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Solid-state refrigeration has emerged as the most promising alternative to conventional refrigeration technology. However, for this technology to be applicable, the caloric effects produced in the alloys must be highly reversible. In this context, we compare the elastocaloric effect of two Ni–Mn–Ga alloys with different types of modulated martensite. The elastocaloric effect, quantified as the isothermal entropy change (ΔSela), was investigated in Ni50Mn28Ga22 and Ni50Mn30Ga20 alloys with 5M and 7M modulated martensite, respectively. Maximum ΔSela values obtained were 1.91 J kg−1 K−1 during cooling and 1.83 J kg−1 K−1 during heating in martensite 5M and 0.19 J kg−1 K−1 during cooling and 0.26 J kg−1 K−1 during heating in martensite 7M, for a constant applied stress of 10 MPa. However, although the 7M modulated martensite exhibited a lower ΔSela, its reversibility was higher. Therefore, our results could be useful for selecting a good material to be used in solid-state refrigeration. [ABSTRACT FROM AUTHOR]

Fabricating a thermo‐electro‐magnetic material that exhibits simultaneously excellent magnetocaloric (MC) and thermoelectric (TE) performance is challenging since the interfacial reaction causes severe deterioration of MC and TE performance. In this work, a construction of multi‐scale interfaces in LaFe10.4Co0.8Si1.8/Bi0.5Sb1.5Te3 (LFS/BST) composites is realized by adopting a low‐temperature high‐pressure sintering strategy. It is revealed in the atomic‐scale that the interfacial reaction between LFS and BST leads to the formation of (Fe,Co)(Sb,Te)2 micro‐grains and LaTe2 nano‐grains, and the latter form low‐mismatch phase boundaries with LFS matrix. Benefiting from the multi‐scale interfacial phases, excellent MC performance of LFS is preserved alongside a minor impact on TE properties, e.g., a peak zT of 1.04 and a small decrease of 3.0% in relative cooling power are achieved in the 2%LFS/BST composite. Compared with other thermo‐electro‐magnetic materials, a good trade‐off between MC and TE performance is realized in LFS/BST composites with simultaneously high MC and TE performance. The 20%LFS/BST composite exhibits a room‐temperature zT of 0.46 with large maximum magnetic entropy change and relative cooling power of 0.81 J kg−1 K−1 and 44.83 J kg−1, respectively. This work provides an effective material design for developing the all‐solid‐state MC/TE hybrid refrigeration technique. [ABSTRACT FROM AUTHOR]

This study investigates the implementation of a cryogenic chiller utilizing a mixed-refrigerant cascade refrigeration cycle (MRCRC). In this setup, R-404A is employed in the high-temperature circuit (HTC), while a mixture of refrigerants is utilized in the low-temperature circuit (LTC). Unlike a conventional MRCRC that operates without a receiver to maintain the composition ratio, this research explores the impact of receiver installation on system performance. Experiments were conducted with and without a receiver to assess performance improvements and device behavior. With a fixed refrigerant charge of 4 kg, the suction and discharge pressures of the LTC compressor remained low and stable after the receiver's installation. The addition of a receiver significantly reduced the cooling time, with further reductions observed as the refrigerant charge increased. The system achieved evaporative heat capacities of 0.59, 1.76, and 2 kW for refrigerant charges of 4, 7, and 9 kg, respectively. Notably, at the maximum refrigerant charge of 11 kg, the evaporative heat capacity peaked at 3.3 kW. These findings indicate that incorporating a receiver is crucial for enhancing the cooling performance of cryogenic coolers using mixed refrigerants and stabilizing device operation. This contrasts with previous studies that omitted receivers due to concerns over potential alterations in the composition ratio of the mixed refrigerant. [ABSTRACT FROM AUTHOR]

The pursuit of high-efficiency and zero-emission refrigeration technologies has spurred interest in electrocaloric (EC) refrigeration utilizing ferroelectric (FE) materials, where accurate characterization of the EC effect is crucial for comprehending its underlying physical mechanisms and for developing high-performance EC materials. In this study, we investigate the influence of unsaturated vs saturated FE polarization characteristics on EC effects using Pb0.99Nb0.02[(Zr0.6Sn0.4)0.85Ti0.15]0.98O3 ceramics. Direct EC measurement reveals that unsaturated loops can introduce substantial errors and even fake negative EC effects when employing the Maxwell approach for indirect EC measurement. In contrast, relatively accurate indirect EC results can be obtained using saturated FE hysteresis loops. Furthermore, it also highlights the necessity for saturated polarization conditions to achieve optimal EC performance in FEs. This work not only emphasizes the importance of carefully selecting polarization data for indirect EC measurements, but also presents a universal strategy to enhance EC effects in various materials. [ABSTRACT FROM AUTHOR]

This study investigates the diffusion and network structure of hydrogen technology from 1980 to 2022. Hydrogen fuel cell technology has the shortest diffusion cycle and high global acceptance. Production technology shows significant global demand, particularly within regional patent families. In contrast, hydrogen storage and fuel cell technologies have more concentrated diffusion, indicating higher adaptation thresholds. Japanese firms are crucial in spreading storage and production technologies, while U.S. enhances diffusion through licensing and transfer. Hydrogen refrigeration technology exhibits a more dispersed bidirectional network. Hydrogen production and fuel cell technologies demonstrate notable activity and network scale in the global market. This research provides valuable insights into the global development of hydrogen technology. [Display omitted] • The evolution of hydrogen technology diffusion was evaluated from 1980 to 2022 using patent data. • Hydrogen fuel cell technology shows the shortest diffusion cycle, hydrogen storage and fuel cell technologies have concentrated diffusion in core countries. • Hydrogen production technology and hydrogen refrigeration technology exhibits broader diffusion. [ABSTRACT FROM AUTHOR]

The reliable operation of scroll compressors is crucial for the efficiency of rotating machinery and refrigeration systems. To address the need for efficient and accurate fault diagnosis in scroll compressor technology under varying operating states, diverse failure modes, and different operating conditions, a multi-branch convolutional neural network fault diagnosis method (SSG-Net) has been developed. This method is based on the Swin Transformer, the Global Attention Mechanism (GAM), and the ResNet architecture. Initially, the one-dimensional time-series signal is converted into a two-dimensional image using the Short-Time Fourier Transform, thereby enriching the feature set for deep learning analysis. Subsequently, the method integrates the window attention mechanism of the Swin Transformer, the 2D convolution of GAM attention, and the shallow ResNet's two-dimensional convolution feature extraction branch network. This integration further optimizes the feature extraction process, enhancing the accuracy of fault feature recognition and sensitivity to data variability. Consequently, by combining the global and local features extracted from these three branch networks, the model significantly improves feature representation capability and robustness. Finally, experimental results on scroll compressor datasets and the CWRU dataset demonstrate diagnostic accuracies of 97.44% and 99.78%, respectively. These results surpass existing comparative models and confirm the model's superior recognition precision and rapid convergence capabilities in complex fault environments. [ABSTRACT FROM AUTHOR]

