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Thermoelectric coolers (TECs) offer a promising solution for direct cooling of local hotspots and active thermal management in advanced electronic systems. However, TECs present significant trade-offs among spatial cooling, heating, and power consumption. The optimization of TECs requires extensive simulations, which are impractical for managing actual systems with multiple hotspots under spatial and temporal variations. In this study, we present a novel machine learning-assisted optimization algorithm for thermoelectric coolers that can achieve global optimal temperature by individually controlling TEC units based on real-time multi-hotspot conditions across the entire domain. We train a convolutional neural network with a combination of the inception module and multi-task learning approach to comprehend the coupled thermal-electrical physics underlying the system and attain accurate predictions for both temperature and power consumption with and without TECs. Due to the intricate interaction among passive thermal gradient, Peltier effect and Joule effect, a local optimal TEC control experiences spatial temperature trade-off which may not lead to a global optimal solution. To address this issue, we develop a backtracking-based optimization algorithm using the machine learning model to iterate all possible TEC assignments for attaining global optimal solutions. For any m × n matrix with NHS hotspots (n, m ≤ 10, 1 ≤ NHS ≤ 20), our algorithm is capable of providing 52.4% peak temperature reduction and its corresponding TEC array control within an average of 1.64 s while iterating through tens of temperature predictions behind-the-scenes. This represents a speed increase of over three orders of magnitude compared to traditional finite element method strategies which take approximately 27 min. [ABSTRACT FROM AUTHOR]

A theoretical study of the mechanism of magnon transfer through a ferromagnetic chain (F) has been carried out from magnetically ordered contact A to similar contact B (AFB system). The regime of spin excitation transport is considered, when the inner section of the chain with identical paramagnetic units acts as a bridge for magnon transfer and thereby is poorly populated by magnons. In this case, the magnon transfer can be carried out by sequential hopping the localized magnon across all units of the chain or/and tunneling the magnon between the terminal units of the chain by a "superexchange" mechanism. The latter involves in the tunneling route the virtual delocalized magnons. The analytical dependence of the corresponding transfer rates on the number of paramagnetic bridge units is found and the magnon analog of the Seebeck and Peltier effects is predicted. [ABSTRACT FROM AUTHOR]

This paper studies multi-physical fields in a piezoelectric semiconductor (PS) fiber with consideration of heat conduction, pyroelectric, and thermoelectric effects. Based on the three-dimensional (3D) framework of piezoelectricity, drift–diffusion theory, Seebeck effect, and Peltier effect, we develop a highly nonlinear one-dimensional (1D) model that incorporates axial deformation, axial variations of the electric field, the redistribution of carriers, and temperature deviation. Combining the 1D nonlinear governing equations and the corresponding boundary conditions, the influence of the thermoelectric coefficients and axial forces on electrostatic potential, carrier redistribution, and temperature variation are solved numerically. Due to the nonlinearity of the model, these solutions are observed without symmetry or asymmetry. Our research shows that the temperature will increase near the action point of the axial force. Therefore, the temperature deviation in the fiber can be controlled by applying axial force at different points. Finally, we examine how the axial forces applied in the fiber affect the current–voltage relation. The presented study provides a potential application for mechanical switches, sensors, or thermal control for PSs. [ABSTRACT FROM AUTHOR]

The dependence of the temperature of charge carriers and phonons on the contact resistance of the Schottky diode is calculated. It is shown that the increase in contact resistance depends on the current passing through the diode, the surface and volume heat transfer coefficients of electrons and phonons, barrier height, the dimensions of the diode, as well as scattering mechanisms, relaxation time of energy and momentum.

Transverse thermoelectric conversion phenomena including the anomalous Ettingshausen effect (AEE) and anomalous Nernst effect (ANE) in magnetic materials are actively investigated to realize versatile cooling and energy harvesting technologies. However, further improvement of the thermoelectric performance of AEE and ANE is still required, and most research efforts have focused on material exploration. Here, a new approach to improve the transverse thermoelectric conversion performance through interface engineering is reported by focusing on the transverse thermoelectric phenomena that output heat currents. A longitudinal charge current in a ferromagnetic metal Ni/nonmagnetic insulator Bi2WO6 hybrid‐structure induces a larger transverse heat current than that of AEE in a Ni single‐layer. It is indicated that the enhancement of the transverse thermoelectric conversion is due to the generation of a heat current concomitant with a spin current induced at the Ni/Bi2WO6 interface. This finding demonstrates that the interface of a magnetic metal/nonmagnetic insulator has a potential to improve the transverse thermoelectric performance, extending the applicability of nonmagnetic insulators to the field of spin caloritronics and thermoelectrics. [ABSTRACT FROM AUTHOR]

