Various Conditions Of Temperature Research Articles

Anti-bacterial films developed by incorporating shikonin extracted from radix lithospermi and nano-ZnO into chitosan/polyvinyl alcohol for visual monitoring of shrimp freshness

In recent years, the utilization of smart colorimetric packaging films for monitoring food freshness has garnered significant concentration. However, their limited tensile strength, hydrophobicity, antioxidant, and antibacterial properties have been substantial barriers to widespread adoption. In this study, we harnessed the potential of biodegradable materials, specifically chitosan/polyvinyl alcohol, alongside shikonin extracted from Radix Lithospermi and ZnO nanoparticles, to create a novel colorimetric sensing film. This film boasts an impressive tensile strength of 82.36 ± 2.13 MPa, enhanced hydrophobic characteristics (exemplified by a final contact angle of 99.81°), and outstanding antioxidant and antibacterial properties. It is designed for real-time monitoring of shrimp freshness. Additionally, we verified the effectiveness of this sensing film in detecting shrimp freshness across varying temperature conditions, namely 25 °C and 4 °C was validated through the measurement of total volatile basic nitrogen (TVB-N). Visual inspection unequivocally revealed a transition in color from dark red to purple-light blue and finally to dark bluish providing a clear indication of shrimp spoilage, which demonstrated a strong correlation with the TVB-N content in shrimp measured through standard laboratory procedures. The colorimetric sensing film developed in this study holds great promise for creating smart labels with exceptional antioxidant and antibacterial properties, tailored for visual freshness monitoring of shrimp.

Quantum cascade laser absorption sensor for in-situ, real-time and sensitive measurement of high-temperature SO2 and SO3

We report a mid-infrared quantum cascade laser absorption sensor capable of measuring SO2 and SO3 simultaneously and sensitively at elevated temperatures. In the sensor development, the intense transitions of SO2 and SO3 in the mid-infrared region of 1129 cm−1 and 1398 cm−1 were exploited by two quantum cascade lasers. A high-temperature multipass cell was adopted to increase the absorption path length to 10 m. The quantitative concentrations of SOx were directly obtained from the calibration-free wavelength modulation spectroscopic method, which was validated at varied temperature and pressure conditions. From Allan deviation analysis, we achieved a minimum detection limit of 8 parts per billion (ppb) for SO2 and 3 ppb for SO3, with an average time of 100 s. Lastly, we successfully demonstrated the real-time and sensitive measurement of SO2 and SO3 during the oxidation reaction of SO2 by O3 at 460 K. Our laser sensor shows great potential for in-situ and real-time monitoring of SOx from combustion emissions.

Evaluation of the safety quality of automotive pyrotechnic articles following their exposure to triaxial vibrations with predetermined thermal conditioning cycles

Pyrotechnic articles fall into the field of dangerous products, Risk Class 1 - explosives, thus requiring the assurance of their security quality in order to make them available on the market. The family of pyrotechnic articles also includes pyrotechnic articles for vehicles. The main types of pyrotechnic articles intended for vehicles are: actuators (triggers), airbag gas generators, airbag modules, igniters, micro gas generators, semifinished products and seat belt pretensioners safety. Since pyrotechnic articles for vehicles are only used in the composition of security devices in vehicles, they must meet the essential security requirements, being subjected to trials and tests based on harmonized standards for this field. The paper highlights the results of the experimental tests that were obtained using the latest generation specialized equipment intended for the determination of the triaxial vibration parameter and under conditions of variable temperature with predetermined cycles, in order to evaluate the security quality of pyrotechnic articles intended for automobiles (pyrotechnic actuator for automotive use, seat belt pre-tensioner) included in category P1.

Influence of adding nanomaterials on shear properties of epoxy resin at different temperatures

Adhesive joints play a vital role in different industries owing to their advantages and ease of application compared to other joining methods. This research focuses on enhancing the mechanical properties of epoxy adhesives by incorporating graphene nanoplatelets (G) and iron-oxide nanofillers (Fe<sub>3</sub>O<sub>4</sub>). Single-lap adhesive joints, including both G and Fe<sub>3</sub>O<sub>4</sub> nanoparticles, are fabricated at 2%, 3%, and 4% weight percentages and tested under tensile load at ambient, 45°C, and 88°C. The results reveal that adding G and Fe<sub>3</sub>O<sub>4</sub> nanofillers enhances shear strength at elevated and room temperatures without altering the epoxy glass transition temperature (Tg). Furthermore, G nanofiller performs better in improving shear strength than Fe3O4. The optimal weight percentage is identified as 3 wt% for G and Fe<sub>3</sub>O<sub>4</sub>, as higher percentages lead to decreased shear strength due to agglomerations. This study provides insight into tailoring epoxy adhesives for improved mechanical performance under varying temperature conditions.

