Abstract:In Mongolia, the sea buckthorn is a nontraditional fruit crop. It has been being planted since 2000 in the Botanical garden of Medicinal plants of Monos group, Mongolia. The purpose of this study was to determine how to change biological active compounds in the Sea-buckthorn berries that depending on harvesting season and to describe which harvesting period is efficient to use. In 2013-2014, fruit samples were prepared from our botanical garden such as: Chuiskaya, Maslichnaya, Vitaminnaya, Oranjivaya, Obilniya and Red cultivars on their chemical composition depended from harvesting season. The chemical compositions of fruit were investigated from 19th August to 20th January. We determined total oil, organic acid contents, β-carotenoid, ascorbic acid, total phenolic content and polysaccharide. The chemical contents were analyzed with the Folin-Ciocalteau assay, colorimetric assay, volume metric analysis method and spectrophotometric method. During the harvesting period, the chemical compositions of samples such as total oil content and polysaccharide content were increased and the contents of organic acid, beta carotenoid and ascorbic acid were decreased. From our study, we concluded that fruit biological active compounds depend from harvest time and it could be used to choose production of seabuckthorn product types.
In this study, removal efficiency of the Reactive blue 50 and adsorption mechanism on the zero valent iron were investigated. Reactive blue 50 which is used to wool and cashmere dyeing were selected due its non-biodegradable and metabolic stability. Zero valent iron particle has been synthesized by chemical method. A systematic characterization of zero valent iron was performed using X-ray diffractometer, scanning electron microscope and infrared spectrometer analysis. The optimal condition of adsorption was determined as initial reactive dye 50 concentration of 150 mg·L-1, zero valent iron mass of 0.2 g and solution pH of 6.0 at room temperature. At optimal condition, organic dye removal in a real wastewater sample from Tsombon Knit LLC was 99.5%.Mongolian Journal of Chemistry 15 (41), 2014, p21-26
Due to global electricity demand and ecological issues, eco-friendly and sustainable energy resource is becoming a hot topic in energy production and future economic development. On this point, efficient catalytic materials for electrochemical hydrogen evolution reaction (HER) are crucial in the research area. HER in alkaline medium has several advantages, including its lower vapor pressure, which helps produce pure hydrogen gas and provides better stability than acidic medium to metal contents by reducing catalyst’s corrosion. Primarily, carbon-based electrocatalytic materials such as hetero-atomic-doped carbon, transition metal-doped carbon, and co-doped carbon show off an effective HER performance. Because it has a large surface area, good chemical stability, it is inexpensive and earth-abundant.
Additionally, spent coffee grounds (SCG) contain a high amount of carbohydrates, melanoidins, and lipids that are given a possibility to be suitable carbon precursors for carbon catalyst synthesis. Moreover, SCG is becoming an environmental issue that produces many tons of waste worldwide each year due to the proliferation of global coffee consumption.
Here, we present cobalt nanoparticles embedded on nitrogen (N)-doped carbon catalyst, synthesized from SCG. Initially, SCG-derived nanoporous carbon was obtained by pyrolysis under high temperatures with KOH and urea. After that, carbon materials were functionalized with cobalt and nitrogen with the simple method.
Cobalt-embedded N-doped carbon catalyst has a high surface area and highly distributed nano-sized pores. Polarization measurement, Tafel plot, electrochemical impedance spectroscopy, chronopotentiometry, and cyclovoltammetry have tested the electrochemical performance. Even though the catalyst contained a negligible amount of cobalt (0.56 at. %), HER catalytic activity in alkaline medium has better resulted than non-functionalized carbon catalysts and was comparable to higher activity benchmark electrocatalysts such as RuO2 and 20% Pt/C. Also, experimental results demonstrate that excellent long-term stability for the alkaline hydrogen evolution. So, synergistic effects of cobalt nanoparticles content and N-doping on the SCG-derived carbon were indicated for efficient catalyst in the alkaline hydrogen evolution application.
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