Ideal Efficiency Research Articles

Ultrahigh energy storage density in epitaxial AlN/ScN superlattices

Dielectric and antiferroelectric materials are particularly promising for high-power energy-storage applications. However, relatively low energy density greatly hinders their usage in storage technologies. Here, we report first-principles-based calculations predicting that epitaxial and initially non-polar AlN/ScN superlattices can achieve an ultrahigh energy density of up to 200 J/cm$^{\textrm{3}}$, accompanied by an ideal efficiency of 100%. We also show that high energy density requires the system being neither too close nor too far from a ferroelectric phase transition under zero electric field. A phenomenological model is further proposed to rationalize such striking features.

Exergy investigation of three ideal regeneration methods for liquid desiccant: Thermal air, mechanical vapor recompression and electrodialysis regeneration

Regeneration process is essential in liquid desiccant dehumidification system. In this paper, three ideal regeneration models for liquid desiccant are established: thermal air (TA) regeneration, mechanical vapor recompression (MVR) regeneration and electrodialysis (ED) regeneration. The expression of exergy conversion relation is derived by exergy analysis method in the three ideal regeneration methods. Main influencing factors of the three ideal regeneration methods are analyzed, and the ideal regeneration efficiency ηid is proposed to compare the performance of these three regeneration methods under ideal conditions. For the ideal TA regeneration, the external heat exergy and air moisture exergy are converted into the solution concentration exergy. And it can utilize the air moisture exergy from the environment for free, ηid > 1. While for the ideal MVR regeneration, the compression work paid by the compressor is converted into solution concentration exergy and heat exergy. And it is difficult to recover heat exergy in the process of isothermal compression, ηid < 1. As for the ideal ED regeneration, the electric work of the applied electric field is completely converted into the solution concentration exergy, ηid = 1. In the typical case, the ideal regeneration efficiency of the TA, MVR and ED regeneration methods are 2.31, 0.98 and 1.00 respectively.

BIM-based analysis of energy efficiency design of building thermal system and HVAC system based on GB50189-2015 in China

Abstract Recently, the application of building information modeling (BIM) in building energy efficiency design programs has been emphasized in research. In China, faced with requirements in building energy efficiency design standards and specifications, researchers have been using BIM as a platform for breaking up bottlenecks in energy simulation and design software, and BIM is considered the key to improve the efficiency of building energy efficiency design. Firstly, based on the trade-off energy consumption judgment method proposed in the ‘Public Building Energy Efficiency Design Standard (GB50189-2015)’, this study combines the BIM platform with an orthogonal simulation design adopting an experimental building construction project in a cold region of China, to thereby study the influences of different envelope structural parameters on cooling and heating loads. Then, this study analyzes the continuity and consistency of data exchange between different BIM-related software, through the modeling software Revit and the sustainable analysis software Ecotect. Finally, through the experiment, the critical factors of the optimized design of the building envelope are investigated and applied for the optimized design of the building thermal system. In addition, this study uses BIM to complete an energy efficiency design for a laboratory heating, ventilation and air conditioning (HVAC) system. According to the experimental results, the following conclusions can be drawn: this study proposes a BIM-based optimized design method of building thermal system, which complies with various Chinese building energy efficiency standards and polices and can be used as a reference for Chinese designers. Also, the issues and challenges in building consumption simulation based on BIM technology and the application of BIM technology in the design of building thermal HVAC systems are discussed, and the development trends of BIM technology in China are analyzed. Building thermal system and HVAC system design are the key points of building efficiency design. The optimized design method proposed in this paper is of great significance to this system design. The optimized design method can improve the design efficiency of designers while complying with China’s standards and policies. Therefore, it can save costs, improve the economic benefits of the projects and, at the same time, obtain an ideal building efficiency design.

Experimental investigation of indoor aerosol dispersion and accumulation in the context of COVID-19: Effects of masks and ventilation.

