602 research outputs found
X-ray spectral and timing properties of the 2001 superburst of 4U 1636-536
Preliminary results are reported on the spectral and timing properties of the
spectacular 2001 superburst of 4U 1636-536 as seen by the RXTE/PCA. The
(broad-band) power-spectral and hardness properties during the superburst are
compared to those just before and after the superburst. Not all of the
superburst emission can be fitted by pure black-body radiation. We also
gathered BeppoSAX/WFC and RXTE/ASM data, as well as other RXTE/PCA data,
obtained days to months before and after the superburst to investigate the
normal X-ray burst behavior around the time of the superburst. The first normal
X-ray burst after the 2001 superburst was detected 23 days later. During
inspection of all the RXTE/ASM data we found a third superburst. This
superburst took place on June 26, 1999, which is ~2.9 yrs after the 1996
superburst and ~1.75 yrs before the 2001 superburst. The above findings are the
strongest constraints observed so far on the duration of the cessation of
normal X-ray bursts after a superburst and the superburst recurrence times.Comment: 4 pages, 4 figures,to appear in the proceedings of "X-Ray Timing
2003: Rossi and Beyond", eds. P. Kaaret, F.K. Lamb, & J.H. Swank (Melville,
NY: AIP
Peculiar spectral and power spectral behaviour of the LMXB GX 13+1
We present results of an analysis of all 480 ks of Rossi X-ray Timing
Explorer Proportional Counter Array data obtained from 17 May 1998 to 11
October 1998 on the luminous low mass X-ray binary GX 13+1. We analysed the
spectral properties in colour-colour diagrams (CDs) and hardness-intensity
diagrams (HIDs) and fitted the power spectra with a multi-Lorentzian model. GX
13+1 traces out a curved track in the CDs on a time scale of hours, which is
very reminiscent of a standard atoll track containing an island, and lower and
upper banana branch. However, both count rate and power spectral properties
vary along this track in a very unusual way, not seen in any other atoll or Z
source. The count rate, which varied by a factor of ~1.6, along a given track
first decreases and then increases, causing the motion through the HIDs to be
in the opposite sense to that in the CD, contrary to all other Z and atoll
sources. Along a CD track, the very low frequency noise uniquely decreases in
amplitude from ~5 to ~2% (rms). The high frequency noise amplitude decreases
from ~4% to less than 1% and its characteristic frequency decreases from ~10 to
\~5 Hz. The 57-69 Hz quasi-periodic oscillation (QPO) found earlier is also
detected, and no kHz QPOs are found. In addition the entire track shows secular
motion on a time scale of about a week. The average count rate as well as the
amplitude of the very low frequency noise correlate with this secular motion.
We discuss a possible explanation for the peculiar properties of GX 13+1 in
terms of an unusual orientation or strength of a relativistic jet.Comment: 15 pages, 13 figures. Accepted for publication in A&
Timing properties and spectral states in Aquila X-1
We have analyzed five X-ray outbursts of the neutron-star soft X-ray
transient Aql X-1 and investigated the timing properties of the source in
correlation with its spectral states as defined by different positions in the
color-color and hardness-intensity diagrams. The hard color and the source
count rate serve as the distinguishing parameters giving rise to three spectral
states: a low-intensity hard state, an intermediate state and a high-intensity
soft state. These states are respectively identified with the extreme island,
island and banana states that characterize the atoll sources. The large amount
of data analyzed allowed us to perform for the first time a detailed timing
analysis of the extreme island state. Differences in the aperiodic variability
between the rise and the decay of the X-ray outbursts are found in this state:
at the same place in the color-color diagram, during the rise the source
exhibits more power at low frequencies (< 1 Hz), whereas during the decay the
source is more variable at high frequencies (> 100 Hz). The very-low frequency
noise that characterizes the banana-state power spectra below 1 Hz cannot be
described in terms of a single power law but a two-component model is required.
