Sambar (dish) sambar are popular for breakfast or an evening snack in the south Indian states. Roadside restaurants often offer free refills of sambar for idli and vadas. Sambar is also served as a side dish for dosa. Sambar (dish) Sambar, also spelled sambhar or sambaar, and pronounced saambaar, is a lentil-based vegetable stew or chowder, originating from the Indian subcontinent, cooked with a tamarind broth. It is popular in South Indian and Sri Lankan cuisines. According to food historian K. T. Achaya, the earliest extant mention of sambar in literature can be dated to the 17th century. Sambar is made either
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.