Constant Low Temperature Research Articles

The role of soil temperature and seed dormancy in the creation and maintenance of persistent seed banks of Nassella trichotoma (serrated tussock) on the Northern Tablelands of New South Wales

A large and persistent soil seed bank characterises many important grass weeds, including Nassella trichotoma (Nees) Hack. ex Arechav. (serrated tussock), a major weed in Australia and other countries. In the present study we examined the effects of constant and alternating temperatures in regulating primary and secondary dormancy and the creation and maintenance of its soil seed bank in northern NSW, Australia. One-month-old seeds were stored at 4, 25°C, 40/10°C and 40°C, in a laboratory, and germination tests were conducted every two weeks. Few seeds germinated following storage at 4°C, compared with seeds stored at 25°C, 40/10°C and 40°C. Nylon bags containing freshly harvested seeds were buried among N. trichotoma stands in early summer, and germination tests conducted following exhumation after each season over the next 12 months. Seeds buried over summer and summer plus autumn had higher germination than seeds buried over summer plus autumn plus winter, but germination increased again in the subsequent spring. Seeds stored for zero, three, six and 12 months at laboratory temperatures were placed on a thermogradient plate with 81 temperature combinations, followed by incubation at constant 25°C of un-germinated seeds. Constant high or low temperatures prolonged primary dormancy or induced secondary dormancy whereas alternating temperatures tended to break dormancy. Few temperature combinations resulted in more than 80% germination.

Comparative Study of Plant Physiological Responses to Long-Term and Short-Term Daily Exposures to Low Temperature in the Presence of Protein-Synthesis Inhibitors

The role of the protein synthesis system in the physiological responses to cold was assessed in chilling-sensitive (cucumber) and cold-tolerant (wheat) plants with the use of protein-synthesis inhibitors on 80S (cycloheximide, CHX) and 70S (chloramphenicol, CAP) ribosomes. The plants were subjected to a constant low temperature (LT treatment) at 12°C for cucumber and 4°C for wheat. Another regimen (DROP treatment) included a 2-h daily temperature drop to 12°C for cucumber and 4°C for wheat at the end of the night. Both inhibitors were found to suppress plant leaf growth under any temperature regimen, including the control (at a constant temperature of 23°C). They also reduced the rates of net photosynthesis, transpiration, dark respiration, and chlorophyll accumulation in all treatments but to a larger degree in the control and DROP-treated plants. The results confirmed the previously established dependence of enhanced cold tolerance on protein biosynthesis on 70S and, especially, 80S ribosomes in the LT-treated plants. It was demonstrated for the first time that the protein synthesis system is involved in the enhancement of plant cold tolerance afforded by short-term daily temperature drops. Temperature drops often occur under natural conditions and are used to reduce stem elongation in greenhouse production as an alternative to the use of retardants. The reported data are novel in that the enhanced cold tolerance of DROP-treated plants is accounted for not only by de novo protein synthesis but also by adaptive posttranslational control.

Numerical simulation of convective heat transport within the nanofluid filled vertical tube of plain and uneven side walls

Two-dimensional transient natural convective flow in a vertical tube of plain and uneven side-walls containing cobalt-kerosene nanofluids is analyzed using a nonhomogeneous dynamic model. The vertical right wall of the enclosure is maintained at a constant low temperature and the left wall is heated by a uniform thermal condition whereas the horizontal side-walls are insulated. The Brownian motion and thermophoretic phenomena of the nanoparticles are considered in the model. The governing nonlinear momentum, energy, and concentration equations are solved numerically using a Galerkin weighted residual finite element method. The thermal, flow and concentration fields are obtained to understand the flow dynamics of cobalt-kerosene nanofluid in two types of enclosures. The local and average Nusselt numbers are analyzed for plain and uneven side walls of the tube for different parameters of the problem. The simulated results are compared with the experimental as well as with the numerical data available in the literature for some special cases. The outcomes show that the tube of having uneven vertical side-walls give higher heat transfer for lower values of the thermal Rayleigh number; whereas for the higher values of the thermal Rayleigh number, the tube of plain vertical side-walls exhibit significantly higher heat transfer rate.

