006469   Nagi M;Chawla S;Jain R (Department of Food & Nutrition, Punjab Agricultural University, Ludhiana) : Study on the nutritional status of selected 13-15 years school girls of Ludhiana city. J Res-Punjab Agric Univ 1999, 36(3-4), 270-9.

One hundred and twenty school girls in the age group of 13-15 years from four Government schools of Ludhiana city were selected for the study. On the basis of their family income they were divided into three experimental groups i.e. income group 1 (IgI) income group II (IgII) and income group III (IgIII). The results showed that the intake was low for all the foods. However, the consumption of fruits, milk and milk products, sugar and jaggery, fats and oils by the subjects of IgII and IgIII was significantly higher (P<0.50) than IgI. The mean daily intake of energy, protein, iron, calcium vitamin A and vitamin C was inadequate as compared to ICMR recommendations. There was no significant difference in energy, protein and iron intakes among the subjects of three groups. The intake of calcium, vitamin A and ascorbic acid by the girls of IgII & IgIII was significantly higher (P<0.5) than those of IgI. The average body weights and heights of the subjects were normal. The hemoglobin (Hb) level of the subjects ranged from 8.5-12.5 g/dl with a mean value of 10.73±0.07 and reported that only 23 per cent of the subjects had acceptable level.

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006468   Mcleod N (NO, , ) : Overview of frying oils - their chemistry, breakdown and maintenance. Beverage Fd Wld 2000, 27(7), 45-52.

006467   Maiti C K;Bera L K;Maikap S;Ray S K; Chakrabarti N B (NO, Indian Institute of Technology, Kharagpur-721 302) : Growth of silicon-germanium alloy layers. Def Sci J 2000, 50(3), 299-315.

Heteroepitaxy techniques for the growth of group IV binary alloys, in particularly SiGe, SiC, GeC and SiSn films are reviewed. Deposition of heteroepitaxial films using various reactors like molecular beam epitaxy, gas source molecular beam epitaxy, and different chemical vapour deposition techniques are compared. Issues related to heteroepitaxial film deposition, such as critical layer thickness are examined. Growth of strained silicon on relaxed SiGe fubber layers, poly-SiGe films and hydrogenated amorphous SiGe (a-SiGe:H) film is also reveiwed.

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006466   Kulshreshtha A K (IPCL, , Vadodara-391 345) : Metallocenes : the millennium plastics - Part .VI. performance tailoring : catalyst design for tailor made polyolefins. Pop Plast Packag 2000, 45(10), 73-4,85.

006465   Khare S K;Nabetani H;Nakajima M (Central Institute of Agriculture Engineering, Indian Council of Agricultural Research, Nabi-Bagh, Bhopal-462 038) : Lipase catalyzed interesterification reactions and their industrial applications. Indian Fd Ind 2000, 19(1), 29-35.

Describes the salient features of lipase catalyzed reactions, highlighting the problems encountered while carrying out the synthetic interesterification reaction in orgainc solvents. Various strategies to modify lipase with specific reference to surfactant lipase complex and stearic acid modification are discussed. Presents applications of lipase in production of structured lipase and oil modifications are also highlighted.

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006464   Kalyanasundaram S;Sundaresan B;Hemalatha J (Department of Physics, Alagappa University, Karaikudi-630 003) : Solvation study of polymers by ultrasonic method. J Polym Mater 2000, 17(2), 155-63.

Method of obtaining the molar solvated volume of polymer in solution from adiabatic compressibility or solvation number is described on the basis of Padova/s model and also the expression for molar solvated volume and intrinsic volume are obtained. The methodology is verified using aqueous PEG (6000) solution at 303 K, 308 K, 313 K and 318 K for various concentrations.

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006463   Gupta D C;Sumana G;Prakash S (Defence R&D Establishment, , Gwalior-474 002) : Polysiloxane based slow release formulations of N,N-diethylphenylacetamide - a broad spectrum insect repellent. J Polym Mater 2000, 17(2), 215-9.

Protection time of N,N-diethylphenylacetamide (DEPA), a broad spectrum insect repellent is concentration dependent. Protection time of DEPA against mosquitoes may be increased by developing its slow release formulations using polysiloxanes as matrix systems. 10-30% DEPA was mixed with polysiloxanes and protection time was found to be 1.0-7.5 hours at DEPA concentrations of 1.0 mg/cm² for different polysiloxane DEPA formulations. Poly(dimethyl-vinylmethyl) siloxane P(DM-VM)S-DEPA formulation show maximum protection time of 7.5 hours at DEPA concentrations 1.0 mg/cm².

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006462   Ganapat I M;Patel B P;Kemkar K (NO, Institute of Armament Technology, Pune-411 025) : Theoretical & experimental studies on vibration and damping of fibre-reinforced cantilever laminates. Def Sci J 2000, 50(3), 325-33.

Vibration and damping analyses of glass fibre-reinforced laminated composite cantilever beams and plates are studied using C¹ finite element using shear deformation theory and also through experiments. The formulation in the theoretical model includes in-plane and rotary inertia terms. The governing equations for the complex eigenvalue problem based on complex elastic moduli are formulated. The solutions are obtained using QR algorith. Parametric study is carried out to highlight the effects of lay-up and ply-angle of the laminates. A limited number of experimental investigations on cantilever laminates are conducted for obtaining the natural frequencies, damping factor and frequency responses. The comparison between the theoretical and the experimental results shows good agreement.

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006461   Fisher J C (Nova Chemical Corporation, , Canada) : Advanced scalairtech - a new approach to easy processing single site resins. Pop Plast Packag 2000, 45(10), 64-72.

NOVA Chemical's advanced Sclairtech Process (AST), when using Ziegler-Natta catalyst produces polymers which exceed the performance of many current competitive metallocene polymer offerings. The ability to accurately control molecular weight and comonomer distribution with the AST technology provides the capability to tailor performance according to the specific end-use requirements of the converter. This presentation will focus on the performance of new resins for the LLDPE and VLDPE films resin segments. When the flexibility of AST is combined with NOVA Chemical's proprietary SSC, the enhanced physical performance of SSC products can be realized, while maintaining ease of processing for the converter. This is achieved through understanding and application of polymer structure-property relationships through modeling and advanced process control.

