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SiC fibers are widely used in composites exposed to high temperature oxidizing environments. The present study compares the oxidation behavior of SiC fibers and the associated changes in tensile strength upon their exposure to dry air and steam for up to 50 hours at temperatures from 950°C to 1350°C. In both cases, the scale thickness and oxide microstructure were analyzed by scanning electron microscopy. When the SiC fibers were oxidized in air, a crack-free amorphous oxide layer formed at temperatures up to 1200°C, whereas a cracked, crystallized oxide layer was found at 1350°C. By contrast under steam environment, a crystalline oxide forms at 950°C for oxidation times longer than 30 h. In both environments, the fiber strength decreased with increasing exposure time and temperature, the degradation being faster after oxidation in steam compared to dry air. This appears to relate to residual stress in the oxide scale and a reduction in the cross section of the load-bearing unoxidized SiC. An increase in defect size may also contribute to the loss of strength. The oxide scale follows parabolic growth kinetics in both dry air and in steam from 950°C to 1350°C, except at 1350°C for over 30 hours. The oxidation rate in steam is faster than that in dry air, with activation energies of 79.8±1.4 kJ/mol in steam and 153.6±3.4 kJ/mol in dry air, respectively. This work is relevant to the application of SiC fibers and SiC fiber reinforced composites in air and steam environments at high temperature. [ABSTRACT FROM AUTHOR]

Low-temperature storage is an important way to maintain the quality of foodstuffs. Meanwhile, the massive power consumption and high operating costs of maintaining low temperatures are the main constraints for applying low-temperature storage applications. Utilizing phase change material (PCM) for low-temperature storage, which can postpone alleviate the electricity requirement, is a workable alternative. In the present study, numerical investigations are conducted to analyze the thermal, economic, and preservation performances in apple refrigerated warehouses (RWHs) with and without on-shelf PCM. The results show that employing on-shelf PCM can reduce the operating cost of the RWH by about 34.1 % without deteriorating apple preservation performance in that the maximal difference in firmness reduction of apple is only about 6.57 %. In addition, the maximum air temperature in the pallet region of the RWH with on-shelf PCM varies from -1 °C to 2.9 °C, which is about 1.1 °C lower than that without on-shelf PCM during the storage process. Meanwhile, the maximum temperature rise rate of apple can be reduced from 0.58 °C/h to 0.21 °C/h with on-shelf PCM. However, the temperature of the apple on the edge of the pallet in the RWH with on-shelf PCM is higher than that in the RWH without on-shelf PCM in the last 6 h of daily storage. [ABSTRACT FROM AUTHOR]

An accurate determination of minimum ignition energy (MIE) is essential for assessing electrostatic hazards and characterising potential for occurrence of combustion in flammable mixtures. This is of utmost importance for hydrogen-air mixtures characterised by a MIE equal to 0.017 mJ, whereas conventional flammable gases are characterised by MIE typically higher than 0.1 mJ. The study aims at developing and validating a CFD three-dimensional model capable to simulate complex unsteady physical and chemical phenomena underlying capacitive discharge spark. The model accounts for the experimental apparatus details, including the effect of electrodes' gap and associated heat losses. The numerical approach accurately reproduced the experimental measurements of MIE for mixtures of hydrogen with air at initial temperature ranging from ambient (T = 288 K) to cryogenic (T = 123 K). Hydrogen concentration in air was included in the range 10–55% for tests at T = 288 K, and 20–60% for tests at T = 173 K and 123 K respectively. Simulations assess the impact of experimental characteristics and design, such as the electrodes' dimension, and numerical features on process dynamics, growth of the flame kernel and MIE predictions. • Development of a CFD 3D model simulating the phenomena underlying a discharge spark. • Inclusion of effect of conductive and radiative heat losses on the MIE predictions. • Validation against tests on H 2 -air mixtures at ambient and cryogenic temperatures. • Simulations provide insights into the process dynamics and flame kernel development. [ABSTRACT FROM AUTHOR]

Liquid hydrogen leakage and diffusion accidents pose serious threats to the safety of personnel and equipment. In the present work, three-dimensional CFD models for liquid hydrogen spills in unstable, neutral and stable atmospheric boundary layers are developed, and the effects of atmospheric boundary layer on prediction accuracy is validated. Spread characteristics of hydrogen vapor cloud under different atmospheric boundary layers are then numerically analyzed. Modeling the stability of atmospheric boundary layer can improve the accuracy and reliability of the prediction results for liquid hydrogen spills. Wind velocity and its gradient, as well as the vertical distribution of air temperature, act upon the spread characteristics of hydrogen vapor cloud. The unstable atmospheric boundary layer could promote the upward movement and the expansion of hydrogen vapor cloud to some extent. The stable atmospheric boundary layer promotes the vertical spread process in early stage, while presents hindering effects as the spill continues. Cloud heights at the end of the spill are respectively 48.6 m, 45.5 m and 30.2 m, under the unstable, neutral, and stable atmospheric boundary layers. In addition, wind flow in stable atmospheric boundary layer has obvious dragging effect on the lateral edge of hydrogen vapor cloud. • Models for liquid hydrogen spill in various atmospheric boundary layers are built. • Cloud spread characteristics under different atmosphere stabilities are analyzed. • Modeling atmosphere stability improves accuracy for spill prediction. • Unstable atmosphere promotes the upward movement and expansion of vapor cloud. • Stable atmosphere hinders cloud spread process in late stage of spill. [ABSTRACT FROM AUTHOR]

The new European F-Gas and PFAS Directives threaten to dramatically reduce quotas or even outright ban synthetic refrigerants, and transition to natural refrigerants in the near future seems inevitable. This article examines eutectic refrigerating systems used in low-temperature transport refrigerators for retail distribution considering transition to natural refrigerants. The main limitation for the operation of eutectic systems is the low evaporation pressure, and various designs addressing this limitation were already tried in the last few years during transition from R507A to R452A and other alternatives. In this article 5 systems with R452A, two with R290 and two with R1270 are compared. The greatest effect was demonstrated by addition of roll-bond plates – it reduced the difference between the inside air and evaporation temperatures by about 3 K. However, this solution is not promising with hydrocarbons due to the higher refrigerant charge. All other solutions together give no more effect than roll-bond plates in terms of evaporation temperature at the end of pull-down. Based on experimental results, the prospects of eutectic refrigeration system with natural refrigerants are reviewed. R290 is not suitable for such systems, but R1270 could be used in systems where eutectic plates just need to be crystallized. However, in weight-optimized systems used in refrigerated vans, the evaporation pressure of R1270 would be lower than atmospheric, which is considered unacceptable due to safety requirements. If this provision remains, the eutectic refrigerators with a single-stage vapour compression refrigerating system become impossible, and more complicated cascade system has to be developed. • The subject of research is the refrigerant of transport refrigerators with eutectic system. • Currently used R452A refrigerant becomes impractical due to F-Gas Quota restrictions. • The main limiting factor is the low boiling pressure at the end of the charging cycle. • The future insights are based on performance of 9 systems with R452A, R290 and R1270. • A possible direction is a low charge R1270 eutectic system with vacuum in the evaporator. [ABSTRACT FROM AUTHOR]

The active and passive oxidation of Al in Al–Al 2 O 3 composites was investigated in air at high temperatures. As fresh air impinged on the surface of the Al–Al 2 O 3 composite sample, a thin Al 2 O 3 layer was preferentially formed via passive oxidation of Al, which consumed most of the oxygen and lowered the local P o 2 inside the sample. At low P o 2 , active oxidation of Al occurred and predominated in the interior transition layer, which further lowered the local P o 2 to extremely low values within the non-oxide stability field. The local equilibrium P Al x O y generated by the active oxidation of Al reached a micro-positive pressure state and served as a gas barrier, hindering the inward diffusion of O 2. The P o 2 inside the composite was lowered by Al in the outer layers via a self-gettering process. Subsequently, Al 4 O 4 C and Al 2 OC-AlN solid solution were formed by both the direct reaction of Al(l) and the indirect reaction of Al x O y (g). After sintering in air, the Al–Al 2 O 3 composite exhibited a functional gradient structure with a thin oxide layer and an interior non-oxide-reinforced corundum. A reaction mechanism model was established. [ABSTRACT FROM AUTHOR]

