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The feasibility of applying a pulsed 300 W Nd:YAG average power laser for autogenous laser beam welding (LBW) of 6061-T6 alloy was studied under the variation of laser current and weld speed from the perspective of weld microstructure, micro-segregation, cracking susceptibility and consequential mechanical characteristics. The results displayed that with proper control of different parameters, the full penetration can be achieved but the formation of typical welding defects, such as crack formation and oxide inclusion could not be prevented. Solidification cracking may be taken place in the fusion zone (FZ) during the solidification, while liquation cracking may preferably be taken place in the partially melted zone (PMZ). This study focuses on these two kinds of cracking and it was observed that significant solute segregation, oxide inclusion and welding associated thermal strain were the governing factors for crack initiation and propagation. While the hardness loss of AA6061-T6 alloy welds was severely affected by both the facts of microsegregation and dissolution of strengthening precipitates. The acquired results provide support for technology optimization of average power Nd:YAG LBW. [ABSTRACT FROM AUTHOR]

Quick removal and low therapeutic efficacy are drawbacks of ocular eye drops. In situ gels were developed using gellan gum and/or sodium carboxymethyl cellulose as an ion activated polymer to enhance the residence time of the drug on the ocular surface and improve the efficacy through the sustained release of acyclovir. The solution containing polymer converted to gel through cross-linking reaction with Ca++ ion present in simulated tear fluid. The optimized formulation (F1 GC: 0.5 % gellan gum+0.5 % carboxymethyl cellulose) showed immediate gelation (within 5 s) that remained for more than 6 h and may prevent drug elimination by tears. The developed formulations were clear and in the pH range of 6.05 to 7.84. The interaction between the carboxyl group of polymers and Ca++ ions was confirmed by Fourier transform infrared spectroscopy. All the formulations showed satisfactory drug content from 91.13-100.61 %. The gel strength of the formulations increased as the concentration of the polymers increased. The prepared in situ gels exhibited a shear thinning pseudoplastic behaviour that may help in the blinking of the eye. Optimized formulation releases the drug for over 8 h and shows the Fickian diffusion release mechanism. The developed formulation may improve the bioavailability of the drug through longer contact time and controlled drug release in the eye. [ABSTRACT FROM AUTHOR]

The present study assessed the nationwide lockdown impacts on the air pollution situation across West Bengal, India. Air pollution data was collected from the online monitoring stations of the Central Pollution Control Board across West Bengal. The gradual declining pattern of overall pollution status was observed during the lockdown phase from the prelockdown phase. The early unlocking stage found slow and gradual increasing air pollution levels. Siliguri's pre-lockdown 'poor' Air Quality Index (AQI) improved in the lockdown phase to 'satisfactory' level. 'Moderate' level AQI in Asansol of the pre-lockdown stage improved to 'satisfactory' level during the lockdown phase. Pre-lockdown AQI of both Kolkata and Howrah changed from 'moderate' to 'good' level during the lockdown phase. Unlike other pollutants, the ozone level increased in Kolkata, Howrah, and Siliguri in the lockdown phase. The early monsoonal washout possibly caused the changes in the pattern of pollution status of specified periods in the 2019 and 2020. Thus, in the study period of lockdown in 2020, the decrease in pollution level may not only caused by the stoppage of vehicles or industry but also have a possible natural influence. [ABSTRACT FROM AUTHOR]

A comparative study has been made for the defect induced room temperature ferromagnetism of single crystal, poly-crystal, and nanorod zinc oxide (ZnO), based on the magnetic properties and electronic properties by means of X-ray absorption near edge structure spectroscopy (XANES), X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy (UPS), valence band photoemission spectroscopy (VB-PES), and SQUID-type magnetometry. Magnetic measurement demonstrates the defect-induced ferromagnetic nature at room temperature in different ZnO films and a strong correlation between their electronic properties and magnetic responses. The higher ferromagnetic behaviour in polycrystalline ZnO is attributed to the increasing number of surface defects and native defect sites (oxygen vacancies and zinc interstitials) present in ZnO. XANES studies reveal that the number of unoccupied p states in polycrystalline ZnO is higher than single crystal ZnO as well as nanorod ZnO. The more amount of oxygen vacancy causes the highest intensity the O 1 s peak to appear in the XANES spectra of polycrystalline ZnO. In polycrystalline ZnO, the binding energy of the Zn 2p3/2 core level peak shifted to lower energy that further confirms the increase of the valence band maximum (VBM) position. The VBM of single crystal, poly-crystal, and nanorod-ZnO is 3.64 eV, 3.99 eV, and 3.71 eV, respectively, obtained from UPS (He-I) measurements. VB-PES studies confirm that the number of electrons in the valence band of O 2p - Zn 4sp hybridized states of poly-crystal ZnO is higher than single crystal and nanorod-ZnO. [ABSTRACT FROM AUTHOR]

The goal of this paper is to investigate the change in energy efficiency of point-to-point (P2P) links in a wireless sensor network (WSN) upon introduction of a third node acting as a relay. In particular, we consider the problem of placing a relay node, either already available in the WSN but was inactive or is inserted after the WSN is formed, on the straight line joining the pair of nodes which terminates the P2P link at both ends. The optimal location is found by devising a fuzzy logic-based scheme whose rules are framed to minimize energy consumption and enhance the lifetime of the WSN. Two variants of the basic two-hop topology have been analysed, first, a non-cooperative variant, where the receiver accepts only the signal from the relay, and second, a more sophisticated variant, where the receiver is able to combine the relayed signal with the original signal from the source. Further, two different combining techniques, maximum ratio combining and selection combining (SC), are considered for the later variant. For our analysis we assumed an adaptive decode and forward (DF) relay for superior outage performance and M-ary quadrature amplitude modulation (MQAM) for better bandwidth efficiency. The η - μ fading model is general in nature and it combines different popular fading models such as Rayleigh, Nakagami-q (Hoyt) and Nakagami-m etc. We were able to show that combining may not always lead to higher energy efficiency, especially for shorter P2P links. We have also investigated how different design parameters such as spectral efficiency, path loss exponent and fading parameters ( η , μ ) affect the optimal relay placement location. [ABSTRACT FROM AUTHOR]

