scholarly journals THE TOTAL LUMINOUS EFFICIENCY OF LUMINOUS BACTERIA

1925 ◽  
Vol 8 (2) ◽  
pp. 89-108 ◽  
Author(s):  
E. Newton Harvey
Keyword(s):  
Power Plant ◽  
Oxygen Concentration ◽  
Luminescence Intensity ◽  
Sea Water ◽  
Luminous Efficiency ◽  
Pure Oxygen ◽  
Cent Oxygen ◽  
Maximum Value ◽  
Cent Efficiency ◽  
Luminous Bacteria

Methods are described for measuring the light emitted by an emulsion of luminous bacteria of given thickness, and calculating the light emitted by a single bacterium, measuring 1.1 x 2.2 micra, provided there is no absorption of light in the emulsion. At the same time, the oxygen consumed by a single bacterium was measured by recording the time for the bacteria to use up .9 of the oxygen dissolved in sea water from air (20 per cent oxygen). The luminescence intensity does not diminish until the oxygen concentration falls below 2 per cent, when the luminescence diminishes rapidly. Above 2 per cent oxygen (when the oxygen dissolving in sea water from pure oxygen at 760 mm. Hg pressure = 100 per cent) the bacteria use equal amounts of oxygen in equal times, while below 2 per cent oxygen it seems very likely that rate of oxygen absorption is proportional to oxygen concentration. By measuring the time for a tube of luminous bacteria of known concentration saturated with air (20 per cent oxygen) to begin to darken (2 per cent oxygen) we can calculate the oxygen absorbed by one bacterium per second. The bacteria per cc. are counted on a blood counting slide or by a centrifugal method, after measuring the volume of a single bacterium (1.695 x 10–12 cc.). Both methods gave results in good agreement with each other. The maximum value for the light from a single bacterium was 24 x 10–14 lumens or 1.9 x 10–14 candles. The maximum value for lumen-seconds per mg. of oxygen absorbed was 14. The average value for lumen-seconds per mg. O2 was 9.25. The maximum values were selected in calculating the efficiency of light production, since some of the bacteria counted may not be producing light, although they may still be using oxygen. The "diet" of the bacteria was 60 per cent glycerol and 40 per cent peptone. To oxidize this mixture each mg. of oxygen would yield 3.38 gm. calories or 14.1 watts per second. 1 lumen per watt is therefore produced by a normal bacterium which emits 14 lumen-seconds per mg. O2 absorbed. Since the maximum lumens per watt are 640, representing 100 per cent efficiency, the total luminous efficiency if .00156. As some of the oxygen is used in respiratory oxidation which may have nothing to do with luminescence, the luminescence efficiency must be higher than 1 lumen per watt. Experiments with KCN show that this substance may reduce the oxygen consumption to 1/20 of its former value while reducing the luminescence intensity only ¼. A partial separation of respiratory from luminescence oxidations is therefore effected by KCN, and our efficiency becomes 5 lumens per watt, or .0078. This is an over-all efficiency, based on the energy value of the "fuel" of the bacteria, regarded as a power plant for producing light. It compares very favorably with the 1.6 lumens per watt of a tungsten vacuum lamp or the 3.9 lumens per watt of a tungsten nitrogen lamp, if we correct the usual values for these illuminants, based on watts at the lamp terminals, for a 20 per cent efficiency of the power plant converting the energy of coal fuel into electric current. The specific luminous emission of the bacteria is 3.14 x 10–6 lumens per cm2. One bacterium absorbs 215,000 molecules of oxygen per second and emits 1,280 quanta of light at λmax = 510µµ. If we suppose that a molecule of oxygen uniting with luminous material gives rise to the emission of 1 quantum of light energy, only 1/168 of the oxygen absorbed is used in luminescence. On this basis the efficiency becomes 168 lumens per watt or 26.2 per cent.

scholarly journals THE RESPIRATION OF LUMINOUS BACTERIA AND THE EFFECT OF OXYGEN TENSION UPON OXYGEN CONSUMPTION

1929 ◽  
Vol 13 (1) ◽  
pp. 27-45 ◽  
Author(s):  
Charles S. Shoup
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Oxygen Tension ◽  
Small Cells ◽  
Pure Oxygen ◽  
Catalytic Surfaces ◽  
Rate Of Oxygen Consumption ◽  
Luminous Bacteria ◽  
Effect Of Oxygen

