Showing papers on "Water flow published in 2020"

Energy costs of salt tolerance in crop plants

Abstract: Agriculture is expanding into regions that are affected by salinity. This review considers the energetic costs of salinity tolerance in crop plants and provides a framework for a quantitative assessment of costs. Different sources of energy, and modifications of root system architecture that would maximize water vs ion uptake are addressed. Energy requirements for transport of salt (NaCl) to leaf vacuoles for osmotic adjustment could be small if there are no substantial leaks back across plasma membrane and tonoplast in root and leaf. The coupling ratio of the H+ -ATPase also is a critical component. One proposed leak, that of Na+ influx across the plasma membrane through certain aquaporin channels, might be coupled to water flow, thus conserving energy. For the tonoplast, control of two types of cation channels is required for energy efficiency. Transporters controlling the Na+ and Cl- concentrations in mitochondria and chloroplasts are largely unknown and could be a major energy cost. The complexity of the system will require a sophisticated modelling approach to identify critical transporters, apoplastic barriers and root structures. This modelling approach will inform experimentation and allow a quantitative assessment of the energy costs of NaCl tolerance to guide breeding and engineering of molecular components.

Experimental and Numerical Analysis for Earth-Fill Dam Seepage

Abstract: Earth-fill dams are the most common types of dam and the most economical choice. However, they are more vulnerable to internal erosion and piping due to seepage problems that are the main causes of dam failure. In this study, the seepage through earth-fill dams was investigated using physical, mathematical, and numerical models. Results from the three methods revealed that both mathematical calculations using L. Casagrande solutions and the SEEP/W numerical model have a plotted seepage line compatible with the observed seepage line in the physical model. However, when the seepage flow intersected the downstream slope and when piping took place, the use of SEEP/W to calculate the flow rate became useless as it was unable to calculate the volume of water flow in pipes. This was revealed by the big difference in results between physical and numerical models in the first physical model, while the results were compatible in the second physical model when the seepage line stayed within the body of the dam and low compacted soil was adopted. Seepage analysis for seven different configurations of an earth-fill dam was conducted using the SEEP/W model at normal and maximum water levels to find the most appropriate configuration among them. The seven dam configurations consisted of four homogenous dams and three zoned dams. Seepage analysis revealed that if sufficient quantity of silty sand soil is available around the proposed dam location, a homogenous earth-fill dam with a medium drain length of 0.5 m thickness is the best design configuration. Otherwise, a zoned earth-fill dam with a central core and 1:0.5 Horizontal to Vertical ratio (H:V) is preferred.

