Influence Of Water Temperature Research Articles

Влияние температуры воды на структуру расхода обменной энергии у рыб

The paper gives the analysis of the influence of water temperature on the structure of metabolic energy in carp and silver carp of different age groups. The thermophilic species 
 of carp and spotted silver carp cultivated in the polyculture with natural nutritive base served as the material for a research conducted in a hatchery “Individual Enterprise of Alekseeva M. V.” in Kuzovatovsky district of the Ulyanovsk region. Analysis of fish metabolic energy was made using the mean of live weight of yearlings and two-year-old species of carp and silver carp. As a result, there have been obtained the values of the metabolic energy in fingerlings and two-year-old species of carp and silver carp at different ranges of water temperature. Metabolism in carp and silver carp species being representatives of thermophilic fish is most effective at temperatures within +18-+30°С. The study showed that a decrease in water temperature by 5°C (from 20 to 15°C) causes a decrease in food activity, the daily feed intake of yearlings and two-year-old species of carp and silver carp decreased by 35-40%. Expense for the basal metabolism and growth did not change. Metabolic energy was used by 10.8-13,3.0 kJ less. Also, yearlings and two-year-old species of carp and silver carp spent less energy on motion activity than in the warmer water. Thus, under a decrease in the water temperature in the pond the costs of maintaining thermal homeostasis in fish increased, while the costs of basal metabolism, on the contrary, decreased. Situation is quite different when the water is warmed up.

Study on Influences of Water Temperature on Stress Distribution for High Arch Dam in Impounding Period

Water temperature affects not only the water quality and ecological balance of the reservoir, but the temperature and stress field distribution of the high arch dam during water storage and operation management. During low water storage and initial operation, the concrete in reservoirs over 100 m deep in particular can easily crack or expand because of low temperature reservoir water. This paper studies the water temperature distribution law of the reservoir during initial storage by establishing a three-dimensional fluid dynamics model. Based on this, this paper explores the three-dimensional temperature field and stress field of the dam body during the storage period, the causes of cracking, and stress distribution in key parts of the arch dam.

수온과 포기강도가 소규모 MBR공정의 막여과 효율에 미치는 영향

수온과 포기강도가 소규모 MBR공정의 막여과 효율에 미치는 영향

Thermal performance difference of phase change energy storage units based on tubular macro-encapsulation

Phase change energy storage (PCES) unit based on macro-encapsulation has the advantage of relatively low cost and potential for large-scale use in building energy conservation. Herein, the thermal performance of PCES unit based on tubular macro-encapsulation was compared and analyzed through numerical simulations using the enthalpy-porosity model with experimental validation. Different pipe materials (galvanized steel, PET, PERT, and PP) and tubular diameters (from 20 mm to 50 mm) were considered for comparison. The encapsulating impact factor (EIF), ratio between the phase change time using certain plastic encapsulation material and that using common galvanized steel, was raised up and used to evaluate the thermal characteristics of the PCES units based on plastic pipes. The calculated results indicate that steel encapsulation is better than plastic encapsulation in terms of thermal performance, but the difference is not obvious. When the water bath temperature changes from 45 ℃ to 55 ℃, the EIF decreases from 1.6 to 1.57, which means that the influence of water temperature on the EIF is small. Increasing thermal conductivity of phase change material (PCM) is a good choice in the present arrangement if the thermal storage process needs to be accelerated.

Temporal Effects of Groundwater on Physical and Biotic Components of a Karst Stream

Although most lotic ecosystems are groundwater dependent, our knowledge on the relatively long-term ecological effects of groundwater discharge on downstream reaches remains limited. We surveyed four connected reaches of a Chinese karst stream network for 72 consecutive months, with one reach, named Hong Shi Zi (HSZ), evidently affected by groundwater. We tested whether, compared with other reaches, HSZ had (1) milder water temperature and flow regimes, and (2) weaker influences of water temperature and flow on benthic algal biomass represented by chlorophyll a (Chl. a) concentrations. We found that the maximum monthly mean water temperature in HSZ was 0.6 °C lower than of the adjacent upstream reach, and the minimum monthly mean water temperature was 1.0 °C higher than of the adjacent downstream reach. HSZ had the smallest coefficient of variation (CV) for water temperature but the largest CV for discharge. Water temperature and discharge displayed a significant 12-month periodicity in all reaches not directly groundwater influenced. Only water temperature displayed such periodicity in HSZ. Water temperature was an important predictor of temporal variation in Chl. a in all reaches, but its influence was weakest in HSZ. Our findings demonstrate that longer survey data can provide insight into groundwater–surface water interactions.