Peltier cells are commonly used in low-power cooling applications, such as automotive refrigerators and electronics temperature regulation systems. These applications are typically low-energy in nature. There is currently a growing emphasis on energy conservation and waste heat utilization in the energy industry. This paper explores the possibility of improving the heating or cooling coefficient of performance (COP) of Peltier cells through intelligent serial and parallel connections. The purpose of this work is to raise the question of whether it would be possible to reconsider the concept of harnessing the "energy" potential of Peltier cells. The utilized model is in line with the current state of the art, and the case study is based on parameters measured on a commercially available Peltier cell. The resulting COP, when considering current materials, remains inferior to the COP of compressor-based heat pumps. For low-power devices, it can represent a technically and economically comparable solution. [ABSTRACT FROM AUTHOR]

In the rapid development of molecular biology, nucleic acid amplification detection technology has received more and more attention. The traditional polymerase chain reaction (PCR) instrument has poor refrigeration performance during its transition from a high temperature to a low temperature in the temperature cycle, resulting in a longer PCR amplification cycle. Peltier element equipped with both heating and cooling functions was used, while the robust adaptive fuzzy proportional integral derivative (PID) algorithm was also utilized as the fundamental temperature control mechanism. The heating and cooling functions were switched through the state machine mode, and the PCR temperature control module was designed to achieve rapid temperature change. Cycle temperature test results showed that the fuzzy PID control algorithm was used to accurately control the temperature and achieve rapid temperature rise and fall (average rising speed = 11 °C/s, average falling speed = 8 °C/s) while preventing temperature overcharging, maintaining temperature stability, and achieving ultra-fast PCR amplification processes (45 temperature cycle time < 19 min). The quantitative results show that different amounts of fluorescence signals can be observed according to the different concentrations of added viral particles, and an analytical detection limit (LoD) as low as 10 copies per μL can be achieved with no false positive in the negative control. The results show that the TEC amplification of nucleic acid has a high detection rate, sensitivity, and stability. This study intended to solve the problem where the existing thermal cycle temperature control technology finds it difficult to meet various new development requirements, such as the rapid, efficient, and miniaturization of PCR. [ABSTRACT FROM AUTHOR]

The dependence of the temperature of charge carriers and phonons on the contact resistance of the Schottky diode is calculated. It is shown that the increase in contact resistance depends on the current passing through the diode, the surface and volume heat transfer coefficients of electrons and phonons, barrier height, the dimensions of the diode, as well as scattering mechanisms, relaxation time of energy and momentum. [ABSTRACT FROM AUTHOR]

In the Markov relaxation and locally quasi-equilibrium distribution approximation, analogues of Onzager's relations for the response functions of the spin current in the nonlinear by intense mechanical and thermodynamic effects regime were obtained by the Kubo method. [ABSTRACT FROM AUTHOR]

Along with the progress of spin science and spintronics research, the flow of electron spins, i.e., spin current, has attracted interest. New phenomena and electronic states were explained in succession using the concept of spin current. Moreover, as many of the conventionally known spintronics phenomena became well organized based on spin current, it has rapidly been recognized as an essential concept in a wide range of condensed matter physics. In this article, we focus on recent developments in the physics of spin, spin current, and their related phenomena, where the conversion between spin angular momentum and different forms of angular momentum plays an essential role. Starting with an introduction to spin current, we first discuss the recent progress in spintronic phenomena driven by spin-exchange coupling: spin pumping, topological Hall torque, and emergent inductor. We, then, extend our discussion to the interaction/interconversion of spins with heat, lattice vibrations, and charge current and address recent progress and perspectives on the spin Seebeck and Peltier effects. Next, we review the interaction between mechanical motion and electron/nuclear spins and argue the difference between the Barnett field and rotational Doppler effect. We show that the Barnett effect reveals the angular momentum compensation temperature, at which the net angular momentum is quenched in ferrimagnets. [ABSTRACT FROM AUTHOR]

The energy crisis and related environmental issues due to the increasing power demand are the primary concerns in today's evolving globe. Modern energy conversion systems need dependability and scalability to overcome obstacles. This manuscript systematically examines recent research on high-performance thermoelectric materials, including novel alloys, nanostructured composites, and flexible materials designed to enhance energy conversion efficiency and adaptability across diverse environments. The literature selection spans peer-reviewed articles, patents, and emerging studies, emphasizing innovations in material properties, manufacturing methods, and design adaptations for transportation-specific challenges. In addition, this paper is organized to provide a dual perspective on both material innovation and practical integration in transportation systems, highlighting recent advancements in manufacturing processes and design. The unique structure of this review illuminates current limitations and prospective research pathways, offering insights for enhancing TEG performance and fostering sustainable, energy-efficient transportation technologies.

