Current Advances in Chemistry and Biochemistry Vol. 10

Study of Decomposition of Chemical Warfare Agents Using Solid Decontamination Substances: An Approach to Assess Degradation Efficiency

2021-07-23T05:27:40+00:00

Decontamination of chemical warfare agents is an important measure leading to elimination or reduction of effects of those substances on persons. Solid decontamination (degradation) sorbents that decompose dangerous substances belong among modern decontamination substances. The aim of the study was to design a procedure for monitoring the degradation of chemical warfare agents using such sorbents. Degradation of soman, VX and sulphur mustard (chemical warfare agents) was monitored using FTIR spectrometry with the ATR technique. During the development and validation of the process, bonds were found in the substance molecule that decomposed and the positions of the absorbance bands that corresponded to the vibration of that bond. The evaluation of degradation efficiency procedure for sorbents on chemical warfare agents was designed based on this study. We present the result of the measurements graphically as the time dependence of the distributed CWA ratio, and the reaction time required to decompose 50 and 90% of the original amount of the substance.

Analytical Technique for Quantifying of Residual Acetamiprid and Imidacloprid in Wheat

2021-07-23T05:30:42+00:00

This chapter presents an analytical technique for residue monitoring of selected neonicotinoids in crops and presents a fast, easy, and space-saving technique of sample preparation followed by a 100% water mobile phase high-performance liquid chromatography (HPLC) coupled photo-diode array detector (PDA) for quantifying acetamiprid (ATP) and imidacloprid (ICP) in wheat. The analytes were extracted from the sample using a handheld ultrasonic homogenizer with water, and purified by MonoSpin® C18-CX, a centrifugal monolithic silica spin mini-column, and quantified within 20 min/sample. The accuracy, precision, and system suitability are well within the international method acceptance criteria. The procedure may be recommended an international harmonized analytical method for ATP and ICP residue monitoring in real wheat.

Study Investigation on Pyrolysis of Shivee Ovoo Coal from Mongolia

2021-07-23T05:32:47+00:00

The goal of our current research on Shivee Ovoo coal was to characterise the initial coal as well as its hard and liquid products after pyrolysis. To begin with, proximal and ultimate analyses of Shivee Ovoo coal have revealed that it is an oxidised brown coal of the lignite type with the B2 mark. The thermal degradation process of Shivee Ovoo coal was investigated using a thermogravimetric analyzer, which for the first time determined the thermal stability of the coal sample by determining thermal indices from the TG curve, such as T_5% -71.85°C; T_15% -321.18 °C; T_25% -490.64°C from the TG curve, which are the characteristics of lower thermal stability.

The yields of produced hard, liquid, and gas products were determined by pyrolysis of Shivee Ovoo coal at various heating temperatures. The most suitable heating temperature was 500°C, which resulted in a higher yield of condensed liquid product -6.28 percent (tar). The yield of all liquid (tar and pyrolysis water) and gas products (44%) indicates that the coal organic material underwent intense thermal decompositions with a greater degree of conversion. This confirms the previously stated and determined reduced thermal stability characteristics of Shivee-Ovoo coal, indicating that it is better suited for gasification and liquefaction. In addition, the yield of hard product (semi-coke) is 56.48 percent at 500^oC, which is an important product of the pyrolysis of Shivee Ovoo coal, and its proximate analysis results show that the volatile matter content decreased three times and the caloric value increased by 1000 kcal/kg when compared to the initial coal sample, indicating that it can be used as a smokeless fuel.

The chemical composition of pyrolysis tar in group organic compounds obtained by chemical analysis shows that the tar consists largely of neutral oils (81.9%), asphalteines (13.6%), free carbons (3.93%), and organic bases, organic acids, and phenolic compounds (less than 1.0%). The tar was also distilled at room temperature, yielding several fractions with varying boiling temperatures, including a yellow colored light fraction -15.93% (18-180°C), a brown colored middle fraction -15.44% (180 -330°C) and ablack colored heavy fraction -44.53% (330°C>).