Analysis of the thermal expansion coefficient of glass- and carbon-fibre-reinforced composites

With the development of manufacturing processes, an increase in the importance of metal-fibre composites in materials engineering is observed. These are materials consisting of appropriately arranged layers of metal and various types of fibres. The very wide use of composite materials in the construction of machine and equipment components means they are often exposed to work in variable temperature conditions. The aim of this article was analysis of the thermal expansion of typical composites: carbon fibre-reinforced polymer, glass fibre-reinforced polymer, glass-reinforced aluminium laminate and carbon-fibre reinforced aluminium laminate. EN AW-6060 aluminium alloy was used as the reference material. The aim of the dilatometric tests was to determine the coefficient of thermal expansion and the dimensional stability of composite materials at elevated temperatures up to 100 °C. The EN AW-6060 aluminium alloy was characterized by the highest linear expansion coefficient (20.27×10−6 1/K). Composites containing glass fibres were characterized by the lowest positive linear thermal expansion coefficient. Among the composite materials tested, CARALLs exhibit the lowest thermal expansion coefficient.

Characteristics of the transient heat transfer of impinging flames and correlation analysis using a new characteristic velocity under CI engine-like conditions

Understanding the transient heat transfer mechanism of impinging flames is a crucial pathway for further improving the thermal efficiency of already efficient compression ignition (CI) engines. In this paper, the investigation of the transient heat transfer of wall-impinging flames was performed in a high-pressure constant-volume vessel. Fast-response thermocouples were installed in the impinging wall to record the transient heat flux. Two-color pyrometry was employed to estimate the mean temperature inside the flame region. Firstly, the transient heat transfer characteristics were investigated under varied ambient density, oxygen concentration, temperature, and injection pressure conditions. The optical flame velocity calculation method was applied to this extensive dataset to develop a heat transfer correlation between Nu and Re with which transient heat transfer coefficients were calculated and compared with the experimental results. From this analysis, cumulative fuel injection velocity was developed as the new characteristic parameter to characterize the transient heat transfer of the wall-impinging flames. Results indicate that the effect of fuel injection pressure on the heat flux is more significant than that of ambient gas conditions, with higher injection pressure causing higher heat flux through the impinging wall. No obvious linear tendency of transient Nu and Re was found when using the optical measurement results of the wall-impinging flame as the characteristic parameter. Instead, the cumulative fuel injection velocity shows a strong linear trend of transient Nu and Re during the transient heat transfer processes of the wall-impinging flame. Moreover, the heat transfer coefficients from the new cumulative fuel injection velocity well fit the experimental results.

Mineral chemistry and thermobarometry of Jurassic arc granitoids: implications for petrotectonic and unroofing history of the southern Colombian Andes

Abstract The Jurassic magmatic record in the southern Colombian (Northern Andes) includes numerous subduction-related I-type calc-alkaline granitoids with diverse structures and textures, formed in two main episodes at ∼195 to 165 Ma and ∼165 to 145 Ma. We provide new insights into the mineral chemistry, estimates of intensive parameters and petrogenetic processes of 12 plutonic occurrences in the region, grouped in 4 petrographic associations. Primary mineral assemblages include labradorite-to-oligoclase, alkali feldspars, ferroan enstatite, Mg-rich augite to ferroan-diopside, tschermakite to hastingsite and hornblende and Mg-rich annite; Fe-rich phlogopite and actinolite are post-magmatic phases. Amphibole chemistry indicates that the older (195–165 Ma) Jurassic bodies formed from relatively highly oxidized (fO2 values buffered at −0.1 ≤ NNO ≤ +1.4) hydrous (∼4 to 6 wt % H2O) magmas and their differentiation involves significant crustal assimilation and/or magma mixing, fractional crystallization and late-magmatic re-equilibration processes. In contrast, the younger (165–145 Ma) Jurassic intrusives, derived from subducted-modified mantle sources, record moderately lower oxidized hydrous conditions (fO2 values −0.7 to 0.8 ≤ NNO; ∼5 wt % H2O) with magma evolution mainly controlled by fractional crystallization and late-magmatic re-equilibration processes. Clinopyroxene-only, amphibole-only and amphibole-plagioclase thermobarometry estimations suggest that the Jurassic occurrences crystallized over variable temperature (647°C–1087°C) and pressure (0.7–6.3 kbar) conditions, corresponding to emplacement depths ranging from ∼15, ∼8 to 11, ∼5 to 7 and <4 km along the arc crustal column. The obtained data combined with time evolution allow the identification of exhumed and fragmented arc blocks in the Jurassic magmatic system and provide an essential link between the orogenic deformation event poorly constrained in the Northern Andes.

