294 research outputs found
2,5-Dimethoxybenzaldehyde thiosemicarbazone
In the title molecule, C10H13N3O2S, the dihedral angle between benzene and –N—C(=S)—N—N=C– planes is 9.20 (6)°. The two methoxy groups are coplanar with the benzene ring [C—O—C—C torsion angles of −2.31 (18) and −6.45 (17)°]. In the crystal structure, molecules are linked by intermolecular N—H⋯S, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network
3-Hydroxy-4-methoxybenzaldehyde thiosemicarbazone hemihydrate
The asymmetric unit of the title compound, C9H11N3O2S·0.5H2O, comprises two crystallograpically independent thiosemicarbazone molecules (A and B) and a water molecule of crystallization. In each of the thiosemicarbazone molecules, intramolecular O—H⋯O and N—H⋯N hydrogen bonds form five-membered rings, producing S(5) ring motifs. Intermolecular O—H⋯S and N—H⋯O interactions between molecule B and the water molecule form a six-membered ring, producing an R
2
2(6) ring motif. Intermolecular N—H⋯S hydrogen bonds form dimers involving pairs of both A and B molecules, which form R
2
2(8) ring motifs. The angles between the aromatic ring and thiourea unit in the two molecules are 0.80 (6) and 3.28 (5)°, which proves that each molecule is fairly planar. The crystal structure is stabilized by intermolecular O—H⋯S (×2), O—H⋯O, N—H⋯S (×2) and N—H⋯O (×2) hydrogen bonds and C—H⋯O (×2) contacts to form a three-dimensional network
Strategy for Dynamic Wisp Removal in James Webb Space Telescope NIRCam Images
The James Webb Space Telescope (JWST) near-infrared camera (NIRCam) has been
found to exhibit serious wisp-like structures in four of its eight
short-wavelength detectors. The exact structure and strength of these wisps is
highly variable with the position and orientation of JWST, so the use of static
templates is non-optimal. Here we investigate a dynamic strategy to mitigate
these wisps using long-wavelength reference images. Based on a suite of
experiments where we embed a worst-case scenario median-stacked wisp into
wisp-free images, we define suitable parameters for our wisp removal strategy.
Using this setup we re-process wisp-affected public Prime Extragalactic Areas
for Reionization and Lensing Science (PEARLS) data in the North Ecliptic Pole
Time Domain Field (NEP-TDF) field, resulting in significant visual improvement
in our detector frames and reduced noise in the final stacked images.Comment: 16 pages, 10 figures, submitted to PASP, comments welcom
S-Benzylthiouronium 3-nitrobenzenesulfonate
In the title compound, C8H11N2S+·C6H4NO5S−, the asymmetric unit is composed of two crystallographically independent S-benzylthiouronium cations and two independent nitrobenzenesulfonate anions. An intramolecular hydrogen bond generates an S(5)S(5) ring motif. The crystal packing is stabilized by intramolecular C—H⋯O and intermolecular C—H⋯O, N—H⋯O and N—H⋯S hydrogen bonds which, along with short S⋯O [3.034 (2) Å] and N⋯O [2.796 (3) Å] contacts, form a two-dimensional network parallel to the ab plane
(E)-3-(2-Chlorophenyl)-1-(4-chlorophenyl)prop-2-en-1-one
The title compound, C15H10Cl2O, adopts an E configuration with respect to the C=C bond of the propenone unit. The dihedral angle between the two benzene rings is 32.4 (1)°. Intramolecular C—H⋯O and C—H⋯Cl hydrogen bonds generate an S(5)S(5)S(5) motif. In addition, the crystal structure is stabilized by weak intermolecular C—H⋯O hydrogen bonds
Turbulent Erosion of Magnetic Flux Tubes
Results from a numerical and analytical investigation of the solution of a
nonlinear axially symmetric diffusion equation for the magnetic field are
presented for the case when the nonlinear dependence of the diffusivity nu(B)
on the magnetic field satisfies basic physical requirements. We find that for
sufficiently strong nonlinearity (i.e. for sufficiently strong reduction of nu
inside the tube) a current sheet is spontaneously formed around the tube within
one diffusion timescale. This sheet propagates inwards with a velocity
inversely proportional to the ratio of the field strength just inside the
current sheet to the equipartition field strength B0/Be, so the lifetime of a
tube with constant internal flux density is increased approximately by a factor
not exceeding B0/Be, even for infinitely effective inhibition of turbulence
inside the tube. Among the applications of these results we point out that
toroidal flux tubes in the solar convective zone are subject to significant
flux loss owing to turbulent erosion on a timescale of about 1 month, and that
turbulent erosion may be responsible for the formation of a current sheet
around a sunspot. It is further proposed that, despite the simplifying
assumptions involved, our solutions correctly reflect the essential features of
the sunspot decay process.Comment: 17 pages, 11 figure