006460   De B;Samanta A;Kanungo S (NO, Regional Institute of Pharmaceutical Science and Technology, Abhoynagar, Agartala-799 005) : Study on deterioration of coconut water. J Instn Chem India 2000, 72(1), 23-5.

Deterioration of coconut was investigated by recording the UV-spectra and pH of the coconut water. The deterioration of fresh consumable coconut water was noted upto fourth days of observation in case of both ripe and unripe, followed by matching with the originally deteriorated coconut water.

006459   Basantia N C;Arora S;Setb R;Ajit Singh (Dairy Chemistry Division, National Dairy Research Institute, Karnal-132 001) : Milk proteins in the preparation of edible coatings. Indian Fd Ind 2000, 19(1), 36-47.

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006458   Ahmed M T;Fahmy T (Polymer Laboratory, Physics Department, Faculty of Science, Mansoura University, Mansoura-35516, Egypt) : Carrier transport and thermally stimulated depolarization current in iodine-doped poly(Vinyl chloride). J Polym Mater 2000, 17(2), 133-8.

DC measurements and thermally stimulated depolarization current (TSDC) of pure and iodine-doped poly (vinyl chloride) films have been studied. The transient current peaks were observed and explained in the light of space charge limited current (SCLC). The average values of drift mobility have been calculated in the order of ≅ 10^-11 cm² V^-1 s^-1 and found to be strongly affected by the presence of iodine and the temperture. The dependence of electrical conductivity and activation energy upon the iodine concentration is explained on the basis of charge transfer complexes of interaction between iodine and polymeric molecules. TSDC studies revealed that the peak temperature shifted to higher values with increasing iodine concentration. The activation energies and relaxation parameters of the relaxation process were evaluated. Based on the results, the origin of the TSDC peak was attributed to a superposition of dipolar relaxation and space charge build up.

19 ref.

006457   Adhikari B;Ghosh A K;Maiti S (NO, , Subarnarekha, J23 Bidhannagar, Midnapore-721 101) : Developments in carbon black for rubber reinforcement. J Polym Mater 2000, 17(2), 101-25.

Trend of research and development in the carbon black technology has been reviewed. Heat treatment of carbon black and carbon black rubber masterbatches, attachment of promoters of coupling agents with carbon black, grafting of oligomers and polymers onto carbon black and various chemical modifications of carbon black were carried out for the improvement in its reinforcing properties. The results of these modification processes have been critically examined and correlated with rubber reinforcement. The overall picture of reinforcement of carbon black on rubber has also been presented.

134 ref.

005299   Verma B B;Pandey R K (Metallurgical Engineering Deptt., R.E. College, Rourkela-796 008) : Effect of loading variables on overload induced delay cycle in fatigue. Trans Indian Inst Metals 2000, 53(3), 291-301.

Investigates the effect of loading variables such as stress intensity range, ΔK, stress ratio, R, and over loading ratio (OLR) on delay cycles, N_D. The study has been conducted on 2024 - T3 Aluminium alloy and 4130 Ce - Mo steel sheets with yield strength of 375 and 587 Mpa respectively. Fatigue tests have been conducted on centrally cracked tension specimens employing an Electro - Magnetic Resonance machine at a frequency of <126> 100 Hz. The crack extension was measured using Electrical Potential Difference (EPD) technique as well as travelling microscope. An attempt has also been made to study the effect of overload induced crack closure and plastic zone size on the retardation behaviour. Further the delay cycle has also been correlated with the retarded crack length, a_D. The important findings of the investigation have been highlighted.

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005298   Valsan M;Nagesha A;Bhanu Sankara Rao K;Mannan S L (Materials Development Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Comparative evaluation of low cycle fatigue and creep-fatigue interaction behaviour of 316L (N) stainless steel, 316 weld metal and 316L(N)/316 weld joint at 873 K. Trans Indian Inst Metals 2000, 53(3), 263-71.

Low cycle fatigue (LCF) and creep-fatigue interaction behaviours of 316L(N) base metal, 316 weld metal and weld joints were studied at 873 K over various strain amplitudes. Hold times were introduced in tension or compression peak strains, with the duration varying from 1 min. to 90 mins. The cyclic hardening observed is attributed to dynamic strain ageing and cyclic softening seen in the weld metal is ascribed to the annihilation of dislocations. The better fatigue and creep-fatigue life (1 min. tension) seen in the weld metal compared to the base metal was due to reduced crack propagation rate associated with crack deflection by many transformed δ-ferrite boundaries. The poor fatigue resistance of the weld joint was ascribed to intergranular crack initiation associated with coarse grain size in the heat-affected zone. The factors that contribute to decrease in fatigue life with hold time were identified to be enhanced intergranular damage, assisted by oxidation.

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005297   Tewari R;Dey G K;Ravi K;Kutty T R G;Banerjee S (Materials Science Division, Bhabha Atomic Research Centre, , Mumbai-400 085) : Hot hardness and indentation creep behaviour of Zr₃Al-Nb alloys. Trans Indian Inst Metals 2000, 53(3), 381-9.

Zr₃Al based intermetallics have been considered as candidate materials for structural components in nuclear reactions. Ternary addition of niobium has been found to influence the microstructure and mechanical properties of these materials. Mechanical properties including creep rates of binary Zr₃Al and ternary Zr₃Al-10Nb alloys measured from microindentation experiments carried out in the temperature range of 300 K to 1300 K. Niobium addition was found to increase the high temperature strength up to about 800 K without sacrificing ductility. However, the onset temperature for softening was lower in the case of the ternary alloy. Creep rates at different temperatures and activation energies of high temperature creep have been determined for both binary Zr₃Al and ternary Zr₃Al-10Nb alloys. Zr₃Al based alloys have shown a lower steady state creep rate than many of the structural intermetallics such as Ni₃Al and FeAl.

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005296   Sundararaman M;Singh V;Chen W;Wahi R P (Materials Science Division, BARC, , Mumbai-400 085) : Stress response behaviour of and microstructural evolution in Nimonic PE16 LCF tested at temperatures up to 923 K. Trans Indian Inst Metals 2000, 53(3), 255-61.

