Interrelation Between Low Temperature and Anaerobiosis in the Induction of Germination of Cocklebur Seed

1978 ◽  
Vol 5 (3) ◽  
pp. 337 ◽  
Author(s):  
Y Esashi ◽  
Y Tsukada ◽  
Y Ohhara
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Low Temperature ◽  
Seed Coat ◽  
Germination Potential ◽  
Anaerobic Induction ◽  
Preceding Period ◽  
Exogenous Ethylene

Non-dormant upper cocklebur (Xanthium pensylvanicum Wallr.) seeds germinated bimodally, in response to low temperature as well as to high temperature. At low temperature, the process was aerobic. Increase in germination potential by pre-exposure to low temperature was termed 'chilling induction'. Similarly to anaerobic induction of cocklebur seed germination, chilling induction required a certain time of presoaking to be effective. The germination pattern was identical in both cases, the seed coat being broken at the axial end. In contrast to anaerobic induction, however, chilling induction was not affected by exogenous ethylene and the effect of chilling was cumulative within 3-4 days, but decreased with increasing duration of chilling beyond these times. The effect of anaerobic induction was enhanced by a pre- ceding chilling, as described in a previous paper and, similarly, the effect of chilling induction for fully presoaked seeds was additively increased by a preceding period of anaerobiosis. However, the effect of the chilling was decreased by a subsequent anaerobiosis.

Enhancement by Low Temperatures of the Anaerobic Induction of Cocklebur Seed Germination

1977 ◽  
Vol 4 (6) ◽  
pp. 849 ◽  
Author(s):  
Y Esashi ◽  
Y Ohhara
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
Gibberellic Acid ◽  
Low Temperatures ◽  
Anaerobic Treatment ◽  
Maximal Response ◽  
Benzyl Adenine ◽  
Anaerobic Induction ◽  
Time Period ◽  
Proportional Increase

Non-dormant, upper cocklebur (Xanthium pensylvanicum Wallr.) seeds, incapable of germinating under ordinary conditions, can germinate when previously subjected to anaerobiosis; this has been termed the anaerobic induction of seed germination. Aerobic presoaking of the seeds was also required for successful anaerobic induction, and exerted two counter-acting effects on seed germination. When the time period of aerobic presoaking was sufficiently prolonged, the increasing duration of an anaerobic treatment resulted in proportional increase of germination potential but, when it was short, the effect of the anaerobiosis was saturated in a few days. Prolonging the aerobic presoaking period caused less response of the seed to the anaerobic induction, suggesting the development of some germination-inhibiting system during the aerobic presoaking period. This system could not develop in the absence of O2 or at low temperature. Thus, low temperature during prolonged presoaking produced a maximal response to anaerobic induction. Various germination stimulants, CO2, ethylene, gibberellic acid and benzyl adenine, did not significantly alter the effects of the presoaking.

scholarly journals Ethylene and lettuce seed germination

2003 ◽  
Vol 60 (3) ◽  
pp. 601-606 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Critical Factor ◽  
Inhibitory Effect ◽  
Lettuce Seed ◽  
A Cell ◽  
Lettuce Seed Germination ◽  
Exogenous Ethylene ◽  
Increased Activity

Ethylene can stimulate seed germination and overcome dormancy in many species. For instance, the inhibitory effect of high temperature on lettuce seed germination can be overcome by exogenous ethylene. Involvement of ethylene in seed germination is a widely accepted fact, but the mechanistic details are poorly understood. A critical factor in ethylene studies is the response of seed germination properties to various ethylene inhibitors. Lettuce seed has been used as a model to study the role of ethylene in seed germination at high temperature. The role of ethylene in germination is not known but either ethylene evolution or addition of 1-aminocyclopropane-1-carboxilic acid (ACC) have been associated with increased activity of endo-beta-mannanase, a cell-wall enzyme that weakens the endosperm and allows lettuce seed to germinate at high temperature. This review describes some results on seed germination studies in response to ethylene and its possible role in promoting germination at high temperature.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Superconducting Wind Generators with Capacities of 10 MW and Larger

2020 ◽  
Vol 10 (10) ◽  
pp. 59-67
Author(s):  
Victor N. ANTIPOV ◽  
◽  
Andrey D. GROZOV ◽  
Anna V. IVANOVA ◽  
◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Wind Power ◽  
State Of The Art ◽  
Superconducting Materials ◽  
Commercial Application ◽  
Synchronous Generators ◽  
High Temperature Superconducting ◽  
Wind Generators ◽  
Main Factor

The overall dimensions and mass of wind power units with capacities larger than 10 MW can be improved and their cost can be decreased by developing and constructing superconducting synchronous generators. The article analyzes foreign conceptual designs of superconducting synchronous generators based on different principles: with the use of high- and low-temperature superconductivity, fully superconducting or only with a superconducting excitation system, and with the use of different materials (MgB2, Bi2223, YBCO). A high cost of superconducting materials is the main factor impeding commercial application of superconducting generators. In view of the state of the art in the technology for manufacturing superconductors and their cost, a conclusion is drawn, according to which a synchronous gearless superconducting wind generator with a capacity of 10 MW with the field winding made of a high-temperature superconducting material (MgB2, Bi-2223 or YBCO) with the «ferromagnetic stator — ferromagnetic rotor» topology, with the stator diameter equal to 7—9 m, and with the number of poles equal to 32—40 has prospects for its practical use in the nearest future.

SOMERS LTA COPPER

Alloy Digest ◽  
1980 ◽  
Vol 29 (12) ◽  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Copper Foil ◽  
Heat Treating ◽  
Dielectric Substrates ◽  
Printed Circuits

Abstract SOMERS LTA Copper is a wrought copper foil that can be annealed at 350 F in 15 minutes to the full-soft condition; its use simplifies the manufacture of printed circuits (LTA = Low-Temperature Annealable). LTA Copper is especially useful for foil weights up to and including one ounce per square foot (0.0014-inch thick) for laminating to high-temperature dielectric substrates. This datasheet provides information on composition, physical properties, and elasticity as well as fatigue. It also includes information on forming, heat treating, and machining. Filing Code: Cu-407. Producer or source: Olin Corporation.

CHRO-MOW

Alloy Digest ◽  
1958 ◽  
Vol 7 (2) ◽  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Steel Company ◽  
Temperature Performance ◽  
Hot Work Steel ◽  
Crucible Steel ◽  
Red Hardness

Abstract CHRO-MOW is a tough hot work steel which will harden from a relatively low temperature in air. It possesses a desirable combination of toughness and red-hardness. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-67. Producer or source: Crucible Steel Company of America.

NICLOY 5

Alloy Digest ◽  
1960 ◽  
Vol 9 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Steel ◽  
Heat Treating ◽  
Low Carbon ◽  
Temperature Performance

Abstract NICLOY 5 is a low carbon, nickel ferritic steel reecommended for low temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-96. Producer or source: Babcock & Wilcox Company.

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

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