Properties of Hard Rubber. XVIII. Action of Hydrocarbon Oils at High Temperatures (Part XV of Swelling of Rubber)

1947 ◽  
Vol 20 (1) ◽  
pp. 171-172
Author(s):  
J. R. Scott
Keyword(s):  
Petroleum Ether ◽  
Plastic Flow ◽  
High Temperatures ◽  
Critical Value ◽  
Transformer Oil ◽  
Aliphatic Hydrocarbons ◽  
Effect Of Temperature ◽  
Pronounced Change ◽  
Noticeable Effect ◽  
Two Samples

Abstract It has already been shown that liquids consisting essentially of aliphatic hydrocarbons, e.g., petroleum ether, paraffin, and transformer oil, had practically no swelling action at 34° C on two samples of hard rubber composed of rubber and sulfur only. Hard rubber shows a pronounced change in properties at temperatures above a critical value (“yield temperature”) in the neighborhood of 50° –80° C, the most noticeable effect being that it becomes much softer and more susceptible to plastic flow. It seemed likely, therefore, that the swelling action of liquids such as those mentioned above might be much greater at temperatures above this critical value. This view was strengthened by the statement of Dunton and Muir that hard rubber is “badly attacked” by immersion for 7 days in “hot” transormer oil. As no data appear to have been published on the effect of temperature on the swelling of hard rubber, experiments were made to examine this effect. Details of the hard rubber samples used are as follows.

scholarly journals Effect of Temperature and Used Ingredients on Rheological Parameters of Pancake Dough

2013 ◽  
Vol 16 (3) ◽  
pp. 63-66
Author(s):  
Peter Hlaváč ◽  
Monika Božiková
Keyword(s):  
Rheological Properties ◽  
Dynamic Viscosity ◽  
Kinematic Viscosity ◽  
Fat Content ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Rotational Viscometer ◽  
Two Samples ◽  
Dynamic And Kinematic Viscosity ◽  
Temperature Dynamic

Abstract This paper presents the selected rheological properties of pancake dough such as dynamic and kinematic viscosity and fluidity. The effect of used ingredients and temperature on rheological properties is investigated. Measurements were performed on three pancake dough samples. In two samples, there was used milk with a different fat content, and in the third sample, all ingredients were in a powder state. A digital rotational viscometer Anton Paar DV-3P was used for measuring the rheological properties. The principle of viscometer measurement is based on the dependence of sample resistance to probe rotation. Results of measurements are shown as graphical dependencies of rheological parameters on temperature. Exponential functions were used to express the dependencies of all rheological parameters on temperature. Dynamic and kinematic viscosity decreased, and fluidity increased with temperature. The highest values of dynamic viscosity were obtained for pancake dough from powder ingredients. A higher fat content of used milk caused higher values of dynamic viscosity.

Temperature-induced pupil movements in insect superposition eyes

2000 ◽  
Vol 203 (4) ◽  
pp. 685-692 ◽  
Author(s):  
P. Nordstrom ◽  
E.J. Warrant
Keyword(s):  
High Temperatures ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Light Level ◽  
Agrotis Segetum ◽  
Effect Of Temperature ◽  
Activation Temperature ◽  
Ambient Light Level ◽  
Wide Range ◽  
Response To Temperature

