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.

Relieving of Residual Stresses in Metal Workpieces at High and Low Temperatures

2021 ◽  
Vol 887 ◽  
pp. 651-656
Author(s):  
Marina V. Polonik
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Residual Stresses ◽  
Low Temperatures ◽  
Creep Properties ◽  
Processing Modes ◽  
Properties Of Materials ◽  
High And Low Temperatures ◽  
Temperature Heating ◽  
High Temperature Heating

On the basis of previously accumulated irreversible deformations, and, consequently, residual stresses, the process of removing residual stresses in metal workpieces under the action of low and high temperatures is simulated. Boundary value problems are solved and here are described regularities that are responsible for removing residual stresses for processing modes: high-temperature heating - cooling, high-temperature heating - holding - cooling, low-temperature heating - holding - cooling. The holding stage is modeled, taking into account the creep properties of materials under Norton creep conditions. According to the dependences of the obtained exact solutions, it is shown that it is the holding process that leads to the relaxation of residual stresses.

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.

Peotoemission Study of Si (001) Surfaces Exposed to as Flux

1989 ◽  
Vol 148 ◽  
Author(s):  
H. Okumura ◽  
K. Miki ◽  
K. Sakamoto ◽  
T. Sakamoto ◽  
S. Misawa ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Electronic Structures ◽  
Low Temperatures ◽  
Dimer Model ◽  
Surface And Interface ◽  
High And Low Temperatures ◽  
Interface Structures ◽  
Temperature Sample

ABSTRACTPhotoemission spectra (XPS and UPS) of As-covered Si (001) surfaces prepared at high (>600ºC) and low (<450ºC) temperatures and GaAs epilayers subsequently grown on them were measured without exposing to air. It was found that the surface electronic structures of As/Si prepared at the low temperature are different from those of the high temperature sample, the spectra of which can be interpreted as a symmetric dimer model. Differences were also observed between the GaAs epilayers on the As—covered Si surfaces prepared at the high and low temperatures. The temperature dependence of the surface and interface structures are discussed.

scholarly journals Growth, flowering and fruiting in tomatoes in relation to temperature, cycocel and GA.

1970 ◽  
Vol 18 (2) ◽  
pp. 105-110
Author(s):  
A.A. Abdalla ◽  
K. Verkerk
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
High Temperatures ◽  
Root Development ◽  
Temperature Regime ◽  
Low Temperatures ◽  
Fruit Set ◽  
High Temperature Regime ◽  
Temperature Regimes ◽  
Dark Green

The effects were assessed of CCC and GA on tomatoes grown either under a high temperature regime (35 degrees day and 25 degrees C. night) or at normal temperatures (22 degrees and 18 degrees ). CCC (0.4%) was applied to the soil in the pots either 2 days after transplanting or at the start of flowering; G A was applied by dipping the first truss in GA (50 p.p.m.). CCC greatly retarded the growth rate of the stems of the plants under both temperature regimes; this effect persisted for about 17 and 24 days under the high and normal temperature regimes, respectively. With plants grown at high temperatures CCC applied at the start of flowering greatly reduced flower shedding and slightly increased the fruit set and fruit development of hand-pollinated flowers. With plants grown at normal temperatures, however, the effects of CCC were slight. CCC-treated plants were sturdy with dark-green leaves which remained green longer, especially under the high temperature regime. More N accumulated in the tissues of plants grown at high temperatures than at normal temperatures, and the N content of the latter plants was considerably increased by CCC treatment. The root development of the CCC-treated plants was much more extensive than that of the untreated plants. The numbers of seeds in the hand-pollinated fruit were not affected by CCC, but at high temperatures there were considerably less seeds than at low temperatures. GA enhanced fruit set of the high-temperature plants, but the fruits were small and seedless. GA also accelerated fruit ripening by 2 and 3 weeks in the plants grown at high and normal temperatures, respectively.-Agric. Univ., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Effect of low temperature on development of the coccidium Eimeria funduli in the Gulf killifish

Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 31-39 ◽  
Author(s):  
M. A. Solangi ◽  
R. M. Overstreet ◽  
J. W. Fournie
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Developmental Stages ◽  
Oocyst Wall ◽  
Hepatic Parenchyma ◽  
Fundulus Grandis ◽  
Exposed Fish ◽  
Liver And Pancreas ◽  
Reduced Rate ◽  
Low Temperature Treatments

