164 research outputs found

    Dark matter assisted Dirac leptogenesis and neutrino mass

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    We propose a minimal extension of the standard model with U(1)_{B-L} \times Z_{2} symmetry. In this model by assuming that the neutrinos are Dirac (i.e. BLB-L is an exact symmetry), we found a simultaneous solution for non zero neutrino masses and dark matter content of the universe. The observed baryon asymmetry of the universe is also explained using Dirac Leptogenesis, which is assisted by a dark sector, gauged under a U(1)_D symmetry. The latter symmetry of the dark sector is broken at a TeV scale and thereby giving mass to a neutral gauge boson Z_D. The standard model Z-boson mixes with the gauge boson Z_D at one loop level and thus paves a way to detect the dark matter through spin independent elastic scattering at terrestrial laboratories.Comment: 12 pages, 10 figures. Accepted for publication in Nuclear Physics

    Forensic Research on Solid State Drives using Trim Analysis

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    There has been a tremendous change in the way we store data for the past decade. Hard Disk Drives, which were one of the major sources of storing data, are being replaced with Solid State Drives considering the higher efficiency and portability. Digital forensics has been very successful in recovering data from Hard Disk Drives in the past couple of years and has been very well established with Hard Disk Drives. The evolution of Solid State Drives over Hard Drive Drives is posing a lot of challenges to digital forensics as there are many crucial factors to be considering the architecture and the way data is stored in Solid State Drives. This paper gives a very detailed picture of the evolution of Solid State Drives over Hard Disk Drives. We understand the differences in their architecture and the ways to extract data from them. We further discuss in detail the various challenges Solid State Drives pose to the field of digital forensics, and we try to answer contradictory beliefs those are 1) Would data be permanently deleted in a Solid State Drives destroying the forensic evidence required to solve a case? 2) Can data be restored in a Solid State Drives by using proper techniques and still can be used as evidence in digital forensics? In this paper, we talk about the introduction of concepts such as the TRIM Command and Garbage collection, their importance, and we set up an experimental scenario where we implement the TRIM command and try extracting data from different types of Solid State Drives. We compare and evaluate the results obtained through the experiment and try to analyze the uses of the TRIM command and its performance over various Solid State Drives. The paper also discusses future work to make the role of Solid State Drives more efficient in digital forensics

    Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties

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    The term Nano in chemistry refers to particles/molecules in the size range 1 to 100 nm. Gold nanoparticles were used in ancient times in making decorative glass as they produce vibrant, size dependent, colors upon interaction with light. Gold is a preferred choice of metal for the synthesis of nanoparticles mainly due to its inertness to atmospheric conditions and most chemicals. Gold thiolate nanomolecules, which is the primary focus of this dissertation research, are chemical molecules with a fixed number of gold atoms and organo-thiolate ligands. They are of the form Aux(SR)y and possess molecule-like properties as a result of distinctive quantum confinement effects occurring at the nanoscale size. The optical and electronic properties of these molecules change as a function of x and y in the formulation Aux(SR) y. The stability of these nanomolecules can be attributed due in part to their symmetrical geometry as evidenced by the X-ray crystallography. Recent research in the field has focused on exploiting the size-dependent properties of gold nanomolecules in applications like nano-electronics, biological sensing and catalysis. But much of the hindrance to these advances come from the lack of established protocols to synthesize monodisperse nanomolecules in high yields. Brust-schiffrin protocol for the synthesis of nanomolecules yields stable products in a two-phase system which can be dried and re-dispersed without affecting the stability. But the protocol has a major drawback of producing a polydisperse mixture of different sizes of nanomolecules. A major portion of my dissertation focuses on addressing this issue of polydispersity of products. In this regard, I have investigated the one-phase synthesis protocol for synthesis of gold-thiolate nanomolecules wherein the gold salt and the capping ligands are essentially dissolved in a single solvent system. This protocol is peculiar in that it yields various sizes which are otherwise not observed

