Comparative study and experimental analysis of pellets from biomass sawdust and rice husk

Sawdust and rice husk are available in abundance and indigenous in Nigeria but have not been exploited because they cannot be used directly in combustion processes due to their loose form unless by pelleting or briquetting. This experimental study assesses the potential of pellets from sawdust (SD) and rice husk (RH). Pallet samples collected from mills were thereafter optimized in ratios (i.e. 90%RH:10%SD, 80%RH:20%SD, 70RH:30SD, 60%RH:40%SD, 50%RH:50%SD, 100%RH and 100%SD) using mixing ratio optimization model. Seven samples were produced using a manual screw press machine and were subsequently categorized in terms of calorific value (CV), proximate and ultimate analyses using the ASTM standards. Results showed that the 100%RH pellets have higher CV of 31,026.3kJ/kg and the 100%SD a value of 26,088.3kJ/kg while the optimized pellets range from 25,867.39kJ/kg to 27,063.60kJ/kg. The CV decreases with increasing ash content of the pellets. It was also observed from the proximate analysis that the 100%RH has low percentages of moisture content, volatile matter and ash content compared to others. The optimized pellets showed that SD has the tendency to reduce the sulfur content in RH; hence, a promising alternative source of energy to the conventional fossil fuel

Study of correlation among ploidy level and steroid glycoalkaloids content in resistance in cultivated and uncultivated potato species from an in vitro genebank

The present research was carried out with the aim to determine the correlation between ploidy level, steroid glycoalkaloids (SGAs) content and resistance against Late blight (Phytophthora infestans (Mont.) de Bary), and Colorado potato beetle (Leptinotarsa decemlineata (Say)) in cultivated and wild Solanum species preserved in the Potato Gene Bank of Czech Republic. In this study 27 species were included which consist of five cultivated and 22 wild species, with a total of 31 genotypes (four species represented by two accessions). In this study 70.97% of genotypes were evaluated as diploid, 3.23% were triploid, 19.35% tetraploid and 6.45% hexaploid as depicted from counting of chromosomes. The highest concentration, of foliage α-solanine (5,450 mg kg-1 ) and α-chaconine (9,420 mg kg-1 ) of dry matter was found in the specie S. yungasense 00070, whereas lowest 1.1 mg kg-1 and 2.3 mg kg-1 in S. pinnatisectum 00051, respectively, Tukey’s test of one way anova was performed for getting significance from the data obtained and found significant variation among species of steroid glycoalkaloids (SGA) content in dry weight at level of P ≤ 0.01. Leaf damages by Leptinotarsa decemlineata under field experiment circumstances were also recorded. In vitro study, S. bulbocastanum PIS 06-17 and S. bulbocastanum 00240 shown resistant to P. infestans upon inoculation of aggressive isolates and strong resistance was observed in S. stoloniferum 00295, S. sucrense 0062 and S. yungasense 0070. Nevertheless, there was no correlation of ploidy level, SGA contents and resistance to the CPB (r = 0.00) and late blight (r = 0.076) found in the investigated Solanum species

Gamma-Ray Emission from Two Blazars Behind the Galactic Plane: B2013+370 & B2023+336

B2013+370 and B2023+336 are two blazars at low-galactic latitude that were previously proposed to be the counterparts for the EGRET unidentified sources, 3EG J2016+3657 and 3EG J2027+3429. Gamma-ray emission associated with the EGRET sources has been detected by the Fermi Gamma-ray Space Telescope, and the two sources, 1FGL J2015.7+3708 and 1FGL J2027.6+3335, have been classified as unidentified in the 1-year catalog. This analysis of the Fermi-LAT data collected during 31 months reveals that the 1FGL sources are spatially compatible with the blazars, and are significantly variable, supporting the hypothesis of extragalactic origin for the gamma-ray emission. The gamma-ray light curves are compared with 15 GHz radio light curves from the 40-m telescope at the Owens Valley Radio Observatory (OVRO). Simultaneous variability is seen in both bands for the two blazar candidates. The study is completed with the X-ray analysis of 1FGL J2015.7+3708 using Swift observations that were triggered in August 2010 by a Fermi-detected flare. The resulting spectral energy distribution shows a two-component structure typical of blazars. We also identify a second source in the field of view of 1FGL J2027.6+3335 with similar characteristics to the known LAT pulsars. This study gives solid evidence favoring blazar counterparts for these two unidentified EGRET and Fermi sources, supporting the hypothesis that a number of unidentified gamma-ray sources at low galactic latitudes are indeed of extragalactic origin.Comment: 10 pages, 7 figures, 6 tables, accepted for publication in The Astrophysical Journa

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

Towards the development of a community-based model for promoting cervical cancer prevention among Yoruba women in Ibadan Nigeria: Application of PEN-3 model

Through the identification of the barriers to the uptake of prevention services for cervical cancer and ways topromote prevention of cervical cancer in the community, this research study purposed the development of a community-based model for promoting cervical cancer prevention among Yoruba women living in Ibadan, Nigeria. An exploratory, descriptive design was used to collect data from 20 health workers and four policy makers using semi-structured interviews and key informant interviews respectively. The PEN-3 cultural model developed by Airhenbuwa in 1998guided the exploration of the barriers to the uptake of available prevention services for cervical cancer, and the ways topromote the prevention of cervical cancer. Three interrelated and interdependent primary domains, namely cultural identity,relationships and expectations, and cultural empowerment, form the basis of the PEN-3 model. Cultural identity emphasisesthe subjective responses in relation to the community and cervical cancer prevention

