2,341 research outputs found

    Masses of 2S single heavy baryons using non-perturbative parameters in HQET

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    We have employed heavy quark effective theory (HQET) to determine the masses of n=2n=2, S-wave charm and bottom baryons. The HQET parameters Λ‟\overline{\Lambda}, λ1\lambda_1 and λ2\lambda_2 are calculated for n=1n=1 using the masses of S-wave baryons. The behavior of ratio of mass terms of n=1n=1 mesons and baryons containing these parameters are also studied by varying the bottom quark mass. The HQET symmetry of Λ‟\overline{\Lambda} parameter is used to find the parameters and masses for n=2n=2 S-wave baryons. The variation of mass of 2S baryons with the non-perturbative parameters λ1\lambda_1 and λ2\lambda_2 for radially excited baryons is discussed. The Regge trajectories are also plotted in the (n,M2)(n,M^2) plane using masses of n=1n=1 and 2 charm and bottom baryons. The Regge trajectories are parallel and equidistant lines in the (n,M2)(n,M^2) plane.Comment: 12 pages, 13 figure

    Design Evaluation and Temperature Rise Test of Flameproof Induction Motor

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    The ignition of flammable gases, vapours or dust in presence of oxygen contained in the surrounding atmosphere may lead to explosion. Flameproof three phase induction motors are the most common and frequently used in the process industries such as oil refineries, oil rigs, petrochemicals, fertilizers, etc. The design of flameproof motor is such that it allows and sustain explosion within the enclosure caused by ignition of hazardous gases without transmitting it to the external flammable atmosphere. The enclosure is mechanically strong enough to withstand the explosion pressure developed inside it. To prevent an explosion due to hot spot on the surface of the motor, flameproof induction motors are subjected to heat run test to determine the maximum surface temperature and temperature class with respect to the ignition temperature of the surrounding flammable gas atmosphere. This paper highlights the design features of flameproof motors and their surface temperature classification for different sizes

    Mycodecolorization Activity of Pleurotus Citrinopileatus for Chemically Different Textile Dye Under Varied Aromatic Amino Acids and Trace Elements

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    In the present study, ligninolytic enzymes laccase (benzenediol: oxygen reductase EC; 1.10.3.2) and Manganese Peroxidase (Mn(II): hydrogen-peroxide oxidoreductase EC; 1.11.1.13) activity and of White Rot Fungi (WRF) Pleurotus citrinopileatus were enhanced with the application of trace metal i.e. Copper and Manganese at 25 ppm and 50 ppm followed by aromatic amino acids (Phenylalanine, Tryptophan and Tyrosine) at 0.02 ÎŒM and 0.4 ÎŒM. Laccase and MnP activity were 213.42U and 202.28U respectively, observed at 300ppm of Methyl Red supplemented with Tyrosine (0.2ÎŒM) followed by treatment of Tryptophan (198.45U and 195.16U) and Phenylalanine (195.85U and 188.15U). Maximum Laccase and MnP activity (Tyrosine treated) were revealed maximum decolorization of Phenol Red and Methyl Red (84.14% and 78.20%) followed by Phenylalanine (80.92% and 73.80%) and Trypatophan (71.22% and 70.12%).  The negative correlation of  Laccase and MnP activity was observed with a higher concentration (>50ppm) of trace metal in the medium, while at 25ppm of copper supplemented medium increase three-fold of Laccase activity (585.56U) as tyrosine medium and similarly, Manganese (25ppm) inosculated medium revealed three-fold more MnP activity (478.95U).  A lower amount of Cu hoists Laccase and MnP activity which decolorized 300ppm of Methyl Red and Phenol Red with maximum percent (92.3% and 88.15%) followed by Mn. Thus, Laccase and MnP enzymes both play an important role in decolorization of dyes, and its activity was enhanced with the application of lower concentration of trace metals followed by aromatic amino acids

    Sparsity-based autoencoders for denoising cluttered radar signatures

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    Narrowband and broadband indoor radar images significantly deteriorate in the presence of target-dependent and target-independent static and dynamic clutter arising from walls. A stacked and sparse denoising autoencoder (StackedSDAE) is proposed for mitigating the wall clutter in indoor radar images. The algorithm relies on the availability of clean images and the corresponding noisy images during training and requires no additional information regarding the wall characteristics. The algorithm is evaluated on simulated Doppler-time spectrograms and high-range resolution profiles generated for diverse radar frequencies and wall characteristics in around-the-corner radar (ACR) scenarios. Additional experiments are performed on range-enhanced frontal images generated from measurements gathered from a wideband radio frequency imaging sensor. The results from the experiments show that the StackedSDAE successfully reconstructs images that closely resemble those that would be obtained in free space conditions. Furthermore, the incorporation of sparsity and depth in the hidden layer representations within the autoencoder makes the algorithm more robust to low signal-to-noise ratio (SNR) and label mismatch between clean and corrupt data during training than the conventional single-layer DAE. For example, the denoised ACR signatures show a structural similarity above 0.75 to clean free space images at SNR of −10 dB and label mismatch error of 50%

