The recovery of Gibberella zeae from wheat straws

1968 ◽  
Vol 8 (32) ◽  
pp. 364 ◽  
Author(s):  
LW Burgess ◽  
DM Griffin
Keyword(s):  
Microbial Activity ◽  
High Temperatures ◽  
Soil Fungus ◽  
Gibberella Zeae ◽  
Moist Soil ◽  
Different Temperatures

Attempts were made to recover Gibberella zeae (Schw.) Petch, a soil fungus which attacks wheat, from wheat straws colonized by the fungus and subsequently exposed in contact with soil at different temperatures and soil moistures. In certain treatments, the fungus could still be recovered after two years. In general, however, recovery declined with time and was adversely affected when the straws were exposed to conditions favouring increased microbial activity (moist soil at relatively high temperatures).

Influence of Heat on Seed Germination of Cistus Laurifolius and Cistus Ladanifer

1992 ◽  
Vol 2 (1) ◽  
pp. 15 ◽  
Author(s):  
L Valbuena ◽  
R Tarrega ◽  
E Luis
Keyword(s):  
Seed Germination ◽  
High Temperatures ◽  
Exposure Time ◽  
Germination Rate ◽  
Heat Exposure ◽  
Cistus Ladanifer ◽  
Different Temperatures ◽  
Petri Dishes ◽  
Germinated Seeds

The influence of high temperatures on germination of Cistus laurifolius and Cistus ladanifer seeds was analyzed. Seeds were subjected to different temperatures for different times, afterwards they were sowed in plastic petri dishes and monitored for germinated seeds over two months.The germination rate observed in Cistus ldanifer was greater than in Cistus laurifolius. In both species, heat increased germination percentages. For Cistus laurifolius higher temperatures or longer exposure times were needed. Germination percentages of Cistus ladanifer were lower when heat exposure time was 15 minutes.It must be emphasized that germination occurred when seeds were not treated, while seeds exposed to 150�C for 5 minutes or more did not germinate.

Linear and non-linear analysis on two-dimensional steel frame under different temperatures

2019 ◽  
Vol 10 (1) ◽  
pp. 48-55
Author(s):  
Parthasarathi N. ◽  
Satyanarayanan K.S. ◽  
Prakash M. ◽  
Thamilarasu V.
Keyword(s):  
High Temperatures ◽  
Progressive Collapse ◽  
Transient State ◽  
Steel Frame ◽  
Frame Structure ◽  
Two Dimensional ◽  
Content Type ◽  
Frame Building ◽  
Different Temperatures ◽  
Steel Frame Structure

Purpose Progressive collapse because of high temperatures arising from an explosion, vehicle impact or fire is an important issue for structural failure in high-rise buildings. Design/methodology/approach The present study, using ABAQUS software for the analysis, investigated the progressive collapse of a two-dimensional, three-bay, four-storey steel frame structure from high-temperature stresses. Findings After structure reaches the temperature results like displacement, stress axial load and shear force are discussed. Research limitations/implications Different temperatures were applied to the columns at different heights of a structure framed with various materials. Progressive collapse load combinations were also applied as per general service administration guidelines. Originality/value This study covered both steady-state and transient-state conditions of a multistorey-frame building subjected to a rise in temperature in the corner columns and intermediate columns. The columns in the framed structure were subjected to high temperatures at different heights, and the resulting displacements, stresses and axial loads were obtained, analysed and discussed.

scholarly journals Effects of High Temperatures on the Physical and Mechanical Properties of Carbonated Ordinary Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Qifang Xie ◽  
Lipeng Zhang ◽  
Shenghua Yin ◽  
Baozhuang Zhang ◽  
Yaopeng Wu
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Elastic Modulus ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Surface Characteristics ◽  
Time Service ◽  
Different Temperatures ◽  
Cooling Methods

