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Anthropogenic activities along with other environmental perturbation influence the vulnerability level of that important water resource, disturbing in a short time, water quality. The aim of this work is to generate an approach to Toltén basin characterization with benthonic macroinvertebrates, physicochemical and bacterial components as indicators of variation in water quality close to human populations and the sectors furthest from them, selecting for this purpose two areas (up and downstream of the basin). We used an ANOSIM two-way analysis to relate abiotic and biotic data and for diversity and biotic index (ChBMWP) we analyzed the benthic macroinvertebrate composition. A principal component analysis for environmental variables strongly separated the analyzed zones by season as the first principal component, showing a clear increase in temperature and electrical conductivity values in spring season. Meantime the pH parameter was observed with interesting variation for longitudinal gradient with incremental values in upstream area. The biotic indexes applied to the samples between seasons reflexes a similar diversity between analyzed sites in upstream with no differences showing a low diversity of macroinvertebrates. However, a significant increase was detected during spring in downstream zone. On the other hand, <em>Pseudomonas </em>genus increase between the most representative microbiological genera in the basin. Our results reinforce the importance not only of frequent seasonal monitoring program but also the critical role of collecting data on total transect basin length to regulate the human activities associated to basin and to protect the water quality.</p> <p><img src="/public/site/images/carlos/1689.JPG"></p> Claudia Jimena Guerrero_Jimenez Claudia Lorena Rabert Alberto Sáez-Arteaga Nicol Loncomán Geraldine Torres Tomás Flores Francisco Llanquín-Rosas María Luisa Valenzuela Roberto Moreno Copyright (c) 2021 SChQ 2021-12-28 2021-12-28 66 4 5307 5311 SUPERPARAMAGNETIC COBALT NANOCOMPOSITES SYNTHESIZED BY SOLVOTHERMAL SYNTHESIS IN A SINGLE STEP <p>In this work we are reporting the synthesis and characterization of superparamagnetic cobalt nanocomposites obtained from the direct reduction of cobalt(II) salts on matrices of graphene (G) and carbon nanodisks/nanocones (Ndc) in the presence of L-serine under solvothermal conditions. The synthesized nanocomposites were characterized by X-ray powder diffraction techniques identifying in all cases the peaks associated to the matrix (G or Ndc) and three peaks at 2θ values of 44,2; 51,5; 75,8<strong>°</strong><strong>,</strong> which correspond to the Miller indices (111), (200), (220), characteristic of a face centred cubic Co<sup>0</sup> phase. The SEM images of cobalt nanocomposites show that the use of an matrix changes the size and distribution of the metallic agglomerates, being possible to observe a more homogenous dispersion of the cobalt agglomerates on the Ndc matrix surface. Cobalt nanocomposites have a superparamagnetic behaviour presenting <em>Hc</em> values of 14 and 60 Oe for NPs-Co<sup>0</sup>/G and NPs-Co<sup>0</sup>/Ndc respectively. The superparamagnetic property of the cobalt nanoparticles and unique properties of the matrix would generate a magnetic material with interesting properties to be studied. More research is needed to give it a potential application.</p> <p><img src="/public/site/images/carlos/1681.png"></p> Carolina Alicia Castillo Vicencio Paula Santana Copyright (c) 2021 SChQ 2021-12-28 2021-12-28 66 4 5312 5315 BRIEF STUDY ON THE DECOMPOSITION OF TEGDME SOLVENT IN THE PRESENCE OF LI2O2 AND H2O2 <p>In this work we studied the decomposition of the TEGDME (tetraethylene glycol dimethyl ether) solvent in conditions simulating the charge of a Li-O<sub>2</sub> cell in the presence and absence of peroxide of hydrogen and peroxide of lithium trough ESR studies.