Significant Effect Of Temperature Research Articles

Impacts of temperature and turbidity on the gill physiology of darter species

Fish gills are complex organs that have direct contact with the environment and perform numerous functions including gas exchange and ion regulation. Determining if gill morphometry can change under different environmental conditions to maintain and/or improve gas exchange and ion regulation is important for understanding if gill plasticity can improve survival with increasing environmental change. We assessed gill morphology (gas exchange and ion regulation metrics), hematocrit and gill Na+/K+ ATPase activity of wild-captured blackside darter (Percina maculata), greenside darter (Etheostoma blennioides), and johnny darter (Etheostoma nigrum) at two temperatures (10 and 25 °C) and turbidity levels (8 and 94 NTU). Samples were collected August and October 2020 in the Grand River to assess temperature differences, and August 2020 in the Thames River to assess turbidity differences. Significant effects of temperature and/or turbidity only impacted ionocyte number, lamellae width, and hematocrit. An increase in temperature decreased ionocyte number while an increase in turbidity increased lamellae width. Hematocrit had a species-specific response for both temperature and turbidity. Findings suggest that the three darter species have limited plasticity in gill morphology, with no observed compensatory changes in hematocrit or Na+/K+ ATPase activity to maintain homeostasis under the different environmental conditions.

In Situ/Operando Techniques for Unraveling Mechanisms of Ionic Transport in Solid-State Lithium Indium Halide Electrolyte

Over the past years, lithium-ion solid-state batteries have demonstrated significant advancements regarding such properties as safety, long-term endurance, and energy density. Solid-state electrolytes based on lithium halides offer new opportunities due to their unique features such as a broad electrochemical stability window, high lithium-ion conductivity, and elasticity at close to melting point temperatures that could enhance lithium-ion transport at interfaces. A comparative study of lithium indium halide (Li3InCl6) electrolytes synthesized through a mechano-thermal method with varying optimization parameters revealed a significant effect of temperature and pressure on lithium-ion transport. An analysis of Electrochemical Impedance Spectroscopy (EIS) data within the temperature range of 25–100 °C revealed that the optimized Li3InCl6 electrolyte reveals high ionic conductivity, reaching 1.0 mS cm−1 at room temperature. Herein, we present the utilization of in situ/operando X-ray Photoelectron Spectroscopy (XPS) and in situ X-ray powder diffraction (XRD) to investigate the temperature-dependent behavior of the Li3InCl6 electrolyte. Confirmed by these methods, significant changes in the Li3InCl6 ionic conductivity at 70 °C were observed due to phase transformation. The observed behavior provides critical information for practical applications of the Li3InCl6 solid-state electrolyte in a broad temperature range, contributing to the enhancement of lithium-ion solid-state batteries through their improved morphology, chemical interactions, and structural integrity.

Impact of Meteorological Parameters on Atmospheric Turbidity over Lumbini, Nepal

The main objective of this research is to study of impact of meteorological parameters on atmospheric turbidity index on Lumbini (27.49o N, 83.28o E, 110 m asl), Nepal for a period of one year (2018). The ground based data of spectral aerosol optical depth (AOD) are derived from Aerosol Robotic Network (AERONET) of NASA. Satellite based data of meteorological parameter (maximum temperature, minimum temperature, dew point, relative humidity, water contend and rainfall) are downloaded from NASA website. Daily, monthly and seasonal variation of atmospheric turbidity is analyzed. The annual average of Angstrom exponential ( α), Angstrom coefficient of turbidity ( β) and Linke turbidity factor (LT) are found 1.0 ± 0.2, 0.36 ± 0.20 and 8.3 ± 2.5 respectively. Correlation coefficient of meteorological parameters with atmospheric turbidity is analyzed. No significant effect of maximum temperature, minimum temperature, dew point and water contend on atmospheric turbidity. There is positive effect of rainfall on α, but negative effects of relative humidity and rainfall on β and LT. Atmospheric turbidity index is an important for the air pollution. Result of this research work is beneficial for the further identification, impact and analysis of atmospheric turbidity index on meteorological parameters at different places with same geographical condition.