In this report, we have investigated the effect of antisite ordering on the magnetic behavior of NixZn1-xFe2O4 nanoparticles for x = 0, 0.25, 0.5, 0.75, and 1. Observed magnetization versus temperature data show systematic gradual changes from antiferromagnetic to ferrimagnetic phase with increasing amount of Ni concentration. Saturation magnetization of the parent Zn ferrite increases when substituted by Ni and then decreases for concentration greater than x = 0.5. Coercivity also shows a concentration dependence. Saturation magnetization has no dependence on cooling field at all concentrations. For x = 0.5 the system act as an extremely soft magnetic material with highest saturation magnetization and lowest coercivity. Site occupancy by cations plays an important role for local moment imbalance between different antiferromagnetic sublattices giving rise to ferrimagnetic interaction upon Ni substituted in Zn ferrite. [ABSTRACT FROM AUTHOR]

The effects of particle size, structure, microstrain, and cation distribution on magnetic property of nanosized Ni0.35Zn0.65Fe2O4 prepared through high-energy ball milling have been explored by a wide variety of experimental technique namely, x-ray diffraction, high-resolution transmission electron microscopy, dc magnetization measurement, and Mössbauer spectroscopy. The sample exhibits mixed magnetic behavior with a collective magnetic state between 300 and 60 K while spin glasslike freezing of magnetic moments has taken place below 60 K. The sample has displayed enhancement in magnetization, magnetic hyperfine field, coercivity, and anisotropy energy. The inherent superparamagnetic relaxation of ferrite nanoparticles has significantly reduced and it shows evidence of magnetic hysterisis at room temperature. These properties could be profitably used to overcome the inherent instability of magnetic nanoparticles. The intersublattice interaction (JAB) in the sample has strengthened due to migration of Fe3+ ions from octahedral (B) site to tetrahedral (A) site and this accounts for the genesis of counterintuitive magnetic enhancement in the sample. [ABSTRACT FROM AUTHOR]

MMP-2 overexpression is strongly related to several diseases including cancer. However, none of the MMP-2 inhibitors have been marketed as drug candidates due to various adverse effects. Here, a set of sulphonyl pyrrolidines was subjected to validation of molecular modelling followed by binding mode analysis to explore the crucial structural features required for the discovery of promising MMP-2 inhibitors. This study revealed the importance of hydroxamate as a potential zinc-binding group compared to the esters. Importantly, hydrophobic and sterical substituents were found favourable at the terminal aryl moiety attached to the sulphonyl group. The binding interaction study revealed that the S1′ pocket of MMP-2 similar to 'a basketball passing through a hoop' allows the aryl moiety for proper fitting and interaction at the active site to execute potential MMP-2 inhibition. Again, the sulphonyl pyrrolidine moiety can be a good fragment necessary for MMP-2 inhibition. Moreover, some novel MMP-2 inhibitors were also reported. They showed the significance of the 3rd position substitution of the pyrrolidine ring to produce interaction inside S2′ pocket. The current study can assist in the design and development of potential MMP-2 inhibitors as effective drug candidates for the management of several diseases including cancers in the future. [ABSTRACT FROM AUTHOR]

Silver nanoparticles of diameters in the range of 4.2–46 nm have been used to grow nanoshells of lithium niobate with thicknesses in the range of 2.2–22 nm in a silicate glass matrix. The lithium niobate shells form a percolative network and show electronic conduction. This has been explained as due to Mott’s variable range hopping conduction mechanism. The hopping is interparticle because the density of localized states is found to be in reasonable agreement with the density of nanoparticles with a core-shell structure. The ac conductivity is shown to be dependent on frequency with the exponent having a value around 0.5. This arises due to the charge motion’s being operative in a two-dimensional structure with one of these dimensions involved in such motion. Optical absorption of the core-shell structured nanoparticles exhibits two peaks—one around 350 nm is ascribed to plasmon resonance of silver nanoparticles which are not covered by a niobate shell, and the other in the range of 550–650 nm is caused by light scattering from the core-shell structure. [ABSTRACT FROM AUTHOR]

Nanocomposites containing silver particles of diameter of 20 nm with silver orthosilicate crystals forming the shell with thickness around 21 nm closely packed in a silicate glass were prepared. The ac conductivity of samples subjected to different heat treatments were measured over the frequency range of 100 Hz to 6 MHz in the temperature range of 500–570 K. The data were analyzed by the Macdonald model based on Kohlrausch-related frequency response formalism designated as CK0. The reference system was taken as the glass-crystal composite containing a lithium orthosilicate crystalline phase. The shape parameter βo for the reference system was found to be 0.33, whereas that for the nanocomposites was extracted to be 0.46. The former implied a one-dimensional lithium ion motion along the grain boundaries of the orthosilicate crystals, whereas the latter indicated that there was a one-dimensional silver ion motion in an effective two-dimensional structure in the shell surface because of a high stress condition along the radial direction of the core-shell composite. [ABSTRACT FROM AUTHOR]

Electronic structures and magnetic behaviours of zinc oxide nanorods (ZnO-NRs) decorated with nanocrystalline "Au"-particles (nc -Au) have been studied using different spectroscopies, superconducting quantum interference device-type magnetometer and plane wave pseudopotential density functional theory calculations. The presence of intrinsic defects viz. zinc interstitials (Zn i) and/or oxygen vacancies (V O) are established using different spectroscopies measurements. Ultraviolet photoelectron spectroscopy and valence band photoemission spectroscopy suggests that the valence band density of states of O 2 p - Zn 4 sp hybridized states of nc -Au/ZnO-NRs is higher than pure ZnO-NRs that could be correlated with its higher ferromagnetic behaviour. An enhanced room temperature ferromagnetism has been observed when nanocrystalline (nc) gold (Au) particles are decorated on the surface of ZnO-nanorods (ZnO-NRs). This enhanced magnetic moment in nc -Au/ZnO-NRs comes from the metallic electrons of nc -Au that induces large orbital magnetic moment at the nc -Au/ZnO-NR interface. Theoretical calculations shows the enhancement of the density of states at the valence band region of ZnO with a decoration of optimum content nc -Au particles along with the increase of oxygen vacancies in nc -Au/ZnO-NRs; that further confirms the enhancement of magnetization. • Magnetic moment comes from metallic electrons at the nc- Au/ZnO-NRs interface. • Magnetization is due to intrinsic defect like zinc interstitials and oxygen vacancies. • VB-DOS of O2 p -Zn4 sp hybridized states of nc -Au/ZnO-NRs is higher than pure ZnO-NRs. • DFT-calculations increases O-vacancies that confirms the enhancement of magnetization. [ABSTRACT FROM AUTHOR]

