Permeation Speed Research Articles

Studying the effect of tillage depth combined with organic amendments and different nitrogen fertilization on improving calcareous soil properties and wheat productivity

<p>Calcareous soil suffers from deprived organic materials, structural properties, increased water holding capacity, deep percolation, crusts and cracks formation, which hinders the roots dispersion and decreases permeation speed. This inhibits the soil physical, hydraulic properties, and its nutritional status. The research objective is to enhance the calcareous soil status and its productivity using eco-friendly conditioners. A Split-split plot field experimental study has been laid at El-Nubaria Agri. Res. Stat., in 2018 and 2019 winter seasons with three replications. The main factor was two depths of tillage: (T<sub>1</sub>) surface tillage (0 – 15 cm) and (T<sub>2</sub>) deep tillage (0 – 60 cm). The sub-main factor was three types of mineral nitrogen (N) fertilization, control (C1) without N application, ammonium nitrate (F1) and urea formaldehyde (F2), while the sub-sub main factor was the types of soil amendments: no amendment (cont.), sugar beet waste (W), K-Humate (KH), Sulphur (S) and compost (Comp). Results have indicated that greater values of organic matter OM and aggregate measured were gained by the surface tillage treatment and using both sugar beet wastes (W) and compost applications. The combination between the deep tillage (T2) and ammonium nitrate (F1) and sugar beet waste (W) has increased the wheat grains and straw yield (ton ha<sup>-1</sup>) and 1000-grains weight (g). Sugar beet waste can be recommended as an economic conditioner enhances the calcareous soil to make it more productive.</p>

A Unified Model for Non-Fickian Diffusion and Anomalous Swelling of Glassy Polymer Gels.

A sheet of glassy polymers placed in a solvent shows swelling behaviors quite different from that of soft polymers (rubbers and gels). (1) Non-Fickian diffusion (called case II diffusion): As solvent permeates into the sample, a sharp front is created between the swollen part and the glassy part, and it moves toward the center at constant speed. (2) Nonmonotonous swelling: The thickness of the sample first increases and then decreases toward the equilibrium value. Here we propose a theory to explain such anomalous behavior by extending the previous theory for swelling of soft gels. We regard the material as a continuum mixture of a glassy polymer network and solvent. We assume that the polymer network is a viscoelastic gel of glassy polymers, and its relaxation time depends strongly on solvent concentration. We show that this theory explains the above two characteristics of glassy polymers in a simple and unified framework. The theory predicts how the permeation speed of the solvent and the characteristic times of the swelling process depend on material parameters and experimental conditions, which can be checked experimentally.

Lignin: Excellent hydrogel swelling promoter used in cellulose aerogel for efficient oil/water separation

HypothesisSuper-hydrophilic/underwater super-oleophobic materials composed of biomass show great advantages for the treatment of oily wastewater due to their inherent fouling resistance. However, the development of three-dimensional materials from biomass for oil–water separation is still a challenge. It is universally acknowledged that constructing a rough structure on the surface of hydrophilic substrates would significantly improve the underwater oleophobicity and oil–water separation performance. ExperimentsIn this work, a three-dimensional lignin/cellulose aerogel (LCA) was developed through sol–gel method with freeze-drying. The rough microstructure and 3D interconnected network composed of lignin and cellulose impart excellent underwater superoleophobicity to LCA for efficient oil–water separation. FindingsThe introduction of lignin to cellulose aerogel could effectively enhance its surface roughness, water permeation speed and underwater oil contact angle. Especially, the swelling properties of the hydrogel could be regulated by modulating the content of lignin, which could further control the pore size of aerogels to optimize the separation flux. The as-prepared aerogel showed remarkable performance in separating various oil–water mixtures and oil-in-water emulsions, with a separation flux of 7646 ± 167 L·m−2·h−1 and oil rejection rate >99 %. These excellent properties combined with its facile fabrication make LCA a promising candidate for the treatment of oily wastewater.

Anti-inflammatory ethosomal nanoformulation in combination with iontophoresis in chronic wound healing: An ex vivo study.