Numerical Simulation Study on the Dynamics of Bluff-Body Flames under Oxygen-Lean Conditions

As modern aeroengine combustors advance towards high temperatures, afterburners are inevitably affected by diminished oxygen content in incoming flows, thus affecting combustion efficiency, instability, and flammability limits. In this study, the dynamic combustion characteristics of V-shaped bluff body-stabilised diffusion flames were investigated using a large eddy simulation method with an oxygen mass fraction range of 14–23% and temperatures ranging from 900 to 1100 K. The results show the significant effects of oxygen content and inflow temperature on the flame/flow behaviours downstream of the bluff-body flame holder. In a separated shear layer, two distinct modes of flow/flame shedding are observed when varying the oxygen content and inflow temperature. The results show that BVK instability governs the far-field wake flow/flame features, whereas the oxygen concentration and temperature significantly affect their oscillation amplitudes. In addition, variations in the incoming oxygen content and temperature shift the axial position of the transition from KH instability to BVK instability. Finally, a spectral analysis is conducted to investigate the characteristics of pressure and heat release pulsations under different scenarios. This study highlights the importance of oxygen content on the combustion dynamics of bluff body-stabilised diffusion flames at various temperatures, which is essential for optimising combustion efficiency and stability in practical applications.

Post-Thaw Storage Temperature Influenced Boar Sperm Quality and Lifespan through Apoptosis and Lipid Peroxidation.

Cryopreservation deteriorates boar sperm quality and lifespan, which restricts the use of artificial insemination with frozen-thawed boar semen in field conditions. The objective of this study was to test the effects of post-thaw storage time and temperature on boar sperm survival. Semen ejaculates from five Landrace boars (one ejaculate per boar) were collected and frozen following a 0.5 mL-straw protocol. Straws from the five boars were thawed and diluted 1:1 (v:v) in BTS. The frozen-thawed semen samples were aliquoted into three parts and respectively stored at 5 °C, 17 °C, and 37 °C for up to 6 h. At 0.5, 2, and 6 h of storage, sperm motility, viability, mitochondrial membrane potential, and intracellular reactive oxygen species (ROS) levels and apoptotic changes were measured. Antioxidant and oxidant levels were tested in boar sperm (SPZ) and their surrounding environment (SN) at each timepoint. The results showed significant effects of post-thaw storage time and temperature and an impact on boar sperm quality (total and progressive motility, VCL, viability, acrosome integrity), early and late sperm apoptotic changes, and changes in MDA levels in SPZ and SN. Compared to storage at 5 °C and 37 °C, frozen-thawed semen samples stored at 17 °C displayed better sperm quality, less apoptotic levels, and lower levels of SPZ MDA and SN MDA. Notably, post-thaw storage at 17 °C extended boar sperm lifespan up to 6 h without obvious reduction in sperm quality. In conclusion, storage of frozen-thawed boar semen at 17 °C preserves sperm quality for up to 6 h, which facilitates the use of cryopreserved boar semen for field artificial insemination.

Determinant factors for berry derived anthocyanin persistency in stirred yoghurts

The development of healthy and functional ingredients has been limited because of their low stability under given environmental and processing conditions, anyhow the use of anthocyanin as a natural food colorant has been recognized through the last decades. Therefore, the main objective of this study is stabilizing the natural colour of stirred yogurts fortified with berry fruit pulps during the entire shelf life of the product by evaluating the factors that affect the stability of anthocyanins. Initially the effect of time-temperature combinations applied in processing fruit pulps was analyzed through 6 different treatments; 85 °C for 1 second, 85 °C for 20 minutes, 90 °C for 2 seconds, 90 °C for 20 minutes, 95 °C for 2 seconds, and 95 °C for 20 minutes. Besides, varying sugar levels (0 %, 20 %, 40 %, 60 %) incorporated fruit pulps, and six yoghurt bases composed with different ratios of Skimmed Milk Powder (SMP), modified starch and gelatin were tested against the color stability of the stirred yoghurt fortified with berry fruit pulps. The color variations in the stirred yoghurts were evaluated in terms of “L, a, b” values represented by the colorimeter. There was a significant (p<0.05) effect of berry fruit pulp processing time and temperature on the colour of the stirred yogurt and processing berry fruits at 95 °C for 20 minutes was identified as the most appropriate treatment to get an optimum colour in stirred yoghurt. Further analysis with varying sugar levels and different yoghurt bases revealed that, both factors are potential determinants that exert a significant effect on the color stability in stirred yoghurts throughout the shelf life. Interestingly, the L color value was greatly affected with varying quantities of sugar and there was no considerable effect of SMP level on the color properties of the yoghurt. However, the modified starch level emphasized an increase in all the three-color properties. Conclusively, the relationship between these determinant factors and the anthocyanin biochemistry should be further studied to obtain the therapeutic as well as industrial advantage of anthocyanin.

