Normal Temperature Conditions Research Articles

Frictional Slip and Incremental Dynamic Analysis of Plate-rubber Bearing Continuous Girder Bridge by Ambient Temperature in Cold Region

Special mechanical environment, the environmental temperature or stress transformation easily to the final mechanical properties of the bridge components performance changes. The impact of the cold zone environment on the plate rubber-bearing beams is the object of study, Jining Road refined mechanics finite element analysis of the structural dynamic response study under seismic action. The results show that low temperature leads to bearing friction slip and material parameter changes, which affects the self-oscillation frequency and seismic susceptibility of the bridge. Due to the temperature-induced changes in the material properties and mechanical properties of the bearings, the first principal period of the bridge increases by 3% at high temperature for the EH and decreases by 19% at low temperature for the EL when compared to the first principal period under normal temperature conditions. Under different extreme temperature conditions, the fundamental period of the bridge is longitudinal, and the effective mode vibration participation mass is more than 90%. The maximum crossover frequency VALmax reaches 75.6 dB. Compared with room temperature, the bearing stress increased by 27.6% to 45.5%. The effect of EL stress change should be considered in the design of bridges in the alpine region.

Gangue grouting filling in subsequent space of coal green mining: methodology and case study

Underground backfilling stands out as a crucial technological strategy for the eco-friendly and effective management of solid waste in mining operations. However, existing backfilling techniques have led to increased production processes at the working face, resulting in a reduction in coal extraction efficiency. Addressing the temporal and spatial interference between mine solid waste backfilling and coal mining is essential. To overcome this challenge, this study introduces a novel post-mining spatial gangue slurry backfilling method. Radar detection was employed to ascertain the typical characteristics of the subsequent space collapse roof shape. Stress monitoring and compaction experiments were conducted to establish the relationship between stress and the bulking coefficient of the overlying rock mass, identifying subsequent spatial void structure characteristics. The development of a CO2 mineralized coal-based solid waste filling material, utilizing conventional low-calcium fly ash under normal temperature and pressure conditions, was presented. This paper provides a comprehensive understanding of the post-mining spatial gangue slurry backfilling method, outlines the spatial layout approach for the corresponding system, and analyzes research challenges associated with gangue slurry backfilling materials and the technology of slurry injection borehole layout. The research aims to innovate an efficient underground disposal model for gangue, contributing to the refinement of the technical system for the comprehensive disposal and utilization of gangue.

Rheological Properties and Segregation of Fresh UHPC with Fibers Affected by Initial Temperature of Concrete Mix

Within the framework of the project GAČR 21-24070S Model of fibre segregation in dependence on rheological properties of fresh HPC, the rheological properties and fibre segregation in fresh concrete mix depending on temperature changes have been verified. The rheological properties and fibre segregation have been verified under three temperature conditions (very low temperatures around 5 °C, normal temperature conditions around 20 °C and high temperatures above 30 °C). Comparison of the properties of UHPC with fibres at different temperature conditions has been performed on fresh mixtures mainly by spill tests. Subsequently, hardened test bodies, i.e. 40/40/160 beams, were verified in tensile bending and compression in all cases. The actual fibre segregation within the individual samples has also been verified by microscopic analysis. Different temperature conditions have been simulated by heating or cooling the input raw materials. The results have been compared by degree of changes in rheological properties and mechanical parameters.

Fabrication and Mechanical Evaluation of Eco-Friendly Geopolymeric Mortars Derived from Ignimbrite and Demolition Waste from the Construction Industry in Peru

