Water Transport Research Articles

A bamboo 'PeSAPK4-PeMYB99-PeTIP4-3' regulatory model involved in water transport.

Water plays crucial roles in expeditious growth and osmotic stress of bamboo. Nevertheless, the molecular mechanism of water transport remains unclear. In this study, an aquaporin gene, PeTIP4-3, was identified through a joint analysis of root pressure and transcriptomic data in moso bamboo (Phyllostachys edulis). PeTIP4-3 was highly expressed in shoots, especially in the vascular bundle sheath cells. Overexpression of PeTIP4-3 could increase drought and salt tolerance in transgenic yeast and rice. A co-expression pattern of PeSAPK4, PeMYB99 and PeTIP4-3 was revealed by WGCNA. PeMYB99 exhibited an ability to independently bind to and activate PeTIP4-3, which augmented tolerance to drought and salt stress. PeSAPK4 could interact with and phosphorylate PeMYB99 in vivo and in vitro, wherein they synergistically accelerated PeTIP4-3 transcription. Overexpression of PeMYB99 and PeSAPK4 also conferred drought and salt tolerance in transgenic rice. Further ABA treatment analysis indicated that PeSAPK4 enhanced water transport in response to stress via ABA signaling. Collectively, an ABA-mediated cascade of PeSAPK4-PeMYB99-PeTIP4-3 is proposed, which governs water transport in moso bamboo.

Two-phase flow in the gas diffusion layer with different perforation of proton exchange membrane fuel cell

ABSTRACT Gas diffusion layer (GDL) is an important pathway for water transport in the proton exchange membrane fuel cell. The presence of excessive liquid water in the cathode GDL will cause “water flooding” and block the reactant transport path to catalyst sites. Therefore, it’s critical to understand water transfer mechanism in GDL and propose novel strategy to improve water management. In this study, the effect of GDL with different perforation holes on liquid water transport behavior are investigated by volume of fluid method. The simulation model is validated by comparing with the reported data. The results show that the GDL with perforation holes will accelerate the liquid water breakthrough. Specially, the GDL with cylindrical perforation achieves the lowest breakthrough pressure, and most excellent water drainage capacity under various pressure drops. The gradient hydrophobic distribution in GDL will improve the water breakthrough path and drainage capacity. However, gradient hydrophobic treatment in GDL with conical perforations will result more water leakage along the though-plane direction. The simulation results will provide significant guidance for designing high performance GDL and improving the water management in proton exchange membrane fuel cell.

Water, Salt, and Ion Transport and Its Response to Water-Saving Irrigation in the Hetao Irrigation District Based on the SWAT-Salt Model

Soil salinization is one of the main hazards affecting the sustainable development of agriculture in the Hetao Irrigation District (HID) of Inner Mongolia. To grasp the water and salt transport patterns and spatial–temporal distribution characteristics of the HID at the regional scale, the improved Soil and Water Assessment Tool with a salinity module (SWAT-Salt) model was used to establish the distributed water and salt transport model for the watershed in this study. The results demonstrated that the modified model could more accurately represent the process of water and salt changes in the HID. The coefficient of determination (R2) in the simulation of streamflow and discharge salt loading was 0.83 and 0.86, respectively, and the Nash–Sutcliffe efficiency (NSE) was 0.80 and 0.74, respectively. Based on this, different hydrological processes (surface runoff, lateral flow, groundwater, soil seepage) as well as spatial–temporal distribution characteristics of water salinity in groundwater and soil were analyzed in the HID. Differences in groundwater and soil salinity in different land uses and soil types were also compared. Of these, surface runoff and lateral flow salt discharge loading are concentrated in the southwestern portion of the basin, while groundwater salt discharge loading is concentrated in the eastern as well as southwestern portions of the basin. The salt discharge loading from groundwater accounts for about 98.7% of the total salt discharge loading from all hydrological pathways and is the major contributing part of salt discharge from the irrigation area. Soil salinity increases gradually from west to east. Groundwater salinity (2946 mg/L) and soil water electrical conductivity (0.309 dS/m) were minimized in the cropland. Meanwhile, rational allocation of irrigation water can appropriately increase the amount of salt discharge loading. In conclusion, the model could provide a reference for the investigation of soil salinization and water–salt management measures in irrigation areas.

