Removal Of Surface Water Research Articles

Engineering a mussel-inspired hemostatic sealant with a strong tissue anchor as a first-aid tissue adhesive

During injury, achieving quick hemostasis, while maintaining adhesive performances on wet tissue and providing appropriate dynamical mechanical properties remain crucial clinical requests for the current tissue adhesives. Here, we design a double-crosslinking tissue adhesive with tunable degradation rate, adhesion strength, mechanical properties, and cell responses, using thiolated gelatin (Gel-SH) or gelatin and tannic acid (TA). We also investigate the role of different concentrations of gelatin (70 and 150 mg/ml), TA (7, 20, and 70 mg/ml), and crosslinkers (sodium periodate (11.3 and 16.8 mg/ml) and Fe3+ ions (1.7 and 4.8 mg/ml)) to provide a balance of covalent and noncovalent interactions leading to establish muscular tissue adhesive strength and superior hemostasis. Our findings reveal that the Gel-SH(gelatin)/TA adhesives have a range of swelling ability (300–700 %), compressive modulus (0.2–1.2 kPa), strength (0.1–0.8 kPa), and toughness (10–15 kJ/m3). In addition, Gel-SH/TA sample shows rapid self-healing ability and offers robust adhesiveness to wet cow skin and cardiac tissue (50–70 kPa) compared to others mainly owing to the improved cohesive strength originating from the range of chemical interaction within the adhesive network and abundant phenolic hydroxyl groups, surface water removal, and dynamic phenol-quinone balance at the tissue interfaces. Meanwhile, Gel-SH/TA adhesive also exhibits high hemocompatibility and hemostatic properties and appropriate in vitro biocompatibility. Notably, Gel-SH/TA adhesive could support attachment, viability and proliferation, of H9c2 cells. Overall, the multifunctional Gel-SH/TA adhesive hydrogel, owing to the range of molecular interactions opens a new opportunity for quick sealing hemostasis and wound healing and could potentially be harnessed for the development of clinically relevant tissue adhesives.

Temperature cycling effect on structural, optical and electrical properties of nanostructured sodium titanates

Sodium titanates represent a promising alternative for the construction of anodes for sodium-ion batteries. To study the electrical response of nanostructured sodium titanate samples under plausible temperature conditions, we evaluate the electrical impedance in the range of temperatures from −30 ∘C to 50 ∘C, and the effect of consecutive temperature cycling. Strong changes in electrical properties are observed during the first temperature cycle, followed by a stabilization in the consecutive cycles. This behavior is reversible when the sample is exposed to external conditions and room temperature for less than an hour. Probably a structural and surface water removal and a surface water reabsorption occur, affecting the charge carriers and with it the impedance. Structurally, no differences are detected before and after the cycles, nor when evaluating only the vacuum process. However, when the optical properties are evaluated we find non-reversible changes after the temperature cycles. The optical behavior after the temperature cycling becomes uniform, the same type of electronic defects become predominant and similar direct and indirect band gap values are obtained, regardless of the starting synthesis condition. These results have significant implications for potential technological applications of these materials.

РЕЗУЛЬТАТИ ЕКСПЕРИМЕНТІВ ІЗ ПІДБОРУ СКЛАДУ ДРЕНУЮЧОГО АСФАЛЬТОБЕТОНУ

Abstract Introduction. It is established that draining asphalt concrete is asphalt concrete of frame type with a very large number of voids between grains of crushed stone. Unlike crushed stone-mastic asphalt concrete in draining asphalt concrete pores are not filled with bituminous sand mortar. The main feature is its porosity, which leads to a slight decrease in its compressive strength at a temperature of 50 ° C, while the shear strength of the coating is very high. It is achieved due to the strength of the crushed stone frame (high internal friction and jamming of gravel grains) and the strength of the binder that binds the grains. Problem statement. The long-term impact on the asphalt road surface of the aquatic environment is a determinant of its durability. The issue of timely removal of surface water from the pavement is a must and is solved by giving the road surface a cross slope. As practice shows, this does not sufficiently protect the road surface from the adverse effects of water. High operational safety, improved road performance is achieved by removing accumulations of water stains from the surface that reduce the adhesion of the wheels to the road surface. These qualities can be improved by the introduction of draining asphalt concrete. Unfortunately, today in Ukraine there are no normative documents that would regulate the design, manufacture and execution of works on this technology, which makes it impossible to use it in practice and limits the optimization and development of the Ukrainian road sector in this direction. Purpose. Perform an analysis of existing experience in the design of draining asphalt concrete. Theoretical and experimental substantiation of the possibility of obtaining draining asphalt concrete with a structure of interconnected open pores, which allows you to quickly drain surface water. Materials and methods. Experimental research of draining asphalt concrete. Results. An analytical review of the experience of designing draining asphalt concrete. The stages of selection of the composition of the mixture were studied and analyzed, experimental studies on the selection of the grain composition and bitumen content in the draining asphalt concrete were carried out. Conclusions. Analysis of experimental studies on the peculiarities of the selection of the composition of draining asphalt concrete found that for the production of draining asphalt concrete using crushed stone of narrow fractions, because it has a special particle size distribution, in contrast to typical dense and crushed-mastic asphalt concrete. to crushed stone materials. The granulometric composition of the mineral part of asphalt concrete mixtures for draining asphalt concrete was selected and the optimal bitumen content for mixtures with different maximum grain sizes was established. Keywords: draining asphalt concrete, asphalt mixtures, grain composition, open voids, porousity.