Ignimbrite rock is a volcanic material located in the Arequipa region (Peru), and for centuries, it has been used as a construction material, giving a characteristic light pastel, white to pink color to the city of Arequipa, with white being the most common. In the present study, the potential use of three types of Arequipa raw materials (ignimbrite rock powder, calcined clay powder, and demolition mortar powder) as the main source of new binders or the manufacture of environmentally friendly mortars, without the addition of ordinary Portland cement (OPC) is discussed. In this work, an in-depth characterization of the materials used was carried out. The proposed fabrication route for geopolymeric materials was considered for the manufacture of binders and mortars using an alkaline solution of NaOH with values between 12 and 18 molar, as a trigger for the geopolymerization process. Geopolymeric mortars were obtained by adding a controlled amount of fine sand to the previously prepared mixture of binder raw material and an alkaline solution. Conventional OPC and geopolymeric mortars manufactured under the same conditions were mechanically evaluated by uniaxial compression tests at a constant compression rate of 0.05 mm/min and under normal conditions of temperature and atmosphere, where the most optimal values were obtained for 15 molar alkaline solutions of ignimbrite without the addition of aggregates, with values of compressive strength of 42 MPa and a modulus elastic of 30 GPa. The results revealed a significant increase in the maximum strength and modulus of elasticity values when the volumetric fractions of OPC are completely replaced with geopolymeric binders in the study conditions of this work, demonstrating the enormous potential of the ignimbrite rock and construction waste studied, as raw material of alternative mortar binders without the addition of OPC. With this work, the ignimbrite rock, of great value in the region and also found in other areas of the Earth’s geography, was characterized and valued, in addition to the calcined clay and demolition mortar of the region.

Transcription and splicing variations of SR genes accompany with genome-wide accumulation of long-introns in pine

Most of mRNAs in Eukaryote were matured after the removal of introns in their pre-mRNA transcripts. Serine/arginine-rich (SR) proteins are a group of splicing regulators regulating the splicing processes globally. Expressions of SR proteins themselves were extensively regulated, at both transcription and splicing levels, under different environmental conditions, specially heat stress conditions. The pine genome is characterized by super-long and easily methylated introns in a large number of genes that derived from the extensive accumulation of transposons (TEs). Here, we identified and analyzed the phylogenetic characteristics of 24 SR proteins and their encoding genes from the pine genome. Then we explored transcription and pre-mRNA splicing expression patterns of SR genes in P. massoniana seedlings under normal and heat stress temperature conditions. Our results showed that the transcription patterns of SR genes in pine exhibited significant changes compared to other plant species, and these changes were not strictly correlated with the intron length and DNA methylation intensity of the SR genes. Interestingly, none of the long introns of SR genes underwent alternative splicing (AS) in our experiment. Furthermore, the intensity of AS regulation may be related to the potential DNA methylation intensity of SR genes. Taken together, this study explores for the first time the characteristics of significant variations in the transcription and splicing patterns of SR proteins in a plant species with an over-accumulation of super-long introns.

A Multi-step High-Performance Liquid Chromatography (HPLC) Technique for the Extraction and Purification of Medical-Grade Cyclosporine A

Cyclosporine A (CsA), a potent immunosuppressive drug, is used to treat autoimmune diseases and prevent organ transplant recipients from rejecting their new organs. Maintaining CsA's uniformity and purity is essential to maintaining its therapeutic efficacy and safety. Impurities and contaminants in CsA formulations can exacerbate side effects and patient toxicity. Purification processes can improve the safety profile of the drug and reduce the likelihood of adverse effects by eliminating impurities. Using High-performance liquid chromatography (HPLC) methods, CsA has been isolated and refined from crude in recent years. However, after the procedure, the CsA purity was not at its best. To solve this issue, this work employs a multi-step HPLC method to increase purity levels to above 95%. When exploring the HPLC detection conditions of CsA, we found that the method from the Chinese pharmacopoeia: acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) was a better mobile phase solution, our further research, including the substitution of tert-butyl methyl ether with other buffer solvents, showed no significant improvement. At the same time, we established that the key factor affecting its separation was temperature. When the temperature is lower than 70 ℃, the HPLC separation effect worsens, the retention time increases, and the peak width becomes longer. Finally, the utilization of acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) as the mobile phase with a column temperature of 70 °C, petroleum ether: acetic acid Ethyl ester (70 : 30) as the mobile phase, and filling the φ 40 mm × 500 mm chromatography column using a 40~60 μm silica gel so that a 10 : 1 height-to-diameter ratio of the packed part is obtained, under normal temperature conditions, resulted in an average cyclosporine A yield of 80.1%. The corresponding average purity was 97.2%, of which the first isolation yield was 82.3%, and the purity was 98.1%.

