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In the present study, bituminous concrete mixes were prepared by adding Zycotherm as modifier and Sulphur as an extender. The physical properties of bitumen blended with Zycotherm and Sulphur were evaluated. For preparing the hot mix asphalt specimens, bitumen was modified with 0.05%, 0.1% and 0.15% of Zycotherm. Sulphur was used as an extender and its percentage was fixed at 35%. Comparison was made between the optimum binder content (OBC) of mixes prepared with neat and modified bitumen prepared using the Marshall mix design. For this purpose, a total of 8 type of asphalt mixtures were made. The OBC was determined and other parameters such as Marshall stability, flow value, voids filled with bitumen (VFB), voids in mineral aggregates (VMA) and unit weights were evaluated at this binder content. Based on the above experimentation and testing, it was concluded that the aggregates and bitumen (virgin and modified) results satisfy the standard requirements and the results are within the specified limits. In terms of physical properties, bitumen containing Sulphur results in changes up to large extent compared to Zycotherm modified bitumen. Addition of Zycotherm results in minor change in the physical properties of bitumen but the incorporation of 0.1% Zycotherm with 35% Sulphur, indicates the utmost Marshall stability and Marshall quotient value at the optimum binder content of 5.43 %.

Static investigation of slim to tolerably thick composite plate built up by single-walled cabon nanotubes (CNT) is examined utilising the limited component technique dependent on higher order zigza...

Geopolymer concrete is gaining a lot of attention among researchers across the globe due to its potential contribution to sustainability. Several studies have considered the use of geopolymer concr...

Concrete is a building material widely used in construction due to its excellent mechanical properties such as compressive strength and bond strength with steel reinforcement. Strength and durabili...

The paper focuses on the review of different techniques for minimization of energy consumption by increasing the heat transfer enhancement in the heat exchangers, which are being used in several fields like solar air heaters, automobile radiators, condenser, and evaporators of power plant units, refrigeration unit, steam turbines, etc. There are several techniques to enhance the heat transfer, and all are classified under Active and passive methods. In Active methods, there is the use of an external power source, while in passive methods the modification of the inner surface of the heat exchanger is made by using inserts, etc. In both, the processes increase in heat transfer also cause the subsequent increases in friction factor causing more pumping power requirement. The present review work presents the various active methods and materials that are used to enhance the heat transfer while keeping the friction factor as low as possible. The new techniques like electroactive and magnetic material are also discussed in the article which enhances the rate of heat transfer in combination with passive methods. The Electrohydrodynamic method shows an increase in heat transfer by 20 times as compared to only 3 times increase in friction factor while using vibration the increases in heat transfer is by 97%. The magnetic material has increased the Nusselt number in combination with the passive technique by 10%.

In the present scenario steel is the frequently used material for industrial applications. Steel is available in different grades in the market also the mechanical properties of AISI 1045 steel can be changed by proper heat treatment processes. A controlled sequence of heating and cooling arrangement is often used to change the physical and mechanical properties of AISI 1045 steel according to the application where it must be used. In the present study, AISI 1045 steel has been selected to analyze the effect of the heat treatment process on its hardness, strength, and toughness as this grade is used in numerous engineering applications nowadays. The AISI 1045 steel is treated by Annealing (Furnace cooling), Normalizing (room temperature), and Quenching (water). Then the samples were tested for hardness, tensile strength, and toughness (Charpy test). The results show that the tensile strength decreases by 12.4%, 6.33%, and 2.29% in annealing, normalizing, and quenching, respectively. The hardness decreases by 20.2 and 9.6% for annealing and normalizing respectively whereas it increases by 19.15% in quenching. It is also found that the toughness increases by 26.67% in normalizing whereas a reduction of 4.0% and 6.67% is noticed for quenching and annealing, respectively.

A low-disorder, two-dimensional electron system (2DES) subjected to a large perpendicular magnetic field and cooled to very low temperatures provides a rich platform for studies of many-body quantum phases. The magnetic field quenches the electrons' kinetic energy and quantizes the energy into a set of Landau levels, allowing the Coulomb interaction to dominate. In excited Landau levels, the fine interplay between short- and long-range interactions stabilizes bubble phases, Wigner crystals with more than one electron per unit cell. Here, we present the screening properties of bubble phases, probed via a simple capacitance technique where the 2DES is placed between a top and a bottom gate and the electric field penetrating through the 2DES is measured. The bubbles formed at very low temperatures screen the electric field poorly as they are pinned by the residual disorder potential, allowing a large electric field to reach the top gate. As the temperature is increased, the penetrating electric field decreases and, surprisingly, exhibits a pronounced minimum at a temperature that appears to coincide with the melting temperature of the bubble phase. We deduce a quantitative phase diagram, as a function of Landau level filling factor (\ensuremath{\nu}) and temperature, for the transition from the bubble to liquid phases for $4\ensuremath{\le}\ensuremath{\nu}\ensuremath{\le}5$.