Prescription of anti‐inflammatory drugs may be considered as a promising strategy in chronic wound healing where the inflammatory disturbance has delayed the healing process. It seems that hydrocortisone 17‐butyrate (HB17) would be promising in the form of a nano‐formulation to enhance drug delivery efficacy. In the present study, transdermal delivery of nano‐HB17 in combination with iontophoresis was investigated ex vivo. Ethosomal‐HB17 was synthesised using lecithin, ethanol and cholesterol with a different ratio by hot method. The negative ethosomal‐HB17 particle size was around 244 ± 4.3 nm with high stability of up to 30 days. Additionally, evaluated entrapment efficiency of HB17 in ethosomes by high performance liquid chromatography was 40.6 ± 2.21%. Moreover, the permeation speed and amount of H17B in complete‐thickness rat skin in the presence and absence of iontophoresis showed that the penetration of free H17B and ethosomal‐H17B formulations were zero and 7.98 μg/cm2 in 120 min, respectively. Whereas in the case of applying iontophoresis, permeation amount obtained was zero and 19.69 μg/cm2 in 30 min in free H17B and ethosomal‐H17B formulations, respectively. It has been concluded that transdermal delivery of ethosomal‐H17B is an effective strategy to enhance drug delivery and it will be improved when it is combined with iontophoresis.

Janus membranes for fast-mass-transfer separation of viscous ionic liquids from emulsions

Separation membranes are urgently desired for the efficient recovery of oil-like ionic liquids (ILs) from industrially applied emulsions. Conventional membranes with asymmetric porous structure and high tortuosity suffer from high trans-membrane resistance and low mass transfer efficiency for this application. Herein, Janus membranes (JMs) are constructed by the single-side modification of hydrophobic poly(vinylidene fluoride) (PVDF) membrane with vertically penetrative pores for the rapid-mass-transfer separation of viscous ILs. A charged and underwater IL-phobic thin layer is facilely co-deposited on one side of the PVDF membranes from polydopamine/poly(diallyldimethylammonium chloride) solution. This single-side modification endows the as-prepared JMs with a deemulsification function to IL-in-water emulsions and a unidirectional transportation ability to hydrophobic ILs. These JMs show an excellent IL recovery capacity with high permeation speed and stable flux during a long-term cyclic separation of IL-in-water emulsions because the vertically penetrative pores with low tortuosity allow to significantly reduce the trans-membrane resistance toward those viscous ILs. Overall, our vertically-channeled JMs provide an ideal material solution for recovering high-viscosity and value-added chemicals from their industrial water mixture in practice, especially from those aqueous emulsions.

Tar Removal from Gasification/Pyrolysis by Emulsion Liquid Membrane: A Short Overview

Tar is among undesirable by-products of producer gas generated from gasification/pyrolysis of biomass. Due to the erosive and corrosive characteristics of tar, a number of tar removal studies have been done. However, considering tar availability in deficient concentration, a highly selective and energy economics method is of importance. Emulsion liquid membrane is a choice of selective and economics method. Some studies on tar removal using emulsion liquid membrane were reported. Information about definition and transport mechanism of emulsion liquid membrane was given. Effects of emulsion formulation on tar removal were described. Effects of some operating conditions in permeation process on tar removal were also presented. The study found that types and concentration of surfactant and diluent as well as emulsification methods need to be properly considered for better result. Whereas permeation speed, volume ratio, and equipment used greatly affect the emulsion breaking and tar removal efficiency. Considering low emulsion breaking, application of Taylor-Couette column as the permeation equipment for further tar removal study is proposed.

Effect of the nixtamalization process on the protein bioaccessibility of white and red sorghum flours during in vitro gastrointestinal digestion

Protein bioaccessibility is a major concern in sorghum (Sorghum bicolor L. Moench) due to potential interactions with tannins affecting its nutritional value. Technological treatments such as boiling or alkaline cooking have been proposed to address this problem by reducing tannin-protein interactions. This research aimed to evaluate the impact of nixtamalization in the protein bioaccessibility from two sorghum varieties (red and white sorghum) during in vitro gastrointestinal digestion. Nixtamalization increased protein bioaccessibility in the non-digestible fraction (NDF) (5.26 and 26.31% for red and white sorghum, respectively). However, cooking showed a higher permeation speed of protein from red sorghum flours at the end of the intestinal incubation (9.42%). The SDS-PAGE profile of the digested fraction (DF) at 90 min of intestinal incubation indicated that, for red sorghum, cooking allows the formation of α and γ-kafirins while nixtamalization increase α-kafirin release. Principal Components Analysis (PCA) showed the association between nixtamalization and dissociation of δα kafirin complexes and increased protein content in the digestible fraction. In silico interactions indicated the highest biding energies for (+)-catechin and kafirin fractions (β-kafirin: −7.0 kcal/mol; γ-kafirin: −5.8 kcal/mol, and δ-kafirin: −6.8 kcal/mol), suggesting a minor influence of depolymerized proanthocyanidin fractions with sorghum proteins as a result of the nixtamalization process. In conclusion, nixtamalization increased the bioaccessibility of sorghum proteins, depolymerizing condensed tannins, and breaking protein-tannin complexes. Such technological process improves the nutrimental value of sorghum, supporting its inclusion in the human diet.

