Search

Mechanical machining processes are being used in the utilization of cutting fluids, cutting fluids improves machining efficiency while also extending tool life by lowering temperature and friction during the machining process. The "flood flow system" is a typical coolant applicant technique in which a huge volume of liquid/coolant is continuously applied to the cutting field. This plan is incredibly inefficient first and foremost, a huge amount of cutting fluid is required secondly the cutting fluids unable to pass through the cutting zone to chip hardness. However, because of the unregulated use of fluid for cutting, there is a risk of economics and environment burden. As a result, a highly practical bridging technology known as "Minimum amount lubrication" was developed. Fluid for cutting/ coolant isdelivered to the cutting field at low rate in this technology. High pressure fluid is sprayed into the scraps is supplied to the cutting field at a very low rate in this technology. Fluid is sprays at high pressure into the cuttings zone, whichhas been combined with compressed air. The "Mist Flow System" is a method of administering cutting fluid/ coolant. This technology necessitates the use of a pneumatic spray nozzle. It is capable of atomizing the fluid with compressedair in the desired ratio and delivering a controlled or (regulated) spray. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) and machine learning (ML) have significantly impacted data analysis in the past few years. Numerous strategies have been developed to accomplish the same. Multiple application fields have used standard machine learning methods. Researchers also worked hard to improve the machine learning algorithm's efficiency. AI and ML often enable applications to perform intelligently. Another aspect was considered, the idea of deep learning, which is the subset of ML. Few deep learning applications have been investigated thus far. In this study, we provide a detailed overview of the literature on machine learning and deep learning applications in the agriculture, medicine, and network fields. This work aims to identify the essential principles of different machine-learning techniques and explore their practical applications in diverse areas, including agriculture, diagnostics, and networking. Moreover, we examine the challenges and opportunities for further investigation based on our discoveries. This article aims to provide a technical reference for decision-makers in many real-world scenarios and application domains, as well as for academic and industry experts. [ABSTRACT FROM AUTHOR]

In this study, the effect of process parameters on lap shear strength of aluminium alloy 6061 sheets with the addition of Al2O3 nanoparticles by Friction Stir Spot Welding (FSSW) was investigated. Three different process parameters which include tool rotational speed, tool plunge rate and dwell time were selected for the investigation. Taguchi method using the L9 orthogonal array was used to optimize the process parameters. The percentage of contribution of process parameters was predicted using analysis of variance analysis. The experimental result shows that among the three process parameters, tool rotational speed plays the significant parameter on lap shear strength of the 6061-T6/Al2O3 composite joint. [ABSTRACT FROM AUTHOR]

