electronic effects were investigated on the singlet–triplet energy gaps of divalent unsaturated seven- membered ring r2c6h6m (m=c, si, ge, sn, pb, r= –h, -ch3, i-pr , t-bu) at b3lyp/6-311++g** level. all the triplet states of r2c6h6c were more stable than the related the singlet states while all the singlet states of r2c6h6m (m= si, ge, sn, pb, r= –h, -ch3, i-pr , t-bu) were more stable than th...

nowadays energy has significant role in socio economic development of counties; any decision on energy sector may affect the broad area in societies. system approach in energy modeling as an efficient method is known by many researchers in management and planning in a country particularly in energy sector. also system dynamics is one of the efficient methods, for reason unique ability at solvin...

scattering of an incoming wave train by a discontinuity at the upper surface of the ocean over a uniform porous bottom of finite depth is considered here in the framework of linearized water wave theory. by employing residue calculus method, the reflection and transmission coefficient are obtained. these coefficients are computed numerically for different values of the porosity parameter g and ...

the solvatochromism of fluoresceine and its derivatives was studied in solvents of different hydrogen bond donor (hbd), hydrogen bond acceptor (hba), donor number (dn) and acceptor number (an) by their uv-vis spectra. results showed that position, intensity and shape of absorption bands change with type of solvent. these changes can be rationalized by solvatochromic parameters such as α, β, et ...

the increasing needs for energy, its high price and its environmental impact on greenhouse gases emission and limited energy resources due to increased research on energy balance in crop production systems. the objective of this research was to compare seedbed preparation and sowing methods in wheat production in kordkoy region with respect to energy use and efficiency. fifteen wheat fields wer...

Recent developments in image quality, data storage, and computational capacity have heightened the need for texture analysis in image process. To date various methods have been developed and introduced for assessing textures in images. One of the most popular texture analysis methods is the Texture Energy Measure (TEM) and it has been used for detecting edges, levels, waves, spots and ripples b...