Hierarchical selective membranes combining carbonaceous nanoparticles and commercial permeable substrates for oil/water separation

Developing a simple and scalable method to create effective oil–water separation membranes and achieving optimal trade-off between its permeability and selectivity are current challenges in membrane technology for oil from water recovery. Herein, new highly hydrophobic/superoleophilic membranes (contact angles of ~143°/~0°) which meet these challenges have been obtained via a one-step process. Metallic meshes, polypropylene non-woven and cotton fabrics were exposed to low power RF-plasma of commercial grade acetylene at room temperature and medium vacuum. This way, plasma polymerized nanoparticles (NPs) were deposited over the substrates. The as-obtained membranes completely prevent the passage of water while allowing a maximum oil flux over 10,000 L m−2h−1 at 116 Pa, achieving an efficiency above 99% and reusability maintaining high performance. By controlling the mass surface density of the NPs deposit, it is possible to change both the membranes water breakthrough pressure and oil permeation speed. Membrane permeabilities were successfully obtained by fitting permeated oil volume vs time data with a Darcy-based model. The influence of surface density of NPs on the permeability and water pressure resistance was described with empirical equations. From the combination of these mathematical relations it is possible to design membranes with optimal trade-off between water pressure resistance and oil permeation speed according to the usage conditions.

Coarse-grained molecular dynamics simulation for uptake of nanoparticles into a charged lipid vesicle dominated by electrostatic interactions.

We use a coarse-grained molecular dynamics simulation to investigate the interaction between neutral or charged nanoparticles (NPs) and a vesicle consisting of neutral and negatively charged lipids. We focus on the interaction strengths of hydrophilic and hydrophobic attraction and electrostatic interactions between a lipid molecule and an NP. A neutral NP passes through the lipid membrane when the hydrophobic interaction is sufficiently strong. As the valence of the positively charged NP increases, the membrane permeation speed of the NP is increased compared with the neutral NP and charged lipids are accumulated around the charged NP. A charged NP with a high valence passes through the lipid membrane via a transient channel formed by charged lipids or transportlike endocytosis. These permeation processes can be classified based on analyses of the density correlation function. When the nonelectrostatic interaction parameters are large enough, a negatively charged NP can be adsorbed on the membrane and a neutral lipid-rich region is formed directly below the NP. The NP is spontaneously incorporated into the vesicle under various conditions and the incorporation is mediated by the membrane curvature. We reveal how the NP's behavior depends on the NP valence, size, and the nonelectrostatic interaction parameters.

Ultrafast, Stable Ionic and Molecular Sieving through Functionalized Boron Nitride Membranes.

Porous membranes play an important role in the separation technologies such as gas purification, solute nanofiltration, and desalination. An ideal membrane should be thin to maximize permeation speed, have optimum pore sizes to maximize selectivity, and be stable in various harsh conditions. Here, we show that the nanometer-thick membrane prepared by means of filtration of functionalized boron nitride (FBN) water suspensions can block solutes with hydrated radii larger than 4.3 Å in water. The FBN membranes with abundant nanochannels reduce the path length of ions. As molecular sieves, the FBN membrane can permeate small ions at an ultrahigh rate-a 25-fold enhancement compared with that of its theoretical diffusion rate and much higher than the graphene oxide membrane. Importantly, the FBN membrane exhibits excellent permeability even when it is immersed in acidic, alkaline, and basic salts solutions because of its intrinsic chemical stability. The molecular dynamics simulations further confirmed that the nanocapillaries formed within the FBN membrane in the hydrated state were responsible for high permeation performance. The simple vacuum filtration fabricated FBN membrane with angstrom-sized channels and ultrafast permeation of ions promises great potential applications in the areas of barrier separation and water purification.

