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In this article, design methodology of dielectric loaded interaction structure with input and output coupling for $Q$ -band gyro traveling wave tube (gyro-TWT) has been described. The particle-in-cell (PIC) simulation of loaded interaction structure for $Q$ -band has been investigated using MAGIC code. The simulation results predict that the interaction structure can produce more than 200-kW output power and 50-dB saturated gain at 45–50-GHz frequency range. A new type of multichannel input coupler and wideband double disk sapphire output window is used to improve the performance of the $Q$ -band gyro-TWT. This article describes the design and simulation of a high-performance TE01 mode $Q$ -band gyro-TWT amplifier that applies the technique of employing a periodic dielectric loaded interaction structure to achieve stability and broad bandwidth. The stability of the gyro-amplifier was excellent and demonstrating that the ceramic loading is a highly effective for suppressing the spurious oscillations in the gyro-TWT amplifier. [ABSTRACT FROM AUTHOR]

Aluminum matrix composites are widely used for making structural components in the aerospace and automobile industries. In order to sustain the operational demand, excellent anti‐wear and corrosion resistance properties are required in the composites. To achieve this, molybdenum disulfide and cerium dioxide reinforced hybrid aluminum‐based composites are fabricated by friction stir processing at different rotational speed and number of passes. Due to grain refinement and better particle distribution at high rotational speed and 2 pass, tensile strength and microhardness improves by sacrificing ductility. However, deterioration of mechanical properties than the as‐received alloy is evident in all the composites due to dissolvement of strengthening precipitates. With increasing tool rotational speed, severe adhesion type of wear shifts to abrasion wear and the wear resistance also improves. All the composites show similar corrosion behavior as the unprocessed alloy. However, the corrosion parameters such as corrosion potential and corrosion current density were influenced by processing conditions. The composite produced with 1500 min−1 and 2 pass exhibits highest wear and corrosion resistance. [ABSTRACT FROM AUTHOR]

The core elements of cardiovascular science have been established by scholarly pursuits of numerous scientists across centuries. In this article, we have tried to trace the evolutionary journey of cardiovascular science from a rudimentary form in ancient period to a robust scientific discipline in modern times. A literature search of relevant, peer-reviewed, published articles was undertaken from indexed databases (Medline & Pubmed, Scopus, Embase, CINAHL Plus, Web of Science and Google Scholar). Cardiovascular science has its roots in antiquity, when Greek scholars mostly relied on philosophical thoughts and ancient texts. This was followed by addition of few structural details to the theory of circulation by Galen based on animal dissection. Arab scholar Ibn al–Nafis provided new insights regarding circulation pathway in humans. Nevertheless, an erroneous concept prevailed into the onset of European Renaissance. Even with legalization of human dissection, little headway could be made till sixteenth century due to persistent reliance of anatomists on ancient Galenic principles. During seventeenth century, the circulatory pathway (as we know it today) was established due to significant contributions from scholars like Harvey and Malpighi. Their efforts were based on findings from experiments and logical conclusions. Eighteenth century witnessed the emergence of autopsy based methods which led to valuable contributions from Vieussens, Thebesius, Morgagni and Hunter regarding normal and pathologic anatomy of cardiovascular system. With structural details mostly established, researchers during nineteenth century focussed on innovations in diagnostic methods based on human experiments. Further development of advanced human experiment models during twentieth century led to emergence of contemporary treatment methods for various cardiac conditions. In the twenty-first century, cardiovascular science is undergoing comprehensive progress at an exponential rate due to technological advances. The evolutionary journey of cardiovascular science as a discipline across centuries has been intriguing and eventful. [ABSTRACT FROM AUTHOR]

The current study intended to optimize the concentration of Oxyrase in the semen dilutor and to evaluate its effect on freezability of spermatozoa of Sahiwal bulls. Supplementation of Oxyrase at 0.125 IU/mL concentration significantly reduced dissolved oxygen (DO) in the dilutor to 4 ppm in 16–18 min at 35 °C. For supplementation studies, a total of 24 ejaculates were categorized into poor and good ejaculates categories (n = 12 each) based on their initial progressive motility. Each ejaculate was further divided into two aliquotes. The first aliquote was diluted with tris-egg yolk extender without Oxyrase (control group) whereas, in the treatment group, Oxyrase was supplemented at the concentration of 0.125 IU/mL of extender. The parameters evaluated include cholesterol and plasma membrane phospholipids (PMP) at fresh, while IPM, acrosomal and plasma membrane integrity, cholesterol, PMP and oxidative stress parameters like lipid peroxidation (LPO), total antioxidant capacity (TAC) and reactive oxygen species (ROS) were evaluated at pre-freeze and post-thaw stages. The IPM and acrosomal intactness were higher (p < 0.05) in treatment group at post-thaw stage in good ejaculates. Oxyrase supplementation resulted in lower (p < 0.05) cholesterol leakage in both categories and lower (p < 0.05) LPO in good ejaculates at post-thaw stage. No statistical difference in ROS was observed between control and treatment groups at all stages whereas, level of TAC was higher (p < 0.05) in the treatment group compared to control group at post-thaw stage of both categories. Therefore, Oxyrase as an oxygen scavenging agent could preserve the post-thaw quality of Sahiwal bull spermatozoa. [ABSTRACT FROM AUTHOR]

The present study aims to examine the deformation and annealing behaviour of Fe–0.07C–20Mn–2.6Si–1.6Al TWIP steel in the viewpoint of microstructural characterisation, fault analysis, triaxial residual stress measurement and mechanism of twin formation. 50% cold deformation results in improvement of hardness and tensile strength (428 HV and 1419 MPa, respectively), whereas annealing at 900 °C of the same leads to improvement in ductility (61%) with the decrease in strength (873 MPa). The residual stress is maximum and compressive in nature in deformed sample which has been diminishing after annealing. Hot rolled and hot rolled-solution treated samples develop dual phase microstructure along with annealing twins, whereas fine nano twins and high dislocation density with dual phase microstructure are apparent after 50% cold deformation. The presence of Shockley partial dislocation, overlapping of stacking faults, Lomer-Cottrell lock, intrinsic and extrinsic stacking faults affect the mechanical properties as obstacles of dislocation movements or assisting twin formation. Goss and Brass components of texture are dominating after rolling, whereas annealing results in weakening of rolling texture components. The nucleation mechanism of twin has been consistent with the pole mechanism along with the deviation process. Hence the present work amplifies the present understanding of deformation and annealing behaviour on low carbon dual phase TWIP steel from different characterisation perspectives. [ABSTRACT FROM AUTHOR]

