scholarly journals Low-Temperature Mechano-Chemical Rubber Reclamation Using Terpinene as a Swelling Agent to Enhance Bond-Breaking Selectivity

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4272
Author(s):  
Lei Guo ◽  
Donghui Ren ◽  
Wenchao Wang ◽  
Kuanfa Hao ◽  
Xiurui Guo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
High Selectivity ◽  
Environmentally Friendly ◽  
Bond Breaking ◽  
Rubber Sample ◽  
Swelling Agent ◽  
Waste Rubber

Common swelling agents used in the mechano-chemical rubber devulcanization process usually require high temperatures to achieve satisfactory swelling effects, which results in severe production of pollutants and reduces the selectivity of bond scissions. This work presents an environmentally friendly swelling agent, terpinene, which can swell the rubber crosslink structures at low temperatures. Both a rubber swelling experiment and a rubber reclaiming experiment with a mechano-chemical devulcanization method are conducted to explore the swelling effects of terpinene. After soaking in terpinene at 60 °C for 90 min, the length elongation of the rubber sample reaches 1.55, which is much higher than that in naphthenic oil and is comparable to that in toluene. When adding 3 phr of terpinene for every 100 phr of waste rubber during the reclaiming process, the bond scissions exhibit high selectivity. After revulcanization, the reclaimed rubbers have a tensile strength of 17 MPa and a breaking elongation of 400%. Consequently, the application of terpinene as the swelling agent in the LTMD method can greatly improve the properties of reclaimed rubbers, thereby enhancing the dual value for the economy and environment.

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

scholarly journals THE INFLUENCE OF TEMPERATURE ON THE ACTION OF STRYCHNIN IN FROGS

1913 ◽  
Vol 18 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Thomas Stotesbury Githens
Keyword(s):  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Room Temperature ◽  
Drug Action ◽  
The State ◽  
Great Caution ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

In order to establish the influence of temperature upon the effect of varying doses of strychnin injected into frogs, the animals must be kept under observation for several days and at various definite degrees of temperature. Statements that the animal was kept "cold," "at room temperature," or "warm" are insufficient. With a certain dose tetanus may result constantly at 30° C. yet never appear at 21° C., and either of these temperatures might be described as warm, when compared to a room temperature of 15° C. Furthermore an animal may apparently fail to respond in the cold to an injection of certain doses of strychnin and yet be found in tetanic convulsions the next day. That an animal may have late, long lasting, or strong tetanus while kept at such a low temperature as 5° C. after an injection of a dose of strychnin smaller than 0.01 of a milligram per frog emphasizes the fact that great caution must be exercised in formulating laws as to the influence of temperature on drug action. The main results of this investigation may be summarized as follows: Doses of strychnin amounting to 0.0006 of a milligram per gram of frog will cause tetanus at all temperatures between 5° C. and 30° C., although at low temperatures the tetanus may appear late. A dose of 0.0003 of a milligram per gram of frog will frequently produce tetanus at 5° C. as well as at 30° or 27° C., but may nevertheless fail to produce any reaction at such an intermediary temperature as 21° C. Smaller doses, 0.0002 of a milligram per gram, will cause tetanus in the cold but not at high temperatures. It may be stated in general that in frogs kept at low temperatures the tetanic state sets in later, continues longer, and each tetanic attack is of longer duration, while in the interval between the attacks the state of tonus is higher and the animals are more irritable than when they are kept at higher temperatures.

A Study of the Rubber-Metal Bond

1946 ◽  
Vol 19 (4) ◽  
pp. 956-967
Author(s):  
S. Buchan ◽  
J. R. Shanks
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Low Temperatures ◽  
Moderate Increase ◽  
Progressive Reduction ◽  
Bonding Agents ◽  
Metal Bond ◽  
Permanent Set ◽  
Vulcanized Rubber ◽  
Derivatives Of

