Sambar (dish) powder. In Andhra Pradesh, it is called as "Pappu chaaru". Apart from dal and tamarind, vegetables used in preparing is few. Vegetables are onions, dosakaaya, bitter gourd and tomatoes. Sambar without lentils (but with vegetables, or dried or fresh fish) is called kuzhambu in Tamil Nadu. Sambar is usually served with steamed rice as one of the main courses of both formal and everyday south Indian cuisine. A two-course meal of sambar mixed with rice and eaten with some sort of vegetable side dish, followed by yoghurt mixed with rice, is a prime southern Indian staple. "Vada" sambar and "idli"
Pulse tube refrigerator developed for cooling of astronomical detectors where liquid cryogens are typically used, such as the Atacama Cosmology Telescope or the Qubic experiment (an interferometer for cosmology studies). PTRs are used as precoolers of dilution refrigerators. Pulse tubes will be particularly useful in space-based telescopes such as the James Webb Space Telescope where it is not possible to replenish the cryogens as they are depleted. It has also been suggested that pulse tubes could be used to liquefy oxygen on Mars. Here the so-called Stirling-type single-orifice pulse-tube refrigerator will be treated operating with an ideal gas (helium) as the working fluid.