The short-term temperature response to smoke from oil fires

1991 ◽  
Vol 18 (10) ◽  
pp. 1873-1876 ◽  
Author(s):  
Douglas L. Westphal ◽  
Owen B. Toon
Keyword(s):  
Temperature Response ◽  
Short Term

The temperature response of leaf dark respiration in 15 provenances of Eucalyptus grandis grown in ambient and elevated CO2

2017 ◽  
Vol 44 (11) ◽  
pp. 1075 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Vinod K. Jacob ◽  
Chris J. Blackman ◽  
Renee A. Smith ◽  
Mark G. Tjoelker ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Tree Species ◽  
Unit Area ◽  
Dark Respiration ◽  
Eucalyptus Grandis ◽  
Temperature Response ◽  
Respiratory Physiology ◽  
Interactive Effects ◽  
Short Term ◽  
Leaf Dark Respiration

The effects of elevated CO2 on the short-term temperature response of leaf dark respiration (R) remain uncertain for many forest tree species. Likewise, variation in leaf R among populations within tree species and potential interactive effects of elevated CO2 are poorly understood. We addressed these uncertainties by measuring the short-term temperature response of leaf R in 15 provenances of Eucalyptus grandis W. Hill ex Maiden from contrasting thermal environments grown under ambient [CO2] (aCO2; 400 µmol mol–1) and elevated [CO2] (640 µmol mol–1; eCO2). Leaf R per unit area (Rarea) measured across a range of temperatures was higher in trees grown in eCO2 and varied up to 104% among provenances. However, eCO2 increased leaf dry mass per unit area (LMA) by 21%, and when R was expressed on a mass basis (i.e. Rmass), it did not differ between CO2 treatments. Likewise, accounting for differences in LMA among provenances, Rmass did not differ among provenances. The temperature sensitivity of R (i.e. Q10) did not differ between CO2 treatments or among provenances. We conclude that eCO2 had no direct effect on the temperature response of R in E. grandis, and respiratory physiology was similar among provenances of E. grandis regardless of home-climate temperature conditions.

Physiological temperature response and embryonic mortality in stressed swine

1975 ◽  
Vol 229 (6) ◽  
pp. 1471-1475 ◽  
Author(s):  
DE Wildt ◽  
GD Riegle ◽  
WR Dukelow
Keyword(s):  
Thermal Environment ◽  
Physiological Responses ◽  
Significant Proportion ◽  
Temperature Response ◽  
Reproductive Function ◽  
Embryonic Mortality ◽  
Delayed Effect ◽  
Short Term ◽  
Embryo Survival ◽  
Early Gestation

Physiological responses and some aspects of reproductive function were examined in mated female pigs subjected to a short-term heat stress during two intervals of early gestation. Trial 1 control and treated animals experienced temperatures of 24.0 and 40.2 degrees C, respectively, from days 2 through 13 of pregnancy. Trial 2 control and treated pigs were exposed to 23.3 and 40.4 degrees C, respectively, from days 14 through 25 of pregnancy. Both high thermal exposures caused significant increases (P less than 0.05) in rectal temperature. At body temperatures of 41.1 degrees C or above, animals became more active and behavioral patterns erratic. Stressed pigs in both trials exhibited adaptation to the short-term high thermal environment as treatment days progressed. Embryonic mortality in the stressed animals in trial 1 was greater than in controls, with the animals in the former group retaining a normal size litter or losing the entire litter by day of slaughter. A significant proportion (P less than 0.01) of litters from stressed animals contained degenerating fetuses at day 42 of gestation, suggesting a continuous or delayed effect of thermal stress on embryo survival.

Plant respiration in productivity models: conceptualisation, representation and issues for global terrestrial carbon-cycle research

2003 ◽  
Vol 30 (2) ◽  
pp. 171 ◽  
Author(s):  
Roger M. Gifford
Keyword(s):  
Global Change ◽  
Temperature Response ◽  
Co2 Concentration ◽  
Carbon Accounting ◽  
Short Term ◽  
Complex Process ◽  
C Cycle ◽  
Terrestrial Carbon Cycle ◽  
Global Change Research ◽  
Plant Respiration