The linear compressor is one of the main energy-consuming components in domestic and space refrigeration systems. Due to the asymmetric leakage in the clearance, the piston offset unavoidably causes the piston to deviate from its designed equilibrium position and worsens the compressor performance. In this paper, a new method is proposed to inhibit the piston offset. A biased center port is employed to direct gas from the back chamber to the front at the position close to the back chamber to balance the pressure on the two sides of the piston. To verify this method, a numerical simulation was performed to calculate the mass flow through the clearance and center port channel, and the average pressure difference across the piston. An experimental bench was established to compare the offset of the structures with no center port, unbiased center port and biased center port. Results show that the biased center port can almost eliminate the piston offset at the designed operating condition. [ABSTRACT FROM AUTHOR]

Refrigeration plays a significant role across various aspects of human life and consumes substantial amounts of electrical energy. The rapid advancement of green cooling technology presents numerous solar-powered refrigeration systems as viable alternatives to traditional refrigeration equipment. Exergy analysis is a key in identifying actual thermodynamic losses and improving the environmental and economic efficiency of refrigeration systems. In this study exergy analyze has been conducted for a solar-powered vapor compression refrigeration (SP-VCR) system in the region of Ghardaïa (Southern Algeria) utilizing R1234ze(E) fluid as an eco-friendly substitute for R134a refrigerant. A MATLAB-based numerical model was developed to evaluate losses in different system components and the exergy efficiency of the SP-VCR system. Furthermore, a parametric study was carried-out to analyze the impact of various operating conditions on the system's exergy destruction and efficiency. The obtained results revealed that, for both refrigerants, the compressor exhibited the highest exergy destruction, followed by the condenser, expansion valve, and evaporator. However, the system using R1234ze(E) demonstrated lower irreversibility compared to that using R134a refrigerant. The improvements made with R1234ze are 71.95% for the compressor, 39.13% for the condenser, 15.38% for the expansion valve, 5% for the evaporator, and 54.76% for the overall system, which confirm the potential of R1234ze(E) as a promising alternative to R134a for cooling applications. [ABSTRACT FROM AUTHOR]

Eggs are among the most nutritious foods, but they are perishable. Immediately after they are laid, ageing processes begin in shell eggs, altering their chemical, physical and functional properties. This study aimed to determine the effect of storage temperature on the shelf life of hen eggs according to changes in some important physical properties (weight, pH, Haugh Unit, Albumen Index, and Yolk Index). The studied temperatures were selected as possible refrigerator and room temperatures (10, 20 and 30°C). It was revealed that temperature significantly influenced egg quality, with the most significant effects observed in the Haugh unit and pH due to weight changes. The highest quality loss occurred at 30°C. The activation energies for each quality parameter were determined using the Arrhenius equation. The pH of the fresh egg was 7.6 ± 0.1 and increased to over 8.5 – 9.0 during storage, depending on the temperature. Haugh unit, albumen index, and yolk index decreased, and the area of both yolk and albumen increased during storage. [ABSTRACT FROM AUTHOR]

Background: The pre-polymerization temperature of resin composite restorative materials could influence their adaptation to cavity details. As a current debate is existing about the refrigeration of resin composite restorative materials, this study was designed to assess the effect of refrigeration of 3 types of resin composite restorative materials with different matrix systems on their marginal adaptation in Class II restorations. Methods: Forty-two sound maxillary molars, each with two separated Class II cavities, were used in this study. The teeth were assigned into 3 main groups (n = 14) according to the restorative /adhesive system used; an Ormocer-based composite (Admira Fusion/Futurabond M+, Voco GmbH, Cuxhaven, Germany), a methacrylate modified Ormocer-based (Ceram.X SphereTEC One/Prime&Bond Universal, Dentsply Sirona GmbH Konstanz, Germany), and a methacrylate-based (Tetric N-Ceram/Tetric N-Bond Universal, Ivoclar Vivadent AG, Schaan, Liechtenstein). Each group was then divided into 2 subgroups (n = 14) according to the gingival margin location; 1 mm above and 1 mm below the cemento-enamel junction (C.E.J). Each subgroup was further divided into 2 categories (n = 7) according to the storage temperature; stored at room temperature or stored in refrigerator at 4°- 5° C. Epoxy resin replicas were observed under scanning electron microscope (SEM) to examine the marginal gaps. A gab scoring system was used to assess the marginal adaptation of each restoration by giving scores on the basis of measurements of the maximum marginal gaps. The data obtained were statistically analyzed using the Chi-square test at a significance level of p < 0.05. Results: None of the tested groups exhibited 100% gap-free margins irrespective of margin location or storage temperature. For both storage temperatures, no statistically significant difference was observed among all tested groups either with margins located above or below C.E.J (p > 0.05). As well, there was no statistically significant difference when comparing both marginal locations for each material (p > 0.05). Regarding the effect of storage temperature, statistically significant difference was only observed between the room-temperature stored groups with margins located above C.E.J and their corresponding groups stored in refrigerator (p < 0.05). Conclusion: The refrigeration of resin composite restorative materials prior to the restorative procedures revealed a deleterious effect on marginal adaptation of the restorations with margins located in enamel regardless the type of material used. [ABSTRACT FROM AUTHOR]

In recent years, the detrimental impact of traditional gas–liquid refrigerants on the environment has prompted a shift towards sustainable solid-state refrigeration technology. The elastocaloric effect, particularly in NiTi-based shape memory alloys (SMAs), presents a promising alternative due to its high coefficient of performance. However, conventional methods for alloy development are inefficient, often failing to meet the stringent requirements for practical applications. This study employed machine learning (ML) to accelerate the design of NiTi-based SMAs with an enhanced elastocaloric effect. Through active learning across four iterations, we identified nine novel NiTi-based SMAs exhibiting phase-transformation-induced entropy changes (ΔS) greater than 90 J/kg·K−1, surpassing most existing alloys. Our ML model demonstrates robust interpretability, revealing key relationships between material features and performance. This work not only establishes a more efficient pathway for alloy discovery but also aims to contribute significantly to the advancement of sustainable refrigeration technologies. [ABSTRACT FROM AUTHOR]