Thermoelectric cooling is a prospective technology that has a lot of advantages; however, its main drawback is its low efficiency compared to other technologies. A lot of scientific research is aimed at the improvement of the efficiency of thermoelectric cooling, including the development of new thermoelectric materials, innovative structures, and better power management strategies. The present work further explores a self-developed recuperative power management approach, which takes advantage of the thermoelectric element's ability to work as an electrical generator. This study relied on the thermal–electrical analogy method to develop a model that is capable of describing the impact of recuperation on the cooling performance while preserving the simplest configuration possible. The influence of different variables was estimated by three suggested quantities for evaluating the gains, losses, and rationality of the recuperative approach. A recovery of up to 10% of the electrical energy supplied to the thermoelectric element was observed experimentally. The ratio between the recovered energy and induced heat losses did not exceed a factor of 0.9. It is concluded that the recuperation process is reasonable only in the case of unavoidable interruption of the cooling process when average-performance thermoelectric elements are used. [ABSTRACT FROM AUTHOR]

Proper air conditioning is crucial for hatching, growing, and reproducing poultry chickens. The existing methods are often costly and only viable for some chicken farmers. This paper presents a novel solar-powered thermoelectric module that utilizes the Peltier effect for efficient cooling and heating in poultry incubators. The proposed system consists of a Peltier module with cool and hot junctions, powered by a solar panel through a charge controller and battery. The cool junction is located in the chicken-breeding and reproduction unit, while the hot junction is situated in the egg-incubation unit. Temperature controllers maintain the required temperatures of 35–40 °C for the egg-hatching and 10–24 °C for the chicken-growing units. The experimental results demonstrate the system's effectiveness in maintaining the desired temperatures. This solar-powered thermoelectric air conditioning system offers advantages over traditional methods, including lower energy consumption, reduced costs, and eco-friendliness. It has the potential to benefit off-grid poultry farmers and reduce energy bills for existing chicken farms. The mathematical modeling, load calculations, and prototype results show that the proposed system is best suited for providing the required cooling and heating effects in poultry incubators. This research represents a significant step forward in temperature control for poultry incubators and could revolutionize poultry farming practices, especially in remote locations with limited electricity access. [ABSTRACT FROM AUTHOR]

In the medical field, refrigeration systems are used to store and transport vaccines, blood, and other medical supplies that require specific temperature ranges to remain effective. As technology continues to advance, the demand for more efficient and sustainable refrigeration systems is also increasing. The freezer compartment is typically designed to maintain a temperature of −18°C to −23°C for storing frozen items. Consequently, this work aims to develop a hybrid refrigeration system that combines a thermoelectric cooler system (TEC) and a vapor compression refrigeration cycle (VCC) system to achieve lower temperatures than conventional refrigerators. Also, the performance of the proposed hybrid refrigeration system is experimentally assessed with various operating conditions, including varying the voltage delivered to the system. The experimental results exhibited that the temperature inside the freezer room reached −33°C, while the cold side temperature is −47°C. Also, the maximum coefficient of performance of the VCC system, TEC, and hybrid system is 2.07, 1.06, and 0.37, respectively, at a DC voltage applied of 6 V. Moreover, the results revealed that the hybrid system combining a TEC and a VCC system can be a valuable technology for specific applications with low temperatures and limited capacity requirements. [ABSTRACT FROM AUTHOR]

The simulation of energy conversion in the branches of a thermoelectric cooler is carried out. The influence of various distributions of the active impurity along the branch of the thermoelement on its efficiency in the mode of maximum temperature drop is considered. The calculation is carried out within the framework of a two-band standard model of the band structure of a semiconductor for non-degenerate charge carriers. The Thomson effect was not taken into account. [ABSTRACT FROM AUTHOR]

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It is extremely important for the performance and success of the system to know the cooling or heating surfaces of the thermoelectric modules (TEMs) as cooler or generator, according to the heat transfer direction, and to carry out their installation correctly, taking this into account. In TEMs, the direction of heat transfer between surfaces changes depending on the applied DC direction, and while one surface of the module cools, the other heats up. In this respect, the state of the positive and negative poles in the design and production of TEMs directly affects the heat transfer direction between the module surfaces. On the other hand, the contact direction of the surfaces of the TEMs used in a designed thermoelectric system (TES) is of great importance in order to perform the heat transfer correctly without loss of performance. In this study, a system is designed to detect the heat transfer direction of TEMs using image processing techniques. The basic principle of the system is to determine the positive and negative poles of the TEMs together with the ceramic plate, using the color-based image processing method, and to determine the heat transfer direction by utilizing their relative positions. With the designed system, the heat transfer direction of TEMs at different illuminance levels is tried to be determined and successful results were obtained. As a result, it is thought that the developed system will contribute to the automatic error control for the production and assembly of TEMs. [ABSTRACT FROM AUTHOR]

The solar-powered thermoelectric refrigerator (SPTR) is an innovative approach that uses solar energy to cool spaces. Its effectiveness relies on solar insolation rates and an intelligent dual-axis solar tracking system (STS) that maximizes solar energy capture. Performance analysis of SPTR with the fixed panel solar system (WST) and dual-axis STS by keeping the SPTR at a standard ambient temperature of 25 °C was carried out under local climate conditions. The experimental test setup includes a thermoelectric refrigerator (TER), thermoelectric module (TEM), solar panels, and STS. The experimental findings showed that the coefficient of performance (COP) of SPTR depends on the solar irradiance, the system's input power, the surface temperature of the solar panels, and the cooling rate. The maximum and minimum values of COPs were 1.19 and 0.27 for directly coupled SPTR with a WST and 2.07 and 0.39 for STS, respectively. Compared with the stand-still solar system, a COP enhancement of 44–75 % is achieved. The results also show that the cooling load is a function of the refrigerated space, and the products are to be cooled, which is affected by the thermoelectric properties of the TEM. The cooling rate is recorded at its maximum when the system is operated using an STS on a clear sunny day with a maximum solar insolation rate. The SPTR has proven to be environmentally friendly, the best alternative to conventional cooling systems, and sustainable due to the independence of traditional energy resources.

