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Although use of thromboelastography (TEG) to diagnose coagulopathy and guide clinical decision-making is increasing, relative performance of different TEG methods has not been well-defined. Rapid-TEG (rTEG), kaolin-TEG (kTEG), and native-TEG (nTEG) were performed on blood samples from burn patients presenting to a regional center from admission to 21 days. Patients were categorized by burn severity, mortality, and fibrinolytic phenotypes (Shutdown [SD], Physiologic [PHYS], and Hyperfibrinolytic [HF]). Manufacturer ranges and published TEG cutoffs were examined. Concordance correlations (Rc) of TEG parameters (R, α-angle, maximum amplitude [MA], LY30) measured agreement and Cohens Kappa (κ) determined interclass reliability. Patients (n = 121) were mostly male (n = 84; 69.4%), with median age 40 years, median TBSA burn 13%, and mortality 17% (n = 21). Severe burns (≥40% TBSA) were associated with lower admission α-angle for rTEG (P = .03) and lower MA for rTEG (P = .02) and kTEG (P = .01). MA was lower in patients who died (nTEG, P = .04; kTEG, P = .02; rTEG, P = .003). Admission HF was associated with increased mortality (OR, 10.45; 95% CI, 2.54-43.31, P = .001) on rTEG only. Delayed SD was associated with mortality using rTEG and nTEG (OR 9.46; 95% CI, 1.96-45.73; P = .005 and OR, 6.91; 95% CI, 1.35-35.48; P = .02). Admission TEGs showed poor agreement on R-time (Rc, 0.00-0.56) and α-angle (0.40 to 0.55), and moderate agreement on MA (0.67-0.81) and LY30 (0.72-0.93). Interclass reliability was lowest for R-time (κ, -0.07 to 0.01) and α-angle (-0.06 to 0.17) and highest for MA (0.22-0.51) and LY30 (0.29-0.49). Choice of TEG method may impact clinical decision-making. rTEG appeared most sensitive in parameter-specific associations with injury severity, abnormal fibrinolysis, and mortality.

The article focuses on the issue of efficiently recovering waste heat from low-exergy process gases, which poses a significant challenge for improving energy efficiency in many industrial sectors. To address this problem, the application of a thermoelectric generator (TEG) has been proposed, allowing for the direct conversion of thermal energy into electrical energy. In the course of the research, experimental measurements were conducted for process gases at temperatures of 240 °C and 300 °C, along with CFD (computational fluid dynamics) simulations using Ansys Fluent 2023 R2 software. These simulations enabled the analysis of the temperature distribution in the TEG and the determination of the safe operating range of the device for process gas temperatures of 350 °C, 400 °C and 450 °C. The results obtained from both experiments and simulations demonstrated the effectiveness of the TEG in recovering waste heat from low-exergy gases. Additionally, these findings suggest the potential for scaling the solution to larger industrial systems, making TEG a promising technology for long-term sustainable development efforts. The developed numerical model proved to be a valuable tool in the design of TEG systems, allowing for the analysis and optimization of heat recovery systems. The innovation of the solution lies in the use of TEG for efficiently utilising waste heat from low-temperature gases, which holds significant potential for improving energy efficiency in processes where traditional energy recovery technologies are not effective. [ABSTRACT FROM AUTHOR]

Graphene analog MXenes are the best options for interface engineering traditional thermoelectric materials. For the first time, a composite‐engineered TEG device composed of heavily doped bismuth and antimony telluride with incorporated Ti3C2Tx (MXene) nanoflakes is developed. Incorporated MXenes improved the electrical conductivity by carrier injection and reduces thermal conductivity by interfacial phonon scattering in both composites. The fabricated composite TEG device resulted in a maximum power of 1.14 mW and a power density of 6.1 mWcm−2. The fabricated composite TEG also demonstrates strong power generation stability and durability. Added MXenes improve the mechanical stability by employing a dispersion‐strengthening mechanism. Conclusively, the developed composite‐engineered TEG device is a facile and efficiency‐improving option for next‐generation bismuth telluride‐based commercial TEG devices. [ABSTRACT FROM AUTHOR]

Gas dehydration plays a critical role in gas refining processes due to the potential problems caused by the presence of water vapor. The inclusion of water vapor can lead to issues such as hydrate formation, pressure drop, and pipeline corrosion. In this research, a deep eutectic solvent (DES) absorbent was employed to absorb water vapor and subsequently, its absorption performance was compared with the absorption of tri-ethylene glycol (TEG) and lithium chloride, the most commonly used absorbents in water vapor separation processes. To do so, the influence of several effective parameters, including the inlet air flow rate, different ratios of choline chloride to urea (ChCl:Urea), the weight percentage of liquid water in the absorbent, and the viscosity of DES were investigated. The results demonstrated that DES is highly efficient for water vapor separation, outperforming both TEG and aqueous lithium chloride solutions. Moreover, increasing the inlet air flow rate was found to decrease absorption recovery due to reduced residence time. Additionally, a ChCl ratio of 1:2 yielded the highest absorption efficiency. [ABSTRACT FROM AUTHOR]

Printing technologies have the potential to reduce the manufacturing costs of many electronic devices significantly. Here, a scalable manufacturing route for high‐performance fully printed thermoelectric generators (TEGs) as a cost‐effective solution for energy harvesting is demonstrated. This work presents a facile one‐pot synthesis method to develop a high‐performance Ag2Se‐based n‐type paste, which is used to fabricate a fully printed origami TEG by employing the Ag2Se‐based material for the n‐type legs and a previously reported Bi‐Sb‐Te‐based paste for the p‐type legs. The n‐type film exhibits a power factor of 13.5 µW cm−1 K−2 and a maximum figure‐of‐merit (ZT) of ≈ 0.92. Furthermore, printable carbon paste is introduced as an effective interface between the thermoelectric and electrode materials, which reduces the contact resistances in the thermoelectric device. The origami folded TEG exhibits an open‐circuit voltage (VOC) of 284 mV, a power output of 370.88 µW, and an exceptionally high power density (pmax) of 10.72 Wm−2 at a temperature difference (∆T) of 80.7 K, considering that the TEG fabrication does not involve any pressure treatment and vacuum sintering. These results underscore the scalability of the presented manufacturing process and the capability of printed origami TEGs for powering the Internet of Things (IoT) with low‐grade waste heat. [ABSTRACT FROM AUTHOR]

