45 research outputs found
Giant Magnetoimpedance (GMI) Effect and Field Sensitivity of Ferrofluid Coated Co66Fe2Si13B15Cr4 Soft Magnetic Amorphous Microwire
AbstractCo66Fe2Si13B15Cr4 based amorphous microwire was developed at the laboratory using in-water quenching apparatus. The field sensitivity of the wire was enhanced when coated with ferrofluids. The presence of coating also decreased the frequency of the magnetising field 5MHz to 1MHz at which the maximum GMI ratio observed
Juveniles in Dewey Decimal Classification
This paper explores the subject juvenile based on subject descriptors in DDC editions. The objectives was to assess the evolution of the subject in DDC. Qualitative assessment of the subject descriptors is made to exhibit the edition wise treatment. Law class holds the maximum number of subject descriptors on juveniles. Edition 21st to 23rd have the maximum share of concepts on juvenile. Standing room concepts which have been providing shelter to the subjects with future prospects are expressed through Example notes and including notes. These subject descriptors’ relation with other disciplines as reflected in See and See also references hint at the cross disciplinary nature of subjects
Treatment of Subject Descriptors on Children in Twenty Three DDC Editions
The study explores the treatment of subject descriptors on children and its correlated subjects in the 23 DDC editions by adopting an assessment and evaluation study. Authors found that the Home and family management (640) class holds the maximum subject descriptors on children
Time-frequency analysis of multiple fringe and nonsinusoidal signals obtained from a fiber-optic vibration sensor using an extrinsic Fabry-Perot interferometer
In the case of multiple fringes and complex frequency measurements, the frequency of the output signal changes rapidly when the vibration changes and frequency breakdown takes place at the turning point. For a particular vibration signature containing many frequency components at different time intervals, it is often difficult to trace the direction of the vibration as well as individual frequency peaks. In such cases, advanced signal-processing scheme is necessary to decode the vibration signature. This paper investigates the data interrogation technique for multifrequency and complex signals of surface Vibration obtained from an extrinsic Fabry-Perot interferometric sensor. In this paper, wavelet transform (WT)-based signal processing methodology has been employed to count of optical fringes with special reference to signals having subfringes. A WT-based tool has also been developed for unambiguous identification of frequency components from a nonsinusoidal vibration. The results of such WT-based analyses are presented, and merits as well as demerits of the proposed methods are discussed
Ocena performansi dizel motora pri upotrebi dizel-etanol-biodizel mešavine goriva
The studies were conducted to standardize the level of constituents to obtain stable diesel-ethanol-biodiesel microemulsions prepared using anhydrous ethanol (200° proof) and aqueous ethanol of 195°, 190°, 185°, 180° and 175° proof and soybean biodiesel under wide ambient temperature range. A total of twenty blends of ethanol-diesel-biodiesel were prepared and their temperature stability in the range of 0-45 0C was studied in an interval of 50 starting from 450C. Based on full range temperature stability, four microemulsions (v/v) 2000[1:0.053:0.14], 2000[1:0.0.053:0.26], 1900[1:0.11:0.62], 1800 [1:0.25:1.54], diesel: ethanol: biodiesel were selected to study engine performance. On the basis of experimental study it was concluded that 2000[1:0.053:0.35] diesel: ethanol: biodiesel microemulsion replacing 28.75 % diesel can be used in CI engine without any need for engine modification.Istraživanja su sprovedena da bi se standardizovao nivo sastojaka u cilju dobijanja stabilnih mikroemulzija dizel-etanol-biodizel, pripremljenih upotrebom dehidriranog etanola (čistoća 200°) i hidriranog etanola čistoće 195°, 190°, 185°, 180° i 175° i biodizela od soje pri širokom opsegu ambijentalnih temperatura. Ukupno dvadeset mešavina dizel-etanol-biodizel je pripremljeno i ispitivana je njihova temperaturska stabilnost u opsegu od 0-45°C, u intervalima od po 5°, počevši od 45°C. Na osnovu punog opsega temperaturske stabilnosti izabrane su četiri mikroemulzije dizel-etanol-biodizel (v/v): 2000[1:0.053:0.14], 2000[1:0.0.053:0.26], 1900[1:0.11:0.62], 1800 [1:0.25:1.54], za ispitivanje performansi motora. Na osnovu eksperimentalnog ispitivanja zaključeno je da se mikroemulzija dizel-etanol-biodizel 2000[1:0.053:0.35] može upotrebiti kao zamena za 28.75% dizel goriva u dizel motoru bez ikakvih modifikacija na motoru
Fibre Bragg grating strain sensor and study of its packaging material for use in critical analysis on steel structure
