Editorial
Hisatoshi Kobayashi; Mikael Syväjärvi
Review Article
Charles Odilichukwu R. Okpala
Abstract
This paper reviews succinctly ozone delivery on food materials incorporating some bio-based processes. Particularly, ozone treatment is among existent bio-based process technologies applicable to wide range of food materials. Since declared 'Generally Recognized As Safe (GRAS)’, the global technological ...
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This paper reviews succinctly ozone delivery on food materials incorporating some bio-based processes. Particularly, ozone treatment is among existent bio-based process technologies applicable to wide range of food materials. Since declared 'Generally Recognized As Safe (GRAS)’, the global technological progress of ozone has had its discharge settings to-date range between laboratory/domestic and industrial scales. Based on medium properties and probably owed to its unstable nature, whilst the chemistry and physics of ozone substantiates not only its efficacy, but also the delivery processes, incorporating both direct/indirect oxidation and ozonolysis contributes to its diversity. Ozone is widely under investigation as sanitizing agent for the food industry. So when it is applied to food materials, key variables of interest can include amount/quantity of concentration and exposure time/periods. Now and on-going into the future, it remains imperative that makers of ozone equipment continually search for 'best' safe applications that would cater for both consumer and industrial needs. Copyright © 2017 VBRI Press.
Research Article
Kate Kotlhao; Moloko D.T. Madiseng; Fanyana M. Mtunzi; Vusumzi E. Pakade; Sekomeng J. Modise; Neelan Laloo; Michael J. Klink
Abstract
Three different types of nanoparticles were synthesised in this study, viz silver (Ag), zinc oxide (ZnO) and titanium dioxide (TiO2) using different chemical methods. These materials were then characterised using Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscopy (FTIR), ...
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Three different types of nanoparticles were synthesised in this study, viz silver (Ag), zinc oxide (ZnO) and titanium dioxide (TiO2) using different chemical methods. These materials were then characterised using Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscopy (FTIR), Ultraviolet Visible Spectroscopy (UV-Vis) and Thermal Gravimetric Analysis (TGA). The materials were also tested for anti-bacterial activity. TEM showed that the particles were in the nano-size range (1 – 100 nm). FTIR and UV-Vis Spectroscopy showed the different absorption bands of the synthesised nanoparticles, respectively. Silver nanoparticles showed greater antibacterial activity against several bacteria than titanium dioxide and zinc oxide nanoparticles. The highest inhibition was observed for Klebsiella pneumoniae. The results showed that antimicrobial activity of nanoparticles increases with increasing concentration of the nanoparticles. Copyright © 2017 VBRI Press.
Research Article
Rapaka S C Bose; L Rangaraj; Abanti Nag
Abstract
The p-type thermoelectric material Ca3Co4O9 were synthesized by the sol-gel synthesis in the presence of complexing agent of citric acid and dispersant of polyethylene glycol 400, and followed by the uni-axial hot-pressing (HP) technique. Observation by X-ray diffraction revealed that the formation of ...
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The p-type thermoelectric material Ca3Co4O9 were synthesized by the sol-gel synthesis in the presence of complexing agent of citric acid and dispersant of polyethylene glycol 400, and followed by the uni-axial hot-pressing (HP) technique. Observation by X-ray diffraction revealed that the formation of phase pure sample on calcination at 1073 K for 4 h. Scanning electron microscopy indicated that the significant enhancement of the grain growth through HP technique. The density of the sintered pellets increased with an increase of applied pressure. The electrical resistivity was greatly reduced with an increase of the applied pressure, whereas the Seebeck coefficient was little increased with an increase of the applied pressure. As a result, the pellet treated by the HP technique under the condition of 1098 K, 25 MPa and 30 min showed a maximum power factor of about 498 μWm-1K-2 at 950K. Copyright © 2017 VBRI Press.
