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The present work focuses on performance improvement and emission reduction of conventional diesel engine's performance by incorporating various designs of intake manifolds while operating on different alternative fuels. The intake manifold was designed in a helical shape to produce higher turbulence in the combustion chamber. Three intake manifolds were designed while varying the internal diameter (ID) of helical shape, namely 1, 2 and 3 ID. In this study, the engine was operated on various alternative fuels, i.e., lemongrass oil, linseed oil and gas-to-liquid fuels. The improvement in performance and reduction in emission of the engine were highest for the engine connected with the 1-ID intake manifold. The gas-to-liquid fuel having the greater cetane number as output of the results is decreased the peak pressure. The oxides of nitrogen were significantly reduced by 51% for the engine connected with the 1-ID design manifold, and exhaust gas temperature also slightly decreased 24% when correlated with the diesel fuel. The presence of more oxygen content in the biodiesel used in the 1-ID manifold design shows the result in reduction of CO and HC by 35% and 46%, respectively, when correlated with the base fuel.

Erosion is the primary concern in gas turbines, power plants, fertilizer plants, jet aircraft and civil aircraft. The military, gas turbine blades are affected by dust clouds ingestion and impingement of slurry particles. In this study, we investigated the erosion rate of Inconel 718 and Ti-6Al-4V turbine blades in the air jet-erosion test rig by ([Formula: see text]m) silica erodent. The primary process parameters, such as velocity (100 and 150[Formula: see text]m/s), impingement angle (30–90∘), feed rate (5–10[Formula: see text]g/min), temperature (30–650∘C) and standoff distance (10–50[Formula: see text]mm) were optimized using response surface methodology (RSM). The design of experiments (DOE) and experimental screening tests were performed to identify the significant process parameters on the erosion of turbine blade materials. To optimize the process parameters, the experiment was conducted to obtain a lowest erosion rate. The ploughing and cutting mechanism of both Inconel 718 and Ti-6Al-4V materials were identified through a scanning electron microscope. As a result, the erosion rate increases with an increase in velocity and temperature; however, the erosion rate decreases with an increase in the impingement angle. The experimental analysis showed that the erosion rate ranged between 0.051–1.914[Formula: see text]mg/g for Inconel 718 and 0.02–1.0095[Formula: see text]mg/g for Ti-6Al-4V.

Exploring non-platinum group metal (n-PGM) based efficient oxygen reduction reaction (ORR) electro-catalysts is highly important for realizing advancement in sustainable next generation-alkaline anion exchange membrane fuel cells (AAEMFCs). Herein, we demonstrate a new “hierarchical shape tuning approach” for the synthesis of controlled sized and shaped non-PGM based Ag ORR electro-catalysts with surface active nano-islands. Hierarchical shapes ranging from spherical (S-AgNs), worm-in-sphere, sphere-in-worm and vermiform (worm-like) Ag nanostructures (V-AgNs) were obtained by precisely varying the ratios of capping agent to dual reducing agents in water at ambient conditions. Compared to S-AgNs, V-AgNs revealed a higher mass normalized ORR Tafel activity (0.303 A mgAg−1 at 0.9 V), onset (1.06 V) and half wave (0.78 V) potentials and higher retention of limiting current density (>88%) after 5000 cycles in 0.5 M potassium hydroxide (KOH) solution attributable to their unique worm like morphology with surface active nano-islands and support free-nature enabled better catalyst utilization. In a fully “non-PGM AAEMFC” (n-PAAEMFC), V-AgNs exhibited the highest fuel cell activity of 115.6 mW cm−2 and stable short-term durability (∼240 h) compared to S-AgNs (41.3 mW cm−2) and previously reported fully n-PAAEMFCs indicating their potential use in next-generation alkaline fuel cells.

A solid-state planar reference electrode (SSPRE) was fabricated and evaluated using polymer membrane, comprising polyvinyl chloride-co-polyvinyl acetate, nitrophenyl octyl ether as plasticizer, and potassium tetraphenylborate as anion blocker, and was used for the fabrication of SSPRE. Screen-printed Ag/AgCl electrode was used as the base electrode for the fabrication of SSPRE and was evaluated in background electrolyte solutions containing KNO3/KCl and was observed that there was no significant potential dependence on anions present in the background electrolyte. Furthermore, SSPRE was tested using a series of cations and anions in solution and varying pH of the background electrolyte with respect to commercial Ag/AgCl with 0.1 M KCl reference electrode. It was noted that the SSPRE provided stable potential by tuning the design of the screen-printed electrodes and the membrane potential. The reference potential does not differ in various background electrolyte solutions, except thiocyanate, which gave a negative shift at high concentration, ca. 0.1 M. Furthermore, the SSPRE was integrated with screen-printed potassium and sodium ion-selective electrodes, and was tested, and the performance was evaluated.