Although the addition of buffers provides improved stability to flucloxacillin (FLU) solutions, unbuffered solutions are often preferred in clinical practice. The first purpose of this study was to investigate whether a 50 mg/mL solution of FLU in normal saline is stable for 24 h at 33 °C so that it can be applied for outpatient parenteral antimicrobial therapy (OPAT) using portable elastomeric infusion pumps (PEIPs). When the PEIPs were stored in an oven at 33 °C and deflated over 24 h, the volume of the collected solution, pH, and FLU concentration were checked every 4 h. Obtaining better results than expected based on the literature data, other storage conditions, such as refrigeration, room temperature (RT), 37 °C, refrigeration followed by 24 h at 33 °C and 37 °C, and different batches/brands, were also tested. This study confirmed the pronounced effect of temperature on the stability of FLU and also showed the relationship between the stability of FLU and the initial pH of the solution. FLU was quite stable at refrigeration and RT conditions, with more than 99% and 95% remaining. After 24 h at 33 °C, more than 92% of FLU was still present in the solution, while this number decreased to less than 85% when the storage temperature reached 37 °C. The remaining percentage was found to be even lower when the solution was stored at 2–8 °C for 6 days, followed by 24 h storage at 33 °C or 37 °C, with losses of 17% and 30%, respectively. The stability of FLU became worse when the initial pH of the solution was lower than 5.9 since the concentration of FLU dropped to less than 90% after 24 h at 33 °C, and a precipitate started to form when the initial pH of the solution was around 5.3. Therefore, FLU in PEIPs could be employed for 24 h if the temperature was ideally not more than 33 °C, while the pH should be not less than 5.9 upon reconstituting the FLU solution. [ABSTRACT FROM AUTHOR]

With the focus on the insufficient origin-based cold storage in China, this study investigates the location and routing problem (LRP) of origin-based cold storage for fresh agricultural products. This study considers the loss of fresh agricultural products in different environments during transportation and presents a cold storage LRP model. To address this issue, a hybrid whale algorithm with heuristic rules is designed, and the effectiveness of the algorithm is verified by standard instances. Finally, taking Chenggu County as a practical case, the influence of cold storage capacity and farmers' demand for refrigeration are analysed. Experimental results show that the proposed algorithm has a good effect in solving medium-scale LRP. As the storage capacity increases, the total cost of the system can be increased by 0.086%. As farmers' demand for refrigeration increases, the total cost of the system can be increased by 34.034%. Farmers' demand has a greater impact on the system's total costs than the cold storage capacity. When optimizing the cold storage layout, changes in fresh agricultural product output in the next few years can be roughly predicted, and the most economical optimization scheme can be obtained. [ABSTRACT FROM AUTHOR]

• An enhanced ejector-subcooler CO 2 transcritical refrigeration cycle is presented. • A parametric analysis and optimization of the enhanced cycle and the baseline cycle are carried out. • The results suggest the integration of the proposed cycle could achieve more compact and reliable systems. • The maximum COP improvements are computed as 11.7%-17.5% when the gas cooler outlet temperature ranges from 35 °C to 50 °C and the evaporating temperature is -40 °C. The main drawback associated with CO 2 refrigeration systems is related to their performance reduction during transcritical operation at warm climate conditions, which may be compensated by better cycle architectures such as the split-cycle with subcooling or the flash-tank configuration, among others. Specifically, the use of standard gas-ejectors together with parallel compressors provides even better efficiency improvements, not being able to use them with low-temperature evaporators to prevent the triple point inside the ejector. This paper proposes an enhanced cycle with a gas ejector for two-stage compressor architectures with vapor injection from the flash-tank, which is able to operate at low evaporating temperatures and that provides a greater performance improvement the more severe the climate conditions are. The methodology conducted is based on a thermodynamic analysis that includes parametric evaluation and cycle optimization, comparing the results to a conventional CO 2 transcritical cycle with flash-tank and dynamic vapor injection architecture. The main results show that a maximum Coefficient of Performance improvement of 17.5% is achievable for transcritical operation at -40 °C evaporating temperature. The compressor displacement capacity required with the enhanced cycle is up to 9% lower for the same refrigeration demand, reducing the electrical consumption as well as the compressor expenditure. Moreover, greater vapor injection mass flow rates are obtained by the gas-ejector injection with discharge temperature reductions up to 18%, enhancing the system reliability. [ABSTRACT FROM AUTHOR]

• Ejector cycles achieved higher performance than booster cycle within the gas cooler outlet temperature range of 31 and 50°C. • Multi-ejectors can be applied to ejector cycles with different configurations. • Up to 17% annual energy consumption reduction was found using ejector cycles. • Unit product exergy costs of ejector cycles are up to 28% lower than booster cycle. Restrictions on high-GWP refrigerants have made the use of transcritical CO 2 refrigeration systems widespread. Using transcritical booster refrigeration cycle in warm climates is unsatisfactory due to its high energy consumption. This paper presents theoretical analysis and performance comparison of three different transcritical CO 2 supermarket refrigeration cycle configurations with ejector expansion in Türkiye, which has different climatic regions. Bin-hour data were derived using hourly dry-bulb temperature values for provinces from 7 different regions in Türkiye. The applicability of multi-ejectors to each modeled cycle was also investigated. Annual energy consumption and environmental impact reductions of up to 17% were obtained using ejector expansion cycle compared to booster cycle. Ejector expansion cycles achieved higher performance than booster cycle up to 46% in terms of exergy efficiency at investigated ambient temperatures. Unit product exergy costs of the ejector cycles were found up to 28% lower than booster cycle. [Display omitted] [ABSTRACT FROM AUTHOR]

Adoption of the new regulation 2024/573 of the European Parliament and of the Council, due to the increase in global warming, commercial refrigeration adapts, together with the reduction of the possibility of using refrigerants with a GWP greater than 150 units starting from 2025. In this way, the transition to refrigerants with GWP less than 150 units becomes mandatory for manufacturers of stationary refrigeration equipment. Refrigerants with GWP below 150 units are from category A2L (slightly flammable refrigerants) and A3L (flammable refrigerants) and this implies greater safety measures in installation and service than in the case of refrigerants from category A1L (nonflammable refrigerants) [ABSTRACT FROM AUTHOR]