In this paper, we describe the hitherto largely overlooked effect of temperature on the pupil of insect compound eyes. In the turnip moth Agrotis segetum and in two other nocturnal insects with superposition eyes, the lacewing Euroleon nostras and the codling moth Cydia pomonella, the pupil not only opens and closes with changes in the ambient light level, as expected, but also with changes in temperature in the absence of light. In complete darkness, the pupil of A. segetum responds over a wide range of temperatures, with the pupillary pigments migrating to a light-adapted position when the animal is exposed to either low or high temperatures. At temperatures between 21.0 and 22.7 C, the pigments migrate to the fully dark-adapted position, resulting in an open pupil and maximal eye glow. Pupil closure at high temperatures shows two distinct thresholds: the first at 23.8+/−0.7 C and a second some degrees higher at 25.7+/−1.2 C (means +/− s.d., N=10). Temperatures exceeding the first threshold (the activation temperature, T(a)) initiate a closure of the pupil that is completed when the temperature exceeds the second threshold (the closure temperature, T(c)), which causes rapid and complete migration of pigment to the light-adapted position. All temperatures above T(a) affect the pupil, but only temperatures exceeding T(c) result in complete closure. Temperatures between T(a) and T(c) cause a slow, partial and rather unpredictable closure. The lacewing and the codling moth both show very similar responses to those of A. segetum, suggesting that this response to temperature is widespread in superposition eyes. The possibility that the ambient temperature could be used to pre-adapt the eye to different light intensities is discussed.

scholarly journals The effect of temperature upon radioactive disintegration

1912 ◽  
Vol 86 (586) ◽  
pp. 240-253 ◽  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Systematic Investigation ◽  
Effect Of Temperature ◽  
Active Matter ◽  
Radium Emanation ◽  
Γ Rays ◽  
Method Of Measurement ◽  
Positive Effect

Within the last few years the influence of high temperature on the activity of radium emanation, of the active deposit, and of radium C has been examined in detail by several authors. The conclusions arrived at have been conflicting, some workers affirming a positive effect of tem­perature, others denying it. This lack of agreement is due, however, to a difference in the method of measurement of the active matter under investigation. Those workers who measured the activity by γ-rays are all agreed that temperature has no effect whatever, while those who measured by β-rays found always an effect of some kind, in many cases of considerable magnitude, and often, indeed, of a very surprising nature. While, however, the fact that there is a β-ray effect is admitted by all, there is still a lack of agreement between the results of the experiments of different workers, and even of different experiments of the same worker, which is hardly to be expected if the effects were due to a definite change in the properties of the disintegrating atoms at high temperatures. In view, therefore, of the uncertainty which has arisen on a point of such great theoretical importance, a systematic investigation was necessary to obtain definite results, whether positive or negative. This the author, at the request of prof. Rutherford, has carried out.

Damage Prediction of CPVC Based on Energy Method at Different Temperatures

2019 ◽  
Vol 820 ◽  
pp. 179-187
Author(s):  
Fatima Gugouch ◽  
Sara Sandabad ◽  
Nadia Mouhib ◽  
Abderrazak En-Naji ◽  
Mohamed El Ghorba
Keyword(s):  
Polyvinyl Chloride ◽  
Tensile Tests ◽  
Critical Value ◽  
Hot Water ◽  
Effect Of Temperature ◽  
Strain Variation ◽  
Damage Prediction ◽  
Test Pieces ◽  
Different Temperatures ◽  
Three Stages

The Chlorinated Polyvinyl Chloride pipes used for the supply of cold and hot water are designed and manufactured for a 50 years predictive life, but defects and harmfulness may occur during the transport process, storage and operation of tubes that significantly affect these forecasts. This work deals with the study of the mechanical behavior of Chlorinated Polyvinyl Chloride (CVPC) specimens subjected to tensile tests under the effect of temperature. Moreover, a study of damage evolution by the ultimate energy makes it possible to determine the three stages of the lifetime of the test pieces studied. On the basis of the stress-strain variation curves plotted from the experimental results, the critical value of the fraction of life corresponding to the acceleration of the damage was determined.

Effect of temperature and moist conditions on seed dormancy cycling of two sympatric limestone species, Begonia guishanensis and Paraisometrum mileense, in southern China

2020 ◽  
Vol 30 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Xiao-Jian Hu ◽  
Cheng Liu ◽  
Ai-Rong Li ◽  
Xiang-Yun Yang ◽  
Carol Baskin
Keyword(s):  
Field Experiment ◽  
High Temperatures ◽  
Seed Dormancy ◽  
Natural Environment ◽  
Southern China ◽  
Soil Seed Bank ◽  
Effect Of Temperature ◽  
Wet Season ◽  
Persistent Soil Seed Bank ◽  
Almost All

