024469   Sreeprasad T S;Samal A K;Pradeep T (Chemistry and Sophisticated Analytical Instrument Facility Dep, Indian Institute of Technology, Madras, Chennai-600 036, Email: pradeep@iitm.ac.in) : Reactivity and resizing of gold nanorods in presence of Cu<. Bull Mater Sci 2008, 31(3), 219-24.

Due to the inherent anisotropy of the system, gold nanorods behave differently in comparison to their spherical counterparts. Reactivity of gold nanorods, in presence of cupric ions, was probed in an attempt to understand the chemistry of anisotropic particles. The reaction progresses through a series of intermediates. It can be arrested at any stage to get nanorods of desired dimension and therefore, can be used for their reshaping. The presence or absence of cetyltrimethylammonium bromide (CTAB) on the nanorod surface was found to be determining the site of initiation of the reaction. When a large concentration of CTAB is present in the system, selective etching of the tips of the nanorod occurs and when the nanorods are purified to reduce the amount of CTAB in the solution, the side faces of the nanorod also get reacted. Gold nanorods are converted to particles by further surface reconstructions in a systematic surface specific chemistry.

4 illus, 39 ref

024468   Sona Wane R S;Naik S D;Apte S K;Kulkarni M V; Kale B B (Information Technology Dep, Centre for Materials for Electronics Technology (C-MET), Panchawati, Pune-411 008, Email: kbbb1@yahoo.com) : CdS/CdSSe quantum dots in glass matrix. Bull Mater Sci 2008, 31(3), 495-99.

The compositions containing 55 and 60% of silica have been formulated for preparation of glass filters having sharp cut-off at 475 and 575 nm. To achieve cut-off at these wavelengths, the glasses have been doped with CdS/CdSSe and melted at 1200-1300°C. The glass samples were transparent and pale yellow in colour due to presence of CdS/CdSSe tiny nano crystal (Q-dots). In situ growth of CdS/CdSSe nano crystals imparts the yellow/orange/red colour to these glasses. Optical study shows that as prepared glasses have optical cut-off in the range 350-370 nm. The linear crystal growth of CdS/CdSSe in glasses exhibits red shift in optical cut-off. The optical filter having cut-off at 475 nm can be prepared by doping CdS and cut-off filter of wavelength 575 nm by CdSSe. The TEM results show that the CdS/CdSSe nano crystals (Q-dots) ranging from 2-5 nm are uniformly distributed into the glass matrix.

3 illus, 2 tables, 10 ref

024467   Singh P;Kumar A;Kaushal A;Davinder Kaur;Pande A;Goyal R N (Physics and Centre of Nanotechnology Dep, Indian Institute of Technology Roorkee, Roorkee-247 667, Email: dkaurfph@iitr.ernet.in) : In situ high temperature XRD studies of ZnO nanopowder prepared via cost effective ultrasonic mist chemical vapour deposition. Bull Mater Sci 2008, 31(3), 573-7.

Ultrasonic mist chemical vapour deposition (UM-CVD) system has been developed to prepare ZnO nanopowder. This is a promising method for large area deposition at low temperature inspite of being simple, inexpensive and safe. The particle size, lattice parameters and crystal structure of ZnO nanopowder are characterized by in situ high temperature X-ray diffraction (XRD). Surface morphology of powder was studied using transmission electron microscopy (TEM) and field emission electron microscope (FESEM). The optical properties are observed using TV-visible spectrophotometer. The influence of high temperature vacuum annealing on XRD pattern is systematically studied. Results of high temperature XRD showed prominent 100, 002 and 101 reflections among which 101 is of highest intensity. With increase in temperature, a systematic shift in peak positions towards lower 2 θ values has been observed, which may be due to change in lattice parameters. Temperature dependence of lattice constants under vacuum shows linear increase in their values. Diffraction patterns obtained from TEM are also in agreement with the XRD data. The synthesized powder exhibited the estimated direct bandgap (_g) of 3-43 eV. The optical bandgap calculated from Tauc's relation and the bandgap calculated from the particle size inferred from XRD were in agreement with each other.

5 illus, 1 table, 19 ref

024466   Singh D P;Singh J;Mishra P R;Tiwari R S; Srivastava O N (Physics Dep, Banaras Hindu Univ, Varanasi-221 005, Email: hepons@yahoo.com) : Synthesis, characterization and aplication of semiconducting oxide (Cu₂O and ZnO) nanostructures. Bull Mater Sci 2008, 31(3), 319-25.

Reports the synthesis, characterization and application of nanostructured oxide materials. The oxide materials (Cu₂O and ZnO) have been synthesized by electrolysis based oxidation and thermal oxidation methods. Cuprous oxide (Cu₂O) nanostructures have been synthesized by anodic oxidation of copper through a simple electrolysis process employing plain water (with ionic conductivity, ~ 6 μS/m) as electrolyte. In this method no special electrolytes, chemicals and surfactants are needed. The method is based on anodization pursuant to the simple electrolysis of water at different voltages. Two different types of Cu₂O nanostructures have been found. One type got delaminated from copper anode and was collected from the bottom of the electrochemical cell and the other was located on the copper anode itself. The nanostructures collected from the bottom of the cell are either nanothreads embodying beads of different diameters, ~10-40 nm or nanowires (length, ~600-1000 nm and diameter, ~ 10-25 nm). Those present on the copper anode were nanoblocks with preponderance of nanocubes (nanocube edge, ~ 400 nm). The copper electrode served as a sacrificial anode for the synthesis of different nanostructures. Aligned ZnO nanorod array has been successfully synthesized by simple thermal evaporation catalyst free method. Detailed structural characterizations revealed that the as synthesized aligned ZnO nanorods are single crystalline, with a hexagonal phase, and with growth along the [0001] direction. The room-temperature photoluminescence spectra showed a weak ultraviolet emission at 380 nm, a broad blue band at 435 nm and a strong orange-red emission at 630 nm. Structural/microstructural characterization of these nanomaterials have been carried out employing scanning (XL-20) and transmission electron microscopic (Philips EM, CM-12 and Technai 20G²) techniques and X-ray diffraction techniques having graphite monochromater with CuKor radiation (A = 1-54439 A) (X'Pert PRO PAN analytical). The UV-visible absorption spectra were recorded on Model-VARIAN, Gary 100, and Bio UV-visible spectrophotometer. The photoluminescence (PL) measurement was carried out at room temperature with a He-Cd, a laser excited at 325 nm.

6 illus, 34 ref

024465   Shukla J M;Patel K H;Patel M R;Patel N K (Chemistry Dep, Sardar Patel Univ, Vallabh Vidyanagar Gujarat) : Two pack ambient cured polyurethane coating through modified and blend of polyols from oleo resinoius sustainable resources. Paintindia 2008, 58(12), 85-104.

Polyurethanes (PU) touch to our lives in unexpected way through the versatile class of thermosetting polymers and largely used in high performance surface coating and paints. It is also true that our absolute reliance is on naphtha product as they are the only source of the chemical required, depletes very rapidly which in turn forces for the search of substitute. In view of this we planned our work by combining vegetable oil fatty acids and synthetic epoxy resin to modify and blend of polyols to produce polyurethane useful for surface coating. The purpose of such combination was to improve the mechanical properties such as hardness, impact strength, and flexibility of coated film. Polyurethane for surface coatings prepared from above modified and blend of polyols with different isocyanate adduct in different ratio were characterized by IR spectroscopy, thermo gravimetric method, end group analysis and mechanical methods to determine scratch, pencil, impact hardness, flexibility and chemical resistance to acid, alkali and salt. Study shows that the material holds promise for use as an effective anticorrosive coating.

