Non-Hermitian Quantum Mechanics with Minimal Length Uncertainty

We study non-Hermitian quantum mechanics in the presence of a minimal length. In particular we obtain exact solutions of a non-Hermitian displaced harmonic oscillator and the Swanson model with minimal length uncertainty. The spectrum in both the cases are found to be real. It is also shown that the models are $\eta$ pseudo-Hermitian and the metric operator is found explicitly in both the cases

Extraction of silicomanganese from marine and low grade mineral resources

Manganese nodule, available in ocean beds, is a potential resource of the future for copper, nickel and cobalt. Recovering only these metals, containing less than 3% by weight, will result in the generation of large amount of residue. In addition to the material losses, several environmental and ecological problems arise out of this. The present study has been aimed at reducing the environmental and ecological problems associated with massive generation of this residue together with utilization of the resources. Presence of ~ 20% manganese and ~16% silicon in the residue has prompted us to check its suitability as a raw material for silicomanganese production. Lower manganese content and lower Mn/Fe ratio of the residue than that required for silicomanganese production has been corrected in this study by suitable blending. The efficacy of blending and its thermodynamic aspects using FACTSAGE software are discussed. The studies conducted indicate viability of bulk utilisation of the residue through silicomanganese production and thereby reducing the burden on environment to a great extent

Dissolution Behaviour of Fe-Co Alloy in Leaching of Sea-Nodule

Recovery of cobalt from the ammoniacal leaching of polymetallic sea-nodules was often found around 50%, whereas copper and nickel recovered in the range of 90-95%. It is believed that Fe-Co alloy system form during reduction roasting is very stable to ammonia solution. To enhance the cobalt recovery some additives were selected and it was observed that by the use of these additives electrochemical dissolution rate increases in comparison to the system without any additive. Also, the presence of additive lowers the dissolution potential to –454 mV which is a requirement for better recovery of cobalt. Work was further extended with the use of metals powder in pure as well as mixed condition in presence these additives and it was found that cobalt recovery increased above 80%

Photocatalytic Removal of Copper and Selenium from Waste water under Visible Light

Zirconia and silica mixed titanium oxides were synthe-sized by modified sol-gel method in presence of a surf-actant (CETAB). Materials were characterized by surface area, XRD, SEM and UV-Vis spectroscopy. Materials are found to be in uniform size and mostly spherical when synthesized in presence of CETAB. Effect of sum factant concentration on the particle size, shape and the catalytic activity is also evaluated. Calcination temp-erature plays an important role on the phase stability and catalytic activity of the materials. It is well observed that without any hole scavenger the efficiency of photocatalytic metal removal is quite low for both the metal ions within 30minuites of reaction. However, addition of hole scavenger increases the activity many folds and hence complete removal of Se and Cu was possible in 30 minutes of reaction. Among all the organic hole scavengers used, sodium formate is found to be the most active one for selenium whereas for copper EDTA is the most suitable one. Reaction pH also plays important role in the efficiency of the metal removal. Above all synth-esized materials are found to be efficient catalyst for visible light reaction. The same catalyst is found to be reusable at least for 5-6 times with 4-5% decrease in the activity

Effect of organic source of nutrients and biofertilizers on growth, yield and quality of turmeric (Curcuma longa L.)

