scholarly journals Kinetics of winter deacclimation in response to temperature determines dormancy status and explains budbreak in differentVitisspecies

2018 ◽  
Author(s):  
Alisson P. Kovaleski ◽  
Bruce I. Reisch ◽  
Jason P. Londo
Keyword(s):  
Cold Hardiness ◽  
Effect Of Temperature ◽  
Good Prediction ◽  
Chilling Requirement ◽  
Perennial Plant ◽  
Different Temperatures ◽  
Winter Cold ◽  
Response To Temperature ◽  
The Relationship ◽  
Kinetics Of

2.AbstractBud dormancy and cold hardiness are critical adaptations for surviving winter cold stress for temperate perennial plant species, with shifting temperature-based responses during the winter. The objective of this study was to uncover the relationship between dormancy transition (chilling requirement) and temperature on the loss of cold hardiness and budbreak. Dormant cuttings ofVitis vinifera,V. aestivalis,V. amurensis, andV. ripariawere examined to determine the relationship between chilling requirement and temperature on rate of deacclimation (kdeacc). Differential thermal analysis was used to determinekdeaccusing mean low temperature exotherms. Effect of chill was evaluated as the deacclimation potential (ψdeacc), which was the change inkdeaccdue to chill accumulation. Budbreak was also evaluated in fully chilled buds at different temperatures. Results indicate that ψdeaccvaries dependent on dormancy state, following a logarithmic response to chill accumulation. The effect of temperature onkdeaccwas exponential at low and logarithmic at high temperatures. The combination of ψdeaccandkdeaccresulted in good prediction of deacclimation. Budbreak phenology was also explained by differences inkdeacc. Deacclimation rates can be used as a quantitative determinant of dormancy transition and budbreak, and to refine models predicting effects of climate change.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

Experimental Research on the Thermal Damage of Concrete

2013 ◽  
Vol 351-352 ◽  
pp. 460-466
Author(s):  
Chao Chen ◽  
Ying She Luo ◽  
Song Hua Tang ◽  
Xuan Zhang
Keyword(s):  
Damage Evolution ◽  
Thermal Damage ◽  
Damage Model ◽  
Effect Of Temperature ◽  
Compression Tests ◽  
Thermal Compression ◽  
Relevant Reference ◽  
Different Temperatures ◽  
The Relationship ◽  
Fire Design

In order to investigate the effect of temperature (from normal temperature to 850°C) coursed by fire on the strength damage of concrete, thermal compression tests for concrete specimens named C35 have been performed under different temperature conditions. Emphasis is laid on the relationship between temperature and thermal damage strength; and the relevant formula is proposed in this paper. The regularity and mechanism of thermal damage evolution in concrete on strength under high temperature are analyzed. Combined the result of tests with the residual strength thermal damage model, we obtain the specific damage variable value D under different temperatures. Finally, we compare the fitting formula curve to relevant reference; there are some important conclusions which can be partly applied to fire design of concrete structure.

THE REACTION BETWEEN CYANATE AND HYPOCHLORITE

1956 ◽  
Vol 34 (4) ◽  
pp. 489-501 ◽  
Author(s):  
M. W. Lister
Keyword(s):  
Activation Energy ◽  
Ionic Strength ◽  
Rate Constant ◽  
Hypochlorous Acid ◽  
Effect Of Temperature ◽  
Slow Step ◽  
True Activation Energy ◽  
Rate Of Reaction ◽  
Different Temperatures ◽  
Kinetics Of

The reaction between sodium hypochlorite and potassium cyanate in the presence of sodium hydroxide has been examined. The main products are chloride, and carbonate ions and nitrogen; but, especially if much hypochlorite is present, some nitrate is formed as well. The rate of reaction is proportional to the cyanate and hypochlorite concentrations, but inversely proportional to the hydroxide concentration: the rate constant is 5.45 × 10−4 min.−1 at 65 °C, at an ionic strength of 2.2. The rate constant increases somewhat as the ionic strength rises from 1.7 to 3.5. The effect of temperature makes the apparent activation energy 25 kcal./gm-molecule. The kinetics of the reaction suggest that the slow step is really a reaction of hypochlorous acid and cyanate ions, and possible intermediate products of this reaction are suggested. Allowing for the different extent of hydrolysis of hypochlorite at different temperatures, the true activation energy is found to be 15 kcal./gm-mol., which is consistent with the observed rate of reaction.