Змочування та контактна взаємодія напівпровідникових оксидних матеріалів Ga2O3, In2O3, ZnO з металічними розплавами у вакуумі

Semiconductor oxide materials such as gallium, indium and zinc oxides play an important role in a development and production of a variety of electronic devices. Experimental studies of these materials allow to define, for example energetic or other physical parameters of the devices created and also to improve existing technologies of their production, metallization and joining of electrocontacts by way of brazing which require additional wetting studies. It should be noted that data on wetting of mentioned oxides by metals are practically absent in literature. Thus a detailed experimental study of the interfacial interaction, adhesion and wetting of Ga2O3, In2O3 and ZnO oxide materials with some pure metal melts (Ga, In, Sn, Au,Ge, Ag, Cu) in vacuum was performed by the sessile drop method using photo- and video- fixing including temporal and temperature dependencies of contact angles. It was found that pure metals don't wet powdery pressed specimens of Ga and In oxides in the temperature range studied and vary in a rather narrow range. For ZnO system the significant effect of experiment temperature and hold-up time on the values of contact angles for some metals (Ga, Ge, Sn, Cu) is observed. For example wetting angles for Ga change from above 90 degrees at low temperatures up to 49 and full spreading at 1173⎯1373 K. This effect may be attributed to the activation of chemical reactions, change of oxide stabilities at high temperatures at the interface. Last metals can be used as adhesive-active additions to base brazing alloy. Keywords: gallium, indium, zinc oxides, semiconductor, wetting, contact interaction, metal melt.

Characterization of nano-silica vegetable grease with diffusing wave spectroscopy DWS and Raman spectroscopy

The diffusing wave spectroscopy (DWS) method made it possible to identify changes in the dynamics of the free movement of particles in the grease under the influence of temperature, which changed the viscoelastic properties of the grease. Changes in the parameters determined by DWS method influenced changes in the chemical structure, which was confirmed by Raman spectroscopy, determining the integral intensity of the unsaturated to saturated bond bands found in the grease. The article presents the results of the influence of temperature on changes in the viscoelastic states of vegetable grease evaluated on the basis of properties determined by DWS (diffusing wave spectroscopy). The following parameters were used to evaluate the viscoelastic states: the intensity correlation function (ICF), the correlation function of mean square displacement (MSD), the elastic modulus G′ and the viscosity modulus G″. A significant effect of temperature on changes in the microstructure of vegetable grease was observed, which was reflected in the viscoelastic parameters. The dynamics of the free movement of molecules in the grease was changed, which affected the elasticity of the system and the displacement of the G′ and G″ modules towards higher frequencies.

Investigation of olive leaf extract as a potential environmentally-friendly corrosion inhibitor for carbon steel

Corrosion constitutes a significant issue in industries that handle metals. Corrosion inhibitors with a low impact on the environment provide a significant economic benefit in various engineering applications. In this work, the effectiveness of olive leaves extract is evaluated as a cost-effective and environmentally-friendly corrosion inhibitor. The corrosion of carbon steel in different concentrations of hydrochloric acid (0.1, 1.0, and 2.0 M) when protected by an aqueous solution of olive leaf extract of concentrations ranging from 10 to 60 ppm is investigated. A green extraction process based upon water extraction is used to ensure minimum impact on the environment. Results show that the corrosion inhibition efficiency increased as the concentration of the olive leaf extract increased. An analysis of variance showed a significant effect of acidic molarity, temperature, and inhibitor concentration on the corrosion rate. A significant statistical model indicates that the inhibitor exhibits higher efficiencies at higher acidic molarity. Results of SEM and EDX also demonstrated that a protective film of the inhibitor on the specimen surface plays a role in corrosion inhibition, suggesting that the inhibitor molecules are adsorbed at the interface between the carbon steel and the acid solution. The study provides an insight on the corrosion mechanism and highlights the potential of olive oil extract as an eco-friendly alternative to traditional corrosion inhibitors.