Turmeric (Curcuma longa L.) being a long crop duration, rhizomatous nature and high productivity it re-quires heavy input of fertilizers. Keeping this in view, an experiment was conducted at the Instructional farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal during 2009-10 and 2010-11 to study the effect of organic source of nutrients and biofertilizers on growth, yield and quality of Turmeric (Curcuma longa L.). The results revealed that application of green leaf manure (from Glyricidia maculata) @ 12tonnes/ha along with rock phosphate @ 0.2 tonnes/ha, wood ash @ 1 tonnes/ha, Azospirillum @ 5kg/ha + PSB @ 5kg/ha (T5) gave the sig-nificantly highest fresh (29.27 tonnes/ha) and dry yield (7.81 tonnes/ha) followed by vermicompost 5 tonnes/ha along with Azospirillum @ 5kg/ha + PSB @ 5kg/ha (T4) (26.30 tonnes/ha and 6.99 tonnes/ha, respectively) which was statistically at par with sole application of 30 tonnes/ha farm yard manure (T2) ( 26.00 tonnes/ha and 6.77 tonnes/ha, respectively). Next highest dry yield (6.40 tonnes/ha) was recorded in control plots (T6) of recommended dose of fertilizers at the rate of 80:80:120 kg N, P2O5 and K2O/ ha along farm yard manure @ 15 tonnes/ha. The lowest fresh yield of 19.31 tonnes/ha and dry yield (5.26 tonnes/ha) was recorded in the treatment of sole application of FYM @ 15 tonnes/ha (T1). Somewhat higher dry recovery percentage was recorded in case of all the organic treatments compared to control treatment (T6). Maximum dry recovery (27.22%) and curcumin content (5.24%) was recorded in the treatment of sole application of FYM @ 15 tonnes/ha (T1). It may be concluded that the application of green leaf manure (from Glyricidia maculata) @ 12tonnes/ha along with rock phosphate @ 0.2 tonnes/ha, wood ash @ 1 tonnes/ha, Azospirillum @ 5kg/ha and PSB @ 5kg/ha was the best treatment followed by application of Vermicompost @ 5 tonnes/ha + Azospirillium @5 kg/ha + PSB @ 5 kg/ha and application of farm yard manure @ 30 tonnes/ha treatments for dry yield and quality of turmeric

Anodic dissolution behaviour of tungsten carbide scraps in ammoniacal media

In the present paper, potentiodynamic studies of WC scrap have been carried out as these studies give better idea about the anodic dissolution behaviour of the scrap material for their recycling to recover metal values. However, it has been seen that anodic passivation retards the dissolution of the scrap and adversely affects the recovery of metals. To minimise the passivity and to increase the anodic dissolution, some chemicals are often used as additives. Two different electrolytes namely hydrochloric acid and aqueous ammonia at varying concentrations had been employed for the above studies. The additives citric acid and oxalic acid were added to the acidic electrolyte whereas ammonium chloride, ammonium carbonate, ammonium sulphate were added in different concentration to the ammoniacal electrolyte. The studies revealed that 2% citric acid in 1N HCl was the optimum to achieve maximum anodic dissolution (current) of WC scrap. On the other hand, 2% NH4Cl was found suitable to obtain maximum anodic dissolution (current) in the ammoniacal (1N) medium. The potentiodynamic studies were followed by the actual electrodissolution experiments in an electrolytic cell with the help of a rectifier. The W and Co were recovered as tungsten oxide and metallic chips, respectively

An overview on different processes for recovery of valuable metals from tungsten carbide scrap.

Cemented tungsten carbide material has been widely used in the hard metal industry for the manufacture of cutting tools, drilling tools, mining and machining tools and high wear resistant parts. When these tool bits and components are scrapped, they are collected and processed for recycling following appropriate methods. Tungsten and cobalt both are strategic rare metals and the cost of these metals entrapped in these scraps is estimated to be very high. Therefore, WC scraps have been considered as an important secondary resource of cobalt and tungsten metals. Recycling of hard materials like tungsten carbide scrap require specialised techniques. This paper presents a review of the different processes reported so far to recover valuable metals (W, Co) from cemented tungsten carbide scrap materials. Recycling techniques following either hydro or pyrometallurgical or a combination of them to recover the valuable metals (W, Co) are discussed. Thermal oxidation in presence of air/oxygen generates friable oxides of metals contained in tungsten carbide hard material, which is either leached in acid/alkali to produce tungsten oxide or subjected to reduction by hydrogen to produce tungsten powder. Direct leaching of tungsten scrap in concentrated acid/alkali solutions has also been investigated and different value added materials like ammonium para tungstate, tungstic acid etc are produced in the subsequent processing of leach liquor. The electrochemical route has emerged as an attractive method as it is a single step dissolution process consuming very low energy. However, passivation has been reported to slow down the dissolution rate and hence, some additives have also been tried for continuous dissolution. The environmental and economical aspects of some of the important processes have also been highlighted in this paper