5,264 research outputs found
Correlating Fermi gamma-ray sources with ultra-high energy cosmic rays
The origin of ultra-high energy cosmic rays (UHECRs) is one of the enduring
mysteries of high-energy astrophysics. To investigate this, we cross-correlate
the recently released Fermi Large Area Telescope First Source Catalog (1FGL)
with the public sample of UHECRs made available by the Pierre Auger
collaboration. Of the 27 UHECRs in the sample, we find 12 events that arrived
within 3.1 degrees of Fermi sources. However, we find similar or larger number
of matches in 63 out of 100 artificial UHECR samples constructed using
positions randomly drawn from the BATSE 4B catalog of gamma-ray bursts (GRBs)
collected from 1991 until 1996. Based on our analysis, we find no evidence that
UHECRs are associated with Fermi sources. We conclude with some remarks about
the astrophysical origin of cosmic rays.Comment: Revised version that considers a smaller deflection angle for UHECRs
(3.1 degrees) and a declination range for the artificial samples that extends
to decl.= +24.8 in response to the referee comments. 4 pages, 2 figures,
submitted to MNRA
Letter to the Editor on: Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy
In this study, a novel method was developed to measure acidic and basic drugs in biological and wastewater samples. The method used magnetic nanoparticles based on Vortex-Assisted Dispersive Micro-Solid Phase Extraction (SPE) and then identifying with HPLC-UV. The magnetic nanoparticle (Fe3O4@SiO2@Kit-6@NH2) has been used as an efficient adsorbent for the extraction of acidic and basic drugs ibuprofen (IFB), fenoprofen calcium (FPC), methocarbamol (MTC), and clonazepam (CZP). The magnetic nanoparticle was characterized by techniques including SEM, XRD, EDX, and FT-IR. The effect of various parameters in the V-D-μ-SPE method was studied completely through the design of the response surface methodology (RSM) of the Box–Behnken design (BBD) based response method and the utility function. The parameters affecting the extraction efficiency were optimized including sample pH, adsorbent amount, absorption time, the salt concentration in the sample solution, CTAB of concentration, desorption time, and the volume of an eluent. After optimization, the limit of detection and calibration curve in the linear range were obtained 0.062–0.32 μg L−1 and 0.1–800 μg L−1, respectively. Its linear correlation was R2> 0.9951. The relative standard deviation (n = 5) was between 2.4 and 5.1. Finally, this method was used to determine target analytes in human serum, urine, and wastewater. • In this study, for the first time, a novel method for the determination of some drugs from human serum, urine, and wastewater samples. • The Synthesized Fe3O4@SiO2@Kit-6@NH2 NPs based V-D-μ-SPE was characterized by techniques including SEM, XRD, EDX, and FT-IR. • The effects of various parameters in the V-D-μ-SPE methods were studied through the design of the RSM of BBD. © 202
Mathematical modeling of ultra wideband in vivo radio channel
This paper proposes a novel mathematical model for an in vivo radio channel at ultra-wideband frequencies (3.1–10.6 GHz), which can be used as a reference model for in vivo channel response without performing intensive experiments or simulations. The statistics of error prediction between experimental and proposed model is RMSE = 5.29, which show the high accuracy of the proposed model. Also, the proposed model was applied to the blind data, and the statistics of error prediction is RMSE = 7.76, which also shows a reasonable accuracy of the model. This model will save the time and cost on simulations and experiments, and will help in designing an accurate link budget calculation for a future enhanced system for ultra-wideband body-centric wireless systems
Possibility of Using a Satellite-Based Detector for Recording Cherenkov Light from Ultrahigh-Energy Extensive Air Showers Penetrating into the Ocean Water
We have estimated the reflected component of Cherenkov radiation, which
arises in developing of an extensive air shower with primary energy of 10^20 eV
over the ocean surface. It has been shown that, under conditions of the TUS
experiment, a flash of the reflected Cherenkov photons at the end of the
fluorescence track can be identified in showers with zenith angles up to 20
degrees.Comment: 5 pages, 3 figures. This preprint corrects errors which appeared in
the English version of the article published in Bull. Rus. Acad. Sci. Phys.,
2011, Vol. 75, No. 3, p. 381. The original russian text was published in Izv.
RAN. Ser. Fiz., 2011, Vol. 75, No. 3, p. 41
Client Satisfaction Towards Quality of Health Services: an Assessment at Primary Healthcare of District Gujranwala
This survey designed to evaluate the satisfaction level and the factors that affect the patient satisfaction regarding health care delivery services with the aim to improve the services in the primary health care settings of Gujranwala. A Cross Sectional Study done on randomly selected patients attending the basic health units of Gujranwala, with more than18 years of age. Pretested structured "Liker scale questionnaire" was used for data collection. Out of total respondents, 62 (41.3%) clients were satisfied with the services provided by the basic health units of Gujranwala. The factors identified to determine patient satisfaction were accessibility of services, behavior of staff, health education, level of cleanliness, drug availability and miscellaneous services. Not a single ranked area of satisfaction noticed. Client\u27s occupation and income had significant relationship with the patient satisfaction level. Gender, age, and education of clients were not contributing factors; they not affect the client satisfaction level.Less than half clients were satisfied with the services provided by the basic health units. Management of health facilities needs to improve the services
Evaluation of ion exchange capacity of acid activated, thermally treated Iranian Na-bentonite as a cheap alternative for ammonium removal in aquaculture farms of Iran and comparison with H-zeolite synthesis
Highest Energy Cosmic Rays and results from the HiRes Experiment
The status of the field of ultrahigh energy cosmic rays is summarized, from
the point of view of the latest results of the High Resolution Fly's Eye
(HiRes) Experiment. HiRes results are presented, and compared with those of the
Akeno Giant Air Shower Array (AGASA), plus the Telescope Array and Pierre Auger
experiments. The HiRes measurements of the cosmic ray spectrum, and the
observation of the GZK cutoff are presented. HiRes results on composition,
searches for anisotropy, measurement of the proton-air total cross section, and
shapes of shower profiles are presented.Comment: 31 pages, 18 figures, submitted to Journal of Physics
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