Plant respiratory regulation is too complex for a mechanistic representation in current terrestrial productivity models for carbon accounting and global change research. Accordingly, simpler approaches that attempt to capture the essence of respiration are commonly adopted. Several approaches have been used in the literature: respiration may be embedded implicitly in growth algorithms; assumed values for specific respiration rates may be adopted; respiration may be calculated in terms of growth and maintenance components; conservatism in the ratio of respiration to photosynthesis (R : P) may be assumed; or a more complex process or residual approach may be adopted. Review of this literature suggests that the assumption of conservative R : P ratio is an effective and practicable approach in the context of C-cycle modelling for global change research and documentation, requiring minimal ecosystem-specific data on respiration.Some long-standing controversies in respiration are now becoming resolved. The apparently wasteful process of cyanide-resistant respiration by the alternative oxidase may not be wasteful, as it is thought to be involved in protecting the plant from 'reactive oxygen species'. It is now clear that short-term respiratory response coefficients of plants (e.g. the Q10) do not predict their long-term temperature response. A new experimental approach suggests that leaf respiration is not suppressed by light as previously thought. Careful experiments, taking account of several proposed measurement artefacts, indicate that plant respiration is not suppressed by elevated CO2 concentration in a short-term reversible way.

ABWR Containment Analysis Model Qualification Using the GOTHIC Code

2009 ◽  
Author(s):  
J. Douglass ◽  
T. George ◽  
N. Jain ◽  
N. Barnett ◽  
D. Gallagher ◽  
...  
Keyword(s):  
Power Plants ◽  
Peak Pressure ◽  
Temperature Response ◽  
Experimental Tests ◽  
Analysis Model ◽  
Compartment Pressure ◽  
Short Term ◽  
Wide Range ◽  
Design Analyses ◽  
Suppression Pool

Westinghouse is developing the capability to perform containment analyses for the advanced boiling water reactor (ABWR) design. These analyses include the following: the short-term primary containment peak pressure and temperature response, short-term suppression pool swell response, and secondary containment compartment pressure and temperature response. The GOTHIC code, developed by Numerical Applications Incorporated (NAI) with funding from the Electric Power Research Institute (EPRI) is used for the ABWR containment response analyses. The code is capable of performing multidimensional analyses for models containing mixtures of air, steam, water, and other gases. It is qualified by a wide range of experimental tests that cover the important phenomena associated with containment design analyses. It has been used extensively for existing BWR and PWR power plants and this paper focuses on the extension to ABWR designs. The GOTHIC ABWR containment modeling approach is described and the results are compared with results from other previously accepted containment analysis methods.

scholarly journals Central limit theorem and the short-term temperature response of coleoptile and hypocotyl elongation growth

2011 ◽  
Vol 77 (4) ◽  
pp. 289-292 ◽  
Author(s):  
Sylwia Lewicka ◽  
Mariusz Pietruszka
Keyword(s):  
Central Limit Theorem ◽  
Limit Theorem ◽  
Central Limit ◽  
Temperature Response ◽  
Elongation Growth ◽  
Short Term ◽  
Crossover Effect ◽  
The Central Limit Theorem ◽  
Long Time ◽  
Mechanical Basis

In this contribution we deal with a new mathematical description of the response of short-term coleoptile/hypocotyl expansion growth to temperature. Although the interest of both the bio-mechanical basis of elongation growth and temperature responses has been studied in plant biology and biophysics for a long time, yet the question of the mode of actions of temperature is very relevant and still open. Here we introduce a simple idea that the normal distribution, due to the central limit theorem (CLT), is able to report on temperature-dependent elongation growth. The numerical fittings for temperature affected growth are in good agreement with empirical data. We suggest that the observation concerning a crossover effect occurring in temperature driven elongation together with CLT leads to the formulation of a hypothesis about the possible universal character of such a description, supposedly for many plant species and families. We conclude with the statement that properly constructed equations of temperature affected growth, should possibly include a specific term proportional to exp[-((T-T0)/T0)<sup>2</sup>] with T0 corresponding to the temperature of the optimum growth.

scholarly journals Comparison of Proportional and On/Off Solar Collector Loop Control Strategies Using a Dynamic Collector Model

1980 ◽  
Vol 102 (4) ◽  
pp. 257-262 ◽  
Author(s):  
S. R. Schiller ◽  
M. L. Warren ◽  
D. M. Auslander
Keyword(s):  
Solar Collector ◽  
Control Strategies ◽  
Model Performance ◽  
Temperature Response ◽  
Short Term ◽  
Flow Rates ◽  
Loop Control ◽  
Advantages And Disadvantages ◽  
Common Control ◽  
State Models