1. The respiration of luminous bacteria has been studied by colorimetric and manometric methods. 2. Limulus oxyhaemocyanin has been used as a colorimetric indicator of oxygen consumption and indicator dyes were used for colorimetric determination of carbon dioxide production. 3. The Thunberg-Winterstein microrespirometer has been used for the measurement of the rate of oxygen consumption by luminous bacteria at different partial pressures of oxygen. 4. The effect of oxygen concentration upon oxygen consumption has been followed from equilibrium with air to low pressures of oxygen. 5. Luminous bacteria consume oxygen and produce carbon dioxide independent of oxygen pressures from equilibrium with air (152 mm.) to approximately 22.80 mm. oxygen or 0.03 atmosphere. 6. Dimming of a suspension of luminous bacteria occurs when oxygen tension is lowered to approximately 2 mm. Hg (0.0026 atmosphere) and when the rate of respiration becomes diminished one-half. 7. Pure nitrogen stops respiratory activity and pure oxygen irreversibly inhibits oxygen consumption. 8. The curve for rate of oxygen consumption with oxygen concentration is similar to curves for adsorption of gasses at catalytic surfaces, and agrees with the Langmuir equation for the expression of the amount of gas adsorbed in unimolecular layer at catalytic surfaces with gas pressure. 9. A constant and maximum rate of oxygen consumption occurs in small cells when oxygen concentration becomes sufficient to entirely saturate the surface of the oxidative catalyst of the cell.

scholarly journals THE OXYGEN CONSUMPTION OF LUMINOUS BACTERIA

1928 ◽  
Vol 11 (5) ◽  
pp. 469-475 ◽  
Author(s):  
E. Newton Harvey
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Oxygen Tension ◽  
Sea Water ◽  
Unit Weight ◽  
Bacterial Surface ◽  
Average Temperature ◽  
Luminous Bacteria ◽  
Sufficient Oxygen ◽  
Correct Comparison

Oxygen consumption of luminous bacteria determined by the Thunberg micro respirometer and by the time which elapses before the luminescence of an emulsion of luminous bacteria in sea water begins to dim, when over 99 per cent of the dissolved oxygen has been consumed, agree exactly. Average values for oxygen consumption at an average temperature of 21.5°C. are 4.26 x 10–11 mg. O2 per bacterium; 2.5 x 104 mg. per kilo and 5.6 mg. O2 per sq. m. of bacterial surface. The only correct comparison of the oxygen consumption of different organisms or tissues is in terms of oxygen used per unit weight with a sufficient oxygen tension so that oxygen consumption is independent of oxygen tension. Measurement of the oxygen concentration which just allows full luminescence, compared with a calculation of the oxygen concentration at the surface of a bacterial cell just necessary to allow the observed respiration throughout all parts of the cell, indicates that oxygen must diffuse into the bacterium much more slowly than through gelatin or connective tissue but not as slowly as through chitin.

scholarly journals THE MINIMUM CONCENTRATION OF OXYGEN FOR LUMINESCENCE BY LUMINOUS BACTERIA

1923 ◽  
Vol 6 (1) ◽  
pp. 13-19 ◽  
Author(s):  
E. Newton Harvey ◽  
Thomas F. Morrison
Keyword(s):  
Sea Water ◽  
Minimum Concentration ◽  
Luminous Bacteria

A method is described for measuring the concentration of oxygen to allow just perceptible luminescence of luminous bacteria. The value turns out to be extraordinarily low, about 0.005 mm. Hg pressure O2 or 1 part by weight oxygen dissolved in 3,700,000,000 cc. sea water.

scholarly journals INTEGRATED SYNOPTICAL METHOD FOR CALCULATING ASSIMILATION CAPACITY OF SEA WATERS

2017 ◽  
pp. 115-120
Author(s):  
Hikmat Hamid oglu Asadov ◽  
Sima Ajdar gizi Askerova
Keyword(s):  
Sea Water ◽  
Water Masses ◽  
Optimum Regime ◽  
Optimization Task ◽  
Maximum Value ◽  
Long Time ◽  
Negative Effect ◽  
Optimum Order ◽  
Assimilation Capacity ◽  
The Given

