A comparative study on compressive deformation and corrosion behaviour of heat treated Ti4wt%Al foam of different porosity made of milled and unmilled powders.

Ti4wt%Al alloy foams of various porosities were prepared using milled and unmilled powders through space holder technique. Crystallographic and morphological change in milled powder compared to the unmilled one were also examined. Space holder content was varied to get foams of different porosities. After sintering, foams were thermally oxidized through heat treatment and characterised in terms of their pore size, pore morphology, pore interconnectivity, phase formation and compressive deformation behaviour. It was observed that plastic collapse stress, elastic modulus, plateau stress and energy absorption capacity are strong function of porosity and these are higher for the foam made of milled powder (Mf) than those of the foam made of unmilled one (Uf). Corrosion behaviour of these foams were examined. Open circuit potential, Tafel plot and electrochemical impedance spectroscopy confirm that Mf has higher corrosion resistance than Uf for the same porosity level. Also, with increasing porosity, corrosion resistance of the foam samples reduces.

Awareness and Attitude of Select Professionals toward Euthanasia in Delhi, India.

INTRODUCTION: The topic of euthanasia has induced differences not only among professionals in the medical fraternity but also in other fields as well. The dying process is being lengthened by the new state of art technologies erupting as such higher pace, and it is at the expense of standard quality of life and of a gracious death. AIM: To study the awareness and attitude toward euthanasia among select professionals in Delhi. METHODOLOGY: It was a questionnaire-based descriptive cross-sectional study. The study population included doctors, nurses, judges, lawyers, journalist, and social activists of Delhi. Tool included a sociodemographic questionnaire, two questions to know awareness regarding euthanasia and a modified euthanasia attitude scale used to measure attitude toward euthanasia. Data were analyzed using Stata 11.2. RESULTS: Through our study, it is evident that professionals who participated in the study (judges, advocates, doctors, nurses, journalists, and social activists) in Delhi were familiar with the term euthanasia. No significant difference was seen in the attitude of professionals of different age group and sex toward euthanasia. CONCLUSION: Through this study, it is found that judiciary group most strongly endorsed euthanasia. The attitude of doctors was elicited from mixed group with doctors belonging to different specialties. Oncologists are not in favor of any form of euthanasia. However, doctors from other specialties did support euthanasia.

Thermal immobilization of Cr, Cu and Zn of galvanizing wastes in the presence of clay and fly ash.

In the present investigation thermal treatment of galvanizing waste with clay and fly ash has been carried out to immobilize Cr, Zn, Cu and other metals of the waste at temperature range 850 degrees C to 950 degrees C. Leaching of the metals from the waste and solidified product was analyzed using toxic characteristic leaching procedure (TCLP). Results indicated that the composition of waste and clay treatment temperature are the key factors in determining the stability of solidified product. After heating at 950 degrees C, the solidified specimens of 10% waste with clay have shown comparatively a high compressive strength and less water absorption. However, a decrease in compressive strength and increase in water absorption were noticed after addition of 15% of waste with clay. The leachability of all the metals present in the waste was found to reduce considerably with the increase of treatment temperature. In the case of Cr and Zn, their leachabilty was found at unacceptable levels from the treated product obtained after heating at 850 degrees C However, their leachability was reduced significantly within an acceptable level after treatment at 950 degrees C. The thermal treatment has shown an increase of re-oxidation trend of Cr (III) to Cr (VI) up to 900 degrees C of heating and this trend became almost zero after heating at 950 degrees C. Addition of fly ash did not show any improvement in strength, durability and leachability of metals from the thermally treated product. X-ray diffraction (XRD) analysis of the product confirmed the presence of mixed phases of oxides of toxic metals.

Thermal treatment of toxic metals of industrial hazardous wastes with fly ash and clay.