In compared to the initial coal sample, scanning electron microscopes (SEM) images of generated activated carbon from pyrolyzed hard residue are different.The original coal sample's SEM picture shows compact solid pieces. In comparison to the initial coal sample, the SEM image of carbonised and activated coal sample shows a porosity structure with meso and macro pores. GC/MS analysis was used to investigate the solubility and chemical composition of neutral oil isolated from Shivee Ovoo coal pyrolysis tar, which yielded a total of 68 peaks (signals) for the soluble in hexane, 100 peaks for the soluble in toluene, and 100 peaks for the soluble in a mixed solvent of methylene chloride and methanol (1:1 volume ratio) fractions. Have been determined and identified 22 organic compounds soluble in hexane, 45 organic compounds soluble in toluene and 21 organic compounds soluble in a mixed solvent of methylene chloride and methanol fractions from each related totally registered peaks. On the basis of proximate and ultimate analysis have been confirmed that the Shivee Ovoo coal is a low-rank lignite coal of B2 mark and it is suitable for thermal processing including pyrolysis.

Chemical Potentials and Heat Production in the Course of Chemical Reactions

2021-07-23T05:38:33+00:00

A major goal of this study is to show how chemical and biochemical reactions occur. Since a large part of the energy transformations occurring via a reaction is always related to changes in potential differences, these phenomenological events are initially also in the foreground. In addition to these energetic changes, however, entropic changes are also important. Here, special emphasis is placed on distinguishing between exchanged and produced entropy. The conversion of energy in chemical reactions into heat energy occupies a special position compared to the conversions of e.g. mechanical or electrical energy in that no forces are involved in the former. Using transport reactions through channels, the process can be expressed in a simplified form. It is made clear that heat generation occurs via energetic transition states, and that it is this generated heat itself that leads to a significant increase in multiplicity. As a result, the reaction process is allowed to take place. The conclusion is that in chemical and biochemical reactions, instead of a force, multiplicity determines the direction and course of such processes.

Determining the Main Provisions of M. Faraday’s Work and Development of Innovative Technologies

2021-07-23T05:40:49+00:00

Ultrasonic Investigation of Ni(NO3)2.6H2O in Glycol + Water Solvent at 303.15 K

2021-07-23T05:47:48+00:00

Various acoustic parameters such as isentropic compressibility (\(\beta\)_s), intermolecular free length (L_f), apparent molar volume (\(\Phi\)_v), apparent molar compressibility (\(\Phi\)_k), molar compressibility (W), molar sound velocity (R), acoustic impedance (Z) of Ni(NO₃).6H₂O in 10%, 20% and 30% Glycol + Water at 303.15K have been determined from ultrasonic velocity (U), density (\(\rho\)) and relative viscosity (\(\eta\)_r) of the solution. These parameters are related with the molar concentration of the solution and reflect the distortion of the structure of the solvent i.e. Glycol + Water. As most of the solvent molecules are engaged in interaction with the solute, addition of more solute molecules to the solvent leads to the acceleration of the process of breaking of aggregates of solvent molecules. This process leads to the inhibition of propagation of sound waves due to large sized solute molecules acting as structure promoters.

Studies on Kinetics and Mechanism of Oxidation of GSH by cis-(diaqua)-bis-(ethylenediamine) Cobalt(III) Ion

2021-07-23T05:56:02+00:00

The kinetics of GSH oxidation to GSSG by cis-(diaqua)-bis-(ethylenediamine) cobalt(III) perchlorate was studied spectophotometrically under pseudo-first order condition using 10³[Co(III)] = 5 mol dm^-3, 2.5 \(\le\) 10²[GSH] \(\le\) 10.00 mol dm^-3, 3.5 \(\le\) pH \(\le\) 5.0, 318K \(\le\) T \(\le\) 333K at a fixed ionic strength I = 0.3 mol dm^-3 (NaClO₄). The disappearance of [Co (III)] at 500 nm with time showed first-order kinetic trend. The first order dependence on [GSH] and pH was observed. Temperature dependence of the second order rate constant k'₂ = k_obs/[GSH] were analyzed for the Co(III)-OH₂³⁺(k₁) and Co(III)-OH²⁺(k₂) reactivities. An outer-sphere complex formation between the Co(III) and GSH followed by one-electron transfer from GSH to Co(III) resulting the formation of Co(II) and GSH radical. The GSH radical under- goes fast dimerisation to GSSG. Activation parameters were calculated. These values favor the electron transfer reaction. Negative value of activation entropy corresponds to ordered transition state.

