A new and extremely sensitive method for measuring nitrogenase activity through acetylene reduction is presented. Ethylene produced by nitrogenase-mediated reduction of acetylene is detected by using laser photoacoustics (LPA). This method possesses a detection limit making it 3 orders of magnitude more sensitive than traditional gas chromatographic analysis. Photoacoustic detection is based on...

Core flooding experiments were conducted with the objective of evaluating near miscible surfactant alternating CO2 injection and the effect of surfactant concentrations on gas-oil and water displacements in porous media. The core samples were provided from a low permeability mixed wet oil reservoir at 156 °F and 1900 psia. In addition, very few studies of surfactant adsorption on car...

In this paper, we report the growth pattern and rate of CH4 hydrate in sandstone pores. A high-pressure, water-wet, transparent micromodel with pores resembling a rock was used to visualize formation at reservoir conditions (P = 35–115 bar T 0.1–4.9 °C). The preferably formed grew along gas–water interface until gas phase completely encapsulated by film. Two different rates were identified on i...

The macroscopic behaviour of air and water in porous media is often approximated using Richards' equation for the fluid saturation and pressure. This equation is parametrized by the hydraulic conductivity and water release curve. In this paper, we use homogenization to derive a general model for saturation and pressure in porous media based on an underlying periodic porous structure. Under an a...

Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2) and with a mixture (30% CO2 and 70% N2) in dry and wet conditions at 25 °C, 50 °C, 60 °C and 75 °C and up to 600 kPa. Interesting values of single gas selectivity up to 60 °C (between 31 and 28 for CO2/N2 and between 33 and 30 fo...

The paper presents the application of Control-Volume Finite Element (CVFE) method in simulation of multi-phase (water, oil, gas) flow through porous media. The numerical model developed using the CVFE method presents advantage in simulation of faulted reservoirs or simulation of complex geometry reservoir. Also, CVFE method can accurate represents the location of wells inside of reservoir, fact...

UNLABELLED Hypothermia is ineffective in 45% of neonates with hypoxic-ischemic encephalopathy. Xenon has additive neuroprotective properties, but is expensive, and its application complicated. Argon gas is cheaper, easier to apply, and also has neuroprotective properties in experimental settings. The aim was to explore the safety of argon ventilation in newborn piglets. METHODS Eight newborn ...

Saturation decompression is a physiological process of transition from one steady state, full saturation with inert gas at pressure, to another one: standard conditions at surface. It is defined by the borderline condition for time spent at a particular depth (pressure) and inert gas in the breathing mixture (nitrogen, helium). It is a delicate and long lasting process during which single milli...

the objective of this research was to investigate the effects of deficit irrigation on physiological and agronomic terms of eggplant to maximize the water use efficiency (wue) without affecting the final yield and fruit quality parameters under arid environment. therefore, two field experiments were conducted at two different sites: ghor al-safi, jordan valley and sail al-karak, karak valley, ka...