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Studies on characteristics and corrosion behaviour of chitosan/eudragit RS100 bilayer film coated Ti-6Al-4V
Get PDFIn the present study, implant material Ti-6Al-4V has been coated with eudragit (EU) and chitosan (CH) polymers to enhance surface properties. The deposition of polymer coating has covered the surface cracks to a significant level and the fact has been confirmed by FE-SEM coupled with EDAX wherein the atomic percentage of Ti (99.90%) in non-coated surface has been decreased markedly to 0.42% after coating. Scratch resistance and adhesion power of bilayer coating has been increased as indicated by the higher critical loads Lc1 (16.71 N), Lc2 (17.56 N), Lc3 (17.96 N) when a progressive load of 1 N to 20 N is applied over the coated surface. Further, Electrochemical impedance spectroscopy (EIS) and potentiodynamic-polarization studies have shown that the value of polarization resistance is inversely proportional to the corrosion rate. Thus decrease in the corrosion rate from 107.5×10-2 (mm year-1) for the non-coated alloy to 2.88×10-2 (mm year-1) for CH/EU coating demonstrated that coating enhanced the corrosion resistance of the alloy in the physiological condition. The in vitro antibacterial test conducted against S. aureus, B. subtilis, P. vulgaris and P. auregenosa has shown a significant inhibition zone of 9 mm, 6 mm, 7 mm and 10 mm, respectively, thus indicating the possible application of the polymeric coating material on the dental implants
Impact of progressive pulse cleaning pressure on polyester filter media performance using pulse jet filtration test rig
Get PDFThe effect of progressive pulse cleaning pressure (2 bar to 3.5 bar) on filtration behaviour of two different polyester needle-punched nonwoven filter materials, viz. PTFE finished and without finished media has been studied at varying dust densities using flyash aerosol. The filter materials have been investigated on a flatbed filtration test rig based on cleaning at a fixed peak pressure drop of 1000 Pascal for an equal number of test cycles during the first three phases (conditioning, ageing and stabilizing phase) and further for the final measuring phase of four hours. The particulate emission and residual pressure drop behaviour are found to be significantly less in the case of PTFE-coated material under all the operating conditions. However, a significant difference among all levels of progressive pulse pressure has been found for both the examined materials
A study of transition spaces in traditional houses of Tamil Nadu
Get PDFArchitecture is inevitably a mechanism for social purposes that could impact the personal and public levels. While architecture is used in many different ways, the arrangement and structure of places are fundamental and essential to people's lives. Thus, the people started to create spaces allowing them to eat, sleep, worship, learn, argue, recreate, and so on in a specific timeframe that has been subjected to the tradition and culture of people. This study is about one such traditional transition space - the thinnai that creates connectivity between the public and private zones in a housing typology. As evolution occurs, these structures, intended for various activities, have vanished, and compound wall structures have enclosed the dwellings. This shortens the connectivity to the external environment. In southern India, the thinnai spaces serve various socio-cultural activities. The typology of the thinnai spaces differs according to the regions of settlement, occupation and religious practices. Such spaces have been recreated due to the refurbishment of the buildings, which will not require them to serve their purpose. The main objective of the paper is to document and analyze the transitional spaces (known as thinnai or raised platform) prevailing near the entrance in the varied typology of traditional houses in a village in Tamil Nadu and to classify them based on the thresholds. The qualitative study was carried out through intense documentation analysis of transition spaces near thresholds in the varied typology of traditional houses in Mangalrevu village Tamil Nadu. The result of the study showed that the transitional spaces that exist near thresholds in traditional buildings have demonstrated extensive functionality and lie in harmony with the people's lifestyle. Further, the authors also classified the types of transition spaces with respect to the thresholds. It is considered the need of the hour to replicate these structures with the same meaning in modern dwellings without any compromises
Preparation and characterization of syrup from native dried date (Phoenix dactylifera L., variety Mech-Degla) fruits
Get PDFPresently, three different evaporation procedures (oven heating, rotary evaporator, and lyophilization) were investigated at laboratory scale, for obtaining date (Phoenix dactylifera L.) syrup (DS) from date juice (DJ). The DJ was prepared by immersion of pitted date fruit (DF) pieces in pure water, according to the local traditional procedure. Compared to oven heating and lyophilization, the use of the rotavapor at 70°C seems to be more rational, since three hours of treatment are needed to reach a total of soluble solids (TSS) of about 61 Bx, against 6 and 18 h in the case of the two other cases, respectively. In addition, the DS thus obtained shows a lowest content in hydroxymethylfurfural (HMF). From the point of view of rheological behavior, the final DS is of pseudo-plastic (Bingham) type, comparable to white syrup taken here as reference. Considering the growing interest for natural products, the DS can advantageously replace commercial white syrups.