• The etiology of liver disease may be associated with specific thromboelastography (TEG)-based coagulation states. • In this retrospective study, the TEG profiles of 1,078 adult liver transplant patients were analyzed. • Liver transplantation candidates with intrinsic liver disease tended to exhibit hypocoagulable TEG patterns, while nonintrinsic disease is associated with hypercoagulability. • Increasing end-stage liver disease severity was also associated with hypocoagulable TEG patterns. Perioperative coagulation management in liver transplantation recipients is challenging. Viscoelastic testing with rotational thromboelastography (TEG) can help quantify hemostatic profiles. The current work aimed to investigate whether the etiology of end-stage liver disease, pretransplant disease severity, or pretransplant thrombotic or bleeding complications are associated with specific TEG patterns. Retrospective cohort study. Single quaternary care hospital. A total of 1,078 adult liver transplant patients. The primary exposure was the etiology of end-stage liver disease classified as either intrinsic or nonintrinsic (eg, biliary obstruction or cardiovascular). Secondary exposures were patients' preoperative Model for End-Stage Liver Disease (MELD) score, Child-Pugh class, presence of major preoperative thrombotic complications, and major bleeding complications. Patients with intrinsic liver disease (84%) showed higher odds of hypocoagulable (odds ratio [OR]: 3.70, 95% confidence interval [CI]: 1.94-7.07, p < 0.0001) and mixed TEG patterns (OR: 4.59, 95% CI: 2.07-10.16, p = 0.0002) compared with those with nonintrinsic disease. Increasing MELD scores correlated with higher odds of hypocoagulable (OR: 1.14, 95% CI: 1.08-1.19, p < 0.0001) and mixed TEG patterns (OR: 1.08, 95% CI: 1.03-1.14, p = 0.0036). Child-Pugh class C was associated with higher odds of hypocoagulable (OR: 8.55, 95% CI: 3.26-22.42, p < 0.0001) and mixed patterns (OR: 12.48, 95% CI: 3.89-40.03, p < 0.0001). Major preoperative thrombotic complications were not associated with specific TEG patterns, although an interaction with liver disease severity was observed. Liver transplantation candidates with intrinsic liver disease tend to exhibit hypocoagulable TEG patterns, while nonintrinsic disease is associated with hypercoagulability. Increasing end-stage liver disease severity, as evidenced by increasing MELD scores and higher Child-Pugh classification, was also associated with hypocoagulable TEG patterns. [ABSTRACT FROM AUTHOR]

AbstractIn the process of purifying natural gas, natural gas dehydration plants use triethylene glycol (TEG) as a solvent for absorption. However, the loss of TEGs in the form of droplets can pollute pipelines and create a technological challenge. Using the geometric optical approximation (GOA) method, a model was developed to predict the scattering of droplets at high pressure. Based on this model, a device was designed and constructed to inspect droplets in external pipelines and distillation column tailgate lines online, which are the outlets of the natural gas dehydration unit (TEG absorber tower) of four columns in stable production. This device analyzes the components of the sampled droplets and performs online inspection to ensure smooth and safe operation. The results of the experiment indicate that the TEG content in the droplet samples exceeded 80%, which helped identify the source of the loss. The amount of treatment directly affected the concentration and distribution features of the entrained droplets, whereas the impact of the gas-phase pressure change was negligible. This study investigated three different forms of filtration separation, which provided industrial data for the separation and recovery process of entrained droplets. This study provides a new testing tool and method to examine plate towers under high pressure and provides a theoretical reference for dewatering procedures in natural gas purification plants. [ABSTRACT FROM AUTHOR]

This paper presents the first in-orbit results of the modular two-unit (2U) nanosatellite SOMP2b, focusing on the satellite bus itself and its scientific payloads. Launched in January 2021, SOMP2b comprises an innovative highly integrated satellite design with a high payload capacity. It contains the in-situ measurement of atomic oxygen in the thermosphere (FIPEXnano), a thermoelectric generator to investigate waste heat recovery in satellites (TEGonSOMP) and a material experiment to study the behaviour of carbon nanotubes in a space environment (CiREX2). The commissioning of the satellite bus was, in most respects, successful. Despite manageable limitations in communication and attitude functions, the payloads TEGonSOMP and FIPEXnano were successfully commissioned. Regarding the failure of CiREX2, countermeasures in fthe orm of in-orbit software updates are being investigated at the time of this publication. [ABSTRACT FROM AUTHOR]

[Display omitted] Thermoelectric materials have a wide range of application because they can be directly used in refrigeration and power generation. And the Bi 2 Te 3 stand out because of its excellent thermoelectric performance and are used in commercial thermoelectric devices. However, n-type Bi 2 Te 3 has seriously hindered the development of Bi 2 Te 3 -based thermoelectric devices due to its weak mechanical properties and inferior thermoelectric performance. Therefore, it is urgent to develop a high-performance n-type Bi 2 Te 3 polycrystalline. In this work, we employed interstitial Cu and the hot deformation process to optimize the thermoelectric properties of Bi 2 Te 2.7 Se 0.3 , and a high-performance thermoelectric module was fabricated based on this material. Our combined theoretical and experimental effort indicates that the interstitial Cu reduce the defect density in the matrix and suppresses the donor-like effect, leading to a lattice plainification effect in the material. In addition, the two-step hot deformation process significantly improves the preferred orientation of the material and boosts the mobility. As a result, a maximum ZT of 1.27 at 373 K and a remarkable high ZT ave of 1.22 across the temperature range of 300–425 K are obtained. The thermoelectric generator (TEG, 7-pair) and thermoelectric cooling (TEC, 127-pair) modules were fabricated with our n-type textured Cu 0.01 Bi 2 Te 2.7 Se 0.3 coupled with commercial p-type Bi 2 Te 3. The TEC module demonstrates superior cooling efficiency compared with the commercial Bi 2 Te 3 device, achieving a Δ T of 65 and 83.4 K when the hot end temperature at 300 and 350 K, respectively. In addition, the TEG module attains an impressive conversion efficiency of 6.5% at a Δ T of 225 K, which is almost the highest value among the reported Bi 2 Te 3 -based TEG modules. [ABSTRACT FROM AUTHOR]