The influence of water temperature on the induction of vitellogenin in walleye pollock Gadus chalcogrammus

This study examined the influence of water temperature on the induction of vitellogenin (VTG) in walleye pollocks (Gadus chalcogrammus) in aquaculture. The full-length VTG-A (or VTG-I) gene of walleye pollock was cloned using RACE (Rapid amplification of cDNA ends)-PCR method from liver tissue and recombinant VTG protein (wpVTG) was expressed in E. coli. The wpVTG protein was used to construct polyclonal antibodies to specifically detect VTG in blood; the antibodies were verified using western blotting. The VTG in blood plasma was determined by ELISA. The relationship between GSI (gonadosomatic index), VTG and body length were all positively correlated, and the results indicated that VTG can be used as an indicator of sex and/or maturation of female G. chalcogrammus in aquaculture. When VTG was measured in by the aqua-cultured female pollocks raised in water temperature of 5 °C, 8 °C, 11 °C, and 14 °C, VTG was detected only at 5 °C and 8 °C. In the histological analysis of VTG-inducing individuals, vitellogenesis was found in ovaries. In those same samples, E2 (17beta-estradiol) was detected in the blood by LC-MS. On the other hand, there was no significant difference in level of VTG induction when E2 of same concentration was treated to hepatocyte culture in different water temperatures. These results seemed to indicate that VTG is not directly affected by water temperature. However, we considered that the water temperature indirectly affect VTG induction by affecting the E2 concentration level.

A method to describe the thermal property of pipe-embedded double-skin façade: Equivalent glass window

The pipe-embedded double-skin façade (PDSF) is a superior approach to decrease building cooling and heating load by using natural energy. With pipes embedded in the shading, the overheating problem in the conventional double-skin façade (DSF) can be eliminated. Unlike the traditional DSF or glass windows, the thermal performance of PDSF depends on the ambient environment and water temperature in the embedded pipes. Although the complicated heat transfer process of PDSF can be numerically solved, it is difficult for engineers to obtain the whole picture of the PDSF at first glance. To easily understand the thermal property of the PDSF, the overall heat transfer coefficient (U value), solar heat gain coefficient (SHGC) and equivalent ambient temperature of the PDSF are derived based on the thermal network. The heat transfer characteristic of the PDSF at different cooling water temperatures is compared with that of the conventional DSF. The results show that the three proposed indices can clearly reflect the thermal property of the PDSF: U value and SHGC reflects the influence of insulation and the transparency respectively, and the equivalent temperature reflects the integrated influence of water temperature and outdoor temperature. The typical PDSF has a higher U value than the DSF in the same structure. However, the SHGC of the PDSF is only 60% of that of the DSF. Although the equivalent ambient temperature depends on the outdoor temperature and water temperature, the weighting of the water temperature is 0.8, which indicates that the equivalent ambient temperature for the PDSF can reach a better level with the appropriate water temperature. Moreover, relatively warm water is suggested on sunny days to reduce the solar heat gain, since the solar heat gain is dominant in the total heat gain. Correspondingly, cool water is recommended for cloudy days to decrease the conductive heat gain.