6 illus 14 tables 21 ref

024464   Shankar S (NO, Arihand Chemicals & Resins (India) Pvt. Ltd., Parel, Mumbai-400 012, Email: shankar.sudrik@arihantchemicals.com) : Green technology-anticorrosive pigments. Paintindia 2008, 58(11), 99-104.

Corrosion inhibiting pigments based on oxy-amino-phosphate of magnesia (OAPM) are environmentally friendly, non toxic, zinc and heavy metals free, as well as efficient and proven substitutes for the currently used anti corrosion pigments. Due to the high effectiveness of OAPM pigments, significantly lower loading is needed in comparison to zinc chromate, basic and modified zinc phosphate, ion exchange pigments and others. This leads to formulation cost effectiveness in addition to the health and environmental advantages.

5 ref

024463   Sen T K;Mishra S;Patel R (Chemical Engineering Dep, Curtin Univ of echnlogy, Perth, Australia) : Removal of methylene blue dye from its aqueous solution by fruit shell of Aegle mermelose as alternative low cost adsoebent. J Instn Engrs-Pt CH 2008, 89(Sep), 33-8.

The use of low cost and ecofriendly adsorbent has been investigated as an ideal alternative for removal of dye from its aqueous solution. Fruit shell of aegle mermelose was collected from local area of Orissa, India and converted into a low cost adsorbent. Batch adsorption experiment of a cationic dye, methy/ene blue onto adsorbent prepared from fruit shell from aqueous solution with respect to the initial dye concentration, temperature, contact time and adsorbent dosage were investigated. It was found that the amount of methylene blue adsorbed decreases with adsorbent dosages, but increases with initial dye concentration and with contact time. Temperature had a mixed effect on the amount of adsorption which depends on the range of temperature. The sorption experiment was analyzed using pseudo-first-order and pseudo-second-order kinetic models and the sorption kinetics was found to follow a pseudo-second-order kinetic model. Rate constants at different initial concentrations were also estimated. The equilibrium. data predominantly follow the most widely used non-linear Freundlich isotherm which has the general form of q_e = K_fC_e^1/n, where Freundlich adsorption constants K_fand n were also determined.

7 illus, 2 tables, 17 ref

024462   Selvaraju T;Sivagami S;Thangavel S;Ramaraj R (School of Chemistry, Madurai Univ, Madurai-625 021, Email: ramarajr@yahoo.com) : Electrochemical and in situ spectroelectrochemical studies of gold nanoparticles immobilized nafion matrix modified electrode. Bull Mater Sci 2008, 31(3), 487-94.

Electrochemical and in situ spectroelectrochemical behaviours of phenosafranine (PS⁺) were studied at the gold nanoparticles (Au_Nps) immobilized Nafion (Nf) film coated glassy carbon (GC) and indium tin oxide (ITO) electrodes. Cyclic voltammetric studies showed that the PS⁺ molecules strongly interact with the Au_Nps immobilized in the Nf matrix through the electrostatic interaction. The presence of Au_Nps in the Nf film improved the electrochemical characteristics of the incorporated dye molecules. The emission spectra of Nf-Au_Nps-PS⁺ films showed that the incorporated PS⁺ was quenched by Au^Nps and it could be explained based on the electronic interaction between the Au^Nps and PS⁺ molecules. The in situ spectroelectrochemical study showed an improved electrochemical characteristic of the incorporated PS⁺ molecules at the ITO/Nf-Au_Nps electrode when compared to the ITO/Nf electrode.

10 illus, 56 ref

024461   Satpute A;Gangotri L T (Surface Dept, Coating Technology Laxminarayan Institute of Technology R T M Nagpur, Nagpur) : Liquid polyester resin a vehicle for coil coating. Paintindia 2008, 58(11), 87-94.

Liquid polyester resins of molecular weight 1000-3000 having terminating carboxy groups were prepared using diethylene glycol and maleic anhydride. Low molecular weight liquid polyester (100% NVM} was found to have the viscosity as low as 10 poise. 1% concentration of hexamine as curing agent was found to be sufficient to give hard dry film within 1 minute at 200°C stoving temperature. Various coil coating compositions were prepared using these liquid polyester resins and 1% hexamine along with colored pigments. The coatings were stoved at 200°C and evaluated for their film properties. The coatings exhibited excellent film properties with scratch hardness more than 2000 gms and 6H pencil hardness, excellent flexibility (OT), excellent resistance to solvents, water and chemicals. They also showed excellent MEK double rub resistance for 100 times, 100% adhesion and excellent impact resistance. The coil coating compositions did not need any primer.

16 tables 6 ref

024460   Sathiyamoorthi R;Manisankar P;Shakkthivel P; Lee M S;Vasudevan T (Chemistry Education Dep, Teachers College, Kyungpook National Univ, Daegu-702 701, Email: drtvasudevan2002@yahoo.com ) : Synthesis, characterization and electrochemical studies of LiNi_0.8M_0.2M₂ cathode material for rechargeable lithium batteries. Bull Mater Sci 2008, 31(3), 441-7.

LiNiO₂ and substituted nickel oxides, LiNi_0.8Mo_0.2O₂ and LiCo_0.8M_0.2O₂ (M = Mg²⁺, Ca²⁺, Ba²⁺), have been synthesized using simple solid state technique and used as cathode active materials for lithium rechargeable cells. Physical properties of the synthesized products are discussed in the structural (XRD, TEM, SEM with EDAX) and spectroscopic (FTIR) measurements. XRD results show that the compounds are similar to LiNiO₂ in structure. TEM and SEM analyses were used to examine the particle size, nature and morphological aspects of the synthesized oxides. The composition of the materials was explored by EDAX analysis. Electrochemical studies were carried out in the range 3-4-5 V (vs Li metal) using 1 M LiBE₄ in ethylene carbonate/dimethyl carbonate as the electrolyte. The doping involving 20% Mg resulted in a discharge capacity of 185 mAhg^-1 at 0-1 mA/cm² and remained stable even after 25 cycles. Discharge capacity retention for Mg doped lithium nickelate at 25th cycle was noted to be nearly 7% higher than for the undoped material.

6 illus, 3 tables, 31 ref

024459   Sajeev U S;Anop Anand K;Menon D;Nair S (Amrita Centre for Nanosciences, Amrita Vishwa Vidyapetham, Health Science Campus, Cochin-682 026, Email: shantinair@aims.amrita.edu) : Control of nanostructures in PVA, PVA/chitosan blends and PCL through electrospinning. Bull Mater Sci 2008, 31(3), 343-51.

Aqueous solutions of polyvinyl alcohol (PVA) were electrospun and its characteristics were studied as a function of applied potential, tip-target distance and solution flow rate. Solutions of PVA and chitosan were homogeneously mixed and electrospun to result in blend nanofibres and their properties were investigated. Conditions were revealed under which multiscale bi-modal fibres could be electrospun in a single step, producing structures that have potential applications in tissue engineering. Electrospun fibres having a bimodal size distribution of poly(caprolactone) (PCL) were also fabricated using a modified electrospinning setup. Nanofibrous microporous PVA scaffolds were fabricated using a cryogenic grinding method with subsequent compaction. Such multiscale porous structures would offer ideal matrices for tissue engineering applications.