Revisiting Dimorphs of 4-n-octyloxybenzoic Acid: Contrasting Mechanical Property and Surface Wettability.

4-n-octyloxy benzoic acid is known to exhibit liquid crystalline properties, and under normal pressure and temperature conditions, it exists as at least two crystalline polymorphs. We revisited the system and discovered that single crystals of one of the polymorphs display plastic deformation, whereas the other is brittle. n-octyl chains are arranged in an end-to-end fashion, forming slip planes in the plastically deformable polymorph, whereas they are interdigitated in the crystal structure of the brittle polymorph. Due to the difference in the arrangement of the -COOH group and alkyl chains, the major faces of the crystals of both polymorphs possess significant differences in the wettability towards moisture.

Environment effect on mechanical parameters of soil-mixing

Soil improvement is originally an economical solution to make soil buildable, particularly compared to deep foundation methods using piles. The object of this research is the understanding of the behavior of soil-mixing material, in particular, what concerns the effect of environmental parameters, whether: temperature, water table level, chemical attacks, the phenomenon of aging etc. on the mechanical and physical characteristics (resistance to simple compression, resistance to simple bending, modulus of elasticity, porosity, density, etc.), of a soil-mixing column, in the short term and long term. The big problem is how to carry out experiments in the laboratory, which will be representative of the different phenomena that take place on a real scale (on site). To do this, our approach consists of studying different soil-mixing mixtures composed of «artificial» soils (clay and sand) and a CEM III/C cement, and with a variable W/C ratio. After making the test pieces, with the different dosages of cements and a ratio between clay and fixed sand, they were kept under normal temperature conditions, in order to reach a maturation age (180 days), to be able to begin the series of experiments. Once the specimens were subjected to the aging test, let’s begin to crush them with simple compression and simple bending. The parametric study highlights a percentage of clay beyond of which the resistance decreases and the rigidity of the material can pose a problem for certain structural uses. The different results obtained show that for a low cement dosage, the humidification-drying cycle influences both the resistance to simple compression and to bending simple, as well as the number of cycles affects the resistance values significantly. On the other hand, for a greater or lesser dosage of cement, the resistance values are not affected. Based on the results obtained, it is possible to conclude that the choice of cement dosage depending on the nature of the soil influences the soil-mixing column and plays an important role on the lifespan of the column; therefore, it is necessary to give primary importance to the choice of cement dosage depending on the nature of the soil treated.

Optimizing intracranial electric field distribution through temperature-driven scalp conductivity adjustments in transcranial electrical stimulation

Transcranial electrical stimulation (TES) is a promising non-invasive neuromodulation technique. How to increase the current intensity entering the skull and reduce scalp shunting has become a key factor significantly influencing regulatory efficacy. In this study, we introduce a novel approach for optimizing TES by adjusting local scalp temperature to modulate scalp conductivity. We have developed simulation models for TES-induced electric fields and for temperature-induced alterations in scalp conductivity. Two common types of stimulation montage (M1-SO and 4 × 1 montage) were adopted for the evaluation of effectiveness. We observed that the modulation of scalp temperature has a significant impact on the distribution of the electric field within the brain during TES. As local scalp temperature decreases, there is an increase in the maximum electric field intensity within the target area, with the maximum change reaching 18.3%, when compared to the electric field distribution observed under normal scalp temperature conditions. Our study provide insights into the practical implementation challenges and future directions for this innovative methodology.