A new series of Lithium hexaferrite with substitution of aluminium and cobalt ions ( M- type ferrites ) compounds were synthesized using reacting oxide by high temperature solid state reaction technique with the general chemical formula Li0.5Fe0.5+xCoxAl12-2xO19(where x = 2, 3, 4, 5 and 6). The structural characterization of compound has been carried out from X-Ray diffraction powder pattern. The compounds are in single hexagonal phase without traces of uncertainly ambiguous reflection. From XRD pattern, lattice parameters has recorded with increasing doped aluminum element in the range from a = 5.807 Å to 5.906 Å and c = 22.507 Å to 22.585 Å pertaining the space group P63R/mmc (No.194) and confirmed from JCPDS data. The mass density of the ferrites were found linearly varies and depends upon the mass and volume of compounds.The X-Ray density has depends upon the lattice constant and molecular weight of the compounds. The average particle size was also estimated. The compounds were studies magnetically by using Guoy’s method in the temperature range 300K to 1000K, the result shows that the compounds are paramagnetic in nature. The Curie molar constant was work out. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) uses MEMS sensor nodes and actuators to sense and control objects through Internet. IOT deploys millions of chemical battery driven sensors at different locations which are not reliable many times because of frequent requirement of charging & battery replacement in case of underground laying, placement at harsh environmental conditions, huge count and difference between demand (24% per year) and availability (energy density growing rate 8% per year). Energy harvester fabricated on silicon wafers have been widely used in manufacturing MEMS structures. These devices require complex fabrication processes, costly chemicals & clean room. In addition to this silicon wafer based devices are not suitable for curved surfaces like pipes, human bodies, organisms, or other arbitrary surface like clothes, structure surfaces which does not have flat and smooth surface always. Therefore, devices based on rigid silicon wafers are not suitable for these applications. Flexible structures are the key solution for this problems. Energy transduction mechanism generates power from free surrounding vibrations or impact. Sensor nodes application has been purposefully selected due to discrete power requirement at low duty cycle. Such nodes require an average power budget in the range of about 0.1 microwatt to 1 mW over a period of 3-5 seconds. Energy harvester is the best alternate source in contrast with battery for sensor node application. Novel design of Energy Harvester based on cheapest flexible non silicon substrate i.e. cellulose acetate substrate have been modeled, simulated and analyzed on COMSOL multiphysics and fabricated using sol-gel spin coating setup. Single cantilever based harvester generates 60-75 mV peak electric potential at 22Hz frequency and approximately 22µW power at 1K-Ohm load. Cantilever array can be employed for generating higher voltage by replicating this structure. This work covers design, optimization, fabrication of harvester and schottky diodes based voltage multiplier. [ABSTRACT FROM AUTHOR]

Rainfall and flow prediction, adapting the Venkataraman single time series approach and Wiener multiple time series approach were conducted for Aralikottai tank system, and Kothamangalam tank system, Tamilnadu, India. The results indicated that the raw prediction of daily values is closer to actual values than trend identified predictions. The sister seasonal time series were more amenable for prediction than whole parent time series. Venkataraman single time approach was more suited for rainfall prediction. Wiener approach proved better for daily prediction of flow based on rainfall. The major conclusion is that the sister seasonal time series of rain and flow have their own identities even though they form part of the whole parent time series. Further studies with other tropical small watersheds are necessary to establish this unique characteristic of independent but not exclusive behavior of seasonal stationary stochastic processes as compared to parent non stationary stochastic processes. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Ever since the early days, man has always admired flying creatures which inspired human to attempt to build a flying machine. The design complication always higher in flapping type of mechanism compared with fixed mechanism, irrespective of sizes of an airplane. In current scenario flapping wing micro air vehicles (MAVs) are used in several different areas for different applications. In this paper focused on analysis an aerodynamics characterization of flapping wing arrangement used for MAV applications. The bio-inspired flapping wing had chosen to analysis the changes of the flow pattern over the flapping wings. The computational method and experimental methods are used to carry out the results. The wing for analysis were inspired from the great black-backed seagull, which has high aspect ratio wings with pointed wingtips and a high camber wing section. A scaled-down model was considered to complete the experimental analysis. The 3-dimensional wing model made with the help of 3-d printed airfoils. The various aerodynamic parameters were calculated and compared. [ABSTRACT FROM AUTHOR]

P2O5─PbO─ Ga2O3─Dy2O3 glasses doped with different concentrations of Bi2O3were prepared by conventional melt quenching technique. The prepared glasses were characterized by optical absorption and luminescence studies. The observed decreasing trend in energy band gap values of the titled glasses indicates the increasing degree of depolymerization in the network with increase in Bi2O3 content. The sample doped with 3 mol % of Bi2O3 exhibits higher luminescence at all excited wavelengths rather than other samples. Significant energy transfer parameters viz., the luminescence quantum efficiency (ηQ), energy transfer efficiency (ηET), energy transfer parameter (Q), energy transfer probability (PDA) and critical transfer parameter (R0) were evaluated for all the titled glasses by using the lifetime values. The evaluated color coordinates values at different excitation wavelengths have revealed that in general these glasses emit bright white light. But in particular the glass sample doped with 3 mol % of Bi2O3 is more suitable for the fabrication of white light emitting diodes (W-LEDs). The correlated color temperature (CCT) values for the prepared glasses are observed in the range 3300 – 4050K which are nearer to commercial and day W-LED sources. From all these investigations it can be seen that the glass doped with 3 mol % Bi2O3 is a potential candidate for the development of W-LEDs. [ABSTRACT FROM AUTHOR]