10 illus, 42 ref

024458   Sahoo K L;Sahu R;Ghosh M;hatterjee S (Metal Extraction and Forming Div, National Metallurgical Laboratory, Jamshedpur-831 007, Email: klsah@nmlindia.org) : Crystallization behaviour and mechanical properties of Al-Ni-La metallic glasses. Bull Mater Sci 2008, 31(3), 433-9.

Alloy ingots with nominal composition, AI₉2_2-xNi₈La_x (x = 4 to 6) and Al_94-xNi₆La_x. (x = 6, 7), were prepared by induction melting in a purified Ar atmosphere. Each ingot was inductively re-melted and rapidly solidified ribbons were obtained by ejecting the melt onto a rotating copper wheel in an argon atmosphere. The crystallization behaviour of melt-spun amorphous ribbon was investigated by means of differential scanning calorimetry (DSC), X-ray diffractometry and transmission electron microscopy. DSC showed that Al₈₆Ni₈La₆ alloy undergoes a three-stage and rest of the alloys undergo a two-stage crystallization process upon heating. The phases responsible for each stage of crystallization were identified. During the first crystallization stage fcc-Al precipitates for low La-containing alloys and for higher La-containing alloys a bcc metastable phase precipitates. The second crystallization stage is due to formation of intermetallic compounds along with fee-Al. Microhardness of all the ribbons was examined at different temperatures and correlated with structural evolutions. Precipitation strengthening of nano-size fcc-M is responsible for maximum hardness in these annealed alloys.

8 illus, 1 table, 19 ref

024457   Rana M;Chandra A (Chemistry Dep, Indian Institute of Technology, Kanpur-208 016, Email: amalen@iitk.ac.in) : Water structure near single and multi-layer nanoscopic hydrophobic plates of varing separation and interaction potentials. Bull Mater Sci 2008, 31(3), 525-32.

Performed a series of molecular dynamics simulations of water containing two nano-scopic hydrophobic plates to investigate the modifications of the density and hydrogen bond distributions of water in the vicinity of the surfaces. Our primary goal is to look at the effects of plate thickness, solute-solvent interaction and also interplate separation on the solvent structure in the confined region between two graphite-like plates and also near the outer surfaces of the plates. The thickness of the plates is varied by considering single and triple-layer graphite plates and the interaction potential is varied by tuning the attractive strength of the 12-6 pair interaction potential between a carbon atom of the graphite plates and a water molecule. The calculations are done for four different values of the tuning parameter ranging from fully Lennard-Jones to pure repulsive pair interactions. It is found that both the solvation characteristics and hydrogen bond distributions can depend rather strongly on the strength of the attractive part of the solute-water interaction potential. The thickness of the plates, however, is found to have only minor effects on the density profiles and hydrogen bond network. This indicates that the long range electrostatic interactions between water molecules on the two opposite sides of the same plate do not make any significant contribution to the overall solvation structure of these hydrophobic plates. The solvation characteristics are primarily determined by the balance between the loss of energy due to hydrogen bond network disruption, cavity repulsion potential and offset of the same by attractive component of the solute-water interactions. Our studies with different system sizes show that the essential features of solvation properties, e.g. wetting and dewetting characteristics for different interplate separations and interaction potentials, are also present in relatively smaller systems consisting of a few hundred atoms.

7 illus, 20 ref

024456   Patra A;Rajesh K;Radhakrishnan T P (School of Chemistry, Hyderabad Univ, Hyderabad-500 046, Email: tprsc@uohyd.ernet.in) : Optical materials based on molecular nano/microcrystals and ultrathin films. Bull Mater Sci 2008, 31(3), 421-7.

Methodologies developed recently for the fabrication of molecular crystals with size variation in the nano to micro regime and polyelectrolyte templated mono and multilayer Langmuir-Blodgett films, are reviewed. The electronic absorption and strong fluorescence in the molecular nano/microcrystals are found to be size-dependent. Crystal structure and computational investigations provide a unified model to explain these observations. Role of polyelectrolyte templating in achieving stable and enhanced optical second harmonic generation response from LB films based on a hemicyanine amphiphile is highlighted.

9 illus, 1 table, 34 ref

024455   Patil P M;Ansari M F;Prasad K M (Indian institue of Natural Resins and Gums, [ICAR], Namkum, Ranchi-834 010) : Comparative performance of water soluble lac varnished using different alkalis. Paintindia 2008, 58(12), 79-84.

Water soluble lac vamishes were prepared using different alkalis like ammonia, borax, morpholine and triethanolamine. Surface coating properties like water resistance, scratch hardness, impact resistance, flexibility of the developed varnishes were carried out. Besides ammonia based lac varnish, films of all the varnishes failed the water resistance test for 24 hrs. Impact resistance was failed while flexibility was passed for all the varnishes. Scratch hardness was recorded to be maximum (1. 350 kg) for triethanolamine based vanish while it was minimum (1,250 kg) for varnish based on borax. The gloss was found to be the maximum (75%) for varnish based on morpholine and minimum (44%) for borax based varnish. All the varnishes were further treated with 2% urea on the weight of shellac to improve the water resistance property. Films of all the varnishes passed the water resistance test except borax based varnish.

2 illus, 4 table, 15 ref

024454   Patel H E;Anoop K B;Sundararajan T;Das S K (Mechanical Engineering Dep, Indian Institute of Technology Madras, Chennai-600 036, Email: skdas@iitm.ac.in) : Model for thermal conductivity of CNT-nanofluids. Bull Mater Sci 2008, 31(3), 381-90.

Work presents a simple model for predicting the thermal conductivity of carbon nanotube (CNT) nanofluids. Effects due to the high thermal conductivity of CNTs and the percolation of heat through it are considered to be the most important reasons for their anomalously high thermal conductivity enhancement. A new approach is taken for the modeling, the novelty of which lies in the prediction of the thermal behaviour of oil based as well as water based CNT nanofluids, which are quite different from each other in thermal characteristics. The model is found to correctly predict the trends observed in experimental data for different combinations of CNT nanofluids with varying concentrations.

3 illus, 12 ref

024453   Panda R;Panda H (NO, Devashish Consultants [p] Ltd. 61, West End City, Bidholia Ramour Road. P.O.: Clutterbuckganj, Bareilly-243 502, Email: communication.rp.1955@gmail.com) : Adhesives for ceramic articles. Paintindia 2008, 58(11), 95-8.

4 tables

024452   Nayar S;Pramanick A K;Guha A;Mahato B K; Gunjan M;Sinha A (NO, National Metallurgical Laboratory, Jamshedpur-831 007, Email: nayar@nmlindia.org) : Biomimetic synthesis of hybrid nanocomposite scaffolds by freeze-thawing and freeze-drying. Bull Mater Sci 2008, 31(3), 429-32.

The aim of this study is to biomimetically synthesize hydroxyapatite-hydrophilic polymer scaffolds for biomedical applications. This organic-inorganic hybrid has been structurally characterized and reveals a good microstructural control as seen by the SEM analysis and the nanosize of the particulates is confirmed by AFM microscopy. The characterization of such nano-structured composites would allow researchers to design new systems, tailoring properties for different applications.

