Temperature Fluctuations Research Articles

Improving operation flexibility of the gas turbine through coolant intercooling and air injection using a sub-compressor

The use of renewable energy, particularly solar and wind power, is increasing, but it is necessary to alleviate the variation of such resources, a key drawback of using renewable energy. In this context, gas turbines capable of fast startup and rapidly changing power following a load have attracted considerable attention. Nevertheless, enhancing the operational flexibility of gas turbines is crucial to ensure their stable operation under various conditions. Several studies have attempted to enhance the flexible operating capabilities, by examining the operational stability assurance under a variety of conditions and life cycle increases by changing the operating conditions. This paper proposes a new gas turbine configuration and operating strategy in which a sub-compressor is used to increase the ramp rate and mitigate the thermal load of the turbine blades. The performance and dynamic behavior of the novel gas turbine was simulated using an in-house program based on the gas path analysis. Specifically, a sub-compressor with an inter-cooler was used to cool the coolant from 398 °C to 300 °C, which increased the gas turbine power by 1.3 MW and efficiency by 0.4%p compared to the conventional gas turbine. In addition, when applying a new operating strategy during the ramp-up phase, a part of coolant air was injected into the combustor to suppress the maximum turbine inlet temperature by 15 °C compared to the conventional gas turbine. As a result, the ramp rate could be doubled (from 18.75 to 37.5 %/min) by alleviating the fluctuations of hot gas temperature in the ramp-up phase.

Development of integrated thermally autonomous reformed methanol-proton exchange membrane fuel cell system

This paper presents a novel thermally autonomous reformed methanol fuel cell (RMFC) system for highly efficient hydrogen production and power generation by integrating a self-heating methanol steam reforming (MSR) microreactor and a high temperature proton exchange membrane fuel cell (HT-PEMFC). The RMFC system would exhibit significant potential for portable use due to its high energy efficiency, compact size and long lifetime. The structural design of the RMFC system including MSR microreactor and HT-PEMFC are studied, and a work flow is developed to enable the startup and stable power output of the system. After that, the microreactor and HT-PEMFC are fabricated, and then integrated to develop the system. Experimental testing results showed that the microreactor can produce a maximum reformate gas of 541 ml/min with a methanol conversion larger than 93.8 %., while maintaining the carbon monoxide concentration below 2 %. The RMFC system can start up within 17 min, the temperature fluctuation is lower than 6.28 % and the maximum output power can reach up to 32.9 W. As for a conservatively designed rating power of 25 W, the calculated energy conversion efficiency of the system can reach about 28.5 %, with good stability during long-term operations.

Recent Insights into the Physio-Biochemical and Molecular Mechanisms of Low Temperature Stress in Tomato.

Climate change has emerged as a crucial global issue that significantly threatens the survival of plants. In particular, low temperature (LT) is one of the critical environmental factors that influence plant morphological, physiological, and biochemical changes during both the vegetative and reproductive growth stages. LT, including abrupt drops in temperature, as well as winter conditions, can cause detrimental effects on the growth and development of tomato plants, ranging from sowing, transplanting, truss appearance, flowering, fertilization, flowering, fruit ripening, and yields. Therefore, it is imperative to understand the comprehensive mechanisms underlying the adaptation and acclimation of tomato plants to LT, from the morphological changes to the molecular levels. In this review, we discuss the previous and current knowledge of morphological, physiological, and biochemical changes, which contain vegetative and reproductive parameters involving the leaf length (LL), plant height (PH) stem diameter (SD), fruit set (FS), fruit ripening (FS), and fruit yield (FY), as well as photosynthetic parameters, cell membrane stability, osmolytes, and ROS homeostasis via antioxidants scavenging systems during LT stress in tomato plants. Moreover, we highlight recent advances in the understanding of molecular mechanisms, including LT perception, signaling transduction, gene regulation, and fruit ripening and epigenetic regulation. The comprehensive understanding of LT response provides a solid basis to develop the LT-resistant varieties for sustainable tomato production under the ever-changing temperature fluctuations.

