Singh J.K.,CIMFR |
Singh B.R.,Indian Central Electronics Engineering Research Institute |
Singh K.,Indian Central Electronics Engineering Research Institute |
Kumar V.,Indian School of Mines
International Journal of Applied Engineering Research | Year: 2010
In this paper an InGaN/GaN MQW based blue LED has been successfully fabricated and tested. It requires a very low bias voltage of 2.8 V and the emission wavelength has been observed to be ~ 455 nm. It can be converted to a white LED by coating with yellowish phosphor usually made of ceriumdoped yttrium aluminum garnet (Ce3+: YAG). In near future it has potential application in various type of illumination and may replace the present lighting accessories like incandescent bulbs, vehicle light, tube lights etc. White LED’s are 10 to 50% more energy efficient, low power consumption of the order of mW and able to reduce our operating cost up to 90%. © Research India Publications.
Ramulu M.,Indian Central Institute of Mining and Fuel Research |
Raina A.K.,Indian Central Institute of Mining and Fuel Research |
Journal of Mines, Metals and Fuels | Year: 2011
The pace of developments in underground blasting technology is insignificant in contrast to developments in opencast blasting. Blasting practices in underground mines has limited flexibility due to many safety criteria, statutory and field constraints. This has narrowed the scope of major modifications in the solid blasting design vis-à-vis the efficiency and yield per round. However, it is high time to balance the opencast and underground mine production, in view of the exhausting reserves in shallow depth and socio-environmental problems due to opencast mining. With this back-drop, Central Institute of Mining & Fuel Research (CIMFR), Regional Centre, Nagpur developed two new underground blasting techniques with simple modifications in explosive loading patterns. They are: (i) in-hole delay solid blasting technique (ii) bottom hole decking technique. The first technique was in-hole delay solid blasting technique by inserting multiple delay detonators in cut holes to improve the solid blasting efficiency. The conventionally available resources are used in this technique without violating the statutory guidelines. The trial blast results indicated improvements in all the parameters like pull, yield per round, powder factor and detonator factor. The overall improvement in pull per round was 49% with 1.5m deep rounds and 40% with 1.8 m deep rounds. The technique also resulted in reduction of ground vibration intensity by 32-37%. Another blasting method developed was bottom hole decking technique by inserting air-deck at the bottom of the blastholes. In this technique a spacer is to be placed at the bottom of the hole and remaining portion of the hole is conventionally charged. The length of spacer is equal to 10-12% of depth of blasthole. A wooden spacer or any antistatic plastic pipe can also be used for decking. The technique was also applied in both soft and medium hard coal formations while exploiting the thin coal seams. The trial blast results indicated improvements in pull, yield per round and powder factor. The overall progress/pull per round observed was 36% with 1.5m deep rounds and it was up to 22% with 1.8m deep rounds with the powder factor (ton/kg) improvement up to 70%. The technique was also resulted in reduction of ground vibrations by 20-26%. The experimental results also reveal that the in-hole delay solid blasting and bottom hole decking techniques are suitable for relatively harder and softer formations respectively for improving blasting productivity.
Dar B.A.,Indian Institute of Integrative Medicine |
Ahmad N.,Indian Institute of Integrative Medicine |
Patial J.,Indian Institute of Integrative Medicine |
Sharma P.,Indian Institute of Integrative Medicine |
And 3 more authors.
Journal of Saudi Chemical Society | Year: 2014
A simple and one pot process for the synthesis of flavanones in the presence of SO42-/ZrO2, a reusable, heterogeneous catalyst has been described. The reactions were conducted both with and without solvent (using toluene as solvent) at 140. °C with reaction times of 3-4. h. Under these conditions several examples were found with very good yields (73-87%) and up to 83% selectivity. The catalyst was easily recycled and reused without loss of its catalytic activity. The present synthetic method is a simple, clean and environment friendly alternative for synthesizing substituted flavanones. © 2011 Production and hosting by Elsevier B.V.
Gupta R.N.,National Institute of Rock Mechanics |
Tunnelling in Rock by Drilling and Blasting: Workshop Hosted by FRAGBLAST 10 - The 10th International Symposium on Rock Fragmentation by Blasting | Year: 2013
The paper describes a controlled blasting strategy adopted to excavate open cut (for tunnel portal) and a new tunnel near an existing railway tunnel with a parting/barrier of about 16 m. The area lies in highly populated vicinity, with an operational railway track passing through an old tunnel with brick lining, high tension electric traction and small hutments. The objective of the study was to prevent any fly rock from the surface blasting and damage to the existing tunnel from the blasting for the new tunnel.