Research on Multi-point Measurement System of Mine Gas Based on TDLA

Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology combines the advantages of wavelength modulation technology and direct absorption spectroscopy technology, and the system achieves highly sensitive and full-range detection of methane gas concentrations. In the system, only the pure optical methane probe is positioned under the mine, which establishes connectivity with the host computer on the surface through the optical fiber. This setup enables the simultaneous detection of 16 channels of methane gas through time-sharing multiplexing technology. Experimental results demonstrate a measurement error of less than ±6.0×10−4 at low concentrations (0∼1%) and within ±6% of the true value at high concentrations under normal temperature and pressure conditions. The full-range linear fit attains 0.9998. According to the one-fold standard deviation, the minimum detection lower limit of the system stands at 68.36 ppm and the measured gas concentrations across different channels of the methane probes remain consistent inhe same environment. This technology provides a new solution for continuous, accurate, and multi-point monitoring of mine gas.

Genetics of biochemical attributes regulating morpho-physiology of upland cotton under high temperature conditions

BackgroundCotton is a strategically important fibre crop for global textile industry. It profoundly impacts several countries' industrial and agricultural sectors. Sustainable cotton production is continuously threatened by the unpredictable changes in climate, specifically high temperatures. Breeding heat-tolerant, high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes. Therefore, the main objective of the current study is to figure out the effective breeding approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding. Initially, the two most notable heat-susceptible (FH-115 and NIAB Kiran) and tolerant (IUB-13 and GH-Mubarak) cotton cultivars were spotted to develop filial and backcross populations to accomplish the preceding study objectives. The heat tolerant cultivars were screened on the basis of various morphological (seed cotton yield per plant, ginning turnout percentage), physiological (pollen viability, cell membrane thermostability) and biochemical (peroxidase activity, proline content, hydrogen peroxide content) parameters.ResultsThe results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait, as revealed by the ability of crossing and their backcross populations to tolerate high temperatures. However, when considering overall yield, biochemical, and physiological traits, the IUB-13 × FH-115 cross went over particularly well at both normal and high temperature conditions. Moreover, overall seed cotton yield per plant exhibited a positive correlation with both pollen viability and antioxidant levels (POD activity and proline content).ConclusionsSelection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms. Therefore, understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.

Observation of Excess Air Discharge in the Budikdamber Pond Aeration System on the Real Effect of Tilapia Fish Health (Oreochromis spp.)

DO levels are needed by fish organisms for metabolic processes, so the value changes quickly. So, giving aeration all the time and siphonization every day is the best treatment in maintaining water quality for growth. However, a study revealed that there is a negative side to excessive aeration until it reaches a saturation point. The results of the study on the process and level of exposure related to gas bubble disease caused by hyperoxia. The first symptom is the presence of gas bubbles under the skin, gas bubbles appear on most of the fins, along the lateral line, gills and in the eyes. Currently, another research is being conducted to prove the real effect of excess aeration, specifically on the health of Tilapia in closed ponds at normal ambient temperatures. In the closed water pond system, air flow is given at 25 mg/L (first pool), 40 mg/L (second pool), and 54 mg/L (third pool), with variable treatment of feed, water quality (temperature & pH). , and the same volume. The focus of the type of fish that will be observed in this research is Tilapia, with a duration of observation for ± 1 month. The maximum DO measurement results at a normal ambient temperature of 25.6 °C pool water is 8.2 mg/L. The optimum DO level in the first pond that is aerated with an air flow of 25 L/m is ± 7.9 mg/L, the optimum DO level in an aerated pond with an air flow of 40 L/m is ± 8.1 mg/L, and the optimum DO level in an aerated pond with an air flow rate of 54 L/m is ± 8.1 mg/L. No matter how big the air flow from the aerator is put into the water, the DO level will not exceed the value of 8.2 mg/L as long as the water temperature is not lower than 25 °C. Tilapia in ponds containing the highest DO levels at normal ambient temperature conditions of this pond water (24.4 – 25.9 °C), grows and develops very well, in fact there is no adverse effect on health.