Investigation of Salmonella enteritidis Growth under Varying Temperature Conditions in Liquid Whole Egg: Proposals for Smart Management Technology for Safe Refrigerated Storage

This study investigates the growth characteristics of Salmonella enteritidis (S. enteritidis) in liquid whole egg under both isothermal and non-isothermal storage conditions to understand the risks associated with inadequate temperature management in the egg industry. Using controlled laboratory simulations, liquid whole egg samples inoculated with S. enteritidis were stored under various isothermal (5, 15, 25, 35, and 45 °C) and non-isothermal conditions (5–10, 15–20, 25–30, 35–40, and 45–50 °C). The growth behavior of the S. enteritidis was analyzed using a two-step predictive modeling approach. First, growth kinetic parameters were estimated using a primary model, and then the effects of temperature on the estimated specific growth rate and lag time were described using a secondary model. Independent growth data under both isothermal and non-isothermal conditions were used to evaluate the models. The results showed that S. enteritidis exhibits different growth characteristics depending on temperature conditions, emphasizing the need for strict temperature control to prevent foodborne illnesses. To address this, a predictive growth model tailored for non-isothermal conditions was developed and validated using experimental data, demonstrating its reliability in predicting S. enteritidis behavior under dynamic temperature scenarios. Additionally, temperature management technologies were proposed and tested to improve food safety during refrigerated storage. This study provides a scientific basis for improving food safety protocols in the egg industry, thereby protecting public health and maintaining consumer confidence amid temperature fluctuations.

Numerical analysis of flow and heat transfer characteristics in Taylor-Couette-Poiseuille flow utilizing Large Eddy Simulation method

The flow and heat transfer characteristics within the Taylor-Couette-Poiseuille configuration induced by supercritical carbon dioxide flowing through the gap between the turbine shaft and the stationary casing were studied using Large Eddy Simulation. Wavelet analysis was used to calculate pressure fluctuations across various frequencies. Computational assessments were carried out to evaluate changes in the field synergy angle and inertial perturbations within the annular gap. A new theory was introduced to seamlessly integrate temperature, pressure, and velocity fields. Additionally, entropy generation in the Taylor-Couette-Poiseuille flow regime was thoroughly examined. The study revealed the emergence of vortices at the rotating wall, indicating a dynamic process in which large-scale vortices dissolve and more minor ones form. As frequency increases, pressure fluctuations grow. Increasing the mass flow rate can reduce the twisting vortex at the rotating wall and delay the onset of temperature fluctuations. Additionally, increasing the mass flow rate enhances the cooling effect on the rotating shaft. In the radial direction, as r increases, the field synergy angle and the inertial disturbance both show a trend of first decreasing and then increasing. The heat transfer performance is best when r = 0.6 and decreases significantly when r = 0.95. The synergy between the temperature gradient field, pressure gradient field, and velocity field shows a trend opposite to the field synergy angle and the inertial disturbance. As one moves from the rotating wall toward the stationary wall, temperature and velocity entropy production rates decrease, with noticeable fluctuations near the rotating wall.

Numerical modeling of heat transfer mechanism in remote sensing bulb of thermal expansion valves

Thermal management of automotive systems has garnered a lot of focus in recent times to improve the energy efficiency of vehicles and address the challenge of global warming. In combustible fuel vehicles, the heat pump compressor is driven by the engine power which leads to changes in operating condition of the cycle while the vehicle is in motion. In electric vehicles, a combined thermal management strategy handles both cabin and battery pack cooling/heating depending on the ambient conditions and power requirements by adjusting refrigerant flow rates and flow directions with sophisticated valves. Irrespective of the vehicle type, effective variable refrigerant flow control is prerequisite to ensure optimum thermal comfort with minimum energy. Thermal expansion valves (TXV) are the most widely used method for regulating mass flow rate of refrigerant during the expansion step of the vapor compression cycle based on the principle of trying to maintain a fixed degree of superheat at the evaporator outlet. Conventional models of the thermal expansion valve ignore the time lag between fluctuation of temperature at the evaporator outlet and the corresponding change in pressure of the TXV remote sensing bulb, treating the valve as an instantaneous element during transient operation. This paper presents a novel method for determining the temperature profile and time constant of the remote sensing bulb response using numerical methods, in an attempt to capture the dynamics of thermal expansion valve in active heat pump cycle. Finite difference method was used to solve for the conduction heat transfer between the bulb and the heat exchanger outlet tube in perfect thermal contact applying the necessary boundary conditions. This improved modeling approach will be helpful in better prediction of the dynamic behavior of thermal expansion valves and how it influences the evaporative heat exchanger performance during transient operations to determine control algorithm and strategies.