4 illus, 7 ref

024451   Nayak S S;Murty B S;Pabi S K (Metallurgical and Materials Engineering Dep, Indian Institute of Technology, Kharagpur-721 302, Email: skpabi@metal.iitkgp.ernet.in) : Structure of nanocomposites of Al-Fe alloys prepared by mechanical alloying and rapid solidification processing. Bull Mater Sci 2008, 31(3), 449-54.

Structures of Al-based nanocomposites of AI-Fe alloys prepared by mechanical alloying (MA) and subsequent annealing are compared with those obtained by rapid solidification processing (RSP). MA produced only supersaturated solid solution of Fe in Al up to 10 at. % Fe, while for higher Fe content up to 20 at.% the nonequilibrium Intel-metallic Al₅Fe₂ appeared. Subsequent annealing at 673 K resulted in more Al₅Fe₂ formation with very little coarsening. The equilibrium intermetallics, AljFe (Al₁₃Fe₄), was not observed even at this temperature. In contrast, ribbons of similar composition produced by RSP formed fine cellular or dendritic structure with nanosized dispersoids of possibly a nano-quasicrystalline phase and amorphous phase along with ff-Al depending on the Fe content in the alloys. This difference in the product structure can be attributed to the difference in alloying mechanisms in MA and RSP.

4 illus, 28 ref

024450   Narayanasamy A;Sivakumar N (Materials Science Centre, Nuclear Physics Dep, Madras Univ, Guindy Campus, Chennai-600 025, Email: ansjourn@rediffmail.com) : Influence of mechanical mlling and thermal annealing on electrical and magnetic properties of nanostructured Ni-Zn and cobalt ferrites. Bull Mater Sci 2008, 31(3), 373-80.

The article reports some of the interesting and important electrical and magnetic properties of nanostructured spinel ferrites such as Ni_0.5Zn_0.5Fe₂O and CoFe₂O₄. In the case of Ni_0.5Zn_0.5Fe₂O d.c. electrical conductivity increases upon milling, and it is attributed to oxygen vacancies created by high energy mechanical milling. The real part of dielectric constant (ε') for the milled sample is found to be about an order of magnitude smaller than that of the bulk nickel zinc ferrite. The increase in Neel temperature from 538 K in the bulk state to 611 K on the reduction of grain size upon milling has been explained based on the change in the cation distribution. The dielectric constant is smaller by an order of magnitude and the dielectric loss is three orders of magnitude smaller for the milled sample compared to that of the bulk. In the case of cobalt ferrite, the observed decrease in conductivity, when the grain size is increased from 8-92 nm upon thermal annealing is clearly due to the predominant effect of migration of some of the Fe³⁺ ions from octahedral to tetra-hedral sites, as is evident from in-field Mossbauer and EXAFS measurements. The dielectric loss (tan δ) is an order of magnitude smaller for the nano sized particles compared to that of the bulk counterpart.

11 illus, 2 tables, 19 ref

024449   Narayanan C M (Chemical Engineering Dep, National of Technology, Durgapur-713 209) : Synthesis of bio-diesel in immobilised enzyme fluidised bed bioreactors-process simulation and software development. J Instn Engrs-Pt CH 2008, 89(Sep), 39-44.

Development of a software package for the design and simulation of immobilized enzyme fluidised bed bioreactorthatis being employed for the synthesis of bio-diesel has been discussed The package involves development of kinetic equations, estimation of effectiveness factor that accounts for resistance to diffusion into the support particles (that carry the immobilized enzyme) and estimation of the required expanded bed height (for attaining the desired fractional conversion of the limiting substrate, namely the vegetable oil) through numerical solution of the performance equations (non-linear differential equations). The applicability and reliability of the package have been ascertained by comparing the package results with the performance data collected from pilot plant bioreactors and laboratory bench scale reactors. Though two representative kinetic models have been considered in the analysis, the package developed is quite versatile and is well adaptable to alternate forms of kinetic models.

6 illus, 7 ref

024448   Nagaraju G;Chandrappa G T;Livage J (Chemistry Dep, Central College Campus, Bangalore Univ, Bangalore-560 001, Email: gtchandrappa@yahoo.co.in) : Synthesis and characterization of silver molybdate nanowires, nanorods and multipods. Bull Mater Sci 2008, 31(3), 367-71.

Silver molybdate nanowires, nanorods and multipeds like structures have been prepared by an organic free hydrothermal process using ammonium molybdate and silver nitrate solutions. The powder X-ray diffraction (PXRD) patterns reveal that the silver molybdate belongs to anorthic structure. The thickness, 200-500 nm, for silver molybdate nanorods/wires and 2-5 μm for microrods are identified from SEM images. UV-visible spectrum of silver molybdate nanorods/nanowires shows maximum absorbance at 408 nm. Photo-luminescence (PL) spectrum exhibits UV emission at 335 nm, violet emission at 408 nm and a weak green emission at 540 nm. The influence of hydrothermal synthesis conditions on silver molybdate nanowires, nanorods and multipods compositions were established.

9 illus, 35 ref

024447   Nag A;Sapra S;Sen Gupta S;Prakash A; Ghangrekar A;Periasamy N;Sarma D D (Centre for Advanced Materials, Indian Association of the Cultivation of Science, Kolkata-700 032, Email: sarma@sscu.iisc.ernet.in) : Luminescence in Mn-doped CdS nanocrystals. Bull Mater Sci 2008, 31(3), 561-8.

Mn-doped CdS nanocrystals (NCs) with size ranging from 1-8-3 nm. Photo-luminescence (PL) spectra of the doped NCs differ from that of the undoped NCs with an additional peak due to Mn d-d transitions. Electron paramagnetic resonance spectra along with X-ray absorption spectroscopy and PL spectra confirm the incorporation of Mn in the CdS lattice. The fact that emissions from surface states and the Mn d levels occur at two different energies, allowed us to study the PL lifetime decay behaviour of both kinds of emissions.

9 illus, 1 table, 25 ref

024446   Murugadoss A;Chattopadhyay A (Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati-781 039, Email: arun@iitg.ernet.in) : Tuning photoluminescence of ZnS nanoparticles by silver. Bull Mater Sci 2008, 31(3), 533-9.

Reports the results of investigation of the interaction of silver with presynthesized ZnS nanoparticles (NPs) that was stabilized by cetyl trimethyl ammonium bromide (CTAB). The photolumines-cence properties of ZnS NPs were followed in the presence of Ag⁺ ions, Ag NPs and by the synthesis of Ag@ZnS core-shell nanoparticles. Observed that CTAB stabilized ZnS NPs emitted broadly in the region from 350-450 nm, when excited by 309 nm light. In the presence of Ag⁺ ions the emission peak intensity up to 400 nm was reduced, while two new and stronger peaks at 430 nm and 550 nm appeared. Similar results were obtained when Ag NPs solution was added to ZnS solution. However, when Ag@ZnS NPs were synthesized, the emission in the 350-450 nm region was much weaker in comparison to that at 540 nm, which itself appeared at a wavelength shorter than that of Ag⁺ ion added ZnS NPs. The observations have been explained by the presence of interstitial sulfur and Zn²⁺, especially near the surface of the nanocrystals and their interaction with various forms of silver. In addition, our observations suggest that Ag⁺ ions diffuse into the lattice of the preformed ZnS NPs just like the formation of Ag⁺ doped ZnS NPs and thus changes the emission characteristics. We also have pursued similar experiments with addition of Mn²⁺ ions to ZnS and observed similar results of emission characteristics of Mn²⁺ doped ZnS NPs.

