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Binder morphology is a critical factor determining the electrode microstructures and properties, which fundamentally controls the charge transport and mechanical performance of the resultant battery. In this case, polytetrafluoroethylene (PTFE) binder is of great interest as it exhibits unique nanofibration capability and mechanical flexibility, which has been broadly applied for dry processing of battery electrodes. However, there is a lack of fundamental study on how binder nanofibration affects the electrochemomechanical properties of electrodes. Here, similar to the fibrous structures of the cell microenvironment, the attempt is to answer this question from the viewpoint of active‐material microenvironment (ME@AM). First, the PTFE nanofibration degree is adjusted by electrode calendering treatment and binder loading. Second, the microstructures, mechanical relaxation behavior, bending capability, and liquid–electrolyte wetting capability of the fibrous ME@AM are comparatively investigated in detail by dynamic mechanical testing. Finally, the superiority of highly fibrous ME@AM in electrochemical performance is confirmed by the C‐rate and cycling stability testing of half‐cells. This study indicates that a highly fibrous ME@AM can remarkably improve the electrochemomechanical properties of electrodes by enhanced capillary action with liquid electrolyte, good electrode flexibility, and structural stability under compression. [ABSTRACT FROM AUTHOR]

The present study aims to assess the viability of hydrovoltaic impact as a potential method for energy generation. This methodology utilizes the capillary action of water in devices composed of nickel (Ni) foam/polyethylene terephthalate (PET) substrates coated with hydrothermally synthesized carbon spheres at various temperatures (180, 200, and 220 °C). The prepared materials and devices were analyzed using a range of analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The SEM images revealed the spherical morphology of the carbon particles and their presence on Ni foam, whereas the XRD patterns indicated that the carbon spheres were amorphous. Spectroscopic analysis revealed the presence of hydroxyl functional groups in all the samples. The performance of the devices was assessed by electrochemical tests, including open-circuit potential (OCP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The device coated with carbon spheres synthesized at 180 °C demonstrated enhanced performance with an elevated OCP value of 0.077 V, increased surface charge area, lower resistance to water, and reduced charge transfer resistance. These findings indicate the successful production of hydrovoltaic energy by utilizing the capillary action of water in carbon-sphere-coated Ni foam/PET devices. [Display omitted] • Hydrovoltaic devices with carbon spheres on Ni-foam/PET substrates were fabricated. • Carbon spheres were synthesized at 180, 200, and 220 °C and drop-cast onto Ni foam. • Devices with carbon spheres at 180 °C showed enhanced performance with a 0.077V OCP. • Capillary action in coated Ni foam with carbon spheres enhances hydrovoltaic efficiency. • Enhanced performance owing to higher OCP, increased surface charge, and reduced Rct. [ABSTRACT FROM AUTHOR]

Porous ionic electrospray emitters have received significant interest for space propulsion due to their performance and operational simplicity. We have developed a diffusion equation for describing the transient flow response in a porous electrospray emitter, which allows for the prediction of the settling time for flow in the porous emitter. This equation accounts for both the change in liquid storage at exposed pores on the emitter with pressure and viscous diffusion through Darcy's law. Transient flow solutions are provided for the most common emitter topologies: pillar, cone, and wedge. Transient flow solutions describe the settling time and magnitude of current overshoot from porous electrosprays, while providing useful guidelines for reducing transient response time through emitter design. Comparing diffusion of pressure to the onset delay model for electrospray emission shows that diffusion is most relevant at higher voltages and when a porous reservoir is used. Accounting for multiple emission sites on the wedge geometry shows that emission sites settle in proportion to emission site spacing to the power − 1.74. Article Highlights: The transient response of porous electrosprays is affected by fluid storage in exposed pores. Pressure diffuses into a porous electrospray through depletion of fluid in exposed pores. Diffusion of pressure complements the existing onset delay model for porous electrosprays. [ABSTRACT FROM AUTHOR]

Purposes It is important to explore the law of capillary action on the corrosion of X70 steel in soil. Methods On the basis of the theory of unsaturated soil and electrochemical impedance spectroscopy, combined with polarization curve technology, electrochemical impedance technology, scanning electron microscopy, and other test methods, the electrochemical corrosion behavior of X70 steel caused by capillarity in silty clay was investigated through the simulation test of one-dimensional soil column instrument under indoor conditions. Findings The test results show that capillary action has a certain influence on the electrochemical corrosion behavior of X70 steel, that is, the corrosion rates of steel sheet at the height of 12 and 27 cm of soil column first increase and then decrease with embedding time, and the corrosion rate of steel sheet at the height of 42 and 57 cm of soil column first decrease and then increase with embedding time; The rising rate of capillary water in silty clay meets the law of being first fast and then slow. Conclusions The corrosion type of X70 steel sheet surface is mainly pitting corrosion, and the corrosion product surface is accompanied by deep and wide cracks. With the increase of soil sample height, the corrosion degree decreases, and the size and number of corrosion pits show a decreasing trend on the whole. In the rising process of capillary water, when X70 steel sheet is at the solid-liquid-gas three-phase boundary, its corrosion rate is the fastest and the corrosion degree is the most serious.

Background Currently, there is no objective and quantified measurement for detecting blood clots during extraction socket hemostasis. It has relied solely on clinical observation, even when conducting clinical research by using extraction sockets as samples. This study aimed to assess the in vitro reliability and clinical-relevant validity of a new objective measurement providing quantified data called blood clot detection (BCD) using a standard capillary tube. Methods The in vitro part of the study was conducted using surplus blood samples from ten healthy participants. Two identical sets of blood samples in simulation reservoirs mimicking bleeding sockets were prepared for reliability tests. Then, the capillary tubes were concurrently placed in the reservoirs. The blood-filled distances were measured. The part of clinical-relevant validity study was conducted in sixteen extraction sockets from each healthy participant. Clinical observation and BCD measurement were evaluated by two calibrated assessors. The total duration of the assessment was a 30-minute. Results The distances of the blood-filled capillary tube were decreased by time. Test and retest reliability analysis of the BCD measurement showed an excellent intraclass correlation coefficient of 0.980 (0.968 to 0.988). The medians of blood-filled distance categorized by clinical observation into active bleeding, sluggish oozing, and clot formation were 13.0 mm (Q1 = 11.7, Q3 = 13.8), 5.6 mm (Q1 = 4.3, Q3 = 7.0), and 0.9 mm (Q1 = 0.5, Q3 = 1.3), respectively. The blood-filled distance of the clot formation group was significantly less than the active bleeding and sluggish oozing (p Conclusions A distance of blood-filled in capillary tube of 0.9 mm from the BCD measurement significantly ensured complete clot formation. The BCD measurement proved to be a quantified tool for objectively measuring hemostasis of bleeding socket.

