Showing papers on "Water flow published in 2017"
TL;DR: A simple model is proposed based on the concept of effective slip, which is a linear sum of true slip, depending on a contact angle, and apparent slip, caused by a spatial variation of the confined water viscosity as a function of wettability as well as the nanopore dimension, which shows that the flow capacity of confined water is 10−1∼107 times that calculated by the no-slip Hagen–Poiseuille equation.
Abstract: Understanding and controlling the flow of water confined in nanopores has tremendous implications in theoretical studies and industrial applications. Here, we propose a simple model for the confined water flow based on the concept of effective slip, which is a linear sum of true slip, depending on a contact angle, and apparent slip, caused by a spatial variation of the confined water viscosity as a function of wettability as well as the nanopore dimension. Results from this model show that the flow capacity of confined water is 10 −1 ∼10 7 times that calculated by the no-slip Hagen–Poiseuille equation for nanopores with various contact angles and dimensions, in agreement with the majority of 53 different study cases from the literature. This work further sheds light on a controversy over an increase or decrease in flow capacity from molecular dynamics simulations and experiments.
393 citations
TL;DR: In this article, the authors demonstrate fluid cooling panels that harness radiative sky cooling to cool fluids below the air temperature with zero evaporative losses, and use almost no electricity, and show that the panels can cool water up to 5'∘C below the ambient air temperature at water flow rates of 0.2'l'min−1'm−2.
Abstract: Cooling systems consume 15% of electricity generated globally and account for 10% of global greenhouse gas emissions. With demand for cooling expected to grow tenfold by 2050, improving the efficiency of cooling systems is a critical part of the twenty-first-century energy challenge. Building upon recent demonstrations of daytime radiative sky cooling, here we demonstrate fluid cooling panels that harness radiative sky cooling to cool fluids below the air temperature with zero evaporative losses, and use almost no electricity. Over three days of testing, we show that the panels cool water up to 5 ∘C below the ambient air temperature at water flow rates of 0.2 l min−1 m−2, corresponding to an effective heat rejection flux of up to 70 W m−2. We further show through modelling that, when integrated on the condenser side of the cooling system of a two-storey office building in a hot dry climate (Las Vegas, USA), electricity consumption for cooling during the summer could be reduced by 21% (14.3 MWh). Radiative sky cooling passively rejects heat from a surface out into space via an atmospheric transparency window, enabling sub-ambient cooling. Goldstein et al. exploit this to show daytime cooling of water by up to 5 ∘C below ambient temperature, equivalent to a heat rejection flux of 70 Wm−2.
318 citations
TL;DR: In this paper, two different freestanding, multifunctional TENGs are successfully developed that can be used to harvest three types of energies including water waves, air flowing, and water flowing.
Abstract: Triboelectric nanogenerator (TENG) has been considered to be a more effective technology to harvest various types of mechanic vibration energies such as wind energy, water energy in the blue energy, and so on. Considering the vast energy from the blue oceans, harvesting of the water energy has attracted huge attention. There are two major types of “mechanical” water energy, water wave energy in random direction and water flow kinetic energy. However, although the most reported TENG can be used to efficiently harvest one type of water energy, to simultaneously collect two or more types of such energy still remains challenging. In this work, two different freestanding, multifunctional TENGs are successfully developed that can be used to harvest three types of energies including water waves, air flowing, and water flowing. These two new TENGs designed in accordance with the same freestanding model yield the output voltages of 490 and ≈100 V with short circuit currents of 24 and 2.7 µA, respectively, when operated at a rotation frequency of 200 rpm and the movement frequency of 3 Hz. Moreover, the developed multifunctional TENG can also be explored as a self-powered speed sensor of wind by correlating the short-circuit current with the wind speed.
250 citations
TL;DR: In this paper, the evaporation-driven water flow within an all-printed porous carbon film can reliably generate sustainable voltage up to 1 V with a power density of ≈8.1 µW cm−3 under ambient conditions.
