83 research outputs found
EVALUATION OF FLOOD DETERMINANTS: EVIDENCE FROM KELANI RIVER IN SRI LANKA
Floods are one of the meteorological occurrences that commonly record as serious catastrophic natural hazard in the world. Flooding ranks among the most devastating types of natural catastrophe in Sri Lanka. A well-known spot in the country for repeated floods may be found along the banks of one major river, the ‘Kelani,' with incredible damages recorded for the human lives and property in the Kaduwela Municipal Council boundaries. Therefore, it is timely requirement for identification of determinants on the recurrent flooding in the area. This research aims to analyze the determinants of flooding based on Kelani River, in Kaduwela Municipal Council limits, focusing on both natural and man-made factors. The research was conducted within the mixed method approach. Sixty households were chosen by systematic random selection to reflect the most vulnerable Grama Niladari divisions, and the data was collected using a structured questionnaire by considering ten determinants and indepth interviews with five experts. Collected data were analyzed using mean value analysis and content analysis to achieve the research objective. The findings revealed that man-made factors are the most affected factors for flooding in the area. Among them, the findings of both analyses indicated that the most significant reasons were non-availability of proper drainage system and violating the existing rules and regulation in the area. The study recommended, the necessity to implement adaptation measures and policies to minimize the flood risk of the area to achieve urban sustainability.
Keywords: Flood Determinants, Flood Risk, Man- made Factors, Natural Factor
Beam Asymmetry Σ for the Photoproduction of η and ή Mesons at Eγ = 8.8GeV
We report on the measurement of the beam asymmetry Σ for the reactions →γp→pη and →γp→pη′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer −t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Ση to Ση′ to these models as this ratio is predicted to be sensitive to the amount of s¯s exchange in the production. We find that photoproduction of both η and η′ is dominated by natural parity exchange with little dependence on −t
On the status and mechanisms of coastal erosion in Marawila Beach, Sri Lanka
Coastal erosion remains a problem in many developing countries because of a limited understating of erosion mechanisms and management. Sri Lanka is one of the countries that recognized coastal erosion management as a governmental responsibility, in 1984. Nevertheless, erosion mechanisms have not yet been fully understood. We investigate the status and mechanisms of coastal erosion using empirically collected data and various techniques, such as Geographic Information System analysis of satellite images, drone mapping, bathymetric surveys, hindcasting of wind-induced wave climate, questionnaires, and semi-structured interview surveys. We identified wave climate change, reduction in river sand supply, interruptions from previous erosion management measures, and offshore sand mining as potential causes of erosion considering sediment flux and rates of erosion. Erosion of Marawila Beach began during 2005–2010 and has been continuing ever since, due to a lack of integration in the beach and the entire sediment system. It is necessary to identify the long-term, large-scale changes in the sediment system through data collection. This study highlights the importance of an integrated coastal erosion management plan and could facilitate better coastal erosion management in Sri Lanka, as well as in other developing countries
Measurement of the J/ photoproduction cross section over the full near-threshold kinematic region
We report the total and differential cross sections for
photoproduction with the large acceptance GlueX spectrometer for photon beam
energies from the threshold at 8.2~GeV up to 11.44~GeV and over the full
kinematic range of momentum transfer squared, . Such coverage facilitates
the extrapolation of the differential cross sections to the forward ()
point beyond the physical region. The forward cross section is used by many
theoretical models and plays an important role in understanding
photoproduction and its relation to the proton interaction. These
measurements of photoproduction near threshold are also crucial inputs
to theoretical models that are used to study important aspects of the gluon
structure of the proton, such as the gluon Generalized Parton Distribution
(GPD) of the proton, the mass radius of the proton, and the trace anomaly
contribution to the proton mass. We observe possible structures in the total
cross section energy dependence and find evidence for contributions beyond
gluon exchange in the differential cross section close to threshold, both of
which are consistent with contributions from open-charm intermediate states.Comment: 15 pages 18 figure
Design and Simulated Performance of Calorimetry Systems for the ECCE Detector at the Electron Ion Collider
We describe the design and performance the calorimeter systems used in the
ECCE detector design to achieve the overall performance specifications
cost-effectively with careful consideration of appropriate technical and
schedule risks. The calorimeter systems consist of three electromagnetic
calorimeters, covering the combined pseudorapdity range from -3.7 to 3.8 and
two hadronic calorimeters. Key calorimeter performances which include energy
and position resolutions, reconstruction efficiency, and particle
