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The idling of automobiles at street intersections can lead to pollutant accumulation which impacts the health of residents in street-facing buildings. Previous research focused on pollutant dispersion within street canyons and did not consider the coupling of indoor and outdoor pollutants. This paper employs the computational fluid dynamics (CFD) method to simulate the dispersion characteristics of vehicle emission pollutants in street canyons, primarily investigating the indoor and outdoor pollutant dispersion patterns under various window opening configurations (single-sided ventilation, corner ventilation, and different positions of the glass under corner ventilation). Additionally, the study considers the impacts of the aspect ratio and ambient wind speed. Studies have shown that corner ventilation is effective in reducing indoor pollutant levels. When the two window glass positions are far away from the center of the intersection, the average CO mass fraction in the single-sided ventilation room is reduced by 87.1%. The average indoor CO mass fraction on the leeward side decreases with the increasing wind speed and aspect ratio. At a wind speed of 8 m/s, the average indoor CO mass fraction on the leeward side decreases to 2.45 × 10−8. At an aspect ratio of 2, the indoor CO mass fraction on the leeward side decreases with increasing floors before stabilizing at approximately 4.77 × 10−9. This study suggests optimal window opening strategies to reduce indoor pollutant levels in street-facing buildings at street intersections, offering guidance to indoor residents on window ventilation practices. [ABSTRACT FROM AUTHOR]

Oral cancer (OC), characterized by malignant tumors in the mouth, is one of the most prevalent malignancies worldwide. Chemotherapy is a commonly used treatment for OC; however, it often leads to severe side effects on human bodies. In recent years, nanotechnology has emerged as a promising solution for managing OC using nanomaterials and nanoparticles (NPs). Nano-drug delivery systems (nano-DDSs) that employ various NPs as nanocarriers have been extensively developed to enhance current OC therapies by achieving controlled drug release and targeted drug delivery. Through searching and analyzing relevant research literature, it was found that certain nano-DDSs can improve the therapeutic effect of drugs by enhancing drug accumulation in tumor tissues. Furthermore, they can achieve targeted delivery and controlled release of drugs through adjustments in particle size, surface functionalization, and drug encapsulation technology of nano-DDSs. The application of nano-DDSs provides a new tool and strategy for OC therapy, offering personalized treatment options for OC patients by enhancing drug delivery, reducing toxic side effects, and improving therapeutic outcomes. However, the use of nano-DDSs in OC therapy still faces challenges such as toxicity, precise targeting, biodegradability, and satisfying drug-release kinetics. Overall, this review evaluates the potential and limitations of different nano-DDSs in OC therapy, focusing on their components, mechanisms of action, and laboratory therapeutic effects, aiming to provide insights into understanding, designing, and developing more effective and safer nano-DDSs. Future studies should focus on addressing these issues to further advance the application and development of nano-DDSs in OC therapy. [ABSTRACT FROM AUTHOR]

Ultra-thin heat pipes are extensively used to address heat dissipation challenges in compact electronic devices with limited space. Research on new types of micro-porous wick is crucial for enhancing the heat transfer of ultra-thin heat pipes. The hydraulic transport properties of micro-porous wick structures are crucial factors for the applications. The inverse opal (IO) micro-porous metal structure has gained extensive attention for its ordered periodic arrangement and high porosity characteristics. In the paper, the copper inverse opal (CIO) and gradient CIO are fabricated by a template-assisted deposition method. Experimental measurements are conducted to study the fluid ascent process within the CIO structure. In addition, a face-centered cubic geometric model is established based on the structure information obtained by a scanning electron microscope (SEM). The calculation employs a porous media model and takes into account the resistance characteristics in the initial phase. The relative error between the simulation and experimental results is less than 7.7%. Furthermore, the fabricated gradient CIO structure is uniform and exhibits a higher permeability than single-pore CIO. The permeability of this gradient CIO is about 1.9–3.2 × 10−14 m 2 . Understanding the microscopic liquid transport process within CIO structures is of great importance in the selection and optimization of capillary wick structures. • The permeability and capillary performance factor of CIO are investigated. • An approach based on the porous media model for simulation of CIO structure is proposed. • Inertial force is considered in the calculation of capillary rise. • The gradient CIO is fabricated by multiple gravity deposition. [ABSTRACT FROM AUTHOR]

The effective management of energy consumption during building operations continues to be of utmost importance. The role of a building's envelope in regulating energy consumption is critical. However, traditional building insulation systems often struggle to maintain optimal indoor temperatures in the face of fluctuating external temperatures. Solar energy, for instance, can easily penetrate a room through windows during the cooling season, leading to increased energy consumption. Similarly, heat dissipates easily during the heating season. To address these challenges, thermal diode composite walls with unidirectional heat transfer offer a groundbreaking approach to simplifying the design of thermal management systems. The thermal diode composite wall effectively controls heat conduction, convection, and radiation through the implementation of different functional layers. By regulating the heat flux through the building envelope, this technology significantly reduces energy consumption during building operations while maintaining a stable indoor temperature. To evaluate the performance of an adaptable thermal diode composite wall, we designed, implemented, and conducted tests on a thermal diode composite wall building. The results of the study demonstrate substantial energy savings, ranging from 3.5% to 69.3% for annual operation in various regions, with better performance observed in colder regions. In the forward heat conduction mode, the temperature difference between the inside and outside wall surfaces reached a maximum of 20.99 K, while in the reverse mode, it reached −35.67 K. These findings highlight the remarkable potential of thermal diode composite walls in significantly improving the energy efficiency and comfort of buildings. Consequently, the adoption of thermal diode composite walls presents numerous opportunities for the development of low-carbon buildings. [ABSTRACT FROM AUTHOR]

Global Warming will probably modify air circulation patterns and increase the severity of droughts, heat waves, heavy precipitation, and floods across the world. A device called 'aerological accelerator' (AeAc) is proposed in this paper to harvest water from the air using a very high tower where the warm and humid air enters from the bottom and rises till the top driven by buoyancy force. This AeAc device is similar in operation principle to a solar chimney power plant (SCPP) with additional features. A mathematical model was developed to calculate the potential energy and water that can be generated in various environments. The calculation results show that clouds are generated within and out of the chimney and the latent heat released by the vapor can noticeably increase the power output of the modified SCPP. With a proper water collecting method, the system can supply water and carbon-free renewable energy for residential and agricultural use. The present study opens the perspective that with minor improvements, significant energy and freshwater production might be possible using these tall engineering structures, whose high chimney can be built thanks to fabric balloons filled with gases lighter than air. • A device called 'aerological accelerator' (AeAc) is proposed to gain water. • Clouds are generated within and out of the chimney. • Water generation under various environment has been analyzed. • The system can supply water for residential and agricultural use. [ABSTRACT FROM AUTHOR]