Abstract: Converting environmental “waste energies” into electricity via a natural process is an ideal strategy for environmental energy harvesting and supplying power for distributed energy-consuming devices. This paper reports that evaporation-driven water flow within an all-printed porous carbon film can reliably generate sustainable voltage up to 1 V with a power density of ≈8.1 µW cm−3 under ambient conditions. The output performance of the device can be easily scaled up and used to power low-power consumption electronic devices or for energy storage. Furthermore, the device is successfully used without electric storage as a direct power source for electrodeposition of silver microstructures. Because of the ubiquity of water evaporation in nature and the low cost of materials involved, the study presents a novel avenue to harvest ambient energy and has potential applications in low-cost, green, self-powered devices and systems.
242 citations
TL;DR: In this paper, a wearable all-fabric-based TEG for water energy harvesting, with additional self-cleaning and antifouling properties is reported for the first time.
Abstract: Realizing energy harvesting from water flow using triboelectric generators (TEGs) based on our daily wearable fabric or textile has practical significance. Challenges remain on methods to fabricate conformable TEGs that can be easily incorporated into waterproof textile, or directly harvest energy from water using hydrophobic textile. Herein, a wearable all-fabric-based TEG for water energy harvesting, with additional self-cleaning and antifouling properties is reported for the first time. Hydrophobic cellulose oleoyl ester nanoparticles (HCOENPs) are prepared from microcrystalline cellulose, as a low-cost and nontoxic coating material to achieve superhydrophobic coating on fabrics, including cotton, silk, flax, polyethylene terephthalate (PET), polyamide (nylon), and polyurethane. The resultant PET fabric-based water-TEG can generate an instantaneous output power density of 0.14 W m−2 at a load resistance of 100 MΩ. An all-fabric-based dual-mode TEG is further realized to harvest both the electrostatic energy and mechanical energy of water, achieving the maximum instantaneous output power density of 0.30 W m−2. The HCOENPs-coated fabric provides excellent breathability, washability, and environmentally friendly fabric-based TEGs, making it a promising wearable self-powered system.
198 citations
TL;DR: In this article, the authors present the results of an experimental investigation of small particle migration from granular sandstone samples under different original porosities, particle size compositions and water flow pressures.
188 citations
TL;DR: It is found that better ecological status is associated with the presence of natural areas in floodplains, while urbanisation and nutrient pollution are important predictors of ecological degradation.
Abstract: Humans have increased the discharge of pollution, altered water flow regime and modified the morphology of rivers. All these actions have resulted in multiple pressures on freshwater ecosystems, undermining their biodiversity and ecological functioning. The European Union has adopted an ambitious water policy to reduce pressures and achieve a good ecological status for all water bodies. However, assessing multiple pressures on aquatic ecosystems and understanding their combined impact on the ecological status is challenging, especially at the large scale, though crucial to the planning of effective policies. Here, for the first time, we quantify multiple human pressures and their relationship with the ecological status for all European rivers. We considered ecological data collected across Europe and pressures assessed by pan-European models, including pollution, hydrological and hydromorphological alterations. We estimated that in one third of EU’s territory rivers are in good ecological status. We found that better ecological status is associated with the presence of natural areas in floodplains, while urbanisation and nutrient pollution are important predictors of ecological degradation. We explored scenarios of improvement of rivers ecological status for Europe. Our results strengthen the need to halt urban land take, curb nitrogen pollution and maintain and restore nature along rivers.
168 citations
TL;DR: Sulfadimidine and sulfadiazine were identified as the main antibiotics that contribute to ecological risk in Poyang Lake, and that the daphnid is the main model organism exposed to these risks.
152 citations
TL;DR: In this article, a dye tracer was introduced to track the water movement, and the physical properties of the soil and the dynamic behavior of water transport in the soil column of the arable layer (0-20 cm) were determined.