In this study, electrochemical reduction behaviour of uranyl ions was investigated from an alkaline oxalate complex electrolyte. Detailed results of scan rates, pH and temperature dependent cyclic voltammetry were analysed to extract diffusion coefficients and to elucidate reduction mechanism. A two-step mechanism was established where the first step involving reduction of UO 2 2+ to UO 2 + was a slower and reversible in nature and the second step was proton assisted reduction of UO 2 + to UO 2 . Detailed speciation study of the electrolyte confirmed [UO 2 (C 2 O 4 ) 3 ] 4− as the predominant species in the pH range 5.0 to 8.5. XPS analyses of as-deposited oxide film confirmed about the formation of UO 2 with a small percentage of UO 3 . For annealed films (at 973 K for 1 h), majority of oxide film was present in mixed valence state containing U 6+ and U 5+ with a small amount of U 4+ . High resolution transmission electron microscope (HR-TEM) examination of as-deposited film revealed the deposition of an ultra-nanocrystalline UO 2 film with average gain size of 3.0 nm. However, annealed sample showed substantial grain growth associated with reduced inter-grain amorphous region. The average grain size obtained was 9.8 nm with lattice fringe spacing was 0.32 nm corresponding to the fcc UO 2 . [ABSTRACT FROM AUTHOR]

In this article, the adsorption of methylene blue (MB) from its aqueous solution onto citric acid treated carbonized bamboo leaves powder as an adsorbent is reported. The adsorbent was characterized by determining the density, pH pzc (6.6), particle size (32.53 μm), and was analyzed by SEM, BET (surface area 393.3 m 2 /g) and FTIR. Batch experiments were performed as a function of various operating parameters - initial concentration (100 to 400 mg/L), contact time (10 to 100 min), adsorbent dose (0.2 to 1.4 g/L), shaker speed (50 to 350 rpm) and temperature (290 to 305 K) at natural pH of 7.5. The batch data followed Temkin isotherm amongst seven isotherms and pseudo-second order kinetic model. Further, analysis of batch data upon various diffusion models indicated that film diffusion was controlling the rate though intra-particle diffusion was taking place. Thermodynamic parameters (ΔG 0 : − 33.70 to − 25.43 kJ/mol; ΔH 0 : 134.97 kJ/mol; ΔS 0 : 554.51 J/mol·K) revealed spontaneity of adsorption and the nature was chemisorption which also followed the activation energy (84.07 to 98.90 kJ/mol) estimated from pseudo-second order rate constant as a function of temperature. Novelties achieved were - higher removal of MB (99.97%), higher adsorption capacity (725 mg/g), final solution pH well within the safe discharge limit. Besides, the seasonal variation was used to investigate the temperature effect in a novel manner. [ABSTRACT FROM AUTHOR]

Electrodeposition of Ni-Zn-P alloy coatings was studied from an electrolyte containing hypophosphorous acid (H 3 PO 2 ) as a source of phosphorus. In this study, the effect of electrolyte pH on deposit composition, current efficiency and anomalous codeposition was investigated in detail. With increase in pH of the electrolyte, the Zn and P-content of the NiZnP alloy coating decreased with commensurate increase in Ni-content. The faradic efficiency of deposition was found to increase with increase in pH and ultimately saturated beyond pH = 10. At lower pH, the anomalous effect of Zn 2+ was prominent which turned into non-anomalous at pH ≥ 9.0. Evidence of simultaneous electroless deposition was noticed during electrodeposition and the corresponding deposition rate was nearly unaffected due to electrolyte pH variation. X-ray diffraction investigation confirmed the deposition of amorphous NiZnP alloys throughout the composition range studied here. Scanning electron microscope (SEM) examination of as-deposited surface showed smooth to nodular growth pattern with multiple cracks depending upon the pH values. The cross-section examination of deposited Ni-Zn-P alloy microstructure revealed growth of multiple layers with non-uniform thickness ranging from 100 nm to 1 μm along the growth direction. Corrosion experiments were performed in static as well as in potentiodynamic conditions in an electrolyte containing Na 2 SO 4 , H 3 BO 3 under neutral condition. Coatings with Zn content in the range 18–22 wt% were found to display open circuit potential (OCP) of − 0.630 to − 0.600 V vs. SCE which are more active but close to steel substrate OCP and hence can be used as a sacrificial coating for the protection of steel for a longer duration. [ABSTRACT FROM AUTHOR]

A novel high-strength steel has been made through thermo-mechanical controlled processing with the finish rolling temperature of 750 °C followed by air cooling. Subsequently, both partial austenitisation at 800 °C and fully austenitisation at 930 °C have been attempted for equal duration of 30 min prior to one step quenching and partitioning (Q&P) at 345 °C below M S temperature (365 °C). As-rolled steel reveals ferrite-bainite-martensite microstructures with a good combination of strength and ductility. After Q&P, all the specimens have exhibited the multiphase microstructures comprising ferrite, lath microstructure (martensite and bainite), and retained austenite with the volume fractions of up to 10.50 wt%. It is evident that partitioning for 30 min leads to good carbon enrichment (>1 wt%) of the austenite phase from the neighbouring martensite or bainite which might be due to fast partitioning kinetics and possible suppression of carbides through a combination of Si and Al additions. The attractive combination of tensile strength (921–922 MPa) and ductility (25–26% total elongation) along with low yield ratio (0.63–0.69) are attributed to ferrite and lath microstructures along with the thin film like carbon enriched retained austenite obtained after Q&P process. [ABSTRACT FROM AUTHOR]

Chemically induced instability in local symmetry of rare earth modified barium zirconate titanate relaxor ceramics Ba 1-x Ln 2x/3 Zr 0.3 Ti 0.7 O 3 (Ln = Sc, La, Sm, Nd, Eu and Gd), where x = 0.02–0.10 and its effect on structural, microstructural, interband transition along with ferroelectric switching polarization are studied experimentally. Rare earth substitution induced A-site vacancies and distortion in three dimensional cation-oxygen networks leads to random local strain with short range ordering. In addition, these cations control the formation of grain, grain boundaries and band gap values. Substitution of rare earth ions induced intermediate energy levels in between conduction and valence band and guided the emission spectra towards blue-green region. At room temperature polarization hysteresis loop and normalized capacitance versus electric field loop indicated the existence of relaxation and polarization switching mechanism in these materials. However, at room temperature feeble polarization switching is observed in case of scandium, europium and gadolinium based BZT compositions indicated a weak relaxor phase whereas in lanthanum, samarium, neodymium substituted BZT materials shows a dominating relaxor phases induced by static and dynamic of nano size polar regions separated by non-polar region. [ABSTRACT FROM AUTHOR]

