2,077 research outputs found

    An Architecture for On board Frequency Domain Analysis of Launch Vehicle Vibration Signals

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    The dynamic properties of the airborne structures plays a crucial role in the stability of the vehicle during flight. Modal and spectral behaviour of the structures are simulated and analysed. Ground tests are carried out with environmental conditions close to the flight conditions, with some assumptions. Subsequently, based on the flight telemetered data, the on-board mission algorithm and the auto-pilot filter coefficients are fine tuned. An attempt is made in this paper to design a novel architecture for analysing the modal and spectral random vibration signals on-board the flight vehicle and to identify the dominant frequencies. Based on the analysed results, the mission mode algorithm and the filter coefficients can be fine tuned on-board for better effectiveness in control and providing more stability. Three types of windows viz. Hann, Hamming and Blackman-Harris are configured with a generalised equation using FIR filter structure. The overlapping of the input signal data for better inclusiveness of the real-time data is implemented with BRAM. The domain conversion of the data from time domain to frequency domain is carried out with FFT using Radix-2 BF architecture. The FFT output data are processed for calculating the power spectral density. The dominant frequency is identified using the array search method and Goldschmidt algorithm is utilised for the averaging of the PSDs for better precision. The proposed architecture is synthesised, implemented and tested with both Synthetic and doppler signal of 300 Hz spot frequency padded with Gaussian white noise. The results are highly satisfactory in identifying the spot frequency and generating the PSD array

    Radioimmunoassay of polypeptide hormones using immunochemically coated plastic tubes

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    A method has been developed for immobilisation of antisera on fresh plastic tubes through an immunochemical bridge. This type of immobilisation has been shown to be more consistent than direct adsorption on plastic. Such immunochemically coated antisera on plastic tube has been used in the development of a noncentrifugation radioimmunoassay. This assay system has been found to be technically as sound as the conventional method

    Comparison of Doppler findings and neonatal outcome in fetal growth restriction

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    Background: Fetal growth restriction (FGR) affects up to 5-10% of pregnancies. It is associated with increased perinatal mortality and morbidity. Doppler studies identify at risk fetuses and help in timing interventions and prognosticate outcomes. The ability of Doppler studies to predict neonatal outcome is studied here.Methods: Prospective study of seventy-two women with singleton pregnancies with gestational age above 28 week and detected to have FGR was done. The patients were subjected to Doppler analysis. Abnormal Doppler indices were compared with neonatal outcomes such as NICU admission, ventilator or CPAP support, sepsis, phototherapy and perinatal mortality.Results: Elevated umbilical artery PI, reduced middle cerebral artery PI and low CP ratio were found in 14, 18 and 36 fetuses. The sensitivity and specificity in predicting neonatal outcome was 25% & 75%, 58.1% and 62% and 17.9% and 75% for umbilical artery PI, MCA PI and CP ratio respectively. None of the Doppler indices showed significant p value. On testing, gestational age at delivery and length of NICU stay, gestational age was a significant determining factor with ‘p’ value of 0.003.Conclusions: Antenatal Doppler analysis of UA and MCA can predict neonatal outcome in FGR fetuses. Though the ‘p’ value was not significant in this study, the sensitivity, specificity, positive predictive value and negative predictive value are comparable to other studies. Gestational age at delivery significantly influences neonatal outcome

    A New Method of Gridding for Spot Detection in Microarray Images

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    A Deoxyribonucleic Acid (DNA) microarray is a collection of microscopic DNA spots attached to a solid surface, such as glass, plastic or silicon chip forming an array. The analysis of DNA microarray images allows the identification of gene expressions to draw biological conclusions for applications ranging from genetic profiling to diagnosis of cancer. The DNA microarray image analysis includes three tasks: gridding, segmentation and intensity extraction. The gridding process is usually divided into two main steps: sub-gridding and spot detection. In this paper, a fully automatic approach to detect the location of spots is proposed. Each spot is associated with a gene and contains the pixels that indicate the level of expression of that particular gene. After gridding, the image is segmented using fuzzy c-means clustering algorithm for separation of spots from the background pixels.  The result of the experiment shows that the method presented in this paper is accurate and automatic without human intervention and parameter presetting. Keywords: Microarray Image, Mathematical Morphology, Image Processin