Taiwan's unique geographic environment combined with climate change leaves it particularly vulnerable to water shortage issues. A new water resource recycling system that adheres to a Low Impact Development (LID) concept and utilizes existing permeable pavement techniques to mitigate water scarcity is presented in this study. The design routes water at the base and subbase layers of a permeable pavement toward a planter box in the median divider island or box culvert below the median divider island. Once the runoff has flowed into the bottom of the planter box or box culvert, it is available for plants via soil capillary action. Through evaporation or transpiration, the water is then returned to the atmosphere and integrated into the water cycle for localized microclimates. This study used a 3D printer to create a small-scale model of the proposed design. Using this small-scale 3D model, a series of capillary experiments were conducted to evaluate the permeable pavement water recycling system. Because the small-scale model is not suitable for long-duration tests, soil column experiments were also used. The soil was compacted to different relative compactions for a 3D model and the soil column experiments were used to evaluate the capillary rise height of the soil. The results showed that when using a silt with low plasticity soil (ML), under low relative compaction, the capillary water can reach the rooting level of appropriately selected plants. Therefore, if the soil around vegetation is correctly compacted, the vegetation's roots will have access to stored water. The proposed permeable pavement water recycling system represents a practical approach to managing stormwater runoff and achieving water conservation objectives. This innovative design not only aims to conserve and protect water resources but also supports sustainable water management practices, thereby helping to mitigate the impacts of climate change. [ABSTRACT FROM AUTHOR]

Soil salt accumulation is a widespread problem leading to diminished crop yield and threatening food security in many regions of the world. The soil salinization problem is particularly acute in areas that lack adequate soil water drainage and where a saline shallow water table (WT) is present. In this study, we present laboratory‐scale column experiments, extending over a period of more than 400 days that focus on the processes contributing to soil salinization. We specifically examine the combined impact of soil compaction, surface water application model and water quality on salt dynamics in the presence of a saline shallow WT. The soil columns (60 cm height and 16 cm diameter) were packed with an agricultural soil with bulk densities of 1.15 and 1.34 g/cm−3 for uncompacted and compacted layers, respectively, and automatically monitored for water content, salinity and pressure. Two surface water compositions are considered: fresh (deionized, DI) and saline water (~3.4 mS/cm). To assess the sensitivity of compaction on salt dynamics, the experiments were numerically modelled with the HYDRUS‐1D computer program. The results show that the saline WT led to rapid salinization of the soil column due to capillarity, with the salinity reaching levels much higher than that at the WT. However, compaction layer provided a barrier that limited the downwards moisture percolation and solute transport. Furthermore, the numerical simulations showed that the application of freshwater can temporarily reverse the accumulation of salts in agricultural soils. This irrigation strategy can help, in the short‐term, alleviate soil salinization problem. The soil hydraulic properties, WT depth, water quality, evaporation demand and the availability of freshwater all play a role in the practicability of such short‐term solutions. The presence of a saline shallow WT would, however, rapidly reverse these temporary measures, leading to the recurrence of topsoil salinization. [ABSTRACT FROM AUTHOR]

Concrete structures partially immersed in seawater will be subjected to severe chloride and sulfate erosion under the capillary and diffusion actions. Nevertheless, the present studies only discuss the capillary action in a static water level environment, without considering the capillary action in a water level fluctuating environment. In this paper, the mechanical properties and ions transmission law of concrete under the capillary and diffusion actions in water level fluctuating environment were investigated through a series of indoor exposure tests. Three erosion solutions were set to study the interaction effects of chloride, sulfate, and magnesium within concrete. Based on the compressive strength tests, the mechanical properties of concrete in a water level fluctuating environment were explored. The natural diffusion tests were carried out to research the sulfate and chloride transmission law within concrete above and in the water level fluctuating zone (WLFZ). Scanning electronic microscopy (SEM), X-ray diffractometer (XRD), and mercury injection porosimeter (MIP) measurements were conducted to analyze the microstructures at various zones of concrete under different erosion solutions. The results show that the concrete partially immersed in WLFZ suffers from severe sulfate attack on mechanical properties due to the dual influences of sulfate chemical and physical crystallization attack. The chloride concentration within concrete above WLFZ is significantly higher under the capillary action. The sulfate concentration within concrete above WLFZ is lower because of the chemical binding of sulfate within concrete. The higher porosity and more capillary pores exist in concrete above WLFZ due to the carbonization and water evaporation. By decreasing the porosity of concrete, sulfate will inhibit the chloride transmission and magnesium will restrain the sulfate and chloride transmission. The transmission mechanisms of erosion ions within concrete above WLFZ consist of vertical transmission under the capillary action and lateral transmission under the diffusion action and water evaporation. [ABSTRACT FROM AUTHOR]

Tow-dimensional and 3-dimensional colloidal structures have been used to study surface-enhanced Raman scattering and localized surface plasmon resonance because of their regular stacking structures. However, freely controlling the number and size of the colloidal assemblies remains a challenge. In this study, we demonstrated the fabrication and mechanism of tiny nanoclusters using spontaneous evaporation-based nanofountain pens (NFPs). A micrometer-scale NFP nozzle was fabricated using a glass capillary. The gold nanoparticles (AuNPs) dispersed ink formed the pendant droplet at the NFP nozzle tip, where the AuNPs accumulated within the pendant droplet because of evaporation. The accumulated AuNPs were transferred onto the substrate via a stamp-like process to create nanoclusters. Using water evaporation analyzed by diffusion equations, we showed that reducing the AuNP accumulation to one hundred is possible. This precise adjustment enables fabrication until submicrometer-level nanoclusters. The fabrication method using NFPs can create 3D structures, and this operation is not significantly affected by the size or composition of the AuNPs. This could be expanded to metabolite-included nanocluster where metabolite can be located at the hot spot among AuNPs. Therefore, we expect that this will be utilized to create SERS signals and conduct disease diagnosis research using extremely small amounts of metabolites. [ABSTRACT FROM AUTHOR]

