Surface barrier

In this paper, a thin stearic acid (SA) film was deposited onto the polyurethane (PU) coatings with different concentrations of stearic acid in the ethanol (1 wt.%, 2 wt.% and 3 wt.%) by centrifuged technique. Fourier transform infrared spectra (FTIR) and water contact angle (WCA) method were performed to characterize and evaluate the hydrophobic layer formed on the surface of the samples.

9p dianmotminh02 03-05-2024 3 2   Download

Ebook "Viral entry into host cells" for a virus to invade a host cell it needs to penetrate the physical barrier imposed by the plasma membrane. Viruses have evolved specialized surface proteins to meet this challenge. These proteins facilitate delivery of the viral genetic information into the host cell by either fusing the viral envelope with a host cell membrane or by forming membrane pores. Membrane fusion and pore formation critically depend on the engagement of host cell receptors and receptor choice is a key determinant of viral tropism.

213p cotieubac1004 15-03-2024 1 0   Download

Ebook "Liquid separations with membranes: An introduction to barrier interference (Second edition)" presents a self-consistent approach to separations of liquids with membranes, contrasting equilibrium separations with the rate-controlling effects of barrier interference on mass transfer. Unlike equilibrium separations, which depend on the thermodynamic condition of the fluid mixtures alone, barrier separations additionally are subject to specific interactions of the mixture components with the barrier.

138p lamquandat 28-12-2023 17 2   Download

The adsorption and mass transport of CO2 and CH4 in CHA zeolite were studied experimentally. First, large and well-defined CHA crystals with varying Si/Al ratios and morphologies ideal for adsorption studies were prepared. Then, adsorption isotherms were measured, and adsorption parameters were estimated from the data.

13p vironald 15-12-2022 4 2   Download

(CH3)3Al (TMA) has been employed for preparation of various thin films. It is also known to be hypergolic in the air. To unveil the hypergolic phenomenon, the mechanism for the reaction of TMA with O2 and/or H2O molecules is studied using computational quantum methods. Our results show that TMA reacts with water much faster than with O2, and water is not an efficient catalyst to help O2 reacting with TMA. The reactions of TMA with water and oxygen molecules can undergo subsequent ones in the air.

5p runordie3 27-06-2022 10 2   Download

This work reports the synthesis and properties of a new membrane based on polyvinyl chloride (PVC) grafting with polyacrylic acid (PAA) using argon (Ar) plasma. The membranes of PVC were synthesized by solutioncasting method, where PAA was deposited as an ultrathin film onto PVC using dielectric barrier discharge at atmospheric pressure with Ar gas. The surface characteristics and chemical composition of the modified membranes were analyzed by water contact angle, scanning electron microscopy, and Fourier transform infrared spectroscopy.

11p tudichquannguyet 29-11-2021 12 2   Download

Wool has disulphide bonds containing-hydrophobic external keratin layers, which act as a barrier for the modification through coating with hydrophilic materials. For that reason, in this work, to ensure a dense and homogenous conductive polymer coating onto the wool, the fabrics were subjected to the reduction process in the aqueous alkaline medium containing agents that can attack these disulphide bonds. Then, one of the polyaniline derivatives, poly(mtoluidine) (PMT), was coated onto wool by in situ polymerization of m-toluidine sulphate using ammonium persulfate (APS) as an oxidant.

16p tudichquannguyet 29-11-2021 9 1   Download

Hybrid paper sheets were prepared by applying a thin coating layer of cross-linked polydimethylsiloxane (PDMS) and inorganic particles onto Whatman Grade 1 filter paper substrates. Several coatings with different inorganic particle contents and types were applied onto the paper substrates to investigate the effect of the variation in the coating formulation on the (i) wetting, (ii) water barrier properties, (iii) air barrier properties, (iv) surface roughness, and (v) mechanical properties of the samples.

11p tudichquannguyet 29-11-2021 12 1   Download

The blood–brain barrier (BBB) is a control mechanism that limits the diffusion of many substances to the central nervous system (CNS). In this study, we designed an in-vitro 3-dimensional BBB system to obtain a fast and reliable model to mimic drug delivery characteristics of the CNS. A support membrane of polycaprolactone nanofiber surfaces was prepared using electrospinning. After confirming the fiber morphology and size, endothelial cells (HUVEC) and glial cells were cultured on either side of this membrane.