Cyclic stress strain behaviour of nickel base superalloy, Nimonic PE16 has been studied at a constant strain rate of 4 x 10^-3S^-1 at different strain amplitudes as a function of γ' particle size for temperatures up to 650°C. Fatigue softening after initial hardening was observed in all samples containing γ' particles up to an average size of 30 nm tested at room temperature while a saturation in the cyclic stress response behaviour after initial hardening was observed in samples containing γ' particles above an average size of 21 nm tested at 650°C. Detailed TEM investigation was carried out to understand the observed fatigue behaviour. Fatigue softening was noticed to be associated with shearing of γ' particles and localisation of slip while saturation behaviour was associated with Orowan looping and non-localisation of slip. Particle size at which the mechanism of deformation changes from shearing to looping decrease with increase of test temperature. This behaviour is explained on the basis of the effect of test temperature on the line tension of dislocations. In the case of shearable precipitates, width of deformation band decreases with increase of temperature reaching that of single slip lines at 923 K. Change of deformation microstructure with testing temperature, γ' free bands at room temperature, fine γ' particles within the bands at 673 K and sheared γ' at 923 K, are explained on the bais of combined effect of mechanical shearing and fatigue enhanced diffusion within bands. Fatigue life decreases with increase of test temperature.

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005295   Subramanya Sarma;Padmanabhan K A;Jaeger G; Koethae A;Schaper M (NO, Indian Institute of Technology, Kanpur-208 016) : On the fatigue thresholds and the fatigue crack growth behaviour of two ferrite-pearlite microalloyed steels. Trans Indian Inst Metals 2000, 53(3), 303-14.

Fatigue thresholds (ΔK_th), crack closure and fatigue crack growth (FCG) behaviour of two microalloyed (MA) ferrite-pearlite SLA steels have been reported. The ΔK_th, crack closure and FCG rates were measured using the dynamic compliance measurement technique. The fatigue thresholds decreased with increasing load ratio, R. This is attributed to the crack closure phenomenon. The theoretically computed crack closure stress intensity K_{cl th} and ΔK_{eff th} were compared with the experimental values. The estimated K_cl was significantly lower than the experimentally measured value in the low carbon MA steel E-38 (ferrite dominant) but marginally higher in the medium carbon MA steel 49MnVS3 (pearlite dominant). The estimated ΔK_{eff th} correlated reasonably well with the experimental values in both the steels. The predicted FCG rates in the Paris region compared well with the experimental results with the Paris exponent m was taken as equal to 2(2n'+1). Transmission electron microscopy in the near threshold region showed dislocation pile ups near the ferrite grain boundary in the low carbon MA steel.

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005294   Sivaprasad S;Tarafder S;Ranganath V R;Ray K K (Fatigue and Fracture Group, National Metallurgical Laboratory, , Jamshedpur-831 007) : Fatigue crack growth studies on Cu-strengthened HSLA steels in air and in simulated sea water. Trans Indian Inst Metals 2000, 53(3), 333-9.

Influence of simulated sea water vis-a-vis air on fatigue crack growth behaviour in two Cu-strengthened HSLA steels at different R-ratios and frequencies has been investigated. These studies have been substantiated with crack closure measurements. The results indicate that the influence of microstructure and R-ratio on FCGR and CFCGR of these steels can be explained primarily using crack closure concepts. The effect of frequency on CFCGR is elucidated through fractographic records of changes in the crack growth mechanisms.

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005293   Singh R S;Singh S P (Department of Ceramic Engineering, Banaras Hindu University, Varanasi-221 005) : V<. Trans Indian Ceramic Soc 2000, 59(3), 47-53,63.

Oxidation-reduction equilibrium in binary alkali silicate glasses containing V³⁺, V⁴⁺ and V⁵⁺ ions was studied at 1400°C in air atmosphere. The ionic equation representing the V³⁺-V⁵⁺ redox equilibrium reaction was used to represent the V³⁺-V⁴⁺-V⁵⁺ redox reactions in glasses as V⁴⁺ ion was an intermediate species. The V³⁺-V⁵⁺ redox equilibrium was found to shift more towards the oxidized state with the increasing ionic radii of alkali ions or with the increasing concentration of alkali oxide in the same series of glasses. The slopes of the straight lines obtained on plotting log ([V⁵⁺]/[V³⁺][pO₂]^1/2) against mol% R₂O (R⁺ = Li⁺, Na⁺ and K⁺ ions) in binary alkali silicate glasses were approximately inversely proportional to the coulombic force between the alkali ions and nonbridging oxygen ions. This indicates that the redox equilibrium shifted more towards oxidized state with increasing oxygen ion activity in the glass. The loss of vanadium from the glass melts with the duration of heat treatment was observed due to volatilisation at higher temperature, which did not influence the V³⁺-V⁵⁺ redox equilibrium. Magnetic susceptibility of the present glasses, measured at room temperature, did not show any sign of paramagnetism which might be due to the presence of smaller concentration of V³⁺ and V⁴⁺ ions in the glass.

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005292   Singh R (Materials Evaluation Division, National Metallurgical Laboratory, CSIR, Jamshedpur-831 007) : Mechanism based approach for remaining life assessment of components exposed to prolonged creep. Trans Indian Inst Metals 2000, 53(3), 175-83.

Attempts to clearly bring out the predictive strengths of two potent parameters: the threshold stress (σ_H) and the creep damage tolerance (λ). The findings are based on systematic study carried out on a Cr-Mo-V main steam pipe line both in the virgin and service exposed conditions. Finally, a life prediction methodology based on σ_H and λ has been proposed for straight pipe lines of the low-alloy ferritic steels.

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005291   Siddiqi N;Bhoi B;Paramguru R K;Sahajwalla V; Ostrovski O (School of Materials Science and Engineering, University of New South Wales, Sydney-2052, Australia) : Effect of different parameters on wettability of graphite by CaO-SiO₂-Al₂O₃-FeO-MgO slag. Trans Indian Inst Metals 2000, 53(4-5), 479-86.