The ongoing COVID-19 pandemic has highlighted the importance of aerosol dispersion in disease transmission in indoor environments. The present study experimentally investigates the dispersion and build-up of an exhaled aerosol modeled with polydisperse microscopic particles (approximately 1 μm mean diameter) by a seated manikin in a relatively large indoor environment. The aims are to offer quantitative insight into the effect of common face masks and ventilation/air purification, and to provide relevant experimental metrics for modeling and risk assessment. Measurements demonstrate that all tested masks provide protection in the immediate vicinity of the host primarily through the redirection and reduction of expiratory momentum. However, leakages are observed to result in notable decreases in mask efficiency relative to the ideal filtration efficiency of the mask material, even in the case of high-efficiency masks, such as the R95 or KN95. Tests conducted in the far field ( distance from the subject) capture significant aerosol build-up in the indoor space over a long duration (). A quantitative measure of apparent exhalation filtration efficiency is provided based on experimental data assimilation to a simplified model. The results demonstrate that the apparent exhalation filtration efficiency is significantly lower than the ideal filtration efficiency of the mask material. Nevertheless, high-efficiency masks, such as the KN95, still offer substantially higher apparent filtration efficiencies (60% and 46% for R95 and KN95 masks, respectively) than the more commonly used cloth (10%) and surgical masks (12%), and therefore are still the recommended choice in mitigating airborne disease transmission indoors. The results also suggest that, while higher ventilation capacities are required to fully mitigate aerosol build-up, even relatively low air-change rates () lead to lower aerosol build-up compared to the best performing mask in an unventilated space.

Boosting catalytic activity of niobium/tantalum-nitrogen active-sites for triiodide reduction in photovoltaics

To fabricate high-quality catalysts with abundant active sites, a series of transition-metal-modified nitrogenous carbon catalysts (Ta-NOC, Nb-NOC, and Nb/Ta-NOC) was successfully fabricated via pyrolysis and ion exchange. Owing to the high conductivity and ion transport capacity of its unique nitrogen-carbon structure, and synergistic effect of dual-metal active sites on modulating electronic structure, Nb/Ta-NOC catalyst exhibited an excellent catalytic performance and a remarkable electrochemical stability in triiodide reduction reaction (IRR) and hydrogen evolution reaction (HER). Nb/Ta-NOC catalyst achieved an ideal conversion efficiency of 8.45% for IRR in solar cells, which was higher than that of Pt electrode (7.63%). Furthermore, Nb/Ta-NOC catalyst exhibited a small overpotential of 145 mV at a current density of 10 mA·cm-2 and a Tafel slope of 77 mV dec-1 for HER. This work provided a new approach for the rational design of the active-sites-rich electrocatalysts for energy conversion applications.

Multistage-responsive nanovehicle to improve tumor penetration for dual-modality imaging-guided photodynamic-immunotherapy

The exploration of an intelligent multifunctional imaging-guided therapeutic platform is of great significance because of its ideal delivery efficiency and controlled release. In this work, a tumor microenvironment (TME)-responsive nanocarrier (denoted as MB@MSP) is designed for on-demand, sequentially release of a short D-peptide antagonist of programmed cell death-ligand 1 (named as PDPPA-1) and a photosensitizer methylene blue (MB). Fe3O4–Au located in the core of MB@MSP is used as a magnetic resonance imaging and micro-computed tomography imaging contrast agent for noninvasive diagnosis of solid tumors and simultaneous monitoring of drug delivery. The PDPPA-1 coated on MB@MSP can be shed due to the cleavage of the peptide substrate by matrix metalloproteinase-2 (MMP-2) that is highly expressed in the tumor stroma, and disulfide bonding is further broken when it encounters high levels of glutathione (GSH) in TME, which finally leads to significant size reduction and charge-reversal. These transitions facilitate penetration and uptake of nanocarriers against tumors. Noticeably, the released PDPPA-1 can block the immune checkpoint to create an environment that favors the activation of cytotoxic T lymphocytes and augment the antitumor immune response elicited by photodynamic therapy, thus significantly improving therapeutic outcomes. Studies of the underlying mechanisms suggest that the designed MMP-2 and GSH-sensitive delivery system not only induce apoptosis of tumor cells but also modulate the immunosuppressive tumor microenvironment to eventually augment the suppression tumor metastasis effect of CD8+ cytotoxic T cells. Overall, the visualization of the therapeutic processes with comprehensive information renders MB@MSP an intriguing platform to realize the combined treatment of metastatic tumors.