Theoretical studies on the total energy, and hydrogen absorption thermodynamics on Zr(Cr 0.5 Ni 0.5) 2 intermetallic compound were performed using absorption models on the most stable sites. In the first stage, Density Functional calculations provide the absorption energies corresponding to hydrogen in different environments. From there, 28 hydrogen absorption locations were found and the corresponding absorption energies were specifically determined. Then, with this information, a theoretical approximation based on the concept of local absorption isotherm and Fermi-Dirac statistics was applied to study the thermodynamics of the system. In this case, and due to the absence of lateral interactions, exact expressions of the thermodynamic functions can be derived. The process was monitored by following the surface coverage as a function of the chemical potential (absorption isotherm), the energy and configurational entropy of the adsorbed phase and the differential heat of absorption. Interesting behaviours were observed and discussed in terms of the absorption microscopic properties (energy distribution of the absorption sites). [Display omitted] • Computed DFT absorption sites energies are used to model absorption isotherms. • A statistical model is based on the integral absorption equation formalism. • The main thermodynamic absorption functions are derived in an exact and closed form. • Absorption isotherms, energy and entropy are discussed using binding energies. • Microscopic properties can be obtained from macroscopic experimental measurements. [ABSTRACT FROM AUTHOR]

Extreme meteorological and hydrological phenomena, including high air temperatures and rainstorms, are becoming increasingly dangerous, causing floods and inundations, as well as long periods without precipitation, which lead to droughts. Green roofs may be one of the possible measures providing solutions to these problems. Rainfall, runoff and water quality data from three different intensive green roof models covered with wildflower meadows (WFs) over 20 months have been analysed to establish the extent to which the type of drainage layer affects hydrological performance. The field experiment was conducted at the Warsaw University of Life Sciences Water Centre park from November 2019 to November 2021. The monitoring of the quality and quantity of runoff was carried out on three models of green roofs incorporating wildflower meadows with drainage layers of 2 cm (WF 1) and 4 cm (WF 2) of polypropylene mat, as well as 6 cm of chalcedony (WF 3), in an urbanized area under moderate climate conditions. The model with the 4 cm polypropylene mat drainage layer retained approx. 6 % more rainwater compared to the model with the one made of chalcedony, and 4 % more than the one with the 2 cm polypropylene mat. Phosphates were detected in most of the leachates from all the wildflower-covered green roof models at 0 ÷ 0.459 mg PO4-P/L, 0 ÷ 0.402 mg PO4-P/L, and 0÷0.360 mg PO4-P/L for WF 1, WF 2 and WF 3. This may suggest that the type of drainage layer was not an important source of phosphates in the leachates. [ABSTRACT FROM AUTHOR]

• A novel tubular indirect evaporative cooler is proposed. • A theoretical model is developed and experimentally validated. • Regression models for air treatment performance prediction are established. • Multi-objective optimization with relative weights of output responses is obtained. • The regression models can predict the cooler's performance in diverse climates. Indirect evaporative cooling (IEC) technology is an energy-efficient approach for regulating the indoor thermal environment of buildings. The conventional tubular indirect evaporative cooler (TIEC) may have a relatively low cooling efficiency due to poor wettability issues. The application of moisture-conducting fibers provides a feasible way to solve the above problem. However, the integration of moisture-conducting fibers with TIEC is still in the exploratory stage. This study proposed a novel moisture-conducting fiber-assisted TIEC and conducted a multi-objective optimization. An experimental facility and theoretical model of the proposed moisture-conducting fiber-assisted TIEC were developed. Based on the numerical model validated by experiments and response surface methodology (RSM), the regression models for performance prediction of the cooler were established. Eight input parameters including inlet air parameters, operating parameters and geometric parameters were selected, and four performance evaluation indicators were chosen as output responses. The parameter sensitivity of the regression models was analyzed. The multi-objective optimization was performed by considering the influence of different relative weights assigned to the output responses. Furthermore, the performance of the optimized cooler applied in different climate zones was predicted. The results showed that the product air temperature drop could achieve 8.8–11.3 °C after cooling by the cooler. The established regression models can predict the performance of the moisture-conducting fiber-assisted TIEC conveniently and effectively, which is expected to guide the design and optimization of engineering practices. [ABSTRACT FROM AUTHOR]

Defining the required trackability level of the target condition for the testing facility reconditioning unit represents an unresolved challenge in improving the reproducibility of load-based tests and corresponding performance rating standards development. To enhance the reproducibility of such testing methodology, this paper presents and discusses a new feed-forward compensation technique based on the development of a transfer function model for the delay and offset characteristics of the psychrometric room's air temperature and humidity modulations with reference to the target signal from the room emulator. It is demonstrated that the proposed methodology enables offset and delay reduction in the trackability of the return air condition within 60 s at different testing conditions, enhances the reproducibility of the test results to limit performance deviations to within 2 %, and achieves closely matched controlled parameter modulations during load-based tests. [ABSTRACT FROM AUTHOR]

• Comprehensive evaluation of Purge section and rotary dehumidifier configurations. • Purge section in desiccant wheel reduces energy use and exit air temperatures. • Multi-sector approach in single wheel enables two-stage dehumidification. • Review highlights the isothermal dehumidification potential of non-adiabatic wheels. This review provides a comprehensive summary of research pertaining to the purge section within desiccant wheels featuring multi-sector configurations. Additionally, it encompasses discussions on innovative wheel designs such as non-adiabatic desiccant wheels and the achievement of two-stage dehumidification from a single wheel employing multi-sector approaches. The review begins by providing a concise historical overview of the desiccant wheel, followed by a systematic classification of the research conducted in this area. Subsequently, various categorizations are presented in a logical sequence, offering a structured understanding of the subject matter. Central to the critical findings of this review is the identification of an optimal purge wheel sector angle, which not only decreases the energy consumption of the desiccant wheel but also significantly reduces the exit temperature of process air. Moreover, the review highlights the potential of achieving isothermal dehumidification through the utilization of non-adiabatic rotary desiccant wheels. Furthermore, the introduction of a multi-sector desiccant wheel is one of the key successes in obtaining two-stage dehumidification and getting multi-output like cooling, heating with dehumidification, and heating with humidification. These are all efficiently derived from a single wheel. [ABSTRACT FROM AUTHOR]

• The operating performances of a CASHP in LTS and HTS were tested. • Compressor speed plays opposite roles in LTS and HTS to affect the pressure ratio and COP. • Changes of the compressor speed in LTS failed to improve the COP of a CASHP unit. • Empirical models predicting COP in LTS and HTS were established. Previous studies on cascade air source heat pumps (CASHPs) mainly focused on overall performances, while impacts of the low temperature stage (LTS) and high temperature stage (HTS) on overall performances were paid less attention to. Therefore, operating performances of a CASHP in LTS and HTS were investigated in this paper, to provide a solution for the optimization of the CASHP. A CASHP unit with a variable speed compressor in LTS and a constant speed compressor in HTS was adopted, and its operating performances were investigated under 26 cases. Results showed that the pressure ratio and COP in LTS and HTS were affected differently by the compressor speed. Specifically, as the speed of the compressor in LTS increased from 30 rps to 90 rps, P rL increased by 151 % ∼ 178 %, and P rH reduced by 38 % ∼ 54 %. Meanwhile, COP in LTS reduced by 21 % ∼ 52 %, but the COP in HTS rose by 54 % ∼ 96 %. Besides, it was found that adjustments of the compressor speed in LTS could improve heating performances of the CASHP. However, when the ambient air temperature and the supply water temperature were consistent, COP changes of the CASHP were limited, only by 0.3 % ∼ 9 %. Furthermore, empirical models of the COP in LTS and HTS were established to predict the COP of the CASHP on different operating conditions. Results of this study were helpful in promoting the configurations and operation control optimization of CASHPs. [ABSTRACT FROM AUTHOR]

Spiral blast freezing is a common unit operation used in food processing facilities for rapidly freezing a variety of foodstuffs. The purpose of a blast freezer is to generate high velocity, low temperature air flow over food products being conveyed within refrigerated enclosures to accomplish the freezing process. However, air flow patterns observed within field operating blast freezers are often suboptimal, resulting in diminished system performance. This paper applies a Monte Carlo simulation technique to a food product freezing simulation in order to identify velocity profiles that optimize the freezing process. A one-dimensional food product model is used to evaluate the interplay between the time variation in the magnitude of the air velocity over food products conveyed through the freezing system and the resulting dwell time needed to achieve a target product core temperature at the blast freezer exit. Temporal heat transfer coefficients derived from field measurements made in a newly installed spiral blast freezer serve as a basis to calibrate the one-dimensional product model. The results of the Monte Carlo analysis show freezing system performance is improved when high and stable air velocities over the product are achieved early in the freezing process dwell time. Air flow patterns within a freezing system that result in high air velocity later in the freezing process dwell time are suboptimal. Field-measured data on a newly installed spiral blast freezer showed this suboptimal air flow pattern and the use of baffling within the spiral enables improved airflow leading to an estimated 10 % increase in production throughput. [ABSTRACT FROM AUTHOR]

