Time Delay Induced Death in Coupled Limit Cycle Oscillators

We investigate the dynamical behaviour of two limit cycle oscillators that interact with each other via time delayed coupling and find that time delay can lead to amplitude death of the oscillators even if they have the same frequency. We demonstrate that this novel regime of amplitude "death" also exists for large collections of coupled identical oscillators and provide quantitative measures of this death region in the parameter space of coupling strength and time delay. Its implication for certain biological and physical applications is also pointed out.Comment: 4 aps formatted revtex pages; 3 figures; to be published in Phys. Rev. Let

Radiation and Chemical Reaction Effects on Unsteady MHD Free Convective Periodic Heat Transport Modeling In a Saturated Porous Medium for Arotating System

A rotating model is extended for a two-dimensional, unsteady, incompressible electrically conducting, laminar immediate convection boundary layer flow of light and mass communicate in a saturated porous crystal ball gazer, among an overall vertical porous surface in the perseverance of radiation and vicious circle effects was considered. The fundamental equations governing the flow are in the art an element of partial differential equations and have been reduced to a inhere of non-linear ordinary differential equations by applying suitable similarity transformations. The problem is tackled analytically using classical two term perturbation technique. Pertinent results with respect to embedded parameters are displayed through graphically for the velocity, Temperature, concentration, skin friction, Sherwood number, Nusselt number are discussed qualitatively

SIMULTANEOUS DETERMINATION OF TIGECYCLINE AND ITS POTENTIAL IMPURITIES BY A STABILITY-INDICATING RP-HPLC-UV DETECTION TECHNIQUE

Objective: Stability representing the RP-HPLC method was established for synchronized quantification of Tigecycline and its impurities. This method was confirmed for its applicability to both tablet dosage and bulk drug forms. Methods: Intended for an isocratic elution, a mobile phase containing methanol: 10 mmol Triethylamine Buffer mixture (75:25 v/v, pH 6.1) was used at 1 ml/min flow rate and Agilent ZORBAX Eclipse XDB C18 (250 mm × 4.6 mm, 5 μm) column. Results: At 231 nm as wavelength, high-pitched peaks of Tigecycline (Tig) and its impurities (1and2) were detected at 6.55, 8.73 and 4.87 min correspondingly. The linearity of tigecycline and its impurities (impurity-1 and 2 and) were estimated with ranging from 75–450 µg/ml for Tigecycline and 1–6 µg/ml for both impurity 1 and 2. The corresponding recognition limits (LOD and LOQ) of the tigecycline and its impurities were originated to be (1.37,0.047 and 0.071 µg/ml) and (4.15, 0.143 and 0.126 µg/ml). Conclusion: The technique was effectively stretched for stability signifying studies under different stress conditions. Justification of the method was done as per the current ICH guidelines

Measurement of turbulence and pitch of the airstream in the 5' × 7' tunnel of Indian Institute of Science

This article does not have an abstract

Reaction of Bis(diethyl dithiocarbamato)nickel(II) with 4-Methyl- & 4-Vinyl-pyridines

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Experimental Evidence of Time Delay Induced Death in Coupled Limit Cycle Oscillators

Experimental observations of time delay induced amplitude death in a pair of coupled nonlinear electronic circuits that are individually capable of exhibiting limit cycle oscillations are described. In particular, the existence of multiply connected death islands in the parameter space of the coupling strength and the time delay parameter for coupled identical oscillators is established. The existence of such regions was predicted earlier on theoretical grounds in [Phys. Rev. Lett. 80, 5109 (1998); Physica 129D, 15 (1999)]. The experiments also reveal the occurrence of multiple frequency states, frequency suppression of oscillations with increased time delay and the onset of both in-phase and anti-phase collective oscillations.Comment: 4 aps formatted RevTeX pages; 6 figures; to appear in Phys. Rev. Let

Magnetohydrodynamic Couette Flow and Heat Transfer in a Rotating System

The influence of electrode geometry for the MHD Couette flow in the presence of the Hall current and heat transfer of a conducting liquid in a rotating system has been studied

Serum alkaline phosphatase and high sensitivity C-reactive protein in type II diabetes mellitus: a risk of cardio vascular disease in South Indian population

Background: Diabetes mellitus (DM) is a clinical syndrome characterized by abnormal metabolism of carbohydrate, protein and fat resulting in hyperglycemia due to absolute or relative deficiency of insulin ending up in vascular complications leading to retinopathy, neuropathy and nephropathy. The aim of the study was to examine the relationship between alkaline phosphatase (ALP) and high sensitive C reactive protein (hsCRP), in type 2 diabetic patients. We assessed the association of ALP and hsCRP levels with CVD complication and determined its utility for CVD risk prediction in type 2 DM subjects with good and poor glycemic control. Further, we investigated correlation between serum ALP and hsCRP level with glycemic control (FBS, PP2BS, HbA1c) in subjects.Methods: A cross sectional study consists of 390 patients out of which 100 normal healthy control (Group I) , 120 patients having type 2 DM with good control (Group II), 170 patients with type 2 DM with poor control (Group III) were selected. Serum ALP, serum hsCRP, FBS, PP2BS, HbA1c, and other biochemical investigations including serum liver enzymes and lipid profile were measured.Results: In Study I Mean serum ALP(145.17±23.91) and hsCRP (2.53±0.76) concentration in group II patients when compared to group I serum ALP(142.17±16.48) and Hscrp (1.51±0.15) shows a significance of ALP (p<0.05) and Hscrp (p<0.001).Study II Mean serum ALP(145.17±23.91) and hsCRP (2.53±0.76) concentration in group II patients when compared to group III serum ALP (147.79±28.95) and Hscrp (3.848±0.47) group shows a significance of ALP (p<0.001) and Hscrp (p<0.05). Study III Mean serum ALP (147.79±28.95) and hsCRP (3.848± 0.47) concentration in group III patients when compared to group I serum ALP (142.17±16.48) and Hscrp (1.51±0.15) shows a high significance of both ALP and Hscrp (p<0.001). Further significant positive correlation was observed between ALP and hsCRP concentration as well as with HbA1c, FBS, and PP2BS.Conclusions: Inflammation along with the poor glycemic control in diabetes play a role in diabetic macrovascular complication like CVD. All these finding are showing a link between CVD, inflammation and glycemic control in patient with type 2 diabetes mellitus

Preparation of transversely isotropic test specimen of natural FRP composite - an innovative approach-II

Fiber Reinforced Plastic (FRP) composites can be broadly classified as synthetic and natural, based on the type of fibers incorporated. Abundantly available natural fibers like toddy palm, sisal, jute and banana are attracting the attention of researchers due to ever increasing demand for lighter, stronger and eco-friendly materials from the industry. However, natural fibers are limited in length, not so uniform in size and behave differently in different atmospheric conditions. Added to this, the inherent tendency of natural fibers to twist and curl in dry conditions poses many problems to researchers while preparing test specimens. Researchers in general and academicians in particular are handicapped by non-availability of relevant literature on fabrication techniques to prepare natural FRP composite test specimens close to their analytical models. Present paper addresses typical problems faced by researchers during preparation of unidirectional continuous fiber reinforced composite test specimen ensuring transversely isotropic nature. Using simple hand tools coupled with a few precautions taken as described herein, prospective researchers can condition natural fibers and prepare composite specimen to suit their requirements.&nbsp