Salvation of a severely resorbed mandibular ridge with a neutral zone technique

The objective of any prosthodontic service is to restore the patient to normal function, contour, esthetics, speech, and health. An optimum denture stability is difficult to achieve in conventional complete dentures. This problem is more magnified in mandibular dentures. The design of prostheses to replace lost teeth and resorbed ridges is largely determined by the position and amount of morphological change in the denture-bearing area of the jaws. A neutral zone may be defined as the space where, during function, the forces of the lips and cheeks pressing inward neutralize the forces of the tongue pressing outward. The neutral zone concept implies acquired muscle control, especially by tongue, lips, and cheeks toward the denture stability. Advocates of the neutral zone concept agree that a lack of favorable leverage is observed when teeth are positioned directly over the ridge. By employing the neutral zone concept, the dislodging muscle energy can easily become a retentive and stabilizing force

Atomic clocks: A brief history and current status of research in India

Frequency corresponding to the energy difference between designated levels of an atom provides precise reference for making a universally accurate clock. Since the middle of the 20th century till now, there have been tremendous efforts in the field of atomic clocks making time the most accurately measured physical quantity. National Physical Laboratory India (NPLI) is the nation's timekeeper and is developing an atomic fountain clock which will be a primary frequency standard. The fountain is currently operational and is at the stage of complete frequency evaluation. In this paper, a brief review on atomic time along with some of the recent results from the fountain clock will be discussed

NPLI Cesium Atomic Fountain Frequency Standard: Preliminary Results

National Physical Laboratory India has developed a cesium atomic fountain frequency standard. The fountain has now become operational and is ready for complete frequency evaluation. In this paper, we report for the first time, the preliminary results obtained with this fountain, which include Ramsey fringes, frequency stability analysis, with an H-maser, and magnetic field mapping in the atomic flight region