In present day, most of the automobile manufacturers depend on active safety systems to prevent collisions because collisions and accidents increase day by day in automobiles. Research statistics reported that 20% of collision occurs due to driver’s fault in the event of driving. It also points out that the causes of fatality rate in vehicles are not only due to fault of the vehicles. The causes of accidents are mainly due to drivers faults in automobile such as health-related issues which are the foremost reason for the accidents. In this study, the proposed system is used to analyze the condition of the driver in the event of health issues while driving tends to warn the driver. The sensor is mounted in the steering wheel for sensing the pulse of the driver during driving. The driver positioning of hands or palm in steering wheel is sensed by the pulse sensor fitted on steering wheel and at the time of abnormality in driver’s pulse rate. The sensor alerts the driver and co-passenger by displaying warning signal in dashboard. The research is carried out especially for the taxi drivers prolong time and for the low-cost vehicles to prevent the fatality rate, injury and damage to the vehicle.

Two wheelers are cheap and most efficient way of transportation; however, it still requires a rider (human) to balance a vehicle at low speeds and traffic conditions to complete the process of moving from point to point. Although a bike is a relative advantage, it still possesses a greater threat in form of accidents. Newspapers in daily basis report such motorcycle accident like skidding to be a major spoiler of a much-enjoyed mode of travel. It requires great deal of physical strength. Consider an aged person who is suffering from diabetes requires heavy relaxation for a duration after prolonged riding, thereby causing a great deal of fatigue. Therefore, it is necessary to bring about modifications to the existing vehicle because they make the riding a lot safer under low speed travel on dry sand surfaces which are common on Indian roads. The motorcycle by itself is self-balancing using their side legs at low speeds and traffics thereby facing many problems like joint pain, fracture, in the worst cases even ligament fracture, etc. The end result is about bringing up the supporting wheel concept on two wheelers is that the two-wheeler would balance itself and can be stabilized against any impact as well as zero velocity equally. Increased maintenance as well as the reduction in fuel economy in four wheels are on the ground all the time and also increases confidence in riding the vehicle entirely for a long period of time. Also, it would not demand much of leg reflexes to act upon the road or the brake foot pedal.

Drilling is one of the important machining operations in polymer matrix composites, which is used to join the polymer composites temporarily. The fiber reinforced polymer composites are widely used in automobile and aerospace fields in which the polymer composites are to be joined with similar or dissimilar materials. The present work focuses on the effects drilling parameters (speed and drill diameter) on kenaf fiber/steel wire mesh hybrid epoxy composites. To obtain the better mechanical properties, the hybrid composites are designed in such way that two layers of kenaf fiber and one layer of steel wire mesh reinforced in epoxy resin matrix. Delaminations, fiber pullout, and cracks are observed in microscopic examinations. Two different parameters of drilling speed and drill diameters are varied to cognizance the mechanism of delamination. The acceptable quality level of drilled holes was measured using toolmakers microscope through by calculating the circularity of drilled holes.

The purpose of engine oil lubrication is to reduce the wear and tear of the engine parts due to friction, corrosion, and to dissipate some amount of heat from the engine. The engine oil quality directly influences the service life and performance of the engine. The part manufacturers specify and list down the oil replacement period depending on the capacity of the engine at the standard test conditions. Conveniently, it is very difficult to determine the condition of the engine lubricating oil in normal operating condition. In this work, a coaxial capacitance sensor is developed to monitor the quality of the engine-lubricating oil. The quality of the oil is monitored by the sensor which will provide suitable capacitance value for the different oil conditions. The obtained capacitance values are monitored with the help of the LCR meter. The capacitance and the dielectric constant increase when the quality of the oil decreases. The different oil samples are tested to predict the parameters such as capacitance and dielectric constant. Finally, the obtained values are compared with the fresh oil to estimate the quality of the oil.

