Gamma Ray Spectrometric Analysis of Naturally Occurring Radioactive Materials (NORMS) in Gold Bearing Soil using NaI (Tl) Technique

In this work, the radioactivity in the gold bearing samples collected from the artisanal mining sites in Birnin Gwari Local Government Area, Kaduna State have been determined, experimental measurements of 226Ra, 232Th and 40K activities concentration in the gold bearing samples have been carried out using a NaI(Ti) gamma ray spectrometer. The measured activity concentration for 226Ra have been found to lie in the specific ranges from 1.0545±0.4983Bq/Kg to 3.8355± 0.3476Bq/Kg while the  mean concentration is 2.383±0.4415Bq/Kg for 232Th, the activity concentration ranges from 9.3501±1.0260Bq/Kg to 66.7047±0.5700Bq/Kg, while the mean activity concentration of 232Th is 32.3644±9.3440Bq/Kg, for 40K,the activity concentration ranges from 120.9953±6.5319Bq/Kg to 815.8631±10.504Bq/Kg, while the mean activity concentration is 383.7924±72.5436Bq/Kg. The mean absorbed dose rate in the study area is 35.7334nGy/hr; while the mean annual effective dose rate is 0.032mSv/year which is lower when compared with tolerable limits of 1mSv/year. Keywords; Natural Radionuclides,Aactivity Concentrations, Absorbed Dose

Analysis of Zr, Pb and Zn in Soil and Cereal Grown Around Birnin Gwari Artisanal Goldmine, Kaduna State-Nigeria

ABSTRACT: Energy Dispersive X-ra

A search for VHE counterparts of Galactic Fermi bright sources and MeV to TeV spectral characterization

Very high-energy (VHE; E>100 GeV) gamma-rays have been detected from a wide range of astronomical objects, such as pulsar wind nebulae (PWNe), supernova remnants (SNRs), giant molecular clouds, gamma-ray binaries, the Galactic Center, active galactic nuclei (AGN), radio galaxies, starburst galaxies, and possibly star-forming regions as well. At lower energies, observations using the Large Area Telescope (LAT) onboard Fermi provide a rich set of data which can be used to study the behavior of cosmic accelerators in the MeV to TeV energy bands. In particular, the improved angular resolution of current telescopes in both bands compared to previous instruments significantly reduces source confusion and facilitates the identification of associated counterparts at lower energies. In this paper, a comprehensive search for VHE gamma-ray sources which are spatially coincident with Galactic Fermi/LAT bright sources is performed, and the available MeV to TeV spectra of coincident sources are compared. It is found that bright LAT GeV sources are correlated with TeV sources, in contrast to previous studies using EGRET data. Moreover, a single spectral component seems unable to describe the MeV to TeV spectra of many coincident GeV/TeV sources. It has been suggested that gamma-ray pulsars may be accompanied by VHE gamma-ray emitting nebulae, a hypothesis that can be tested with VHE observations of these pulsars.Comment: Astronomy and Astrophysics, in press, 17 pages, 12 figures, 5 table

Phase-resolved Crab pulsar measurements from 25 to 400 GeV with the MAGIC telescopes

We report on observations of the Crab pulsar with the MAGIC telescopes. Our data were taken in both monoscopic (> 25GeV) and stereoscopic (> 50GeV) observation modes. Two peaks were detected with both modes and phase-resolved energy spectra were calculated. By comparing with Fermi- LAT measurements, we find that the energy spectrum of the Crab pulsar does not follow a power law with an exponential cutoff, but has an additional hard component, extending up to at least 400 GeV. This suggests that the emission above 25 GeV is not dominated by curvature radiation, as suggested in the standard scenarios of the OG and SG models.Comment: 4 pages, 2 figures, Proc. TAUP 2011, submitted for publication in JCP

A new, very massive modular Liquid Argon Imaging Chamber to detect low energy off-axis neutrinos from the CNGS beam. (Project MODULAr)

The paper is considering an opportunity for the CERN/GranSasso (CNGS) neutrino complex, concurrent time-wise with T2K and NOvA, to search for theta_13 oscillations and CP violation. Compared with large water Cherenkov (T2K) and fine grained scintillators (NOvA), the LAr-TPC offers a higher detection efficiency and a lower backgrounds, since virtually all channels may be unambiguously recognized. The present proposal, called MODULAr, describes a 20 kt fiducial volume LAr-TPC, following very closely the technology developed for the ICARUS-T60o, and is focused on the following activities, for which we seek an extended international collaboration: (1) the neutrino beam from the CERN 400 GeV proton beam and an optimised horn focussing, eventually with an increased intensity in the framework of the LHC accelerator improvement program; (2) A new experimental area LNGS-B, of at least 50000 m3 at 10 km off-axis from the main Laboratory, eventually upgradable to larger sizes. A location is under consideration at about 1.2 km equivalent water depth; (3) A new LAr Imaging detector of at least 20 kt fiducial mass. Such an increase in the volume over the current ICARUS T600 needs to be carefully considered. It is concluded that a very large mass is best realised with a set of many identical, independent units, each of 5 kt, "cloning" the technology of the T600. Further phases may foresee extensions of MODULAr to meet future physics goals. The experiment might reasonably be operational in about 4/5 years, provided a new hall is excavated in the vicinity of the Gran Sasso Laboratory and adequate funding and participation are made available.Comment: Correspondig Author: C. Rubbia (E-mail: [email protected]), 33 pages, 11 figure

