scholarly journals Temperature effects on performance and physiology of two prairie stream minnows

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Bryan D Frenette ◽  
Lindsey A Bruckerhoff ◽  
Michael Tobler ◽  
Keith B Gido
Keyword(s):  
Temperature Gradient ◽  
Temperature Effects ◽  
Laboratory Experiments ◽  
Physiological Traits ◽  
Critical Thermal Maxima ◽  
Stream Size ◽  
Size Gradient ◽  
Prairie Stream

The observed distributions of two grazing minnows differ along a stream-size gradient in grassland streams and may be linked to temperature. In laboratory experiments, we assayed a suite of physiological traits along a temperature gradient and found that species differed in critical thermal maxima, with subtle differences in other traits.

Environmental impacts of aquifer thermal energy storage investigated by field and laboratory experiments

2013 ◽  
Vol 4 (2) ◽  
pp. 77-89 ◽  
Author(s):  
Matthijs Bonte ◽  
Boris M. Van Breukelen ◽  
Pieter J. Stuyfzand
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Temperature Effects ◽  
Laboratory Experiments ◽  
Potential Temperature ◽  
Arsenic Concentration ◽  
Observation Data ◽  
Aquifer Thermal Energy Storage ◽  
Field Investigations

Aquifer thermal energy storage (ATES) uses groundwater to store energy for heating or cooling purposes in the built environment. This paper presents field and laboratory results aiming to elucidate the effects that ATES operation may have on chemical groundwater quality. Field data from an ATES site in the south of the Netherlands show that ATES results in chemical quality perturbations due to homogenisation of the initially present vertical water quality gradient. We tested this hypothesis by numerical modelling of groundwater flow and coupled SO4 transport during extraction and injection of groundwater by the ATES system. The modelling results confirm that extracting groundwater from an aquifer with a natural quality stratification, mixing this water in the ATES system, and subsequent injection in the second ATES well can adequately describe the observation data. This mixing effect masks any potential temperature effects in typical low temperature ATES systems (<25 °C) which was the reason to complement the field investigations with laboratory experiments focusing on temperature effects. The laboratory experiments indicated that temperature effects until 25 °C are limited; most interestingly was an increase in arsenic concentration. At 60 °C, carbonate precipitation, mobilisation of dissolved oxygen concentration, K and Li, and desorption of trace metals like As can occur.

scholarly journals Direction, ontogeny, and mechanism of the temperature-size rule operating in a large marine crab, Chionoecetes opilio

2020 ◽  
Author(s):  
Bernard Sainte-Marie ◽  
Jean-François Ouellet ◽  
Hélène Dionne
Keyword(s):  
Temperature Effects ◽  
Laboratory Experiments ◽  
Snow Crab ◽  
Temperature Sensitive ◽  
Chionoecetes Opilio ◽  
Determinate Growth ◽  
Settlement Size ◽  
Initial Difference ◽  
Time Invariant ◽  
Opposite Response

Abstract The classic temperature-size rule (TSR) states that ectotherms mature smaller in warmer than in colder conditions; the reverse TSR is the opposite response. We combined field observations with laboratory experiments and published information to synthesise the response of snow crab (Chionoecetes opilio), a marine brachyuran with determinate growth, to temperature. Size at onset of physiological maturation/maturity and after terminal moult (TM) were positively related to temperature, thus indicating the reverse TSR. Moult increment varied little with temperature, but crabs were larger at instar in colder than in warmer water due to an initial difference in settlement size that propagated to higher instars, suggesting classic TSR prior to settlement. The pattern of increasing TM size with temperature was caused by crabs moulting more times before TM in warmer than in colder water. Intermoult period (IP) declined exponentially with temperature, and lower instars were more temperature sensitive than higher instars. Temperature effects on IP were strong enough to explain changes in size and instar number at TM under a possible time-invariant maturation schedule. Skip moulting was observed in the smallest crabs reared in the laboratory and resulted in high mortality. The reverse TSR in snow crab seems to be adaptive to coping with ectotherm predation.

Thermal Effects on Far-Field Distributed Acoustic Strain-Rate Sensors

2021 ◽  
Author(s):  
Smith Edward Leggett ◽  
Ding Zhu ◽  
Alfred Daniel Hill
Keyword(s):  
Phase Shift ◽  
Temperature Gradient ◽  
Strain Rate ◽  
Hydraulic Fracture ◽  
Thermal Effects ◽  
Temperature Effects ◽  
Fiber Optic ◽  
Displacement Discontinuity ◽  
Observation Well ◽  
Optical Phase

Abstract Fiber-optic cables cemented outside of the casing of an unconventional well measure cross-well strain changes during fracturing of neighboring wells with low-frequency distributed acoustic sensing (LF-DAS). As a hydraulic fracture intersects an observation well instrumented with fiber-optic cables, fracture fluid injected at ambient temperatures can cool a section of the sensing fiber. Often, LF-DAS and distributed temperature sensing (DTS) cables are run in tandem, enabling the detection of such cooling events. The increasing use of LF-DAS for characterizing unconventional hydraulic fracture completions demands an investigation of the effects of temperature on the measured strain response by LF-DAS. Researchers have demonstrated that LF-DAS can be used to extract the temporal derivative of temperature for use as a differential-temperature-gradient sensor. However, differential-temperature-gradient sensing is predicated on the ability to filter strain components out of the optical signal. In this work, beginning with an equation for optical phase shift of LF-DAS signals, a model relating strain, temperature, and optical phase shift is explicitly developed. The formula provides insights into the relative strength of strain and temperature effects on the phase shift. The uncertainty in the strain-rate measurements due to thermal effects is estimated. The relationship can also be used to quantify uncertainties in differential-temperature-gradient sensors due to strain perturbations. Additionally, a workflow is presented to simulate the LF-DAS response accounting for both strain and temperature effects. Hydraulic fracture geometries are generated with a 3D fracture simulator for a multi-stage unconventional completion. The fracture width distributions are imported by a displacement discontinuity method program to compute the strain-rates along an observation well. An analytic model is used to approximate the temperature in the fracture. Using the derived formulae for optical phase shift, the model outputs are then used to compute the LF-DAS response at a fiber-optic cable, enabling the generation of waterfall plots including both strain and thermal effects. The model results suggest that before, during, and immediately following a fracture intersecting a well instrumented with fiber, the strain on the fiber drives the LF-DAS signal. However, at later times, as completion fluid cools the observation well, the temperature component of the LF-DAS signal can equal or exceed the strain component. The modeled results are compared to a published field case in an attempt to enhance interpretation of LF-DAS waterfall plots. Finally, we propose a sensing configuration in order to identify the events when "wet fractures" (fractures with fluids) intersect the observation well.