Hydroxyapatite [Hap] is considered one of the most efficient biomaterials with a commonly accepted formula Ca10[PO4]6 [OH]2. To boost the biological and physical properties of the Hap crystal, a lot of elements such as Ag, F, Mg, CO3, Zn, Bi, and Na have been used for doping hydroxyapatite. In this study, the Silver-substituted hydroxyapatite (Ag-Hap) synthesized through chemical co-precipitation was investigated. The crystal structure, phase purity and functional groups of the synthesized sample were explored through X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy. The surface morphology properties and elemental analysis by Scanning electron microscope (SEM), Energy dispersive X-spectroscopy (EDAX) are studied. [ABSTRACT FROM AUTHOR]

Nanocomposite films of an organic dye-polymer (Indigo Carmine-PVA) system were fabricated and their optical limiting behaviour was investigated under excitation with 532 nm laser pulses of 5 ns temporal width using the open aperture Z-scan technique. The samples displayed optical limiting behavior under the experimental conditions. The Atomic Force Microscopic (AFM) analysis of the surface topography revealed homogeneous distribution of nanoclustered aggregates grown within the polymer matrix and an average roughness of ∼2.02 nm for the surface. The estimated values of the effective nonlinear absorption coefficient, βeff (∼10-7-10-8 cm/W) marked up to the highest reported ones in literature in the nanosecond regime. The results indicate that these nanocomposite films are potential materials for optical limiting devices used for the protection of human eyes and other delicate optical sensors from laser induced optical damage. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed for evaluating the photophysical and photochemical properties of a sequence of carbazole based metal-free organic dyes modified using different π-conjugation spacer units, such as thiopine, pyrrole, furan, thiazole and isoxazole. Moreover, the modified dyes were subjected to investigation towards their non-linear optical (NLO) features. The results revealed that dipole moment (μ), static polarizability (α), anisotropic polarizability (Δα) and hyperpolarizability (first order (β) and second order (γ)) of modified dyes are considerably enhanced as a consequence of changing the spacer unit. Likewise, light harvesting efficiency and oscillator strength of the modified dyes are enhanced upon wavelength of absorption is red-shifted by influence of spacer moieties. We believe that our calculations provide a more profound physical perception on structural property relationship for carbazole based dyes and give a hint to create potential sensitizers for opto-electronic and dye-sensitized solar cell applications. [ABSTRACT FROM AUTHOR]

Quantum mechanical calculations for calculating energies, vibrational wave numbers and geometries of 7- amino-4-methylcoumarin (7A4MC) have been performed by Hartree-Fock Molecular Orbital Theory (HFMOT) and Density Functional Theory (DFT) by hybrid functional B3LYP containing 6-311++G(d,p) as a basis set. Optimum values of geometrical parameters determined through HFMOT and DFT calculations are well accordance with experimental data obtained from X-ray diffraction analysis. A comprehensive interpretation of infrared spectra belong to 7A4MC is also described. Non-linear optical investigations of 7A4MC have also carried out by HFMOT and DFT through hybrid functional B3LYP with 6-311++G(d,p) as a basis set. Natural bond orbital examination of 7A4MC is also performed. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed for evaluating the photophysical and photochemical properties of a sequence of carbazole based metal-free organic dyes modified using different π-conjugation spacer units, such as thiopine, pyrrole, furan, thiazole and isoxazole. Moreover, the modified dyes were subjected to investigation towards their non-linear optical (NLO) features. The results revealed that dipole moment (μ), static polarizability (α), anisotropic polarizability (Δα) and hyperpolarizability (first order (β) and second order (γ)) of modified dyes are considerably enhanced as a consequence of changing the spacer unit. Likewise, light harvesting efficiency and oscillator strength of the modified dyes are enhanced upon wavelength of absorption is red-shifted by influence of spacer moieties. We believe that our calculations provide a more profound physical perception on structural property relationship for carbazole based dyes and give a hint to create potential sensitizers for opto-electronic and dye-sensitized solar cell applications. [ABSTRACT FROM AUTHOR]