The aim of the current article is to explore methods for boosting the productivity of PVT (photovoltaic thermal) unit in the presence of dust. This investigation centers on a PVT system comprising a cooling tube equipped with anchor-shaped fins, coupled with photovoltaic (PV) cells integrated with thermoelectric generator (TEG) modules to augment electrical output. To optimize system performance amidst dusty conditions, a hybrid nanofluid consisting of a mixture of water and Fe3O4/SiO2 nanoparticles is employed within the cooling tube. Additionally, a self-cleaning technique is implemented by coating the glass layer with SiO2 nanoparticles to mitigate the impact of dust deposition. The study evaluates the photovoltaic (ηPV), thermoelectric (ηTE), and thermal (ηTh) performances of two structural configurations: case A, without fins, and case B, with fins. Various values of inlet velocity (Vin) and the fraction of additives (ϕ) are investigated to assess their influence on system performance. The utilization of Fe3O4/SiO2–water hybrid nanofluid in PVT cooling tubes is shown to improve heat transfer, stability, and thermal management, thereby enhancing overall system efficiency. Notably, the positive impact of loading hybrid nanoparticles for the structure without fins is approximately three times greater than that for the finned case. In scenarios where dust deposition occurs within case B, reductions in ηPV, ηTE, and ηTh are observed, emphasizing the detrimental effects of dust. However, the application of nanoparticle coatings on the glass of the finned case leads to significant augmentations in ηPV, ηTE, and ηTh, underscoring the efficacy of this approach in maintaining system performance in dusty environments. Specifically, with dust deposition within case B, the ηTh, ηTE, and ηPV reduce by 14.05%, 12.06%, and 38.19%, respectively. Furthermore, the study highlights the influence of Vin on ηPV for both cases A and B, with notable improvements observed when the glass is coated with nanoparticles. Additionally, in the absence of dust, increases in the velocity of the hybrid nanofluid and the installation of fins are shown to enhance temperature uniformity across the panel. Specifically, the augmentation of ηPV with the rise of Vin for cases A and B enhances by about 8.07% and 4.93%, respectively, if the glass is coated with nanoparticles. [ABSTRACT FROM AUTHOR]

In current work, the productivity of a photovoltaic thermal (PVT) unit impacted by dust accumulation was improved using magnetic force. The magnetic force was implemented to a cooling duct with Y-shaped fins, while solar irradiation was included as heat sources in the equations. Dust effects were simulated by adjusting the optical properties. The addition of a thermoelectric generator (TEG) layer boosted the electrical output. The cooling fluid was a homogeneous water and iron oxide mixture. Dust accumulation led to a 9.3 % drop in thermal performance, but the use of magnetic force enhanced electrical efficiency. Higher concentrations of additives improved system performance, with a maximum gain of 15.88 % at the highest inlet velocity (Vinlet). Increasing Vinlet further improved thermal efficiency (ηth) by 10.96 %, photovoltaic efficiency (ηPV) by 1.16 %, and thermoelectric efficiency (ηTE) by 33.53 %. Moreover, the application of Lorentz force increased isothermal uniformity by approximately 5.91 %

Household biomass gasifier stoves (HBGSs) are used in remote areas using natural firewood that is burned in the HBGS for general purposes, such as cooking and warming in winter. The heat dissipation from the walls is assumed to be heat loss. This paper evaluates the electrical performance of thermoelectric generators (TEGs) using heat recovered from the hot walls of an HBGS, considering the effect of three primary air valve angles of 0°, 9°, and 18°. The heat recovered from the HBGS that is electrically transferred through a TEG is assessed. The results showed that the wall heat loss increases with the primary air valve angle of the HBGS. The upper zone near the HBGS gas combustion zone exhibits higher wall temperatures than the middle and lower zones, with a maximum wall temperature of 140°C resulting in an output voltage of 2.55 V. However, the middle and lower zones are also considered as their capacities are consistent with the TEG temperature range. The heat loss from the HBGS is considerably larger than that from other heat sources, and the specific heating area of the heat source is a variable that should be considered to increase the number of TEGs to achieve the desired output values for practical applications. Furthermore, this research serves as a guideline for applying TEGs to recover waste heat from various applications. [ABSTRACT FROM AUTHOR]

As the industry develops more and more, heat is produced during fabrication processes, resulting in an excess of heat. One of the ways to solve the problem can be the conversion of excess heat into electricity using a thermoelectric generator (TEG). The authors of this paper propose a method of using thin-film TEGs for electricity generation, a procedure that has been given little attention to in the literature. In this study, thin TEGs (about 50–100 nm thick) were obtained from Bi-Ni, using magnetron sputtering technology. This type of TEG can be used not only as a device that generates electricity, but also as a protective layer for various systems, protecting them from environmental influences. In addition, such TEGs can be formed on a complex, uneven surface, with various details changing their geometric shape. As shown from XRD studies, the obtained Bi-Ni layer is polycrystalline. XRD studies help to determine whether the layer obtained is composed of pure layers of Bi and Ni metals or whether metal oxides have formed (metal oxides have a negative effect on electrical conductivity). An increase in the temperature from 80 to 120 K, respectively, increases the voltage generated by the TEG from 0.01 to 0.03 V. Meanwhile, the efficiency of such TEG element changes from 1 to 4.5% when the temperature change increases from 30 to 119 K. [ABSTRACT FROM AUTHOR]

Implementing fully integrated start-up energy harvesting (EH) systems is very challenging. The most popular start-up circuit implementations use a low-voltage ring oscillator (RO). The characteristics of this RO rapidly deteriorate at VDD values below the transistor’s threshold voltage. A novel delay cell based on a Schmitt trigger (ST) inverter leveraging dynamic body biasing (DBB) is proposed to mitigate this deterioration. The RO of the proposed cell, implemented in a 22 nm FD-SOI CMOS technology, is compared against conventional and state-of-the-art circuits implemented in the same technology. Simulated results show the proposed RO achieves the highest output swing and DC gain within the 40 to 100 mV supply voltage range. A prototype chip comprising a 27-stage RO was fabricated and tested in a 22 nm FD-SOI CMOS technology. When fed by a 50 mV supply voltage, this RO produces an output swing of $\mathbf {80\%}$ of that voltage while oscillating at a 0.8 kHz clock frequency and consuming 300 pW. In reported experiments, oscillations started with VDD as low as 32 mV. To the authors’ knowledge, the proposed CMOS RO operates with the second-lowest ever reported supply voltage. Combining its low power and low area, this RO is most suitable for EH systems with restricted power and area budget.

