scholarly journals Temperature Dependent Seed Germination of Dalbergia nigra Allem (Leguminosae)

2001 ◽  
Vol 44 (4) ◽  
pp. 401-404 ◽  
Author(s):  
Fernanda G. A. Ferraz-Grande ◽  
Massanori Takaki
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
High Temperatures ◽  
Broad Temperature Range ◽  
Optimum Temperature ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dalbergia Nigra ◽  
The Mean ◽  
Kinetics Of

The germination of endangered species Dalbergia nigra was studied and 30.5° C was found as optimum temperature, although the species presented a broad temperature range where germination occurs and light had no effect. The analysis of kinetics of seed germination confirmed the asynchronized germination below and above the optimum temperature. The light insensitive seed and germination also at high temperatures indicated that D. nigra could occur both in understories and gaps where the mean temperature was high.

scholarly journals The combustion of aromatic and alicyclic hydrocarbons. II. The ignition of aromatic hydrocarbons at high temperatures

1939 ◽  
Vol 171 (946) ◽  
pp. 421-433 ◽  
Keyword(s):  
High Temperatures ◽  
Aromatic Hydrocarbons ◽  
Isothermal Oxidation ◽  
Present Communication ◽  
Temperature Range ◽  
Benzene Toluene ◽  
The Subject ◽  
Kinetics Of

In the first paper of this series (Burgoyne 1937) the kinetics of the isothermal oxidation above 400° C of several aromatic hydrocarbons was studied. The present communication extends this work to include the phenomena of ignition in the same temperature range, whilst the corresponding reactions below 400° C form the subject of further investigations now in progress. The hydrocarbons at present under consideration are benzene, toluene, ethylbenzene, n -propylbenzene, o-, m - and p -xylenes and mesitylene.

scholarly journals Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

2003 ◽  
Vol 60 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
High Temperatures ◽  
Lactuca Sativa ◽  
Lettuce Seed ◽  
Temperature Dependent ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Lettuce Seed Germination ◽  
Dark Green

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

Temperature-Dependent Maximum Daily Consumption of Juvenile Salmonids by Northern Squawfish (Ptychocheilus oregonensis) from the Columbia River

1991 ◽  
Vol 48 (12) ◽  
pp. 2491-2498 ◽  
Author(s):  
Steven Vigg ◽  
Craig C. Burley
Keyword(s):  
Simulation Modeling ◽  
Pacific Salmon ◽  
Columbia River ◽  
Temperature Dependent ◽  
Daily Consumption ◽  
Preferred Temperature ◽  
Temperature Range ◽  
Juvenile Pacific Salmon ◽  
The Mean ◽  
Ad Libitum Feeding

Maximum daily consumption rate (Cmax as ration or number) of northern squawfish (Ptychocheilus oregonensis) from the Columbia River increased exponentially as a function of temperature. Predator weight did not explain a significant independent proportion of variation in Cmax. The mean maximum daily ration, determined from replicate ad libitum feeding on juvenile Pacific salmon (Oncorhynchus spp.), was 0.47, 0.70, 3.39, and 4.50 cg∙g−1 at 8.0, 12.5, 17.0, and 21.5 °C, respectively. The corresponding mean daily number eaten was 0.50, 1.17, 4.25, and 7.01 prey per predator at the four increasing temperatures. To quantify the temperature-dependent consumption relation, replicate Cmax data within the preferred temperature range were fitted to exponential and exponential sigmoid models. On the basis of a knowledge of thermal relations of northern squawfish, we combined hypothetical Cmax data at temperature extremes with our mean experimental results to fit an algorithm suitable for use in simulation modeling. Both the generalized gamma and biological-rate (Thornton and Lessem. 1978. Trans. Am. Fish. Soc. 107: 284–287) algorithms were suitable to describe a hypothetical temperature–Cmax model over the entire environmental temperature range of 0–27 °C observed in the Columbia River.

scholarly journals Temperature-dependent Self assembly of biofilaments during red blood cell sickling