A transpiration-type thermoelectric-power-generating paper based on previously developed carbon nanotube (CNT) composite paper, which is a composite material of CNTs and pulp that can generate thermoelectric power, was developed. The newly developed thermoelectric-power-generating material does not require an external high-temperature heat source due to the ability of paper to absorb liquid through capillary action and heat of vaporization generated when the liquid evaporates. The aim of this study is to investigate the feasibility of realizing the transpiration-type thermoelectric-power-generating paper. To begin with, the type of paper used as raw material for the composite paper was examined, and the fabrication process was modified in order to obtain more efficient liquid absorption based on capillary action. Then, the absorbing ability of the liquid was evaluated. Next, the feasibility of thermoelectric power generation using the heat of vaporization was confirmed. Moreover, for more efficient thermoelectric conversion, multisheet structures were also studied. Through several experiments, the material's feasibility was verified, and it was confirmed that more power can be easily obtained through the use of multiple sheets. Specifically, a single sample spontaneously generated a temperature difference of up to 1.7 °C due to the heat of vaporization, generating an electromotive force of 36 μ V. From the sample with a five-sheet structure, an electromotive force of 356 μ V was obtained at a temperature difference of 2 °C. This material can be used in watery environments, such as rivers, lakes, and hot springs, and is expected to become a new energy-harvesting device. [ABSTRACT FROM AUTHOR]

Resin pre-coating technology is widely used in all aspects of composite materials, especially in the repair of composite materials. The pre-coating is formed by combining acetone with the resin, which is diffused and cured by the epoxy adhesive at the same time. It acts as an interlock to prevent the interface from debonding and to fill in the damaged cracks. The capillary action of acetone allows the resin to permeate the cracks in the fiber damage layers, thus filling the cracks and completing the repair. The pre-coating solutions of 10 wt%, 20 wt%, 25 wt%, 35 wt%, and 45 wt% resin were applied to damaged areas respectively, and cured at 60°C for 7 days. The crack filling effect was observed by scanning electronic microscopy (SEM). At the same concentration, the effect of prolonged repair time was also studied. The other two repair times were 14 days and 30 days respectively. In addition, the tensile properties of the materials before and after repair were tested and compared. The results showed that 25 wt% resin pre-coating had the best repair performance after 7 days, with a repair rate of 27%, which was 22% higher than the conventional repair without resin pre-coating. However, the repair effect became more obvious after the extension of repair time, and the repair effect of 25 wt% resin pre-coating reached 44% after 30 days curing. Therefore, it was found that the resin can fully penetrate the cracks in the damaged area with resin pre-coating technology, and 25 wt% resin pre-coating solution is the best choice. [ABSTRACT FROM AUTHOR]

Response of gerbera var. Arka Nesara was studied under different soil-less production systems with the aim to improve quality, productivity and water use efficiency, in completely randomized design with eight treatments viz., deep flow technique (DFT), nutrient film technique (NFT), aggregate wick system (AWS) with pots on NFT bench, AWS with pots on ground, AWS with grow bags on ground, AWS on soil bed, aeroponics and conventional soil-based drip system, which were replicated five times. Results revealed that AWS with pots on ground recorded maximum plant height (31.66 cm), leaf length (21.31 cm), leaf breadth (9.96 cm) and stalk diameter near neck (4.75 mm), minimum stem deviation (1.27 cm) and stem deflection (2.2°), prolonged vase life (9.2 days), greater water use efficiency (92 mL/plant/day) and water saving (83.46%). Hence, cultivation of gerbera var. Arka Nesara under aggregate wick system with pots on ground could be the superior alternative for traditional soil cultivation. [ABSTRACT FROM AUTHOR]

Lab-scale stirrer bubble and lab-scale stepped continuous flow capillary columns were developed to neutralize lime precipitation treated slaughterhouse wastewater (SWW) and recover the volatilized ammonia, using atmospheric CO2. These experiments were carried out using central composite design based on the response surface methodology. The carbonation process occurred in both processes. For the bubbling process, numerical optimization indicated a final pH of 8 with calcium and ammonium nitrogen removals of 76.0 and 66.2%, respectively, applying 21 h, air flow rate at 65 L h−1, the stirring speed at 52 rpm, and SWW volume at 178 mL. It was also observed that increasing the air flow rate can avoid the stirring step. For the capillary process, a pH of 8.2 and calcium and ammonium nitrogen removals of 81.0 and 57.5% were achieved, applying a SWW flow rate at 1.2 mL min−1, air flow rate at 90 L h−1, and capillary area at 700 cm2. Under optimal conditions, the flow capillary column was able to neutralize different SWW volumes, 178–478 mL, without significant differences in the collected samples, with the operation time varying between 4.48 and 10.20 h, respectively.

Taiwan’s unique geographic environment combined with climate change leaves it particularly vulnerable to water shortage issues. A new water resource recycling system that adheres to a Low Impact Development (LID) concept and utilizes existing permeable pavement techniques to mitigate water scarcity is presented in this study. The design routes water at the base and subbase layers of a permeable pavement toward a planter box in the median divider island or box culvert below the median divider island. Once the runoff has flowed into the bottom of the planter box or box culvert, it is available for plants via soil capillary action. Through evaporation or transpiration, the water is then returned to the atmosphere and integrated into the water cycle for localized microclimates. This study used a 3D printer to create a small-scale model of the proposed design. Using this small-scale 3D model, a series of capillary experiments were conducted to evaluate the permeable pavement water recycling system. Because the small-scale model is not suitable for long-duration tests, soil column experiments were also used. The soil was compacted to different relative compactions for a 3D model and the soil column experiments were used to evaluate the capillary rise height of the soil. The results showed that when using a silt with low plasticity soil (ML), under low relative compaction, the capillary water can reach the rooting level of appropriately selected plants. Therefore, if the soil around vegetation is correctly compacted, the vegetation’s roots will have access to stored water. The proposed permeable pavement water recycling system represents a practical approach to managing stormwater runoff and achieving water conservation objectives. This innovative design not only aims to conserve and protect water resources but also supports sustainable water management practices, thereby helping to mitigate the impacts of climate change.

Abstract: The idea proposed in this study can be used in remote areas to lift the water spontaneously instead of using electrical pumps. This research aims to lift the underground water to a high altitude by designing a passive system that simulates the rising water in tall plants due to capillary action and evaporation. The study assumed a set of micro-tubes to lift the underground water to a tank. The flow rate due to capillary rise and evaporation were analytically determined by mathematical models based on energy equations in fluid mechanics calculated using MATLAB software. The study results have shown that a ‎system consisting of 2-10 billion micro-tubes can supply between 16-65 kg of water daily to a tank, depending on the ‎environmental conditions‎. It was found that a set of tubes with a 20 μm diameter was a suitable choice to raise the water to 7.5 m, where 0.8 m rising was due to the capillary action, whereas the rest was due to the evaporation process suction head.