The growing number of energy-autonomous applications raises the need for reliable DC energy harvesting techniques such as Thermoelectric Generators (TEGs). One key issue, however, is the minimum voltage (40–60 mV) required for start-up in small TEG energy harvesting sources. We review in this paper recent start-up solutions for TEG energy harvesting technologies. Different solutions have been categorized into 5 main approaches: external battery, extra-fabrication-process-based, transformers, multisource energy harvesting, and DC-AC-DC conversion using oscillators. The “DC-AC-DC conversion ring oscillators” approach is then shown to be the most promising solution in line with DC energy harvesting applications because it offers several advantages over other approaches, such as allowing full integration with good performance, compatibility with regular CMOS technology, and lower cost. Then, its different implementations are discussed and a detailed analysis is provided to identify their respective advantages and limitations.

This paper presents a simulation model for a system equipped with thermoelectric elements, considering the impact of independent thermal contact resistances on each side of the module. An analytical model was constructed, taking into account the asymmetry of thermal resistances between the generator/cooler and the respective heat source/heat sink. A comparative analysis of thermoelectric device operating indicators such as conducted heat, efficiency, and the electricity/cooling power produced was performed. The selection of electrical current in the circuit was analysed based on the maximization of power or efficiency. This paper discusses deviations from ideal conditions, specifically the absence of thermal resistance between the heat source/sink and the thermoelectric junction. The model accurately simulates the operating conditions of the thermoelectric system with a low computational cost. The results indicate that the total thermal resistance, rather than its location, predominantly affects the operation of the thermoelectric generator. However, in cooling operations, the influence of thermal resistance significantly depends on the cooling power demand and temperature. [ABSTRACT FROM AUTHOR]

In this research, a thermoelectric generator is used to absorb waste heat on the walls of a wood charcoal burning stove to produce electrical energy. The research was carried out using 4 Thermoelectric Generators (TEGs) attached to the outer wall of the furnace. The walls of the charcoal stove's combustion chamber are designed with aluminum plates. A water block cooling system with water flow is used to overcome the increase in heat at the cold side of TEG. The DC water pump power used to circulate the water block is 215 L/h, 275 L/h, 320 L/h, 350 L/h, 375 L/h, and 400 L/h. This research aims to find the most optimal water flow rate at a water block. Temperature measurements are carried out on the recent and bloodless facets of the TEG, and the temperature of the inlet and outlet water of the water block. Changes in TEG voltage, current, and output power are recorded with a multimeter connected to the acquisition data. Analysis of energy balance and heat transfer was carried out in the furnace's combustion chamber. The experimental results show that the cooling water flow rate of 275 L/h can produce the highest electrical power, around 11.17 W. The use of TEGs as a medium for generating electrical energy from wasted heat through the furnace's walls can meet some of a household's electrical energy needs. [ABSTRACT FROM AUTHOR]

Coupling different energy conversion systems together to have more sustainable energy systems can be a promising way to cope with the challenges of the energy consumption crisis. In the current work, an organic Rankin cycle (ORC) has been coupled with some other units like the Kalina cycle and some other subunits including a proton exchange membrane (PEM) electrolyzer, fuel cell, and thermoelectric generator (TEG). Two layouts of systems have been considered for evaluation. In the modified system to enhance the overall performance of the unit, fuel cells and a TEG have been utilized. Having analyzed the system from technical and economical viewpoints it is concluded that the proposed system has an energy and exergy efficiency of 16.77% and 61.69%, respectively. The results show that 0.0001632 mol/h of hydrogen can be produced with the electrolyzer system. The comparison of the suggested system with basic plant indicated that the suggested system generated 155.33 kW electrical power while the basic system generated 146.2 kW. Exergy examination represents that the condenser with 20.13 kW has the highest rate of exergy destruction rate. A parametric analysis has been performed for different parameters of the system and the calculation represents that the energy efficiency and overall exergy destruction rate with the defined electricity cost rate show a different behavior, which indicates the necessity of multi-objective optimization. For the improved plant according to the four parameters, multi-objective optimization has been done according to the genetic algorithm and the most optimal state of the system has been extracted based on three-objective optimization. In the optimum state, the exergy efficiency of the system and electricity cost obtained 62% and 10.72 $/h. • A system is designed to use the geothermal energy with relatively low temperature. • The waste of PEM FC can be employed to power generation and system improvement. • Exergy efficiency and electricity cost rate optimum values are 63% and 10.7 $/h. • The best optimum states of suggested system are determined. [ABSTRACT FROM AUTHOR]

This paper deals with an electrothermal model of a thermoelectric converter dedicated to performing simulations of coupled thermal and electrical phenomena taking place in harvesting processes. The proposed model is used to estimate the electrical energy gain from waste heat that would be sufficient to supply electronic circuits, in particular autonomous battery-less nodes of wireless sensor networks (WSN) and Internet of Things (IoT) devices. The developed model is not limited to low-power electronic solutions such as WSN or IoT; it can also be scaled up and applied to simulations of considerably higher thermal power conversion. In this paper, a few practical case studies are presented that show the feasibility and suitability of the proposed model for complex simultaneous simulation processes in both the electrical and thermal domains. The first example deals with a combined simulation of the electrothermal model of a thermoelectric generator (TEG) and an electronic harvester circuit based on Analog Devices' power management integrated circuit LTC3108. The second example relates to the thermalization effect in heat sink-less harvesting applications that could be mitigated by a pulse mode operation. The unique contribution and advancement of the model is the hierarchical structure for scaling up and down, incorporating the complexity of the Seebeck effect, the Joule effect, heat conduction, as well as the temperature dependence of the used materials and the thermoelectric pellet geometries. The simulations can be performed in steady as well as transient states under changing electrical loads and temperatures. [ABSTRACT FROM AUTHOR]