Waste generated from galvanizing and metal finishing processes is considered to be a hazardous due to the presence of toxic metals like Pb, Cu, Cr, Zn, etc. Thermal treatment of such types of wastes in the presence of clay and fly ash can immobilizes their toxic metals to a maximum level. After treatment solidified mass can be utilized in construction or disposed off through land fillings without susceptibility of re-mobilization of toxic metals. In the present investigation locally available clay and fly ash of particular thermal power plant were used as additives for thermal treatment of both of the wastes in their different proportions at 850, 900 and 950 degrees C. Observed results indicated that heating temperature to be a key factor in the immobilization of toxic metals of the waste. It was noticed that the leachability of metals of the waste reduces to a negligible level after heating at 950 degrees C. Thermally treated solidified specimen of 10% waste and remaining clay have shown comparatively a higher compressive strength than clay fired bricks used in building construction. Though, thermally heated specimens made of galvanizing waste have shown much better strength than specimen made of metal finishing waste. The lechability of toxic metals like Cr, Cu, Pb and Zn became far below from their regulatory threshold after heating at 950 degrees C. Addition of fly ash did not show any improvement either in engineering property or in leachability of metals from the solidified mass. X-ray diffraction (XRD) analysis of the solidified product confirmed the presence of mixed phases of oxides of metals.

Thermal stabilization of metal finishing waste with clay.

Thermal treatment of metal finishing waste with locally available clay, in their varying ratios, was carried out at 850 degrees C and above temperatures. In the presence of 1:1 ratio of waste and clay a solidified product was obtained at 950 degrees C. Measurement of an appreciably high compressive strength, approximately 500 kg cm(-2) and a very small (0.4%) water absorption from the solidified product indicated its stable nature. Toxicity Characteristic Leaching Procedure (TCLP) test of the waste showed nearly 85 to 90% decrease of leaching of Fe, Cu, Ni, Zn, Mn and Cr after thermal treatment compared to their leaching without treatment. No hexavalent chromium (Cr(VI)) was observed from the leachate of the solidified product. This indicates the absence of re-oxidation phenomena of chromium during thermal treatment up to 950 degrees C. X - ray diffraction (XRD) of solidified product indicated the presence of hematite, and aluminum silicate as main phases of the solidified product. Involvement of the above waste metals with these phases during thermal treatment could be the reason for their immobilization.

Effects of pH on Cr-Fe interaction during Cr(VI) removal by metallic iron.

In the present investigation, the effect of pH on Cr-Fe interactions has been studied by carrying out Cr(VI) removal utilising metallic iron from the dichromate solutions of pH 2 to 7 by batch shaking process. Since the presence of ferrous iron in the solution is mainly responsible for Cr(VI) reduction, solubility of iron from the metallic iron was also measured. The maximum Cr(VI) removal efficiency was found at pH 2 but pH 3 was considered to be a suitable solution condition for Cr(VI) removal due to the occurrence of a minimum level of iron in the treated solution. Chemical analysis of Cr(VI)-reacted iron and treated dichromate solutions has indicated the reduction of Cr(VI) to Cr(III) at the metal surface itself at pH 2 and 3 and in the solution at pH 4 and above. A considerable decrease in chromium concentration on the iron surface in the pH range 4 - 7 as compared to pH 2 and 3 was also observed by EDXA analysis. These studies confirmed that after reduction, involvement of Cr(III) with Fe takes place at the metallic iron surface itself at pH 2 and 3 while it reduces with the rise of pH.

Cr(VI) removal in acidic aqueous solution using iron-bearing industrial solid wastes and their stabilisation with cement.