Studies on the humidity and temperature reactions of Dermestes maculatus Deg. (Col., Dermestidae), with reference to infestation in dried fish in Nigeria

1970 ◽  
Vol 60 (1) ◽  
pp. 23-31 ◽  
Author(s):  
S. Afolabi Toye
Keyword(s):  
Temperature Gradient ◽  
Laboratory Experiments ◽  
Heat Treatments ◽  
Dermestes Maculatus ◽  
Dried Fish ◽  
And Storage

Infestations of Dermestes maculatus Deg. in dried fish at Dugbe market, Ibadan, are favoured by traditional packaging and display methods. In laboratory experiments last-instar larvae and adults showed low thigmokinesis and a bias towards the dry end of a 50–100% r.h. gradient; in alternative humidities between 40% and 100% last-instar larvae and adults selected 60–80% r.h., adults having a stronger preference than the larvae for the higher humidity; in a temperature gradient last-instar larvae and adults avoided the 30–45° C zone and showed low thigmokinesis and immobilisation at 19° C. These findings were generally consistent with observations in the market. Heating dried fish in an oven at 60° C for 30 min killed all larvae and adults of D. maculatus present. Two 30-min heat treatments at four-day intervals in a simple charcoal-fired oven and storage in metal containers would control the pest.

scholarly journals The steady-state crystal size of deforming ice

1994 ◽  
Vol 20 ◽  
pp. 13-18 ◽  
Author(s):  
T.H. Jacka ◽  
Li Jun
Keyword(s):  
Crystal Growth ◽  
Steady State ◽  
Temperature Effects ◽  
Crystal Orientation ◽  
Laboratory Experiments ◽  
Crystal Size ◽  
Large Strains ◽  
Polar Ice ◽  
Temperature Dependent ◽  
Arrhenius Relation

Previous studies have established that, together with the development of a preferred crystal-orientation fabric in ice undergoing creep deformation to high strains, there also develops a tertiary equilibrium crystal size, i.e. the crystal size, rather than affecting the creep rate, is a result of the deformation to large strains.Equilibrium crystal size is considered here as a “balance” between crystal growth with time as a function of temperature and crystal change as a result of temperature dependent deformation. The temperature effects in these two processes (Arrhenius relation) are similar and consideration of the activation energies for the two processes indicates that it may be appropriate to cancel them, yielding a dependence of equilibrium crystal size on stress alone. The results from laboratory experiments of steady-state crystal size plotted as a function of stress support the above proposition.The possibility of using the relationships between steady-state crystal size and deviatoric stress as a polar ice-mass piezometer is discussed.

scholarly journals Dry after-ripening, light, cold stratification and temperature effects on seed germination of Primula poissonii from Yunnan, China

2019 ◽  
Author(s):  
Deli Peng ◽  
Xiaojian Hu ◽  
Hang Sun ◽  
Zhimin Li
Keyword(s):  
Seed Germination ◽  
Temperature Gradient ◽  
Temperature Effects ◽  
Southwest China ◽  
Alpine Region ◽  
Wild Plant ◽  
Cold Stratification ◽  
Light Requirement ◽  
Alternating Temperature ◽  
Improve Seed Germination

Primula poissonii, an attractive wild plant growing in the subalpine/alpine region of southwest China, has low seed germination in cultivation. This study attempted to improve seed germination by testing the effect of several treatments including dry after-ripening (DAR), light, cold stratification (CS) and temperature gradient treatments. DAR increased germination at 15/5 and 25/15°C, as compared with fresh seeds. DAR seeds germinated significantly better (> 80%) at higher temperatures (20-28°C) than at lower (10°C, < 20%; 15°C, < 30%) and extreme high temperatures (30°C, < 55%; 32°C, 0%). Incubation at alternating temperature (25/15°C) did not significantly improve germination; whereas at 15/5°C germination increased significantly, compared with the corresponding constant temperature (20 and 10°C, respectively). DAR seeds had a strict light requirement at all temperatures. As DAR and CS are sufficient to break seed dormancy, the seeds of P. poissonii appear to have non-deep PD. For non-dormant cold-stratified seeds, the estimated Tb and thermal time (θ50) were 2.3°C and 74.1°Cd, respectively.

scholarly journals CO2 and temperature effects on morphological and physiological traits affecting risk of drought-induced mortality

2018 ◽  
Vol 38 (8) ◽  
pp. 1138-1151 ◽  
Author(s):  
Honglang Duan ◽  
Brian Chaszar ◽  
James D Lewis ◽  
Renee A Smith ◽  
Travis E Huxman ◽  
...  
Keyword(s):  
Temperature Effects ◽  
Physiological Traits ◽  
Morphological And Physiological Traits
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