Particle packing density mainly influences the behavior of concrete. Experimental determination of particle packing density is arduous and time-consuming. Thus, artificial neural network (ANN) is a tool that helps in determining particle packing density faster and accurately. ANN is used to predict the properties of the concrete with natural aggregates only. However, utilization of alternative fine aggregates is a need of hour. The aim of this paper is to apply ANN to predict particle packing density of combined aggregates, viz. coarse, intermediate and fine aggregates. In addition, alternative fine aggregates, namely crushed rock sand (CRS), recycled fine aggregate (RFA) and coal bottom ash (CBA) are used. In this study, the main constraints used to design ANN are size distribution and packing density of individual aggregates. Feedforward network is used to determine particle packing density of combined aggregates. A total of 231 experimental datasets are used to train ANN for each alternative fine aggregate, and the results were compared. It was observed that the error percentages are well below 5% of experimental and ANN optimization analyses. The optimum packing proportions for river sand, CRS, RFA and CBA were 40:20:40, 30:30:40, 30:30:40 and 30:20:50, respectively.

Conducting polymers namely polyaniline (PANI), polypyrrole (PPy) and their copolymer poly(Aniline-co-Pyrrole)(PAPY) were prepared via in-situ polymerization process. The X-ray diffraction (XRD), infra-red (IR)and field emission-scanning electron microscopy (FESEM) studies confirm the formation of polyaniline, polypyrrole and their copolymer with aniline and pyrrole. The XRD pattern of copolymer displayed an amorphous structure as compared to polycrystalline homopolymers. FE-SEM results of Poly (Ani-co-Py) shows the existence of agglomerated spherical structured particles in the copolymer matrix, while the polyaniline and polypyrrole exhibit the porous tubular and spherical structures, respectively. Thermo gravimetric analysis (TGA) shows that the copolymer is more stable as compared to their homopolymers at higher temperature. Four probe resistivity (FPR) studies indicate that copolymer has the lower conductivity and act as a diode. Vector network analyzer (VNA) measurements observe a significant shielding effectiveness (SE) for all the conducting polymers.

This research investigated the thermal conductivity of Adobe mixed with Quartz in view of their availability usage as building materials. The thermal conductivities of disc made from Adobe-Quartz chippings were determined. The values of the thermal conductivities obtained were between 0.6Wm-1k-1and 0.9Wm-1k-1, these values could be used to identify Adobe/Quartz as one of the engineering materials used in building construction. Adobe/Quartz was prepared in discs form of the same diameters and thicknesses and was also compressed under the same pressure of 15 atmospheres (100: 0, 95: 5and 80: 20). The average values of the thermal conductivities were between 0.07Wm-1Ҡ-1 and 0.93Wm-1Ҡ-1, for sample contained the proportion of (80:20) and the sample of ratio (95:5). MATLAB 7.0 and EXCEL software were used in the various computations, especially in determining dT/dt, Root mean square error (RMSE), Curve fittings parameter and the correlation coefficient, R2. An average correlation coefficient of 0.78 was existed between Adobe-Quartz ratio and thermal conductivity. The equation, y = -0.11x2 + 0.01x + 1.03 is the general equation that can be used for the prediction of average thermal conductivity at various ratios. Where y is the average thermal conductivity and x here signifies the ratios. This also indicates that compacted Adobe-Quartz of low density will be a suitable thermal insulator when used as aggregates in walls.

The scope of present study is to assess the suitability of locally available waste products such as wood ash as a soil admixture to improve the engineering properties of frost-affected subgrade soil against the seasonal freezing–thawing effects. The proctor compaction analysis was carried out to evaluate the OMC and MDD of the frost-affected soil treated with wood ash and cement. Freezing–thawing effect on the hydraulic conductivity and strength was evaluated by falling head permeability method and UCS tests, respectively. The prepared samples were frozen at -18 °C for 24 h, and then, it was allowed to thaw at room temperature for 24 h to complete one cycle. Several freezing and thawing cycles were performed for each mixes. In this study, the frost-affected soil was treated with cement and wood ash with percentage varying from 2%, 4%, 6% for cement and 5%, 10%, 15%, 20% for wood ash, respectively. It was found that addition of wood ash increases the OMC and decreases the MDD, but when it was treated with cement, only OMC decreases, and MDD increases. After application of two cycles of freezing–thawing, the coefficient of permeability of soil was found to be zero or no voids with the mix proportions of S + 4% C + 20% WA. From the UCS tests, it was observed that parent soil, S + C and S + WA mixes show decrease in strength when subjected to freeze–thaw cycles compared to S + 4%C + 20%WA mix which shows higher UCS value after several freeze–thaw cycles.