Effect of different factors such as slag chemistry, temperature and graphite type on wettability of graphite by CaO-SiO₂-Al₂O₃-FeO-MgO slags were investigated by using the sessile drop technique where wettability was detrmined by direct measurement of the interfacial contact angles. Interaction effects of these parameters were also determined by using a simple statistical procedure. SIO₂ did not affect wettability. MgO had a deterimental effect, whereas, FeO content, temperature and graphite with ash content upto 0.3% had beneficial effects on wettability. The most significant effect was realised from FeO content mostly towards the higher value of 9.16%. Interaction effects were not so significant. The energy released on the interface due to the reduction reaction of FeO by carbon had a direct correlation with decrease in surface tension of FeO containing slags which in turn improved wettability.

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005290   Sharma R;Vali S A;Shastri P N;Rao B Y (Post Graduate Teaching Department of Home-Science, Nagpur University, Nagpur) : Storage studies of wheat germ oil. J Dairying Fd Home Sci 2000, 19(2), 135-7.

Characteristics and constants of freshly extracted wheat germ oil were : specific gravity 0.9233; refractive index at 25°C 1.4760; saponification value 190.9; peroxide value 39.1 (meq of peroxide/kg of oil) and free fatty acid 13.8%. Storage studies of wheat germ oil in polypropylene (pp) and high density polyethylene (HDPE) bottles showed a gradual increase in free fatty acid content and fluctuations in peroxide value throughout the storage period of one year.

005289   Sen S K;Dhua S K;Prasad M S;Ray A;Mishra K B; Jha S;Bhattacharyya S K (Research and Development Centre for Iron and Steel, Steel Authority of India Ltd., Ranchi-834 002) : Effect of aluminium and non-metallic inclusions on fatigue crack growth rate and fracture toughness of wheel and axle steels. Trans Indian Inst Metals 2000, 53(3), 327-32.

Wheel and Axle steels experience fatigue and certain impact loads during use as wheel and axle assembly in mobile engine, wagons and coaches. Quality control is essential during production of steel and subsequent processing for making wheel and axle. Aluminium killed steels should have 0.025% Al in case of wheels and 0.02% Al for axles because Al content determines total inclusion, type, size and their distributions and subsequent effect on mechanical properties. It was found that if total inclusion content is more than 0.25% then both fatigue and fracture toughness values decrease. If fatigue crack growth rate (FCGR) is more then fracture toughness will be less. Finer the pearlite colony size better are strength and toughness properties. If MnS covers oxide inclusions then their adverse effect decreases. When small amount of ferrite/cementite are present at the pearlite grain boundary the steel toughness improves. Decrease in pearlite interlamellar spacing will increase mechanical properties. Oxide or mixed inclusions break during use of wheel and axle steel and are sources of crack nucleation.

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005288   Sekar N (Dyes Division, UDCT Matunga, Mumbai-400 019) : Developments in heterocyclic disperse dyes - an update. Colourage 2000, 47(1), 43-5.

Chemistry of disperse dyes based on aminoindazoles and pyridobenzimidazole couplers have been reviewed.

005287   Sekar N (Dyes Division, UDCT, Matunga, Mumbai-400 019) : Electrical and electronic properties of phthalocyanines - an explanatory note. Colourage 2000, 47(10), 36-7.

005286   Satyanarayana D V V;Malakondaiah G;Sarma D S (Defence Metallurgical Research Laboratory, , Kanchanbagh P.O., Hyderabad-500 058) : Effect of ageing time on the creep behaviour of NiAl hardended austenitic stainless steel. Trans Indian Inst Metals 2000, 53(3), 243-8.

Effect of ageing time at 973 K on creep deformation and fracture behaviour of a model NiAl hardened austenitic stainless steel was studied. The creep behaviour of the alloy aged for 5, 15 and 50 h at 973 K differed considerably at high stresses while it was fairly matching at low stresses. Such a behaviour was attributed to stress dependent change in dislocation bypass mechanism from Orown bowing or particle shearing in the high stress regime to climb over particles in the low stress regime. Experiment creep rupture data for all the three ageing times followed modified Monkman-Grant relation indicating that fracture and thereby time-to-rupture is controlled by power-law growth of cavities.

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005285   Sasikala G;Ray S K;Mannan S L;Mathew M D (Materials Development Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Creep damage and fracture behaviour of a type 316L(N) stainless steel and its weld metal. Trans Indian Inst Metals 2000, 53(3), 223-9.

Creep deformation and fracture behaviour of a nitrogen bearing type 316L stainless steel and its weld metal at 873 and 923 K have been reported. At both the temperatures, the weld metal exhibited rupture lives lower by a factor of 5 to 10 than those of the base metal depending on the applied stress (σ) level. At 873 K, the minimum creep rate (ε_s) for the weld metal was higher at high stresses and lower at low stresses compared to the base metal. At 923 K, however, the weld metal exhibited ε_s lower by a factor varying from 5 to 10 compared to that for the base metal. The rupture ductility of the weld metal was always found to be lower than that of the base metal for identical test conditions. Validity of Monkman-Grant and modified Monkman-Gran relations was examined for both base and weld metals. It was found that the base metal obeyed both the relations in the whole range of test conditions with a single slope, while the weld metal exhibited two slope behaviour. The observed differences are discussed in the light of transformation of δ-ferrite into brittle phases like sigma phase and its influence on deformation and damage.

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005284   Sandhya R;Bhanu Sankara Rao K;Mannan S L (Materials Development Group, IGCAR, Kalpakkam-603 102) : Effect of coldwork on the low cycle fatigue and creep-fatigue interaction properties of alloy D9. Trans Indian Inst Metals 2000, 53(3), 273-6.

Alloy D9, a 15Cr-15Ni, Ti modified stainless steel is a candidate material for fast reactor core components due to its excellent resistance to void swelling. The alloy with Ti/C ratio of 4 has been investigated for its Low Cycle Fatigue (LCF) and Creep-Fatigue Interaction (CFI) properties in solution annealed and 20% cold worked condition. LCF tests have been conducted in air at 823k and 923K, while CFI tests were performed at 923K using holds at peak tensile strain. Under continuous cycling LCF conditions, solution annealed material exhibited superior LCF resistance than cold worked material at both 823 and 923K, except at low strain ranges at 923K. The solution annealed material underwent cyclic hardening while cold worked material displayed cyclic softening. Under CFI conditions, solution annealed material exhibited a recovery in life at longer hold times, while coldworked material exhibited a continuous decrease in life with increasing hold time. The LCF and CFI properties have been correlated with the substructural recovery and precipitation at these temperatures.