Research Article
Martin Kurdve; Fredrik Henriksson; Magnus Wiktorsson; Patrick Denzler; Mats Zackrisson; Marcus Bjelkemyr
Abstract
This paper links production system research to advanced material research for the vehicle industry. Facilitated by need for reduction of fuel use, the automotive industry is pushing a radical change from using steel structures to new mixed materials structures. In production systems optimised ...
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This paper links production system research to advanced material research for the vehicle industry. Facilitated by need for reduction of fuel use, the automotive industry is pushing a radical change from using steel structures to new mixed materials structures. In production systems optimised for steel, the changes will affect productivity and material efficiency. Four industrial case studies focusing on production economy and productivity give implications of production technology demands on the material selection regarding new joining techniques and additive or forming methods which has to be investigated when considering new materials. Material efficiency analysis shows that minimising spill in production operations and regulatory demand of recycling needto be considered in material development, which implies both design for disassembly, advanced separation processes and use of recycled raw materials. To be successful in new material introduction, new information flows and knowledge sharing moving from operations and manufacturing development to materials development and design are needed. The material developers could use axiomatic design strategies to structure the production system demands on the materials. State of the art lightweight producers in vehicle and automotive industry are likely early adopters to advanced lightweight structures with need of information flows between material development and operations.Copyright © 2017VBRI Press.
Research Article
M. Gurubhaskar; Narayana Thota; A.C. Kasi Reddy; Y.P. Venkata Subbaiah
Abstract
Tin mono-sulfide thin films were prepared using a two-step process consisting of DC sputtered deposition of Sn precursors over glass substrate held at 150 oC, followed by sulfurization for 1 hour at different temperatures ranging from 250 oC to400 oC. The influence of the sulfurization temperature on ...
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Tin mono-sulfide thin films were prepared using a two-step process consisting of DC sputtered deposition of Sn precursors over glass substrate held at 150 oC, followed by sulfurization for 1 hour at different temperatures ranging from 250 oC to400 oC. The influence of the sulfurization temperature on resultant films was studied in terms of its structure, morphology and opto-electronic properties. X-ray diffraction study revealed that the films sulfurized at lower temperature (~250 oC) had prominent SnS2 phase in addition to SnS. A single-phase tin mono-sulfide planes corresponding to orthorhombic structure has been observed at 300 oC and found to be highly crystalline at 350 oC. Further, three distinct Raman modes observed at 95, 190 and 218 cm-1 for Sn precursors sulfurized at 350 oC, strongly supporting the formation of single phase SnS. The optimized SnS film showed a direct band gap of 1.35 eV with an absorption coefficient of 5 x 104 cm-1. The valence states of Sn (+2) and S (-2) determined from X-ray photoelectron spectroscopy analysis for Sn precursors sulfurized at 350 oC, indicating the existence of SnS. These films had stoichiometric atomic ratio of Sn/S ~ 1 with surface roughness of 20 nm. All the films have shown p-type conductivity and the Sn precursors sulfurized at 350 oC exhibited relatively high conductivity of 0.947 x 10-2 (Ω cm)-1. The optoelectronic properties of SnS films reported in the present work would be highly suitable for device fabrication and promising as an alternative absorber for thin film solar cells. Copyright © 2017 VBRI Press.
Research Article
Shivani A. Singh; Pravin. S. More; Dattatray. J. Late; Rajesh W. Raut
Research Article
Mine Uslu Uysal
Abstract
Adhesively bonded technique is preferred more than bolted joining technique for glass connections. Glass panels supported by metal frame are generally used to glazing applications. Obtaining the critical buckling temperature is highly important and also thermal buckling behaviour of the glass joints ...