• VPD and R g predominantly drive variations in tree-level transpiration. • Soil moisture availability did not limit tree-level transpiration. • Xylem sap flow exhibited a strong correlation with VPD, R g , and RH. • Significant correlation (P < 0.001) was observed between actual and potential transpiration. • Apple tree water usage was higher in the early season compared to mid- and late seasons. Understanding the environmental drivers and hydraulic dynamics of plants is pivotal for elucidating future water use strategies and refining precise irrigation techniques. In our investigation, we focused on the daily and seasonal fluctuations in sap flow (SF) using compensation heat-pulse techniques on 7-year-old 'Gamhong' apple trees. Predictions of stand transpiration were integrated using the Penman-Monteith grass reference evapotranspiration. Additionally, we measured leaf-level diurnal and seasonal stomatal conductance (g s), leaf water potential (Ψ Leaf), and transpiration rate (E) to explore the relationship between plant-level transpiration and orchard microclimate. Diurnal SF exhibited a pattern similar to global radiation (R g) and vapor pressure deficit (VPD), increasing in the morning with a peak in the afternoon and decreasing towards evening. Seasonal water use varied, with rates of 10.62 ± 0.282 L day-1 in early (May–June), 8.40 ± 0.222 L day-1 in mid- (July–August), and 5.96 ± 0.154 L day-1 in late season (September–October). Plant water consumption was influenced by weather conditions and evaporative demand driven by atmospheric VPD and R g. Clear and sunny days resulted in higher water use (10.23 ± 0.291 L day-1) compared to partially sunny but windy days (9.85 ± 0.32 L day-1) and cloudy/rainy days (5.37 ± 0.176 L day-1). Plant transpiration strongly correlated with VPD (R² = 0.565), R g (R² = 0.616), relative humidity (R ² = 0.623), and wind velocity (u, R ² = 0.684), while no significant correlation was observed with air temperature (T a , R ² = 0.19) or soil moisture status (Ψ soil , R² = 0.19). VPD and R g emerged as the primary drivers, with Ψ soil playing a minor role and not limiting tree-level transpiration. Leaf-level g s , Ψ Leaf , and E displayed similar diurnal trends. In our study, the integrated daily sap flow provided valuable insights into plant-water relations differently across growing seasons and its relationship with reference evapotranspiration (E o). The Penman–Monteith equation, using grass reference evapotranspiration indicated a positive correlation (R ² = 0.764, P < 0.001) between actual and estimated transpiration. However, the slope of the relationship differed significantly from 1.0, suggesting that E o per unit leaf area of grass corresponds to E 288 = E o /2.88 (L m-2 of leaf area d-1), which underestimated evapotranspiration. [ABSTRACT FROM AUTHOR]

• Satellite image (Landsat 8) used to estimate land surface temperature in a Mountainous region. • Single Channel JM&S and Split Window algorithms compared with observed temperatures. • Split Window algorithm depicted lower MAE and closer agreement with observations. Studying Land Surface Temperature (LST) provides various scientific, environmental, and practical advantages. It aids climate monitoring, urban heat island studies, environmental assessments, agriculture, urban planning, infrastructure development, and remote sensing. Algorithm selection depends on research constraints and goals, considering different algorithm strengths and limitations. In this study, the LST around the Sabalan volcanic peak was estimated using Landsat 8 satellite images captured by the OLI and TIRS, employing the Single Channel JM&S and Split Window algorithms. The obtained surface temperatures from both algorithms were converted to air temperature. Subsequently, the pixel air temperatures were compared to the corresponding synoptic station air temperatures of the studied region, considering the satellite's passage time. This comparison was executed using regression analysis (R2 and correlation coefficients) and statistical indices such as Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) to validate the data. The results indicated R2 values and correlation coefficients of 0.04 and 0.97, respectively, for the Single Channel algorithm, and 0.12 and 0.69 for the SW algorithm, signifying a positive relationship and close alignment between these datasets. Furthermore, the examination of the results revealed root mean square error and mean absolute error with minimum errors of 4.20, 3.88, and 8.14, 8.97 °C in the SW method. By assessing the difference between mean LST and the synoptic station air temperatures, the SW approach exhibited lower temperature discrepancies across all stations and lower estimation errors compared to the Single Channel method, thus displaying higher accuracy and closer conformity to the actual temperature. [ABSTRACT FROM AUTHOR]

This paper compares the performance of a vertical-finned microchannel heat exchanger (VMHX) and a 2-row fin-tube heat exchanger (FTHX) under wet and frosting conditions. The VMHX features vertically oriented fins with an extension at the windward side and parallel microchannel tubes, allowing for efficient water drainage and better performance than conventional microchannel heat exchangers with parallel serpentine fins. However, the performance of the VMHX has not been sufficiently compared to that of FTHX. After conducting experiments under specific operating conditions, the VMHX exhibits better water drainage performance than the FTHX at higher inlet air velocities, higher maximum heat flow, and time-integrating heat flow under certain operating conditions. Although the heating time is relatively shorter than the 2-row FTHX, these results suggest that the VMHX may be a more suitable option for applications requiring efficient water drainage and heat transfer. Additionally, the operating conditions significantly affect the heat exchanger's performance. The performance of VMHX is analyzed under different inlet air velocities, inlet air temperatures, and evaporation temperatures. The results indicate that frost itself had no effect on the heat exchanger performance and that the decrease of the inlet air flow rate was the main factor that decreased the heat exchanger performance. Overall, the results of this study provide valuable insights into the performance of VMHX and FTHX under wet and frosting conditions and the impact of various operating parameters on VMHX performance. These findings can inform the development of more efficient and reliable heat exchangers for various applications. [ABSTRACT FROM AUTHOR]

This manuscript investigates the effect of diabatic imparity on two-dimensional ( 2 - D ) transient fins having naturally obtained non-linear variation of temperature-dependent conductivity. The diabatic imparity arises due to asymmetrical convection coefficient on the surfaces, implemented using different Biot numbers on each respective surface of the fin, which resembles pragmatic industrial applications. The transient solution of 2-D fin has been obtained using a Lattice Boltzmann ( LB ) solver, firstly, the suitability of 2 - D LB formulation is established with the validity of the existing results, and subsequently extending the LB formulation for the present study. The numerical solution is determined under the two types of step-changing boundary conditions at the fin root having (i) heat flow and (ii) temperature . Results have been plotted graphically, and these include instantaneous isotherms , equilibrium isotherms , and threshold iso-temporal lines. Reported results facilitate the fin designer to examine the effect of diabatic imparity on the attainment of steady-state and occurrence of transverse temperature gradient on 2 - D transient fin. The reported results provided are pertinent to the pragmatic application and are seldom reported in the literature. The outcomes of the present investigation are eminently informative to practising engineers and will serve as design monograms. [ABSTRACT FROM AUTHOR]

Lake-effect snowfall (LES) occurs when cold air moves across open lakes. LES is expected to occur more frequently over the TP, due to the intensified lake expansion caused by intensified global warming. Thus, there is an urgent need to comprehensively assess the LES over the TP. Here, we revealed that the LES is triggered by westerly southward shift leading to the drop in air temperature and is positively correlated with lake area, wind speed and longitude across 12 large lakes (>300 km2) based on satellite observations and reanalysis data. Using a sensitivity model simulation, we determined that large lakes in the southern TP contributed to more than 50% of the snowfall in the downwind area in 2013. Projections indicate that the westerly-triggered LES will increase under the future RCP4.5 climate warming scenario, highlighting the importance of developing adaptive policies to address the growing risks associated with future LES. [ABSTRACT FROM AUTHOR]

• Fruit temperatures across the supply chain varied between 16 °C and 31 °C. • Temperature variations of fruits in upper and base cartons differed during cruising. • Carton positions in the ULD container showed no impact on product quality. • Superior product quality was obtained during storage at 16 °C compared to 21 °C. • Estimation of product mass loss using model based on temperature and humidity history. An air cargo supply chain for fresh mango was investigated from Thailand to France. Measurements of air temperature, air relative humidity, and fruit (peel) temperature were conducted using thermo-hygrometer data loggers in cartons. In a Unit Load Device (ULD) containing 148 cartons, twenty-seven instrumented cartons were placed at different positions to observe spatial and temporal temperature variations during 12 h cruising. At the destination, mango quality attributes were assessed at different time-points during 15-day storage at 16.1 °C and 21.6 °C. Throughout the supply chain, fruit temperatures ranged from 16.6 °C to 30.5 °C. During cruising, fruit temperatures in upper cartons remained almost constant, whereas base carton temperatures continuously decreased from 26.1 °C to 18.1 °C. Because of a short cruising period in comparison to a storage duration at the destination and proper ambient temperature condition during the experiment, carton position in the ULD had no discernible impact on fruit quality during storage. Fruit stored at 16.1 °C preserved superior fruit quality compared to 21.6 °C storage. For the same storage temperature, better quality of fruits stored in Thailand demonstrated the impact of air shipment on product degradation. The measured temperature and relative humidity evolutions were used as input parameters of a mass loss evolution model. A comparison with the measured data exhibited good agreement (RMSE < 1.8 % mass loss). Considering 10 % mass loss as a critical value, this model allows an estimation of the product shelf life based on a supply chain scenario. [ABSTRACT FROM AUTHOR]