Predicting the impact of water transport on carbonation-induced corrosion in variably saturated reinforced concrete

A modelling framework for predicting carbonation-induced corrosion in reinforced concrete is presented. The framework constituents include a new model for water transport in cracked concrete, a link between corrosion current density and water saturation, and a theory for characterising concrete carbonation. The theoretical framework is numerically implemented using the finite element method and model predictions are extensively benchmarked against experimental data. The results show that the model is capable of accurately predicting carbonation progress, as well as wetting and drying of cracked and uncracked concrete, revealing a very good agreement with independent experiments from a set of consistent parameters. In addition, insight is gained into the evolution of carbonation penetration and corrosion current density under periodic wetting and drying conditions. Among others, we find that cyclic wetting periods significantly speed up the carbonation progress and that the induced corrosion current density is very sensitive to concrete saturation.

Wooden Boats and Shipping Organizations in the Middle Reaches of the Yangtze River (1700-1850)

Between 1700 and 1850, there were an estimated 125,000 wooden boats in the middle reaches of the Yangtze River, with a load capacity of more than two million tons. The transport capacity and the wide distribution of these boats demonstrate that the relationship between multitiered markets was growing closer, and China’s national market was expanding more widely. In this period, direct supervision from government was so difficult to implement effectively that the task of ensuring the safety and order of water transportation fell to the commercial agencies, such as boat brokers 船行 and quay controllers 埠头. The wooden-boat shipping business in the middle Yangtze River during the Qing dynasty was not in a totally disordered state. The spontaneously formed boatmen gangs 船帮 and boatmen lineages 船民家族 played an active and influential role in a specific area of local river transportation in the middle Yangtze River, illustrating that local arbitration and mediation mechanisms were formed to deal with socioeconomic conflicts among shipowners, merchants, local communities, and local governments in the regional commercial transportation network. However, it was not until the end of the nineteenth century that a powerful shipping institution or merchant’s organization that could effectively regulate the water transportation emerged, nor were there socioeconomic mechanisms set up to deal with the many kinds of shipping disputes that existed in the reaches of the middle Yangtze.

Arbuscular Mycorrhizal Fungi Improve Lycium barbarum Potassium Uptake by Activating the Expression of LbHAK

Arbuscular mycorrhizal (AM) fungi can establish a mutualistic relationship with the roots of most terrestrial plants to increase plant nutrient uptake. The effects of potassium uptake and transport by AM symbiosis are much less reported compared to other nutrients. In this research, a heterologous yeast system was used to verify that the LbHAK has capacity for potassium uptake. The split-roots system implemented using seedlings of Lycium barbarum confirmed that R. irregularis locally induced LbHAK expression, which means that LbHAK is only expressed in mycorrhizal roots. Furthermore, the impacts of overexpression of LbHAK on the growth, nutrients and water uptake, and transport of mycorrhizal tobacco (inoculation with Rhizophagus irregularis) at 0.2 mM and 2 mM K conditions were assessed. The mycorrhizal tobacco growth and potassium accumulation were significantly enhanced through LbHAK overexpression in tobacco. In addition, overexpression of LbHAK substantially enhanced phosphorus content, while stimulating the expression of NtPT4, Rir-AQP1, and Rir-AQP2 in mycorrhizal tobacco. Moreover, LbHAK overexpression greatly promoted AM colonization. LbHAK has a potential role in facilitating potassium absorption through the mycorrhizal pathway, and overexpression of LbHAK in tobacco may promote the transport of potassium, phosphorus, and water from AM fungi to tobacco. These data imply the important roles played by the LbHAK in AM-fungi-induced potassium uptake in L. barbarum and in improving plant nutrients and AM colonization.