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

Particle acceleration and non-thermal emission during the V407 Cygni nova outburst

On March 2010, the symbiotic binary V407 Cyg erupted as a result of a nova explosion. The event gave rise to a two-week long burst of >100MeV gamma-rays detected by Fermi/LAT, a unique observation testifying to particle acceleration in the system. The outburst can be considered a scaled-down supernova, with short dynamical time scale, and thus can constitute a test case for theories of the origin of galactic cosmic rays. We aim at determining the properties of the accelerated particles and identifying the origin of the high-energy radiation. We developed a model for diffusive shock acceleration and non-thermal emission in V407 Cyg, complemented by an evaluation of the thermal emission from the shocked plasma. We considered both leptonic and hadronic contributions to the non-thermal processes, and investigated the effect of many binary and nova parameters. The gamma-ray emission is mostly of leptonic origin and arises predominantly from inverse-Compton scattering of the nova light. Upscattering of the red giant photons is a minor contribution. Matching the light curve requires gas accumulation in the vicinity of the white dwarf, as a consequence of wind accretion, while the spectrum imposes particle scattering close to the Bohm limit in the upstream equipartition magnetic field. The nova accelerated protons (respectively electrons) with energies up to ~300GeV (respectively ~20GeV), for a total non-thermal energy 10^43 erg after two weeks, representing ~10% of the initial nova kinetic energy. The electron-to-proton ratio at injection is 6%. The V407 Cyg eruption can be understood from the same principles that are invoked for particle acceleration in supernova remnants, although without the need for strong magnetic field amplification. The population of novae in symbiotic systems is a negligible source of Galactic cosmic rays, and most likely not a class of TeV-emitters.Comment: 19 pages, 25 figures, accepted for publication in A&A. Revised version includes clarifications suggested by the referee of the journal, plus a new part on the radio emission aspect

Application of gamification for sustainable construction: an evaluation of the challenges

Purpose This paper aims to identify and evaluate the challenges affecting the adoption of gamification practices in developing countries through the lens of the Nigerian construction industry. Design/methodology/approach A scoping literature review was conducted through which challenges to the adoption of gamification practices were identified, which helped in the formulation of a questionnaire survey. Data was obtained from construction professionals including architects, builders, engineers and quantity surveyors. Retrieved data were analyzed using several statistical tools such as percentages, frequencies, mean item scores (MIS) and exploratory factor analyses. Findings Based on the MIS ranking results, the top five significant challenges to the adoption of gamification were lack of capacity and expertise, lack of budgeting for innovation, lack of technical infrastructure, hesitation to adopt and limited internet connectivity. Through factor analysis, the challenges identified were categorized into five principal clusters, namely, organizational challenges, technical-related challenges, human-related challenges, data security challenges and economic challenges. Practical implications The identification and evaluation of the key challenges hindering the adoption of gamification practices would help construction organizations and stakeholders to understand the need to embrace and implement the concept into their activities, operations and processes to improve the engagement and motivation levels of employees. Originality/value To the best of the authors’ knowledge, this study is the first of its kind in the study area to identify and evaluate the challenges affecting the adoption of gamification practices using a structured quantitative approach

A Beta Beam complex based on the machine upgrades for the LHC

The Beta Beam CERN design is based on the present LHC injection complex and its physics reach is mainly limited by the maximum rigidity of the SPS. In fact, some of the scenarios for the machine upgrades of the LHC, particularly the construction of a fast cycling 1 TeV injector (``Super-SPS''), are very synergic with the construction of a higher $\gamma$ Beta Beam. At the energies that can be reached by this machine, we demonstrate that dense calorimeters can already be used for the detection of $\nu$ at the far location. Even at moderate masses (40 kton) as the ones imposed by the use of existing underground halls at Gran Sasso, the CP reach is very large for any value of $\theta_{13}$ that would provide evidence of $\nu_e$ appearance at T2K or NO$\nu$A ($\theta_{13}\geq 3^\circ$). Exploitation of matter effects at the CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy in significant areas of the $\theta_{13}-\delta$ plane

Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS

We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3 sigma (pre-trials) detection has a full angular extent of roughly 0.6deg by 0.4deg. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1-0) emission, 0.4deg away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. The VHE energy spectrum measured with VERITAS is well characterized by a power law dN/dE = N_0(E/3 TeV)^{-G} with a differential index of G = 2.29 +/- 0.33stat +/- 0.30sys and a flux of N_0 = (1.15 +/- 0.27stat +/- 0.35sys)x 10^{-13} cm^{-2} s^{-1} TeV^{-1}. The integral flux above 1 TeV corresponds to ~5 percent of the steady Crab Nebula emission above the same energy. We describe the observations and analysis of the object and briefly discuss the implications of the detection in a multiwavelength context.Comment: 5 pages, 2 figure