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Synthesis of Yttria-Stabilized Zirconia Nano Powders for Plasma Sprayed Nano Coatings
Plasma sprayed Yttria Stabilized Zirconia (YSZ) coatings, with few microns sized microstructure/grain morphology has been well researched, reported and established as an industrial Thermal Barrier Coatings (TBC) material/system. However, nano structured YSZ coatings possess improved characteristics when compared with their micron sized counterparts. However, due to their nano sizes, light weight, and low density, plasma spray coating process of nano powders suffers from flowability issues due to lack of nano powder inertia/momentum, leading to poor deposition/uneven coating thickness. In this research work, nano structured YSZ coatings were synthesized by using an Atmospheric Spray Coating (APS) facility. Nano powders of YSZ were used as the starting materials to prepare micron sized plasma sprayable powders. 80?m thick NiCrAlY bond coat (commercial) and 200?m thick YSZ top coat with nano microstructure (lab synthesized) were built on steel substrates. The starting nano crystalline (YSZ) powders, measuring 30-70 nanometers (nm) were synthesized in the laboratory via chemical method (sol-gel) by employing zirconium oxy chloride hexa-hydrate and yttrium nitrate as precursors, citric acid as chelating agent and ethylene glycol for the diversification reaction followed by calcination @ 1000C. They were then re-constituted into micron sized (53-106 ?m) plasma sprayable powders by agglomerating with polyvinyl alcohol (PVA) binders. The nano crystallite morphology of powders and coatings were analyzed by Scanning Electron Microscope (SEM), chemical composition by Energy Dispersive spectroscopy (EDS) and crystal structural phase by X-ray diffraction (XRD). The influence of calcination temperature of 1150C on nano crystallite morphology was also studied. 2019 Elsevier Ltd. -
Synthesis of Value Added Refractories from Aluminium Dross and Zirconia Composites
Results of a developmental study on the potential to synthesize industrial grade refractories from aluminum dross with un-stabilized zirconia are reported. The merit of the developed product to perform as refractories suitable for use at or above 1000C was assessed by studying the thermo-physical behavior as per guidelines of ASTM and IS. Aluminum dross, an industrial waste (slag) is generated in several millions of tons in the production of Aluminum and is dumped into landfills, which releases poisonous gases like methane and ammonia upon contact with moisture present in the land and the heat generated by the earth, warranting stringent mitigation efforts. Rich in aluminum metal (?15%), ?-Al2O3 (7-15%), MgAl2O4 (10-15%) and AlN (20-30%), the general prime dross composition draws interest due to its abundance and presence of ?-Al2O3 and MgAl2O4, for the production of refractories with insulating, shock resistance and stability at high temperature (?1000C and above) characteristics. Nevertheless, presence of AlN, a good thermal conductor acts as a deterrent in the production of refractories. Aluminium dross (after leaching out AlN) was processed with un-stabilized zirconia (monoclinic ZrO2) to synthesize the refractory composites. Conventional process (calcination, ball milling, compaction and sintering (1550C/6 hrs)) was employed. Characterization involved thermal shock cycling (air quench at furnace ambient of 1000C and room temperature) to determine the number of shock cycles endured before failure. Structural phase analyses at various stages of processing were carried out by via XRD. Magnesia present in dross did not appear to stabilize either the tetragonal or cubic ZrO2. Microstructural and chemical composition studies were carried out via SEM and EDS. The favourable results confirm the viability of the process methodology. 2019 Elsevier Ltd. -
Synthesis of UWB Pulse Shaper for Efficient Pulse Propagation in Human Tissue
In this paper, a filter based pulse shaper is proposed for efficient Ultra-wideband (UWB) pulse transmission through human tissues. A bandpass Finite Impulse Response (FIR) filter is synthesized and its closed form expression for the impulse response coefficients is obtained. The filter shapes the basic UWB pulse, to closely fit the desired Federal Communication Commission (FCC) mask specifications, to achieve high spectral utilization efficiency. In this approach, the effects due to Gibb's phenomenon are minimized thereby resulting in lower dominant sidelobe of the resultant UWB pulse. The interference between adjacent pulses of the UWB data stream is minimized thus it allows shorter duration UWB pulses to be synthesized leading to higher data rate transmission compared to some techniques in literature. 2020 IEEE. -
Synthesis of Thiazines, Thiazinones and N-Cycloalkyl Azoles Via Novel Synthetic Routes