&nbsp; We detected the formation of radical species, although in low concentrations, originating from solvent decomposition reactions during the oxidation process, in the absence of peroxides. On the other hand, when introducing H<sub>2</sub>O<sub>2</sub> and H<sub>2</sub>O into the system, oxygen-centered radical species superoxide and hydroxyl were detected. In addition, in the presence of Li-O<sub>2</sub>, carbon-centered radical species were detected that clearly show the decomposition of the solvent.&nbsp; Finally, the results show that it is very important that the charging process of a Li-O<sub>2</sub> cell is carried out through direct oxidation via 2 e- to Li<sub>2</sub>O<sub>2</sub> to avoid formation of radical species that cause deterioration of the solvent.</p> <p><img src="/public/site/images/carlos/1847.JPG"></p> Paulina Márquez Mauricio Moncada-Basualto Caudio Olea-Azar Francisco Herrera Macarena García María Jesús Aguirre Copyright (c) 2021 SChQ 2021-12-28 2021-12-28 66 4 5316 5319 PREPARATION AND APPLICATION OF KOH IMPREGNATED SEPIOLITE AS A SOLID BASE CATALYST FOR BIODIESEL PRODUCTION USING MICROWAVE IRRADIATION <p>An active basic solid catalyst for biodiesel production was obtained via KOH impregnation onto sepiolite support followed by high temperature calcination. The transesterification of rapeseed oil over the resulting nanocomposite structure was investigated using a microwave reactor. Morphological and structural characterization of sepiolite and KOH impregnated sepiolite was carried out by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy analysis. Optimization of the operational parameters such as methanol to oil molar ratio, catalyst loading, reaction temperature and reaction time were examined. Reusability of the catalyst and the reactions utilizing waste cooking oil were also studied. Obtained results indicated that the basic heterogeneous catalysis diminishes the saponification during the transesterification reaction and that microwave heating was very effective at shortening the biodiesel production time. However, the reusability of the KOH impregnated sepiolite catalysts and their structural stability require further investigation</p> <p><img src="/public/site/images/carlos/1801.JPG"></p> M. Hamdi Karaoğlu Vladimir Zholobenko Sema Aslan Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5320 5323 UTILIZING CARBON NANOTUBES AS EFFICIENT NANOADSORBENT FOR PANTOPRAZOLE REMOVAL FROM AQUEOUS SAMPLES: KINETICS, ISOTHERM, AND THERMODYNAMIC STUDIES <p>In this work, carbon nanotubes (MWCNTs) were utilized as efficient adsorbents for pantoprazole (PP) removal. We used MWCNTs that were synthesized using the chemical vapor deposition process. The physical characteristics of MWCNTs were described by Brunauer-Emmett-Teller (BET) contact area, surface functional group analysis by the point of zero charge (pH<sub>PZC</sub>), Fourier transform infrared (FTIR) analysis, Scanning electron microscope (SEM), X-ray diffraction (XRD), and Transmission electron microscopy (TEM). The single-point BET surface area of the MWCNTs was found to be 98.7 m<sup>2</sup> g<sup>-1</sup>, with the median pores' diameter of 30.9 nm and an average pore(s) volume of 0.764 cm<sup>3</sup> g<sup>-1</sup>. Effective parameters on the PP removal including, pH, contact time and initial amount of adsorbents were optimized, revealing maximum PP removal at pH=6.0 after 25.0 min when 0.026 g MWCNTs. The pseudo second-order kinetic model for adsorption of PP on the surface of both adsorbents revealed the high value of correlation coefficient, indicating the high ability of the pseudo second-order model for representation of experimental results. Adsorption equilibrium studies indicated that the Freundlich isotherm efficiently represented MWCNTs adsorption data. The thermodynamic parameters (Gebbs free energy, enthalpy, and entropy) of adsorption process were calculated. Results had shown that adsorption of PP on the MWCNTs is feasible, spontaneous, and exothermic process in the temperature range of 25-76 °C.