Testing Procedures on the Assessment of the Effects Temperature on Residual Shear Strength of Soils

Testing Procedures on the Assessment of the Effects Temperature on Residual Shear Strength of Soils

The content of polyphenolic compounds in buckwheat grass depending on agrotechnical and abiotic factors and the assessment of the possibility of its use in food technologies

Relevance. Buckwheat is a source of many biologically active substances. Especially there are a lot of them in leaves and inflorescences from which it is possible to get tea beverages for specialized and functional nutrition. These plant parts are rich in polyphenolic compounds (PC), the main one being rutin. Their content in the plant depends on many factors.The aim of this study is to estimate the effect of sowing dates, ultraviolet (UV) radiation and temperature on PC accumulation in buckwheat plants.Methods. Buckwheat seeds were sown four times in June-July. The PC content of buckwheat water-ethanol extracts and water infusions was determined by Folin-Ciocalteu, method antioxidant activity — by DPPH radical scavenging method.Results. The sowing dates influence the PC content. At the earlier sowing dates of seeds the accumulation of PC in the extracts was higher (8.42–9.33%) in comparison with the later ones (6.10%). The PC content in the infusions varied from 2.10 to 2.83%. There are indications of a direct relationship between the accumulation of PC and the level of UV radiation during the growing season requiring further verification. A significant effect of temperature was not revealed. The AOA of all samples was high. The content of PC in aqueous infusions allows us to recommend buckwheat grass as a raw material for tea beverages.

METHOD OF CALCULATING THE UNSTATIONARY TEMPERATURE FIELD PARTS OF THE SPHERICAL FORM OF THE STRUCTURE FLIGHT APPARATUS OF UNMANNED AVIATION COMPLEXES

The design of unmanned aircraft vehicles during operation is exposed to significant temperature effects, which causes changes in the dielectric characteristics of radio technical elements and can lead to failures of on-board radio electronic equipment, as a result of which the task of determining the amount of temperature change in the compartments where the radio electronic equipment is located is performed. At the same time, some external elements of the aircraft vehicle can have complex structures with shapes close to spherical and different thicknesses in each cross-sectional structure.&#x0D; There is a need to develop a method for calculating the non-stationary temperature field with the purpose of finding out the real conditions in which all the elements of the aircraft structure work, which would help to determine how the temperature of the structure changes during any flight. At the same time, it is necessary to take into account the three dimensions of temperature gradients on spherical parts of structures of various shapes, namely nose part, rounded wing and others. In them, as a rule, each cross-section of the wall has its own thickness and, according to each cross-section, the temperature distribution along the thickness of the wall will correspond, that is, it is necessary to ensure the redistribution of temperature along the structural element, the calculation of which month. In addition, it is necessary to note that the wall of the aircraft can be multi-layered and the properties of its material can change along with the change in temperature. Considering the fact that it is impossible to take into account all the listed features by analytical methods, when choosing a calculation method, it will be advisable to stop at numerical methods.&#x0D; One of the most well-known numerical methods is the finite difference method with an implicit calculation scheme, which has an indisputable advantage for modeling - absolute stability with sufficient changes in time and coordinate steps. We will use the level of thermal conductivity in spherical coordinates in order to increase the accuracy of the calculation, for which solution, after finding out the boundary conditions, we will perform a one-dimensional calculation of the temperature by thickness in each mesh section of the structure, and also perform a calculation of the two-dimensional "heat flow" along the solid between the points, that are located on the same thickness, but have a temperature difference. Thus, when calculating the temperature field, the sphericity and multi-lay redness of the structural elements is taken into account, and the property of the material of the aircraft structure changes depending on the temperature.

Chronic Thermal Acclimation Effects on Critical Thermal Maxima (CTmax) and Oxidative Stress Differences in White Epaxial Muscle between Surface and Cave Morphotypes of the Mexican Cavefish (Astyanax mexicanus).

