Ethnomedicinal Uses of Some Plant Species by Ethnic and Rural Peoples of the Salem District of Tamilnadu with Special Reference to the Conservation of Vanishing Species

Salem district sustain a very rich traditional medicinal plant wealth and inherits unique plant and animal communities. Due to deforestation, loss of biodiversity and indiscriminate exploitation of wild and natural resources many valuable herbs like Abrus precatorius, Gloriosa superba, Martynia annua, etc., are in the verge of extinction. The present paper enumerates status, conservation strategies and traditional uses of 68 plant species by the ethnic and rural people of Salem district of Tamilnadu. The claims were gathered by interviewing traditional healers, especially villagers of the study area. Attempt was made to verify the efficacy of claims with actual beneficiaries, though it was not possible in all cases due to social customs

Development of a Nonlinear Model for Subgrid Scale Turbulence and it\u27s Applications

The present work addresses the fundamental question involving the modeling of subgrid-scale turbulence as a function of resolved field. A new-nonlinear model has been developed from the constitutive equation of subgrid stresses extending the Reynolds stress model proposed by Warsi. The time scale is expressed in terms of subgrid scale kinetic energy as opposed to strain rate tensor. Effort has been made to identify the terms appearing in the modeled subgrid stresses with Reynolds term , Leonard\u27s term and cross term . The physical nature of these terms can be best understood from the triadic interactions in wave number space. Understanding these three terms leads to decouple the complex nature of the subgrid stresses. Modeling of these terms separately helps to capture the physics of the problem accurately. The turbulent field is assumed to be isotropic and Kolmogrov\u27s hypothesis is used. The model coefficients are expressed as universal constants for Gaussian filter so as to satisfy the dissipation criteria in inertial subrange. Further dissipation term is assumed to be isotropic and equilibrium condition is used. Although the definition of the subgrid stress terms becomes less clear and separate for smooth filter, an attempt has been made to compare the stress terms with the exact definition obtained for sharp cut-off filter. An estimate of the backscatter of energy can be obtained from the Eddy-Damped Quasi Normal Markovian (EDQNM) theory. The model coefficients thus obtained are tested with results of plain homogeneous shear layer. The model results have been compared with the mixed-nonlinear model and Smagorinsky model. A priori test shows that new-nonlinear model has a good correlation with Smagorinsky model, which in turn has good correlation with experimental results, and has the behavior of the mixed-nonlinear model. The above model has been used for solving two-dimensional flow over backward facing step as a test case. The numerical model solves the vertically hydrostatic boundary layer equation. The top boundary is assumed to be a free surface. Terrain following coordinate system has been used. Because of the non-negativity of the subgrid scale dissipation term i.e. backscatter of energy, the nature of the solution is stochastic. The deterministic solution is obtained by clipping the dissipation term. The results are compared with the experimental data of Kim et al. Good agreement with the experimental data is obtained for the velocity profile and SGS kinetic energy. The reattachment point obtained is at 5.2h (h is the step height), which is less compared to 6h as suggested by other authors. This discrepancy may be due to the assumptions involved in the equations, which is being solved. The model is further extended for the diffusion of scalar variables and to include the buoyancy effect. It is implemented to explore the hydrostatic flow over three dimensional elliptical mountain ridges, where Boussinesq approximation is used for variable density. The flow characteristics have been studied for the various aspect ratios of the mountain and Froude?s number (Nh/U) based on Brunt-Vaisala frequency (N). The phenomenon of upstream blocking and Lee-vortices generation has been studied

Preclinical valuation of anti-hyperglycemic and antioxidant action of Nirmali (Strychnos potatorum) seeds in streptozotocin-nicotinamide-induced diabetic Wistar rats: A histopathological investigation

AbstractThis study aimed to evaluate the antidiabetic activity of Strychnos potatorum seeds in streptozotocin-nicotinamide–induced diabetes in experimental animals. Noninsulin-dependent diabetes mellitus (NIDDM) was induced in overnight fasted rats by an intraperitoneal injection (i.p.) of 60 mg/kg streptozotocin (STZ) and, after a 15-minute interval, 120 mg/kg of nicotinamide. S. potatorum extract 200 mg/kg or 400 mg/kg body weight was administered orally to the rats once daily for 21 days. The blood glucose level was assessed by a glucometer. The serum levels of cholesterol, triglycerides, and total lipid were determined by using diagnostic kits. Measurement of catalase (CAT), superoxide dismutase (SOD), glutathione–S-transferase (GST), reduced glutathione (GSH), and glutathione peroxidase (GPx) were determined to ascertain the antioxidant activity. A significant reduction in the blood glucose level was observed in diabetic animals treated with the different doses of the extract, compared to untreated diabetic rats. The treatment with the extract significantly increased the levels of GSH, GPx, GST, CAT, and SOD in the drug-treated group to levels comparable to the levels in the diabetic control group. The result of this study thus shows that 50% of the ethanolic extract at different doses possesses significant antidiabetic activity and potent antioxidant potential in diabetic conditions

