Cooling rate studies of rocks from two basic dykes

1982 ◽  
Vol 46 (340) ◽  
pp. 387-394 ◽  
Author(s):  
G. M. Corrigan
Keyword(s):  
Crystal Growth ◽  
Cooling Rate ◽  
Incubation Period ◽  
The Other ◽  
Textural Features ◽  
Variable Rate ◽  
Constant Rate ◽  
Loop Technique ◽  
Basaltic Melts ◽  
Cooling Model

SynopsisNucleation and crystal growth of plagioclase have been studied in two basaltic melts by one atmosphere, constant-rate and variable-rate cooling experiments using the wire-loop technique (Donaldson et al., 1975). Constant-rate cooling studies indicate that the length of the incubation period prior to nucleation varies systematically with the degree of supercooling and with the cooling rate. Attempts to determine the rates at which the marginal parts of two dykes (from the Isle of Arran, SW Scotland) cooled, by the attempted reproduction of the natural textural features, in constant-rate cooling experiments suggest that for one of the dykes, plagioclase phenocrysts at the contact could have grown at a cooling rate of approximately 3°C/hour and the groundmass plagioclase laths at faster cooling rates in excess of 10°C/hour. For the other dyke the plagioclase laths in the rocks 0.5 cm from the dyke contact probably grew at rates slower than 2°C/hour. Attempts to validate experimentally the Jaeger (1957) cooling model for the two dykes suggest that the dykes cooled at much slower rates than the theory predicts.

Crystal growth and nucleation in flash-injected diabase dikes

1978 ◽  
Vol 15 (12) ◽  
pp. 1904-1923 ◽  
Author(s):  
Norman H. Gray
Keyword(s):  
Crystal Growth ◽  
Unit Volume ◽  
The Other ◽  
Crystal Shape ◽  
Rapid Cooling ◽  
Other Hand ◽  
Controlling Mechanism ◽  
Oxide Crystals ◽  
Basaltic Melts

Z, the number of either plagioclase, clinopyroxene, or opaque oxide crystals per unit volume, varies across the widths of 10 'flash-injected' diabase dikes in a manner which is well described by the equation[Formula: see text]where y is the distance from the contact. This relationship can be shown to be a consequence of the interaction of crystal growth and nucleation during the cooling of the dikes if[Formula: see text]The value of the exponent n in [i] is a function both of m in [ii] and the dominant growth-controlling mechanism during the main nucleation period. The n values of the minerals in the dikes examined cluster around −0.9, −1.5, and −2.2. On the basis of these data it appears that m is approximately constant and equal to 3.0 in basaltic melts. On the other hand, it appears that the dominant growth-controlling mechanism during nucleation is dependent on the exact composition of the melt. For example, the clinopyroxenes in the quartz and olivine tholeiitic diabases studied, differ significantly both in their crystal shape and n values. Departures from [i] are found within a few centimetres of the contact where, because of the rapid cooling, the assumption of constant m in [ii] is not valid.

scholarly journals Study of Struvite Crystal Growth with The Addition of Tartaric Acid

2021 ◽  
Vol 328 ◽  
pp. 01003
Author(s):  
Dyah Suci Perwitasari ◽  
Sintha Soraya Santi ◽  
Stefanus Muryanto ◽  
J Jamari ◽  
AP Bayuseno
Keyword(s):  
Aqueous Solution ◽  
Crystal Growth ◽  
Tartaric Acid ◽  
Rate Constant ◽  
The Other ◽  
Molar Ratio ◽  
Other Hand ◽  
Constant Rate ◽  
Manufacture Industry ◽  
Crystal Mass

The purpose of this study was to study the growth of struvite crystals from the effect of adding tartaric acid additives to an aqueous solution containing Mg2+, NH4+, and PO43-with a molar ratio of 1:1:1. The results of the study, it was found that the more the concentration of tartaric acid additive was added, it got smaller the rate constant was. By decreasing the value of the constant rate, the growth of struvite crystals also decreased then the growth of struvite crystals became inhibited. On the other hand, struvite has the potential to be used as a fertilizer. The concentration of tartaric acid also had a significant effect on controlling the production of struvite. The optimum crystal mass was obtained at a concentration of 20 ppm tartaric acid, a temperature of 40oC and a stirrer rotation of 300 rpm so that it can be applied in manufacture industry of struvite fertilizer.

