•Zn-Al- layered double hydroxides were successfully doped with phosphate ions.•Phosphate loaded nanocontainers showed better inhibition effect than nitrate one and formed passive film on steel ...surface.•Silane film including Zn-Al-PO43− nanocontainer significantly reduced cathodic delamination of epoxy coating on steel.•The improvement of self-healing ability of the coatings loaded with Zn-Al-PO43− was much higher than Zn-Al-NO3−.
This study aims at synthesis and characterization of Zn-Al-PO43− and Zn-Al-NO3− layered double hydroxides (LDHs) through employing FE-SEM, EDS and X-ray photoelectron spectroscopy (XPS) analyses. The smart release ability of the inhibitive spices from LDHs were checked by EIS, polarization and surface analysis tests in 3.5wt.% NaCl solution. A two-layer coating system consisting of silane primer filled with LDHs and epoxy-polyamide top coat were applied on steel and then the active inhibition capability of the coatings was investigated. The addition of Zn-Al-PO43− LDH to the silane coating provides efficient inhibition behavior by releasing PO43− anions through ion exchange process.
Surface modification of graphene oxide (GO) has been performed by grafting of polyisocyanate (PI) resin. Results obtained from X-ray photo electron spectroscopy, thermal gravimetric analysis and ...X-ray diffraction analysis revealed that the PI resin chains were successfully attached onto the surface of GO nanosheets through covalent bonding with hydroxyl and carboxylic groups leading to amides and carbamate esters bonds formation. Subsequently, the PI functionalized GO sheets were incorporated into the polyurethane (PU) matrix. The X-ray diffraction analysis showed that surface modification of GO nanosheets with PI enhanced the level of exfoliation of PI–GO in the PU matrix. Scanning electron microscope analysis showed the enhanced interaction between GO and PU matrix after functionalization by PI resin. The electrochemical impedance spectroscopy and salt spray tests were performed to reveal the effects of addition of 0.1wt.% GO and PI–GO nanosheets on the corrosion protection properties of the PU coating. Also, the adhesion loss of the coatings was obtained by pull-off adhesion test after 30days immersion in 3.5wt.% NaCl solution. It was found that incorporation of 0.1wt.% surface modified GO nanosheets into the PU matrix resulted in significant improvement of the coating corrosion protection properties and ionic resistance.
Supplementing palmitic acid (C16 : 0) in combination with modifying the dietary n-6:n-3 fatty acid (FA) ratio may benefit energy metabolism and milk responses of dairy cows. Twelve Holstein cows (70 ...(sd 11) days in milk) were used in a replicated 4 × 4 Latin square and allocated to four low-fibre diets (18·5 % forage neutral-detergent fibre) supplemented with no FA (CON), or 2·4 % C16 : 0-enriched supplement (PAL), 2·4 % mixture (2:1) of C16 : 0 and n-6 FA (PW6), and mixture (2:1) of C16 : 0 and n-3 FA (PW3). The dietary ratio of n-6:n-3 was increased with PW6 (10:1) and decreased with PW3 (2·8:1), whereas PAL alone made no change in the ratio (about 7:1). Compared with CON, all FA-supplemented treatments increased milk yield. However, feed and energy intakes were higher in PAL than PW3 or PW6, resulting in greater feed efficiency for PW3 and PW6 than PAL. Dietary FA supplements decreased milk protein concentration but tended to increase protein yield. Compared with CON and FA mixtures, PAL increased milk fat content and tended to increase milk SFA and atherosclerotic index. The concentration of milk n-3 FA was similar between CON and PW3. Feeding PAL increased milk energy output and decreased energy partitioning towards body reserves (−4·2 %), while this measure was positive for other treatments. Blood TAG and NEFA concentrations, but not β-hydroxybutyrate, were increased by FA-supplemented treatments. Feeding C16 : 0 combined with either n-6 or n-3 FA enhanced feed efficiency, alleviated the negative impacts on body energy reserves, but lowering the dietary n-6:n-3 ratio improved the FA profile of milk.
