Conformance control in oil reservoir based on magnetorheological behavior of nanoparticle suspension.

Water shut off and performance control in oil reservoirs involve many techniques both for reducing the water cut and for enhancing oil production with the aim of making it economical and environmental friendly. Therefore, suitable nanoparticles for injection in an oil reservoir regarding nano size, spherical morphology, and better dispersibility were synthesized by one step, facile, and inexpensive method and then characterized in this work. In addition, new magnetorheological (MR) fluids based on the crude oil and the nanoparticles were developed, and the analysis of their rheological properties carried out by rotational and oscillation tests showed their ability of forming gel-like structure. Furthermore, from the core flooding experiment investigated, values of both resistance factor and residual resistance factor showed that the MR fluids exhibit a solid-like form with the magnetical field applied in oil reservoirs, thereby reducing the water cut.

Quantum chemistry aspects of the solvent effects on 3,4-dimethyl-2,5-dihydrothiophen-1,1-dioxide pyrolysis reaction.

A theoretical density functional theory (DFT) study was employed to investigate solvent effects on a retro-cheletropic ene reaction. The use of a nonpolar solvent in this retro-ene reaction is desirable to improve the reaction rate. Interactions between 14 different solvents and the reaction mixtures (reactant and transition state) were considered using DFT solvation calculations. These results were used to determine the role of solvents on the rate constants. Theoretical calculations at the B3LYP/6-311++G(d,p) level revealed that in the presence of solvents with low polarity the reaction becomes faster, which is in accordance with experimental data. Transition state-solvent interactions were analyzed by the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis. Finally, several correlations between electron densities in bond critical points of the C-S bond and interaction energy as well as vibrational frequencies at the transition state have been investigated.

1,1'-(Ethane-1,2-di-yl)dipyridinium dichromate(VI).

In the cation of the title salt, (C(12)H(14)N(2))[Cr(2)O(7)], the two pyridinium moieties are in an anti orientation with respect to one another. The dihedral angle between the pyridine rings is 6.3 (2)°. The N-C-C-N torsion angle is 177.5 (2)°. In the dianion, the Cr(VI) ions are in a slightly distorted tetra-hedral coordination environment and the bond angles at the independent Cr(VI) ions are in the ranges 105.93 (10)-110.60 (11) and 107.35 (11)-111.07 (12)°. The Cr-O-Cr angle is 127.96 (12)°. The crystal used was an inversion twin with refined components of 0.510 (19) and 0.490 (19).

Synthesis of TiC@C-anatase/rutile@polyvinyl alcohol/xylan: a powerful photocatalyst for degradation of organic pollutant under visible light.

In this study, a composite bearing titanium carbide (TiC), titanium dioxide (TiO2), polyvinyl alcohol and xylan (TiC@C-anatase/rutile@polyvinyl alcohol/xylan) was synthesized and applied as a photocatalyst for the degradation of bromophenol blue (BPB) solution through several steps. Nanostructure of TiC and TiO2 in the anatase and rutile phases was obtained through heat treatment of TiC at different times and temperatures (TiC@AR) which led to a reduction in energy bandgap from UV to visible light, in addition to the enhancement of the surface activity. After TiC@AR polymerization by xylan and polyvinyl alcohol and obtaining TiC@AR/PX, the energy bandgap reduced to IR range (52% of the sunlight) while showing an enhancement in the surface activity. The photocatalytic activity of the compounds was tested by studying the decomposition of BPB solution under visible light. The result illustrated the ability of TiC and TiC@AR to decrease the concentration of BPB after 150 min by 35% and 37%, respectively, while this reduction was 72% for TiC@AR/PX. Considering the effective parameters, the energy bandgap and the surface layer played key roles in photocatalytic degradation.

1,1'-(Ethane-1,2-di-yl)dipyridinium bis-(iodate).

The title salt, C(12)H(14)N(2) (2+)·2IO(3) (-), exhibits two crystallographically independent iodate anions, the I atoms of which are each in a trigonal-pyramidal environment. In the dication, the two pyridine rings adopt an anti conformation with respect to each other; the angle between these two rings is 3.84 (19)°. In the crystal structure, C-H⋯O hydrogen bonds between the cations and anions lead to the formation of layers arranged parallel to the ab plane. I⋯O halogen bonds [R(2) (2)(4) graph-set motif] range between 2.873 (2) and 3.036 (3) Šand connect neighbouring IO(3) (-) anions with each other along [100], so as to create a three-dimensional network.

Triphen-yl[2-(triphenyl-phosphanium-yl)eth-yl]phosphanium bis-(periodate).

In title salt, C(38)H(34)P(2) (2+)·2IO(4) (-), the P atoms of the dication and the I atoms of the periodate anions are each in a slightly distorted tetra-hedral environment. In the dication, the two -P(C(6)H(5))(3) groups adopt a gauche conformation with respect to each other. In the crystal, several C-H⋯O hydrogen bonds between the cations and anions lead to a two-dimensional arrangement along (101).

Investigation of static magnetic field effect on horseradish peroxidase enzyme activity and stability in enzymatic oxidation process.