Temperature increase may not necessarily penalize future yields of three major crops in Xinjiang, Northwest China

Future food production is at risk due to climate change, particularly in arid regions with limited water resources and extensive irrigated agriculture. This study utilized the DSSAT model in conjunction with downscaled data from 21 global climate models (GCMs) under two shared socioeconomic pathways (SSP2–4.5 and SSP5–8.5) to assess the impact of projected climate change on irrigated crop phenology, yield, and evapotranspiration (ETc) of cotton, maize, and winter wheat in the Shihezi region of Xinjiang, China. The results indicated that temperature and precipitation in the region were expected to increase gradually from 2021 to 2100. Climate change has resulted in earlier anthesis and physiological maturity of all three crops. Future climatic conditions could reduce maize yields to 16.02 %. Conversely, the yields of cotton and winter wheat increased, with cotton yields rising by 1.23–10.94 % and winter wheat yields by 3.19–14.07 %. Additionally, ETc for cotton, maize, and winter wheat could rise in the future. The irrigation water demands could increase by 41.1–96.4 mm for cotton and 27.3–37.9 mm for maize, while the demand for winter wheat could decrease by 0.5–36.2 mm. Warming was significantly correlated with the changes in the yield and water use efficiency (WUE) of cotton, maize, and winter wheat. The temperature increases of +0.5°C to +3.0°C (relative to baseline) at 0.5°C intervals were analyzed to evaluate their effects on yield and WUE. The yields varied from −0.93 % to 6.15 % for cotton, −43.42 % to −7.99 % for maize, and 4.28–9.92 % for winter wheat. The WUE changes ranged from −29.03 % to −1.08 % for cotton, −43.06 % to −7.66 % for maize, and 0.69–3.47 % for winter wheat. Contrary to the common belief that rising temperatures generally harm crop yields, our study suggests that temperature fluctuations may benefit certain crops in specific regions. These results could provide theoretical guidance for implementing adaptive measures to future climate change in regions with conditions similar to Shihezi, Xinjiang, China, to ensure crop security and sustainable water management.

Warming events and their causes at the Bering Sea section B in summer of 1999–2019

Based on hydrological data for the Bering Sea from 1999 to 2019 during the Chinese National Arctic Research Expeditions (CHINAREs), along with oceanographic and meteorological data from the National Centers for Environmental Information (NCEI) and the European Centre for Medium-Range Weather Forecasts (ECMWF), we investigated trends in summer at the Bering Sea section B over the past 20 years and their underlying causes. The results revealed a pronounced rise in temperature at the Bering Sea section B in 2003, 2014, 2016, 2018, and 2019, suggesting a shift towards a new phase of warmth starting in 2014. In warm years (2003, 2014, 2016, 2018, and 2019), the mean maximum temperature in the upper layer in the basin north of 57°N and on the continental shelf were roughly 2.7 °C, 2.6 °C higher than that in cold years (1999, 2008, 2010, and 2012). Additionally, the mean minimum temperature of the cold water in the middle layer in the basin was roughly 0.7 °C higher in the warm years compared to the cold years. This difference between the warm and cold years was evident in the heat content: the average heat content in the upper to middle layers in the basin north of 57°N and on the continental shelf were about 1.2 and 0.9 GJ/m2 higher, respectively, in the warm years than the cold years. However, there was a modest warming trend in the basin south of 57°N, and the temperature in the mid-layer on the continental shelf showed year-to-year stability, in contrast to the significant warming observed elsewhere. Further study suggested that temperature fluctuation in the basin was closely tied to seasonal 2-m air temperature. In addition, the southern basin, divided at 57°N, experienced larger positive or negative anomalous wind stress curl compared to the northern basin. This discrepancy resulted in differing causes of temperature variation between the two regions. Temperature change in the upper layer on the continental shelf was attributed to an increase in cumulative net heat flux resulting from reduced sea ice, while the temperature in the middle layer on the continental shelf was limited by the enhanced density gradient between the upper and middle layer caused by melt ice, preventing significant warming. Overall, the thermal state for the Bering Sea section B was influenced by a combination of factors, including net heat flux, sea ice, and atmospheric conditions, contributing to the year-to-year variation characterized by alternating cold and warm regimes.

Cold-induced degradation of core clock proteins implements temperature compensation in the Arabidopsis circadian clock.