Abstract Although the practice of bonding rubber to metal has been in use for many years, no theories appear to have been advanced which explain adequately the mechanism of bonding. It has been stated that the brass bond between rubber and metal functions through chemical linkages, but this can only be regarded as tentative and has yet to be proved. No attempt has been made to find out how ebonite functions as a bonding medium or the more recently discovered derivatives of rubber, such as sulfonated rubber, chlorinated rubber, and rubber hydrohalides. Until it is properly elucidated just how bonding agents do act, further logical development of improved bonding media cannot be pursued. It is intended in this paper to show how the rubber-metal bond behaves at subnormal temperatures and how a low temperature technique may be used for studying the mechanism of bonding. The effect of low temperatures on the tensile strength and associated properties of vulcanized rubber, such as hardness, permanent set, flexibility, resilience and flexing, has been dealt with fairly comprehensively in the literature. Progressive reduction in temperature leads to only a moderate increase, for example, in tensile strength, until the point is reached at which the rubber stiffens and freezes, when a marked increase occurs. Examination of a brass-bonded unit at low temperatures revealed that the graph obtained for bond strength was very similar in slope and character to that for tensile strength. The similarity is illustrated by the data in Table 1 and in Figure 1.

scholarly journals Effects of ambient temperature on body size and organ development in broilers

2020 ◽  
pp. 28-35
Author(s):  
Qiao Yingying ◽  
Oleksandr Kyselov ◽  
Liu Changzhong
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Growth And Development ◽  
Broiler Chickens ◽  
Control Group ◽  
Organ Development ◽  
Poultry House ◽  
Temperature Group

The current study investigated the effect of poultry house temperature change on the growth and development of both broiler chickens themselves and the development of their individual organs. Following 42 days of rearing, results showed that the body oblique length, chest width, chest depth, chest angle, keel length, pelvic width, and tibial length of broilers in the low temperature group were significantly lower than those of the control group (P<0.05), while the breast depth of broiler chickens in the high-temperature group was significantly lower than those in the control group (P<0.05). Furthermore, low temperatures significantly increased the function of the heart, liver, spleen and pancreas of broiler chickens (P<0.05). After 7 days of rearing, the bursal index of broilers in the high temperature group was significantly higher than in the control group as well as in the low temperature group (P<0.05). Previous research has established that high and low temperatures significantly affect the growth and development as well as the immunity of broiler chickens, namely that low environmental temperatures have a more adverse effect on broiler chickens than high temperatures. Consequently, using and maintaining high temperatures early in rearing helps to improve the immunity of broilers and improve their performance. The results of our study provides an opportunity to provide both a theoretical and a practical basis for accurate temperature setting in poultry houses for effective breeding of broiler chickens, which will make it possible to increase the productivity of broiler chickens and increase the economic efficiency of the poultry house. Key words: temperature, breeding, body weight, organ development, broilers chickens.

scholarly journals Some properties of the metallic state I—Metallic hydrogen and its alloys

1937 ◽  
Vol 159 (897) ◽  
pp. 295-306 ◽  
Keyword(s):  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Simple Structure ◽  
Negative Ions ◽  
Energy Change ◽  
Metallic State ◽  
Metallic Hydrogen ◽  
Hydrogen Atoms ◽  
Energy Of Formation

An investigation of the properties of metallic hydrogen is of particular interest, on account of the simple structure of a metal composed of protons and electrons. A calculation of the energy change on forming a body centred lattice of metallic hydrogen from hydrogen atoms has recently been made by Wigner and Huntingdon (1935). They find that the energy of formation of metallic hydrogen from hydrogen atoms would be 10 kcal., and of metallic deuterium from deuterium atoms 11·6 kcal., but that metallic hydrogen (Graham’s hydrogenium) would only be stable relatively to covalent hydrogen at pressures not less than 2·5 × 10 5 atmospheres. Experiments on hydrogen at these pressures have not yet been realized. It is however possible to study the properties of metallic hydrogen in a number of alloys. At high temperatures, hydrogen dissolves to an appreci­able extent in a number of metals (Sieverts and Gotta 1928), but at low temperatures the only examples where hydrogen dissolves appreciably without forming covalent links (as GeH 4 ) or negative ions (as LiH) are the “metallic” hydrides of transitional elements such as palladium, tantalum, titanium, etc. The exceptional position of these low temperature alloys of metallic hydrogen is referred to again below. The evidence that hydrogen is in the metallic state has been reviewed (Ubbelohde 1931) and may be summarized by the statements that the hydrogen dissolves as atoms, and that at least a portion of these atoms is ionized to give electrons and protons.