A Convenient Synthesis of Ethyl 1-Amino-3-(Substituted Phenyl)-2-Cyano-3H-Benzo[4,5]Thiazolo-[3,2-a] Pyridine-4-Carboxylate Derivatives and Some of Their Reactions: Scientific Explanation

2021-07-23T06:01:40+00:00

The presented compounds were createdby interaction of ethyl 2-(benzo[d]thazol-2-yl)acetate (3) with different arylidinemalononitrile derivatives (4a-c) in EtOH/TEA solution at room temperature. When 3 was treated with 2- (ethoxymethylene)-malononitrile (4f) under same reaction conditions, the ethyl iminothiazolopyridine-4-carboxylate (6) was obtained. Ethyl (amino(methoxy)methyl)-3-(substitutedphenyl)^-1-oxo^-1H-benzo[4,5]thiazole[3,2-a]pyridine-4- carboxylate (8a,b) was obtained on the basis of reaction of 3 with different cyanoacrylate derivatives (7a,b) in MeOH/TEA at room temperature, while the diethyl thiazolo[3,2-a]pyridine-4-carboxylate derivative (8c) was obtained under the same conditions of reaction. The amino-imino derivative (10) was also fully prepared and used to synthesis new pyrido[3,2- e][1,2,4]triaziolo[1,5-c]pyrimidine-5-carboxylate derivatives (12). All of the newly synthesised compounds' structures were confirmed using elemental analysis and spectroscopic data. The triazolo[1,5-c]pyrimidine-5-carboxylate derivatives (12a-c) were obtained when 10a was reacted with electrophilic reagents.

Saussurea lappa: Possible Relief for Migraine Patients

2021-07-23T06:07:44+00:00

Migraine headaches have become a very common disorder. Individual loss of productivity due to migraines has social and economic effects for society, and the actual treatment of migraines has not only medical, but serious economic and social implications as well. Since ancient times, care givers have used Saussurea lappa root for medicinal purposes because it contains different therapeutic advantages as a treatment for headaches. This study conducted a clinical trial to evaluate the relieving effects of Saussurea lappa on migraine patients. Blood samples were analyzed for determination of liver, kidney functions, and hematology parameters before and after treatment. Serotonin and its precursor tryptophan, magnesium, and calcium concentrations were also analyzed before and after treatment, because they play a role in migraine pathogenesis. The trial included 42 subjects divided into three groups: Group I (22 patients) received treatments of Saussurea lappa (1 g/500 ml/day); Group II (10 individuals), controls, received the same treatment with the same dose of Saussurea lappa; and Group III (10 patients), received antimigraine drugs (Amitriptyline 20 mg/day and Ibuprofen 400 mg/day). Results showed no significant changes in the concentrations of liver, kidney functions, or hematology parameters before or after treatment, except for calcium. High calcium levels are generally associated with headaches. The results showed that calcium concentration decreased in patients after treatment with Saussurea lappa, indicating that this root could have an effect in relieving headaches by lowering calcium levels. Since magnesium and serotonin, and its precursor tryptophan, markedly decrease during migraines, this study measured both. The results revealed increased magnesium and serotonin levels in the control group after two weeks of treatment and slightly decreased levels in patients after treatment with Saussurea lappa. This could be due to the fact that the duration of the treatment was not long enough to show real significance. This study found Saussurea lappa a safe and effective alternative therapeutic agent. Key words: Saussurea lappa, migraine, serotonin.