Experimental Study on Subgrade Soil Properties using Sea Water as Partial Replacement to Fresh Water in Coastal Areas

At present , the fresh water availability is very important factor specially in coastal areas the ground water table providing with sea water . If we utilize the waste water nothing but sea water is used as parital replacement to the fresh water for the construction of subgrade soil for flexible pavements ,we will reduce the utilization of fresh water to the construction works as well as economical for transportation of fresh water to construction site. Sub grade is a component which can taken all compression loads from sub base, base and surface courses and transfer to it to below the ground surface. This paper deals with the sub-grade properties using sea water as partial replacement to fresh water in coastal areas. In order to determine the properties of soil by taking various percentages I.e, 10%,20%,30%,40% and 50%of salt water as partially replaced to normal water. In this study, Proctor’s compaction tests, core cutter test,Atterberg limits and CBR soaked and un-soaked tests are conducted on locally available soil with sea water to normal water. For this study it is identified that the engineering properties of the soil like void ratio,posrosity,degree of saturation does not loose their characterstics in all conditions. The soil with at optimum value is 40% of sea water has CBR soaked value is obtained 6.83% and un-soaked value is obtained 7.0% is just increased when compared with conventionally soil. Key Words: CBR-Soaked, Un-soaked,sea water, locally available water, compaction test, atter berg limits

A Study on the Rainfall-Storage Volume-Target Water Level Curve for Flood Control on the Small Size Dam: Case study for Goesan Dam

Dams in South Korea serve various functions, including water supply, hydropower, and transportation; in particular, they are responsible for a significant portion of flood control. This study aims to propose a methodology that field engineers can easily utilize to assess the hydrological conditions of small dams that require simultaneous discharge during flood inflow due to limited storage capacity. Therefore, the relationship between rainfall, storage volume, and target water level was established for dams. This relationship is represented as a curve and is based on the storage volume during the rising phases of floods. Historical data of the Goesan Dam, located in the Dalcheon Basin of the Han River, including inflow, discharge, and rainfall were collected at 10-minute intervals. Analysis was conducted on four major flood events occurring since 2018. The proposed methodology was applied to derive the rainfall-storage volume-target water level curve for the Goesan Dam. Subsequently, the appropriate flood response water level for the Gosan Dam was calculated, and its applicability was examined.

Converging Hydrogen-Bonded Water Transport Channel with External Magnetic Field in a Janus Molecular Cobalt Phosphate for Enhanced Oxygen Evolution Reaction (OER) Activity

Converging Hydrogen-Bonded Water Transport Channel with External Magnetic Field in a Janus Molecular Cobalt Phosphate for Enhanced Oxygen Evolution Reaction (OER) Activity

Built-in Electric Fields in Heterostructured Lamellar Membranes Enable Highly Efficient Rejection of Charged Mass.

Separation membranes with homogeneous charge channels are the mainstream to reject charged mass by forming electrical double layer (EDL). However, the EDL often compresses effective solvent transport space and weakens channel-ion interaction. Here, built-in electric fields (BIEFs) are constructed in lamellar membranes by assembling the heterostructured nanosheets, which contain alternate positively-charged nanodomains and negatively-charged nanodomains. We demonstrate that the BIEFs are perpendicular to horizontal channel and the direction switches alternately, significantly weakening the EDL effect and forces ions to repeatedly collide with channel walls. Thus, highly efficient rejection for charged mass (salts, dyes, and organic acids/bases) and ultrafast water transport are achieved. Moreover, for desalination on four-stage filtration option, salt rejection reaches 99.9% and water permeance reaches 19.2 L m-2 h-1 bar-1. Such mass transport behavior is quite different from that in homogeneous charge channels. Furthermore, the ion transport behavior in nanochannels is elucidated by validating horizontal projectile motion model.

Built‐in Electric Fields in Heterostructured Lamellar Membranes Enable Highly Efficient Rejection of Charged Mass

Separation membranes with homogeneous charge channels are the mainstream to reject charged mass by forming electrical double layer (EDL). However, the EDL often compresses effective solvent transport space and weakens channel‐ion interaction. Here, built‐in electric fields (BIEFs) are constructed in lamellar membranes by assembling the heterostructured nanosheets, which contain alternate positively‐charged nanodomains and negatively‐charged nanodomains. We demonstrate that the BIEFs are perpendicular to horizontal channel and the direction switches alternately, significantly weakening the EDL effect and forces ions to repeatedly collide with channel walls. Thus, highly efficient rejection for charged mass (salts, dyes, and organic acids/bases) and ultrafast water transport are achieved. Moreover, for desalination on four‐stage filtration option, salt rejection reaches 99.9% and water permeance reaches 19.2 L m‐2 h‐1 bar‐1. Such mass transport behavior is quite different from that in homogeneous charge channels. Furthermore, the ion transport behavior in nanochannels is elucidated by validating horizontal projectile motion model.

