background and objectives: psychrotrophic bacteria can produce enzymes at low temperatures; this provides a wide biotechnological potential, and offers numerous economical advantages over the use of mesophilic bacteria. in this study, extracellular protease production by psychrotrophic rheinheimera sp. (km459533) was optimized by the response surface methodology. materials and methods: the cult...

Treated sea water is the most significant source of water and surfactant floods. The various chemicals employed in treatment plants should be compatible with surfactant systems. Based on surface tension experiments, the activity of these chemicals is examined over a wide range of concentrations in different solutions, including distillated water, sea water by using three types of surfactant mix...

Along with high sensitivity in detecting gas, the response and recovery times of semiconductor gas sensors are of considerable importance for real life applications. In most cases, the recovery time is more than the response time. At the same time, water vapor present in the ambient, is chemisorbed on the tin oxide, SnO2 surface and the water molecules dissociate into hydroxyl species, which ac...

Ultrasonic technology and response surface methodology (RSM) wereused for optimization of extraction of condensed tannins from the leaf, acron, gland and gall of oak. Three independent variables such as solvent percentage (%), temperature (°C) and time (min) were studied. Effect of methanol concentration was found to be significant on all responses. Optimal ultrasonicassisted extraction (UAE) c...

The ultrasound-assisted (UA) soybean oil methanolysis using KOH as a catalyst was studied at different reaction conditions in a microreactor. Box–Behnken experimental design, with three variables, was performed and the effects of three reaction variables i.e. reaction temperature, catalyst concentration and the methanol-to-oil molar ratio on fatty acid methyl ester (FAME) yield were evaluated b...

Objective(s): ISCOMATRIX vaccines have now been shown to induce strong antigen-specific cellular or humoral immune responses to a broad range of antigens of viral, bacterial, parasite or tumor. In the present study, we investigated the role of ISCOMATRIX charge in induction of a Th1 type of immune response and protection against Leishmania major infection in BALB/c mice.  Materials and Methods:...

Fitting response surface models is usually carried out using statistical packages to solve complicated equations in order to produce the estimates of the model coefficients. This paper proposes a new procedure for fitting response surface models to mixed two-level and four-level factorial designs. New and easier formulae are suggested to calculate the linear, quadratic and the interaction coeff...

Immobilizing of zero-valent iron in mono- and bi-metallic systems on the bentonite clay surface as new nanocatalyst were synthesized and used to degrade model acidic dyes from aqueous media. The Fourier-transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis were ...