Exploring the status of ethnic tribal value addition practices of Jackfruit (Artocarpus heterophyllus Lam.) in Garo Hills of Meghalaya, India
Get PDFJackfruit gets wasted to the tune of $5.8 million every year from 0.4-0.5 million jackfruit trees in Garo Hills due to lack of suitable infrastructure, limited scientific know-how regarding processing and storage, and restricted market access. The study aims to explore the status of jackfruit cultivation and utilisation of locally available jackfruit and to document the value addition practices followed by ethnic tribal communities in the Garo Hills of Meghalaya, India, to augment the standardisation of the sustainable value addition practices for the region. The study was conducted in all five districts of Garo Hills. Two blocks from each district were selected through a simple random sampling method. Twenty respondents from each selected block were selected through the snowball sampling method, thereby making a total of 200 respondents. Identification and documentation of ethnic value addition practices of tribal communities were done through Focused Group Discussion with the relevant stakeholders. Data were analysed with descriptive statistics and Duncan Multiple Range Test. The average wastage percentage was more than half of the jackfruit production in Garo Hills, as very few respondents (30.5%) engaged in value addition practices and due to negligible marketing of raw jackfruit (3970 kg). Identification, documentation of ethnic value addition practices, and their utilisation study provide a clear indication of the need for standardisation of these value addition practices through laboratory research to befit the local demand and outside market as well.
Synthesis, DFT and antioxidant studies of 2-(alkylamino)-4-(naphth-2-yl) thiazole
Get PDF2-(Alkylamino)-4-(naphth-2-yl)thiazoles have been synthesised from 2-bromoacetyl naphthalene and characterized by UV, IR, and 1H NMR. The geometry of the molecules is optimised using the Gaussian 09 software programme and the B3LYP/6-31G density functional theory (DFT) approach. The bond lengths, bond angles, and dihedral angles of 2- (alkyamino)-4-(naphth-2-yl)thiazoles have been studied. Vibrational bands to distinct structural groups and their relevance have been predicted using vibrational spectra analysis and shown to be reliable when compared to experimental data and with literature observations. Atomic charges have been estimated using the Mulliken population analysis. The charge transfer within the molecule is confirmed by the computed energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The molecular docking study has been carried out
Synthesis of high temperature resistant ZrO2-SiO2 composite aerogels via supercritical fluid deposition
Get PDFA series of ZrO2-SiO2 composite aerogels have been synthesized by adjusting the volume of tetraethoxysilane (TEOS) during supercritical fluid drying process. ZrO2 aerogels have been prepared via the sol-gel reaction using ZrOCl2ꞏ8H2O and the gel initiator malic acid as raw materials. Then the ZrO2-SiO2 composite aerogels have been obtained by supercritical fluid deposition (SCFD). The samples have been characterized applying XRD, FTIR, SEM, TEM, TGA and Nitrogen adsorption-desorption. The introduction of SiO2 can effectively restrain the growth of the nanoparticles and the transformation of crystalline phase, and reduce the linear shrinkage of the aerogels. It indicates the improvement of the thermostability of the ZrO2-SiO2 composite aerogels
Biodegradable nonwoven bonded fabric from Tossa jute and polylactic acid fibre for carry bag
Get PDFA sustainable flexible nonwoven fabric has been developed using jute (Corchorus olitorius) and polylactic acid (PLA) fibres. The thermal bonding technique has been used to soften the PLA component which behaves as the matrix in jute fibre reinforcement. The central composite rotatable design has been adapted to understand the effects of the independent variables, such as PLA content, roller temperature and roller pressure on mechanical properties, such as tenacity, breaking elongation, initial modulus, energy-at-break, bursting strength and tear strength. Considering the linear, quadratic and two-way interactive effects of independent variables, the second-order polynomial has been suggested which proves good association. The optimised process parameters are PLA content 30%, jute content 70%, roller temperature 170°C and roller pressure 150 N/cm2. The property comparison with commercial bag fabric shows that the developed jute-PLA fabric is better in many useful aspects. Three types of bags with carrying capacity of 2.5, 5 and 10 kg have been prepared. The results of the hanging test, wetting test, drop resistance test and atmospheric resistance test of the developed bag in comparison to the commercial bag show that the developed bag from jute-PLA performs better. No significant change is found after 10 wetting-drying cycles and hence, the bags are reusable. The fabric can be used successfully as a carry bag or shopping bag. As the process and components of developed fabric are ecofriendly, it will be sustainable and ecofriendly
RF and Crosstalk Characterization of Chip Interconnects Using Finite Element Method
Get PDFThis paper presents new finite element method (FEM) based approach for radio frequency (RF) and crosstalk (X talk) characterization of chip interconnects. Being based on scattering parameters (S-parameters), this approach truly and accurately demonstrates the transmission line behavior of chip interconnects over a wideband of frequencies. To demonstrate FEM based method, a single-line and a 3-line interconnect test structures on SiO2-Si substrate have been designed and simulated in High Frequency Structure Simulator (HFSS). The RF and crosstalk characterization of chip interconnect materials Copper (Cu), doped multilayer Graphene Nanoribbon (DMLGNR), and neutral multilayer Graphene Nanoribbon (NMLGNR) have been demonstrated in terms of transmission coefficient (Sij & Smn) from 1 to 1000 GHz. The single-line three-dimensional (3D) structures comprising of Cu, DMLGNR, and NMLGNR have maximum transmission loss values of -15.93 dB, -22.03 dB, and - 13.73 dB at frequencies of 643 GHz, 402 GHz, and 643 GHz, respectively whereas three-line bus structure exhibit maximum victim-line transmission loss values of -15.28 dB, -17.47 dB, and -15.98 dB at frequencies of 247 GHz, 829 GHz, and 377 GHz, respectively. Further, the crosstalk results have demonstrated that as frequency increases significant crosstalk is observed between nearby lines due to electromagnetic interference and coupling (EMI/EMC) issues