AbstractIn the face of increasing environmental temperatures, operative differences between mitochondrial function and whole-animal phenotypic response to the environment are underrepresented in research, especially in subtemperate ectothermic vertebrates. A novel approach to exploring this connection is to examine model species that are genetically similar but that have different whole-animal phenotypes, each of which inhabits different environments. The blind Mexican cavefish (Astyanax mexicanus) has the following two morphotypes: a surface form found in aboveground rivers and an obligate cave-dwelling form. Each morphotype inhabits vastly different thermal and oxygen environments. Whole-animal and mitochondrial responses to thermal acclimation and oxidative stress, with respect to increasing temperatures, have not been previously determined in either morphotype of this species. Here, we chronically acclimated both morphotypes to three temperatures (14°C, 25°C, and 31°C) to establish potential for acclimation and critical thermal maxima (CTmax) for each morphotype of this species. After measuring CTmax in six cohorts, we additionally measured enzymatic antioxidant capacity (catalase, superoxide dismutase, and glutathione peroxidase activities), peroxyl scavenging capacity, and lipid peroxidation damage in white epaxial muscle for each individual. We found a significant effect of acclimation temperature on CTmax (, ) but no effect of morphotype on CTmax (, ). Additionally, we found that morphotype had a significant effect on glutathione peroxidase activity, with the surface morphotype having increased glutathione peroxidase activity compared with the cave morphotype (, ). No other oxidative stress variable demonstrated significant differences. Increases in CTmax with chronic thermal acclimation to higher temperatures suggests that there is some degree of phenotypic plasticity in this species that nominally occupies thermally stable environments. The decreased glutathione peroxidase activity in the cave morphotype may be related to decreased environmental oxygen concentration and decreased metabolic rate in this environmentally constrained morphotype compared to in its surface-living counterparts.

Performance Investigation on a Double-Slope Passive Solar Desalination System Targeting towards Sustainable Development of Oman

In recent times, academicians and scientists have developed many methods for purifying saline water into pure water that is suitable for drinking, as well as other suitable applications. Fortunately, solar desalination has been a very popular technique, which uses eco-friendly solar energy. In this work, a passive-type double-slope solar still was designed and fabricated according to the Global Positioning System (GPS) coordinates of Nizwa city in Oman. Economically and readily available materials, such as acrylic, glass, and foam insulation materials, were used in the construction of the double-slope solar still in addition to the conventional materials used for the supporting structure of the solar still. The climatic factors (such as the solar radiation and ambient temperature), design factors (such as the exposure surface area, inclination, insulation material and thickness, and glazing material), and operating parameters (such as the glass temperature, feed water temperature and yield) obtained were considered in the study to estimate the performance of the solar still. DHT 11 sensors with Arduino programming were used in the experiment to record the temperatures at specific locations on the solar still daily with regular time intervals for a period of 3 to 4 weeks. The solar still was designed to operate from February to March 2023. The temperatures were recorded every two hours daily, whereas the yield was recorded at the end of the day of operation. The quality of the yield was estimated through the measurement of pH and TDS (Total Dissolved Solids) values. The energy and exergy analysis of the desalination unit was carried out to estimate the thermal performance of the system. A significant effect of solar intensity and ambient temperature was observed on the thermal performance of the system and on the quality of the drinking water. An energy efficiency ranging between 30 to 45% and exergy efficiency ranging between 2 to 3.5% was obtained in the system, which was reasonably better for a thermal system involving a renewable source of energy.

Mechanical behavior and optimization of constitutive prediction model for Epoxy/Al energetic composite materials considering temperature and strain rate effects

Epoxy/Al as a functional structural energetic composite material that can be used as an adhesive, energetic fragments and warhead shells due to its high energy density, low density, and high strength. It can release a large amount of chemical energy (about 21.36 kJ/g) through chemical reactions when subjected to high-speed impact and thermal stimulation. Whether used as a matrix or auxiliary component, it has enormous development potential. Therefore, it is particularly important to study the mechanical properties of Epoxy/Al energetic composite materials under different temperature environments and strain rates of loading. This article describes the preparation of Epoxy/Al specimens with a mass percentage of 70%–30% using vacuum curing after 24 h under 0.8 Bar and 50 °C. The mechanical properties of Epoxy/Al specimens under different loading conditions were characterized using a high and low temperature universal testing machine and a separate Hopkinson experimental system. The modulus prediction method of binary composite materials was improved by combining SEM (scanning electron microscopy) and microstructure, and an adaptive constitutive model was developed combined with the K Srinivas model and neural network model based on the Sherwood Frost empirical constitutive relationship. The results show that Epoxy/Al energetic composite material has a significant temperature effect. When the temperature exceeds 100 °C, Epoxy/Al energetic composite material will be a significant physical and chemical property transition (the specimen exhibits viscous fluid characteristics and gradually begins to slowly decompose). As the temperature decreases, the specimen gradually exhibits a certain degree of brittleness and strength is improved. Due to the deformation, displacement, and interfacial debonding of internal particles during the loading process, Epoxy/Al materials exhibit excellent impact energy absorption effects, with energy absorption reaching 15.30 MJ/m3 at room temperature, and unit mass cost much lower than popular CFRP (carbon fiber-reinforced polymer) materials (CFRP energy absorption cost is 0.268 J/g/£, while Epoxy/Al materials do not exceed 0.013 J/g/£). During the dynamic loading process, Epoxy/Al energetic composite materials exhibit a phenomenon of structural reconstruction and enhancement throughout the entire loading process. The maximum strength at room temperature can reach 240.70 MPa, which is superior to all existing energetic materials of the same type. By introducing interface effects and quantifying them in the Halpin Tsai model, the existing prediction method for the Young's modulus of binary particle added composite materials has been effectively improved, reducing the prediction error of the Young's modulus of Epoxy/Al energetic composite materials from 14.2% to 2.4%. The numerical simulation results indicate that the newly developed constitutive model has high accuracy and can better reflect the mechanical properties of Epoxy/Al materials. The development method of this constitutive model has a positive contribution to the development of composite materials.

