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L-Malic acid potassium bromide MAPB, a new semi organic material was synthesized successfully by solution growth method. Single crystal x-ray diffraction analysis reveals the cell parameters of the grown crystal and it crystallized in cubic system. The molecular structure of MAPB was identified by FTIR spectral analysis. The lower cut-off wavelength (λ = 272 nm), optical energy band gap (5049 eV) and Urbach energy (0.2381 eV) of MAPB crystal was determined by using UV–Vis-NIR spectral studies. The single electronic transitional band structure of the material was identified by photoluminescence spectrum. The various morphological formations on the grown crystal were analyzed by scanning electron microscope (SEM) study. The second order nonlinear optical properties of grown MAPB were measured by Kurtz and Perry powder technique. The thermal stability of MAPB crystal was studied by differential scanning calorimetric technique. The relative dielectric property was rigorously analyzed with various temperature ranges. Vickers micro hardness test suggest that the material belongs to soft material category. Z-scan study was employed to analyze the third order non-linear optical characteristics like refractive index (n2), the absorption coefficient (β) and third order susceptibility (χ3).

Composite materials have been employed major part in current era for its light weight, good stiffness, high specific strength and flexible nature. In this research, The hybrid composites of unsaturated polyester based Coir/Napier grass hybrid fiber are prepared. The hybrid composites were prepared in the following proportion of Coir/Napier grass 100:0, 75:25, 50:50, 25:75 and 0:100 ratios whereas overall fibre weight ratios were maintained at 0.4Wf. Coir/Napier grass fibers are united in the same matrix (unsaturated polyester) to prepare hybrid composites and the tensile, flexural and impact properties are studied experimentally. A significant improvement in tensile, flexural and impact properties of Coir/Napier grass fiber hybrid composites is found. The morphology of coir/Napier grass fiber hybrid composite was investigated using scanning electron microscope.

Difficult-to-machine materials like composites, super alloys and ceramics are cut by Abrasive water jet cutting (AWJC). However, the failure of the jet to cut through the work piece is a major issue particularly in thicker materials. The jet’s inability to produce longer smooth cut surface, minimum surface roughness and minimum kerf taper are the major challenges the researchers are trying to find solutions. This paper addresses the three issues in cutting of aluminum 7075 hybrid metal matrix composites. The hybrid composite is developed by incorporating two reinforcements (B4C and TiC) into Aluminum matrix. Cutting experiments were carried out on Pure AL7075, AL7075 + (2.5%B4C + 2.5%TiC), AL7075 + (5%B4C + 5%TiC)AL7075 + (7.5%B4C + 7.5%TiC). The surface generated, smooth cut region and kerf taper were analyzed on the all composite machined using AWJC machine.

This work presents the machinability study of copper alloys using Electro-chemical Micro-Machining (EMM) for conicity and material removal rate (MRR). Applied voltage (AV), duty cycle (DC) and electrolyte concentration (EC) is chosen as the control parameters. Experiments trails were investigated based on L9 Orthogonal Array (OA). The mathematical equation for conicity and MRR are developed using MINITAB software. Analysis of Variance (ANOVA) is performed for finding the most significant factor. Based on ANOVA, contribution for parameters A, B, and C on MRR are found to be 60.88%, 14.40%, and 13.30% respectively. The significant factor on MRR is AV which is found to be 60.88%. For conicity, contributions of factors A, B, and C were found to be 65.54%, 18.63%, and 03.37% respectively. The significant factor on concity is AV which is found to be 65.54%.

Various fields of engineering such as automobile, aerospace and construction industries are employs Aluminum alloys and its composites due to its high strength to weight ratio. But they possess poor wear resistance due to low hardness. In this research, shot peening treatment is used to enhance the wear resistance ability of the composites. Micro hardness and surface roughness of AL7075 Hybrid metal matrix composites are examined after shot peening treatment. For this, the aluminum alloy specimens are subjected to shot peening for 30, 60, 90, 120 and 150 s time. The results reveal that the shot peening treatment increases micro -hardness and surface roughness up to 90 s. The specimen after 120 s peening demonstrates the marginal improvement in micro hardness and slight reduction in surface roughness.

