1,230 research outputs found
Efficient Synthesis of Aromatic Quinoxaline Derivatives
Quinoxaline and its derivatives have many antimicrobial properties that make them possible substitutes for current medication, with abilities including antibacterial, anticancer, antiviral, and antifungal among others [1]. It is important to be able to quickly and effectively develop new compounds. Current methods to synthesize quinoxaline derivatives are cumbersome, with long reaction times, low yields, and required solvents that add hazards and costs. Microwave-assisted synthesis is a novel methodology to synthesize quinoxaline derivatives in only 5 minutes with no solvent. This study analyzes microwave irradiation as a synthesis technique
The Application of Landsat TM Data and SRTM Data for Detection Vulnerability Assessment of Flood in Bengawan Solo Watershed
Bengawan Solo watershed is one of watershed that has frequent floods. Due to high rainfall in the rainy season, the river can't accommodate the surface runoff and resulted flooding around the area. The high rainfall is not only causing flood in some areas upstream watershed, but also threaten the downstream areas in East Java province, especially Bojonegoro, Lamongan, Tuban and Gresik. Data of remote sensing and Geographic Information System (GIS) could detect assessment vulnerability of flooding. The research objective is to study flood vulnerability assessment in Bengawan Solo watershed using remote sensing data. The method is the combination of information from remote sensing data, i.e.. (1) to combine band 4 with band 7 Landsat TM in which the flood pixel value is ≤ 78; (2) to detect flow accumulation using SRTM data; and (3) to detect flooding areas at the altitude of 0-50 m. The result obtained from the study is the flood vulnerability in Bengawan Solo watershed including Sragen District (Masaran, Plupuh, Gesi, Sidoharjo Sub District); Ngawi (Widodaren, Kedungalar, Pitu SubDistrict); Tuban District (Rengel, Plumpang, Widang Sub District); Bojonegoro (Padangan, Malo, Kalitidu, Trucuk, Bojonegoro,Dander, Kanor, Baureno, Sumberejo Sub District); Lamongan (Laren, Solokuro, Karanggeneng, Kalitengah Sub District); Gresik Regency (Hamlet and Bungah Sub District)
Australia Telescope Compact Array Radio Continuum 1384 and 2368 Mhz Observations of Sagittarius B
We present images of the Sagittarius (Sgr) B giant molecular cloud at 2368
and 1384 MHz obtained using new, multi-configuration Australia Telescope
Compact Array (ATCA) observations. We have combined these observations with
archival single-dish observations yielding images at resolutions of 47" by 14"
and 27" by 8" at 1384 and 2368 MHz respectively. These observations were
motivated by our theoretical work (Protheroe et al. 2008) indicating the
possibility that synchrotron emission from secondary electrons and positrons
created in hadronic cosmic ray (CR) collisions with the ambient matter of the
Sgr B2 cloud could provide a detectable (and possibly linearly polarized)
non-thermal radio signal. We find that the only detectable non-thermal emission
from the Sgr B region is from a strong source to the south of Sgr B2, which we
label Sgr B2 Southern Complex (SC). We find Sgr B2(SC) integrated flux
densities of 1.2+/-0.2 Jy at 1384 MHz and 0.7+/-0.1 Jy at 2368 MHz for a source
of FWHM size at 1384 MHz of ~54". Despite its non-thermal nature, the
synchrotron emission from this source is unlikely to be dominantly due to
secondary electrons and positrons. We use polarization data to place 5-sigma
upper limits on the level of polarized intensity from the Sgr B2 cloud of 3.5
and 3 mJy/beam at 1384 and 2368 MHz respectively. We also use the angular
distribution of the total intensity of archival 330 MHz VLA and the total
intensity and polarized emission of our new 1384 MHz and 2368 MHz data to
constrain the diffusion coefficient for transport of the parent hadronic CRs
into the dense core of Sgr B2 to be no larger than about 1% of that in the
Galactic disk. Finally, we have also used the data to perform a spectral and
morphological study of the features of the Sgr B cloud and compare and contrast
these to previous studies.Comment: 7 pages, 4 figures, matches version published in the Astronomical
Journa
Respon GA3 Terhadap Induksi Tunas Mikro Tanaman Karet (Hevea Brasiliensis (Muell). Arg)