Strain studies in civil structures, aircrafts, oil pipelines, etc. are pivotal in avoiding unexpected failures. Long-term strain study of structures also helps in setting the design limits of similar structures. Conventionally, most structures rely on maintenance schedules, visual inspection and a few conventional sensors. But the high cost of maintenance, lack of precision in visual inspection and susceptibility of sensors to harsh environmental conditions have made structural health monitoring (SHM) a necessity. Over the past few decades. fibre Bragg grating (FBG) sensors have emerged as a suitable, accurate and cost-effective tool in SHM. Fibre Bragg gratings are obtained by creating periodic variations in the refractive index of the core of an optical fibre. These periodic variations are created by using powerful ultraviolet radiation from a laser source. Periodic structure acts as a Bragg reflector of particular wavelength. Minute change in the periodic structure due to external perturbation will cause appreciable wavelength shift. This shift in turn can be translated to measurand related to perturbation. The main advantages of FBGs over other optical sensor schemes are its low cost, good linearity, wavelength multiplexing capacity, resistance in harsh environments and absolute measurement. FBG sensor technology is now on the verge of maturity after almost two decades of active research and development in this field. Efforts are now concentrating on delivering complete FBG sensor systems including front-end electronics. This paper demonstrates with the aim to provide different design and experimental packaging procedures of indigenously developed FBG sensors for strain measurement. Various model of loading on FBG have been tried to explore with particular attention on the primary packaging of the sensor for application on steel cantilever structure and cement concrete. Preliminary packaging has been done with composite materials such as epoxy resin casting and fibre reinforced plastic (FRP) composites. Encouraging results are obtained and presented in this paper. The results are compared with the standard FBG sensors and with mechanical strain gauge. (C) 2009 Elsevier B.V. All rights reserved
Wavelet analysis of optical signal extracted from a non-contact fibre-optic vibration sensor using an extrinsic Fabry-Perot interferometer
Interferometric optical fibre sensors have proved to be many orders of magnitude more sensitive than their electrical counterparts, but they suffer from limitations in signal demodulation caused by phase ambiguity and complex fringe counting when the output phase difference exceeds one fringe period and for multiple fringes. This paper presents a novel signal decoding technique based on the wavelet transform of optical data extracted from a non-contact vibration sensor using an extrinsic Fabry-Perot interferometer (EFPI) implemented using single-mode fibre. The EFPI cavity has been used to generate an optical interference signal between two parallel, highly reflective surfaces separated by a variable distance. Firstly, a few recorded experimental results of the interference fringe formation due to vibration are presented in this paper. Then the wavelet transform is used for decoding the vibration signature for three major purposes of the data analyses, namely elimination of noise from the optical signals collected in real time, identification of the frequency breakdown points of the signal efficiently and automatic counting of the interference fringes. In turn, the wavelet transform is successfully employed to decode the vibration signature from the non-stationary output signal of an EFPI sensor
Fibre Bragg grating strain sensor and study of its packaging material for use in critical analysis on steel structure
Strain studies in civil structures, aircrafts, oil pipelines, etc. are pivotal in avoiding unexpected failures. Long-term strain study of structures also helps in setting the design limits of similar structures. Conventionally, most structures rely on maintenance schedules, visual inspection and a few conventional sensors. But the high cost of maintenance, lack of precision in visual inspection and susceptibility of sensors to harsh environmental conditions have made structural health monitoring (SHM) a necessity. Over the past few decades. fibre Bragg grating (FBG) sensors have emerged as a suitable, accurate and cost-effective tool in SHM. Fibre Bragg gratings are obtained by creating periodic variations in the refractive index of the core of an optical fibre. These periodic variations are created by using powerful ultraviolet radiation from a laser source. Periodic structure acts as a Bragg reflector of particular wavelength. Minute change in the periodic structure due to external perturbation will cause appreciable wavelength shift. This shift in turn can be translated to measurand related to perturbation. The main advantages of FBGs over other optical sensor schemes are its low cost, good linearity, wavelength multiplexing capacity, resistance in harsh environments and absolute measurement. FBG sensor technology is now on the verge of maturity after almost two decades of active research and development in this field. Efforts are now concentrating on delivering complete FBG sensor systems including front-end electronics. This paper demonstrates with the aim to provide different design and experimental packaging procedures of indigenously developed FBG sensors for strain measurement. Various model of loading on FBG have been tried to explore with particular attention on the primary packaging of the sensor for application on steel cantilever structure and cement concrete. Preliminary packaging has been done with composite materials such as epoxy resin casting and fibre reinforced plastic (FRP) composites. Encouraging results are obtained and presented in this paper. The results are compared with the standard FBG sensors and with mechanical strain gauge. (C) 2009 Elsevier B.V. All rights reserved