The activity of Horseradish Peroxidase (HRP) Enzyme exposed to a static magnetic field (SMF) during the oxidation reaction of pyrogallol (PGL) and the epigallocatechin gallate (EPCG) flavonoid was recorded at different times. As the data showed, the enzyme activity increased by 77.17% with increasing incubation time up to 30 min. The kinetic parameters KM and Vmax for PGL sample incubated in SMF for 30 min were 5.641 × 10-3 mM, 4.424 × 10-2 mmol/min, respectively, and for EPCG sample with the same condition were 8.65 × 10-4 mM, 2.37 × 10-3 mmol/min, respectively. Exposure of HRP enzyme to SMF changed the optimum pH from 7.0 to 6.0 in 10 min, but did not create any change in the optimum temperature of the enzyme. After 120 h, the residual activity of normal enzyme was 17% higher than that of the incubated enzyme. The structural changes of the control and HRP enzyme incubated in SMF were investigated by relative viscosity, fluorescence and CD, UV-Vis spectrophotometry. The structural changes in the presence of SMF were found to cause changes in the enzyme activity. In fact, changes in the amount of hydrogen bonds between enzymes and solvents can be a reason for this behavior from a molecular point of view. Using a static magnetic field can provide a new approach to control and direct enzyme-based biological processes.

Moisturizing effects of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) using deionized and magnetized water by in vivo and in vitro methods.

OBJECTIVES: The present study aimed to determine and compare moisturizing and occlusion effects of different solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) using magnetized water and deionized water. MATERIALS AND METHODS: SLN formulations were prepared using various lipids, including Tripalmitin, Compritol®, Precirol®, and emulsifiers including Poloxamer and Tween 80. NLC formulations were also prepared with oleic acid and the same solid lipids. Two types of formulations were prepared; first with deionized water and then with magnetized water. Formulations were prepared using high shear homogenization and ultrasound methods. The products were analyzed by PSA (particle size analyzer), DSC (differential scanning calorimetry), and TEM (transmission electron microscopy). The moisturizing effect of formulations was determined by in vivo and in vitro methods. RESULTS: Findings of the assessments demonstrated that in products prepared with magnetized water, 5% SLN Precirol® had the most moisturizing effect in vivo and 5% SLN Compritol® had the most moisturizing effect in vitro. The use of magnetized water in formulations can improve the effectiveness and increase the stability of moisturizing products. CONCLUSION: In this study, all products prepared with magnetized water showed more stability, smaller size, and more moisturizing effects compared with products prepared with deionized water.

The effect of magnetized water on the oxidation reaction of phenol derivatives and aromatic amines by horseradish peroxidase enzyme.

The present study aimed to investigate, for the first time, the rate of the oxidation reaction of some derivatives of phenol and aromatic amines, that is, pyrogallol, catechol, resorcinol, ortho-aminophenol, meta-aminophenol, para-aminophenol, ortho-phenylenediamine, and para-phenylenediamine, in the presence of hydrogen peroxide in pure and magnetized solvents using horseradish peroxidase enzyme. The reaction was studied in the absence and presence of a magnetized solvent under completely identical conditions. The results showed that magnetized solvent could change the structure of the enzyme and reduce its activity. In addition, it affected the rate of oxidation of the selected derivatives through altering the strength of the hydrogen bonds of the system. The changes in the structure and activity of the enzyme were examined using UV-Vis and fluorescence spectroscopy as well as viscosity measurement technique. Examination of the secondary structure via the far UV-CD spectrum indicated the increase in the alpha helical structure in the magnetized solvent. When dissolved in a magnetized solvent, hydrogen peroxide as an enzyme substrate reduced the rate of enzymatic reaction and provided lower saturation conditions for the enzyme compared with when it was dissolved in the pure solvent.

Effect of Magnetized Water on the Mechanical and Durability Properties of Concrete Block Pavers.

In this research, the effect of magnetized water on the mechanical and durability behavior of concrete block pavers was investigated. For this purpose, a total of five mixes were prepared with water that passed through a permanent magnetic field 10, 20, 40, and 80 times at a constant speed of 2.25 m/s. Compressive strength, splitting tensile strength, flexural strength, resistance to sulfuric acid attack, water absorption tests, and Scanning Electron Microscopy (SEM) analyses were conducted. The compressive strength, splitting tensile strength, and flexural strength test results showed a significant positive effect of using magnetized water. The remaining tests also revealed that using magnetized water increases the resistance of concrete block pavers to sulfuric acid attack and decreases their water absorption.

Cu(ii) immobilized on Fe3O4@APTMS-DFX nanoparticles: an efficient catalyst for the synthesis of 5-substituted 1H-tetrazoles with cytotoxic activity.

