Chemical characterisation of the gases released at Gyali Island, Dodecanese, Greece and preliminary estimation of the CO2 output

2020 ◽  
Vol 139 (3) ◽  
pp. 1-13
Author(s):  
Kyriaki Daskalopoulou ◽  
Sergio Calabrese ◽  
Antonina Lisa Gagliano ◽  
Konstantinos Kyriakopoulos ◽  
Lorenza Li Vigni ◽  
...  
Author(s):  
Alexander G. Okhapkin ◽  
Tabet Hhedairia

The preliminary estimation of composition and structure of diatoms in the benthos of the Oka River allowed to determine the clear spatiotemporal confinedness of structure in such communities of them which has the most diverse composition in the low water period while water temperature decreasing.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1999
Author(s):  
Guanyong Sun ◽  
Bin Li ◽  
Hanjie Guo ◽  
Wensheng Yang ◽  
Shaoying Li ◽  
...  

Carbon included in coke and coal was used as a reduction agent and fuel in blast furnace (BF) ironmaking processes, which released large quantities of carbon dioxide (CO2). Minimizing the carbon consumption and CO2 output has always the goal of ironmaking research. In this paper, the reduction reactions of iron oxides by carbon, the gasification reaction of carbon by CO2, and the coupling reactions were studied by thermodynamic functions, which were derived from isobaric specific heat capacity. The reaction enthalpy at 298 K could not represent the heat value at the other reaction temperature, so the certain temperature should be confirmed by Gibbs frees energy and gas partial pressure. Based on Hess’ law, the energy consumption of the ironmaking process by carbon was calculated in detail. The decrease in the reduction temperature of solid metal iron has been beneficial in reducing the sensible heat required. When the volume ratio of CO to CO2 in the top gas of the furnace was given as 1.1–1.5, the coupling parameters of carbon gasification were 1.06–1.28 for Fe2O3, 0.71–0.85 for Fe3O4, 0.35–0.43 for FeO, respectively. With the increase in the coupling parameters, the volume fraction of CO2 decreased, and energy consumption and CO2 output increased. The minimum energy consumption and CO2 output of liquid iron production were in the reduction reactions with only CO2 generated, which were 9.952 GJ/t and 1265.854 kg/t from Fe2O3, 9.761 GJ/t and 1226.799 kg/t from Fe3O4, 9.007 GJ/t and 1107.368 kg/t from FeO, respectively. Compared with the current energy consumption of 11.65 GJ/t hot metal (HM) and CO2 output of 1650 kg/tHM of BF, the energy consumption and CO2 of ironmaking by carbon could reach lower levels by decreasing the coupled gasification reactions, lowering the temperature needed to generate solid Fe and adjusting the iron oxides to improve the iron content in the raw material. This article provides a simplified calculation method to understand the limit of energy consumption and CO2 output of ironmaking by carbon reduction iron oxides.


Hydrobiologia ◽  
2006 ◽  
Vol 557 (1) ◽  
pp. 97-106 ◽  
Author(s):  
N. Chartosia ◽  
A. Koukouras ◽  
M. Mavidis ◽  
M. -S. Kitsos

1987 ◽  
Vol 62 (5) ◽  
pp. 2003-2012 ◽  
Author(s):  
N. Lamarra ◽  
B. J. Whipp ◽  
S. A. Ward ◽  
K. Wasserman

Breathing has inherent irregularities that produce breath-to-breath fluctuations (“noise”) in pulmonary gas exchange. These impair the precision of characterizing nonsteady-state gas exchange kinetics during exercise. We quantified the effects of this noise on the confidence of estimating kinetic parameters of the underlying physiological responses and hence of model discrimination. Five subjects each performed eight transitions from 0 to 100 W on a cycle ergometer. Ventilation, CO2 output, and O2 uptake were computed breath by breath. The eight responses were interpolated uniformly, time aligned, and averaged for each subject; and the kinetic parameters of a first-order model (i.e., the time constant and time delay) were then estimated using three methods: linear least squares, nonlinear least squares, and maximum likelihood. The breath-by-breath noise approximated an uncorrelated Gaussian stochastic process, with a standard deviation that was largely independent of metabolic rate. An expression has therefore been derived for the number of square-wave repetitions required for a specified parameter confidence using methods b and c; method a being less appropriate for parameter estimation of noisy gas exchange kinetics.