Abstract As the core components of fifth‐generation (5G) communication technology, optical modules should be consistently miniaturized in size while improving their level of integration. This inevitably leads to a dramatic spike in power consumption and a consequent increase in heat flow density when operating in a confined space. To ensure a successful start‐up and operation of 5G optical modules, active cooling and precise temperature control via the Peltier effect in confined space is essential yet challenging. In this work, p‐type Bi0.5Sb1.5Te3 and n‐type Bi2Te2.7Se0.3 bulk thermoelectric (TE) materials are used, and a micro thermoelectric thermostat (micro‐TET) (device size, 2 × 9.3 × 1.1 mm3; leg size, 0.4 × 0.4 × 0.5 mm3; number of legs, 44) is successfully integrated into a 5G optical module with Quad Small Form Pluggable 28 interface. As a result, the internal temperature of this kind of optical module is always maintained at 45.7°C and the optical power is up to 7.4 dBm. Furthermore, a multifactor design roadmap is created based on a 3D numerical model using the ANSYS finite element method, taking into account the number of legs (N), leg width (W), leg length (L), filling atmosphere, electric contact resistance (Rec), thermal contact resistance (Rtc), ambient temperature (Ta), and the heat generated by the laser source (QL). It facilitates the integrated fabrication of micro‐TET, and shows the way to enhance packaging and performance under different operating conditions. According to the roadmap, the micro‐TET (2 × 9.3 × 1 mm3, W = 0.3 mm, L = 0.4 mm, N = 68 legs) is fabricated and consumes only 0.89 W in cooling mode (QL = 0.7 W, Ta = 80°C) and 0.36 W in heating mode (Ta = 0°C) to maintain the laser temperature of 50°C. This research will hopefully be applied to other microprocessors for precise temperature control and integrated manufacturing.

Entropy is one of the less discussed and analyzed among the state functions studied in the thermodynamics of electrochemical systems. Few universities and post-graduate Electrochemistry courses and textbooks deal with this function's basic aspects. Consequently, the importance of its practical applications needs to be thoroughly studied. Entropy changes are related to the reversible heat released or absorbed in electrochemical reactions. This reversible heat is also named molar electrochemical Peltier heat, which phenomenologically differs from the conventional Peltier heat used in physics and thermoelectric theory. In a simple and detailed manner, this manuscript presents fundamental concepts plus practical and experimental aspects for quantifying entropy changes and the associated molar electrochemical Peltier heat effects in a reversible and isothermal half-cell electrochemical reaction. The differences between the conventional and molar electrochemical Peltier heat are also presented. Electrochemistry professors can use the material included here to encourage university and post-graduate students to further their knowledge and understanding of the electrochemical processes. [ABSTRACT FROM AUTHOR]

Internal combustion engine inefficiencies and waste heat emissions raise environmental concerns, as they waste fuel energy in the form of heat, increasing fuel consumption and greenhouse gas emissions. Additionally, waste heat contributes to the urban heat island effect. Waste heat recovery is a vital solution, capturing and repurposing heat to reduce fuel use, emissions, and costs while promoting sustainability, innovation, and economic growth. Polygenerative waste heat recovery maximizes energy efficiency by generating multiple forms of energy from a single source, enhancing overall sustainability. The proposed Trinitor model is a polygenerative system encompassing power generation, product drying, space cooling/heating, and oxygen production. Power generation utilizes exhaust heat stored in a phase change material (PCM) to generate electricity through a Hot Air Turbine. The PCM also stores heat from the PVT thermal collector and supports produce drying. In the space cooling/heating process, the temperature contrast resulting from the hot air generated by the turbine and the cooled air from the Cooling chamber is harnessed by the Seebeck principle within the TEG, converting heat energy into electricity, and it is possible to create temperature variations using the Peltier Effect by supplying electricity. Oxygen production involves dehumidifying air, separating oxygen from hydrogen using an electrolyzer and storing oxygen for civilian use. A component review identifies SiC wall flow-diesel particulate filters (DPF), a paraffin-based Latent Heat Storage System, and electric-assisted turbo compounding as cost-effective for energy production. Produce drying relies on hot air or infrared drying, a revolving wicks humidifier, and a cooling coil dehumidifier. Space cooling/heating needs a water-type PV/T collector, MPPT charge controller, lithium-ion batteries, and ceramic TEGs. A PEM electrolyzer with appropriate components (bipolar plates, electrodes, catalyst, membrane, and gasket) enhances oxygen production efficiency. Based on existing literature, the trinitor has the potential to attain an overall efficiency ranging from 40.12–54.81%. Thus, a combination of low-efficiency processes results in a highly efficient waste heat recovery Trinitor system, with further improvements possible through identified components' integration. [ABSTRACT FROM AUTHOR]