The Molecular Mechanism of Relatively Low-Temperature-Induced Broccoli Flower Bud Differentiation Revealed by Transcriptomic Profiling

Broccoli (Brassica oleracea L. var. italica) has a large, edible green flower head, which is one of its critical economic traits. A prerequisite of broccoli flower head formation is flower bud differentiation (FBD). Low-temperature treatment is an effective way to induce FBD in broccoli. However, the molecular mechanism underlying low-temperature-induced broccoli FBD remains largely unclear. In this study, using broccoli cultivar Zhongqing 10 as the experimental material, we investigated the effects of low-temperature treatment on FBD by comparing the plants grown at low temperatures (17 °C/9 °C, 16 h/8 h) with the control plants grown under normal temperature conditions (25 °C/17 °C, 16 h/8 h). After 15 days of different temperature treatments, the flower buds of the plants growing under the low-temperature condition started to differentiate. However, the control plants remained in the vegetative growth stage, indicating that low temperature successfully induced flower bud formation. Subsequently, a global transcriptomic analysis was conducted to detect the differentially expressed genes (DEGs) during low-temperature-induced FBD in broccoli. A total of 14 DEGs in five phytohormone signaling pathways, 42 DEGs in nine transcription factor families, and 16 DEGs associated with the floral development pathways were identified. More DEGs were present in the auxin signaling pathway than in other phytohormone signaling pathways, which indicated that the auxin signaling pathway played a critical role in modulating low-temperature-induced FBD in broccoli. Furthermore, four TF classes, including bZIP, GCM domain factors, MADS-box factors, and C2H2 zinc finger factors, possessed enriched motifs, indicating that their closely related DETFs ABI5, HY5L, WRKY11, WRKY15, WRKY22, SOC1, AGL8, FLC, SPL8, and SPL15 may be directly involved in the transcription regulation of broccoli FBD. This study provides an important basis for further investigation of the molecular regulatory mechanism of broccoli flower development under low temperatures.

Theoretical Justification of Structural, Magnetoelectronic and Optical Properties in QFeO3 (Q = Bi, P, Sb): A First-Principles Study.

One of the primary objectives of scientific research is to create state-of-the-art multiferroic (MF) materials that exhibit interconnected properties, such as piezoelectricity, magnetoelectricity, and magnetostriction, and remain functional under normal ambient temperature conditions. In this study, we employed first-principles calculations to investigate how changing pnictogen elements affect the structural, electronic, magnetic, and optical characteristics of QFeO3 (Q = Bi, P, SB). Electronic band structures reveal that BiFeO3 is a semiconductor compound; however, PFeO3 and SbFeO3 are metallic. The studied compounds are promising for spintronics, as they exhibit excellent magnetic properties. The calculated magnetic moments decreased as we replaced Bi with SB and P in BiFeO3. A red shift in the values of ε2(ω) was evident from the presented spectra as we substituted Bi with Sb and P in BiFeO3. QFeO3 (Q = Bi, P, SB) showed the maximum absorption of incident photons in the visible region. The results obtained from calculating the optical parameters suggest that these materials have a strong potential to be used in photovoltaic applications.

Degradation of Azo Dye Solutions by a Nanocrystalline Fe-Based Alloy and the Adsorption of Their By-Products by Cork.

In this study, the efficiency of mechanically alloyed Fe80Si10B10 in degrading basic red 46 azo dye is investigated. Moreover, the influences of different parameters, such as pH and time, on the elimination of the aromatic derivatives obtained as by-products of the fracture of the azo group are also analyzed. After beginning the reduction to the normal conditions of pH (4.6) and temperature, the experimental findings showed a discoloration of 97.87% after 20 min. The structure and morphology of the nanocrystalline Fe80Si10B10 powder were characterized by SEM and XRD before and after use in the degradation process. The XRD patterns of the Fe-Si-B powder after redox reaction suggest that the valent zero Fe of the alloy is the reducing agent. Powdered cork was then used as a biosorbent for the removal of the by-products generated, resulting in increasing removal percentages from pH 7 (26%) to pH 9 (62%) and a contact time of 120 min. The FTIR spectrum of the cork after adsorption shows a shift of the bands, confirming the interaction with the aromatic amines. The present findings show that metallic powders and natural cork perform well together in removing azo dye solutions and their degradation products.