2021 ◽  
Author(s):  
Arabinda Behera ◽  
Oshin Sharma ◽  
Debjani Paul ◽  
Anirban Sain
Keyword(s):  
Self Assembly ◽  
Kinetic Monte Carlo ◽  
Lag Time ◽  
Vital Role ◽  
Temperature Dependent ◽  
Opposite Case ◽  
Assembly Kinetics ◽  
The Mean ◽  
Kinetics Of

Molecular self-assembly plays vital role in various biological functions. However, when aberrant molecules self-assemble to form large aggregates, it can give rise to various diseases. For example, the sickle cell disease and Alzheimer’s disease are caused by self-assembled hemoglobin fibers and amyloid plaques, respectively. Here we study the assembly kinetics of such fibers using kinetic Monte-Carlo simulation. We focus on the initial lag time of these highly stochastic processes, during which self-assembly is very slow. The lag time distributions turn out to be similar for two very different regimes of polymerization, namely, a) when polymerization is slow and depolymerization is fast, and b) the opposite case, when polymerization is fast and depolymerization is slow. Using temperature dependent on- and off-rates for hemoglobin fiber growth, reported in recent in-vitro experiments, we show that the mean lag time can exhibit non-monotonic behaviour with respect to change of temperature.

scholarly journals The Kinetics of the Reaction C2H5• + HI → C2H6 + I• over an Extended Temperature Range (213–623 K): Experiment and Modeling

2015 ◽  
Vol 229 (10-12) ◽  
Author(s):  
Nicholas Leplat ◽  
Jozef Federič ◽  
Katarína Šulková ◽  
Mária Sudolská ◽  
Florent Louis ◽  
...  
Keyword(s):  
Rate Constants ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dependent Rate ◽  
Highly Correlated ◽  
Kinetics Of

AbstractThe present study reports temperature dependent rate constantsHighly correlated

scholarly journals Kinetics of the gas-phase reactions of OH radicals with alkanes and cycloalkanes

2003 ◽  
Vol 3 (6) ◽  
pp. 2233-2307 ◽  
Author(s):  
R. Atkinson
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Relative Rate ◽  
Oh Radicals ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dependent Rate ◽  
Temperature Ranges ◽  
Kinetics Of

Abstract. The available database concerning rate constants for gas-phase reactions of the hydroxyl (OH) radical with alkanes through early 2003 is presented over the entire temperature range for which measurements have been made (~180-2000 K). Measurements made using relative rate methods are re-evaluated using recent rate data for the reference compound (generally recommendations from this review). In general, whenever more than one study has been carried out over an overlapping temperature range, recommended rate constants or temperature-dependent rate expressions are presented. The recommended 298 K rate constants, temperature-dependent parameters, and temperature ranges over which these recommendations are applicable are listed in Table 1.

The Temperature Dependent Damping Behavior of Novel Nanocomposites for Structural Materials Applications

2003 ◽  
Vol 791 ◽  
Author(s):  
Ramazan Asmatulu ◽  
Rick Claus ◽  
Jeff Mecham ◽  
Dan Inman
Keyword(s):  
Fine Particles ◽  
Mechanical Vibration ◽  
Broad Temperature Range ◽  
Test Results ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Interfacial Sliding ◽  
Damping Behavior ◽  
Resonance Frequencies ◽  
Substrate Surfaces

ABSTRACTNear nanoscale fine particles including vanadium dioxide (VO2) and zinc oxide (ZnO) were incorporated into matrix materials (tin and polymer adhesives). A number of mechanical damping tests were conducted on the prepared composite materials at frequency ranges of 0 − 2 kHz and over a broad temperature range. The mechanical vibration test results showed that VO2 and ZnO gave significantly higher negative-stiffness (or damping) at approximately 68 °C (155 F) and 29 °C (85 F). For example, approximately 15% and 12% damping values were achieved at first and second resonance frequencies, respectively, which can potentially prevent vibration on the materials. This significant improvement on the damping of the nanocomposite material may be because of the ferroelasticity, viscoelasticity and/or interfacial sliding at those particular temperatures. It was also observed the etching of substrate surfaces improved adhesion and contributed consistent results to vibration testing reproducibility. Thus, it is concluded that nanocomposite existing damping properties can be an important method to achieve large damping responses over a broad temperature range.