We theoretically investigate the Seebeck and Peltier effect across an interacting quantum dot (QD) coupled between a normal metal and a Bardeen–Cooper–Schrieffer superconductor within the Coulomb blockade regime. Our results demonstrate that the thermoelectric conversion efficiency at optimal power output (optimized with respect to QD energy level and external serial load) in NQDS nanodevice can reach up to 58 % η C , where η C is Carnot efficiency, with output power P max ≈ 35 fW for temperature below the superconducting transition temperature. Further, the Peltier cooling effect is observed for a wide range of parameter regimes, which can be optimized by varying the background thermal energy, QD level energy, QD-reservoir tunneling strength, and bias voltage. The results presented in this study are within the scope of existing experimental capabilities for designing miniature hybrid devices that operate at cryogenic temperatures. [ABSTRACT FROM AUTHOR]

The Kelvin relation, relating the Seebeck coefficient and the Peltier coefficient, is a theoretical basis of thermoelectricity. It was first derived by Kelvin using a quasi-thermodynamic approach. However, Kelvin's approach was subjected to much criticism due to the rude neglect of irreversible factors. It was only later that a seemingly plausible proof of the Kelvin relation was given using the Onsager reciprocal relation with full consideration of irreversibility. Despite this, a critical issue remains. It is believed that the Seebeck and Peltier effects are thermodynamically reversible, and therefore, the Kelvin relation should also be independent of irreversibility. Kelvin's quasi-thermodynamic approach, although seemingly irrational, may well have touched on the essence of thermoelectricity. To avoid Kelvin's dilemma, this study conceives the physical scenarios of equilibrium thermodynamics to explore thermoelectricity. Unlike Kelvin's quasi-thermodynamic approach, here, a completely reversible thermodynamic approach is used to establish the reciprocal relations of thermoelectricity, on the basis of which the Kelvin relation is once again derived. Moreover, a direct thermodynamic derivation of the Onsager reciprocal relations for fluxes defined as the time derivative of an extensive state variable is given using the method of equilibrium thermodynamics. The present theory can be extended to other coupled phenomena. [ABSTRACT FROM AUTHOR]

Solar-powered thermoelectric air conditioning systems offer distinct advantages over traditional cooling methods, including thermal comfort, absence of moving parts, and eco-friendliness as they operate on solar energy. Despite these benefits, they exhibit a lower coefficient of performance (COP) compared to conventional systems. In this study, a solar-powered thermoelectric air conditioning system based on the Peltier effect was experimentally investigated in Baghdad during September (39 °C to 32 °C). The system was designed to cool a small 1 m² test room. The six Peltier modules were divided into groups, each powered by a different electrical source with varying ON/OFF intervals. The highest COP achieved was 0.649, with an optimal outlet air temperature of 22-23 °C and a 20 minute switching cycle. Notably, the inlet air velocity directly influenced COP and outgoing air temperature. The study also indicated improved performance at reduced air flow, making Peltier air coolers ideal for hot regions. [ABSTRACT FROM AUTHOR]

Intense physical activity and high ambient temperature cause construction workers to be exposed to an increased risk of overheating, especially in the summer season. Personal cooling systems have great potential to support workers' thermoregulation and reduce this risk. In particular, solutions based on the thermoelectric effect can provide high cooling effectiveness and ergonomics at the same time. In this paper, a newly developed active clothing solution with flexible thermoelectric modules intended for outdoor activities is presented. The active clothing was subjected to utility tests on a treadmill under laboratory conditions with the participation of potential end users. A comparison of results from cooled and uncooled places indicated a reduction in local skin temperature of as much as 2.7 °C. Moreover, a gradual decrease in temperature in the uncooled place during the experiment was observed. Based on the positive results from this evaluation, the personal cooling system was integrated into active clothing within the ASSIST-IoT NGIoT reference architecture. This allows contextual and personalized adjustment of the cooling power to be provided using AI techniques and, additionally, by using data from a weather station and a smartwatch. Training procedures and models for the AI system are proposed, with special attention paid to the privacy aspect. [ABSTRACT FROM AUTHOR]