Effects of Rare Earths on Structural Transformation of Heavy Rail Steel

2011 ◽  
Vol 194-196 ◽  
pp. 237-242
Author(s):  
Cheng Jun Liu ◽  
Ya He Huang ◽  
Mao Fa Jiang
Keyword(s):  
Cooling Rate ◽  
Incubation Period ◽  
Rare Earths ◽  
Rail Steel ◽  
Vacuum Induction Furnace ◽  
Critical Cooling Rate ◽  
The Stability ◽  
Heavy Rail ◽  
Electronic Microscope ◽  
Heavy Rail Steel

Clean heavy rail steel was prepared by the process of vacuum induction furnace smelting, forge work and rolling. Effects of Rare earths (RE) on phase transformation and microstructure of heavy rail steel were investigated by thermal simulation machine, metallographic microscope and scanning electronic microscope. Thermal simulate tests indicate that, RE can move the C curve of pearlite transformation to lower right, prolong the incubation period of pearlite and improve the stability of undercooled austenite. The minimum incubation period of pearlite transformation is increased from 24s to 30s by RE. Furthermore, RE can decrease the critical cooling rate of pearlite transformation from 1°C•s-1to 0.5°C•s-1and the critical cooling rate of quenching from 15°C•s-1to 13°C•s-1. Additionally, RE can fine the annealing and anormalizing pearlite notably. The pearlite laminae distance of heavy rail steel added RE is decreased by 12.9% (annealing) and 13.3% (normalizing), respectively.

On the incubation period in neurolues

1927 ◽  
Vol 23 (10) ◽  
pp. 1046-1050
Author(s):  
E. V. Sukhova
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Incubation Period ◽  
The Other ◽  
Other Hand ◽  
General Number ◽  
The Central Nervous System

Speaking about syphilis lesions of the central nervous system, it is impossible not to note that these lesions are among the most severe diseases of the latter. But, on the other hand, their severity is redeemed to some extent by the specific means of combating them which we have in our hands. In this case, the fight against neurolues is reduced not so much to its treatment as to its prevention. Hence the interest with which the question of the influence of various conditions on the occurrence of syphilitic lesions of the central nervous system has recently begun to be comprehensively discussed and the exact causes which, from the general number of syphilitics, distinguish the group subsequently condemned to neurolues have been sought to be elucidated.

Sodium Benzoate Inhibits Growth of or Inactivates Listeria monocytogenes

1988 ◽  
Vol 51 (7) ◽  
pp. 525-530 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Incubation Period ◽  
Sodium Benzoate ◽  
The Other ◽  
Complete Inhibition ◽  
Initial Population ◽  
Limited Growth ◽  
Complete Inactivation ◽  
Low Concentrations ◽  
Slight Growth

The ability of Listeria monocytogenes to grow or survive was determined using tryptose broth at pH 5.6 or 5.0, supplemented with 0, 0.05. 0.1, 0.15. 0.2. 0.25 or 0.3% sodium benzoate, and incubated at 4,13,21 or 35°C. The bacterium grew in benzoate-free controls under all conditions except at 4°C and pH 5.0. At pH 5.6 and 4°C, after 60 d, L. monocytogenes (initial population ca. 103/ml) was inactivated by 0.2, 0.25 and 0.3% sodium benzoate. Other concentrations of benzoate permitted slight growth during the first 36 d of incubation followed by a decrease in populations of the pathogen. At pH 5.0 and 4°C, from 0.15 to 0.3% benzoate completely inactivated the pathogen in 24 to 30 d, whereas the other concentrations caused a gradual decrease in the population during the 66-d incubation period. At 13°C and pH 5.6, L. monocytogenes grew (more at lower than higher concentrations of benzoate) in the presence of all concentrations of benzoate except 0.25 or 0.3%, which prohibited growth throughout a 264-h incubation period. Reducing the pH to 5.0 minimized growth at the two low concentrations of benzoate and caused slight decreases in population at the other concentrations of benzoate. At 21 and 35°C and pH 5.6, appreciable growth of L. monocytogenes occurred in the presence of 0.2% or less sodium benzoate, whereas higher concentrations were inhibitory, permitting little if any growth by the pathogen. Reducing the pH to 5.0 allowed limited growth of the pathogen at 21 and 35°C when the medium contained 0.05 or 0.1% sodium benzoate. Higher concentrations caused either complete inhibition or inhibition plus partial or complete inactivation of the pathogen during incubations of 117 h at 21°C or 78 h at 35°C.