1981 ◽  
Vol 50 (2) ◽  
pp. 392-398 ◽  
Author(s):  
H. V. Forster ◽  
G. E. Bisgard ◽  
J. P. Klein

The purpose of this study was to determine the effect of peripheral chemoreceptor denervation on ventilatory acclimatization of goats during chronic hypoxia. After 1 h of stimulated altitude (PB 450 Torr), arterial O2 tension (PaO2) in seven normal goats averaged 42 Torr, and arterial CO2 tension (PaCO2) was 1.3 Torr below control (P less than 0.001). In these goats nearly 66% of the increase in alveolar ventilation (VA) associated with acclimatization occurred between 1.5 and 4 h of hypoxia. Acclimatization was complete by the 3rd day of hypoxia, and it caused 1) a 23% increase in VA/CO2 output (P less than 0.001); 2) a 5-Torr increase in PaO2 (P less than 0.001); and 3) a 6.5-Torr decrease in PaCO2 (P less than 0.001). Denervation of the carotid chemoreceptors in seven goats caused hypoventilation during eupnea at sea level (PaCO2 change from control +7 Torr, P less than 0.001). Denervation also attenuated but did not eliminate peripheral chemoreceptor responsiveness. No additional changes were observed following attempted denervation of the aortic chemoreceptors. After 1 h of simulated altitude (PB 530 Torr), PaO2 in the denervated goats averaged 46 Torr, and PaCO2 was increased 1.1 Torr above control (P less than 0.001). In these goats VA did not change significantly during the subsequent 3 days of hypoxia. Accordingly, we conclude that the peripheral chemoreceptors are essential for ventilatory acclimatization of goats during chronic hypoxia.


2020 ◽  
Vol 139 (3) ◽  
pp. 325-340
Author(s):  
Alessandro Aiuppa ◽  
Ausonio Ronchi ◽  
Marcello Bitetto ◽  
Andrea L. Rizzo ◽  
Fatima Viveiros ◽  
...  
Keyword(s):  

1925 ◽  
Vol 8 (2) ◽  
pp. 21-31 ◽  
Author(s):  
G. H. Parker

1. Quiescent sciatic nerve of the frog discharges CO2 at the average rate of 0.00876 mg. CO2 per gram of nerve per minute. 2. Sciatic nerve steeped one minute in boiling water discharges CO2 at first at a low rate and after an hour and a half not at all. 3. Degenerated sciatic nerve discharges CO2 at a slightly higher rate than normal living nerve does. 4. Connective tissue from the frog discharges CO2 at an average rate of 0.0097 mg. per gram of tissue per minute. 5. Assuming that a nerve is composed of from one-half to one-quarter connective tissue the CO2 output from its strictly nervous components is estimated to be at a rate of 0.008 mg. CO2 per gram of nerve per minute. 6. Stimulated sciatic nerve increases the rate of its CO2 output over quiescent nerve by about 14 per cent. When this number is corrected for strictly nervous tissue the rate is about 16 per cent. 7. The increased rate of CO2 production noted on stimulation in normal sciatic nerves was not observed when they were boiled, blocked, or degenerated. It was also not observed with stimulated strands of connective tissue.


1999 ◽  
Vol 49 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Takahiro YUNOKI ◽  
Masahiro HORIUCHI ◽  
Tokuo YANO

2013 ◽  
Vol 34 (2) ◽  
pp. 253-260 ◽  
Author(s):  
W. Czerwiński ◽  
R. Gancarz ◽  
E. Przybyłka ◽  
J. S. Wieczorek

The physiological activity of twenty one 9-amine-9-fluorenephosphonic acid derivatives was tested. The compounds were synthesized by the Wrocław Technical University. <i>Spirodela oligorrhiza</i> was used as the test plant. There was tested the inhibiting influence of these compounds on the growth of <i>Spirodela</i> and synergism with the herbicide "mecoprop". Ethyl esters substituted at the nitrogen atom with buthyl and heptyl group appeared to be most active. Their concentration of 0.5-1.5 × 10<sup>-5</sup> M inhibited the growth of <i>Spirodela</i> by 50%. Most of the 9-amine-9-fluorenephosphonic acid derivatives tested with different substitutes showed a strong synergism with the herbicide "mecoprop". An addition of these compounds to sublethal solution of the herbicide killed <i>Spirodela</i> within 10-20 houres.


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