• Filtering OH rotational temperature estimates perturbations having periods of 0.7–8.2 h. • Statistical approaches allow subtracting uncorrelated random noise. • Seasonal and interannual variations of residuals reflect climatology of correlated wave processes. Ground-based observations of the natural hydroxyl (OH) nightglow at altitudes of 85–90 km are used for deriving the rotational temperature of excited OH, which is close to the neutral atmospheric temperature. For filtering of mesoscale perturbations, we use differences between pairs of measured values of OH rotational temperature separated with fixed time intervals in the range of 0.5–2 h. The filtering is applied for studying mesoscale variations of temperature near the mesopause according to the data of spectral OH nightglow measurements at observatories of Zvenigorod (56°N, 37°E.) in the years 2004–2016, Tory (52°N, 103°E) in 2012–2017 and Maymaga (63°N, 130°E) in 2000–2015. Monthly-mean values and variances of temperature disturbances with periods 0.7–8.2 h are determined. Semiempirical and statistical approaches are used to estimate and subtract variances of the instrumental dark current noise and uncorrelated in time fluctuations. Seasonal and interannual variations in standard deviations of correlated in time mesoscale perturbations of the OH rotational temperature at the considered observational sites are studied. They can give information about multiyear changes in the activity of atmospheric acoustic-gravity waves propagating through the OH layer near the mesopause. [ABSTRACT FROM AUTHOR]

One of the buzz words in current research depends for a weather forecast is the atmospheric temperature, and this value may change at any time. Predicting air temperature exactly is necessary since it is particularly important for various communities and events. In today's world of massive amounts of data and unforeseen data fluctuations, long-short term memory (LSTM), a sort of neural network method, is becoming more and more popular. The present work employed a sequence to sequence LSTM autoencoder to forecast Indian weather patterns. The prediction model was trained using historical data obtained from the Khordha district administration. The proposed method primarily emphasizes two phases of the procedure. The present study involves an examination of a proposed model, wherein a comparison is made between four distinct variants of LSTM techniques: vanilla LSTM, stacked LSTM, bidirectional LSTM, and convLSTM. The objective of this analysis is to predict temperature patterns. Additionally, this paper utilizes an LSTM autoencoder model to forecast the temperature for the subsequent two-year period in the Khordha district of Odisha, India. The experimental investigation demonstrates that the utilization of Stacking encoder-decoders with bidirectional LSTM cells leads to a notable enhancement in the accuracy of the model, resulting in maximum efficacy. A notably lower Mean Absolute Error (MAE) result suggests that the 9-layer stacked autoencoder model has superior performance in predicting both the minimum and maximum temperature. [ABSTRACT FROM AUTHOR]

Reducing the amount of sulfur in fuels is the simplest way to reduce the emission of sulfur oxide gases into the air. Among various desulfurization methods, adsorptive desulfurization stands out for its mild conditions and affordability. This research used ZSM-5 zeolite as a desulfurization adsorbent. However, adsorption capacity and selectivity are two major challenges that adsorptive desulfurization is facing. Introducing mesoporosity into zeolite is a potential solution. The study focused on mesoporous formation via desilication and dealumination. Desilication involved treating zeolite with 0.2 M and 0.5 M NaOH, while dealumination used 1 M HCl at 80 °C. Adsorbent properties were analyzed using XRD, BET, FT-IR, and FE-SEM. Initial findings indicated dealumination removed only extra-framework aluminum. Conversely, desilication removed silicon, producing a hierarchical structure even at reduced concentrations. Des-0.5M also exhibited the highest adsorption capacity for thiophene compared to the Parent sample, increasing from 4.5 to 11 mgS/g. Moreover, the adsorption capacity for larger sulfur molecules such as dibenzothiophene increased from 2.5 to approximately 6 mgS/g, indicating the significance of the hierarchical structure developed in the adsorbents. In summary, this study highlights the potential of mesoporous formation through desilication to enhance the adsorption capacity of ZSM-5 zeolite for the adsorptive desulfurization of fuels. [Display omitted] • Mesoporous ZSM-5 boosts fuel desulfurization by adsorption. • Desilication and dealumination enhance sulfur removal. • DesNa-0.5 M shows top adsorption, removing 220 mgS/L thiophene, 98 mgS/L dibenzothiophene. • Increasing mesopores while maintaining micropores enhances sulfur removal. • DesNa-0.5 M exhibits high surface area, structure, and crystallinity. [ABSTRACT FROM AUTHOR]

As part of "The Earth Summit Mission-2022" during the second Tibetan Plateau Scientific Expedition and Research (STEP) in April and May 2022, we conducted the ozone sounding experiment (an ozonesonde mated to a radiosonde) at Mt. Qomolangma Base Camp (MQBC; 86.85°E, 28.14°N; 5200 m), a location at an extremely high altitude. A total of ten sounding profiles were obtained between April 30 and May 06, 2022, of which seven profiles were above 35 km in altitude, with a maximum detection altitude up to 39.0 km. This study presents the temporal variation and vertical distributions of atmospheric temperature, humidity, and ozone during the MQBC campaign. The averaged ozone concentration was high (68.3 ppbv) at the surface and then increased smoothly until peaking (∼110 ppbv) in the middle troposphere (approximately 10 km), and afterward, the ozone concentration increased rapidly from the upper troposphere to a maximum of ∼10 ppmv at ∼30 km. The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure, and transport from the southern flank of the Himalayas occurred during the campaign period. The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35 km in altitude. The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder (MLS) onboard the Aura satellite and the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. [ABSTRACT FROM AUTHOR]

• A direct evaporative cooler (DEC) integrates with split air conditioner (SAC). • DECSAC significantly improves C O P by 10.54 %−70.14 %. • Total cost rate (T C R) of DECSAC reduces by 5.07 %−25.36 %. • Water consumption for 1 kWh energy saving varies between 5.5 – 9.8 L. • Simple payback period lies between 1.21 to 2.99 years with maximum I R R being 59 %. As concerns regarding energy consumption and environmental impact continue to grow, the need for efficient and sustainable cooling technologies becomes increasingly significant. Among various alternatives, direct evaporative cooling (DEC) has emerged as a promising solution due to its energy-efficient operation and low environmental footprint. This paper aims to provide a comprehensive thermo-economic assessment of a 5.25 kW capacity split air conditioner (SAC) integrated with direct evaporative cooling, focusing on evaluating its performance, energy consumption, coefficient of performance (C O P) , and economic viability. A numerical model is developed to determine the reduction in the condenser inlet air temperature due to direct evaporative cooling. The ambient temperature (30–45 ⁰C), relative humidity (20–80 %), and evaporator temperature (3–12 ⁰C) are taken as the design variables. Box–Behnken design (BBD) technique of response surface methodology is applied for multi-objective optimization. The C O P , total cost rate (T C R) , and total exergy destruction ( E ˙ D , t ) are set as the objective functions. Cooling capacity, life period, operation time, interest rate, maintenance factor, and electricity cost are taken as constants. The thermoeconomic optimization evolved maximized C O P enhancement of 68.94 %, and reduction in TCR and E D , t by 26.12 % and 57.23 %, respectively. The water consumption to energy saving ratio varies from 5.5 to 9.8 L/kWh for different months of the cooling season. The thermoeconomic performance and sustainability of DECSAC is observed to significantly improve compared to conventional SAC specifically in hot-dry climates. The simple payback of the proposed system ranges between 1.21 to 2.99 years depending upon the operating conditions. [ABSTRACT FROM AUTHOR]