7 illus, 33 ref

024445   Mukherjee R;Sharma A;Patil G;Faruqui D;Gooh Pattader P S (Chemical Engineering Dep, Indian Institute of Technology, Kanpur-208 016, Email: ashutos@iitk.ac.in) : Soft lithography meets self-organization: some new developments in meso-patterning. Bull Mater Sci 2008, 31(3), 249-61.

Study is a brief review of the recent and ongoing work on simple, rapid, room temperature, pressure-less and large area (~ cm²) imprinting techniques for high fidelity meso-patterning of different types of polymer films. Examples include soft solid polymer films and surfaces like cross-linked polydimethylsiloxane (PDMS) and polyacrylamide (PAA) based hydrogels, thermoplastics like polystyrene (PS), polymethyl-methacrylate (PMMA) etc both on planar and curved surfaces. These techniques address two key issues in imprinting: (i) attainment of large area conformal contact with the stamp, especially on curved surfaces, and (ii) ease of stamp detachment without damage to the imprinted structures. The key element of the method is the use of thin and flexible patterned foils that readily and rapidly come into complete conformal contact with soft polymer surfaces because of adhesive interfacial interactions. The conformal contact is established at all length scales by bending of the foil at scales larger than the feature size, in conjunction with the spontaneous deformations of the film surface on the scale of the features. Complex two-dimensional patterns could also be formed even by using a simple one-dimensional master by multiple imprinting. The technique can be particularly useful for the bulk nano applications requiring routine fabrication of templates, for example, in the study of confined chemistry phenomena, nanofluidics, bio-MEMS, micro-imprinting, optical coatings and controlled dewetting.

10 illus, 75 ref

024444   Mishra P R;Srivastava O N (Physics Dep, Banaras Hindu Univ, Varanasi-221 005, Email: hepons@yahoo.com) : On the synthesis, characterization and photocatalytic applications of nanostructured TiO₂. Bull Mater Sci 2008, 31(3), 545-50.

Nanocrystalline semiconducting materials are attracting much attention due to their potential applications in solar energy conversion, nonlinear optics, and heterogeneous photocatalysis. In the investigation, nanostructured TiO₂ photocatalysts, are synthesis zed which have been used in the photocatalytic degradation of phenol (one of the most common water pollutants). These catalysts have been prepared through sol-gel technique using titanium tetra-isopropoxide as a raw material for synthesis. Characterization techniques such as XRD, SEM and TEM have been employed for structural/microstructural investigations. XRD results show that the as synthesized TiO₂ nanopowder exhibit anatase phase, TiO₂. The average sizes of the TiO₂ nanopowders are ~ 5-10 nm. The optical properties of the samples were investigated through UV-visible and fluorescence techniques. It has been observed that absorption edge corresponds to ~ 410 nm (band-gap, ~ 3-02 eV). The emission peak in the fluorescence spectrum at ~ 418 nm corresponds to the bandgap energy of ~ 2-97 eV. Concentration of phenol (initial concentration, ~ 100 ppm) with illumination time was monitored by measuring the absorbance of pure and illuminated phenol through UV-visible spectrophotometer. Salient feature of the study relates to the fact that the present sol-gel synthesized TiO₂ nanopowders have been found to be better photocatalysts for phenol degradation than the presently employed commercial TiO₂ (P-25, Degussa) photocatalyst. Thus, whereas phenol concentration, with the presently synthesized TiO₂ nanopowders, the concentration of phenol decreases up to ~ 32% but for commercial TiO₂ nanopowder (P-25, Degussa), it decreased only up to ~ 25%. The improved surface area is considered as an important factor for the aforesaid decrease in phenol concentration.

7 illus, 27 ref

024443   Mann A K;Varandani D;Mehta B R;Malhotra L K; Mangamma G;Tyagi A K (Physics Dep, Indian Institute of Technology Delhi, New Delhi-110 016, Email: brmehta@physics.iitd.ernet.in) : Formation of InN nanoparticle and nanorod structures by nitrogen plasma annealing method. Bull Mater Sci 2008, 31(3), 233-40.

In the study, a novel method involving nitrogen plasma annealing has been reported for preparing InN nanoparticle/nanorod structures and for improving the properties of InN nanoparticle layers. Plasma annealed structures have been characterized by X-ray diffraction, atomic force microscopy and pho-toluminescence spectroscopy techniques. InN nanoparticle layers have been prepared using activated reactive evaporation set up. It has been observed that there is a remarkable improvement in the conductivity and crys-tallinity of InN nanoparticle layers on annealing in nitrogen plasma. This has been attributed to the increase in the nitrogen content of the samples. Experiments involving plasma annealing of In nanorods deposited oxide template has also been carried out. It was found that on plasma treatment In nanorods get converted to mixed phase InN nanorods with hexagonal and cubic fractions.

9 illus, 1 table, 17 ref

024442   Malshe V C (NO, ICT, Mumbai) : Thermoplastic elastomers. Paintindia 2008, 58(11), 109-16.

6 illus, 7 ref

024441   Kundu T K;Mishra S (Physics Dep, Visva-Bharati, Santiniketan-731 235, Email: tkkundu1968@yahoo.com) : Nanocrystalline spinel ferrites by solid state reaction route. Bull Mater Sci 2008, 31(3), 507-10.

Nanostructured NiFe₂O₄, MnFe₂O₄ and (NiZn)Fe₂O₄ were synthesized by aliovalent ion doping using conventional solid-state reaction route. With the doping of Nb₂O₅, the size of NiFe₂O₄ is reduced down to 33 nm. Similarly, nanostructured manganese ferrites (MnFe₂O₄) with diameters in the range of 45-30 nm were synthesized by Ti⁴⁺ ion doping. Particle diameters in all the specimens are found to decrease with increasing dopant content. The substitution of Nb^s+ or Ti³⁺ ions essentially breaks up the ferrimagnetically active oxygen polyhedra. This created nanoscale regions of ferrites. Saturation magnetization and coercive field show a strong dependence on the size of the ferrite grains. Superparamagnetic behaviour is observed from the Mossbauer spectra of nanostructured NiFe₂O₄, if the particle size is reduced to 30 nm. Zero field cooled and field cooled curves from 30 nm sized MnFe₂O₄ particles showed a peak at T_B (~125 K), typical of superpara-magnetic blocking temperature. These results are explained in terms of core/shell structure of the materials. The d.c. resistivity of the doped specimens decreases by atleast five orders of magnitude compared to pure sample. This is ascribed to the presence of an interfacial amorphous phase between the sites.

4 illus, 2 tables, 13 ref

024440   Kundu T K;Jana A;Barik P (Physics Dep, Siksha-Bhavan, Santiniketan-731 235, Email: tkkundu1968@yahoo.com) : Doped barium titanate nanoparticls. Bull Mater Sci 2008, 31(3), 501-5.