In two outbursts a new 6-10 Hz QPO has been discovered and tentatively
identified with the normal/flaring branch-like oscillation observed only at the
highest inferred mass accretion rates. We have compared the spectral and timing
properties of Aql X-1 with those of other atoll and Z sources. Our results
argue against a unification scheme for these two types of neutron-star X-ray
binaries.Comment: 24 pages, 4 tables, 9 figures, accepted for publication in Ap
Comparative compositions of grain of tritordeum, durum wheat and bread wheat grown in multi-environment trials
Three genotypes each of bread wheat, durum wheat and tritordeum were grown in randomized replicated field trials in Andalusia (Spain) for two years and wholemeal flours analysed for a range of components to identify differences in composition. The contents of all components that were determined varied widely between grain samples of the individual species and in most cases also overlapped between the three species. Nevertheless, statistically significant differences between the compositions of the three species were observed. Notably, tritordeum had significantly higher contents of protein, some minerals (magnesium and iron), total phenolics and methyl donors. Tritordeum also had higher levels of total amino acids (but not asparagine) and total sugars, including raffinose. By contrast, bread wheat and tritordeum had similar contents of the two major dietary fibre components in white flour, arabinoxylan and β-glucan, with significantly lower contents in durum wheat
PENYALAHGUNAAN ASET NEGARA DALAM BENTUK JARINGAN SATELIT UNTUK KEPENTINGAN KORPORASI DIHUBUNGKAN DENGAN UNDANGUNDANG NOMOR 36 TAHUN 1999 TENTANG TELEKOMUNIKASI JO UNDANGUNDANG NOMOR 20 TAHUN 2001 TENTANG TINDAK PIDANA KORUPSI
telekomunikasi sebagaimana dilakukan oleh IM2. IM2 telah menyalahgunakan pita
frekuensi 2.1 Ghz, dan secara melawan hukum beroperasi pada jaringan tersebut sehingga
menimbulkan kerugian negara. Berdasarkan hal tersebut maka penulis tertarik meneliti,
bagaimana Undang-Undang Telekomunikasi jo Peraturan Menteri Komunikasi dan
Informatika dan Undang-Undang Tindak Pidana Korupsi mengatur mekanisme pemanfaatan
aset negara berupa jaringan satelit, mengapa aset negara berupa jaringan satelit kerap kali
disalahgunakan didalam pemanfaatannya oleh korporasi, serta bagaimana upaya yang dapat
dilakukan untuk melindungi aset negara dalam bentuk jaringan satelit terhadap
penyalahgunaan yang dilakukan oleh korporasi.
Penelitian ini menggunakan spesifikasi penelitian yang bersifat deskriftif analitis
dengan pendekatan yuridis normatif dibantu yuridis empiris, data yang diperlukan dalam
penelitian ini dikumpulkan melalui studi kepustakaan dan studi lapangan, kemudian
dianalisis menggunakan teknik analisis data berupa yuridis kualitatif.
Pemanfaatan aset negara berupa jaringan satelit melalui pita frekuensi merupakan
salah satu hak yang dalam pemanfaatannya diatur oleh peraturan perundang-undangan agar
tercipta keadilan, kepastian dan ketertiban, keamanan, keseimbangan, perlindungan dan
pemeliharaan dalam pemanfataannya. Jaringan satelit yang merupakan jaringan satelit aset
negara pemanfaatannya mensyaratkan izin dan pembayaran tarif tertentu, sehingga
konsekuensinya ketika terjadi penyalahgunaan pemanfaatan jaringan satelit, negara akan
mengalami kerugian. Aset negara berupa jaringan satelit kerap kali disalahgunakan didalam
pemanfaatannya oleh korporasi disebabkan beberapa faktor diantaranya faktor hukum itu
sendiri dalam hal ini peraturan perundang-undangannya, faktor penegak hukum, faktor sarana
atau fasilitas yang mendukung pengawasan dan penegakan hukum itu sendiri, faktor
masyarakat, yakni lingkungan dimana hukum tersebut berlaku atau diterapkan, dalam hal ini
yaitu lingkungan korporasi, faktor kebudayaan yakni kurangnya kesadaran hukum korporasi
dalam upaya pemanfaatan aset negara secara berkeadilan dan tertib sesuai peraturan
perundang-undangan yang berlaku, dimana pemanfaatan yang tidak secara berkeadilan akan
membawa negara menuju kepada kehancuran. Upaya yang dapat dilakukan untuk melindungi
aset negara dalam bentuk jaringan satelit terhadap penyalahgunaan yang dilakukan oleh
korporasi harus berangkat dari beberapa faktor yang menjadi penyebab penyalahgunaan
pemanfaatan jaringan satelit diantaranya yaitu melalui upaya preventif berupa revisi
perunang-undangan, pengawasan, sosialisasi sert upaya represif berupa penegakan hukum.