Quantum mechanical calculations for calculating energies, vibrational wave numbers and geometries of 7- amino-4-methylcoumarin (7A4MC) have been performed by Hartree-Fock Molecular Orbital Theory (HFMOT) and Density Functional Theory (DFT) by hybrid functional B3LYP containing 6-311++G(d,p) as a basis set. Optimum values of geometrical parameters determined through HFMOT and DFT calculations are well accordance with experimental data obtained from X-ray diffraction analysis. A comprehensive interpretation of infrared spectra belong to 7A4MC is also described. Non-linear optical investigations of 7A4MC have also carried out by HFMOT and DFT through hybrid functional B3LYP with 6-311++G(d,p) as a basis set. Natural bond orbital examination of 7A4MC is also performed. [ABSTRACT FROM AUTHOR]

Multi component PbO–Al2O3–TeO2–GeO2–SiO2 glasses doped with different concentrations of V2O5 ranging between 0 and 1.0 mol % were prepared by melt quenching technique. XRD and SEM techniques have been employed for the confirmation of glass ceramic nature of the samples. Optical absorption spectra of these samples exhibited two broad bands at about 626 and 831 nm corresponding to ²B2g→²B1g and ²B2g→²Eg transitions, respectively. The optical band gap has shown the maximal value, 3.16 eV for 0.4 mol % of nucleating agent V2O5 beyond this concentration it is observed to decrease. The EPR spectra of the doped glass ceramics have exhibited a well resolved hyperfine pattern consists of eight parallel and eight perpendicular lines which are the characteristics of VO2+ ions. The increase in the intensity of the resonance signal beyond 0.4 mol % of V2O5 has been attributed to the increase in the concentration of paramagnetic vanadyl ions. The analysis of these spectroscopic investigations reveals that the glass ceramics doped with 1.0 mol % of V2O5 are suitable for semiconducting devices. [ABSTRACT FROM AUTHOR]

Glass ceramics with the composition 10CaF2−20ZnO–(15-x)Bi2O3−55P2O5:x Fe2O3(0≤x≤2.5) were synthesized by melt-quenching technique and heat treatment. These glass ceramics were characterized by XRD and SEM. Spectroscopic studies such as optical absorption, EPR were also carried out on these glass ceramics. From the absorption spectra the observed bands around 438 and 660nm are the octahedral transitions of Fe3+ (d5) ions and another band at about 536 nm is the tetrahedral transition of Fe3+ (d5) ions. The absorption spectrum also consist of a band around 991 nm and is attributed to the octahedral transition of Fe2+ ions. The EPR spectra of the prepared glass ceramics have exhibited two resonance signals one at g1=4.32 and another signal at g2=2.008. The observed decrease in band gap energy up to 2 mol% Fe2O3 doped glass ceramics is an evidence for the change of environment around iron ions and ligands from more covalent to less covalent (ionic) and induces higher concentration of NBOs which causes the depolymerization of the glass ceramic network. [ABSTRACT FROM AUTHOR]

Materials reduced to the Nano scale can exhibit different properties compared to what they exhibit on a micro scale, enabling unique applications. When TiO2 is reduced to Nano scale it shows unique properties, of which the electrical aspect is highly important. This paper presents increase in the energy gap and decrease in conductivity with decrease in particle size of pure Nano TiO2 synthesized by hydrolysis and peptization of titanium isopropoxide. Aqueous solution with various pH and peptizing the resultant suspension will form Nano TiO2 at different particle sizes. As the pH of the solution is made acidic reduction in the particle size is observed. And it is confirmed from XRD using Scherer formula and SEM, as prepared samples are studied for UV absorbance, and DC conductivity from room temperature to 400°C. From the tauc plot it was observed, and calculated the energy band gap increases as the particle size decreases and shown TiO2 is direct band gap. From Arrhenius plot clearly we encountered, decrease in the conductivity for the decrease in particle size due to hopping of charge carriers and it is evident that, we can tailor the band gap by varying particle size. [ABSTRACT FROM AUTHOR]