An organic/inorganic hybrid corrosion inhibitive pigment based on zinc acetate/benzotriazole was synthesized. The chemical composition of the pigment was investigated by X-ray photoelectron ...spectroscopy and Fourier transform infrared spectroscopy. In addition, the morphology of the pigment was studied by scanning electron microscopy. The pigment solubility in 3.5 wt.% NaCl solution was characterized by UV–Visible, total carbon content and inductively coupled plasma-optical emission spectrometer analyses. The corrosion inhibition properties of the zinc acetate/benzotriazole was compared with conventional zinc phosphate pigment in 3.5 wt.% NaCl solution containing pigments extracts on mild steel samples by polarization test and electrochemical impedance spectroscopy. X-ray photoelectron spectroscopy and scanning electron microscopy characterizations were performed on the steel samples exposed to the extracts to investigate the surface chemistry and morphology of the pigment, respectively. Also, the effects of addition of zinc acetate/benzotriazole and zinc phosphate pigments on the corrosion protection performance of the epoxy coating were studied. Results obtained from X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses confirmed that a complex of Zn-benzotriazole was successfully synthesized. The zinc acetate/benzotriazole pigment showed good solubility in NaCl solution and released inhibitive species including benzotriazole and Zn2+ cations. Zinc acetate/benzotriazole pigment showed good inhibitive properties and reduced dissolution rate of steel through forming Fe-benzotriazole and Zn-benzotriazole complexes, and Zn(OH)2 on the cathodic sites. Also, zinc acetate/benzotriazole enhanced the corrosion protection performance of the epoxy coating and reduced cathodic delamination rate of the coating more than zinc phosphate pigment.
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•A hybrid inhibitive pigment based on zinc acetate/benzotriazole was synthesized.•The chemical composition and morphology of the pigment was investigated.•Zinc acetate/benzotriazole pigment showed good inhibitive properties.•Zinc acetate/benzotriazole enhanced the corrosion resistance of the epoxy coating.
•Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method.•Corrosion inhibition activity of pigments compare with zinc phosphate (ZP).•LZP showed superior corrosion inhibition ...effect in EIS measurements.•Evaluation of adhesion strength and dispersion stability.
Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP.
The objective of this experiment was to evaluate the effects of starter supplementation with fat sources differing in their fatty acid (FA) profile on performance of dairy calves during cold season. ...Sixty Holstein calves (3 d of age; 39.7 ± 3.8 kg of body weight) were randomly assigned to 1 of 5 starter diets supplemented with (1) no fat or oil source (control), (2) 3% palm fat (PLF), (3) 3% soybean oil (SBO), (4) 3% tallow (TAL), and (5) a 3.2% mixture (MIX) of PLF, SBO, and fish oil. The fat supplements were substituted for corn in the basal starter diet. Both the control and fat-supplemented diets contained similar amounts of dietary crude protein (19.4%), but the latter had a slightly higher quantity of calculated metabolizable energy (3.17 vs. 3.07 Mcal/kg) than did the former. Calves were reared outdoor in individual pens during the cold of winter with a mean ambient temperature of 5.0°C during the study period. Whole milk was offered twice daily from d 3 to 45 and once from d 46 to 49. The animals were weaned on d 50 and monitored in their individual pens until d 70. Supplementation with SBO and MIX increased both the dietary concentration and ratio of essential FA (n-6 and n-3), whereas supplementation with TAL and PLF made no change in the essential FA profile. Starter intake and average daily gain were not affected by PLF and TAL supplements, but were reduced as a result of feeding MIX. Feeding supplemental SBO did not affect starter intake, but tended to improve average daily gain and final body weight. Fat sources had no effects on body skeletal measurements, fecal score, digestibility, ruminal pH, ammonia, and total volatile FA concentrations; however, feeding MIX increased rumen molar proportion of propionate. No differences were observed in blood metabolites across the treatments during the preweaning period. Plasma concentrations of triacylglycerol and cholesterol increased when fat sources were supplemented and glucose concentration increased when SBO was supplemented during the postweaning period. Overall, addition of 3% PLF or TAL to the diet of young calves failed to improve growth performance. Although addition of SBO and MIX increased the dietary essential FA concentration, calf performance was only improved when SBO was supplemented.