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Adhesively bonded technique is preferred more than bolted joining technique for glass connections. Glass panels supported by metal frame are generally used to glazing applications. Obtaining the critical buckling temperature is highly important and also thermal buckling behaviour of the glass joints should be considered. Stability of the joint is influenced by many design parameters such as types of adhesive/adherent materials. This paper presents a finite element method (FEM) of adhesively bonded scarf joint under thermal loading. Finite element models for the glass joint having isotropic (Aluminum and Steel) or anisotropic (Boron-epoxy, Kevlar-epoxy and E glass-epoxy) adherents were established by ANSYS® commercial program. FEM analysis was based on the usage of special surface to surface contact elements. The effects of adherent properties on the critical buckling temperature were investigated. Adhesively bonded scarf joint mode shapes were presented for the first five modes. Among the anisotropic adherent materials, the highest critical buckling temperature was determined for the boron-epoxy/glass joint. Additionally, the results showed that the adherent materials should be chosen carefully for adhesively bonded glass joints. Copyright © 2017 VBRI Press.
Research Article
Mukesh Kumar; Neelam Kumari; Vinod Karar; Amit L Sharma
Abstract
HfO2 thin films have gained much significance in recent years as a promising dielectric material for semiconductor electronics added to their wide applications in the field of optical filters as a high index material. The resistance of HfO2 films to impurity diffusion and intermixing at the interface ...
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HfO2 thin films have gained much significance in recent years as a promising dielectric material for semiconductor electronics added to their wide applications in the field of optical filters as a high index material. The resistance of HfO2 films to impurity diffusion and intermixing at the interface as well as higher environmental stability have made these films one of the most extensively studied upon materials in laser optics, optical coatings and semiconductor domain. In the present study, Hafnium Oxide film was deposited on glass substrate using reactive oxygenated E-Beam deposition technique with in-situ quartz crystal thickness monitoring to control the film thickness and rate of evaporation. The coated substrate was optically characterized using spectrophotometer and Variable Angle Spectroscopic Ellipsometry (VASE) to determine its transmission spectra as well as optical constants. The coated sample was put under thermal stress testing in a test chamber with temperature variation from -40° to + 65° C in a cyclic manner for 7 cycles with a rate of temperature change of 5° C/minute. The coated sample was again optically characterized to investigate the effect of thermal cycling on its optical performance and physical parameters. Copyright © 2017 VBRI Press.
Research Article
M. K. Gupta; Kunwar Rohit
Abstract
In present work, epoxy based glass composite is prepared using hand lay-up method followed by static compression with varying numbers of woven glass layers. Dynamic mechanical properties of prepared glass composites are studied in terms of storage modulus (E'), loss modulus (E''), damping (Tand) and ...
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In present work, epoxy based glass composite is prepared using hand lay-up method followed by static compression with varying numbers of woven glass layers. Dynamic mechanical properties of prepared glass composites are studied in terms of storage modulus (E'), loss modulus (E''), damping (Tand) and glass transition temperature (Tg) as a function of temperature. The results indicated that value of E' and Tg increases whereas value of Tand decreases as increase in temperature. In addition, value of Tg obtained from Tand curve is found lower than that obtained from peak of E'' curve. The present glass composites are suitable for constructions, automobiles and aerospace industries due to its better dynamic mechanical properties and thermal stability. Copyright © 2017 VBRI Press.
Research Article
P. Prabukanthan; R. Lakshmi; T. Rajesh Kumar; S. Thamaraiselvi; G. Harichandran
Abstract
Electrochemical deposition (ECD) of FeS2 thin films from aqueous solution contains FeSO4, Na2S2O3.5H2O and H2SO4. ECDs were performed at different bath temperatures (30, 40, 50, 60 and 70°C) with constant pH (~2). FESEM images shows that the grains are as deposited films with stoichiometric ...