Highlights • Increase of Zn L3-edge and O K-edge intensity indicates the increase of local density of states. • Increase of density of states is due to the surface defects and/or dangling bonds in ZnO. • The Zn 2p3/2 core level XPS studies confirm the formation of oxygen vacancies/defects. • Room temperature ferromagnetism is due to vacancies/defects. Abstract Defect induced room temperature ferromagnetism (RT-FM) in Ar+ implanted ZnO single crystal (ZnO-SC) is observe from the electron Spin Resonance (ESR) spectra and is correlated with their electronic structure studies using synchrotron radiation based X-ray absorption near edge structure (XANES) spectroscopy and valence band photoemission spectroscopy (VB-PES). Enhancement of absorption intensity at the edge of XANES spectra of Ar+ implanted ZnO indicates the increase of local density of states (DOS); which arises from the surface defects and/or dangling bonds in ZnO. VB-PES spectra change upon Ar+ implantation, becoming broader, implying the induced surface defects in ZnO-SC. X-ray photoelectron spectroscopy studies confirm that the Zn 2 p 3/2 core level peak shifts in lower energy side in Ar+ implanted ZnO-SC that is associated with the formation of oxygen vacancies/defects in ZnO-SC which is responsible for the RT-FM. [ABSTRACT FROM AUTHOR]

In this Letter, a reconfigurable half-mode substrate integrated waveguide (HMSIW)-based leaky-wave antenna (LWA) configuration with its edge loaded with the periodic strips is investigated. A good impedance matching is obtained using the loaded configuration. A microstrip line with a tapered-line transition is used to feed the proposed antenna structure. Beam scanning of 24°–66° in the frequency band 9.07–11.04 GHz is achieved with the maximum gain of 14.58 dBi at the frequency 10.07 GHz with a corresponding beam direction of 48°. Thereafter, the edge of the strips is loaded in the middle with variable capacitors connected through narrow stubs to scan the beam at a fixed frequency. The variation in reflection and transmission coefficients, beam angle and antenna gain with variation in the capacitor value for the loaded configuration is investigated. [ABSTRACT FROM AUTHOR]

In this Letter, a reconfigurable half‐mode substrate integrated waveguide (HMSIW)‐based leaky‐wave antenna (LWA) configuration with its edge loaded with the periodic strips is investigated. A good impedance matching is obtained using the loaded configuration. A microstrip line with a tapered‐line transition is used to feed the proposed antenna structure. Beam scanning of 24°–66° in the frequency band 9.07–11.04 GHz is achieved with the maximum gain of 14.58 dBi at the frequency 10.07 GHz with a corresponding beam direction of 48°. Thereafter, the edge of the strips is loaded in the middle with variable capacitors connected through narrow stubs to scan the beam at a fixed frequency. The variation in reflection and transmission coefficients, beam angle and antenna gain with variation in the capacitor value for the loaded configuration is investigated. [ABSTRACT FROM AUTHOR]

The microscopic structure and texture of coke are intrinsically important to the cold strength indices (M10 and M40) and hot strength indices (CRI and CSR) properties of the coke. Traditionally, Blast Furnace (BF) coke is characterized by its composition, porosity, and strength indices. There are different conventional methods for the determination of porosity as well as the structure of coke mass. In the present work, a comparative study was carried out for measurement and interpretation of the coke microstructure using volumetric analysis, image analysis, mercury porosimetry, and X-ray Computed Tomography (CT) scan measurements. The measurement of coke structural parameters based on image analysis provided information on porosity, pore size distribution, pore wall thickness, radius, perimeter, shape, and other structural parameters. Image analysis provided much more structural information on coke as compared to the volumetric method which is desirable for scientific investigation. [ABSTRACT FROM AUTHOR]

Abstract Two-dimensional graphene oxide (GO) nanomaterials offer interesting physical/chemical properties and have been explored for potential use in electronics, magnetic, catalysis, and energy storage applications, because of its high charge-carrier mobility and high specific surface area. This study investigates the electronic and magnetic properties of nitrogenated graphene oxide (GO-N x), and nitrogenated graphene oxide functionalized with iron oxide (GO-N x :Fe). Four different nitrogen (N) precursor viz. ammonium hydroxide (NH 4 OH), hexamethylenetetramine (C 6 H 12 N 4), acetonitrile (C 2 H 3 N), and carbamide (CH 4 N 2 O) are used to synthesis " GO-N x " using chemical route. As C 6 H 12 N 4 based- GO-N x shows higher ferromagnetism, thus it is further functionalized with iron oxide using three different iron (Fe) precursors viz. ferric oxide (Fe 2 O 3), ferroso-ferric oxide (Fe 3 O 4), and iron oxide-hydroxide (FeOOH) to tune this room temperature ferromagnetism (RTFM). The electronic structure of " GO-N x " and " GO-N x :Fe " are characterized using C 1 s , O 1 s , N 1 s and Fe 2 p core-level X-ray photoelectron spectroscopy (XPS) and their corresponding magnetic behaviours are correlated with the SQUID-measured M-H loops. The magnetic moment changes due to the conversion and formation of different nitrogen bonded carbon along with the different phase of iron oxide. The tuning of magnetization in " GO-N x " and " GO-N x :Fe " using different N-precursors and/or Fe-precursors is an efficient route to tailor the electronic/magnetic properties of graphene-oxide for different electronic and magnetic device applications. Graphical abstract Unlabelled Image Highlights • Electronic and magnetic behaviours of GO-N x and GO-N x :Fe composites are studied. • For this study X-ray photoelectron spectroscopy, M-H hysteresis loops are used. • Magnetization of GO-N x :Fe composites is higher than GO-N x. [ABSTRACT FROM AUTHOR]

Diamond-like carbon (DLC) films and nanocrystalline silver particles containing diamond-like carbon (DLC:Ag) films were electrodeposited on n -type silicon substrate ( n -Si) to prepare n -Si/DLC and n -Si/DLC:Ag heterostructures for photovoltaic (PV) applications. Surface plasmon resonance (SPR) effect in this cell structure and its overall performance have been studied in terms of morphology, optical absorption, current-voltage characteristics, capacitance-voltage characteristics, band diagram and external quantum efficiency measurements. Localized surface plasmon resonance effect of silver nanoparticles (Ag NPs) in n -Si/DLC:Ag PV structure exhibited an enhancement of ∼28% in short circuit current density ( J SC ), which improved the overall efficiency of the heterostructures. [ABSTRACT FROM AUTHOR]