005283   Ray A K;Tiwari Y N;Chaudhuri S;Tarafder S; Singh R (MRE Division, National Metallurgical Laboratory, , Jamshedpur-831 007) : Residual life assessment of FCCU reactor plate. Trans Indian Inst Metals 2000, 53(3), 427-33.

Evaluation of mechanical properties is a powerful tool for investigating and assessing the performance of service exposed materials. The trends recently observed in a service exposed (32 years) plain carbon steels used as a reactor vessel material in a petrochemical industry have been highlighted. Health assessment of both base and welded joint was made using destructive accelerated stress rupture and tensile tests at different temperatures, and some nondestructive tests. From the stress rupture tests it could be concluded that a life of more than 10 years at the hoop stress level of the material can be obtained, provided no localised damages in the form of cracks or dents have been developed. It is recommended that a health check may be carried out after 5 years of service exposure at 758 K.

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005282   Rathaur A K;Solanky M J (NO, Mahaan Proteins Ltd., Kosi Kalan) : Storage related sensory changes in lassi. J Dairying Fd Home Sci 2000, 19(2), 100-4.

Storage studies were carried out on lassi stored at 37±2°C and 7±1°C. The colour and appearance remained practically unaffected during storage. Maximum changes occurred in control from flavour point of view. Control L₆₅ and L₇₀ stored at 37±2°C were rejected on 8th, 12th and 16th day, respectively. While the product stored at 7±1°C was rejected on 15th, 39th and 35th day. Body and texture characteristic was restricted by the thermal treatment employed and were minimum in L₇₀. Acidity was the least affected organoleptic attribute. The product at the rejection stage obtained =<62> 50 per cent marks.

005281   Ramachandra C;Kashyap K T;Najundaswamy G S; Sridharan N S;Chatterji B (Central Materials and Processes Laboratory, Foundry and Forge Division, Hindustan Aeronautics Limited, Bangalore-560 017) : Creep-fatigue interaction of a high temperature (α + β titanium alloy at room temperature. Trans Indian Inst Metals 2000, 53(3), 277-82.

Ti-6Al-1, 6Zr-3.3Mo-0.3Si (VT 9) is an (α + β) titanium alloy of Russian origin designed for applications as compressor disc and blade in jet engines for use upto the temperatures of 773K. These alloys are known to exhibit an appreciable amount of creep even at ambient temperatures. Thus creep and low cycle fatigue (LCDF) interaction at room temperature is an important phenomenon during service. The β transus temperature of this alloy is ≈ 1233K. The alloy was β solution treated at 129K for 0.5 hours and air cooled (AC). The AC material when aged at 973K for 12 hours is designated as ACA. The Coffin-Manson (C-M) plots for AC and ACA conditions showed dual slopes. These plots were placed correspondingly lower when compared to those of oil quenched (OQ) and oil quenched and aged (OQA) conditions reported in the literature. The hold period during LCF testing in OQ condition has caused higher percentage of reduction in fatigue life as compared to that in AC condition. While, aging of the AC condition showed marginal effect on the fatigue life due to hold period, it is significant in OQ condition. The reduction in fatigue life in OQA condition due to hold period is comparable to that in AC condition. The behaviour of the material under these thermally treated conditions can be explained based on the microstructural changes namely the clustering of silicide forming elements, formation of silicides on aging and enriching of alpha in α alloying elements.

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005280   Ramachandra C;Kashyap K T;Najundaswamy G S; Chatterji B;Sudhaker Nayak H V;Ramakant Hebbar K (Central Materials and Processes Laboratory, Foundry and Forge Division, Hindustan Aeronautics Limited, Bangalore-560 017) : Study of the change in deformation mode under low cycle fatigue conditions of a commercial (α+β) titanium alloy. Trans Indian Inst Metals 2000, 53(3), 463-9.

Commerical (α+β) titanium alloy Ti-6Al-1.6Zr-3Mo-0.3Si (designated as VT9) of Russian origin is used for compressor discs and blades in jet engines up to temperatures of 773K. The β transus for this alloy is <126> 1233K for 0.5 hour and cooled at different rates namely water quenching (WQ), air cooling (AC) and furnace cooling (FC). The blanks WQ, AC and FC were aged at 973K for 12 hours and these were designated as WQA, ACA and FCA respectively. Low cycle fatigue (LCF) testing was carried out for all the conditions namely WQ, WQA, AC, ACA and FC, FCA at room temperature in the total strain amplitude range of 0.70% ± 1.7% at a frequency of 0.2Hz using triangular wave form. While Coffin-Manson (C-M) plots between plastic strain amplitude versus number of reversals to failure showed dual slopes in WQA, AC, ACA and FC conditions, single slope was observed in WQ and FCA conditions. Study of the slip activity on the surface close to the fracture end of the specimen failed in LCF for the AC and FCA conditions using scanning electron microscopy (SEM) clearly correlated with the results of TEM study. For other thermally treated conditions namely WQ, WQA and FC, FCA, SEM technique was used to study the slip band activity close to the fracture ends of the specimens failed under fatigue conditions from lower and higher strain amplitude regions. In the case of WQ and FCA where single slope is seen in C-M plots, there is no difference in the slip band activity and thus it indicates no change in deformation mode. However, distinct differences in slip band activity in specimens from lower and higher strain amplitude regions conform to the dual slope behavior in C-M plots in WQA and FC conditions.

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005279   Rajeshkumar S;Sandhya V S;Pillai P K;Warrier K G K (Ceramics Division, Regional Research Laboratory, , Thiruvananthapuram-695 019) : Synthesis of high surface area porous silica through aging techniques. Trans Indian Ceramic Soc 2000, 59(3), 64-7.

Silica gels prepared from tetraethylorthosilicate (TEOS) were aged in ethanol/water medium and subsequently in ethanol/TEOS after washing with ethanol. They were further exchanged with isopropanol and dried. The gels have a specific surface area 1142 m²g^-1, pore volume 1.19 cm³g^-1, bulk density 0.43 gcm^-3 and an average pore size of 41.68 Angstrom. The parent gel without any treatment has a specific surface area of 610 m²g^-1. The structural changes with aging treatments were characterized and discussed. The microporous nature of the parent gel changes to mesoporous one during the course of aging. An enhancement in the densification temperature of the aged samples reveals high temperature pore stability.

