abstract the oak leafroller moth , tortrix viridana l. is a destructive pest within it’s spreading area which invades the oak species, especially in west and northwest forests of iran, in recent years. some parts of west azarbayjan’s forests which are located in piranshahr and sardasht region have been affected by this pest since 1989 that oak trees vigor and survival have been gone down result...

A ring R is uniquely (nil) clean in case for any $a in R$ there exists a uniquely idempotent $ein R$ such that $a-e$ is invertible (nilpotent). Let $C =(A V W B)$ be the Morita Context ring. We determine conditions under which the rings $A,B$ are uniquely (nil) clean. Moreover we show that the center of a uniquely (nil) clean ring is uniquely (nil) clean.

Diberikan sebarang ring R dan semigrup S. Ring R[S] adalah himpunan semua fungsi f dari S ke dengan supp(f) berhingga yang dilengkapi operasi penjumlahan pergandaan sama pada polinomial R[X]. Di sisi lain, matriks M_n (R) atas berukuran n×n perkalian matriks. dalam penelitian ini, dikonstruksi (R_1 [S_1 ] ) (R_2 [S_2 R_1,R_2 S,S_2 semigrup. Selain itu, didefinisikan pemetaan τ menggunakan homom...

use of the double ring infiltrometer to measure soil water infiltration in center pivot irrigation systems is not an accurate approach; because the real conditions of infiltration under center pivot sprinklers is different from what happens in the double ring. in this study, the infiltration parameters were determined under real conditions of a center pivot system. for this purpose, a single ri...

Nitro-containing heteroaromatic derivatives structurally related to nitroimidazole (Metronidazole) are being extensively evaluated against Helicobacter pylori isolates. On the other hand, 1,3,4-thiadiazole derivatives have also demonstrated promising antibacterial potential. In present study, we evaluated anti-H. pylori activity of novel hybrid molecules bearing nitroaryl and 1,3,4-thiadiazole ...

 Let $R$ be an associative ring with identity and $Z^*(R)$ be its set of non-zero zero divisors.  The zero-divisor graph of $R$, denoted by $Gamma(R)$, is the graph whose vertices are the non-zero  zero-divisors of  $R$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$.  In this paper, we bring some results about undirected zero-divisor graph of a monoid ring o...

In this paper the transmittance of metal-insulator-metal (MIM) waveguides containing semi-circular ring shaped and rectangular ring shaped grooves are investigated. By varying groove parameters their effects on the transmittance of the MIM waveguides are investigated. The results show that the transmittance spectra of the waveguides have maximum and minimum points, and by using appropriate para...