WATER DISPOSAL SYSTEMS.AS ONE OF THE MAIN FACTORS INFLUENCING ROAD SURFACE DESTRUCTION

In our time, the problem of proper water disposal systems is acute. Surface water disposal systems.is an engineering system, the main purpose of which is the timely removal of melt and rainwater from the site. This system must work smoothly, because the accumulation of moisture entails many negative consequences for structures, soil, plants, and the like. The rainwater from the site should be as thought out and implemented as much as possible, taking into account the characteristics of each type of site. Special attention should be paid to water disposal systems from highways. Excess water on transport routes and streets poses a very serious hazard to drivers, passengers and pedestrians. In addition, it is the reason for disruptions in transport links.
 The installation of such a system in the streets should ensure the strength and stability of road structures, as well as create favorable conditions for the operational use of city roads because of the rapid and complete removal of surface water entering the street gutter of a stormwater drainage system. This system is an integral part of the general stormwater drainage system from the territory of the settlement. Therefore, its design is carried out in conjunction with the general drainage system from all over the city and is called stormwater sewer system (drains). That is, it is a sewer that consists of rainwater catchments, sand traps, rainwater gutters, pipes and catch basins. Its primary purpose is to dispose rain, melt water and surface water from internal drainage systems of buildings, too, after watering and washing the streets, receiving water release from drainage systems, from drainage of tram tracks and road drainage of shallow foundation, etc.
 Therefore, the design of drainage systems in the streets and on the roads is carried out in compliance with the norms and rules specified in DBN B.2.5-75 and DBN B 2.3-5: 2018.

Effect of Waterlogging on Element Concentrations, Growth and Yield of Wheat Varieties Under Farmer’s Sodic Field Conditions

Six promising waterlogging tolerant varieties of wheat along with two local varieties were evaluated on farmer’s sodic field (pH, 8.9) under drained and waterlogged conditions. Waterlogging was imposed for 12 days at 25 days after sowing. The redox potential (Eh) value of the soil was reduced to +90 mV at 12 days of waterlogging and after removal of surface water, 16 days were taken to reach above the anoxic limit (≤+350 mV) of soil. Waterlogging reduced significantly the shoot dry weight of all varieties, but to a lesser extent for the tolerant varieties, KRL3–4, Kharchia65 and KRL99. Waterlogging caused many fold increase in leaf Fe, Al, Na and Na/K ratio and decrease in leaf K, P and S as compared to drained treatment; these increases or decreases in elements were above or below their critical toxicity or deficiency levels. The waterlogging tolerance of varieties based on relative shoot dry weight showed a significant negative correlation with leaf Na and Na/K ratio. As compared to drained condition, the reduction in grain yield ranged from 11 to 27 % in waterlogged treatments. KRL3–4 and NW1014 showed less yield loss and had significantly higher grain yield than local variety under waterlogging. Thus, these two varieties can be recommended for planting in study area. These results suggest for selecting a right tolerant variety for increasing wheat yield in a specific soil and waterlogging environment.