scholarly journals High and Low Temperature Properties of FT-Paraffin-Modified Bitumen

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hassan Fazaeli ◽  
Hamid Behbahani ◽  
Amir Ali Amini ◽  
Jafar Rahmani ◽  
Golazin Yadollahi
Keyword(s):  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Permanent Deformation ◽  
Weight Percent ◽  
Asphalt Mixtures ◽  
Considerable Influence ◽  
Modified Bitumen ◽  
Fischer Tropsch ◽  
Performance Grade

This paper presents the results of an experimental research on the effects of “Fischer Tropsch-Paraffin” (Sasobit) content on physical and rheological properties of Sasobit modified bitumen at various operational temperatures. For this purpose, bitumen with a Performance Grade (PG) of 58–22 is selected as the base and later it is modified with 1, 2, 2.5, 3, and 4 weight percent of FT-Paraffin (Sasobit). The performance of modified bitumen at high, intermediate, and low temperatures is evaluated based on Strategic Highway Research Program (SHRP) Superpave tests. Results of the study show that FT-paraffin improves the performance of bitumen at high temperatures in addition to increasing the resistance of mixture against permanent deformation. Despite the advantages of FT-paraffin on bitumen performance at high temperatures, it does not show a considerable influence on the intermediate and low temperature performance of bitumen. The effect of FT-paraffin content on the viscosity of modified bitumen is also investigated using Brookfield Viscometer Apparatus. Results show that increasing the additive content lowers the viscosity of modified bitumen. This in return can reduce the mixing and compaction temperature of asphalt mixtures.

The graft polymerization of vinyl benzoate and trans-stilbene onto polyurethane to control its mechanical and shape memory properties

2016 ◽  
Vol 88 (2) ◽  
pp. 121-132
Author(s):  
Yong-Chan Chung ◽  
Jin Cheol Bae ◽  
Byoung Chul Chun
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Shape Memory ◽  
Low Temperatures ◽  
Shape Recovery ◽  
Graft Polymerization ◽  
Control Series ◽  
Trans Stilbene ◽  
Shape Retention ◽  
Low Temperature Flexibility

Vinyl benzoate (VB series) and trans-stilbene (SB series) were added onto polyurethane (PU) via graft polymerization, and the spectroscopic, thermal, tensile, shape memory, and low-temperature flexibility properties of the resulting polymers were compared with those of unmodified PU. The melting temperature ( Tm) and glass transition temperature ( Tg) of the soft segments are not significantly different for the VB and SB series compared with unmodified PU. The tensile strengths of the VB and SB series sharply increase with increasing vinyl polymer content, whereas the control series does not exhibit an increase in tensile strength. The VB series exhibits excellent shape recovery at 10℃ compared with unmodified PU, and the shape recovery of the SB series remains above 90% at 45℃. The shape retention values of the VB (−45℃) and SB series (–25℃) are not less than 90%. The selected PUs demonstrate better flexibilities at extremely low temperatures compared with unmodified PU. Therefore, the graft polymerization of vinyl benzoate or trans-stilbene onto PU improves the tensile strength, shape recovery at low temperatures, and low-temperature flexibility of the polymer without decreasing the tensile strain or shape retention.