Heterocyclic building blocks have gained the utmost importance in recent past on the newlineaccount of their significance in biological and pharmaceutical fields. Among these newlinenitrogen and sulphur containing heterocyclic building blocks such as thiazines, newlinethiazinones and N-cycloalkyl heterocyclic motifs hold an important role in medicinal newlinechemistry. Thiazine cores are used for the treatment of various life threating diseases newlinelike cancer, cardiovascular and fabry diseases. Drugs containing thiazinone cores were used to treat Parkinson, Alzheimer s and various neuro degenerative diseases. Ncycloalkyl azole motifs are used to treat various life threating cancers like neck, lung, prostate, breast etc. As per the literature review, synthesis of these motifs are done using multi steps and harsh conditions, which limited the substrate scope. In this thesis we describe our studies on development of one pot, mild condition for newlinesynthesis of thiazinone cores using P(NMe2)3 (HMPT). We had developed HMPT [P(NMe2)3] mediated reactions towards synthesis of Carbon-Nitrogen/Carbon-Sulphur bond. The developed methodology was extended for thiazine cores as well. This new synthetic methodology is useful to synthesize various N, S-heterocycles including the novel spiro molecules. HMPT reagent under the mild and aerobic reaction conditions provided the access for many manifold immense molecules. Molecular docking studies were conducted for the synthesized compounds considering MOA-B inhibitors as target. MOA-B inhibitor motifs were approved for the treatment of Parkinson illness. The synthesized thiazine and thiazinone molecules showed good binding affinity in molecular docking studies conducted. We had developed a new strategy using T3P (1-Propanephosphonic anhydride, ~ 50 % wt, in EA solution) mediated synthetic procedure for the synthesis of N-cycloalkyl newlineazoles. -
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Synthesis of spray dried nano 8YSZ plasma sprayable powder and plasma sprayed thermal barrier coatings with nano grained microstructure /
Patent Number: 202241011004, Applicant: S. Gowtham Sanjay.
Plasma sprayed 8% yttria stabilized zirconia, i.e. 8Y203-Zr02(8YSZ) coatings with nano grained microstructure are expected to possess superior thermal barrier properties when compared with the coating of same composition but with large micron sized grains in its microstructure. 8YSZ nano powders were spray dried to be converted into easily flowing micron sized (>20 and <100u) plasma sprayable powders. The powders were plasma spray coated on stainless steel (SSL 304) and Aluminium-silicon (Al-Si) alloy substrates. -
Synthesis of spray dried nano 8YSZ plasma sprayable powder and plasma sprayed thermal barrier coatings with nano grained microstructure /
Patent Number: 202241011004, Applicant: S. Gowtham Sanjay.
Plasma sprayed 8% yttria stabilized zirconia, i.e. 8Y203-Zr02(8YSZ) coatings with nano grained microstructure are expected to possess superior thermal barrier properties when compared with the coating of same composition but with large micron sized grains in its microstructure. 8YSZ nano powders were spray dried to be converted into easily flowing micron sized (>20 and <100u) plasma sprayable powders. The powders were plasma spray coated on stainless steel (SSL 304) and Aluminium-silicon (Al-Si) alloy substrates. -
Synthesis of SnO2-Sodium alginate-polyethylene glycol-crocin nanocomposite for enhanced antimicrobial and anticancer activity
Bacteria and fungi contribute to antibiotic resistance, posing a growing threat to human health, while cervical cancer remains a significant health concern, impacting women's well-being and mortality rates worldwide. In the present work, the efficiency of formulated tin oxide-sodium alginate-polyethylene glycol-crocin nanocomposites (SnO2-SAPEG-Cro-NCs) on antimicrobial as well as growth inhibition and apoptosis induction in cervical cancer cells was evaluated. The developed nanostructure was exposed to several spectroscopic investigations, including UV, FTIR, XRD, PL, EDAX, DLS studies, and FESEM structural observation. The results of the antimicrobial study revealed increased inhibition zones from 8.5 to 16 mm around the SnO2-SAPEG-Cro-NCs treatment over different pathogens, which proves its antimicrobial efficacy. The findings of the MTT study demonstrated that SnO2-SAPEG-Cro-NCs (0.510 ?g/mL) treatment remarkably inhibited the HeLa cell viability with IC50 concentration of 5 ?g/mL. The SnO2-SAPEG-Cro-NCs-treated HeLa cells also revealed increased intracellular ROS generation at 5 and 7.5 ?g/mL, which may facilitate oxidative stress-mediated cell death. Further, the dual staining and DAPI staining results demonstrated that the SnO2-SAPEG-Cro-NCs treatment effectively increased the apoptosis in the cervical cancer HeLa cells. Overall, the outcomes authorized that SnO2-SAPEG-Cro-NCs is an excellent antimicrobial and anticancer agent for future use. 2024 Elsevier B.V. -
Synthesis of Quinoxalin-2(1 H)-ones and Hexahydroquinoxalin-2(1 H)-ones via Oxidative Amidation-Heterocycloannulation
A metal-catalyst-free synthesis of substituted quinoxalin-2-ones from 2,2-dibromo-1-arylethanone by employing an oxidative amidation-heterocycloannulation protocol is reported. The substrate scope of the reaction has been demonstrated and a possible mechanism for this reaction has also been proposed. 2020 GeorgThieme. All Rights Reserved. -