The precise prediction of moisture variations within concrete is of great significance because various deterioration phenomena spanning corrosion to carbonation are induced by mass transfer facilitated by the presence of moisture. Under actual environmental conditions, concrete is exposed to numerous wetting and drying cycles. Thus, to accurately predict moisture variations it is essential to consider the effect of these conditions. This study investigates the effect of alternate wetting and drying cycles on moisture penetration through concrete at the mesoscale using a 3D discrete network model based on a Rigid Body Spring Model (RBSM). For modeling moisture transport during wetting, the non-linear diffusion equation is used and the effects of capillary suction in moisture transport are also considered. On the other hand, moisture transport during drying is modeled as an evaporation-diffusion process. The simulation results obtained using this discrete network model are validated against the available experimental outcomes. During the wetting cycle, the moisture content in regions close to the exposed surface rapidly increases and approaches the maximum saturation. The effect of subsequent drying is seen only until a certain depth below the exposed surface, known as the influential depth. It is also observed that moisture continues to penetrate deeper into a specimen even during a drying cycle.

Passive production of synthesis gas from liquid methanol using a packed bed of porous particles supporting a catalyst is investigated. Heating of an upper side of the packed tube the bottom of which is immersed in liquid methanol causes upward flow by the capillary action enhanced by evaporation and syn-gas is produced in temperature increased dried region. The extension of the dried region toward the wetted region reduces considerably the responsiveness in the productions of the reactant vapor and syn-gas due to the high flow resistance of the bed. Utilization of a combined particle bed, which consists of two different size particles geometrically arranged and separates the dried and wetted regions to the prescribed ranges, allows low flow resistance and, as a result, causes significant increases in the mass flow rate and the responsiveness. [ABSTRACT FROM AUTHOR]

A microbial fuel cell (MFC) biosensor with an anode as a sensing element is often unreliable at low or significantly fluctuating organic matter concentrations. To remove this limitation, this work demonstrates capillary action-aided carbon source delivery to an anode-sensing MFC biosensor for use in carbon-depleted environments, e.g., potable water. First, different carbon source delivery configurations using several thread types, silk, nylon, cotton, and polyester, are evaluated. Silk thread was determined to be the most suitable material for passive delivery of a 40 g L−1 acetate solution. This carbon source delivery system was then incorporated into the design of an MFC biosensor for real-time detection of toxicity spikes in tap water, providing an organic matter concentration of 56 ± 15 mg L−1. The biosensor was subsequently able to detect spikes of toxicants such as chlorine, formaldehyde, mercury, and cyanobacterial microcystins. The 16S sequencing results demonstrated the proliferation of Desulfatirhabdium (10.7% of the total population), Pelobacter (10.3%), and Geobacter (10.2%) genera. Overall, this work shows that the proposed approach can be used to achieve real-time toxicant detection by MFC biosensors in carbon-depleted environments. [ABSTRACT FROM AUTHOR]

Avoiding wicking in a suture to recover the wound and avoid infection is critical. In this paper, the capillary rise method is applied to evaluate the wicking property of tubular braided structures. Effects of the tubular braid's structural parameters, namely braid angle, interlacement pattern, structural axis, and the position of the yarns parallel to the axis are investigated. The results indicate that with the increase in braid angle, the wicking height descends and has the greatest effect on the wicking property among the studied parameters. It is also observed that under the same braid angle, the wicking height of the Two over Two braid is larger than the regular braid. Moreover, the presence of core yarns in a braided structure increases the wicking height. Among the studied parameters, the structural axis does not have a significant effect on this behavior. The results of statistical study confirm the experimental data and show that it is better to use biaxial braided structures with a regular pattern in the production of braided sutures. This work not only examines some factors effect on a vital feature of the braided suture but also underlines the importance of choosing the braid suture. [ABSTRACT FROM AUTHOR]

A highly sensitive pressure sensor with nanoscale features was developed based on the gradient concentration of Ti3C2Tx (MXene). The fabrication strategy involved electrostatic adsorption and capillary action utilizing a carbonized sponge as the substrate. In this approach, hexadecyl trimethyl ammonium bromide (CTAB) was added dropwise to the bottom of the carbonized melamine sponge, facilitating the self-assembly of MXene and achieving a gradient attachment of conductive fillers onto the substrate. Furthermore, a layer of polyvinyl alcohol fibers was electrospun between the sensor bottom and the electrode to enhance sensor sensitivity. The pressure-sensitive sensor prepared by this method exhibited an exceptionally strong response within the pressure range of 0–3 kPa. It demonstrated an ultrahigh sensitivity of 381.91 kPa–1, with a rapid deformation response of 100 ms and a quick recovery response of 30 ms. Notably, the sensor also demonstrated outstanding durability, enduring 8000 loading–unloading cycles without performance degradation. Moreover, it achieved a minimum detection limit as low as 0.1 Pa. Finite element numerical analysis confirmed that the MXene/CTAB/CMF composite prepared using this approach exhibited superior sensing performance under similar deformation conditions. Importantly, this pressure sensor's exceptional sensing capabilities extended to detecting various physiological signals in the human body and daily work scenarios. When integrated with a microprocessor, it accurately processed complex data sets, highlighting its great potential for practical applications. [ABSTRACT FROM AUTHOR]

In paper-based microfluidics, the simplest devices are colorimetric, giving qualitative results. However, getting quantitative data can be quite a bit more difficult. Distance-based devices provide a user-friendly means of obtaining quantitative data without the need for any additional equipment, simply by using an included ruler or calibrated markings. This article details the development of a quantitative DNA detection device that utilizes the aggregation of polystyrene microspheres to affect the distance that microspheres wick through filter paper. The microspheres are conjugated to single-stranded DNA (ssDNA) oligomers that are partially complementary to a target strand and, in the presence of the target strand, form a three-strand complex, resulting in the formation of aggregates. The higher the concentration of the target strand, the larger the aggregate, and the shorter the distance wicked by the microspheres. This behavior was investigated across a wide range of target concentrations and under different incubation times to understand aggregate formation. The device was then used to successfully detect a target strand spiked in extracted plant DNA.

