‎let $g$ be a finite group‎. ‎we say that the derived covering number of $g$ is finite if and only if there exists a positive integer $n$ such that $c^n=g'$ for all non-central conjugacy classes $c$ of $g$‎. ‎in this paper we characterize solvable groups $g$ in which the derived covering number is finite‎.‎

‎Let $G$ be a finite group‎. ‎We say that the derived covering number of $G$ is finite if and only if there exists a positive integer $n$ such that $C^n=G'$ for all non-central conjugacy classes $C$ of $G$‎. ‎In this paper we characterize solvable groups $G$ in which the derived covering number is finite‎.‎ 

Background: In food industry, carotenoids are used as food colorants conferring yellow to red color. This research was designed to study on lipid and β-carotene production by Rhodosporidium diobovatum cultured with different Carbon to Nitrogen (C/N) ratios. Methods: R. diobovatum was cultured in a medium containing 40 g/l glucose (as the carbon source) and different C/N ratios (20, 50, and 80)...

The objective of this study is to identify the most suitable portions of the C1 coking coal seam in the North Block of the East-Parvadeh coal deposit (Central Iran), according to ash and sulfur values, using C-N fractal modeling. Based on the C-N log-log plots, different geochemical populations were evaluated based on their sulfur and ash content. They were then divided into five populations ea...

The Zouzan area is located in the SE of Torbat-e- Heydarieh city (NE Iran). This area is located on north part of the Lut block which consists of basaltic andesite, tuff and porphyritic andesite. The purpose of this research is to investigate the enrichment of metal elements in the Zouzan area and provide a metallic geochemical model. For this purpose, 488 stream samples were analyzed using by ...

In class, we have assumed that the concentration, the number of free monomers in the volume, does not change in time, C = n/V = const. Assume now, that no new monomer is added to the solution as the filament grows and therefore C = C(t). • Sketch the evolution of the free monomer concentration C as a function of time t. • Determine the tangent to the curve at t → 0. • Determine the asymptotic v...

The leaf nitrogen content is generally accepted as an indicator of food quality and as a factor affecting host selection by phytophagous insects. The alate pea aphids (Acyrthosiphon pisum Harris, Aphididae) were given a choice among non-nodulated pea plants (Pisum sativum L.) supplied with one of four nitrate-N levels (0, 3, 15 and 30 mM). When whole plants were exposed to aphids for 7 days, th...

In this study a parasitological investigation on 238 samples of Neogobius species from the south-east of Caspian Sea was carried out. The samples including Neogobius melanostomus (35), N. fluviatilis pallasi (103), N. kessleri gorlap (70) and N. bathybius (30) were seasonally seined by beach net during one year (summer 2006-spring 2007), fixed in 10 % buffer formalinand transferred to the labor...

The analytic, open-form solution for the steady-state, 2-dimensinal partial differential equation describing the concentration profile for the gas solute in a falling liquid film flowing under a steady-state laminar condition was shown. The overall mass transfer coefficient, c k , for a binary diffusion system, was evaluated in light of the analytic solution and was tested for oxygen absorption...