Phase evolution and microwave dielectric properties of SrTiO3 added ZnAl2O4–Zn2SiO4–SiO2 ceramics

Phase evolution and microwave dielectric properties of SrTiO3 added ZnAl2O4–3Zn2SiO4–2SiO2 ceramics system were investigated. With the addition of SrTiO3, the sintering temperature for dense ceramic is reduced from 1320 °C to 1180–1200 °C. According to the nominal composition ZnAl2O4–3Zn2SiO4–2SiO2-ySrTiO3, phase evolution is revealed by XRD patterns and Back Scattering Electron images: Zn2SiO4, ZnAl2O4 and SiO2 phases coexist at y = 0; SrTiO3 reacts with ZnAl2O4 and SiO2 to form SrAl2Si2O8, TiO2 and Zn2SiO4 at y = 0.2 to 0.8, and SiO2 phase disappears at y = 0.8; new phase of Zn2TiO4 is obtained at y = 1. The existence of TiO2 has important effect on the dielectric properties. The optimized microwave dielectric properties are obtained at y = 0.6 and the ceramics show low dielectric constant (7.16), high-quality factor (57, 837 GHz), and low temperature coefficient of resonant frequency (−30 ppm °C−1).

The Fitness and Economic Benefits of Rearing the Parasitoid Telenomus podisi Under Fluctuating Temperature Regime.

Successful biological control requires detailed knowledge about the mass rearing conditions of the control agents in order to ensure higher quality of field-released insects. Thus, we investigated whether rearing fluctuating thermal condition would affect the fitness and costs of the parasitoid wasp Telenomus podisi Ashmead (a biocontrol agent used for controlling the Neotropical brown stink bug Euschistus heros (Fabricius)) when compared with parasitoid reared at constant temperature condition, which is commonly used in insect facilities. Parasitoids were reared under either constant (continuous exposure at 25 ± 2°C) or fluctuating temperature conditions (i.e., 30 ± 2°C during day and 20 ± 2°C at night) during four consecutive generations. Our results indicated that tested fluctuating temperature is more suitable for rearing of T. podisi as such temperature condition not only resulted in fitness benefits (e.g., shorter developmental time, longer female longevity, higher fecundity/fertility) but also reduced (approximately 23.5%) the estimated costs for producing the parasitoids. Furthermore, rearing T. podisi under fluctuating temperatures improved tolerance to low constant temperatures (i.e., 20°C) without changing the tolerance to constant high temperatures (30°C) in the fourth generation. Surprisingly, even parasitoids that developed under fluctuating thermal conditions performed better than those reared at constant temperature of 25°C. Collectively, our findings suggest that T. podisi reared under fluctuating thermal condition can tolerate better fluctuating temperatures that normally occur both during long periods of transport and in agricultural ecosystems, which will increase the quality and productivity of mass-reared T. podisi for inundative releases.

Numerical study and parameter optimization of partial journal bearing using MOPSO algorithm

In this paper, multi-objective particle swarm optimization method is developed for optimizing thermo-hydrodynamic journal bearings. This paper focuses on the use of multi-objective particle swarm optimization algorithm with a combination of the thermal hydrodynamic governing equations of the fluid film (i.e. momentum and energy equations) to optimize hydrodynamic partial pad journal bearings and compare with other articles. The governing equations are solved by the central difference method with a successive over-relaxation scheme and the backward difference with an iterative technique. In the paper, the lubricant viscosity changes with the temperature variation in whole fluid film. In this optimization, the bearing power loss, the minimum oil film thickness, and the maximum oil temperature are considered as objective functions and the radial clearance and length to diameter ratio are selected as design variables. The results of the objective functions are compared to other articles. Also, this study discusses the entropy and availability of two concentric cylinders with low curvature and constant wall temperature. Calculations showed that by increasing the Eckert number, the availability increases.

Finite volume method for mixed convection flow of Ag–ethylene glycol nanofluid flow in a cavity having thin central heater

The article focuses on the mixed convective flow of Ag–ethylene glycol nanofluid. The analysis is carried out for a cavity having center as heated. The relatively moving side walls of cavity are retained at low constant temperature while constant heat source is examined in the bottom wall. The rest of the bottom and top walls remain insulated. Cattaneo–Christov heat flux is implemented in the analysis of heat transfer. Heat transfer rate is dig out for the case of Fourier’s heat flux, as for the case of Cattaneo–Christov heat flux it gives implicit expression, which is difficult to analyze and simplify. The problem is analyzed numerically via projection method. Higher heat transfer is observed for the Fourier’s law as compare to Cattaneo–Christov heat flux. The results are expressed by isotherms, streamlines, velocity field, and average Nusselt numbers.