In the present research, the different simultaneous reductions of oxides of nitrogen (NOx) as well as smoke are compared. The methods are gasoline fumigation (GF), exhaust gas after treatment using water scrubbing (EGAT) method and gasoline fumigation along with nanoadditive. Gasoline fumigation was achieved by controlling the electronic injector fitted at the intake manifold using the open ECU software. An exhaust management set-up is invented, which is attached to the tailpipe of the engine. This precedes the exhaust and injects water in the tailpipe and sends it over the silica gel chamber. The aluminium oxide nanoliquid was blended with diesel in mass fractions of 50 ppm. The features of a single direct injection (DI) diesel engine are studied for GF, EGAT and gasoline fumigation along with 50 ppm nanodiesel blend (50AONP – D +GF). EGAT shows higher NOx and smoke emission reductions compared than diesel, gasoline fumigation and gasoline fumigation with nanoadditives. The simultaneous reduction in NOx and smoke, increase in BTE at high power and reduction in CO and HC when nanoadditive is used, shows gasoline fumigation as the effective method for diesel engines.

Millions of consumers and thousands of enterprises use cellular networks for mobile broadband services for high speed internet connectivity. This increases the immensity on various cellular network providers to afford the reliable and secure communication. The main purpose of 5G system is to become a reliable in communication standards and to provide an innovation platform for businesses and organizations to create and deploy new add-on services. Cloud radio access networks (CRAN) are an encouraging technology that will allow 5G mobile communication systems to satisfy the industry's needs and demands of end users with higher mobility and seamless connectivity. CRAN is characterized by centralized processing and control, providing collaborative access to the radio networks, and integrated with cloud based systems. Meanwhile, energy-efficient operation must be delivered together with cost savings in deployment and functioning in the network. However, CRAN technology in 5G mobile communication systems has to face multiple intrinsic security issues related with virtual system functions and cloud computing environment. This architecture allows coverage of maximum distance with fiber optic links up to 20 kilometers with low latency. Very high bandwidth collaboration between the interconnected systems in the network is possible in CRAN systems. Real time virtualization enforces the dynamic allocation of resources among the functional modules in accordance with the network capacity and the load distribution. This may obstruct the rate of successful establishment in the global market. It is critical to identify these challenges to enable C-RAN to function on its full potential and adoptive the deployment of future 5G mobile systems. This paper focuses on various security challenges and the privacy issues found in Cloud Radio Access Networks (CRAN). CRAN is characterized by centralized processing and control, providing collaborative access to the radio networks, and integrated with cloud based systems. The security issues at various levels and components are identified through several literatures and are tabulated in Table I. For this segregation, we have considered three major components of the systems as SDN, NFV and Cloud environment. We also have identified related security solutions for issues addressed and suggested some future guidelines for secure 5G systems.

For the first time, we report a facile one pot aqueous method for support-free Pd85Pt15 nano-porous structures (NPoS) synthesis from PdMn nano-alloys at ambient conditions. A hierarchical approach was successfully employed through a simple “self-settlement” process with descending amounts of carbon to carbon-free electro-catalysts to improve catalyst utilization and avoid carbon degradation during fuel cell operating conditions. Pd85Pt15 NPoS exhibits enhanced methanol resistive oxygen reduction reaction (ORR) activity owing to the presence of highly active and unique surface PdPt islands compared to HiSPEC Pt/C catalysts. Accelerated durability tests of the support-free PdPt NPoS show enhanced durability in harsh acidic environment (1.0 N H2SO4) compared to HiSPEC Pt/C and DOE 2017–2020 durability target. Preliminary direct methanol fuel cell studies using hierarchically derived Pd85Pt15 NPoS variants were performed at ultra-low Pt content. The effects of carbon content and catalyst layer thickness on fuel cell activities are well discussed.

Aziridinofullerene-porphyrin (C60-TPP) dyad was synthesized using triethyl phosphite mediated [2+1] cycloaddition reaction. Structural elucidation of the compound was carried out using NMR and FT-IR spectroscopic methods. The synthesized C60-TPP was further characterized using UV-Vis absorption and photoluminescence emission studies. An optical study of the synthesized compound shows absorption maxima at 424 nm, around 516, 550, and 593 nm with small broad absorption peaks at 360 and at 480 nm. Photoluminescence studies of the compound shows emission maxima at around 597, 652 and 717 nm. Electrochemical studies of the compound shows oxidation potentials at 0.30, 0.52, 0.74 V and reduction potentials at−1.69,−2.07 and−2.42 V with respect to internal Fc/Fc+ reference corresponding to porphyrin and fullerene C60 moiety in the compound and the formation of C60-TPP. Furthermore, the absence of obtain XPS peaks corresponding to nitro group in C60-TPP confirms the conversion of nitro group to aziridine group.

