Competition between Spiral-Defect Chaos and Rolls in Rayleigh-Benard Convection

We present experimental results for pattern formation in Rayleigh-Benard convection of a fluid with a Prandtl number, Pr~ 4. We find that the spiral-defect-chaos (SDC) attractor which exists for Pr~1 has become unstable. Gradually increasing the temperature difference from below to well above its critical value no longer leads to SDC. A sudden jump of temperature difference from below to above onset causes convection to grow from thermal fluctuations and does yield SDC. However, the SDC is a transient; it coarsens and forms a single cell-filling spiral which then drifts toward the cell wall and disappears.Comment: 9 pages(RevTeX), 5 jpg figures, To appear as Rapid Communication in PR

A ‘never before’ presentation of a common Mullerian abnormality

Transvaginal septum is one of uncommon Mullerian anomalies which may lead to infertility. We all depend so often on HSG and MRI for investigating these infecund patients. Here we bring out how a distended vaginal cavity with contrast mimicked the uterine cavity on HSG misleading the clinician. The septum was missed on MRI too initially. A simple surgical correction and the patient was able to conceive in her very first cycle