High-throughput microstructure printing technology using inflatable thin membrane with microchannel

Low-cost manufacturing technology for a micro-sized structure is receiving a lot of attention as human society is getting mixed with sensors and electronics. A template printing technology which forms micro-patterns by letting ink dried within a solvent permeable template is an attractive alternative of traditional costly micro-fabrication. However, low printing speed and lack of scalability have been recognized as a major drawback of this method. Here, we propose a novel printing machine using an inflatable polymer template. It is expected that thin membrane improves the printing speed due to its high permeation speed; however, the theoretical prediction and experimental proof of this approach has not been studied. A 450-μm thick membrane is fabricated by the casting polydimethylsiloxane (PDMS) on a silicon master mold, fixed to a printer head, and inflated to contact with substrate uniformly. The permeation mechanism is investigated by using both of the numerical simulation and experiments and discovers that the diffusion in thin membrane obeys an analytical solution for Fick’s diffusion in steady state, while a conventional bulk template (10 mm) is in non-steady state. The printing system composed of pneumatic lines, a flash sintering unit, and a printer head holds the membrane is prototyped to ensure reproducibility of this novel method, five times faster printing speed compared to the ordinal method is confirmed.

Study of the ground water permeation s influence on energy pile heat exchange in porous medium soil

Energy pile heat storage technology is a typical soil source heat pump system, and features and parameters of soil have great influence on the heat storage of energy pile. Ground water permeation will take heat in soil away directly and if the permeation speed is too fast, the heat storage system of the energy pile even cannot store heat. In order to guarantee that the heat storage system of the energy pile can function well in practical working conditions, it is necessary to do further quantitative study of the ground water permeation’s influence on soil source heat pump. This study focuses on soil permeation’s influence on energy pile heat exchange through establishing the energy pile heat storage model and finds that when the permeation speed is less than 3×10-7m/s, it is the desirable heat storage condition; when the permeation speed is more than 1×10-6m/s, the energy pile heat storage system cannot store heat at all.

Dispersion of particles in wall-bounded particle-laden turbulent flows with high wall permeability

A series of numerical simulations were performed to investigate the distribution and deposition properties of particles in turbulent flows bounded by permeable walls using the Large Eddy Simulation (LES) with a Lagrangian trajectory approach. The wall permeation speeds were taken from 10−4 to 10−2 of the bulk velocity. The directions of the permeation speed were the same at both walls, and they were inward on one wall but outward on the other wall to reserve the fluid mass. Particles with Stokes number (respecting viscous time scale) around 0.1, 1 and 10 were released in the fully developed turbulent channel flow. The particle–particle interaction and the retroaction from particles to the fluid were neglected. The fluid-phase turbulence statistical properties and particle's transport characteristics by vortexes were then analyzed in details. If the wall permeation exists, the turbulence intensities will be depressed close to the outward permeable wall but increased near the inward permeable wall. Not influenced by the wall permeation, the suspended particles with St+ ∼O(1) tend to accumulate in the less vortical zones away from the wall, while those particles in the flow regions near the outward permeable wall will distribute disregarding of the vorticity. The turbulence structures near the outward permeable wall are found to exert promotional effects on the particle deposition rate, but such effects are different for particles with various Stokes number. A distribution tendency of streamwise streaks for the deposited particles is also found on the wall imposed by the high outward permeation speed and the clustering deposition pattern is more obvious with increasing particle Stokes number.

Study on Variable Permeability of Porous Carbon Graphite

To study the permeation mechanics during the impregnation of carbon graphite for mechanical applications, a permeation test with single-phase water saturated is conducted on carbon graphite porous medium, testing the permeability of the porous medium. The result of the test shows that the porosity of carbon graphite for mechanical applications is between 9.24% ~27.41% and the permeability of the samples is not a fixed value, averagely between 0.071mD and 9.953mD; and that the permeability of porous carbon graphite is resulted from the factors of pore structure properties of the porous medium, permeation force field and fluids properties. Based on the rules of permeability and permeation speed change, the permeability of carbon graphite porous medium can be classified into three categories: low-high-stable permeability, fluctuating permeability, and decreasing permeability.