Post-tensioning tendon force estimation using eddy currents at various temperature conditions

This study proposes an eddy current-based tensile force estimation technique for a post-tensioning (PT) tendon under varying temperature conditions. The tensile force in the internal PT tendon is inferred by measuring the compressive stress on the external anchor head. A dual-coil probe consisting of two identical eddy current coils with orthogonal orientations measures the unidirectional loading level based on the piezoresistive effect. The temperature effect is eliminated using identical eddy current signal alternations in the coils under temperature variation. The performance of the proposed technique was evaluated by estimating the tensile force of a PT tendon under various loading and temperature conditions. The uniqueness of this study lies in the (1) design and fabrication of a dual-coil probe for unidirectional loading level estimation, (2) elimination of the effect of temperature on tensile force estimation, and (3) experimental validation under various loading and temperature conditions.

Modeling the curing kinetics of two thermoset adhesives under varying temperature conditions

AbstractThis paper presents detailed curing kinetics models for two thermoset adhesives. The cure kinetics were characterized using differential scanning calorimetry in both anisothermal and isothermal modes. The Sestak–Berggren autocatalytic model was applied to describe the anisothermal cure kinetics of the two adhesives with the Malek and undetermined coefficients methods determining their kinetic parameters. The Kamal autocatalytic model was adopted for the isothermal curing processes with the Kenny analytical‐graphical method determining the kinetic parameters. A modified Kamal model was developed by introducing a concept of the maximum degree of cure (DOC) and temperature‐depended kinetic parameters to describe the isothermal cure kinetics of the adhesive with a typical exothermic peak, and an extended Kamal model was further proposed by adding an initial‐phase‐control term to the modified Kamal model to describe the isothermal cure kinetics of the adhesive with two exothermic peaks. The results showed that the presented curing kinetics models with the determined parameters can precisely predict the evolutions of the DOC of the two thermoset adhesives in both anisothermal and isothermal modes.

Metabolomic and Transcriptomic Insights into Anthocyanin Biosynthesis in ‘Ziyan’ Tea Plants under Varied Photoperiod and Temperature Conditions

(1) Background: Anthocyanins, the main pigments in plants, are influenced by both temperature and photoperiod. However, the specific mechanisms underlying anthocyanin accumulation in tea plants in response to these two environmental factors remain unclear. (2) Methods: This study subjected potted ‘Ziyan’ tea plants to four types of day-length and temperature treatments (HL (28 °C, 16 h), HS (28 °C, 8 h), LL (18 °C, 16 h), and LS (18 °C, 8 h)), and then conducted targeted metabolomic and transcriptomic analyses of the samples. (3) Results: Long photoperiods and low temperatures both promoted anthocyanin accumulation in the new shoots of the tea plants. Furthermore, the enhancing effects of these two environmental factors on anthocyanin accumulation are additive and exhibit interactive effects. Through a combined analysis of metabolomics and transcriptomics, five key differentially accumulated metabolites (DAMs) and twenty-two key differentially expressed genes (DEGs) were identified, the latter being found to participate in the regulation of anthocyanin biosynthesis pathways under varying light and temperature conditions. In summary, extended photoperiods primarily increase the content levels of ten metabolites, including cyanidin and naringenin-7-O-glucoside, by upregulating CHS, F3H, and ANS genes. In contrast, low temperatures primarily enhance the synthesis of seven anthocyanins, including cyanidin and cyanidin-3-O-rutinoside, by upregulating the ANS and UFGT genes. (4) Conclusions: Collectively, the differences in the expression levels of CHS, F3H, ANS, and UFGT might be responsible for ‘Ziyan’ tea plants’ purple shoot coloration, providing important data towards the discovery of candidate genes and molecular bases controlling the purple leaves of these tea plants under varied photoperiods and temperatures.

