Editorial
Editor .
Abstract
Dear Readers,International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased toannounce the 26th Assembly of Advanced Material Congress (AMC) is a comprehensive forum to discussthe recent trends in the translational research, innovations and technology for market. The ...
Read More
Dear Readers,International Association of Advanced Materials (IAAM, www.iaamonline.org) is pleased toannounce the 26th Assembly of Advanced Material Congress (AMC) is a comprehensive forum to discussthe recent trends in the translational research, innovations and technology for market. The AMC (www.advancedmaterialsseries.com/cmc19) offers a global platform to the industries and academia for the commercialization of progressive research. With the feat from extremely successful past three meetings, BCS is now delighted to announce the 4th BCS on the Materials Innovation and Technology, which is going to organize during 10-13 June 2019 in Stockholm (Sweden) and Helsinki (Finland) while cruising across the Baltic Sea.
Helen Hein; Joachim Schwarte
Abstract
Facing climate change, ecological sustainability forms an important task of recent research, which is scientifically evaluated with life cycle assessments (LCAs). Heating purposes in residential sectors cause substantial amounts of CO2 emissions. Therefore, sustainable insulation material development ...
Read More
Facing climate change, ecological sustainability forms an important task of recent research, which is scientifically evaluated with life cycle assessments (LCAs). Heating purposes in residential sectors cause substantial amounts of CO2 emissions. Therefore, sustainable insulation material development is essential, whereby aerogels are an attractive substitute with low thermal conductivities. The HOMESKIN project aimed to develop an aerogel-based insulation material that achieves minor environmental impacts by material recycling and efficient manufacturing [1]. The LCA is conducted with GaBi in accordance with EN ISO 14040/14044. However, performing LCA in this state of research has proved difficulties. Therefore, in this study, impacts are investigated on how uncertainties due to missing data and resultant assumptions contribute to deviations in results. For generating LCAs, detecting high energy processes is essential as well as materials with significant environmental impacts. This information considers confidential data and is often not completely accessible, especially for innovative products. Besides, aerogels are produced with chemicals whose economic data are extremely rare or might be outdated. Assumed values could cause uncertainties that are difficult to predict. Furthermore, scale-up scenarios create additional uncertainties. The study demonstrates that environmental impacts in early development stages can hardly be assessed – which indicates that LCA generates pessimistic or too optimistic results. Copyright © 2018 VBRI Press
P Swapna; S Venkatramana Reddy
Abstract
Pure and (Ni, Al) co-doped ZnO nanostructures are prepared lucratively by chemical co-precipitation process at room temperature by means of poly ethylene glycol (PEG) as stabilizing agent. Zinc acetate dehydrate and potassium hydroxide are used as preliminary materials. The synthesized samples are characterized ...
Read More
Pure and (Ni, Al) co-doped ZnO nanostructures are prepared lucratively by chemical co-precipitation process at room temperature by means of poly ethylene glycol (PEG) as stabilizing agent. Zinc acetate dehydrate and potassium hydroxide are used as preliminary materials. The synthesized samples are characterized by XRD, Scanning Electron Microscopy (SEM) with EDS, Photoluminescence (PL), and Transmission Electron Microscopy (TEM). X-RAY Diffraction pattern reveals that both pristine and co-doped samples acquire hexagonal wurtzite crystal structure with no secondary phase and nonappearance of secondary phase indicates the nonexistence of impurities. SEM descriptions illustrate that all the particles are almost spherical shape and EDAX analysis reveals that doing well incorporation of dopants and lack of impurities. PL spectrum shows that all the samples containing peaks in the visible region, which will be defect related peaks. Doped samples show high intensity peaks compared with the undoped sample. TEM images reveals the nature of the particles as spherical and size of nanoparticles are confirmed the XRD data. HRTEM images plainly be evidence for nanoparticles are about 5nm with unambiguous lattice fringes. Copyright © 2018 VBRI Press.
Matthias Arzig; TaChing Hsiao; Peter J. Wellmann
Abstract
In this work we studied the influence of three different SiC powder size distributions and the sublimation behavior during physical vapor transport growth of SiC in a 3 inch crystal processing configuration. The evolution of the source material as well as of the crystal growth interface was carried out ...
Read More
In this work we studied the influence of three different SiC powder size distributions and the sublimation behavior during physical vapor transport growth of SiC in a 3 inch crystal processing configuration. The evolution of the source material as well as of the crystal growth interface was carried out using in‐site X‐ray computed tomography. Two SiC powders exhibited a single modal D90 size distribution of ca. 50 μm and ca. 200 μm, respectively. In both cases the average SiC powder density was 1.2 g/cm3. The third powder was a mixture of the above mentioned source materials and exhibited a bimodal particle size distribution. The corresponding average SiC powder density was 1.7 g/cm3. In this latter case the in‐itu X‐ray computed tomography study revealed an improved growth interface stability that enabled a much longer crystal growth process. During process time, the sublimation‐recrystallization behavior of the mixed SiC powder showed a much smoother morphology change and slower materials consumption as well as much more stable shape of the growth interface than in the case of the less dense SiC source. By adapting the size distribution of the SiC source material we achieved to significantly enhance stable growth conditions. Copyright © 2018 VBRI Press.
