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101.
《印度化学会志》2021,98(12):100229
The coal fly ashes contain high concentration of toxic metals. The sorption plays crucial part to retard the movement of contaminants through the liner. In the present investigation to examine the potential of fine-grained soil as liner material, obtained from bank of River Ganga, was assessed in terms of its adsorption capability. Batch adsorption of Pb(II) and Cr(VI) were performed. Maximum adsorption of Cr(VI) (65.76%) at pH 3 for adsorbate and adsorbent dose of 5 mg/L and 2 g/L and maximum adsorption of Pb(II) (96.84%) at pH 5 for adsorbate and adsorbent dose of 5 mg/L and 1.5 g/L, respectively, were observed. Adsorption of Pb(II) and Cr(VI) follow Freundlich isotherm equation. The soil column studies were performed at various bed heights (2, 3 and 5 cm) in down flow mode. The tracer studies were conducted using NaCl to estimate the hydrodynamic parameters and they were considered as input parameters for modelling of fate and transport of contaminants in soil using HYDRUS 1D software for assessing the potential use of soil as liner material in ash pond structures. 相似文献
102.
Muhammad Zahoor Manzoor Ahmed Sumaira Naz Musarrat Ayaz 《Natural product research》2015,29(12):1170-1172
Nature provides a variety of drugs and medicinal agents derived from plants. This study was conducted to determine antimicrobial, antioxidant and cytotoxic activities of extracts of Melia azedarach bark with methanol/water (9:1 v/v), chloroform, butanol, hexane, water and ethyl acetate. For the determination of the antimicrobial activities, the agar well diffusion method was employed. Cytotoxicity was studied by brine shrimp lethality assay; antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl. The chloroform extract was active against Enterobacter aerogenes and Proteus mirabilis, the ethyl acetate extract had highest antibacterial spectrum against Pseudomonas aeruginosa, the n-hexane extract had highest inhibition against E. aerogenes, the aqueous extract showed highest activities against P. mirabilis, the butanol fraction showed highest activities against E. aerogenes and the methanolic extract was highly active against P. mirabilis. 相似文献
103.
Uche Samuel Ndidi Ismaila Alhaji Umar Aminu Mohammed Cosmas Samuel Amos Oladiran Oladeru Rahinat Nimma Yakubu 《Natural product research》2015,29(12):1153-1156
The effect of aqueous extract of Acacia albida stem bark was investigated in Wistar albino rats infected with Trypanosoma evansi. The extract showed highest reduction in parasitemia at the dose of 600 mg/kg body weight (bw). A dose of 300 mg/kg bw improved packed cell volume the most by 14.35%. The group treated with 150 and 600 mg/kg bw of the extract showed significant decrease (P < 0.05) in alanine transaminase and aspartate transaminase levels which were lower than those of the group treated with diminazene aceturate. The group treated with 150 mg/kg bw of the extract showed the least urea, albumin and protein level and lowest relative organ weight. There was a significant difference (P < 0.05) in the levels of catalase and Thiobarbituric acid reactive substances in liver and kidney of the animals in the infected-untreated group and the extracts-treated groups. The results of this study show that the extracts of A. albida have antitrypanosomal activity against T. evansi infection. 相似文献
104.
Coupling nanotechnology with biocatalysis, a highly sensitive glucose biosensor for the study of electrochemical behaviors of glucose oxidase (GOx) was proposed by using monkshoodvine root–bark like carbon (MLC) as the platform for the biocatalytic deposition of AuNPs. The biosensor showed a linear range from 0.25 to 130 μM with a detection limit of 0.1 μM (S/N = 3) towards glucose and sensitivity of 3010 μA/mM. K value was calculated to be 67.4 μM. Furthermore, the proposed AuNPs/GOx–MLC modified pyrolytic graphite electrode (AuNPs/GOx–MLC/PGE) achieved direct electron transfer of GOx. Γ* was calculated to be 2.79 × 10?11 mol/cm2 and ks was 1.79 s?1. It also showed a remarkable electrocatalysis towards glucose. 相似文献
105.
C. Baiocchi E. Marengo M. A. Roggero D. Giacosa L. Vietto S. Toccori 《Chromatographia》1994,39(7-8):481-489
Summary Reversed-phase high performance liquid chromatography with diode array detection was used to analyze phenolic compounds contained in bark extracts of two different poplar clones known to have different resistance toDiscosporium populeum infection. Statistical treatments both monovariate and multivariate were applied to the results in order to identify regularities useful to discriminate the polar resistance and to check the importance of seasonal and cultivation site related factors. For the two clones examined phenolic compounds showed great discrimination ability not influenced by either sample collection period or cultivation site. 相似文献
106.
This study aimed to investigate the effect of ultrasonic power and temperature on the impurity removal rate during conventional and ultrasonic-assisted leaching of aphanitic graphite. The results showed that the ash removal rate increased gradually (∼50 %) with the increase in ultrasonic power and temperature but deteriorated at high power and temperature. The unreacted shrinkage core model was found to fit the experimental results better than other models. The Arrhenius equation was used to calculate the finger front factor and activation energy under different ultrasonic power conditions. The ultrasonic leaching process was significantly influenced by temperature, and the enhancement of the leaching reaction rate constant by ultrasound was mainly reflected in the increase of the pre-exponential factor A. Ultrasound treatment improved the efficiency of impurity mineral removal by destroying the inert layer formed on the graphite surface, promoting particle fragmentation, and generating oxidation radicals. The poor reactivity of hydrochloric acid with quartz and some silicate minerals is a bottleneck limiting the further improvement of impurity removal efficiency in ultrasound-assisted aphanitic graphite. Finally, the study suggests that introducing fluoride salts may be a promising method for deep impurity removal in the ultrasound-assisted hydrochloric acid leaching process of aphanitic graphite. 相似文献
107.