The aim of the research was to know effect of GA3 to rubber plant in micro shoot formation. The research was conducted at the rubber plant microcutting labortory PT Perkebunan Nusantara III Kebun Gunung Pamela, Tebing Tinggi, North Sumatera, Indonesia from April 2015 to Juli 2015. The Completely randomize design was used with two factors,i.e.:the addition of GA3 (GA3 0 mg/l; GA3 0.5 mg/l; GA3 1 mg/l; GA3 1.5 mg/l) and the immersion of nodes (GA3 0 mg/l; GA3 5 mg/l; GA3 10 mg/l; GA3 15 mg/l) with seven replications. The result showed that addition of 0.5 mg/l GA3 of significantly affected the percent of shoot emergence but no significantly different age of shoot emergence and immersion of nodes of 0 mg/l significantly affected the percent of shoot emergence but no significantly different age of shoot emergence and the interraction that addition of 0.5 mg/l GA3 and immersion of nodes significant affected the percent of shoot emergence on age of shoot emergence but no significantly different.Keywords : rubber, micro shoot, addition of GA3, immersion of nodesThe aim of the research was to know effect of GA3 to rubber plant in micro shoot formation. The research was conducted at the rubber plant microcutting labortory PT Perkebunan Nusantara III Kebun Gunung Pamela, Tebing Tinggi, North Sumatera, Indonesia from April 2015 to Juli 2015. The Completely randomize design was used with two factors,i.e.:the addition of GA3 (GA3 0 mg/l; GA3 0.5 mg/l; GA3 1 mg/l; GA3 1.5 mg/l) and the immersion of nodes (GA3 0 mg/l; GA3 5 mg/l; GA3 10 mg/l; GA3 15 mg/l) with seven replications. The result showed that addition of 0.5 mg/l GA3 of significantly affected the percent of shoot emergence but no significantly different age of shoot emergence and immersion of nodes of 0 mg/l significantly affected the percent of shoot emergence but no significantly different age of shoot emergence and the interraction that addition of 0.5 mg/l GA3 and immersion of nodes significant affected the percent of shoot emergence on age of shoot emergence but no significantly different
Frame-dragging effects on magnetic fields near a rotating black hole
We discuss the role of general relativity frame dragging acting on magnetic
field lines near a rotating (Kerr) black hole. Near ergosphere the magnetic
structure becomes strongly influenced and magnetic null points can develop. We
consider aligned magnetic fields as well as fields inclined with respect to the
rotation axis, and the two cases are shown to behave in profoundly different
ways. Further, we construct surfaces of equal values of local electric and
magnetic intensities, which have not yet been discussed in the full generality
of a boosted rotating black hole.Comment: to appear in the proceedings of "The Central Kiloparsec in Galactic
Nuclei (AHAR 2011)", Journal of Physics: Conference Series (JPCS), IOP
Publishin
The Sound Emission Board of the KM3NeT Acoustic Positioning System
We describe the sound emission board proposed for installation in the
acoustic positioning system of the future KM3NeT underwater neutrino telescope.
The KM3NeT European consortium aims to build a multi-cubic kilometre underwater
neutrino telescope in the deep Mediterranean Sea. In this kind of telescope the
mechanical structures holding the optical sensors, which detect the Cherenkov
radiation produced by muons emanating from neutrino interactions, are not
completely rigid and can move up to dozens of meters in undersea currents.
Knowledge of the position of the optical sensors to an accuracy of about 10 cm
is needed for adequate muon track reconstruction. A positioning system based on
the acoustic triangulation of sound transit time differences between fixed
seabed emitters and receiving hydrophones attached to the kilometre-scale
vertical flexible structures carrying the optical sensors is being developed.
In this paper, we describe the sound emission board developed in the framework
of KM3NeT project, which is totally adapted to the chosen FFR SX30 ultrasonic
transducer and fulfils the requirements imposed by the collaboration in terms
of cost, high reliability, low power consumption, high acoustic emission power
for short signals, low intrinsic noise and capacity to use arbitrary signals in
emission mode.Comment: 9 pages, 4 figure
High-Resolution, Wide-Field Imaging of the Galactic Center Region at 330 MHz
We present a wide field, sub-arcminute resolution VLA image of the Galactic
Center region at 330 MHz. With a resolution of ~ 7" X 12" and an RMS noise of
1.6 mJy/beam, this image represents a significant increase in resolution and
sensitivity over the previously published VLA image at this frequency. The
improved sensitivity has more than tripled the census of small diameter sources
in the region, has resulted in the detection of two new Non Thermal Filaments
(NTFs), 18 NTF candidates, 30 pulsar candidates, reveals previously known
extended sources in greater detail, and has resulted in the first detection of
Sagittarius A* in this frequency range.
A version of this paper containing full resolution images may be found at
http://lwa.nrl.navy.mil/nord/AAAB.pdf.Comment: Astronomical Journal, Accepted 62 Pages, 21 Figure
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