Nickel (Ni) and iron (Fe) ion doped BaTiO₃ nanoparticles through a chemical route using poly vinyl alcohol (PVA). The concentration of dopant varies from 0 to 2 mole% in the specimens. The results from X-ray diffractograms and transmission electron micrographs show that the particle diameters in the specimen lie in the range 24-40 nm. It is seen that the dielectric permittivity in doped specimens is enhanced by an order of magnitude compared to undoped barium titanate ceramics. The dielectric permittivity shows maxima at 0-3 mole% doping of Fe ion and 0-6 mole% of Ni ion. The unusual dielectric behaviour of the specimens is explained in terms of the change in crystalline structure of the specimens.

8 illus, 25 ref

024439   Krishan Kumar;Barmanray A (Food Technology Dep, Guru Jambheshwar Univ of Science and Technology, Hisar-125 001, Email: krishankumar_2007@rediffmail.com) : Shelf-life studies on pickled button mushroom (Agaricus bisporus). Mushroom Res 2008, 17(1), 25-30.

Two types of pickles were prepared from white button mushroom (Agaricus bisporus) as per FPO specifications. Two types of oils i.e. mustard and sesame oil were used for pickle preparation. Six recipes, three for each type of pickle were used for developing the product. Sensory evaluation showed that recipes B and E were most acceptable, which were prepared with mustard and sesame oil, respectively securing highest organoleptic scores. Products developed were evaluated for their physico-chemical, organoleptic and microbial qualities for one year at two months interval. Values for moisture and titratable acidity decreased gradually during storage. pH increased during storage for both types of pickles. There was no significant change in fat, protein and ash content of both types of pickles. Ascorbic acid decreased during storage for one year. There were no appreciable changes in organoleptic scores during storage and products were acceptable even after one year. Microbial examination showed significant increase in total viable count during storage for one year but it remained in the range of 2 log cycles throughout the storage period.

7 tables, 11 ref

024438   Koraddi V;Sumangala P R (NO, College of Rural Home Science, University of Agricultural Sciences, Dharwad-580 005, Email: sumangalapatre@yahoo.co.in) : Effect of different packing materials on sensory profiles of vegetables stored in refrigerator at household level. Int J agric statist Sci 2009, 5(1), 223-9.

Comparison between different packing materials irrespective of vegetables, revealed that the mean Sensory Evaluation Index (SEI) score was highest in polyethylene (55.77) followed by low density polyethylene (LDPE) bag (53.32) and plastic container (50.82). Plastic container for fenugreek, chillies, beans, carrot and tomato; while polyethylene bag for coriander and cucumber and LDPE bag for lady's finger can be recommended.

3 table, 6 ref

024437   Kaya C;Kola O;Ozer M S;Altan A (Food Engineering Dep, Faculty of Agriculture, University of Goziosmanpasa, Tokat-60240, Turkey, Email: ckaya@mail.gap.edu.tr) : Some characteristics and fatty acids composition of wild apricot (Prunus pseudoarmeniaca l.) kernel oil. Asian J Chem 2008, 20(4), 2597-2602.

The oil composition and some physical and chemical characteristics of wild apricot (P pseudoarmeniaca L.) kernel oil (WAO) grown in Turkey were determined. Wild apricot kernel contain about 48-50 % crude oil of total dry matter. The oil consist of 93 % of unsaturated fatty acids and the main fatty acids are oleic (75 %), linoleic (175 %), palmitic (4.5 %) and stearic (2 %) acids. The other characteristics of the wild apricot oil are approximately as follows: refractive index (20λC), 1.469; specific gravity, 0.914 g/cm¹; insoluble matter in the ether, 0.5 %; unsaponifiable matter, 0.7 % and iodine value, 92.

3 tables, 31 ref

024436   Kamil M;Sardar N;Ansari M Y (Petroleum studies Dep, Aligarh Muslim Univ, Aligarh-202 002) : Experimental study on adulterated gasoline and diesel fuels. J Instn Engrs-Pt CH 2008, 89(Sep), 23-8.

Automotive petro-fuels mean particularly gasoline and diesel which are provided mainly from petroleum industry by refining crude oil. Adulteration of these petro-fuels with low priced materials is wide spread throughout the world in general, and India in particular. This can result in sub-optimal performance of transportation fuels, resulting emissions of toxic pollutants from vehicles. Therefore, the present experimental study is carried out systematically on adulterated gasoline and diesel fuels with kerosene, diesel and used oil respectively. Various tests related to these petro-fuels were carried out and compared with the standard specifications. The results have been discussed qualitatively taking into account the changes in characteristics of these fuels and their impact on engine performance and exhaust emissions.

5 illus, 9 tables, 13 ref

024435   Kalele S;Deshpande A C;Singh S B;Kulkarni S K (DST Unit on Nanoscience and Nanotechnology, Physics Dep, Pune Univ, Pune-411 007, Email: skk_surface@yahoo.com) : Tuning luminescence intensity of RHO6G dye using silver nanoparticles. Bull Mater Sci 2008, 31(3), 541-4.

The photoluminescence (PL) from rhodamine (RHO6G) dye dispersed in ethanol has been studied in the presence of different amounts of citrate stabilized silver nanoparticles of size, ~10 nm. Enhancement as well as quenching of luminescence intensity has been observed and it was found that luminescence intensity can be tuned by adding various amounts of silver nanoparticles to the RIIO6G dye dispersion. The luminescence spectra of dye consist of two peaks at 440 nm and 550 nm. Peak at 440 nm shows an enhancement in intensity at all the concentrations of added silver nanoparticles with the maximum intensity for dye with 0.25 ml silver nanoparticles (82% enhancement in the luminescence intensity). PL intensity of intense peak at 550 nm of dye molecules was found to be quenched in presence of silver nanoparticles and maximum quenching was found to be 41% for the dye with 1 ml silver nanoparticles. However, for lowest concentration of silver nanoparticles viz. (0-01 ml), enhancement in intensity was observed (13% enhancement than the dye molecules). The quenching as well as enhancement in the intensity can be understood by considering the possibility of three different phenomena. It has been reported earlier that when metal nanoparticles are in close proximity to the fluorophores, quenching of luminescence occurs, whereas when metal nanoparticles are located at certain distance, enhancement in luminescence is observed. This effect has been explained by coupling of surface plasmon resonance from metal nanoparticles with fluorophore, resulting in the increase of excitation and emission rate of the fluorophore in the localized electromagnetic field. The quenching and enhancement of luminescence intensity of the dye molecules can also be explained as the transfer of electrons from dye to the silver nanoparticles and to an extent it can be attributed to the aggregation of dye molecules upon addition of silver nanoparticles.

4 illus, 18 ref

024434   Kala S;Mehta B R (Physics Dep, Indian Institute of Technology Delhi, New Delhi-110 016, Email: brmehta@physics.iitd.ernet.in) : Hydrogen-induced electrical and optical switching in Pd capped Pr nanoparticle layers. Bull Mater Sci 2008, 31(3), 225-31.