Research on ultrasonography and elastography instrumentation is crucially dependent on the quality of tissue-mimicking phantoms on which the instrumental parameters are tested. The phantoms should ideally possess values of various acoustic parameters corresponding to normal and abnormal tissues of different types and these properties should not change significantly with time. Designing such phantoms requires a molecular level understanding of the material to be used. In this context, polyacrylamide gels made from corresponding monomer, initiator and cross-linker were developed. An understanding of the network structure of these hydrogels at the molecular level was made possible using fluorescence spectroscopy with anilinonaphthylsulfonate as an extrinsic fluorescent probe. TiO2 was used to adjust the acoustic transparency so as to bring the ultrasound reflection parameters close to those of human tissues. It was found that the network structure of poly-acrylamide (PAM) hydrogels as well as their acoustic and viscoelastic properties could be conveniently varied by altering the composition of the components. This understanding at the molecular as well as the bulk level was then used to develop tissue phantoms appropriate for imaging in ultrasound-B and elastography modes. [ABSTRACT FROM AUTHOR]

Naphthol Green B dye-polyvinyl alcohol composite films were fabricated and their nonlinear absorption properties were investigated using the Z-scan technique under excitation with 5ns laser light pulses at 532 nm. The samples displayed a switchover from saturable absorption to reverse saturable absorption with increase in either intensity or concentration. The measured values of β and IS were found to be of the order of 10-7 cm/W and 109 W/cm2 respectively. The atomic force microscopic analysis of the composite films revealed homogeneous distribution of aggregated nanoclusters marked by a low average surface roughness ≈1.8 nm. [ABSTRACT FROM AUTHOR]

Glass ceramics with composition 10Na2O− 30PbO−10Bi2O3−(50-x)SiO2: xV2O5 (0 ≤ x ≤ 5) were synthesized by melt quenching and heat treatment method. XRD and SEM studies have indicated that the samples contain well defined and randomly distributed grains of different crystalline phases. Optical absorption spectra of these samples exhibited two absorption bands at 629 and 835 nm which are the characteristics of V4+ ions. The EPR spectra of these samples have exhibited well resolved hyperfine structure consisting of sixteen-eight parallel and eight perpendicular lines with a raise in their intensity with an increase in the content of V2O5 up to 3 mol% indicates the increase of redox ratio V4+/V5+ in the glass ceramic matrix. [ABSTRACT FROM AUTHOR]

NPs of Ce1-xCrxO2 (x=0, 0.04, 0.08, 0.12) have been synthesized by solution combustion method using glycine as fuel. The effect of chromium on structural and dc electrical conductivity of cerium oxide nanoparticles were investigated. The obtained powder is characterized by UV-visible spectrometer, X-ray diffractometer (XRD), Scanning electron microscope (SEM) and Energy dispersive X-Ray analysis (EDS). X-ray diffraction analysis carried out on calcined samples reveals that successful incorporation of Cr2+ in CeO2 lattice where as SEM studies confirms the porous morphological structure of the prepared sample. The Keithley source meter is used to measure the dc conductivity of samples in the temperature range from 303K to 623K. The conductivity was found to be increases with increase of temperature as well as the Cr concentration due to semiconducting behavior of material and change in the charge carrier concentration. The activation energy decreases with increasing chromium concentration. The present work deals with the effect of chromium additive on structural and the D.C electrical properties Ce1-xCrxO2 NPs. [ABSTRACT FROM AUTHOR]