Sandwich structured lead-free ceramics based on Bi0.5Na0.5TiO3 for high energy storage

With the rapid development of electronic information technology and the rising environmental concerns as well as the tendency of electronic devices towards miniaturization and integration, enhancing the energy storage properties of lead-free ceramic capacitors is one of the imperative issues. Although a large number of efforts have been contributed to optimize the energy storage properties of lead-free ceramics, the conflict between the polarization and electric breakdown strength seriously impedes the improvement of energy storage density significantly. Herein, inspired by the layered composites of sandwich, the sandwich structured lead-free ceramics based on Bi0.5Na0.5TiO3 were designed and fabricated to overcome the above challenge effectively. The theoretical simulations and experiment results demonstrate that the polarization and electric breakdown strength can be optimized synchronously via the sandwich structured design. An ultrahigh recoverable energy storage density of ~ 6 J cm−3 and a nearly ideal energy conversion efficiency of ~ 95% can be obtained for the prepared sandwich structured lead-free ceramics. Meanwhile, the maximum applied electric field can be enhanced to more than 500 kV cm−1. The energy storage capabilities also exhibit outstanding stability over a broad temperature range, frequency range and cycle numbers. These results reveal that the Bi0.5Na0.5TiO3-based lead-free ceramics of this study have a great potential for high energy storage capacitors applications.

An approach to quantify the dependence of economy on resource efficiency: A case study in Beijing-Tianjin-Hebei region of north China

The improvements of resource efficiency are crucial for economic development of a city. Currently, the variations of utilization efficiency of ecological resources have been studied much, but whether the efficiency has been good enough for driving the economy, is still unknown. Here, we introduced an efficiency dependence index (EDI) to assess the effects of utilization efficiency of land, energy and water resources on economy and evaluated the promotion potentials of resource efficiency. The Beijing-Tianjin-Hebei (BTH) region of north China was selected to validate the method. First, a non-collinear index system was built. After that, the EDI and the score of resource efficiency (SRE) index were constructed based on the generalized linear regression method. The main results were: (1) The efficiency contributions to economy in primary industry (4 of 13 cities) were far weaker than those in secondary industry (10 of 13 cities). (2) Water efficiency of primary industry in developed cities need further promotions. Energy efficiency needs more improvements especially in medium and small cities in both primary and secondary industries. (3) The efficiency utilization patterns of effective efficiency (EE), potential efficiency (PE) and no efficiency (NE) were categorized, and there were 26 of 65 (40%) counts of indicators performed EE, 31% counts of indicators presented PE and 29% counts of indicators showed NE. The improvement of water efficiency was the key driver to promote the resource efficiency. (4) By comparing current and ideal resource efficiency levels (via SRE), it showed that only 1 city reached to 80% of the ideal efficiency, 3 cities showed 70%, 4 cities showed 60% and 5 cities reached to less than 50% of the ideal resource efficiency. Policy suggestions of optimizing energy structure and pay attention to the comprehensiveness of resource efficiency were provided. This paper could serve as a reference for resource management.

Survey of Teachers' quality of Work Life in Mehriz in 2018

Introduction: The quality of work-life plays a significant role in employee satisfaction and organizational effectiveness. Due to their direct educational impacts, teachers play a unique role in nurturing future generations of society. This study aimed to investigate the quality of the work-life of teachers in Mehriz City. Methods: This descriptive practical study was carried out among 440 people as the study population. We selected 248 people randomly by cluster sampling method. The data collection tools included the Ilgan Quality of work-life Questionnaire. To analyze the data, we used descriptive and inferential statistics and SPSS software. Results: The findings showed that the quality of the work-life of teachers was at a desirable level, but the wages and benefits were at an unacceptable level. Conclusion: The findings of this study emphasized that the principal concern of the teachers in Mehriz was the issue of wages and benefits. Therefore, teachers not satisfied with their current salary cannot have ideal creativity, planning, and educational efficiency. Although the reward of a teacher's work is not just in the form of material rewards, the reality is that a decent wage is a necessity to live a dignified life.

A novel metamaterial gain-waveguide nanolaser

Researchers in silicon photonics have been searching for suitable and efficient light-emitting sources that are compatible with silicon-on-insulator technology. In this work, a novel continuous-wave silicon compatible metamaterial nanolaser was designed and numerically demonstrated. This novel nanolaser was constructed around a new metamaterial traveling-wave gain-waveguide, which was placed in line with silicon-on-insulator input and output waveguides, and lases at 1550 nm (i.e., in the telecom range) when pumped at 800 nm. The metamaterial waveguide consists of periodic and alternating nanoscale gain stripes (InGaAsP) and air gaps. It supports fundamental single-mode propagation for both pump and laser signals. It can efficiently couple light into the input and output silicon waveguides. The laser gives simultaneous forward and backward outputs. Besides, the metamaterial allows for efficient pump-power absorption and laser emission, which results in an almost ideal internal quantum efficiency (≅99.1%), low lasing threshold (≅200 µW), very good lasing slope efficiency (≅43.5%), and narrow laser linewidth (≅0.88 nm).