Manuel A. Vieira; Manuela Vieira; Paula Louro; Pedro Vieira
Abstract
In this paper the use of Visible Light Communication (VLC) in Vehicle Communication Systems is analyzed. The system aims to ensure communication between LED based emitters and SiC based receivers located at the vehicles. The proposed smart lighting system combines the functions of lighting, positioning, ...
Read More
In this paper the use of Visible Light Communication (VLC) in Vehicle Communication Systems is analyzed. The system aims to ensure communication between LED based emitters and SiC based receivers located at the vehicles. The proposed smart lighting system combines the functions of lighting, positioning, and communications. The SiC receivers is used as a encoder/decoder device. This photosensitive element features active filter properties, it multiplexes the modulated polychromatic signal coming from the LEDs in an electrical signal, performs multiplexing/demultiplexing techniques and decode the received information. A traffic scenario is established and two connected vehicular communications simulated. Infrastructure-to-Vehicle (I2V) follow by Vehicle-to-Vehicle (V2V) communications are analyzed. In the V2V communication, the emitter is based on the front headlights of the vehicle, while for the study of the I2V communication system, the emitter was built on the streetlights. The VLC receiver acts as a Wavelength Division Multiplexer (WDM) and increases the signal conditioning capability to decode the transmitted information. Each receiver is a two terminal p-i'(a-SiC:H)-n/p-i(a-Si:H)-n heterostructure located on both the tails and on the top roof of vehicles. The spectral sensitivity of the receiver and its optical gain are analyzed. For message transmission, the individual chips of the white trichromatic RGB LEDs are modulated acting, for data transfer, as individual VLC channels. A violet LED is used for error control and to identify the ID position of the transmitter. Free space is the medium of transmission. An on-off modulation scheme (OOK) is used to transmit data. An algorithm for decoding information is established. The connected I2V2V system was tested. The experimental results show that using white modulated LEDs for lighting and data transmission and a SiC WDM device to decode the information is possible to build a VLC vehicular system that ensures de communication between the outside infrastructures and the cars. Copyright © 2018 VBRI Press.
Sudha C. Angadi; Lata S. Manjeshwar; Tejraj M. Aminabhavi
Abstract
Nanocomposite microspheres of chitosan (CS) with magnesium aluminum silicate (MAS) and enteric coated with poly(vinyl acetate phthalate) (PVAP) have been prepared and examined for controlled release (CR) of capecitabine, an anticancer drug. The microspheres have been characterized by X-ray diffraction ...
Read More
Nanocomposite microspheres of chitosan (CS) with magnesium aluminum silicate (MAS) and enteric coated with poly(vinyl acetate phthalate) (PVAP) have been prepared and examined for controlled release (CR) of capecitabine, an anticancer drug. The microspheres have been characterized by X-ray diffraction (XRD) to study the drug distribution, DSC to understand thermal stability and Fourier transform infrared (FTIR) spectroscopy to investigate the chemical interactions as well as to assess the structures of drug-loaded formulations. Surface morphology of the microspheres was investigated by scanning electron microscopy (SEM). The size distribution of the formulated microspheres studied by particle size analyzer was in the range of 303-350 μm, while their encapsulation efficiencies ranged from 50 to 58%. Equilibrium swelling of the microspheres was measured in both pH 1.2 and 7.4 media. In vitro release of capecitabine has shown a dependence on polymer-clay composition, amount of crosslinking agent and extent of enteric coating. The formulations extended the release of drug up to 32 h. The enteric coating with PVAP effectively reduced the burst release of the drug in gastric pH medium. The present method offers promising results for controlled release of short-acting drugs. Copyright © 2018 VBRI Press.
Research Article
Syed Gulraze Anjum; Aboo Bakar Khan; Mohammad Jawaid Siddiqui; Parvez Ahmad Alvi
Abstract
In this article, we have computationally analyzed the Type-I InGaAsN/GaAs (dilute N) material system based step-index separately confined heterostructure (STINSCH) consisting of a compressively strained single quantum well layer. The whole structure is assumed to be grown on GaAs substrate. The optical ...