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Electrochemical deposition (ECD) of FeS2 thin films from aqueous solution contains FeSO4, Na2S2O3.5H2O and H2SO4. ECDs were performed at different bath temperatures (30, 40, 50, 60 and 70°C) with constant pH (~2). FESEM images shows that the grains are as deposited films with stoichiometric iron pyrite thin films were successfully formed at 50, 60 and 70°C and S/Fe ratio in as-deposited films were ~2. GAXRD studies of as-deposited at 30 and 40°C FeS2 thin films shows a minor phase of orthorhombic marcasite and major cubic pyrite phase observed. As-deposited thin films at 50, 60 and 70°C brings about the formation of FeS2 with single crystalline cubic phases with a strong (111) preferred orientation and without any contribution of marcasite phase. When the bath temperature was increased, as-deposited thin films of crystalline size, thickness and roughness value increased due to rate of formation FeS2 increased. Raman spectra of the FeS2 thin films presented characteristic peaks of S-S active mode at 377 cm-1. The optical spectra of the as-deposited FeS2 thin films with different bath temperatures showed a clear absorption edge band gap of these films from 0.86 to 0.96 eV. As-deposited FeS2 thin films at different bath temperatures show p-type conductivity. Copyright © 2017 VBRI Press.
Research Article
Naveen M. Tripathi; S. S. Mallick
Abstract
This paper presents results of an ongoing investigation into the modelling of pressure losses through bends during pneumatic conveying of fly ash. For the reliable design of pneumatic conveying systems, an accurate prediction of bend pressure drop is of paramount importance as the same can significantly ...
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This paper presents results of an ongoing investigation into the modelling of pressure losses through bends during pneumatic conveying of fly ash. For the reliable design of pneumatic conveying systems, an accurate prediction of bend pressure drop is of paramount importance as the same can significantly influence the total pipeline pressure loss. In the present study, seven existing bend models (Schuchart, Singh and Wolf, Rossetti, Westman, Bradley, Pan, Pan and Wypych, Das and Meloy models) were used to predict the total pipeline pressure drop for conveying fine fly ash through two test rigs: 63.5 mm I.D. x 24 m long and 54 mm I.D. x 70 m long. Comparisons between the predicted pneumatic conveying characteristics using the seven bend models and the experimental data have shown that the trends and values of the total pipeline pressure drops can significantly vary depending on the choice of bend model. While some models have provided increasing values of bend pressure drops with rise in air flows, some other models have produced reversed characteristics. It is concluded that the parameter grouping used in the existing bend models are not generally capable of predicting bend pressure drop reliably and therefore, further research is required to better understand the flow mechanisms of gas-solids flows across bends towards developing improved bend models. Copyright © 2017 VBRI Press.
Harishchandra Singh; Ashok K. Yadav; Manavendra N. Singh; Anil K. Sinha
Abstract
Fe2TeO6 (FTO), an antiferromagnetic magnetoelectric material which crystallizes in tetragonal (P42/mnm, 136) crystal structure, shows close to room temperature interesting magnetic interactions. To understand the complexity in its magnetism, a huge variation in its magnetic properties has been reported ...
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Fe2TeO6 (FTO), an antiferromagnetic magnetoelectric material which crystallizes in tetragonal (P42/mnm, 136) crystal structure, shows close to room temperature interesting magnetic interactions. To understand the complexity in its magnetism, a huge variation in its magnetic properties has been reported by various groups, which have been attributed to the presence of Fe2O3 (an impure phase) in the final FTO compound. Herein, synthesis using alternate ingredients and Synchrotron structural investigation of single phasic FTO are presented. Out of the several initial ingredients (Fe2O3, Fe3O4 with TeO2, Te(OH)6) in solid state reaction route, only the reaction between Fe3O4 and TeO2 results in the single phasic FTO (not reported so far), while the others (Fe2O3 with TeO2 or Te(OH)6) result in certain amount of Fe2O3 impurity. Rietveld refinement on Synchrotron X-ray Diffraction data and Fe K edge Extended X-ray Absorption Fine Structure data provide the overall similarity between the average crystalline structure and local structure of FTO, indicating the intrinsic nature of it’s complex magnetic behavior. Copyright © 2017 VBRI Press.