Two-dimensional guanidinium-based covalent organic nanosheets for controllable recognition and specific enrichment of global/multi-phosphopeptides

Highly specific capture of phosphopeptides, especially multi-phosphopeptides, from complex biological samples is critical for comprehensive phosphoproteomic analysis, but it still poses great challenges due to the lack of affinity material with ideal enrichment efficiency. Here, two-dimensional (2D) covalent organic framework (COFs) nanosheets was applied for selective separation of phosphopeptides for the first time. Particularly, by incorporating guanidinium units, the 2D guanidinium-based COF nanosheets (denoted as TpTGCl CONs) exhibited controllable and specific enrichment performance towards global/multi-phosphopeptides. TpTGCl CONs was easy to prepare and showed large surface area, low steric hindrance, abundant accessible interaction sites and high chemical stability. Taking these merits together, TpTGCl CONs exhibited excellent efficiency for phosphopeptide enrichment, such as low detection limits (0.05 fmol μL−1 for global phosphopeptides and 0.1 fmol μL−1 for multi-phosphopeptides), high selectivity (1:5000 of molar ratios of β-casein/BSA for both global and multi-phosphopeptides), high adsorption capacity (100 mg g−1 for global phosphopeptides and 50 mg g−1 for multi-phosphopeptides). Furthermore, TpTGCl CONs could be reused due to the high chemical stability. In addition, TpTGCl CONs were successfully applied to controllable and specific capture of endogenous global/multi-phosphopeptides from human serum and human saliva, indicating its good potential in rapid and sensitive detection of biomarkers from biological fluid. Finally, rat liver protein digest was used to confirm the high specificity of TpTGCl CONs towards multi-phosphopeptides and demonstrated its potential as an ideal enrichment probe for comprehensive phosphoproteomic analysis.

PP and LDPE polymer composite materials blend: A review

Abstract This research explores a segment of the mechanical, thermal & physical characteristics of a polymer polypropylene (PP) mixture including low density polyethylene (LDPE). There were mixing syntheses (pure PP, 25 LDPE/75PP, 50LDPE/50PP, 75LDPE/25LDPE, pure PP) that were examined. As outcome, the expansion of LDPE to PP has decreased, with improved thickness, elasticity, bending efficiency, versatile modulus and hardness. In a (25LDPE/75PP) arrangement the prevailing elasticity was achieved while the (50LDPE/50PP) synthesis was attributed to ideal bent efficiency. High density polyethylene (HDPE) blowing in different proportions PP/polyethylene (PEs) can remove sorting course employed during even recycling course. PP has interesting features like outstanding process ability &tolerance to chemicals. Inadequate versatility, however, limits its usage in specific applications. Mixing PP with relative PEs may enhance its versatility. Universal kinetics of PP crystallization have been affected greatly by the existence of PEs of various structures of the ramifications. Existence of LDPE reduced overall summation ratio while HDPE increased the process of crystallization. No negative effect was observed in the studied parameter range on mechanical performance and the related crystallinity.

Simulation of Fuel Cell Power Generation System Based on AMESim

Fuel cell has become the main power source of the fuel cell electric vehicle due to its advantages of high ideal energy conversion efficiency, low noise, high reliability and maintainability. The fuel cell power generation system is an integrated system including the fuel cell stack. Its physical model covers many subjects such as electricity, thermodynamics, hydrodynamics and electrochemistry, which makes it difficult to change the simulation of fuel cell power generation system. In order to study the characteristics of fuel cell system, the model of proton exchange membrane fuel cell system is set up using AMESim. The model mainly includes fuel cell stack, gas supply subsystem, cooling subsystem and DC/DC converter. On this basis, the characteristics of fuel cell stack and its subsystems under dynamic conditions are analyzed.

Using a Partially Evaporating Cycle to Improve the Volume Ratio Problem of the Trilateral Flash Cycle for Low-Grade Heat Recovery.