In this study, iron-bearing industrial solid wastes iron filings, ETP sludge of steel and red mud of aluminium industries; were used for Cr(VI) removal at pH 3. A complete removal of Cr(VI) was found for initial 10 mg 1(-1) of 100 ml solutions in the presence of 2.5 g iron filings, 8 g ETP sludge and 10 g red mud for up to one hour of shaking at room temperature. After Cr(VI) removal, inclusion of chromium on the reacted iron filing surface was demonstrated by EDAX analysis. Leachability of chromium and iron from the reacted wastes was determined by using Toxicity Characteristics Leaching Procedure (TCLP). This test showed a very low level of leachability of chromium as Cr(III) and iron from the reacted wastes. To minimise their leachability further, Cr(VI)-reacted solid wastes were stabilised with Portland cement in their 3:1 ratio. Leachability tests of stabilised wastes by TCLP indicated a considerable decrease in leachability of chromium and iron compared with the that of reacted wastes alone. To explore the possibility of utilisation in building materials, bricks of cement-mixed Cr(VI)-reacted wastes were made and their comprehensive strength, durability and leachability under immersion conditions were measured.

Influence of dissolved oxygen on aqueous Cr(VI) removal by ferrous ion.

Hexavalent chromium [Cr(VI)] is a highly toxic and carcnogenic pollutant, introduced to the environment due to several industrial activities. Ferrous iron (Fe(II)], an important natural reductant of the Cr(VI), and its release from iron-bearing materials is now becoming a viable alternative for transforming Cr(VI) to the relatively non toxic trivalent form of chromium [Cr(III)]. Cr(VI) removal by ferrous ion at different pH is widely discussed in the literature but the influence of dissolved oxygen on the Cr(VI) removal with respect to pH, is still a contradictory subject. In the present study a systematic approach has been made to estimate the Cr(VI) removal by ferrous ion in oxygen-free and oxygen-containing aqueous solutions of pH 3 to 7. Quantitative analysis results suggest that the influence of dissolved oxygen on the Cr(VI) reduction starts at pH 4. Though, its effect appears to be in significant up to pH 6, becomes quite pronounced at pH 7 because nearly 10 to 12% less removal of the Cr(VI) was observed in the presence of the stoichiometric requirement of three equivalents of Fe(II) in oxygenated solution of pH 7. This was evidenced by carrying detailed spectrophotometric absorption measurements of the Cr(VI) in the presence of Fe(II) in its different equivalent ratios in oxygenated and deoxygenated solutions.

Organotin compounds in surface and pore waters of Ganga Plain in the Kanpur-Unnao industrial region, India.

Organotin compounds (OTCs) belong to those chemicals most toxic to the aquatic organisms which are deliberately introduced into the aquatic system through anthropogenic activities. Various species of organotin compounds were detected in surface and pore waters of the Ganga Plain in Kanpur-Unnao industrial region in pre-and post-Monsoon periods of 1995. The extraction of these compounds was performed using a method of direct aqueous phase in situ ethylation with sodium tetraethylborate (NaBEt4). After extraction into hexane, they were detected by GC-MIP-AED. The water of this area is contaminated with dimethyltin (DMT), monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) compounds. Concentrations of these compounds in surface water of the pre-Monsoon period of 1995 range from 2.1 to 70.1 ng Sn/l for MBT, 1.7-101.1 for DBT and 2.9-19.8 for TBT, whereas in pore water; 9.7-23.5 ng Sn/l for MBT, 11.2-18.0 for DBT and 8.7-32.6 for TBT. However, in the post-Monsoon period of 1995, surface water shows considerable decrease in concentrations: DMT below detection-1.8 ng Sn/l, DBT 3.0-5.4, TBT 3.1-3.6 and MBT is below detection. This study is a preliminary documentation of water pollution by OTCs in the Kanpur-Unnao region of the Ganga Plain and suggests the necessity of further detailed OTCs studies in other regions of the Ganga Plain.

Hospital management training in the North Eastern Region.

The article highlights the lack of training facilities for hospital management in the entire North Eastern Region, explores the quantum of need of the training in the region by identifying hospitals, other health institutions and manpower in the region which require, for their qualitative and quantitative improvement, the expertise in hospital management, and recommends suitable courses of hospital management to start with.