Effect of abiotic stress on the gameophyte of Pyropia katadae var. hemiphylla (Bangiales, Rhodophyta)

Pyropia germplasm qualified for drift system culture is highly applicable in China. The current farmed species are tolerant to abiotic stresses, but vulnerable without air drying. Pyropia katadae var. hemiphylla inhabits mid-intertidal marshes and is a candidate for drift-system farming. Here, the performance of the gametophytes under varying environmental conditions was investigated. The thalli endured a short period (<5 days) at 22 °C, but was highly vulnerable to 28 °C. During 8 days of culture, the thalli grew at 8 − 17 °C, and growth was higher at 8 °C. Thalli with water loss ≤ 34 % recovered the optimum photochemical efficiency of PS II (F v/F m) by up to 100 %, and the net photosynthetic rate (P n) by over 70 %. This reduced to 50 % in the thalli with water loss ≥ 45 %. Removal of surface water and moderate water loss significantly increased photosynthesis recovery from 1 day of −20 °C freezing, and the maximum recovery (80 % P n and 97 % F v/F m) occurred in the thalli with water loss of ~30 %. During 10 days of culture, thalli maintained active photosynthesis and growth under salinity 22.6–36.6; however, those in salinity ≤ 7.8 or ≥50.6 lost fresh weight, while those in salinity ≤ 7.8 were characterized by reduced F v/F m, P n, and heavy thallus disruption. The above results indicated that P. katadae var. hemiphylla thalli adapted to low temperature, moderate desiccation, freezing, and salinity fluctuation. A farming strategy for this species is discussed.

Drying and property studies on protective coatings formed by spontaneous surface polymerization

Drying studies on a protective coating formed by spontaneous polymerization on aluminum are described. The polymer coating studied here was formed from styrene, n-phenyl maleimide (NPMI), bismaleimide (BMI), and 2-(methacryloyloxy) ethyl acetoacetate (MEA). The coating successfully changed into an adherent film through drying in the presence of a coalescing solvent. Drying at a high temperature (> 170°C) enhanced the performance of the coating in terms of corrosion resistance and adhesion. It was found that the drying process involved removal of surface water on the substrate followed by formation of a dense protective layer associated with thermal crosslinking of g -diketone functional groups in the coating. The reaction mechanism, glass transition temperature, adhesion strength to aluminum, and corrosion resistance of these coatings are reported. The resultant coatings show excellent adhesion strength in a torsional test and very good resistance under the ASTM B-117 accelerated salt fog test.

Correlation of TiO2 photocatalytic activity and diffuse reflectance spectra

Photocatalytic activity of TiO2 samples prepared by aqueous hydrolysis of TiCl4 and deposition with NH3 in gaseous acetone photocatalytic oxidation has been found dependent on calcination temperature. The activity reaches its maximum at calcination temperature 450°C and then decreases, all the samples being anatase. The photocatalytic activity of the samples in a series of different calcination temperatures correlates well with reflectance of the samples in the visible light region. The increase in calcination temperature from 320 to 500°C results in the growth of TiO2 crystallites, decrease in BET surface area, slight changes in lattice parameters, and removal of weak surface Bronsted acid centers that are speculated to be OH groups. TiO2 prepared by deposition with NaOH exhibits much higher photocatalytic activity. The only paramagnetic species detected in the TiO2 samples was NO that resulted from oxidation of lattice-captured NH3. No NO was detected in TiO2 prepared by deposition with NaOH. The concentration of NO increases steadily with calcination temperature as indicated by ESR spectra. The observed correlation of diffuse reflectance and photocatalytic activity was attributed to opposite effects of the increase of crystallinity and removal of surface water and hydroxyl groups.

Ecological recovery of vegetation at a former industrial sludge basin and its implications to phytoremediation.

Examination of a former industrial sludge basin containing organic pollutants showed that the basin had undergone substantial ecological recovery through natural forces following the removal of surface water in 1982. Conventional phases of ecological recovery (plant invasion and succession) have occurred, but the structure of the biodiverse plant community (51 species and 22 families) was different from that at a recovering non-polluted disturbed site. Three plant species (Bermuda grass, mulberry, and sunflower) believed to be early invaders of the basin still persist in large numbers indicating that these species are well suited to cope with normal environmental stresses at this area (i.e. seasonal drought and flood) as well as organic pollutants. There was an indication that early invaders of the site fostered disappearance of contaminants thereby creating more favorable conditions for a broader spectrum of plants to grow. Vegetation analyses of naturally vegetated hazardous waste sites hold promise as a screening device for identifying plant species and management practices worthy of further phytoremediation investigations.