Coal mine in arid and semi-arid area is one of the most severely degraded ecosystems on the earth. The continuous decrease in groundwater level caused by coal mining will inevitably affect biogeochemical environment of the vadose zone, and then lead to the replacement of surface vegetation. Yimin open-pit coal mine was taken as an example to reveal the relationship between the groundwater depth and soil water content (SWC), soil salt content, soil electrical conductivity (SEC), soil organic matter (SOM), soil available potassium (SAK), soil available nitrogen (SAN), vegetation coverage, aboveground biomass and species richness. The results show that, the change of groundwater depth can affect soil properties and then change the characteristics of surface vegetation, and the change of surface vegetation can also react on soil properties. Vegetation coverage and aboveground biomass are negatively correlated with groundwater depth, and positively correlated with SWC, SEC, SOM and SAK. The shallow groundwater table is conducive to the accumulation of SOM, so that the surface biomass and vegetation coverage are high. The higher the surface biomass, the more the SAN is absorbed. Under natural conditions, the relative strength of biological nitrogen fixation and plant absorption determine the content of SAN. In the research area, when the depth of groundwater is less than 0.4 m will cause soil salinization, then lead to low species richness; Species richness is exponentially correlated with groundwater depth and decreases with the increase in groundwater depth. [ABSTRACT FROM AUTHOR]

Absorption-dominated electromagnetic interference (EMI) shielding materials are more attractive to manage the increasing electromagnetic radiation pollution than conventional reflection-dominated counterparts due to their advantages of balancing the efficient EMI shielding performance while minimizing the secondary pollution of the reflected electromagnetic (EM) wave. Herein, we first fabricate ferroferric oxide/carbon nanotubes/waterborne polyurethane (Fe3O4/CNTs/WPU) aerogels and then coat Ti3C2Tx MXene at the bottom to construct an asymmetric structure. Moreover, the medium or transition layer is formed during the coating process of MXene-ferroferric oxide by the gravity and aerogel's capillary action. This delicate design makes them with obvious absorption, transition, and reflection layers according to the progressive modular design principle. The composite aerogels show an average EMI shielding effectiveness (SE) of 20.06 dB, low reflectivity of 0.396, and specific EMI SE of SSE/t of 332.60 dB cm2 g–1 in the X-band when the MXene content is only 2.35 vol %. Additionally, the resultant aerogels exhibit remarkable flexible and mechanical properties, which could even bear weights of about 4500 times their own weight. In sum, this work provides a promising absorption-dominated EMI shielding candidate with flexible and high strength features. [ABSTRACT FROM AUTHOR]

A transpiration-type thermoelectric-power-generating paper based on previously developed carbon nanotube (CNT) composite paper, which is a composite material of CNTs and pulp that can generate thermoelectric power, was developed. The newly developed thermoelectric-power-generating material does not require an external high-temperature heat source due to the ability of paper to absorb liquid through capillary action and heat of vaporization generated when the liquid evaporates. The aim of this study is to investigate the feasibility of realizing the transpiration-type thermoelectric-power-generating paper. To begin with, the type of paper used as raw material for the composite paper was examined, and the fabrication process was modified in order to obtain more efficient liquid absorption based on capillary action. Then, the absorbing ability of the liquid was evaluated. Next, the feasibility of thermoelectric power generation using the heat of vaporization was confirmed. Moreover, for more efficient thermoelectric conversion, multisheet structures were also studied. Through several experiments, the material’s feasibility was verified, and it was confirmed that more power can be easily obtained through the use of multiple sheets. Specifically, a single sample spontaneously generated a temperature difference of up to 1.7 °C due to the heat of vaporization, generating an electromotive force of 36 μV. From the sample with a five-sheet structure, an electromotive force of 356 μV was obtained at a temperature difference of 2 °C. This material can be used in watery environments, such as rivers, lakes, and hot springs, and is expected to become a new energy-harvesting device.

Tow-dimensional and 3-dimensional colloidal structures have been used to study surface-enhanced Raman scattering and localized surface plasmon resonance because of their regular stacking structures. However, freely controlling the number and size of the colloidal assemblies remains a challenge. In this study, we demonstrated the fabrication and mechanism of tiny nanoclusters using spontaneous evaporation-based nanofountain pens (NFPs). A micrometer-scale NFP nozzle was fabricated using a glass capillary. The gold nanoparticles (AuNPs) dispersed ink formed the pendant droplet at the NFP nozzle tip, where the AuNPs accumulated within the pendant droplet because of evaporation. The accumulated AuNPs were transferred onto the substrate via a stamp-like process to create nanoclusters. Using water evaporation analyzed by diffusion equations, we showed that reducing the AuNP accumulation to one hundred is possible. This precise adjustment enables fabrication until submicrometer-level nanoclusters. The fabrication method using NFPs can create 3D structures, and this operation is not significantly affected by the size or composition of the AuNPs. This could be expanded to metabolite-included nanocluster where metabolite can be located at the hot spot among AuNPs. Therefore, we expect that this will be utilized to create SERS signals and conduct disease diagnosis research using extremely small amounts of metabolites.

The quantitative effect of particle shape, porosity, wettability, particle size, and solution viscosity on the residence time distribution (RTD) profiles of non-reactive, steady-state, drip-irrigated ore beds characteristic of heap leaching systems is presented. Results were obtained using step-up tracer tests and allowed for the analysis of preferential flow behaviour within the systems. The key findings were as follows. Increased particle sphericity enhanced channelling in beds of smaller particles, but not for larger particle sizes. Higher particle wettability caused greater liquid dispersion during both initial wetting studies and at steady-state fluid flux. Higher porosity levels and the inclusion of fines in mixed sized beds resulted in longer average solute residence times, higher liquid hold-up, longer solution and tracer breakthrough times, and increases in drain-down moisture percentages. Increasing the irrigation fluid's viscosity, reflective of the increase in ionic concentrations in leach solutions, reduced both the solution and tracer breakthrough times and increased dispersion with signs of more discontinuous or isolated fluid volumes at steady-state. These results highlighted the importance of the inclusion of fines in agglomerated beds to improve uniform wetting especially those with low to moderate particle porosities (<2.5 m2/g specific surface area). The viscosity results suggest that there may be changes in preferential flow extent, due to variations in viscosity owing to the increasing sulphate concentration within the liquid phase in heaps and with time. [ABSTRACT FROM AUTHOR]