Synthesis of porous graphene sheets from agricultural waste by chemical methods
A facile technique to synthesise wrinkled graphene like nano carbon (GNC) agricultural waste like wood and coconut charcoal is reported in the current study. The charcoal is produced by thermal decomposition of wood and coconut shell and is intercalated by Hummer's method. It is separated by centrifugation and sonication to get few layer graphene sheets. The structural and chemical changes of the nanostructure are elucidated by Raman spectroscopy, TEM, SEMEDS and XPS. Raman spectra revealed the existence of highly graphitized amorphous carbon, which is confirmed by the appearance of five peaks in the deconvoluted first order Raman spectra. The SEM analysis reveals the formation of large area graphene sheets with nanoporous structure in it. The TEM/SAED analysis exhibits the presence of short range few layers graphene. 2018 World Research Association. All rights reserved. -
Synthesis of Online Criminal User Behaviours Disseminating Bengali Fake News Using Sentiment Analysis
Even though research on artificial intelligence (AI) is still in its early phases, the field is growing in popularity. We created a hybrid machine learning model to better understand the pattern of results connected to illegal user behaviour. Then, after identifying the components of illegal user activity, we created a theory for forecasting criminal user behaviour that explains the patterns and results. Our study focuses on offenders spreading misleading information online and makes use of a Bengali dataset. Sentiment analysis is a modern technology that can help us understand how individuals feel in different scenarios during their everyday lives. To comprehend the pattern behind this agenda, machine learning and deep learning techniques will be applied throughout the categorization process. To determine the possible attitudes driving criminal conduct that spreads misleading information, sentiment levels on social media may be monitored or studied. This study examines the use of several artificial intelligence approaches to assess sentiment in social media data in order to identify criminal user activity occurring throughout the world. The hybrid model CNN with Adam optimizer exhibits higher precision levels while doing sentiment analysis. In addition to identifying solutions to the issues that people currently face in the modern world, we also propose a new categorization system for illicit user activity. In our analysis of the research's shortcomings, we make recommendations for a broader research agenda on illicit user conduct and how one can forecast the criminal user behaviour on psychological aspects. Our model was thus able to draw 87.33% accuracy in determining criminal behaviour patterns. The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024. -
Synthesis of novel Se capped polymer photocatalyst mobilized under visible light: Exploration of piezoelectric effect and charge transfer mechanism in polymer matrix
The present study has shown the original and promising usage of zero valent metallic selenium in the photocatalysis process under visible light. Selenium (Se) dispersed into the Polyvinyl Chloride (PVC) and Polyvinylidene Fluoride (PVDF) polymeric solution (Se-PVC/Se-PVDF matrix) by reflux-calcination method. The SEM and TEM results shows Se nanoparticles are well disseminated into the polymer solution and homogenously mixed to avert cluster of particles. The results shows that Se-PVC matrix effectively enhanced the generation rate of photoinduced electrons and reduced transfer resistance endorsed by photoluminescence, transient photocurrent, and electrical impedance spectroscopy techniques. Further, photocatalytic activity studied in presence of potassium iodide (KI) and isopropyl alcohol (IPA). The decrease in photocatalytic activity order is: Se-PVC > Se-PVDF > Se-PVC + KI > Se-PVDF + KI > Se-PVC + IPA > Se-PVDF + IPA systems. The piezoelectricity phenomena and Surface Plasmon Resonance (SPR) effect proposed for Se-PVC/Se-PVDF matrix and correlated with photocatalytic mechanism for the degradation of Methyl Orange (MO). 2023 Elsevier B.V. -
Synthesis of Nanoflowers using Garcinia gummi-gutta Leaf Extract via Green Route for Enhanced Antifungal and Anti-cancerous Activities
Due to its envisaged relevance in nanomedicine and materials research, the bio-engineering of nanoparticles (NPs) is becoming progressively more promising. Compared to physical and chemical processes, green synthesis produces NPs that are less hazardous to the environment. The usage of phytochemicals in Garcinia gummigutta (L.) leaf extract (GGL) in the bio-reduction of GGL-Ag NPs with potential antifungal and anti-cancerous activities was the main focus of the current study. UV-vis spectrophotometry at 442 nm verified the synthesized GGL-Ag NPs. The average diameters of the synthesized GGL-Ag NPs were determined by scanning electron microscopy (SEM and zeta-sizer studies to be 166.69 nm and 148.2 nm, respectively. Energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) examinations