Antioxidant and Antihemolytic Activities of Ethanolic Extract of Flowers,Leaves, and Stems of Hyssopus officinalis L. Var. angustifolius

In this study, antioxidant and antihemolytic activities of ethanolic extract of flowers, leaves, and stems of Hyssopus officinalis L. Var. angustifolius were investigated employing different in vitro assay systems. Extracts showed good antioxidant activity. IC₅₀ for 1,1-diphenyl-2-picryl hydrazyl radical-scavenging activity were 148.8 ± 4.31 μg mL^?1 for flowers, 79.9 ± 2.63 μg mL^?1 for stems, and 208.2 ± 6.45 μg mL^?1 for leaves. All extracts showed moderate iron (II) chelating ability. Extracts exhibited good antioxidant activity in the hemoglobin-induced linoleic acid model and also they were capable of scavenging hydrogen peroxide in a concentration dependent manner. Extracts showed good antihemolytic activity againts hydrogen peroxide-induced hemolysis (IC₅₀ were 48.51 ± 2.27 μg mL^?1 for flowers, 19.47 ± 0.73 μg mL^?1 for leaves, and 63.1 ± 2.65 μg mL^?1 for stems). The total amount of phenolic compounds in the extracts was determined as gallic acid equivalents and total flavonoid content was calculated as quercetin equivalents from a calibration curve.     

Removal of Trichloroethylene by Clay Modified with Cationic Surfactant in Aqueous Solutions: Equilibrium,Kinetic, and Thermodynamic Study

Trichloroethylene (TCE) is commonly found in ground water, and it may serve as a major source of many types of cancers such as kidney, liver, lymphatic glands, and spinal cord. In the present research, TCE uptake from aqueous media by montmorillonite (Mt) modified by tetradecyl trimethyl ammonium bromide (TTAB) surfactant was explored. Firstly, the characteristics of raw and modified montmorillonite (raw-Mt and TTAB-Mt) were analyzed by SEM, FTIR, XRD, and XRF instruments. Then, the sorption process was evaluated as a function of different factors such as surfactant loading rate, pH, ionic strength, contact time, sorbent dosage, TCE concentration, temperature, and regeneration agent. The maximum TCE sorption by the modified clay was obtained at surfactant loading rate of 120% cation exchange capacity of the clay. The maximum removal efficiency of TCE by the modified clay was 99.6% at pH 5 and 30 min contact time. The findings also exhibited that the isotherm and kinetic sorption followed the Freundlich and pseudo-second-order models, respectively. It can be concluded that TTAB-Mt, as a cheap, abundant, non-toxic, and environmental friendly adsorbent can be considered to remove TCE in aqueous phase.     

Preparation of highly stable bimetallic Ni–Cu catalyst for simultaneous production of hydrogen and fish-bone carbon nanofibers: Optimization,effect of catalyst preparation methods and deactivation

This paper presents the preparation of highly stable nano-porous Ni–Cu catalysts for simultaneous production of CO_x–free hydrogen and carbon nano-fibers. The main features of this work focuses on the optimization, methods of catalyst preparation and application of an experimental model for deactivation. The fresh catalysts and the deposited carbon were characterized by SEM, TEM, XRD and Raman spectroscopy. Whatever to be the preparation methods, performance tests showed that the presence of Cu as promoter in Ni–Cu–MgO catalysts, enhanced the catalytic activity, substantially at higher temperatures with the best result obtained for Ni–Cu–MgO catalyst prepared by one step sol- gel method, reaching a hydrogen concentration of 70 vol% (160.51 mol H₂/mol Ni-1 h) and a smaller value of I_D/I_G (less imperfection) for produced carbon nano-fibers at 670 °C. Detailed rate-based model for deactivation of catalyst was found to be dependent on the time, reaction temperature and partial pressure of methane and indicated that the reaction of deactivation could be modeled by a simple hyperbolic model.