Pollution of sea waters is one of major attributes of coastal industrial centers and the norming of such emissions is one of major countermeasures. The assimilation capacity of sea waters is a major factor relevant at norming and planning of outflows into sea waters. At present time the synoptical method has been developed, which doesn’t require carrying out long time and repeated observing of the level of pollution of sea waters. This method has formed the basis for developing the integrated synoptical method for calculating sea water assimilation capacity. The suggested method provides for division of the sea waters into separated homogenous water masses. The aim of the study is to develop an inverse integrated synoptical method allowing synthesizing of such an optimum order for loading separate water masses with pollutants upon, at which the calculated total value of assimilation capacity would reach its maximum. The article shows the possibility of utilization of known synoptical method for determining assimilation capacity of sea waters in the inverse order, i.e. for calculating the maximum value of pollutant put into the fixed zone of sea waters, upon a condition of reaching the given amount of assimilation capacity and absence of essential negative effect on ecosystem. The task of calculating an optimum regime function of discrete type, upon which the integrated value of assimilation capacity would reach the maximum value, has been formulated. The solution of analogue equivalent of the formed optimization task is carried out using the Euler equation for a non-conditional variation optimization task, taking into account the accepted limitation condition. The recommendations on optimum loading of different sea water zones with determined type of pollutant have been given.

scholarly journals The mechanism of ciliary movement.—IV. The relation of ciliary activity to oxygen consumption

1924 ◽  
Vol 96 (673) ◽  
pp. 95-114 ◽  
Keyword(s):  
Sea Water ◽  
Atmospheric Oxygen ◽  
Pure Oxygen ◽  
Active Movement ◽  
Ciliary Activity ◽  
Partial Recovery ◽  
Ciliary Movement ◽  
Hydrogen Recovery ◽  
Typical Experiment ◽  
Time Required

Engelmann (5) showed that the cells of the ciliated epithelium of the frog’s œsophagus remain active for as much as two hours after the tissue is exposed to an atmosphere of hydrogen. From this he concluded that the cells contained a considerable store of intramolecular oxygen, on which they could draw in the total absence of atmospheric oxygen. This experiment is, however, not conclusive. In the case of the cilia on the gills of Mytilus edulis , the absolute time required for cessation of movement in hydrogen depends very largely on the amount of water in contact with the tissue. Oxygen dissolved in an undisturbed drop of water is only slowly removed by a current of hydrogen; in a large drop of water there is, therefore, more oxygen available for the use of the tissue than is the case when the experiment is performed with tissue simply moistened with water. If a piece of gill, kept moist but not immersed in sea-water, is placed on a coverslip in an Engelmann gas chamber and exposed to an atmosphere of hydrogen, active movement persists for 30 to 45 minutes; the speed of the beat gradually falls, and after 60 to 75 minutes all movement ceases. If air be admitted when the movement has begun to slow down partial recovery takes place at once, and is soon complete. If, however, the cilia have become almost inactive in hydrogen, recovery in air is much slower, and may not be complete for about half an hour. In pure oxygen recovery is much more rapid. In order to determine to what extent the prolonged activity of the cells in an atmosphere of hydrogen is due to free oxygen in the water or tissue, the experiments were repeated with hæmoglobin in sea-water. A solution of hæmoglobin was used of such a strength as would enable a film of liquid in contact with the tissue to give a well-marked spectrum with a Zeiss microspectroscope. The following table gives the details of a typical experiment.

scholarly journals Pengaruh Ketinggian Dan Panjang Saluran Air Laut Terhadap Daya Yang Dihasilkan Pada Prototype Tidal Barrage

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Bima Sakti ◽  
Nur Rani Alham ◽  
Ahmad Nur Fajri ◽  
Ilham Rizal Ma’rif
Keyword(s):  
Power Plant ◽  
Electricity Generation ◽  
Power Plants ◽  
Sea Water ◽  
Electrical Energy ◽  
Limited Resources ◽  
Natural Ecosystem ◽  
Tidal Power ◽  
Water Turbine ◽  
Water Turbines

<em>The need for electricity in Indonesia is very important considering the limited resources and the lack of manpower, making Indonesia desperately need to increase electricity generation. One source of energy that can be converted into electrical energy is tidal barrage using the tidal barrage method. The application of this energy is still very small in Indonesia but there are a number of areas that have the potential to be implemented by the power plant. Tidal power plants that utilize the potential energy contained in the differences in tides and tides of sea water by trapping water in dams and then moving water turbines and when the water turbine is connected to a generator can produce electrical energy. Related to how the output of the generated power can it is known by looking at what height the water level drives the turbine. This type of power plant is environmentally friendly because it does not damage the natural ecosystem and the dam can be used for various activities.</em><em></em>

scholarly journals The solubility of calcium carbonate in tropical sea water

1941 ◽  
Vol 25 (2) ◽  
pp. 235-242 ◽  
Author(s):  
C. L. Smith
Keyword(s):  
Calcium Carbonate ◽  
Solubility Product ◽  
Sea Water ◽  
Natural Conditions ◽  
The West ◽  
Equilibrium Conditions ◽  
Maximum Value ◽  
Andros Island ◽  
Tropical Sea ◽  
Made In