The effect of temperature on cold hardening of Loliutn perenne seedlings

1980 ◽  
Vol 95 (1) ◽  
pp. 77-81 ◽  
Author(s):  
M. P. Fuller ◽  
C. F. Eagles
Keyword(s):  
Lolium Perenne ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Leaf Growth ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Screening Techniques ◽  
Temperature Regimes ◽  
Different Temperatures ◽  
Cool Night

SummaryThe variation in hardening responses under different temperature regimes for three cultivars of Lolium perenne L. is described. The relative cold hardiness of the cultivars was modified by different temperatures during hardening. A threshold temperature existed above which hardening did not occur, but this temperature varied between cultivars.Although continuous low temperatures (2 °C) favoured hardening, hardening also occurred under warm day and cool night conditions (15:2 °C) where cultivars showed contrasting hardiness responses in daylengths of 16, 12 and 8 h. Under some of these conditions both leaf growth and hardiness were possible.The significance of these results is discussed in terms of the development of screening techniques and breeding objectives.

scholarly journals REDUCTION OF NITRIC OXIDE WITH CARBONACEOUS MATERIALS FROM PEAT

2005 ◽  
Vol 4 (1) ◽  
Author(s):  
E. L. Schultz ◽  
R. F. P. M. Moreira ◽  
H. J. José
Keyword(s):  
No Reduction ◽  
Activated Carbons ◽  
Physical Activation ◽  
Carbonaceous Materials ◽  
Experimental Conditions ◽  
Gaseous Products ◽  
Different Temperatures ◽  
The Relationship ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The direct NO reduction to produce N2 and CO2 using carbonaceous materials, chars and activated carbons, was studied. Chars were prepared from peat by pyrolysis, at temperatures ranging from 873 K to 1073 K. Activated carbons were prepared by the physical activation of chars with steam, in a steel reactor, at 1073 K for 12 minutes, 25 minutes and 45 minutes. The kinetics of NO reduction using chars and activated carbons produced at different experimental conditions were evaluated at different temperatures in the range 623-723 K. The gaseous products were essentially CO2 and N2 and the amount of CO produced was negligible. The effect of the temperature on the kinetics of reduction was also evaluated and the relationship between the rate constant and the temperature showed an Arrhenius dependence. Activation energies of the NO reduction were in the range 6.75 to 7.97 kcal.mol-1 for the chars and in the range 8.14 to 9.52 kcal.mol-1 for the activated carbons.

Phenomenological effect of temperature on the order n of the reaction of the curing kinetics in an EPDM polymer

2021 ◽  
pp. 1-12
Author(s):  
Salvador Gomez-Jimenez ◽  
Ana Maria Becerra-Ferreiro ◽  
Eduardo D Jareño-Betancourt ◽  
Jose M Vazquez-Penagos
Keyword(s):  
Cure Kinetics ◽  
Analytical Description ◽  
Curing Kinetics ◽  
Effect Of Temperature ◽  
Crosslinking Reaction ◽  
Precise Control ◽  
The Best Approximation ◽  
Short Period ◽  
Different Temperatures ◽  
Kinetics Of

Abstract The precise control of curing reaction parameters allows a better crosslinking polymer. Modeling and optimization of this process require a correct kinetic of curing model. The kinetics of the crosslinking reaction is studied for the ethylene propylene diene monomer (EPDM) synthetic elastomer by movile die rheometer (MDR). The kinetic parameters of reaction were calculated from Kamal-Ryan, Sestak-Berggren, and the Isayev-Deng methods at different temperatures. An Arrhenius-type function for the order of reaction n is introduced to improve the adjusting. A comparative study of Sestak-Berggren and Isayev-Deng models was made to validate and determine which model best describes the behavior of vulcanization. The best approximation was obtained with the model Isayev-Deng. Finally, taking the model with the best fit, a graphical and analytical description of the cure kinetics was developed. The order of reaction is predicted to better establishment of processing time. It was noted that for EPDM at higher temperatures, the increase of the rate of reaction occurs in short period of time, which could cause premature curing if the supply system is inadequate.

scholarly journals Effect of temperature and enzyme/substrate ratio on the hydrolysis of pea protein isolates by trypsin

2011 ◽  
Vol 20 (No. 1) ◽  
pp. 1-6 ◽  
Author(s):  
m. Karamać ◽  
r. Amarowicz ◽  
h. Kostyra
Keyword(s):  
Effect Of Temperature ◽  
Degree Of Hydrolysis ◽  
Protein Isolates ◽  
Pea Protein ◽  
Enzyme Substrate ◽  
Different Temperatures ◽  
Ph Stat ◽  
Substrate Ratio ◽  
Stat Method ◽  
The Relationship

Two pea protein isolates, Pisane and Propulse, were hydrolysed by trypsin. The degree of hydrolysis (DH) was computed using a pH-stat method. Enzymatic treatment of the pea protein isolates was conducted at four different temperatures, namely 35, 40, 45 and 50°C. The relationship between DH and E/S ratio was studied at 50°C and at four different E/S ratios; these were 5, 15, 25, 35 mAU/g (AU – Anson unit). For Pisane the highest value of the final DH (10.4%) was obtained at 45°C, whereas for Propulse the optimal temperature was 50°C and a DH value of 13.2% was attained. In the case of Pisane, the highest DH (11.5%) was recorded if the enzyme/substrate ratio was 35 mAU/g whereas for Propulse, the highest DH (13.2%) was observed at an E/S ratio of 15 mAU / g.  