CO2 refrigeration and heat pump systems have gained widespread attention due to their environmentally friendly features. However, their application is limited by high operating pressure and limited refrigeration performance. To address this, the technology of adding other refrigerants to CO2 to form a CO2-based mixture has emerged as an effective solution, as it reduces operating pressure and improves energy efficiency. Although CO2-based mixtures can be mixed in any ratio, there is an optimal composition ratio that maximizes performance under given working conditions. However, as working conditions change, the optimal composition ratio also changes, and fixed compositions cannot achieve the best energy efficiency throughout the year. Therefore, this paper studies four types of CO2-based mixtures, namely CO2/R32, CO2/R290, CO2/R1270, and CO2/R1234yf， and proposes a CO2-based mixture refrigeration and heat pump systems composition adjustment scheme that adjusts the system's composition according to different working conditions. The paper designs two composition adjustment strategies, studies the limits of composition adjustment using different methods, and evaluates the energy-saving performance of different adjustment methods. The results show that the maximum range of composition adjustment is between.25 and.97， and the energy-saving of up to 27.2% can be achieved through composition adjustment in some areas. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials and their heterostructures have been widely explored for high-performance energy conversion applications. The Thomson effect—a higher order transport process—plays an important role in thermoelectric devices, yet its effect on the performance of thermionic devices remains unknown thus far. Here, we investigate the performance of thermionic refrigeration in vertically stacked heterostructure (VHS) and laterally stitched heterointerface (LHS) composed of a graphene and a 2D semiconductor (i.e., MoS 2 and WSe 2) in the presence of the Thomson effect. Using a temperature-dependent Seebeck coefficient, we derived the analytical expressions of the cooling efficiency and the effective Z T. We shall show that the Thomson effect improves the coefficient of performance (COP) by up to 20%, particularly, in the case where the temperature difference between the cold and the hot electrodes is large. However, the Carnot efficiency decreases with the temperature difference. The overall COP is reduced by the Thomson effect. We calculate the COP in graphene/MoS 2 /graphene and graphene/WSe 2 /graphene VHS and LHS devices. We show that the LHS composed of WSe 2 significantly outperforms the VHS and MoS 2 counterpart. These findings provide an understanding of thermionic processes in the higher-order transport regime and shall offer insights into the design of novel 2D material heterostructure thermionic energy converters. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the effects of a decreasing refrigerant charge on the performance and operating conditions of an R513A water-to-water heat pump equipped with a large liquid receiver, an electronic expansion valve, and a vapor accumulator at the compressor inlet. The mass of the refrigerant inside the machine is progressively extracted to simulate refrigerant leakages occurring during the normal operation or in case of failures. The results show that the subcooling is the parameter mostly affected by a refrigerant charge variation since it rapidly collapses to 0 K with the charge reduction. Furthermore, it is possible to identify three different zones in which almost all the properties analyzed (COP, heating capacity, operating pressures and expansion valve opening) exhibit peculiar trends with the charge decrease: subcooling sensitivity zone, constant parameters zone, and compressor failure risk zone. The extension of these zones is determined by the size of the liquid receiver which is installed in the system and, for the heat pump under consideration, is between 100% and 95% of the initial charge for the first zone, between 95% and 40% for the second zone, and below 40% for the third zone. [ABSTRACT FROM AUTHOR]

• The matching relationship of high-performance GWOT at different ω is obtained. • The maximum increase in η by adjusting n is about 8 % over that at the design point. • The increase in the ω leads to a maximum reduction in η of about 25 %. • There will be a maximum of about 15 per cent liquid loss. The gas wave oscillation tube (GWOT) transfers energy directly between gases of varying pressures using non-constant motion waves, and its low rotational speed operation offers a broader application potential in two-phase refrigeration compared to turbomachinery. The GWOTs achieve a high performance by optimizing the relationship between tube length, deflection displacement, rotational speed, and incident excitation wave (S1) velocity. However, under the liquid-carrying conditions, the optimizing matching relationship of the GWOTs deviates, leading to a decline in performance, so it is necessary to explore the matching relationship of the high performance of the GWOTs under the liquid-carrying conditions. This study focuses on "spoon" GWOTs, analyzing the impact of rotational speed, liquid-carrying capacity, and deflection displacement on their refrigeration performance under a fixed tube length through experimental analysis. It is found that the refrigeration efficiency at the design parameters of the GWOTs decreases by a maximum of about 25 % with the increase in the amount of liquid-carrying capacity within the study area of this paper, while the refrigeration efficiency can be improved by a maximum of about 8 % by varying the rotational speed. The findings provide valuable insights for enhancing the liquid-carrying performance of the GWOTs and promoting the application expansion of GWOTs in the field of gas-liquid two-phase. [ABSTRACT FROM AUTHOR]

Due to long lifetime, low level vibration and negligible electromagnetic interference, the Joule-Thomson (JT) cryocooler working at liquid helium temperature has been used in space. However, its cooling capacity and thermodynamic efficiency still need to be further improved under a certain mass limit, which is an essential improvement for space-efficient application of the JT cryocooler. Therefore, in this study, optimization design is carried out for a JT cryocooler working at liquid helium temperature. Based on the modification of Stirling cryocooler, pulse tube cryocooler and JT compressor, the developed JT cryocooler can provide a cooling capacity of 0.36 W at 4.18 K while the total input power and the total mass (without cryostat) are 1157 W and 26.8 kg, respectively. Compared with the literature research, it can be found that the developed JT cryocooler is suitable for space applications. [ABSTRACT FROM AUTHOR]

The incorporation of ejectors into heat pump and refrigeration cycles has been the subject of growing interest, largely due to their simple structure, high reliability, and cost-effectiveness. This paper investigates the recent advancements in novel design concepts of ejector-enhanced vapor compression heat pump and refrigeration cycles. An overview of novel single-stage and two-stage compression cycles utilizing a single or multiple ejectors is provided. First, the system setup, operational principles, description, and figures of the existing schemes are provided. Second, the main results, such as the coefficient of performance (COP), volumetric heating capacity and exergy destruction, are discussed. In conclusion, the paper presents a coherent summary of the current developments, future prospects, and the current knowledge gap. A plethora of research is present in developing theoretical systems with high efficiency. However, experimental tests for real-life implementations are limited. This review aims to provide the reader with an overview of recent theoretical and experimental studies. [ABSTRACT FROM AUTHOR]

【Objective】Telenomus remus is the dominant egg parasitoid of Spodoptera frugiperda, and Spodoptera litura is an excellent host for the reproduction of T. remus. The study was conducted to clarify the effects of refrigeration temperature and duration of S. litura eggs on the reproductive ability of T. remus, which would provide references for the biological control of S. frugiperda.【Method】Different refrigeration temperatures (4, 8, 12 ℃ ) and durations (0, 3, 6, 9, 12 d) were designed to refrigerate the eggs of S. litura for the parasitism of T. remus, the effects of parasitism rate, emergence rate and female ratio of T. remus were analyzed.【Result】The results showed that both the refrigeration temperature and duration of S. litura eggs could significantly affect the parasitism rate, emergence rate and female ratio of T. remus (P < 0.01). Overall, with the decrease of refrigeration temperature and the prolongation of refrigeration duration of S. litura eggs, the parasitic reproduction indicators of T. remus showed a downward trend. The most suitable refrigeration condition were obtained at 8 ℃ or 12 ℃ for 3 d, which had no significant effect on T. remus reproduction compared with the control (P > 0.05). The parasitism rate, emergence rate and female ratio of S. litura eggs were 85.98%, 94.71%, 56.15% (8 ℃, 3 d) and 85.49%, 94.61%, 60.00% (12 ℃, 3 d), respectively. It had a significant effect on the parasitism of S. litura eggs when the eggs were refrigerated at 12 ℃ for 6 d or 9 d (P < 0.05). The parasitism and reproduction of T. remus were affected to a certain extent, but it could still maintain the normal reproduction of the population, which could be used as an alternative refrigeration condition for S. litura eggs. It also had a significant effect on the parasitism of S. litura eggs (P < 0.05) when the eggs were refrigerated under other conditions which should not be considered as suitable refrigeration condition for the eggs of S. litura.【Conclusion】For short-term refrigeration, the condition at 8 or 12 ℃ for 3 d is recommended for S. litura eggs; while for longer duration, 12 ℃ can be selected, but the refrigeration time should not exceed 9 d. [ABSTRACT FROM AUTHOR]

