Electrical conductivity and dielectric measurements of CoMTPP

Results of X-ray diffraction patterns (XRD) show that the powder of 5,10, 15,20-Tetrakis(4-methoxyphenyl)-21H,23H-porphine cobalt(II) (CoMTPP) has polycrystalline nature with triclinic structure. Miller's indices, (hkl), values for each diffraction peak in XRD spectrum are calculated. The electrical conductivity and dielectric properties of bulk CoMTPP have been investigated in the frequency range 42 Hz–5 MHz and in the temperature range 298–413 K. The frequency dependence of electrical conductivity, σ (ω, Τ), follows the Jonscher's universal dynamic law. The obtained results have been discussed in terms of the correlated barrier hopping (CBH) model, which is well adapted to CoMTPP semiconductor material. Complex impedance data are obtained at different frequency and temperature. The best fitting for the Cole–Cole plots can be represented by an equivalent circuit element composed of RQC. The conductivity in the direct regime, σ_dc, is described by the variable range hopping (VRH). The values of dielectric constant, ?^′ (ω), and dielectric loss, ?″ (ω), are found to be decrease with increasing frequency due to the interface states capacitance.     

Characterization and electrochemical investigations of micellar/drug interactions

The effect of adding surface-active agents to electrolytes containing isoniazid (INH), an antituberculous drug, on the voltammetric response of carbon paste electrode (CPE) was studied. The enhancement of current signal due to the oxidation process was a function of the amount of analyte, pH of the medium, surfactants’ type, and chain length and aromaticity and accumulation time at the electrode surface. Eight surfactants were used, three anionic type, sodium dodecyl sulphate (SDS), sodium octyl sulphate (SOS) and sodium dodecyl benzene sulphonate (SDBS), three cationic type, cetyl trimethyl ammonium bromide (CTAB), trimethyl octyl ammonium bromide (TMOB) and cetyl pyridinium bromide (CPB) and two nonionic surfactants, albumin and Triton X-405. Addition of SDS and SDBS to the isoniazid-containing electrolyte was found to enhance the oxidation current signals while SOS showed an opposite effect. The addition of either the cationic or nonionic surfactants was found to decrease oxidation current signals. To confirm the interactions between surfactant and isoniazid, absorbance spectroscopy has been performed. NMR measurements gave a good expectation for the location and orientation of INH in different micelles and gave a similar conclusion to that obtained from electrochemical and UV–vis data. The use of SDS in the electrochemical determination of isoniazid using differential pulse voltammetry at carbon paste electrode improved the limit of detection to 6.29 ng mL⁻¹. The validity of using this method in the determination of drug active ingredient in tablet formulations was also demonstrated.     

Valencia orange-seed oil

Summary California Valencia orange seeds contain a fairly high percentage of oil, the recovery of which by conventional methods of pressing appears to present no unusual problems. When refined, bleached, and deodorized the oil would be quite acceptable as a food oil. It contains a very small proportion of linolenic acid but is otherwise similar to other seed oils of like iodine value.     

EFFECT OF ABIETIC ACID DERIVATIVE SURFACTANTS ON CALORIFIC VALUE AND FLOW OF CRUDE OIL AND SOME DISTILLATES

A series of abietic monoester and amide have been prepared by esterification of abietic acid with long chain alcohol blend (Nafol 20⁺), polyethylene glycol (PEG 400, 600, 1000 and 4000) and hexadecylamine. The abietic diester derivatives were prepared by esterification of abietic-maleic anhydride adduct with Nafol 20⁺ only or polyethylene glycol-1000 and Nafol 20⁺. These reactions were carried out to prepare eight abietic acid derivatives. The products were purified and characterized by FTIR and ¹H NMR analyses. The surface-active properties of these compounds were correlated with their effect on pour point and calorific values of crude oil. From the results, it has been found that the compound EA23-MN, which has the more negative value of ΔG_ad, exhibited maximum pour point depression and increases the calorific values of crude oil and some distillates.     

Synthesis and antibacterial activity of thioglycolic amino acid derivatives and dipeptides containing the 2-methyl-3,4-dihydroquinazolin-4-one moiety

3-(2′-Chloroethyl)-2-methyl-3,4-dihydroquinazolin-4-one ( I ) was reacted with sodio (sodium thioglycolate) in dry dioxane and yielded compound II . By using thionyl chloride, this compound was converted to the corresponding acid chloride ( III ). The prepared acyl chloride ( III ) was allowed to interact with different α-amino acids such as Gly, L -Ala, L -B-Phe, DL -Asp, L -Glu, L -Thr and L -Val to give new amino acid derivatives ( IVa – g ). A selected C-terminal derivative of glycine ( IVa ) was converted into acid chloride ( V ). The acid chloride formed was reacted with L -Ala, L -B-Phe, DL -Asp, L -Glu, L -Thr and L -Val and yielded the new dipeptides VIa – f . The structures of the synthesized compounds were elucidated by elemental analysis and IR spectra. The prepared peptides were tested for their antimicrobial activities by comparison with tetra-cycline as a reference compound.     