Enhancing Temperature-Dependent Li-Ion Battery Behavior Predictions with Transfer Learning

Lithium-ion batteries (LiBs) are crucial in modern energy applications, with their performance significantly influenced by temperature variations. LiBs undergo temperature-dependent chemo-mechanical processes that contribute to capacity fade. Accurate assessment of capacity degradation during cycling necessitates consideration of various factors, including temperature, depth of discharge, cell chemistry, charge/discharge rate, and others. Publicly accessible datasets often encompass only a restricted spectrum of the aforementioned battery health influencers. However, obtaining comprehensive real-world data encompassing diverse temperature conditions poses challenges and requires substantial resources. To address the data scarcity, we propose a novel approach utilizing transfer learning to improve predictive models for temperature-dependent behavior in Li-ion batteries. In this study, we generate synthetic data simulating battery behavior under specific temperature ranges. The pre-training of the machine learning model on this synthetic data enables the capture of complex interplays between temperature and battery phenomena, identifying unique patterns and relationships. Subsequently, we transfer the acquired knowledge to the target domain, facilitating predictions for battery behavior under varying temperature conditions. Fine-tuning the pre-trained model using real-world data from the target domain ensures adaptability to new temperature conditions. The data efficiency gained from synthetic data generation in the source domain allows effective pre-training, even with limited real-world data in specific temperature regimes. Moreover, the model with its transfer learning method acquires a robust understanding of the underlying features governing temperature-dependent battery behavior, enabling better generalization and enhanced predictions for effective battery management across diverse environmental conditions. In addition to the sensitivity analysis to identify the most significant impact on the predictive model’s performance in the focused temperature range, we compare the performance of the fine-tuned model with other predictive models that do not utilize transfer learning. Our findings could offer cost-effective, rapid, and accurate predictions, ensuring robust performance in scenarios with limited real-world data. As the demand for Li-ion batteries grows across various applications, these insights hold significant potential in advancing the development of efficient and reliable energy storage systems.

A novel battery thermal management system for cooling/preheating utilizing a polymer intercell heat exchanger with phase change material

The surge in electric vehicle adoption has spurred numerous investigations into battery thermal management systems, crucial for the stable operation of batteries. However, existing studies inadequately address the combined challenges of varied temperature conditions and the imperative to reduce weight for enhanced fuel efficiency. In response, this study proposes a liquid-based thermal management system, integrating a polymer-material heat exchanger with a phase change material, to enhance thermal performance and gravimetric energy density, simultaneously. The proposed structure excels in cooling performance, achieving target temperatures with a minimum decrease of 1.7 ℃ in maximum temperature and a temperature difference of at least 2.6 ℃ under fast charging conditions compared to alternatives. Furthermore, it exhibits unparalleled thermal homogeneity, reducing temperature differences by 4.8 ℃ with an optimal preheating duration under sub-zero conditions. Substituting metal with lightweight polymer material enhances gravimetric energy density alongside improved thermal performance. An upgraded polymer material reduces preheating time by 500 s, while an improved phase change material lowers maximum temperature and temperature difference by up to 3.0 ℃ and 1.0 ℃, respectively, during cooling. This research provides insights into comprehensive battery thermal management, addressing temperature regulation, weight reduction, and overall performance enhancement for electric vehicles.

Fragmentation of data packets in wireless sensor network with variable temperature and channel conditions