    Effect of Magnetic activity on scintillation at Equatorial Region during Low Solar Activity

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    Single and dual frequency GPS receivers used in low-latitude regions can suffer from rapid amplitude and phase fluctuations known as scintillation. Intense signal fluctuations cause GPS receivers to stop tracking the signals from GPS satellites in a process sometimes called “loss of lock”. This may increase navigation errors or, in some cases, cause navigation failure. Data recorded from ground-based GPS scintillation monitors (GSV 4004A GPS receiver) installed at the Space Science Laboratory, Department of Physics, Barkatullah University, Bhopal (23.2ÂșN, 77.4ÂșE; Geomagnetic 14.2ÂșN) are used. Different phases of geomagnetic storms affect the generation and development of ionospheric irregularities differently. Results shows that occurrence of scintillation observed during summer months are relatively weak as compared to those recorded during winter and equinox months. The enhancement in magnetic activity leads to a suppression of pre-midnight scintillations during the equinox and during the winter, whereas as enhancement is observed in summer months. The generation or inhibition of irregularities during the main phase/recovery phase of a magnetic storm depends upon the location of the station and local time. Keywords: Scintillation, Geomagnetic storms, Magnetic activit

    Do recent supernovae Ia observations tend to rule out all the cosmologies?

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    Dark energy and the accelerated expansion of the universe have been the direct predictions of the distant supernovae Ia observations which are also supported, indirectly, by the observations of the CMB anisotropies, gravitational lensing and the studies of galaxy clusters. Today these results are accommodated in what has become the `concordance cosmology': a universe with flat spatial sections t=constant with about 70% of its energy in the form of Einstein's cosmological constant \Lambda. However, we find that as more and more supernovae Ia are observed, more accurately and towards higher redshift, the probability that the data are well explained by the cosmological models decreases alarmingly, finally ruling out the concordance model at more than 95% confidence level. This raises doubts against the `standard candle'-hypothesis of the supernovae Ia and their use to constrain the cosmological models. We need a better understanding of the entire SN Ia phenomenon in order to have cosmological consequences from them.Comment: Replaced with published versio

    Analysis of genetic diversity among tropical and subtropical maize inbred lines using SSR markers

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    Genetic diversity of 24 tropical and subtropical elite maize lines was assessed at molecular level employ-ing 42 Simple Sequence Repeats. A total of 107 alleles with an average of 2.55 alleles per locus were detected. The Polymorphism Information Content (PIC) values of 42 SSR loci ranged from 0.08 (UMC1428) to 0.68 (UMC2189 and UMC2332) with the overall calculated PIC mean value of 0.44, whereas the Discrimination Rate (DR) value for SSR markers ranged from 0.09 (UMC2089) to 0.42 (UMC1311) with the average DR value of 0.26. Pair-wise genet-ic similarity (GS) values, calculated by Jaccard’s coefficients, ranged between 0.25 and 0.78 with a mean genetic similarity of 0.63, indicating the existence of adequate amount of genetic divergence among the genotypes selected for the study. The cluster dendrogram separated all the inbred lines into six main clusters with sub clusters based on genetic similarity. Factorial analysis also confirmed a nearly similar pattern for grouping these inbred lines as pre-sented by cluster dendrogram. In this study, SSR markers were found to be powerful tool for detection of genetic diversity in maize inbred lines. These findings could provide information for effective utilization of these materials for development of maize hybrids as well as for genetic improvement of inbred lines

    Retrospection of heatwave and heat index

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    The frequency and intensity of extreme events especially heat waves (HW) are growing all around the world which ultimately poses a serious threat to the health of individuals. To quantify the effects of extreme temperature, appropriate information, and the importance of HW and heat index (HI) are carefully discussed for different parts of the world. Varied definitions of the HW and HI formula proposed and used by different countries are carried out systematically continent-wise. Different studies highlighted the number of definitions of HW; however, mostly used Steadman’s formulae, which was developed in the late 1970s, for the calculation of HI that uses surface air temperature and relative humidity as climatic fields. Since then, dramatic changes in climatic conditions have been observed as evident from the ERA5 datasets which need to be addressed; likewise, the definition of HW, which is modified by the researchers as per the geographic conditions. It is evident from the ERA5 data that the temperature has increased by 1–2 °C as compared to the 1980s. There is a threefold increase in the number of heatwave days over most of the continents in the last 40 years. This study will help the researcher community to understand the importance of HW and HI. Furthermore, it opens the scope to develop an equation based on the present scenario keeping in mind the basics of an index as considered by Steadman
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