The period of circadian clocks is maintained at close to 24 hours over a broad range of physiological temperatures due to temperature compensation of period length. Here, we show that the quantitative control of the core clock proteins TIMING OF CAB EXPRESSION 1 [TOC1; also known as PSEUDO-RESPONSE REGULATOR 1 (PRR1)] and PRR5 is crucial for temperature compensation in Arabidopsis thaliana. The prr5 toc1 double mutant has a shortened period at higher temperatures, resulting in weak temperature compensation. Low ambient temperature reduces amounts of PRR5 and TOC1. In low-temperature conditions, PRR5 and TOC1 interact with LOV KELCH PROTEIN 2 (LKP2), a component of the E3 ubiquitin ligase Skp, Cullin, F-box (SCF) complex. The lkp2 mutations attenuate low temperature-induced decrease of PRR5 and TOC1, and the mutants display longer period only at lower temperatures. Our findings reveal that the circadian clock maintains its period length despite ambient temperature fluctuations through temperature- and LKP2-dependent control of PRR5 and TOC1 abundance.

Non-steady flow decomposition behaviors of heat and mass transfer on intrinsic kinetics for methane hydrate particles transported in pipelines

The differential equations governing the decomposition rate and activation energy, convective mass transfer, methane diffusion and fugacity, as well as heat conduction and enthalpy change were derived by integrating thermal convection, heat conduction, mass transfer and intrinsic kinetics. Mathematical models for decomposition kinetics and thermodynamics in a non-steady field were solved using a radial logarithmic grid for node division and discretization of the equations. The study elucidated the heat and mass transfer processes as well as decomposition kinetics in pipelines by analyzing the impacts of particle size, temperature, pressure, flow rate and activation energy on decomposition rate. The results indicated that compared with the isothermal decomposition of the intrinsic kinetic model and static experimental decomposition, the complex non-steady multiphase flow model offers a more accurately simulation of hydrate decomposition as well as associated heat and mass transfer processes. Hydrate decomposition is characterized as a non-isothermal dynamic ablation process with heat transfer rate and intrinsic kinetics dominating during the preliminary stage and the stable stage, respectively. An increasing in the slurry temperature, temperature fluctuation and flow rate accelerated the heat transfer rate capacity, enhanced convective heat transfer capacity and facilitated hydrate decomposition, with the mass transfer rate exhibiting lesser influence. The particle surface area and slurry temperature exhibited the most significant influence on hydrate decomposition, which was followed by flow rate. Upon increasing particle size from 1 mm to 5 mm and the temperature from 293 K to 313 K, the decomposition rate increased by 20.7 times and 13.5 times, respectively. Furthermore, enhancing temperature and flow rate while decreasing particle size and pressure decreased both the decomposition time and the duration required for the decomposition rate to reach its peak. Additionally, the decomposition rate and its constant vary with the activation energy.

Salt weathering resilience in masonry: An accelerated laboratory study involving wind-induced variations

Salt weathering resistance is a critical parameter governing the durability of coastal masonry units and mortars. Accelerated weathering cycles are employed at the laboratory to investigate the responses of substrates and mortars upon exposure to salt, moisture, temperature fluctuations and humidity. In this paper, the individual and synergistic performances of bricks and mortar formulations when exposed to accelerated salt weathering cycles are investigated, incorporating the influence of wind on their resilience. The study examines the behaviour of brick-mortar sandwich specimens and separate specimens of bricks and mortar mixtures comprising cement, dry hydrated lime, fly ash, and limestone. These specimens are exposed to repeated weathering cycles in a 5 % sodium sulphate solution. Along with the mass variations during each weathering cycle, physicomechanical, microstructural, mineralogical and morphological characterization of the specimens are used to compare their salt weathering resistance. The results highlight that the responses of individual masonry components might not collectively translate to the overall performance of the combined system due to hygric resistance, which is minimal when the components have comparable pore size distribution. Higher microporosity (pores of diameter between 0.1 μm and 10 μm) and mechanical strength enough to resist the crystallization stresses together provide better resistance to salt weathering to the individual mortars. However, pore structure compatibility and pore fraction similarity between the components govern the behaviour of the combined system and, therefore, reflect the better performance of sandwich specimens with brick and lime mortars. The study demonstrated that wind accelerates material degradation during salt weathering through progressive erosion, accelerated evaporation and subsequent formation of isolated thenardite.