Graphical abstract This paper talks about 3 effects of the MEMS based DSC. (a) The thermal conduction between the two cells. (b) The response time induced transition temperature shift. (c) The scanning rate induced transition temperature shift. Highlights • This paper proposed a general MEMS based DSC model which consists of flexible substrate, vanadium based thermistors for temperature sensing and micro heaters for sensitivity calibration. • This paper studied the temperature distribution in the substrate with different distances between the sample and reference heaters. It compares the heat conduction between the sample and reference cells with different distances which provides a guidance for minimal DSC unit design with negligible heat conduction between the two cells. • This paper systematically studied the response time induced DSC curve distortion and the transition temperature shift. The research can be used for DSC data correction, especially, the transition temperature shift removal. • The paper studied the relationship between the scanning rate and the transition temperature using lysozyme sample in DSC tests. The experiment results fits the simplified Lumry-Eyring model well. • The paper provides a pathway for highly integrated MEMS DSC array design and the correction of DSC data considering the influence of both the response time and the scanning rate of DSC. Abstract Thin film based differential scanning calorimeter (DSC) was developed and utilized for the study of phase-transition kinetics in protein samples. In this paper, we proposed a MEMS based DSC model. The distance between the sample and reference cell was optimized based on the thermal analysis result. The influence of the response time to the shape of the DSC thermograms and the transition temperature was also studied systematically. Meanwhile, Lumry-Eyring model was used to investigate the relationship between the scanning rate and the transition temperature. The modeling result was verified by the lysozyme denaturation tests. This study provided a pathway for the optimization of MEMS based DSC array and the correction of the DSC thermograms. [ABSTRACT FROM AUTHOR]

Highlights • A energy harvester using the gamma heating effect was conceptualized. • A energy harvester using the existing temperature within the canister was designed. • The thermal energy harvester can supply enough energy for the electronics for 50 years. Abstract Monitoring the conditions inside enclosed metal vessels as found in spent fuel canisters and nuclear reactor pressure vessels is crucial to ensuring safe dry cask storage and reactor operation. In this paper two energy harvesters, a gamma radiation energy harvester and a thermal energy harvester, are designed to power wireless through-wall communication and in-situ monitoring of interior conditions in nuclear canisters. Their performance over 50 years of service in the canister is analyzed using radiation and thermal modeling of the canister, and a scaled experiment is performed to validate the designs. The gamma radiation energy harvester was found to have an energy output of 17.8 mW during the first-year of canister storage. However, its power out decreases to less than 1.0 mW after 50-years storage. The thermal energy harvester proved to be more practical with a simulated power output of 93.9 mW and an experimental output of 46.3 mW even after 50-years storage in the canister. Cost-benefit analysis and discussion for both energy harvesters were also given. [ABSTRACT FROM AUTHOR]

Abstract Thermoelectric cooler (TEC) is a solid-state component that utilizes Peltier effect to dissipate the heat of the electronic packaging system. It shows unique advantages over conventional cooling technology by quiet operation, long lifetime, and ease of integration. However, the internal heat accumulation caused by Joule heat exposes the TEC to the risk of thermal-mechanical failure during long-term operation in realistic thermal environment. In this paper, a heat-generating chip was employed to the cold-end of the module to serve as the finite thermal load while the heat sink at the hot-end was modeled by heat transfer coefficient. Based on the thermoelectric (TE) and thermal stress analyses, we developed a three-dimensional numerical model of a compact TEC, which took into account the temperature dependent TE material properties. It was found that the thermal load attached to Peltier junction can cause extreme high levels of thermal stress, which might cause dislocations and cracks of the material layers. The influences of electrical current, leg length, ceramic plate and bonding layers on the thermal stress levels were examined. These results presented an optimized design with predictive thermo-mechanical performance to realize minimum thermal stress levels, which provided a useful guide to achieve high reliability in a compact TEC. Highlights • Finite element simulations with temperature-dependent properties are carried out. • The effect of thermal load on the thermo-mechanical performance is investigated. • The effects of current, leg length, ceramic plate and bonding layers are examined. • An optimized design to realize minimum thermal stress levels is provided. [ABSTRACT FROM AUTHOR]

Highlights • Both the unsteady RANS and the LES models were employed in the numerical study. • The fluid dynamics within the fluidic oscillators was analyzed. • The heat removal performance of the sweeping jets and impinging jet were compared. Abstract Using an unsteady jet created by the fluidic oscillator represents many opportunities to enhance the heat removal performance of impinging jet. Numerical simulations were conducted to compare the heat transfer performance of two fluid oscillators and a direct jet with unsteady Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) turbulence models implemented. Time-resolved and time-averaged flow fields and heat transfer results were presented. Simulation results showed that the fluid dynamic and heat transfer performance predicted by the RANS and LES models matched well for different Reynolds numbers.The self-oscillating impinging jets were beneficial in enhancing the heat removal performance by increasing the average Nusselt numbers and covering a larger impinging cooling surface. The wide impinging zone and significant heat transfer enhancement suggested it was promising to implement self-oscillating impinging jet concept into existing cooling technologies, such as multi-phase cooling and thin film cooling, for the next-generation high-performance heat exchangers. [ABSTRACT FROM AUTHOR]

The figure of merit of thermoelectric materials is temperature dependent, and thus the local compatibility factor changes significantly along the thermo-element length. A local optimization method to maximize the efficiency of a function graded thermoelectric generator was proposed and discussed in this paper. By adjusting the cross-sectional area and segment's thickness, the reduced current equaled the compatibility factor of the material at every local thermo-element layer. This method can use the full potential of existing materials by maximizing the efficiency at every local thermo-element segment. For such a TEG working in a temperature range of 300–1100 K, the efficiencies of P-type segmented Bi 0.5 Sb 1.5 Te 3 /BiSbTe/-PbTe/FeNbSb thermo-element and a N-type segmented Bi 2 Te 2.79 Se 0.21 /Bi 2 Te 2.9 Se 1.1 /SnSe/SiGe thermo-element were 25.70% and 21.73%, respectively, much higher than the conventional segmented thermo-elements. The overall efficiency of the device was more than 23.72%, making it a promising technology to harvest energy from medium and high-temperature industrial components. The optimized TEG can be fabricated by SLS/SLM technology. [ABSTRACT FROM AUTHOR]

A compact thermoelectric energy harvester is developed to harvest the thermal energy from the hot surface of the gas turbine, providing continuous and reliable power for the sensing and monitoring system in the gas turbine. An experimental prototype is built and the performances of the energy harvester with different electrical load resistances and source temperatures are characterized. A mathematical iterative method, taking account of Thompson Effect, line spacing gap heat leakage, material property variations, and thermal resistance of the ceramic covering layer, is used to analyze the performance of the segmented thermoelectric generator (TEG) module with good accuracy. Based on this model, the temperature profiles and heat fluxes along the thermo-elements, efficiency, and heat leakage through the filling gap material are analyzed. The prototype, with a source temperature of 325 °C, has a voltage output of 2.4 V and power output of 0.92 W, which is more than enough to power a sensor node in the gas turbine. A higher power output can be expected with some improvement on the prototype design. [ABSTRACT FROM AUTHOR]

A detailed three-dimensional thermal and fluid analysis of a vertical dry storage cask with a canister containing 32 high-burnup pressurized water reactor (PWR) spent fuel assemblies for a storage of 50 years was carried out using a CFD simulation. The input decay heat value was calculated based on a Westinghouse 17 × 17 PWR fuel assembly using the well validated package ORIGAMI imbedded in SCALE, with a total heat load of 38.44 kW for year 5 and 10.67 kW for year 55. The temperature-dependent and anisotropic thermal properties of the fuel assemblies, filling gas within the canister, and air covering the canister were considered in order to preserve accuracy. A peak temperature of 621.4 K occurred in the upper part of the fuel assemblies for at year 5, deceasing to 423.0 K after 50-year service. The simulation results shed light on the temperature and flow environment within the canister for an operational time of 50 years. [ABSTRACT FROM AUTHOR]

The solar updraft power plant system (SUPPS) is a low-temperature solar thermal system which utilizes both the buoyancy effect of hot air generated inside a greenhouse by solar radiation and the chimney effect to generate electricity without producing either greenhouse gases or hazardous waste. In this work, a brief review is presented concerning new developments in experimental setups, thermodynamic analyses, turbine, chimney, energy storage, mathematical models and CFD simulations, as well as special applications, and the effects of the ambient cross wind (ACW) on SUPPS. Then as a case study, we show the developments of three SUPPS numerical models to explore the impact of ambient cross wind on large-scale SUPPSs. Three large-scale SUPPSs with similar configurations are investigated: one with a conventional horizontal canopy; one with a familiar sloped canopy design; and one with eight radial partition walls (RPWs) uniformly distributed under the collector canopy. The models are used to evaluate the effects of ACW on the fluid flow and heat transfer processes under various environmental conditions. The velocity, pressure, and temperature contours in and out of the three plants along with the power output of the turbine are analyzed and compared. The results indicate that both the sloped canopy with a lower collector inlet and the RPWs designs are effective in improving the performance of a SUPPS by reducing the amount of heated air escaping from the collector under ACW. An added benefit is that some wind energy is partly harnessed thanks to the design of the RPWs. [ABSTRACT FROM AUTHOR]

The utilization of solar energy to maintain a stable and comfortable air temperature in the built environment has opened up many opportunities for energy saving. However, the periodical nature of the sunlight intensity introduced extra difficulty in the utilization of solar energy. In this paper, a novel concept of jointly using a thermal diode bridge (TDB) and phase change materials (PCMs) was proposed to continuously control the air temperature in built environments during the heating seasons. During the daytime, the solar energy was efficiently harvested and stored in the PCMs, so the indoor temperature was significantly reduced; at nighttime, the thermal energy stored in the PCMs could be used for space heating without heat loss to the outdoor through heat convection. Because of the existence of the TDB, the heat flux going through the building envelope could be passively controlled. An analytical study to evaluate the operating performance of applying such TDB to controlling the zone air temperature in a built environment was carried out and the results were presented. It was demonstrated that the zone air temperature variation in the built environment was significantly reduced, without any electrical energy consumption and greenhouse gas emission. • A thermal diode bridge (TDB) was built to control the heat transfer directions in the building envelope. • The PCMs integrated in the TDB was used to store the solar heat and stabilize the temperature of the built environment. • A mathematical model was built to analyze the energy saving and temperature control performance of the TDB. [ABSTRACT FROM AUTHOR]

The thermoelectric generator (TEG) is a distinctive solid-state heat engine with great potential in various scale energy harvesting. Device-level heat transfer coupled with energy conversion makes the accurate analysis of the system very complicate. In this paper, the thermodynamic analysis in a TEG module is carried out to study the influence of the contact layer resistance, Thompson Effect, Joule heat, and thermo-pellet gap heat leakage on the performance of the TEG. All expressions of power output, current, matching load resistant factor, and efficiency of the device are derived and compared with a commercial module. The equations for the simplified model are also given concisely in order to give a full picture of TEG modeling. The research can evaluate the combined influence of all the factors and redress some derivations in the existing models. [ABSTRACT FROM AUTHOR]

• A self-powered wireless through-wall communication system for nuclear waste storage. • The thermoelectric generator could withstand 124 MRads and provide enough power. • Sensing and communication electronics were implemented using JFETs under 2 Mrad. • The through-wall ultrasound data transmission system survived 101 MRads. • The integrated system could work appropriately under 195 ℃ before electronics died. Many nuclear facilities, such as spent fuel storage dry casks and nuclear reactor pressure vessels, are entirely sealed by metal layers to prevent harmful radiation. For safety and security operations, the temperature, pressure, radiation, and humidity inside the vessel needs to be closely monitored. However, no practical technology is currently available to realize the through-wall data communication and monitoring for these vessels due to the inside harsh environment of high temperature and nuclear radiation. In this paper, an innovative self-powered wireless through-wall data communication system for the nuclear environment is presented, which demonstrates a successful solution to such challenges. The presented system is composed of four modules, i.e., energy harvester with power management circuits, ultrasound wireless communication using high-temperature piezoelectric transducers, electronic circuits for sensing and data transmission, and radiation shielding for electronics. Constitutive functions of each module were firstly designed and followed by the system integration. Experiments were conducted subsequently to validate the designed functions and evaluate the performance of the integrated system. Results showed that the average power of over 40 mW was harvested from the thermal flow inside the nuclear spent fuel canisters which could provide enough energy to operate the sensing and data communication systems. The gamma radiation test results showed that the thermoelectric energy harvester and ultrasound transceivers can withstand radiation dosing over 100 Mrad. Furthermore, temperature shock tests demonstrated that the entire system including the shielded electronics can survive and maintain their functionalities at temperatures as high as 195℃. Under the in-lab mocked-up high temperature conditions and radiation shielding, the proposed system is foreseen to survive and operate stably for fifty years inside a nuclear spent fuel canister, and send the frequency modulated data out of the canister for 3 s in every 10 min. [ABSTRACT FROM AUTHOR]

• The influences of the geometric parameters of the reactor on the SCPP-HPCR are investigated. • A formula is proposed to calculate the CO 2 emissions reduction of the system. • The optimal operating conditions of the SCPP-HPCR is analyzed. • 2.38 kg of CH 4 is degraded and 375.52 kg of CO 2 is reduced through the system one day. The increase of 1.09 °C in global temperature resulted in significant catastrophes because of the extreme climate. The climate change rate can be slowed down by reducing the levels of CH 4 and CO 2 in the atmosphere. The solar chimney power plant integrated with a honeycomb photocatalytic reactor (SCPP-HPCR) uses the photocatalytic technology to remove atmospheric CH 4. In addition, CO 2 emissions can be reduced from coal fired power plant due to the generating capacity of the system. In this paper, the influence of the geometric parameters of the reactor and turbine on the overall performance of the SCPP-HPCR is studied by numerical simulation. The obtained results showed that the flow resistance inside the system was mostly caused by the HPCR at low turbine speed, and primarily by the turbine at high turbine speed. Reducing the pore diameter of the reactor could improve the photocatalytic performance of the SCPP-HPCR more than increasing the turbine speed. The SCPP-HPCR having a pore diameter of 3 mm, porosity of 0.85, and constant turbine speed of 180 rpm, built in Qianyanzhou, China, could remove 2.38 kg of CH 4 and reduce 375.52 kg of CO 2 in one day. [ABSTRACT FROM AUTHOR]

Thermoelectric generator is a device taking advantage of the temperature difference in thermoelectric material to generate electric power, where the higher the temperature difference of the hot-cold ends, the higher the efficiency will be. However, higher temperature or higher heat flux upon the hot end will cause strong thermal stress which will negatively influence the lifecycle of the thermoelectric module. This phenomenon is very common in industrial applications but seldom has research work been reported. In this paper, numerical analysis on the thermodynamics and thermal stress performance of the thermoelectric module has been performed, considering the variation on the thickness of materials; the influence of high heat flux on thermal efficiency, power output, and thermal stress has been examined. It is found that under high heat flux imposing upon the hot end, the thermal stress is so strong that it has a decisive effect on the life expectation of the device. To improve the module’s working condition, different geometrical configurations are tested and the optimum sizes are achieved. Besides, the side effects on the efficiency, power output, and open circuit voltage output of the thermoelectric module are taken into consideration. [ABSTRACT FROM AUTHOR]

A simplified solar updraft device adapted from the Trombe wall concept was built to process large‐scale airflow using only solar energy. The performances were systematically studied using experimental measurements and numerical models, with the focus of investigating whether this device can generate enough airflow under low solar intensities, and developing a fast‐analytical mathematical model to effectively and efficiently find design rules for further application. The experimental results prove that the air mass flow rate generated by solar updraft in a 0.9 m2 solar updraft device can be as high as 75.6 kg/h when the solar radiation is only 120 W/m2. A comparison of two numerical models shows that it is feasible to develop a fast‐analytical tool based on widely available MATLAB with low demand for computing resources and to provide guidance on how a future device should be designed for particular applications. The study also investigated the effects of a wider range of solar radiation intensities, air channel height and thickness on the updraft performances (e.g., air temperature, airflow velocity, and mass flow rate). [ABSTRACT FROM AUTHOR]

Incorporating support structures into solid–liquid phase change materials (SLPCMs) addresses fluid dynamics challenges during phase transitions, albeit at the cost of reduced phase change enthalpy. We propose a novel approach for developing self-sustaining, porous phase change materials. This process begins with the fabrication of self-sustaining poly(acrylic acid) octadecyl ester aerogels through cross-linking polymerization and thermally induced phase separation (TIPS) followed by ambient drying to shape the aerogel. This aerogel demonstrates exceptional energy storage capacity, impressive room-temperature elasticity, and significant load-bearing strength. Leveraging this aerogel as a scaffold, we employ a 'one-step' technique to produce phase change gels (PCGs). This method, in which EI functions both as a solvent and as SLPCMs, yields PCGs with a high latent heat capacity of 192 J g−1, outstanding phase change elasticity, and structural stability, proving highly effective in photoelectric thermal management. Notably, the 'one-step' process for fabricating self-supporting PCGs circumvents conventional steps like solvent extraction and phase change material absorption in traditional porous foam production. This simplification streamlines manufacturing and facilitates the large-scale production of phase change materials that are morphologically stable, possess high latent heat, and exhibit superior mechanical properties. [ABSTRACT FROM AUTHOR]

A novel micro non-premixed combustor with a flame holder and preheating channels is developed to improve the non-premixed flame stabilization for the first time. The numerical results indeed show that the methane-air non-premixed flames can maintain stable with no flashback or pulsating flame even at the stoichiometric ratio compared to the premixed flame, which indicates that the flame stabilization in the present combustor is indeed excellent. The maximum flame temperature at each operating condition is higher than the corresponding adiabatic flame temperature. The excess enthalpy ratio (R eer) is larger at a smaller nominal equivalence ratio (ϕ) and a bigger Reynolds number (Re), and the maximum R eer reaches 36.7%. With the decrease of ϕ , the area of excess enthalpy zone increases at smaller Re (<160), but expands firstly and then shrinks at a larger Re (≥160). In addition, some new non-premixed flame propagation characteristics are found. At the larger ϕ (>0.6), the flame top presents the "Λ" shape, which is significantly different from the flame topology structure of methane/air premixed flame. The standoff distance (S root) between the flame root and the flame holder at the larger Re decreases firstly and then increases with the decrease of ϕ , and the anomalous and non-monotonic S root are both found. These interesting flame propagation features are reported for the first time for the micro non-premixed flame. Researchers can gain insight into micro non-premixed flame propagation characteristics under the competitive effect between the combustion reaction and mixed performance through the present work. [ABSTRACT FROM AUTHOR]

Thermoelectric cooling is an ideal solution for chip heat dissipation due to its characteristics of no refrigerant, no vibration, no moving parts, and easy integration. Compared with a traditional thermoelectric device, a thin-film thermoelectric device significantly improves the cooling density and has tremendous advantages in the temperature control of electronic devices with high-power pulses. In this paper, the transient cooling performance of a compact thin-film thermoelectric cooler with a horizontal structure was studied. A 3D multi-physics field numerical model with the Thomson effect considered was established. And the effects of impulse current, thermoelectric leg length, pulse current imposition time, and the size of the contact thermal resistance on the cooling performance of the device were comprehensively investigated. The results showed that the model achieved an active cooling temperature difference of 25.85 K when an impulse current of 0.26 A was imposed. The longer the length of the thermoelectric leg was, the more unfavorable it was to the chip heat dissipation. Due to the small contact area between different sections of the device, the effect of contact thermal resistance on the cooling performance of the device was moderate. [ABSTRACT FROM AUTHOR]

• The concept of the SC in buildings coupling PCRs for atmosphere CH 4 removal was quantitively verified. • The effects of CH 4 degradation and indoor ventilation by the system were analyzed. • The photocatalytic efficiency, purification rate, and fresh air rate were analyzed. • The new system could degrade 57.27 μg/s of atmospheric CH 4 under optimal conditions. The techniques for the removal of methane from the atmosphere are highly challenging due to its stable chemical properties, dispersed sources, and low concentrations. This paper proposes a practical small-scale solar chimney (SC) in buildings with photocatalytic reactors (PCRs) for atmospheric methane removal. Two comprehensive numerical models on photocatalytic reaction and indoor ventilation are developed. The numerical simulation considers the performance of methane removal and indoor air ventilation of the proposed system, as well as its specific crucial parameters such as the type of PCRs, solar radiation, and flow channel width. The obtained results show that the SC with honeycomb photocatalytic reactor (HPCR) is more able to remove atmospheric methane than SC with plate photocatalytic reactor (PPCR) under the premise of meeting the ventilation standards. In addition, there is a maximum methane purification rate of 57.27 μg/s under the condition that the air gap width is 0.3 m, the length of the HPCR is 1.5 m, and the porosity is 0.85. It is then proved that the SC in buildings with PCRs can allow small-scale, zero-energy consumption, continuable, and decentralized low-concentration atmospheric methane removal while improving the indoor ventilation. [ABSTRACT FROM AUTHOR]

A fabric air dispersion system (FADS) is a type of flexible air supply system that integrates air transmission and distribution. This innovative system has the potential to address common issues such as uneven air supply and surface condensation, which are often associated with traditional ventilation systems. Existing numerical simulation studies on fiber ducts have encountered problems with mesh generation and simulation accuracy. This work develops a simulation method based on the equivalent discounting method to overcome these challenges. The proposed method is utilized to investigate the flow and heat transfer characteristics inside fiber ducts while also examining the effects of various shapes and opening configurations. The findings indicate that the temperature rise inside the duct is positively correlated with flow rate, with higher temperatures resulting from faster flow speeds. The temperature rise of FADS with four rows of openings increased by 0.4 k compared to other opening methods. Additionally, the study shows that increasing the number of rows of openings in the fiber duct leads to a faster decay of flow velocity and a higher temperature rise. At the same time, increasing the number of openings in the duct slightly reduces flow velocity while slightly increasing the temperature rise. The presence of more fiber duct elbows leads to greater local resistance, which accelerates the decay of the flow velocity and increases the temperature rise. Compared to the "1"-shaped FADS, the temperature rises of the "L"-shaped and "U"-shaped systems have increased by 0.9 k and 2.9 k, respectively. [ABSTRACT FROM AUTHOR]

A mathematical model was established to analyze the heat transfer and thermal stress behavior of a segmented thermoelectric generator (STEG). Temperature gradient-induced thermal stress was studied with non-uniform steady heat flux (including Gaussian heat flux and parabolic heat flux), uniform heat flux, and transient heat flux applied to the surface of the hot end, respectively. The results showed that the heat fluxes applied to the hot end lead to uneven temperature distribution on the whole surface of the thermoelectric generator. Thermal stress in the horizontal direction is the major cause of fatigue damage and failures of STEG. When the heat concentration ratio increases, the horizontal temperature uneven distribution will also increase. The thermal stress on the hot end varied significantly reaching the maximum value as high as 16.3 GPa. In addition, the transient heat stress in the system gives rise to periodic stress fluctuations up to 0.6 GPa, which can seriously affect the life cycle of the system. [ABSTRACT FROM AUTHOR]

Safety is the most important issue in the development of nuclear energy. This paper reports experimental studies of a thermoelectric energy harvesting system designed for integration in a nuclear power plant capable of performing in radiation rich environments and producing enough power to run wireless sensors meant to increase plant safety. Furthermore, the system, which utilizes wasted heat present in coolant system piping, has the unique ability to provide power in both normal and accidental situations, to run the sensors without the need for external power. Two energy harvesting prototypes were designed utilizing a heat pipe for heat transfer. The first can supply a maximum power of 2.25 W using two Bi2Te3 thermoelectric modules of 2.79cm (1.1'') \times 2.79 cm (1.1”), in a source temperature near 250 °C. A second design was put forward to extend the application in higher-temperature primary loops, in which one PbTe-Bi2Te3 hybrid TEG module of 5.6cm (2.2'') \times 5.6 cm (2.2”) can provide a power of 3.0 W when the hot side temperature reaches 340 °C. In addition to the energy harvester, wireless communication circuits were developed along with an integrated power management circuit for wireless data transmission. A high intensity gamma radiation experiment was conducted during which each component was irradiated. A total dose of 200 kGy±10% (20M rads) was applied to the first prototype in order to approximate the expected lifetime accumulation for one implemented thermoelectric generator. Results showed that thermoelectric modules used in the prototype had no reduction in voltage output throughout irradiation. Throughout the experiment the harvester system witnessed a small voltage drop in open circuit voltage attributed to a reduction in heat pipe performance from radiation exposure. We also acquired a baseline radiation survivability level for non-hardened, non-shielded electronics of 10^2 Gy. [ABSTRACT FROM PUBLISHER]

A thermoelectric energy harvester composed of two thermoelectric modules, a wicked copper-water heat pipe, and finned heat sinks has been designed, modeled, and tested. The harvester is proposed to power sensor nodes on heating/cooling, steam, or exhaust pipes like these in power stations, chemical plants and vehicle systems. A model to analyze the heat transfer and thermoelectric performance of the energy harvesting system has been developed and validated against experiments. The results show that the model predicts the system power output and temperature response with reasonable accuracy. The model developed in this paper can be adapted for use with general heat sink, heat pipe, and thermoelectric systems. The design, incorporating a heat pipe and two 1.1″ by 1.1″ Bi 2 Te 3 modules generates 2.25 W ± 0.13 W power output with a temperature difference of 128 °C ± 1.12 °C and source temperature of 246 °C ± 1.9 °C, which is more than enough to operate wireless sensors or some actuators. The use of a heat pipe in this design increased the power output by 6 times over conventional designs. Based on the model, further improvement of the power output and energy harvesting efficiency of the system has been suggested by optimizing the number of thermoelectric modules. [ABSTRACT FROM AUTHOR]

Summary: The greenhouse effect is exacerbated as greenhouse gas concentrations rise. Capturing and degrading methane in the atmosphere can effectively slow the trend of global temperature rise. The solar chimney power plant integrated with photocatalytic reactor (SCPP‐PCR) is a promising concept for both clean electricity generation and large‐scale atmospheric methane removal. In this paper, this concept was for the first time quantitatively verified by integrating a photocatalytic reactor in the collector of SCPP to realize the above two targets. A systematic numerical model was proposed to evaluate the performance of degradation of methane and the electricity generation of the SCPP‐PCR. The results revealed that the methane purification rate decreased with increasing turbine rotational speed, but the photocatalytic efficiency improved. In this research, the start of the PCR was set at the entrance of the collector, and it was cost‐effective to lay 40 m in the radial direction with an investment of $4587 (around 0.37% of the total investment of the system). The system could degrade 30 595.47 g of atmospheric methane and reduce CO2 emissions by 245.38 kg in the daytime in Wuhan. It was revealed that SCPP‐PCR could be crucial for reducing greenhouse gas and limiting climate change. [ABSTRACT FROM AUTHOR]

Dental follicles are necessary for tooth eruption, surround the enamel organ and dental papilla, and regulate both the formation and resorption of alveolar bone. Dental follicle progenitor cells (DFPCs), which are stem cells found in dental follicles, differentiate into different kinds of cells that are necessary for tooth formation and eruption. Runt‐related transcription factor 2 (Runx2) is a transcription factor that is essential for osteoblasts and osteoclasts differentiation, as well as bone remodeling. Mutation of Runx2 causing cleidocranial dysplasia negatively affects osteogenesis and the osteoclastic ability of dental follicles, resulting in tooth eruption difficulties. Among a variety of cells and molecules, Nel-like molecule type 1 (Nell-1) plays an important role in neural crest-derived tissues and is strongly expressed in dental follicles. Nell-1 was originally identified in pathologically fused and fusing sutures of patients with unilateral coronal synostosis, and it plays indispensable roles in bone remodeling, including roles in osteoblast differentiation, bone formation and regeneration, craniofacial skeleton development, and the differentiation of many kinds of stem cells. Runx2 was proven to directly target the Nell-1 gene and regulate its expression. These studies suggested that Runx2/Nell-1 axis may play an important role in the process of tooth eruption by affecting DFPCs. Studies on short and long regulatory noncoding RNAs have revealed the complexity of RNA-mediated regulation of gene expression at the posttranscriptional level. This ceRNA network participates in the regulation of Runx2 and Nell-1 gene expression in a complex way. However, non-study indicated the potential connection between Runx2 and Nell-1, and further researches are still needed. [ABSTRACT FROM AUTHOR]

Orthodontic tooth movement is a mechanobiological reaction induced by appropriate forces, including bone remodeling. The mechanosensitive Piezo channels have been shown to contribute to bone remodeling. However, information about the pathways through which Piezo channels affects osteoblasts remains limited. Thus, we aimed to investigate the influence of Piezo1 on the osteogenic and osteoclast factors in osteoblasts under mechanical load. Cyclic stretch (CS) experiments on MC3T3-E1 were conducted using a BioDynamic mechanical stretching device. The Piezo1 channel blocker GsMTx4 and the Piezo1 channel agonist Yoda1 were used 12 h before the application of CS. MC3T3-E1 cells were then subjected to 15% CS, and the expression of Piezo1, Piezo2, BMP-2, OCN, Runx2, RANKL, p-p65/p65, and ALP was measured using quantitative real-time polymerase chain reaction, western blot, alkaline phosphatase staining, and immunofluorescence staining. CS of 15% induced the highest expression of Piezo channel and osteoblast factors. Yoda1 significantly increased the CS-upregulated expression of Piezo1 and ALP activity but not Piezo2 and RANKL. GsMTx4 downregulated the CS-upregulated expression of Piezo1, Piezo2, Runx2, OCN, p-65/65, and ALP activity but could not completely reduce CS-upregulated BMP-2. The appropriate force is more suitable for promoting osteogenic differentiation in MC3T3-E1. The Piezo1 channel participates in osteogenic differentiation of osteoblasts through its influence on the expression of osteogenic factors like BMP-2, Runx2, and OCN and is involved in regulating osteoclasts by influencing phosphorylated p65. These results provide a foundation for further exploration of osteoblast function in orthodontic tooth movement. • 15% cyclic stretch is optimal for MC3T3 to express Piezo and osteoblast markers. • Piezo1 and Piezo2 channels were upregulated by cyclic stretch stimuli in MC3T3. • Blocking/activating Piezo1 regulates Piezo2. • Blocking/activating Piezo1 regulates BMP-2, OCN, Runx2, P-P65/P65, ALP activity. [ABSTRACT FROM AUTHOR]

The solar chimney power plant (SCPP) provides the approach to achieving carbon neutrality goals. The power generation of the system decreases drastically due to the ambient crosswinds (ACWs). In this paper, three wind resistant structures, including blockage wall, radial partition wall (RPW), and porous wall are adopted to weaken the effects of the ACWs. In addition, the flow characteristics and power generation performance of each system are investigated in the first consideration of the 3D turbine by developing a numerical model. The results reveal that the negative effects caused by the ACWs on the system are attenuated by integrating the three structures. The adverse effect of weak winds on the SCPP is greatly weakened by integrating a blockage wall, but is not significant for robust winds. For SCPP with RPWs, the velocity is slightly increased due to the improved collector flow path by the RPWs at ACW = 0 m/s. The maximum power generation is 93.68 kW, an increase of 1.22 times over the SCPP. The uneven forces on the turbine blades due to the ACWs can be mitigated by integrating porous wall, enhancing turbine stability. In addition, the fluctuation of the power generation is less than 30 % under ACWs. • The performance of the SCPP is studied in open space. • Three structures are adopted to weaken the negative effects of the ACWs. • The effect of ACWs on the SCPP is weakened by integrating a blockage wall. • The maximum power generation increased by 22 % by integrating RPWs. • The fluctuation of the power generation is less than 30 % due to a porous wall. [ABSTRACT FROM AUTHOR]

This research introduces a novel TLFD-GA algorithm for the three-level criteria optimization of organic Rankine cycle (ORC) power plants. It replaces the non-dominated sorting of NSGA-II with three-level fuzzy decision to simultaneously optimize environmental, thermodynamic, and techno-economic criteria. The algorithm provides direct optimization results without needing additional decision-making methods. Furthermore, the impact of pressure drop in plate heat exchangers is investigated, revealing a proportional relationship between pressure drop and the increment of evaporation pressure. A parametric study on 24 basic and recuperative trans -critical geothermal ORC systems indicates that compensating for pressure drop leads to a 5% decrease in thermodynamic performance, a 20% decrease in techno-economic performance, and a 20–60% increase in heat transfer area per net output power. After TLFD-GA optimization, the saving to investment ratio improves by an average of 4.5% across scenarios. R1270 stands out with a remarkable ratio of 3.13 and 4.32 in medium and high-temperature geothermal reservoirs. Moreover, the proposed TLFD-GA optimization algorithm has demonstrated its superiority in terms of superb convergence and stability when compared to NSGA-II, which suggests its prospective application in the low-carbon and green energy fields. • A novel TLFD-GA algorithm is developed to achieve three-level criteria optimization. • Multi-objectives cover the environmental, thermodynamic and techno-economic criteria. • The optimal solutions are output directly without additional decision-making methods. • The effect of pressure drop on the optimal parameters of ORC system is investigated. • The superiority of TLFD-GA is verified by comparison to NSGA-II. [ABSTRACT FROM AUTHOR]

Two large earthquakes occurred in the western part of China in 2008, one of them being the Yutian (35.6°N, 81.6°E) M7.3 earthquake that occurred on March 21 (BJT) and the other the Wenchuan (31.0°N, 103.4°E) M8.0 earthquake that occurred on May 12 (BJT). In this paper, the West Continental China (included in 20.0°-50.0°N, 70.0°-110.0°E region) was the study region for verifyong the predictability of the pattern informatics (PI) method using the receiver-operating characteristic curve (ROC) test and R score test. Different forecasting maps with different calculating parameters were obtained. The calculating parameters were the grid size Δ x, base time t, reference interval t to t, change interval t to t, and forecasting interval t to t. In this paper, the base time t fixed to June 1, 1971, the ending forecast time t fixed to June 1, 2008, and the forecasting interval t to t changed from 1 to 10 years, and the grid sizes were chosen as 1° × 1° and 2° × 2°, respectively. The results show that the PI method could forecast the Yutian M7.3 and Wenchuan M8.0 earthquakes only using suitable parameters. Comparing the forecast results of grid sizes 1° × 1° and 2° × 2°, the models with 2° × 2° grids were better. Comparing the forecast results with different forecasting windows from 1 to 10 years, the models with forecasting windows of 4-8 years were better using the ROC test, and the models with forecasting windows of 7-10 years were better using the R score test. The forecast efficiency of the model with a grid size of 2° × 2° and forecast window of 8 years was the best one using either the ROC test or the R score test. [ABSTRACT FROM AUTHOR]

The urban heat island (UHI) effect resulted from urbanization as well as industrialization has become a major environmental problem. UHI effect aggravates global warming and endangers human health. Thus, mitigating the UHI effect has become a primary task to address these challenges. This paper verifies the feasibility of a three-dimensional turbulent porous media model. Using this model, the authors simulate the urban canopy wind-heat environment. The temperature and flow field over a city with a concentric circular structure are presented. The impact of three factors (i.e., anthropogenic heat, ambient crosswind speed, and porosity in the central area) on turbulent flow and heat transfer in the central business district of a simplified city model with a concentric circular structure were analyzed. It is found that the three-dimensional turbulent porous media model is suitable for estimating the UHI effect. The UHI effect could be mitigated by reducing the artificial heat and improving the porosity of the central city area. [ABSTRACT FROM AUTHOR]

• The numerical simulation is used to validate the effectiveness of atmospheric methane removal by SCPP-PCR. • The performance and influencing factors of photocatalytic oxidation of methane by the SCPP-PCR were analyzed. • The photocatalytic efficiency and purification rate were introduced to evaluate the effect of SCPP-PCR on methane removal. • The optimum dimension of photocatalytic reactor with pore diameters of 2–4 mm was determined. Methane (CH 4) is the second largest contributor to global warming among all greenhouses gases. A solar chimney power plant integrated with a photocatalytic reactor (SCPP-PCR) is a promising large-scale method for removing CH 4 from the atmosphere. This study used computational fluid dynamics (CFD) to investigate the performance and factors influencing photocatalytic oxidation of methane by the SCPP-PCR system. The geometry of a SCPP is the same as the prototype of the SCPP built in Manzanares (Spain). The PCR is designed based on a honeycomb monolith photoreactor. The numerical results revealed that the SCPP-PCR system can degraded 21,312 g methane per day with the actual solar radiation data when the channel diameter of the honeycomb PCR was 4 mm and channel length was 8 m. Although increasing the length or decreasing the channel diameter of the PCR would improve photocatalytic efficiency, the rate of airflow of the system would be reduced. The maximum methane purification rate of the SCPP-PCR system was determined. [ABSTRACT FROM AUTHOR]

During their rapid economic development and industrialization, megacities in the developing nations with high populations (especially in the east and south Asia) are plagued by severe air pollution problems (e.g., heavy haze), which impose a threat not only to public health but also to the sustainable development of society and the economy. To relieve the burden of air pollution for the general public, this article reviewed several geoengineering measures based on solar chimneys, which have the large-scale elimination ability on pollutants in the air, particularly for particulate matter. These geoengineering measures include driving the polluted air penetrate the planetary boundary layer into the troposphere to avoid the dramatic growth of concentrations of particulate matter, spraying water on the top of the solar chimney into the air to scavenge pollution, and intercepting fine particles in the air driven by the solar energy with large filters. Compared with traditional methods (e.g., giant spray trucks), those solar chimney geoengineering measures have the following advantages: 1) they can be operated 24 h a day, thus keeping the pollution removal function stable and continuous; 2) they are environment-friendly and can generate clean electricity to compensate for energy consumption; 3) they are also robust and operational with very low maintenance for a long period. Given the advantages of the solar chimney geoengineering measures and the economic and human health losses caused by air pollution, those geoengineering approaches deserve to be studied further and implemented in those countries that are suffering from heavy air pollution problems. [ABSTRACT FROM AUTHOR]

The freeze-melting process can be a viable method for the purposes of desalination because of its low energy consumption, ignorable corrosion issues, and without huge pressure or membrane replacement work. Large contact area for heat and mass transfer per unit mass of water between the water and air and low heat resistance results in higher energy efficiency during spray freezing desalination process compared to other freezing desalination methods. A 200 m high desalination tower was proposed in this paper that could generate 27.7 kg / s fresh water in the form of water droplets with 2 mm diameter at an atmospheric temperature of −26° C. This research has founded that the natural convective airflow induced by the heat released by the warm water in the freezing process could generate through the wind turbine mounted in this system approximately one-third of the energy consumed by the water pump of the system. This free energy has never been studied in previous research. The power consumption required to produce 1 m 3 fresh water in this system is approximately 1.07 kWh. Compared to traditional desalination methods, the power consumption of our new spray freezing desalination system is much lower than previous systems with the same mass flow rate of fresh water. Only 375.4 kJ cold energy to produce one-kilogram fresh water. Thus, this spray freezing desalination system could be employed in desalination industry if free cold energy (e.g. from the cold atmosphere or the regasification process of LNG) and seawater resources are available. • The free energy released from the frozen water during spray freezing process was utilized for power generation. • A one-dimensional mathematical model was developed for compressible airflow in the energy-generation tower. • The friction between water droplets with the airflow was considered in this model. • The factors which could affect desalinated water and electricity output were analyzed. [ABSTRACT FROM AUTHOR]

• A three-dimensional numerical model based on the finite element method has been developed. • A multi-factor roadmap for the design of wearable micro-TEGs is proposed. • A micro-TEG module is fabricated to verify the theoretical roadmap. • The maximum power density reached 1.79 μW/cm2 for the micro-TEG module worn on the wrist. To further meet the requirement of the Internet of Things (IoT), more and more sensors need to be integrated inside wearable devices. Wearable TEGs directly convert the heat flow generated by the temperature difference between a human body and the environment into electricity, thus acting as a permanent energy supply for sensor systems. In this work, considering the body's thermoregulation function in the wearing scenario, a three-dimensional numerical model based on the finite element method has been developed to systematically study the power generation performance of micro-TEGs. The multi-factor design involves the packing density (p d), leg width (w), leg height (l) and convective heat transfer coefficient (h) at the cold side of the generator. On this basis, we have proposed a multi-factor roadmap for the design of wearable micro-TEGs with the required power density and open circuit voltage. The theoretical roadmap modeling was verified by fabricating a micro-TEG module of 20 × 20 mm2, with w = 0.5 mm, l = 1.38 mm, and the leg density of p d = 33 legs/cm2. When worn on the wrist (T core = 37 ℃, T air = 22 ℃), a steady voltage output of ∼ 21.0 mV was generated and the corresponding maximum power density reached 1.79 μW/cm2. [ABSTRACT FROM AUTHOR]

Five large earthquakes of M ≥ 7.0 (based on the magnitude scale of the China Earthquake Networks Center) occurred in and near the Tibetan Plateau during 2008-2014, including the Wenchuan M8.0 earthquake on May 12, 2008 (BJT). In this paper, the Tibetan Plateau was chosen to be the study region, and calculating parameters of pattern informatics (PI) method with grid of 1° × 1° and forecasting time interval of 8 years were employed for the retrospective study according to the previous studies for M7 earthquake forecasting. The sliding step of forecasting interval was 1 year, and the hotspot diagrams of each forecasting interval since 2008 were obtained year by year. The relationships among the hotspots and the M ≥ 7.0 earthquakes that occurred during the forecast intervals were studied. The predictability of PI method was tested by verification of receiver-operating characteristic curve (ROC) and R score. The results show that the successive obvious hotspots occurred during the sliding forecasting intervals before four of the five earthquakes, while hotspots only occurred in one forecasted interval without successive evolution process before one of the five earthquakes, which indicates that four of the five large earthquakes could be forecasted well by PI method. Test results of the predictability of PI method by ROC and R score show that positive prospect of PI method could be expected for long-term earthquake forecast. [ABSTRACT FROM AUTHOR]

The acceleration of urbanization process, which triggered a series of environmental issues, has become increasingly prominent. Air pollution, especially atmospheric fine particulate matter (PM 2.5 ), is one of the most severe pollutions affecting the human health and living standard. In this article, a novel solar chimney with an inverted U-type cooling tower and a water spraying system (SCIUCTWSS) was proposed to mitigate the urban air pollution. In this system, an inverted U-type cooling tower was used to take place of the traditional chimney erected in the center of the collector; a water spraying system was installed at the turning point of the inverted U-type cooling tower to enhance the driving force; a filtration screen is placed near the entrance of the collector to filter out PM 2.5 and large particulate matter from the airflow. The clean air out of the system’s outlet can immediately improve the air quality in the spectrum of human activity. A mathematical model to describe the fluid flow, heat transfer of the system was further developed. Influence of injected water from the water spraying system on the pressure, velocity, temperature, and air density distributions were analyzed. The numerical simulation results indicated that water injection is efficient that can strengthen the natural convection and has a positive influence on the heat transfer process within the system. This proposed SCIUCTWSS in this article is able to process atmospheric air at a volume flow rate of 810 m 3 /s, corresponding to the volume of 69,984,000 m 3 of air to be cleaned in one day. However, in view of the economic and human comfort, the amount of injected water should be taken into comprehensive consideration. [ABSTRACT FROM AUTHOR]