A smartphone-based plant-wearable microfluidic sensor based on capillary adsorption and driving electrolyte flow in micro-channels has been developed for in-situ detection of methyl parathion (MP). This sensor could achieve online collection, flow enrichment and reliable electrochemical detection of MP. Laser direct writing technology was adopted to construct laser induced graphene-gold nanoparticles (LIG-Au) electrodes and micro-channel molds in one step, where the molds were used to produce PDMS micro-channels. The microfluidic sensor, made of LIG-Au on polyimide film and PDMS channels, could be attached to plant surfaces, and the capillary action of the micro-channel drove electrolyte flow to accelerate the pre-enrichment process of MP detection, shortening detection time (saving about 381 s of pre-enrichment time). The proposed microfluidic sensor had excellent MP detection performance from 0.001 μM to 200 μM and low detection limit of 0.000646 μM. It was used to detect MP on epipremnum aureum and lettuce, in which the good spiking recoveries verified its reliable real samples determination. This novel microfluidic sensor provides new vision for low-cost, simple fabrication, in-situ collection, rapid real sample detection of MP, demonstrating enormous application prospects in the fields of monitioring food safety and safeguarding human health. [Display omitted] • A plant-wearable microfluidic sensor was developed for in-situ detection of MP. • One-step fabrication of LIG-Au and micro-channel mold by laser direct writing. • The capillary action achieved electrolyte collection and self-drive. • Flowing electrolyte accelerated substance transmission to save pre-enrichment time. • The sensor was successfully used for reliable detection of MP on plant surfaces. [ABSTRACT FROM AUTHOR]

This study comparatively investigated and evaluated three volumetric methods for vertical porosity distribution measurement of pervious concrete pavement: the incremental water displacement method (IWDM), slice-water displacement method (SWDM) with nondemoulding cutting, and computed tomography (CT) scanning method (CTSM). The regional porosity in pervious concrete consolidated by surface compaction increases with the vertical depth, with porosity differences of approximately 10.31%, 8.57%, and 8.80% between the top and bottom regions in the IWDM, CTSM, and SWDM, respectively. Capillary action in the IWDM increases the porosity of the bottom region 120-100 mm from the surface by approximately 0.76% and reduces the porosity of the top region 20-0 mm by approximately 0.75%, but it hardly affects the porosity of 4 other middle regions. The overall porosity determined with the SWDM is very close to that determined with the traditional water displacement method (WDM), with differences of <0.4%, indicating that the knockout effect is almost completely eliminated by the mould protection measure. The CTSM tends to yield a higher overall porosity than that determined with the IWDM, SWDM, and WDM, with average differences of 1.54%, 1.51%, and 1.58%, respectively. The results provide evidence to select the appropriate methods. [ABSTRACT FROM AUTHOR]

This work demonstrates a novel, non-fluorescence approach to the length identification of polymerase chain reaction (PCR) and recombinase polymerase amplification (RPA) products, utilizing capillary flow velocities on paper microfluidic chips. It required only a blank paper chip, aminated microspheres, and a smartphone, with a rapid assay time and under ambient lighting. A smartphone evaluated the initial capillary flow velocities on the paper chips for the PCR and RPA products from various bacterial samples, where the pre-loaded aminated microspheres differentiated their flow velocities. Flow velocities were analyzed at different time frames and compared with the instantaneous flow velocities and interfacial tension (γ LV ) data. Subsequent error analysis justified the use of the initial time frames. A robust linear relationship could be established between the initial flow velocities against the square root of the product lengths, with R 2 values of 0.981 for PCR and 0.993 for RPA. The assay seemed not to have a significant dependency on the cycle numbers and initial target concentrations. This novel method can be potentially used with various paper microfluidic methods of nucleic acid amplification tests towards rapid and handheld assays., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Edge-delamination of carbon fiber reinforced plastics (CFRP) has been successfully repaired using a novel technique named resin pre-coating (RPC). The acetone-diluted resin does not only adhere to the surface but penetrates deeply into sub-surfaces through capillary action. In the current study, Carbon Nanotube (CNT) was tentatively added into RPC to further strengthen the bonding. DSC analysis and FTIR results showed no chemical effect on resin curing through adding CNT. Likewise, using CNT as additives has not changed the surface properties of RPC solution with 5 wt% resin and 95 wt% acetone. Compressive testing was performed to validate the effect of CNT incorporation (with four concentrations: 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) on RPC repair. The results show that the 5% RPC solution mixing 1.5 wt% of CNT works best with a 22% increase over only RPC in repair effectiveness. SEM revealed CNT bridging at the fracture surface of the RPC/CNT-repaired sample.

A microbial fuel cell (MFC) biosensor with an anode as a sensing element is often unreliable at low or significantly fluctuating organic matter concentrations. To remove this limitation, this work demonstrates capillary action-aided carbon source delivery to an anode-sensing MFC biosensor for use in carbon-depleted environments, e.g., potable water. First, different carbon source delivery configurations using several thread types, silk, nylon, cotton, and polyester, are evaluated. Silk thread was determined to be the most suitable material for passive delivery of a 40 g L−1 acetate solution. This carbon source delivery system was then incorporated into the design of an MFC biosensor for real-time detection of toxicity spikes in tap water, providing an organic matter concentration of 56 ± 15 mg L−1. The biosensor was subsequently able to detect spikes of toxicants such as chlorine, formaldehyde, mercury, and cyanobacterial microcystins. The 16S sequencing results demonstrated the proliferation of Desulfatirhabdium (10.7% of the total population), Pelobacter (10.3%), and Geobacter (10.2%) genera. Overall, this work shows that the proposed approach can be used to achieve real-time toxicant detection by MFC biosensors in carbon-depleted environments.

Two-phase flow liquid-liquid separation in a microseparator has promising use in microfluidic field such as downstream biodiesel purification. The present study aims to investigate the effect of daughter channel (DC) geometry on liquid-liquid separation in a new design of microseparator. Olive oil and water were selected as continuous and dispersed phase, respectively. Different DC intervals (500–1000 µm) and angles (60°-120°) were designed to generate nine single-sided DC microseparator configurations. Further, these were arranged in mirrored configurations to generate nine double-sided DC microseparator configurations. At continuous phase flow rate (QCP) of 0.5 ml/h, interval of 500 µm and angle of 90° achieved best performance with highest oil purity of 100% in secondary channel outlet (SC_Outlet) and lowest oil purity of 26% in main channel outlet (MC_Outlet). The results revealed that the design of DC with lower pressure drop led to better separation performance. Furthermore, the occurrence of Jamin effect in the DC could cause hindrance in the two-phase flow liquid-liquid separation. The use of double-sided DC microseparator configuration further improves the separation performance. Overall, an excellent separation of oil was successfully achieved. [ABSTRACT FROM AUTHOR]

