654 research outputs found
Sort by
MEMS Display: Emerging Technology for Next Generation Avionics Display
No full textAvionics display systems using CRTs as core of the
projection system suffer from reliability issues added to
increased weight and cost of the associated circuitry. Though CRTs offer some advantages in the form of good brightness and contrast ratio even in the high ambient light conditions, recent advancement in micro electomechanical system (MEMS) based display technology ushered in an era of miniature displays having low power consumption and better reliability. Digital Micromirror Device (DMD) array from Texas Instruments and Laser Scanning Displays (LSD) have shown enormous potential to be the suitable replacement to the CRTs in air-borne applications. Head up Displays (HUD) using DMD micromirror array and a novel Head Mounted Display (HMD) technology known as the Retinal Scanning Display (RSD) using LSDs are being tested and further improved to meet the military standards
Magnetic Field-Guided Orientation of Carbon Nanotubes Through their Conjugation with Magnetic Nanoparticles
No full textLow intensity magnetic fields (22mT) rendered by a pair of bar magnets have been used to achieve in situ precise orientation of multiwalled carbon nanotubes (MWCNTs) and their directional deposition on solid substrates. The nanotubes were imparted magnetic characteristics through Fe3O4 (magnetite) nanoparticles covalently attached to their surface. The side walls of nanotubes were first acid oxidized with H2SO4/HNO3 (3:1 v/v) mixture and amine-functionalized magnetic nanoparticles were then interfaced to ends and side walls of the nanotubes through covalent linkages in the presence of a zero length cross linker, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide. Fourier transformed infrared spectroscopic investigations affirmed the functionalization of nanostructures and formation of a magnetic nanohybrid. Transmission electron microscopy results revealed the attachment of nanoparticles along the side walls of MWCNTs. A flow cell was utilized to orient magnetic nanohybrid in the desired direction and also to create thin films of aligned MWCNTs. Further, directional assembly of magnetic MWCNTs at different orientation angles on solid substrates was studied by field emission scanning electron microscopy and optical microscopy. The procedure can be scaled to align CNTs on large surface areas for numerous applications, e.g., nanosensors, field emitters, and composites
Impedance study of tea with added taste compounds using conducting polymer and metal electrodes
No full textIn this study the sensing capabilities of a combination of metals and conducting polymer sensing/working electrodes for tea liquor prepared by addition of different compounds using an impedance mode in frequency range 1 Hz-100 KHz at 0.1 V potential has been carried out. Classification of six different tea liquor samples made by dissolving various compounds (black tea liquor + raw milk from milkman), (black tea liquor + sweetened clove syrup), (black tea liquor + sweetened ginger syrup), (black tea liquor + sweetened cardamom syrup), (black tea liquor + sweet chocolate syrup) and (black tea liquor + vanilla flavoured milk without sugar) using six different working electrodes in a multi electrode setup has been studied using impedance and further its PCA has been carried out. Working electrodes of Platinum (Pt), Gold (Au), Silver (Ag), Glassy Carbon (GC) and conducting polymer electrodes of Polyaniline (PANI) and Polypyrrole (PPY) grown on an ITO surface potentiostatically have been deployed in a three electrode set up. The impedance response of these tea liquor samples using number of working electrodes shows a decrease in the real and imaginary impedance values presented on nyquist plots depending upon the nature of the electrode and amount of dissolved salts present in compounds added to tea liquor/solution. The different sensing surfaces allowed a high cross-selectivity in response to the same analyte. From Principal Component Analysis (PCA) plots it was possible to classify tea liquor in 3-4 classes using conducting polymer electrodes; however tea liquors were well separated from the PCA plots employing the impedance data of both conducting polymer and metal electrodes
Optical fiber nano-tip and 3D bottle beam as non-plasmonic optical tweezers
No full textWe report a simple fiber nano-tip as non-plasmonic optical
tweezer, which can manipulate submicron particles in a non-contact manner. The efficiency of an optical tweezer can be enhanced by using nondiffracting type optical beams such as Bessel beam or self-imaged Bessel beam (3D bottle beam). The present work, for the first time, realizes a nonplasmonic optical tweezer based on a miniaturized axicon like single-mode optical fiber nano-tip. The tip generates non-diffracting type 3D bottle beam by virtue of its changing wedge angle. The nano-tip is prepared from a
photosensitive single-mode optical fiber by employing a novel chemical etching technique. We experimentally demonstrate trapping of ~60 nm silver particle and ~160 nm silica particle using this nano-tip optical tweezer. The nano-tweezer also succeeds to pick up the particles from
aqueous solution. The proposed nano-tweezer working at smaller laser powers opens new avenues for nanomanipulation and analysis of submicroscale specimens in the biological and physical sciences