The Plutonium Temperature Effect Program

Various theoretical studies have shown that highly diluted plutonium solutions could have a positive temperature effect, but up to now, no experimental program has confirmed this effect. The French Plutonium Temperature Effect Experimental Program (or PU+ in short) aims to effectively show that such a positive temperature effect exists for diluted plutonium solutions. The PU+ experiments were conducted in the “Apparatus B” facility at the CEA VALDUC research center in France. It involved several sub-critical approach-type experiments using plutonium nitrate solutions with concentrations of 14.3, 15, and 20 g/L at temperatures ranging from 20 to 40 °C. Fourteen (five at 20 g/L, four at 15 g/L, and five at 14.3 g/L) phase I experiments (consisting of independent sub-critical approaches) were performed between 2006 and 2007. The impact of the uncertainties on solution acidity and plutonium concentration made it difficult to demonstrate the positive temperature effect, requiring an additional phase II experiment (with a unique plutonium solution) from 22 to 28 °C that was performed in July 2007. This phase II experiment has shown the existence of a positive temperature effect of ~+5.17 pcm/°C (from 22 to 28 °C for a plutonium concentration of 14.3 g/L). It has recently been possible to confirm the results of this program with MORET 5 calculations by generating thermal scattering data S(α,β) at the correct experimental temperatures. This paper finally presents a fully documented experimental program highlighting the Plutonium Temperature Effect theoretically described in the literature. Its high level of precision and its “one-step” approach to criticality allowed it to show a significant positive temperature effect for a rather small variation of temperature (+6 °C). The order of magnitude of the effect was confirmed with Monte Carlo calculations using thermal scattering data for hydrogen in the solution produced by IRSN for the purpose of the comparison.

Effect of thermal treatment of chromium iron melts on the structure and properties of castings

The article describes the results of experimental studies for the effect of thermal treatment (TTM) of G-X300CrMo27-1 high-chromium cast iron samples in the solid–liquid and liquid state on the structure, phase composition, and properties of ingots. For ingots with a carbon content of 2.8 to 4.5 wt%, cooled at a rate of 3.3 * 10−2 deg s−1, the dependencies of the structure, phase composition, composition of primary, eutectic carbides and matrix, hardness HV and microhardness of its individual phases and resistance to abrasive wear from the temperature of isothermal holding at TTM. A significant effect of the TTM temperature of melts on the structure and properties of high-chromium cast iron ingots was detected. The temperatures of inflection on the plotted curves for the characteristics of the structure and properties of the ingots were associated with a phase transition in iron at 1400 °C and with a point on the phase diagram liquidus of the Fe-Cr system. This as well as an increase in the concentration of chromium in the composition of primary carbides with an increase in the TTM temperature up to 1480 °C, made it possible to assume that (Cr, Fe)7C3 clusters stable in composition were formed in the melt of such cast irons below ∼1500 °C. The reasons for the decrease in the size of primary carbides during G-X300CrMo27-1 molten chromium iron overheating above 1500 °C were substantiated based on these data. During the TTM of fine-crystalline ingots made of hypereutectic cast iron in the temperature range between the liquidus and solidus lines, it was detected that the primary carbides (Cr, Fe)7C3 recrystallized resulting in a significant decrease in the chromium content and an increase in the iron content in them. At the same time, their sizes did not change significantly. Their share increased, and the share of eutectic carbides decreased. Such a process also had a significant impact on the properties of the resulting ingots. The most preferable temperatures of hot metal cast irons in the liquid and solid–liquid states were identified based on the results of the studies.