In the present work, the structural and optical properties of the pristine and argon (Ar) ion irradiated RF-sputtered ZnO thin films have been studied using X-ray diffraction (XRD), UV–visible spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The ion irradiation was performed at a constant fluence of 5 × 1015 ions/cm2, and the incident ion energy was varied from 300 keV to 1 MeV. The XRD pattern of the pristine ZnO film shows amorphous-like behavior, whereas ion irradiated films exhibit the evolution of hexagonal wurtzite structure along c-axis (002) orientation at higher energies. The crystallinity of the films was found to improve with the ion irradiation at increased energy, and the crystallite size varies from 5.4 to 23.0 nm. The surface features of the pristine and ion irradiated films were recorded by SEM and AFM both. The 3 D images show growth of cone-like structure with enhanced energy-dependent ion irradiation. However, beyond 800 keV, dissolution of grains was noticed. With UV–visible spectroscopy, the transparency of the films was noticed to decrease with increasing the incident ion energy, and the optical band gap as measured using Tauc plots was found to vary from 3.31 to 3.26 eV. With chosen incident ion energies, viz. 300 keV, 550 keV, 800 keV, and 1 MeV, the ratio of the electronic to nuclear energy loss (Se/Sn) takes the value of 1, 2, 3, and 4 as deduced using SRIM Monte-Carlo simulation program and, and this provides us a probe to verify the synergistic effect of ion irradiation in tailoring the properties of ZnO. The ion-induced tunability of the structural and optical properties in such oxide films facilitates the wide range of applications mainly the piezoelectric transduction mechanism and fabrication of optoelectronics devices.

An experimental programme was undertaken to investigate the performance of rubber modified bituminous mixes by using rubber as an aggregate, bitumen modifier and filler. The research was carried out in three stages. In the first stage, bitumen was modified by blending it with 5, 10, 15 and 20% (by weight of bitumen) crumb rubber (75–150 µ). In the second stage, fine aggregates in bituminous mixes were replaced with 2.5, 5, 7.5 and 10% rubber aggregates (

In this paper, we investigated the effect of film thickness on structural, surface morphology and optical properties of ZnO thin films grown by pulsed laser deposition (PLD) method. Thickness of the films was varied by keeping all other PLD parameters same to investigate thickness dependence on the structural and optical properties of ZnO thin films. The prepared thin films have been characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), UV- visible (Uv–Vis) and photoluminescence (PL) spectroscopy. XRD confirms the formation of crystalline c-axis orientated hexagonal wurtzite structure of ZnO thin films. AFM depicts that roughness and grain size of the ZnO films increase with increase in the films thickness. The direct optical band gap of the ZnO films calculated using Tauc's plot increase from 3.28 eV to 3.34 eV as the thickness of the films varies from 55 nm to 220 nm. The high quality c-axis orientated ZnO thin films with minimum strain and tuneable optical properties could be used as a transparent conducting oxide (TCO) for optoelectronic applications.

Present work reports on the synthesis of 2-dimensional (2D) CuO nanostructures with enhanced NO2 gas sensing properties by a facile solvothermal method. 2D CuO nanostructures were investigated usin...

Fibres are used in concrete to improve its structural integrity. Nowadays, among all basalt fibres, an inert mineral fibre is gaining more importance due to its exceptional properties, which include resistance to corrosion and low thermal conductivity. It also improves tensile strength, flexural strength and toughness of concrete. It can be used to extend the life of important concrete structures such as nuclear power plants, highways, bridges and runways. Basalt fibre in concrete is still an exploratory area due to limited studies. Therefore, a systematic study on basalt fibre-reinforced concrete was carried out with percentage volume fraction of fibre 0.50 (13.0 kg/m3), 0.75 (19.5 kg/m3) and 1.00 (26.0 kg/m3). The increase in compressive, splitting tensile and flexural strength is in the order of 26.79, 42.71 and 44.06%, respectively, for 0.50% dosage of basalt fibre as compared to control concrete. In addition, basalt fibre is found to be amorphous and hydrophilic in nature.

Cubic Cu2−x SnxO (0 ≤ x ≤ 0.4) nanostructures have been developed with the solvothermal method. X-ray diffraction data analysis confirms the formation of a pristine Cu2O phase below $x = 0.3$ Sn2+ substitution, and SnO-related phases appear in 0.3 substitute sample indicating phase segregation starts at $x \ge 0.3$ . The magnetization versus applied field (M − H) curves have been determined using a vibrating sample magnetometer at 300 K which reveals that ferromagnetic behavior of synthesized nanomaterials is reliant on the substituent concentration and enhanced gradually with its addition in the material. Photoluminescence spectra show that ferromagnetism originates from the induced magnetic moment in defects created as cation vacancies in the host material. Beside these, the dielectric measurements were performed at various frequencies (20 Hz–1 MHz) and in the temperature range of 100 to 350 K.

In the present paper, we have successfully synthesized Ag ZnO nanocomposite thin films by RF-magnetron sputtering technique at room temperature. Systematic investigations of thermal-induced structural and optical modifications in Ag ZnO thin films have been observed and described. The Ag ZnO thin films were annealed at three different temperatures of 300 °C, 400 °C and 500 °C in vacuum to prevent the oxidation of Ag. The presence and formation of Ag nanoparticles were estimated by transmission electron microscopy. X-ray diffraction analysis revealed the structural information about the crystalline quality of ZnO. The crystallinity as well as the crystallite size of the films have been found to be improved with annealing temperatures. The estimated crystallite size was ∼15.8 nm for as-deposited film and 19.0 nm for the film at a higher temperature. The chemical composition and structural analysis of as-deposited film were carried out by X-ray photoelectron spectroscopy. A very sharp absorption band appeared at ∼540 nm for Ag NPs that is associated with the surface plasmon resonance band of Ag. A noticeable red shift of about ∼12 nm has been recorded for films annealed at 500 °C. Atomic force microscopy has been utilized to examine the surface morphology of the as-deposited and annealed films. The grain size was found to be increase with increasing annealing temperature, while no significant changes were observed in the roughness of Ag ZnO thin films. Raman spectroscopy revealed lattice defects and disordering in the films after the thermal annealing.