This study examined the trilateral flash cycle characteristics (TFC) and partially evaporating cycle (PEC) using a low-grade heat source at 80 °C. The evaporation temperature and mass flow rate of the working fluids and the expander inlet’s quality were optimized through pinch point observation. This can help advance methods in determining the best design points and their operating conditions. The results indicated the partially evaporating cycle could solve the high-volume ratio problem without sacrificing the net power and thermal efficiency performance. When the system operation’s saturation temperature decreased by 10 °C, the net power, thermal efficiency, and volume ratio of the trilateral flash cycle system decreased by approximately 20%. Conversely, with the same operational conditions, the net power and thermal efficiency of the partially evaporating cycle system decreased by only approximately 3%; however, the volume ratio decreased by more than 50%. When the system operating temperature was under 63 °C, each fluid’s volume ratio could decrease to approximately 5. The problem of high excessive expansion would be solved from the features of the partially evaporating cycle, and it will keep the ideal power generation efficiency and improve expander manufacturing.

A Composable Multifactor Identity Authentication and Authorization Scheme for 5G Services

The fifth-generation (5G) mobile communication technology has already deployed commercially and become a global research focus. The new features of 5G include unlimited information exchange, a large variety of connections with independent energy, and diversified high transmission rate services. Collective synergy of services is expected to change the way of life and future generations and introduce new converged services to the ICT industry. Different application services have to meet differentiated security demands. From the perspective of security, in order to support the multiservice of 5G services, it is necessary to consider the new security mechanism driven by the service. Based on 5G massive data stream, the 5G system can provide customized real-world services for potential users and reduce the user experience gap in different scenarios. However, 3GPP Extensible Authentication Protocol (EAP), which is the present entity authentication mechanism for the 5G service layer, is only an individual authentication architecture and unable to fulfill the flexible security objectives of differentiated services. In this paper, we present a new hierarchical identity management framework as well as an adaptable and composable three-factor authentication and session key agreement protocol for different applications in 5G multiservice systems. Finally, we propose an authorization process by combining with the proposed three-factor authentication mechanism and Service-Based Architecture (SBA) proposed by the 3GPP committee. The proposed mechanism can concurrently provide diverse identity authentication schemes corresponding to four different security levels by easily splitting or assembling three-factor authentication protocol blocks. The proposed scheme can be simultaneously applied to a variety of applications to improve the efficiency and quality of service and reduce the complexity of the whole 5G multiservice system, instead of designing or adopting several different authentication protocols. The performance evaluation results indicate that the proposed scheme can guarantee the multiple security of the system with ideal efficiency.

Hydrometallurgical enhanced liberation and recovery of anode material from spent lithium-ion batteries

The efficient recycling of spent anode material (SAM) from spent lithium-ion batteries (LIBs) is generally critical in terms of electronic waste recyclingas well as increasing resource shortage and environmental problems. This research reported a novel and green method to recycle lithium, copper foil, and graphite from SAM by water leaching treatment. The results indicated that 100% of graphite was exfoliated from the anode material and 92.82% leaching efficiency of lithium was obtained under the optimal conditions of 80 °C, 60 g/L, 300 rpm, and 60 min, respectively. This finding revealed that the SAM got a full liberation characteristic due to the removal of binder, which produced an ideal leaching lithium efficiency rivaling the acids’ performance. The mechanism of the liberation of SAM and lithium leaching is presented based on the analysis of results. The graphite was purified and recovered after water leaching treatment. Besides, lithium was recovered in the form of lithium carbonate (Li2CO3), and the copper foil was recovered in a sheet. This study endeavors to develop an economical and environmentally feasible plan to recycle graphite, copper, and lithium from SAM.

Application of Dynamic Skip Fire for NO &lt;sub&gt;x&lt;/sub&gt; and CO2 Emissions Reduction of Diesel Powertrains

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Dynamic Skip Fire (DSF®) has been shown to significantly reduce CO2 on gasoline engines and has been in mass production since 2018. Diesel Dynamic Skip Fire (dDSF™) builds upon the technology and extends it to diesel engine applications. dDSF is an advanced cylinder deactivation technology that allows the deactivation of any number of cylinders dynamically to deliver the requested torque while maintaining acceptable noise, vibration, and harshness (NVH) performance. NO&lt;sub&gt;x&lt;/sub&gt; regulations are becoming progressively more stringent on light, medium and heavy-duty (HD) diesel engines. Meeting low NO&lt;sub&gt;x&lt;/sub&gt; standards is becoming increasingly challenging, especially in lightly loaded operating conditions where maintaining ideal aftertreatment system efficiency is difficult. Most existing techniques to increase aftertreatment temperatures at low loads incur a fuel consumption penalty, which increases greenhouse gas emissions. In this study, dDSF is shown to combine benefits by reducing both NO&lt;sub&gt;x&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; simultaneously. Detailed studies were conducted on a Cummins X15 HD diesel engine. Engine testing and vehicle level simulation studies were followed by transient testing conducted on an engine dynamometer as well as on-road vehicle tests. NVH testing and evaluation was performed at the vehicle level to characterize vehicle response and ensure acceptability. dDSF calibrations were optimized to provide best thermal benefits at low loads. System level considerations such as coordination of air handling and fueling during transitions between firing densities, detection of valve actuation errors and mitigation of oil consumption concerns were studied. Results from system simulations using engine test data show 74% reduction of NO&lt;sub&gt;x&lt;/sub&gt; and 5.0% reduction in CO2 on the Low Load Cycle (LLC) compared to the baseline engine with conventional thermal management. This simultaneous reduction helps compliance of NO&lt;sub&gt;x&lt;/sub&gt; regulations while also reducing overall greenhouse gas emissions.&lt;/div&gt;&lt;/div&gt;

