scholarly journals Removal of Dissolved Oxygen in Sudachi Juice by Nitrogen Gas Pressurization

2005 ◽  
Vol 52 (4) ◽  
pp. 178-182 ◽  
Author(s):  
Yoshihisa Muramoto ◽  
Katsuhiro Tamura ◽  
Takanori Taniwaki ◽  
Shingo Takai ◽  
Yoshihisa Suzuki
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Gas

Nitrogen Gas Purging for the Deoxygenation of Polyaromatic Hydrocarbon Solutions in Cyclohexane for Routine Fluorescence Analysis

2008 ◽  
Vol 62 (3) ◽  
pp. 333-336 ◽  
Author(s):  
Todd Pagano ◽  
Adam J. Biacchi ◽  
Jonathan E. Kenny
Keyword(s):  
Dissolved Oxygen ◽  
Fluorescence Intensity ◽  
Fluorescence Analysis ◽  
Polyaromatic Hydrocarbon ◽  
Nitrogen Flow Rate ◽  
Nitrogen Gas ◽  
Experimental Conditions ◽  
Fluorescence Studies ◽  
Gas Purging ◽  
Collisional Deexcitation

During routine fluorescence analysis, the presence of dissolved oxygen in solutions can result in the dynamic quenching of a fluorophore's emission through collisional deexcitation of the fluorophore's excited state. In order to avoid this type of fluorescence quenching, dissolved oxygen is often removed from solutions by an inert gas purging procedure. However, the details and quantification of this purging process are often limited in fluorescence studies. In this work, standard 10 mm × 10 mm fluorescence cuvettes are filled with polyaromatic hydrocarbon (PAH) solutions in cyclohexane and purged using nitrogen gas, and the experimental purging parameters (nitrogen flow rate, amount of volatile solvent loss, and rate of oxygen removal) are measured and analyzed. For experimental conditions similar to those used in this study, we are able to provide useful guidelines for the deoxygenation of solutions, specifically the purge times required for solutions of fluorophores with various fluorescence lifetimes. Enhancement factors, or F0/ F values (the ratio of fluorescence intensity of a completely deoxygenated solution to the fluorescence intensity of an aerated solution), for chrysene, phenanthrene, naphthalene, and pyrene solutions in cyclohexane were found to be 3.61 ± 0.02, 4.17 ± 0.02, 7.63 ± 0.07, and 21.81 ± 0.35, respectively.

Supersaturation of Nitrogen in Water During Passage Through Hydroelectric Turbines at Mactaquac Dam

1973 ◽  
Vol 30 (9) ◽  
pp. 1392-1394 ◽  
Author(s):  
J. Rod Macdonald ◽  
R. A. Hyatt
Keyword(s):  
Dissolved Oxygen ◽  
New Brunswick ◽  
Salmo Salar ◽  
Hydroelectric Station ◽  
Gas Bubbles ◽  
Anguilla Rostrata ◽  
Fish Kills ◽  
Nitrogen Gas ◽  
Dissolved Nitrogen ◽  
Generating System

Two fish kills occurred at the Saint John River, New Brunswick, below the Mactaquac Hydroelectric Station in the summer of 1968. Gas bubbles, commonly associated with nitrogen supersaturation, were observed on dead and dying salmon (Salmo salar) and eels (Anguilla rostrata). Tests showed that the concentrations of dissolved oxygen and nitrogen gases were substantially increased when water passed through the turbine generating system at low generating levels. Concentrations of dissolved nitrogen gas increased by as much as 20% above atmospheric equilibrium.

Aeration of water with oxygen microbubbles and its purging effect

2017 ◽  
Vol 825 ◽  
pp. 16-28 ◽  
Author(s):  
Tatsuya Yamashita ◽  
Keita Ando
Keyword(s):  
Dissolved Oxygen ◽  
Tap Water ◽  
Gas Bubbles ◽  
Circulation System ◽  
Dissolved Gases ◽  
Binary Diffusion ◽  
Nitrogen Gas ◽  
Dissolved Nitrogen ◽  
Supplemental Experiment ◽  
Glass Surfaces

In this paper, we apply aeration with oxygen microbubbles to tap water; the intent is to quantitatively evaluate whether nitrogen gas originally dissolved in the water under the atmosphere is purged by the aeration with oxygen microbubbles. Oxygen microbubbles are continuously injected into the circulation system of tap water open to the atmosphere. While the concentration of dissolved oxygen (DO) can be detected by a commercial DO meter, that of dissolved nitrogen (DN) is unavailable. To detect the DN level, we observe the growth of millimetre-sized gas bubbles nucleated at glass surfaces in contact with the aerated water and compare it with the multi-species theory of Epstein and Plesset where the (unknown) DN concentration is treated as a fitting parameter. In the theory, we solve binary diffusion of each gas species (oxygen or nitrogen) in the water independently, under the assumption that the dissolved gases are sufficiently dilute. Comparisons between the experiment and the theory suggest that the DN in the water is effectively purged by the oxygen aeration. The supplemental experiment of aeration with nitrogen microbubbles is also documented to show that the DO can be effectively purged as well.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

A conduction-cooled stage for high-resolution Cryo-SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1282-1283
Author(s):  
John G. Sheehan
Keyword(s):  
High Resolution ◽  
Liquid Nitrogen ◽  
Mechanical Stability ◽  
Cooling System ◽  
Cold Trap ◽  
Nitrogen Gas ◽  
Particulate Suspensions ◽  
Advantages And Disadvantages ◽  
Convection Cooling ◽  
Styrene Butadiene

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.

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