Steganography for Invisible Communication: A Review
No full textSteganography is the science and art of embedding secret messages in innocuous looking carriers in such a way that it does not draw the attention of anyone other than the sender and the targeted recipient, thus a method for secret and invisible communication which provides security through obscurity. Its main purpose is to hide the occurrence of communication over a public channel. Steganography has been used since ancient times and has grown exponentially in the recent past because of the improvements in computing power. Earlier, steganography was implemented using some physical medium i.e. some tangible objects but now a days, it is implemented electronically by using several other intangible objects i.e. data can be hidden using any type of media, be it image in bmp, jpeg, gif format or some music file, video clip, text file, SMS etc. In this paper, different types of techniques used to hide data have been discussed with major focus on image based modern steg-anographic techniques
A fluorescence based assay with pyranine labeled hexa-histidine tagged Organophosphorus hydrolase (OPH) for determination of organophosphates
No full textOrganophosphorus hydrolase has been employed extensively for catalysis based biosensor synthesis with optical, potentiometric and amperometric based detection mechanism. The present study reports the response of bioconjuagtes prepared by utilizing OPH and pH sensitive polyanionic fluorophore i.e. pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt) in different molar ratios by the aid of electrostatic force. Two types of bioconjugates were prepared, one of them contained mature form of OPH obtained from Escherichia coli cells expressing organophosphate degrading (opd) gene from a tac promoter, whereas the variant OPH6His, has 6× histidine tail at C-terminus. The investigation was carried out utilizing the bioconjugates of different molar ratios prepared with both the enzymes and ratio showing maximum degree of labeling with pyranine was selected for the detection of organophosphates in standard samples. The lower limit of detection for paraoxon was ∼20 ppb and for methyl parathion and coumaphos it was ∼50 ppb under optimized conditions (55–60 °C) with the reaction time of 3 min. These features of the prepared conjugate make it a strong contender for the development of the field deployable biosensor for organophosphates estimation
Immobilization of enzyme on long period grating fibers for sensitive glucose detection
No full textGlucose oxidase (GOD) immobilized longperiodgrating (LPG) fibers have been proposed for the specific and sensitivedetection of glucose. The treatment of LPG fibers with aminopropyl triethoxysilane has induced biding sites for the subsequent GOD immobilization. Field emission scanning electron microscopy, confocal laser scanning microscopy, infrared spectroscopy and Raman spectroscopy have provided detailed evidences about the effectiveness of the adopted biofunctionalization methodology. The enzyme activity is conserved during the immobilization step. Fabricated LPG sensor was tested on different glucose solutions to record the transmission spectra on an optical spectrum analyzer. The wavelength shifts in the transmission spectra are linearly correlated with the glucose concentration in the range of 10–300 mg dL−1. The fabricated sensor gives fast response and is demonstrated to be of practical utility by determining glucose contents in blood samples. Proposed technique can further be extended to develop LPG fiber based novel, sensitive and label free nanosensors for disease diagnosis and clinical analysis
Voltammetric Determination of Fluoride Ion Using Galvanostaticaly Grown Poly(3-hexylthiophene) Film
No full textPoly (3-hexylthiohene) films have been prepared by galvanostatic technique on platinum surface. The structure and surface morphology of the film was characterized by cyclic voltammetry (CV), FTIR and SEM imaging. Cyclic voltamogram of poly (3-HTh) film showed only one reduction peak at potential 0.82 V. Cyclic voltammogram of the poly (3-HTh) film when recorded in fluoride ion solution showed two redox pair at E1/2 = 0.048 V (A/A’) and E1/2= 0.074 V (B/B’). The former peak may be attributed to [BF4]-/[BF4]2- redox couple and later peak to the presence of loosely bound fluoro-borate anions in the polymeric film respectively. Diffusion controlled process may be the possible reaction mechanism. The diffusion coefficient (D) and rate of reaction (R) for the reaction (B/B’) are calculated as 9.29 ´10-3 cm2 s-1 and 5.61 ´ 10-9 mol s-1 respectively. Poly (3-HTh) films showed detection limit as low as 2.5 mM
Computational Analysis of Photosynthesis Measurement System using Multivariate Data Analysis
No full textThis paper presents the statistical analysis on Photosynthesis rate. Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. Computational analysis on Photosynthesis rate is done by using Unscramble software. Photosynthesis rate is very much affected by various environmental parameters. This paper computes the various parameters involved in Photosynthesis & then finds a relation between various parameters. The computational analysis helps to find out the optimum conditions for Photosynthesis rate so that we can provide those optimum conditions in green house, Precision Agriculture like environment to increase crop growth & yield1