Different intermediate steps exist between solar energy as input and hydrogen as output. Most of the findings in this domain revolved around water electrolysis as an intermediate step to produce hydrogen. Therefore, the discussion in the work is intended to discuss water-splitting-based hydrogen production through electrolysis. The electrolysis process requires continuous electrical input. Installed solar PV is inevitably supposed to be under prolonged solar irradiance. The prolonged solar incidence causes the panel to get heated, leading to lower overall performance. Thermoelectric Generators (TEGs) convert the waste heat into additional electrical energy apart from the panel. In the experimentation of the work, the effect of temperature gradient is explored. During the implementation of PV-TEG, TEG electrical output can be improved with the help of auxiliary heat dissipators. This study includes graphite as a heat dissipator and a Hofmann voltameter for hydrogen production. Under 800 W/m2 of solar irradiation, the maximum hydrogen yield is obtained when PV-TEG (with graphite sheet) is connected to the Hofmann voltameter. The yield ranges from 0.132 bar/sec to 0.137 bar/sec. [ABSTRACT FROM AUTHOR]

Background and Aims Hemostasis in cirrhotics exist in rebalance, defects in prohemostatic drivers are compensated by commensurate changes in antihemostatic drivers. Conventional coagulation tests (CCTs) in cirrhotics assess only procoagulant factors therefore poor predictors of bleeding risk. CCTs are routinely used before invasive procedures and attempts are made to correct these abnormalities before invasive procedures such practices are not evidence-based, and may even be harmful. Thromboelastography (TEG) hence is promising in evaluating the coagulation status of cirrhotics prior to procedures. TEG-guided transfusion can avoid unnecessary blood product transfusions. Methods The prospective study included 133 cirrhotic patients undergoing central line placement, Conventional coagulation tests (CCTs), and Thromboelastography (TEG) were done in all patients and they were observed for postprocedural bleeding. Results 133 cirrhotic patients (mean age of 46 yrs, 90.9% males) with 90.9% and 9.1% patients in child t pugh (CTP) class B, C. All underwent central line placement. Bleeding time, clotting time were normal in all. PT/INR was prolonged in all. Comparison of TEG parameters (Rtime and MA) with INR and platelet counts showed a lower percentage of abnormal values of R time and MA value compared to INR and platelet count, with no post-procedural bleed. No correlation between CCTs and TEG variables and CTP score. None received blood transfusion preprocedure. Conclusion Abnormal CCTS do not predict bleeding risk, TEG guided coagulopathy assessment is an important pre-invasive procedure evaluation for individuals with cirrhosis. [ABSTRACT FROM AUTHOR]

In this study, two algorithms, the student psychology-based optimization (SPBO) and the mutation/particle swarm optimization (MPSO/PSO) were invoked to optimize the output power of a TEG module. The results indicate that compared to the MPSO/PSO, the SPBO has a better global searching ability under a low population size, while involving fewer adjustable parameters. The original SPBO algorithm was modified by introducing a mutation (M-SPBO). Then, the global searching ability, convergency, and repeatability of the M-SPBO were evaluated. The mutation subprogram improved the global searching ability of the original SPBO. With a high population size, the repeatability was also improved. [ABSTRACT FROM AUTHOR]

In this study, a new envelope winglet vortex generator is numerically analyzed and installed on the hot side of the thermoelectric generator (TEG) exhaust heat exchanger. Experiments for the TEG-based waste heat recovery (WHR) system integrated with engine exhaust have identified the best design configuration for the envelope winglet vortex generator in terms of pitch/channel height ratio (P/H) and tilt angles (θ ). The system's feasibility has been proven by contrasting the current thermoelectric-based WHR with conventional alternator technology. Numerical research showed that the more significant flow rates in longitudinal envelope winglet VGs resulted in a larger radius. The envelope winglet profile has a sizable impact on the performance of the innovative TEG system with a vortex generator in the exhaust heat exchanger. The current analysis indicates that the exhaust heat exchanger arrangement with a pitch/channel height ratio (P/H) of 3 and a tilt angle (θ ) of 60° produces the system's best power output. Maximum power output and maximum net power output at engine load L3 are shown at θ = 60° and 105 and 56.86% higher than those of the smooth channel, respectively. However, the largest power out and net power output increases are determined to be 68.08 and 42.28%, respectively, for P/H = 3. The recommended envelope winglet Vortex Generators (VGs) in engine operating mode L3 can raise brake-specific fuel consumption (BSFC) by up to 0.82%. The engine would operate at this mode's lowest fuel consumption and emissions. [ABSTRACT FROM AUTHOR]

Background: The most common haemostatic abnormality in dogs with cancer is hypercoagulability. A transient hypercoagulability has been documented in people with hepatocellular carcinoma (HCC) that resolves within weeks following hepatic tumour resection. Objective: The objective was to compare the haemostatic status of dogs with liver tumours and healthy control dogs, by comparing coagulation and thromboelastography (TEG) measurements at three time points. Methods: Liver tumour and healthy control dogs receiving surgery for liver lobectomy and ovariohysterectomy, respectively, were prospectively enrolled. All dogs had blood collected at three time points: pre‐operative, 24 h post‐operative and ~2 weeks post‐operative. Haematological and haemostatic values were compared across time points in each group using repeated measures ANOVA tests. Results: Ten and eight dogs were enrolled for the liver and control groups, respectively. Platelet count was significantly higher in the liver group than the control group at all time points, but within the normal range (pre‐operative: 438.7 vs. 300.9 × 109/L, p =.0078; 24 h post‐operative: 416.2 vs. 283.9 × 109/L, p =.0123; 10–14 days post‐operative: 524.6 vs. 317.3 × 109/L, p =.0072). The measure of the overall coagulant state (G‐value) was significantly increased for the liver group compared to the control group at all time points (pre‐operative: 15.6 vs. 8.6 d/sc, p =.0003; 24 h post‐operative: 18.3 vs. 11.2 d/sc, p =.039; 10–14 days post‐operative: 15.1 vs. 9.6 d/sc, p =.015). Conclusion: The liver group was hypercoagulable based on elevated G‐values at all time points compared to the control group. This hypercoagulability was attributed to the effect of hepatic tumours alone, and not secondary to surgery and anaesthesia. [ABSTRACT FROM AUTHOR]