of the GGL-Ag NPs confirmed the crystalline nature and the elemental constitution of the NPs. Additionally, the synthesized GGL-Ag NPs' FTIR spectra demonstrated the presence of Phyto components acting as capping agents. Zeta potential measurements (-26.2 4.13 mV) authenticated the stability of the synthesized GGL-Ag NPs. Antimicrobial activity testing of the GGL-Ag NPs demonstrated considerable suppression against Candida tropicalis and Candida albicans at a dose of 100 g/ml and 60 g/ml. Additionally, the synthesized GGL-Ag NPs have demonstrated considerable cytotoxic effects on the Hep-G2 cell line. The current study results show that GGL-Ag NPs may be produced at a low cost and with minimal environmental impact for nanobiotechnology and biomedicine usage. 2024, Brawijaya University. All rights reserved. -
Synthesis of nanocarbon-polyaniline composite and investigation of its optical and electrical properties
The polyaniline-nanocarbon (PANI-NC) composite was synthesized by in situ polymerization of the aniline monomer (PBC-A&B) with reduced carbon from bituminous coal (RBC). The X-ray analysis confirmed the formation of the polyaniline-graphene oxide composite. The XRD result shows that the stacking height of the PBC-A increased due to the attachment of nitrogen group to the carbon lattice. The result of CHNS confirmed the increase in composition of nitrogen in PBC-A due to the treatment of RBC with aniline to form the polymer-nanocarbon composite. Optical analysis by UV absorption spectra revealed that the band gap is in the range of 3.29-4.27 eV. The AC conductivity, dielectric permittivity, and dielectric loss of the composite are measured within a frequency response of 10 Hz to 1 MHz. It is observed that one can tailor the band gap of the PANI-GO composite by varying the concentration of reduced carbon from coal. 2019 Elsevier Ltd. All rights reserved. -
Synthesis of nano-crystalline tin dioxide and its effect on calcination
Nitrate-citrate gel-combustion method was used in this study to prepare nano-crystalline tin dioxide. The samples were calcined at a temperature range of 543-1173 K. The prepared powder was characterized by SEM, TEM and X-ray diffraction. On increasing the temperature with limited supply of air (calcination), there is a systematic increase in tin content accompanied by a reduction in oxygen. The tetragonal nano tin structure formed during the process has about 20 nm in lateral size. With increase in calcination temperature, the carbon content systematically decreased. 2017, Chemical Publishing Co. All rights reserved. -
Synthesis of Magnetorheological fluid Compositions for Valve Mode Operation
Smart materials such as Magnetorheological Fluids (MRF) have become sought-after material in wide ranging applications due to the ability to change properties in a controlled manner under application of stimulation such as a variable current, magnetization, heat, force, stress and deformation. Magnetorheological fluids in the rheological fluid domain has found use due to its ability to change its shear strength based on the applied magnetic field. Magnetorheological fluids are composed of magnetizable micron sized iron particles and a non-magnetizable base/carrier fluid. The shear strength of commercially available MRF varies from 0 to 100kPa under the effect of the magnetic field. In a valve mode, the Magnetorheological damper (MR Damper or MRD), the MR fluid flows between two-fixed poles, which are parallel to each other. When the fluid flows between them, due to the applied magnetic field the magnetic particles align themselves in a chain form (on state) which is easily reversible when the field is removed (off state). Physical change of the fluid from liquid to semi-solid is controlled by the magnetic field, which makes the fluid a reliable member in active vibration control applications. In this study, two types of magnetizable particles (Carbonyl iron (CI) and Electrolytic iron (EI)) are taken and characterized using an Anton Paar MCR 702 rheometer set-up, in on and off states. To overcome issues like sedimentation, agglomeration and corrosion of the MR fluid, the iron particles are coated with natural gum like guar and xanthan, to the carrier fluid grease and other thixotropic additives are added. The addition of grease and thixotropic additives will inhibit the microbiological degradation of natural gum over an extended period. These engineered MR fluids are then used to analyze the performance of designed and developed stand-alone MR damper, which is tested using an electro-dynamic shaker. The response and damping performance of the MR Damper is analyzed with controlled changes in variables including percentage of additives in MR fluid & magnetization values 2019 Elsevier Ltd. -
Synthesis of Inorganic Nanoparticles Using Traditionally Used Indian Medicinal Plants