Reaching of negative temperatures for various applications such as food industry, medicine or experimental physics implies the use of cryogenic fluids (especially liquid nitrogen) or refrigeration heat pumps. The technological progress in materials science in the last years allowed the development of other methods to obtain low temperatures needed for such applications, by means of using the Peltier effect. The Peltier modules were developed and perfected in last decades, in order to allow temperature differences of 20 ºC to 85 ºC between the two faces of one module when one side is kept at room temperature, and an electric current is supplied. Thus, the possibility of developing devices which allow obtaining and controlling temperatures up to -50 ºC were opened, eliminating all the difficulties related to the use of cryogenic agents, which imply the need of Dewar storage vessels, cryogenic transfer lines and controlling of cryogenic liquid such as liquid helium or liquid nitrogen (with boiling temperature of -196 ºC, at atmospheric pressure) or refrigeration systems. In this work are presented the design, execution and testing results of a thermally controlled enclosure aimed for the calibration of temperature sensors, in the range of -50 to +20 ºC, using Peltier modules. Despite the high electric power consumption of the Peltier modules needed to cool down the enclosure due to the low COP (coefficient of performance) compared to the conventional refrigeration systems, this approach in obtaining negative temperatures presents important advantages such as the lack of maintenance, low volume, simplicity of temperature control and high temperature stability (0.1 ºC). [ABSTRACT FROM AUTHOR]

This article discusses the potential applications of semiconductor fibers in clinical and translational medicine. Semiconductor fibers have the ability to monitor and measure various physiological parameters, making them suitable for use in medical devices. They can be used for thermoregulation, pulse monitoring, and have potential applications in implantable sensors, neural interfaces, and tissue engineering. However, further research is needed to fully understand the biophysics of semiconductor fibers and their practical use in clinical settings. The study was supported by various funding sources and the authors declare no conflicts of interest. [Extracted from the article]

In the rapid development of molecular biology, nucleic acid amplification detection technology has received more and more attention. The traditional polymerase chain reaction (PCR) instrument has poor refrigeration performance during its transition from a high temperature to a low temperature in the temperature cycle, resulting in a longer PCR amplification cycle. Peltier element equipped with both heating and cooling functions was used, while the robust adaptive fuzzy proportional integral derivative (PID) algorithm was also utilized as the fundamental temperature control mechanism. The heating and cooling functions were switched through the state machine mode, and the PCR temperature control module was designed to achieve rapid temperature change. Cycle temperature test results showed that the fuzzy PID control algorithm was used to accurately control the temperature and achieve rapid temperature rise and fall (average rising speed = 11 °C/s, average falling speed = 8 °C/s) while preventing temperature overcharging, maintaining temperature stability, and achieving ultra-fast PCR amplification processes (45 temperature cycle time < 19 min). The quantitative results show that different amounts of fluorescence signals can be observed according to the different concentrations of added viral particles, and an analytical detection limit (LoD) as low as 10 copies per μL can be achieved with no false positive in the negative control. The results show that the TEC amplification of nucleic acid has a high detection rate, sensitivity, and stability. This study intended to solve the problem where the existing thermal cycle temperature control technology finds it difficult to meet various new development requirements, such as the rapid, efficient, and miniaturization of PCR.

Thermoelectric air condition system (TEACs) powered by solar photovoltaics is useful for thermal comfort applications, especially when there is a direct energy source like sunlight. This paper presents experimental investigations of solar-powered thermoelectric air conditioning for both cooling and heating modes. The experiments were carried out in a test room whose volume is 1 m3 under the climatic conditions of the city of Baghdad. In the summer, the thermoelectric device functions as a Peltier cooler. The cold side absorbs the heat from the inside to lower the room's temperature. As for winter, the heat is released from the thermoelectric Peltier module by reversing the current applied to the thermoelectric Peltier to raise the room's temperature. In this work, the thermoelectric air condition system was supplied with different electrical power supply values with time intervals between the ON/OFF operations. The results showed that the system could heat and cool the air well in different operation conditions. The lowest temperature (22°C) is achieved in the cooling mode, with a Coefficient of Performance (COP) of 0.64 and an exergy efficiency of 0.47. In contrast, in the heating mode, the highest temperature is (31°C) with a COP of 0.87 and exergy efficiency of 0.75. This simple and eco-friendly method can minimize the cooling and heating load in the room.

This work describes the design and operation of a prototype platform (MicroCrys) developed to automate the on-chip dialysis crystallization of proteins via chemical composition and temperature control, facilitating the optimization of crystallization conditions and the exploration of protein phase diagrams. A custom-built computer software (LabVIEW) displaying a user-friendly graphical interface has been designed to manipulate all the separate functionalities of the MicroCrys platform. These include visualization and recording, fluidic components for mixing, circulating and dynamically exchanging the crystallization solutions in the dialysis chip and a customized metallic support for thermal regulation via the Peltier effect. Two model soluble proteins, hen egg white lysozyme (HEWL) and thaumatin from Thaumatococcus daniellii, were used to exemplify the competence of MicroCrys for growing high-quality protein crystals for in situ X-ray diffraction experiments at room temperature. HEWL was also used to validate the compatibility of the dialysis chips with the lipid cubic phase (LCP) crystallization method and the microcrystals were used for room temperature in situ synchrotron serial X-ray crystallography (SSX). Finally, SERCA (sarco/endoplasmic reticulum Ca2+-ATPase) from Oryctolagus cuniculus has been used as a case study to demonstrate the feasibility of on-chip microdialysis crystallization of membrane proteins. [ABSTRACT FROM AUTHOR]