Lead free niobium modified piezoelectric ceramics Bi 0.5 Na 0.25 K 0.25 Nb x Ti 1-x O 3 (BNKT) (x = 0.0, 0.015 and 0.025) compositions along with their structural and opto-electrical properties are investigated. At room temperature Rietveld refinement analysis on x-ray diffraction data revealed the evidence of tetragonal (P4mm) + cubic (Pm3m) mixed phases at 0.015Nb-BNKT composition and at higher niobium concentration it moves towards cubic phase. Presence of local disorder controls the Raman active vibrational modes along with excitation and emission spectra in these materials. The temperature dependence dielectric constant is investigated in the frequency range of 1 kHz–100 kHz. The broadening of dielectric peak and frequency dependence behavior indicated a relaxor property in these materials. Induced A-site vacancies and coexistence of tetragonal-pseudocubic phases lower the depolarization temperature ( T d ) with niobium concentration. The structural mix phases have been correlated with the piezoelectric coefficients and the composition x = 0.015 depicts the better piezoelectric properties amongst the studied compositions which is endorsed to the mixed symmetry of tetragonal and cubic phases. [ABSTRACT FROM AUTHOR]

In this study, temporal MODIS-Terra MOD13Q1 data have been used for identification of wheat crop uniquely, using the noise clustering (NC) soft classification approach. This research also optimises the selection of date combination and vegetation index for classification of wheat crop. First, a separability analysis is used to optimise the date combination for each case of number of dates and vegetation index. Then, these scenes have undergone for NC soft classification. The resolution parameter (δ) was optimised for the NC classifier and found to be a value of 1.6 × 104for wheat crop identification. Classified outputs were analysed by receiver operating characteristics (ROC) analysis for sub-pixel detection. Highest area under the ROC curve was found for soil-adjusted vegetation index corresponding to the three different phenological stages data sets. From this study, the data sets corresponding to the Sowing, Flowering and Maturity phenological stages of wheat crop were found more suitable to identify it uniquely. [ABSTRACT FROM PUBLISHER]

In the present study, the variation of superparamagnetic (SPM) and ferromagnetic (FM) components and their effect on giant magnetoresistance (GMR) in electrodeposited CoCu/Cu multilayers (ML's) were investigated in the temperature range 30–300 K. For this, two different kinds of ML's, one with discontinuous Co-layer consisting of large superparamagnetic (SPM) ( t Co = 0.2 and 0.3 nm) fractions and the other with continuous Co-layer containing large ferromagnetic (FM) ( t Co = 2 and 3 nm) content were considered. Magnetoresistance measurements showed increase in MR magnitude with decrease in temperature associated with magnetic conversions in the magnetic Co-layers. At 300 K, a substantial difference in magnitude of MR was found for multilayers with t Co = 0.3 (5.07%) and 3 nm (8.82%). However, at 30 K very close values of MR for multilayer pair with t Co = 0.3 (16.48%) and 3 nm (17.72%) ensures a significant transformations of SPM to FM fractions in Co-layer at t Co = 0.3 nm. Similar results were obtained for the other pair of ML's i.e. t Co = 0.2 and 2 nm. This study suggests a suitable minimization of SPM content in the Co-layer could be another effective mechanism in maximizing the MR value. The measured temperature dependence of MR obeyed a simple T 1 law. [ABSTRACT FROM AUTHOR]

The electrodeposition of thick metallic molybdenum coating from aqueous electrolyte considered difficult for a long time owing to high reactivity with oxygen. In the present study, a successful attempt was made to electrodeposit thick (~ 25 μm), metallic bright Mo coating by DC electrolysis from a water deficient aqueous electrolyte containing molybdate ions. Energy-dispersive spectroscopic (EDS) analysis confirmed the presence of Mo along with low content of oxygen on top surface. The crystal structure of as-deposited Mo coating was amorphous in nature, as monitored by in situ XRD investigation, which transformed into crystalline BCC structure upon vacuum annealing. The surface morphology of Mo coatings as investigated by scanning electron microscopy (SEM) revealed the presence of several cracks without any grain structure. Transmission electron microscope micrographs showed the featureless microstructure of amorphous molybdenum, which was further ascertained by the appearance of a continuous ring pattern in the selected area electron diffraction pattern (SAED). XPS analysis confirmed deposition of reduced Mo(0) metal and the top layer converted to Mo oxides upon keeping in ordinary atmosphere. Nanoindentation measurements showed a drastic improvement of nanohardness of as-deposited (2186 ± 455 MPa) to coatings (4187 ± 910 MPa) after annealing at 700 °C. [ABSTRACT FROM AUTHOR]

The present study deals with the influence of cold rolling on microstructure, texture and mechanical properties of low carbon high Mn TWIP steel. It is noticed that the hardness, yield strength and tensile strength of the specimens increase whereas percentage elongation decreases as the amount of cold rolling reduction increases. The fully austenite phase with the average grain size of about 55 µm along with annealing twins became fragmented and flattened when subjected to 10–50% cold deformation. The cold deformation results in the evolution of sub-structure, comprising dislocations, twins as well as interaction of dislocations and twins. The hot rolled and air cooled sample (0% cold deformation) reveals γ-fibre (〈111〉//ND) texture, whereas cold rolled samples shows Goss texture ({110}〈001〉) and Brass texture ({110}〈112〉) components, which are expected after cold deformation of austenitic steels having lower stacking fault energy in the range of 15–40 mJ/m 2 . X-ray line profile analysis through extended convolution multiple whole profile fitting method is utilised to quantify the dislocation density and planar fault (twin) probability for the cold rolled samples with different degree of reduction. Fractography shows that with the increase in cold deformation, fractures become more and more brittle in nature. [ABSTRACT FROM AUTHOR]

The present research aims to extract moist deciduous forest (MDF) from Moderate Resolution Imaging Spectroradiometer (MODIS) temporal data by using the fuzzyc-means (FCM)-based noise clustering (NC) soft classification approach. Seven-date temporal MODIS data were used to identify MDF, and temporal Advanced Wide Field Sensor (AWiFS) data were used as reference data for testing. Different types of spectral indices were used to generate the temporal data set combinations for both MODIS and AWiFS. The NC resolution parameter deltawas optimized to achieve the best output. It was found that for both AWiFS and MODIS data, optimum NC outputs were obtained whenreached close to 105. For assessment of the accuracy, NC classified outputs were optimized using the entropy approach. The optimized data set of AWiFS was then used for assessing the accuracy of the optimized data set of MODIS using fuzzy error matrix (FERM), composite operators (MIN-MIN, MIN-PROD, and MIN-LEAST), and a sub-pixel confusion-uncertainty matrix (SCM). It was found that the temporal data set combination corresponding to ‘Three’ date yields the highest overall accuracy for all accuracy assessment techniques. In all cases, the ‘Three’ date combination corresponds to the three scenes pertaining to different phenological activity of the MDF. This ‘Three’ date combination, along with the soil-adjusted vegetation index (SAVI), yielded the highest overall accuracy values, namely 94.88% and 94.84% for MIN-LEAST and MIN-PROD, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Neodymium doped Barium Zirconate Titanate (Ba1−x Nd2x/3)(Zr0.3Ti0.7)O3 (x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10) ceramics were prepared using the solid state reaction route. Structural characterizations of the materials were done by using X-ray diffraction and Raman spectroscopy. XRD study suggested that all the compositions were of single phase cubic perovskite structure with space group Pm-3m while Raman spectra revealed that the replacement of the Ba2+ ions by Nd3+ ions significantly reduced the intensity of the Raman active modes and shifted them towards higher energy side. Room temperature optical property was analyzed by photoluminescence spectroscopy, which confirmed formation of shallow defects in the band gap. Photoluminescence property was attributed to the presence of polar [TiO6] distorted clusters in the globally cubic matrix. As a result PL emission spectra of these materials were found to belong to violet–blue regions. Microstructural study of sintered pellets revealed that the grain sizes increase with increase in doping concentration. The temperature dependence of the dielectric properties was investigated in the frequency range 1 kHz to 1 MHz. The broadening in the dielectric constant peak around the phase transition temperature and shifting of the temperature maximum towards higher temperatures with increase in frequency indicated a relaxor type of behavior. [Copyright &y& Elsevier]