Polymer materials synthetic fibers, for example, glass and carbon gives point of interest of high stiffness and strength to weight proportion when compare with conventional construction materials, for example wood, cement and steel. The accessibility of natural fibers and comfort of manufacturing have attempted researchers to try locally accessible inexpensive fibers and do study for their feasibility of strengthening purpose. Accordingly, many researchers do broad study on the properties of polymer matrix composite. The synthetic fiber substituting with the natural fiber for example, jute, sisal, pineapple and bamboo. The natural fiber removed by retting and manual procedures were exposed to soluble base treatment. this study is concerned with the investigation of mechanical properties of Grewia Optiva and jute fiber with epoxy resin matrix-based polymer composites. study investigate the tensile, bending and abrasion behavior of composites material made by grewia optiva and jute into epoxy resin. result shows that the better tensile strength of Grewia optiva fiber composite.

Magnetic nanocrystalline NiFe2O4 nanoparticles of size ranging between 13 and 19 nm were synthesized by the hydrothermal method using polyethylene glycol (PEG) as surfactant. The role of annealing on phase, crystallite size, and morphology was determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Energy-dispersive X-ray spectroscopy (EDX) was used for qualitative analysis. X-ray diffraction confirmed the single phase of as-obtained particles. TEM revealed a spherical morphology having an average particle size of 13.73 nm at 523 K and rises to 14.89, 16.42, and 21.14 nm at 623, 723, and 823 K respectively, which is approximately the same as the crystallite size determined from XRD. EDX results confirmed that elemental ratios were in stoichiometry. Fourier transform infrared (FTIR) spectral analysis demonstrates the formation of M-O bond in NiFe2O4 nanoparticles. The optical spectra obtained from UV-visible spectroscopy revealed that nanoparticles have direct allowed energy band gap of 2.34, 2.47, 2.70, and 2.20 eV at 523, 623, 723, and 823 K respectively. A vibrating sample magnetometer (VSM) was used at room temperature for magnetic measurements which further showed ferromagnetic behavior of as-synthesized material. In addition, it was found that saturation magnetization increases with an increase of annealing temperature while coercivity decreases with temperature.

Historically chromite was used as a component in magnesia chrome refractory due to its high flexible character (low modulus of elasticity). But use of magnesia chrome bricks in the sintering zone of cement rotary kiln causes environmental pollution due to the formation of Cr6+ compounds. To meet the above challenge and operational demands due to increased use of alternative fuels, now-a-days iron-alumina or hercynite spinel is being used instead of chromite as chrome free material. Till date hercynite is rarely available in nature and electro-fusion is the main process of manufacturing hercynite in the industry. However, the main drawbacks of electrofusion process are time and energy consumption. This paper describes the synthesis of hercynite by plasma fusion, which is a new, faster and economic process, and also its refractory properties for application in cement rotary kiln. Bulk density of plasma fused hercynite is 3.86 g.cm–3 and thermal expansion at 1000°C is 0.85%. The developed magnesia he...

In India, chromite is used for making magnesia chrome bricks due to its low modulus of elasticity. But the use of magnesia chrome bricks in the sintering zone of cement rotary kilns causes environmental pollution due to the formation of Cr+6 compounds. In order to meet the above challenges and to satisfy the operational demands due to use of alternative fuels, now-a-days, galaxite spinel is being used in place of chromite as a chrome free material. Galaxite is not available in nature and electro fusion is the main process by virtue of which it is industrially manufactured. However, the main drawback of electro-fusion process is both time and energy consumption. In such a backdrop, the present work has been carried out which describes the synthesis of galaxite by plasma fusion process and also the characterization of its refractory properties for application in cement rotary kilns. This alternative process is absolutely new, faster in approach and also economically viable. The developed magnesia galaxite brick shows higher performance rate and is also economically cost effective as compared to the conventional magnesia chrome and magnesia galaxite bricks, presently available in the market.

In the present work, swift heavy ion (SHI) irradiation induced modifications in structural and optical properties of Ag-ZnO nanocomposite thin films have been investigated. Ag-ZnO nanocomposite (NCs) thin films were synthesized by RF magnetron sputtering technique and irradiated with 100 MeV Ag7+ ions at three different fluences 3 × 1012, 1 × 1013 and 3 × 1013 ions/cm2. Rutherford Backscattering Spectrometry revealed Ag concentration to be ∼8.0 at.%, and measured thickness of the films was ∼55 nm. Structural properties of pristine and irradiated films have been analyzed by X-ray diffraction analysis and found that variation in crystallite size of the film with ion irradiation. X-ray photoelectron spectroscopy (XPS) indicates the formation of Ag-ZnO nanocomposite thin film with presence of Ag, Zn and O elements. Oxidation state of Ag and Zn also estimated by XPS analysis. Surface plasmon resonance (SPR) of Ag nanoparticle has appeared at ∼475 nm in the pristine thin film, which is blue shifted by ∼30 nm in film irradiated at fluence of 3 × 1012 ions/cm2 and completely disappeared in film irradiated at higher fluences, 1 × 1013 and 3 × 1013 ions/cm2. A marginal change in the optical band gap of Ag-ZnO nanocomposite thin film is also found with increasing ion fluence. Surface morphology of pristine and irradiated films have been studied using Atomic Force Microscopy (AFM). Raman and Photo-luminance (PL) spectra of nanocomposite thin films have been investigated to understand the ion induced modifications such as lattice defects and disordering in the nanocomposite thin film.