The compressor is the most core component of refrigeration products, and its performance directly affects the overall performance of the product. The exhaust silencing chamber and coil are key components of a refrigeration compressor, and their working stability and lifespan determine the reliability and economy of the refrigeration compressor. This paper obtains reference data for the fluid domain of the exhaust silencing chamber through simulation analysis and image processing of the existing exhaust silencing chamber structure and inner diameter size of the coil. Then, the optimal model of the prioritized exhaust chamber is obtained through pattern recognition method. Based on the image processing method, the internal flow field of the exhaust chamber are obtained, providing a strong reference for the optimal structural design of the exhaust silencing chamber and coil of the refrigeration compression body. [ABSTRACT FROM AUTHOR]

Isentropic (adiabatic) compression of superheated vapor in vapor compression refrigeration cycles usually results in some discharge superheat, i.e. the discharge temperature exceeding the condensing temperature. Large discharge superheat reduces both operating range and compression efficiency. Sub-isentropic compression with heat rejection to the heat sink is therefore superior to adiabatic compression, as it results in lower discharge superheat and improved efficiency. However, significant temperature reduction by heat transfer through the working chamber walls is difficult to facilitate in common refrigeration compressors, particularly reciprocating compressors. Refrigerant and oil injection is a well-established method for reducing temperatures and increasing efficiency in screw and scroll compressors, as well as multi-stage systems. In comparison, effective methods for temperature reduction in single-stage reciprocating compressors are fairly limited. Therefore, a concept for high-pressure liquid injection is proposed. By means of a pump and injection valve, high-pressure liquid refrigerant is injected into the working chamber and atomized. The compressed gas is cooled through the evaporation of the injected liquid. The injection valve allows for control over the injection timing and quantity, enabling adjustment of the temperature profile, which is a major distinction from existing refrigerant injection methods. The coupled compression-injection process is evaluated for various refrigerants using an energetic chamber model. The injection is found to be particularly suitable for refrigerants with a large evaporation heat and a shallow dew line slope. For the example of ammonia, a theoretical reduction in compression work of 8.9% at an evaporation temperature of −10 °C and a condensing temperature of 45 °C is found. • Proposal of high-pressure liquid injection for reciprocating compressors. • Theoretical evaluation using energetic chamber model. • Potential for significant efficiency improvement compared to isentropic compression. • Increased operating range due to reduced discharge temperature. [ABSTRACT FROM AUTHOR]

Purpose: Generic lorazepam oral solution is supplied in a 30 mL multi-dose bottle requiring protection from light and refrigeration, with a beyond use date of 90 days once the bottle is opened. The repackaging of 1 mL doses of lorazepam oral solution into oral syringes allows for facilitated dispensing, yet no available data supports repackaging and storing lorazepam oral solution in syringes. The validation and application of a stability-indicating high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method for the quantification of lorazepam allowed for the determination of the stability of lorazepam oral solution when stored in oral syringes. Methods: A stability-indicating HPLC-UV method was developed for the quantification of lorazepam in oral solution. The method was validated using guidance from USP < 1225 >. For the stability investigation, 2 mg/mL lorazepam oral solution was aliquoted into clear plastic oral syringes in 1 mLmilliliter doses from 2 multi-dose stock bottles and randomly allocated for storage in room temperature or refrigerated environment. Baseline lorazepam concentrations were measured on the day the study was initiated and designated as 100% initial concentration samples. Subsequent samples were analyzed in triplicate at time points of 24, 48, and 96 hours and 7, 10, 14, 21, 30, and 60 days. Results: The calibration curves on three non-consecutive days met the linearity criteria of R 2 > 0.99. Inter- day and intra-day precision and accuracy (percent relative standard deviation and percent error) were ≤2% over three days. During the stability investigation, percent initial concentration of lorazepam from room and refrigerated syringes remained above 90% for the duration of the study. Conclusion: The stability-indicating HPLC-UV method was successfully applied to the investigation of lorazepam oral solution stability when stored in syringes at room and refrigerated temperatures. The emergent need for use of lorazepam concentrate for inpatients and the restrictions of how the medication is supplied necessitated a need for the evaluation of repackaging into unit dose syringes for immediate availability from automated dispensing cabinets. Lorazepam oral solution stored in clear plastic syringes maintained greater than 90% initial concentration at both room and refrigerated temperatures for 60 days. [ABSTRACT FROM AUTHOR]

Due to the strong dependence of the food industry on the cold chain, utilizing an optimal refrigeration facility plays a crucial role. This study focuses on the pattern of energy consumption, energy performance and exergy efficiency, and environmental effects (3E) of compression refrigeration systems used in multi-purpose cold storage. Depending on the climate and storage conditions, cooling load distribution between above and below zero evaporators significantly affects energy consumption and exergy efficiency. The limitations of each system in different cooling load demands using eco-friendly refrigerants determine that R717/R290, R290, and R134a are the optimal refrigerants for cascade, two-stage, and one-stage systems, respectively. The results show that cascade system is the least constrained operationally and technically. Its exergy efficiency is up to 4% higher than two-stage system, depending on how the refrigeration load is distributed. Two-stage system has the highest seasonal energy performance ratio (SEPR) (13% more than cascade in hot and humid climate). Its energy consumption is 18–25% less than cascade system depending on climate. Furthermore, it was found that the one-stage system is only suitable for hot and humid climates while two other systems operate well in all climates throughout the year. The amount of SEPR under cold climates for cascade system is 14% more than hot and humid climates and 3% more than moderate climates. [ABSTRACT FROM AUTHOR]

For half a century, only Bi2Te3-based thermoelectrics have been commercialized for near room temperature applications including both power generation and refrigeration. Because of the strong layered structure, Bi2Te3 in particular for n-type conduction has to be texturized to utilize its high in-plane thermoelectric performance, leaving a substantial challenge in toughness. This work presents the fabrication and performance evaluation of thermoelectric modules based on n-type Ag2Se paring with commercial p-Bi2Te3. Ag2Se mechanically allows an order of magnitude larger fracture strain and thermoelectrically secures the module efficiency quite competitive to that of commercial one for both refrigeration and power generation within ± 50 K of room temperature, enabling a demonstration of a significantly tougher alternative to n-type Bi2Te3 for practical applications. The authors report better toughness in n-type Ag2Se than commercial Bi2Te3. The fabricated n-Ag2Se/p-Bi2Te3 modules show good performance and long-term stability for both refrigeration and power generation near room temperature. [ABSTRACT FROM AUTHOR]