Finite element modeling of early-age temperature development of in-situ concrete under variable ambient temperatures

The early-age temperature rises in in-situ concrete, caused by the exothermic hydration of cement, poses a significant risk of thermal cracking in concrete structures. This issue is particularly critical in large-scale structures, where thermal cracking can lead to serious structural integrity issues. Therefore, the accurate prediction of the concrete hydration temperature development is paramount for predicting and mitigating early thermal cracking in concrete. However, one of the main challenges in predicting in-situ concrete temperatures is the significant effect of variable ambient temperature on cement hydration rates and concrete heat dissipation. To address this challenge, this paper presents a finite element modeling (FEM) approach that accurately predicts the early-age temperature development of in-situ concrete by adequately considering the effect of variable ambient temperatures. The model integrates the heat of hydration of the cement, the impact of ambient temperature variations, and the heat transfer through the concrete and insulation mould. The cement hydration rate under real-life ambient temperatures is simulated using an Arrhenius-based method, which mathematically adjusts the isothermal calorimetry curves to reflect the actual conditions. Additionally, the study investigates the inhibitory effect of Ground Granulated Blast-furnace Slag (GGBS) on the early hydration temperature of concrete, with experimental tests and FEM simulations conducted on concrete mixes where up to 70% of the cement was replaced with GGBS. The validity of the FEM model was confirmed through comparison with concrete semi-adiabatic tests, demonstrating that the model provides accurate predictions of the temperature development of in-situ concrete. Importantly, the results indicate that the adjusted isothermal calorimetry curves successfully capture the ambient temperature effect on the cement hydration rate. The results provide valuable insights for the design of concrete structures, particularly in preventing early-age thermal cracking.

Influence of the Bed Temperature on the Operational Reliability of a Hybrid Constructed Wetland Wastewater Treatment Plant in South-Western Poland—A Case Study

The aim of this study was to assess the influence of atmospheric air temperature on the efficiency and reliability of pollutants removal from wastewater. The studied facility was a hybrid constructed wetland wastewater treatment plant with vertical and horizontal flow serving a single-family building in the village of Krajanów in south-western Poland. The operation of the facility was evaluated on the basis of studies conducted in 2021–2022. The tests included a physico–chemical analysis of wastewater treated mechanically in a settling tank and effluents from constructed wetland beds with the vertical and horizontal flow. The following parameters were determined: BOD5, COD, total suspended solids, total nitrogen, and total phosphorus. No statistically significant effect of air temperature on the analyzed pollutants removal levels was found. The temperature in the soil–plant bed never fell below 0 °C, and so the wastewater flowing through the beds never froze. The discussed facility was characterized by high efficiency and reliability of the tested pollutants removal across the seasons. The mean concentrations of pollutants in treated wastewater did not exceed the limit values specified in the currently binding legal act. It was shown that hybrid constructed wetlands can be successfully used for wastewater treatment in the climatic conditions of southern Poland.

Theoretical Analysis Of The Photon Production Rate in the Quark-Gluon Interaction According To The Quantum Cromodynamic QCD Theory

In this work, we have used the QCD dynamic scenario of the quark gluon interaction to investigate and study photon emission theoretically based on quantum theory. The QCD theory is implemented by deriving the photon emission rate equation of the state of ideal QGP at a chemical potential. The photon rate of the quark-gluon interaction has to be calculated for the anti up-gluon interaction in the g → γ system at the temperature of system with critical temperature ( 132.38, , and 198.57) MeV and photon energy ( GeV. We investigated a significant effect of critical temperature, strength coupling, and photon energy on the photon rate contribution. Here, the increased photon emission rate and decreased strength coupling of the quark-gluon reaction due to the decrease in temperature of the system from 360 MeV to 180 MeV are predicted. Photon energy in the range (1 to 10) GeV and the rate spectrum of four varieties of critical temperatures are presented. The interesting point in our results is the minimum value of photon rate, especially in the photon energy E=10 GeV of flavor which reflects the poor coupling between quark and gluon in the the g → γ system which was already expected. The features of QCD results are achieved in the case of flavors for the photon energy E=1 to 10 GeV, the strength coupling and the photo meason rate are calculated theoretically. We can notice that the asymptotic behavior, which was characterized by a hadronic phase limit, will be satisfied.