Abstract: Advancements in reproductive technologies have shown seminal plasma (SP) as a nutritive-protective medium for spermatozoa metabolism, function and transport. At the same time quality variables and thus freezability of spermatozoa are influenced by SP proteins originating from male reproductive tract. One such protein, viz. PDC-109 is reported to influence freezability of spermatozoa in cattle. Thus the present investigation was designed to evaluate effect of seminal PDC-109 protein concentration on post-thaw cholesterol content and semen quality variables (SQP) as an indicator of membrane integrity and freezability, respectively of buffalo spermatozoa. Ejaculates (n =42) selected on the basis of mass activity and individual motility were divided into three parts, first part for SP proteins isolation, second for cholesterol estimation and third part was cryo-preserved to evaluate freezability based on post-thaw SQP, viz. individual progressive motility, viability and acrosome integrity of spermatozoa. A total of 28 (66.7%) and 14 (33.3%) ejaculates from four bulls were found as freezable or non-freezable, respectively. Though total seminal plasma protein (TSPP) concentration was found similar in freezable and non-freezable ejaculates, the heparin binding proteins (HBP) content in non-freezable semen was greater (P <0.01) than freezable ejaculates. There was a similar trend for the PDC-109 protein content in respective ejaculates. Cholesterol content of spermatozoa and SQP were greater (P <0.05 and 0.01, respectively) in freezable as compared to non-freezable ejaculates of each bull at post-thaw stage. This study showed that concentrations of HBP and PDC-109 in non-freezable semen might be responsible for greater cryo-damage reflecting in poor freezability of buffalo spermatozoa. [Copyright &y& Elsevier]

Abstract: An ultra-low carbon Ti-containing microalloyed steel has been thermo-mechanically controlled rolled and water-quenched. Microstructural characterization of the samples finish rolled in the temperature range of 750–850°C revealed the presence of polygonal ferrite, quasi-polygonal ferrite, acicular ferrite and granular bainite. Micro-texture study showed the dominance of random texture and cube orientation at higher deformation temperatures, whilst, α-fiber and γ-fiber components intensified with the decrease in finish rolling temperature. Characteristic ferrite-bainite microstructure with fine ferrite grain size (<4µm) and a uniform distribution of fine TiC particles (<100nm) offered decent combination of strength (yield strength: 478–497MPa, ultimate tensile strength: 557–571MPa), ductility (total elongation: 20–26%), and impact toughness (110–114J at −40°C). Such a combination of mechanical properties makes the steel a potential choice for pipeline application. [Copyright &y& Elsevier]

Abstract: Electrodeposited CoW alloy and CoW–WC nanocomposite coatings were produced and investigated under dry and wet sliding conditions. Incorporation of WC nanoparticles (average size ∼500nm) into CoW matrix improves the hardness and coefficient of friction. The measured wear volume of CoW–WC nanocomposites under dry sliding was almost half of the one on CoW coatings. Under wet sliding in a 0.5M NaCl solution at room temperature, the open circuit potential recorded on both CoW–WC nanocomposites and CoW alloys during sliding became nobler compared to starting point but it dropped suddenly down to active potential region after counter body retrieval. [Copyright &y& Elsevier]

Abstract: Let be a -uniform hypergraph that has a geometric realization in . We show that there is a set of edges of that meets all copies of the complete subhypergraph in with , where denotes the maximum size of a set of pairwise edge-disjoint copies of in . This generalizes a result of Tuza on planar graphs. For we also prove two fractional weakenings of the same statement for arbitrary 3-uniform hypergraphs. [Copyright &y& Elsevier]

An analysis to determine performance parameters for dispersion characteristics and interaction impedance of helix traveling-wave tube using metamaterial is presented. The conventional positive dielectric supports of the helix slow-wave structure have been replaced by an equivalent homogeneous metamaterial medium. The analysis has been carried out in tape helix model, to include the effects of space harmonics. Structure characteristics, namely, dispersion and interaction impedance have been studied, as the former predicts the phase velocity of the RF wave and the latter has direct relevance to the device gain. It has been observed that, with metamaterial supported helix, both phase velocity and interaction impedance increase as compared to conventional positive dielectric supports. The results have been presented for fundamental space harmonic mode. [ABSTRACT FROM AUTHOR]

Abstract: A new low carbon titanium and niobium microalloyed steel has been thermomechanically processed in a pilot plant unit. Phase transformation phenomenon of the above steel during continuous cooling has been assessed. Evolution of microstructure and mechanical properties has also been studied at different finish rolling temperatures. A mixture of intragranular ferrite with granular bainite and bainitic ferrite along with inter-lath and intra-lath precipitation of (Ti, Nb)CN particles are the characteristic microstructural feature of air cooled steel. However, mixture of lower bainite and lath martensitic structure along with similar type (Ti, Nb)CN precipitate is observed in water quenched steel. High yield strength (896–948 MPa) with high tensile strength (974–1013 MPa) has been achieved with moderate ductility (16–17%) for the selected range of finish rolling temperature for air cooled steel. However, the water quenched steel yields higher yield strength (1240–1260 MPa) as well as higher tensile strength (1270–1285 MPa) but with lower ductility (13–14%) for the selected range of finish rolling temperature. Fairly good impact toughness values in the range of 50–89 J are obtained for the air cooled steel which are marginally higher than those of water quenched steel (42–81 J). [Copyright &y& Elsevier]