Since last few decades optics has already proved its strong potentiality for conducting parallel logic, arithmetic and algebraic operations due to its super-fast speed in communication and computation. So many different logical and sequential operations using all optical frequency encoding technique have been proposed by several authors. Here, we have keened out all optical dibit representation technique, which has the advantages of high speed operation as well as reducing the bit error problem. Exploiting this phenomenon, we have proposed all optical frequency encoded dibit based XOR and XNOR logic gates using the optical switches like add/drop multiplexer (ADM) and reflected semiconductor optical amplifier (RSOA). Also the operations of these gates have been verified through proper simulation using MATLAB (R2008a). [ABSTRACT FROM AUTHOR]

A Disintegrin and Metalloproteinase 17 (ADAM17), a Zn2+-dependent metalloenzyme of the adamalysin family of the metzincin superfamily, is associated with various pathophysiological conditions including rheumatoid arthritis and cancer. However, no specific inhibitors have been marketed yet for ADAM17-related disorders. In this study, 94 quinolinyl methoxyphenyl sulphonyl-based hydroxamates as ADAM17 inhibitors were subjected to classification-based molecular modelling and binding pattern analysis to identify the significant structural attributes contributing to ADAM17 inhibition. The statistically validated classification-based models identified the importance of the P1' substituents such as the quinolinyl methoxyphenyl sulphonyl group of these compounds for occupying the S1' - S3' pocket of the enzyme. The quinolinyl function of these compounds was found to explore stable binding of the P1' substituents at the S1' – S3' pocket whereas the importance of the sulphonyl and the orientation of the P1' moiety also revealed stable binding. Based on the outcomes of the current study, four novel compounds of different classes were designed as promising ADAM17 inhibitors. These findings regarding the crucial structural aspects and binding patterns of ADAM17 inhibitors will aid the design and discovery of novel and effective ADAM17 inhibitors for therapeutic advancements of related diseases. [ABSTRACT FROM AUTHOR]

Studies on free standing flexible composite films of Polyvinylidene fluoride (PVDF) incorporated with CaCu 3 Ti 4 O 12 (CCTO) functionalized by silver (Ag) nanoparticles (PVDF/CCTO:Ag) are presented here. CCTO nanoparticles were prepared by the sol-gel technique and thereafter covered with Ag nanoparticles by a modified seeding method. PVDF polymer filled with CCTO:Ag exhibited a higher dielectric constant (about 20% increment) and lower loss than PVDF polymer filled with pure CCTO at the same vol% of filler concentration. Transmission electron microscopy (TEM) studies revealed the size of the CCTO and of the Ag nanoparticles on the surface of CCTO. Differential scanning calorimetry (DSC) studies showed that both melting temperature and melting enthalpy were lower for PVDF/CCTO:Ag than for PVDF/CCTO with the same vol% of filler concentration. [ABSTRACT FROM AUTHOR]

Diamond-like carbon (DLC) films with tunable optical bandgap (E) were successfully deposited on glass and n-Si (100) substrates by radio frequency (RF)-sputtering technique in different argon (Ar) and acetylene (CH) plasmas. The bandgap of the films can be tuned from 1.41 to 1.28 eV, which correlates with the sp content, which increases from 56.3 to 63.7 %, respectively. The different ratios of sp/sp lead to different bandgaps of the DLC films. Plasmonic nanoparticles of silver (Ag) were also embedded in the DLC matrix by reactive magnetron sputtering to study the enhancement of light absorption in DLC films. The absorption coefficient significantly increased when the DLC films were incorporated with 10 at.% of silver nanoparticles. Raman and X-ray photoelectron spectroscopy (XPS) studies were utilized to determine the bonding nature and sp/sp ratios of DLC-Ag films. [ABSTRACT FROM AUTHOR]

Magnetic nanometric skyrmions are small complex vortex-like topological defects, mainly found in non-centrosymmetric crystals such as MnSi. They have potential applications for future spintronic devices. In this article, the structural, electronic, and magnetic states of the Mn atoms in a polycrystalline MnSi thin film facing a c-sapphire substrate were studied using x-ray diffraction, x-ray photo-emission spectroscopy, resonance photoemission spectroscopy (RPES), and extended x-ray absorption fine structure (EXAFS). The valence band spectra indicate the metallic nature of the film. The RPES study reveals the presence of major itinerant Mn 3d states near EF and also the mixed Mn 3d and Si 3s–3p states from 5.3 to 11.3 eV. The EXAFS spectrum does not show the existence of oxygen vacancies in the system, and the obtained magnetic moment in the non-stoichiometric MnSi thin film is a combination of the partially itinerant and partially localized Mn 3d states. [ABSTRACT FROM AUTHOR]

Plasmid-mediated AmpC (pAmpC) and ESBL co-production was detected in Escherichia coli a major etiologic agent of urinary tract infection. Isolates resistant to cefoxitin by CLSI methodology were tested for pAmpC beta-lactamase using phenylboronic acid and ESBLs by combined disk diffusion method. pAmpC/ESBL genes were characterized by PCR and sequencing. Transconjugation experiments were done to study the transfer of pAmpC and ESBL production from clinical isolates as donor to E. coli J53 AziR as recipient. Incompatibility groups of transmissible plasmids were classified by PCR-based replicon typing (PBRT). Among 148 urine culture positive isolates, E. coli was reported in 39.86 % (59/148), with 93.22 % (55/59) of cefoxitin resistance. pAmpC production was detected in 25, with varied distribution of blaCMY-2 and blaDHA-1type genes alone ( n = 13 and 7 respectively) or in combination ( n = 5). ESBL co-production was observed in 88 % (22/25) of pAmpC producing isolates with predominance of blaTEM ( n = 20). Twenty-three transconjugants showed transmission of pAmpC-and ESBL-resistant genes with co-carriage of blaCMY-2 and blaTEM ( n = 15) in plasmids of IncF type ( n = 9) being predominant, followed by IncI1 ( n = 4) and IncH1 ( n = 2) in combination. All clinical isolates were clonally diverse. Resistance against different beta-lactams in uropathogenic E. coli has been an emerging concern in resource- poor countries such as India. Knowledge on the occurrence of AmpC beta-lactamases and ESBL amongst this pathogen and its transmission dynamics may aid in hospital infection control. [ABSTRACT FROM AUTHOR]

Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD), which has a major impact on salmonid aquaculture globally. An Enterobacter species, C6-6, isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum), has been identified as a potential probiotic species providing protection against BCWD. This study examined the effects of alginate microencapsulation on the protective efficacy of C6-6 against BCWD in vivo when administered to rainbow trout fry orally or by intraperitoneal (IP) injection. Viable C6-6 bacteria were microencapsulated successfully, and this process (microencapsulation) did not significantly deteriorate its protective properties as compared to the administration of non-microencapsulated C6-6 bacteria. Both oral and IP delivery of C6-6 achieved significantly better protection than control treatments that did not contain C6-6 bacteria. The highest relative percent survival (RPS) resulted from IP delivery (71.4%) and was significantly greater than the highest oral RPS (38.6%). Successful intestinal colonization was not critical to protective effects of C6-6. The study showed that C6-6 administration, with or without encapsulation, was a viable choice for protecting fry from BCWD especially when administered intraperitoneally. [ABSTRACT FROM AUTHOR]

MMP-2 is potentially contributing to several cancer progressions including leukaemias. Therefore, considering MMP-2 as a promising target, novel anticancer compounds may be designed. Here, 32 in-house arylsulfonyl L-(+) glutamines were subjected to various structure-based computational modelling approaches to recognize crucial structural attributes along with the spatial orientation for higher MMP-2 inhibition. Again, the docking-based 2D-QSAR study revealed that the Coulomb energy conferred by Tyr142 and total interaction energy conferred by Ala84 was crucial for MMP-2 inhibition. Importantly, the docking-dependent CoMFA and CoMSIA study revealed the importance of favourable steric, electrostatic, and hydrophobic substituents at the terminal phenyl ring. The MD simulation study revealed a lower fluctuation in the RMSD, RMSF, and Rg values indicating stable binding interactions of MMP-2 and these molecules. Moreover, the residual hydrogen bond and their interaction analysis disclosed crucial amino acid residues responsible for forming potential hydrogen bonding for higher MMP-2 inhibition. The results can effectively aid in the design and discovery of promising small-molecule drug-like MMP-2 inhibitors with greater anticancer potential in the future. [ABSTRACT FROM AUTHOR]

Aluminum antimonide films (AlSb) were successfully deposited on glass substrates by ablating an aluminum antimonide target using pulsed Nd-YAG laser. Films deposited at substrate temperatures ~773 K and above showed zinc blende structure. Increase in substrate temperature culminated in grain growth in the films. Photoluminescence studies indicated a strong peak ~725 nm (~1.71 eV) and ~803 nm (~1.55 eV). Films deposited at higher deposition temperatures indicated lower residual strain. Characteristic Raman peaks for AlSb at ~151 cm −1 followed by two peaks located at ~71 cm −1 and ~116 cm −1 were also observed. [ABSTRACT FROM AUTHOR]

The rapid proliferation of electronic devices in the last two decades has compelled the researchers to find a remedy for one of the most toxic and hazardous waste materials – the waste Printed Circuit Boards. Numerous articles have been published demonstrating the process routes for recycling of this toxic but otherwise useful waste due to nearly 30% metal content. In this paper, more than 150 related articles mostly published in the last 15 years and covering the broad areas like characterization of waste Printed Circuit Boards, health hazards associated with the processing and the different routes of recycling have been analyzed to provide a comprehensive overview on this topic. Physical separation processes employing electrostatic separator, magnetic separator, froth floatation, etc., has been reviewed for separation of metals and non-metals, along with useful utilizations of the non-metallic materials. The recovery of metals from this waste material through pyrometallurgical, hydrometallurgical or bio-hydrometallurgical routes is also critically discussed. [ABSTRACT FROM AUTHOR]

Silver nanoparticles were embedded in zinc oxide matrix by using sputtering-cum-evaporation technique. Particle size and metal volume fraction were tailored by varying the amount of silver in the Al-ZnO matrix. Strong surface plasmon resonance peak in the optical absorbance spectra was observed at ∼500 nm. Electrical conductivity was measured in the temperature range of 80-220 K when illuminated at 500 nm, and in dark to explain the observed transport processes associated with this material. [ABSTRACT FROM AUTHOR]

The effect of nano-Ag (n-Ag) plasmonic layer in InP/CdS solar cell structure was examined. An enhancement of short circuit current improving the overall cell efficiency was observed in InP/n-Ag/CdS cells. Location of the plasmonic layer in the above cell structure has been analyzed critically. The effect of introducing plasmonic layer on the overall performance of the cell has been studied in terms of the morphology, particle size distribution, optical absorption, I-V, C-V characteristics, and lifetime of the photo-generated carriers. Secondary ion mass spectroscopy (SIMS) studies were carried out for investigating possible interface alloying. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis of n-Si/diamond-like carbon (DLC) bi-layer films was realized by depositing DLC films on n-Si (100) substrate by a simple electrodeposition technique using acetonitrile (CH3CN) as the electrolyte. The films were characterized by Field Emission Scanning Electron Microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier Transformed Infrared spectroscopy (FTIR) and Raman studies. Solar cell characteristics were investigated critically. Open circuit voltage (V oc ) and short circuit current density (J sc ) obtained for the best n-Si (100)/DLC structure were 335mV and 9.6mA/cm2, respectively, corresponding to a total conversion efficiency of η= 1.65%. Open circuit photovoltage decay measurement was carried out to determine the carrier lifetime. Photoinduced charge separation in the n-Si (100)/DLC structure could be associated with an increase in the dielectric constant and a decrease in the device resistance. The process is cheap, reproducible and scalable, involving significantly lesser process steps. This is likely to usher in a new hope to the current competitive scenario of photovoltaic (PV) technology. [Copyright &y& Elsevier]

Abstract: Residual CdCl2 in chemical bath deposited (CBD) CdS layer was utilized to observe grain growth in CdTe layer for glass/SnO2/CBD-CdS/CdTe structures. The above as-deposited composite films were subjected to rapid thermal annealing (RTA) for observing grain growth and subsequent cell fabrication. The films were characterized by studying their microstructural and compositional properties. Interfacial mixing behavior was studied by secondary ion mass spectroscopy (SIMS) measurements which showed a slight interfacial diffusion of the CdS layer into the CdTe layer. Performance of a photovoltaic (PV) cell structure with non-optimized thickness of the CdTe and CdS layers obtained by this technique was studied. Carrier life time was obtained from V oc decay measurement. Photoinduced charge separation observed in this glass/SnO2/CBD–CdS/CdTe structure was associated with an increase in the dielectric constant and a decrease in the device resistance. [Copyright &y& Elsevier]