Experimental Investigation of Water Temperature Influence on Suspended Sediment Concentration

Health of coastal ecosystems depends on the quantity and quality of suspended sediments brought by the rivers from land to the estuary. Behaviour of suspended sediments depends on water and sediment characteristics. Water temperature affects suspended sediment behaviour but has not been fully understood. Increase in water temperature due to global warming creates ecological issues. In the present study, influence of water temperature rise on suspended sediment concentration (SSC) has been studied under controlled laboratory conditions. Experiments were conducted in an annular flume using kaolin (d50 = 6.9 μm) at different water temperatures (T = 30o, 40o, and 50 °C) and salinities (S = 0, 1, 2, 5, and 10 g/L). Results show that both SSC and particle size increased with an increase in water temperature, but both decreased with an increase in water salinity. For S ≥ 2 g/L, the influence of water temperature on both SSC and settling velocity of suspended sediments was more significant compared to S < 2 g/L. For a unit increase in water temperature (°C), the SSC increased by 0.18%, 0.30%, 0.73%, 0.89%, 2.05% and settling velocity decreased by 1.71%, 2.15%, 3.64%, 3.17%, 3.45%, for water salinities of 0, 1, 2, 5 and 10 g/L, respectively. Empirical equations for determining the SSC at any time t and at any length L along the flow direction have been developed and verified.

Preliminary Experiment of U-Shaped Heat Pipe as Passive Cooling System in High Temperature Gas-Cooled Reactor Cooling Tank

When station blackout occurs on high temperature gas-cooled reactor, the decay heat will be absorbed by a residual heat dissipation system (known as cooling tank) which connected to the reactor cavity cooling system. The U-shaped heat pipe as passive cooling system is proposed as new feature of technology to absorb the decay heat in the high temperature gas-cooled reactor cooling tank, and to keep the water remains in its operating temperature and level. This research objective is to know thermal resistance of U-shaped heat pipe scale model based on variation of heat load and coolant velocity. The influence of water temperature in the circulating thermostatic bath as heat load on evaporator section and air velocity which flowed into the horizontal condenser fin were investigated experimentally. The heat loads were varied at water temperature of 45, 50, and 60°C. The air velocities were varied at 0.45, 0.83, and 1.06 m/s. The experiment result showed the lowest thermal resistance of 0.000027±0.0000000593 °C/W when U-shaped heat pipe was operated at hot water temperature of 60°C and air velocity of 1.06 m/s. The investigation result can be used as a model and initial knowledge to design large scale of U-shaped heat pipe as a passive cooling system in cooling tanks connected to high temperature gas-cooled reactor cavity cooling system. This result is also useful regarding to the thermal management of passive cooling process in cooling tank and it can improve the nuclear safety and be able to overcome the thermal problems caused by station blackout in high temperature gas-cooled reactor.

Mechanisms for Temperature Modulation of Feeding in Goldfish and Implications on Seasonal Changes in Feeding Behavior and Food Intake.

In fish models, seasonal change in feeding is under the influence of water temperature. However, the effects of temperature on appetite control can vary among fish species and the mechanisms involved have not been fully characterized. Using goldfish (Carassius auratus) as a model, seasonal changes in feeding behavior and food intake were examined in cyprinid species. In our study, foraging activity and food consumption in goldfish were found to be reduced with positive correlation to the gradual drop in water temperature occurring during the transition from summer (28.4 ± 2.2°C) to winter (15.1 ± 2.6°C). In goldfish with a 4-week acclimation at 28°C, their foraging activity and food consumption were notably higher than their counterparts with similar acclimation at 15°C. When compared to the group at 28°C during summer, the attenuation in feeding responses at 15°C during the winter also occurred with parallel rises of leptin I and II mRNA levels in the liver. Meanwhile, a drop in orexin mRNA along with concurrent elevations of CCK, MCH, POMC, CART, and leptin receptor (LepR) transcript expression could be noted in brain areas involved in feeding control. In short-term study, goldfish acclimated at 28°C were exposed to 15°C for 24 h and the treatment was effective in reducing foraging activity and food intake. The opposite was true in reciprocal experiment with a rise in water temperature to 28°C for goldfish acclimated at 15°C. In parallel time-course study with lowering of water temperature from 28 to 15°C, short-term exposure (6–12 h) of goldfish to 15°C could also increase leptin I and II mRNA levels in the liver. Similar to our seasonality study, transcript level of orexin was reduced along with up-regulation of CCK, MCH, POMC, CART, and LepR gene expression in different brain areas. Our results, as a whole, suggest that temperature-driven regulation of leptin output from the liver in conjunction with parallel modulations of orexigenic/anorexigenic signals and leptin responsiveness in the brain may contribute to the seasonal changes of feeding behavior and food intake observed in goldfish.