Rice necrosis mosaic virus (RNMV), upon inoculation, induced higher growth and yield in Ludwigia perennis and Corchorus olitorius. Crops of commercial importance, including arhar, rice bean, cotton and tomato, were tested for growth promotion and higher productivity upon RNMV inoculation. Plant growth characteristics and biochemical components were measured from control, inoculated and energised plants. To understand the molecular basis behind such phenomenon, tomato plants were selected for subtractive hybridisation and reverse northern analysis due to its known gene sequences. Significant changes in biological properties and biochemical components in all the inoculated test plants over control were observed along with better seed quality. Over-expression of genes falling in different functional categories like photosynthesis, plant growth and development, and membrane transport explained the virus-induced growth promotion phenomenon as well as the temporary passage of this property through seeds of inoculated plants. [ABSTRACT FROM AUTHOR]

Abstract: The paper deals with an optimal inventory replenishment policy for a deteriorating item considering time-quadratic demand and time-dependent partial backlogging which depends on the length of the waiting time for the next replenishment over a finite time horizon and variable replenishment cycle. The model is solved analytically to obtain the optimal solution of the problem. It is then illustrated with the help of numerical examples. [Copyright &y& Elsevier]

Aims: Present report describes the in vitro antimalarial activity and docking analysis of seven 4-aminoquinoline-clubbed 1,3,5-triazine derivatives on pf-DHFR-TS. Methods and Results: The antimalarial activity was evaluated in vitro against chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compounds were docked onto the active site of pf-DHFR-TS using docking server to explicate necessary structural requirements for antimalarial activity. Conclusion: Title molecules demonstrated considerable bioactivity against the malaria parasite. Docking analysis revealed deep engulfment of the molecules into the inner groove of pf-DHFR-TS active site by making stable ligand-receptor posses. Hydrophobic interaction was identified as the only major interacting force playing a role between ligand-receptor interaction and minor with hydrogen bonds. Significance and Impact of the study: The study provided the novel insight into the necessary structural requirement for rationale-based antimalarial drug discovery. [ABSTRACT FROM AUTHOR]

We study theoretically the unsteady gravity-driven thermal convection flow of a viscous incompressible absorbing-emitting gray gas along an inclined plane in the presence of a pressure gradient and significant thermal radiation effects. The Rosseland diffusion flux model is employed to simulate thermal radiation effects. The momentum and energy conservation equations are nondimensionalized and solved exactly using the Laplace transform technique. Expressions are derived for the frictional shearing stress at the inclined plane surface and also the critical Grashof number. The effects of time (T), Grashof number (Gr), Boltzmann-Rosseland radiation parameter (K1), and plate inclination (α) on velocity (u) and temperature (θ) distributions are studied. The flow is found to be accelerated with increasing inclination of the plane, increasing free convection effects, and for greater thermal radiation contribution but decelerated with progression of time. Temperature is found to be enhanced with progression of time and with greater thermal radiation contribution. Applications of the model arise in solar energy collector analysis and industrial materials processing. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, copper bearing low carbon microalloyed ultrahigh strength steel has been produced on a pilot scale. Transformation of the aforesaid steel during continuous cooling has been evaluated. The steel sample has been thermomechanically processed followed by either air cooling or water quenching. Variation in microstructure and mechanical properties at different finish rolling temperatures has been studied. A mixture of granular bainite, bainitic ferrite and precipitation of nano-sized (Ti, Nb)C particles is the characteristic microstructural feature of air cooled steel. On the other hand, predominantly lath martensitic structure along with the similar type of microalloying precipitates of air cooled steels and Cu precipitates are obtained in case of water quenched steel. The best combination of strength (1364–1403MPa) and ductility (11–14%) has been achieved for the selected range of finish rolling temperature of water quenched steel. [Copyright &y& Elsevier]

Abstract: In this paper, an EOQ (Economic Order Quantity) model is developed for a deteriorating item having time dependent demand when delay in payment is permissible. The deterioration rate is assumed to be constant and the time varying demand rate is taken to be a quadratic function of time. Mathematical models are also derived under two different circumstances, i.e. Case I: The credit period is less than or equal to the cycle time for settling the account and Case II: The credit period is greater than the cycle time for settling the account. The results are illustrated with numerical examples. Justification for considering a time quadratic demand and permissible delay in payment are discussed. [Copyright &y& Elsevier]

Abstract: The paper describes an EOQ model of a perishable product for the case of price dependent demand, partial backordering which depends on the length of the waiting time for the next replenishment, and lost sale. The model is solved analytically to obtain the optimal price and size of the replenishment. In the model, the customers are viewed to be impatient and a fraction of the demand is backlogged. This fraction is a function of the waiting time of the customers. In most of the inventory models developed so far, researchers considered that inventory accumulates at the early stage of the inventory and then shortage occurs. This type of inventory is called IFS (inventory followed by shortage) policy. In the present model we consider that shortage occurs before the starting of inventory. We have proved numerically that instead of taking IFS, if we consider SFI (shortage followed by inventory) policy, we would get better result, i.e., a higher profit. The model is extended to the case of non-perishable product also. The optimal solution of the model is illustrated with the help of a numerical example. [Copyright &y& Elsevier]

We study theoretically the incompressible, viscous, oscillatory hydromagnetic Couette flow in a horizontal fluid-saturated highly permeable porous medium parallel-plate channel rotating about an axis perpendicular to the plane of the plates under the action of a uniform magnetic field, B0, inclined at an angle θ to the axis of rotation. The flow is generated by the non-torsional oscillation of the lower plate of the channel. The reduced unsteady momentum equations are nondimensionalized with appropriate variables. Exact solutions under specified boundary conditions are obtained using the Laplace transform method (LTM). The flow regime is found to be controlled by a rotational parameter (K2), which is the reciprocal of the Ekman number (Ek), the square of the Hartmann magnetohydrodynamic number (M2), a porous medium permeability parameter (Kp), which is the inverse of the Darcy number (Da), oscillation frequency (ω), dimensionless time (T), and magnetic field inclination (θ). The influence of these parameters on the primary (u1) and secondary (v1) velocity field is presented graphically and studied in detail. Asymptotic behavior of the solutions is also examined for several cases of the square of the Hartmann number, rotation parameter, and oscillation angular frequency. The existence of modified Hartmann boundary layers is also identified. The present study has important applications in MHD (magnetohydrodynamic) energy generator flows, chemical engineering magnetic materials processing, conducting blood flows, and process fluid dynamics. [ABSTRACT FROM AUTHOR]

