in the present study, a new gas diffusion electrode (gde) (based on pt/nafion membrane) is fabricated. the electrochemical results show that the new gde has the highest electrochemical activity toward the oxygen reduction reaction (orr) among the three electrodes. the sem and xrd findings show that a platinum layer can be attached to nafion membrane closely and firmly with a strong peak corresp...

the major limitation in the application of bioactive molecule is their low permeation across plasma membrane. in 1988 it was discovered, that a natural polycationic protein, the trans-acting activator of transcription (tat) of the human immunodeficiency virus (hiv-1), passed very efficiently through cell membrane of cultured mammalian cells. tat became known as the first cell penetrating peptid...

Maximum Power Point (MPP) tracker has an important role in the performance of fuel cell (FC) systems improvement. Tow parameters which have effect on the Fuel cell output power are temperature and membrane water. So contents make the MPP change by with variations in each parameter. In this paper, a new maximum power point tracking (MPPT) method for Proton Exchange Membrane (PEM) fuel cell is pr...

the kinetics of the potassium thiocyanate transport mediated by dicyclohexyl-18-crown-6 (l) through a bulk liquid membrane is studied experimentally and theoretically. the proposed model is based on the assumption of a pure diffusion of the complex salt [k·l]+scn¯ through the liquid membrane stagnant films at the interfaces. it illustrates the connection between liquid-liquid extraction equilib...

Nowadays, oily wastewater is increasing along with the growth of various industries. So, wastewater treatment is necessary in order to protect the environment. In this study, a mullite ceramic membrane was prepared. Then, oily wastewater treatment with 200 mg L-1 concentration was investigated by the response surface methodology based on Box-Behnken design (BBD) using Design-Expert 7...

nowadays, membrane processes are widely used for high purity nitrogen production. separation of air by membranes is a flexible process in which the investment and operational costs are lower than for example adsorption or cryogenic processes. such processes are based on relative permeability of air components which are transported by the pressure difference between two sides of the membrane. ma...

introduction: we have recently reported the presence of two potassium currents with 598 and 368 ps conductance in the rough endoplasmic reticulum (rer) membrane. the 598 ps channel was voltage dependent and atp sensitive. however, the 368 ps channel was rarely observed and its identity remained obscure. since cationic channels in intracellular organelles such as mitochondria and rer play import...

The total volume of water on Earth is circa 300 million cubic miles, with close to 98.0% being salt water and the remaining 2.0% fresh water. It has been increasingly more challenging to harvest fresh water from surface water, seawater and even from wastewater due to the combination of factors, viz. burgeoning population growth, rapid industrialization and climate change. Recently, membrane dis...

Supramolecular chemistry can be defined as a field of chemistry, which studies the complex multi-molecular species formed from molecular components that have relatively simpler structures. This field has been subject to extensive research over the past four decades. This review discusses classification of supramolecules and their application in design and construction of ion selective sensors.