identification will be presented.Comment: 19 pages, 22 figures, 5 table
Characterization of common carp (Cyprinus carpio L.) interferon regulatory factor 5 (IRF5) and its expression in response to viral and bacterial challenges
AI-assisted Optimization of the ECCE Tracking System at the Electron Ion Collider
The Electron-Ion Collider (EIC) is a cutting-edge accelerator facility that
will study the nature of the "glue" that binds the building blocks of the
visible matter in the universe. The proposed experiment will be realized at
Brookhaven National Laboratory in approximately 10 years from now, with
detector design and R&D currently ongoing. Notably, EIC is one of the first
large-scale facilities to leverage Artificial Intelligence (AI) already
starting from the design and R&D phases. The EIC Comprehensive Chromodynamics
Experiment (ECCE) is a consortium that proposed a detector design based on a
1.5T solenoid. The EIC detector proposal review concluded that the ECCE design
will serve as the reference design for an EIC detector. Herein we describe a
comprehensive optimization of the ECCE tracker using AI. The work required a
complex parametrization of the simulated detector system. Our approach dealt
with an optimization problem in a multidimensional design space driven by
multiple objectives that encode the detector performance, while satisfying
several mechanical constraints. We describe our strategy and show results
obtained for the ECCE tracking system. The AI-assisted design is agnostic to
the simulation framework and can be extended to other sub-detectors or to a
system of sub-detectors to further optimize the performance of the EIC
detector.Comment: 16 pages, 18 figures, 2 appendices, 3 table
ECCE Sensitivity Studies for Single Hadron Transverse Single Spin Asymmetry Measurements
We performed feasibility studies for various single transverse spin
measurements that are related to the Sivers effect, transversity and the tensor
charge, and the Collins fragmentation function. The processes studied include
semi-inclusive deep inelastic scattering (SIDIS) where single hadrons (pions
and kaons) were detected in addition to the scattered DIS lepton. The data were
obtained in {\sc pythia}6 and {\sc geant}4 simulated e+p collisions at 18 GeV
on 275 GeV, 18 on 100, 10 on 100, and 5 on 41 that use the ECCE detector
configuration. Typical DIS kinematics were selected, most notably
GeV, and cover the range from to . The single spin
asymmetries were extracted as a function of and , as well as the
semi-inclusive variables , and . They are obtained in azimuthal moments
in combinations of the azimuthal angles of the hadron transverse momentum and
transverse spin of the nucleon relative to the lepton scattering plane. The
initially unpolarized MonteCarlo was re-weighted in the true kinematic
variables, hadron types and parton flavors based on global fits of fixed target
SIDIS experiments and annihilation data. The expected statistical
precision of such measurements is extrapolated to 10 fb and potential
systematic uncertainties are approximated given the deviations between true and
reconstructed yields. The impact on the knowledge of the Sivers functions,
transversity and tensor charges, and the Collins function has then been
evaluated in the same phenomenological extractions as in the Yellow Report. The
impact is found to be comparable to that obtained with the parameterized Yellow
Report detector and shows that the ECCE detector configuration can fulfill the
physics goals on these quantities.Comment: 22 pages, 22 figures, to be submitted to joint ECCE proposal NIM-A
volum
ECCE unpolarized TMD measurements
We performed feasibility studies for various measurements that are related to
unpolarized TMD distribution and fragmentation functions. The processes studied
include semi-inclusive Deep inelastic scattering (SIDIS) where single hadrons
(pions and kaons) were detected in addition to the scattered DIS lepton. The
single hadron cross sections and multiplicities were extracted as a function of
the DIS variables and , as well as the semi-inclusive variables ,
which corresponds to the momentum fraction the detected hadron carries relative
to the struck parton and , which corresponds to the transverse momentum of
the detected hadron relative to the virtual photon. The expected statistical
precision of such measurements is extrapolated to accumulated luminosities of
10 fb and potential systematic uncertainties are approximated given the
deviations between true and reconstructed yields.Comment: 12 pages, 9 figures, to be submitted in joint ECCE proposal NIM-A
volum
Open Heavy Flavor Studies for the ECCE Detector at the Electron Ion Collider
The ECCE detector has been recommended as the selected reference detector for
the future Electron-Ion Collider (EIC). A series of simulation studies have
been carried out to validate the physics feasibility of the ECCE detector. In
this paper, detailed studies of heavy flavor hadron and jet reconstruction and
physics projections with the ECCE detector performance and different magnet
options will be presented. The ECCE detector has enabled precise EIC heavy
flavor hadron and jet measurements with a broad kinematic coverage. These
proposed heavy flavor measurements will help systematically study the
hadronization process in vacuum and nuclear medium especially in the
underexplored kinematic region.Comment: Open heavy flavor studies with the EIC reference detector design by
the ECCE consortium. 11 pages, 11 figures, to be submitted to the Nuclear
Instruments and Methods
- …