The nanoparticles are incorporated into the composite to mark their unique properties. This work investigates the hybrid epoxy nanocomposite and the impact of nanographite reinforcement. The composite was prepared by using a mechanical stirring technique. The amount of nanographite was added in different volumes, i.e., 1.0, 1.5, and 2.0 wt.%. Results of mechanical and dynamic loading properties were analyzed in accordance to the quantity of nano-G. The fiber and matrix interfacial bonding enrichments were evident in high-resolution SEM images-tensile fracture surface. Finally, the optimum content of nanoparticle which impacts the sample greatly was found to be 1.5 wt.%.

The progress of single crystal followed by C4H6O6 (tartaric acid) and BaCl2 (barium chloride) (TABC; third-order nonlinear optics semi-organic) was synthesized with slow evaporation method using distilled water at room temperature. TABC single crystal was introduced into various characterizations like X-ray diffraction to determine inter atomic cell parameter values. The samples are crystalline structure of monoclinic, which have space group of P2. The functional groups of the current material are identified using FT-IR spectrum. Optical parameters like transparency, energy bandgap and Urbach energy have been determined using UV–vis–NIR spectrum. The thermal stability of the material was investigated by differential scanning calorimeter analysis. The mechanical property was studied using Vickers microhardness test. The surface morphology of the material was determined by scanning electron microscope technique. The change in dielectric behaviour of TABC with respect to the function of frequency at various temperatures has been keenly absorbed and discussed. The third-order nonlinear optical parameters were measured using Z-scan analyses.

l-Malic acid sodium nitrate, a novel semi organic nonlinear optical crystal was grown from aqueous solution by slow evaporation method at room temperature. The cell parameters for the grown crystal were determined by using single crystal X-ray diffraction method. The different functional groups with different modes of vibrations were confirmed by FTIR spectral analysis. The optical absorption studies show that the crystal has wide optical transparency in the entire visible region. From UV absorption profile, the electronic optical band gap and Urbach energy is calculated as 5.0 eV and 0.1401 eV. The photoluminescence spectra exhibit different peaks to indicate the single transitional band structure and high purity of the grown crystal. The EDAX and SEM study shows the presence of elements in the grown crystal and growth of second layer over the surface. The second harmonic generation efficiency was confirmed by the Kurtz powder method using Nd:YAG laser with fundamental wavelength of 1064 nm. DSC study shows that the grown crystal was thermally stable up to 273 °C. The dielectric behavior of the grown crystal was measured in the frequency range 50 Hz–5 MHz at different temperatures. The Vickers micro hardness studies were carried out on the grown crystals and there by Vickers hardness number (Hv) and work hardening coefficient (n) were calculated.

Urea lead acetate, a novel semi organic non linear optical crystal having dimensions 16 × 8 × 8 mm3 has been synthesized using slow evaporation technique. The lattice parameters for the grown crystals were determined using single crystal XRD. The presence of functional groups for the grown crystals was confirmed using fourier transform infrared spectroscopy. The optical absorption studies show that the material has wide optical transparency in the entire visible region. The thermal analysis studies indicate that the material possess optimum thermal stability. The mechanical properties of the grown crystals have been studied using Vickers micro hardness tester for different loads. The second harmonic generation was confirmed by Kurtz powder method and it is found to be 0.8 times more than that of KDP crystal.

This article explores the extraction and characterization of natural fiber from the agro-waste of Lagenaria siceraria (LS)plant stem (commonly known as „bottle guard‟) for the first time. The extracted fiber from the waste stems has highcellulose content (79.91 %) with good tensile strength (257–717 MPa) and thermal stability (withstand up to 339.1°C). Theimmense percentage of crystalline index (92.4%) with the crystalline size (7.2 nm) as well as low density (1.216 g/cm3) ofthe LS fiber renders their possibilit

This research explores the extraction and characterization of natural fiber from the agro-waste of Lagenaria siceraria (LS) plant stem (commonly known as bottle guard). The extracted fiber from the waste stems has high cellulose content (79.91 %) with good tensile strength (257–717 MPa) and thermal stability (withstand up to 339.1°C). The huge percentage of crystalline index (92.4%) with the crystalline size (7.2 nm) as well as low density (1.216 g/cm3) of the LS fiber renders their possibility to use as an effective reinforcement material in lightweight eco-friendly composites for various industrial applications.