Pongamia seed cake as a valuable source of plant nutrients for sustainable agriculture
Pongamia, a multipurpose leguminous tree containing non-edible oil, grows widely in India. Oil extracted from the seeds of Pongamia is used as energy source as well as in tanneries while the cake (a byproduct after extracting oil) was found to be rich in all plant nutrients in general and nitrogen (4.28%) and sulfur (0.19%) in particular. Both nitrogen and sulfur were found to be deficient in 100 and 80%, respectively, in soil samples from farmers' fields in Powerguda village of Adilabad district, Andhra Pradesh, India. Use of Pongamia seed cake as a source of plant nutrients for maize, soyabean and cotton was found beneficial in participatory research and development trials on farmers' fields. Further, application of critically deficient micronutrients such as zinc and boron and secondary nutrient sulfur increased crop yields by 16.7 and 19% in soyabean and cotton, respectively. In addition, B:C ratios of 5.03, 1.81 and 2.04 were obtained for soyabean, maize and cotton, respectively, with use of cake as a source of N, however it needed higher initial investment
GAMA/DEVILS: Cosmic star formation and AGN activity over 12.5 billion years
We use the Galaxy and Mass Assembly (GAMA) and the Deep Extragalactic Visible
Legacy Survey (DEVILS) observational data sets to calculate the cosmic star
formation rate (SFR) and active galactic nuclei (AGN) bolometric luminosity
history (CSFH/CAGNH) over the last 12.5 billion years. SFRs and AGN bolometric
luminosities were derived using the spectral energy distribution fitting code
ProSpect, which includes an AGN prescription to self consistently model the
contribution from both AGN and stellar emission to the observed rest-frame
ultra-violet to far-infrared photometry. We find that both the CSFH and CAGNH
evolve similarly, rising in the early Universe up to a peak at look-back time
~Gyr (), before declining toward the present day. The
key result of this work is that we find the ratio of CAGNH to CSFH has been
flat () for ~Gyr
up to the present day, indicating that star formation and AGN activity have
been coeval over this time period. We find that the stellar masses of the
galaxies that contribute most to the CSFH and CAGNH are similar, implying a
common cause, which is likely gas inflow. The depletion of the gas supply
suppresses cosmic star formation and AGN activity equivalently to ensure that
they have experienced similar declines over the last 10 Gyr. These results are
an important milestone for reconciling the role of star formation and AGN
activity in the life cycle of galaxies.Comment: 16 pages, 10 figures. Figures 9 and 10 are the main results. Accepted
for publication in Monthly Notices of the Royal Astronomical Societ
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Age matters: differences in exercise-induced cardiovascular remodelling in young and middle aged healthy sedentary individuals.
AIMS: Remodelling of the cardiovascular system (including heart and vasculature) is a dynamic process influenced by multiple physiological and pathological factors. We sought to understand whether remodelling in response to a stimulus, exercise training, altered with healthy ageing. METHODS: A total of 237 untrained healthy male and female subjects volunteering for their first time marathon were recruited. At baseline and after 6 months of unsupervised training, race completers underwent tests including 1.5T cardiac magnetic resonance, brachial and non-invasive central blood pressure assessment. For analysis, runners were divided by age into under or over 35 years (U35, O35). RESULTS: Injury and completion rates were similar among the groups; 138 runners (U35: n = 71, women 49%; O35: n = 67, women 51%) completed the race. On average, U35 were faster by 37 minutes (12%). Training induced a small increase in left ventricular mass in both groups (3 g/m2, P < 0.001), but U35 also increased ventricular cavity sizes (left ventricular end-diastolic volume (EDV)i +3%; left ventricular end-systolic volume (ESV)i +8%; right ventricular end-diastolic volume (EDV)i +4%; right ventricular end-systolic volume (ESV)i +5%; P < 0.01 for all). Systemic aortic compliance fell in the whole sample by 7% (P = 0.020) and, especially in O35, also systemic vascular resistance (-4% in the whole sample, P = 0.04) and blood pressure (systolic/diastolic, whole sample: brachial -4/-3 mmHg, central -4/-2 mmHg, all P < 0.001; O35: brachial -6/-3 mmHg, central -6/-4 mmHg, all P < 0.001). CONCLUSION: Medium-term, unsupervised physical training in healthy sedentary individuals induces measurable remodelling of both heart and vasculature. This amount is age dependent, with predominant cardiac remodelling when younger and predominantly vascular remodelling when older
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