This study formalizes and solves the problem of minimizing the energy dissipated by a node in order to successfully transmit the initial data amount during one round of communication over a wireless channel affected by Rice fading under varying temperature conditions. In this work, the models for the temperature dependence of the parameters in an incoherent frequency shift key (FSK) demodulator are presented and investigated for the first time, taking into account both the frequency separation and the synchronization type of the clock generator. The studied orthogonality coefficients of FSK signals represent internal parameters in the proposed model of the incoherent Rice wireless channel. This model allows the analytical relationship between the bit error probability (BEP) and node heating temperature, signal fading depth in the channel (Rician K-factor), and signal-to-noise ratio (SNR) to be established.Since it is necessary to retransmit the entire data packet when an erroneous bit is detected in a communication system that uses an automatic repeat request, at high BEP values, it is recommended to fragment packets in order to improve the energy efficiency of the nodes. By using the developed models for calculating energy losses during the communication round, it was determined that optimal fragmentation options (OFO) for data packets can be identified within specific ranges of temperature and Rician K-factor, which includes the overhead costs for packeting and retransmission. As a result, OFO matrices of packets in the "temperature – K-factor" (t0–K) coordinate system were obtained for minimizing the energy loss of nodes at different SNR values. In our example of using TI CC2500 node transceivers for 90-day monitoring of corn vegetation, the t0K-Frag algorithm reduced node energy losses by a factor of K = 3.3 compared to the case of transmitting an unfragmented packet of initial length.

Far-red light and temperature interactively regulate plant growth and morphology of lettuce and basil

Both the spectral quality of light, particularly the ratio of red (R; 600–700 nm) to far-red light (FR; 700–800 nm), and temperature can regulate phytochrome activities, subsequently influencing plant growth and morphology. However, our understanding of how light quality and temperature interact to control phytochrome-mediated morphological responses is largely limited to hypocotyl elongation in Arabidopsis seedlings. In this study, we quantified the interactive effects between FR light and temperature on morphological traits of agronomic and horticultural significance in two crops with contrasting morphology and growth habits, lettuce (Lactuca sativa L.) ‘Rex’ and basil (Ocimum basilicum) ‘Genovese’. Plants were grown under blue (B), green (G), R, and FR LED light with three spectral treatments [B25G25R200 (0%FR), B25G25R175FR25 (10%FR), B25G25R150FR50 (20%FR); the subscript represents photon flux density in μmol m−2 s−1] and five temperature regimes [Day (℃)/Night (℃); 20/20, 24/24, 28/28, 20/28 (–DIF), 28/20 (+DIF); DIF represents differential day/night temperature]. Total photon flux density in each spectral treatment was 250 μmol m−2 s−1 (400–800 nm; 12-h photoperiod). As FR light percentage and temperature increased, leaf length and plant height increased in both species. However, the effects of FR light and temperature were interdependent. Specifically, the stimulative effects of FR light on extension growth generally diminished under warmer temperatures and in the –DIF treatment (20/28 ℃). Total leaf area increased with increasing FR percentage under 20/20 and 24/24 ℃ treatments in both lettuce and basil. However, under 28/28 ℃, increasing the FR percentage from 0% to 20% caused a decrease in lettuce leaf area while having no effect on basil leaf area. Similar to responses in total leaf area, dry biomass significantly increased with increasing FR percentage under cooler temperatures. Under warm temperature of 28/28 ℃, dry biomass decreased with increasing FR percentage in lettuce, whereas no significant difference was observed in basil. Due to the interaction between FR and temperature, phytochrome photoequilibrium (PPE) estimated from photoconversions alone was less predictive of plant morphology under varying temperature conditions. Those results indicate that light spectrum and temperature interactively regulate the activity of phytochromes, plant morphology, and subsequent plant growth in both lettuce and basil, and thus should be co-optimized in controlled environment crop production systems.

Energy and exergy analysis with cost-efficiency comparison of modified phase change material (PCM) integrated with solar panel thermal system

This study investigates the efficiency and cost-effectiveness of integrating Phase Change Materials (PCMs) into solar panels to optimize power output and power conversion efficiency under varying temperature conditions. By applying PCMs, temperature fluctuations can be reduced, maintaining solar panels at an optimal temperature for power generation. The research employs modeling and simulation techniques, focusing on energy and exergy analysis of solar energy storage systems based on pure and modified PCMs such as Paraffin wax, Sodium acetate trihydrate, Sodium sulfate decahydrate, etc. Temperature and light intensity data are collected in the Wangchan district, Rayong province, using a light intensity sensor and a thermocouple. The study analyzes each layer of the solar panel, employing numerical methods and matrix solutions to solve the system of non-algebraic equations, yielding temperature values for each component layer. The thermodynamic properties of the modified PCMs are calculated theoretically, and their cost-efficiency is analyzed by comparing the solar panel’s increased power area density generation after applying specific PCMs to the cost of the PCM. The simulation results demonstrate that the solar panel integrated with PCM generates up to 11.1% more power than a regular solar panel, assuming negligible heat loss from the sides of the solar panel and an average temperature during the melting and solidification processes for the PCMs. Moreover, the best cost-efficiency of the modified PCM is achieved, with an increase of up to 637.7%, using a combination of paraffin wax and polyethylene glycol.

