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Optimizing Single Point Diamond Turning for Mono-Crystalline Germanium Using Grey Relational Analysis
No full textIn this paper the results of an experimental study conducted for precision machining of mono-crystalline germanium with single point diamond turning (SPDT) have been reported. The input parameters include the top rake angle, tool overhang, depth of cut, tool feed rate, and rotational speed of the workpiece. The flat profile is generated on a disk of mono-crystalline germanium possessing three performance characteristics: surface roughness (Ra), profile error (Pt), and waviness error (Wa). The process parameters are optimized to obtain the best surface finish with minimum profile and waviness errors by using the Taguchi method. The grey relational analysis is employed for carrying out multiresponse optimization of performance parameters. The best value of surface finish obtained after multiresponse optimization is 10.7 nm having a profile error and a waviness error of 0.202 µm and 0.046 µm, respectively
Improved thresholding based on negative selection algorithm (NSA)
No full textThresholding is a tool of image segmentation which groups the pixels in a logical way. In this paper, a novel algorithm based on negative selection algorithm a model of artificial immune system is proposed for image thresholding. The proposed algorithm is applied on the thresholded images of lathe tool produced using maximum information entropy (MIE) and global thresholding based technique resulting in an improved image. To verify the algorithm and results, it has also been applied on some of the inbuilt MATLAB (MATrix LABoratory) images. Histogram is employed to analyze the results. Further, the results of improved algorithm are compared with the results of MIE and the global thresholding methods to check the effectiveness of the proposed method. The experimental results confirm the potential of the developed algorithm
Intelligent Nano-tech Switch for Advanced Automated Plant Growth Regulation
No full textPrecise control of plant growth is important to know the effect of external growth factors on crop yield. A nano-tech switch mechanism automaticallyoperated by plant stem expansion was designed to control the major external growth factors for plant such as light and water level in soil. Nano level expansion of stem produced by the dynamism of fluid (water) uptake by stimulation of sunlight is measured using laser interferometry to determine the elasticity of switch. Switching parameter was determined by nano level growth characteristics which were mathematically correlated
with fluid flow rate and elastic property of the stem. Supply of two major external growth factors in irrigation system were controlled intelegently by plant morphological and physical response, which are dependent on other major
and minor growth factors and with their variable combinations. The methodology is useful in irrigation system
Analysis of gas flow dynamics in hollow core photonic crystal fibre based gas cell
No full textGas flow dynamics in hollow core photonic crystal fibre (HC-PCF) is a trivial problem to study the gas filling time in HC-PCF gas sensor and other gas filled HC-PCF devices. This article analyzes the pressure dependence of gas diffusion coefficient in core and cladding holes of HC-PCF under the same condition of temperature and pressure during filling of methane and acetylene gas. An analytical model has been proposed to study the gas flow dynamics in core and cladding of HC-PCF. Due to gas filling, as the pressure varies inside the HC-PCF, at each increment of time, this model computes the change in pressure and respective gas diffusion coefficient. Using incremental gas diffusion coefficient, this model computes the gas filling time in a process similar to practical scenario. The gas filling time inside the core and cladding holes of HC-PCF for both methane and acetylene gas has been analyzed in this article. The results obtained can be utilized for HC-PCF based gas cell design
Civil Structural Health Monitoring Using FBG Sensors: Trends and Challenges
No full textStructural Health Monitoring (SHM) is a promising and challenging field of research of the 21st century. Civil structures are the most precious economic assets of any country, proper monitoring of these are necessary to prevent any hazardous situation and ensuring safety. FiberBragg Grating (FBG) sensors have emerged as a reliable, in situ, nondestructive device for monitoring, diagnostics and control in civil structures. FBG sensors offer several key advantages over other technologies in the structural sensing field. In this article, recent research and development activities in SHM using FBG sensors have been presented. Some of the strain-temperature discrimination techniques recently proposed by us have also been discussed. Distributed strain sensing in a concrete bridge(field trial) using FBG sensors has been presented
