ABSTRACT
Asphaltenes are heavy constituents of crude oil which affect the flow and viscosity of crude oil. They also stabilize water-in-oil emulsions which makes the separation process of water from oil during the primary treatment processes for crude oils more difficult and costly. Measuring asphaltenes has great importance, especially for crude oil production companies. Gravimetric and spectroscopic measurement methods are the basic techniques used by international references such as ASTM and IP. A new methodology has been introduced as a modification of ASTM D6560 gravimetric methodology by using the centrifugation technique in the separation of asphaltenes for different oil samples with the API gravity change from 17.4 (oil S1) to 39.8 (oil S5). The new methodology has the advantages of consuming little time, and multiple sample processing and can be done in the field and also in the lab. Moreover, it has good repeatability, reproducibility, and working range values compared to the reference gravimetric ASTM and IP methods. The repeatability of the new method was found to be 8.0% at its maximum value (S1, has a low asphaltene content), while the minimum value was found to be 3.75% (S10, has the highest asphaltene content). It was found that the maximum reproducibility value was 17.0% for the S1 sample and the minimum was 0.0% for S9 and S10 samples.
ABSTRACT
An ecofriendly resorcinol derivative, dimethyl-4,6-dihydroxyisophthalate (DDIP) is examined as an anticorrosion agent for low carbon steel (CS) in a 0.5 mol L-1 HCl solution. Electrochemical and chemical methods are used to determine the effectiveness of the inhibitor. The DDIP compound decreased the rate of CS corrosion. The mitigation efficiency rose from 61.8 to 79.9% as the DDIP dose increased from 50 to 300 ppm in the corrosive medium. At 300 ppm, however, the efficiency decreased from 79.9 to 70.05% as the temperature increased from 25 to 55 °C. Physical quantities and thermodynamic parameters are discussed. The compound's adsorption follows Langmuir's concept. Adsorption of the DDIP compound is a mix of physisorption and chemisorption. The difference in E corr values is less than 85 mV, indicating that the examined compound is a mixed-type inhibitor. Scanning electron microscopy and atomic force microscopy revealed the development of a coherent film at CS in the presence of the DDIP inhibitor. The results obtained using various techniques were closely related, indicating validity and accuracy. The interaction between the DDIP molecules and the CS was explained by the density functional theory and Monte Carlo simulation. The quantum characteristics confirmed that the DDIP compound is a promising inhibitor.
ABSTRACT
The mazout properties were improved using ecofriendly ways because of its wide range of applications, abundance and low cost. In this study, the effect of biodiesel blending on the properties of mazout was investigated. Biodiesel was prepared from waste cooking oil. The mazout properties such as viscosity and density improved with the increase in volume ratio of biodiesel to mazout. The mazout viscosity decreases with an average value of 12% as the biodiesel is added with a volume ratio of 10%. In contrast, when a 10% volume ratio of the biodiesel is added to mazout, the heating value decreases by 1.5%. Although the calorific value of mazout decreases after the blending process, the blending method is considered a method that saves energy compared to the heating method to reduce the viscosity. The cost of improved mazout depends on the cost of biodiesel production. The more the cost of biodiesel production approaches the cost of mazout, the more expensive the use of the blending method compared to the heating method. Moreover, the blending method is a very effective method to reduce the percentages of harmful compounds such as sulfur, and the compound percentages that occupy volumetric proportions of fuel such as water content.
ABSTRACT
In one-pot strategy, diazotization of methyl anthranilate 5 followed by addition of amino acid ester hydrochloride, we have prepared methyl-2-(4-oxobenzotriazin-3(4H)-yl)alkanoates 6a-c. Starting with hydrazides 7a,b, N-alkyl-2-(4-oxobenzotriazin-3(4H)-yl)alkanamides 9-10(a-h) and methyl-2-(2-(4-oxobenzotriazin-3(4H)-yl)alkanamido)alkanoates 11-12(a-e) were prepared via azide coupling. Hydrazones 13-15 were prepared via condensation of hydrazides 7a,b with 4-methoxybenzaldehyde, 4-dimethylaminobenzaldehyde, and/or arabinose. Molecular docking was done for synthesized compounds using MOE 2008-10 software. The compounds 9a, 12a, 12c, 13a, 13b, and 14b have the most pronounced strong binding affinities toward the target E. coli Fab-H receptor, whereas compounds 3, 11e, 12e, and 13a have the most pronounced strong binding affinities toward the target vitamin D receptor. The in vitro antibacterial activities of the highest binding affinity docked compounds were tested against E. coli, Staphylococcus aureus, and Salmonella spp. Majority of the tested compounds showed effective positive results against E. coli, while they were almost inactive against Staphylococcus aureus and Salmonella spp . The in vitro cytotoxic activities of the highest binding affinity-docked compounds were tested against the human liver carcinoma cell line (HepG2). Some compounds showed potent cytotoxic activity with low IC50 values, especially for 3 (6.525 µM) and 13a (10.97 µM) than that for standard drug doxorubicin (2.06 µM).