Abstract: The in situ electrochemical deposition of nanostructured MoS x (x =1.5–1.7) based thin films on various substrates from aqueous solutions is reported. The as-deposited amorphous films transform on annealing into crystalline ones as revealed by a stepwise high temperature X-ray diffraction (XRD). Both Raman spectroscopy and XRD crystal structure analyses confirmed the formation of inorganic fullerene-MoS x nanoparticles (IF-MoS x ). The as-deposited thin films have a featureless surface morphology, but after annealing either a nanotube or a nanorod structure along with numerous smaller nanoballs appear at the surface. An investigation by transmission electron microscopy unearths the presence of nanoballs, nanoribbons, and nanotubes throughout the annealed MoS x thin films. The size of the nanoballs is in the range of 5–10nm. The nanotubes have a diameter of 10–400nm, and a length of up to several micrometers as evidenced by SEM. The catalytic effect of transition metals on the growth of nanotubes is noticed. The temperature-induced transformation from amorphous to crystalline structured MoS x films results in a large lowering of the coefficient of friction under sliding against corundum in ambient air of 50% relative humidity. [Copyright &y& Elsevier]

Abstract: A spatial process observed over a lattice or a set of irregular regions is usually modeled using a conditionally autoregressive (CAR) model. The neighborhoods within a CAR model are generally formed using only the inter-distances or boundaries between the regions. To accommodate directional spatial variation, a new class of spatial models is proposed using different weights given to neighbors in different directions. The proposed model generalizes the usual CAR model by accounting for spatial anisotropy. Maximum likelihood estimators are derived and shown to be consistent under some regularity conditions. Simulation studies are presented to evaluate the finite sample performance of the new model as compared to the CAR model. Finally, the method is illustrated using a data set on the crime rates of Columbus, OH and on the elevated blood lead levels of children under the age of 72 months observed in Virginia in the year of 2000. [Copyright &y& Elsevier]

Abstract: Ni/Cu multilayers were electrodeposited from a single solution electrolyte by galvanostatic method. Interface roughness, magnetization and magneto-transport studies of Ni/Cu multilayers on Si(111)/Ti/Cu substrate were carried out for samples deposited from three different electrolytes, viz. pure sulphate, sulphate–citrate and sulphate-polyethylene glycol-8000 (PEG-8000). The top Ni-layer morphology of these samples was characterized by atomic force microscope (AFM). Detailed analysis of the morphological data showed a typical two-dimensional fractal growth pattern in all the three cases. The structural parameters like interface roughness, density and thicknesses of Ni and Cu layers were extracted from neutron reflectivity (NR) study. The order of interface roughness obtained from NR and AFM was found to be quite close. The sample deposited from sulphate–citrate electrolyte was found to have minimum interface roughness. The polarized neutron reflectometry (PNR) measurement showed reduced magnetic moment value (∼0.41±0.01μB) for nickel layers compared to bulk value in all the three samples. The magnetoresistance (MR) of these samples were measured at room temperature. An attempt has been made to explain the observed MR results in terms of granular structure and scattering mechanism involving super-paramagnetic and ferromagnetic particles in these samples. [Copyright &y& Elsevier]

Abstract: The present study concerns the influence of Cu addition on the synergistic effects of Ti–B in low carbon thermomechanically processed steels. Effective retardation of the γ→α transformation due to the combined addition of Ti and B is known to enhance the hardenability of a wide range of low carbon microalloyed steel. On the other hand, addition of Cu in low carbon age hardenable steel suppresses the pearlitic transformation resulting into a microstructure constituted by interspersed islands of martensite in ferritic matrix. Therefore, it may be of interest to examine the role of Cu on the synergistic contribution of Ti and B in respect of increasing hardenability of austenite. In the present study, effects due to the addition of Ti, B and Cu in different steels are interpreted in respect of microstructure–property correlation. It is demonstrated that the addition of 1.5wt% Cu perceptibly enhances the synergistic effect as manifested by lowering the transformation temperature of austenite. Addition of 0.8wt% Ni in Cu–Ti–B steel does not alter the transformation temperature of austenite to any appreciable extent. However, Cu–Ni–Ti–B steel has resulted into the enhancement of strength–ductility combination. [Copyright &y& Elsevier]

Abstract: The present work aims to study the ageing behaviour of directly quenched Cu-added microalloyed steels. Temperatures related to precipitation of Cu and recovery of dislocations retained in the microstructure after quenching of the steels from finish rolling temperature are determined by differential scanning calorimetric method. Ageing of the directly quenched steels has resulted in the reduction in hardness and strength with concomitant improvement of ductility. 1.5wt% Cu-added Ti–B microalloyed steel has yielded the most attractive combination of strength and ductility. Presence of Ni in the 1.5wt% Cu-added Ti–B microalloyed steel indicates sluggish kinetics of Cu precipitation. Ageing has generally deteriorated the impact toughness except for Ni containing Cu-added microalloyed steel above −25°C temperature. Formation of recovered dislocation cells and fine ɛ-Cu precipitates during ageing have contributed to the microstructural softening and hardening, respectively. [Copyright &y& Elsevier]

Abstract: The present study concerns determination of activation energies of copper-bearing low carbon microalloyed steels processed under different thermomechanical schedules. Selected samples were subjected to 50% cold deformation to examine the effect of prior strain on precipitation of copper. Activation energies were determined by the Kissinger method using differential scanning calorimetry plots obtained at various heating rates. The results are suitably compared with the published results. In view of the results of differential scanning calorimetry, isothermal ageing treatments have been carried out along with suitable microstructural investigations. An attempt has also been made to correlate the variation of hardness and microstructural evolution during ageing treatment. [Copyright &y& Elsevier]

Abstract: Pulse electrolysis was employed to deposit heterogeneous Cu–Co alloys from complexed sulphate–citrate electrolyte. The crystal structure, surface morphology and microstructure of the deposited alloys were analysed to understand the effect of process parameters on the deposit. X-ray and selected area electron diffraction (SAED) studies showed that as-deposited films were composed of two phases, a solid solution of face centred cubic Cu–Co phase and a hexagonal close packed Co phase. Pulse electrolysis and addition of saccharine within the electrolyte were found to enhance in forming two-phase structure. Surface morphology of the pulse current (PC) plated alloys was found to be smoother than their direct current (DC) counterparts. Presence of saccharine within the electrolyte led to further improvement in brightness of the deposits top layer. Microstructural investigations revealed that the deposited alloys were nanocrystalline in nature. Further refinement in grain size and increased homogeneity in microstructure were observed in the presence of saccharine. [Copyright &y& Elsevier]

Abstract: The present study concerns the influence of ageing parameters on the microstructure and mechanical properties of a duplex stainless steel. Microstructural evolution is extremely sensitive to chi and sigma phase precipitation during ageing treatment. The precipitation of chi phase increases with the increase of ageing time from 15 min to 120 min at 900 °C. The precipitation rate of secondary phases in 900 °C is faster than that at 700 °C. High hardness is directly related to the abundant chi and sigma phase precipitation in the microstructure. Sigma phase was completely dissolved by heat treatment at 1000 °C; the mechanical properties were then influenced by the sigma-free equivalent volume fractions of ferrite and austenite. [Copyright &y& Elsevier]

