239 research outputs found

    A Monte Carlo study of two Compton camera’s first plane detectors

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    Purpose: The suitability of two possible detectors, silicon and germanium as the Compton camera’s first plane detector has been investigated using a robust Monte Carlo approach. Methods: The GEANT4 simulation software was used to simulate the radiation transport and interactions with matter. Investigations were first done by relating the impact of Doppler broadening on the Compton camera angular uncertainty, energy spectra and reconstructed source image. Then, the impact of geometry and interaction type on the Compton camera performance was evaluated as well. Results: Analyses suggest that silicon of about 1 cm thickness would be suitable as the Compton camera first plane detector. The choice of silicon is however not completely flawless, Doppler broadening for this detector material contributes as much as 7.3 mm and 2.4 mm to full-width-half-maximum image resolution at 140.5 keV and 511 keV respectively. Conclusions: It is envisioned that with improved reconstruction technique, silicon would be the best first plane detector for the Compton camera

    MURRAYA KOENIGI-A BOON IN DIFFERENT PATHOLOGICAL CONDITIONS

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    Since very long period of time medicinal plants or their bioactive compounds have been utilized by majority of world population particularly in developing countries for primary and traditional healthcare system. At present scenario, people are more interested to use herbal drugs because they are considered as safe and inexpensive having no adverse effects. Different parts of the plants like roots, leaves, stem, bark, fruits and seeds have been used in treatment of different diseases and strengthening the immune system.  Murraya koenigii, is a herb from mainly Asian origin, it has therapeutic applications such as in bronchial disorders, piles, vomiting, skin diseases, night blindness, dysentery, diarrhoea, bites of poisonous animals, bruises and eruption etc. The present review is an attempt for description of M. koenigii, its phytochemical constituents and various pharmacological activities.                      Peer Review History: Article received on- 11 November,   Revised on- 18 December,    Accepted on- 26 December, Available online 15 January 2017 Academic Editor: Dr. Ali Abdullah Al-yahawi, Al-Razi university, Department of Pharmacy, Yemen, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:        Reviewer's Comments: Average Peer review marks at initial stage: 4.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Masoumeh Divar, Shiraz University, Shiraz, Iran, [email protected] Dr. Mohamed Salama, Modern University for Technology & Information, Egypt, [email protected] Similar Articles: A REVIEW ON CONSTITUENTS, PHARMACOLOGICAL ACTIVITIES AND MEDICINAL USES OF GLYCYRRHIZA GLABR

    Understanding Accretion Outbursts in Massive Protostars through Maser Imaging

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    The bright maser emission produced by several molecular species at centimeter to long millimeter wavelengths provides an essential tool for understanding the process of massive star formation. Unimpeded by the high dust optical depths that affect shorter wavelength observations, the high brightness temperature of these emission lines offers a way to resolve accretion and outflow motions down to scales below \sim1 au in deeply embedded Galactic star-forming regions at kiloparsec distances. The recent identification of extraordinary accretion outbursts in two high-mass protostars, both of which were heralded by maser flares, has rapidly impacted the traditional view of massive protostellar evolution, leading to new hydrodynamic simulations that can produce such episodic outbursts. In order to understand how these massive protostars evolve in response to such events, larger, more sensitive ground-based centimeter wavelength interferometers are needed that can simultaneously image multiple maser species in the molecular gas along with faint continuum from the central ionized gas. Fiducial observations of a large sample of massive protostars will be essential in order to pinpoint the progenitors of future accretion outbursts, and to quantify the outburst-induced changes in their protostellar photospheres and outflow and accretion structures. Knowledge gained from these studies will have broader impact on the general topic of accretion onto massive objects.Comment: Science white paper submitted to the Astro2020 Decadal Survey. arXiv admin note: substantial text overlap with arXiv:1806.0698