Handbook Of Soil Sciences: Properties And Processes

Abstract: Soil Physics Introduction Markus Tuller Physical Properties of Primary Particles Joseph M. Skopp Soil Structure Teamrat A. Ghezzehei Mechanics of Unsaturated Soils for Agricultural Applications Rainer Horn and Stephan Peth Soil Water Content and Water Potential Relationships Dani Or, Jon M. Wraith, David A. Robinson, and Scott B. Jones Water Flow in Soils David E. Radcliffe and Jirka Simunek Water and Energy Balances in the Soil-Plant-Atmosphere Continuum Steven R. Evett, John H. Prueger, and Judy A. Tolk Solute Transport Feike J. Leij and Antonella Sciortino Gas Transport in Soils Dennis E. Rolston and Per Moldrup Soil Thermal Regime Robert Horton and Tyson Ochsner Soil Spatial Variability Ole Wendroth, Sylvia Koszinski, and Vicente Vasquez Soil Chemistry Introduction Donald L. Sparks Soil Organic Matter Jeffrey A. Baldock and Kris Broos Soil Solution Paul Schwab Kinetics and Mechanisms of Soil Chemical Reactions Donald L. Sparks Oxidation-Reduction Phenomena Bruce R. James and Dominic A. Brose Soil Colloidal Behavior Sabine Goldberg, Inmaculada Lebron, John C. Seaman, and Donald L. Suarez Ion Exchange Phenomena Ian C. Bourg and Garrison Sposito Chemisorption and Precipitation Reactions Robert G. Ford Role of Abiotic Catalysis in the Transformation of Organics, Metals, Metalloids, and Other Inorganics Pan Ming Huang and A.G. Hardie Soil pH and pH Buffering Paul R. Bloom and Ulf Skyllberg Soil Mineralogy Introduction Joseph W. Stucki Alteration, Formation, and Occurrence of Minerals in Soils G. Jock Churchman and David J. Lowe Phyllosilicates Hideomi Kodama Oxide Minerals in Soils Nestor Kampf, Andreas C. Scheinost, and Darrell G. Schulze Poorly Crystalline Aluminosilicate Clay Minerals James Harsh Soil Biology and Biochemistry: Soil Biology in Its Second Golden Age Introduction E.A. Paul and P. Nannipieri Microbiota Raffaella Balestrini, Valeria Bianciotto, Paola Bonfante, Michael Schloter, Sharath Srinivasiah, R. Greg Thorn, Kurt E. Williamson, and K. Eric Wommack Soil Fauna Michael Bonkowski, M.A. Callaham, Jr., Marianne Clarholm, David C. Coleman, D.A. Crossley, Jr., Bryan Griffiths, Paul F. Hendrix, Mark G. St. John, Robert McSorley, and P.C.J. van Vliet Microbially Mediated Processes Susumu Asakawa, Else K. Bunemann, Emmanuel Frossard, E.G. Gregorich, Jan Jansa, H.H. Janzen, Michael A. Kertesz, Makoto Kimura, Loretta Landi, David Long, Terence L. Marsh, Paolo Nannipieri, Astrid Oberson, Giancarlo Renella, and Thomas Voice Nitrogen Transformations Richa Anand, Jean-Claude Germon, Peter M. Groffman, Jeanette M. Norton, Laurent Philippot, James I. Prosser, and Joshua P. Schimel Molecular Techniques Judith Ascher, Yin Chen, Guo-Chun Ding, Holger Heuer, Jiri Jirout, Deepak Kumaresan, J. Colin Murrell, Giacomo Pietramellara, Kornelia Smalla, and Maria Teresa Ceccherini Pedology Introduction Larry T. West and Larry P. Wilding Geomorphology of Soil Landscapes Douglas A. Wysocki, Philip J. Schoeneberger, Daniel R. Hirmas, and Hannan E. LaGarry Pedogenic Processes Judith Turk, Oliver A. Chadwick, and Robert C. Graham Soil Taxonomy Robert J. Ahrens and Richard W. Arnold Other Systems of Soil Classification Erika Micheli and Otto C. Spaargaren Classification of Soils Olafur Arnalds, Fredrich H. Beinroth, J.C. Bell, J.G. Bockheim, Janis L. Boettinger, M.E. Collins, R.G. Darmody, Steven G. Driese, Hari Eswaran, Delvin S. Fanning, D.P. Franzmeier, C.T. Hallmark, Willie Harris, Wayne H. Hudnall, Randall K. Kolka, David J. Lowe, Paul A. McDaniel, D.G. McGahan, H. Curtis Monger, Lee C. Nordt, Chien-Lu Ping, Martin C. Rabenhorst, Paul F. Reich, Randall Schaetzl, Joey N. Shaw, Christopher W. Smith, Randal J. Southard, David Swanson, C. Tarnocai, Goro Uehara, Larry T. West, and Larry P. Wilding Land Evaluation for Landscape Units J. Bouma, J.J. Stoorvogel, and M.P.W. Sonneveld Hydropedology Phillip Owens, Henry Lin, and Zamir Libohova Subaqueous Soils Mark H. Stolt and Martin C. Rabenhorst Digital Soil Mapping Alex. B. McBratney, Budiman Minasny, Robert A. MacMillan, and Florence Carre Soil Change in the Anthropocene: Bridging Pedology, Land Use and Soil Management Daniel deB. Richter Jr. and Arlene J. Tugel Noninvasive Geophysical Methods Used in Soil Science James A. Doolittle Index

The pervasive and multifaceted influence of biocrusts on water in the world's drylands.