Abstract: The covering of complete plastic films on soil would affect physical and biochemical properties of the soil microenvironment. Residual plastic film fragments (RPFF), which is left behind after retrieving the most of plastic films, could affect the flow behavior in the arable layer. This study was designed to assess the potential effects of RPFF on soil physical properties, water infiltration and distribution in the soil. Treatments with and without residual plastic film fragments (RPFF and NRPFF, respectively) were performed. A dye tracer was introduced to track the water movement, and the physical properties of the soil and the dynamic behavior of water transport in the soil column of the arable layer (0–20 cm) were determined. The initial gravimetric water content, bulk density, total porosity in 0–20 cm was significantly different between RPFF and NRPFF treatment. The dark blue area in maize root and densely rooted zones under RPFF decreased by 99% and 4%, respectively, relative to that under NRPFF. The sharply changing state of infiltration and outflow indicated that water flowed along a preferential path, e.g., macro-pores in NRPFF and residual plastic film pieces in RPFF. After clearing the RPFF, the time of equilibrium in 0–5, 5–10, 10–15, and 15–20 cm soil columns decreased by 48%, 50%, 49%, and 45%, respectively. Our results highlighted that the presence of RPFF significantly influenced soil physical properties, altered soil water distribution, and decreased the matching degree of the flow distribution region and the maize root (densely rooted) zone. The present study demonstrated that the importance of clearing the RPFF for irrigation water management in agriculture produces.
145 citations
TL;DR: In this article, a Janus copper sheet, composed of a superhydrophobic upper surface and a super-hydrophilic lower surface, is shown to be stable at the air/water interfaces, showing improved interfacial floatability.
Abstract: Interfacial materials exhibiting superwettability have emerged as important tools for solving the real-world issues, such as oil-spill cleanup, fog harvesting, etc. The Janus superwettability of lotus leaf inspires the design of asymmetric interface materials using the superhydrophobic/superhydrophilic binary cooperative strategy. Here, the presented Janus copper sheet, composed of a superhydrophobic upper surface and a superhydrophilic lower surface, is able to be steadily fixed at the air/water interfaces, showing improved interfacial floatability. Compared with the floatable superhydrophobic substrate, the Janus sheet not only floats on but also attaches to the air–water interface. Similar results on Janus sheet are discovered at other multiphase interfaces such as hexane/water and water/CCl4 interfaces. In accordance with the improved stability and antirotation property, the microboat constructed by a Janus sheet shows the reliable navigating ability even under turbulent water flow. This contribution should unlock more functions of Janus interface materials, and extend the application scope of the binary cooperative materials system with superwettability.
141 citations
TL;DR: This work shows that, in the absence of visual information, larval zebrafish (Danio rerio) perform rheotaxis by using flow velocity gradients as navigational cues, and presents behavioural data that support a novel algorithm based on such local velocityGradients that fish use to avoid getting dragged by flowing water.
Abstract: In the absence of visual information, larval zebrafish (Danio rerio) use their mechanosensory lateral line to perform rheotaxis by using flow velocity gradients as navigational cues. Imagine you are a very small fish in the ocean being carried along in a uniform flow in darkness. How do you sense that you are in a flow at all? From your frame of reference you would be stationary. Even so, fish — even very small ones — consistently orientate themselves against the current. So how do they detect the current to begin with? Florian Engert and colleagues show that larval zebra fishes use their mechanosensory lateral line to detect tiny vortices in the water flow, as well as how these vortices evolve with time. This enables them to deduce flow direction. When flying or swimming, animals must adjust their own movement to compensate for displacements induced by the flow of the surrounding air or water1. These flow-induced displacements can most easily be detected as visual whole-field motion with respect to the animal’s frame of reference2. Despite this, many aquatic animals consistently orient and swim against oncoming flows (a behaviour known as rheotaxis) even in the absence of visual cues3,4. How animals achieve this task, and its underlying sensory basis, is still unknown. Here we show that, in the absence of visual information, larval zebrafish (Danio rerio) perform rheotaxis by using flow velocity gradients as navigational cues. We present behavioural data that support a novel algorithm based on such local velocity gradients that fish use to avoid getting dragged by flowing water. Specifically, we show that fish use their mechanosensory lateral line to first sense the curl (or vorticity) of the local velocity vector field to detect the presence of flow and, second, to measure its temporal change after swim bouts to deduce flow direction. These results reveal an elegant navigational strategy based on the sensing of flow velocity gradients and provide a comprehensive behavioural algorithm, also applicable for robotic design, that generalizes to a wide range of animal behaviours in moving fluids.