Technology development in the modern era encourages the utilization of efficient technologies, such as the Internet of Things (IoT) and Cyber-Physical Systems (CPS). This study focuses on developing a cyber-physical system using smartphones to control and monitor refrigeration systems in fishing vessels. Through performance testing, IoT and CPS technologies have been successfully implemented to monitor refrigeration system temperature in real-time, optimize performance, and take preventive actions as needed. The testing included the temperature control and monitoring of the primary sensor of the refrigeration machine. The accuracy of the application was evaluated by adding a reference sensor using the standard deviation as a measure between the primary and reference sensors. The test results consist of three data points. First, the test on data 1 shows the room temperature before activating the refrigeration machine, with an average difference of 2.6 and a standard deviation of 0.985. The second aspect involves a sudden pipe leakage, resulting in a difference of approximately 0.9 with a standard deviation exceeding 1.1. The third aspect includes the average difference in the measurements after activating the refrigeration machine, which indicates a higher consistency between the primary and reference sensors. The research findings indicate a minimal standard deviation, indicating a high level of measurement accuracy. Implementing this system is expected to enable the control and monitoring of refrigeration systems, assist fishermen in minimizing losses, and improve the quality of fishery products. [ABSTRACT FROM AUTHOR]

This article presents the performance estimation of a single-stage vapor adsorption system employing various carbon-based adsorbents with ethanol refrigerant, coupled with a small-scale biomass-based heating unit for space cooling, refrigeration, and heat-pumping applications. A detailed parametric investigation highlights the effects of operating temperatures, and heat exchanger to adsorbent mass ratio on specific cooling energy (SCE), coefficient of performance (COP), uptake efficiency (ηu), and mass of adsorbent to combustion fuel (mad/mcf) to identify the suitable adsorbent and sorption bed designs for each application. The numerical findings reveal that the flat-finned tube (FFT) adsorber outperforms traditional-finned tube (TFT) and tube & shell-type (T&S) adsorbers, achieving 19% and 30% higher COP, respectively, with biomass carbon-ethanol pair. The H2-treated Maxsorb-III shows the greatest optimal cooling COP (0.73), followed by the biomass-carbon (0.72) for refrigeration and space cooling. For heat pumping applications, biomass carbon-ethanol achieves the highest heat pumping COP (1.84) at a desorption temperature of 90°C, surpassing H2-treated Maxsorb-III. Further, the biomass-derived activated carbon requires the lowest amount of adsorbent per unit mass of combustion fuel in the biomass heating unit. The present thermodynamic analysis is a precursor for optimization of the potential heat-exchanger geometries and operating parameters, with the high-performance carbon adsorbents. [ABSTRACT FROM AUTHOR]

The present study deals with the performance evaluation of four CO2 booster refrigeration system configurations: a conventional, a parallel compressor, an ejector-based, and an NH3/CO2 cascade configuration, under the ambient conditions of the city of Bucaramanga, Colombia. Applying detailed energy and exergy analyses, as well as an evaluation of environmental impact through Total Equivalent Warming Impact (TEWI), it was identified that the ejector-based configuration as the most energy-efficient, exhibiting a 13.2% reduction in annual power consumption compared to the conventional system. The cascade configuration demonstrated the lowest exergy destruction above 26°C, highlighting its potential under higher ambient temperatures. Furthermore, the ejector-based configuration consistently achieved the highest 2nd law efficiency across the temperature range set. The environmental impact analysis showed the ejector-based configuration also had the lowest TEWI, with a 14.36% reduction. The results underscore the importance of selecting appropriate refrigeration configurations based on local climate conditions. [ABSTRACT FROM AUTHOR]

Rural residency is an independent risk factor for being overweight, but little is known about why this is so. The purpose of our study was to gain insight into what Norwegian rural children say about a rural diet in comparison to an urban one. Child‐friendly methods were used. We found a discrepancy between what the children said they eat – traditional, 'healthy' foods, and what they ate – largely ultra‐processed foods. We explored this by using the frameworks of imagined foodways and biopedagogies. Their imagined foodways were rooted in notions of 'traditional food', connected to surrounding nature and a history of farming and hunting. Urban people were perceived as eating an inferior diet of very unhealthy and ultra‐processed foods of which they do not know the origin of. As a result, the children rejected specific health‐ and nutrition recommendations that were incompatible with their notions of traditional foods, leading to a more calorie dense diet than their urban counterparts. Our research adds to knowledge on what role a rural diet can play on the prevalence of overweight in rural areas, and how biopedagogies can be recontextualized within different cultural fields. [ABSTRACT FROM AUTHOR]

This work involves an experimental study on the performance of automobile air-conditioning systems by adding AlO nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed cooling of refrigeration systems and to compare it with the system operated using only oil. The AlO nanoparticles have been added to the oil compressor for different ranges of mass concentration (Ø = 0.1%, Ø = 0.15% and Ø = 0.2%). The stability of AlO nanoparticles has been tested by direct observation for different time periods. The results indicated that the air conditioning system that operated by using AlO-oil was better than the system that operated with pure oil. For Ø = 0.2%, the results indicated that the cooling speed and the efficiency of the system operated with AlO-oil are increased by 13% and 18%, respectively, as compared to the pure oil system. This study shows that the thermos-physical properties of refrigerant oil are enhanced by 15% when Ø is increased. [ABSTRACT FROM AUTHOR]

The Cape gooseberry (Physalis peruviana L.) is renowned for its distinctive appearance and functional properties. Colombia has emerged as the world's leading producer and exporter of Cape gooseberries, with annual export growth of 1.2%, predominantly to countries such as the USA and the Netherlands. Traditionally sold with its calyx intact to minimize water loss and deterioration, recent interest in selling Cape gooseberries without the calyx to reduce volume has raised concerns regarding shelf life. Consequently, research has pivoted toward post-harvest management to extend shelf life. An experiment was conducted to explore various treatments and temperatures (5, 10, and 18 ℃), meticulously monitoring fruit quality over time. Findings underscore that calcium chloride and refrigerated storage at 10 ℃ preserve the quality of the Cape gooseberry fruit for up to 20 days. Moreover, temperature and time exerted a significant influence on fruit quality and physicochemical properties, with interactions impacting conservation methods. The application of calcium chloride as a barrier method yielded optimal preservation outcomes, safeguarding key fruit properties. Conversely, sodium hypochlorite treatment at 18 ℃ accelerated fruit ripening owing to heightened respiratory intensity. This study not only sheds light on effective preservation strategies for Cape gooseberries but also underscores the intricate interplay between environmental factors and post-harvest management techniques. By enhancing our understanding of these dynamics, the study catalyzes advancements in fruit preservation practices, thereby fortifying the agricultural and economic sectors, both domestically and internationally. [ABSTRACT FROM AUTHOR]