    Crop Recommendation System Using Improved Apriori Algorithm

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    A crop suggestion system is a technologically advanced tool that helps farmers choose which crops to plant in a certain location or with precise environmental circumstances. These systems use a variety of data sources and analytical methods to give farmers customized crop recommendations. This work presents the Crop Recommendation System Using an Improved Apriori Algorithm, which is an Apriori-based crop recommendation system. The goal of the system is to assist farmers in making well-informed choices about which crops to grow and what fertilizers to use depending on the properties of the soil and environment. With consideration for crop variety, climate, and soil nutrient content, the suggested method is an enhanced version of the Apriori algorithm. Tests of the updated algorithm on a dataset of soil samples from different parts of India revealed that it could correctly suggest the optimal crop. The model's output, association rules, is a suggestion system that farmers can use to boost crop productivity while lowering input costs. The method suggested operates in three phases: In the first stage, preprocessing the data is carried out to gather the input parameters that are crucial for determining the recommendation system. In Stage 2, the recommendation system's association rules are extracted by using an iterative approach to determine the threshold support count and confidence. Stage 3: The recommendation system's knowledge base is formed by pruning the top 8 apriori rules depending on priority. From the experiments, it is evident that the improved apriori algorithm-based extracted recommendation system is an interesting development in precision agriculture that could raise farming practices' sustainability and efficiency

    Spread Spectrum based QoS aware Energy Efficient Clustering Algorithm for Wireless Sensor Networks

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    Wireless sensor networks (WSNs) are composed of small, resource-constrained sensor nodes that form self-organizing, infrastructure-less, and ad-hoc networks. Many energy-efficient protocols have been developed in the network layer to extend the lifetime and scalability of these networks, but they often do not consider the Quality of Service (QoS) requirements of the data flow, such as delay, data rate, reliability, and throughput. In clustering, the probabilistic and randomized approach for cluster head selection can lead to varying numbers of cluster heads in different rounds of data gathering. This paper presents a new algorithm called "Spread Spectrum based QoS aware Energy Efficient Clustering for Wireless sensor Networks" that uses spread spectrum to limit the formation of clusters and optimize the number of cluster heads in WSNs, improving energy efficiency and QoS for diverse data flows. Simulation results show that the proposed algorithm outperforms classical algorithms in terms of energy efficiency and QoS

    Leptogenesis and eV scale sterile neutrino

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    We consider the minimal extended seesaw model which can accommodate an eV scale sterile neutrino. The scenario also includes three heavy right handed neutrinos in addition to the light sterile neutrino. In this model, the active-sterile mixing act as non-unitary parameters. If the values of these mixing angles are of O(0.1)\mathcal{O}(0.1), the model introduces deviation of the PMNS matrix from unitarity to this order. We find that the oscillation data from various experiments imposes an upper bound on the lightest heavy neutrino mass scale as 1011\sim 10^{11} GeV in the context of this model. We study {\it vanilla} leptogenesis in this scheme, where the decay of the heavy right handed neutrinos in the early universe can give rise to the observed baryon asymmetry. Here, even though the eV scale sterile neutrino does not participate directly in leptogenesis, its effect is manifested through the non-unitary effects. We find that the parameter space that can give rise to successful leptogenesis is constrained by the bounds on the active-sterile mixing as obtained from the global analysis.Comment: 20 pages, 8 figures, Accepted for publication in PR

    Evaluate the importance of giving antenatal corticosteroids in respiratory distress syndrome in preterm neonates

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    Respiratory distress syndrome (RDS) is one of the leading causes of early neonatal morbidity and mortality in late preterm infants (LPIs) worldwide. The aim: The study is intended to evaluate the importance of giving antenatal corticosteroids in decreasing respiratory distress syndrome in preterm neonates. Materials and methods: Prospective cohort study done in all preterms delivered in the hospital attached to those admitted in our neonatal intensive care unit during the study duration are taken as the source. All preterm babies are admitted to the neonatal intensive care unit. Results: The overall incidence of RDS in this study was 30 (15 %), among which 7 (7 %) were exposed to steroids, and 23 (23 %) were not exposed to steroids. Antenatal corticosteroids were significantly associated with reduced incidence of RDS in preterms (neonates born between 28–37 weeks of gestational age). The overall incidence of TTN (transient tachypnea) was found to be 46 (28 %) in this study, among which 14 (14 %) were exposed to steroids, and 32 (32 %) were not exposed to steroids. Antenatal corticosteroids were significantly associated with reduced incidence of TTN in preterms. Antenatal corticosteroids significantly reduce the need for supplemental oxygen, NICU admission, need for CPAP and mortality rate. The dose of antenatal corticosteroids was significantly associated with the incidence of RDS and TTN. 2 doses of steroids reduced RDS and TTN significantly compared to the single dose, which was just significantly associated. This study found no significance between RDS and TTN with gestational age, mode of delivery, birth weight and RDS among steroid-exposed babies. Conclusion: The use of antenatal corticosteroids should be promoted because they successfully lowered morbidity and mortality among premature newborns in the population studied. In order to optimise proper and timely prenatal corticosteroid treatment, this study underlines the necessity for quality improvement initiatives
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