Isotope Distribution Analysis in H₂18O Pulse-Labeled Trees Frozen with Liquid Nitrogen.

Tracer injection has long been recognized as a valuable tool for delineating tree hydraulics and assessing water transport pathways. Recently, isotope tracers have emerged as innovative instruments for investigating tree hydraulics, providing new insights into tree water dynamics. Nevertheless, there is a critical need for further research to comprehensively grasp water movement and distribution within trees. A previously introduced technique for analyzing the isotopic ratio of water in wet tissues, offering millimeter-scale resolution for visualizing tracer movement, faces challenges due to its underdeveloped sample preparation techniques. In this study, we introduced an H2 18O tracer into S. gracilistyla samples, exclusively comprising indeterminate roots, stems, and leaves, cultivated through hydroponics and grown within the current year. Our objective was to assess the axial distribution of the tracer in the xylem. Additionally, we devised a novel method for preparing frozen wet tissue samples, enhancing the repeatability and success rate of experiments. The results demonstrated that all frozen wet tissue samples exhibited an average water loss rate of less than 0.6%. Isotopic analysis of these samples unveiled a consistent decline in tracer concentration with increasing height in all Salix specimens, with three out of five samples revealing a significant isotope gradient. Our findings affirm the efficacy and practicality of combining isotopic labeling with freezing, stabilization, and preparation techniques. Looking ahead, our isotopic labeling and analysis methods are poised to transcend woody plants, finding extensive applications in plant physiology and ecohydrology.

A Review on the Improvement of Saline-alkali Soil by Organic Fertilizer

 In recent years, soil salinization has become a serious problem in the global environment. The application of organic fertilizer to improve saline-alkali soil has been widely concerned because of its advantages of improving soil fertility, improving soil structure and improving soil salt ion composition. This paper reviews the mechanism of saline-alkali soil improvement, and expounds the improvement prospect of organic fertilizer on saline-alkali soil from the influence of organic fertilizer on soil physical and chemical properties, water and salt transport law, crop yield and quality, in order to provide theoretical guidance for saline-alkali soil restoration.

Combined effect of grooves and nanoflower structured Co3O4 coating on bamboo wood for highly efficient solar steam generation at indoor and outdoor conditions.

Currently, interfacial solar steam generation (ISSG) in desalinating water has become very popular for obtaining purified water from polluted water. However, finding an efficient evaporator with low cost is a challenging task for researchers. In this work, we introduce natural bamboo wood (BW) that acts as an interfacial evaporator for obtaining purified water. Four different wood evaporators namely, flat wood (BW-FW), two-cut grooved wood (BW-2G), four-cut grooved wood (BW-4G), and four-cut grooved with Co3O4-coated wood (BW-4G/Co3O4) are used to study the mass loss (ML), evaporation rate (ER), and evaporation efficiency (EY). From the observations, BW-4G/Co3O4 gives an admirable ML, ER, and EY of 4.4 g, 3.366 kg m-2 h-1, and 91.34% under 1 sun illumination for 60 min. Also, the BW-4G/Co3O4 evaporator is kept under natural sun illumination. It achieves 17.8 g of ML, 1.92 kg m-2 h-1 of ER, and 76% of EY respectively under 604.762 W/m2 solar illumination for 8 h. The reasons for the observed results are as follows: (i) the presence of grooves increases the exposing area for solar illuminations, (ii) super hydrophilicity nature of wood gives continuous replenishment of water from the bottom to the evaporative surface, (iii) the excellent salt rejection property of wood aids in continuous water transportation without salt accumulations. As a result of the condensed seawater samples, the ion concentrations (zinc, magnesium, cadmium, lead, copper, and sodium) come under WHO standards. Consequently, it gives better dye water separation from polluted water.

