Asian Journal of Chemical Sciences 2021-01-24T12:20:45+00:00 Asian Journal of Chemical Sciences Open Journal Systems <p style="text-align: justify;"><strong>Asian Journal of Chemical Sciences (ISSN: 2456-7795)</strong> aims to publish high quality papers (<a href="/index.php/AJOCS/general-guideline-for-authors">Click here for Types of paper</a>) in all aspects of Chemical Sciences. The journal also encourages the submission of useful reports of negative results. This is a quality controlled, OPEN peer reviewed, open access INTERNATIONAL journal.&nbsp;</p> Biosynthesis of Manganese Nanoparticles (MnNPs) from Brassica oleraceae (Cabbage leaves) and its Antibacterial Activity 2021-01-24T12:20:45+00:00 Sharmila Pradhan Amatya Santu Shrestha <p>Manganese nanoparticles are promising material for various applications such as water remediation, catalytic oxidation reactions, bio sensors, etc for their superior adsorbing, electrochemical, catalytic, magnetic, supercapactive like properties additionally, MnNPs possess significant medicinal values, hence, this research aims at synthesizing MnNPs biogenically, characterize them to explore antibacterial activity. Aqueous cabbage extract was allowed to react with precursor KMnO<sub>4</sub> solution to synthesize the MnNPs. Then, MnNPs were characterized by: visual observation, UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX). Finally, agarwell diffusion was employed to study antibacterial activity against human pathogenic bacteria: <em>staphylococcus aureus</em> ATCC 25923, <em>escherichia coli</em> ATCC 25922 and <em>salmonella typhi</em>. Turning of purple color solution to reddish brown after stirring was the indication of the formation of nanoparticles. The formation of MnNPs was confirmed by appearance of sharp peak at 420 nm, the assigned band for MnNPs and the energy absorption band at 6 keV in EDX spectrum. Diffraction pattern of MnNPs revealed polycrystalline type with crystallite size of 10.70 nm. FT-IR result showed the chief biomolecules: flavoniods, alkaloids, proteins present in the extract which acts as reducing agent. FE-SEM confirmed the formation of spherical and ellipsoidal shaped agglomerated MnNPs. Agarwell diffusion method showed zone of inhibition (ZOI) of range 10-13 mm with (gram + ve and gram –ve) bacteria. Cabbage mediated biosynthesis of MnNPs is found simple, ecofriendly. This work revealed the formation of agglomerated MnNPs confirmed from uv-vis spectra and FE-SEM. Chief biomolecules of the extract act as reducing agent and stabilizing agent. Results of agarwell diffusion method depicted MnNPs are promising material for its antibacterial properties.</p> 2021-01-09T00:00:00+00:00 ##submission.copyrightStatement## Design and Optimization of Lactic Acid Purification Process by Reactive Distillation with Isoamyl Alcohol 2021-01-24T12:20:42+00:00 Ying Wang Jumei Xu Zuoxiang Zeng Weilan Xue Zhijie Mao <p>The purpose of this study was to investigate a continuous process for the recovery of lactic acid from fermentation broth. A reactive distillation process to purify lactic acid by esterification with isoamyl alcohol and hydrolysis was designed and simulated by Aspen. Five columns were included in the process: esterification column, purification column, hydrolysis column, dehydration column and recovery column. Effects of process parameters (operating pressure, feed composition, feed position, number of reaction and separation stages, and reboiler duty) of the esterification column on the yield and purity of lactic ester was evaluated. Further evaluation was carried out to reveal the effects of process parameters of the hydrolysis column on the yield and purity of lactic acid. The total annual cost of the whole process was calculated. Simulation studies are carried out using Aspen Plus RADFRAC module. It was shown that under the optimized condition, the concentration of lactic acid can reach up to 82.4 wt%, and the organic acid impurities were less than 3 ppm. Compared with the traditional usage of methanol and butanol, the isoamyl alcohol process can save about 20% of the total annual cost at the same output of lactic acid. Results obtained in this work can be used for scale-up study of an industrial reactive distillation operation as an efficient and economical alternative to recover lactic acid from fermentation broth.</p> 2021-01-13T00:00:00+00:00 ##submission.copyrightStatement## Standards for the Research and Registration of Drinking Mineral and Mountain Spring Waters in Bulgaria 2021-01-24T12:20:44+00:00 Ignat Ignatov <p>In Bulgaria is observed a great variety of spring waters. They are mineral and mountain spring waters. According to their temperature they can be cold (up to 37 °С), warm (from 37°C to 60 °C) and hot (over 60 °C). This is temperature standard in Bulgaria, European Union.</p> <p>The mountain spring waters are cold with temperature up to 25 °С.</p> <p>In Bulgaria for drinking mineral and mountain spring waters are valid Ordinance No 9 / 2001, Official State Gazette, issue 30, and decree No. 178 / 23.07.2004. There are include:</p> <ol> <li>Physicochemical parameters;</li> <li>Microbiological data;</li> <li>Radiological study.</li> </ol> <p>The aim of the publication is to show the results regarding Ordinance No. 9 / 2001, Official State Gazette, issue 30, and decree No 178 / 23.07.2004 with research of Nedyalka Valcheva, Trakia University, Stara Zagora. There are also including author research.</p> <p>By their chemical composition they fall into three categories – low mineralized (up to 2 g/L), moderately mineralized (2 to 15 g/L) and highly mineralized (15&nbsp;- 30 g/L). According to their chemical composition the mineral waters are divided into sulphate, sulfide, hydrogen carbonate, chloride and carbonic containing waters.</p> 2021-01-13T00:00:00+00:00 ##submission.copyrightStatement## Neural Network Algorithm and Its Application in Supercritical Extraction Process 2021-01-24T12:20:44+00:00 Yu Qi Zhaolan Zheng <p>Artificial neural network (ANN)algorithms can be used for multi-parameter optimization and control by simulating the mechanisms of the human brain. Therefore, ANN is widely used in many fields such as signal processing, intelligent driving, face recognition, and optimization and control of chemical processes. As a green and efficient chemical separation process, supercritical extraction is especially suitable for the separation and purification of active ingredients in natural substances. Because there are many parameters that affect the separation efficiency of the process, the neural network algorithm can be used to quickly optimize the process parameters based on limited experimental data to determine the appropriate process conditions. In this work, the research progress of neural network algorithms and supercritical extraction are reviewed, and the application of neural network algorithms in supercritical extraction is discussed, aiming to provide references for researchers in related fields.</p> 2021-01-13T00:00:00+00:00 ##submission.copyrightStatement##