Antihepatotoxic Potential of Citrullus colocynthis Root Extract, Fractions and Isolated Compounds

Medicinal plants are considered to be effective and safe alternative treatment for liver toxicity. The article reveals the hepatoprotective activity of the ethanolic extract of the roots of the Citrullus colocynthis commonly known as INDRYAN using carbon tetrachloride (CCl4) experimental model in albino rats. After receiving significant protection of Ethanolic extract on liver the extract further undergone fractionation into three fractions & the activity was localized in the toluene fraction. These on purification led to the isolation of two pure compounds which were identified as - Cucurbitacin B[1] and Colocynthin [2]. The pure compound shows reduction in enzymatic level viz. (SGOT 68.09%, SGPT 63.64%, ALP 76.81%, BL 68.22%) and (SGOT 71.28%, SGPT 65.24%, ALP 80.68%, BL 54.92%) at 50 mg/ kg dose respectively whereas drug Silymarin showed reduction as (SGOT 79.73%, SGPT 74.26%, ALP 87.88%,BL 82.75% ) at 25 mg/kg dose level. On comparing the obtained data it was observed that the roots of C. colocynthis Sch. exhibited significantly better hepatoprotective activity, thus justifying the traditional claims

ANTI-HYPERGLYCEMIC ACTIVITY OF HYDRO-ALCOHOLIC BARK EXTRACT OF MANILKARA HEXANDRA (ROXB) IN STREPTOZOTOCIN INDUCED DIABETIC RATS

Objective: Manilkara hexandra Roxb. (Family: Sapotaceae) is a common evergreen tree and commercial crop in India which is widely used as antibacterial, diuretic, anthelmintic, antioxidant and antidiabetic in folklore medicine in India. The objective of the study was to evaluate the antidiabetic activity of Manilkara hexandra bark in streptozotocin-induced diabetes in experimental animals.Methods: Non-insulin-dependent diabetes mellitus (NIDDM) was induced in overnight fasted rats by an intra-peritoneal injection (i. p.) of 60 mg/kg streptozotocin. 50 % ethanolic extract of M. hexandra, 250 mg/kg or 500 mg/kg body weight was administered orally to the rats once daily for 21 d. The blood glucose level was assessed by a glucometer. The serum levels of cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol were determined by using diagnostic kits.Results: A significant reduction (p<0.001) in the blood glucose level was observed in diabetic animals treated with the different doses of the extract, compared to untreated diabetic rats. The drug posses good hypolipidemic effect by normalizing the lipid parameters. This also evidenced by histopathological examination of isolated organs viz. pancreas and kidney showing reduced the injuries induced by streptozotocin.Conclusion: The result of this study thus shows that 50 % of the ethanolic extract at different doses possesses significant antidiabetic activity and potent hypolipidemic potential in diabetic conditions.Keywords: Antidiabetic, Bark extract, Histopathology, Manilkara hexandra, Streptozotoci

GRAPHENE CONJUGATED USNIC ACID NANO-FORMULATION FOR THE TREATMENT OF TOPICAL FUNGAL INFECTION:

Objective: The study aims to investigate the antifungal response of the dug usnic acid with the carrier graphene. Methods: Nano-precipitation method by sonication was adopted to formulate the conjugate. SEM test was performed to check the shape and average size of the conjugate. FTIR test was performed for the chemical interaction between the drug and the carrier. Ointment was prepared by the fusion method and the viscosity test was performed by Brookfield viscometer. Spreadability test was performed by slide method. Animal activity was performed to confirm the antifungal effect of the formulated nano-conjugate. Statistical analysis was done by Anova. Results: SEM study shows that the conjugate is in the nano range and possess a spherical shape. FTIR study shows no interaction between the drug and the carrier. The result of in vitro drug release study shows that the conjugate posses a higher drug release rate as compared to the drug alone. Topical drug administration is more suitable for the treatment of the fungal infection, so the nano-conjugate was incorporated into the ointment by geometric mixing. The viscosity and the spreadability test were performed on the different formulations of the ointment and the suitable one was selected for the topical administration. Anti-fungal study had been performed on the Wistar albino rats for 6 d. Skin culture of rats was performed for the formation of the fungal colonies. Statistical analysis by Anova gives p<0.001. It was found that the normal form of usnic acid, graphene and the nano form both possess anti-fungal activity as 3/6 and 2/6 experimental animals are cured by normal formulation and nano-formulation. Conclusion: The present anti-fungal study revealed that the nano-form of the conjugate possess higher anti-fungal activity than the normal formulation of usnic acid with graphene

Assessment of Neural Network Augmented Reynolds Averaged Navier Stokes Turbulence Model in Extrapolation Modes