Considering the exclusive environmental conditions and geological characteristics, Indian flora is extensive and rich in medicinal plants. From primeval times, plant parts and their metabolites have been widely explored for various practices including medicinal as well as culinary. The phytochemicals present in these plants are potential reducing agents for the bio-fabrication of these nanoparticles. The non-toxic nature and combination of the plant phytochemicals with precursor ions act as key aspects for synthesized nanoparticles. The present review highlights the potential applications of Inorganic nanoparticles synthesized from 148 traditionally used medicinal plants present in the Indian geographical region. In addition, parameters that influence the green synthesis of Inorganic nanoparticles such as the extraction methods, solvents used for extraction, the concentration of precursor and plant phytochemicals, pH, temperature, reaction time, and characterization techniques of the nanoparticles are discussed. Thus, the review provides information on the research that has been done in the area of green synthesis using Indian medicinal plants. 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Synthesis of high temperature (1150 C) resistant materials after extraction of oxides of Al and Mg from Aluminum dross
Aluminum Dross (Al-dross) is a well-known Industrial waste generated in an Aluminium industry from the melting of the metal itself. It gets made yearly in hundreds of thousands of tons worldwide, due to the wide use and demand of Aluminum in almost every industry. However, Al-dross is not completely a waste as it contains two compounds of interest, namely Aluminum Oxide (Al2O3) and Magnesium Aluminate (MgAl2O4). They are the basic compounds present in any refractory which are products featuring low thermal conductivity and high temperature shock characteristics in the order of 1000 C+. Thus, Aluminum Dross becomes a vital candidate to be considered for the extraction of the two of the aforementioned compounds. Recent studies have shown that Al-dross indeed can be used to extract Al2O3 and MgAl2O4. However, Al-dross also contains Aluminum Nitride (AlN) a compound that exhibits the exact opposite properties demonstrated by refractories. In addition to being technically unsuitable for use as refractory material, AlN also possesses another huge issue. When Al-dross is dumped into landfills, the AlN present in the dross combines with the moisture in the soil and is energized by geothermal heat which leads into an exothermic reaction, thereby releases highly toxic and health hazardous gases. Keeping the above techno-environment challenges in mind, prior to utilizing the beneficiated Al-dross in any industrial application, it is important to leach out the AlN from the dross in an environment friendly manner. This paper deals with the successive leaching of AlN from the Al-dross using two laboratory procedures. Sintered (to be added) pellets made out of the processed powder in the lab were subjected to analysis of structural phases and chemical constituents by employing XRD and EDS. Cyclic thermal shock test cycles were also carried out by subjecting the pellets to 1150 C and quenching in air alternately, to study the refractory characteristics. 2019 Elsevier Ltd. All rights reserved. -
Synthesis of Graphene Oxide Nano Structures from Kerosene Soot and its Impedance Analysis
Graphene oxide was synthesized from kerosene soot, by adapting three different treatments. The properties of each sample were studied using X-ray diffraction, UV-visible spectroscopy, FTIR and impedance measurements. The XRD results showed that the structural parameters (layer spacing, number of layers) were in agreement with expected values, indicating the reliability of kerosene soot as a precursor for graphene. The grain size was found to be small (1 to 2 nm) confirming the nanostructure of kerosene soot. The UV-visible spectra revealed high band gap even while conductivity was appreciably high. Other characteristic measurements showed frequency-independent conductivity, low resistance and low capacitance. FTIR spectra of all the treated samples and the precursor show the differences brought about in functionalization, due to the different methods of treatment. These differences, however, does not appreciably affect parameters such as band gap, conductivity and dielectric loss in any drastic way. 2018 Chemical Publishing Co. All Rights Reserved. -
Synthesis of emeraldine PANI polymer-reduced graphene and its use as polyelectrolyte
Abstract: Reduced graphene oxide (rGO)/polyaniline (PANI) composites grabbed the interest of researcher towards the development of electrolyte material. In present research work, we have focused on the synthesis of rGO and PANI by chemical method. The composites are prepared using different amounts of rGO/PANI and lithium carbonate. The main objective is to enhance structural and electrochemical properties of polymer composites. It is observed that proper interface of polymer composites leads towards the desired chargedischarge capacity and cyclic stability with the diffusion of electrons and electrolyte ions. This particular study can be further used for the development of electrochemical device applications. Graphic abstract: [Figure not available: see fulltext.]. 2019, Springer-Verlag GmbH Germany, part of Springer Nature.