The Effect of Low Temperature on Laying Performance and Physiological Stress Responses in Laying Hens.

The present study investigated the effect of low temperature on laying performance, egg quality, body temperature, yolk malondialdehyde, yolk corticosterone, and serum biochemistry in laying hens. A total of 40 laying hens (Hy-Line Brown) aged 36 weeks were housed in one of two environmental chambers kept at 12 ± 4.5 °C (low temperature) or 24 ± 3 °C (normal temperature) for 4 weeks. Low vs. normal temperature significantly increased (p < 0.05) live body weight, feed intake, and feed conversion ratio in laying hens. Skin surface temperature, but not rectal temperature, was decreased in laying hens exposed to low vs. normal temperature. Hens exposed to low temperature laid an intense eggshell color compared with those raised in a normal temperature. Malondialdehyde concentrations in yolk were increased in low-temperature-exposed laying hens compared with those at normal temperature conditions, but this effect was only noted on day 7, post the low-temperature exposure (p = 0.04). Finally, low vs. normal temperature increased the concentrations of total cholesterol and triglyceride in serum. Collectively, this study indicates that exposure to low temperature in laying hens initially disrupted antioxidant system and altered lipid metabolism in laying hens without inducing stress responses.

Elucidation of the Mechanism of Rapid Growth Recovery in Rice Seedlings after Exposure to Low-Temperature Low-Light Stress: Analysis of Rice Root Transcriptome, Metabolome, and Physiology.

Late spring cold is a disastrous weather condition that often affects early rice seedlings in southern China, limiting the promotion of direct seeding cultivation. However, there are few reports on the effect of these events and on the growth recovery mechanism of rice root systems after rice seedlings are exposed to this stress. This study selected the strong-growth-recovery variety B116 (R310/R974, F17) and the slow-recovery variety B811 (Zhonghui 286) for direct seeding cultivation and exposed them to low temperature and low-light stress to simulate a late spring cold event in an artificial climate chamber. The treatment consisted of 4 days of exposure to a day/night temperature of 14/10 °C and a light intensity of 266 µmol m-2s-1 while the control group was kept at a day/night temperature of 27/25 °C and light intensity of 533 µmol m-2s-1. The results showed that 6 days after stress, the total length, surface area, and volume of B116 roots increased by 335.5%, 290.1%, and 298.5%, respectively, while those of B811 increased by 228.8%, 262.0%, and 289.1%, respectively. In B116, the increase in root fresh weight was 223.1%, and that in B811 was 165.6%, demonstrating rapid root recovery after stress and significant differences among genotypes. The content of H2O2 and MDA in the B116 roots decreased faster than that in the B811 roots after normal light intensity and temperature conditions were restored, and the activity of ROS metabolism enzymes was stronger in B116 roots than in B811 roots. The correlation analysis between the transcriptome and metabolome showed that endogenous signal transduction and starch and sucrose metabolism were the main metabolic pathways affecting the rapid growth of rice seedling roots after exposure to combined stress from low temperature and low light intensities. The levels of auxin and sucrose in the roots of the strong-recovery variety B116 were higher, and this variety's metabolism was downregulated significantly faster than that of B811. The auxin response factor and sucrose synthesis-related genes SPS1 and SUS4 were significantly upregulated. This study contributes to an understanding of the rapid growth recovery mechanism in rice after exposure to combined stress from low-temperature and low-light conditions.