Investigating thermal and UV ageing effects on crumb rubber modified bitumen enhanced with emission reduction agents and carbon black

Over time, bitumen experiences deterioration due to factors like the exposure to oxygen, solar irradiation, and temperature fluctuations. While laboratory techniques like rolling thin film oven (RTFO) and pressure ageing vessel (PAV) were developed to simulate field ageing, they do not accurately replicate environmental factors normally occurring in the field, particularly solar irradiation. Limited research has focused on understanding the ageing processes of crumb rubber modified bitumen (CRMB). This study investigated how different ageing conditions affect the chemo-rheological properties of CRMB and CRMB with geopolymer-based fly ash (GFA), Portland cement paste (PCP), and carbon black (CB). GFA and PCP were added to reduce noxious fumes and VOC emissions from CRMB whereas CB is commonly employed as an antioxidant agent. RTFO and PAV were used to simulate short- and long-term ageing, while a SUNTEST XLS+ weatherometer was used for thermal and UV ageing simulations. A dynamic shear rheometer and attenuated total reflectance Fourier transform infrared spectroscopy were employed for rheological and chemical analysis. Results indicated that extended exposure to thermal conditioning and UV irradiation had the most impact on the chemo-rheological properties of the binders. The incorporation of CR into bitumen enhanced ageing resistance and mitigated the potential for stiffening and embrittlement. The addition of GFA, PCP, and CB to CRMB had a negligible impact on the chemo-rheological properties when subjected to RTFO, PAV, and thermal conditioning. However, following UV ageing, these additives led to a slight increase in carbonyl bonds and greater stiffness compared to pure CRMB

Endophytic Bacterial Biofilm-Formers Associated with Antarctic Vascular Plants.

Deschampsia antarctica and Colobantus quitensis are the only two vascular plants colonized on the Antarctic continent, which is usually exposed to extreme environments. Endophytic bacteria residing within plant tissues can exhibit diverse adaptations that contribute to their ecological success and potential benefits for their plant hosts. This study aimed to characterize 12 endophytic bacterial strains isolated from these plants, focusing on their ecological adaptations and functional roles like plant growth promotion, antifungal activities, tolerance to salt and low-carbon environments, wide temperature range, and biofilm formation. Using 16S rRNA sequencing, we identified several strains, including novel species like Hafnia and Agreia. Many strains exhibited nitrogen-fixing ability, phosphate solubilization, ammonia, and IAA production, potentially benefiting their hosts. Additionally, halotolerance and carbon oligotrophy were also shown by studied bacteria. While some Antarctic bacteria remain strictly psychrophilic, others demonstrate a remarkable ability to tolerate a wider range of temperatures, suggesting that they have acquired mechanisms to cope with fluctuations in environmental temperature and developed adaptations to survive in intermediate hosts like mammals and/or birds. Such adaptations and high plasticity of metabolism of Antarctic endophytic bacteria provide a foundation for research and development of new promising products or mechanisms for use in agriculture and technology.

Pedestal properties of negative triangularity discharges in ASDEX Upgrade

Abstract In this work, we explore the pedestal properties of negative triangularity discharges with upper triangularity of δ u ≈ − 0.35 and with both ion ∇ B drift directions. In all cases, the discharges undergo a transition to H-mode with accompanying edge-localized modes (ELMs) that are not explained by the peeling-ballooning stability analysis alone. A variation in the ion ∇ B drift direction is observed. A lower pressure gradient, shallower radial electric field well and increased temperature fluctuations are measured in the favorable case. In addition, irregular ELMs are present. This difference is more pronounced in electron cyclotron resonance heating (ECRH) plasmas compared to plasmas with combined neutral beam injection and ECRH. A comparative analysis between two discharges, featuring similar plasma parameters but varied shaping, suggests that an interplay between other parameters, such as magnetic shear, the timing of the auxiliary heating and shaping, might play a strong role in low- to high-confinement transitions. While the low shaping discharge maintained L-mode, the high shaping discharge entered H-mode with ELMs, contrary to expectations.