    FORMULATION AND EVALUATION OF FINASTERIDE SUSTAINED-RELEASE MATRIX TABLETS USING DIFFERENT RATE CONTROLLING POLYMERS

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    Objective: Finasteride is chemically considered a synthetic 4-azasteroid drug used in the treatment of anti-hyperplasia. In matrix system of sustained release drug is dispersed homogenously throughout a polymeric matrix. The aim of the present investigation was to develop oral controlled release matrix tablet formulations of Finasteride with different polymer ratios. Methods: The granules were evaluated for angle of repose, bulk density and Compressibility index before being punched as tablets. Total 5 varieties o of tablets were compressed using polymers (HPMC, EC, Eudragit RS100) in different ratio. The tablets were subjected to weight variation test, drug content, hardness, friability, and in vitro release studies. Different models for kinetic study were applied like zero order, first order, Higuchi, Hixson Crowell and Korsmeyer to study the release pattern and mechanism. Results: All the formulations showed uniform thickness. In a weight variation test, the pharmacopoeial limit for percentage deviation for the tablets of more than 250 mg is ±5%. The formulation MT5 showed a comparatively high hardness value of 4.8±0.22 kg/cm2. Matrix tablets of batch MT1 shows maximum release 86.42% in 10 hrs. Conclusion: Observations of all formulations for physical characterization had shown that, all of them comply with the specifications of official pharmacopoeias and/or standard references. Study concludes that Finasteride can be delivered effectively in the form of matrix tablets.   Peer Review History: Article received on- 16 November,    Revised on- 25 December,    Accepted on- 28 December, Available online 15 January 2017 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia,  Indonesia, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:        Reviewer's Comments: Average Peer review marks at initial stage: 4.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Barkat Ali Khan, Kampala International University , Uganda, [email protected] Dr. Dalia Kamal Zaffar Ali, Modern University for technology and information, Egypt, [email protected] Similar Articles: FORMULATION AND EVALUATION OF COLON TARGETED MATRIX TABLETS CONTAINING EXTRACT OF SOLENOSTEMMA ARGEL (HARGEL) A COMPREHENSIVE REVIEW ON SUSTAINED RELEASE MATRIX TABLETS: A PROMISING DOSAGE FORM DEVELOPMENT AND CHARACTERIZATION OF DIRECT COMPRESSED MATRIX MINI TABLETS OF NAPROXEN SODIU

    An extraordinary outburst in the massive protostellar system NGC 6334I-MM1 : quadrupling of the millimeter continuum

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    Based on sub-arcsecond Atacama Large Millimeter/submillimeter Array (ALMA) and Submillimeter Array (SMA) 1.3 mm continuum images of the massive protocluster NGC 6334I obtained in 2015 and 2008, we find that the dust emission from MM1 has increased by a factor of 4.0 ± 0.3 during the intervening years, and undergone a significant change in morphology. The continuum emission from the other cluster members (MM2, MM4, and the UCH ii region MM3 = NGC 6334F) has remained constant. Long-term single-dish maser monitoring at HartRAO finds that multiple maser species toward NGC 6334I flared beginning in early 2015, a few months before our ALMA observation, and some persist in that state. New ALMA images obtained in 2016 July–August at 1.1 and 0.87 mm confirm the changes with respect to SMA 0.87 mm images from 2008, and indicate that the (sub)millimeter flaring has continued for at least a year. The excess continuum emission, centered on the hypercompact H ii region MM1B, is extended and elongated (1″6 × 1″0 ≈ 2100 × 1300 au) with multiple peaks, suggestive of general heating of the surrounding subcomponents of MM1, some of which may trace clumps in a fragmented disk rather than separate protostars. In either case, these remarkable increases in maser and dust emission provide direct observational evidence of a sudden accretion event in the growth of a massive protostar yielding a sustained luminosity surge by a factor of 70 ± 20, analogous to the largest events in simulations by Meyer et al. This target provides an excellent opportunity to assess the impact of such a rare event on a protocluster over many years.PostprintPeer reviewe

    First Image of the Sun with MeerKAT Solar Observations: Opening a New Frontier in Solar Physics

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    Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging the highly dynamic solar coronal emissions spanning a large range of angular scales at radio wavelengths is extremely challenging. At GHz frequencies, the MeerKAT radio telescope is possibly globally the best-suited instrument at the present time and can provide high-fidelity spectroscopic snapshot solar images. Here, we present the first images of the Sun made using the observations with the MeerKAT at L-band (856 -- 1711 MHz). This work demonstrates the high fidelity of the MeerKAT solar images through a comparison with simulated radio images at the MeerKAT frequencies. The observed images show extremely good mophological similarities with the simulated images. A detailed comparison between the simulated radio map and observed MeerKAT radio images demonstrates that there is significant missing flux density in MeerKAT images at the higher frequencies of the observing band, though it can potentially be estimated and corrected for. We believe once solar observations with the MeerKAT are commissioned, they will not only enable a host of novel studies but also open the door to a large unexplored phase space with significant discovery potential.Comment: Preparing for submission, 14 pages, 9 figure

    The extraordinary outburst in the massive protostellar system NGC6334I-MM1 : emergence of strong 6.7 GHz methanol masers

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    C. J. Cyganowski acknowledges support from the STFC (grant number ST/M001296/1).We report the first sub-arcsecond VLA imaging of 6 GHz continuum, methanol maser, and excited-state hydroxyl maser emission toward the massive protostellar cluster NGC6334I following the recent 2015 outburst in (sub)millimeter continuum toward MM1, the strongest (sub)millimeter source in the protocluster. In addition to detections toward the previously known 6.7 GHz Class II methanol maser sites in the hot core MM2 and the UCHII region MM3 (NGC6334F), we find new maser features toward several components of MM1, along with weaker features ∼1” north, west, and southwest of MM1, and toward the non-thermal radio continuum source CM2. None of these areas have heretofore exhibited Class II methanol maser emission in three decades of observations. The strongest MM1 masers trace a dust cavity, while no masers are seen toward the strongest dust sources MM1A, 1B and 1D. The locations of the masers are consistent with a combination of increased radiative pumping due to elevated dust grain temperature following the outburst, the presence of infrared photon propagation cavities, and the presence of high methanol column densities as indicated by ALMA images of thermal transitions. The non-thermal radio emission source CM2 (2” north of MM1) also exhibits new maser emission from the excited 6.035 and 6.030 GHz OH lines. Using the Zeeman effect, we measure a line-of-sight magnetic field of +0.5 to +3.7 mG toward CM2. In agreement with previous studies, we also detect numerous methanol and excited OH maser spots toward the UCHII region MM3, with predominantly negative line-of-sight magnetic field strengths of -2 to -5 mG and an intriguing south-north field reversal.PostprintPeer reviewe

    Target of Opportunity observations of flaring blazars with H.E.S.S. \

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    Blazars are the most common class of TeV extragalactic emitters. In the framework of the AGN unified model, they are understood as AGNs with a relativistic jet pointing close the line of sight. They are characterized by extreme variability, observed to be as fast as minutes. These flares are usually observed at multiple wavelengths and their study require fast reaction and coordination among multiwavelength observatories. An important part of blazars observations with the H.E.S.S. array of Cherenkov telescopes is thus in the form of Target of Opportunity (ToO) observations. In this contribution the H.E.S.S. blazar ToO program is presented, with a focus on recent results.Comment: to appear in the proceedings of the ICRC 2023 Conferenc

    The extraordinary outburst in the massive protostellar system NGC6334I-MM1 : flaring of the water masers in a north-south bipolar outflow driven by MM1B

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    C.J. Cyganowski acknowledges support from the STFC (grant number ST/M001296/1).We compare multi-epoch sub-arcsecond VLA imaging of the 22 GHz water masers toward the massive protocluster NGC6334I observed before and after the recent outburst of MM1B in (sub)millimeter continuum. Since the outburst, the water maser emission toward MM1 has substantially weakened. Simultaneously, the strong water masers associated with the synchrotron continuum point source CM2 have flared by a mean factor of 6.5 (to 4.2 kJy) with highly-blueshifted features (up to 70 km s-1 from LSR) becoming more prominent. The strongest flaring water masers reside 3000 au north of MM1B and form a remarkable bow shock pattern whose vertex coincides with CM2 and tail points back to MM1B. Excited OH masers trace a secondary bow shock located ~120 au downstream. ALMA images of CS (6-5) reveal a highly-collimated north-south structure encompassing the flaring masers to the north and the non-flaring masers to the south seen in projection toward the MM3-UCHII region. Proper motions of the southern water masers over 5.3 years indicate a bulk projected motion of 117 km s-1 southward from MM1B with a dynamical time of 170 yr. We conclude that CM2, the water masers, and many of the excited OH masers trace the interaction of the high velocity bipolar outflow from MM1B with ambient molecular gas. The previously-excavated outflow cavity has apparently allowed the radiative energy of the current outburst to propagate freely until terminating at the northern bow shock where it strengthened the masers. Additionally, water masers have been detected toward MM7 for the first time, and a highly-collimated CS (6-5) outflow has been detected toward MM4.PostprintPeer reviewe
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