Dimensionless analysis of flow and heat transfer characteristics in a high-speed rotor–stator disk cavity based on similarity criteria

Turbine disk cavity system is of great importance for improving the rotating turbine blades cooling efficiency and preventing gas invasion. This study focuses on turbine disk cavity characteristics at high-speed rotational conditions due to complicated flow and heat transfer mechanisms. Then, a novelty method is proposed to reveal multiple similarity criterion numbers of rotor–stator disk cavity between actual engine and experimental case conditions, based on the dimensionless analysis. Especially, a new evaluation standard including the dimensionless adiabatic wall temperature and dimensionless heat flux is put forward and proved to be equally important with the Nusselt number. Results show that the dimensionless heat flux in the turbine disk cavity mainly depends on Reynolds number and Mach number, while the dimensionless adiabatic wall temperature is dominated only by the same Mach number. When only Reynolds numbers or Mach numbers are considered, the relative error can reach 14.5% on the similarity of dimensionless heat flux. Noteworthily, the effect of thermal boundary of turbine disk cavity should not be ignored in the rotor–stator disk cavity, which will bring 28.8% deviation to the similarity of the Nusselt number. Therefore, this study can provide a theoretical method and engineering application to obtain flow and heat transfer characteristics of actual engine turbine disk cavity under experiment case with normal temperature conditions.

Enhanced Electrochemical and Safety Performance of Electrocatalytic Synthesis of NH3 with Walnut Shell-Derived Carbon by Introducing Sulfur

An efficient catalyst is key to achieving the synthesis of electrochemical ammonia and improving safety. In this work, using biomass walnut shell as a carbon source and sodium thiosulfate as a sulfur source, sulfur-modified walnut shell-derived carbon material was synthesized via a simple low-temperature impregnation method at room temperature and atmospheric pressure as an effective electrochemical ammonia synthesis catalyst with high thermal stability. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption–desorption apparatus, thermogravimetry (TG), and other characterization methods were applied to analyze the micro-morphology and physicochemical structure of the electrocatalyst. The synthesized ammonia performance of the catalyst was measured using an ultraviolet (UV) spectrophotometer and electrochemical workstation. The catalyst design used the doping of sulfur atoms to create rich catalytic active sites, while the presence of elemental sulfur on the catalyst surface provided hydrophobicity, which was conducive to inhibiting competitive hydrogen evolution reaction (HER) and enhancing the electrocatalytic ammonia synthesis performance of the catalyst. Under normal temperature and pressure conditions, when a voltage of −0.45 V was applied, the ammonia yield in 0.05 M H2SO4 electrolyte was 10.39 μgNH3 mgcat.−1 h−1. The results showed that the introduction of sulfur effectively improved the electrocatalytic and thermal safety performance of bio-derived carbon materials, and the test presented that the performance of the catalyst was stable and reusable.

A novel solar system for photothermal-assisted electrocatalytic nitrate reduction reaction to ammonia

The traditional Haber-Bosch process for ammonia synthesis is plagued by high energy consumption and significant CO2 emissions, leading to a noticeable environmental impact. As a promising solution, solar photovoltaic electrocatalytic synthesis of ammonia has garnered significant attention. This study designed an electrocatalytic nitrite reduction system for ammonia production that employs solar photothermal-assisted and investigate the effects of different photovoltaic power supply voltage, heating temperatures, and flow velocities. The results demonstrate. the maximum ammonia production performance was achieved at 1.3 V under normal temperature conditions, resulting in a maximum current density and ammonia production rate of 26 mA cm−2 and 1422.4 μg, respectively. Upon heating to 40 °C, the maximum average current density of the system is 40 mA cm−2, and ammonia production is 2293 μg, representing 53.8 % and 61.2 % increasing in comparison to ambient temperatures. Although elevating the temperature to 60 °C led to increased average current density and ammonia production, the system's stability decreased to certain extent. Cyclic electrolysis conducted at 1.1 V and 40 °C for an hour revealed that ammonia production is 553.2 μg, 957.8 μg, 714.6 μg for flow rates of 10 mL/min, 20 mL/min, and 40 mL/min, respectively. These findings provide a reliable reference for implementing solar energy as a power source in ammonia synthesis.