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A simple, compact and cost-effective optical interferometer using a grating and holographic optics
Get PDFA new scheme for making a simple, compact and cost-effective two-beam optical interferometer using a commercially available diffraction grating and a single plate holographic optical element is described. The procedure for the generation of holographic optical element using a diffraction grating and the related techniques to realize the proposed interferometer along with typical experimental results has been presented. The proposed interferometer is simple, works well with a single collimated beam, and is quite suitable for performing optical test studies on phase (transparent) objects in real-time
Detection mechanism of Metal Oxide Gas Sensor under UV Radiation.
No full textThe effect of ultraviolet radiation on the sensing mechanism of polycrystalline metal oxide gas sensor has been studied analytically. The model used to describe the sensing mechanism is based on the combination of the neck mechanism and grain boundary mechanism. We found that increasing the UV radiation flux density increases the conductivity of the film by decreasing the resistance. It has been shown theoretically that due to incident UV radiation, it is possible to detect the gas even at room temperature. The effect of radiation on the sensitivity is discussed as a function of grain size and chemisorbed gas concentration
Realization of holographic optics based interferometer for study of phase objects
Get PDFThe paper describes different configurations for realization of a simple, compact and robust holographic optics based interferometer, which makes use of minimal bulk optical components. The optical arrangements in the proposed interferometer set-ups involve a very simple alignment procedure and conventional holographic recording material is used in the formation of holographic optical elements. Recording schemes for the formation of holographic optical elements and the related techniques for the realisation of three different interferometer set-ups along-with the experimental results have been presented. The proposed interferometer set-ups are quite suitable for performing optical test studies on phase (transparent) objects in real time
Technologies convergence in recent instrumentation for natural disaster monitoring and mitigation
No full textIn this paper, efforts have been made to highlight how a number of advanced technologies have been blended together to configure the state of the art instruments and networks for natural disaster mitigation. The recent technological advances in seismological instrumentation have been discussed at greater length whereas snow - avalanche, and landslides monitoring instruments have been touched in brief. The present paper describes how the current advancements in seismic sensor technology, seismic data acquisition systems, data communication, computer hardware, and software engineering etc. have made possible to design and configure 'Seismic Alert Systems' to avert the colossal losses to strategic installations during major earthquakes. The design concept of a Seismic Alert System to safeguard Delhi and area around has been illustrated. Paper highlights briefly how the use of information technology has realized 'Virtual Seismic Network' (VSN) to provide rapidly the access to earthquake information via - Internet connectivity. The applications of front ranking technologies namely - Global Positioning System (GPS), and Space based Disaster Management System (DMS) for monitoring and studying the natural hazards, have been described briefly. In order to handle post disaster scenario on emergent basis, some sophisticated instruments for rescue operations alongwith suitable sensing techniques and technologies have been identified for futuristic research and development
DNA Electronics- DNA and electronics seem to be two different things, but a series of events has highlighted the unusual ability of DNA to form electronic components
No full textLarge area molecular junction-Ls "I have proven to be a robust and reliable system for studying electronic transport through molecules, shedding plenty of light on the parameters that affect it. We propose the use of this system for a systematic study of the charge transport properties of DNA molemles and how this depends on the molecules’ structure or environment. This knowledge can not only be used to design and synthesize DNA molecules that carry desired properties, such as rectification, for use in DNA molecular electronics devices, but provide valuable information for D.\lA's complex role in biology as well
Security Holograms Readable with an Encoded Key Hologram
No full textA simple and cost effective two-step method for making security holograms, which are readable with an encoded key hologram, has been presented. These security holograms contain an additional security feature which can be read only by using an encoded key hologram in the reading process. In the final reading process, the sharp focus spot emerges only when the security hologram is illuminated by the decoding, reconstructing beam generated from the encoded key hologram. Since the verification/identification pattern in these holograms is a sharp focus spot rather than an image pattern, this type of security holograms are suitable for both visual as well as machine inspection. They can also be used as security codes for better protection against counterfeiting in the embossed holograms. Experimental results achieved have been discussed
Training effectiveness of Engineering Students: A Case Study
No full textProject-based training in an industrial environment is considered for engineering students prior to their graduation. The relevance or effectiveness of such training is deliberated by correlating the training need assessment and its fulfilment as a case study. The need and effectiveness are studied as for the students' choices and preferences of project work, methods and inputs used and technical skills enhanced during training. Finally, the role of industry and faculty at the industry-institute interface is highlighted for its mutual gains
Measurement of temperature profile of two-dimensional slot burner using a lau phase interferometer with linear gratings.
No full textWe have investigated the utility of a Lau phase interferometer with linear gratings and white light source to measure the temperature and temperature profile of a flame produced by a slot burner used in an atomic absorption spectrophotometer. The temperature values measured using a Lau phase interferometer and a thermocouple and multilogger are in good agreement. The effect of aspirating water through a nebulizer on the temperature profile and details of theoretical analysis and experimental investigations are also presented
Poly (DL -Lactide-CoGlycolide) Nano-particle based Inhalable Sustained Drug Delivery System for Experimental Tuberculosis
No full textOBJECTIVES: To improve the bioavailability of antitubercular drugs (ATDs) as well as to assess the feasibility of administering ATDs via the respiratory route, this study reports the formulation of three frontline ATDs, i.e. rifampicin, isoniazid and pyrazinamide encapsulated in poly (DL-lactide-co-glycolide) nanoparticles suitable for nebulization. METHODS: Drug-loaded nanoparticles were prepared by the multiple emulsion technique, vacuum-dried and nebulized to guinea pigs. The formulation was evaluated with respect to the pharmacokinetics of each drug and its chemotherapeutic potential in Mycobacterium tuberculosis infected guinea pigs. RESULTS: The aerosolized particles exhibited a mass median aerodynamic diameter of 1.88 0.11 microm, favourable for bronchoalveolar lung delivery. A single nebulization to guinea pigs resulted in sustained therapeutic drug levels in the plasma for 6-8 days and in the lungs for up to 11 days. The elimination half-life and mean residence time of the drugs were significantly prolonged compared to when the parent drugs were administered orally, resulting in an enhanced relative bioavailability (compared to oral administration) for encapsulated drugs (12.7-, 32.8- and 14.7-fold for rifampicin, isoniazid and pyrazinamide, respectively). The absolute bioavailability compared to intravenous (i.v.) administration was also increased by 6.5-, 19.1- and 13.4-fold for rifampicin, isoniazid and pyrazinamide, respectively. On nebulization of nanoparticles containing drugs to M. tuberculosis infected guinea pigs at every 10th day, no tubercle bacilli could be detected in the lung after five doses of treatment whereas 46 daily doses of orally administered drug were required to obtain an equivalent therapeutic benefit. CONCLUSIONS: Nebulization of nanoparticles-based ATDs forms a sound basis for improving drug bioavailability and reducing the dosing frequency for better management of pulmonary tuberculosis
Capacitive Moisture Measurement of Grains
No full textThe Paper describes a multigrain moisture meter, based on the principle of dielectric variation. The difference in dielectric constants of the dry sample and water is utilised to perform moisture detection. Conversion of a capacitor into grain moisture sensor is practically achieved by placing the test sample as a dielectric between the platens. It results in dielectric change. Changes of moisture content affect the dielectric constant of the sample thereby affecting the value of measured capacitance. The resultant capacitance variation is read out as change in moisture level. It is processed further and moisture percentage displayed. A micro-controller has been incorporated to determine moisture content of different grains/seeds without any repeated calibration or reference to any charts. The behaviour of the sensor has been studied with different grains/seeds at various moisture level