AbstractInformation about seed dormancy cycling and germination in relation to temperature and moisture conditions in the natural environment is important for the conservation and restoration of rare species, including Begonia guishanensis and Paraisometrum mileense, two sympatric perennial limestone (karst) species. Dry afterripening (DAR) and wet and dry (WD) cycles at 15/5 and 25/15°C as well as moist chilling (MC) at 15/5°C were used to mimic the natural environment at different times of the year. A field experiment was conducted to monitor seasonal changes in germination responses of the seeds. About 40–65% of B. guishanensis and 5% of P. mileense seeds were dormant at maturity. DAR at 25/15 and 15/5°C as well as MC and WD cycles at 15/5°C alleviated dormancy for B. guishanensis but not P. mileense, and WD cycles at 25/15°C induced a deeper conditional dormancy for both species. Seeds of B. guishanensis exhibited dormancy cycling in the field, with increased dormancy under natural WD cycles at relatively high temperatures during the transition from the dry to the wet season in April to May and decreased dormancy during the wet season from June to October. KNO3 mitigated the dormancy-inducing effect of both artificial and natural WD cycles at relatively high temperatures for B. guishanensis. The field experiment indicated that seeds of B. guishanensis may be able to form a persistent soil seed bank, while almost all seeds of P. mileense germinate at the beginning of the wet season in the field.

Effect of Temperature on Response of Tomatoes to Several Dinitroaniline Herbicides and Phosphorus

Weed Science ◽  
1976 ◽  
Vol 24 (1) ◽  
pp. 115-119 ◽  
Author(s):  
H. P. Wilson ◽  
F. B. Stewart ◽  
T. E. Hines
Keyword(s):  
High Temperatures ◽  
Phosphorus Content ◽  
Dry Weight ◽  
Field Studies ◽  
Effect Of Temperature ◽  
Controlled Environment ◽  
Effects Of Temperature ◽  
Environment Chamber ◽  
Chamber Studies ◽  
Dinitroaniline Herbicides

Effects of temperature on response of transplanted tomatoes (Lycopersicon esculentumMill. ‘Campbell 17′) to trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine], and isopropalin (2,6-dinitro-N,N-dipropylcumidine) were investigated in field studies. Trifluralin and nitralin caused greater reductions in growth and yields of tomatoes transplanted early in April than to tomatoes transplanted around May 1. Responses to profluralin were similar but total yields of early transplanted tomatoes were not reduced although initial yields were below those of tomatoes treated with isopropalin. In controlled environment chamber studies, percent phosphorus of plant tops was reduced by trifluralin at low temperatures but was not influenced by trifluralin at high temperatures. Tomoto responses to phosphorus as reflected by plant fresh weight, dry weight and phosphorus content (mg/plant) were reduced by trifluralin at low and high temperatures.

Boudinage-type Structures at Sørfinnset, Gildeskaal, North Norway

1964 ◽  
Vol 101 (6) ◽  
pp. 488-495 ◽  
Author(s):  
R. Bradshaw ◽  
M. K. Wells
Keyword(s):  
Plastic Flow ◽  
High Temperatures ◽  
Lower Surface ◽  
Biotite Gneiss ◽  
North Norway

AbstractA layer of massive and lineated hornblende-biotite-gneiss has fractured along ac-joints (perpendicular to the layering and b–lineation), at regular intervals along its lower surface in contact with a thin marble bed. The joints have been opened from below and the marble has penetrated upwards to form intrusive tongues caused by extremely plastic flow folding, as shown by the unbroken banding in the marble. The structure constitutes a variety of one-sided boudinage involving segmentation in the lowest metre or so of the hornblendic rock, while the extreme marble deformation is all accommodated in a few centimetres thickness. The structures must have developed at relatively high temperatures to allow contemporaneous segregation of quartz-feldspar pegmatite veins from the hornblendic rock, and of diopside reaction skarns at the marble junctions.

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