Common control strategies used to regulate the flow of liquid through flat-plate solar collectors are discussed and evaluated using a dynamic collector model. Performance of all strategies is compared using different set points, flow rates, insolation levels and patterns, and ambient temperature conditions. The unique characteristic of the dynamic collector model is that it includes the effect of collector capacitance. Short term temperature response and the energy-storage capability of collector capacitance are shown to play significant roles in comparing on/off and proportional controllers. Inclusion of these effects has produced considerably more realistic simulations than any generated by steady-state models. Simulations indicate relative advantages and disadvantages of both types of controllers, conditions under which each performs better, and the importance of pump cycling and controller set points on total energy collection.

scholarly journals Laboratory Evaluation and Control of Slocum Glider C–T Sensors

2011 ◽  
Vol 28 (6) ◽  
pp. 838-846 ◽  
Author(s):  
Nevio Medeot ◽  
Rajesh Nair ◽  
Riccardo Gerin
Keyword(s):  
Temperature Response ◽  
Sensor Data ◽  
Laboratory Evaluation ◽  
Short Term ◽  
Sensor Performance ◽  
Conductivity Sensor ◽  
Salinity Data ◽  
Extraneous Material ◽  
And Control

Abstract Unaccounted transient or permanent changes in sensor performances can compromise the overall quality of datasets obtained with a glider. From the specific perspective of the principal physical variables (temperature and conductivity), the main short-term risk is the deterioration of the quality of salinity data that is primarily due to the fouling of the glider’s conductivity sensor, especially when the glider approaches the sea surface and is deployed in coastal waters. Another potential short-term risk is a sudden shift in the glider’s temperature response caused by the blanketing of the temperature sensor by extraneous material. The long-term risks are the intrinsic drifts of the two sensors as specified by the sensor manufacturer. Given the way a glider operates, it is practically impossible to obtain sufficiently representative temperature and salinity samples in the field for effective comparisons with sensor data. Hence, laboratory testing of the temperature and conductivity sensors is one approach used to estimate the qualitative changes in pre- and postdeployment sensor performance in order to mitigate measurable drift effects on the collected data. This paper presents a systematic procedure that can be used to conduct reproducible laboratory evaluations of the temperature and conductivity sensors on a Teledyne Webb Research (TWR) Slocum glider. It is shown that the data from such tests can give useful information regarding the data quality as a result of fouling of the sensors during missions. Obviously, this kind of information is valuable when the reliability of mission-generated temperature and conductivity data, which are used to determine salinity, have to be assessed.

Long- and short-term temperature differences affect organic and inorganic nitrogen availability in forest soils

2015 ◽  
Vol 95 (2) ◽  
pp. 77-86 ◽  
Author(s):  
S. A. Boczulak ◽  
B. J. Hawkins ◽  
D. G. Maynard ◽  
R. Roy
Keyword(s):  
Microbial Communities ◽  
Forest Soils ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Soil Microbial Communities ◽  
Temperature Response ◽  
High Elevation ◽  
N Cycling ◽  
Short Term ◽  
Soil Microbial

Boczulak, S. A., Hawkins, B. J., Maynard, D. G. and Roy, R. 2015. Long- and short-term temperature differences affect organic and inorganic nitrogen availability in forest soils. Can. J. Soil Sci. 95: 77–86. Soil microbial activity determines rates of decomposition and is strongly influenced by temperature. Soil microbial communities may be adapted to site characteristics, including temperature, through physiological modification of microbial populations or changes in species composition; however, response to short-term changes in temperature may also occur. We searched for evidence of short- and long-term temperature response of microbial communities involved in soil nitrogen (N) cycling by measuring the relative availability of organic and inorganic N forms in forest soils from a high and a low elevation site, incubated at 10, 16 and 20°C for 16 wk. By week 16, ammonium concentrations were greater in soils incubated at 16 and 20°C than at 10°C, and in soil from the low elevation site, compared with high elevation. Nitrate concentrations increased in soil from the low elevation site incubated at 16 and 20°C, but changed little in other treatments. Assessment of autotrophic nitrification potential showed gross nitrification in soil from the low elevation site was likely from classical chemolithotrophic nitrifiers. Organic N concentration increased over time in the 16 and 20°C incubations of soil from the low elevation site, but only increased in the 20°C treatment for soil from the high elevation site. Long-lasting site effects were indicated by the more active microbial community in soil from low elevation, which could be related to site temperature. Evidence of short-term temperature response of N cycling processes was observed in soils from both elevations.

Sign in / Sign up

Export Citation Format

Share Document