22 research outputs found
Effects of Schwarzschild Geometry on Isothermal Plasma Wave Dispersion
The behavior of isothermal plasma waves has been analyzed near the
Schwarzschild horizon. We consider a non-rotating background with
non-magnetized and magnetized plasmas. The general relativistic
magnetohydrodynamical equations for the Schwarzschild planar analogue spacetime
with an isothermal state of the plasma are formulated. The perturbed form of
these equations is linearized and Fourier analyzed by introducing simple
harmonic waves. The determinant of these equations in each case leads to a
complex dispersion relation, which gives complex values of the wave number.
This has been used to discuss the nature of the waves and their characteristics
near the horizon.Comment: 17 pages, 3 figures accepted for publication in J. Korean Physical
Societ
Timelike and Spacelike Matter Inheritance Vectors in Specific Forms of Energy-Momentum Tensor
This paper is devoted to the investigation of the consequences of timelike
and spacelike matter inheritance vectors in specific forms of energy-momentum
tensor, i.e., for string cosmology (string cloud and string fluid) and perfect
fluid. Necessary and sufficient conditions are developed for a spacetime with
string cosmology and perfect fluid to admit a timelike matter inheritance
vector, parallel to and spacelike matter inheritance vector, parallel to
. We compare the outcome with the conditions of conformal Killing vectors.
This comparison provides us the conditions for the existence of matter
inheritance vector when it is also a conformal Killing vector. Finally, we
discuss these results for the existence of matter inheritance vector in the
special cases of the above mentioned spacetimes.Comment: 27 pages, accepted for publication in Int. J. of Mod. Phys.
Building resilient future: information technology and disaster management - a Malaysian perspective
The recent evets of flooding, earthquakes, uncontrolled wildfires, hurricanes, and deadly storms in world has considered a serious threat to mankind and preparing for devastating disasters has never been more critical and urgent. Emergency Events Database suggests that by year 2050 the damages to flood related incidents to coastal cities will cost near to US$1 trillion. Risk from acts of nature cannot be fully prevented but needs to minimize and safe the innocent lives and property by utilizing disaster management technique to mitigate the losses. This paper presents Information Technologies applications in disaster management phases such as Mitigation, Preparedness, Response and Recovery. Geographic Information System, Remote Sensing, mobile technology, drone, and satellite imagery and MOBILISE analytic platform considered as effective and efficient ways of strengthening resilience when disaster strikes and tremendously helpful for coordinating responses and accelerating the recovery of individuals and communities in the aftermath of recent natural disasters
Complex Wave Numbers in the Vicinity of the Schwarzschild Event Horizon
This paper is devoted to investigate the cold plasma wave properties outside
the event horizon of the Schwarzschild planar analogue. The dispersion
relations are obtained from the corresponding Fourier analyzed equations for
non-rotating and rotating, non-magnetized and magnetized backgrounds. These
dispersion relations provide complex wave numbers. The wave numbers are shown
in graphs to discuss the nature and behavior of waves and the properties of
plasma lying in the vicinity of the Schwarzschild event horizon.Comment: 21 pages, 9 figures, accepted for publication Int. J. Mod. Phys.
Toward an integrated disaster management approach: How artificial intelligence can boost disaster management
Technical and methodological enhancement of hazards and disaster research is identified
as a critical question in disaster management. Artificial intelligence (AI) applications, such as tracking
and mapping, geospatial analysis, remote sensing techniques, robotics, drone technology, machine
learning, telecom and network services, accident and hot spot analysis, smart city urban planning,
transportation planning, and environmental impact analysis, are the technological components of
societal change, having significant implications for research on the societal response to hazards
and disasters. Social science researchers have used various technologies and methods to examine
hazards and disasters through disciplinary, multidisciplinary, and interdisciplinary lenses. They
have employed both quantitative and qualitative data collection and data analysis strategies. This
study provides an overview of the current applications of AI in disaster management during its
four phases and how AI is vital to all disaster management phases, leading to a faster, more concise,
equipped response. Integrating a geographic information system (GIS) and remote sensing (RS)
into disaster management enables higher planning, analysis, situational awareness, and recovery
operations. GIS and RS are commonly recognized as key support tools for disaster management.
Visualization capabilities, satellite images, and artificial intelligence analysis can assist governments
in making quick decisions after natural disasters
Renal tumouroids: challenges of manufacturing 3D cultures from patient derived primary cells.
Recent advancements in 3D in vitro culture have allowed for the development of cancer tissue models which accurately recapitulate the tumour microenvironment. Consequently, there has been increased innovation in therapeutic drug screening. While organoid cultures show great potential, they are limited by the time scale of their growth in vitro and the dependence upon commercial matrices, such as Matrigel, which do not allow for manipulations of their composition or mechanical properties. Here, we show a straightforward approach for the isolation and culture of primary human renal carcinoma cells and matched non-affected kidney. This approach does not require any specific selection for cancer cells, and allows for their direct culture in amenable 3D collagen-based matrices, with the preservation of cancer cells as confirmed by NGS sequencing. This method allows for culture of patient-derived cancer cells in 3D microenvironment, which can be used for downstream experimentation such as investigation of cell-matrix interaction or drug screening. [Abstract copyright: © 2022. Crown.
Renal tumouroids: challenges of manufacturing 3D cultures from patient derived primary cells
Recent advancements in 3D in vitro culture have allowed for the development of cancer tissue models which accurately recapitulate the tumour microenvironment. Consequently, there has been increased innovation in therapeutic drug screening. While organoid cultures show great potential, they are limited by the time scale of their growth in vitro and the dependence upon commercial matrices, such as Matrigel, which do not allow for manipulations of their composition or mechanical properties. Here, we show a straightforward approach for the isolation and culture of primary human renal carcinoma cells and matched non-affected kidney. This approach does not require any specific selection for cancer cells, and allows for their direct culture in amenable 3D collagen-based matrices, with the preservation of cancer cells as confirmed by NGS sequencing. This method allows for culture of patient-derived cancer cells in 3D microenvironment, which can be used for downstream experimentation such as investigation of cell-matrix interaction or drug screening