Read More
In this article, we have computationally analyzed the Type-I InGaAsN/GaAs (dilute N) material system based step-index separately confined heterostructure (STINSCH) consisting of a compressively strained single quantum well layer. The whole structure is assumed to be grown on GaAs substrate. The optical gain spectra have been calculated and compared for single quantum well structure for the two different carrier densities under TE and TM polarization modes at room temperature. The size of the STINSCH based nano-scale heterostructure taken as a whole including SQW together with barriers and claddings is 47nm. In order to validate the computed optical gain, the anti-guiding factor has also been evaluated for the same nano-heterostructure. The GAIN software package has been utilized to obtain the various lasing properties like optical gain, modal gain, and anti-guiding factor. Therefore, this lasing nano-heterostructure may found application in optical fiber communication systems as a light source because of less attenuation and minimum optical loss. Copyright © 2018 VBRI Press.
Saji S K; R Radhakrishnan; T Jeyasingh; R Vinodkumar; Shibu M. Eappen; P R Sobhana Wariar
Abstract
perovskite material was prepared by solution combustion technique. XRD results revealed that the material crystallizes in a rhombohedral crystal symmetry with space group Rc. The ac conductivity and dielectric properties of the sintered pellet of the sample have been investigated in the frequency ...
Read More
perovskite material was prepared by solution combustion technique. XRD results revealed that the material crystallizes in a rhombohedral crystal symmetry with space group Rc. The ac conductivity and dielectric properties of the sintered pellet of the sample have been investigated in the frequency range 1Hz to 1MHz for a wide range of temperatures. The experimental results indicate that the ac conductivity (ω), dielectric constant () and dielectric loss ( ) depends on depends on the temperature and frequency. The ac conductivity was found to obey the power law with and the behavior of exponent n with temperature and the value of n suggest ion hopping is the charge transport mechanism in the material. The obtained results are compared to the principal theories that describe the universal dielectric response behavior. The value and were found to be temperature and frequency dependent. Copyright © 2018 VBRI Press.
B. Sreenivasulu; S Venkatramana Reddy; P. Venkateswara Reddy
Abstract
Pure and (Mn, Ni) co-doped ZnS nano particles are synthesized by co-precipitation method using Poly Vinyl Pyrrolidone (PVP) as stabilizer. Powder XRD results exhibit cubic blended structure for all samples. The average crystallite sizes observed to be between around 2-3 nm. Uneven changes of crystal ...
Read More
Pure and (Mn, Ni) co-doped ZnS nano particles are synthesized by co-precipitation method using Poly Vinyl Pyrrolidone (PVP) as stabilizer. Powder XRD results exhibit cubic blended structure for all samples. The average crystallite sizes observed to be between around 2-3 nm. Uneven changes of crystal structure of concerned nanoparticles are confirmed by the Transmission Electron Microscopy (TEM) studies. The crystalline sizes obtained from TEM (3-5 nm) agree well those of XRD data. The SEM micro graphs of (Mn, Ni) co-doped nanoparticles result in agglomeration with spherical shape. The EDAX Spectra reveal that in the chemical composition of the prepared samples, the co-doped elements are incorporated into ZnS lattice. Photoluminescence (PL) has been studied at 306 nm wavelength. Pure sample exhibits sharp peaks at 438 nm, 450 nm and 466 nm. The (Mn, Ni) co-doped powders exhibit slightly less intense peaks. The magnetic measurements reveal that the co-doped nanoparticles exhibit Room Temperature Ferromagnetism (RTFM). Copyright © 2018 VBRI Press.
Research Article
R Subba Reddy; S Uthanna; A Sivasankar Reddy; T. Srikanth; B. Radha Krishna
Abstract
Zinc oxide thin films were deposited by RF magnetron sputtering on p-type (100) silicon and glass substrates held at room temperature by varying the oxygen partial pressures and the optimized films was annealing at different temperatures. The deposition rate of the films was decreased from 5.8 to 2.5 ...
Read More
Zinc oxide thin films were deposited by RF magnetron sputtering on p-type (100) silicon and glass substrates held at room temperature by varying the oxygen partial pressures and the optimized films was annealing at different temperatures. The deposition rate of the films was decreased from 5.8 to 2.5 nm /min with increase of oxygen partial pressures. X- ray diffraction results reveal that the films deposited at oxygen partial pressure of 2x10-2 Pa the (100) preferred orientation peak crystallinity became better. Raman spectroscopy analysis shows an improvement in the crystalline quality of the films at 2x10-2 Pa. Fourier transform infrared spectroscopy of ZnO films confirms the presence Zn-O bonding. The nanorods were observed at oxygen partial pressure of 5x10-2 Pa. The maximum transmittance of 97% and crystallite size of 21 nm was observed at oxygen partial pressure of 2x10-2 Pa. The as deposited films annealed at 473 K the intensity of (100) phase was decreased. The RMS roughness of the as deposited ZnO films was 7.3 nm, and it increased to 30 nm for the films annealed at 473K. Optical spectra revealed the films annealed at 673 K show the optical band gap of 3.17 eV. Copyright © 2018 VBRI Press.