scholarly journals Acrylic resin disinfection by peracetic acid and microwave energy

2015 ◽  
Vol 63 (3) ◽  
pp. 315-318 ◽  
Author(s):  
Carmen Beatriz Borges FORTES ◽  
Vicente Castelo Branco LEITUNE ◽  
Fabrício Mezzomo COLLARES ◽  
Nélio Bairros DORNELLES JUNIOR ◽  
Stéfani Becker RODRIGUES ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Microwave Irradiation ◽  
Incubation Period ◽  
Peracetic Acid ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
The Other ◽  
Disinfection Methods ◽  
Acrylic Resins ◽  
Irradiation Power

Objective: The objective of this study was to evaluate the effectiveness of disinfection methods in microwave and immersion in peracetic acid in heat-cured, self-cured and microwave-cured acrylic resin, contaminated with Candida albicans. Methods: Five specimens were prepared for each type of acrylic resin. All were infected with Candida Albicans, incubated at 37°C for 24 hours. The group which underwent microwave energy was irradiated with a power of 840W for 1 minute and the other group underwent disinfection by soaking of 0.2% peracetic acid for 5 minutes. Results: All samples proved to be contaminated after the incubation period. After the different processes of disinfection, both immersion in 0.2% peracetic acid as microwave irradiation were effective in disinfection of the 3 types of acrylic resins contaminated by Candida Albicans. Conclusion: Concluded that soaking in 0,2% peracetic acid for 5 minutes with microwave irradiation power 840W for 1 minute are effective methods for disinfecting heat-cured acrylic resin, self-cured acrylic resin and microwave-cured acrylic resin, contaminated with Candida Albicans.

Effect of behavioral variables on cooling rate of man in cold water

1975 ◽  
Vol 38 (6) ◽  
pp. 1073-1077 ◽  
Author(s):  
J. S. Hayward ◽  
J. D. Eckerson ◽  
M. L. Collis
Keyword(s):  
Body Size ◽  
Cooling Rate ◽  
Rectal Temperature ◽  
Body Surface ◽  
Cold Water ◽  
The Other ◽  
Ocean Water ◽  
Protective Behaviors ◽  
Control Behavior ◽  
Behavioral Variables

Five different behaviors of man while in cold ocean water (9–10 degrees C) were assessed for their effect on rate of progress into hypothermia. With subjects wearing lifejackets, two thermally protective behaviors were studied which reduce exposure to the water of areas of body surface with high relative heat loss potential. One was huddling of three persons and the other a self-huddle behavior (HELP or Heat Escape Lessening Posture). These two behaviors resulted in significant reductions of rectal temperature cooling rate of 66 per cent and 69 per cent, respectively, of that of a control behavior. With no flotation available, two survival swimming behaviors (treading water and drownproofing) were shown to result in significant increases in cooling rate to 134 per cent and 182 per cent, respectively, of the control behavior. Potential swimming distance of subjects wearing a life-jacket was 0.85 miles in water near 12 degrees C before predicted incapacitation by hypothermia. It was concluded that behavioral variables can be of major importance in determining survival time in cold water through modulation of cooling rate associated with other variables such as fatness, body size, and clothing.

scholarly journals Biology of the Wild SilkmothAnaphe panda(Boisduval) in the Kakamega Forest of Western Kenya

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
N. Mbahin ◽  
S. K. Raina ◽  
E. N. Kioko ◽  
J. M. Mueke
Keyword(s):  
Life Cycle ◽  
Incubation Period ◽  
Rainy Season ◽  
Dry Season ◽  
Developmental Period ◽  
The Other ◽  
Western Kenya ◽  
Kakamega Forest ◽  
Pupal Period ◽  
Indigenous Forest