Cu(ii) immobilized on deferasirox loaded amine functionalized magnetic nanoparticles (Cu(ii)/Fe3O4@APTMS-DFX) as a novel magnetically recyclable heterogeneous catalyst is able to catalyze the [3 + 2] cycloaddition reactions of various organic nitriles with sodium azide. Using this method, a series of 5-substituted-1H-tetrazoles under mild conditions in DMSO were prepared. The reaction involves mild reaction conditions with efficient transformation capability. The developed catalyst could be easily separated by applying an external magnetic field. Furthermore, it could be recycled for 5 runs with negligible leaching of copper from the surface of the catalyst. The catalyst was characterized by various techniques such as FT-IR, TGA, VSM, SEM-EDX, and ICP-OES. Several derivatives of 1H-tetrazoles were prepared using this catalyst, and their structures were confirmed using different techniques. Then, the synthesized anthraquinones were evaluated for their cytotoxicity against several cell lines including MCF-7, MAD-MD-231, HT-29, HeLa, neuro-2a and L-929. The results obtained from the MTT assay revealed that the 6 derivatives exhibited a high level of cytotoxicity. In order to determine the cytotoxicity mechanism, 2 derivatives with the highest cytotoxic activity were selected, and an apoptosis assay was carried out by flow cytometry, which supported that apoptosis is the major mechanism.

ZnO-Nanorods as an Efficient Heterogeneous Catalyst for the Synthesis of Thiazole Derivatives in Water.

Aims & Scope: Thiazole derivatives are produced using one-pot multicomponent reactions of acid chlorides, potassium thiocyanate, amino acids, alkyl bromides and ZnO nanorods (NR-ZnO) as the catalyst in water at ambient temperature. These reactions were no't performed without using NR-ZnO as the catalyst. Nanorods of ZnO have been prepared by reflux procedure using sodium dodecylsulfate (SDS). Nanorods of ZnO showed a considerable improvement in the yield of the product and displayed significant reusable activity. MATERIALS AND METHODS: In these reactions, all chemicals were prepared from Fluka (Buchs, Switzerland). Nanorods of ZnO were synthesized in the laboratory according to literature report. By using an electrothermal 9100 apparatus, melting points of synthesized compounds were determined. Heraeus CHN-O-Rapid analyzer was employed for elemental analyses for C, H, and N. FINNIGANMAT 8430 spectrometer operating at an ionization potential of 70 eV was used for mass spectra. Shimadzu IR-460 spectrometer was employed for IR spectra. BRUKER DRX-500 AVANCE spectrometer at 500.1 and 125.8 MHz was used for 1H, and 13C NMR spectra for solutions in CDCl3 with TMS as internal standard or 85% H3PO4 as external standard, respectively. RESULTS: We describe a facile and green synthetic method for the synthesis of thiazole derivatives 5 from acid chlorides, potassium thiocyanate, alkyl bromides and amino acids using NR-ZnO- as the catalyst in water at room temperature. CONCLUSION: In conclusion, we describe an efficient, green procedure and high yielding synthesis of thiazole derivatives using acid chlorides, potassium thiocyanate, alkyl bromides and amino acids in the presence of NR-ZnO as the catalyst in water at room temperature.

Hirshfeld surface analysis of the 1,1'-(ethane-1,2-diyl)dipyridinium dication in two new salts: perchlorate and peroxodisulfate.

In the title salts, C12H14N2(2+)·2ClO4(-), (I), and C12H14N2(2+)·S2O8(2-), (II), the dication is organized around an inversion centre located at the centre of the -CH2CH2- bridge and the two pyridine segments are anti with respect to one another. The peroxodisulfate anion in (II) also exhibits inversion symmetry. Hirshfeld surface analysis shows closely similar Hirshfeld surface shapes for the dications in the two salts, reflecting similar intermolecular contacts and similar conformations. The two-dimensional fingerprint plots (FPs) are quite asymmetric, due to the presence of more than one component (cation and anion). The most striking of the complementary features for each of the FPs of the dications is the broad green spike in the region d(e) > d(i), without the presence of a corresponding spike in the region d(e) < d(i), reflecting the absence of O···H contacts. Moreover, H···O interactions (51% in the dications of both salts) outnumber other contacts in both crystal structures.

Effects of magnetized water on ovary, pre-implantation stage endometrial and fallopian tube epithelial cells in mice.

BACKGROUND: Magnetized water has made many improvements in industry, agriculture and medicine. However its utilization in medicine still remains controversial. OBJECTIVE: In this study we aimed to investigate the effects of magnetized water on height of epithelial cells in pre-implantation stage endometrium and fallopian tube and number of corpus lutea in female mice. MATERIALS AND METHODS: Eighty female NRMI mice were recruited to this experimental study and randomly divided into two groups: the control group which drank normal water and the experimental (case) group which drank magnetized water for 2 weeks. Super-ovulation was induced in these mice and then they were mated with male mice as well. Samples of ovary, uterus and fallopian tube were obtained at the pre-implantation stage. Then, after preparation, the number of corpus lutea in each ovary was counted and the height of fallopian and endometrial epithelial cells was measured by light microscopy. RESULTS: Data analysis showed a significant increase in the mean number of corpus lutea and the height of epithelial cells in fallopian tube comparing the case with the control group (p=0.01, p=0.002 respectively) whereas uterus epithelial cells of the case group showed insignificant increase in height, in compare with the control group (p=0.052). CONCLUSION: Our results suggest that magnetized water intake increases the number of corpus lutea and the height of fallopian tube epithelial cells. Further research is needed to determine whether this will increase in the success rate of fertility.