The critical micelle concentration (CMC) of nonylphenolethoxylate (NPE) surfactant has been determined by measuring the surface tension as a function of the molar concentration of the surfactant in aqueous and binary mixture of water + methanol solutions at a temperature range from 20?C to 35?C. The interfacial parameters ?max, Amin, ?cmc and ?G?ads were calculated. The results indicate that the CMC increases as the temperature increases and that the addition of methanol the CMC decreases. The thermodynamic parameters such as standard Gibbs free energy (?G?), enthalpy (?H?), and entropy (?S?) of micellization were estimated using the change of CMC with temperature. The enthalpy – entropy compensation behavior of the surfactant was evaluated and a good linearity in the compensation plot has been observed.
A new spectrophotometric method for individual and simultaneous determination of cefixime and cephalexin depending on the first and second derivative mode techniques. The first and second derivative spectra of these compounds permitted individual and simultaneous determination of cefixime and cephalexin in concentration interval of (4– 24μg.ml-1 ) by measuring the amplitude of peak-to-base line, pea to peak at certain wavelengths and the area under peak at selected spectrum intervals. The methods showed reasonable precision and accuracy and have been applied to determine cefixime and cephalexin in two different pharmaceutical preparations.
The Reversed Phase High Performance Liquid Chromatography (RP-HPLC) has been used for the separation of Poly aromatic hydrocarbons(PAHs) by using column Reprosil 100 C 18 which was found to be a suitable one for this purpose. The result showed that using mobile phase of (Acetonitrile-water) Reversed Phase HPLC , flow rate of (1.2 ml/min) , column temperature (30CËš) and wave length of (254nm), give a complete separation with a good resolution . The total separation time was less than 20 min. The result of the study showed that the vegetables of Baghdad city were polluted by poly aromatic hydrocarbons(PAHs) in different places where samples taken because of drainage of the heavy water ,industrial trash and trash of oil colanders. -
... Show MoreIn this study, performance characteristics such as power take off (PTO) power consumption, fuel consumption, fuel consumption for the unit field-unit product were determined at different working speeds with two different PTO applications (540 and 540E) in a single row disc type silage machine. In particular, the 540E PTO application greatly reduces fuel consumption for unit work. The best results in terms of hourly fuel consumption were achieved in 540E PTO application and V1 working speed. When the field - product fuel consumption is evaluated, the best results were obtained with the 540E PTO application at the V3 working speed. When an evaluation is made considering all the parameters, it is concluded that the 540E PTO application will p
... Show MoreA new reversed phase- high performance liquid chromatographic (RP-HPLC) method with Ultraviolet-Visible spectrophotometry has been optimized and validated for the simultaneous extraction and determination of organic acids present in Iraqi calyces of Hibiscus Sabdraffia Linn. The method is based on using ultrasonic bath for extracting organic acids. Limit of detection in µg/ml of Formic acid, Acetic acid, Oxalic acid, Citric acid, Succinic acid, Tartaric acid, and Malic acid 126.8498×10-6, 113.6005×10-6, 97.0513×10-6, 49.7925×10-6, 84.0753×10-6, 92.6551×10-6, and 106.1633×10-6 ,respectively. The concentration of organic acids found in dry spacemen of calyces of Iraqi Hibiscus Sabdraffia Linn. under study: Formic acid, Acetic acid,
... Show MoreThe study involved the removal of acidity from free fatty acid via the esterification reaction of oleic acid with ethanol. The reaction was done in a batch reactor using commercial 13X zeolite as a catalyst. The effects of temperatures (40 to 70 °C) and reaction time (up to 120 minutes) were studied using 6:1 mole ratio of pure ethanol to oleic acid and 5 wt. % of the catalyst. The results showed that acid removed increased with increasing temperature and reaction time. Also, the acidity removal rises sharply during the first reaction period and then changes slightly afterward. The highest acidity removal value was 67 % recorded at 110 minutes and 70 °C. An apparent homogeneous reversible reaction kinetic model has been proposed a
... Show MoreObjective: To evaluate two kinds of extraction (aqueous and ethanolic) for coriander using seeds, leaves and stems and
studying their antibacterial activity against nine different microorganisms.
Methodology: Coriander was selected to carry out this study. Seeds, leaves and stems were collected from local markets in
Baghdad then dried in shade for at least 10 days and grinded to fine powder. Aqueous hot extracts for 1hr. at (50
c) and
cold extracts for 24 hrs at (4
c) were performed by using seeds, leaves and stems then studied antibacterial effect against
nine different microorganisms by using well diffusion technique. Cold aqueous extracts of coriander seeds for 48 hrs. and
72 hrs and ethanolic extraction
An experimental of kinetics investigation of the solution free radical polymerization of isopropylacrylamide (IPAM) initiated with potassium persulfate (PPS) was conducted. The reactions were carried out at constant temperature of 60 °C in distilled water under unstirred and inert conditions. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were investigated over a wide range. Under the conditions of our work, the orders 0.38 and 1.68 were found with respect to initiator and monomer, respectively. However, the rate of polymerization (Rp) is not straight forwardly corresponding monomer concentration. The value 46.11 kJ mol1 was determined as the o
... Show MoreSimple and sensitive batch and Flow-injection spectrophotometric methods for the determination of Procaine HCl in pure form and in injections were proposed. These methods were based on a diazotization reaction of procaine HCl with sodium nitrite and hydrochloric acid to form diazonium salt, which is coupled with chromatropic acid in alkaline medium to form an intense pink water-soluble dye that is stable and has a maximum absorption at 508 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 1-40 and 5-400 µg.ml-1 of Procaine HCl, with detection limits of 0.874 and 3.75 µg.ml-1 of Procaine HCl for batch and FIA methods respectively. The FIA average sample throughput was 70 h-1. A
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