Aceclofenac is one of the commonly used Nonsteroidal anti-inflammatory drugs representing the variety of therapeutic applications including management of pain, inflammation, rheumatoid arthritis, and osteoarthritis, etc. But very low solubility and dissolution rate of aceclofenac compromise its therapeutic effectiveness. So, current work focuses on the improvement of solubility and dissolution of aceclofenac by the cocrystal approach. Aceclofenac was screened with various coformers selected from Generally Recognized as Safe and Everything Added to Foods in the United States list using Molecular orbital package 2016 software to find out novel cocrystals of aceclofenac with improved biopharmaceutical properties. Novel cocrystals of aceclofenac with urea were synthesized by mechanochemical grinding method. The synthesized cocrystals (Aceclofenac-Urea neat grinding and Aceclofenac-Urea liquid assisted grinding) were characterized carefully by Differential scanning calorimetry, infrared spectroscopy and powder X-ray diffraction to verify the formation of the cocrystals. Pharmaceutically significant properties such as powder dissolution rate, solubility, and stability of the synthesized cocrystals were evaluated. Compared to aceclofenac, the synthesized cocrystals showed improved solubility and dissolution rate. The synthesized cocrystals were found to be non-hygroscopic and stable under ambient conditions.

Tungsten-based (W-based) nanoparticles are produced through electrochemical spark erosion process. In this investigation, the parametric effects of voltage, tool rotation and pulse on time on production rate of W-based nanoparticles are analyzed. The shape and size of the produced nanoparticles are controlled through proper controlling of the referred parameters. Small size particles are obtained with low voltage and pulse on time, but with high tool rotation speed. The ANN-predicted values of this study are in close agreement with the observed experimental values for all the test formulations. It can be concluded that the process optimization via ANN modeling has been found to be very efficient for determining the performance linked with the electrochemical spark erosion process. The devised neural network provided an average prediction error of 1.52% for training and 3.78% in case of testing. The formulated models can predict results which are in close agreement with the test results. The produced W-based nanoparticles are used for sensing the NO2 and CO2 gases.

We report on the enhanced near-band edge emission with negligible defect-assisted emission in ZnO nanocrystalline thin films of varying thickness on c-sapphire substrates. X-ray diffraction studies reveal wurtzite structure of thin films grown preferentially along (002) plane. The crystallinity and grain size of the deposited films have been increased with increase in film thickness. The band gap of the films was calculated by Tauc’s plot which shows negligible change in band gap with increase in thickness of ZnO film. The various Raman modes observed in ZnO thin films of different thicknesses support the formation of hexagonal wurtzite structure. The room temperature photoluminescence (PL) spectrum shows the strong near-band edge emission in the wavelength range 378–381 nm which further enhances with film thickness. The enhanced PL emission in near ultraviolet visible (UV) region with negligible defect-assisted emission may find potential applications in ZnO-based UV-excited light-emitting diodes.

This paper discusses the effect of defects and role of charge carriers in setting up the long range magnetic order in Mn doped 3C-SiC. Using complementary experiments like temperature variation of Electron Spin Resonance (ESR) and DC magnetic susceptibility, the nature of magnetic interactions, spin dynamics and anisotropy have been investigated. The variation of ESR parameters such as, g value, peak to peak line width ( Δ H pp ), spin density ( N s ) and spin–spin relaxation time ( T 2 ) as a function of temperature and dopant concentration confirms the presence of exchange interaction present in the system. The decrease in resonance field H r as a function of temperature indicates the strengthening of internal field already existing in Mn doped 3C-SiC samples. This result confirms that defect induced magnetism could be enhanced by introducing holes in to the host wide band gap semiconductor.

Cu doped ZnO (Cu–ZnO) nanocomposite thin films were successfully synthesized at room temperature by RF magnetron sputtering. The signature of Cu in pristine ZnO thin films was confirmed by Rutherford Backscattering Spectroscopy (RBS) with atomic concentration of ~10%. The Cu–ZnO thin films were irradiated with 800 keV Ar ion beam at three different ion fluences viz. 5 × 1015, 7 × 1015 and 9 × 1015 ions/cm2. As characterized by X-ray diffraction, the pristine and irradiated films show a hexagonal wurtzite structure with remarkable intensities of (100), (002) and (101) orientations. The surface morphology of the pristine and irradiated films was recorded using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The images clearly show the grain growth near the surface of films with increasing the ion fluences. The surface plasmon absorption (380 nm onwards) indicating the formation of metal nanoparticles in oxide matrices was confirmed by UV–visible spectroscopy of ion irradiated films. The electrical properties of the pristine and irradiated films were deduced by current voltage (I–V) and Hall measurements. The conductivity of the film increases as irradiation proceeds, achieves a maxima and then decreases with further processing of the ion beam. This study explores ion beam irradiation as a versatile tool to tailor the physical properties of nanocomposite thin films. Further, the properties can be precisely controlled by optimizing ion fluences and incident ion energy as well.