Research on the dynamic mechanical properties and constitutive model of metal rubber under impact loading

The development of lightweight, impact-resistant and high energy dissipation materials is of great significance to reduce the hazards of explosions and impacts. Metal rubber (MR) has the characteristics of low density, high damping performance and high elasticity, which shows great potential in the field of protection. However, there are few studies on the dynamic mechanical response of MR under high-speed impact. A series of experiments were carried out to study the mechanical properties of MR. It is found that the deformation mechanism of the metal wire inside the MR determines the mechanical properties. Under quasi-static conditions, the stress-strain of MR includes an elastic stage, a softening stage and a hardening stage, and the stress-strain under high-speed impact includes an elastic stage, a softening stage and a failure stage. In addition, the smaller the wire diameter, the higher the load-bearing capacity of the MR. The damage characteristics of MR under high-speed impact are divided into expansion failure and compaction failure, which will affect mechanical performance in the failure stage. The calculated energy absorption and ideal energy absorption efficiency show that MR is a material with excellent energy absorption properties. The dynamic elastic modulus and dynamic peak stress of MR have strain rate effect and density effect. A constitutive model based on Sherwood-frost equation was established, which can precisely forecast the dynamic mechanical properties.

Designing high-performance spin filters and valves based on metal-salophen molecular chains

Metal-salophen molecular chains are promising candidates for designing spintronic devices due to their magnetic coupling, thermal stability and self-assembly. Based on first principles calculations, we systematically investigate the energetic, electronic, magnetic, and spin-resolved transport properties of salophen-based molecular chains with various metal centers, i.e. X-salophen (X = Sc-Ni and Y-Mo). The results show that the X-salophen (X = Sc-Ni and Y-Mo) molecular chains have high energetic stability and synthetic feasibility. The magnetic moments of transition metal atoms at the molecular centers decrease by 0.87 μB–3.98 μB compared with the isolated atoms, as a result of electron rearrangement during forming coordinate bonds. The band structures exhibit a prominent spin polarization around Fermi level of X-salophen (X = Co, Cr, Fe and Mo) molecular chains. The devices based on these chains present excellent spin-polarized transport performance in the low bias range: X-salophen (X = Co, Cr, Fe and Mo) molecular devices with parallel spin configurations exhibit almost ideal spin filtering efficiency of 100% independent of the bias, and as for antiparallel spin cases, the devices show dual-direction spin-filtering effect; a giant magnetoresistance effect of 102 to 103 is found for Cr, Fe and Mo cases under low bias, and 109 for Co case in whole considered bias range. Our study provides a reference for designing high-performance spintronic devices based on metal-salophen molecular chains.

Refrigeration of COVID-19 Vaccines: Ideal Storage Characteristics, Energy Efficiency and Environmental Impacts of Various Vaccine Options

This article considers the ideal storage conditions for multiple vaccine brands, such as Pfizer, Moderna, CoronaVac, Oxford–AstraZeneca, Janssen COVID-19 and Sputnik V. Refrigerant fluid options for each storage condition, thermal load to cool each type of vaccine and environmental impacts of refrigerants are compared. An energy simulation using the EUED (energy usage effectiveness design) index was developed. The Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines show 9.34-times higher energy efficiency than Pfizer. In addition, a TEWI (total equivalent warming impact) simulation was developed that prioritizes direct environmental impacts and indirect in refrigeration. From this analysis, it is concluded that the cold storage of Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines in Brazil generates 35-times less environmental impact than the Pfizer vaccine.