In this article, a study of ZnO doping in poly-dimethyl-siloxane (PDMS) polymer, which is used as one tribo layer in tribo-electric energy harvesters (TEG) is corroborated to enhance the electrical properties, open circuit voltage (Voc)and short circuit current (ISC). A parallel plate device configuration of metal-to-dielectric approach is carried out making use of copper as metal and PDMS polymer with ZnO doping as a dielectric film. The double sided copper tape of 99.99 % purity and 60 μm thickness is used to realize the top tribo layer whiledielectric PDMS polymer film with ZnO doping of 8 wt%, 13 wt%, and 18 wt% is spin coated at 1000 rpm on single side copper coated FR4 substrate to make the bottom tribo-electic layer. The mechanical force is applied in tapping mode on top layer by Universal Testing Machine (UTM). The prototype device is characterized by Agilent DSO, which revealed peak output voltage of 15 V, 20 V, 30 V, and 41 V and peak-to-peak output voltage 38 V, 50 V, 60 V, and 69 V in pure PDMS, PDMS+8 % ZnO, PDMS+13 % ZnO, and PDMS+18 % ZnO respectively. The output peak current is obtained 9 nA, 20 nA, 30 nA, and 32 nA and peak-to-peak current 31 nA, 49 nA, 51 nA, and 60 nA respectively. The performance of ZnO doped PDMS TEG has increased adequately, up to 68.44 % Of Voc and 71.87 % of Isc.with respect to pure PDMS. A scanning electron microscope (SEM) is used to confirm polymer film morphology and ZnO doping percentage in PDMS is validatedby energy dispersive X-ray spectroscopy.

This article presents research about a hybrid power system dedicated to Internet of Things (IoT) nodes. As an introduction, performance tests of the harvesters, that is, a 40 × 40 mm Peltier cell based on Bi2Te3 and three solar cells, monocrystalline, polycrystalline, and amorphous, are presented. The study established the dependence of the effect of generated power on the load resistance. Thus, it states how the internal resistance of the harvesters changes. Following the above tests, a complete power unit with a single harvester and an LTC3108 conversion circuit, as well as an energy buffer in the form of a 1 mF supercapacitor, were built and tested. The unit with a thermoelectric generator generated power from 14 to 409 µW. The unit with a 65 × 65 mm polycrystalline cell generated power from 150 to 409 µW. Next, a hybrid system was built and tested with both of the aforementioned harvesters, which generated power from 205 to 450 µW at 2000 lx illumination and a temperature difference of 20 °C for the thermoelectric generator claddings. [ABSTRACT FROM AUTHOR]

Green hydrogen is a buzzword in today's renewable energy applications research domain. This paper analyzes the performance of the photovoltaic (PV) and thermoelectric generator (TEG) systems for the same reason. The prototype system includes PV, TEG, a heat sink, and a Hofmann Voltameter. The output of the PV–TEG is initially connected to a Hofmann Voltmeter to conduct electrolysis of groundwater and seawater. Further, a heat sink is pasted on each TEG using a thermally conductive adhesive. Then again, PV–TEG/heat sink output is connected to the Voltameter for electrolysis on the same water source samples. Finally, the comparative exploration is done to give insights into PV–TEG applications for hydrogen production. The explorative study shows a DC voltage gain of up to 1.77 times concerning TEG alone. Further, at 849 W/m2 of solar irradiance, it is observed that hydrogen production varies from 0.1552 to 0.1639 bar/sec in the case of groundwater and that of seawater goes from 0.1362 to 0.1413 bar/sec when PV–TEG with a heat sink is connected to Voltameter. [ABSTRACT FROM AUTHOR]

BackgroundEnd stage renal disease (ESRD) is associated with elevated fibrinogen levels and fibrinolysis inhibition. However, there is a paucity of data on how renal transplantation impacts coagulation. we hypothesize that renal transplantation recipients with good functioning grafts will have improved fibrinolytic activity following surgery.MethodsKidney recipients were analyzed pre-operatively and on post-operative day 1(POD1) using three different TEG assays with and without two concentration of tissue-plasminogen activator (t-PA). TEG indices and percent reduction in creatinine from pre-op to POD1 were measured, with >50% defining "good" graft function. Follow up was done at 6, 12, and 24 months.ResultsPercent lysis(LY30) on POD1 the t-PA TEG was significantly correlated to change creatinine from pre-op to POD-1(p = 0.006). A LY30 ≥ 23% was associated with good early graft function, and lower creatinine at 24-months(p = 0.028) compared to recipients with low POD1 LY30.ConclusionsPost-operative tPA-TEG LY30 is associated with favorable early and late outcomes in kidney transplant.

In this research, a thermoelectric generator is used to absorb waste heat on the walls of a wood charcoal burning stove to produce electrical energy. The research was carried out using 4 Thermoelectric Generators (TEGs) attached to the outer wall of the furnace. The walls of the charcoal stove’s combustion chamber are designed with aluminum plates. A water block cooling system with water flow is used to overcome the increase in heat at the cold side of TEG. The DC water pump power used to circulate the water block is 215 L/h, 275 L/h, 320 L/h, 350 L/h, 375 L/h, and 400 L/h. This research aims to find the most optimal water flow rate at a water block. Temperature measurements are carried out on the recent and bloodless facets of the TEG, and the temperature of the inlet and outlet water of the water block. Changes in TEG voltage, current, and output power are recorded with a multimeter connected to the acquisition data. Analysis of energy balance and heat transfer was carried out in the furnace’s combustion chamber. The experimental results show that the cooling water flow rate of 275 L/h can produce the highest electrical power, around 11.17 W. The use of TEGs as a medium for generating electrical energy from wasted heat through the furnace’s walls can meet some of a household’s electrical energy needs.