TL;DR: The positive effects of AMF on soil aggregation, water flow and disease resistance are equal to the effect ofAMF on plant nitrogen and phosphorus uptake, however, AMF had no effect on the uptake of other nutrients, plant water content, allelopathic transport or production of chemical defense compounds.
Abstract: Arbuscular mycorrhizal fungi (AMF) can increase plant fitness under certain environmental conditions. Among the mechanisms that may drive this mutualism, the most studied is provisioning of nutrients by AMF in exchange for carbon from plant hosts. However, AMF may also provide a suite of non-nutritional benefits to plants including improved water uptake, disease resistance, plant chemical defense, soil aggregation, and allelochemical transport and protection. Here, we use a meta-analysis of 93 studies to assess the relative effect of AMF on nutritional and non-nutritional factors that may influence plant fitness. We find that the positive effects of AMF on soil aggregation, water flow and disease resistance are equal to the effect of AMF on plant nitrogen and phosphorus uptake. However, AMF had no effect on the uptake of other nutrients, plant water content, allelopathic transport or production of chemical defense compounds. We suggest future research directions, including experimentally assessing the relative contribution on plant fitness of AMF interactions by untangling the independence of alternative benefits of AMF from an increase in nutrient uptake. This will lead to a more holistic view of the mycorrhizal-plant association and a more accurate picture of the net impact on the plant or plant community in question.
TL;DR: In this article, a MoS2/PDMS nanocomposite was fabricated in order to overcome the requirement of light assistance in degradation process, which has limited the application of photocatalysts.
TL;DR: This work establishes molecular insight into the effects of configurational structures and salt species on desalination performance, providing useful guidelines for the design of multilayer GO membranes.
Abstract: Transport of ionic solutions through graphene oxide (GO) membranes is a complicated issue because the complex and tortuous structure inside makes it very hard to clarify. Using molecular dynamics (MD) simulations, we investigated the mechanism of water transport and ion movement across multilayer GO. The significant flow rate is considerably influenced by the structural parameters of GO membranes. Because of the size effect on a shrunken real flow area, there is disagreement between the classical continuum model and nanoscaled flow. To eliminate the variance, we obtained modified geometrical parameters from density analysis and used them in the developed hydrodynamic model to give a precise depiction of water flow. Four kinds of solutions (i.e., NaCl, KCl, MgCl2, and CaCl2) and different configurational GO sheets were considered to clarify the influence on salt permeation. It is found that the abilities of permeation to ions are not totally up to the hydration radius. Even though the ionic hydration shell...
TL;DR: Wang et al. as mentioned in this paper proposed a modified input-output analysis to provide a unified framework to balance urban energy and water use, by using the case of China's capital city Beijing.
TL;DR: This model shows how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla, and identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity.
Abstract: The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth, which ultimately dictates microbiota composition. Combining measurements of bacterial physiology with analysis of published data on human physiology into a quantitative, comprehensive modeling framework, we show how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla. Mechanistically, our model shows that local pH values in the lumen, which differentially affect the growth of different bacteria, drive changes in microbiota composition. It identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity, and generates testable predictions on their effects. Our findings show that a predictive and mechanistic understanding of microbial ecology in the gut is possible. Such predictive understanding is needed for the rational design of intervention strategies to actively control the microbiota.
TL;DR: In this article, both vertical and lateral flows of rock and water occur within eroding hills, and the depth intervals of water table fluctuation for interflow and groundwater flow are characterized by changes in composition, fracture density, porosity, and permeability.
TL;DR: A designated hand-washing sink lab gallery is used to model dispersion of green fluorescent protein (GFP)-expressing Escherichia coli from sink wastewater to the surrounding environment to further define the mode of transmission of bacteria from a P-trap reservoir to a vulnerable hospitalized patient.