Fires are always known for seriously deteriorating concrete in structures, especially for those with certain carbonation due to long-time service. In this paper, 75 prism specimens were prepared and divided into four groups (three carbonated groups and one uncarbonated group). Specimens were tested under different temperatures (20, 300, 400, 500, 600, and 700°C), exposure times (3, 4, and 6 hours), and cooling methods (water and natural cooling). Surface characteristics, weight loss rate, and residual mechanical properties (strength, initial elastic modulus, peak, and ultimate compressive strains) of carbonated concrete specimens after elevated temperatures were investigated and compared with that of the uncarbonated ones. Results show that the weight loss rates of the carbonated concrete specimens are slightly lower than that of the uncarbonated ones and that the cracks are increased with raising of temperatures. Surface colors of carbonated concrete are significantly changed, but they are not sensitive to cooling methods. Surface cracks can be evidently observed on carbonated specimens when temperature reaches 400°C. Residual compressive strength and initial elastic modulus of carbonated concrete after natural cooling are generally larger than those cooled by water. The peak and ultimate compressive strains of both carbonated and uncarbonated concrete specimens increase after heating, but the values of the latter are greater than that of the former. Finally, the constitutive equation to predict the compressive behaviors of carbonated concrete after high temperatures was established and validated by tests.

scholarly journals On a formula for the elastic force of vapour at different temperatures

1851 ◽  
Vol 5 ◽  
pp. 738-740
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Elastic Force ◽  
French Academy ◽  
Different Temperatures ◽  
Series Of Experiments ◽  
Better Than

The author adopts as the basis of his formula the first series of experiments at high temperatures made by the French Academy, and those of Magnus at low temperatures. For the Academy’s experiments, he adopts the indications of the smaller thermometer in the steam in preference to those of the larger thermometer in the water. Of Dr. Young’s sort of formulae, he notices that of the Aca­demy and several others with exponents varying from 5 to 7. From the elasticity at freezing, as given by Magnus, compared with four of the Academy’s experiments, he shows that for the range of observation the number 6 is preferable to 5 as an exponent; but, as he states, no formula of this sort with a constant index can be found to agree with the observations throughout. The formula of Magnus he finds to agree with these observations better than any of the others; but being adapted to the air-thermo­meter, and therefore not convenient for ordinary use, he gives his own formula adapted to the mercurial thermometer, t = 500 + 225 log A / 5 - log A, t being the temp. Cent., and A the elasticity in atmospheres of 0 m .76 at zero, or 30 inches at 58° Fahr.; the temperature being given, the formula becomes log A = 5 - 1625 / 225 + t .

Persistent, vertical-migration rhythms in benthic microflora.: II. Field and Laboratory Studies On Diatoms From The Banks Of The River Avon

1966 ◽  
Vol 46 (1) ◽  
pp. 191-214 ◽  
Author(s):  
F. E. Round ◽  
J. D. Palmer
Keyword(s):  
High Temperatures ◽  
Vertical Migration ◽  
Laboratory Experiments ◽  
Biological Clock ◽  
Diatom Species ◽  
Laboratory Studies ◽  
Natural Conditions ◽  
Constant Illumination ◽  
Different Temperatures ◽  
Clock Hypothesis

The vertical migration of two Euglena species and several diatom species into and out of the sediment on the banks of the River Avon has been studied under natural conditions. All species have been shown to migrate vertically upwards when exposed during daylight. Tidal flooding of the sediment is generally preceded by re-burrowing of the algae beneath the surface. Methods have been devised to follow these migrations in both the field and laboratory. Laboratory experiments show that these migrations are rhythmic, continuing under constant illumination and temperature and removed from tidal influence. The effect of three different temperatures and three different light intensities has been investigated. Transfer from low to high temperatures has been shown to reset the phase of the rhythm. The results are discussed in relation to other work and to the ‘biological clock’ hypothesis.