Study Objective: Severe coronavirus disease 2019 (COVID‐19) increases the risk of thrombotic complications with unfractionated heparin (UFH) as a commonly used agent in managing venous thromboembolism (VTE). The optimal anticoagulation intensity and monitoring parameters in intensive care unit (ICU) COVID‐19 patients remains controversial. The primary study aim was to evaluate the relationship between anti‐Xa and thromboelastography (TEG) reaction (R) time in patients with severe COVID‐19 receiving therapeutic UFH infusions. Design: Single‐center, retrospective study conducted over a 15‐month period (2020–2021). Setting: Academic medical center (Banner University Medical Center Phoenix). Patients: Adult patients with severe COVID‐19 administered therapeutic UFH infusions with one or more corresponding TEG, and anti‐Xa assessments drawn within ≤2 hours of each other were included. The primary end point was the correlation between anti‐Xa and TEG R time. Secondary aims were to describe the correlation between activated partial thromboplastin time (aPTT) and TEG R time, as well as clinical outcomes. Pearson's coefficient was used to evaluate the correlation using a kappa measure of agreement. [ABSTRACT FROM AUTHOR]

The concept of employing thermoelectric generators (TEGs) to recover energy from waste heat has gained popularity, with applications that range from milliwatt to kilowatt levels of output power. In this study, a hybrid photovoltaic panel and thermoelectric generator (HPVTEG) system consisting of an integrated heat exchanger, a commercial polycrystalline silicon photovoltaic (PV) panel and a commercial bismuth telluride TEG was proposed. Here, TE components can be used to cool PV modules, increasing their output power via the Seebeck effect. The main finding is that the hybrid system has a reduced average temperature of 16.01°C. The average power of the stand-alone PV panel is 28.06 W, but that of the HPVTEG system is 32.76 W, which is an increase of 4.7 W. The conversion efficiency and power of the hybrid system increased by 16.7% and 16.4%, respectively, compared with a stand-alone PV panel. The HPVTEG system achieved an average exergy efficiency of 12.79% compared with 10.98% for a stand-alone PV panel. According to the calculation results, the levelized cost of energy (LCOE) of the stand-alone PV panel can range from 0.06741 to 0.10251 US$/kWh depending on how many days it is in operation, while the LCOE of the HPVTEG system can range from 0.06681 to 0.10160 US$/kWh. [ABSTRACT FROM AUTHOR]

The rising in placenta accreta spectrum (PAS) incidence, highlights the need for critical care allotment for these patients. Due to risk for hemorrhage and possible hemorrhagic shock requiring blood product transfusion, hemodynamic instability and risk of end-organ damage, having an intensive care unit (ICU) with surgical expertise (surgical ICU or equivalent based on institutional resources) is highly recommended. Intensive care units physicians and nurses should be familiarized with intraoperative anesthetic and surgical techniques as well as obstetrics physiologic changes to provide postpartum management of PAS. Validated tools such of bedside point of care ultrasound and viscoelastic tests such as thromboelastogram/rotational thromboelastometry (TEG/ROTEM) are clinically useful in the assessment of hemodynamic status (shock diagnosis, assessment of both fluid responsiveness and tolerance) and transfusion guidance (in patients requiring massive transfusion as opposed to tranditional hemostatic resuscitation) respectively. The future of PAS management lies in the collaborative and multidisciplinary environment. We recommend that women with high suspicion or a confirmed PAS should have a preoperative plan in place and be managed in a tertiary center who is experienced in managing surgically complex cases. Key Points The rising in placenta accreta spectrum incidence highlights the need for critical care expertise. Emerging tools such as point-of-care ultrasound and thromboelastography/rotational thromboelastometry represent new avenues for real time optimization of hemodynamic and hematological care of patients with PAS. Patients with PAS should be referred to a tertiary center having an intensive care unit (ICU) with surgical expertise (or equivalent based on institutional resources). [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential of supercritical carbon dioxide (sCO2), organic Rankine cycle (ORC), and thermoelectric generator (TEG) systems for application in automotive exhaust waste heat recovery (WHR) applications. More specifically, this paper focuses on heavy-duty diesel engines applications such as marine, trucks, and locomotives. The results of the simulations show that sCO2 systems are capable of recovering the highest amount of power from exhaust gases, followed by ORC systems. The sCO2 system recovered 19.5 kW at the point of maximum brake power and 10.1 kW at the point of maximum torque. Similarly, the ORC system recovered 14.7 kW at the point of maximum brake power and 7.9 kW at the point of maximum torque. Furthermore, at a point of low power and torque, the sCO2 system recovered 4.2 kW of power and the ORC system recovered 3.3 kW. The TEG system produced significantly less power (533 W at maximum brake power, 126 W at maximum torque, and 7 W at low power and torque) at all three points of interest due to the low system efficiency in comparison to sCO2 and ORC systems. From the results, it can be concluded that sCO2 and ORC systems have the biggest potential impact in exhaust WHR applications provided the availability of heat and that their level of complexity does not become prohibitive. [ABSTRACT FROM AUTHOR]

Drinking water is becoming increasingly scarce as the world's population grows and climate change continues. However, there is great potential to improve drinking water pipelines, as 30% of fresh water is lost between the supplier and consumer. While systematic process monitoring could play a crucial role in the early detection and repair of leaks, current practice requires manual inspection, which is both time-consuming and costly. This project envisages maintenance-free measurements at numerous locations within the underground infrastructure, a goal that is to be achieved through the use of a harvesting device mounted on the water pipe. This device extracts energy from the temperature difference between the water pipe and the soil using a TEG (thermoelectric generator), takes sensor measurements, processes the data and transmits it wirelessly via LoRaWAN. We built 16 harvesting devices, installed them in four locations and continuously evaluated their performance throughout the project. In this paper, we focus on two devices of a particular type. The data for a full year show that enough energy was available on 94% of the days, on average, to take measurements and transmit data. This study demonstrates that it is possible to power highly constrained sensing devices with energy harvesting in underground environments. [ABSTRACT FROM AUTHOR]

Thermoelectric devices have several advantages, including no moving parts, noise-free operation, long service life, zero-emission, and precise temperature control. Therefore, they have been widely used in solid-state cooling, heating, and power generation. The study of the Thermoelectric Peltier Effect Demonstrator can provide insights into the potential applications and benefits of thermoelectric devices. This research aims to investigate the Thermoelectric Peltier Effect Demonstrator and its applications in solid-state cooling and heating. Specifically, the study aims to examine the Peltier effect generated by applying an electric current to the TEC-12706 and TEG-SP1848 modules connected to a heatsink and placed in a container filled with water. The research methodology involves conducting experiments using the Thermoelectric Peltier Effect Demonstrator. The modules are connected to the heatsink and placed in a water-filled container, and an electric current is applied to generate the Peltier effect. The temperature changes on both sides of the modules and the amount of heat transfer are measured and recorded. The results of the experiments show that the Thermoelectric Peltier Effect Demonstrator can effectively generate the Peltier effect and produce temperature differences between the two sides of the modules. The amount of heat transfer can also be controlled by adjusting the electric current. These findings demonstrate the potential applications of thermoelectric devices in solid-state cooling and heating, as well as their ability to provide more precise temperature control compared to conventional compressors.