Applicability of Single-Layer Graphene as a Hydrogen-Blocking Interlayer in Low-Temperature PEMFCs.

Gas crossover is critical in proton exchange membrane (PEM)-based electrochemical systems. Recently, single-layer graphene (SLG) has gained great research interest due to its outstanding properties as a barrier layer for small molecules like hydrogen. However, the applicability of SLG as a gas-blocking interlayer in PEMs has yet to be fully understood. In this work, two different approaches for transferring SLG from a copper or a polymeric substrate onto PEMs are compared regarding their application in low-temperature PEM fuel cells. The SLG is sandwiched between two Nafion XL membranes to form a stable composite membrane. The successful transfer is confirmed by Raman spectroscopy and in ex situ hydrogen permeation experiments in the dry state, where a reduction of 50% upon SLG incorporation is achieved. The SLG composite membranes are characterized by their performance and hydrogen-blocking ability in a fuel cell setup at typical operating conditions of 80 °C and with fully humidified gases. The performance of the fuel cell incorporating an SLG composite membrane is equal to that of the reference cell when avoiding the direct etching process from a copper substrate, as remnants from copper etching deteriorate the performance of the fuel cell. For both transfer processes, the hydrogen crossover reduction of SLG composite membranes is only 15-19% (1.5 barabs) in the operating fuel cell. Further, hydrogen pumping experiments suggest that the barrier function of SLG impairs the water transport through the membrane, which may affect water management in electrochemical applications. In summary, this work shows the successful transfer of SLG into a PEM and confirms the effective hydrogen-blocking capability of the SLG interlayer. However, the hydrogen-blocking ability is significantly reduced when running the cell at the typical humidified operating conditions of PEM fuel cells, which follows from a combination of reversible interlayer alteration upon humidification and irreversible defect formation upon PEM fuel cell operation.

Water will Find Its Way: Transport through Narrow Tunnels in Hydrolases.

An aqueous environment is vital for life as we know it, and water is essential for nearly all biochemical processes at the molecular level. Proteins utilize water molecules in various ways. Consequently, proteins must transport water molecules across their internal network of tunnels to reach the desired action sites, either within them or by functioning as molecular pipes to control cellular osmotic pressure. Despite water playing a crucial role in enzymatic activity and stability, its transport has been largely overlooked, with studies primarily focusing on water transport across membrane proteins. The transport of molecules through a protein's tunnel network is challenging to study experimentally, making molecular dynamics simulations the most popular approach for investigating such events. In this study, we focused on the transport of water molecules across three different α/β-hydrolases: haloalkane dehalogenase, epoxide hydrolase, and lipase. Using a 5 μs adaptive simulation per system, we observed that only a few tunnels were responsible for the majority of water transport in dehalogenase, in contrast to a higher diversity of tunnels in other enzymes. Interestingly, water molecules could traverse narrow tunnels with subangstrom bottlenecks, which is surprising given the commonly accepted water molecule radius of 1.4 Å. Our analysis of the transport events in such narrow tunnels revealed a markedly increased number of hydrogen bonds formed between the water molecules and protein, likely compensating for the steric penalty of the process. Overall, these commonly disregarded narrow tunnels accounted for ∼20% of the total water transport observed, emphasizing the need to surpass the standard geometrical limits on the functional tunnels to properly account for the relevant transport processes. Finally, we demonstrated how the obtained insights could be applied to explain the differences in a mutant of the human soluble epoxide hydrolase associated with a higher incidence of ischemic stroke.

Investigation of short‐term effects of forage radish on water and solute transport through a tracer test and inverse modeling