In this study, modification in the properties of hydrogen-induced switchable mirror based on Pr nanoparticle layers is reported. The reversible changes in hydrogen-induced electrical and optical properties of Pd capped Pr nanoparticle layers have been studied as a function of hydrogenation time and compared with the conventional device based on Pd capped Pr thin films. Faster electrical and optical response, higher optical contrast and presence of single absorption edge corresponding to Pr trihydride state in hydrogen loaded state have been observed in the case of nanoparticle layers. The improvement in the electrical and optical properties have been explained in terms of blue shift in the absorption edge due to quantum confinement effect, larger number of interparticle boundaries, presence of defects, loose adhesion to the substrate and enhanced surface to volume atom ratio at nanodimension.

7 illus, 1 table, 25 ref

024433   Halakatti S V;Malshet K K;Hemalatha S (Extension Education Unit, Agricultural Technology Information Centre, University of Agricultural Sciences, Krishinagar, Dharwad-580 005, Email: sunilvhalakatti@redifmail.com) : Evaluation of oil seed production technology in Northern transitional zone of Karnataka. Int J agric statist Sci 2009, 5(1), 205-9.

Attempt is made to study the economic feasibility of technology transfer and adoption in oil seed crops. It was observed that there was a high degree of variation in potential and demonstration yield in oilseeds due to technology and extension gaps. The technology gaps were more compared to extension gap, resulting in poor adoption of technology. This highlighted the need to educate the farmers in the adoption of improved technology. A few constraints were also expressed by the respondents in adopting the recommended practices.

4 tables, 2 ref

024432   Ghosh P;Sadhu S;Sen T;Patra A (Materials Science and Centre for Advanced Materials Dep, Indian Association for the Cultivation of Science, Kolkata-700 032, Email: msap@iacs.res.in) : Upconversion emission of BaTiO₃ : Er nanocrystals. Bull Mater Sci 2008, 31(3), 461-5.

Reports the dopant concentration and pump-power dependence upconversion emission properties of erbium doped BaTiO₃ nanocrystals derived from sol-emulsion-gel method. Green (550 nm) and red (670 nm) upconversion emissions were observed at room temperature from the ⁴S_3/2 and ⁴F_9/2 levels of Er³⁺: BaTiO₃ nanocrystals. It is found that at 850 mW of cw excitation power (at 980 nm) the total luminescence was 17130 Cd/m² for 1000°C heated 0-25 mol% Er-doped BaTiO₃ nanocrystals. It is worthwhile to mention that the unusual power-dependent upconversion luminescence (saturation) is observed at higher dopant concentration (2-5mol%) and high pump power. Our analysis confirms that the depletion of the excited state is responsible for the relevant fluorescence upconversion. We have again confirmed that a two-photon excited state absorption process occurs for all samples.

6 illus, 14 ref

024431   Ghosh M;Bhattacharyya R;Raychaudhuri A K (DTS Unit for Nanoscience, S.N. Bose National Centre for Basic Sciences, Kolkata-700 098, Email: arup@bose.res.in) : Growth of compact arrays of optical quality single crystalline ZnO nanorods by low temperature method. Bull Mater Sci 2008, 31(3), 283-9.

Reports the synthesis and optical properties of compact and aligned ZnO nanorod arrays (dia, -50-200 nm) grown on a glass substrate with varying seed particle density. The suspension of ZnO nanoparti-cles (size, ~15 nm) of various concentrations are used as seed layer for the growth of nanorod arrays via self-assembly of ZnO from solution. Studied the effect of various growth parameters (such as seeding density, microstructure of the seed layer) as and as the growth time on the growth and alignment of the nanorods. We find that the growth, areal density and alignment of the nanorods depend on the density of seed particles which can be controlled. It is observed that there is a critical density of the seed particles at which nanorod arrays show maximum preferred orientation along [002] direction. The minimum and maximum radius of the aligned nanorods synthesized by this method lie in the range 50-220 nm which depend on the seeding density and time of growth. These nanorods have a bandgap of 3-3 eV as in the case of bulk crystals and show emission in the UV region of the spectrum (~ 400 nm) due to excitonic recombination and defect related emission in the visible region.

5 illus, 1 table, 34 ref

024430   Ganguly U P (NO, , Flat No. B-17/257, Kendriya Vihar, VIP Road, Kolkata-700 052) : Determination of the bed concentration of the elutriating component in particular fluidization. J Instn Engrs-Pt CH 2008, 89(Sep), 18-22.

The phenomenon of elutriation had earlier been stated to be a rate governed process like drying, sedimentation and others, where the elutriable solids (finer/lighter) continuously leave the system. The concentration (mass fraction) of such component from a mixed mass of solids falls off steadily till this attains a constant value indicating a state of equilibrium when the entire process of elutriation comes to an end. A method has been described to calculate the concentration of the elutriating solids remaining in the fluidized bed at any time. The method is based upon the predetermined values of initial concentration, C₀; the equilibrium bed concentration, C_E; the order of the elutriatiofi rate process n; and the overall elutriation rate constant, k₀. Excellent agreement between the experimental values of C and those, calculate by the proposed method, has been observed. The standard deviation for 309 data points has been found to be ±3.16% only.

3 illus, 1 table, 5 ref

024429   Ganguly A;Maiti M;bhowmick A K (Rubber Technology Centre, Indian Institute of Technology, Kharagpur-721 302, Email: anilkb@rtc.iitkgp.ernet.in) : Structure-property relationship of specialty elastomer clay nanocomposites. Bull Mater Sci 2008, 31(3), 455-9.

The work deals with the synthesis of specialty elastomer [fluoroelastomer and poly (sty-rene-b-ethylene-co-butylene-b-styrene (SEBS)]-clay nanocomposites and their structure-property relationship as elucidated from morphology studies by atomic force microscopy, transmission electron microscopy and X-ray diffraction and physico-mechanical properties. Due to polarity match, hydrophilic unmodified montmorillonite clay showed enhanced properties in resulting fluoroelastomer nanocomposites, while hydro-phobic organo-clay showed best results in SEBS nanocomposites.

6 illus, 1 table, 17 ref

024428   Ganguli A K;Vaidya S;Ahmad T (Chemistry Dep, Indian Institute of Technology, New Delhi-110 016, Email: ashok@chemistry.iitd.ernet.in) : Synthesis of nanocrystalline materials through reverse micelles: a versatile methodology for synhesis of complex metal oxides. Bull Mater Sci 2008, 31(3), 415-19.

Describe methodology to obtain important metal oxides like ceria, zirconia and zinc oxide. The oxalate of cerium, zirconium and zinc were synthesized using the reverse micellar route. While nanorods of zinc oxalate with dimension, 120 nm in diameter and 600 nm in length, could be obtained, whereas spherical particles of size, 4-6 nm, were obtained for cerium oxalate. These precursors were heated to form their respective oxides. Mixture of nanorods and nanoparticles of cerium oxide was obtained. ZrO₂ nanoparticles of 3-4 nm size were obtained by the thermal decomposition of zirconium oxalate precursor. ZnO nanoparticles (55 nm) were obtained by the decomposition of zinc oxalate nanorods. Photoluminescence (PL) studies at 20 K shows the presence of three peaks corresponding to free excitonic emission, free to bound and donor-acceptor transitions. We also synthesized nanoparticles corresponding to Ba_1-xPb_xZrO₃ using the reverse micellar route. The dielectric constant and loss were stable with frequency and temperature for the solid solution.

