50 research outputs found
Review on Advanced Control Technique in Batch Polymerization Reactor of Styrene
Polymerization process have a nonlinear nature since it exhibits a dynamic behavior throughout the process. Therefore, accurate modeling and control technique for the nonlinear process needs to be obtained
Potential of using ICT in Islamic-based education.
The advancement of Information Communication Technology (ICT) nowadays gives a great challenge to educators in order to continuously play significant roles in the borderless globalization of information era. This
challenge should not be regarded as a threat but should be accepted as a great reward to education world. Thus, the main purpose of this paper is to discuss the potentials of using ICT in Islamic-based education and learning
processes. In Islam, the use of modern technology is encouraged as it helps towards the development of positive thinking, the ability to innovate and to trigger the drive for self-improvement. Hence, in order to identify and
promote ways in which ICT can enhance the reach and quality of Islamicbased education, this paper has focus how ICT can make the Islamic Studies courses is very interesting and entertaining and it can be proven that it is not impossible to transform a dry and plain subject to be fun and
interactive lesson
Anti-angiogenic effect of polygonum species: a comprehensive review of literature
Angiogenesis is a physiological, tightly regulated process which is characterized by the development of new blood vessels. Compounds with the potential to control angiogenesis would be highly valuable as therapeutics, as an imbalance in angiogenesis may lead to several pathological disorders, including cancer, retinopathy, and arthritis. In this study, the anti-angiogenic effect of Polygonum sp. has been comprehensively reviewed and this plant also has been known to possess other medicinal benefits such as antioxidative, anti-inflammatory, anti-proliferative, and anti-tumor agents. Hence, this study systematically identified the evidence reporting the anti-angiogenic effects of Polygonum sp. Four electronic databases, namely PubMed, Ovid MEDLINE, Scopus and Web of Science were searched for relevant articles. Based on the pre-set eligibility criteria, 50 relevant articles were identified, and ten qualified articles were selected and reviewed. It was demonstrated that four namely P. cuspidatum, P. barbatum, P. hydropiper, and P. perfoliatum showed anti-angiogenic activities mainly through inhibition of the vascular endothelial growth factor-signaling pathways. Therefore, these species Polygonum have the potential to be developed as natural anti-angiogenic agents for prevention and treatment of various diseases related to pathological angiogenesis
Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory
In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data
Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory
The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle
Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects
The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E be able to explain the observations
Measuring the muon content of inclined air showers using AERA and the water-Cherenkov detector array of the Pierre Auger Observatory
The dynamic range of the upgraded surface-detector stations of AugerPrime
The detection of ultra-high-energy cosmic rays by means of giant detector arrays is often limited by the saturation of the recorded signals near the impact point of the shower core at the ground, where the particle density dramatically increases. The saturation affects in particular the highest energy events, worsening the systematic uncertainties in the reconstruction of the shower characteristics. The upgrade of the Pierre Auger Observatory, called AugerPrime, includes the installation of an 1-inch Small PhotoMultiplier Tube (SPMT) inside each water-Cherenkov station (WCD) of the surface detector array. The SPMT allows an unambiguous measurement of signals down to about 250m from the shower core, thus reducing the number of events featuring a saturated station to a negligible level. In addition, a 3.8m2 plastic scintillator (Scintillator Surface Detector, SSD) is installed on top of each WCD. The SSD is designed to match the WCD (with SPMT) dynamic range, providing a complementary measurement of the shower components up to the highest energies. In this work, the design and performances of the upgraded AugerPrime surface-detector stations in the extended dynamic range are described, highlighting the accuracy of the measurements. A first analysis employing the unsaturated signals in the event reconstruction is also presented
The second knee in the cosmic ray spectrum observed with the surface detector of the Pierre Auger Observatory
Investigating multiple elves and halos above strong lightning with the fluorescence detectors of the Pierre Auger Observatory
ELVES are being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, in the province of Mendoza (Argentina), the world’s largest facility for the study of ultra-high energy cosmic rays. This study exploits a dedicated trigger and extended readout. Since December 2020, this trigger has been extended to the three High levation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, allowing a study of ELVES from closer lightning. The high time resolution of the Auger telescopes allows us to upgrade reconstruction algorithms and to do detailed studies on multiple ELVES. The origin of multiple elves can be studied by analyzing the time difference and the amplitude ratio between flashes and comparing them with the properties of radio signals detected by the ENTLN lightning network since 2018. A fraction of multi-ELVES can also be interpreted as halos following ELVES.
Halos are disc-shaped light transients emitted at 70-80 km altitudes, appearing at the center of the ELVES rings, due to the rearrangement of electric charges at the base of the ionosphere after a strong lightning event