A machine-learned (ML) model is developed to enhance the accuracy of turbulence transport equations of Reynolds Averaged Navier Stokes (RANS) solver and applied for periodic hill test case, which involves complex flow regimes, such as attached boundary layer, shear-layer, and separation and reattachment. The accuracy of the model is investigated in extrapolation modes, i.e., the test case has much larger separation bubble and higher turbulence than the training cases. A parametric study is also performed to understand the effect of network hyperparameters on training and model accuracy and to quantify the uncertainty in model accuracy due to the non-deterministic nature of the neural network training. The study revealed that, for any network, less than optimal mini-batch size results in overfitting, and larger than optimal batch size reduces accuracy. Data clustering is found to be an efficient approach to prevent the machine-learned model from over-training on more prevalent flow regimes, and results in a model with similar accuracy using almost one-third of the training dataset. Feature importance analysis reveals that turbulence production is correlated with shear strain in the free-shear region, with shear strain and wall-distance and local velocity-based Reynolds number in the boundary layer regime, and with streamwise velocity gradient in the accelerating flow regime. The flow direction is found to be key in identifying flow separation and reattachment regime. Machine-learned models perform poorly in extrapolation mode, wherein the prediction shows less than 10% correlation with Direct Numerical Simulation (DNS). A priori tests reveal that model predictability improves significantly as the hill dataset is partially added during training in a partial extrapolation model, e.g., with the addition of only 5% of the hill data increases correlation with DNS to 80%.Comment: 50 pages, 18 figure

HYPOGLYCEMIC AND ANTIHYPERLIPIDEMIC EFFECTS OF ADIANTUM CAUDATUM IN ALLOXAN INDUCED DIABETES IN RATS

ABSTRACTObjective: To investigate the hypoglycemic and antihyperlipidemic effect of a successive ethanolic extract of Adiantum caudatum (EEAC) whole plantin alloxan induced diabetic rats.Methods: Diabetes was induced in Wistar albino rats by the administration of alloxan (140 mg/kg b. w., i.p.). EEAC (200 mg/kg b. w., p.o.) wasadministered to diabetic rats for 21 days in alloxan induced diabetic rats. The effect of EEAC on blood glucose and body weight was studied in alloxaninduced diabetic rats. All these effects were compared with glibenclamide (10 mg/kg b. w., p.o.) as a reference antidiabetic drug.Results: The administration of EEAC (200 mg/kg b. w., p.o.) resulted in a significant decrease in blood glucose level and a significant increase in bodyweight in alloxan induced diabetic rats. Furthermore, EEAC showed antihyperlipidemic activity as evidenced by a significant decrease in serum totalcholesterol and triglyceride levels in alloxan induced diabetic rats.Conclusion: The results suggest that the EEAC possess a promising hypoglycemic effect in alloxan induced diabetic rats.Keywords: Hypoglycemic, Antihyperlipidemic, Adiantum caudatum, Alloxan, Diabetes

ON THE VORTEX BREAKDOWN PHENOMENON IN HIGH ANGLE OF ATTACK FLOWS OVER DELTA WING GEOMETRIES

ABSTRACT Using computational methods, an investigation was performed on the physical mechanisms leading to vortex breakdown in high angle of attack flows over delta wing geometries. For this purpose, the Second International Vortex Flow Experiment (VFE-2) 65° sweep delta wing model was studied at a root chord Reynolds number (Re cr ) of 6 × 10 6 at various angles of attack. The open-source computational fluid dynamics (CFD) solver OpenFOAM was used in parallel with the commercial CFD solver ANSYS® FLUENT. For breadth, a variety of classic closure models were applied, including unsteady Reynolds-averaged Navier-Stokes (URANS) and detached eddy simulation (DES). Results for all cases are analyzed and flow features are identified and discussed. The results show the inception of a pair of leading edge vortices originating at the apex for all models used, and a region of steady vortical structures downstream in the URANS results. However, DES results show regions of massively separated helical flow which manifests after vortex breakdown. Analysis of turbulence quantities in the breakdown region gives further insight into the mechanisms leading to such phenomena

Numerical investigation of shallow-water effects on hydrokinetic turbine wake recovery

Thrust, power and intermediate wake predictions obtained using resolved rotating blade with sliding mesh simulations for a hydrokinetic turbine (HKT) are assessed using the open-source flow solver OpenFOAM. Single- and two-phase URANS and DES computations are performed for three-blade, 0.5m diameter (D) turbine mounted on a stanchion that intersects the free surface with a tip-speed ratio λ = 6.15. The thrust and power predictions compare within 5% of the experimental data. Results show that the thrust predictions are dominated by the pressure distribution on the blades, whereas the shear stress plays a significant role in the power predictions. The turbine performance showed unsteadiness with amplitudes around 3% of the mean, due to the disruption of the flow each time a blade passed in front of the stanchion. The wake recovery is primarily due to the growth of shear layers (originating from the blade tips) towards the turbine axis, which are primarily caused by the cross-plane turbulent velocity. The shear layer growth is enhanced by the turbulence produced by the stanchion. Predictions of the mean wake profile compared within 10% of the experimental data, which is significant improvement over previous Fluent predictions that showed large errors of 22%. The improved predictions in OpenFOAM is attributed to better turbulence predictions. Two-phase results show that the interaction between the wake and free-surface is initiated by the interaction of stanchion with the free-surface. The free-surface creates a blockage effect that accelerates the flow in the upper bypass region and enhances the wake recovery