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005278   Rajanna K;Jayaraman G;Prasad C R;Chowdary K M (Metallurgy Department, BHEL R and D, , Hyderabad-500 093) : Application of Barkhausen noise in creep and fatigue damage assessment. Trans Indian Inst Metals 2000, 53(3), 361-8.

Majority of thermal power plant components undergo damages due to fatigue, creep, or combined fatigue-creep effects during service. These damages involve changes in residual stress and microstructure, whose presence is known to influence the Barkhausen Noise amplitude in ferro-magnetic materials. Present investigation aims at applying Barkhausen Noise (BN) to assess these damages. Methods for fatigue damage assessment in steam turbine rotor, casing and boiler water feed pump shaft steels through residual stress measurements using BN have been established. Attempts have been made to correlate the magnetic paramter (MP) values with respective rupture lives in some of the creep resistant steels subjected to different aging times. Correlations between MP ratio (MP/MP_o) and creep strain were established for rotor steel. Results obtained in this investigation have indicated the possibility of employing the Barkhausen noise for assessing fatigue/creep damage in thermal power plant materials.

005277   Raghavan S (Department of Metallurgical Engineering, Indian Institute of Technology, Chennai-600 036) : Electrochemical determination of the thermodynamic activities of calcium oxide in {xCaO+(1-x) CdO}(s,sln) using calcium β"-alumina solid electrolyte galvanic cell. Trans Indian Inst Metals 2000, 53(4-5), 531-3.

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005276   Prasad C R;Chowdary K M (Corporate (R and D) Division, BHEL, , Hyderabad-500 093) : Metallurgical study of a last stage nuclear turbine blade failure. Trans Indian Inst Metals 2000, 53(3), 457-62.

A 236 MW capacity nuclear turbine which had logged about 17,000 hrs of operation suffered a catastrophic failure causing extensive damage to steam turbine, generator, bus duct, civil structures etc. The Low pressure (LP) turbine, on being opened, revealed that 16 blades of the last stage (stage 5) were broken. Out of these, two blades adjacent to one another, failed at the first serration of the blade root. All the other blades had failed in the porfile protion of the blade. The aim of the metallurgical investigation was mainly, to ascertain whether the fatigue of the two blades in the root portion was consequential or not. The metallurgical observations coupled with other relevant data were thoroughly examined and the conclusions were arrived at. The initial cracking in the root portion of the blades was similar to thoe observed in blades of the same design in other parts of the world. These cracks were arresting type and cannot land to failure. It was opined that the failure of the blades was consequential and would not have occurred otherwise.

005275   Paradkar A G;Rao A V;Gogia A K (Defence Metallurgical Research Laboratory, , P.O. Kanchanbag, Hyderabad-500 058) : Effect of microalloying in a near α titanium alloy. Trans Indian Inst Metals 2000, 53(3), 231-42.

IMI 834 is a recently developed alloy, for aeroengine applications up to 863K. These alloys exhibited the best high temperature properties of all the near α alloys. Exploratory research work conducted for further enhancement of high temperature capabilities of IMI 834 by microalloying has been presented. Panackes of IMI 834 alloy with microadditions such as tantalum, bismuth, iron, cobalt, nickel, boron and misch metal (Mm) were prepared by vacuum arc melting. These alloys were evaluated for strength and creep at 873 K for varieties of microstructures. The results indicate that alloys containing eutectoid formers (ion, cobalt, nickel, and bismuth) show the lower strength whereas alloys containing tantalum, boron, Mn exhibit higher strength than the base IMI 834. Eutectoid formers, in general, have adverse effect on the creep properties as well. Alloying additions that are isomorphous in titanium such as tantalum have not resulted in the improvement of the creep properties. An assessment of creep properties of the alloys containing boron and Mn indicates that creep properties of these alloys are relatively insensitiive to cooling rates. This allows optimisation of other properties such as yield strength by choice of an appropriate heat treatment without deterioration of creep properties.

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005274   Ohki M;Hwu T C;Mutoh Y (NO, Niigata University, Nigata, Japan) : Thermal cycle damage of wear-resistant ceramic coatings. Trans Indian Inst Metals 2000, 53(3), 135-40.

Two kinds of alumina-based ceramic coatings (A : 90% Al₂O₃ - 10% CeO₂ and B : 70% Al₂O₃ - 10% CeO₂ - 20% ZrO₂), which has high wear-resistance and low friction and are expected to be applied as to a cylinder liner for sutomobile engine, were prepared for thermal cycle tests. Thermal conductivity of the ceramic coating layer was measured. Thermal stress in the coating layer during the thermal cycle was analyzed by the finite element method. Surface cracks were nucleated during thermal cycle test. The resistance to thermal cycle damage (crack nucleation) for the specimen B with zirconia content was superior compared to the specimen A. This results from the high toughness due to low porosity and zirconia content and the low thermal stress of the specimen B.

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005273   Nageswara Rao M (NO, Mishra Dhatu Nigam Ltd., Hyderabad) : Development of creep and fatigue resistant alloys at Midhani - cast superalloys. Trans Indian Inst Metals 2000, 53(3), 475-8.

Advancements realised in modern jet engines would not have been possible but for the advent of superalloys with superlative performance. Developments in materials have been stronlgy triggered by the need to design and build jet engines with increasing and daunting performance levels. The introduction of cast superalloys marks a turning point in attainment of high performance levels, so relevant in the context of service in air borne gas turbine engines. The type of loading encountered in these engines is highly complex - it is a combination of highly corrosive environment, complex variations in temperature and complicated mechanical loading involving both creep and fatigue type. Advanced cast superalloys have established themselves for blading and other critical components in the high temperature part of the gas turbine engine. MIDHANI has now established technologies for manufacture of high duty cast superalloy grades for production of these components. The capability of MIDHANI to manufacture high temperature superalloys thus stands graduated from manufacture of a wide spectrum of wrought superalloys to state-of-the-art cast superalloys. Describes the salient features of four grades of cast superalloys and their productionisation at MIDHANI.