</p> <p><img src="/public/site/images/carlos/1809.JPG"></p> Neda Sadeghpour Mehdi Vadi Narges Bagheri Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5324 5331 INVESTIGATION OF “MCM-22”, “ZSM-12 & 35 COMPOSITE”, AND “ZEOLITE AL-MORDENITE & ZSM-39 COMPOSITE” CRYSTALS BY ANALYSIS OF CHARACTERIZATION TECHNIQUES <p>Zeolites are three-dimensional, microporous, crystalline solids with well-defined structures that contain aluminum, silicon, and oxygen in their form. Cations and water are located in the pores of zeolites. They have a framework structure, in which interconnected cavities are occupied by large metal cations (positively charged ions), and water molecules. The formation of specific zeolites can occur by more than one crystallization pathway. Control in the crystallization pathway can lead to the formation of different species. In this study, two new zeolite nanocomposites were synthesized using fixed raw materials including solvent, reagent (which acts as a template in the formation of zeolite morphology), silica source, and sodium hydroxide alkali. “MCM-22” mesoporous was first synthesized and then a new morphology of “MCM-22” was synthesized by changing the temperature, time, and amount of water. Also, two nanocomposites “ZSM-12 &amp; 35 Composite” and “Zeolite Al-mordenite &amp; ZSM-39 Composite” were synthesized with very different properties in terms of surface to volume ratio, acidity, specific surface area, ratio of Si to Al, and three-dimensional crystal structure. Various characterization techniques were used to provide information to better understand the structural properties of crystalline zeolites. They were then characterized, and analyzed using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier-Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray Spectroscopy (EDS), Mapping, and BET/BJH (Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH)) techniques. The results showed that the synthetic zeolites, despite having the same precursors, differed in terms of surface to volume ratio, acidity, specific surface area, Si/Al ratio, and three-dimensional crystal structure.</p> <p>&nbsp;</p> <p><img src="/public/site/images/carlos/1865.JPG"></p> Mina Kamani Masoumehalsadat Rahmati Samira Amiri Khoshkar Vandani Ghazaleh Chizari Fard Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5332 5338 THE COMPUTATIONAL INVESTIGATION OF SIXTEEN ANTIVIRAL DRUGS AGAINST MAIN PROTEASE (MPRO) AND SPIKE PROTEASE (SPRO) OF SARS-2-COV-19 <p>In this research, the fourteen commonly used antiviral drugs were investigated through the computational tools against CoV-19 or SARS-2, as well as two small bioactive molecules from the cannabis plant, Tetrahydrocannabinol (THC) and Cannabinol (CBN). Thus, these were selelcted for molecular docking against main protein (5r7y) and spike protein (6xs6) of coronavirus. It was illustrated that the binding energies of M<sup>pro</sup> for Pimodivir, Baloxavir Marboxil, Lopinavir, Baricitinib, Remdesivir, THC, Darunavir, Galidesivir, Nitazoxanide, CBN, Ritonavir, Penciclovir, Ribavirin, Favipiravir, Umifenovir, and Chloroquine were -8.6, -7.7, -7.6, -7.5, -7.3, -6.8, -6.6, -6.6, -6.6, -6.5, -6.5, -6.3, -6.2, -6.0, -5.7 and -5.4 kcal/mol,&nbsp;respectively, which could be supported for good binding molecules against micropathogens, where it was -9.8, -6.9, -6.9, -7.1, -7.1, -7.1, -7.5, -6.0, -6.2, -7.4, -5.8, -5.9, -5.7, -5.6 and 5.4, respectively, for S<sup>pro</sup>. Among these, Pimodivir is a best-bonded molecule with M<sup>pro</sup> and S<sup>pro</sup> in view of molecular docking score. Secondly, the ligand interaction was accounted for this protein against required corona virus protein consisting of weak H bonding, hydrophobic bond and Van dar Waal interaction. For justification of molecular docking, the molecular dynamics was calculated for top six scored drugs where the root mean square deviation(RMSD) and root mean square fluctuation (RMSF) were showed that the six drugs for both main protein and spike protein. &nbsp;Additionally, the chemical hardness and softness have calculated, and the lowest value of softness has found in sample 06 and 13 around 0.24. The HOMO-LUMO gap has calculated with a different value for all, but the lowest value has obtained for 01. Finally, the pharmacokinetics and Lipisinki rule were calculated, and all of these molecules had satisfied the Lipisinki rule. Finally, using the admetsar online data base, absorption, distribution, metabolism, excretion and toxicity have calculated.