Graphene has drawn a great attention in the recent research innovations mainly due to its structural geometry, which is composed of one-atom thick planar sheet of hexagonally arrayed sp2 carbon atoms. Development of nanocomposites utilising graphene as the nanofiller offer desired properties to the added polymer matrix. Furthermore, incorporation of functional groups such as hydroxyl, epoxy, carboxyl, etc. on the basal plane of graphene enhances the interaction with the polymer matrices. Better interaction between the nanofiller and the polymer leads to exfoliation of the nanofiller in the matrices, which indeed significantly improves the physical, mechanical, thermal, electrical, electronic properties, etc., of the polymer. The review article explores the recent research findings on the development of polymeric nanocomposites utilising pure and functionalised graphene. The article focuses on the method of synthesis of graphene and functionalised graphene, followed by their characterisation methods and inferences. It also summarises the routes for the preparation of graphene and modified graphene-based polymer nanocomposites. The work highlights the enhancement of properties observed due to the addition of graphene and modified graphene to the polymer matrices. Several surface modifications done on GNS in order to achieve better dispersion of the same in the polymer matrix has been discussed. The review article portrays the recent research reports on graphene and modified graphene-based polymer nanocomposites. Techniques such as cryomilling, latex technology and lyophilisation as applied to polymer nanocomposites have been reviewed. Also, each of the literatures has been reviewed under the synthesis of filler and the preparation of the polymer nanocomposite separately which would serve as a guidance for future research. Literatures in which different carbon nanofillers have been compared to find the optimum filler has also been discussed.

Several research works have been carried out on biodiesel combustion, performance and emissions till today. But very few studies have been made about the chemistry of biodiesel that affects the diesel engine operation. Biodiesel is derived from vegetable oil or animal fats, which comprises of several fatty acids with different chain length and bonding. The present work focuses on the effect of biodiesel molecular weight, structure (Cis & Trans), and the number of double bonds on the diesel engine operation characteristics. Three types of biodiesel with different molecular weight and number of double bond were selected for the experimental studies. The biodiesels were prepared and analyzed for fuel properties according to the standards. A constant speed diesel engine, which develops 4.4 kW of power, was run with biodiesels and its performance was compared with diesel fuel. The results show that Linseed oil methyl ester with high linolenic (unsaturated fatty acid ester) does not suit best for diesel engine due to high oxides of nitrogen emission and low thermal efficiency.

Recent research on green composites addresses the environmental threats of solid waste disposal by suggesting sustainable methods. This study aims at identifying potential reinforcement of lignocellulosic fibre extracted from the solid agro waste pile of Lagenaria siceraria (LS) plant. The thermal stability and mechanical strength of raw L. siceraria fibres (LSFs) were modified by alkali treatment (2%-15% w/v of NaOH) at different temperatures (room temperature to 70°C) and time intervals (30 min to 6 h). The result showed that 4% alkali treatment at 45°C for 40 min improves the physicochemical properties of the LSFs. The higher cellulose content (86.49%) and lower hemicellulose (4.23%) and lignin (6.98%) content of optimally treated LSFs significantly improve the mechanical property with a higher tensile strength (436.8 N), elongation at break (5.47%) and thermal stability (355.5°C) compared to raw LSFs. It was found that the alkali-treated fibres with additional toughness and fatigue strength reduce environmental threats by sustainable development.