Abstract: There have been an increasing number of reports implicating Gammaproteobacteria as often carrying genes of drug resistance from colonized sink traps to vulnerable hospitalized patients. However, the mechanism of transmission from the wastewater of the sink P-trap to patients remains poorly understood. Herein we report the use of a designated hand-washing sink lab gallery to model dispersion of green fluorescent protein (GFP)-expressing Escherichia coli from sink wastewater to the surrounding environment. We found no dispersion of GFP-expressing E. coli directly from the P-trap to the sink basin or surrounding countertop with coincident water flow from a faucet. However, when the GFP-expressing E. coli cells were allowed to mature in the P-trap under conditions similar to those in a hospital environment, a GFP-expressing E. coli-containing putative biofilm extended upward over 7 days to reach the strainer. This subsequently resulted in droplet dispersion to the surrounding areas (<30 in.) during faucet operation. We also demonstrated that P-trap colonization could occur by retrograde transmission along a common pipe. We postulate that the organisms mobilize up to the strainer from the P-trap, resulting in droplet dispersion rather than dispersion directly from the P-trap. This work helps to further define the mode of transmission of bacteria from a P-trap reservoir to a vulnerable hospitalized patient.IMPORTANCE Many recent reports demonstrate that sink drain pipes become colonized with highly consequential multidrug-resistant bacteria, which then results in hospital-acquired infections. However, the mechanism of dispersal of bacteria from the sink to patients has not been fully elucidated. Through establishment of a unique sink gallery, this work found that a staged mode of transmission involving biofilm growth from the lower pipe to the sink strainer and subsequent splatter to the bowl and surrounding area occurs rather than splatter directly from the water in the lower pipe. We have also demonstrated that bacterial transmission can occur via connections in wastewater plumbing to neighboring sinks. This work helps to more clearly define the mechanism and risk of transmission from a wastewater source to hospitalized patients in a world with increasingly antibiotic-resistant bacteria that can thrive in wastewater environments and cause infections in vulnerable patients.
TL;DR: In this article, a graphene-piezoelectric material heterostructure is proposed for harvesting energy from water flow; it is shown that the introduction of a piezolectric template beneath graphene results in an obvious voltage output up to 0.1 V even with deionized (DI) water.
Abstract: Recently, liquid flow over monolayer graphene has been experimentally demonstrated to generate an induced voltage in the flow direction, and various physical mechanisms have been proposed to explain the electricity-generating process between liquid and graphene. However, there are significant discrepancies in the reported results with non-ionic liquid: the observed voltage responses with deionized (DI) water vary from lab to lab under presumably similar flowing conditions. Here, a graphene-piezoelectric material heterostructure is proposed for harvesting energy from water flow; it is shown that the introduction of a piezoelectric template beneath graphene results in an obvious voltage output up to 0.1 V even with DI water. This potential arises from a continuous charging–discharging process in graphene, which is suggested to be a result of a relatively retarded screening effect of the water for the generated piezoelectric charges than that of the graphene layer, as revealed by first-principles calculations. This work considers a dynamic charge interaction among water, graphene, and the substrate, highlighting the crucial role of the underlying substrate in the electricity-generating process, which will greatly enhance understanding of the flow-induced voltage and push the graphene-water nanogenerator close to practical applications.
TL;DR: This study addresses and conceptualizes the possible dependence of ecosystem services on prevailing air and/or water flow processes and conditions, and particularly on the trajectories and associated spatial reach of these flows in carrying services from supply to demand areas in the landscape.
TL;DR: Healthcare facilities with endemic NTM should consider similar tap water avoidance and engineering strategies to decrease risk of NTM infection and investigate and mitigated a 2-phase clonal outbreak of M. abscessus linked to hospital tap water.