Introduction: Lebanon faces severe economic and energy crises, impacting its healthcare system, particularly vaccine storage. Traditional gas or kerosenepowered refrigerators often fail to maintain necessary temperatures for vaccine efficacy. This study explores transitioning to solar direct-drive (SDD) refrigerators to ensure reliable vaccine storage. Methods: A multi-phase methodology was employed, beginning with an inventory assessment of existing cold chain equipment. The implementation involved stepwise replacement of identified refrigerators across health facilities, including Primary Health Care Centers (PHCCs) and dispensaries. Feasibility, cost-effectiveness, and environmental impact were evaluated. Results: Findings indicate that solarization significantly reduces vaccine wastage, ensures stable temperatures, and cuts operational costs by decreasing dependence on non-renewable energy sources. Over 1,000 SDD units were installed across more than 800 health facilities. Additionally, PHCC solarization improved vaccine preservation and enhanced the resilience of health services overall. Discussion: The solarization initiative demonstrates the critical role of renewable energy in strengthening healthcare infrastructure, especially in crisis-hit regions. Solar-powered systems provide a reliable and sustainable solution for vaccine storage, reduce carbon footprints, and build public trust in the immunization system. Challenges included geographical and structural limitations, which were addressed through comprehensive planning and collaboration with local stakeholders. Solarization of Lebanon's vaccine cold chain and PHCCs marks a significant step towards sustainable and resilient healthcare infrastructure. The model offers a robust framework for other regions facing similar economic and energy challenges, highlighting the importance of renewable energy solutions in healthcare. [ABSTRACT FROM AUTHOR]

Hydrofluorocarbon (HFC) refrigerants (such as R134a and R404A), which are widely used in commercial refrigeration systems, contribute greatly to global warming. Because the global warming potential (GWP) values of HFC refrigerants are high. With increasing concerns about the environment (global warming, climate change, etc.) various legal regulations have been made to limit or phase out the use of refrigerants with high GWP values. To use the R471A refrigerant developed by Honeywell in 2022 as an environmentally friendly new-generation refrigerant in the commercial refrigeration system, the performance of the R471A refrigerant should be comprehensively evaluated. In this study, energy, exergy, and environmental analyses of using R471A refrigerant instead of R404A in low and medium-temperature commercial refrigeration systems were carried out and presented. Evaporator temperatures of − 30 °C, − 25 °C, − 20 °C, − 15 °C and − 10 °C and condenser temperatures of 30 °C, 40 °C, and 50 °C were selected to represent low and medium cooling temperatures and hot and cold country seasons. It was seen that R471A presents a lower mass flow rate (between 67 and 71%) and cooling capacity (between 61 and 68%) than R404A however has higher COP (between 6% and 14%) and R404A has exergy efficiency value of 6–14% lower than R471A. Also, from an environmental point of view, R471A has better environmental results than R404A. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate hyperbaric storage at room temperature (75–200 MPa, 30 days, 18–23 °C, HS/RT) on Clostridium perfringens spores in brain-heart infusion broth (BHI-broth) at pH 4.50, 6.00, and 7.50 and coconut water (pH 5.40). Both matrices were also pasteurized by high pressure processing (600 MPa, 3 min, 17 °C, HPP) to simulate commercial pasteurization followed by HS, in comparison with refrigeration (5 °C, RF). The results showed that, at AP/RT, spores' development occurred, except at pH 4.50 in BHI-broth, while for RF, no changes occurred along storage. Under HS, at pH 4.50, neither spore development nor inactivation occurred, while at pH 6.00/7.50, inactivation occurred (≈2.0 and 1.0 logs at 200 MPa, respectively). Coconut water at AP/RT faced an increase of 1.6 logs of C. perfringens spores after 15 days, while for RF, no spore development occurred, while the inactivation of spores under HS happened (≈3 logs at 200 MPa). HPP prior to HS seems to promote a subsequent inactivation of C. perfringens spores in BHI-broth at pH 4.50, which is less evident for other pHs. For HPP coconut water, the inactivation levels under HS were lower (≈2.0 logs at 200 MPa). The Weibull model well described the inactivation pattern observed. These results suggest that HS/RT can be simultaneously used as a tool to avoid C. perfringens spores' development, as well as for its inactivation, without the application of high temperatures that are required to inactivate these spores. [ABSTRACT FROM AUTHOR]

The classical thermoacoustic refrigeration adopts gases with ideal-gas properties as working fluids. Herein, the thermoacoustic refrigeration using a compressible liquid as the working fluid is investigated for the first time. Two models are utilized parallelly: a highly-simplified short refrigerator model and a far-more realistic full-scale thermoacoustic refrigerator model. The results from the short refrigerator model show that, ideally, the coefficient of performance can reach above 70% of the Carnot limit. In the full-scale system discussion, the coefficient of performance of the system can reach as high as 4.1 in a typical working condition for air conditioning (pumping heat from 285 K to 310 K), with respect to 36% of the Carnot limit. When pumping heat from 332 K to 357 K, the coefficient of performance can reach 44% of the Carnot limit. These results indicate that the efficiency of the thermoacoustic refrigeration with a compressible liquid as the working fluid is potentially high, but with a much smaller displacement amplitude of the fluid. As a result, both the acoustic source (the linear motor, for instance) and the heat exchanger can be much more compact, so that the mass and the volume of the system can be greatly reduced, as well as the cost. • Both an idealized and a full-size refrigerator using liquid are modeled. • The liquid thermoacoustic refrigeration may be as efficient as the gas system. • Both the linear motor and the heat exchanger can be much more compact. [ABSTRACT FROM AUTHOR]

• A diffusion-heat-flow coupling model at extremely low temperatures is established. • Friction and phase separation of 3He-4He mixtures are introduced in the model. • Mechanism of heat and mass transfer in mixing chamber is analyzed. • A temperature of 8.01 mK is obtained in the mixing chamber. • Parameter sensitivity analysis of the mixing chamber is performed. Dilution refrigeration using a 3He-4He mixture as a working medium has gradually become one of the most important methods to obtain millikelvin temperature. At present, the study on dilution refrigeration is mainly aimed at commercializing the whole product. However, the heat and mass transfer characteristics of 3He-4He at extremely low temperatures in the mixing chamber lack systematic study. In this study, a diffusion-thermal-flow coupling model in the mixing chamber is established for the first time in view of the low-temperature characteristics of 3He-4He mixtures. An improved two-fluid model is introduced, considering the finite solubility of 3He in the superfluid 4He and the friction between the components of the mixed working medium. The mechanism of refrigeration and diffusion at extremely low temperatures is analyzed. The refrigeration and mass transfer rates caused by diffusion have almost the same variation trend, and the cooling power of 4.9 μW at 20 mK is obtained. The sensitivity of the heat and mass transfer process to the 4He viscosity coefficient is analyzed. The lowest temperature of 8.01 mK is obtained through parameter adjustment in the mixing chamber. Finally, the cooling capacity is transferred layer by layer from the phase interface to both sides, and it is obviously affected by the inlet, showing a bending trend. The refrigeration capacity of the mixing chamber increases rapidly with the increase of the inlet flow rate when the inlet flow rate varies from 25 μmol/s to 50 μmol/s. [ABSTRACT FROM AUTHOR]