Separation of CD34+ cells from human peripheral blood through polyurethane foaming membranes

Cell separation from peripheral blood was investigated using polyurethane (PU) foaming membranes and PU membranes (pore size, 5 or 12 mum) at different blood permeation speeds. Permeation ratio of hematopoietic stem cells (CD34(+) cells) through the PU membranes was the lowest among the blood cells at any blood permeation speed. This is thought to be because CD34(+) cells are more adhesive than red blood cells (RBCs), platelets, T cells, and B cells. Primitive hematopoietic stem and progenitor cells tend to adhere to the surface of mature blood cells, because of the high expression of cell-adhesion molecules on the surface of the cells. Human serum albumin solution was exposed to PU-COOH membranes to detach adhered cells from the surface of the membranes, allowing isolation of CD34(+) cells and reduction of RBCs in the permeate solution. Most purified CD34(+) cells (high recovery ratio of CD34(+) cells divided by recovery ratio of RBCs) were obtained in the recovery process using PU-COOH membranes (pore size, 5.2 microm) at a permeation speed of 0.3-1 mL/min.

Experimental studies of solid state surface wetting of tin (Sn) on aluminium (Al)

Under ultra high vacuum (UHV) conditions tin (Sn) forms a monoatomic wetting layer on aluminium (Al) surfaces if Sn-islands formed by a preceding deposition process are present. Previous experimental observations and Kinetic Monte Carlo (KMC) simulations suggest that wetting layer formation is governed by thermally activated surface diffusion and adsorption processes. This paper presents a systematic study of the wetting of the inner and outer interfaces of Al by Sn in sandwich systems consisting of a 400 nm Al-base layer, a 10 nm Sn interlayer and a 400 nm thick Al capping layer. The morphology and chemical composition of the sandwich systems is investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The wetting process is studied by scanning auger electron spectroscopy (AES) under UHV conditions. Depositing the Al-capping layer at different deposition rates allows for the assessment of the influence of the grain boundary density on the velocity of Sn-transport through the Al-capping layer. Studying the permeation speed of Sn through the capping layer at different temperatures shows that Sn penetrates the capping layer much more rapidly at elevated temperatures thus corroborating the involvement of thermally activated mechanisms in the transport process. # 2005 Elsevier B.V. All rights reserved.

Li mass transfer through a metallic Ag film covering on a carbon fiber anode

Ag was observed to be an effective additive to improve the anode performance of carbon for Li-ion secondary batteries. A graphitized carbon fiber entirely covered with an Ag film by vacuum deposition was examined by cyclic voltammetry (CV) in a 1:1 (v/v) mixed electrolyte solution of ethylene carbonate (EC) and dimethyl carbonate (DMC) containing 1 M LiClO 4. A large sharp peak due to the intercalation of Li into the carbon at about 0.15 V vs. Li/Li + was observed to be enhanced by the deposition of the Ag film. The peak height due to the deintercalation of Li was also enhanced compared with that in the absence of the film. This seems to suggest that Li can be intercalated into the carbon fiber through the Ag film. Using a bipolar cell constructed with a thin Ag foil which separates an electrolyte containing 1 M LiClO 4 in one compartment from water not containing Li ion in the counter compartment, a Li + concentration increase was confirmed in the water during polarization. The Li permeation speed was estimated using the diffusion coefficient by the potential step (time lag) method. The diffusion coefficients of Li in Ag ranged from 10 −6 to 10 −10 cm 2/s during Li extraction polarization. This experimental evidence supports the postulate that Li can move freely in the Ag film deposited on the surface of carbon.

Microvascular permeability of rat cerebral pia mater by using image computer analysis.

Microcirculation viviperception and fluorescent tracer techniques were used and digital image analysis applied for quantitative measurement of fluorescein sodium (FiNa) permeability in microvessels of the cerebral pia mater. The diffusion permeation equations of FiNa within the blood vessels and through the vessel walls into the perivascular tissue of normal rats and ischemic rats were established with two vessels as study object, thus the permeation speed equations under different ischemic conditions were deduced. Based on analysis of the results, we deduced the relation between the permeability and the intersection angle of two vessels. logarithm model showed a good fit of the experiment data. The permeation equation showed logarithmic distribution and then tended towards stability. FiNa could pass through microvessel walls with the highest speed in the one-hour ischemic rat group, and the permeation speed of FiNa in rats receiving reperfusion after twelve hours of ischemia was much faster than that in normal rats. the method can be useful for quantitative analysis of cerebral pia mater microvascular permeability