Abstract: Background Nontuberculous mycobacteria (NTM) commonly colonize municipal water supplies and cause healthcare-associated outbreaks. We investigated a biphasic outbreak of Mycobacterium abscessus at a tertiary care hospital. Methods Case patients had recent hospital exposure and laboratory-confirmed colonization or infection with M. abscessus from January 2013 through December 2015. We conducted a multidisciplinary epidemiologic, field, and laboratory investigation. Results The incidence rate of M. abscessus increased from 0.7 cases per 10000 patient-days during the baseline period (January 2013-July 2013) to 3.0 cases per 10000 patient-days during phase 1 of the outbreak (August 2013-May 2014) (incidence rate ratio, 4.6 [95% confidence interval, 2.3-8.8]; P < .001). Thirty-six of 71 (51%) phase 1 cases were lung transplant patients with positive respiratory cultures. We eliminated tap water exposure to the aerodigestive tract among high-risk patients, and the incidence rate decreased to baseline. Twelve of 24 (50%) phase 2 (December 2014-June 2015) cases occurred in cardiac surgery patients with invasive infections. Phase 2 resolved after we implemented an intensified disinfection protocol and used sterile water for heater-cooler units of cardiopulmonary bypass machines. Molecular fingerprinting of clinical isolates identified 2 clonal strains of M. abscessus; 1 clone was isolated from water sources at a new hospital addition. We made several water engineering interventions to improve water flow and increase disinfectant levels. Conclusions We investigated and mitigated a 2-phase clonal outbreak of M. abscessus linked to hospital tap water. Healthcare facilities with endemic NTM should consider similar tap water avoidance and engineering strategies to decrease risk of NTM infection.
TL;DR: It is shown that livestock and rabbits degrade soil health through grazing, and its effects are strongest under low or moderate productivity; however, kangaroo effects are benign.
Abstract: Summary
Grazing is one of the most widespread forms of intensive management on Earth and is linked to reductions in soil health. However, little is known about the relative influence of herbivore type, herbivore intensity and site productivity on soil health. This lack of knowledge reduces our capacity to manage landscapes where grazing is a major land use.
We used structural equation modelling to assess the effects of recent (cattle, sheep, goats, kangaroos and rabbit dung) and historic (cattle, sheep/goat livestock tracks) herbivore activity on soil health at 451 sites across 0·5 M km2 of eastern Australia. We assessed the direct and indirect effects of increasing herbivore intensity, using dung and livestock tracks, on 15 morphological, physical and chemical attributes that are indicative of soil health, and we used these attributes to derive three indices representing the capacity of the soil to maintain its structural integrity (stability), cycle nutrients (nutrients) and maintain water flow (infiltration).
Grazing had negative effects on the three soil health indices, but these effects varied with productivity. Grazing intensity was associated with strong reductions in the stability and nutrient indices under low productivity, but these effects diminished with increasing productivity. Herbivore effects on individual attributes varied in relation to productivity level and were strongly herbivore specific, with most due to cattle grazing, and to a lesser extent, sheep, goats and rabbits. Few effects due to kangaroos or historic grazing by livestock were observed.
Synthesis and applications. Our study shows that livestock and rabbits degrade soil health through grazing, and its effects are strongest under low or moderate productivity; however, kangaroo effects are benign. Our findings support calls for resource management agencies to consider site productivity, as well as herbivore type and intensity, when developing strategies to manage grazing by livestock, and feral and native herbivores.
TL;DR: In this paper, the authors proposed two interception strategies based on field experiments: on-stream and off-stream, and the former is suitable for nitrate removal and the latter targets only the most polluted water flow.
TL;DR: In this article, the authors analyzed the influence of shear processes on nonlinear flow behavior through 3D rough-walled rock fractures and found that the relationship between the volumetric flow rate and hydraulic gradient can be well fit using Forchheimer's law.
TL;DR: This study presents a critical social-ecological tool for widening the evidence-base to a more holistic understanding of the system dynamics of multiple environmental stressors in ecosystems and for developing more effective knowledge-inclusive partnerships between indigenous communities, researchers and policy decision-makers.
TL;DR: In this paper, the authors proposed a novel system of ducted nozzle configuration around the Savonius rotor to increase the efficiency of the turbine, and the maximum power coefficient of the ducted turbine was increased by 78% compared to the conventional modified rotor.
TL;DR: In this article, two abundant coffee waste residues (powder and defatted cake) were treated using subcritical water (SubCW) for hydrolysis and extraction of reducing sugars and phenolic compounds from coffee residues under semi-continuous flow conditions.