Series of novel energy-saving window coatings based on F–Nb–TiO 2 /SiO 2 nanocomposites with superhydrophobic self-cleaning performance were successfully prepared. Surface modification of F–Nb–TiO 2 and SiO 2 nanoparticles by aminopropyl triethoxy silane and perfluorooctyltriethoxysilane produced hydrophobic powders. With the help of the hierarchical structures of F–Nb–TiO 2 /SiO 2 nanocomposites, superhydrophobic surfaces were obtained. The water contact angle of the composite coatings reached 155.6°. The prepared superhydrophobic coatings shown superior anti-fouling property and good mechanical performance. Furthermore, the composite coating can shield most of solar radiation. The composite coating lowed the air temperature of the simulate house by 11 °C in the outdoor thermal experiments. The integration of good solar filtration and exceptional anti-fouling performance makes F–Nb–TiO 2 /SiO 2 coatings suitable candidates for energy-saving window coatings. [ABSTRACT FROM AUTHOR]

Nitrogen heterocyclic organics are promising hydrogen storage carriers with the advantage of being capable of large-scale transportation over long distances using existing oil and gas facilities. However, traditional methods for the hydrogenation and dehydrogenation of organic hydrogen carriers usually require high temperature and pressure conditions and external hydrogen supplies, which hinder their large-scale applications, as well as having certain safety risks. In this paper, a reversible electrochemical hydrogen storage system using quinoxaline as a hydrogen carrier was developed with potential for use at room temperature and atmospheric pressure. Experiments revealed that the hydrogenation conversion of quinoxaline reached 95% within 120 min at −0.20 V vs. RHE, and the dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline reached 100% within 30 min at 1.30 V vs. RHE. This means that the system achieved quick and efficient reversible hydrogen storage. The Pd/NF dual-function electrode prepared by spontaneous redox reaction still showed high catalytic activity after 8 cycles, indicating its good long-term stability. The proton donor in the electrochemical hydrogenation process of quinoxaline was water, which completely eliminates the safety risk from the use of external hydrogen. This work provides a simple and reliable strategy for efficient hydrogen storage using nitrogen heterocyclic organics. [Display omitted] • The hydrogenation conversion of quinoxaline reached 95%. • The optimum dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline was 100%. • Pd/NF electrode was operated as a dual-function electrocatalyst. • Efficient reversible hydrogen storage was achieved at 25 °C and atmospheric pressure. • The H∗ required for the electrochemical hydrogenation of quinoxaline came from H 2 O. [ABSTRACT FROM AUTHOR]

• 23 synoptic stations network is used to evaluate five temperature datasets in Ghana. • The assessment is carried out from multiple perspectives, including climatology. • Multiple performance metrics are used to assess the robustness of the datasets. • Using CRU, CPC, and TerraClimate in Ghana is most recommended. Global temperature datasets have become increasingly accessible in recent years, yet their performance in regions with sparse data remains a subject that requires thorough investigation, especially in areas where validation is essential. This study addresses this urgency, given the significant impact of the increase in global temperature, as highlighted in the IPCC's 6th Assessment Report, on regional and local levels. In this research, we evaluated air temperature datasets from Climatic Research Unit (CRU TS4.05), Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), Climate Prediction Centre (CPC), European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA-5), and TerraClimate (hereinafter referred to as Gridded Temperature Datasets - GTDs). Our assessment involved comparing and validating these datasets against reference ground observation data from 23 synoptic stations, spanning 40 years from 1981 to 2020, to ensure robustness in regions with sparse data. We conducted a spatio-temporal investigation to explore temperature patterns, and evaluated their capacity to reproduce inter-annual and intra-seasonal variability. To assess dataset performance, we employed a group of statistical metrics, including root-mean-square error (RMSE), mean absolute error (MAE), percentage bias (PBIAS), and correlation coefficient (R). The GTDs consistently captured the annual climatological cycle distribution over Ghana. The correlation coefficient values significantly varied across the 23 synoptic stations and three climatic zones. At the annual level, CPC exhibited R values ranging from 0.53 to 0.93, while CRU ranged from 0.48 to 0.88. The bias for CPC and CRU spanned from 2.40 to −0.35 °C and 2.07 to −0.91 °C, respectively. Overall, CRU, CPC, and TerraClimate demonstrated the most consistent near-surface temperature patterns over Ghana, outperforming other datasets. Based on our findings, we recommend these datasets for model evaluation and assessment in Ghana, given their strong performance in capturing temperature variations. [ABSTRACT FROM AUTHOR]

The effects of the burnt-to-unburnt temperature ratio (T b / T u) (reciprocal density ratio) on thermoacoustic combustion instability were investigated in a hydrogen-rich ram combustor by controlling the inlet air temperature under cruising conditions. Steady and unsteady combustion dynamics were investigated with the simultaneous measurement of combustion pressure and near-infrared (NIR) emissions. Time-resolved NIR images were analyzed using dynamic mode decomposition (DMD) to extract modes of the combustion instability, which show two oscillation modes: longitudinal (500 Hz) and flame-vortex interaction modes (2000 Hz) with a Strouhal number of approximately 0.5. The thermoacoustic combustion instability was not excited at T b / T u = 3.3, but was excited at T b / T u = 2.6 and 2.9. The DMD modes show that the structure of the vortex mode is similar to that of the fourth longitudinal mode at T b / T u = 2.6 and 2.9, indicating that the coupling of the vortex and the fourth longitudinal modes excited the thermoacoustic combustion instability. • The burnt-to-unburnt temperature ratio T b / T u influenced thermoacoustic instability (TI) in a hydrogen-rich combustor. • Dynamic mode decomposition analysis extracted a longitudinal mode (500 Hz) and a vortex mode (2000 Hz). • At low T b / T u , TI was excited owing to the similar structures of the vortex and fourth longitudinal modes. • Vortex mode was changed by the enhanced vortex formation near the injectors at high T b / T u. • At high T b / T u , TI was not excited owing to the low correlation between the vortex and fourth longitudinal modes. [ABSTRACT FROM AUTHOR]

The investigation of hydrogen diffusion and explosion characteristics after accidental hydrogen leaks in hydrogen refuelling stations can provide the theoretical reference of the safe application of hydrogen refuelling stations. The numerical study analyses the effects of plateau environment on the dispersion and explosion characteristics of combustible clouds, visualises the diffusion and explosion process of hydrogen-air combustible clouds and quantifies the hydrogen concentration and explosion pressure at monitoring points. Results show that combustible clouds may appear upstream of the leak hole due to the presence of obstacles. The low atmospheric pressure conditions in the plateau areas result in high hydrogen concentration near the blast wall and large combustible cloud size. The hydrogen concentration near the blast wall and combustible cloud volume are also shown a positive correlation with air temperature, which will be detrimental to fire protection in hydrogen refuelling stations. After the explosion of the hydrogen clouds, the mortality zone (explosion overpressure ≥0.69 bar) is observed near the blast wall and at high leak volumes, the hazardous zone (0.07 bar ≤ explosion overpressure ≤0.69 bar) may spread over the blast wall into the crowded area. However, the blast wall blocks the development of the high-temperature zone, which has a positive effect on preventing the spread of the explosion flame. An examination of the pressure monitoring point data reveals that there appears to be an opposite effect of atmospheric pressure on the positive and reverse overpressure. The maximum peak blast overpressure in calculated domain indicates that both higher air temperatures and atmospheric pressures promote the growth of explosion overpressure. • Hydrogen leak and explosion in a plateau hydrogen refuelling station are studied. • Fires in hydrogen refuelling stations may be more likely in high air temperature. • Positive and reverse overpressure differently correlate with atmospheric pressure. • High atmospheric pressure and temperature may contribute to explosion intensity. [ABSTRACT FROM AUTHOR]

In this paper, the "flash brazing" of SiC is successfully achieved using Ag-Cu-Ti alloy in air for seconds at an ultra-low furnace temperature of 400 °C. The interface temperature reaches over 900 °C at an ultra-fast rate via the electric field assistance. The microstructure illustrates that SiC reacts with Ag-Cu-Ti alloy to form TiC to achieve the strong bonding of the joint, and the middle part of the joint is composed of silver-based solid solution and copper-based solid solution. With the increase of brazing holding time, the amount of copper-based solid solution in the joint gradually grows, and the shear strength of the joints first increases and then decreases. The maximum strength value of 70 MPa is obtained at 400 °C−10 A-60s. This method could help to improve the efficiency of ceramic bonding greatly. [ABSTRACT FROM AUTHOR]