Distribution and Release Characteristics of Phosphorus in a Reservoir in Southwest China

Dam construction changes the nutrient transport of a river system. Phosphorus is an important fundamental material in the global biochemical cycle and is always a limiting factor in the primary productivity of reservoirs. Extending the study of phosphorus in reservoirs is necessary given the dam construction in southwest China. Zipingpu Reservoir was chosen as the research site in this study. The form and distribution of phosphorus in the reservoir’s surface sediments and overlying water were analyzed. The results showed that overall, the total phosphorus (TP) content of surface sediments in the Zipingpu Reservoir decreased from the tail to the front of the dam. The TP content ranged from 682.39 to 1609.06 mg/kg, with an average value of 1121.08 mg/kg. The TP content at some sampling points was affected by exogenous input. Inorganic phosphorus (IP) was the main form of phosphorus in surface sediments and had a proportion of 89.38%. Among the forms of IP, the content of Ca-P was larger than that of O-P; Ex-P, Fe-P, and Al-P had the lowest contents. Particulate phosphorus (PP) was the main form of phosphorus in the overlying water of the Zipingpu Reservoir and was strongly affected by hydrodynamic conditions. The content of total dissolved phosphorus (TDP) in the overlying water was relatively low. To further understand the risk of phosphorus release in the surface sediments in the reservoir, the rate and flux of phosphorus exchange at the sediment-overlying water interface were investigated through laboratory experiments. The results showed that both water temperature and pH significantly affected the sediment release rate, but the influence of water temperature was more significant. Acidic and alkaline conditions were conducive to the release of phosphorus from sediment, while a neutral environment was not. The release rate significantly increased with increasing water temperature, and a positive linear relationship was found between these two parameters. The sediment exhibited absorption characteristics when the water temperature was extremely low and exhibited releasing characteristics at a high temperature. These results could provide a theoretical basis for the management and protection of reservoir water environments.

Влияние температуры воды и освещённости на рост и развитие самок и самцов породы форели «Ропшинская золотая»

Влияние температуры воды и освещённости на рост и развитие самок и самцов породы форели «Ропшинская золотая»

Influence of Water Temperature on Air Temperature around Eastern and Western Coastal Areas of the Korean Peninsula during Winter

Influence of Water Temperature on Air Temperature around Eastern and Western Coastal Areas of the Korean Peninsula during Winter

О влиянии температуры воды на распределение крабов в районе северных Курильских островов

О влиянии температуры воды на распределение крабов в районе северных Курильских островов

Evidence of a hydraulically challenging reach serving as a barrier for the upstream migration of infection-burdened adult steelhead.

Anadromous fishes such as steelhead trout, Oncorhynchus mykiss, are exposed to a suite of infectious agents and migratory challenges during their freshwater migrations. We assessed infectious agent load and richness and immune system gene expression in gill tissue of Bulkley River (British Columbia, CA) steelhead captured at and upstream of a migratory barrier to evaluate whether infectious burdens impacted migration success. We further considered the potential influences of water temperature, sex and fish size on host infectious agents and transcription profiles. There were eight infectious agents detected in steelhead gill tissue, with high prevalence of the bacteria Candidatus Branchiomonas cysticola (80%) and Flavobacterium psychrophilum (95%) and the microparasite Sphaerothecum destruens (53%). Fish sampled at the falls had significantly greater relative loads of Ca. B. cysticola and F. psychrophilum, higher infectious agent richness and differential gene expression compared to fish captured upstream. Flavobacterium psychrophilum was only associated with immune gene expression (particularly humoral immunity) of fish sampled at the falls, while water temperature was positively correlated with genes involved in the complement system, metabolic stress and oxidative stress for fish captured upstream. This work highlights interesting differences in agent-host interactions across fisheries and suggests that hydraulic barriers may reduce the passage of fish with the heaviest infectious agent burdens, emphasizing the selective role of areas of difficult passage. Further, this work expands our knowledge of infectious agent prevalence in wild salmonids and provides insight into the relationships between infectious agents and host physiology.