Modelling time‐varying low‐temperature‐induced mortality rates for pupae of Tuta absoluta (Gelechiidae, Lepidoptera)

AbstractIn a series of laboratory experiments, acclimated pupae of Tuta absoluta were exposed to various constant low temperatures in order to estimate their maximum survival times (Kaplan–Meier, Lt99.99). A Weibull function was fitted to the data points, describing maximum survival time as a function of temperature. In another experiment at −6°C, the progress of mortality increasing with exposure time was identified. These values were fitted by a sigmoidal function converging asymptotically to 100% mortality for very long exposure times. Analysing mortality data from the maximum survival experiment by a generalized linear model showed a significant common slope parameter (p < .001) that reveals parallelism of the survival curves at each temperature if a log time axis is used. These curves appear stretched (time scaled) if plotted with a nonlogarithmic time axis. By combining these mathematical relations, it was possible to calculate a species‐specific ‘mortality surface’ which exhibits mortalities, depending on temperature and duration of exposure. In order to accumulate hourly mortalities for courses of varying temperatures, an algorithm was developed which yields mortality values from that surface taking into account the attained mortality level. In validation experiments, recorded mortalities were compared against modelled mortalities. Prediction of mortality was partially supported by the model, but pupae experiencing intensely fluctuating temperatures showed decreased mortality, probably caused by rapid cold hardening during exposure. Despite this observation, mortality data converged to distinct levels very close to 100% depending on the intensity of temperature fluctuations that were characteristic for different types of experiments. The highest mortality limit occurred at intensely fluctuating temperatures in laboratory experiments. This constituted a benchmark that was not reached under various field conditions. Thus, it was possible to identify temperature limits for the extinction of field populations of Tuta absoluta pupae.

Entropy generation analysis of convective airflow in a solar updraft tower power plant

AbstractThe main objective of this numerical investigation is to interpret the entropy generation for free convection airflow in a solar tower updraft system. The ground surface is subjected to uniform hot temperature and the collector cover is maintained at lower constant temperature while the chimney wall is adiabatic. Two dimensionless equations of steady laminar free convective airflow are discretized using the finite volume approach. Numerical solutions were accomplished for different values of the Rayleigh number. Results are given in terms of isotherms, velocity magnitude, local entropy generation associated with thermal and fluid friction, local total entropy generation and local Bejan number contours for Rayleigh number ranging between 103 and 108. The reported results show that thermal and frictional irreversibilities are proportional to the Rayleigh number. Also, it was found that, at lower Rayleigh, total irreversibility is attributable to the thermal irreversibilities and occurs essentially in the collector section. At higher Rayleigh, frictional irreversibilities are increased significantly and become the dominant source of irreversibility in the solar tower, and the chimney section is the main contributor in the total irreversibility in the system.

The effective role of ascorbic acid in the photoelectrocatalytic reduction of CO2 preconcentrated on TiO2 nanotubes modified by ZIF-8

This work is aimed at investigating the effects of ascorbic acid as sacrificial agent in the photoelectrocatalytic reduction of CO2 to alcohol. The results show that the addition of electron donor agent (0.2 mol L−1 ascorbic acid) to the electrolyte (0.1 mol L−1 sodium sulfate pH 4.5) led to an improvement of 22% and 12% in CO2/methanol and CO2/ethanol conversion respectively, after 3 h of photoelectrolysis conducted on TiO2 nanotubes decorated with ZIF-8 nanoparticles under Eapp = 0.1 V and UV–Vis irradiation. The photoelectrocatalytic results were compared with photocatalytic, photolytic and electrocatalytic performance. The findings of this work unfold an interesting perspective for the use of sacrificial agent in photoelectrocatalysis and the generation of products of great energetic value from pollutants that cause environmental degradation in systems carried out under constant pressure and low temperature.

Immediate Transcriptional Response to a Temperature Pulse under a Fluctuating Thermal Regime.