005272   Nagesha A;Valsan M;Mannan S L (Materials Development Group, IGCAR, Kalpakkam-603 102) : Hold time effects on the low cycle fatigue behaviour of a Nimonic PE-16 superalloy. Trans Indian Inst Metals 2000, 53(3), 283-90.

Creep-fatigue interaction behaviour of a Nimonic PE-16 superalloy has been studied in solution-annealed condition and two double-aged conditions (microstructures with γ' of 18nm and 35nm diameters) at 923L. Tests were carried out over various strain amplitudes with hold time of 1 and 10 min. duration introduced in peak tension and compression strain. The cyclic stress response of the alloy was characterized by an initial hardening, a softening and a saturation regime. Further, at 923 K, the cyclic stress response was found to increase with increase in the duration of the hold. Tension hold was observed to be more damaging than compression hold, and the fatigue life decreased with increase in the duration of the hold in tension. Accelerated intergranular crack initiation and propagation reduced fatigue life under hold times in tension. Moreover, oxidation was found to reduce fatigue life under long hold periods.

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005271   Mukhopadhyay S;Das S K (NO, College of Ceramic Technology, 73 A.C. Banerjee Lane, Calcutta-700 010) : Role of alumina sol on the physical properties of low cement castables. Trans Indian Ceramic Soc 2000, 59(3), 68-74.

Deals with the performance of alumina bearing sol, prepared through sol-gel route, when used as a bonding agent in low cement refractory castable composition. The physical properties of the samples prepared by different processing technique (tapping and vibration) are compared. The results indicate that the simple tapping technique may be a cost-effective solution in order to achieve desired high temperature properties. Also the increase in solid content by heat treatment of a particular sol upgrades its reactivity and improves the properties of a castable at elevated temperatures. CRD and SEM studies confirm the presence of corundum as a major phase and mullite as a minor.

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005270   Moorthy V;Choudhary B K;Vaidyanathan S; Jayakumar T;Bhanu Sankara Rao K;Baldev Raj (Metallurgy and Material Group, Indira Gandhi Centre for Atomic Researc, , Kalpakkam-603 102) : Identification of different stages of low cycle fatigue damage using magnetic Barkhausen emission in 9Cr-1Mo ferritic steel. Trans Indian Inst Metals 2000, 53(3), 347-52.

Magnetic Barkhausen emission (MBE) technique has been used to assess the low cycle fatigue (LCF) damage in 9Cr-1Mo ferritic steel. LCF tests have been carried out at ambient temperature at total strain amplitudes of ±0.25, ±0.50 and ±0.75%. MBE measurements have been performed on LCF tested specimens interrupted at various life fractions. The various stages of LCF such as cyclic hardening, cyclic softening, saturation and crack initiation and propagation have been examined and identified using peak height value of the root mean square (RMS) voltage of MBE. The cyclic hardening, which occurred in the early stage of LCF cycling, decrease the MBE peak height value. The progressive cyclic softening stage displayed reversal in MBE response i.e., the MBE peak high value increased following softening due to rearrangement of dislocations into cells. Further, the saturation stage, where the stress value remained constant for a large number of cycles due to formation of stable dislocation substructure, results in a constant value of MBE. Finally, the onset of rapid stress drop and cusp formation in the stress-strain hysteresis loop, which indicate surface crack initiation and propagation, exhibited a rapid increase in the MBE peak values. This is also confirmed by MBE measurements on the crack and away from the crack using surface MBE probe. The increase in MBE is ascribed to the movement of additional reverse domains produced at the crack surfaces.

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005269   Mathew M D;Yang H;Movva S;Murty K L (Indira Gandhi Centre for Atomic Research, , Kalpakkam) : High temperature deformation characteristics of tin-based solder alloys: application to electronic packaging. Trans Indian Inst Metals 2000, 53(3), 369-79.

Deformation characteristics of pure tin metal, Sn-3.5Ag and Sn-5Sb have been investigated at various temperatures between ambient and 473 K from constant load creep tests in order to understand the deformation behaviours of these materials. Automated ball indentation (ABI) studies were also carried out as a non-destructive testing technique to characterize the mechanical properties of these alloys. Power-law relationships between strain rate and stress were observed under both loading conditions. The stress exponents and the activation energies were determined and the values correspond to creep deformation by dislocation climb controlled by lattice diffusion in pure tin and Sn-3.5Ag, and viscous glide controlled by pipe diffusion in Sn-5Sb alloy. Excellent agreement was found between creep and ABI results of Sn-5Sb alloy but such a correlation was not evident in the case of pure tin ad Sn-3.5Ag alloy. Agreement between creep and ABI data indicates that ABI can be successfully applied for studying the deformation behaviour of Sn-5Sb solder joints in actual components in the electronic packaging industry. These results on bulk materials are compared with the initial results on the creep behaviour of solder bump arrays.

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005268   Mannan S L;Valsan M (Materials Development Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Low cycle fatigue behaviour of 316 L (N) austenitic stainless steel base metal, weld metal and weld joint. Trans Indian Inst Metals 2000, 53(3), 141-53.

Low cycle fatigue (LCF) behaviour of 316L(N) base metal, 316 weld metal and 316L(N) weld metal in the temperature range, 300 to 873 K is presented. These results are compared with the LCF behaviour of weld joints. Tests were carried out at various strain amplitudes and strain rates. In these test conditions, cyclic hardening observed was attributed mainly to dynamic strain ageing, whereas cyclic softening seen in the weld metal was ascribed to annihilation of dislocations. 316L(N) base metal exhibited better fatigue life than 316 weld metal at 773 K, whereas 316 weld metal showed superior fatigue resistance at specific strain rates at 823 and 873 K. The better fatigue life of 316 weld metal was due to the beneficial effects of crack deflection by numerous transformed δ - ferrite boundaries in the austenite matrix. The transformation of δ-ferrite to brittle phases was less pronounced in 316L(N) weld metal, which in turn, showed a lesser tendency for crack deflection leading to reduced fatigue life. At high temperatures. oxidation served to reduce the fatigue life. Weld joints showed the least fatigue life which was associated with the accelerated intergranular crack initiation and propagation in the coarse grained heat affected zone.

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005267   Linga Murty K (NO, N.C. State University, Raleigh NC 27695-7909, United States of America) : Deformation mechanisms and transients in creep of zircaloys : applications to nuclear technology. Trans Indian Inst Metals 2000, 53(3), 107-20.