Gallium antimonide (GaSb) films were deposited onto fused silica and n-Si (100) substrates by coevaporating Ga and Sb from appropriate evaporation sources. The films were polycrystalline in nature. The size and the shape of the grains varied with the change in the substrate temperature during deposition. The average surface roughness of the films was estimated to be 10 nm. Grain boundary trap states varied between 2×10 and 2.2×10 cm while barrier height at the grain boundaries varied between 0.09 eV and 0.10 eV for films deposited at higher temperatures. Stress in the films decreased for films deposited at higher temperatures. XPS studies indicated two strong peaks located at ∼543 eV and ∼1121 eV for Sb 3d and Ga 2p core-level spectra, respectively. The PL spectra measured at 300 K was dominated by a strong peak located ∼0.55 eV followed by two low intensity peaks ∼0.63 eV and 0.67 eV. A typical n-Si/GaSb photovoltaic cell fabricated here indicated V∼311 mV and J∼29.45 mA/cm, the density of donors ( N)∼3.87×10 cm, built in potential ( V)∼0.48 V and carrier life time ( τ)∼28.5 ms. Impedance spectroscopy measurements indicated a dielectric relaxation time ∼100 μs. [ABSTRACT FROM AUTHOR]

Introduction of plasmonic layer in p-Si/undoped CdS/indium doped CdS (p-Si/CdS/In:CdS) solar cell indicated an enhancement of short circuit current which improved the overall increase in efficiency. The location of n-Ag layer and the possible interdiffusion of n-Ag at the interface were examined critically by secondary ion mass spectroscopy. The effect of plasmonic layer in the above cell structure and its overall performance has been critically studied in terms of the morphology, particle size distribution, optical absorption, current-voltage ( J- V) characteristics, capacitance-voltage ( C- V) characteristics, and lifetime of the photo-generated carriers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Grain growth in CdTe using residual CdCl2 in CBD-CdS. [•] Excellent interface boundaries studied by TOF-SIMS. [•] Eliminating the additional steps of CdCl2 treatment after CdTe deposition for grain growth. [ABSTRACT FROM AUTHOR]

This study aimed at determining the physico-morphological attributes, in vitro fertility and their interrelationships in semen of Sahiwal bulls. Semen samples were collected weekly for 6 weeks from ten mature Sahiwal bulls divided randomly into 5 groups. The mean (±SEM) of ejaculate volume (mL), mass activity (score 0-5), progressive sperm motility (%), sperm concentration (106/mL), live sperm (%), abnormal sperm (%), intact acrosome (%), hypo-osmotic swelling (HOS) positive sperm (%), sperm penetration distance (SPD, mm) were 4.28, 3.17, 76.73, 1185.53, 83.37, 9.97, 82.70, 79.00 and 56.85, respectively. The bulls varied significantly (P<0.05) in all their ejaculates characteristics Moreover, HOS positive sperm also had significant (P<0.01) positive correlation with mass activity (r=0.756), progressively motile sperm (r=0.374), live sperm (r=0.395) and SPD (r=0.681), and negative correlation with abnormal sperm (r=-0.463). Sperm penetration distance has significant (P<0.05) positive correlation with mass activity (r=0.776), progressively motile sperm (r=0.653), sperm concentration (r=0.365) and HOS positive sperm (r=0.681), and negative correlation with intact acrosome (r=-0.415). Overall semen quality of Sahiwal bulls was found optimum for use in breeding programme. [ABSTRACT FROM AUTHOR]

This paper attempts to examine the physical and financial performance of some primary dairy co-operatives in west Bengal state in Indian context. The study suggests that financial performance indicators dominate over physical ones, and all the dominating variables have long term positive impact on primary milk producers' co-operative societies (PMPCSs). Also, the significant impact of financial performance variables contributes to high profit efficiency for all primary dairy co-operative societies under study. These results seem to suggest that in order to strengthen the dairy development programme on co-operative line at the primary level more emphasis should be given to these dominating physical and financial performance variables in general and physical dominating variables in particular. [ABSTRACT FROM AUTHOR]

We report on the role that oxygen vacancies have in determining the magnetic properties of Cu-doped ZnO. The observed magnetic hysteresis and the temperature dependence (irreversibility) of magnetization behave like supermoments blocked along random directions for a low-temperature annealed sample. The magnetic hysteresis (finite coercivity and low field saturation) and the irreversibility of temperature-dependent magnetization are destroyed upon thermal annealing. We propose that oxygen vacancies play an important role in inducing supermoments to explain the observations. [ABSTRACT FROM AUTHOR]

Abstract: Composite films of BN/Pd were synthesized by depositing thin films of BN by pulsed laser deposition technique and evaporating a thin layer of palladium on top of it to form a bi-layer structure. This bi-layer structure was then subjected to rapid thermal annealing for the incorporation of Pd in BN. The films thus obtained were characterized by SEM, XRD and FTIR studies. Liquid petroleum gas (LPG) sensing properties were also investigated critically. Very stable and reproducible LPG sensing properties and comparatively at lower operating temperature of 460K would make this material superior to prevalent oxide based sensors. [Copyright &y& Elsevier]

Among various matrix metalloproteinases (MMPs), overexpression of MMP9 has been established as a key player in a variety of cancers. Therefore, MMP9 has emerged as a promising biomolecule that may be targeted to design potent inhibitors as novel anticancer therapeutics. In this study, a large database containing 1,123 drug-like MMP-9 inhibitors was considered for robust classification-dependent fragment-based QSAR study through SARpy, Bayesian classification, and recursive partitioning analyses and were validated by both internal and external validation techniques. In a nutshell, all these classification-dependent techniques revealed some common structural alerts and sub-structural fingerprints responsible for modulating MMP-9 inhibition. These observations are in agreement with the interactions obtained from the ligand-bound co-crystal structures of MMP-9 justifying the robustness of the current study. Finally, based on these crucial structural fragments, some new lead compounds were designed and further validated by the binding mode of interaction analysis. Therefore, these findings may be beneficial in designing novel and potential MMP-9 inhibitors in the future as a weapon to combat several cancers. [ABSTRACT FROM AUTHOR]

Abstract: Polycrystalline zinc telluride films were successfully deposited on glass substrates at different temperatures ranging from 300K to 773K by ablating a ZnTe target (99.99%) by a pulsed laser beam. Microstructural studies indicated an increase in the average crystallite size from 40nm to ∼75nm with the increase in substrate temperature during deposition. X-ray diffraction patterns indicated that structure of the films depended on the deposition temperature. The band gap as determined from the transmittance versus wavelength traces was found to vary between 2.32 and 2.38eV. The PL spectra measured at 300K were dominated by a strong peak located at ∼1.77eV which overshadowed the band edge luminescence peak at ∼2.23eV. Characteristics Raman peaks for ZnTe at ∼173cm−1 (TO) and ∼199cm−1 (LO) were also observed. [Copyright &y& Elsevier]