2012 1st International Conference on Recent Advances in Information Technology, RAIT-2012 | Year: 2012
The word "cyber law" encompasses all the cases, statutes and constitutional provisions that affect persons and institutions who control the entry to cyberspace, provide access to cyberspace, create the hardware and software which enable people to access cyberspace or use their own devices to go "online" and enter cyberspace. In simple way we can say that cyber crime is unlawful acts wherein the computer is either a tool or a target or both. Cyber crimes can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation and mischief, all of which are subject to the Indian Penal Code. The abuse of computers has also given birth to a gamut of new age crimes that are addressed by the Information Technology Act, 2000. © 2012 IEEE.
Singh R.P.,CIMFR |
Sahaya R.R.,NPCIL |
Parmanick D.,NPCIL |
Journal of Mines, Metals and Fuels | Year: 2015
A test was carried out at CIMFR experimental fire gallery with slight modifications in the system to study the burning behavior of diesel fuel in closed chamber under different fuel-oxygen ratios. The gallery is divided into two zones, first 10.5 m long segment is non-firing zone, the second 22m long segment is firing zone and the third 33 m long segment is again a non-firing zone. Eighteen numbers of K type thermocouples were used to measure the temperature distribution inside the test chamber. Out of 18 thermocouples, 10 were fitted at ceiling and 4 on each side walls. Sensors were connected to data logger for continuous recording of data. Experiments carried out in fuel rich, oxygen rich and stoichiometry conditions, the quantity of fuel burn out are almost equivalence and proportionate. The result showed that the even after the presence of 14.11 percentage of oxygen, 155 ml diesel was left out in the tray.
Sahay N.,CIMFR |
Haldar A.C.,ECL |
Ray S.K.,Coal India Ltd |
Kumar N.,Coal India Ltd |
Sinha A.,Indian Central Institute of Mining and Fuel Research
Journal of Mines, Metals and Fuels | Year: 2015
Occurrence of Fuel-rich open fire is one of the serious threats to safety and productivity of coal mines. Many a times it causes virtual closure of mine for a long period or forever. Recovery of such mine needs to address several technical challenges. It requires careful approaches for safe sealing, avoidance of situation for occurrence of explosion and strategies for quick recovery of the mine. Based on the above, a new comprehensive approach comprising safe sealing, control of fire, ventilation control, quick isolation of fire affected area, cooling of hot coal heaps and treatment of fallen coal by inhibitors suggested and implemented by authors for recovery of Kunustoria colliery (ECL) affected with fuel-rich open fire are briefly discussed in this paper.
Sahay N.,Indian Central Institute of Mining and Fuel Research |
Journal of Mines, Metals and Fuels | Year: 2013
Problem of coal seam fire due to spontaneous heating is globally recognised by all coal producing countries because it is an inherent property of coal. Since all coals are prone to spontaneous heating provided it is allowed to oxidize in favourable situation, hence proper diagnosis of the problem and application of comprehensive technology is required to address the problem. Authors have conducted a studies in an opencast mine for better understanding of the problem of fire. The findings may be helpful in safe extraction of coal from fire affected developed seams through opencast.
Kumar S.,CIMFR |
Kumar M.,CIMFR |
Journal of Mines, Metals and Fuels | Year: 2010
At present utilization of fly ash is carried out in the area of bricks, cement, concretes, agriculture and mine filling. The possibility may be investigated to utilize fly ash in quick isolation of fire affected area in underground coal mines by making mine seals. In view of above development of fly ash based composition suitable for construction of alternative mine seals in underground mines will have direct practical application and will provide an alternative to conventional seal as well as it will make control of fire easy and isolation of the area very quick during emergency. Five fly ash samples collected from different thermal power stations and analyzed in respect of their physical properties viz. colour, lumpiness, particle size, leaching behaviour, bulk density, moisture content and combustible material to find their suitability for use in making mine seals.
Kumar A.,CIMFR |
Tewary B.K.,CIMFR |
Banerjee M.,CIMFR |
Banerjee M.,Ranchi University |
Journal of Mines, Metals and Fuels | Year: 2010
Suspended fine particulate matters generated from different mining activities such as washing and crushing of coal affect large volume of natural water. The present paper highlights a simple method to improve the settlement rate of dispersed coal fine particles by incorporating them into a coarser particulate matrix. The process mentioned herein consists of three steps viz. activation of coal fine in aqueous medium, tether of activated particles to the anchor particles and pass them into straight flow stream. The activation of coal fines suspended in the effluent water may be an amine group of polymer which can link to a particle surface of metal oxide to complete the interaction for sedimentation of coal fines. The coagulated coal fine is further separated by gravitation and filtration process.