The discontinuity of pore structure and hydraulic properties between layered soils has a significant influence on the transportation of water and salt. Based on the field investigation, the laboratory soil column tests of two soil layer binary structure combinations (loess-sandy silt and loess-silty clay) were designed. Through the model tests, the influence of soil layer structure on capillary water distribution and salt accumulation under different groundwater supply conditions was discussed. The test results show that under the condition of capillary water supply, the upper-fine and lower-coarse soil layer structure composed of loess-sandy silt is beneficial to capillary water and salt transportation. After 60 days of evaporation, the surface content of the upper-fine and lower-coarse soil column is twice of the upper-coarse and lower-fine soil column. Under the condition of no capillary water supply, the total amount and rate of upward migration of water and salt in the sandy silt layer is greater than that of the silty clay layer, and finally the ion content of each of the overlying soil layer in the upper-fine and lower-coarse soil column is greater than the upper-coarse and lower-fine soil column. The research results provide experimental reference for the prevention of saline soil disease in layered soil areas.

This study investigated the effects of mean particle size fraction, bottom particle size, particle porosity and wettability on solution scale preferential flow behaviour via step input tracer tests in drip irrigated, narrowly and mixed-sized beds under steady state fluid flux. Nine solute transport models were used to quantify this behaviour reflected in the residence time distribution (RTD) profiles. Four were empirical models: three compartmental model configurations (CM-1, CM-2, CM-3) and tanks-in-series (TIS) model. The remainder five models were semi-empirical: advection dispersion (AD), piston exchange (PE), piston exchange - diffusion variant (PE-D), piston dispersion and exchange (PDE) and piston dispersion and exchange - diffusion variant (PDE D). The model fit results showed that the mono-porosity TIS, AD and CM-2 models were the worst performers, while the dual porosity PDE and novel PDE-D models achieved the lowest average error values across the various systems. Higher levels of particle wettability coupled with capillary effects produced peculiar RTD curves that were relatively more difficult for the mono-porosity models to simulate. The model parameters investigated included the longitudinal dispersion coefficient (D ds), dead to total volume fraction (V D / V T), dynamic to total saturation fraction (β d / β T), overall mass transfer coefficient (K m a) and maximum diffusional pore length (X). The results showed that an increase in the average particle size within the beds led to higher V D / V T , D ds and X values, but lower β d / β T and K m a values. These indicate an overall increase in solution scale preferential flow behaviour. Decreased capillary suction and connectivity between particle pores and inter-particle voids were deemed responsible for the results. Higher levels of particle porosity acted as a buffer against these effects. Overall, the results highlight the benefit of the addition of fines (0.1–1 mm particles) during the agglomeration process in heaps to help reduce solution scale preferential flow behaviour and increase liquid hold-up. This is more necessary when the ore has low to moderate levels of porosity (surface area: < 2 m2/g) and will also increase the modelling options available as most models performed better fitting data from such beds. • Exploration of the effects of particle properties on steady state fluid profiles in laboratory scale, drip irrigated beds. • Rigorous comparison of the residence time distribution data fitting capabilities of nine solute transport models. • Detailed analysis of different solute transport modelling parameters used to describe fluid profiles in drip irrigated beds. • Discussion of the effect of model structure and classification on the fitting capabilities of nine solute transport models. [ABSTRACT FROM AUTHOR]

Background: The imperfect material effect is one of the most important themes to obtain photo-realistic results in rendering. Textile material rendering has always been a key area in the field of computer graphics. So far, a great deal of effort has been invested in its unique appearance and physicsbased simulation. The appearance of the dyeing effect commonly found in textiles has received little attention. This paper introduces techniques for simulation of staining effects on textiles. Pulling, wearing, squeezing, tearing, and breaking effects are more common imperfect effects of fabrics, these external forces will cause changes in the fabric structure, thus affecting the diffusion effect of stains. Based on the microstructure of yarn, we handle the effect of the stain on the imperfect textile surface. Our simulation results can achieve a photo-realistic effect.

Traditionally, specific bioreceptors such as antibodies have rapidly identified bacterial species in environmental water samples. However, this method has the disadvantages of requiring an additional process to conjugate or immobilize bioreceptors on the assay platform, which becomes unstable at room temperature. Here, we demonstrate a novel mix-and-match method to identify bacteria species by loading the bacterial samples with simple bacteria interacting components (not bioreceptors), such as lipopolysaccharides, peptidoglycan, and bovine serum albumin, and carboxylated particles, all separately on multiple channels. Neither covalent conjugation nor surface immobilization was necessary. Interactions between bacteria and the above bacteria interacting components resulted in varied surface tension and viscosity, leading to various flow velocities of capillary action through the paper fibers. The smartphone camera and a custom Python code recorded multiple channel flow velocity, each loaded with different bacteria interacting components. A multi-dimensional data set was obtained for a given bacterial species and concentration and used as a machine learning training model. A support vector machine was applied to classify the six bacterial species: Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecium, and Bacillus subtilis. Under optimized conditions, the training model predicts the bacterial species with an accuracy of > 85% of the six bacteria species. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) is a ceramic material with excellent dielectric and thermal properties, and it is used in the microelectron and energy fields. Despite polishing, the roughness (rms >10 nm) of AlN wafers fabricated by sintering fails to meet the surface requirements (rms <0.5 nm) for direct wafer bonding. However, rough-surface wafer bonding of paired AlN and AlN can be achieved with the following procedure: (1) rough surfaces are activated by oxygen plasma to introduce strong capillary action, (2) reactions of AlN and bonding species (OH−) are promoted by clamping during storage and annealing and (3) low-temperature annealing (<150 °C) joins the two surfaces of AlN/AlN by synthesizing Al 2 O 3 at the bonding interface. TEM and XPS results show that a transition layer exists between bonding surfaces wherein the concentration of nitrogen decreases while that of oxygen significantly increases. [ABSTRACT FROM AUTHOR]

For the first time, multiple parallel microchannels in a single microgroove have been fabricated by the heating-assisted micromolding in capillaries technique (HAMIMIC). Microchannel development, cross-sectional shape, and length were all explored in depth. The factors affecting the cross-sectional shape and length of the double-microchannel were also discussed. Finally, a special-shaped PDMS guiding mold was designed to control the cross-sectional shape and length of multiple parallel microchannels for controlled growth. The HAMIMIC technique provides a low-cost, straightforward, and repeatable way to create multiple parallel microchannels in a single microgroove, and will promote the progress of bifurcated vessels and thrombus vessels preparation technology. [ABSTRACT FROM AUTHOR]