Poly(fluorene-alt-benzothiadiazole) having 5 and 10% equivalent meso-tetraphenylporphyrin (m-MTPCC) linked through oxyethylene spacer in carbazole (P2, P3) and the parent poly(9,9-di-hexylfluorene-alt-2,1,3-benzothiadiazole) (P1) were synthesized using Suzuki polymerization reaction. These polymers were characterized using FT-IR, 1H NMR, TGA and gel permeation chromatography. The synthesized polymers are soluble in common organic solvents and are found to be thermally stable. Weight average molecular weights of the polymers were 51.895, 71.224 and 34.789 kDa for P1, P2 and P3, respectively. These copolymers (P2 and P3) shows absorption maxima at around 320, 422, 452 nm and emission maxima at 540 nm in solution, whereas in film state, these polymers (P2 and P3) shows absorption maxima at around 322, 422, 466 and 554 nm and emission at around 539, 654 and 718 nm. The photoluminescence emission at 648 and 720 nm when excited at 320 nm shows that energy transfer from polymer backbone to porphyrin. Surface morphology, optical absorption and emission properties of these polymers with PCBM were also studied. Electrochemical characterization of these polymers shows deep HOMO levels for P2 and P3 when compared with parent polymer and the details are reported.

Herein, we report a simple and elegant aqueous synthesis of Pd100-xPtx (x=5, 10, 15 and 20) nano-porous structures (NPoS) derived from Pd100-xMn2x (x=5, 10, 15 and 20) nano-alloys. Pd100-xPtx/C NPoS exhibit enhanced oxygen reduction reaction (ORR) activity along with higher retention of figure of merit in the presence of methanol compared to HiSPEC Pt/C catalyst. The ORR mass and specific activity values of Pd100-xPtx/C NPoS are high and exceed the U.S. department of energy (DOE) 2017–2020 targets. The enhanced methanol tolerance and ORR activity of Pd100-xPtx/C NPoS is attributed to their unique surface active Pd−Pt islands on nano-porous Pd. Direct methanol fuel cell performance studies employed using Pd85Pt15/C NPoS as cathode material (0.4 mgPt/cm2) and HiSPEC PtRu/C NPs as anode material (0.2 mgPt/cm2) shows improved direct methanol fuel cell (DMFC) single cell activity at low Pt loading and the results are presented.

We report an enhanced power conversion efficiency (PCE) of 11.7% ± 0.2 and a fill factor (FF) of 71% for dye-sensitized solar cells (DSSC) with an active area of 0.16 cm2 after modifying the TiO2photoanode with size-selective (ca. 2 nm) N,F,S-codoped graphene quantum dots (NFS-GQDs) that exhibit a photoluminescence quantum yield (PLQY) of 70%. An upward shift in the Fermi level has been observed, perhaps responsible for the improved performance along with the possibility of preventing the back electron transfer from TiO2. Mott Schottky analysis indicates a shift (52 mV)in the flat band potential, which is directly related to the Voc of the system. Detailed characterization (IPCE, TCSPC etc) indicates the important role of hetero atoms in facilitating the enhanced performance. Thus, our results suggest that the incorporation of size controlled, hetero atom doped GQDs can enhance the efficiency of DSSCs enabling more opto-electronic applications.

Gold-platinum nano-porous structures (Au100-xPtx NPoS) with unique surface enriched Au−Pt islands are synthesised through a galvanic replacement strategy from Au100-xAg2x nano-alloys with ultra-low platinum loading (x=1.25, 2.5 and 5). Formic acid oxidation reaction (FAOR) on Au100-xPtx/C NPoS shows a distinct peak at around 0.5 V related to CO2 formation. A characteristic peak at around 1.5 V increases with increasing FA concentration owing to the direct FAOR by nano-porous Au centers. FAOR peaks and If/Ib peak current ratios indicates that, Au100-xPtx/C NPoS facilitates direct FAOR pathway unlike HiSPEC Pt/C (dehydration pathway). Based on the enhanced chrono-amperometric response, Tafel behaviour and mass activity values, Au97.5Pt2.5/C NPoS (5.5 A/mgPt) reflects as the optimal catalyst for efficient FAOR. The intriguing catalytic role of surface enriched Au−Pt islands present on nano-porous Au greatly helps in determining the superior FAOR activity in Au97.5Pt2.5/C NPoS towards direct dehydrogenation pathway at ultra-low Pt content compared to other NPoS and HiSPEC Pt/C catalysts.