Defense organization is one of the most reputed organization where best of the officers and soldiers serve for the safety on one’s country, without complaining about anything and giving their all in to protect us from various threats that could lead to disintegration of the country. Thus, the main motive to develop this device is to help our defense services to get the best, while they are giving their best for the country. The idea is to develop a device that would counter the recoil of the gun used by the officers and soldiers, to make them more efficient. Keeping in mind that the renewable resources of energy are depleting at a fast pace and pollution is increasing day by day leading to global warming, we have taken air as our resource to produce the desired effect. The device would be developed using aluminium, compact single cylinder air compressor and arduino programming to measure the pressure required for each shot fired from the gun. The principles of Law of conservation of momentum are applied to reduce the recoil of the gun to 80 %, thus helping in better aiming and precision. By installing this device, the demerits that makes AK47 a primitive gun would be subdued and without buying the expensive advanced guns, the arsenal would be upgraded at minimal cost possible.

In the present study, 100 MeV Ag7+ ion beam-induced structural and optical modifications of nanocrystalline ZnO thin films are investigated. The nanocrystalline ZnO thin films are grown using radio frequency magnetron sputtering and irradiated at fluences of 3 × 1012, 1 × 1013 and 3 × 1013 ions/cm2. The incident swift heavy ions induced change in the crystallinity together with the preferential growth of crystallite size along the c axis (002) orientation. The average crystallite size is found to be increased from 10.8 ± 0.7 to 20.5 ± 0.3 nm with increasing the ion fluence. The Atomic force microscopy analysis confirms the variation in the surface roughness by varying the incident ion fluences. The UV–visible spectroscopy shows the decrement in transmittance of the film with ion irradiation. The micro-Raman spectra of ZnO thin films are investigated to observe ion-induced modifications which support the increased lattice defects with higher fluence. The variation in crystallinity indicates that ZnO-based devices can be used in piezoelectric transduction mechanism.

We herein demonstrate novel inorganic–organic hybrid nanoparticles (HNPs) composed of inorganic NPs, NaY0.78Er0.02Yb0.2F4, and an organic β-diketonate complex, Eu(TTA)3Phen, for energy harvesting applications. Both the systems maintain their core integrity and remain entangled through weak interacting forces. HNPs incorporate the characteristic optical behaviour of both the systems i.e. they give an intense red emission under UV excitation, due to Eu3+ in organic complexes, and efficient green upconversion emission of Er3+ in inorganic NPs for NIR (980 nm) excitation. However, (i) an energy transfer from Er3+ (inorganic NPs) to Eu3+ (organic complex) under NIR excitation, and (ii) an increase in the decay time of 5D0 → 7F2 transition of Eu3+ for HNPs as compared to the Eu(TTA)3Phen complex, under different excitation wavelengths, are added optical characteristics which point to an important role of the interface between both the systems. Herein, the ultra-small size (6–9 nm) and spherical shape of the inorganic NPs offer a large surface area, which improves the weak interaction force between both the systems. Furthermore, the HNPs dispersed in the PMMA polymer have been successfully utilized for luminescent solar collector (LSC) applications.

The aim of the present work to investigate the performance of oil derived from the waste plastic on diesel engine. Waste plastic fuel (WPF) is derived from the waste plastics by catalytic pyrolysis. Test were employed to completely characterize the Fuel by determining the physical, chemical and spectroscopic like FTIR, GC-MS properties of WPF and WPF-diesel blends in different proportions and to evaluate the performance and emission characteristics of these fuel and their blends on a single cylinder diesel engine and finally the results were compared with reference test fuel diesel. It is observed that the engine can operate with neat WPF and their blends without any modification and can be used as an alternative fuel for diesel engine. However, it is found that WPF10D90 (10% waste plastic oil and 90% diesel fuel) shows similar results as compare to diesel.

We have carried out a comparative study of upconversion (UC), photoluminescence (PL) and quantum cutting (QC) emission of three rare-earth activators (Tm, Pr and Tb) in the presence of Yb ion in La2O3 host. IR quantum cutting is of particular importance and has been observed on the principle of energy transfer from a particular lanthanide ion to Yb3+ ions. A UV/visible photon is splitted into two IR photons via the involvement of two Yb3+ ions. Phosphors were prepared by conventional solution combustion method and crystallizes into hexagonal phase of La2O3 having space group P63/mmc. Study summarizes that, La2O3 matrix is a potential host for different lanthanide ions, particularly Tm, Tb and Pr, to achieve the UC, PL and QC emission. The upper limit of NIR quantum cutting efficiency is observed maximum for Tm ion which is 180%, while Pr also gives a similar efficiency value (178%). The upper limit of NIR quantum cutting efficiency for Tb is relatively less (153%), however it is remarkably better than previous reported values. The material could be useful for different optical applications including for spectral modifications.