Dehydration of Flocs by Freezing

A conceptual model was developed to explain the freeze/thaw conditioning process. This process transforms difficult-to-dewater residuals into a slurry of granular particles (zots) from which water readily drains. The conceptual model states that the most important effect of freezing and thawing is the removal of surface water from the colloidal particles comprising the floc. In addition to creating a drier floc, this dehydration may also explain the irreversibility of the process: dehydration causes the particles to come into close contact, at which point a new bond forms. Formation of a new bond explains the strength and granularity of the zots.

Atomic and molecular imaging at the single-cell level with TOF-SIMS.

A complete cold chain freeze-fracture methodology has been developed to test the feasibility of using time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging for the molecular analysis of frozen hydrated biological samples. Because the technique only samples the first few monolayers of a sample, water on the surface of a sample can be a major source of interference. This problem can be minimized by placing a cold trap (fracture knife and housing at -196 degrees C) near the fractured sample that is held at a warmer temperature (-97 to -113 degrees C). This results in removal of surface water and prevents condensation on the surface. Although this approach is effective, it has been found that sample warming needs to be carefully controlled due to the volatility of other matrix molecules and the morphological effects imparted onto the cell surface during drying. By utilizing the above handling technique, it has been possible to demonstrate for the first time that TOF-SIMS imaging technology can be used to obtain images of molecular species across a cell surface with a submicrometer ion probe beam. Images of small hydrocarbons and the deliberately added dopants DMSO and cocaine have been obtained with TOF-SIMS of the single-cell organism Paramecium.

Surface water management under varying drainage conditions for rice on an acid sulphate soil in the Mekong Delta, Vietnam

In the period 1990–1992, three field experiments were carried out to evaluate the effects of (repeated) removal of surface water under varying drainage conditions, with the aim of alleviating suspected Fe toxicity aggravated by H 2S together with Al toxicity. The experiments were carried out on a poorly drained, heavy textured, acid sulphate soil (typic Sulfaquept) of low permeability. The results of the experiments indicate that surface water management can alleviate nutritional disorders and increase yield. These effects are, however, overruled by the influence of the general drainage condition of the land. Evaluation of agronomic and soil chemical parameters indicates that in the Hoa An conditions a percolation rate of 0.8–1.0 mm day −1 appears to be optimal to prevent most adverse soil conditions. A set of practical soil- and water-management measures is presented which can be used to improve the yield under similar hydrological and soil conditions.

The interaction of mechanically generated turbulence and interfacial films with a liquid phase controlled gaslliquid transport process

The liquid phase rate-controlled transport of C0 2 across a gas/liquid interface into water was studied using a non-invasive laser-induced fluorescence (LIF) technique. Turbulence in the liquid layer was generated by a vertically-oscillating grid. The CO 2 /water interface was cleaned by removal of surface water with additive-free lens paper, or 100% rayon cloth followed by surface vacuuming with a glass Pasteur pipette. The liquid phase mass transfer coefficient k L was measured under conditions of varying turbulence intensity and scale for each surface cleaning procedure. Transport rates were also measured for an uncleaned surface and in the presence of a deliberately created organic monolayer. All of the results were used to test the surface renewal models of Fortescue and Pearson and Lamont and Scott. A model for wind-dominated gasiliquid transfer developed by Cohen was used to relate the present data to k L measurements for gas exchange in wind tunnels. This comparison indicates that wind tunnel results may be related to stirred-tank experiments using the turbulent dissipation rate Ԑ and a surface renewal model. DOI: 10.1111/j.1600-0889.1986.tb00256.x

Dewatering Dredged Sediment for Agriculture

ABSTRACT SAMPLES of the bed sediment from a fresh water lake in Central Illinois were applied to farmland. Hauled sediments were placed into production in 1981. Corn yields were greater than the surrounding soil. Hydraulically dredged sediments were dewatered using three subsurface drainage treatments. The major benefit of the subsurface drainage system is the removal of surface water through surface cracks to the filter material surrounding the drains. The design of the project assured that minimal water quality effects occurred in the public water supply lake.

Sources of Water Contributed to the Bay of Fundy by Surface Circulation

The returns from the 35,000 drift bottles launched in the Gulf of Maine area since 1919 have been analyzed to determine the annual cycle of surface drift. The source of surface flow into the Bay of Fundy expands from a minimum during January in the offing of the eastern side of the bay to a maximum in May which includes most of Georges Bank, the Gulf of Maine and the southwestern Scotian Shelf, then commencing in September gradually contracts toward the minimum.Secular variations in the removal of surface water from the Bay of Fundy, indicative of changes in the Maine eddy, were noted during 1957 and 1958.