Researching novel cooling and heating technologies as alternatives to conventional vapor-compression refrigeration cycles has received growing attention in recent years. Thermoelectric (TE) systems rank among promising emerging technologies within this category. This paper presents a comprehensive investigation, utilizing numerical modeling and analysis via COMSOL Multiphysics along with experimental validation, to evaluate the performance of a radiant cooling ceiling panel working on thermoelectric principles. Performance metrics are based on thermal comfort levels within the designed test chamber. The system comprises a rectangular test chamber (~1.2 m × 1.2 m × 1.5 m) with a centrally positioned ceiling panel (dimensions: 0.6 m × 0.6 m × 0.002 m). Four TE modules are attached on top of the ceiling panel, facilitating effective cooling to regulate the ceiling temperature to the desired setpoint. The resultant lower ceiling temperature enables heat exchange within the chamber environment via radiation and convection mechanisms. This study examines the time-dependent variations in mean radiant temperature and operative temperature under natural convection conditions, with comfort level assessment carried out using the PMV method according to ASHRAE Standard 55. An experimental chamber is built to validate the numerical model by performing experiments at various ceiling temperatures. Design challenges are discussed in detail. The results of this investigation offer valuable insights into the anticipated thermal comfort achievable through TE-based radiant cooling systems across various operating conditions. [ABSTRACT FROM AUTHOR]

A high battery temperature has been shown to be critical for lithium-ion batteries in terms of performance, degradation, and safety. Therefore, a precise knowledge of heat sources and sinks in the battery is essential. We have developed a thermal model for lithium-ion batteries, a model that includes terms not included before, namely, Peltier and Dufour heat effects. The model is derived using non-equilibrium thermodynamics for heterogeneous systems, the only theory which is able to describe in a systematic manner the coupling of heat, mass, and charge transport. The idea of this theory is to deal with surfaces as two-dimensional layers. All electrochemical processes in these layers are defined using excess variables, implying, for instance, that the surface has its own temperature. We show how the Peltier and Dufour heats affect a single cell and may produce an internal temperature rise of 8.5 K in a battery stack with 80 modules. The heat fluxes leaving the cell are also functions of these reversible heat effects. Most of the energy that is dissipated as heat occurs in the electrode surfaces and the electrolyte-filled separator. The analysis shows that better knowledge of experimental data on surface resistances, transport coefficients, and Dufour and Peltier heats is essential for further progress in thermal modeling of this important class of systems. [ABSTRACT FROM AUTHOR]

Thermoelectric cooling (TEC) reverses the electrical energy to temperature caused by the Peltier effect, where a temperature difference occurs between two conductors, that is, hot and cold junctions. This article presents the enhanced heat transfer of a TEC module using a TEC1‐12710 model integrated with a wavy channel heat sink using ferrofluid as a coolant under continuous and pulsating flows, where the differences in the distance of the magnetic field are considered. Square permanent magnets measuring 30 mm × 20 mm × 4 mm (width × length × height) are used to transmit a magnetic field to the heat sink and then tested under a magnetic distance of 10–30 mm. The test is performed at a water flow rate from 0.0083 to 0.028 kg/s and supplied with a constant TEC voltage of 12 V. By applying a magnetic field to the TEC module with a magnetic distance of 20 mm and a ferrofluid concentration ratio of 0.015%, the cooling efficiency increases by approximately 18.64%. Hence, using pulsating flow may improve thermal efficiency by approximately 23%. The results show an exponential increase in the cooling efficiency when both passive and active cooling techniques are used. [ABSTRACT FROM AUTHOR]

The fresh sap harvested from the unbloomed inflorescence of the adult spadix of coconut tree (Cocus nucifera L.) is known as "neera." It must be collected below room temperature to prevent naturally occurring fermentation. The study aims to design and choose the Peltier cooling neera collection system (PCNCS) for integration with the neera tapping machine. With a 12 V 6 A Peltier module powered by a direct current, this collecting system operates via the Peltier effect. In each of the four designs, two Peltier modules were used. Since the heatsink and fan must be fixed in each design, they have unique dimensions and capabilities. A 305 W solar panel powers the system, charging a 12 V 100 Ah lead‐acid battery. The test was conducted for 210 min by dispensing a 219 mL sample of neera from a plastic drip bottle at a flow rate of 1.5 liters per day. The design boxes include a variety of models, including elongated cuboidal boxes, cuboidal boxes, cubic boxes, and triangular prism boxes. The corresponding designs reached temperatures of 16.5, 19, 22, 20, and 18°C. Two alternative Peltier fixing position models were applied in the cubic box design. Among the four potential designs, the elongated cuboidal box with a COP of 0.7323 has been chosen since its trial result shows the lowest temperature. Practical Applications: The Solar‐powered Peltier‐based cooling neera collecting system can be used to collect the unfermented neera and store the harvested neera for a specific time. The cooling collection system can help the tapper collect the neera without climbing the coconut tree. It can also reduce the labor charge from the daily climbing of coconut trees to harvest neera. The designed system allows us to serve the neera in a short period because it is collected and discharged frequently. Also help to the farmers to increasing their economy by means reducing the operating cost. [ABSTRACT FROM AUTHOR]