AbstractThe benefits of using cover crops for improving soil and water quality are well known. Less clear is whether cover crops, especially those forming a taproot system, can favor solute transport down to the groundwater by modifying soil hydraulic properties and solute dynamics. In this study, we employed 12 lysimeters to conduct a comparative analysis between a taproot cover crop, specifically forage radish (FR), and bare soil (BS), under three water table management conditions. Our objective was to evaluate whether the enhancement of root‐derived macroporosity could have modified water and solute dynamics, and offset the benefits provided by FR that is commonly used to mitigate solute leaching. A tracer solution of bromide (Br−) was added to lysimeters, and solute flux concentrations were determined at different depths during a 25‐day test. Soil moisture and pressure heads were monitored. Water and solute transport parameters were estimated by inverse modeling using HYDRUS‐1D. A complementary laboratory experiment was performed to quantify the effect of FR root apparatus on the macropore structure by using noninvasive X‐ray microtomography (µCT). Results showed that the growth of FR within the lysimeters induced alterations in water and solute dynamics compared with BS. This is primarily attributed to its proficiency as solute scavenger, with an uptake capacity of up to 47% of the total injected tracer. Our comparative analysis instead revealed subtle differences in soil structure and hydraulic properties brought about by the presence of FR. Major changes were observed for the saturated hydraulic conductivity (Ks), which increased from an average of 8.4–49.8 cm day−1 within the 20–45 cm layer in BS and FR, respectively. Additionally, there was a difference in immobile water content (θim), with the values in FR averaging 21% lower than those in BS. These modifications can be attributed to the formation of fissures and channels, primarily concentrated in the proximity of taproot development, without extending into deep preferential flow pathways. These structural changes were supported by the nondestructive µCT analyses. Upon aggregating the effects observed, solute movement to groundwater was not affected by FR compared to BS conditions.

Wind‐Driven Seasonal Variability of Deep‐Water Overflow From the Pacific Ocean to the South China Sea

AbstractThe South China Sea (SCS) is a semi‐enclosed marginal sea linked to the broader oceans via various geographically constrained channels. Beneath the main thermocline depth, Luzon Strait is the only conduit for water‐mass exchanges. Observations indicate a substantial seasonal variability in the inflow transport of deep water from the Pacific Ocean. This study aims to identify and examine key drivers for such seasonal changes. It is found that seasonal variability of the deep‐water transport into the SCS is primarily driven by surface wind stress. An imbalance in wind‐driven exchanges of surface water between the SCS and external seas demands compensational transports in subsurface layers so that the net volume transport into the SCS is conserved, resulting in seasonal variations in deep‐water overflow. Changes in Karimata Strait exert a particularly influential impact on deep‐water inflow, likely due to its unique position as the sole connecting channel across the Equator.

Rapid recovery of old steel piping capacity with energy saving effect by reducing hydraulic resistance values

The design of repair work for the reconstruction of pressure steel pipelines using Swagelining technology by pulling pre-compressed polymer pipes into old pipelines is considered. Information on regulatory and technical documentation and the field of application of advanced technology, on installation and operation conditions, as well as on the comparative assessment of energy consumption after reconstruction of dilapidated sections of pipelines with polymer pipes with the possibility of minimizing energy consumption during water transportation under conditions of non-thermal operation of the pipeline with changes in hydraulic characteristics is presented.

Safety of Tap Water in Terms of Changes in Physical, Chemical, and Biological Stability

Monitoring the quality of tap water in the distribution system and the ability to estimate the risk of losing its sanitary safety is an important aspect of managing the collective water supply system. During monitoring, the physical, chemical, and biological stability of water was assessed, which is the main determinant ensuring the appropriate quality of water for consumers. The physicochemical and microbiological quality of water was analyzed for two distribution systems (DSs), including the analysis of heavy metals (Zn, Fe, Mn, Cr, Ni, Cu, Cd, Pb). The tests carried out showed that in both distribution systems, the water supplied to consumers met the guidelines for water intended for human consumption. It can be considered that the risk of uncontrolled changes in water quality in DSs with an average water production of <10,000 m3/d and the length of water pipelines < 150 km is very low. The water introduced into the system differed in the place of water intake and water purification technology, which influenced the final water quality. In DS(II), higher values were recorded for hardness, conductivity, calcium, alkalinity, nitrates, and DOC. It was found that the content of heavy metals during water transport to the consumer increased in the case of DS(I) for Zn, Ni, Cu, Cd, and Pb, and in the case of DS(II) for Fe, Mn, Ni, Cu, Cd, and Pb. The observed differences resulted from the different quality of the intake water as well as from different materials used to build internal installations and their age and technical condition. The analyzed tap water was characterized by physical and chemical stability. However, the water did not meet the guidelines for water biostability due to the increased content of biogenic substances.