We demonstrate electrochemical cycling-induced reduction of MoO3 to monoclinic molybdenum dioxide and molybdenum sub-oxides (MoO3-x), which exhibit excellent electrochemical hydrogen evolution reaction (HER) activity. The conversion of MoO3 during cycling was probed; after 250 cycles, the redox peaks were found to diminish with an onset potential shift and increased HER current density. At 400 cycles, the insertion/deinsertion processes observed in the initial cycles are completely absent and the HER current density is enhanced to the maximum. The effect of MoO3 morphology and size on the electrochemical reduction of MoO3 was also studied.

A series of alternate block copolymers of polyphenylene vinylenes that have 1,3-dioctyloxy phenylene in the center of kinked m-terphenyl group as one of the building blocks with either one of the aromatic groups, viz., 1,4-dioctyloxy benzene, 4,6-dioctyloxy benzene and 4,4′-dioctyloxy biphenyl, was synthesized through Heck polymerization. These alternate block copolymers, viz., poly(2,5-bis(octyloxy)phenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P1), poly(2,4-bis(octyloxy)phenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P2) and poly(4,4′-bis(octyloxy-3,3′-biphenylene vinylene alt 4′,6′-bis(octyloxy)-1,1′:3′,1″-terphenylene) (P3), were characterized for their thermal and optical properties. The synthesized polymers had good solubility in organic solvents and were stable up to 350 °C. The molecular weights of the synthesized polymers were in the range 4370–10,900 Da with polydispersity range 1.52–1.65, which were measured by the gel permeation chromatography technique. The optical properties of these polymers showed absorptions in solution at around 400, 329, and 345 nm for P1, P2, and P3 polymers, respectively. The photoluminescence emission maxima of the polymers were at around 461 nm with a shoulder 439 and 424 nm for P1, P2, and P3, respectively. Photoluminescence emission of films of these polymers showed minimum redshift (20 nm) when compared with spectra of their solutions. The optical and photoluminescence emission properties of these polymers were found to vary on the backbone structure.

In the present work, a siloxane based flexible substrate for optoelectronic applications with improved flexibility and high temperature withstanding capacity has been fabricated and the details are reported. The structural and optical properties of the substrate were characterized and the optical transparency is found to be about 90% − 95% in the visible region. The substrate withstands temperatures up to 300 °C without significant degradation and has a low thermal coefficient of expansion. Fourier transform infrared spectral data show the materials in the prepared substrate and SEM studies show the surface and cross-sectional characteristics of the substrate. It has good mechanical strength, can withstand a high breaking load of 7 N, has a average tensile strength of 48.86 MPa and high average tensile modulus of 127.32 and also possesses excellent surface smoothness and resistance to both chemical and moisture with better rigidity; it will be a long lasting alternative for flexible plastic substrates. The optical characteristics such as refractive index (n) and extinction coefficient (k) are also reported. © 2016 Society of Chemical Industry

Organic Light Emitting Diode (OLED) has major applications in the field of displays, lighting and visible light communication. Due to the advantages of low cost, light weight, low power and high efficiency, flexible organic light emitting diode have attracted the interest of researchers all over the World. Flexible OLEDs are considered to be the best suitable candidate for next generation lighting devices. In this research, a new flexible and transparent substrate with an average transmittance of 60-70% in the visible region (300-700nm) is synthesized with the help of organic materials such as tetraphenylphosphonium modified lithium saponite (TPP-LiSA), Synthetic Saponite (SA) and N, N-dimethylformamide (DMF). The as-synthesized substrate exhibits refractive index as close as glass which makes this substrate to be used for flexible displays. Characteristics such as extinction coefficient (k), absorption of the synthesized substrate are also calculated.