Abstract: Two abundant coffee waste residues (powder and defatted cake) were treated using subcritical water (SubCW) for hydrolysis and extraction of reducing sugars (RS), total reducing sugars (TRS), and total phenolic compounds (TPC) under semi-continuous flow conditions The flow-through process was carried out at 150, 175, 200 and 250 °C, with a water flow of 10 mL/min and reaction pressures of either 225 or 30 MPa For treated coffee powder, the maximum observed sugar recovery was 63% for RS (150 °C and 30 MPa) and 90% for TRS (150 °C and 30 MPa) The maximum TPC recovery was 2664 mg GAE (Gallic Acid Equivalent)/g powder coffee, observed at 200 °C and 225 MPa For the defatted coffee cake, the maximum sugar yields were 879% and 1723% for RS and TRS; both observed at a treatment temperature of 175 °C The highest TPC yield was 5531 mg TPC GAE/g defatted coffee cake, also at 175 °C HPLC was used to quantify specific carbohydrates (arabinose, cellobiose, glucose, and xylose), 5-hydroxy-methyl-furfural (5-HMF) and furfural in both coffee waste hydrolyzates, providing evidence of thermal degradation of the coffee carbohydrates Scanning electron microscopy of the treated samples revealed particles deposited on the surface and other signs of physical degradation of the biomass structure Fourier Transform Infrared Spectroscopy of the residues revealed that the density of surface bound acid groups increased with increasing treatment temperature The results presented here provide a basis for the use of subcritical water to obtain reducing sugars and phenolic compounds from coffee residue
TL;DR: The results of this study suggested that urbanization resulted in less diverse and more tolerant stream macroinvertebrate assemblages mainly via increased nutrient concentrations and reduced substrate coarseness.
TL;DR: In this article, a Fickian-based particle shifting algorithm with a selectively activated free-surface correction is developed for air-water simulations to prevent the creation of unnatural voids and maintain numerical stability through nearly uniform distributions.
Abstract: A numerical inconsistency has emerged for multi-phase smoothed particle hydrodynamics simulations when using very high resolution, made possible by graphical processing units. In violent flows unphysical voids and phase separation occur ultimately leading to numerical instability. New Fickian-based particle shifting algorithms with a selectively activated free-surface correction are developed for air–water simulations to prevent the creation of unnatural voids and maintain numerical stability through nearly uniform distributions. Using the shifting algorithm without surface correction in the air phase is recommended, with marginal improvements if the shifting algorithm is not applied in water. However, maintaining shifting in water would avoid possible void occurrence. The improvement is demonstrated using a dry-bed dam break and a sloshing tank case. A 3D case involving the impact of the water flow on an obstacle is compared with experimental data. The multi-phase SPH scheme gives closer agreemen...
TL;DR: Water transport in combination with plant productivity was examined in tomato plants grown under contrasting VPD gradients, finding that net water saving can be increased by enabling greater planting densities and improving the evaporative efficiency of the mechanical system.
Abstract: Although atmospheric vapour pressure deficit (VPD) has been widely recognized as the evaporative driving force for water transport, the potential to reduce plant water consumption and improve water productivity by regulating VPD is highly uncertain. To bridge this gap, water transport in combination with plant productivity was examined in tomato (Solanum lycopersicum L.) plants grown under contrasting VPD gradients. The driving force for water transport was substantially reduced in low-VPD treatment, which consequently decreased water loss rate and moderated plant water stress: leaf desiccation, hydraulic limitation and excessive negative water potential were prevented by maintaining water balance. Alleviation in water stress by reducing VPD sustained stomatal function and photosynthesis, with concomitant improvements in biomass and fruit production. From physiological perspectives, suppression of the driving force and water flow rate substantially reduced cumulative transpiration by 19.9%. In accordance with physiological principles, irrigation water use efficiency as criterions of biomass and fruit yield in low-VPD treatment was significantly increased by 36.8% and 39.1%, respectively. The reduction in irrigation was counterbalanced by input of fogging water to some extent. Net water saving can be increased by enabling greater planting densities and improving the evaporative efficiency of the mechanical system.