The response of ectotherms to temperature stress is complex, non-linear, and is influenced by life stage and previous thermal exposure. Mortality is higher under constant low temperatures than under a fluctuating thermal regime (FTR) that maintains the same low temperature but adds a brief, daily pulse of increased temperature. Long term exposure to FTR has been shown to increase transcription of genes involved in oxidative stress, immune function, and metabolic pathways, which may aid in recovery from chill injury and oxidative damage. Previous research suggests the transcriptional response that protects against sub-lethal damage occurs rapidly under exposure to fluctuating temperatures. However, existing studies have only examined gene expression after a week or over many months. Here we characterize gene expression during a single temperature cycle under FTR. Development of pupating alfalfa leafcutting bees (Megachile rotundata) was interrupted at the red-eye stage and were transferred to 6°C with a 1-h pulse to 20°C and returned to 6°C. RNA was collected before, during, and after the temperature pulse and compared to pupae maintained at a static 6°C. The warm pulse is sufficient to cause expression of transcripts that repair cell membrane damage, modify membrane composition, produce antifreeze proteins, restore ion homeostasis, and respond to oxidative stress. This pattern of expression indicates that even brief exposure to warm temperatures has significant protective effects on insects exposed to stressful cold temperatures that persist beyond the warm pulse. Megachile rotundata’s sensitivity to temperature fluctuations indicates that short exposures to temperature changes affect development and physiology. Genes associated with developmental patterning are expressed after the warm pulse, suggesting that 1 h at 20°C was enough to resume development in the pupae. The greatest difference in gene expression occurred between pupae collected after the warm pulse and at constant low temperatures. Although both were collected at the same time and temperature, the transcriptional response to one FTR cycle included multiple transcripts previously identified under long-term FTR exposure associated with recovery from chill injury, indicating that the effects of FTR occur rapidly and are persistent.

Analysis of underfloor electrical heating system integrated with coconut oil-PCM plates

In the present study, coconut oil was used as a new bio-based phase change material (PCM) to be integrated with a quarter-scale insulated prototype of an underfloor heating system and its performance was investigated. Two different cases were studied. In the first case, the PCM was placed in an aluminum container that was positioned above an electrical heater, and the adaptation of the PCM to the floor was investigated. The second case was a control test in the absence of PCM plates. To simulate real severe winter conditions, the prototype was tested in an agricultural refrigerator to ensure constant low ambient temperature. The versatility of the underfloor system with PCM facilitates a reduction in heating load during winter while maintaining residential thermal comfort. An economic study was then conducted based on contemporary electricity shifts to inspect the system’s ability in peak load shifting. The results show that the PCM achieved an increase of 53.7% in the duration of energy transfer across charging and discharging. Furthermore, the use of the bio-PCM facilitated a shift in electricity consumption from peak time to off-peak time, yielding an annual cost reduction of 58.9% when compared with that achieved in the control test.

Exposure of Avian Embryos to Cycling Incubation Temperatures Reduces Adult Bactericidal Ability.

In birds, the temperature at which eggs are incubated shapes many aspects of hatchling phenotype, but long-term effects are less studied. We studied the effect of incubation temperature and pattern on the subsequent development of innate immune function in Japanese quail (Coturnix japonica). We incubated quail eggs in one of three replicated treatments: control (37.5°C), low (36.0°C), and cyclical incubation. The cyclical treatment had the same average temperature as the low-temperature treatment (36.0°C) and an upper temperature that was the same as the control. When individuals were 5, 20, and 55 d of age (i.e., adults), we measured the ability of blood plasma to kill Escherichia coli. Throughout development there was a nonsignificant trend for immune function to be lower in the cycling treatment. In adulthood, however, individuals incubated at cycling temperatures had significantly lower immune function than control birds but did not differ from individuals incubated at constant low temperatures. Males and females responded similarly to the incubation treatment, but females developed a greater plasma bactericidal ability than males. We conclude that variation in innate immune function of adult birds is shaped by temperature fluctuations experienced during incubation.

Numerical analysis of natural convective heat transport of copper oxide-water nanofluid flow inside a quadrilateral vessel

Nanofluid based heat transfer approaches have a tremendous prospect to develop novel cost-effective cooling technologies. In response to this potential development, a problem of unsteady copper oxide-water nanofluid flow and natural convective heat transfer within a quadrilateral vessel with uniform heating of bottom wall using modified Buongiorno model are investigated. The sloping wall of the vessel is maintained at constant low temperature and the uniform thermal condition on the bottom heated wall is considered, whereas the upper horizontal wall is regarded as adiabatic. The governing equations along with boundary conditions are solved using the Galerkin finite element method. Partial differential equation solver COMSOL Multiphysics with Matlab interface is used in the simulation. The results of the present problem of a certain situation as a special case have been verified by the previously published standard numerical investigations. The flow, thermal and concentration fields, local and average Nusselt number for various pertinent parameters entered into the problem have been analyzed. The time evolutions for a steady-state solution are also examined. The results show that the adjustment factor with the optimal nanoparticle volume fraction and the thermal Rayleigh number controls the optimal heat transfer. The trapezoidal vessel having higher sloping angles with the vertical axis exhibits higher heat transfer. Heat transfer decreases rapidly in 1–10 nm size nanoparticles for a nanofluid solution.