Locomotory responses to temperature in the grain weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae)

1969 ◽  
Vol 47 (2) ◽  
pp. 217-224 ◽  
Author(s):  
C. A. Barlow ◽  
W. D. Kerr
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Temperatures ◽  
Test Temperature ◽  
Low Temperatures ◽  
Testing Temperature ◽  
Sitophilus Granarius ◽  
Extreme Temperatures ◽  
Rearing Temperature ◽  
Orientation Mechanism

The speed or orthokinesis and turning rates or klinokinesis of individual adults of the grain weevil, Sitophilus granarius (L.), were affected by both the rearing temperature and the testing temperature. In general, orthokinesis decreased with a decrease in temperature, but weevils reared at a low temperature showed a smaller decrease than those reared at a high temperature. Klinokinesis was greater when differences between rearing and test temperatures were large and least when the differences were small or absent. Effects of differences between rearing and test temperatures were less if weevils were kept at the test temperature for 24 hours before testing and absent if beetles were at the test temperature for 2 weeks. Orthokinesis was shown to be an unsatisfactory orientation mechanism at low temperatures although it may operate with some efficiency at moderately high temperatures. Klinokinesis was much more effective at extreme temperatures and is probably the chief locomotory mechanism of orientation to temperature in this species.

THE CAUSE OF BOLTING IN SWEDE TURNIPS (BRASSICA NAPUS VAR. NAPOBRASSICA (L.) PETERM.)

1934 ◽  
Vol 11 (6) ◽  
pp. 733-750 ◽  
Author(s):  
F. H. Peto
Keyword(s):  
Brassica Napus ◽  
Low Temperature ◽  
High Temperatures ◽  
Root Development ◽  
Growth Temperature ◽  
Vegetative Growth ◽  
Low Temperatures ◽  
Initial Growth ◽  
High And Low Temperatures ◽  
Low Temperature Treatments

The relation of growth temperature to "bolting" (premature seed-stalk development) in swede turnips was investigated by growing plants in a greenhouse at high and low temperatures for different periods of time at various stages of their development. It was found that an initial growth temperature of approximately 53° F. for 30 to 50 days induced incipient bolting 71 days after seeding, as indicated by a rapid increase in internode length accompanied by a retarded root development. Flowering was inhibited to a large extent by growth temperatures above 65° F. in plants that had shown incipient bolting as a result of previous low-temperature treatments. None of the plants grown continuously at high temperatures gave any indication of bolting. It may be concluded, therefore, that high temperatures favor vegetative growth while low temperatures favor sexual reproduction.

Features of the Reinforcing Action of Carbon Blacks Deduced from the Tear Propagation of Filled Vulcanizates

1961 ◽  
Vol 34 (1) ◽  
pp. 57-65
Author(s):  
A. I. Lukomskaya
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Stress Distribution ◽  
Carbon Black ◽  
Natural Rubber ◽  
High Temperatures ◽  
Low Temperatures ◽  
Temperature Range ◽  
Carbon Blacks ◽  
Tear Propagation

Abstract 1. The reinforcing action of carbon blacks is most clearly apparent in the knotty tearing of carbon black rubbers. 2. Knotty tearing is characteristic of rubbers filled with carbon black in definite ranges of deformation and temperature, the position of which depends upon the type of rubber and carbon black. 3. With high contents of contact gas black in vulcanizates of sodium butadiene (SKB) and butadiene sytrene (SKS-30) rubbers two ranges of knotty tearing occur. The first is situated at relatively high temperatures and low rates and the second at relatively low temperatures and higher rates. Reduction in the content of black in these vulcanizates leads to the disappearance of the high temperature range of knotty tearing and the displacement of the low-temperature range towards higher temperatures and low rates. This position of the ranges (at medium rates and temperatures) is characteristic also of the said synthetic rubbers containing thermal black. 4. The first range of knotty tearing of filled SKB and SKS-30 vulcanizates with contact black is linked with the presence in them of carbon black chains, while the second range, existing also with vulcanizates with thermal black, is connected with the presence of carbon black particles. 5. Within the ranges ofr ates from 40 to 1000 mm/min and of temperatures from 40 to +100° C filled vulcanizates of natural rubber have one range of knotty tearing situated at lower rates. In the case of the presence in them of contact gas black the range is shifted towards higher rates than in the case of thermal black. 6. Increasing the length of the nick in testpieces being tested for tear propagation leads to a shift in the range of knotty tearing towards higher rates and widens it with respect to temperatures. This same effect is noted on altering the shape of the testpiece, starting with the Delft testpieces and proceeding to types A, B, and C, i.e. increasing the nonuniformity of stress distribution in the deformed testpieces.

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