12p thiencuuchu 27-11-2021 13 1   Download

In this paper, we report the synthesis of rGO-TiO2 nanocomposite electrode and its effect on the performance of DSCs. The nanocomposite rGO-TiO2 photoelectrode was examined by means of current-voltage (I-V) characteristics of the solar cell when illuminated and in the dark. The results indicate that, unlike the Nb2O5 that forms an energy barrier at the surface and SrTiO3 that shifts the conduction band of the TiO2 in the negative direction, rGO doping allows more dye to be adsorbed due its large surface area thus improving the light harvesting efficiency (LHE).

13p kequaidan8 02-11-2020 10 2   Download

Ce (III) salt-activated CeO2 nanoparticles were incorporated into waterborne epoxy coating to improve the UV stabilisation of epoxied system. The surface morphology of the coatings was examined by using color spectrophotometer during the UV exposure test. The degradation of the epoxy coatings was observed by the change of barrier property determined by electrochemical impedance spectroscopy. The effect of activated nanoparticles on the impact resistance and adherence properties was also evaluated by impact strength test and cross-cut test.

10p angicungduoc5 13-06-2020 12 0   Download

Dedifferentiation of chondrocytes during cell expansion is one of the barriers in tissue construction for cartilage repair. The one-step process of cell expansion and maintenance of chondrogenic activity could be obtained using the G5 surface. Human chondrocyte sheets were successfully constructed with high chondrogenic activity.

11p vihamax2711 21-04-2020 25 3   Download

To investigate the H2 purification mechanism of V membranes, we studied the adsorption, dissociation, and diffusion properties of H in V, an attractive candidate for H2 separation materials. Our results revealed that the most stable site on the V (1 0 0) surface is the hollow site (HS) for both adsorbed H atoms and molecules. As the coverage range increases, the adsorption energy of H2 molecules first decreases and then increases, while that of H atoms remains unchanged.

10p trinhthamhodang1 14-11-2019 10 1   Download

Study of nuclear fuel cycle in Vietnam at the aspect of domestic production, the exploitation and process of uranium ore were began. These processes generated large amounts of radioactive waste overtiming. The naturally occurring radioactive material and technologically enhanced radioactive material (NORM/TENORM) waste, which would be large, needs to be managed and disposed reasonably by effective methods.

6p vineptune2711 04-11-2019 13 0   Download

The cuticular wax layer covers the aerial surface of plants and acts as a barrier between plants and the environment. The cuticle plays a key role in the protection of plants from pathogens, UV light, and transpiration. Variation in the wax quality and quantity is influenced by factors like the solvent used for extraction, species, ontogeny, and season.

15p caplock2711 21-02-2019 15 1   Download

The random distribution of TiO2 anatase nanoparticle in PPy matrix forms variety of carrier barriers on the surface and inside of the materials. As expectation, the charge exchange between oxygen and the PPy affects the carrier barrier’s regions and then modify the electrical properties of PPy.

10p thuyliebe 08-10-2018 50 0   Download

The exocyclic hydroxymethyl group of the
-D-1-amino-1-deoxyglucopyranose can rotate around the carbon-carbon bond. Potential energy surface for this rotation has been investigated using ab initio quantum chemical methods. Relevant stationary points, including for the first time rotational transition states have been characterized by full geometry optimization using basis sets 6-31G(d) and 6-31G(2d,lp). There is a total of six stationary points along the hydroxymethyl rotational surface, including three minima and three transition states were identified.

5p uocvong04 24-09-2015 41 2   Download

High up among the heather-clad hills which form the broad dividing barrier between England and Scotland, the little river Esk brawls and bickers over its stony bed through a wild land of barren braesides and brown peat mosses, forming altogether some of the gloomiest and most forbidding scenery in the whole expanse of northern Britain.

61p chonguoinoiay 23-02-2013 47 4   Download

Engineered barriers to isolate potentially harmful waste from humans and ecosystems have been used for over 35 years, and much has been written about them and their constituent components. However, few reports have provided an overall assessment of the performance of engineered barrier systems. The last broad assessment was conducted in 1995 (Rumer and Mitchell, 1995). Since that time, new materials and sensor technologies have been introduced and models to predict contaminant transport have improved.

134p mnemosyne75 02-02-2013 52 9   Download

Epithelial mucins are large complex cell surface and secreted glycoproteins produced by mucosal epithelial cells. Mucins are a major component of the interface between the external world and mucosal tissues, where they provide lubrication, hydration, and a biological and physical barrier to potential toxins, particles, and pathogens. Mucins provide many challenges to researchers due to their large size, complex biochemical nature, and the viscous gels that they form when secreted.

342p hotmoingay 04-01-2013 63 6   Download