Present work describes the synthesis of coumarin Mannich bases 4-7 by the application of Mannich reaction on 7-hydroxy-4-methyl coumarin 3 using conventional as well as microwave technology to compare the feasibility, reaction time and yield of the product. For this, 7-hydroxy-4-methyl coumarin 3 was prepared using Pechmann condensation reaction and Mannich bases (4-7) were synthesized by the reaction of 3 with various secondary amines. A comparison between the conventional and microwave methods demonstrated that the microwave assisted synthesis was more convenient and simpler method with better yield and lesser formation of by-products of compounds 4-7 as compared to conventional method of synthesis.
Luminescence spectral changes of solid EuCl3·6H2O in the presence of N, N–dimethylformamide (DMF) and methanol (MeOH) vapors were studied. Difference spectra and 2 dimensional correlation spectra obtained from luminescence spectra were used to determine base components of the luminescence bands, and band intensities were obtained using deconvolution procedure with curve fitting technique. Spectral changes were explained using relative intensities of bands. Luminescence spectra under DMF and MeOH vapor solvents showed considerable spectral changes in 5D0→7F1 region which were not observed in the corresponding liquid solutions. Significant spectral changes were observed on deliquescence under MeOH vapor, but small under DMF vapor. The spectrum in solid state under MeOH vapor became closer in feature to that in MeOH solution after the deliquescence, but that under DMF vapor did not to that in DMF solution. The difference was explained in terms of Cl- behavior. The effect of phase change caused by deliquescence was small.
The corrosion resistance behavior of inhibitor enriched organically-modified silane (Ormosil) thin films on 2024-T3 aluminum alloy substrates were investigated using accelerated salt spray analysis techniques such as ASTM B117. The specified literature composition of the sol-gel mixture was used due to its appropriate inorganic/organic ratio producing a highly adherent film to the underlying AA substrate to be used on Al 2024 alloys on aircrafts. Inhibitors used were synthesized via methods described in author’s previous studies. Several inhibitors, that were initially tested for corrosion inhibition of Aluminum 2024 alloy in aqueous solutions, revealed success when incorporated into the sol-gel coating including chromium borate, chromium oxyhydroxide and chromium octanoate. Certain concentrations of chromium acetate and chromium hydroxide also revealed positive results. With the addition of these inhibitors, corrosion resistance properties of the sol-gel coating increased not only against uniform corrosion demonstrated by the unscribed samples but also against crevice corrosion, that is filiform corrosion, and against pitting corrosion demonstrated by the scribed samples.
Aims: To identify the specific routes of arsenic contamination in the soil at coal fired industrial area by using Chemical Mass Balance (CMB8).
Study Design: The prime objectives of the study are:
1. Measuring the chemical composition of soil at different distance from the industrial site.
2. Analyzing the relation between arsenic concentration with distance.
3. Carryout apportionment of arsenic in soil by using Chemical Mass Balance (CMB).
Place and Duration of Study: The study has been conducted in North India industrial area from 2010 to 2011 for one hydrological year.
Methodology: As per the objectives of the study we have collected the soil by using space time frame work. We have classified entire site as near site (~1km) (receptor 1), near far site (~ 2-2.5km) (receptor 2) and far site (~ 2.5-5km) (receptor 3). The soil has been collected vertically at 15cm and 45 cm depth from surface at all receptors. In case of sampling at paved road (S-5) we collect 1kg of road soil by digging road, we have collected 1kg soil sample from municipal waste dumping source (S-3) and civil construction source (S-4). As far as vehicle exhaust source (S-2) chemical profile concern black smoky depositions in automobile exhaust silencers of diesel fuel based heavy duty trucks and petrol based cars have been collected and scum were mixed together for development of chemical profile.
Results: The results shown that the clay particles size (<2 µm) ranged from 2.6- 18.4 g/kg with a mean value of 12.4 g/kg at source sites and at receptor site the ranges is 19.5-67.4 g/kg with the mean value of 44.8 g/kg. The PH values are generally sub alkaline. The content of TOC at source sites in the soil ranged between3.8-64.8 g/kg with higher mean value at S-4, and at the same time at the receptor site it has the range of 6.3-21.8 g/kg with higher mean value at R-3.
Conclusion: It has been found that the point and area sources have sown the dominating contribution of arsenic contamination in soil.
The aim of this paper is to assess the full potentialities of spectroscopy techniques in the art work investigation and to explore the capabilities in the determination of the chemical and mineralogical composition of ancient pottery excavated from Kottapalayam village, Karur district, Tamilnadu. Spectroscopic techniques such as FT-IR. X-ray diffraction, thermal gravimetric analysis and scanning electron microcopy (SEM) coupled with energy dispersive X-ray spectrometer (EDX) are utilized in this work. The constituent of the minerals is identified with help of FTIR and compared with XRD. The combined mineralogical results showed that the pottery samples from Kottapalayam were fired in between 800ºC-850ºC. The microstructure and elemental composition of the pottery sample were evaluated from their microphotograph by Scanning Electron Microscope (SEM) along with energy dispersive X-ray spectrometer (EDX). The results are discussed and the conclusion is drawn.
Aim: To develop and optimize two spectrophotometric methods for the determination of raloxifene hydrochloride in pure and dosage forms; using Tetracyanoquinodimethane (TCNQ) and Folin Ciocalteu’s reagents.
Study Design: Charge transfer reaction and chromogen formation.
Place of Study: Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Egypt.
Methodology: The first method was based on the reaction of raloxifene base as n-electron donor with TCNQ as π acceptor to form a green colored charge transfer complex, measured at 842.5 nm against its corresponding reagent blank in the concentration range of (2-16 mg/ml). The second method was based on the reaction of raloxifene hydrochloride as reducing agent with Folin Ciocalteu’s reagent to form a blue colored chromogen, measured at 750 nm against its corresponding reagent blank in the concentration range of (4-32 mg/ml).
Results: Different parameters affecting the reactions were studied including; amount of the reagent, reaction time and stability of the color. For the first method: the amount of the reagent (TCNQ) used was 1:7 molar ratio of drug: reagent, maximum color intensity was attained upon allowing the reaction to proceed in a boiling water bath for 10 minutes, the formed color was found to be stable for more than one hour, and the stoichiometry of the reaction was found to be (1:1) raloxifene hydrochloride: TCNQ. For the second method: raloxifene hydrochloride was dissolved in 10% aqueous methanolic solution, maximum color intensity was attained upon allowing the reaction to proceed for 10 minutes at room temperature and the formed color was found to be stable for about one hour.
Conclusion: The methods were successfully applied for the determination of the drug in its pharmaceutical dosage form and validity of the method was assessed by applying the standard addition technique. The results were statistically compared with those obtained by the reference method showing no significant difference between them.
Poly vinyl alcohol (PVA) / TiO2 composites were prepared by sol gel method. The structural, micro structural and the dielectric properties of the composites were studied using X- ray diffraction( XRD), Scanning Electron Microscopy (SEM) and Hioki 3522-50 LCR Meter respectively. The electrical conductivity of composites has been investigated at different temperatures at frequency ranging from 50 Hz to 5 MHz. The electrical conductivities of the composites were found to increase with increase in TiO2 concentration and with increasing temperature.
Schiff’s bases containing heterocyclic scaffolds have been known to possess a wide range of biological and pharmacological activities for a long time. In recent years, they have gained significant interest in the area of drug research and development owing to their broad bioactivities such as antibacterial, antifungal, anti-inflammatory, anticonvulsant, antiviral and anticancer activities. In this paper, biologically relevant Schiff’s bases derived from a diverse group of heterocyclic scaffolds have been intensively reviewed.