Stringent emission norms and rapid depletion of petroleum resources have resulted in a continuous effort to search for alternative fuels. Hydrogen is one of the best alternatives for conventional fuels. Hydrogen has both the benefits and limitation to be used as a fuel in an automotive engine system. In the present investigation, hydrogen was injected into the intake manifold by using a hydrogen gas injector and diesel was introduced in the conventional, mode which also acts as an ignition source for hydrogen combustion. The flow rate of hydrogen was set at 5.5 l min−1 at all the load conditions. The injection timing was kept constant at top dead center (TDC) and injection duration was adjusted to find the optimized injection condition. Experiments were conducted on a single cylinder, four stroke, water-cooled, direct injection diesel engine coupled to an electrical generator. At 75% load the maximum brake thermal efficiency for hydrogen operation at injection timing of TDC and with injection duration of 30°CA is 25.66% compared with 21.59% for diesel. The oxides of nitrogen (NOX) emission are 21.7 g kWh−1 for hydrogen compared with diesel of 17.9 g k Wh−1. Smoke emissions reduced to 1 Bosch smoke number (BSN) in hydrogen compared with diesel of 2.2 BSN. Hydrogen operation in the dual fuel mode with diesel exhibits a better performance and reduction in emissions compared with diesel in the entire load spectra. Copyright © 2009 John Wiley & Sons, Ltd.

Electrodeposition was performed in a conventional three-electrode cell. Ag / AgCl was used as the reference electrode to which all potentials were referred. The working and counter electrodes were made of titanium (Ti, 99.99%) and platinum, respectively. The Ti substrates and counter electrode were polished and cleaned with distilled water prior to the deposition process. An EG&G Princeton Applied-Research Potentiostat (Versastat model) driven by the Electrochemical-Analysis-System software (model 270) was used to control the electrodeposition process and to monitor the current and voltage profiles. The electrolytes were prepared by using analytical-grade reagents and deionized water. Sodium tartrate was used to chelate with Zn 2 + to obtain a Zn-tartrate complex. Nitrogen gas was flowed into the solutions prior to mixing to remove any dissolved O 2 . Hydrochloric acid was added to prevent the formation of hydroxyl species and insoluble compounds. The depositions were carried out at room temperature by varying the deposition potential to determine the optimal conditions of deposition of zinc-sulfide thin films.

Cobalt(II)–titanium(IV)-substituted barium ferrite forming the chemical formula of BaCo x Ti x Fe 12−2 x O 19 ( x = 1–6) have been investigated using X-ray diffraction spectroscopy (XRD), Superconducting Quantum Interference Device (SQUID) and high-resolution transmission electron microscopy (HRTEM). The specimen of magnetoplumbite (M-type) Co–Ti-substituted BaFe 12 O 19 were synthesised via sol–gel method using ethylene glycol as precursor. Significant increase in line broadening of the XRD patterns were observed indicating the decrease of particle sizes due to the Co(II)–Ti(IV) substitution. BaCo 3 Ti 3 Fe 6 O 19 showed the highest coercivity but moderate saturation and remnant magnetisations. HRTEM imaging showed that Co(II)–Ti(IV) substitution in the system of BaCo x Ti x Fe 12−2 x O 19 ( x = 1–6) produced no drastic change in the structure of the M-type ferrites. Most of the M-types crystals examined by HRTEM displayed a long axis perpendicular to the c -axis of the M-type structure. Disordered crystals showing the intergrowth between Co–Ti-substituted barium ferrite and the spinel-structured iron oxide were detected.

Electrodeposition in the presence of triethanolamine in aqueous solution was found to offer some improvements in the synthesis of nickel selenide thin film. The presence of triethanolamine also showed its capacity for improving the longevity of the deposition as well as the adhesion of the deposited films on the titanium substrate. Photoelectrochemical analysis reveals outstanding photoactivity for the thin film deposited at −0.70 V, while the optical study shows an energy gap of about 2.0 eV. The film exhibited p-type semiconductor behavior. The scanning electron microscope results showed that the samle deposited in the presence of triethanolamine produced better and smoother surface coverage and bigger grain size.