Viljem Vek Tja&#x;a &#x;midovnik Miha Humar Ida Poljan&#x;ek Primo Oven 《Molecules (Basel, Switzerland)》2023,28(1)
The main objective of our study was to investigate the possible differences in the chemical composition of extractives from the bark of silver fir (Abies alba) with respect to the location of the bark sample on the tree, viz. differences in extract composition between stem bark and branch bark samples. Extractives in the bark samples from branches, depending on the distance of the sample from the trunk, were also analysed, and the stem bark samples were analysed with respect to their inner and outer parts. The results of the chemical analysis of extractives were supported by information about their antifungal and antioxidant effects. After felling and sampling silver fir trees, the collected bark samples were ground and freeze-dried. Extraction of bark samples was followed by a system of accelerated extraction using only water as a solvent. The extracts were analysed chemically using gravimetry, spectrophotometry and chromatography. Free-radical-scavenging activity was measured using the DPPH method, and the antifungal effect towards three moulds and three wood-decaying fungi was investigated with antifungal assay using the agar well diffusion method. It was found that the moisture content in bark samples decreased intensively just after the bark samples were peeled off the stem. Detailed chromatographic analysis showed that the bark extracts contained 14 compounds, among which phenolic acids, flavonoids and lignans were found to be the characteristic ones. The content of hydrophilic extractives in the branch bark samples decreased with increasing distance of the sample location from the tree stem. The largest amounts of phenolic extractives were measured in stem bark, followed by branch bark sampled at the point at which the branch entered the tree. Analysis of the separated parts of the bark showed that the outer layers of stem bark contained larger amounts of phenolic extractives, as well catechin and epicatechin, compared to the inner layers. Concentrated extracts of branch bark showed the largest free-radical-scavenging activity among the investigated samples, while strong antifungal effects of the bark extract were not found. 相似文献
108.
M. Abdallah Hatem M. Altass B. A. AL Jahdaly M. M. Salem 《Green Chemistry Letters and Reviews》2018,11(3):189-196
The inhibiting impact of natural aqueous extracts of some plants such as curcumin, parsley and cassia bark extracts for the corrosion of carbon steel (C-steel) in 0.5 M H2SO4 solution was inspected utilizing some techniques such as galvanostatic and potentiodynamic anodic polarization and weight loss measurements. Outcomes indicated that the percentage inhibition efficiency increases with increasing the concentration of the extract due to its horizontal adsorption on the C-steel surface. The process of adsorption is followed by the Temkin isotherm. These natural extracts acted as pitting corrosion inhibitors by shifting the pitting potential to more noble values. The sequence of inhibition efficiency of the natural extracts decreases in the following order: cassia bark extract > parsley extract > curcumin extract. This arrangement is related to the molecular size of the major components of the three natural extracts used. 相似文献
109.
Ahmed El Nemr;Abdualah Elhebshi;Ibrahim Ashour;Mohamed S. El-Deab;Nehal A. Barghout;Nnabuk Okon Eddy;Safaa Ragab; 《中国化学会会志》2024,71(2):174-196
This work tested the ethanol extract of camphor tree Cinnamomum camphora bark (CTBEE) as a green corrosion inhibitor of low carbon steel (LCS) in 0.5 M H2SO4 with and without the synergistic effect of 4000 ppm NaCl or 800 ppm of KI. The corrosion protection of LCS was significantly increased in the presence of CTBEE-KI and CBWE-NaCl blends compared with CTBEE alone, according to data performed by electrochemical impedance spectroscopy (EIS) and electrochemical polarization (EP) analyses. The formation of a film by the blends blocks the LCS surface area, preventing corrosive gradients from reaching its surface. Inhibition efficiency (IE%) of 81% and 89% were obtained in the presence of 800 ppm CTBEE-4000 ppm NaCl and CTBEE-800 ppm KI, respectively, compared with IE of 65% in the presence of 800 ppm CTBEE only. A maximum IE% of 89% and 97% were reached after 72 h of immersion in the presence of CTBEE-NaCl and CTBEE-KI, respectively. Potentiodynamic experiments indicate that the blends act as mixed-type inhibitors. The inhibition efficiency of CTBEE, CTBEE-KI, and CTBEE-NaCl remained effectively high during the testing period of immersion time, which proved the excellent stability of CTBEE in the corrosive acidic media. 相似文献
110.
Vázquez G. González-Álvarez J. López-Suevos F. Freire S. Antorrena G. 《Journal of Thermal Analysis and Calorimetry》2002,70(1):19-28
Differential scanning calorimetry (DSC) was used to compare the thermal curing of two adhesives suitable for using in the
manufacture of exterior-grade plywood boards: a commercial phenol-formaldehyde (PF) resin, and a tannin-phenol-formaldehyde
(TPF) resin developed in our laboratory. The experimental curves were well simulated by means of the Model Free Kinetics isoconversional
method incorporated in the Mettler-Toledo STARe software package. The corresponding kinetic calculations predict that the TPF resin cures faster than the PF resin. This
finding implies the possibility that the TPF resin may allow the achievement of higher productivity by permitting the use
of shorter press times than with conventional PF resins.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献