Penegakan hukum harus dilaksanakan tanpa pandang bulu, sebagai bentuk keyakinan atas
doktrin hukum, bahwa setiap orang mempunyai kedudukan yang sama di depan hukum.
Kata Kunci: Penyalahgunaan Aset Negara, Jaringan Sateli
Relations Between Timing Features and Colors in the X-Ray Binary 4U 0614+09
We study the correlations between timing and X-ray spectral properties in the
low mass X-ray binary 4U 0614+09 using a large (265-ks) data set obtained with
the Rossi X-ray Timing Explorer. We find strong quasi-periodic oscillations
(QPOs) of the X-ray flux, like the kilohertz QPOs in many other X-ray binaries
with accreting neutron stars, with frequencies ranging from 1329 Hz down to 418
Hz and, perhaps, as low as 153 Hz. We report the highest frequency QPO yet from
any low mass X-ray binary at 1329+-4 Hz, which has implications for neutron
star structure. This QPO has a 3.5-sigma single-trial significance, for an
estimated 40 trials the significance is 2.4-sigma. Besides the kilohertz QPOs,
the Fourier power spectra show four additional components: high frequency noise
(HFN), described by a broken power-law with a break frequency between 0.7 and
45 Hz, very low frequency noise (VLFN), which is fitted as a power-law below 1
Hz, and two broad Lorentzians with centroid frequencies varying from 6 to 38 Hz
and 97 to 158 Hz, respectively. We find strong correlations between the
frequencies of the kilohertz QPOs, the frequency of the 6 to 38 Hz broad
Lorentzian, the break frequency of the HFN, the strength of both the HFN and
the VLFN and the position of the source in the hard X-ray color vs. intensity
diagram. The frequency of the 97 to 158 Hz Lorentzian does not correlate with
these parameters. We also find that the relation between power density and
break frequency of the HFN is similar to that established for black hole
candidates in the low state. We suggest that the changing mass accretion rate
is responsible for the correlated changes in all these parameters.Comment: ApJ, referee
Comparative Compositions of Grain of Bread Wheat, Emmer and Spelt Grown with Different Levels of Nitrogen Fertilisation
Five cultivars of bread wheat and spelt and three of emmer were grown in replicate randomised field trials on two sites for two years with 100 and 200 kg nitrogen fertiliser per hectare, reflecting low input and intensive farming systems. Wholemeal flours were analysed for components that are suggested to contribute to a healthy diet. The ranges of all components overlapped between the three cereal types, reflecting the effects of both genotype and environment. Nevertheless, statistically significant differences in the contents of some components were observed. Notably, emmer and spelt had higher contents of protein, iron, zinc, magnesium, choline and glycine betaine, but also of asparagine (the precursor of acrylamide) and raffinose. By contrast, bread wheat had higher contents of the two major types of fibre, arabinoxylan (AX) and _-glucan, than emmer and a higher AX content than spelt. Although such differences in composition may be suggested to result in effects on metabolic parameters and health when studied in isolation, the final effects will depend on the quantity consumed and the composition of the overall diet
Comparative compositions of metabolites and dietary fibre components in doughs and breads produced from bread wheat, emmer and spelt and using yeast and sourdough processes.
Wholemeal flours from blends of bread wheat, emmer and spelt were processed into bread using yeast-based and sourdough fermentation. The bread wheat flour contained significantly higher concentrations of total dietary fibre and fructans than the spelt and emmer flours, the latter having the lowest contents. Breadmaking using sourdough and yeast systems resulted in changes in composition from flour to dough to bread including increases in organic acids and mannitol in the sourdough system and increases in amino acids and sugars (released by hydrolysis of proteins and starch, respectively) in both processing systems. The concentrations of fructans and raffinose (the major endogenous FODMAPs) were reduced by yeast and sourdough fermentation, with yeast having the greater effect. Both systems resulted in greater increases in sugars and glycerol in emmer than in bread wheat and spelt, but the significance of these differences for human health has not been established
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