The development of a novel numerical model for droplet drying is the topic of this paper. The three main stages of droplet drying are distinguished, viz. unhindered evaporation of a 'wet' particle (the droplet), restricted drying at a falling rate due to the formation of a crust around a wet core, and inert heating of the dry porous particle. Each stage is mathematically detailed to replicate all phenomena occurring throughout the drying process. The focus, however, is on the falling rate drying regime which is described in terms of Stefan diffusion of water vapour through the pores of a thickening crust. To this end, the model needs the material properties. This permits the droplet characteristics to be determined by composition rather than through single-droplet drying experiments. Finally, the model is validated against five of such experiments from literature using skim milk. Good agreement is found at each comparative case for the particle mass and temperature throughout the various drying regimes providing that for good reasons in three cases a lower drying air temperature is applied than reported for the experiments. The model is capable of predicting the entire drying process at low computational cost and without requiring empirical input. [Display omitted] • New model for falling rate drying based on transport resistances in porous crust. • Stefan diffusion of vapour via crust channels, heat conduction via solid crust. • Modelling all drying stages, giving particle mass and particle temperature vs time. • Successful model validation with experimental data on single dairy particle drying. • In some cases, lower air temperature needed in model than reported from experiment. [ABSTRACT FROM AUTHOR]

Potato late blight (PLB) caused by Phytophthora infestans (Mont.) de Bary, its incidence and development are highly dependent on meteorological conditions. To solve the problem of PLB in mountainous terrain under the condition of limited meteorological monitoring capability, the air temperature and humidity was estimated based on the basic meteorological datasets, the forecast effect of the onset period and infection cycle of PLB based on CARAH rules was evaluated. The average MAE, RMSE and CI of the estimated air temperature and observations were 1.17 °C, 1.52 °C and 0.95, respectively. The average MAE, RMSE and CI of the estimated relative humidity and observations were 8.0 %, 10.7 % and 0.53, respectively. The curve of the infection cycle of PLB at different locations were estimated from the basic meteorological datasets based on the CARAH rules, and the false alarm and missing ratios were 8.8 % and 4.6 % respectively. It may be delayed by 1 or 2 fungal generations compared to the observations, and then the protective fungicide should be adjusted to a systemic fungicide. The false alarm of the infection cycle of PLB may increase in dry air conditions, and the missing report may occur in humid condition. [ABSTRACT FROM AUTHOR]

• Two improved Brayton refrigeration air cycles for wastewater treatment are developed. • These two new systems have no air condensation during the expansion process. • The system coupled with a reheater can achieve the exergy efficiency of 70.7%. • The system using a solar collector can acquire the dry air with 163.6 ℃. • System using a solar collector can increase system efficiency ratio to 2.18 kg/(kW h). The Brayton refrigeration air cycle for electroplating wastewater treatment can achieve 100% recovery of water, but there is air condensation during the expansion, which can damage the expander. In order to avoid the harmful air condensation during the expansion, an improved Brayton refrigeration air cycle coupled with a reheater and an improved Brayton refrigeration air cycle using a solar collector for electroplating wastewater treatment are developed in this paper. For these two new systems, as the solar collector or reheater is used to heat the air at the outlet of the chiller, there is no air condensation during the expansion. When the wastewater needs to be treated by the air with low temperature, the reheater can be used at the outlet of the compressor to heat the air after the condensation dehumidification, which can increase the system efficiency ratio and exergy efficiency to 1.21 kg/(kW h) and 70.7%, respectively. When the wastewater needs to be treated by the air with high temperature, the solar collector can be used to heat the air after the condensation dehumidification, which can increase the air temperature at the inlet of the tower and system efficiency ratio to 163.6 °C and 2.18 kg/(kW h), respectively. [ABSTRACT FROM AUTHOR]

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are membrane-spanning lipids produced by bacteria that are ubiquitous in natural sedimentary archives and preserved over geologic timescales. The main influence on their distributions in the environment appears to be temperature, thus making them a potentially powerful proxy for paleotemperature reconstruction. Application of recent lacustrine brGDGT-based temperature calibration models to specific regions results in inaccurate reconstructed temperatures suggesting that regional or site-specific temperature calibration models may be necessary. Using an extended data set of 692 lake sediment samples from across the globe we determined whether brGDGT distributions in samples from the same regions or sites are significantly different from one another via hierarchical agglomerative clustering analysis (HAC). Results of HAC analysis showed four significant clusters with varying geographic distributions. Cluster 1 samples are mainly located at high latitudes (Mean Annual Air Temperature; MAAT = 3.10 ± 5.91 °C). Cluster 2 samples are concentrated in the Tibetan Plateau (MAAT = 1.54 ± 5.91 °C). Cluster 3 samples span temperate-tropical latitudes (MAAT = 17.26 ± 8.16 °C). Cluster 4 samples are mainly located in Central and South America (MAAT = 24.56 ± 4.01 °C). The clustering led us to develop random forest regression models to predict temperature (MAAT and Months Above Freezing, MAF, air temperature) based on samples within each cluster (cluster-specific temperature models). Model performance was the highest for Cluster 3 (MAF: R2 = 0.78, RMSE = 2.85 °C, n = 261; MAAT: R2 = 0.76, RMSE = 4.07 °C, n = 270), followed by Cluster 1 (MAF: R2 = 0.54, RMSE = 1.67 °C; n = 219; MAAT: R2 = 0.62, RMSE = 3.62 °C, n = 226) and Cluster 4 (MAF: R2 = 0.58, RMSE = 2.46, n = 67; MAAT: R2 = 0.59, RMSE = 2.52 °C, n = 67). The Cluster 2 model had the lowest model performance (MAF: R2 = 0.42, RMSE = 4.51, n = 38; MAAT: R2 = 0.51, RMSE = 1.74 °C, n = 129). We also developed a random forest classification model to predict the cluster assignment for new samples (cluster prediction model with an overall accuracy of 95%), which informs the user as to which cluster-specific temperature model(s) to apply to their samples. Finally, we applied our approach (i.e., cluster assignment followed by cluster-specific temperature reconstruction) to seven published lacustrine (paleo)records and illustrate pitfalls among the temperature reconstructions from brGDGT-based temperature calibration models. Overall, our study defines broad geographic relationships among lacustrine brGDGT distributions and air temperature while underscoring model limitations for paleotemperature reconstruction and subsequent interpretation. [ABSTRACT FROM AUTHOR]

Smog chambers are the effective tools for studying formation mechanisms of air pollution. Simulations by traditional smog chambers differ to a large extent from real atmospheric conditions, including light, temperature and atmospheric composition. However, the existing parameters for mechanism interpretation are derived from the traditional smog chambers. To address the gap between the traditional laboratory simulations and the photochemistry in the real atmosphere, a vehicle-mounted indoor-outdoor dual-smog chamber (JNU-VMDSC) was developed, which can be quickly transferred to the desired sites to simulate quasi-realistic atmosphere simultaneously in both chambers using "local air". Multiple key parameters of the smog chamber were characterized in the study, demonstrating that JNU-VMDSC meets the requirements of general atmospheric chemistry simulation studies. Additionally, the preliminary results for the photochemical simulations of quasi-realistic atmospheres in Pearl River Delta region and Nanling Mountains are consistent with literature reports on the photochemistry in this region. JNU-VMDSC provides a convenient and reliable experimental device and means to study the mechanism of atmospheric photochemical reactions to obtain near-real results, and will make a great contribution to the control of composite air pollution. [ABSTRACT FROM AUTHOR]

• Drop-in comparison of R513A and R516A for R134a were tested in refrigeration and air conditioning conditions. • R516 proved to be more suitable for low. • Compressor volumetric efficiency, pressure ratio and superheating for R516A have a similar behavior to R134a. refrigeration temperatures. • The differences in COP of R516A are reduced by up to 5.4% compared to R134a. This paper presents the experimental energy behavior of R516A and R513A compared to R134a as baseline refrigerant in refrigeration and air conditioning temperatures. The comparative is made in an evaporating temperatures range of 261 K to 285 K with step 4 K increases, taking condensing temperatures of 308 K, 313 K, and 318 K. Results show that the best energy performance was reached by R134a while the worst were for R513A in all experimental tests, here R516A shows the smallest difference respect to R134a being just 5.4%. Also, R134a showed lower values in discharge pressure respect to its replacements, while R516A exhibited the lower discharge temperatures. R513A showed lower useful superheating for refrigeration applications, while R516A achieved the minor useful superheating for air conditioning temperatures only below R134a. Finally, R513A reached the higher value of volumetric refrigeration capacity for air conditioning temperatures at 308 K condensing temperature. All results were obtained considering the optimal refrigerant mass charge which were 682 g, 655 g, and 632 g for R134a, R513A and R516A, respectively. [ABSTRACT FROM AUTHOR]