Cold-Adapted Protein Kinases and Thylakoid Remodeling Impact Energy Distribution in an Antarctic Psychrophile.

The Antarctic psychrophile Chlamydomonas sp. UWO241 evolved in a permanently ice-covered lake whose aquatic environment is characterized not only by constant low temperature and high salt but also by low light during the austral summer coupled with 6 months of complete darkness during the austral winter. Since the UWO241 genome indicated the presence of Stt7 and Stl1 protein kinases, we examined protein phosphorylation and the state transition phenomenon in this psychrophile. Light-dependent [γ-33P]ATP labeling of thylakoid membranes from Chlamydomonas sp. UWO241 exhibited a distinct low temperature-dependent phosphorylation pattern compared to Chlamydomonas reinhardtii despite comparable levels of the Stt7 protein kinase. The sequence and structure of the UWO241 Stt7 kinase domain exhibits substantial alterations, which we suggest predisposes it to be more active at low temperature. Comparative purification of PSII and PSI combined with digitonin fractionation of thylakoid membranes indicated that UWO241 altered its thylakoid membrane architecture and reorganized the distribution of PSI and PSII units between granal and stromal lamellae. Although UWO241 grown at low salt and low temperature exhibited comparable thylakoid membrane appression to that of C. reinhardtii at its optimal growth condition, UWO241 grown under its natural condition of high salt resulted in swelling of the thylakoid lumen. This was associated with an upregulation of PSI cyclic electron flow by 50% compared to growth at low salt. Due to the unique 77K fluorescence emission spectra of intact UWO241 cells, deconvolution was necessary to detect enhancement in energy distribution between PSII and PSI, which was sensitive to the redox state of the plastoquinone pool and to the NaCl concentrations of the growth medium. We conclude that a reorganization of PSII and PSI in UWO241 results in a unique state transition phenomenon that is associated with altered protein phosphorylation and enhanced PSI cyclic electron flow. These data are discussed with respect to a possible PSII-PSI energy spillover mechanism that regulates photosystem energy partitioning and quenching.

The effect of various after-ripening temperature regimens on the germination behaviour of Ambrosia artemisiifolia

Ambrosia artemisiifolia (common ragweed) is an annual weed known to infest crops and disturbed areas, and cause human pollinosis. To examine the effect of different thermal regimens on seed germination, during seed after-ripening, a study was conducted for two years. In 2012 (year 1) and 2013 (year 2), ragweed seeds collected from a single wheat stubble field were divided and stored under one of the five temperature regimens: constant −20 °C, +5 °C, room temperature (18 °C), +25 °C, and field conditions. Germination tests were performed every 15 days of storage from day 17 to day 213. Storage conditions showed a strong influence on ragweed seed germination duration. At constant low temperatures (−20 °C), seed behaved in an opposite manner depending on the year; in year 1 germination was inhibited while it was stimulated in year 2. At higher temperatures, seed dormancy was unbroken due to a lack of exposure to low temperatures. Under field conditions, seeds reached a high level of germination after a few days of storage due to temperature fluctuations. The different behaviours of ragweed seeds shown at constant temperatures revealed different dormancy depths in the two years that might be due to population variability and maternal environment differences during seed maturation.

Simulation of Forced Convection in a Channel Containing Three Obstacles over Backward and Forward Facing Steps by LBM

This study describes numerically forced convection laminar fluid flow simulation in a two dimensional channel containing three obstacles over backward and forward facing steps by using the lattice Boltzmann method (LBM). The LBM and the finite difference successive over relaxation method are simultaneously used to simulate the equations which govern the flow in terms of vorticity equation and energy equation. Heated fluid is impinged to flow in the channel while the solid surfaces of obstacles and channel are maintained at a lower constant temperature. The impacts on the temperature distribution and flow for changing Reynolds number are recapitulated for a fixed Prandtl number. Also, the impacts of Prandtl numbers on the flow and temperature distribution are discussed in this study. Two levels of Nusselt numbers, the local values and the mean values on the surfaces of the three obstacles, are emphasized to illustrate heat transfer rate from fluid. It is observed that 80% increase at heat transfer is noticed due to increase of Reynolds number of 100 within the range from 100 to 300. It is also observed that 60–30% increase at heat transfer is observed due to increase of Prandtl number of unity within the range from 0.71 to 13.4.