scholarly journals Kinetics of the gas-phase reactions of OH radicals with alkanes and cycloalkanes

2003 ◽  
Vol 3 (4) ◽  
pp. 4183-4358 ◽  
Author(s):  
R. Atkinson
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Relative Rate ◽  
Oh Radicals ◽  
Reference Compound ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dependent Rate ◽  
Kinetics Of

Abstract. The available database concerning rate constants for gas-phase reactions of the hydroxyl (OH) radical with alkanes through early 2003 is presented ove the entire temperature range for which measurements have been made (~180–2000 K). Measurements made using relative rate methods are re-evaluated using recent rate data for the reference compound (generally recommendations from this review). In general, whenever more than one study has been carried out over an overlapping temperature range, recommended rate constants or temperature-dependent rate expressions are presented.

Barite Nucleation and Inhibition at 0 to 200°C With and Without Thermodynamic Hydrate Inhibitors

SPE Journal ◽  
2010 ◽  
Vol 16 (02) ◽  
pp. 440-450 ◽  
Author(s):  
Chunfang Fan ◽  
Amy T. Kan ◽  
Ping Zhang ◽  
Mason B. Tomson
Keyword(s):  
High Temperatures ◽  
Inhibition Efficiency ◽  
Saturation Index ◽  
Pressure Change ◽  
Accurate Method ◽  
Nucleation Kinetics ◽  
Temperature Range ◽  
Mineral Scale ◽  
Relationship Of ◽  
Kinetics Of

Summary In this study, we modified the commonly employed dynamic-tube-blocking methodology and built an apparatus to study the nucleation kinetics of barite-scale formation at high temperatures in the presence and absence of scale inhibitors. Barite formation was detected by monitoring pressure change over a micrometer-sized in-line filter, and this has been proved to be an easy and accurate method to study mineral-scale-nucleation kinetics at high temperatures. Additionally, we investigated the nucleation kinetics of barite at 0–25°C with and without thermodynamic hydrate inhibitors. By using this modified dynamic-tube-blocking technique, we successfully measured the nucleation kinetics of barite in 1M NaCl solutions over a temperature range from 25 to 200°C and at various supersaturation conditions. We also evaluated the inhibition efficiency of barite precipitation at this high temperature range. On the basis of the experimental results, the relationship of precipitation kinetics of barite as a function of temperature and saturation index was established. The inhibition efficiency of the phosphonate inhibitor [bis-hexamethylenetriamine-penta (methylene phosphonic) acid (BHPMP)] on barite precipitation has been evaluated over the same range of conditions. The Ca2+ effect on the inhibition efficiency of BHPMP at a low temperature (4°C) and at high temperatures (175–200°C) was investigated also. Results of this study have been incorporated into the scale-prediction software ScaleSoftPitzer.

scholarly journals Phytochrome and temperature control of seed germination in Muntingia calabura L. (Elaeocarpaceae)

2001 ◽  
Vol 44 (3) ◽  
pp. 297-302 ◽  
Author(s):  
Idalina T. de A. Leite ◽  
Massanori Takaki
Keyword(s):  
Seed Germination ◽  
Temperature Control ◽  
White Light ◽  
Pioneer Species ◽  
Optimum Temperature ◽  
Response Curves ◽  
Temperature Range ◽  
Short Period ◽  
Muntingia Calabura

The temperature range of germination of seeds of Muntingia calabura L. was 15-35° C and the optimum temperature at 35° C where more seeds germinated at short period. The fluence response curves demonstrated the involvement of phytochrome in the control of germination through the low fluence response. The effect of photoperiod showed that the species need long daily exposures to white light and that shade light inhibited completely seed germination, confirming as pioneer species that colonized only large gaps in the forest.

Sign in / Sign up

Export Citation Format

Share Document