of the Pinctada margaritifera have been investigated through a series of morphological, crystallographical and biochemical characterizations. It is often said that the polygonal transverse shape of the prisms result from the competition for space between adjacent crystals....

blue with nitrites (Schultz, 1931). This group does, however, behave as a consistent chromatographic series. A rather similar family of pigments occurs in several archaeogastropod shells, especially among the red Trochidae and Fissurellidae, though chromatograms of these forms could not be repeated to our satisfaction owing to shortage of material. In other forms related to the porphyrin-produc...

Heterogeneous nuclear ribonucleoproteins (hnRNPs) have fundamental roles in the post-transcriptional control of gene expression. Here, a cDNA encoding a presumed full-length RNA-binding protein was isolated from pearl oyster (Pinctada fucata) using reverse transcription-polymerase chain reaction with degenerate primers, and rapid amplification of cDNA ends. The full-length cDNA consists of 2737...

The hazardous effect of water pollution on the histopathology of gill organ of the pearl oyster, Pinctada radiata was studied with respect to polycyclic aromatic hydrocarbon contamination in Al-Khiran coast at Kuwait. Thirty oyster samples from each site, site one where dead oysters were located, site two which is two kilometers away from site one and the control site which is ten kilometers aw...

Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of...

Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors ...