A Prototype Knowledge-Based System for Ceramic Matrix Composites Material Selection of Automotive Engine Components

The aim of this research project is to develop prototype knowledge based system for ceramic matrix composites of automotive engine components. The materials are selected from ceramic matrix composites. The selected materials will be able to increase the efficiency of an engine and reduce weight. The designed knowledge based system consists of a knowledge based, material database and product design parameters. The development of such expert system for ceramic matrix composites leads to further increase in their application in high temperature field. The proposed system helps to select the suitable materials for automobile engme components. The materials chosen for the research are ceramic matrix composites. For selecting materials to engine components, few specifications are laid out as constraints in tenus of rule conditions. The materials, which satisfy the conditions, are selected as suitable materials. The rules based reasomng are used to select the materials. For different range of constraint values, the selected materials will vary. As for as constraint values are concerned, the values are selected from the product design specifications. The product design specifications are chosen from the past design and are calculated from the design procedures. The selected materials are ranked according to the properties and stored as result. The most suitable material is labeled as best material and the next level of materials are ranked according to the propertie

Characterization Of Fretting Fatigue of 7075-T6 Aluminium Alloy

The main aim of the research work is to present theoretical and experimental approaches to the problem of fretting fatigue using 7075-T6 aluminum alloy as a specimen and En24 steel as a pad. A literature review is carried out to explain the contact mechanics of complete contact configuration for the fretting fatigue loading condition. The literature review includes fretting fatigue crack initiation, crack propagation and failure mechanisms and concludes with the different fretting fatigue test facilities. A novel fretting fatigue test rig has been designed to measure and control the critical parameters: normal load, frictional force and relative displacement at the contact interface using a data acquisition facility. The crack initiation and propagation data also recorded during the experiments to ascertain the crack behavior. The fretting fatigue tests have been carried for the three cyclic axial stresses 290 MPa, 300 MPa and 325 MPa with normal stress 45 MPa, 60 MPa, 90 MPa. During the experiments the frictional force, Q is measured and plotted with the number of cycles. The frictional force response increases rapidly during initial stage of experiments and attains a steady state condition approximately after 100 cycles and dwells there until the specimen fails. The frictional force versus axial load hysterias loops for different cycles are drawn which shows that the contact zone experiences partial slip regime. The Coulomb law is applied to determine the coefficient of friction which shows that higher coefficient of friction is observed for the lower normal stress and decreases gradually with an increases in normal stress. The crack propagation with dl/dN and Ak, growth curves shows that considerable retardation in crack growth is observed for the higher normal stress of 90 MPa with the three axial stresses which are caused by crack closure due to high compressive normal load. The experimental observation of fretting fatigue life results shows that increase in normal stress reduces the crack initiation cycles as well as the total life to failure for that constant axial stress. The fatigue life reduces by an average factor of 7.34, 12.46 and 17.48 respectively for the axial stress of 290 MPa with the normal stress of 45 MPa, 60 MPa and 90 MPa. The similar behaviour is observed for the other combinations fretting fatigue loading condition. A theoretical model is developed using the asymptotic analysis to study the equivalence of stress state at the pad edge for the complete contact of dissimilar materials with Dundurs parameters a,p and at the root of the notch based on the order of stress singularity, (A-1). The strain energy density criterion is applied to predict the crack initiation angle using the order of stress singularity, (A-1). The crack initiation angle compares well with the experimental angle values, which is obtained through the scanning electron microscope. A fretting fatigue life prediction model is developed based on the strain energy density criterion in which a critical process zone size is used to estimate crack initiation life and crack analogue model is used to determine the crack propagation life. The critical process zone size is estimated using the notch analogy for the fretting fatigue loading condition. The theoretically calculated crack initiation and propagation lives compares well with the experimental results

Transesterification of Jatropha oil using immobilized Pseudomonas fluorescens

Transesterification of vegetable oils is an important reaction that produces fatty acid alkyl esters, methyl and ethyl esters which are excellent substitutes for diesel fuel. Biodiesel prepared by catalyzedmild transesterification has become of much current interest for alternative fuel production. In the present study the ability of a commercial immobilized Pseudomonas fluorescens MTCC 103 to catalyze the transesterification of Jatropha oil and methanol was investigated. The cell of P. fluorescens was easily immobilized within the sodium alginate during batch process. The important parameters like reaction temperature, pH, oil/methanol molar ratio, amount of beads and reaction time was studied. From the study it was found that maximum yield of biodiesel was obtained at the optimum conditions ofat 40ºC, pH of 7.0, molar ratio of 1:4, amount of beads of 3 g and reaction time of 48 h. The physical properties of the products were analyzed and the results were compared with conventional petroleumbased diesel and it was found that the product can be used as an effective alternate fuel in existing diesel engine without any hardware engine modifications

Green synthesis of silver nanoparticles using Pimpinella anisum seeds: Antimicrobial activity and cytotoxicity on human neonatal skin stromal cells and colon cancer cells

Background: The present study focused on a simple and eco-friendly method for the synthesis of silver nanoparticles (AgNPs) with multipurpose anticancer and antimicrobial activities. Materials and methods: We studied a green synthesis route to produce AgNPs by using an aqueous extract of Pimpinella anisum seeds (3 mM). Their antimicrobial activity and cytotoxicity on human neonatal skin stromal cells (hSSCs) and colon cancer cells (HT115) were assessed. Results: A biophysical characterization of the synthesized AgNPs was realized: the morphology of AgNPs was determined by transmission electron microscopy, energy dispersive spectroscopy, X-ray powder diffraction, and ultraviolet-vis absorption spectroscopy. Transmission electron microscopy showed spherical shapes of AgNPs of P. anisum seed extracts with a 3.2 nm minimum diameter and average diameter ranging from 3.2 to 16 nm. X-ray powder diffraction highlighted the crystalline nature of the nanoparticles, ultraviolet-vis absorption spectroscopy was used to monitor their synthesis, and Fourier transform infrared spectroscopy showed the main reducing groups from the seed extract. Energy dispersive spectroscopy was used to confirm the presence of elemental silver. We evaluated the antimicrobial potential of green-synthesized AgNPs against five infectious bacteria: Staphylococcus pyogenes (29213), Acinetobacter baumannii (4436), Klebsiella pneumoniae (G455), Salmonella typhi, and Pseudomonas aeruginosa. In addition, we focused on the toxicological effects of AgNPs against hSSC cells and HT115 cells by using in vitro proliferation tests and cell viability assays. Among the different tested concentrations of nanoparticles, doses 10 µg led to increased cytotoxicity. Conclusion: Overall, our results highlighted the capacity of P. anisum-synthesized AgNPs as novel and cheap bioreducing agents for eco-friendly nanosynthetical routes. The data confirm the multipurpose potential of plant-borne reducing and stabilizing agents in nanotechnology

CeO₂-CePO₄ and Ag@CeO₂-CePO₄ nanocomposites from Penaeus semisulcatus for heavy metals sensing, UV shielding and cytotoxic applications

CeO2-CePO4 and Ag@CeO2-CePO4 nanocomposites (NCs) were prepared using Penaeus semisulcatus and characterized by various analytical techniques. The NCs exhibited spherical morphology, with average particle sizes measuring 2.36 nm, 3.30 nm and 29.64 nm for the samples air dried, annealed at 550 °C and 800 °C respectively, and the Selected Area Electron Diffraction patterns from HR-TEM revealed their crystalline nature. In 3d X-ray Photoelectron Spectra (XPS) of NCs, the highest binding energies were observed at 916.46 eV (3d3/2) and 898.16 eV (3d5/2) with spin–orbit splitting of 18.3 eV. The X-Ray Diffraction (XRD) patterns of the NCs showed peaks typical of both CeO2 and CePO4 phases. The Fourier Transform-Infra Red (FT-IR) spectrum contained bands due to Ce-O stretching at 560 cm−1 and PO43- groups at 1008 and 711 cm−1, which was further substantiated by Raman spectrum, which had an intense peak at 468 cm−1 corresponding to F2g band of CeO2 and another peak at 976 cm−1 due to PO43- tetrahedron. In the Ultraviolet-Visible Diffuse Reflectance Spectra (UV-Vis DRS), the broad absorption peak at 352 nm and minor peaks around 300 nm confirmed the formation of CeO2-CePO4 NCs. The green synthesized NCs were excellent fluorescence sensors for Pb2+, Cd2+ and Hg2+ in a wide range of concentrations, from 5.0x10-9 M to 4.0x10-5 M. The concentration Vs. emission fitting plot had three distinctive linear ranges. At a low concentration range (5x10-9 to 3.5x10-7 M), the limit of detection for Pb2+, Cd2+ and Hg2+ was found to be 2.41x10-8, 2.56x10-8 and 3.11x10-8 M. The sensitive detection of a mixture of heavy metal ions in ppb levels by biocompatible NCs gained insight in treating aqueous industrial wastes. Further, NCs showed cytotoxicity and UV shielding properties.</p

Differences in the food of the young and the adult Indian mackerel, Rastrelliger kanagurta (Cuv.)

The problem of the food of fishes with its varied bearings on their shoaling habits and migrations has engaged the attention of fishery biologists since the beginning of the present century. The mackerel is an important food fish in both hemispheres. Several contributions have been made to our knowledge of the food of the Indian mackerel, Rastrelliger kanagurta, which contributes to one of the largest fisheries of India. All these observations, except those of Chacko, which are from the Gulf of Manaar, are confined to the west coast of India. According to these workers, mackerel is a noted plankton feeder, securing its food by filtration. Chidambaram, while observing the adult mackerel as plankton feeder, suggested the carnivorous habits of the young mackerel. Later, in a detailed account on the food of this fish, Bhimachar and George observe that "the food of the young mackerel does not radically differ from that of the adult". Pradhan has arrived at a similar conclusion regarding the food of mackerel; but one will not fail to note from his observations that young mackerel less than 89 mm. in total length are not represented in his material

Biofilm formation on copper and its control by inhibitor/biocide in cooling water environment

The present study has successfully identified the nitrate reducing bacteria present in the cooling water system and also investigated the performance of industrially applied biocide and inhibitor on the bacterial inhibition. In order to carry out the objective of this study, facilities and methods such as 16S rRNA gene sequencing, Lowry assay, SEM, EIS, ICP-MS and weight loss analysis were being utilized. In this study, two out of the five morphologically dis- similar colonies identified through 16S rRNA gene sequencing, namely the Massilia timonae and the Pseudomonas, were being utilized in the biocorrosion study on copper metal. From the surface analysis using SEM demonstrated the phenomenon of biofilm formation on the copper surface. 2-methylbenzimidazole has the addition of methyl group in the diazole ring position of benzimidazole it has create basicity environment and inhibit the metal deterioration. Meanwhile, it is also deducible from the EIS and protein analysis that com- bination of biocide with either of the inhibitors gives rise to better biocorrosion suppression (0.00178 mpy and 0.00171mpy) as compared to the sole effect of either biocide or inhibitor (0.00219 mpy, 0.00162 and 0.00143). Biocorrosion system biocide with MBM was found to exhibit 65% corrosion inhibition efficiency. Moreover, adoption of 2-Methylbenzimidazole seems to display better performance as compared to Multionic 8151, which is adopted in cooling water system

Magnetic nanoparticles are highly toxic to chloroquine-resistant Plasmodium falciparum, dengue virus (DEN-2), and their mosquito vectors

SURESH KUMAR SUBBIAH (A04156) / / / Kadarkarai Murugan,Jiang Wei,Mohamad Saleh Alsalhi,Marcello Nicoletti,Manickam Paulpandi,Christina Mary Samidoss,Devakumar Dinesh,Balamurugan Chandramohan,Chellasamy Paneerselvam,Jayapal Subramaniam,Chithravel Vadiva

Comparative Angiogenic Activities of Induced Pluripotent Stem Cells Derived from Young and Old Mice

Advanced age is associated with decreased stem cell activity. However, the effect of aging on the differentiation capacity of induced pluripotent stem (iPS) cells into cardiovascular cells has not been fully clarified. We investigated whether iPS cells derived from young and old mice are equally capable of differentiating into vascular progenitor cells, and whether these cells regulate vascular responses in vivo. iPS cells from mouse embryonic fibroblasts (young) or 21 month-old mouse bone marrow (old) were used. Fetal liver kinase-1 positive (Flk-1+) cells, as a vascular progenitor marker, were induced after 3 to 4 days of culture from iPS cells derived from young and old mice. These Flk-1+ cells were sorted and shown to differentiate into VE-cadherin+ endothelial cells and α-SMA+ smooth muscle cells. Tube-like formation was also successfully induced in both young and old murine Flk-1+ cells. Next, hindlimb ischemia was surgically induced, and purified Flk-1+ cells were directly injected into ischemic hindlimbs of nude mice. Revascularization of the ischemic hindlimb was significantly accelerated in mice transplanted with Flk-1+ cells derived from iPS cells from either young or old mice, as compared to control mice as evaluated by laser Doppler blood flowmetry. The degree of revascularization was similar in the two groups of ischemic mice injected with iPS cell-derived Flk-1+ cells from young or old mice. Transplantation of Flk-1+ cells from both young and old murine iPS cells also increased the expression of VEGF, HGF and IGF mRNA in ischemic tissue as compared to controls. iPS cell-derived Flk-1+ cells differentiated into vascular progenitor cells, and regulated angiogenic vascular responses both in vitro and in vivo. These properties of iPS cells derived from old mice are essentially the same as those of iPS cells from young mice, suggesting the functionality of generated iPS cells themselves to be unaffected by aging

Fabrication of nano-mosquitocides using chitosan from crab shells: impact on non-target organisms in the aquatic environment

Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV–vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8–10 ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments