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The formation of shear-thinning fluid [sodium alginate (SA) solution] droplets in a continuous Newtonian fluid phase is studied numerically. The influences of shear thinning effects on the interface evolution, flow regimes, droplet size, and formation frequency are examined. A regime diagram is summarized in terms of the Capillary number of the continuous phase (Ca) and the concentration of the shear-thinning fluid (cnN-f, the concentration of the SA solution). The results show that the regime transition from dripping to jetting caused by increasing Cais delayed when the dispersed phase is a shear-thinning fluid, which is advantageous in the production of highly monodispersed droplets. Additionally, cnN-fshows a distinct influence on dripping and jetting regimes. In dripping regimes, increasing cnN-fresults in decreased droplet size with a high formation frequency. This study provides a theoretical reference for the preparation of shear-thinning fluid droplets and is also helpful in clarifying the formation mechanism of non-Newtonian droplets.

Efficient thermal management of lithium-ion battery, working under extremely rapid charging-discharging, is of widespread interest to avoid the battery degradation due to temperature rise, resulting in the enhanced lifespan. Herein, thermal management of lithium-ion battery has been performed via a liquid cooling theoretical model integrated with thermoelectric model of battery packs and single-phase heat transfer. Aiming to alleviate the battery temperature fluctuation by automatically manipulating the flow rate of working fluid, a nominal model-free controller, i.e., fuzzy logic controller is designed. An optimized on-off controller based on pump speed optimization is introduced to serve as the comparative controller. Thermal control simulations are conducted under regular operating and extreme operating conditions, and two controllers are applied to control battery temperature with proper intervals which is conducive to enhance the battery charge-discharge efficiency. The results indicate that, for any operating condition, the fuzzy logic controller shows excellence in terms of the tracking accuracy of set-point of battery temperature. Thanks to the establishment of fuzzy set and fuzzy behavioral rules, the battery temperature has been throughout maintained near the set point, and the temperature fluctuation amplitude is highly reduced, with better temperature control accuracy of ∼0.2°C (regular condition) and ∼0.5°C (extreme condition) compared with ∼1.1°C (regular condition) and ∼1.6°C (extreme condition) of optimized on-off controller. While in the case of extreme operating condition, the proposed optimized on-off controller manifests the hysteresis in temperature fluctuation, which is ascribed to the set of dead-band for the feedback temperature. The simulation results cast new light on the utilization and development of model-free temperature controller for the thermal management of lithium-ion battery.

As the promising cooling method for the next generation of data centers, the internal heat transport mechanism and enhancement mechanism of single-phase immersion liquid-cooled (SPILC) systems are not yet well understood. To address this, a steady-state three-dimensional numerical model is constructed herein to analyze flow and thermal transport capacities in servers using SPILC and traditional air-cooling methods. Moreover, this paper emphasizes the influence of component positioning, and underscores the benefits of optimizing coolant flow distribution using baffles. The results indicate that the SPILC system outperforms the traditional air-cooling approach at the same inlet Reynolds number (Re). When Re=10 000, the SPILC method reduces the maximum temperature by up to 70.13%, increases the average convective heat transfer coefficient by 287.5%, and provides better overall thermal uniformity in data center servers. Moreover, placing devices downstream of high-power components creates “thermal barriers” and degrades thermal transport for upstream devices due to increased flow resistance. Excessive spacing between high-power devices can lead to the formation of bypass channels, further deteriorating heat transfer. Additionally, the addition of baffles in the inlet section of SPILC systems effectively enhances heat dissipation performance. To maximize the heat dissipation capacity, minimizing bypass channels and optimizing the flow distribution of coolants are crucial.

Cascade utilization is the most promising solution for efficient recovery of industrial waste heat. In this paper, a combine cooling and power(CCP) system including an organic Rankine cycle (ORC) and an absorption refrigeration cycle (ARC) is proposed, aiming to realize the cascade utilization of efficient utilization of low-grade flue gas. With the objective of maximizing the equivalent specific net power output, a particle swarm optimization (PSO) algorithm is employed to optimize the operation parameters of proposed system and the composition and mass fractions of zeotropic working fluid. The results indicate that the proposed system can realize efficient cascade utilization for flue gas waste heat energy. The optimized proposed system achieves a specific net power output of 6.09 kW/kgFG of a specific refrigeration capacity of 27.65kW/kgFG. Additionally, heat exchanger exergy losses account for 73.7% and 53.6% of the total exergy losses in the ORC and ABR subsystems, respectively. Therefore, optimizing the heat exchanger equipment is a feasible approach to further enhance the thermodynamic performance of the proposed system.

A hybrid multiphase lattice Boltzmann model is adopted to investigate the flow boiling heat transfer process in a horizontal microchannel with consideration of bubble dynamics. The flow pattern transition in a microchannel, involving single-phase flow, bubbly flow, slug flow, and contact-slug flow, is reproduced by varying the heat flux. The influencing parameters, including the liquid mass flux, the heating wall wettability, and the confinement height of channels, on dynamic bubble behaviors and heat transfer performance are discussed. The results indicate that a sequence of single-phase flow, bubbly flow, slug flow, and contact-slug flow occurs in a microchannel with increasing heat flux. Correspondingly, the dominant heat transfer mechanism experiences the liquid convection (single-phase flow), nucleate boiling (bubbly flow), the microlayer evaporation (slug flow), and the hybrid gas convection and microlayer evaporation (contact-slug flow). The increase of mass flux or confinement height extends the range of heat flux for high-efficiency bubbly and slug flow. The hydrophilic heating wall is preferred for better heat transfer performance in a microchannel due to the strengthened microlayer evaporation and less vapor occupation of the effective nucleation area.

Relevant advancements in microbial fuel cells (MFCs) are impeded by the limited oxygen reduction reactions at the cathode. The challenge prompted the development of a jarosite-biochar catalyst using a straightforward biomineralization method. Through X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, we observed a reduction in the agglomeration phenomenon of nano jarosite and a decrease in particle size. The biochar-jarosite MFC demonstrated a significant increase in voltage (682.5 mV) and a maximum power density of 1211 mW/m2. Electrochemical impedance spectroscopy (EIS) showed that the charge transfer resistance of the cathode decreased from 2580 Ω to 111 Ω, demonstrating excellent oxygen reduction reaction (ORR) performance. The jarosite-biochar significantly enhanced the MFC degradation of Cr (VI), exhibiting a 5.2-fold increase, while demonstrating exceptional stability. The X-ray photoelectron spectroscopy (XPS) of Fe and Cr on the surface of jarosite-biochar further substantiates the role of jarosite as an electron mediator between biochar and Cr (VI) in the MFC. Our study presents a cost-effective and efficient biomineralization strategy for the modification of cathode materials in MFCs, offering significant potential for enhancing the catalytic performance of iron-containing carbonaceous composites in Cr (VI) environments.

Cognitive decline is thought to be more prevalent in elderly persons with periodontitis. Greater adherence to Healthy Eating Index (HEI)-2015 has been reported to improve cognitive function in the elderly population. However, whether the benefits of HEI-2015 on cognitive function apply to elderly patients with periodontitis remains unknown.

Organic Rankine cycle (ORC) is an attractive method for recovery of liquefied natural gas (LNG). Zeotropic mixtures are optimal working fluids for improving the ORC power generation performance. In this study, eight CO2-based binary mixtures were selected as alternative working fluids for the utilization of medium-temperature LNG cold energy for ORC. The effect of CO2-based binary mixture on thermodynamic performance of ORC was presented and investigated. The genetic algorithm was applied to optimize the thermodynamic performance of ORC so as to determine the optimal working fluid among CO2-based binary mixtures. The results indicate that CO2-based binary mixtures significantly improve the thermodynamic performance of ORC in the recovery of LNG cold energy when compared with pure-CO2ORC. There is a specific CO2mass fraction that leads to the highest net power output of the ORC, and the mass fraction of CO2increases with higher condensation temperatures (For CO2/Propane, the condensation temperatures are −55 °C, −40 °C, and −30 °C, and this CO2mass fraction is 0.35, 0.65, and 0.8, respectively). Furthermore, the ORC using CO2/R134a exhibits the highest net power output at 13.50 kW among the eight alternative CO2-based binary mixtures.

In this paper, a free energy lattice Boltzmann model of vapor condensation on a surface with a wettability gradient is developed and numerically analyzed to understand the microscopic behaviors of self-propelled droplet condensation. The effect of wettability gradient on droplet self-motion and coalescence as well as vapor condensation is examined and investigated. The condensation rate is presented during the whole droplet condensation process to analyze the role of wettability gradient on droplet condensation. The results indicate that the surface with wettability gradient is preferred for vapor condensation owing to the appearance of self-propelled droplet condensation. Condensate film is initially spread on the high surface energy region, and liquid nucleation sites form, grow and, subsequently, coalesce with other droplets on low surface energy regions. The condensation rate is higher on a surface with a larger wettability gradient due to the more effective removal of condensate. In addition, the condensation rate fluctuates with time at the quasi-steady-state stage. During the condensation process, the droplet coalescence triggers a sudden peak of condensation rate, and the generation of new nucleation results in a rapid increase in the condensation rate.

A mathematical model of the charging process for a structured packed-bed latent thermal energy storage unit with phase change material capsules is established. The thermal-hydrodynamic characteristics of the unit are investigated. The impacts of the heat transfer fluid inlet velocity, heat transfer fluid inlet temperature, initial temperature of the latent thermal energy storage unit, and diameters of the phase change material capsules are analyzed. The charging performance of a scaled-up latent thermal energy storage unit is studied. The numerical results indicate that the structured packing configuration of the structured packed-bed latent thermal energy storage unit influences the periodic flow characteristics of the latent thermal energy storage unit. The melting behaviors in each phase change material capsule are synchronous due to the excellent heat transfer capacity of the latent thermal energy storage unit. With the increasing initial temperature of the latent thermal energy storage unit, the duration of the charging process varies little, but the total heat storage capacity of the unit decreases. The decreasing diameter of the phase change material capsule significantly shortens the charging process of the latent thermal energy storage unit. The total heat storage capacities of the latent thermal energy storage unit with different phase change material capsule diameters are nearly the same. The heat storage capacity of the phase change material unit can be easily scaled up by adding more phase change material capsules and extending the phase change material capsule zone. The scale-up of the structured packed-bed latent thermal energy storage unit does not affect the charging time of the latent thermal energy storage unit.

A gravitational flat-plate heat pipe is designed and fabricated in this paper to serve as a heat spreader to diffuse the local heat source to the hot side of the thermoelectric power module. Based on this, an experimental test for the thermoelectric power generation system is conducted to study the influences of the heat spreader on the temperature uniformity and power generation performance when exposing to a local heat source. In addition, the effects of the heating power, inclination angle, and local heat source size on the power generation performance of the thermoelectric power module using a flat-plate heat pipe as a heat spreader are examined and compared with that using a metal plate. The results indicate that the gravitational flat-plate heat pipe has considerable advantages over the metal plate in the temperature uniformity. The superiority of temperature uniformity in the improvement of power generation performance for the thermoelectric power system using a heat pipe is demonstrated. Particularly, the heat pipe shows good adaptability to placement mode and the local heat source size, which is beneficial to the application in the thermoelectric power generation.

Accurate identification of tumor margins during cancer surgeries relies on a rapid detection technique that can perform high-throughput detection of multiple suspected tumor lesions at the same time. Unfortunately, the conventional histopathological analysis of frozen tissue sections, which is considered the gold standard, often demonstrates considerable variability, especially in many regions without adequate access to trained pathologists. Therefore, there is a clinical need for a multitumor-suitable complementary tool that can accurately and high-throughput assess tumor margins in every direction within the surgically resected tissue. We herein describe a high-throughput three-dimensional (3D) histological electrophoresis device that uses tumor-specific proteins to identify and contour tumor margins intraoperatively. Testing on seven cell-line xenograft models and human cervical cancer models (representing five types of tissues) demonstrated the high-throughput detection utility of this approach. We anticipate that the 3D histological electrophoresis device will improve the accuracy and efficiency of diagnosing a wide range of cancers.

Methanol-based physical absorption with good capture ability of CO2and H2S is commercially used in the acid gas removal (AGR) unit. However, the huge energy consumption for cooling methanol and acid gas prevent its massive development. An increasing number of experimental and numerical work has been reported on the benefits of using nanofluid to improve the CO2absorption at room temperature to lower the energetic cost. The purpose of this paper is to realign the study with the industrial process by confronting the approach reported in the publications and conclusions with the reality of the overall industrial operations. A brief discussion on the industrial operations of CO2removal by methanol solution without nanoparticles is firstly given, with the observations and technical difficulties involved. Then, the available of the Rectisol-based variants for CCS will be reviewed, including the issues of designed models, simulations and the compute of absorption performance. Subsequently, the benefit of nanoparticles to the Rectisol process is studied. Finally, a critical review is performed on the results available in the publications and will propose several suggestions to their evaluation for industrial application. It is suggested that using nanoparticles to enhance absorption and desorption process of CO2capture has big room for mature because of the limited data under industrial conditions.

For the thermal performance enhancement of electronic components under intermittent high heat load, this paper proposes a gravity heat pipe with heat storage (GHPHS) that couples the advantages of GHPs and latent heat storage (LHS) units. A three-dimensional heat transfer model of GHPHS is developed and numerically studied, focusing on the comparison with traditional GHPs. Furthermore, the effects of the position and fin number of LHS units as well as the type and filling rate of phase change materials (PCMs) are investigated. The results indicate that the average heat source temperature reduces by 48.4 % and the maximum temperature duration shortens by 50 % with adding LHS units into GHPs, which can reduce the transient heat load shock and enhance the overall temperature uniformity. Moreover, the closer the LHS units is to heat sources, the better the temperature uniformity of GHPs is. When gallium is the PCM, the maximum heat source temperature reduces by 26 % when compared with the paraffin, and the increase in PCM fill rate facilitates a delay in the onset of maximum temperature and enhances the temperature uniformity. The fin number significantly affects the competition mechanisms between heat convection and conduction during the melting and solidification. As the fin number increases from 38 to 150, the maximum temperature of heat sources decreases by 29.7 % and the overall temperature uniformity of GHPs increases by 31.7 %. However, there is a limit to the influence of fin number on the thermal enhancement of GHPHSs.