A solar chimney power plant (SCPP) is not only a solar thermal application system to achieve output power, but also a device extracting freshwater from the humid air. In this article, we proposed a SCPP with collector being replaced by black tubes around the chimney to warm water and air. The overall performance of SCPP was analyzed by using a one-dimensional compressible fluid transfer model to calculate the system characteristic parameters, such as chimney inlet air velocity, the condensation level, amount of condensed water, output power, and efficiency. It was found that increasing the chimney inlet air temperature is an efficient way to increase chimney inlet air velocity and wind turbine output power. The operating conditions, such as air temperature and air relative humidity, have significant influence on the condensation level. For water generation, chimney height is the most decisive factor, the mass flow rate of condensed water decreases with increasing wind turbine pressure drop. To achieve the optimum peak output power by wind turbine, we should set the pressure drop factor as about 0.7. In addition, increasing chimney height is also an efficient way to improve the SCPP efficiency. Under ideal conditions, the system total efficiency of a SCPP with a height of 3000 m can be up to nearly 7%. [ABSTRACT FROM AUTHOR]

In order to improve the performance and maximize the efficiency of energy conversion of thermoelectric generator (TEG), a mathematical model to predict the maximum energy conversion efficiency of TEG is developed. Then, a new compact thermoelectric generator (C-TEG) and a dimensional optimized TEG (DO-TEG) are proposed in this article. The compact thermoelectric generator is designed via logical intersection angle selection and layout, thus to improve the electric performance per unit volume. Finally, we compared the output electric performance of C-TEG and traditional thermoelectric generator (T-TEG) and that of DO-TEG under design and off-design conditions via numerical simulations. The results indicate that C-TEG has an excellent electric performance whose voltage, power, and efficiency decrease slightly whereas the output voltage, work, and efficiency compared with that of T-TEG have been significantly improved, with the amplitude increasing with the increase of resistant value of external loads. [ABSTRACT FROM AUTHOR]

• The mode-decoupling capability of the HIIRS was analyzed and validated. • The damping range and the coupling effects between the damping and the stiffness of the HIIRS were investigated. • A piecewise-linearizing method was proposed to model the accumulator and thus to determine the analytical solution of the roll and pitch stiffness of the HIIRS. • The HIIRS could reduce the roll angle and pitch angle by 34.42% and 28.91%, while harvesting power as 87.69 W and 147.86 W, respectively. An innovative hydraulic integrated interconnected regenerative suspension system (HIIRS), which can simultaneously harvest suspension vibration energy and enhance the vehicle handling performance, is studied in this paper. One big challenge for the HIIRS is the mode-decoupling problem among the four vehicle vibration modes, namely bounce, roll, pitch, and warp modes. This paper comprehensively studied why and how the HIIRS could decouple the four modes. Specifically, the nonlinear fluidic model of the HIIRS was built and integrated with a 14DOF nonlinear vehicle model. Based on the model, the damping range and the coupling effects between the damping and the stiffness of the HIIRS were investigated. The roll and pitch stiffness of the HIIRS were calculated, where a novel piecewise-linearizing method was proposed to determine the analytic expression of the stiffness. Numerical experiments were conducted to demonstrate the mode-decoupling capability of the HIIRS and the influence of its parameters on the vehicle dynamics and the energy harvesting performances. In addition, the anti-roll, anti-pitch, and energy harvesting performances of the HIIRS were also studied and compared with a conventional off-road vehicle. The roll angle in a double lance change scenario and the pitch angle in a straight-line braking scenario could be respectively reduced by 34.42% and 28.91% when the initial system pressure in the HIIRS was 40 bar and the load resistance was 10 Ω. The corresponding regenerative power was 87.69 W and 147.86 W for the two cases. [ABSTRACT FROM AUTHOR]

Abstract: Existing research indicated that the ambient crosswind (ACW) has very complex influences on the SUPPS both through the chimney outlet and collector inlet as demonstrated by numerical analysis from the Spanish prototype. But what influence exert ACW through chimney outlet and collector inlet independently on the overall performance of SUPPS is still unclear. In this research, two geometrical models are constructed for numerical simulation on industrial-scale SUPPS in the vicinity of 10 MW. In model 1, ACW acts on both chimney outlet and collector inlet; in model 2, ACW acts only on the chimney outlet. Fluid flow, heat transfer and power output performances of SUPPS are investigated and discussed. It is found that, the negative effect of ACW only occurs at the collector inlet, with cold ambient air into the collector resulting in changing of fluid distribution and deterioration of buoyant driving force, whereas the positive effect occurs at the chimney outlet, with strong ACW passing by the chimney outlet causing entrainment of buoyant airflow within the chimney outlet. To avoid deterioration and to improve the overall performance of SUPPS, effective measures can be taken to prevent ACW from entering the collector inlet and also to induce beneficial effects of high altitude strong ACW blowing across the chimney outlet. [Copyright &y& Elsevier]

• A microchannel heat exchanger made by the fluidic oscillators array was designed. • The oscillation modes of two parallel fluidic oscillators were studied. • The time-resolved pressure field and velocity field were analyzed. • The heat transfer performance of the fluidic oscillators array was evaluated. Impinging jet played an important role in cooling technology. The steady-state jet could be transformed into an oscillatory one based on the intrinsic flow instability mechanisms by using self-oscillating fluidic oscillators. In this paper, a high-performance microchannel heat exchanger based on a fluidic oscillator array was presented. The fluidic oscillators were tilted at an angle of 30° above the impinging surface to extend the influence area of the jets. The unsteady RANS turbulence models were adopted to study the fluid dynamic and heat transfer performance of the jet array. The time-resolved pressure field and velocity field were calculated to show that the parallel oscillators would produce three modes, including co-directional oscillation, reverse oscillation, and irregular oscillation, under synchronous and asynchronous output phases. The sweeping jets improved the heat removal performance by increasing the average Nusselt number and enlarging the influence range on the external flow field. The heat removal performance of the sweeping jets was almost equivalent under different oscillation modes. [ABSTRACT FROM AUTHOR]

The spatial and temporal variation of LURR (Load/Unload Respond Ratio) in California during April 2002 to June 2004 was studied in this paper. The result shows that before the San Simeon earthquake (35.7 N, 121.1 W) on Dec. 22, 2003, Y/ Y c anomalous region occurred successively near the epicenter from April 2002 to June 2002, and the maximum anomaly of Y/ Y c occurred in May, 2002. The published research work pointed out that the Y/ Y c anomaly near the San Simeon earthquake appeared from March, 2002. Compared with the five earthquake cases out of the six with M ≥ 6.5 in California during the period from 1980 to 2001, the maximum Y/ Y c and duration of Y/ Y c anomaly before this earthquake are among the normal ranges, but the time delay from the maximum anomaly time to the occurrence time of this earthquake is the longest one. The result also shows that two areas with Y/ Y c anomalies occurred from Oct. 2002 and Dec. 2002, respectively. According to statistical characteristics of the relationship between Y/ Y c anomalies and the coming earthquakes, the seismic tendency in California was discussed in this paper. [ABSTRACT FROM AUTHOR]