The K2K SciBar Detector

A new near detector, SciBar, for the K2K long-baseline neutrino oscillation expe riment was installed to improve the measurement of neutrino energy spectrum and to study neutrino interactions in the energy region around 1 GeV. SciBar is a 'fully active' tracking detector with fine segmentation consisting of plastic scintillator bars. The detector was constructed in summer 2003 and is taking data since October 2003. The basic design and initial performance is presented.Comment: 7 pages, 4figures, Contributed to Proceedings of the 10th Vienna Conference on Instrumentation, Vienna, February 16-21, 200

DNA barcoding of Tribolium castaneum (Coleoptera: Tenebrionidae) from selected states in Nigeria based on mitochondrial DNA sequences

Tribolium castaneum also known as red flour beetle is one of the most important pests of stored grain product with a cosmopolitan distribution in Nigeria and all over the world contributing to food spoilage. The aim of this study was to characterize the T. castaneum by morphometric and molecular analyses. Samples of yam flour with evidence of the red flour beetles present inside were obtained from four locations in Kwara, Kogi, Oyo and Ekiti states in Nigeria. Morphological and molecular identifications of T. castaneum were carried out using standard methods. A dissecting microscope was used to identify the beetles and measurements were taken using ImageJ. Genomic DNA was extracted and checked on 1.5% agarose gel to confirm the presence of DNA. Species-specific primers were used to amplify mitochondrial cytochrome oxidase I (COI) gene of T. castaneum and the PCR amplicon size was also checked on 1.5% agarose. Morphometric measurements showed that the highest mean number (33.00±4.24 mm) of T. castaneum larvae observed was recorded on day 61 in Ilorin and the lowest was in Iwo, Osun state (4.00±0.00 mm) on the same day. The mean of the total body length of larvae from sampling sites was (1.31±0.37 mm) with minimum and (1.63±1.14 mm) maximum lengths respectively. There was no significant difference (p>0.05) between the mean length of the larvae collected from the study locations. Aligned cytochrome oxidase subunit 1 (COI) sequences of 313bp were analyzed. Phylogenetic analysis inferred by maximum likelihood method showed that the T. castaneum sequences analyzed for this study and sequences obtained from GenBank formed a monophyletic group. The molecular and phylogenetic analyses confirmed the presence of a single species of T. castaneum. The results from this study showed low levels of genetic diversity and variability in the studied T. castaneum populations. The observed genetic similarity in T. castaneum could be due to the fact that they were probably from similar origin when compared with those in the GenBank database. However, further studies are needed with more samples to characterize T. castaneum species from stored food grains across Nigeria

A connection between star formation activity and cosmic rays in the starburst galaxy M 82

Although Galactic cosmic rays (protons and nuclei) are widely believed to be dominantly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery [1]. The active regions of starburst galaxies have exceptionally high rates of star formation, and their large size, more than 50 times the diameter of similar Galactic regions, uniquely enables reliable calorimetric measurements of their potentially high cosmic-ray density [2]. The cosmic rays produced in the formation, life, and death of their massive stars are expected to eventually produce diffuse gamma-ray emission via their interactions with interstellar gas and radiation. M 82, the prototype small starburst galaxy, is predicted to be the brightest starburst galaxy in gamma rays [3, 4]. Here we report the detection of >700 GeV gamma rays from M 82. From these data we determine a cosmic-ray density of 250 eV cm-3 in the starburst core of M 82, or about 500 times the average Galactic density. This result strongly supports that cosmic-ray acceleration is tied to star formation activity, and that supernovae and massive-star winds are the dominant accelerators.Comment: 18 pages, 4 figures; published in Nature; Version is prior to Nature's in-house style editing (differences are minimal

Observations of the unidentified gamma-ray source TeV J2032+4130 by VERITAS

TeV J2032+4130 was the first unidentified source discovered at very high energies (VHE; E $>$ 100 GeV), with no obvious counterpart in any other wavelength. It is also the first extended source to be observed in VHE gamma rays. Following its discovery, intensive observational campaigns have been carried out in all wavelengths in order to understand the nature of the object, which have met with limited success. We report here on a deep observation of TeV J2032+4130, based on 48.2 hours of data taken from 2009 to 2012 by the VERITAS (Very Energetic Radiation Imaging Telescope Array System) experiment. The source is detected at 8.7 standard deviations ($\sigma$) and is found to be extended and asymmetric with a width of 9.5$^{\prime}$$\pm$1.2$^{\prime}$ along the major axis and 4.0$^{\prime}$$\pm$0.5$^{\prime}$ along the minor axis. The spectrum is well described by a differential power law with an index of 2.10 $\pm$ 0.14$_{stat}$ $\pm$ 0.21$_{sys}$ and a normalization of (9.5 $\pm$ 1.6$_{stat}$ $\pm$ 2.2$_{sys}$) $\times$ 10$^{-13}$TeV$^{-1}$ cm$^{-2}$ s$^{-1}$ at 1 TeV. We interpret these results in the context of multiwavelength scenarios which particularly favor the pulsar wind nebula (PWN) interpretation

Neutrino masses from new generations

We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, $\mu - e$ conversion in nuclei and $\mu \rightarrow e \gamma$ experiments. We also discuss the detection prospects at LHC.Comment: 28 pages, 4 figures. Version to be published. Some typos corrected. Improved figures 3 and