613 research outputs found
Micellar-polymer for enhanced oil recovery for Upper Assam Basin
One of the major enhanced oil recovery (EOR) processes is chemical flooding especially for the depleted reservoirs. Chemical flooding involves injection of various chemicals like surfactant, alkali, polymer etc. to the aqueous media. Bhogpara and Nahorkatiya are two depleted reservoirs of upper Assam basin where chemical flooding can be done to recover the trapped oil that cannot be recovered by conventional flooding process. Micellar-polymer (MP) flooding involves injection of micelle and polymer to the aqueous phase to reduce interfacial tension and polymer is added to control the mobility of the solution, which helps in increasing both displacement and volumetric sweep efficiency and thereby leads to enhanced oil recovery. This work represents the use of black liquor as micelle or surfactant that is a waste product of Nowgong Paper Mills, Jagiroad, Assam, which is more efficient than the synthetic surfactants. The present study examines the effect of MP flooding through the porous media of two depleted oil fields of upper Assam basin i.e. Bhogpara and Nahorkatiya for MP EOR. This work also compares the present MP flood with the earlier work done on surfactant (S) flooding. It was experimentally determined that the MP flood is more efficient EOR process for Bhogpara and Nahorkatiya reservoirs. The study will pertain to the comprehensive interfacial tension (IFT) study and the displacement mechanism in conventional core samples
An efficient modification of the Hofmann rearrangement : synthesis of methyl carbamates
—A series of methyl carbamates was synthesized using NaOCl as an oxidant in the presence of KF/Al 2O 3/MeOH at reflux
in excellent yields
EVALUATION OF ROLE OF FICUS BENGALENSIS IN MODULATION OF COGNITIVE IMPAIRMENT AND OXIDATIVE STRESS IN DIABETIC RATS
Objectives: Our objective was to study the effects of Ficus benghalensis on cognitive behavior and oxidative stress in diabetic rats and to compare with vitamin C and glimepiride.
Methods: Wistar rats of either sex randomized into five groups of diabetic rats by streptozocin (STZ), five groups of non-diabetic rats (distilled water) (n=10). Subgroup division (F. benghalensis dose I and II, i.e., 50 mg/kg and 100 mg/kg; Vitamin C 100 mg/kg and glimepiride 0.5 mg/kg) were done. Each drug was given to one diabetic and one non-diabetic group. Other set served as control. Assessment of blood glucose, cognitive function (using continuous avoidance apparatus and Morris water maze test), and oxidative stress (measuring Malondialdehyde (MDA), reduced glutathione (GSH) levels) were done on Day 0 and 30. The acquisition phase of cognitive behavior tests was assessed on 0, 14, and 29 days and retention phase was assessed on 1, 15, and 30 day.
Results: As compared to control group, F. benghalensis dose I, dose II, and glimepiride showed significant decrease (p<0.001) in blood glucose. F. benghalensis dose I, dose II, vitamin C, and glimepiride group showed significant decrease in acquisition and retention of transfer latency on 29 and 30 days. Significant increase in retention of step-down latency on 30 day was shown by both the doses of F. benghalensis. Both doses of F. benghalensis, vitamin C and glimepiride group showed significant increase in retention of Quadrant-time in comparison to control on 30 days. Significant decrease in brain MDA levels while a significant increase in brain GSH levels was observed in all groups except control.
Conclusion: F. benghalensis reverses behavioral and biochemical changes induced by STZ and effects are comparable with that of vitamin C and glimepiride
Phase structure of charged AdS black holes surrounded by exotic fluid with modified Chaplygin equation of state
By considering the concept of the modified Chaplygin gas (MCG) as a single
fluid model unifying dark energy and dark matter, we construct a static,
spherically charged black hole (BH) solution in the framework of General
Relativity. The criticality of the charged anti-de Sitter (AdS) BH with a
surrounding MCG is explored in the context of the extended phase space, where
the negative cosmological constant operates as a thermodynamical pressure. This
critical behavior shows that the small/large BH phase transition is analogous
to the van der Waals liquid/gas phase transition. Accordingly, along the
phase spaces, we derive the BH equations of state and then numerically evaluate
the corresponding critical quantities. Similarly, critical exponents are
identified, along with outcomes demonstrating the scaling behavior of
thermodynamic quantities near criticality into a universal class. The use of
\emph{geometrothermodynamic} (GT) tools finally offers a new perspective on
discovering the critical phase transition point. At this stage, we apply a
class of GT tools, such as Weinhold, Ruppeiner, HPEM, and Quevedo classes I and
II. The findings are therefore non-trivial, as each GT class metric captures at
least either the physical limitation point or the phase transition critical
point. Overall, this paper provides a detailed study of the critical behavior
of the charged AdS BH with surrounding MCG
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