Hydrogen storage is a critical bottleneck to hydrogen economy. Presently none of the solid-state hydrogen storage materials (metal hydrides) reaches the capacity vs performance target (6.5 wt.% at 85 °C/5-12 bar, 1500 cycles) for the commercialization of light duty H2 fuel cell vehicles. A few reversible hydrogen storage materials (e.g. MgH2, LiBH4/MgH2 composite) possess adequate capacity, but their performance needs to be improved significantly. Metal oxide additives improve the hydrogen storage performance of metal hydrides, but the additive-hydride reaction mechanism remains not well understood. In this context, the present chapter discusses how various metal oxide additives interact with metal hydrides and facilitate the low temperature de/ab-sorption of hydrogen. The metal oxide additives may either directly catalyze the reaction without making any chemical changes or they catalyze indirectly by making active in situ products. In this chapter, various oxides and hydride combinations of the latter category are analyzed, and factors governing the improved hydrogen ab-/desorption performance are highlighted.

Mg(OH)2 and MgO nano particles having flake, like morphology have been synthesized using hydrothermal method. XRD pattern revealed the formation of hexagonal phase for Mg(OH)2 while cubic phase for MgO. SEM images shows the transformation of morphology from nanoflakes to nanoballs like shape upon change in crystal structure from hexagonal Mg(OH)2 tocubic MgO. Thermal decomposition and percentage weight loss were calculated through thermogravimetric analysis (TGA) and it is inferred that defects related to oxygen vacancies are responsible for the magnetic propertiesand the origin of d° ferromagnetism in these non-magnetic oxides.

The defect induced magnetism has initiated a lot of interest in field of spintronics. In this regard, SiC is a promising material because of its unique properties under extreme conditions. Hence it will be very much interesting to investigate the interaction between defects and itinerant carrier in doped SiC for spintronics application. We report the structural stability and magnetic interaction in Cr doped 3C-SiC synthesized by Thermal Plasma Technique. The EPR spectrum of undoped 3C-SiC shows a sharp resonance line corresponding to $g=2.00$ associated with the defects present in the system. Anomalous temperature evolution tendency of the relative intensity of EPR spectra can be attributed to magnetically correlated defects in the host matrix. For the first time we report the detailed quantitative analysis of X-band and Q-band EPR study in Cr doped 3C-SiC which reveals that Cr can be in multivalent state. The non monotonous variation of Longitudinal Mode (LO) of the Raman spectra has been explained based on the interaction between carriers and surface plasmon using Longitudinal optical plasmon coupling model (LOPC). The carrier density calculated by using LOPC fit with experimental data varies from $1.8\times10^{15}$ to $4.2\times10^{17}$ cm$^{-3}$. Room temperature magnetic measurements exhibit ferromagnetic behavior with non-zero coercivity for all the samples up to 7 T field. We, for the first time, show the Curie temperature to be above 760 K. Quantitative analysis of magnetic interaction validates the applicability of Bound Magnetic Polaron Model (BMP) which probably arises from the exchange interaction of Cr$^{3+}$ ions with related (Si, C) defects. The polaron density estimated from the BMP fit agrees well with the carrier density obtained from the line shape fitting of Raman spectra., Major revision, Title of the paper changed, 14 Pages, 50 Figures, 7 Tables

Fine powders of (Al2O3)100–x(SiC)x (0 ≤ x ≤ 50) composites were prepared by chemical route (named as pyrophoric technique) to achieve a uniform mixture of SiC in an alumina matrix. The chemically synthesized fine SiC/Al2O3 composite powders were sintered to form composites at 1450°C which is well below the sintering temperature of SiC. Sintering was performed in an argon atmosphere. Highly dense SiC/Al2O3 microstructures were achieved. An improvement in bulk density and hardness has been achieved for SiC/Al2O3 composites with 20 wt% of SiC. Hexagonal-shaped grains have been obtained in (Al2O3)50(SiC)50 composite with well-connected grain boundaries. The peak position of alumina in SiC/Al2O3 composites shifts toward lower wavenumbers in Fourier transform infrared spectroscopy and higher wavenumbers in Raman spectroscopy due to the incorporation of SiC in the composites. The optical band gap decreases with the addition of SiC and the composite behaves more like a semiconductor rather than an insulator. Thes...

A technique to determine the permeability from X-ray microtomographic images was developed and applied to paper structures. The images are thresholded and a skeleton of the pore space is obtained from the images. The skeleton is represented by means of a network of resistances. The total resistance of the network along the principal directions is now determined both in the in-plane (X, Y) as well as through the plane (Z) directions. The network resistance for structures at each section is determined. From this data, a correlation length for the network resistance is obtained. Correlation length data are used for determining the effect of heterogeneities on transport properties of paper structures. From this analysis, it is possible to analyze and simulate the moisture transport processes such as wicking and drying in paper, reproducing smaller-scale variations. Permeabilities in the thickness direction were calculated from the X-ray microtomographic reconstructions of the pore space. A set of pape...

