176 research outputs found
Gravity and Large Extra Dimensions
The idea that quantum gravity can be realized at the TeV scale is extremely
attractive to theorists and experimentalists alike. This proposal leads to
extra spacial dimensions large compared to the electroweak scale. Here we give
a very systematic view of the foundations of the theories with large extra
dimensions and their physical consequences.Comment: 26 pages, 3 diagram
Supernovae as Probes of Extra Dimensions
Since the dawn of the new millennium, there has been a revived interest in
the concept of extra dimensions.In this scenario all the standard model matter
and gauge fields are confined to the 4 dimensions and only gravity can escape
to higher dimensions of the universe.This idea can be tested using table-top
experiments, collider experiments, astrophysical or cosmological observations.
The main astrophysical constraints come from the cooling rate of supernovae,
neutron stars, red giants and the sun. In this article, we consider the energy
loss mechanism of SN1987A and study the constraints it places on the number and
size of extra dimensions and the higher dimensional Planck scale.Comment: 5 pages, no figures, new references are adde
Intra annual Variability of the Arabian Sea high salinity water mass in the South Eastern Arabian Sea during 2016 17
Intra-annual variability of the Arabian Sea high salinity water mass (ASHSW) in the South Eastern Arabian Sea (SEAS) and Gulf of Mannar (GoM) are addressed in this paper by utilisng the monthly missions carried out onboard INS Sagardhwani during 2016-17. Our observations revealed that the ASHSW was evident along the SEAS irrespective of seasons, whereas in the GoM the presence of ASHSW was observed during winter. The processes such as downwelling/up-welling, coastal currents, intrusion of low saline waters, stratification are clearly affects the spreading of the ASHSW. The characteristics such as core salinity value, depth and thickness of ASHSW exhibited remarkable spatio-temporal variability. Lateral mixing with the low saline waters in the region during winter reduces its core salinity. The intrusion of low saline waters was clearly seen upto 15 ON but the intrusion of low saline waters is not flowing through the GoM. The interface between the ASHSW and the prevailing low saline waters showed strong horizontal gradients of salinity. The presence of the ASHSW makes difference in the SLD and the below layer gradient which is sufficient to complicate or influence sound transmission. The spatio temporal variability of the ASHSW and its acoustic relevance are documented in this paper
Phytochemical Screening and Profiling of Secondary Metabolites of Annona Muricata Bark
Screening of phytochemicals is a precious stair in the detection of bioactive principles present in medicinal plants and may lead to novel drug discovery). In present study aimed to investigate the preliminary phytochemical screening, fluorescence, and spectroscopic characterization in Annona muricata bark. The qualitative analysis of aqueous, hexane, ethanol, hydro-ethanolic and methanol extracts of Annona muricata bark were investigated. Among the various extracts, the hydro-ethanolic extract of Annona muricata bark contains a higher concentration of phytochemicals than other extracts and is used for subsequent studies. Quantitative analysis revealed that the Annona muricata bark has contain significant amount of phenol, flavonoids, saponin, tannin and alkaloids were present. Histochemical analysis further confirmed the presence of phytochemicals in Annona muricata bark. UV-VIS spectral analysis we can confirm that the presence of tannins and flavonoids. FTIR analysis had confirmed the presence of alcohol, phenol, aromatic, carboxylic acid, and aliphatic amines. Results of the study concluded that rich source of phytochemicals in Annona muricata bark is responsible for their therapeutic effects. So, it is recommended as a plant of phytopharmaceutical importance and further studies are needed with these plants to evaluate their pharmacological potentials of the bioactive compounds responsible for their bio-activities and other medicinal values
Detecting the Anti-Social Activity on Twitter using EGBDT with BCM
The rise of social media and its consequences is a hot topic on research platforms. Twitter has drawn the attention of the research community in recent years due to various qualities it possesses. They include Twitter's open nature, which, unlike other platforms, allows visitors to see posts posted by Twitter users without having to register. In twitter the sentiment analysis of tweets are used for detecting the anti-social activity event which is one of the challenging tasks in existing works. There are many classification algorithms are used to detect the anti-social activities but they obtains less accuracy. The EGBDT (Enhanced Gradient-Boosted Decision Tree) is used to optimize the best features from the NSD dataset and it is given as input to BCM (Bayesian Certainty Method) for detecting the anti-social activities. In this work, tweets from NSD dataset are used for analyzing the sentiment polarity i.e. positive or negative. The efficiency of the proposed work is compared with SVM, KNN and C4.5. From this analysis the proposed EGBDT and BCM obtained better results than other techniques
Addressing the IoT Schemes for Securing the Modern Healthcare Systems with Block chain Neural Networks
This paper provides a wide-range of literature review of various IOT with AI based enabling wearable technologies and protocols used for medical (IoT) with a taught of examining the present and future smart health care technologies. Despite recent advances in medical systems, biomedical hardware, the growth of IoT in medicine continues to advance in terms of biomedical hardware, monitoring figures like cancer patient data disease indicators, temperature levels, oxygen levels, and glucose levels. In the near future, medical IoT is expected to replace the old traditional healthcare systems to smart Ai-IoT based healthcare systems. In our paper we provided a theoretical approach of the most relevant protocols and wearable technologies used for the IoT health care medical systems. We also provided a proposed smart AI based intelligent IoT frameworks for hospital systems settings
Inundation mapping – a study based on December 2004 Tsunami Hazard along Chennai coast, Southeast India
Tsunami impact study has been undertaken along Chennai coast starting from Pulicat to Kovalam. The study area Chennai coast is mainly devoted to prepare large scale action plan maps on tsunami inundation incorporating land use details derived from satellite data along with cadastral data using a GIS tool. Under tsunami inundation mapping along Chennai coast an integrated approach was adopted to prepare thematic maps on land use/land cover and coastal geomorphology using multispectral remote sensing data. The RTK dGPS instruments are used to collect elevation contour data at 0.5 m intervals for the Chennai coast. The GIS tool has been used to incorporate the elevation data, tsunami inundation markings obtained immediately after tsunami and thematic maps derived from remote sensing data. The outcome of this study provides an important clue on variations in tsunami inundation along Chennai coast, which is mainly controlled by local geomorphologic set-up, coastal zone elevation including coastal erosion protection measures and near shore bathymetry. This study highlights the information regarding most vulnerable areas of tsunami and also provides indication to demarcate suitable sites for rehabilitation
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