Experimental Investigation on Thermal Insulation of Sustainable 3D Printable Concrete by Using Corncob Powder

The construction industry is witnessing the latest technology advancement in the form of 3D printing, which promises to revolutionize the sector by reducing costs, material wastage, and environmental impact. One significant approach to achieving these goals is through the incorporation of various supplementary cementitious materials. This research work aims to study the utilization of corn cob powder (organic waste from agricultural industries) as a thermal insulation material in conjunction with other cement supplementary materials (fly ash, and silica fume). The study focuses on evaluating the material’s rheological properties, such as slump, initial and final setting times, and flowability. Furthermore, the investigation extends to analyzing the hardened properties of the concrete, including compressive strength, split tensile strength, and flexural strength under varying temperature conditions. Results shown that the compressive, split tensile and flexural strength was increased up 5 % to 7% with the inclusion of corn cob powder at 5% and it exhibits good resistance to high temperatures.

Aramid Fiber Composites for Sporting Equipment: Exploring Preparation Methods and Mechanical Properties

This study investigates the novel utilization of aramid fiber composite materials in sports equipment, elucidating their mechanical properties and development processes. Aramid fibers, despite their relatively brief 30-year existence in the materials realm, have emerged as pivotal elements in composite material research. Their exceptional traits, including high tensile strength, resistance to corrosion, impact resilience, pliancy, and effective thermal insulation, have rendered them pivotal in diverse applications, particularly in sports equipment. This research delves into the meticulous preparation methods of aramid fiber composites and comprehensively analyzes their mechanical attributes. Experimental findings ascertain a direct and proportional relationship between the tensile strength of these composites and the surface density of the fabric. Moreover, investigations into impact strength and wear rate, particularly at a 10% aramid fiber content, showcase optimal performance under varying temperature conditions. This study accentuates the immense potential of aramid composites in elevating the performance and durability of sports equipment, thereby paving the way for significant advancements in this domain.

Assessment of the feasibility for hybrid seawater district cooling model under variable seawater temperature condition: Case study in South Korea

Assessment of the feasibility for hybrid seawater district cooling model under variable seawater temperature condition: Case study in South Korea

Effect of Ti3C2Tx MXenes on tribological and rheological properties of greases

As a two-dimensional nanomaterial, Ti3C2Tx MXenes can form a stable friction protective film on the matrix surface, which can effectively improve the anti-friction and anti-wear properties of grease under variable load, variable frequency, variable temperature and constant conditions. In this work, the friction coefficient and wear rate of the grease doped with 2 wt% Ti3C2Tx are 27% and 56% lower than those of the base grease under the friction conditions of 50 °C, 100 N and 20 Hz, respectively. The grease doped with 2 wt% Ti3C2Tx can withstand greater stress and its structure is more stable, which is proved by rheological tests.

Experimental investigation on system performance of an instant heat pump water heater with combined condenser

To solve the problem of poor heat transfer effect in the subcooled region of integrated condenser, a combined condenser for instant heat pump water heater (IHPWH) was proposed and designed based on the condenser design model, aiming at obtaining an optimal design method of condenser. The off-design performances of heat pump water heater (HPWH) with a combined condenser (HPWHCC) and HPWH with an integrated condenser (HPWHIC) were investigated and compared based on the Mopt IHPWH test unit, aiming at verifying the feasibility of using a combined condenser replacement of an integrated condenser in the IHPWH. The results show that the heat transfer area of combined condenser is only 83.33 % of that of integrated condenser. Compared with the HPWHIC, the HPWHCC achieves basically equivalent COP and heating capacities and slightly higher discharge temperatures under variable heat sink outlet temperature (HSOT) condition and variable heat sink inlet temperature (HSIT) condition. Therefore, the combined condenser has the obvious potential to replace the integrated condenser in the IHPWH. The HSOT has a remarkable influence on the COP of HPWHIC and HPWHCC but a small influence on their heat capacities, while the HSIT has a small influence on their COP and heat capacities.