Enhanced stimulated Raman scattering by suppressing stimulated Brillouin scattering in liquid water

Stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) are two kinds of emblematic inelastic scattering processes resulting from the interaction of high-intensity laser with matter. Generally, competition between SBS and SRS is a common phenomenon in many substances. In liquid or high-pressure gas, if a single longitudinal mode laser is used as a pump source, both SBS and SRS can be excited, but the SBS will become very strong due to higher gain and optical phase conjugation. In comparison, the SRS gain is typically 2 orders of magnitude smaller than the SBS gain so that most of the pump laser energy is spent on the SBS and the SRS is greatly suppressed. To improve the output energy of SRS in liquid medium, a method of suppressing the SBS process by controlling temperature of medium is proposed. The SRS generation system using broadband pulse laser of 532 nm in wavelength as a pumping source is designed, the output energy of forward SRS (FSRS) and backward SBS (BSBS) in water with different temperatures are measured, and the physical mechanisms of the influences of water temperature, pumping linewidth and thermal defocusing on the output energy of SRS are analyzed. The experimental results indicate that by reducing the water temperature, the SBS process can be significantly suppressed, and the beam distortion caused by thermal defocusing effect can be reduced, thus effectively improving the output energy of SRS. Unlike the single longitudinal mode laser, when the pump source is handled in multiple longitudinal modes with a wide linewidth, the gain of FSRS is higher than that of the backward SRS (BSRS). Meanwhile, since the SBS gain coefficient is restricted by the linewidth of the pump laser, the FSRS process is dominant and both backward SBS and BSRS are significantly suppressed. It is necessary to state that none of the influence of backward SRS, self-focusing, optical breakdown and other non-linear effects on the output energy of SRS is considered in this paper, and only the effectiveness of reducing temperature to improve the energy output of forward SRS is verified from the perspective of temperature change. The results are of great significance for the multi-wavelength conversion of SRS in liquid medium.

Hydrology and water temperature influence recruitment dynamics of the threatened silver perch Bidyanus bidyanus in a regulated lowland river

Understanding the influence of extrinsic factors such as hydrology and hydraulics on recruitment provides essential insight to inform management of fish populations. The critically endangered silver perch Bidyanus bidyanus is a long-lived, potamodromous pelagophil endemic to Australia’s Murray–Darling Basin. Declines of this species are often attributed to river regulation, although quantitative studies linking hydrology and hydraulics to key aspects of its life cycle are sparse. We used a multidecadal age-structured dataset collected from a locally abundant population of silver perch to quantify the relative importance of different abiotic drivers on year-class strength (recruitment). Silver perch recruited across highly variable hydrological conditions. The strongest year classes were associated with a combination of low to average river discharge (i.e. within channel) and high water temperatures over the peak spawning period, followed in the next year by extended high flows and widespread flooding that promoted survival of age-1+ juvenile fish. We suggest that conditions affecting the growth and dispersal of juvenile fish, in addition to the spawning period, are critical in governing recruitment dynamics. This highlights the need for multiyear flow plans for freshwater fish populations.

