Measuring Seepage through Salmon Spawning Gravel

1955 ◽  
Vol 12 (5) ◽  
pp. 706-741 ◽  
Author(s):  
R. A. Pollard
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Oxygen Supply ◽  
Field Method ◽  
Seepage Rate ◽  
Groundwater Seepage ◽  
Salmon Eggs ◽  
Flow Through ◽  
Stream Bed

The rate of oxygen supply to salmon eggs incubating in a stream bed depends on the oxygen concentration in the groundwater and the rate of seepage through the redd. Wickett (1954) devised a simple field method of both sampling the groundwater for the determination of its dissolved oxygen content and measuring the seepage rate, using one tool, a standpipe. The theory of seepage is outlined to show the factors governing the velocity of flow through a redd. Alternative ways of measuring this velocity were examined; the best one is a modification of Wickett's procedure using a similar standpipe. A new field procedure for measuring the oxygen concentration and groundwater seepage rate in a stream bed is recommended.

Spectrophotometric Determination of Dissolved Oxygen Concentration in Water

1974 ◽  
Vol 31 (9) ◽  
pp. 1529-1530 ◽  
Author(s):  
W. S. Duval ◽  
P. J. Brockington ◽  
M. S. von Melville ◽  
G. H. Geen
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Spectrophotometric Determination ◽  
Iodine Concentration ◽  
Colorimetric Determination ◽  
Dissolved Oxygen Concentration ◽  
Winkler Method ◽  
Time Required

A modification of the Winkler method which increases precision while decreasing time required for oxygen analysis is described. The technique involves colorimetric determination of liberated iodine concentration at 287.5 nm.

Determination of dissolved oxygen by use of a spectrophotometric flow-through sensor

1993 ◽  
Vol 284 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Antonio Sanz-Martínez ◽  
Angel Ríos ◽  
Miguel Valcárcel
Keyword(s):  
Dissolved Oxygen ◽  
Flow Through

The Oxygen Supply to Salmon Eggs in Spawning Beds

1954 ◽  
Vol 11 (6) ◽  
pp. 933-953 ◽  
Author(s):  
W. Percy Wickett
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Oxygen Demand ◽  
Subsurface Water ◽  
Flow Section ◽  
Apparent Velocity ◽  
Low Oxygen ◽  
Salmon Eggs ◽  
Controlled Flow

By using standpipes set 12 inches into the stream bottom the oxygen content and apparent velocity of the gravel water in the controlled-flow section of Nile Creek were observed. Values of dissolved oxygen content and velocity that just supply the full oxygen demand of salmon eggs were defined. The high mortalities of chum salmon eggs in the pre-eyed stage, that have been found in certain areas, may be explained on the basis that oxygen demands of 0.00013 to 0.0003 mg./egg/hr. at temperatures of 0.1° to 8.2 °C. were not being met, owing to very low oxygen content or very low apparent velocity of the water in the gravel. Values as low as 0.2 p.p.m. and 2 mm./hr. were recorded. A portable gravel-water sampler is described, which can be used (1) to obtain samples of subsurface water for the determination of dissolved oxygen; and (2) to calculate apparent velocity of gravel water from rate of dilution of an added dye.

scholarly journals Tactic Responses to Oxygen in the Phototrophic Bacterium Rhodobacter sphaeroides WS8N

2002 ◽  
Vol 184 (20) ◽  
pp. 5590-5598 ◽  
Author(s):  
Simona Romagnoli ◽  
Helen L. Packer ◽  
Judith P. Armitage
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Rhodobacter Sphaeroides ◽  
Response Regulator ◽  
Electron Flow ◽  
Spatial Behavior ◽  
Wild Type ◽  
Wide Range ◽  
Flow Through ◽  
Regulator Genes

ABSTRACT The temporal and spatial behavior of a number of mutants of the photosynthetic, facultative anaerobe Rhodobacter sphaeroides to both step changes and to gradients of oxygen was analyzed. Wild-type cells, grown under a range of conditions, showed microaerophilic behavior, accumulating in a 1.3-mm band about 1.3 mm from the meniscus of capillaries. Evidence suggests this is the result of two signaling pathways. The strength of any response depended on the growth and incubation conditions. Deletion of either the complete chemosensory operons 1 and 2 plus the response regulator genes cheY4 and cheY5 or cheA2 alone led to the loss of all aerotactic responses, although the cells still swam normally. The Prr system of R. sphaeroides responds to electron flow through the alternative high-affinity cytochrome oxidase, cbb 3, controlling expression of a wide range of metabolic pathways. Mutants with deletions of either the complete Prr operon or the histidine kinase, PrrB, accumulated up to the meniscus but still formed a thick band 1.3 mm from the aerobic interface. This indicates that the negative aerotactic response to high oxygen levels depends on PrrB, but the mutant cells still retain the positive response. Tethered PrrB− cells also showed no response to a step-down in oxygen concentration, although those with deletions of the whole operon showed some response. In gradients of oxygen where the concentration was reduced at 0.4 μM/s, tethered wild-type cells showed two different phases of response, with an increase in stopping frequency when the oxygen concentration fell from 80 to 50% dissolved oxygen and a decrease in stopping at 50 to 20% dissolved oxygen, with cells returning to their normal stopping frequency in 0% oxygen. PrrB and CheA2 mutants showed no response, while PrrCBA mutants still showed some response.

scholarly journals Determination of the Zone Endangered by Methane Explosion in Goaf with Caving of Longwalls Ventilated on „Y“ System

2016 ◽  
Vol 24 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Jarosław Brodny ◽  
Magdalena Tutak
Keyword(s):  
Oxygen Concentration ◽  
Underground Mining ◽  
Ventilation System ◽  
Hard Coal ◽  
Methane Drainage ◽  
Endogenous Fire ◽  
Flow Through ◽  
Selection Of ◽  
Sufficient Oxygen

Abstract One of the most dangerous and most commonly present risks in hard coal mines is methane hazard. During exploitation by longwall system with caving, methane is emitted to mine heading from the mined coal and coal left in a pile. A large amount of methane also flows from neighboring seams through cracks and fissures formed in rock mass. In a case of accumulation of explosive methane concentration in goaf zone and with appropriate oxygen concentration and occurrence of initials (e.g. spark or endogenous fire), it may come to the explosion of this gas. In the paper there are presented results of numerical analysis of mixture of air and methane streams flow through the real heading system of a mine, characterized by high methane hazard. The aim of the studies was to analyze the ventilation system of considered heading system and determination of braking zones in goaf zone, in which dangerous and explosive concertation of methane can occur with sufficient oxygen concentration equal to at least 12%. Determination of position of these zones is necessary for the selection of appropriate parameters of the ventilation system to ensure safety of the crew. Analysis of the scale of methane hazard allows to select such a ventilation system of exploitation and neighboring headings that ensures chemical composition of mining atmosphere required by regulation, and required efficiency of methane drainage. The obtained results clearly show that numerical methods, combined with the results of tests in real conditions can be successfully used for the analysis of variants of processes related to ventilation of underground mining, and also in the analysis of emergency states.

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