Abstract: The capture and use of water are critically important in drylands, which collectively constitute Earth's largest biome. Drylands will likely experience lower and more unreliable rainfall as climatic conditions change over the next century. Dryland soils support a rich community of microphytic organisms (biocrusts), which are critically important because they regulate the delivery and retention of water. Yet despite their hydrological significance, a global synthesis of their effects on hydrology is lacking. We synthesized 2,997 observations from 109 publications to explore how biocrusts affected five hydrological processes (times to ponding and runoff, early [sorptivity] and final [infiltration] stages of water flow into soil, and the rate or volume of runoff) and two hydrological outcomes (moisture storage, sediment production). We found that increasing biocrust cover reduced the time for water to pond on the surface (-40%) and commence runoff (-33%), and reduced infiltration (-34%) and sediment production (-68%). Greater biocrust cover had no significant effect on sorptivity or runoff rate/amount, but increased moisture storage (+14%). Infiltration declined most (-56%) at fine scales, and moisture storage was greatest (+36%) at large scales. Effects of biocrust type (cyanobacteria, lichen, moss, mixed), soil texture (sand, loam, clay), and climatic zone (arid, semiarid, dry subhumid) were nuanced. Our synthesis provides novel insights into the magnitude, processes, and contexts of biocrust effects in drylands. This information is critical to improve our capacity to manage dwindling dryland water supplies as Earth becomes hotter and drier.

Water in Nanopores and Biological Channels: A Molecular Simulation Perspective.

Abstract: This Review explores the dynamic behavior of water within nanopores and biological channels in lipid bilayer membranes. We focus on molecular simulation studies, alongside selected structural and other experimental investigations. Structures of biological nanopores and channels are reviewed, emphasizing those high-resolution crystal structures, which reveal water molecules within the transmembrane pores, which can be used to aid the interpretation of simulation studies. Different levels of molecular simulations of water within nanopores are described, with a focus on molecular dynamics (MD). In particular, models of water for MD simulations are discussed in detail to provide an evaluation of their use in simulations of water in nanopores. Simulation studies of the behavior of water in idealized models of nanopores have revealed aspects of the organization and dynamics of nanoconfined water, including wetting/dewetting in narrow hydrophobic nanopores. A survey of simulation studies in a range of nonbiological nanopores is presented, including carbon nanotubes, synthetic nanopores, model peptide nanopores, track-etched nanopores in polymer membranes, and hydroxylated and functionalized nanoporous silica. These reveal a complex relationship between pore size/geometry, the nature of the pore lining, and rates of water transport. Wider nanopores with hydrophobic linings favor water flow whereas narrower hydrophobic pores may show dewetting. Simulation studies over the past decade of the behavior of water in a range of biological nanopores are described, including porins and β-barrel protein nanopores, aquaporins and related polar solute pores, and a number of different classes of ion channels. Water is shown to play a key role in proton transport in biological channels and in hydrophobic gating of ion channels. An overall picture emerges, whereby the behavior of water in a nanopore may be predicted as a function of its hydrophobicity and radius. This informs our understanding of the functions of diverse channel structures and will aid the design of novel nanopores. Thus, our current level of understanding allows for the design of a nanopore which promotes wetting over dewetting or vice versa. However, to design a novel nanopore, which enables fast, selective, and gated flow of water de novo would remain challenging, suggesting a need for further detailed simulations alongside experimental evaluation of more complex nanopore systems.

Non-contact cylindrical rotating triboelectric nanogenerator for harvesting kinetic energy from hydraulics

Abstract: Hydraulics provide a unique and widely existed mechanical energy source around us, such as in water or oil pipes, and sewers. Here, a non-contact cylindrical rotating triboelectric nanogenerator (TENG) was developed to harvest the mechanical energy from water flows. Operation of the TENG was based on the non-contact free-rotating between a curved Cu foil and a flexible nanostructured fluorinated ethylene propylene (FEP) polymer film. The free-standing distance between two rotating interfaces avoided abrading of electrode materials. The TENG was able to effectively convert mechanical energy of the water flow into electricity. When driven by water flow, the output voltage and current of the TENG reached 1,670 V and 13.4 A, respectively. Without any energy storage component, the produced electricity could instantaneously power 12 white light emitting diodes (LEDs) bulbs and a digital timer. This non-contact rotating TENG would provide new opportunities for harvesting energy from many types of hydraulics as a self-sustainable power source for sensing, detection, and protection.