Meltwater temperature in streams draining Alpine glaciers

Climate change is significantly impacting lotic environments, through changes to hydrology, biodiversity and species distribution. Effects of climate change are greatest at high elevation and biota in and around glacier-fed rivers is likely, therefore, to be at great risk. How climate change influences hydrology will have great impact on river water temperature as glacier-fed rivers in Alpine environments are extremely sensitive to climatic change. This paper assesses five rivers: Four glacier-fed rivers (36.9–83.7% basin glacierisation) located in the Swiss Alps, and one located in an ice-free catchment in the Bernese Oberland, Switzerland. The aim was to assess the impact of basin characteristics on river water temperature. A distinct paradoxical relationship was identified whereby water temperature in some glacier-fed rivers was reduced during the time of highest incoming shortwave radiation receipts and high air temperature. Whether a summer cooling effect presented itself in all glacier-fed rivers within this study was researched. The key findings were that the identified summer cooling effect was not present in all rivers, despite percentage glacierisation. Percentage glacier cover has often been reported as they key determiner of water temperature in such rivers. More important was the stream dimensions, notably stream surface area. Understanding the controlling factors that influence water temperature of glacier-fed rivers will help river managers and planners in understanding how climate change will affect fisheries downstream of glaciers over the coming decades. This may allow plans to be introduced to try and mitigate warmer water temperature that will result, in some glacier-fed rivers, as the climate warms.

Spatiotemporally explicit model averaging for forecasting of Alaskan groundfish catch.

Fisheries management is dominated by the need to forecast catch and abundance of commercially and ecologically important species. The influence of spatial information and environmental factors on forecasting error is not often considered. I propose a forecasting method called spatiotemporally explicit model averaging (STEMA) to combine spatial and temporal information through model averaging. I examine the performance of STEMA against two popular forecasting models and a modern spatial prediction model: the autoregressive integrated moving averages with explanatory variables (ARIMAX) model, the Bayesian hierarchical model, and the varying coefficient model. I focus on applying the methods to four species of Alaskan groundfish for which catch data are available. My method reduces forecasting errors significantly for most of the tested models when compared to ARIMAX, Bayesian, and varying coefficient methods. I also consider the effect of sea surface temperature (SST) on the forecasting of catch, as multiple studies reveal a potential influence of water temperature on the survival and growth of juvenile groundfish. For most of the preferred models, inclusion of SST in the model improved forecasting of catch. It is advisable to consider both spatial information and relevant environmental factors in forecasting models to obtain more accurate projections of population abundance. The STEMA method is capable of accounting for spatial information in forecasting and can be applied to various types of data because of its flexible varying coefficient model structure. It is therefore a suitable forecasting method for application to many fields including ecology, epidemiology, and climatology.

Experimental investigation on effects of water-based ultrasonic vibrations, transverse magnetic field and water temperatures on percussion laser drilling performance

A novel magnetic-ultrasonic assisted laser drilling technology, which integrates and couples water-based ultrasonic vibrations with an external transverse magnetic field for assisting the process of percussion laser drilling, is reported to carry out laser drilling experiments for improving hole drilling performance. The influence of water temperature on drilling performance for water-based magnetic-ultrasonic assisted percussion laser drilling technology is first reported. The influential mechanisms and roles of magnetic assistance and/or water-based ultrasonic assistance on the process and performance of percussion laser drilling were analysed, including both blind hole and through hole drilling. The effects of water-based ultrasonic vibrations and/or magnetic assistance on laser drilling performance were systematically studied via corresponding comparisons. It was demonstrated that the couple magnetic-ultrasonic assistance effectively increased laser drilling performance, by increasing laser energy absorption efficiency inside a drilling hole, enhancing material removal, increasing drilled depth, reducing recast layer formation and hole taper, improving microstructure and micro hardness performance, and relieving residual stress. Besides, it was reported that the uniform mechanical vibrations induced by water-based ultrasonic assistance effectively relieved residual stress (65.8% reduction) for the drilled specimen. The addition of an external transverse magnetic field could further relieve residual stress with a reduction percentage of 89.1%, resulting from the coupled magnetic-ultrasonic assistance. In addition, the water medium with a relatively high temperature was helpful for decreasing residual stress on the drilled sample. The alteration of water temperature (from 33.9 °C to 64.2 °C) not only greatly changed the value but also changed the direction of the residual stress (hole entrance: changing from −163 MPa to +32 MPa; hole exit: changing from −284 MPa to +64 MPa). However, the water temperature showed small effects on microstructure, micro hardness, recast layer thickness, hole cross-section, hole circularity deviation, and hole taper angle.