Abstract: Application of the liquid emulsion membrane (LEM) technology to the industrial scale is hindered by the challenges imposed by stability of the emulsion during the transfer of the solute (pertraction). One of the important factors which leads to the instability is swelling. Emulsion undergoes swelling due to the osmotic gradient across the membrane as well as due to the occlusion of the external phase into the membrane phase; the latter is caused by the hydrodynamic deformation of the membrane globules. In the present work, we have studied swelling of the emulsion phase in a water-in-oil-in-water type LEM system. Nitric acid is the internal aqueous phase and is encapsulated in organic membrane phase composed of DEHPA–kerosene-SPAN80. Demineralised water is used as the external phase. The effect of the composition of the system and the hydrodynamic condition on the rate of swelling has been studied. A mathematical model has been developed to describe the effects of the relevant parameters on swelling of the emulsion. The globules of the emulsion are viewed as having a core-shell structure, based on the visual evidence. The model takes into account both the osmotic and the occlusion modes of swelling and also the leakage of the internal phase. The predictions of the model are found to be in good agreement with the experiments. The model would be useful for evaluating the rate of pertraction of a solute through the membrane–strip combination used in the present study. The study would also be useful for tuning the design and the operating parameters in LEM pertraction to achieve minimum swelling of the emulsion. [Copyright &y& Elsevier]

Abstract: Present investigation concerns the effect of pre-strain on the precipitation of copper during ageing of directly quenched Ti–B micro-alloyed steels. The differential scanning calorimetric study of the directly quenched samples reveals that copper precipitation occurs between 350–500 °C. Pre-straining of the directly quenched samples broadens the temperature range within which the peaks for copper precipitation overlap with the peaks due to other low temperature reactions like recovery and/or tempering. 50% pre-straining of 1.5 wt.% copper added steel prior to ageing triggered the precipitation reaction at a temperature ∼350 °C with pronounced decrease in the activation energy values from 182 to 126 kJ/mol. Micro-structural investigations have revealed the formation of cell structures within the martensite laths after ageing of the pre-strained directly quenched samples. While pre-straining has increased the strength with concomitant deterioration in ductility; ageing of the pre-strained samples has revealed perceptible improvement in elongation. [Copyright &y& Elsevier]

India is a land of diverse topography, climate and natural resource. There are 12 major rivers and 48 lesser rivers with a total catchment area of 277.6 million ha. The freshwater resources of the country, which are varied, harbor 587 species of finfishes, and account for 9.3 percent of global inland fish production. India's natural capital of fish habitat resource has been eroded as reflected in loss of biodiversity and reduced fish landings. Studies on the ecology, environment and fisheries of five major river systems, in addition to reservoirs and flood plain lake fisheries, have been conducted with greater focus on water quality and less on physical habitat parameters. River conservation programs cover major rivers in 10 states of the country; the 'Ganga Action Plan' being the most important. These projects target improvement in water quality and not fish habitat. Lack of concern for fish habitat is reflected in the planning of Farakka Barrage, a large dam built to divert the flow of River Ganga (The Ganges) into the Hooghly River, and its impact on the 'Hilsa' run. Environmental laws have not achieved desired results for lack of enforcement mechanisms. Freshwater habitat management in India raises both concern and hope. Concern arises out of the missing elements in current fish habitat research, planning and management of resource. The hope for the future is increasing public awareness on the need for better resource management and environmental conservation. In the backdrop of the learning from implementation of the eco-restoration programmes, the task appears to be not only challenging but also demanding in terms of participation of stakeholders, commitment of resources, backup of research support, monitoring of environmental standards, enforcement of regulations and setting up of priorities in terms of conservation of the natural assets. [ABSTRACT FROM AUTHOR]

Abstract: The present study aimed to throw light to any gross morphological changes of placenta that might contribute to the development of idiopathic IUGR. Gross examination of placentas from full-term uncomplicated pregnancies delivering singleton live IUGR babies, and live normal-weight babies (controls) were performed; then the results were compared. Fifty full-term freshly delivered placentas were collected both from normal deliveries and C.S. Twenty-eight (28) placentas were associated with IUGR and twenty-two (22) were from controls. The positions of insertion of the umbilical cords, placental weights, volumes and diameters were noted. These gross examinations revealed that the control placentas were bigger in diameters, had usual positions of insertion of umbilical cords, mean placental weight was 416.77 gm and mean placental volume was 343.86 ml. In cases of IUGR placentas, there were some abnormal positions of insertion of umbilical cords in 11% placentas (marginal in 7.14% and velamentous in 3.57%), and placental weight and volume was significantly lower (p value<0.001). The placentas associated with IUGR were smaller in diameters than those of control group of placentas. The mean placental co-efficient of IUGR group in the present study was 0.156 (range 0.11–0.22) and that of the control group was 0.138 (range 0.12–0.18). The greater placental co-efficient in IUGR indicates that although both placentas and babies in IUGR had less weight, placental sizes were not relatively less. In fact, these placentas were functional, and even tried to compensate the abnormal morphology. Therefore, though IUGR fetuses were more frequently associated with morphologically abnormal placentas, it could not be conclusively decided whether this abnormal gross morphology actually contributed to the intrauterine growth restriction. [Copyright &y& Elsevier]

Abstract: The electrodeposition of Ni/Cu multilayer coatings with varied Ni sublayer thickness (t Ni) ranging 1.8–11 nm, keeping Cu sublayer thickness (t Cu) fixed at 1.97 nm, has been carried out from sulphate based electrolyte. Residual stress and crystal structure of the electrodeposited multilayers were characterized by X-ray diffraction (XRD) method. It was found that the stress level within the deposited multilayer decreases with increase in t Ni. Coefficient of friction (COF) and sliding wear test of the deposited multilayer coatings have been carried against standard WC ball in ball-on-plate geometry under dry condition. After wear test, the wear scar morphology was examined under laser surface profilometry and scanning electron microscopy (SEM) for calculation of wear volume and evaluation of wear mechanism respectively. The COF was found to be dependent on load and t Ni. A typical sinusoidal variation of COF with sliding distance was noticed indicating stick–slip behaviour under adhesive–abrasive wear process. The hardness of the multilayers was found to be dependent on wavelength of the modulation. Among multilayers, sample with t Ni =7.2 nm has shown the lowest wear rate owing to its high (H/E) ratio, high hardness and low residual stress. The calculated wear rate order was found to be quite well matching with the order of elastic strain to failure, i.e. (H/E) ratio of the multilayers. The multilayers with very high and low t Ni showed poor wear behaviour due to very weak multilayer effect. [Copyright &y& Elsevier]