Graphitic carbon continues to dominate as the choice anode material in lithium-ion batteries despite its theoretical specific capacity of 372 mAhg −1 . Tailored forms of graphite with higher practical capacities should, therefore, be of interest to the industry. This paper reports the production of a kish graphitic anode material from polyvinyl chloride by simultaneous carbonization of the polymer and dissolution of the resulting carbon in an iron melt to produce a supersaturated solution of carbon in iron, and subsequent precipitation of the carbon as graphite upon cooling. Our study presents a process for converting non-biodegradable plastic wastes that litter our surroundings into a technologically useful product. The new material exhibits a first-cycle reversible capacity of 444 mAhg −1 and sustains at least 200 cycles at C/10 rate before its capacity drops below 372 mAhg −1 .

Cross-linked polymer (CLP) composed of poly(ethylene glycol) methyl ether acrylate and poly(ethylene glycol) diacrylate has been used in synthesizing gel electrolyte. A set of electrolyte samples was synthesized using gel casting method by varying the weight percentage ratio of cross-linked polymers from 2–14 % in an incremental order (2 %) with respect to poly (ethylene oxide) (PEO) and evaluated its performance by employing in the fabrication of dye-sensitized solar cells. The synthesized polymer was subjected to different analytical techniques such as NMR, TGA, DSC, GPC, and FTIR to confirm the materials. The molecular weight of the CLP has been measured using GPC and the obtained value is found to be 3.655 KDa with polydispersity of 1.94. The CLP-PEO gel electrolyte with 10 % weight ratio has obtained the highest ionic conductivity of 3.07 × 10−6 S/cm−1 at room temperature and best photo-conversion efficiency of 5.1 % was achieved for the same.

Fabrication of quasi solid state dye sensitized solar cell with a stable gel electrolyte employing poly(ethylene oxide) (PEO)-poly(ethylene glycol) (PEG) is reported in this paper. PEO-PEG with either one of alkali iodides (LiI or NaI or KI), 1,2-dimethyl-3-propyl imidazolium iodide (DMPI), 4-tertbutylpyridine (TBP) and iodine in acetonitrile were used for the gel electrolyte preparation. The ionic conductivity and the triiodide diffusion coefficient of the gel electrolytes were measured by Electrochemical Impedance Spectroscopy. The photoconversion efficiency of gel state DSSC with NaI was found to be 5.4% at 100 mW/cm 2 with AM 1.5 Gfilter. When nanocrystalline TiO 2 was used as the filler in the gel electrolyte, the photoconversion efficiency was found to be increased up to 6.3%. The quasi solid state DSSC retained its initial value for 600 hours aging under ambient conditions.

An effectual functionalized synthetic resin involving anthranilic acid/4-nitroaniline/formaldehyde was synthesized for the detoxification of hazardous metal ions. The resin was characterized by Fourier transform infrared, 1H, and 13C nuclear magnetic resonance spectroscopy, and its morphology was established through scanning electron microscope and X-ray diffraction. The resin was analyzed by thermogravimetric analysis to assess the thermal stability, in which the resin could be used in high temperature aqueous solutions for the elimination of harmful metal ions. The ion-exchange property of the resin was evaluated by batch technique for specific metal ions viz. Fe3+, Co2+, Ni2+, Cu2+, Zn2+, and Pb2+. The study was extended to three variations such as effect of metal ion uptake in the presence of various electrolytes in different concentrations, effect of pH, and effect of contact time. The outcome proved that the resin can be used as a strong cation-exchanger to remove various metal ions from the solutions. The resin could be regenerated and reused with quantitative recovery of metal ions for few cycles. On comparison with the earlier reported resins, the synthesized resin has found excellent capability of metal ion recovery. The resin possesses an utmost ion-exchange capacity, which is in good harmony with isotherm models and kinetics. Copyright © 2015 John Wiley & Sons, Ltd.

White light emitting alkali metal ion co-doped single host lattice phosphors Sr 2.955 B 2 O 6 :0.02Ce 3+ , 0.005Eu 2+ , 0.02A + [A=Li, Na and K] were synthesized by high temperature solid state reaction. The synthesized phosphors were characterized by powder X-ray diffraction and Fourier transform infrared spectroscopic techniques. The optical properties were studied using diffuse reflectance UV–vis reflectance spectroscopy and photoluminescence (PL) spectroscopy. The role of Ce 3+ as a sensitizer of Eu 2+ was found from PL excitation results. The PL white light emission depends on the nature of co-doped alkali metal ion charge compensator.