Investigating Mechanical Characteristics of Rocks Under Freeze–Thaw Cycles Using Grain-Based Model

AbstractBased on the discrete element method (DEM), a water-contained grain-based model (GBM) is developed in this study to evaluate the effects of freeze–thaw cycles (FTCs) on the mechanical characteristics of the rock. A set of freeze–thaw and uniaxial compression tests is carried out to explore the impact of micro damage caused by FTCs on the mechanical prosperities of rock samples. By monitoring the development and distribution of micro-cracks during freeze–thaw test and uniaxial compression test, the damage mechanism of FTCs is revealed from a microscopic perspective, which shows that FTCs deteriorate the strength and brittleness parameters as exponential functions. The parametric analysis is carried out to explore the influence of porosity and mineral components on the mechanical behaviors of rock against freeze–thaw and uniaxial loadings. Based on the parametric analysis results, it is found that UCS, Young’s modulus, and total strain energy at peak stress decrease with the increase of porosity and clay content, which emphasizes the contributions of porosity and mineral components on the mechanical properties of rock samples. It is proved that the water-contained grain-based model developed in this study can capture the damage caused by FTCs on the mechanical performance of rock from a microscopic perspective, which provides novel perspectives on the phenomenon of rock degradation in response to fluctuations in temperature.

Development and Characterization of Olaparib-Loaded Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Pharmaceutical Applications.

This study aims to enhance the solubility of Olaparib, classified as biopharmaceutical classification system (BCS) class IV due to its low solubility and bioavailability using a solid self-nanoemulsifying drug delivery system (S-SNEDDS). For this purpose, SNEDDS formulations were created using Capmul MCM as the oil, Tween 80 as the surfactant, and PEG 400 as the co-surfactant. The SNEDDS formulation containing olaparib (OLS-352), selected as the optimal formulation, showed a mean droplet size of 87.0 ± 0.4 nm and drug content of 5.53 ± 0.09%. OLS-352 also demonstrated anticancer activity against commonly studied ovarian (SK-OV-3) and breast (MCF-7) cancer cell lines. Aerosil® 200 and polyvinylpyrrolidone (PVP) K30 were selected as solid carriers, and S-SNEDDS formulations were prepared using the spray drying method. The drug concentration in S-SNEDDS showed no significant changes (98.4 ± 0.30%, 25℃) with temperature fluctuations during the 4-week period, demonstrating improved storage stability compared to liquid SNEDDS (L-SNEDDS). Dissolution tests under simulated gastric and intestinal conditions revealed enhanced drug release profiles compared to those of the raw drug. Additionally, the S-SNEDDS formulation showed a fourfold greater absorption in the Caco-2 assay than the raw drug, suggesting that S-SNEDDS could improve the oral bioavailability of poorly soluble drugs like olaparib, thus enhancing therapeutic outcomes. Furthermore, this study holds significance in crafting a potent and cost-effective pharmaceutical formulation tailored for the oral delivery of poorly soluble drugs.

Short-term temperature changes affected the predation ability of Orius similis on Bemisia tabaci nymphs

Abstract Bemisia tabaci (Gennadius), a major pest that can adversely affect economies and agriculture globally, is particularly sensitive to climate change-induced temperature fluctuations, which can intensify its outbreaks. Orius similis Zheng, a primary natural predator of B. tabaci, also experiences temperature-related effects that influence its biocontrol efficacy. Thus, understanding the response of O. similis to temperature changes is pivotal for optimizing its biocontrol potential. Herein, our investigations showed that the functional response of O. similis to both high- and low-instar nymphs of B. tabaci adheres to the type II model at temperatures of 19, 22, 25, 28, and 31 °C. At 28 °C, O. similis exhibits the highest instantaneous attack rate (high-instar: 1.1580, low-instar: 1.2112), and the shortest handling time per prey (high-instar: 0.0218, low-instar: 0.0191). The efficacy of O. similis in controlling B. tabaci nymphs follows the sequence: 28 °C > 25 °C > 31 °C > 22 °C > 19 °C. Additionally, search efficiency inversely correlates with prey density. Simulations using the Hessell–Varley interference model indicate that increased density of O. similis under any temperature condition leads to reduced predation rates. Moreover, O. similis shows a predation preference for low-instar nymphs of B. tabaci, with higher predation level observed at the same temperature. In conclusion, for effective control of B. tabaci in field releases, O. similis should be optimally released at temperatures between 25 and 28 °C to preferably target the egg or early nymph stages of B. tabaci and determining the appropriate number of O. similis is important to minimize interference among individuals and enhance biocontrol efficacy.