Electrochemical assisted photodegradation of oxalate ions using titanium dioxide coated on indium tin oxide glass substrates were studied. The titanium dioxide (TiO2) films were prepared by dip-coating method. The photodegradation study under illumination with halogen and ultraviolet lamp was carried out using linear sweep voltammetry. The effect of heat treatment, light source, intensity of light, concentration of oxalate ion, number of dip-coating and applied potentials have been investigated. Ultraviolet light was found to induce higher photodegradation reaction compared to halogen lamp.

Tin selenide thin films have been deposited on indium tin oxide glass slides in alkaline medium. The method is based on simple bath deposition technique that requires less chemicals and monitoring. Uniform and well-adhered films were obtained upon required deposition period. X-ray, morphology, optical and photoelectrochemical study was carried out for the as-deposited film. The films were polycrystalline and covered the surface of the substrate completely. Photoelectrochemical test shows a p-type conduction mechanism. The band gap was found to be about 1.25 eV with direct transition.

Nickel selenide thin films have been potentiostatically electrodeposited on titanium substrate at room temperature from aqueous solution containing Ni-EDTA and Na2SeO3. Various deposition potentials were attempted in order to determine the optimum electrodeposition potential. The films were characterised using x-ray diffraction analysis (XRD) and the photoactivity of the electrosynthesised films were studied using linear sweep voltammetry (LSV). The band-gap energy was determined using UV-visible spectroscopy. The XRD analysis indicated the formationof polycrystalline Ni3Se2. The film exhibited p-type semiconductor behaviour with good photosensitivity. The bandgap energy (Eg) was about 1.4eV.

Tin selenide were prepared chemically in alkaline aqueous solution. The crystalline powder was coated onto microscope glass slides using polyvinyl alcohol solution. The coatings were subjected to annealing at various temperatures to study the effect towards the structure, morphology and composition of the material. The product prepared was characterised using various techniques. The photoresponse for the samples were also studied. The photoelectrochemical (PEC) cell configuration was p-SnSe | (0.01 M K4Fe(CN)6¾0.01 M K3Fe(CN)6.3H2O¾0.1 M Na2SO4| Pt).

Cathodic electrodeposition in the presence of sodium dodecyl-sulphate in aqueous solution was used to prepare CuSe thin film deposited on titanium substrates. The effect of deposition potential, concentrationand deposition time were studied to determine the optimum condition for the electrodeposition process. The films were characterized by X-ray diffractrometry. Scanning electron microscopy was used to studythe morphology of the deposits. The photoresponse of the films prepared was analysed using linear sweep voltammetry in the presence of sodium thiosulphate.