Background: Coronavirus disease 2019 (COVID-19) is associated with a prothrombotic state; leading to multiple sequelae. We sought to detect whether thromboelastography (TEG) parameters would be able to detect thromboembolic events in patients hospitalized with COVID-19. Methods: We performed a retrospective multicenter case–control study of the Collaborative Research to Understand the Sequelae of Harm in COVID (CRUSH COVID) registry of 8 tertiary care level hospitals in the United States (US). This registry contains adult patients with COVID-19 hospitalized between March 2020 and September 2020. Results: A total of 277 hospitalized COVID-19 patients were analyzed to determine whether conventional coagulation TEG parameters were associated with venous thromboembolic (VTE) and thrombotic events during hospitalization. A clotting index (CI) >3 was present in 45.8% of the population, consistent with a hypercoagulable state. Eighty-three percent of the patients had clot lysis at 30 min (LY30) = 0, consistent with fibrinolysis shutdown, with a median of 0.1%. We did not find TEG parameters (LY30 area under the receiver operating characteristic [ROC] curve [AUC] = 0.55, 95% CI: 0.44-0.65, P value =.32; alpha angle [α] AUC = 0.58, 95% CI: 0.47-0.69, P value =.17; K time AUC = 0.58, 95% CI: 0.46-0.69, P value =.67; maximum amplitude (MA) AUC = 0.54, 95% CI: 0.44-0.64, P value =.47; reaction time [R time] AUC = 0.53, 95% CI: 0.42-0.65, P value =.70) to be a good discriminator for VTE. We also did not find TEG parameters (LY30 AUC = 0.51, 95% CI: 0.42-0.60, P value =.84; R time AUC = 0.57, 95%CI: 0.48-0.67, P value.07; α AUC = 0.59, 95%CI: 0.51-0.68, P value =.02; K time AUC = 0.62, 95% CI: 0.53-0.70, P value =.07; MA AUC = 0.65, 95% CI: 0.57-0.74, P value <.01) to be a good discriminator for thrombotic events. Conclusions: In this retrospective multicenter cohort study, TEG in COVID-19 hospitalized patients may indicate a hypercoagulable state, however, its use in detecting VTE or thrombotic events is limited in this population. [ABSTRACT FROM AUTHOR]

One of the significant factors contributing to high energy consumption is the unutilized waste heat from flue gas in industrial boilers. Thermoelectric generator (TEG) technology can directly convert thermal energy into electrical energy, and has been gradually applied in the field of waste heat recovery due to its simple and reliable structure, environmental protection, and other advantages. In this paper, a thermoelectric generator simulation system of boiler flue gas waste heat is proposed. The experimental platform is designed by simulating the flue gas waste heat temperature condition of boiler, and the structure of cold end module and hot end module is optimized. During the experiment, the fixed temperature difference was set at 120 °C (hot end:150 °C~cold end: 30 °C). An analysis is conducted on the volt-ampere characteristics and output power of the TEG module. The output characteristics of the TEG system are analyzed under the conditions of variable load, constant load, different pump speed, different heat dissipation modes, and series and parallel connection method. The results show that the experimental platform can instantaneously and accurately test the output parameters of the TEG system, and ensure the intended design requirements. When the ratio of the load resistance to the internal resistance of the TEG module is approximately 1–1.15, the output power of the system reaches its maximum. In order to optimize the output power of the TEG system, a power prediction-based adaptive variable step size maximum power point tracking (MPPT) algorithm is introduced. Additionally, a corresponding mathematical model is formulated. Simulations demonstrate that the time of the improved algorithm to reach the stable maximum power point is 1.54 s faster than that of the traditional algorithm. The improved MPPT algorithm satisfies the criteria for speed and accuracy, diminishes superfluous energy waste, and enhances the overall system efficiency. The research results have certain guiding significance for the design and application of subsequent TEG system. [ABSTRACT FROM AUTHOR]

When thermoelectric generators can be used to convert heat into power, the efficiency of this process is low. The efficiency with which TEGs convert energy is improved via a new method called maximum power point tracking (MPPT). This study aims to examine the possibility of utilizing an artificial neural network (ANN) to monitor the amount of data that can be stored in PowerPoint. The neural network is trained using the error backpropagation method. One of the benefits of using a neural network is its speed and accuracy while tracking the Maximum PowerPoint. In order to test the suggested MPPT technique, MATLAB/SIMULINK software was used to simulate the TEG mode's performance. MPPT was developed and used to regulate SEPIC converter switching technology. The temperature is used as an input variable in this technique. Under a variety of temperature conditions, the proposed methodology for studying dynamic responses to track the TEG system's maximum power point and power generated. We found that the intelligent technique's output has high tracking speed, tracking accuracy, and minimized oscillation around the maximum power point (MPP). [ABSTRACT FROM AUTHOR]

Thermoelectric devices may have an essential role in the development of fuel-saving, environmentallyfriendly, and cost-effective energy sources for power generation based on the direct conversion of heat into electrical energy. A wide usage of thermoelectric energy systems already exhibits high reliability and long operation time in the space industry and gas pipe systems. The development and application of solar thermoelectric generators (TEGs) arelimited mainly by relatively low thermoelectric conversion efficiency. Forthe first time, we propose to use the direct energy conversion of solar energy by TEGs based on the high-performance multilayer thermoelectric modules with electric efficiency of ~15%. Solar energy was absorbed and converted to thermal energy, which is accumulated by a phase-change material (aluminum alloys at solidification temperature ~900 K). The heat flow from the accumulator through the thermoelectric convertor (generator) allows electrical power to be obtained and the exhaust energy to be used for household purposes (heating and hot water supply) or for the operation of a plant for thermal desalination of water. [ABSTRACT FROM AUTHOR]