Five new polymers were synthesized by Suzuki coupling reaction using 9,9-dihexylfluorene-2,7-diboronic acid and 3,3′-dibromo-4,4′-dialkoxybiphenyl as the starting materials. The synthesized alternating copolymers were characterized using gel permeation chromatography, 1H and 13C NMR, FT-IR, optical absorption and emission spectroscopic techniques. The thermal behavior of these polymers was analyzed using thermal gravimetric analysis and temperature modulated differential scanning calorimetric studies. The thermal studies show all the polymers were stable up to 300 °C and the glass transition temperature depends on the alkyl chain length. All the polymers have absorption around 330 nm in solution as well as in film, whereas the polymers have emission around 390 nm in both solution and film. Absorption and emission properties of the synthesized materials are not significantly different in solution, but are dramatically different as thin films at different annealing temperatures.

A novel terpolymer involving 2-amino-6-nitrobenzothiazole and ethylenediamine with formaldehyde was synthesized by a polycondensation technique using glacial acetic acid as a reaction medium. The resulting chelating terpolymer resin was characterized using elemental analysis, physicochemical parameters, and UV-visible, Fourier transform infrared, 1H NMR and 13C NMR spectral studies. Average molecular weights of the terpolymer were determined using gel permeation chromatography. The surface morphology and the nature of the terpolymer were investigated using scanning electron microscopy and X-ray diffraction. The chelation ion-exchange property of the terpolymer was determined against some common metal ions such as Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Pb2+ using the batch equilibrium method. Effects of parameters such as the pH, contact time and various electrolyte concentrations were studied. The reusability of the terpolymer was checked in terms of its effective repeated usage. The results of the Langmuir and Freundlich adsorption isotherm models were best fitted with each other and the reaction kinetics followed pseudo second-order kinetics. The terpolymer showed good results against Fe3+, Cu2+ and Ni2+ ions compared to those against the other metal ions. © 2014 Society of Chemical Industry

Electrochemical properties of FeNbO 4 as a lithium insertion anode material were studied with a view to understand structure–property relationships. Orthorhombic and monoclinic polymorphs of FeNbO 4 were synthesized and characterized by powder X-ray diffraction and laser Raman spectroscopy. Possible redox reactions, as deciphered from cyclic voltammograms, suggest the structural similarity between orthorhombic and monoclinic polymorphs upon lithium insertion. A coating of carbon led to a remarkable improvement in the electrochemical performance of monoclinic FeNbO 4 . The coated material exhibited an average reversible capacity of 125.5 mAh g −1 . The material also sustained hundreds of charge/discharge cycles and exhibited good rate capability. Upon coating with carbon, the monoclinic FeNbO 4 transformed into FeNb 2 O 6 . The conversion and stability were confirmed by powder XRD and laser Raman studies of carbon-coated material before and after 450 cycles. The in situ conversion of FeNbO 4 into FeNb 2 O 6 during carbon coating was further supported by EPR studies in which the absence of signal for the carbon-coated material indicated conversion of Fe 3+ to Fe 2+ . Our study reveals the possibility of exploring potential materials in the Fe–Nb–O system and enhancing their performance as anode materials for lithium-ion batteries.

For the first time, we are reporting the synthesis of Au100-xPtx nanoporous materials in the size range of 7-10 nm through the galvanic replacement of Ag by Pt from Au100-xAg2x spherical nano-alloys (x = 20, 15, 10 and 5) in an aqueous medium. The galvanic replacement reaction follows the 'Volmer-Weber' growth mode, resulting in the formation of surface bound platinum islands on a nanoporous gold surface. The high angle annular dark field image and low angle X-ray diffraction studies confirm the presence of nanoporous Au100-xPtx NPs. The electrochemical studies using the Au85Pt15/C catalyst show excellent methanol tolerance behaviour and better performance towards oxygen reduction reaction (ORR) in terms of high mass activity, mass-specific activity and figure of merit (FOM) when compared to HiSPEC Pt/C commercial catalyst. Preliminary studies on a full cell using nanoporous Au85Pt15/C (loading 1.0 mg cm(-2)) as the cathode material and Pt-Ru/C (loading: 0.5 mg cm(-2)) as the anode material performed better (38 mW cm(-2)) than the HiSPEC Pt/C cathode material (16 mW cm(-2)).