Verrucarin A and roridin E produced on rocket by Myrothecium roridum under different temperatures and CO2 levels

2017 ◽  
Vol 10 (3) ◽  
pp. 229-236 ◽  
Author(s):  
P. Bosio ◽  
I. Siciliano ◽  
G. Gilardi ◽  
M.L. Gullino ◽  
A. Garibaldi
Keyword(s):  
Disease Severity ◽  
High Temperatures ◽  
Maximum Level ◽  
Temperature Influence ◽  
Eruca Sativa ◽  
Mycotoxin Production ◽  
Co2 Levels ◽  
The Future ◽  
Different Temperatures ◽  
Myrothecium Roridum

The behaviour of Myrothecium roridum, artificially inoculated on cultivated rocket (Eruca sativa), has been evaluated under eight different temperature and CO2 concentration combinations (from 14-18 °C to 26-30 °C and with 400-450 or 800-850 ppm of CO2). The pathogen isolate used for this study was inoculated on rocket and disease severity increased with high temperatures for both CO2 levels. Verrucarin A and roridin E mycotoxins were produced under all the tested temperatures at high CO2 conditions. The maximum level of verrucarin A was found at 14-18 °C and 800-850 ppm of CO2, and the maximum roridin E production was detected at 26-30 °C with 800-850 ppm of CO2. The results obtained in this study show that both the CO2 concentration and the temperature influence disease severity and mycotoxin production in different ways. An increase in temperature, which is favourable for attacks of the pathogen, could induce the spread of M. roridum in temperate regions, and this pathogen could take on even greater importance in the future, considering its ability to produce mycotoxins.

The stability of soil aggregates as affected by organic materials, microbial activity and physical disruption

Soil Research ◽  
1978 ◽  
Vol 16 (1) ◽  
pp. 9 ◽  
Author(s):  
JM Tisdall ◽  
B Cockroft ◽  
NC Uren
Keyword(s):  
Microbial Activity ◽  
Organic Materials ◽  
Sandy Loam ◽  
Soil Aggregates ◽  
Moist Soil ◽  
Severe Restriction ◽  
Wetting And Drying ◽  
Fine Sandy Loam ◽  
The Stability

On moist incubation the equivalent of 50 t ha-1 or more of ground, readily decomposable organic materials greatly increased the proportion of stable aggregates of Shepparton fine sandy loam within 1-4 weeks; the aggregates remained stable for up to 32 weeks if left undisturbed. Severe restriction of microbial activity in aggregates of Shepparton fine sandy loam by sterilization or dryness increased the effect of physical disruption associated with intermittent wetting and drying, and simulated cultivation. The results suggest that microorganisms in non-sterile moist soil can produce bonding substances which compensate partially for those bonds broken physically.

scholarly journals On the behaviour of barnacles. IV: The influence of temperature On cirral activity and survival of some warm-water species

1962 ◽  
Vol 42 (2) ◽  
pp. 163-177 ◽  
Author(s):  
A. J. Southward
Keyword(s):  
High Temperatures ◽  
The North ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Balanus Eburneus ◽  
North Atlantic Area ◽  
Brackish Water Species ◽  
Atlantic Area ◽  
Water Species ◽  
Very High

SUMMARYThe range of temperatures over which the cirri were active and the frequency of beating at different temperatures were measured in four species of barnacles collected on the southern and south-western coasts of France. The extremes of high temperature at which the animal remained irritable or could survive were assessed in these species and in a further group of species from Trinidad, West Indies.The results are discussed in comparison with previous evidence for species of more northern distribution, and related to the geographical range of the species and the ecological niche occupied. For example, the brackish water species, Balanus eburneus and B. improvisus, have similar patterns of cirral activity, but the greater tolerance of high temperatures shown by the former is obviously connected with its more tropical distribution. Differences in temperature tolerances of varieties of JB. amphitrite from Europe and Trinidad, possibly related to differences in the tide levels at which they live, tend to reinforce their separation on morphological grounds. More pronounced differences between Chthamalus depressus and C. stellatus confirm the separation of these two species which were formerly regarded as varieties. The relatively lower rate of beating of C. depressus which is not found north of the Mediterranean and its greater tolerance of high temperatures compared with C. stellatus, may be related to its more southern distribution and its ability to live at very high levels on the shore. These two species and C. fragilis from Trinidad all show greater tolerance of high temperatures than the species of Balanus and Tetraclita, which are found at lower levels on the shoreIt is concluded that in the North Atlantic area there may be only two main distributional groups of species of acorn barnacles, Arctic and Tropical, overlapping in the Temperate regions, with few or no intermediate forms, and that there is as yet no evidence for the existence of physiological races in these species.

