Articles written in Sadhana
Volume 17 Issue 3-4 September 1992 pp 327-354 Emerging Optoelectronic Technologies
Considerable progress has been made in the field of optoelectronics in the last thirty years. The two principal drivers for this progress have been the invention of the laser and low-loss optical fibres. But what is optoelectronics? Optoelectronics is more than just a marriage of electronics and optics. It represents the higher order integration of technical achievements in electronics and photonics to allow one to chose what, where, when, and how to address both old and new problems and opportunities for increasing customer satisfaction in the areas of information movement and management. I will review the progress in the field and share my insights into where the future lies. The important question no longer is if optics will replace electronics in many of the technologies underlying information movement and management; it is when and to what degree. The limitation no longer arises from the technical capabilities, it comes from economics and social values provided by the increased capabilities in communications and computers.
Volume 45 All articles Published: 3 June 2020 Article ID 0143
The size of coal chips, produced during coal cutting operations, is of prime importance from the viewpoint of feed size desired by power plants. Proper chip size in cutting can eliminate primary crushing and in-turn save energy. Achieving a designated size of chip is intimately linked with the drum design inter alia thewrap angle, line spacing of picks and pick size. Operating parameters namely cutting speed and drum speed also influence the output. Considering the increased need to produce a sized product for cost-effective mining, adesign methodology was developed to achieve a required chip size for surface miners with a middle drum configuration. Various pick, drum and operational parameters were taken into account for the development ofdrum design, namely drum width, drum diameter, pick size, clearance angle, rake angle, cutting angle, lacing pattern, angle of wrap, depth of cut, indented depth of cut and pick spacing. Limiting factors for drum design such as the number of picks, pick temperature, strength of pick, depth of cut and dust generation were discussed. A new drum configuration for achieving 100 mm chip size was validated which showed close agreement with the output produced using 2200SM model surface miner