On the kinetic temperature of a one-dimensional crystal on the long-time scale

We investigate the dynamics of the kinetic temperature of a finite one-dimensional harmonic chain, the evolution of which is initiated by a thermal shock. We demonstrate that the kinetic temperature returns arbitrarily close to its initial state (the one immediately following the thermal shock) infinitely many times, and we give an estimate for the time elapsed until the recurrence. This assertion is closely related to the Poincare recurrence theorem and we discuss their relation. To estimate the recurrence time we use its averaging along system’s trajectory and provide a rigorous mathematical definition of the mean recurrence time. It turns out that the mean recurrence time exponentially increases with the number of particles in the chain. A connection is established between this problem and the local theorems of large deviations theory.Previous studies have shown that in such a one-dimensional harmonic chain, at times of order N, a thermal echo phenomenon is observed — a sharp increase in the amplitude of kinetic temperature fluctuations. In the present work, we give a rigorous mathematical formulation to this phenomenon and estimate the amplitude of the fluctuations.The research is funded by the Ministry of Science and Higher Education of the Russian Federation within the framework of the Research Center of World-Class Program: Advanced Digital Technologies (agreement №075-15-2020-311 dated 04.20.2022).

Exogenous nitric oxide and hydrogen sulfide as biotechnological tools for enhancing plant adaptation to cold

The challenge of increasing plant tolerance to low temperatures is still relevant despite the upward trend in the average temperatures on Earth. Sharp temperature fluctuations during growing periods and cultivation of thermophilic crops in more northern latitudes increase the likelihood of plants being damaged by cold. Physiologically active substances, primarily hormones and signalling molecules, are considered to be effective for increasing plant tolerance to extreme temperatures. In the last decade, among such compounds, researchers' and practitioners' considerable attention has been paid to gasotransmitters – gaseous substances that are synthesized by living organisms and perform signalling functions. The review analyses the molecular mechanisms of stress protective effects of two major gasotransmitters – nitric oxide (NO) and hydrogen sulfide (H2S). In particular, the physiological effects of gasotransmitters that are attributed to their ability to cause post-translational modifications of numerous target proteins as well as those related to their functional interactions with other signaling intermediaries, primarily ROS and calcium ions, are discussed. The available data on the actions of donors of these gasotransmitters on thermophilic and cold-tolerant plants are summarized. Particular attention is paid to the influence of exogenous NO and H2S on the antioxidant system in plants, their ability to accumulate osmolytes and other low-molecular compounds with multifunctional stress protective effects. Data on the influence of gasotransmitters on fruits during low-temperature storage are analysed separately. It is emphasized that increased storability of fruits under the influence of NO and H2S donors is largely controlled by the ability of both gasotransmitters to inhibit ethylene synthesis. It was concluded that exogenous nitric oxide and hydrogen sulfide could be effective tools for increasing tolerance of different plant taxon’s to low temperatures and used in crop production and storage technologies for fruits and vegetables.

Features and processes of rock weathering in central Dronning Maud Land, Antarctica

In this study, we have investigated rock weathering phenomena in the central part of Dronning Maud Land, Antarctica. The area is characterized by low mean annual temperatures (−18 °C), strong katabatic winds, and minimal liquid water at the surface. Weathering features, including ventifacts, tafoni, and grus accumulations, are characterized through field observations, rock surface temperature measurements, and microscopic analysis. Abrasion by sand and ice particles transported by strong winds has locally resulted in ridge-shaped ventifacts and rock surfaces with elongated pits, furrows, and grooves. The abrasion-caused features, such as polished facets, keels, and grooves, indicate a northeast-facing wind direction, aligning with the present-day wind regime. The dominant weathering processes in coarse-grained intrusive rocks are oxidation and granular disintegration. Fe-oxidation induces cracking, increasing the porosity and enhancing susceptibility to further weathering. Additionally, temperature fluctuations on rock surfaces caused by solar radiation create thermal stress, which can lead to the formation of microcracks. These microcracks, formed due to thermal expansion, are likely to propagate through subcritical cracking, which is a slow, long-term process. Together, Fe-oxidation, thermal expansion, and subcritical cracking are important mechanisms contributing to long-term weathering and rock decay. Salt weathering, facilitated by snow and ice meltwater, particularly within tafoni, leads to flaking and disintegration of the parent rock. These findings shed light on the complex interactions shaping the geomorphology of central Dronning Maud Land and provide insights into long-term weathering processes operating in Antarctica's extreme environment.