A theoretical model was developed to predict the diffusion process of hydrogen clouds in a crosswind field with an atmospheric inversion layer in this work to evaluate the safety of liquid hydrogen spills. The theoretical model was verified by the experimental results carried out by NASA. The results show that the maximum deviation of diffusion cloud centerline heights of the theoretical model and experiments is 8.92%. The mechanism of the inversion layer suppressing cloud rise is revealed from the theoretical model, atmospheric temperature gradient is closely related to the air density gradient. Compared to the case without atmospheric inversion layer, the cloud height decreases by 2.60%, 5.22%, and 8.70% and the cloud concentration increases by 6.20%, 12.78%, and 22.30% for the temperature gradient of 0.03, 0.06 and 0.10 K/m, respectively. The velocity of crosswind is 1.7 m/s, 2.7 m/s, 3.6 m/s, and 6.0 m/s in the temperature gradient of 0.10 K/m inversion layer environment, the height of the cloud is 34.77 m, 24.05 m, 16.83 m, and 11.16 m, and the hydrogen concentrations of the cloud centerline are 10.22%, 13.67%, 17.54%, and 28.92%, respectively. Therefore, it is significant to consider the crosswind field and atmospheric inversion layer for liquid hydrogen diffusion. • A theoretical model was developed to predict hydrogen clouds in atmospheric inversion layer. • The model considers the combined effects of crosswind field and temperature stratification. • The mechanism of inhibiting the rise of hydrogen clouds at the atmospheric inversion layer. • Increasing of temperature gradient inhibit the hydrogen cloud rise and increase concentration. [ABSTRACT FROM AUTHOR]

• High tunnels altered microclimatic conditions surrounding blueberry plants. • Leaf stomatal conductance decreased together with elevating VPDl. • Net photosynthesis was during whole day measurements higher under the high tunnel. • Microclimatic changes during the day decreased Fv'/Fm' similarly at both sites. • At noon, higher zeaxanthin and VAZ were measured in leaves under the high tunnel. In a two-year experiment, the aim of our study was to evaluate the physiological and chemical response of highbush blueberry (Vaccinium corymbosum L.) 'Duke' plants to changed microclimatic conditions that may occur during production in a protected environment—in this case, high tunnels and a hail net. Measurements were performed from 7.00 a.m. to 7.00 p.m. on days with different weather conditions in 2020 and 2021. In the second year of the experiment, both photosynthetic pigments and phenolics were measured in the leaves. The air temperature, relative humidity, photosynthetic photon flux density (PPFD), substrate temperature, and water content were dramatically altered by the protected environment. Along with an increased air temperature and VPDl (leaf vapor pressure deficit), significant reductions in net photosynthesis (Pn), stomatal conductance (gs), and Fv'/Fm' (actual PS II efficiency) were detected under both protected environments, with higher values under the high tunnel. Elevated zeaxanthin and AZ/VAZ concentrations were detected in the leaves from 7.00 a.m. to 12.00 p.m., after which these concentrations reduced and continued to do so until the evening. Significance was also observed between high-tunnel and hail-net conditions. Individual and total phenolic concentrations in the leaves did not significantly change during the daytime, but significantly higher values were detected under the hail net. Our results indicate that, regarding photosynthetic pigments and phenolics, modified microclimatic conditions, i.e. elevated air temperature and reduced light quantity under different types of protected environments strongly affect the physiological status of highbush blueberry 'Duke' plants and the chemical composition of leaves. [ABSTRACT FROM AUTHOR]

One of the most important environmental worries related to poultry production is ammonia gas emission which is affected by poultry manure moisture. This research was aimed at investigating poultry manure drying in a hot air dryer and its influence on ammonium nitrogen losses to provide an overview of ammonia gas emissions and absorption of emitted ammonia by a spray scrubber. The effect of air temperature (60–80 °C), air relative humidity (8–18 %), manure depth (2–4 cm), and air velocity (2–3 m s−1) were analyzed to optimize the drying process. The optimization of ammonia absorption involved analyzing the effects of absorbent solution temperature (30–50 °C), solution pH (2−4), and nozzle operating pressure (0.2–0.6 Mpa). The Box–Behnken design was applied to optimize these processes. Manure depth was the factor that had the most significant effect on both drying duration and ammonia emission (ammonium nitrogen losses). during the drying process, the ammonium nitrogen losses increased with increasing the manure depth and decreasing the air velocity and air temperature. The optimum ammonium nitrogen was 570,330 mg h lit−1 at an air temperature of 60 °C, air relative humidity of 8.11 %, manure depth of 3.95 cm, and air velocity of 2 m s−1. Both the temperature of the absorbent solution and the solution pH had opposite effects on the ammonia absorption. Increasing nozzle operating pressure increased ammonia absorption. The maximum ammonia absorption was obtained at a solution temperature of 49.2 °C, solution pH of 2, and nozzle operating pressure of 0.58 Mpa. At these conditions, the amount of ammonium sulfate in the absorbent solution was 9.09 g lit−1 and the efficiency of the spray scrubber was 66.79 %. So, we can be sure that ammonia emission from poultry manure and the absorption of emitted ammonia can be controlled by varying the investigated variables. [ABSTRACT FROM AUTHOR]

[Display omitted] Urban thermal anisotropy (UTA) drastically impacts satellite-derived urban surface temperatures and fluxes, and consequently makes it difficult to gain a more comprehensive understanding of global urban climates. However, UTA patterns and associated biases in observed urban climate variables have not been investigated across an adequate number of global cities with diverse contexts; nor is it known whether there are globally measurable factors that are closely related to the UTA intensity (UTAI, quantified as the maximum difference between the nadir and off-nadir urban thermal radiation). Here we investigate the UTAI over more than 5500 cities worldwide using multi-angle land surface temperature (LST) observations from 2003 to 2021 provided by Moderate Resolution Imaging Spectroradiometer (MODIS). The results show that the global mean UTAI can reach 5.1, 2.7, 2.4, and 1.7 K during summer daytime, winter daytime, summer nighttime, and winter nighttime, respectively. Using nadir LST observations as a reference, our analysis reveals that UTA can lead to an underestimation of satellite-based urban surface sensible heat fluxes (H) by 45.4% and surface urban heat island intensity (I s) by 43.0% when using LST observations obtained from sensor viewing zenith angles (VZAs) of ±60°. Practitioners can limit the biases of H and I s within ±10% by using LSTs from sensor VZAs within ±30°. We also find that UTAI is closely related to urban impervious surface percentage and surface air temperature across global cities. These findings have implications for angular normalization of satellite-retrieved instantaneous LST observations across cities worldwide. [ABSTRACT FROM AUTHOR]

Heat pumps are used for energy-efficient heating in electric vehicles. If ambient air is used as a heat source, frost may form on the surface of the exterior heat exchanger at low ambient temperatures. If significant amounts of frost accumulate, the heat exchanger performance degrades and it must be defrosted. The aim of this work is the energy analysis of a heat-release-controlled vehicle heat pump with a direct flat tube evaporator in cyclic frosting and defrosting operation. The effects of fan speed and number of refrosting phases on the heat quantity released per frosting phase are analyzed on a laboratory test rig. The experiments show that the heat quantity released decreases with lower fan speed and increasing number of frosting phases. Defrosting operation parameters are also examined using the test rig and it is found that shorter defrosting times can be achieved at higher compressor speeds and larger expansion valve openings. A numerical model of the heat pump in cyclic frosting and defrosting operation is developed and validated using test rig data. An average relative deviation of less than 7% is determined between the model and experimental data. The heat pump is then integrated in a prototypical vehicle and the model is calibrated with experimental data from test drives. A numerical study of the validated vehicle heat pump model in cyclic frosting and defrosting operation shows a maximum increase of the mean total electric power consumption of 33% between dry air and saturated moist air at an ambient temperature of 0 °C. At an ambient temperature of -10 °C the mean total electric power consumption increases by 17% from dry air to saturated moist air conditions. • Experimental analysis of a vehicle heat pump in a cyclic frosting operation. • Experimental analysis of a defrosting process of a vehicle heat pump. • Modeling of cyclic frosting and defrosting process for a vehicle heat pump. • Model validation on a test rig and a prototypical vehicle. • Vehicle heat pump energy analysis in cyclic frosting and defrosting operation. [ABSTRACT FROM AUTHOR]