Abstract: In the present study, [Ni (4.5 nm)/Cu (t Cu =2, 4 and 8 nm)] multilayers were pulse electrodeposited on stainless steel (AISI SS 304) substrate from sulphate based single bath technique. X-ray diffraction (XRD) was used to investigate the structure and stress of the Ni/Cu multilayer. The results from XRD analysis indicated that the deposited multilayers had a preferred crystal orientation of [111] and presence of satellite reflection suggested the formation of superlattice. The stress level within the deposited multilayers was found to be sensitive to the sublayer thickness. Sliding wear behaviour of electrodeposited Ni/Cu multilayer films has been investigated against a tungsten carbide (WC) ball as the counter body and compared with that of the constituents, Cu and Ni coatings. The wear tests were carried out by using a reciprocating ball-on-flat geometry at translation frequencies of 5 and 10 Hz, slip amplitude of 1 mm and at five different loads of 3, 5, 7, 9 and 11 N. Friction force was recorded on-line during the tests. At the end of the tests, the wear scars were examined by laser surface profilometry and scanning electron microscopy (SEM). Friction coefficient was found to be dependent on load and Cu layer thickness (t Cu) and the values for multilayers were border between Ni and Cu. Among multilayers, sample with minimum t Cu has shown the lowest friction coefficient and wear rate. With increasing t Cu, the wear mechanism changes from pure abrasive wear at t Cu = 2 nm, to particle entrapment at t Cu = 4 nm to particle embedding at t Cu = 8 nm. Detailed investigation of the wear scar morphology as well as wear rate measurement revealed that at low loads, (H/E) ratio and residual stress governed the wear rate and the principle wear mode was abrasive cutting. At intermediate loads, the role of residual stress became insignificant while wear was governed by (H/E) ratio and plastic deformation. However, at higher loads, plastic deformation played the major role. [Copyright &y& Elsevier]

Abstract: Fifteen Black Bengal kids of about 3 months of age and body weight ranging from 3.8 to 4.9kg were randomly distributed into three groups of five. Kids grazed native pasture 8h/d. The kids in group I received supplementary concentrate (maize 35%, mustard cake 32%, rice bran 30%, mineral mixture 2% and common salt 1%) at approximately 2% of BW. However, 25 and 50% of the concentrate was replaced with jackfruit leaves for groups II and III, respectively. Total dry matter intake (DMI) was significantly higher in groups II and III than for group I due to greater forage consumption. Digestibility of CP (P <0.05) decreased and that of NDF increased (P <0.01) with increasing level of jackfruit leaves in the diet. Digestibility of ADF (P <0.01), hemi cellulose (P <0.05) and cellulose (P <0.01) was higher in groups II and III in comparison to group I. Ruminal pH and TVFA concentration were not significantly different among the groups; however, rumen ammonia-N concentration decreased (P <0.01) with increased level of jackfruit leaves in the diet. Similarly, plasma urea nitrogen and blood glucose levels were also reduced (P <0.05) with increasing level of jackfruit leaves in the diet Average daily gain (ADG) was 47.33, 45.11 and 35.56g/d in groups I, II and III, respectively. ADG and DMI/kg gain were not adversely affected when the level of replacement was restricted to 25%; however, at the 50% of replacement both parameters were adversely affected (P <0.05). From the results of this experiment, it was concluded that jackfruit leaves might replace 25% of the supplemental concentrate for growing kids grazing in native pasture of northeast India. [Copyright &y& Elsevier]

Abstract: Nanocrystalline (nc) Ni–Cu alloys have been electrodeposited by using pulse current (PC) as well as direct current (dc) electrolysis. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to characterise the deposits. High-resolution electron microscopic (HREM) examination revealed that deposited nc alloys were dense in nature. Corrosion behaviour of both nc as well as Monel-400 were compared in 3.0wt.% NaCl solution and was found that corrosion current density (i corr) of nc alloys were superior to Monel-400. Both optical as well as scanning electron microscopic (SEM) examination of the corroded surface revealed a well-defined pitting type of attack for Monel-400 unlike nc alloys; akin to homogeneous corrosion. [Copyright &y& Elsevier]

Abstract: During superposed deformation, an early fold (F 1) may either tighten or open out. Opening out is possible if, during the second deformation, there is a bulk extension across the F 1 axial plane. The theoretical model indicates that the rate of opening out is largely controlled by the initial tightness of the fold. The results of the numerical model are in agreement with analog experiments of superposed buckling and show that if there is a relatively small range of variation of initial tightness of F 1 folds, the range of fold tightness becomes much larger after the opening out of the folds in the second deformation. Consequently, the refolded structure may show a close association of different modes of superposed buckling. In a type-2 fold interference, the continued opening out of F 1 invariably causes a replacement of the initial F 1 hinge line by a new and more sinuous hinge line. When the shortening direction (P 2) of the second deformation was at an acute angle to the F 1-axis, depending upon their local orientation with respect to P 2, the F 1 folds were tightened in some places and were opened out elsewhere. When the enveloping surface is inclined in the direction of maximum stretching of second deformation, segments of F 1 and F 2 hinge lines may both rotate to lie in the extension field and both F 1 and F 2 may open out with progressive deformation. If F 1 has a low pitch, and P 2 is parallel to the F 1-axis, the two sets of hinge lines may become subparallel at an advanced stage of deformation. The resulting structure is morphologically similar to non-planar sheath folds. [Copyright &y& Elsevier]

The fractal image compression is inherently time intensive and thus there is a growing need to increase its speedup. This paper presents a fast encoding scheme where the domain blocks are searched randomly for every range block. An analysis of the basic fractal image compression method has been carried out and on the basis of the analysis a method for image characterization has been proposed. Then a detailed theoretical analysis of this randomized fractal compression scheme has been presented and the results are validated with the experimental ones. The random approach has been found to be quite efficient giving considerable increase in speed-up compared to several other approaches. [Copyright &y& Elsevier]

An oscillatory flow of a viscous incompressible fluid in a porous elastic vessel of variable cross-section has been investigated. The study pertains to a case where the motion is oscillatory, the shear rate is high, and the Reynolds number as well as the horizontal velocity gradient is small. Because of this, the method of linear approximation of the equations governing the flow has been employed in the analysis. The vessel wall is taken to be tethered, porous, thin, and elastic. The dissipation due to filtrate permeation through the membrane wall has been taken into account. The computational work presented at the last part of the paper has been performed for two different geometries of the wall, by considering the blood as a viscous fluid. On the basis of the theoretical investigation, it has been predicted that the geometry as well as the elasticity of the vessel wall contributes significantly to the velocity distribution in the small vessels and also that the magnitude of the radial velocity at any radial station is more than that in a uniform vessel. [Copyright &y& Elsevier]