[Display omitted] Responsive photonic crystals have attracted much attention due to their strong capability to manipulate the propagation of light in the visible region, but it is still a big challenge to invisibility and mechanical stability. Here, the novel Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals, which have high mechanical stability and can release visible patterns after wetting with water, are discussed. The Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals are also responsive to the concentration of ethanol, and the structural color response times increase with increasing ethanol concentration. This design uses the selective infiltration, hydrogen bonding and capillary action of solvent to realize the spectral diversity of reflectance. Owing to the high polarity and hydrogen bonding ability of carboxyl groups, water molecules are adsorbed easily by the poly(acrylic acid) gel. Subsequently, the encrypted information is decrypted due to the redshift of the structural color. Because of its lower polarity and hydrogen bonding ability relative to water, ethanol can impede the absorption of solvent by gel. Therefore, the ethanol concentration can be identified based on the structural color response time. Furthermore, reliable information decryption methods make Poly(ether sulfone)/Poly(acrylic acid) inverse opal photonic crystals potentially uesful as trusted encryption devices. [ABSTRACT FROM AUTHOR]

The quantitative effect of particle shape, porosity, wettability, particle size, and solution viscosity on the residence time distribution (RTD) profiles of non-reactive, steady-state, drip-irrigated ore beds characteristic of heap leaching systems is presented. Results were obtained using step-up tracer tests and allowed for the analysis of preferential flow behaviour within the systems. The key findings were as follows. Increased particle sphericity enhanced channelling in beds of smaller particles, but not for larger particle sizes. Higher particle wettability caused greater liquid dispersion during both initial wetting studies and at steady-state fluid flux. Higher porosity levels and the inclusion of fines in mixed sized beds resulted in longer average solute residence times, higher liquid hold-up, longer solution and tracer breakthrough times, and increases in drain-down moisture percentages. Increasing the irrigation fluid’s viscosity, reflective of the increase in ionic concentrations in leach solutions, reduced both the solution and tracer breakthrough times and increased dispersion with signs of more discontinuous or isolated fluid volumes at steady-state. These results highlighted the importance of the inclusion of fines in agglomerated beds to improve uniform wetting especially those with low to moderate particle porosities (2/g specific surface area). The viscosity results suggest that there may be changes in preferential flow extent, due to variations in viscosity owing to the increasing sulphate concentration within the liquid phase in heaps and with time.

Despite the potential shown by previous investigations on the use of ultrasound for the remediation of oil-contaminated sand, the influence and interactions among ultrasonic parameters and oily sand are unclear, leading to possible ineffective treatment and high-power consumption. In order to improve the process efficiency, this work analyzes the effects of ultrasonic power, frequency, and load toward the cleaning of crude oil–contaminated sand, using two different sample positions and sand types. Crude oil–contaminated beach sand and produced sand from offshore oil well were used as samples. They were cleaned in custom-made ultrasonic bath reactor for 10 min with power from 30 to 120 W, frequency covering 25–60 kHz, and sand load of 10–100 g. With experimental design consisting multiple factors and levels, the interactions between factors in all possible combinations were determined using ANOVA (n = 210). From p-value based at 95% confidence interval and extensive F test, the three most significant factors were the sand type, the ultrasonic frequency, and the interaction between sand type and frequency. The best setting for suspended samples involved high frequency of 60 kHz, whereas bottom samples preferred low frequency at 28 kHz. This finding was justified when the acoustic pressure attenuation, standing wave pattern, and surface pitting/cracking were found in correlation with the cleaning results. Overall, the maximum treatment under ultrasonic bath solely gained around 60%, improvable by hybrid cleaning with other techniques such as chemical, biological, mechanical, and thermal. [ABSTRACT FROM AUTHOR]

Based on multiphase flow theory and capillary mechanics, the dimensionless bond number expression of the influence of string grille wire spacing on droplet spreading is derived. Taking a liquid film formed by spreading droplets based on Kelvin correlation, the Young–Laplace equation, and the Hagen–Poiseuille law, an equation for calculating the thickness and height of the liquid film is established with temperature, relative humidity and molar volume of liquid phase as independent variables. According to the theory of string grille filtration and dust removal, a dust removal efficiency calculation model covering the wet string grille wire group is constructed based on the liquid film thickness, height, wire diameter, water film area, and vortex shedding frequency. Finally, a theoretical analysis of the influence of water film area on the efficiency of wet string grille dust removal is carried out based on the spray pressure and the ratio of string grille wire distance to wire diameter. It is found that the effect of spray pressure on water film area and dust removal efficiency is more significant than the string grille wire distance diameter ratio. Moreover, the optimized combination of wet string grille wire distance diameter ratio 0.84, wind speed 3 m/s and spray pressure 0.8 MPa is found, which could provide an important reference for engineering applications. [ABSTRACT FROM AUTHOR]

Various surface modifications controlling wettability and wickability have effectively enhanced the critical heat flux (CHF) in saturated pool boiling. Among them, this paper focuses on the CHF enhancement using a honeycomb porous plate (HPP). The HPP, which is commercially available, was generally used to filter exhaust gases from combustion engines, and has micron-order pores and millimeter-order holes which is called as a “cell”. Once an HPP was installed on the heated surface, the CHF in saturated pool boiling of water was improved more than approximately three times compared with a bare surface. The enhancement may be caused by: (1) the liquid supply due to capillarity, (2) liquid flowing down through the cells of an HPP due to gravity onto the heated surface, and (3) the release of vapor generated through the cells. However, the liquid supply process to heated surface due to (1) and (2) has not been clarified yet. Therefore, it is necessary to elucidate the detailed liquid supply mechanism for further CHF enhancement. In the present paper, two separate sets of experiments have been designed to investigate the liquid supply effect to the heated surface independently, namely, (1) automatic liquid supply due to capillary action by the porous part and (2) bulk liquid flowing down through the cells of an HPP. In summary, the measured values from the experiment extracting the liquid supply due to capillarity were in good agreement with the proposed capillary limit model. Moreover, for the high heat flux region (more than 3.5 MW/m2), the liquid supply due to the capillary force is dominant in enhancing the CHF. It was concluded that the keys to further CHF enhancement were the promotion of gas-liquid circulation based on the capillary limit model and improvement of wickability of the heated surface.