In a previous paper (Smith, 1940b) the chemical changes observed in ocean sea water flowing across the shallow banks on the west coast of Andros Island (Bahamas) were reported. High salinities were produced by evaporation and calcium carbonate was precipitated. From the data obtained under natural conditions a maximum value of the solubility product constant of calcium carbonate in sea water was suggested. There was no reason to believe, however, that this value of the constant represented the true equilibrium conditions, and experiments have since been made in the laboratory with a view to bringing water from these banks into equilibrium with solid calcium carbonate.

Impact of oxygen concentration and laser power on occurrence of intraluminal fires during shared-airway surgery: an investigation

2008 ◽  
Vol 122 (12) ◽  
pp. 1335-1338 ◽  
Author(s):  
V Dhar ◽  
K Young ◽  
S A R Nouraei ◽  
G S Sandhu ◽  
T Tatla ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Analysis Of Variance ◽  
Laser Power ◽  
Porcine Model ◽  
Tissue Injury ◽  
Ignition Time ◽  
Cent Oxygen ◽  
Average Standard Deviation ◽  
Time To Ignition ◽  
Power Setting

AbstractObjectives:Airway fires pose a risk during laser microlaryngoscopy, and neurosurgical cotton patties, used to prevent tissue injury from stray laser beams, are a potential ignition source. Using a configuration approximating clinical practice, we experimentally assessed the relative impact of changing different ‘fire triad’ components on the occurrence of airway fires, in order to better inform patient care.Methods:The relative effects of wet vs dry neurosurgical patties, oxygen concentration and laser power setting on the patty ignition time were studied in a cadaveric porcine model. Data were analysed using t-test and two-way analysis of variance.Results:Dry patties ignited after 2.3 ± 1.2 seconds (average ± standard deviation) of continuous 5 W laser fire at 50 per cent oxygen concentration, compared with 63.9 ± 27.8 seconds for wet patties under the same laser and oxygen settings (p < 0.0001). There was a statistically significant reduction in the time to patty ignition when laser power settings were increased from 5 to 7.5 W, but no further reductions occurred when the power was further increased to 10 W (p < 0.05; Tukey test for multiple comparisons; two-way analysis of variance). There was no significant reduction in the time to ignition between oxygen concentrations of 50 and 75 per cent, but the time to ignition fell significantly when the oxygen concentration was further increased to 100 per cent.Conclusion:We suggest that surgical patties should always be soaked and should be used for relatively short periods, in order to prevent drying. If at all possible clinically, prolonged laser use at high power settings and ventilation with 100 per cent oxygen should be avoided.

Adapting the Zero-Emission Graz Cycle for Hydrogen Combustion and Investigation of Its Part Load Behaviour

2016 ◽  
Author(s):  
Wolfgang Sanz ◽  
Martin Braun ◽  
Herbert Jericha ◽  
Max F. Platzer
Keyword(s):  
Power Plant ◽  
High Efficiency ◽  
Energy System ◽  
Hydrogen Combustion ◽  
Pure Oxygen ◽  
Working Fluid ◽  
Parameter Study ◽  
Additional Parameter ◽  
Part Load ◽  
Zero Emission

A modern energy system based on renewable energy like wind and solar power inevitably needs a storage system to provide energy on demand. Hydrogen is a promising candidate for this task. For the re-conversion of the valuable fuel hydrogen to electricity a power plant of highest efficiency is needed. In this work the Graz Cycle, a zero emission power plant based on the oxy-fuel technology, is proposed for this role. The Graz Cycle originally burns fossil fuels with pure oxygen and offers efficiencies up to 65 % due to the recompression of about half of the working fluid. The Graz Cycle is now adapted for hydrogen combustion with pure oxygen so that a working fluid of nearly pure steam is available. The changes in the thermodynamic layout are presented and discussed. The results show that the cycle is able to reach a net cycle efficiency based on LHV of 68.5 % if the oxygen is supplied “freely” from hydrogen generation by electrolysis. An additional parameter study shows the potential of the cycle for further improvements. The high efficiency of the Graz Cycle is also achieved by a close interaction of the components which makes part load operation more difficult. So in the second part of the paper strategies for part load operation are presented and investigated. The thermodynamic analysis predicts part load down to 30 % of the base load at remarkably high efficiencies.

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