• Temperature-distributed refrigeration power is transferred from inside a regenerator. • Temperature-distributed transfer coefficient (TTC) increases with discrete points. • Internal DC transfer method eliminates radial thermal resistance and improves TTC. • Combining DC flow and discrete method increases TTC up to 90 %. • TTC of these new methods is 1–2 times higher than previous transfer methods. The temperature-distributed regenerative refrigeration cycle utilizes the real-gas properties to generate the temperature-distributed refrigeration power and improves the cooling performance and liquefaction rate of cryogenic gases. The temperature-distributed refrigeration power is distributed in the volume of the regenerator. It is challenging to transfer this distributed refrigeration power, and the regenerative heat loss is usually inevitable. The transfer process of the temperature-distributed refrigeration power is studied in this paper. A comprehensive investigation into associated influencing factors is presented in this paper. Furthermore, a parameter of the temperature-distributed transfer coefficient (TTC) is proposed to evaluate the transfer process. This study extends into a broader range of the discrete transfer method from liquid-helium temperatures to ambient temperatures and further analyzes the rules from scattered points to multiple points. The internal DC flow method is adopted to eliminate the radial thermal resistance and improve the TTC, recognizing the constraints of the traditional distributed transfer method (coiling heat exchange tubes outside the regenerator). The TTC of the distributed method with the DC flow is improved around 1–2 times by optimizing the mass flux of multi-strand DC flow and temperature range. It is also improved 1.5–2 times by combining the DC flow and discrete method. Additionally, the TTC is improved about 1–1.5 times with the DC flow when using the refrigeration power for gas liquefaction. [ABSTRACT FROM AUTHOR]

This manuscript presents an innovative simulation study focusing on a solar-powered refrigeration system featuring a mechanical porous sub-cooler. The research evaluates the system's performance by employing diverse porous materials within the sub-cooler, aiming to address the pressing need for sustainable cooling solutions and decreasing dependence on conventional energy sources. The novelty of this study lies in its pioneering approach to bridging a significant void in the current body of the literature. By offering a comprehensive numerical simulation, this research seamlessly integrates three crucial aspects: solar energy utilization, porous media dynamics, and the utilization of diverse refrigerants. The system under scrutiny comprises a 4-ton sub-critical refrigeration unit, incorporating essential components such as a compressor, condenser, porous sub-cooler, expansion valve, and evaporator, with R454B serving as the designated refrigerant. Uniquely, it integrates a solar-powered mechanical porous sub-cooling sub-cycle employing the refrigerant R454C, solved utilizing Engineering Equation Solver (EES) while considering Jordan's climate conditions. The investigation encompasses a range of condensing temperatures from 25 to 40 °C, evaporation temperatures spanning from − 5 to 10 °C, and condensing pressures ranging from 25 to 45 Kpa. The study meticulously analyzes the coefficient of performance and power consumption, considering factors such as sub-cooler porosity, condensing pressure, evaporation temperature, compressor efficiency, and ambient temperature. Remarkably, the results highlight that reducing porosity and condensing pressure significantly enhance the coefficient of performance by approximately 84% and reduce power consumption by 30.2%. Furthermore, enhancements in base-cycle compressor efficiency and decreased sub-cooler porosity also positively impact the coefficients of performance. Particularly noteworthy is the finding that increasing compressor efficiency and decreasing porosity lead to a remarkable 182% increase in the coefficient of performance. This study underscores the critical significance of sub-cooler porosity, compressor efficiency, and condensing pressure for achieving optimal system performance. Moreover, the innovative design of the solar panel system ensures sufficient power generation for continuous operation, thereby conserving utility power during peak solar generation periods. Leveraging the solar-powered mechanical sub-cooling system not only enhances the overall coefficient of performance but also diminishes reliance on utility power, thus contributing to sustainability efforts in refrigeration technology. The model's credibility is affirmed through validation against existing experimental data, further consolidating the reliability and relevance of the study's findings. [ABSTRACT FROM AUTHOR]

With the improvement of the national economic level and the diversity of medical equipment needs, the car refrigerator as an important carrier in the cold chain logistics link is rapidly developed. According to the different applications, there are differences in the refrigeration technologies and cooling capacity of car refrigerators. Around car refrigerators, the development status of car refrigerator refrigeration technologies is reviewed, the characteristics and functions of car refrigerators are introduced, the mechanism and characteristics of several refrigeration technologies under different scenarios are studied, and the potential development and application directions of car refrigerators with different refrigeration technologies are summarized. The research results are of certain practical significance to the improvement of the last-mile of cold chain logistics. [ABSTRACT FROM AUTHOR]

Because of serious concerns about global warming, manufacturers have started phasing out high global warming potential (GWP) refrigerants in commercial refrigeration equipment (e.g., R-134a). As a potential replacement, propane (R-290) is an environmentally friendly refrigerant for commercial refrigeration equipment because its GWP is only three. However, propane is flammable and is therefore classified as a Class A3 refrigerant per ASHRAE Standards, so safety is a very important consideration when propane-based equipment is designed and deployed in buildings. In the event of a refrigerant leak, flammability of the refrigerant depends on the refrigerant's local concentration, which is highly affected by the indoor air environment, including temperature and air flow. In this study, a ventilation system attached to a commercial R-290 refrigeration device was designed to eliminate the flammability risk. Moreover, a computational fluid dynamics (CFD) model was developed to investigate the refrigerant leak, thereby evaluating effects of the ventilation system. The CFD model can visualize the flammable zones owing to the leak. [ABSTRACT FROM AUTHOR]

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This paper investigates the effects of sodium laureth sulfate (SLES) on the wettability of the surface of the two most common recycled plastics in refrigeration equipment: HIPS (high-impact polystyrene) and ABS (acrylonitrile–butadiene–styrene). These plastics, in the form of flakes, were identified on the basis of their FTIR spectra, and then, they were subjected to a study of contact angles using the sessile droplet method. The solutions for the angle analysis included tap water with the addition of SLES. The results of this study showed that at SLES concentrations of 0.1 g/L and 0.2 g/L, the differences in the contact angles for HIPS and ABS were 10.76° and 10.10°, respectively. This research confirmed the potential of using SLES as a support for the flotation separation of plastics with similar densities and surface characteristics, such as HIPS and ABS. [ABSTRACT FROM AUTHOR]

Magnetocaloric refrigeration has remained a promising alternative to conventional refrigeration for the last few decades. The delay in reaching the market is significantly based on materials' related issues, such as hysteresis/reversibility, mechanical stability, or formability. This perspective paper shows the current trends in magnetocaloric materials research, highlighting the families of alloys and compounds that are gaining attention in the recent years. It also includes an overview of novel approaches that can be used to analyze these properties that could improve the applicability of magnetocaloric materials. [ABSTRACT FROM AUTHOR]