A study on the life cycle of the silkmothAnaphe panda(Boisduval) was conducted in two different habitats of the Kakamega Forest in western Kenya: Ikuywa, an indigenous forest, and Isecheno, a mixed indigenous forest. Eggs were laid in clusters, and the incubation period ranged from 40 to 45 days. Larvae fed onBridelia micrantha(Hochst) and passed through seven instars. The developmental period took between 83 to 86 days in the dry season and 112 to118 days in the rainy season. The pupal period ranged between 158 and 178 days in the rainy season and, on the other hand, between 107 and 138 days in the dry season. But the later caught up in development with those that formed earlier. Moths emerged from mid-October until mid-May. Longevity of adultAnaphe pandamoths took between 4 and 6 days, but generally females seemed to live longer than males. The moth also seems to have higher lifespan in the indigenous forest compared to the mixed indigenous forest.

Inverse changes in plasma prolactin and LH concentrations in female canaries after disruption and reinitiation of incubation

1984 ◽  
Vol 103 (2) ◽  
pp. 251-256 ◽  
Author(s):  
A. R. Goldsmith ◽  
S. Burke ◽  
J. M. Prosser
Keyword(s):  
Incubation Period ◽  
The Other ◽  
External Stimulus ◽  
Breeding Cycle ◽  
Plasma Prolactin ◽  
Incubation Behaviour ◽  
Incubating Birds ◽  
Egg Removal ◽  
Female Canaries

ABSTRACT Prolactin and LH concentrations were measured in the plasma of female canaries sampled during the breeding cycle and after disruption and reinitiation of incubation behaviour. The late incubation period was characterized by low LH and high prolactin concentrations, and canaries separated from their nests at this stage showed an increase in LH and a decline in prolactin within 3 h. In one experiment mean (±s.e.m.) concentrations before and 24 h after nest deprivation were: prolactin 397 ± 86 and 18 ± 5 μg/l; LH 1·04±0·21 and 2·03±0·17 μg/l. Female canaries which abandoned their nests after the eggs had been removed also showed an increase in LH together with a fall in prolactin 24 h after egg removal. When nest-deprived canaries were allowed to resume incubation, plasma prolactin increased again within 5 h and after 2 days had reached levels normal for incubating birds (398± 46 μg/l). Concentrations of LH changed more gradually but had decreased 2 days after the resumption of incubation. Thus prolactin and LH show inverse changes after the disruption and reinitiation of incubation behaviour; it is not clear, however, if the change in one is dependent on the other or if both hormones are responding to the same external stimulus. J. Endocr. (1984) 103, 251–256

scholarly journals The possibility of obtaining beta-anhydrite from waste nitrogypsum

2004 ◽  
Vol 40 (1) ◽  
pp. 89-100 ◽  
Author(s):  
S. Marinkovic ◽  
A. Kostic-Pulek ◽  
S. Popov ◽  
J. Djinovic ◽  
Prvoslav Trifunovic
Keyword(s):  
Compressive Strength ◽  
Crystal Growth ◽  
Compression Strength ◽  
The Other ◽  
Solid Ratio ◽  
Double Salts ◽  
Ir Analysis

The possibility of obtaining ? - anhydrite from nitrogypsum, which is waste from a nitrocellulose plant, was investigated. It was shown by means of qualitative IR analysis that the product obtained by heating nitrogypsum for 5 hours at 700 o C was ? - anhydrite. When the ?- anhydrite was mixed with water at a W/S (water/solid) ratio of 0.54 in presence of different accelerators (CaO, mixture CaO - ash, ash, Na2SO4 and K2SO4), pastes were formed which hardened on standing. The compressive strength of the hardened samples was measured after 7 and 28 days and their composition determined by qualitative IR analysis. On the basis of these results, it was observed that a relationship exists between the composition (depending on the used accelerator) and the compression strength of the samples. Namely, the formation of large cores of double salts: syngenite (K2SO4 ?CaSO4 ?H2O) and glauberite (Na2SO4 ?CaSO4), in the presence of the accelerators K2SO4 and Na2SO4, respectively, was due to the rapid and complete crystallization of the dihydrate (CaSO4 ?2H2O). This fast crystal growth of the dihydrate resulted in high compressive strengths of these samples. In the other samples (prepared in presence of the accelerators: CaO, mixture CaO - ash and ash), dihydrate did not form and, consequently, their compressive strength was low.

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