Constant Electricity Generation in Nanostructured Silicon by Evaporation‐Driven Water Flow

Abstract: Recently, hydrovoltaic technology emerged as a novel renewable energy harvesting method, which dramatically extends the capability to harvest water energy. However, the urgent issue restricting its device performance is poor carrier transport properties of the solid surface if large charged interface is considered simultaneously. Herein, a hydrovoltaic device based on silicon nanowire arrays (SiNWs), which provide large charged surface/volume ratio and excellent carrier transport properties, yields sustained electricity by a carrier concentration gradient induced by evaporation-induced water flow inside nanochannels. The device can yield direct current with a short-circuit current density of over 55 μA cm-2 , which is three orders larger than a previously reported analogous device (approximately 40 nA cm-2 ). Moreover, it exhibits a constant output power density of over 6 μW cm-2 and an open-circuit voltage of up to 400 mV. Our finding may pave a way for developing energy-harvesting devices from ubiquitous evaporation-driven internal water flow in nature with semiconductor material of silicon.

Correlation appraisal of antibiotic resistance with fecal, metal and microplastic contamination in a tropical Indian river, lakes and sewage

Abstract: The present study compares the prevalence of antibiotic-resistant bacteria (ARB) in the urban water of Ahmedabad (India), to understand the correlation of ARB with the fecal, metal, and microplastic contamination. Eleven samples, i.e., three locations of Sabarmati River along with one sample each from two (Chandola and Kankaria) lakes, and influents and effluents from three Sewage Treatment Plants (STPs) were analyzed in this study. E. coli isolated from the samples were subjected to three fluoroquinolones (Levofloxacin (LVX), Ciprofloxacin (CIP), and Norfloxacin (NFX)) and three non-fluoroquinolones (Kanamycin Monosulphate (KM), Tetracycline (TC), and Sulfamethoxazole (ST)) antibiotics for resistance quantification. Prevalence of the E. coli in the Sabarmati River (19,467–76,600 cfu mL−1) was higher than the lakes and STP(s), except the influent sample at Juhapura STP. Among the lake samples, Kankaria Lake (KL) exhibited 0% resistance towards all six antibiotics despite 5× prevalence of E. coli than that of Chandola Lake (CL) exhibiting up to 60% resistance for non-fluoroquinolones and 40% resistance to NFX. Multivariate statistical analyses suggest that resistance for ST, KM, and TC is more prevalent and correlated with electrical conductivity (EC), finer size microplastic, manganese (Mn), and nickel (Ni), whereas the resistance for fluoroquinolones (LVX, CIP, and NFX) seems highly influenced by seasonal temperature variation. Larger size microplastic clustered with salinity, ORP, and Pb. Further, fecal contamination and antibiotic resistance seem to be governed by the same source and processes, yet it does not show good correlation except for the river samples. This result may be attributed to the dynamic river–human interface, substantial wastewater discharge into the river, stagnant water flow, and urbanization-related discharge conditions rather than the upstream condition.

Wastewater Treatment by a Natural Wetland: The Nakivubo Swamp, Uganda : Processes and Implications

Abstract: The Nakivubo swamp is located in Uganda, near its capital Kampala, and has been receiving wastewater from Kampala for over 30 years This swamp consists of a floating root mat co-dominated by the sedges Cyperus papyrus and Miscanthidium violaceum Tbe partially treated wastewater mostly flows beneath the floating mat into Lake Victoria via the Murchison Bay Papyrus has a loose floating root mat which facilitates vertical mixing bebfl/een the interstitial mat water and the free water column beneath the mat This leads to a less steep gradient of nutrients over the vertical profile and facilitates nutrient uptake from the water column by papyrus vegetation In comparison, Miscanthidium has a thick compact floating root mat This mat structure prevents free vertical and lateral mixing of the mat water with the water column beneath This leads to reduced interactions of theplants with wastewater in these zones, and therefore less nutrient abstraction by plants from the wastewater Differences in the morphological, hydraulic, physico-chemical, floristic and overall wastewater treatment performance between areas covered by the two major vegetation types were elucidated Water flow is highly channelised and hydraulic retention times in the swamp during the rainy periods may be as low as 18 hours Nutrient uptake and removal efficiency of nutrients and faecal coliforms is higher in zones dominated by papyrus compared to those of Miscanthidium The potential of this swamp to remove nutrients and pathogens from wastewater in a sustainable way (with emphasis on the description and quantification of their pathways), while maintaining ecological quality and biodiversity, was investigated