429 research outputs found
Crossover from Diffusive to Superfluid Transport in Frustrated Magnets
We investigate the spin transport across the magnetic phase diagram of a
frustrated antiferromagnetic insulator and uncover a drastic modification of
the transport regime from spin diffusion to spin superfluidity. Adopting a
triangular lattice accounting for both nearest neighbor and next-nearest
neighbor exchange interactions with easy-plane anisotropy, we perform atomistic
spin simulations on a two-terminal configuration across the full magnetic phase
diagram. We found that as long as the ground state magnetic moments remain
in-plane, irrespective of whether the magnetic configuration is ferromagnetic,
collinear or non-collinear antiferromagnetic, the system exhibits spin
superfluid behavior with a device output that is independent on the value of
the exchange interactions. When the magnetic frustration is large enough to
compete with the easy-plane anisotropy and cant the magnetic moments out of the
plane, the spin transport progressively evolves towards the diffusive regime.
The robustness of spin superfluidity close to magnetic phase boundaries is
investigated and we uncover the possibility for {\em proximate} spin
superfluidity close to the ferromagnetic transition.Comment: 9 pages, 7 figure
3D Deep Learning on Medical Images: A Review
The rapid advancements in machine learning, graphics processing technologies
and availability of medical imaging data has led to a rapid increase in use of
deep learning models in the medical domain. This was exacerbated by the rapid
advancements in convolutional neural network (CNN) based architectures, which
were adopted by the medical imaging community to assist clinicians in disease
diagnosis. Since the grand success of AlexNet in 2012, CNNs have been
increasingly used in medical image analysis to improve the efficiency of human
clinicians. In recent years, three-dimensional (3D) CNNs have been employed for
analysis of medical images. In this paper, we trace the history of how the 3D
CNN was developed from its machine learning roots, give a brief mathematical
description of 3D CNN and the preprocessing steps required for medical images
before feeding them to 3D CNNs. We review the significant research in the field
of 3D medical imaging analysis using 3D CNNs (and its variants) in different
medical areas such as classification, segmentation, detection, and
localization. We conclude by discussing the challenges associated with the use
of 3D CNNs in the medical imaging domain (and the use of deep learning models,
in general) and possible future trends in the field.Comment: 13 pages, 4 figures, 2 table
SCIENTIFIC VALIDATION AND STANDARDIZATION OF PARPATAKA AN AYURVEDIC DRUG WITH RESPECT TO FUMARIA INDICA
Objective: Fumaria indica is an essential curative herb and asserted as a prevalent weed across the plains of India. The entire plant is popularly employed in conventional systems of medicine for its therapeutic activities like anthelmintic, diuretic, diaphoretic, laxative, purging and stomachic. The entire plant is regarded to have therapeutical purposes in Ayurvedic and Unani systems of medicine and is employed in the preparation of important Ayurvedic formulation Parpataka. In Unani systems of medicine, it is used as shahtara. This contemporary study is intended to authenticate and validate the species Fumaria indica with respect to Parpataka drug.
Methods: The chief objective of this contemporary research work is to assess the various pharmacognostic properties like Macroscopical, Microscopical, Physiochemical and Fluorescence studies. Microscopical studies include cell structure and their arrangement, Physicochemical parameter s include loss on drying, total ash value, acid insoluble ash, water-insoluble ash, various extractive values etc. Qualitative tests for various functional groups were also carried out.
Results: The microscopical characters of leaf, stem and roots, physicochemical, preliminary phytochemical profiles were established.
Conclusion: The pharmacognostical screening on Fumaria indica is significant data for the identification and to determine the quality and purity of the plant material in future reviews
STANDARDIZATION OF BALAMULA CHURNA (SIDA CORDIFOLIA L. ROOT POWDER)
Objective: In this study, an attempt was made to generate information based on, physicochemical parameter preliminary phytochemical screening and HPTLC data needed for proper identification and authentication of Balamula Churna.
Methods: The physicochemical parameters such as water-soluble extractive, alcohol soluble extractive and loss on drying at 105 °C, total ash and acid insoluble ash were determined according to standard methods. HPTLC studies were conducted and Rf values were documented.
Results: Physicochemical parameter value were documented as pH (6.81%), LOD (7.5%), water-soluble extractive value (6.32%), alcohol soluble extractive value (5.92%) total Ash (9.00%) and Acid Insoluble Ash (1.60%). Preliminary phytochemical screening reveals the presence of glycoside, alkaloid, carbohydrate, phenol, flavonoid and saponin. HPTLC screening showed the presence of significant phytoconstituents with Rf value 0.02, 0.27, 0.34 and 0.96.
Conclusion: All the results obtained from this study can be helpful in evaluation quality, detection of adulteration and substitution and emphasizing the importance of standardization
Chemical looping combustion of biomass for renewable & non- CO2 emissions energy- status and review
World depends on fossil fuel combustion for thermal energy generation. Fossil fuel combustion leads to the generation of CO2 and ex-tinction of non-renewable resources. To meet the future energy demands replacement of existing technologies should take place in the view of large quantities of GHG’s emissions from fossil fuels and their extinction. Chemical looping combustion (CLC) is primarily a combustion technique with an inherent separation of CO2 from the flue gases. Due to its advantage of negative CO2 emissions, chemical looping combustion got attention of many researchers since last one and half decade. Recent research advancements in the CLC provided a platform for further research and developments in chemical looping combustion of biomass. This paper reviews the CLC of biomass to present the overview of chemical looping combustion technology and its status of biomass utilization as a fuel in CLC reactors
Environmental geotechnics: Challenges and opportunities in the post-Covid-19 world
The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for the development of the environmental geotechnics field. This discipline should make full use of geoenvironmental researchers' and engineers' professional skills and expertise to look for development opportunities from this crisis, to highlight the irreplaceable position of the discipline in the global fight against pandemics and to contribute to the health and prosperity of communities, to serve humankind better. In order to reach this goal while taking into account the specificity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the uncertainty of its environmental effects, it is believed that more emphasis should be placed on the following research directions: pathogen-soil interactions; isolation and remediation technologies for pathogen-contaminated sites; new materials for pathogen-contaminated soil; recycling and safe disposal of medical wastes; quantification of uncertainty in geoenvironmental and epidemiological problems; emerging technologies and adaptation strategies in civil, geotechnical and geoenvironmental infrastructures; pandemic-induced environmental risk management; and modelling of pathogen transport and fate in geoenvironment, among others. Moreover, Covid-19 has made it clear to the environmental geotechnics community the importance of urgent international co-operation and of multidisciplinary research actions that must extend to a broad range of scientific fields, including medical and public health disciplines, in order to meet the complexities posed by the Covid-19 pandemic
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