Mixed convection and entropy production in a nanofluid-filled closed space with inclined magnetic field

A computational analysis has been performed to study the impact of magnetic field on entropy generation due to mixed convective nanofluid flow with top and bottom side moving lid-driven closed space. The sinusoidal heating was applied to left vertical side, while the right side was under lower constant temperature. Top and bottom sides move in the opposite direction in lateral axis. A monolithic Galerkin finite element approach has been adopted for the spatial discretization and the Crank–Nicolson for the temporal integration of various values of the governing parameters such as magnetic field inclination angle ( $$0^{\circ }\le \gamma \le 90^{\circ }$$ ), Hartmann number ( $$0\le Ha \le 100$$ ), Richardson number ( $$0.01 \le Ri \le 10$$ ) and nanoparticle volume fraction ( $$0\le \phi \le 0.04$$ ). Thus, heat and fluid flow and entropy generation results are presented. It is found that inclination angle of magnetic field plays significant role in fluid flow and heat transfer, and entropy generation is affected slightly by variation of nanoparticles volume fraction. Heat transfer increases almost 400% with the increase in Reynolds number.

Rapid detection of Mycobacterium ulcerans with isothermal recombinase polymerase amplification assay.

BackgroundAccess to an accurate diagnostic test for Buruli ulcer (BU) is a research priority according to the World Health Organization. Nucleic acid amplification of insertion sequence IS2404 by polymerase chain reaction (PCR) is the most sensitive and specific method to detect Mycobacterium ulcerans (M. ulcerans), the causative agent of BU. However, PCR is not always available in endemic communities in Africa due to its cost and technological sophistication. Isothermal DNA amplification systems such as the recombinase polymerase amplification (RPA) have emerged as a molecular diagnostic tool with similar accuracy to PCR but having the advantage of amplifying a template DNA at a constant lower temperature in a shorter time. The aim of this study was to develop RPA for the detection of M. ulcerans and evaluate its use in Buruli ulcer disease.Methodology and principal findingsA specific fragment of IS2404 of M. ulcerans was amplified within 15 minutes at a constant 42°C using RPA method. The detection limit was 45 copies of IS2404 molecular DNA standard per reaction. The assay was highly specific as all 7 strains of M. ulcerans tested were detected, and no cross reactivity was observed to other mycobacteria or clinically relevant bacteria species. The clinical performance of the M. ulcerans (Mu-RPA) assay was evaluated using DNA extracted from fine needle aspirates or swabs taken from 67 patients in whom BU was suspected and 12 patients with clinically confirmed non-BU lesions. All results were compared to a highly sensitive real-time PCR. The clinical specificity of the Mu-RPA assay was 100% (95% CI, 84–100), whiles the sensitivity was 88% (95% CI, 77–95).ConclusionThe Mu-RPA assay represents an alternative to PCR, especially in areas with limited infrastructure.

Experimental Research on the Impact of Water-cement Ratio and Admixture on Hydration Heat of Cementitious Material at Constant Low Temperature of 3°C

This paper, to investigate the impact of water-cement ratio and admixtures on the hydration heat of cementitious material at constant low temperature of 3°C, measured the hydration heat values of cementitious material with various water-cement ratios and admixtures in 28d with the direct approach described in Test Methods for Heat of Hydration of Cement (GB/T 12959-2008). The results show that at constant low temperature of 3°C, the hydration heat of cementitious material rises with the increase of water-cement ratio. However, as the water-cement ratio is fixed, the hydration heat of the cementitious material decreases with the adding of fly ash and mineral powder, but there is no proportional relationship between the two. After comparing the hydration heat of cementitious material of different blending materials and amounts with the cementitious material without any admixture, it was found that at the initial stage, the admixture adding would significantly affect the hydration heat while latter the impact decreased greatly. At the 28d, the difference in hydration heat is generally within 10%.