SUMMARYEimeria funduli, a coccidium infecting the liver and pancreas of killifishes and requiring an intermediate host, was allowed to develop at 22±2 °C for 5, 10, 15 or 20 days (schizont through zygote stages) in Fundulus grandis and was then exposed to 10·0±0·5 °C for 20 days or to 7·0±0·5 °C for 5 or 20 days. Both low temperature treatments inhibited all developmental stages, except for the case of fish infected for 5 days before exposure to 7 °C in which infections were eliminated. Returning fish back to a temperature of 22 °C for 20 days resulted in resumed development of all stages at the same or somewhat reduced rate. In all cases, intensity of infections was greatly reduced during exposure to low temperatures. Many organisms exhibited abnormalities. Gamonts and zygotes were atrophied or disintegrated within their parasitophorous vacuoles in all exposures and, in fish exposed to 7 °C for 20 but not 5 days, about 30% of the oocysts were abnormal, with from 1–8 sporoblasts. Areas of degeneration or necrosis incorporated aggregates and single parasites in both the pancreas and the hepatic parenchyma. The granulocytic inflammatory response, which at 22 °C was normally restricted to the period spanning development of gamonts and formation of the oocyst wall, was inhibited or delayed from infiltrating infected, diseased areas at low temperatures. The response intensified after cold-exposed fish were returned to 22 °C. A fibroid, non-granulocytic response occurred in fish introduced 5 days post-infection to 10°C before being returned to warm water. Two other types of lesion occurred in the pancreas. The first could develop into necrosis and was associated with low temperature; it did not always involve infected tissue. The other, a degenerating focal alteration, was not necessarily associated with infections or low temperatures.

Temperature Tolerance in Young Pacific Salmon, Genus Oncorhynchus

1952 ◽  
Vol 9 (6) ◽  
pp. 265-323 ◽  
Author(s):  
J. R. Brett
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Oncorhynchus Tshawytscha ◽  
Prolonged Exposure ◽  
Pacific Salmon ◽  
Vertical Gradient ◽  
Temperature Tolerance ◽  
Preferred Temperature ◽  
High And Low Temperatures ◽  
Temperature Responses

Lethal limits of high and low temperatures were determined for the young of five species of Pacific salmon, the spring (Oncorhynchus tshawytscha), the pink (O. gorbuscha), the sockeye (O. nerka), the chum (O. keta) and the coho (O. kisutch).For acclimation temperatures ranging from 5° to 24 °C. significant differences between species in their resistance to high temperatures was obtained. The spring and coho were most resistant. The pink and chum salmon were least resistant, and the sockeye was distinguishable from the latter two by greater resistance for prolonged exposure to high temperatures. No species could tolerate temperatures exceeding 25.1 °C. when exposed for one week.A fanning-out of the opercula was shown to be directly correlated with the onset of death from a low temperature. By use of this criterion mixed lethal effects at low temperatures were demonstrated and found to be influenced by the size of the fish and by the salinity of the water. None of the species could withstand temperatures lower than 4 °C. when acclimated to 20 °C. and above. When taken from holding troughs as low as 5 °C., coho and sockeye could not tolerate long exposure (four days) to 0 °C.In a vertical gradient little difference in preferred temperature was observed, either between species or for different acclimation temperatures. The 12° to 14 °C. stratum was the region of greatest concentration.Specific differences in temperature responses are in keeping with taxonomic and ecological distinctions.

scholarly journals Environmental tests of vapor compression heat pump for space applications

2020 ◽  
pp. 240-240
Author(s):  
Xudong Ma ◽  
Rui Ma ◽  
Yilin Ye ◽  
Suying Yan ◽  
Feng Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Heat Pump ◽  
Low Temperatures ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Space Applications ◽  
Suitable Temperature ◽  
High And Low Temperatures

Heat pumps are needed to provide a suitable temperature for both people and equipment in spacecraft. This paper reports on work designed to see if vapor compression heat pumps, in particular, can be expected to function normally in space. A vapor compression heat pump was built and tested under conditions of high temperature (70?C), low temperature (0?C), and near-vacuum (10-4 Pa). It was found that the coefficient of performance of this heat pump was 2.99 at both high and low temperatures, and was 2.1 under near vacuum conditions. The results suggest that vapor compression heat pumps are suitable for use in space.

scholarly journals Forcing Temperature Affects Postproduction Quality, Dark Respiration Rate, and Ethylene Responsiveness of Pelargonium × domesticum

1992 ◽  
Vol 117 (4) ◽  
pp. 596-599 ◽  
Author(s):  
Kathleen B. Evensen ◽  
Karen M. Olson
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Dark Respiration ◽  
Floral Display ◽  
Dark Respiration Rate ◽  
Respiration Rates ◽  
Carbohydrate Depletion ◽  
Higher Temperature ◽  
High And Low Temperatures ◽  
Reduced Rate

Postproduction quality, net C exchange, and petal abscission in response to ethylene were compared following forcing at 21(day)/16C(night) or 18/13C(18-hour photoperiod) of two cultivars of Pelargonium × domesticum L.H. Bailey. Fewer petals of 2- to 6-day-old florets abscised in response to 60 minutes of 0.7 μl ethylene/liter on plants forced at low temperature than on plants forced at 3C higher temperature. Forcing temperature did not affect floret longevity or the number of florets opening during forcing, but the floral display under simulated consumer conditions was prolonged in low-temperature plants by the continued development of buds. Dark respiration rates at 21C were lower in leaves from plants forced at low temperature than in leaves of plants forced at the higher temperature. Differences in postproduction quality between plants forced at high and low temperatures may have been related to the reduced rate of carbohydrate depletion in low-temperature plants.

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.

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