scholarly journals The absorption of light by elements in a state of vapour: The halogens

1921 ◽  
Vol 99 (701) ◽  
pp. 456-461 ◽  
Keyword(s):  
Absorption Spectra ◽  
High Temperatures ◽  
Great Influence ◽  
Maximum Absorption ◽  
Constant Mass ◽  
Complex Molecules ◽  
Absorption Of Light ◽  
Different Temperatures ◽  
Temperature And Pressure ◽  
Lower Temperature

In previous papers we have given an account of the effect produced on the light of the Nernst filament by passing it through the vapour of the elements of the sulphur, phosphorus and mercury groups and have shown the bearing of the phenomena observed upon the constitution of the vapour in each case. In the present paper we propose to deal with chlorine, bromine, and iodine, the only other elements which lend themselves readily to this method of investigation. Ten years ago the absorption spectra of bromine and iodine were investigated by Evans by a method similar to that which we employ. He showed that the absorption varies with the temperature and pressure and drew from his results the conclusion that at sufficiently high temperatures the vapour of these elements is diactinic. This he explained by assuming that the monatomic molecules into which the more complex molecules are gradually resolved as the temperature is raised are colourless and without absorbent action on light at any rate within the limits λ 3500 to λ 6800. In most of his experiments the pressure was kept constant by connecting the observation tube in which the vapour was heated with a reservoir of the element maintained at a constant and lower temperature. The mass of the vapour at different temperatures was, therefore, variable. Our experiments were designed to show the effect produced by a constant mass of vapour on the absorption when the temperature was varied over as wide a range as possible. For this purpose a known quantity of the element under examination was enclosed in a sealed vacuous tube and the temperature gradually raised, observations upon the absorption being made at intervals. Under these conditions while the mass of the vapour remains the same throughout, the pressure increases both with the rise of temperature and as a consequence of the dissociation of the molecules. As, however, the tubes were evacuated with the Sprengel pump and the initial pressures were, therefore, low, it is improbable that the changes of pressure had any great influence upon the phenomena. This view is confirmed by the fact that observations made upon different quantities of the element showed only such differences of spectra as might be expected from the variation in the mass of the substance employed. In no case, so far as we observed, was the temperature of maximum absorption altered.

scholarly journals On the application of liquids formed by the condensation of gases as mechanical agents

1833 ◽  
Vol 2 ◽  
pp. 193-193
Keyword(s):  
Latent Heat ◽  
High Temperatures ◽  
High Pressures ◽  
Elastic Force ◽  
Muriatic Acid ◽  
Different Temperatures ◽  
Great Pressure ◽  
Very High ◽  
Sulphuretted Hydrogen

The elasticity of vapours, in contact with the liquids from which they are produced under high pressures in high temperatures, is known to increase in a higher ratio than the arithmetical one of the temperature; but the exact law is not determined, and the loss of latent heat in compression, and the re-absorption in expansion, renders the advantage of steam under great pressure and at very high temperatures doubtful in an economical view. No such doubt, however, exists in regard to those fluids which require very great compression for their existence, and where common temperatures are sufficient to produce an immense elastic force. Thus sulphuretted hydrogen, which condenses into a liquid under a pressure of 14 atmospheres at 3°, had its elastic force increased so as to equal a pressure of 17 atmospheres by raising its temperature to 47°. Liquid muriatic acid at 3° exerted an elastic force equal to the pressure of 20 atmospheres, at 25° = 25 atmospheres, and at 51° = 45 atmospheres. After some experimental illustrations of the expansibility of the vapour of sulphuret of carbon at different temperatures, the author adverts to the possible application of the difficultly compressible gases, as mechanical agents, and to their power of producing cold by the rapidity of their evaporation.

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