Abstract: Polycrystalline cadmium telluride films were successfully deposited on glass substrates by ablating a CdTe target by pulsed Nd–YAG laser. Microstructural studies indicated an increase in the average crystallite size from 15nm to ∼50nm with the increase in substrate temperature during deposition. The films deposited here were slightly tellurium rich. X-ray diffraction pattern indicated that the films deposited at 300K had wurtzite structure while those deposited above 573K were predominantly of zinc blende structure. Residual strain in the films deposited at 300K was quite low as compared to those deposited at higher temperatures. PL spectra of all the CdTe films were dominated by a strong peak at ∼921nm (∼1.347eV) followed by a low intensity peak at ∼863nm (∼1.438eV). Characteristics Raman peaks for CdTe indicated a peak at ∼120cm−1 followed by peaks located at ∼140cm−1 and 160cm−1. [Copyright &y& Elsevier]

Advantages of direct current (DC) application, concurrently with waterflooding, in mobilizing trapped oil is investigated. Application of DC on completely water swept core recovered 3–9% additional oil, which is slightly less when DC is applied from the beginning of waterflooding process. Reduced water requirement (15–22%) and permeability enhancement up to 40% are found to be added benefits. The effect is more pronounced in higher permeability core and higher density oil. These phenomena are attributed to formation of clay colloids and mobilization of trapped oil along with connate water due to the added dynamics of electrokinetic and electrochemical processes. [ABSTRACT FROM AUTHOR]

The merits of using electrokinetic phenomena to improve reservoir permeability on sandstone reservoir core plugs are investigated with detail clay mineralogy studies. Normal and reverse DC configuration is applied along with waterflood and studies are conducted on single-phase and two-phase fluid saturation conditions. The produced brines are acid digested and analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). In single-phase flow experiments, permeability enhanced 180% with the normal electrode configuration but negligible change is observed in reverse configuration. In two-phase flow 59% and 10% permeability enhancement is observed in normal and reverse configurations, respectively. In addition, 11.6% additional oil is recovered from normal configuration. The results are examined in terms of electrolyte movement and resulting changes within the clay microstructure. In normal electrode configuration, formation of colloidal clay suspension and flowing out along with produced brine is evident. This has resulted in increased pore passage and core permeability, whereas in the reverse configuration, clay structures remained unchanged. The given explanations are supported by ICP-MS and X-ray diffraction results. [ABSTRACT FROM AUTHOR]

Abstract: Most of the extended reach horizontal wells and also the vertical wells with permeability heterogeneities often experience premature and excessive water production from multiple, high permeability streaks and conductive fractures. Bullhead and Relative Permeability Modifier (RPM) treatment often fails to achieve the desired result, as in most cases the situation warrants isolation and protection of the oil producing zones, from highly damaging polymeric gels. Protection of oil zones in a highly fractured reservoir is technically and economically a huge challenge because of knowledge on the complexity of fracture network. This paper describes the application of three chemical fluid compositions in sequence, as an alternate rigless water control option whose self-selectivity and effectiveness in controlling water production are verified in the laboratory in simulated fractured reservoir condition. The first fluid is designed to protect the matrix by creating an impermeable filter cake on low permeable oil saturated zones, keeping the water swept fractures open for gel treatment. The second fluid is a cross-linkable polymer gelant to shutoff the fractures and the third fluid is an enzyme breaker for cleaning the filter cakes form matrix zones. After completion of the treatments, return permeability measurement was carried out which shows 85–90% reduction of water permeability with less than 15% reduction of oil permeability. Microscopic investigations on treated core plug show very little invasion of polymer gel into the matrix area, whereas the fractures are almost completely sealed. The technology could be suitably applied without rig deployment and at a low cost. However, the fluid composition, pumping pressure and flow rate need to be customized based on the candidate well and the actual reservoir parameters. [Copyright &y& Elsevier]

A composite technology on "PLC based integrated control and monitoring system for conveyors and other equipment of an underground coal mine" has been designed, developed and implemented successfully for conveyors in Churi mines of North Karnpura area ofCCL, Ranchi by R&D Centre for Iron and Steel (RDCIS), SAIL, Ranchi in association with CMPDIL, Ranchi and Churi Mines, CCL, Ranchi. For the first time, Programmable Logic Control (PLC) based monitoring and control system has been introduced in an underground coal mine duly approved by DGMS (Director General of Mines & Safety). With the PLC based integrated control system, proper monitoring and control can be ensured from a central location, which is a very useful feature as far as underground mines are concerned leading to enhanced super-vision of the mining process. The system is totally indigenous and has the approval of DGMS for use in intake airways of a below ground coal mines of degree-1 gassiness. The jobs carried out are the followings: * Design and development of a total PLC based composite technology for underground conveyor control and monitoring * Laboratory development of zero speed sensor with intrinsic safety requirement (at RDCIS lab) * Installation and commissioning of comprehensive mimic panel along with main PLC unit at surface level and remote I/O units/stations with all auxiliary switches etc. in the underground and surface level. * Installation and commissioning of pull cord, belt sway and zero speed sensors. * Establishment of a fiber optic communication network between various nodes at underground and at surface level, where PLC unit is installed. * Development and commissioning of new starter for enabling exchange of various inputs/outputs between remote I/O, starter, main PLC system. * Design and fabrication of special flame proof enclosure for remote I/O station in underground level, duly approved by DGMS. * Design and fabrication of mimic panel to display all major parameters for running of conveyors with audiovisual display. The deployment of the system has resulted in easier fault diagnosis, troubleshooting and facilitates in the reduction of downtime, thereby increase in production. Development of indigenous technology shall further help in horizontal transfer of technology across underground coal mines based on conveyor control system for transporting of material from underground to surface level. [ABSTRACT FROM AUTHOR]