6 illus, 1 table, 16 ref

024427   Gadgile D P;Chavan A M (Botany Dep, Seed Pathology and Fungal Biotechnology Lab, Dr. Babasaheb Ambedkar Marathwada Univ, Aurangabad-431 004, Email: ram_mango@yahoo.com) : Changes in ascorbic acid (Vitamin C) contents of mango pulp due to different isolates of Aspergillus niger. Bionano Front 2009, 2(2), 69-70.

During storage conditions mango gets infected by several fungal diseases like Rhizopus rot, Anthracnose, stem end rot, Aspergillus niger rot, Among these diseases Aspergillus niger rot is -very serious disease and it causes change in biochemical content of mango pulp. In present investigation spore suspension of Aspergillus niger isolates was inoculated in Same aged and surface sterilized ripened mangos of five varieties that is Alphanso, Benishan, Dasheri, Kesar and Local variety. After seven days, change in vitamin C content was estimated by titratioh method. Ascorbic acid was found to be decreased significantly due to all five isolates A. nigerin all five Mango varieties.

1 illus, 1 table, 7 ref

024426   Dhingra V (Regional Forensic Science Lab, , Gwalior, Madhya Pradesh) : Identification of unknown lachrymatic chemical. Indian Internet J Forensic Med Toxicol 2008, 6(1-2), 20-2.

Describes the identification of unknown lachrymatic chemical, which were spilled during transportation caused suffocation and left several persons with tears and results panic in public. By applying chemical colour tests and gas chromatographic analysis, the chemical identified as formalin, which is used as preservative for biological specimens.

^ccr2 ref

024425   Dev A;Chaudhuri S;Dev B N (Materials Science Dep, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, Email: msbnd@iacs.res.in) : ZnO 1-D nanostructures: low temperature synthesis and characterization. Bull Mater Sci 2008, 31(3), 551-9.

ZnO is one of the most important semiconductors having a wide variety of applications in photonic, field emission and sensing devices. It exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the ZnO crystal. Among various nanostructures, oriented 1-D nanoforms are particularly important for applications such as UV laser, sensors, UV LED, field emission displays, piezoelectric nanogenerator etc. We have developed a soft chemical approach to fabricate well-aligned arrays of various 1-D nanoforms like nanonails, nanowires and nanorods. The microstructural and photoluminescence properties of all the structures were investigated and tuned by varying the synthesis parameters. Field emission study from the aligned nanorod arrays exhibited high current density and a low turn-on field. These arrays also exhibited very strong UV emission and week defect emission. These structures can be utilized to fabricate efficient UV LEDs.

8 illus, 1 table, 37 ref

024424   Deodhar K K (Spectra Consultech, [Exclusive Representative of General Trade Italy], Kothrud, Pune, Email: krion_kd@yahoo.com) : Premium patented real wood effect technology and system to imitate natural wood pattern with powder on powder coating process of architectural aluminium profiles, doors, sheets. Paintindia 2008, 58(12), 105-12.

024423   De G;Medda S K;De S;Pal S (Sol-Gel Div, Central Glass and Ceramic Research Institute, Kolkata-700 032, Email: gde@cgcri.res.in) : Metal nanoparticle doped coloured coatings on glasses and plastics through tuning of surface plasmon band position. Bull Mater Sci 2008, 31(3), 479-85.

Several noble metal nanoparticles doped sol-gel derived thin coloured films have been synthesized and characterized. These are pure (Ag, Au, Cu and Pt), mixed/alloy (Ag-Cu, Au-Cu, Au-Ag and Au-Pt) nanoparticles in SiO₂, Au in mixed SiO₂-TiO₂ and SiO2-ZrO₂, Au and Ag nanoparticles in inorganic-organic hybrid film matrices etc. This investigation leads to the development of tailor-made coloured coatings by tuning the surface plasmon resonance (SPR) band positions originating from the embedded nanometals by controlling mainly (i) refractive index of the film matrices and (ii) nanoalloy composition. In the later case a new layer-by-layer (two-layer) synthetic protocol has been developed to prepare binary nanoalloy particles with controlled atomic ratios.

6 illus, 2 tables, 22 ref

024422   Datta D;Dey Sarkar N;Deb Sarkar A; Bandyopadhyay A (Chemical Engineering Dep, Heritage Institute of Technology, Kolkata-700 107) : Adsorptive removal of phenol utilizing flyash. J Instn Engrs-Pt CH 2008, 89(Sep), 6-10.

An experimental study was conducted with flyash as a low cost adsorbent material for removal of phenol from synthetic waste water. Batch sorption tests were conducted to study sorption kinetics and sorption isothermal adsorption capacity of the sorbent. Batch study comprised of varying flyash dose, phenol concentration, pH etc. A maximum phenol removal of approximately 98% was obtained at a pH of 7.0, when adsorbent dose and initial sorbate concentration were 800 gm/l and 20 mg/l, respectively. Phenol removal efficiency varied from 95.92% to 97.75% after a 4 h contact period at an adsorbent dose of 800 gm/l and at pH =7.0 for all other initial phenol concentrations (40 mg/l, 60 mg/l and 80 mg/l). Adsorption kinetics was found to follow first order reaction and Freundlich isotherm model. Batch desorption test was also performed for potential regeneration of the spent flyash using different chemicals like acetone, ethanol and sodium chloride. Acetone solution (10%) was found to have high desorption capacity to regenerate the spent flyash.

5 illus, 2 tables, 5 ref

024421   Datta D;Bhattacharjee C;Datta S (Chemical Engineering Dep, Heritage Institute of Technology, Kolkata-700 107) : Whey protein fractionation using membrane filtration. J Instn Engrs-Pt CH 2008, 89(Sep), 45-50.

Provides a review, starting from the very beginning of membrane technology to its recent form of obtaining high resolution separation in commercial scale. Specific data and information from various research papers have been presented in order to show the growth and state-of-the-art technology in the perspective of whey Protein fractionation. Advantages of separation of individual whey proteins like a-Lactalblumin (α-LA), β-Lactoglobulins (β-LG) and Bovine Serum Albumin (BSA) etc. have been discussed with the help of high performance tangential flow filtration (HPTFF) module and rotating disc membrane module. Potential application of protein separation by means of ultrafiltration followed by ion exchange membrane chromatography (IEMC) have also been presented.

^iia3 illus, 2 tables, 25 ref

024420   Das A;Das S;Raychaudhuri A K (DTS Unit for Nanoscience, S.N. Bose National Centre for Basic Sciences, Kolkata-700 098, Email: arup@bose.res.in) : Growth of two-dimensional arrays of uncapped glod nanoparticles on silicon substrates. Bull Mater Sci 2008, 31(3), 277-82.

A method of preparing large area patterned 2D arrays of uncapped gold (Au) nanoparticles has been developed. The pattern has been formed using self-assembly of uncapped Au nanoparticles. The Au nanoparticles were synthesized via toluene/water two phase systems using a reducing agent and colloidal solution of Au nanoparticles was produced. These nanoparticles have been prepared without using any kind of capping agent. Analysis by TEM showed discrete Au nanoparticles of 4 nm average diameter. AFM analysis also showed similar result. The TEM studies showed that these nanoparticles formed self-assembled coherent patterns with dimensions exceeding 500 nm. Spin coating on silicon substrate by suitably adjusting the speed can self-assemble these nanoparticles to lengths exceeding 1 μm.

6 illus, 17 ref