We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration a...

The Gas Push–Pull Test (GPPT) is a tool for measuring in situ soil processes including methane oxidation. To quantify methane oxidation, methane and non-reactive gases selected based on transport behaviour similar to methane, were injected into soil above a petroleum hydrocarbon contaminated aquifer and gas samples were extracted over time. The rate of loss of methane was compared to the loss o...

Air is injected locally at the base of an immersed granular bed. The gas, which is forced to flow gently through the material, creates several paths between the grains. We observe that the latter gas venting results in the emission of bubbles in a localized region at the free surface. Additional experiments, performed in two dimensions, permit a direct visualization of the paths, and a theoreti...

Phenylalanine in serum and urine was determined by gas chromatography after it was converted, by action of nitrous acid, to the corresponding hydroxy acid, phenyllactic acid. After extraction with ether, the phenyllactic acid was derivatized with bis(trimethylsilyl) trifluoroacetamide under mild conditions, and the product was injected directly into the gas chromatograph. The precision of the m...

Field trials were conducted to test the effectiveness of a gas exploding device called “Rodentorch” in reducing pest populations of ground squirrels and prairie dogs. Ignition of a propane/oxygen mixture injected for 30 seconds into burrows reduced prairie dog activity 13.0%. Doubling the injection time in prairie dog burrows to 60 seconds resulted in a 63.3% reduction. Reduction in ground squi...

We investigate the validity of fluctuation theorems for an asymmetric rotor experiment in a granular gas. A first state, with a Gaussian distribution of the angular velocity, is found to be well described by a first order Langevin equation. We show that fluctuation theorems are valid for the injected work and for the total entropy production. In a second state, the angular velocity distribution...

Introduction The synthesis of single-crystal silicon nanocrystals we present is performed in the gas phase of a radio frequency (rf) discharge. The plasma is produced in a discharge box, enclosed in a vacuum vessel, containing an Ar/SiH4 mixture (92:8). The typical pressure is 0.12 mbar while typical rf injected power is 10 W. Gas temperature can be decreased to -40 oC. Dust particle formation ...

In this work, the claim that optically thick gases can emit as blackbodies is refuted. The belief that such behavior exists results from an improper consideration of heat transfer and reflection. When heat is injected into a gas, the energy is primarily redistributed into translational degrees of freedom and is not used to drive emission. The average kinetic energy of the particles in the syste...

Methods. Dutch-belted rabbit were used to create a model for traction retinal detachment. Seven to 10 days after vitreous gas compression, 25,000 homologous fibroblasts were injected into the vitreous cavity. Subsequently, the eyes received either sham injections or doses of 6, 30, or 60 nmol of aclacinomycin A, respectively. The fundus findings were documented on days 7, 14, and 28 after the f...

The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method was used to measure temperature and the absolute mole fractions of N2, O2 and H2 in a supersonic non-reacting fuel-air mixing experiment. Experiments were conducted in NASA Langley Research Center’s Direct Connect Supersonic Combustion Test Facility. Under normal operation of this facility, hydrogen and air burn to increase the...