• Measured data of in-flight conditions revealed the decreasing trend of air and fruit temperatures. • Difference in mass loss of mangoes transported via direct and indirect flights was obviously detected. • Kinetic models could predict product temperature, mass loss and peel color change as a function of a supply chain scenario. • Stable ambient temperature and relative humidity are key factors determining the preservation of product quality. Four instrumented boxes of mangoes Mangifera indica L. cv. "Nam Dok Mai" were shipped from Bangkok, Thailand, to Paris, France, without control of the boxes' positions on the aircraft. Two boxes were shipped via a direct flight and two boxes were shipped via an indirect flight. For each box, the internal air temperature, the external air temperature and relative humidity and surface temperature of two fruits were recorded throughout the supply chain from a packing house in Thailand to a storage room in France. A maximum fruit temperature of 33 °C (during transport from an orchard to the packing house) and a minimum fruit temperature of 8 °C (in a cold room of the logistics company following arrival at the airport in France via the indirect flight) were observed. The slight temperature difference between the air and the fruit surface temperature (< 1 °C on average) for both direct and indirect flights suggests that the air was stagnant inside the box and, thus conduction was the main heat transfer mode. Models of product temperature, mass loss, and peel color changes throughout the supply chain were developed. The numerical and the experimental values were in good agreement. These models were able to predict the product mass loss and peel color evolution as a function of a supply chain scenario. [ABSTRACT FROM AUTHOR]

• System development of water adsorption on zeolite 13X from moist air was proposed. • A novel adsorption heat pump system was assessed experimentally and numerically. • Supplying moist air up to 95 °C increased the bed temperature to 200 °C. • At 70 °C, both linear driving force and the Arrhenius correlations approached the tendency. • Linear driving force model resulted more appropriate under any conditions. This work investigated the generation of high-temperature steam by feeding saturated moist air through a steam generation system containing a zeolite 13X packed bed. The use of moist air was a unique aspect, which demonstrated a novel approach to steam generation system design. The issue with the steam generation system in previously existing published research works is that it needs high regeneration energy. In order to solve this issue, it is desirable to employ moist air as the working medium. In order to better understand the physical processes involved, numerical modeling of zeolite energy storage was also performed in addition to the experimental work. As the result, when the temperature of the moist air was raised from 30 to 95 °C, the maximum temperature of the resulting water vapor reached to about 200 °C. The maximum temperature of the water vapor was not greatly affected by the superficial velocity of the moist air between 0.108 and 0.216 m N /s. In the case that the moist air temperature was high, the maximum temperature of water vapor could be predicted based on correlations between the heat balance and adsorption equilibrium, assuming that temperatures of the moist air and zeolite were identical. The numerical technique also included a comparison between Arrhenius and linear driving force models. At higher temperature input moist air, both models resulted the close tendency. [ABSTRACT FROM AUTHOR]

The present study is aimed at putting forward a novel temperature controller (including software and hardware) for a fan-and-damper refrigerator considering the electric current drawn by the single-speed compressor as the process variable. The control algorithm consists in a dynamic reference modification of a PI controller, together with a set of empirical conjectures. In addition, a purpose-built electronic board was designed and prototyped. All experiments were performed in-house with the refrigerator placed in a climate chamber. The refrigerator was tested at two different surrounding air temperatures (16 and 25 °C) under pulldown, defrost recovery, and variable ambient temperature regimes. It was noted that the proposed controller was able to maintain the refrigerator temperature within ±1 °C tolerance bounds – figures like those obtained for the baseline thermistor-based temperature controller – albeit being less costly. [ABSTRACT FROM AUTHOR]

Electrocatalytic water-gas shift reaction (EWGSR) at room temperature and atmospheric pressure is an emerging process for high-pure hydrogen production without an additional H 2 separation procedure. Therefore, developing efficient electrocatalysts of EWGSR is one of the critical factors for its wide applications. Herein, the effects of support and calcinated temperature on the EWGSR performance are highlighted by systematically investigating the Pt/γ-Fe 2 O 3 , Pt/CeO 2 , Pt/TiO 2 , and Pt/α-Fe 2 O 3 catalysts. The results reveal that the γ-Fe 2 O 3 supported Pt catalyst (calcined at 400 °C) exhibits the lowest anodic onset potential and the highest activity compared to these prepared catalysts, and the mass activity is 3.5 times as high as 20% Pt/C. Furthermore, the onset potential for the EWGSR shows a strong correlation with the active O in the amorphous PtOx structures, where the active O atoms can promote the activation of the OH− and reduce the onset potential of the reaction. The significantly enhanced catalytic performance and durability are more responsible for the exposed Pt0 and the weak adsorption of CO on the Pt/γ-Fe 2 O 3 catalyst. This study provides a new and promising route for designing excellent Pt catalysts for EWGSR in the hope that it can be helpful to the scholars in this orientation. [Display omitted] • The Pt/γ-Fe 2 O 3 presents the lowest onset potential and best reactivity for EWGSR. • The Pt/γ-Fe 2 O 3 possesses the Pt0 coupled PtOx with an active oxygen site. • The reduced onset potential is responsible for the active O in PtOx structure. • The enhanced activity is positive relative to the weak absorption of CO. • The Pt0 coupled PtOx serves as the optimal active site for EWGSR. [ABSTRACT FROM AUTHOR]

Thermal stratification widely exists in large reservoirs, causing significant inflow-outflow temperature difference (IOTD), which goes against the downstream ecology. Reservoir optimal operation has recently been conducted to regulate the outflow temperature, while its effects for cascade reservoirs urgently needed to be illuminated. Taking the typical Xiluodu-Xiangjiaba cascade reservoirs (XXCR) as study case, this paper had built a multi-objective optimal operation model combing the non-dominated sorting genetic algorithm II (NSGA-II) and a hydrodynamic-temperature model, and the total power generation (TPG) and IOTD were simultaneously considered. The effects of different inflow discharge and global warming scenarios were analyzed. This paper showed the following: (1) The IOTD and TPG of XXCR showed a positively linear relationship with the water level of the superior Xiluodu Reservoir (XLD), instead of the inferior Xiangjiaba Reservoir (XJB). (2) The reservoir with larger water volume and depth (such as XLD) determined the thermal structure and hydropower generation in cascade reservoirs, compared with the inferior reservoir (such as XJB). (3) As the inflow discharge or air temperature increased, the slope between the IOTD and TPG in the Pareto front curve increased. The results of this paper could support the ecological operation for cascade reservoir to regulate the outflow temperature. [Display omitted] [ABSTRACT FROM AUTHOR]

• MacCormack scheme based Numerical Model for simulating temperature profile in landfill. • Model Considers waste stratification as new and old as aerobic and anaerobic. • Includes depth Variability in density, moisture content & hydraulic conductivity. • A correlation of 0.8 and 0.73 is obtained in calibration & validation. • Landfill temperature rises at all depths and in all season. Elevated Landfill temperatures have an undesirable effect on landfill cover, stability, slope and leachate migration pattern. Thus, to predict the temperature profile in the landfill a distributed numerical model using MacCormack finite difference method is developed. The developed model considers stratification of the upper and lower layers of the waste as new and old waste by assigning different values of heat generation for aerobic and anaerobic processes. Further, as the new layers of the waste get accumulated over the older layers, the density, moisture content and hydraulic conductivity of the underlying waste layers get modified. The mathematical model utilizes a predictor–corrector approach with a Dirichlet boundary at the surface and no flow condition at the bottom. The developed model is applied to the Gazipur site located in Delhi in India. A correlation coefficient of 0.8 and 0.73 is obtained between the simulated and observed temperatures in calibration and validation respectively. The result shows that the temperature at all the depths and in all the seasons was found to be higher than the atmospheric temperature. The maximum difference of 333 °C was observed in December, and the minimum difference of 22 °Cs was observed in June. The temperature rise is higher in the upper waste layers as it undergoes aerobic degradation. The locus of the maximum temperature gets modified with moisture movement. Since the developed model shows a good agreement with the field observation, it can be used to predict the temperature variation within the landfill under different climatic conditions. [ABSTRACT FROM AUTHOR]

There has been growing concern over improving the driving range of electric vehicles (EVs) and achieving rapid cabin thermal comfort upon entering a hot-soaked vehicle, thereby reducing occupant stress and discomfort. This comprehensive review focuses on the interior cabin soak temperature of commercial vehicles impacts when parked under direct sunlight and; evaluates the potential, characterization, drawbacks, and recent developments of the temperature reduction approaches in improving safety, comfort and fuel efficiency. Various cabin temperature reduction methods in the literature have been collected, analyzed, and evaluated. It has been found that cabin temperature threatens children and pets, leading to discomfort upon entry and reaching deadly levels. The most feasible passive technologies include implementing phase- change-materials (PCMs), solar chimneys, aluminium covers, solar-powered ventilation, and reflective glass. The colour of the car's bodywork should also be considered, as it has a significant impact on reducing the cabin air temperature. The choice of technology depends on factors such as energy source type, economic feasibility, end-user behaviour, and government regulations. [ABSTRACT FROM AUTHOR]