abstract increased knowledge of russian knapweed biology would facilitate development of an optimum control program. to examine germination characteristic of this weed, several experiments were conducted in weed research department, plant pest and diseases research institute of tehran during 2003. first experiment was a factorial with 3 replications to break seed dormancy of this weed. first fa...

the taguchi design of experiments was used to test the relative importance of medium components and environmental factors on poly(β-hydroxybutyrate)(phb) production by ralstonia eutropha. the optimum condition was obtained as: fructose concentration, 15 g/l; c/n ratio, 7.4; agitation speed 200 rpm; culture time, 40 h; temperature, 25 ° c; seed age, 15 h. at optimum condition the yield of phb pr...

The germination response of Hylocereus setaceus seeds to isothermic incubation at different water potentials was analysed by using the thermal time and hydrotime models, aiming to describe some germination parameters of the population and to test the validity of the models to describe the response of the seeds to temperature and water potential. Hylocereus setaceus seeds germinated relatively w...

In the present study, silica aerogel- egg shell was synthesized for dye removal of colored wastewater. The nano composite structure was characterized by Fourier transform infrared spectra FTIR and scanning electron microscope SEM.The ability of nano composite absorption was assessed for removal basic violet 16BV16 dye from aqueous solutions and was compared with two other adsorbents such as egg...

AaCel9A [β-1,4-endoglucanase, (E.C:3.2.1.4)], was immobilized onto glutaraldehyde activated chitosan macrosphere by covalent attachment. The properties of the immobilized AaCel9A were investigated by determining the optimum pH and optimum temperature for activity, thermal stability, and kinetic parameters. The immobilization process shifted the enzyme’s optimum temperature from 65 °C for the fr...

In order to evaluate cardinal temperatures and optimum thermal range of germination of three medicinal plants including Ajowan, Fennel and Dill an experiment was conducted in a Completely Randomized Design with three replications. Temperatures considered for this study were: 5, 10, 15, 20, 25, 30 and 35 ?C. Results indicated that temperature affected germination rate and percentage of these cro...

Effect of temperature on the chemiluminescence (CL) of Luminol in some aqueous aliphatic amines such as ethyl amine (EA), diethyl amine (DEA), and triethyl amine (TEA), have been studied and reported. On the basis of experimental results, it is found that the chemiluminescence intensity initially increased with temperature, attains an optimum value of particular temperature and then decrease on...

In this article CuO/water nanofluid was synthesized by using polyvinylpyrolidone (PVP) as the dispersant.  Thenanofluid stability period and the heat transfer enhancement were determinedby measuring the thermal conductivities. To study the nano-fluid stability, zeta (ζ) potential, and absorbency were measured under different pH values and PVP surfactant concentrations; also thermal conductivity...

The present study aims at designing a promising Microbial Fuel Cell (MFC) to utilize wastewater in order to generate electricity. Two types of salt bridge have been used in MFC (KCl and NaCl). The maximum electricity generation with 1M KCl and NaCl has been 823 and 713 mV, respectively. Varied salt concentrations (0.5M, 1M, 2M, and 3M) of salt bridge in MFC have been analyzed with different fac...