abstractthe purpose of this study was to investigate the controllable operating parameters influence, including ph, solid content, collector, co-collector, and depressant dose, and conditioning time, on apatite flotation kinetics. four first order flotation kinetic models are tested on batch flotation time-recovery profiles. the results of batch flotation tests and the fitting of first-order ki...

this paper investigates the importance of considering biomass growth and decay for predicting a field scale microbial degradation of btex plume in an unconfined aquifer system in the pump station area of tehran oil refinery (tor), iran. a two-dimensional finite volume model has been presented to predict multi-species reactive transport incorporating physical, chemical and biological processes i...

The removal of Cd2+ and Pb2+ ions from wastewater using p-tert-butyl-calix[4] arene was investigated in terms of initial pH, initial concentration, adsorbent dosage, contact time and temperature. The maximum adsorption occurred at the pH value of 6. The adsorbent studied exhibits high efficiency for Cd (II)and Pb (II) adsorption and the equilibrium states could be achieved in 10 min. Adsorption...

a modification of peng-robinson equation is described wherein in the parameter b is expressed as a linear function of temperature. the modified equation is then applied to a series of light hydrocarbons and refrigerants, and predicted values for vapor pressure, saturated vapor volume, saturated liquid volume and the heat of evaporation are compared with the corresponding experimental data. cons...

Cluster distribution kinetics is adopted to explore the kinetics of polymer crystallization. Population balance equations based on crystal size distribution and concentration of amorphous polymer segments are solved numerically and the related dynamic moment equations are also solved. The model accounts for heterogeneous or homogeneous nucleation and crystal growth. Homogeneous nucleation rates...

Aim: The objective of this work was to study the effects of formulation variables on the release kinetics of paracetamol tablet formulation. Materials and Methods: Paracetamol tablets were formulated using wet granulation (WG) and direct compression (DC) using two predetermined pressures. Avicel, dicalcium phosphate (DCP) and pregelatinized starch (PGS) were used as directly compressible...

this paper considers the possibility of spontaneous transition of aracemic mixture (composed of equal amounts of two enantiomeric species, say l and d) into a monochiral state (in which only one enantiomer, say l, is present). transitions of this kind have been recently experimentally observed. a plausible approach to this phenomenon is a model put forward by frank, based on simple laws of chem...

Risk-based assessment methods are commonly used at the contaminated sites by hydrocarbon pollutants. This paper presents the results of a two-dimensional finite volume model of reactive transport of biodegradable BTEX which have been developed for the saturated zone of an unconfined aquifer in the Pump station area of Tehran oil refinery, Iran. The model governing equations were numerically sol...

We describe a web tool ENZO (Enzyme Kinetics), a graphical interface for building kinetic models of enzyme catalyzed reactions. ENZO automatically generates the corresponding differential equations from a stipulated enzyme reaction scheme. These differential equations are processed by a numerical solver and a regression algorithm which fits the coefficients of differential equations to experime...