Refractories for Electric Arc Furnace

Since the first commercial application for steelmaking in 1903, Electric Arc Furnace has been considered as a versatile equipment for production of Steel. It was initially caused for making high quality steels e.g. Stainless steel etc. with high cost of production. However, with the development in the engineering and technology after World War-II, cost of production through this route has become very competitive and production through this route started growing constantly. The annual growth rate has been indicated as 2.5 - 3% currently and a world production level of around a billion tone is expected by the turn of the century. The increase in the share of EAF steelmaking process has been made possible because of introduction of furnaces with large capacity, availability of power at a comparatively lower rate and also the change in process technology which has allowed to use various types of input material. However, with high power rating in the furnaces, the conditions towards the refractory became very severe. Continuous development in Refractories technology as well as in the process engineering, specific consumption of refractories gradually came down. Further in many areas, use of refractories materials have been replaced or minimised with the introduction of water cooled panels

Dissociation Constant of Partly Neutralized Polyacrylic Acid from Measurement of Its pH at Different Salt Concentrations

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A new study of muons in air showers by NBU air shower array

The North Bengal University (NBU) air shower array has been in operation in conjunction with two muon magnetic spectrographs. The array incorporates 21 particle density sampling detectors around the magnetic spectrographs covering an area of 900 sq m. The layout of the array is based on the arrangement of detectors in a square symmetry. The array set up on the ground level is around a 10 m high magnetic spectrograph housing. This magnetic spectrograph housing limits the zenith angular acceptance of the incident showers to a few degrees. Three hundred muons in the fitted showers of size range 10 to the 4th power to 10 to the 5th power particles have so far been scanned and the momenta determined in the momentum range 2 - 440 GeV/c. More than 1500 recorded showers are now in the process of scanning and fitting. A lateral distribution of muons of energy greater than 300 MeV in the shower size range 10 to the 5th power to 7 x 10 to the 5th power has been obtained

A new study of shower age distribution in near vertical showers by EAS air shower array

The air shower array has been developed since it started operation in 1931. The array covering an area of 900 sq m now incorporates 21 particle density sampling detectors around two muon magnetic spectrographs. The air showers are detected in the size range 10 to the 4th power to 10 to the 6th power particles. A total of 11000 showers has so far been detected. Average values of shower age have been obtained in various shower size ranges to study the dependence of shower age on shower size. The core distance dependence of shower age parameter has also been analyzed for presentation

Thermomechanical Processing for Tailoring Properties in Steels

A look into the simple iron-carbon equilibrium diagram (Fig.1) which is a graphical representation of different phases as a function of temperature and composition shows that a variety of steels with any desired combination of phases can be produced"by employing suitable techniques of heat treatments, mechanical processing or a combination of these. Thus, this diagram acts as a tool in producing the required degree of phases like ferrite, austenite cemen-tite etc in the micro-structure to give the expected prop-erties. Three horizontal lines in the diagram represents the three invariant transformations signifying the co-existence of phases in equilibrium at fixed temperature, of which the lower one is of our concern

Internal magnetic fields in thin ZnSe epilayers

Strain induced spin-splitting is observed and characterized using pump-probe Kerr rotation spectroscopy in n-ZnSe epilayers grown on GaAs substrates. The spin-splitting energies are mapped out as a function of pump-probe separation, applied voltage, and temperature in a series of samples of varying epilayer thicknesses and compressive strain arising from epilayer-substrate lattice mismatch. The strain is independently quantified using photoluminescence and x-ray diffraction measurements. We observe that the magnitude of the spin splitting increases with applied voltage and temperature, and is highly crystal direction dependent, vanishing along [1 1-bar 0].Comment: 9 pages, 3 figure

Effect of Pruning on Productivity in Sweet Orange

To sustainable production of quality fruits in eight year old sweet orange plants of cv. Mosambi budded onto Citrus jambheri rootstock, and grown in laterite soil at Jhargram, Paschim Medinipur, a canopy management trial was conducted for two consecutive years. The treatments included T1: No pruning; T2: Removal of dead and dry shoots and branches; T3: T2 + Removal of thin shoots and water-sprouts arising from the leaders at 90° angle; T4: T3 + Removal of selected laterals; T5: T4 + Removal of selected leaders for formation of open-centre-canopy. Randomized Block Design with five replications was set up. Results indicated that fruit production improved with regular pruning. Significantly high fruit retention (68%) with maximum number of fruits (250) was recorded in plants where open-canopy was maintained by judicious removal of the leaders, laterals, thin shoots and dead wood. Trees with open-canopy not only resulted in 71.4% increase in fruit number, but also enhanced fruit weight by 17.9% over Control. Significantly good fruit quality in terms of TSS, total sugars and Vitamin C content was recorded in fruits from the open canopy treatment. Dry weight of shoots / branch was lowest (1.50kg) in open-canopy treatment and highest in the unpruned Control (3.0kg). Foliar N, P and K status did not vary significantly with different pruning practices