    Brief Review of literature on Puti Lohas

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    Rasashastra is a science which deals with the pharmaceuticals of medicines out of mercury, minerals, metals, gem stones and animal products etc. Loha and Dhatu are consider as one and the same. Puti Lohas are those drugs which emits bad smell while they are melting. Many references of Puti Lohas is available in Ayurvedic classics since Vedakala to modern texts. Puti Lohas cannot be degraded since they are having their own identity in mineralogy and clinical practice of Ayurveda

    Solid State Chemistry of Thallous Molybdate

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    849-85

    Revealing the mechanical and microstructural performance of multiphase steels during tensile, forming and flanging operations

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    The mechanical performance of Dual Phase (DP) and Complex Phase (CP) steels was investigated by SEM analysis, tensile testing, Forming Limit Curve investigation and flange formability testing. The alloys of interest were Dual Phase (DP) untempered, Dual Phase (DP) tempered and Complex Phase (CP) steels. Phase content analysis showed that the distribution of the ferrite and martensite phases was the same for the two DP alloys, but the grain size and condition (tempered/untempered) for the martensite islands was much different in the two alloys. In the tempered DP steel, the smaller grain size for the martensite and the tempering process resulted in increased elongation, more formability and ability to form a flange (flangeability). In CP steels the soft ferrite phase is replaced by harder bainite, yielding a bainitic-martensitic microstructure. Bainite reduced the total elongation of the alloy during tensile testing, reduced the formability (especially under plane strain conditions) of the alloy but improved the flangeability of the alloy. Under flanging conditions, CP steels deformed to higher strains, at tighter radii with minimum springback. Microstructural inspections at the outer radius of the flanged specimens revealed that in CP steels bainite deforms similarly to martensite, therefore the strain partitioning is smaller in CP steels in comparison to DP steels. Plastic deformation in CP steels upon flanging occurs with the formation of strong slip bands in both martensite and bainite. In contrast, the martensite and ferrite grains in DP steels deform quite differently leading to strong strain localisations. Void nucleation and cracking occurred at the martensite islands or within the soft ferrite phase next to the martensite islands. In CP steels no voids or damage was observed within the matrix. A special case study was done with a thicker and stronger alloy, a Martensitic 1400 steel to reveal the flangeability limits for advanced high strength steels. Neither cracks nor damage were observed visually on the flanged specimens. However SEM observations at the outer radius of the flanged samples revealed significant void growth at inclusion sites and cracks nucleating within the matrix adjacent to the inclusions.Publisher Statement: This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/)</p

    Influence of seed treatment and packaging materials on seed longevity of cluster bean [Cyamopsistetra gonoloba (L.) Taub.]

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    An experiment was conducted to investigate the influence of packaging materials and seed treatments on storability of cluster bean under ambient conditions of Bengaluru. The experiment consisted of six treatments viz. control (T1), bavistin @ 2 g kg-1 (T2), spinosad @ 0.04 ml/kg (T3), neem leaf powder @ 1:20 ratio (T4), Acorus calamus@ 10 g kg-1 (T5) and cow dung powder @ 10 g kg-1 (T6) and three packaging materials viz., cloth bag (C1) super grain bag (C2) and poly lined cloth bag (C3). Treated seed samples were stored in three containers under ambient storage conditions up to the duration of which seeds maintain minimum seed certification standards and samples were drawn at bimonthly intervals for ascertaining the seed quality parameters. The study suggested that seed treat-ment could be useful to prolong the storage life of cluster bean seeds. The seeds treated with spinosad (0.04 ml/kg) and stored in super-grain bag were better for maintenance of higher seed quality parameters [germination (80.00%), root length (11.70 cm), shoot length (13.60 cm), mean seedling dry weight (152 mg), seedling vigour index I and II (2024&amp;12140) and TDH activity (1.224) with low electrical conductivity (0.368 dSm-1)] up to 18 months under ambient conditions of Bengaluru (room temperature). Super-grain bag proved to be better storage container with higher seed quality attributes viz., germination (72.38 %), seedling vigour index-I (1726), total dehydrogenase activity (1.201) and other seed quality parameters compared to cloth bag. The study suggested that use of appropriate packaging material and seed treatment could be useful to prolong the storage life of cluster bean seeds
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