Zirconium alloys are commonly used as cladding tubes in water reactors and undergo complex biaxial creep deformation. The anisotropic nature of these hcp metals makes it relatively complex to predict their dimensional changes in-reactor. These alloys exhibit transients in creep mechanisms as stress levels change. The underlying creep mechanisms and creep anisotropy depend on the alloy composition as well as the thermomechanical treatment. Reports first the anisotropic biaxial creep of cold-worked and recrystallized Zircaloy-4 in terms of Hill's generalized stress formulation. The temperature and stress dependencies of the steady-state creep-rate are described followed by predictive models for transient and transients in crep (due to sudden stress changes) which incorporate an elastic strain. The effect of recrystallization on creep anisotropy is pointed out along with an extension of the model to radiation creep of irradiated cladding. While Zircaloy-4 exhibited class-M creep, Nb additions resulted in class-A creep behavior with the characteristic stress exponent of 3. Nb-modified Zircaloy sheet revealed changes in creep mechanism to class-M type at high stresses, and viscous creep at low stresses. Implications of these various features in the predictions of cladding dimensions during reactor operation as well as during the dry storage of spent fuel are discussed.

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005266   Latha S;Mathew M D;Bhanu Sankara Rao K;Mannan S L (Materials Development Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Creep deformation behaviour of alloy D9 cladding tubes. Trans Indian Inst Metals 2000, 53(3), 249-53.

Creep properties of Alloy D9 (a titanium-modified austenitic stainless steel) cladding tubes in 20% cold worked condition have been evaluated at 973 K in the stress range 125-250 MPa and compared with creep properties of 20% cold worked 316 stainless steel cladding tubes and 20% cold worked Alloy D9 bars produced indigenously. Alloy D9 cladding tubes exhibited a lower creep rate and a prolonged secondary stage compared to 316 stainless steel cladding tubes. The creep deformation behaviour of both Alloy D9 and 316 stainless stell cladding tubes could be described by a power law relationship between steady state creep rate and stress. Steel state creep rate of Alloy D9 was lower by an order of magnitude as compared with 316 stainless steel cladding tubes. Rupture lives of Alloy D9 cladding tubes were found to be nearly six times higher than the rupture lives of 316 stainless steel cladding tubes. The rupture ductility of Alloy D9 cladding tubes was less when compared with 316 stainless steel cladding tubes. Alloy D9 cladding tubes exhibited higher rupture lives than the bars under indentical stress conditions. Metallographic investigations carried out on Alloy D9 bars revealed extensive creep damage in the form of wedge-type cracks. The creep properties of Alloy D9 have been rationalised on the basis of precipitation and damage behaviour.

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005265   Laha K;Chandravathi K S;Bhanu Sankara Rao K; Mannan S L;Sastry D H (Materials Development Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Microstructural evaluation and creep deformation and rupture behaviour of 9Cr-1Mo steel base metal, weld metal and weld joint. Trans Indian Inst Metals 2000, 53(3), 217-21.

Deformation and creep rupture behaviour of 9Cr-1Mo ferritic steel base metal, weld metal and cross weld joint at 823 K over a stress range of 130-250 MPa have been evaluated. The weld metal exhibited significantly higher creep rupture life than the base metal and the weld joint showed inferior creep rupture life. The weld joint crept at a faster rate while the weld metal deformed at a slower rate than the base metal. Transgranular fracture prevailed over the stress range examined. Microstructure developed across the weld joint and the changes of the microstructures that occurred during creep test have been characterized. Failure in the weld joint specimens took place in the intercritical structure of heat affected zone. Intergranular creep damage comprising cavities and cracks were not seen in the tested samples. Ductility was marginally reduced with increasing rupture time for all the material conditions. The rupture elongation exhibited by base metal was higher than that shown by weld metal and weld joint.

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005264   Kotov K I;Tovarovskiy I G;Singh S B; Ramachandran V;Sinha P K;Mondal A C;Savostyanov J V;Myasojedov V A (NO, VO "Tyazhpromexport", Institute of Ferrous Metallurgy of National Acad, Ukraine) : Technological improvement and slag analysis optimization process for updated blast furnace, Durgapur Steel Plant. Trans Indian Inst Metals 2000, 53(4-5), 487-99.

Reconstruction of the blast furnace No.2 in Durgapur Steel Plant has been carried out with formation of technical base for implementation of the modern technology of a blast furnace smelting. It allowed increase the design productivity of the blast furnace in comparison with that achieved before from 0.65-0.85 up to 1.3 t/m³ per day and reduce the design coke rate from 800-900 to 700 kg/t of hot metal (carbon up to 520 Kg/t) with improvement of hot metal quality (reducation of sulphur content to 0.47%, silicon to 0.8-1.07%). Based on development of possibilities formed during reconstruction on modern technology, the coke rate has been reduced in comparison with the design for 10% and more, and the ways of further improvement of smelting indices were traced to blast temperature increase with its humidification removal of raw flux from blast furnace burden, updating of technological process control etc. with achievement of coke rate less than 600 kg/t (carbon - less than 450 kg/t). It was revealed the worth while and technical possibility to increase slag basicity CaO/SiO₂ up to 1.0-1.05 and magnesium oxide in it up to 10-11%, which will allow reduction in sulphur content to 0.025%, silicon to 0.7% while keeping or increasing the smelting products temperature.

005263   Khosla M K;Bhasin M (Regional Research Laboratory, , Jammu Tawi-180 001) : Biosynthetic correlation of major essential oil components in Ocimum carnosum LK and Otto. Indian Perfumer 2000, 44(2), 55-9.

Biosynthetic correlation of major components - elemicin and methyl eugenol - in essential oil of O. carnosum were studied at five different stages of development, viz. vegetative, pre-flowering, inflorescence initiation, full mature inflorescence and seed-formation stages. The study revealed that methyl eugenol acts as the precursor, because when the elemicin percentage shows its maximum (32.12%) at full mature inflorescence stage, the percentage of methyl eugenol becomes minimum (10.59%). Though the percentage of methyl eugenol is maximum (72.98%), the elemicin percentage decreases to minimum (8.37%) at pre-flowering stage.