Mineral bone disorder (MBD) is an important complication of chronic kidney disease (CKD). However, there are limited data on the pattern of MBD in Indian CKD population. The aim of this study was to describe spectrum of MBD in patients with CKD in our center. This was a hospital-based cross-sectional observational study. Patients with stage 4 and 5 CKD were included in this study. Those receiving calcium supplement, vitamin D or its analogues, and calcimimetic were excluded. Serum/plasma levels of creatinine, albumin, calcium, phosphate, total alkaline phosphatase (TAP), intact parathormone (iPTH), and 25-OH vitaminD (25-vitD) were measured. Radiological survey of bones was carried out in all cases, and echocardiography done in selected patients. Statistical analysis was done using Sigmaplot 10.0 software. A total of 150 patients (114 males, 36 females) were included in this study. Mean age was 45.67±16.96 years. CKD stage 4 and 5D were found in 26% (n=39) and 74% (n=111) of study population, respectively. The most common underlying native kidney diseases in patients of CKD 4 and 5D were diabetic nephropathy (41.03%) and CGN (41.44%), respectively. Median (first quartile, third quartile) values for serum levels of corrected calcium (cCa), phosphate, cCaXPO4 product, TAP, plasma iPTH, and 25-vitD in stage 4 CKD were 8.36 (7.79, 8.91) mg/dL, 4.9 (3.92, 6.4) mg/dL, 41.11 (34.01, 53.81) mg2/dL2, 97 (76.5, 184.25) IU/L, 231 (124.5, 430.75) pg/mL, and 12 (6.98, 23.55) ng/mL, respectively; and in stage 5D CKD were 8.36 (7.66, 8.95) mg/dL, 5.7 (4.23, 6.95) mg/dL, 46.5 (37.16, 54.47) mg2/dL2, 180 (114.5, 276.25) IU/L, 288 (169.75, 625.0) pg/mL, and 18.4 (10.0, 26.4) ng/mL, respectively. Prevalence of hypocalcemia (56.41% vs. 54.95%), hyperphosphatemia (64.10% vs. 70.27%), and hyperparathyroidism (84.62% vs. 88.29%) was not different between patients with CKD 4 and 5D. However, iPTH level outside the target range and increased TAP level were significantly (P<0.001) more common in CKD stage 5D. Multiple logistic regression analysis for hyperparathyroidism revealed significant inverse correlation with cCa in CKD 5D. There were no significant differences in vitamin D status and prevalence of valvular calcification between CKD stage 4 and 5D-X-ray revealed renal osteodystrophy in 8 (5.33%) patients, while it was normal in 118 (78.67%) patients. Secondary hyperparathyroidism, hyperphosphatemia, hypocalcemia, increased TAP, and 25-OH vitamin D deficiency and insufficiency were quite common in CKD 4 and 5 patients. The commonest type of MBD in CKD 4 and 5D was secondary hyperparathyroidism. [ABSTRACT FROM AUTHOR]

The survival of transplant recipients is significantly lower than age-matched controls in the general population. The aim of this study was to analyze the trends in mortality of renal allograft recipients at our centre. We retrospectively analyzed data from all patients who were transplanted between October 1988 and June 2010 and were followed at our center. Patients were considered to have death with graft function (DWGF) if death was not preceded by return to dialysis or re-transplantation. The study included 98 renal allograft recipients (male : female - 7.99 : 1). The mean recipient and donor ages were 35.06 ± 11.84 (range: 15-69) and 41.17 ± 10.44 (range: 22-60) years, respectively. Basic kidney diseases were CGN (chronic glomerulonephritis) (60.20%), CIN (chronic interstitial nephritis) (15.31%), DN (diabetic nephropathy) (8.16%), ADPKD (autosomal dominant polycystic kidney disease) (2.04%) and others (14.29%). They were followed up for a mean 79.91 ± 60.05 patient-months. Mortality occurred in 25 (25.51%) patients (male : female - 4 : 1). Causes of death were sepsis/ infection (36%), coronary artery disease (28%), CVA (8%), failed graft (4%), and rest unknown (24%). DWGF was 88% of total death and contributed to 78.57% of total graft loss. Overall patient survival at 1, 5, 10, and 15 years were 90.8%, 80.2%, 65.6%, and 59.1%, respectively (Kaplan-Meier analysis). Those who died exhibited significant differences in recipient's age (median 40 years vs 31 years, P=0.007), pretransplantation hypertension (HTN) (100% vs 65.75%, P<0.001), post-transplant infection (76% vs 42.47%, P=0.005), coronary artery disease (28% vs 1.37%, P<0.001), and serum creatinine at last follow up (median 2.3mg/dL vs 1.56mg/dL, P=0.003). Cardiovascular disease, in addition to infection, is an important cause of death during the first 15 years following renal transplantation even in nondiabetic recipients. Death with functioning graft is of concern. [ABSTRACT FROM AUTHOR]

Tannic acid, a nontoxic, easily biodegradable compound, is evaluated for scale inhibitor squeeze application in a sandstone reservoir. For this purpose, we designed a new inhibitor squeeze evaluation system, a combined core flood–tube blocking apparatus with appropriate pressure–temperature and data logging arrangement, that can simulate the near-wellbore reservoir as well as downhole locations. Berea sandstone core plugs represented the formation rock and the extended flow tube represented the wellbore. Backflow tests were conducted to measure scale precipitation within the core plug and wellbore flow restriction. A 10 pore volume (PV) tannic acid solution was squeezed through the core plug and after a 14-hr adsorption period, anion and cation brines were squeezed separately through the core plug followed by the tube. The tests were compared with a control and a commonly used phosphonate scale inhibitor. The results showed that a fast rate of permeability reduction due to scale deposition took place in the control experiment starting at the initial brine injection stage and, in the case of the phosphonate scale inhibitor squeeze, there was significant reduction in permeability due to the squeeze itself. There was also progressive reduction of permeability due to less control of scaling phenomena. However, the tannic acid–treated core showed a slight improvement in core permeability and no scale deposition took place up to 250 PV of brine injection. Scanning electron microscopy and inductively coupled plasma (ICP) studies explain the formation stimulating mechanism of this new scale inhibitor. [ABSTRACT FROM PUBLISHER]

A rectangular waveguide feed to the dielectric resonator antenna (DRA) is proposed. A three-layer DRA structure is used to achieve enhanced and broadband coupling to the waveguide. The antenna topology is easy to realise and does not need additional coupling or matching elements to effectively excite the DRA. The configuration also affords ease in frequency tuning without sacrificing bandwidth or radiation performance. The full-wave Green's function approach is presented for the analysis of such multilayer structures with an arbitrary number of layers with greatly reduced computational overhead. The modes of the multilayer DRA can be identified from the analysis, which can be used to explain the broadband nature of the coupling. The double-summation representation of the homogeneous Green's function has been extended to the multilayer case, leading to a substantial reduction in computation time for the input impedance. [ABSTRACT FROM AUTHOR]