</p> <p>&nbsp;</p> <p><img src="/public/site/images/carlos/1798.JPG"></p> Ajoy Kumer Unesco Chakma Md. Tawhidul Islam Debashis Howlader Tomal Hossain Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5339 5351 INVESTIGATION OF HYDROCHEMICAL DYNAMICS OF GROUNDWATER IN COASTAL BLOCKS OF TIRUVALLUR DISTRICT, TAMILNADU, INDIA <p><em>This paper presents the behaviour of cation and anion in samples of water collected from the coastal blocks of Tiruvallur District, Tamilnadu, India. 13 physiochemical parameters are investigated on the uniformly collected groundwater samples. It is revealed that fifty percentage of groundwater samples surpassed water quality levels pertaining to drinking and irrigation. In this investigation, descriptive statistical analysis is performed to understand groundwater characteristics. The hydrochemical dynamics of groundwater are evaluated using graphical plots Piper, Wilcox, and Gibbs. Through the Piper plot, it is concluded that high concentrations of sodium would induce cation exchange between Ca<sup>2+</sup> and Mg<sup>2+</sup> from the soil. This may lead to the acceleration of air and water circulation through the soil in wet conditions. The inference of the Piper plot is supported by end result of Gibbs plot. Gibbs plot indicates evaporation dominance of anthropogenic activities, while Wilcox plot clearly indicates groundwater's suitability for irrigation purposes. Moreover, the cation concentration is seen to be high on the eastern portion of the chosen area. The level of groundwater treatment should be adequately determined for potable purposes and for agricultural purposes as the study concludes the intrusion of saline water, rock water interaction and irrigation flows.</em></p> <p>&nbsp;</p> <p><em><img src="/public/site/images/carlos/1914.jpg"></em></p> GEETHA SUBBIAH SUNIL J DHARMENDIRA KUMAR M Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5352 5357 EXFOLIATION OF NANOGRAPHENE FROM WASTE BATTERIES AND ITS APPLICATION IN METHYLENE BLUE DYE REMOVAL <p>In the process of recovering wealth from waste, graphene has been exfoliated electrochemically from the graphite rods used in waste batteries (AA and AAA). This exfoliated graphene is analyzed using Raman spectroscopy, TEM, and found to be a mesoporous nanoparticle with a BET surface area of 710.396 m<sup>2</sup>/g and a pore size of 14.81 Å. Highly toxic methylene blue(MB) dye is being chosen for adsorption using the as-prepared graphene by varying the graphene dosage, contact time, temperature, and MB dye concentration. From UV, XRD, and FTIR the adsorption of MB on graphene has been confirmed. The graphene’s adsorption at 30<sup>0</sup>C was 272 mg/g. The adsorption followed Temkin isotherm and the mechanism was pseudo-second-order. Thermodynamic relations show the adsorption process to be spontaneous and chemical in nature.</p> <p>&nbsp;</p> <p><img src="/public/site/images/carlos/1832.JPG"></p> Bogeshwaran K K. Sathish Kumar B. Karunanithi M. Srividhya G. Gowri Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5358 5364 A QUANTUM MECHANICS AND MOLECULAR MECHANICS STUDY OF THE EFFECTS OF DIFFERENT SOLVENTS AND TEMPERATURES ON THE CONNECTIONS OF METHOTREXATE DERIVATIVES ANTICANCER DRUG TO NANOTUBES CARRIERS <p>In this study, the interactions of two effective derivatives of the methotrexate anticancer drug with Single-wall carbon nanotubes (SWNTs) and Boron nitride nanotubes (BNNTs) in the gas phase were investigated using the DFT calculations. Through the DFT method, the effects of different solvents on the interaction of methotrexate derivatives with SWNTs and BNNTs within the Onsager self-consistent reaction field (SCRF) model, as well as the effects of temperature on the stability of interactions between compounds in various solvents were studied. Thermodynamic parameters, Frontier Molecular Orbitals (FMOs) and Total Density of States (DOS) of the title compounds were also studied using theoretical calculations. Molecular properties of the structures such as the ionization potential (I), electron affinity (A), chemical hardness (η), electronic chemical potential (μ) and electrophilicity (ω) were investigated as well. Also, the interaction of methotrexate derivatives with SWNTs and BNNTs was examined via Amber, Opls, Charmm and MM+ force fields through the molecular mechanic (MM) method. The calculations were carried out through the Monte Carlo simulation methods at different temperatures. The effects of gas phase and various solvent media with different dielectric constants (water, DMSO, methanol, ethanol, CH2Cl2 and DMF) on the interaction of methotrexate derivatives were investigated using the aforementioned force fields. The most significant finding is that with respect to both thermodynamic properties and conformer populations, the Monte Carlo and Molecular Mechanics-Quantum Mechanics results are in agreement.</p> <p>&nbsp;</p> <p><img src="/public/site/images/carlos/1868.JPG"></p> V. Khodadadi Neda Hasanzadeh H. Yahyaei A. Rayatzadeh Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5365 5379 GENERAL GROUP VI TRANSITION NANOSTRUCTURED METAL OXIDES AND THEIR INCLUSION INTO SOLID MATRICES BY A SOLUTION-SOLID APPROACH <p>A facile and general solution//solid-state (SSS) approach to the synthesis of nanostructured metal oxides Cr<sub>2</sub>O<sub>3</sub>, MoO<sub>3</sub> and WO<sub>3</sub> was investigated. They are made from solid-state pyrolysis of the metal- macromolecular precursors PS-co-4-PVP●MCl<sub>n</sub> and Chitosan●MCl<sub>n</sub> with M= Cr, Mo and W, which were easily prepared by direct reaction of the salts CrCl<sub>3</sub>, MoCl<sub>4</sub> and WCl<sub>4 &nbsp;&nbsp;</sub>with the respective polymer. The size and morphology of the products, the nanostructured oxides Cr<sub>2</sub>O<sub>3</sub>, MoO<sub>3</sub> and WO<sub>3</sub> depend on the polymer and on the coordination degree of the precursor<strong>. </strong>Cr<sub>2</sub>O<sub>3</sub> as well as WO<sub>3</sub>, prepared from this method were included in silica and Titania matrix using an also solution//solid-state approximation. The nanoparticles of Cr<sub>2</sub>O<sub>3 </sub>and WO<sub>3 </sub>are in general distributed with uniformity within the amorphous silica. A probable formation mechanism of the Cr<sub>2</sub>O<sub>3</sub>, MoO<sub>3</sub> and WO<sub>3 </sub>nanoparticles was proposed. <strong>&nbsp;</strong>The nanocomposites&nbsp; <strong>&nbsp;</strong>Cr<sub>2</sub>O<sub>3</sub>//SiO<sub>2</sub> and WO<sub>3</sub>//SiO<sub>2 </sub>could be useful materials in catalysis.</p> <p>&nbsp;</p> <p><img src="/public/site/images/carlos/1923.JPG"></p> Carlos Diaz Maria Luisa Valenzuela Valdes Lilia Zepeda Constanza Valenzuela Pablo Herrera Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5380 5386 DEVELOPMENT AND ASSESSMENT OF SPECTROSCOPY METHODOLOGIES AND CHEMOMETRICS STRATEGIES TO DETECT PHARMACEUTICALS BLEND ENDPOINT IN A PHARMACEUTICAL POWDER BLEND <p>Manufacturing pharmaceutical products is one of the most regulated industrial processes due to the importance of its effects on human health. These processes require many physical and chemical determinations through chromatographic techniques coupled with different detectors. However, the pharmaceutical industry is not considering the growth that spectroscopic techniques have had in these fields of application, especially to monitor the blending process.</p> <p>This study evaluates different sampling methods for pharmaceutical blending processes by near-infrared spectroscopy (NIRS) and Vis-NIR spectroscopy. The pharmaceutical mixture consisted of three active ingredients at different concentrations. Various qualitative and quantitative strategies were used to evaluate the endpoint of the blending process. The results revealed the feasibility of different spectral analyses to establish the homogeneity of the mixture, which may be especially useful for applications at the industrial level in routine analysis or as a first choice. HPLC confirmed the final blend.</p> <p><strong> <img src="/public/site/images/carlos/20001.JPG"></strong></p> Cesar Pino-Torres Rosario Castillo-Felices Rodolfo Mundaca-Uribe Paola Méndez-Herrera Mario Aranda-Bustos Carlos G Peña-Farfal Copyright (c) 2021 SChQ 2021-12-29 2021-12-29 66 4 5387 5397