Light harvesting efficiency of hybrid nano-composite for photovoltaic application
No full textA composite of polyaniline (PANI) and cadmium sulfide nanoparticles (CdS NPs) has been synthesized electrochemically, which has further been used for the fabrication of photovoltaic cell. The composite (PCdS) has been characterized for its optical and electrochemical behavior. The efficacy of this composite for being used in photovoltaic cell has been studied by measuring its photo-electrochemical and photovoltaic response. The composite based device showed open circuit voltage (Voc) of 0.332 V and short circuit current (Isc) of 284 µA under an illumination of the 590 nm yellow incandescent light bulb having an intensity of 5.3 mW cm−2. The efficiency and fill factor for our proposed solar cell were 0.48% and 27% respectively. Photo-electrochemical response showed excellent photon conversion behavior with respect to light intensity, thus confirming flow of electrons through external load during illumination of the cell
Bioconjugation of anti estrogen alpha antibody with CdSSe/ZnS quantum dots for molecular sensing of a breast cancer antigen
No full textIn this present work, amine functionalized CdSSe/ZnS (core/shell) QDs have been conjugated with an anti-ERα antibody, which is a specific antibody against breast cancer antigen ERα. The bioconjugation reaction has been optimized with respect to the pH, reaction time and ionic strength of the media. Molecular interaction between the QDs conjugated antibodies and a dye (FITC) labeled ERα antigen provided a fluorescence resonance energy transfer (FRET) based pathway for quantitative detection of antigen. Upon excitation with 465 nm light, the PL intensity of FRET donor (QDs) decreases proportionally with increasing antigen concentration. Simultaneously, increase in the PL intensity of the FRET acceptor was observed. FRET immunoassay of ERα is sensitive and a wide linear range of detection (10–300 ng mL−1 ERα) observed. FRET efficiency of ∼70% has been achieved. Estimated limit of detection of ERα is 120 pM
Strain and temperature discrimination technique by use of A FBG written in erbium doped fiber
No full textWe propose and demonstrate strain and temperature discrimination technique using a single fiber Bragg grating (FBG) written in the core of an erbium doped fiber. We observed that amplified spontaneous emission power varying linearly from the erbium doped fiber with temperature which determines temperature changes and strain is estimated by subtracting the wavelength shift due to temperature change, from the measured shift corresponding to the dip in the transmission spectrum of the FBG. A simple and compact FBG sensor is presented with improved rms errors of 21.2 μɛ and 1 °C over ranges of 0–800 μɛ and 40–95 °C, respectively. The sensor is shown to have strain and temperature sensitivity of 0.8 pm/μɛ and 12 pm/°C
Highly sensitive chemosensing of trinitrotoluene with europium organic framework/gold nanoparticle composite
No full textA nanocomposite of luminescent europium organic framework (EuOF) and gold nanoparticles (AuNPs) has been investigated for photoluminescence (PL) quenching based highly sensitive detection of trinitrotoluene (TNT). The nanocomposite ‘EuOF/AuNP’ has been synthesized by initiating the growth of EuOF in the presence of AuNPs. The successful synthesis of the product has been verified with the help of electron microscopy and X-ray diffraction analysis. EuOF/AuNP nanocomposite offers reproducible and stable measurements of TNT. The linear dynamic range of detection is 5–800 ppb with the estimated detection limit of 18 ppb. The presence of other closely related aromatic compounds such as phenol, o-cresol, toluene, benzene, nitrobenzene and nitrophenol do not influence the sensing of TNT
Nanocomposite of europium organic framework and quantum dots for highly sensitive chemosensing of trinitrotoluene
No full textLuminescent metal-organic frameworks (MOFs) are considered as next-generation sensor materials for small molecules and explosives. In the present work, a nanocomposite of luminescent europium organic framework (EuOF) and CdSe quantum dots (QDs) has been first time investigated for photoluminescence (PL) based highly sensitive detection of trinitrotoluene (TNT). The nanocomposite EuOF/QD has been synthesized by initiating the growth of EuOF in the presence of QDs. The successful synthesis of the product has been verified with the help of electron microscopy, X-ray diffraction analysis, and surface area measurements. Compared to EuOF alone, the EuOF/QD nanocomposite offers reproducible and stable measurements. The linear range of PL quenching based detection of TNT with EuOF/QD nanocomposite is 5-1000 ppb with the detection limit of 3 ppb. The detection of TNT with EuOF/QD is selective with respect to some other investigated aromatic compounds, such as phenol, o-cresol, toluene, benzene, nitrobenzene and nitrophenol