Recent studies demonstrated a high antioxidant capacity for pomegranate components due to their rich bioactive compounds, such as conjugated fatty acids and phenolics. The objective of the present ...study was, therefore, to assess whether pomegranate seed or pomegranate seed pulp (peel + seed) supplementation could be effective to improve antioxidant status, and hence metabolic profile and performance in periparturient dairy cows. After a 1-wk pretreatment period, Holstein cows (primiparous n = 12, multiparous n = 18) were assigned to 3 dietary treatments from 25 d before expected calving through 25 d postcalving. The dietary treatments included (1) control (CON); (2) diet supplemented with pomegranate seeds (PS; 400 g/cow per day); and (3) diet supplemented with pomegranate seed pulp (PSP; 400 g of seeds/cow per day + 1200 g of peels/cow per day). Compared with CON, supplementation with either PS or PSP had no effects on dry matter intake, rumen fermentation, and plasma concentrations of cholesterol, total protein, globulin, and aspartate amino transferase, but enhanced plasma total antioxidant activity, and lowered triacylglycerol, free fatty acids (FFA), and β-hydroxybutyrate at both pre- and postpartum periods. Plasma concentration of glucose, albumin, malondialdehyde (MDA) and blood superoxide dismutase (SOD) activity were not affected by dietary treatments at prepartum, whereas SOD activity increased and glucose, albumin, MDA, and FFA-to-albumin ratio decreased by feeding both by-products at postpartum period. In contrast to PS, supplementing PSP resulted in a greater decrease in plasma glucose and triacylglycerol concentration and higher increase in SOD activity. Energy- and fat-corrected milk yields were higher in cows fed PSP diet compared with those fed CON or PS diets, but content of milk fat, protein, and lactose were similar across the dietary treatments. These findings indicated that dietary pomegranate by-products supplementation, in particular PSP, could improve antioxidant status, which was associated with a decline in lipid oxidation (FFA and β-hydroxybutyrate) and peroxidation (MDA) and an enhancement in glucose utilization as well as fat-corrected milk yield.
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•GO nanosheets were modified with polyisocyanate (PI).•PI grafting on the GO increased its interlayer distance.•PI–GO/Polyurethane nanocomposites were prepared.•PI enhanced the ...dispersion/exfoliation of GO in the polyurethane resin.•PI/GO improved the mechanical properties of the polyurethane coating.
Polyisocyanate-functionalized graphene oxide (PI–GO) was synthesized at various functionalization reaction times of 24, 48 and 72h. The modified GO sheets were characterized by X-ray photo electron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermal gravimetric analysis, and atomic force microscope. It was shown that PI polymer has been successfully grafted on the surface of GO through covalent bonding between the hydroxyl and carboxyl groups of the GO with isocyanate groups of PI. The results obtained from X-ray diffraction analysis also revealed that the interlayer distance of the GO increased after modification. The highest amount of PI grafted on the GO surface was obtained after a 72h modification reaction. The modified and unmodified GO sheets were then incorporated into a polyurethane (PU) matrix to prepare PU/PI–GO and PU/GO composites. It was found that addition of only 0.1wt% PI–GO significantly increased the Young’s modulus, work of fracture, stress at break, and elongation at break of PU/PI–GO composite as compared to the neat PU sample and the PU/GO composite.
In this paper the peristaltic flow of nanofluids in drug delivery systems is studied analytically and numerically. The flow is considered under low Reynolds number with long wavelength approximation. ...Least squares method (LSM), Galerkin method (GM) and fourth-order Runge–Kutta numerical method (NUM) are used to solve the present problem. The results are presented to study temperature, velocity, nanoparticle fraction field and pressure gradient. The effects of some physical parameters such as Brownian motion parameter, thermophoresis parameter, thermal Grashof number and basic-density Grashof number on non-dimensional velocity, nanoparticle fraction distribution and temperature profiles are considered. Early results implied that increasing thermal Grashof number reduces the axial velocity profile, while increasing species Grashof number has conversed treatment.
•The peristaltic flow of nanofluids in drug delivery systems is studied.•The temperature distribution is increased by increasing the Brownian motion parameter.•The magnitude of the axial velocity is decreased with increasing the thermal Grashof number.
In this paper, ZnAl layered double hydroxide particles surface were decorated with SiO2 nanoparticles to investigate the influence of SiO2 nanoparticles presence on molybdate anion loading and ...release behavior as a corrosion inhibitor. For this purpose, we have synthesis a carbonate-based layered double hydroxide (LDH). Nano SiO2 particles were used to decorate the surface of carbonate-based LDH nano-plates. Molybdate was then intercalated into LDH interlayer space through an ion exchange process. Characterization of the synthesized nano-plates was done by XRD, FTIR, FE-SEM, and ICP tests. The decorated nano-plates were employed in silane coating to investigate and compare their corrosion protective properties using EIS and polarization tests. The results illustrated that the protective functioning enhanced after SiO2 decoration. Moreover, molybdate loaded in SiO2 decorated LDH had a better protective functioning, and provided more extended protection due to its higher loading, and controlled release of molybdate anions.
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•A carbonate-based layered double hydroxide (LDH) was synthesized.•Nano SiO2 particles were decorated on the LDH nano-plates (LDH@SiO2).•Molybdate was intercalated into LDH galleries through an ion exchange process.•LDH@SiO2 had a better protection than neat LDH due to higher molybdate loading.
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