Peltier effect is an important thermoelectric phenomenon which stands for the generation of temperature gradient of the interface between two dissimilar conductors by the electric current flowing through them. In this work, we investigate the Peltier effect in serially coupled noninteracting double quantum dot system under a bias voltage. By means of an accurate hierarchical equations of local temperatures of the two dots differ from each other by applying an electric current through the dots. We then analyze theoretically the influence of interdot and dot-lead coupling on the thermopower and electric current. Finally, we elucidate the variation of Peltier heat and Joule heat with the interdot coupling and dot-lead coupling, which leads to the changes in the local temperature of the quantum dots. [ABSTRACT FROM AUTHOR]

Thermoelectric modules (TEMs) have great potential in energy conversion. There is research about performance improvements of thermoelectric generator (TEG) and thermoelectric coolers (TECs). However, TEMs are always studied separately, and no research focuses on the influence of the Peltier effect of TEG on the TEC–TEG hybrid system, in which TEG is driven directly by TEC. Herein, an experimental setup is built to discover how the Peltier effect produced by the TEG affects the exergy of the TEC–TEG system especially for the included TEC. The temperature variation of hybrid system caused by the Peltier effect of TEG is studied, and the relationship between performance of every single part and the Peltier effect of TEG is revealed. The performance of the hybrid system and the single TEC system is also compared. It is shown in the results that the Peltier effect produced by TEG is beneficial to the operation of TEC in the system. And, the adverse influence of Peltier effect produced by TEG on itself can be compensated. After thermal‐resistance optimization of hybrid system, the total output power of the hybrid system is up to 14.2% higher than that of the single TEC system in same conditions. [ABSTRACT FROM AUTHOR]

• Solar cooling system consisting of a DSSC and a ATEC is established. • The hybrid system is analyzed in terms of energy and exergy. • The hybrid system performance with and without Thomson effect is compared. • The effects of key parameters on the hybrid system performance are revealed. For round shaped cooling space, a dye-sensitized solar cell (DSSC) is used to drive annular thermoelectric cooler (ATEC) to solve the performance deterioration caused by geometric mismatch, in which ATEC considers Seebeck effect, Peltier effect and Thomson effect. Considering all kinds of irreversible losses between DSSC and ATEC, the mathematical formula of performance parameters of hybrid system is derived. The effects of Schottky barrier height, thickness of TiO 2 film, thickness of ATEC, number of thermoelectric elements and annular parameter of the ATEC on the cooling capacity and coefficient of performance (COP) of the coupling system are analyzed theoretically. The theoretical calculation results show that the maximum cooling capacity and COP of the hybrid system are 68.75 W/m2 and 0.071, respectively. In addition, it can be found that the positive Thomson effect had a positive influence on the thermoelectric cooling system. The findings of this work have the potential to provide fresh light of solar-driven annular thermoelectric cooler matching with actual round shaped cooled spaces. [ABSTRACT FROM AUTHOR]

One of the renewable energy sources that is presently being developed in Indonesia is the technology that converts solar energy into electrical energy using solar cells or PV panels. The power output of a solar panel is influenced by several factors, including solar radiation intensity, panel surface temperature, shading, and the angle of solar incidence. One factor that can influence the efficiency of a solar panel is the temperature of the solar module. The efficiency of a solar panel decreases as its temperature increases. Installing a Peltier TEC1-12706 on a PV panel will have an impact on heat absorption on the surface of the PV panel, thereby optimizing the power output of the PV panel. This study utilizes three monocrystalline solar panels with a power rating of 50 Wp, which are installed under three conditions: the first solar panel without a Peltier device, the second solar panel with twenty Peltier devices connected in series beside the solar panel, and the third solar panel with twenty Peltier devices connected in series both beside and beneath the solar panel. The output of these solar panels is remotely monitored using IoT as a connection to facilitate the monitoring and control of measured variables, including ambient temperature, solar panel surface temperature, voltage, current, solar panel output power, and efficiency. The data is collected at a height of approximately 12 meters in an outdoor laboratory at the Telecommunications Department of the Electrical Engineering Polytechnic of Sriwijaya Palembang. The measurements are collected between approximately 07:00 to 17:00 local time. The research results reveal that the monocrystalline PV panel with Peltier devices connected in series beneath and beside the solar panel has a higher absorption temperature compared to the solar panel without a Peltier device. Irradiance and ambient temperature have an influence on the voltage and current of the PV panel. The measured irradiance is directly influenced by the ambient temperature. The PV panel, with the addition of Peltier devices beneath and beside it, has an output voltage of 0.3 volts, a higher current value of 0.37 amperes, an increase in output power of 8.9 watts, and an overall average efficiency enhancement of 32.6% compared to the PV panel without a Peltier device. [ABSTRACT FROM AUTHOR]