Anti-nociceptive and anti-inflammatory effects of some Jordanian medicinal plant extracts

An impaired host defense mechanism is well known in patients with liver cirrhosis (LC). Using a sinusoidal lavage method, lymphocytes were obtained from LC rats that were administered thioacetamide, and natural killer (NK) activity was measured by 51Cr-release assay. The NK cell count was measured by flow cytometric analysis using monoclonal antibody (Mab) 3.2.3 and/or CD 3-8+ as markers for NK cells, and by immunohistochemical staining using Mab 3.2.3. Furthermore, interferon (IFN) alpha was administered to LC rats and the subsequent changes in hepatic NK activity and NK cell count were observed. In the large granular lymphocyte (LGL)-rich fraction (Fr.1, LGLs: 60-90%), the NK activity was significantly lower in the LC rats (40.0 +/- 3.8%) compared to that in the control rats (48.4 +/- 4.3%) (P < 0.005). In addition, the number of NK cells in the liver tissues of the LC rats was significantly lower compared to that in the liver tissues of the control rats by morphometric analysis (P < 0.05). For LC rats, NK activity of the Fr.1 24 hr after IFN alpha administration (5 x 10(4) IU/100 g body weight) increased significantly (P < 0.005). Hepatic NK activity and NK cell count were reduced in the LC rats, and recovered following IFN alpha administration. The results obtained in this study may give clues to better understanding the impaired host defense mechanism in LC patients.     

Calculation and measurement of kinetic parameters of Pakistan Research Reactor-1 (PARR-1)

Rossi-Alpha (β_eff/Λ) for critical reactor measured experimentally by noise analysis technique at PARR-1 core at 35.26 full power days burn up. In noise analysis technique the inherent reactivity fluctuations are taken as input to reactor system and the neutron density population fluctuations are considered as output of the reactor system. The auto power spectral density of the linear channel is taken and used to find out the break frequency by non-linear least square fitting method, which leads to β_eff/Λ = 161.45 s⁻¹. Calculations were performed with the help of computer codes WIMSD/4 and CITATION. The calculated β_eff/Λ = 161.07 s⁻¹ at 35.26 full power days burn up. The measured and calculated values for Rossi-Alpha are in good agreement within 0.235% of error.     

Micellization and Adsorption Behaviors of New Reactive Polymerizable Surfactants Based on Modified Nonyl Phenol Ethoxylates

The synthesis and characterization of a series of polymerizable surfactants based on alkyl phenol ethoxylate backbone and carboxylic or anhydride chain ends were investigated. Surface activities of these polymerizable surfactants were investigated to correlate their structure and their performances. The new bifunctional surfmers were prepared by reacting polyoxyethylene 4-nonyl-2-propylene-phenol nonionic reactive surfactants with maleic anhydride. The chemical structure of the prepared surfactants was characterized by ¹³C and ¹H NMR analyses. The surface activities of the modified polymerizable surfactants were measured from the adsorption isotherm measurements which were determined from the relationship between the concentrations and surface tension of surfactants in aqueous medium at different temperatures. Critical micelle concentration (CMC) values were determined for water soluble surfactants. It was found that CMC decreases with the incorporation of the anhydride and acid groups in the chemical structure of polyoxyethylene 4-nonyl -2-propylene-phenol nonionic surfactant. surface-active parameters such as area per molecule at the interface (A _min), surface excess concentration (Γ_max) and the effectiveness of surface tension reduction (π_CMC) were measured from the adsorption isotherms of the modified surfactants. Some thermodynamic data for the adsorption process were calculated and discussed. The data indicated that the new surfmers are more reactive than the simple polyoxyethylene 4-nonyl-2-propylene-phenol and more adsorbed at interfaces. We have performed a preliminary experiment to explore the emulsification efficiency of the newly synthesized reactive surfactants in equal volume oil–water emulsions. Different emulsion types and stabilities were obtained.     

Characterization of commercial chili sauce varieties according to their chemical and physical properties using chemometric methods

Different varieties of chili sauces that are commercially available in Malaysia were randomly collected and their physical and chemical parameters were determined. Initially, pattern recognition techniques were applied in order to categorize the chili sauce varieties. With the aid of principal component analysis and cluster analysis, it is possible to visualize the clustering tendencies of the different varieties of chili sauces where four major clusters, namely chili sauces, general chili ketchups, hot/garlic added ketchups, and Thai ketchups have been successfully partitioned. Color and taste parameters have been found to be the most discriminating variables among them. With the K-nearest neighbor technique, a good prediction of chili sauces’ categories could be achieved. With appropriate customer preference survey, it would be possible to map these characteristics to the preferences. This would certainly help producers of chili sauces in upgrading the quality and taste of their products.