The thermal diffusivities of some polystyrene supported Schiff base complexes of cobalt(II), copper(II) with complexes of the type, [ML2X2], (where M= Co(II) or Cu(II); L=NBPBI, 1-nitrobenzyl-2-nitrophenyl benzimidazole and X=Cl−, Br− or I−) have been determined by the laser induced photoacoustic effect. The effect of the metal as well as the halogen part on the thermal diffusivities of these complexes has been studied. The photoacoustic (PA) effect has now emerged as an elegant, sensitive and non-destructive method to obtain information on the thermal and optical properties of materials [1–8]. The success of this new spectroscopic technique is mainly due to the fact that only the absorbed light contributes to the signal giving a large signal to noise ratio. According to the Rosencwaig-Gersho theory [1], the primary source of the acoustic signal in the cell arises from the periodic heat flow from the solid to the coupling medium, as the solid is cyclically heated by the absorption of chopped light. The periodic flow of this heat into the coupling medium produces pressure fluctuations which are detected as an acoustic signal by a microphone at the modulation frequency, f . The thermal properties of the sample play a significant role in this energy conversion (optical to acoustical). This suggests the possibility of using the PA effect for the study of thermal properties of solids such as the thermal diffusivity and specific heat capacity. A search through the literature reveals that very few PA studies have been carried out on metal complexes and that no work has been reported on polymer supported benzimidazole complexes. Complexes of benzimidazole have attracted a great deal of attention in recent years due to its potential applications in various fields like bio-medical, biochemistry etc. because of its antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, analgesic, antipyretic, antihelmentic, germicidal and immunochemical agent activities. Complex compounds of transition metal ions with imidazole, benzimidazole and their substituted ligands have been studied extensively [9–13]. Some of the Co(II) and Cu(II) complexes reported have shown better catalytic activity, particularly towards synthetically important reactions of oxidation of substituted phenols, in which Co(II) and Cu(II) play a major role in catalyzing these types of reactions. Polymer-bound complexes also gained considerable attention recently due to their pronounced catalytic efficiency [14, 15] particularly in the oxidation reactions. Studies on magnetic and optical properties reveal that the polymer support brings about modifications in the structure of the complex. Other physical parameters like melting point and molar conductance are also found to change on a polymer support [16]. A single beam PA spectrometer is assembled for the present investigation [17]. The 488 nm line of an Argon ion laser (LiCONiX 5300) has been used as the pump source. The acoustic signal generated in the PA cell is detected by a sensitive microphone (sensitivity∼100 mV/Pa) kept close to the sample compartment in a separate port. The microphone output is processed by means of a lock-in amplifier (EG & G, 5208). Charpentier et al. [7] have presented a frequency analysis of the PA signal for the determination of thermal diffusivity. Determining the characteristic frequency ( fc) from the log(amplitude) vs. log(frequency) plot where there is a change of slope and knowing the actual thickness of the sample (ls), the thermal diffusivity (α) can be calculated using the relation, α= l2 s fc. The ligand, NBPBI, was prepared by changing only the reaction time from 12 to 24 h as described by Subba Rao and Ratnam [18]. The samples [Co(NBPBI)2Cl2] and [Co(NBPBI)2Br2] were prepared by adding solutions of cobalt(II) chloride hexahydrate and cobalt(II) bromide solutions respectively to the ligand solution. The resulting greenish solution on refluxing for about two hours, produced crystals which were filtered, washed with chloroform and dried under vacuum over anhydrous CaCl2 [19]. The polymer-bound Schiff base ligand was prepared by condensing aminomethylated polystyrene with quinoxaline-2-carboxaldehyde. A solution of quinoxaline-2-carboxaldehyde (0.5 g in minimum amount of DMF) was added to aminomethylated polystyrene (5.0 g) and the reaction mixture was refluxed for about 5 h. The brown colored product thus formed was filtered, washed several times with DMF and acetone and dried in air and also under vacuum over anhydrous

Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms. Hence in the present study, the combustion of hydrogen-diesel duel fuelled engine was investigated. Hydrogen was injected in the intake port during the suction stroke and diesel was injected inside the combustion chamber near TDC. The start of injection for hydrogen was maintained at 5° BGTDC and the duration of the injection was maintained at three different periods of 30°, 60°, and 90° crank angles with different hydrogen injection flow rates, 2 lpm, 3.5 lpm, 5.5 lpm, 7.5 lpm and 9.5 lpm. The result shows that the hydrogen injection duration of 30° crank angles and flow of 7.5 lpm gives higher brake thermal efficiency by about 8%. Smoke emissions decrease by 60% and NO X emission increase by 3% at optimised full load condition.

The Ni 4 S 3 thin films were prepared by chemical bath deposition method. The chemical bath contained nickel sulphate and sodium thiosulfate which supplied the Ni 2+ and S 2- ions, respectively. The structure and morphology of the films were studied using X-ray diffraction and atomic force microscopy technique, respectively. Absorbance spectra data of the films were obtained by UV-Vis spectrophotometer. The influence of pH was investigated in order to determine the best conditions for deposition process. The number of peaks attributable to cubic structure of Ni 4 S 3 increased to three as the pH was increased to 2.5 according to XRD analysis. In optical absorption spectra, we found that the highest absorbance value was obtained for the films deposited at pH 2.5. Also, the AFM image revealed that the films were smooth, compact and uniform at this pH value. The band gap of films ranged from 0.85 to 1.8 eV depending upon the pH value. Key words : Nickel sulphide; Thin films; Solar cells; Semiconductor. DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8192 Bangladesh J. Sci. Ind. Res. 46(2) , 243-246, 2011