Effect of Photon Flux Density and Temperature on the Production of Halogenated Monoterpenes by Plocamium cartilagineum (Plocamiaceae, Rhodophyta)

2004 ◽  
Vol 59 (9-10) ◽  
pp. 679-683 ◽  
Author(s):  
Rodrigo Palma ◽  
Mario Edding ◽  
Juana Rovirosa ◽  
Aurelio San-Martín ◽  
Victor H. Argandoña
Keyword(s):  
Growth Rate ◽  
Marine Alga ◽  
Effect Of Temperature ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Relative Growth ◽  
Halogenated Monoterpenes ◽  
Different Temperatures ◽  
The Relationship ◽  
Plocamium Cartilagineum

Abstract The effect of different photon flux densities (PFD) and temperatures on the relative growth rate (RGR) and the concentration of three halogenated monoterpenes in samples of Plocamium cartilagineum L.( Dixon), a marine alga (Rhodophyceae), were studied. The highest RGR (22.8 ± 0.04 d-1) was obtained at 15 °C and 41 μmol m-2 s-1 of PFD and the lowest (18.0 ± 0.2 d-1) was obtained at 18 °C and 120 μmol m-2 s-1. The different temperatures and light used in assays did not affect significantly the production of organic compounds. The production of mertensene and violacene was not affected significantly. However, compound 1 reached the highest concentration at 15 °C and 65 μmol m-2 s-1. The relationship between growth and production of monoterpenes of P. cartilagineum and the effect of temperature and the PFD were analyzed.

Study on Kinetics of Straw Stalk Gasification in CO2 with Random Pore Model

2014 ◽  
Vol 618 ◽  
pp. 316-320
Author(s):  
Hua Fei ◽  
Jin Ming Shi ◽  
Yuan Lin Li ◽  
Kai Luo
Keyword(s):  
Experimental Data ◽  
Reaction Model ◽  
Carbon Conversion ◽  
Pore Model ◽  
Different Temperatures ◽  
Shrinking Core ◽  
The Relationship ◽  
Kinetics Of ◽  
Core Reaction ◽  
Random Pore Model

The gasification of straw stalk in CO2 environment was studied by isothermal thermogravimetric analysis. The characteristics of rice straw and maize stalk gasification at different temperatures were examined under CO2 atmosphere. The relationship between reaction time and carbon conversion of two biomass chars was analyzed by the random pore model (RPM), and compared with the simulation of the shrinking core reaction model (SCRM). The results show that the random pore model is better to predict the experimental data at different temperatures. This means that the characteristics of pore structure for the influence of biomass chars gasification is well reflected by parameter ψ used in RPM. It indicates that the RPM can be applied to the comprehensive simulation of biomass chars gasification in CO2 environment.

Effect of Temperature and Bicarbonate Concentration on the Kinetics of UO2(s) Dissolution Under Oxidizing Conditions

1996 ◽  
Vol 465 ◽  
Author(s):  
J. de Pablo ◽  
I. Casas ◽  
J. Giménez ◽  
M. Molera ◽  
M. E. Torrero
Keyword(s):  
Dissolution Rate ◽  
Solid Particles ◽  
Effect Of Temperature ◽  
Bicarbonate Concentration ◽  
Rate Laws ◽  
Carbonate Concentration ◽  
Hydrogen Carbonate ◽  
Different Temperatures ◽  
Flow Through ◽  
Kinetics Of

ABSTRACTThe dissolution rate of unirradiated UO2 (s) has been studied as a function of hydrogen carbonate concentration at three different temperatures (298.15 K, 313.15 K and 333.15 K) under oxidizing conditions in a continuous flow-through reactor with a thin layer of solid particles (particle size from 100 to 300 μm). From the results of these experiments, two different rate laws have been determined. At high temperature (313.15 K and 333.15 K), we obtained a dissolution rate proportional to hydrogen carbonate concentration while at 298.15 K, the rate almost depends on the square root of the hydrogen carbonate concentration. This indicates a different reaction mechanism depending on temperature which can be related to the oxidation step of the overall process. The apparent activation energy obtained was 41 kJ mo1−1.

Sign in / Sign up

Export Citation Format

Share Document