The present study reports significant enhancement in the red upconversion emission of Er(3+) in NaSc0.8Er0.02Yb0.18F4 upconversion nanoparticles (UCNPs), via a two step process, (i) codoping of Gd(3+) ion at Sc(3+) site and (ii) attaching gold nanoparticles (AuNPs) at the surface of these codoped nanostructures, and further probes the use of these Gd:UCNPs@AuNPs for bioimaging application. The Gd(3+) codoping tailors the particle size (reduces) of UCNPs and bring out Er(3+)-Yb(3+) ion pair in close proximity, which promotes the cross relaxation mechanism and boosts the population in red emitting level (4)F9/2. Further, attachment of AuNPs on the surface of UCNPs gives 2-fold advantages, that is, reduction in green band (through resonance energy transfer with efficiency 31.54%) and enhancement in red band (through plasmonic effect). It gives red to green (R/G) ratio nearly 20:1 (almost single band red UC), which is quite promising for imaging application. In addition to this, codoping of Gd(3+) enhances the magnetic moment appreciably and the obtained magnetic moment for NaSc0.75Er0.02Yb0.18Gd0.05F4 UCNPs (∼1.7 emu/g) is close to the reported values for bioseparation in case of NPs. This shows the potential of the material for multimodal (optical and magnetic both) imaging application. These magnetoluminescence particles were found safe up to 1 mg/mL dose as assessed by cytotoxicity measurement in human cervical cancer (HeLa) and lung cancer (A549) cells. Ultrafine nanoparticles, transparent, and stable colloidal solution and the unique red UC emission endow these NPs as optical probe for imaging applications.

In the present investigation a new ternary ceramic matrix composite is developed from Indian fly ash by thermal treatment under reducing atmosphere. The ternary mixture, comprising of Al2O3-SiC-C, is formed by insitu conversion of SiO2 to SiC in the fly ash under reducing atmosphere. Analyses of the treated product by XRD, SEM, and EDAX have ensured formation of SiC from SiO2. Converted SiC are rod shaped whiskers with the aspect ratio ranging between 40 to 50. The ternary mixture is added to aluminum melt in a bottom pouring pit type resistance furnace for the preparation of novel aluminum fly ash metal matrix composite (ALFMMC). Physical and mechanical properties of the novel ALFMMC (treated fly ash) composite are evaluated. For comparison purpose, aluminum fly ash composite is prepared with (untreated flyash) under identical condition of melting and casting. Wear resistance is found to be superior for the novel composite.

In this report, ternary nanocomposite Polyaniline/Mg0.5Cu0.5Fe2O4 decorated with Ag particles has successfully synthesized. The synthesis route is based upon mixing the silver particles via the chemical oxidation polymerization of aniline monomer doped with ferrites in different weight ratio. This nanocomposite has been analyzed by XRD, TEM, TGA, and VSM for the crystalline, structural, thermal and magnetic properties. XRD and TEM confirm the formation of ferrites and polyaniline phases in the sample with silver particles. VSM characterization shows that the saturation magnetization of the Polyaniline/Mg0.5Cu0.5Fe2O4 composite decreases on coating with nanosilver particles. Thermogravimetric analysis reveals that the mixing of ferrites and silver nanoparticles in PANI has improved its thermal stability. These samples having good thermal, magnetic and conducting properties are expected to be useful in electromagnetic interference shielding applications.

Nanoemulsions are colloidal dispersion systems that are thermodynamically stable, composed of two immiscible liquids mixed along with emulsifying agents (surfactants and co-surfactants) to form a single phase. Nanoemulsions have extensively been investigated as drug delivery systems. This review aims to provide consolidated information regarding various formulation and characterization techniques developed for nanoemulsions. Nanoemulsions are formulated using two different methods, the persuasion method and the Brute force method. Various characterization techniques for nanoemulsions include determination of entrapment efficiency, particle size, polydispersity index, zeta potential as well as characterization through differential scanning calorimetry, Fourier-transform infrared spectroscopy and transmission electron microscopy. Nanoemulsions are further evaluated by studying in vitro drug release, in vitro permeation, stability and thermodynamic stability, shelf life, dispersibility, viscosity, surface tension, friccohesity, refractive index, percent transmittance, pH and osmolarity.

A study on the nigella seeds (Ajmer Nigella-1) was performed to investigate the effect of seeds moisture content on their physical properties as these are very important to design post harvest equipments. The physical properties of the nigella were evaluated as a function of moisture contents in the range of 5.2 to 25.1% dry basis (d.b.). Seed geometric parameters such as average length, width, thickness, geometric mean diameter, volume, increased with the increase in seed moisture, except seed sphericity and surface area, which remain unchanged as statistically non-significant. The 1000-seed mass increased linearly with increase in moisture. Bulk density and true density of nigella decreased when seed moisture content was raised from 5.2 to 25.1% d.b. The porosity of nigella increased up to 19.9% moisture content and then decreased slightly. The angle of repose and coefficients of static friction on four different surfaces (plywood, mild steel, galvanized iron and glass) and terminal velocity increased with seed moisture. Key words: Nigella sativa, physical properties, frictional properties, seed spices.