Relaxation dominated cosmological expansion

The behavior near the singularity of an isotropic, homogeneous cosmological model with a viscous fluid source is investigated. This turns out to be a relaxation dominated regime. Full extended irreversible thermodynamics is used, and comparison with results of the truncated theory is made. New singular behaviors are found and it is shown that a relaxation dominated inflationary epoch may exist for fluids with small heat capacity.Comment: 7 pages, LaTeX. To be published in Physics Letters

Effect of different types and levels of Organic Manures on Yield and Yield Components of Garlic (Allium sativum L) at Kadawa, Kano, Nigeria

Effects of different types and levels of organic manures on the yield and yield components of garlic (ex- Kofa var) was investigated. Two experiments were conducted under irrigation at the Institute for Agriculture Research (I.A.R) Kadawa in the Sudan Savanna zone of Nigeria during 2007/2008 and 2008/2009 (Nov- Mar) dry seasons. The treatments consisted of five levels (0, 2.5, 5.0, 7.5 and 10.0 tons/ha) of three types of organic manures (poultry droppings (P.D), farm yard manure (FYM)and cow dung (CD) laid out in a Randomized Complete Block Design (RCBD) with four replications. Yield parameters studied included cured bulb weight , average bulb diameter, average number of cloves/bulb, average weight of cloves and cured bulb yield (kg/ha). The results showed Significant (P=0.5) effect of all organic manures with highest yield values obtained from poultry droppings, then cow dung and farmyard manure respectively. Increasing levels of all applied manures from 0- 10 tons/ha significantly increased all yield parameters assessed. Thus for optimum yield of garlic at Kadawa, the use of 7.5-10 tons/ha of poultry dropping could be recommended.Keywords: Poultry droppings (PD), Farm yard manure (FYM), Cow dung (CD), Kadawa, Sudan Savanna, Garlic, Irrigation, yield and yield components

Effects of disc speed and height of flow mechanism of a solid manure spreader on uniformity of spreading and swath width

The aim of this study was to investigate the effects of disc speed and height of flow mechanism of a solid manure spreader in order to maintain uniformity of spread and swath width for optimum crop growth. The study was done using complete randomized design with three factors considered: tractor forward speed, height of flow mechanism (broadcasters) gate opening rates, (15, 30, 45cm) and disc speed (150, 300, 450rpm) applied according to SAE S341.2, 1999 test code. Results obtained and compared with an imported spreader shows that the developed spreader recorded the highest application rate of 4082.1kg/ha against that of the imported spreader of 1875.3kg/ha while the swath width was 9.5m compared to 9.0m of the imported. Results obtained also shows that the spreader gave a more uniform spread pattern of manure at a lower openning of 15cm height of flow mechanism and lesser disc speed of 150rpm. Disc speed and height of flow mechanism were found to be the major determining factor influencing spreading uniformity and swath width of cow dung manure for optimum crop growth

Neutron spectrum parameters in two irradiation channels of the Nigeria research reactor-1 (nirr-1) for use in k0-naa

For the utilization of the NIRR-1 to include the k0-standardization method, the following neutron spectrum parameters in one inner and one outer irradiation channels were determined using the “Cd-ratio for multi-monitor method”: The thermal to epithermal flux ratio, f, and the epithermal flux shape factor, α. These parameters determined in the inner irradiation channel A1,are: α = - 0.046 ± 0.005 and f = 18.4 ± 0.34 and for the outer irradiation channel A2 α = + 0.024 ± 0.002 and f = 49.5 ± 0.96. The results compare well with reported values obtained from other reactor facilities with similar core configuration such as the Slowpoke and Miniature Neutron Source Reactor facilities available in literature

Determination of neutron-induced activation cross sections using nirr-1

Thermal Activation cross-sections for the (n, γ) reaction were experimentally measured using NIRR-1 facilities. The irradiated target isotopes were 71Ga, 109Ag, 55Mn 94Zr; 96Zr; 238U, 74Se, 75As and 48Ca. In order to obtain reliable activation cross sections, careful attention was paid to neutron irradiation and to the measurement of induced activity. The values obtained for the ten (n, γ) reactions were compared against the comprehensive evaluated values listed in Mughabghab, (2003) and other evaluated data libraries. The values were found to compare well with values evaluated by Mughabghab and those from other libraries

Bibliometric Analysis of International Journal of Research in Education, 2004 – 2012

This study is a bibliometric analysis of the International Journal of Research in Education for the period between 2004 and 2012. The authors have tried to analyse the number of articles, authorship pattern, bibliographical forms of citations, geographical distribution of authors, authors’ institutional affiliations, citation pattern, subject coverage, etc. The study reveals that 347 articles were published during the period. 226(65.1%) articles were contributed by single authors while the rest 121 (34.9%) were by joint authors. The study also revealed that 94.2% of the contributions are from Nigeria. Majority (40.9%) of the contributors preferred books as source of information. Universities topped ranking of institutional affiliations of contributors with 41.8%. Finally, curriculum and teaching is the most researched subject. Keywords: Bibliometric analysis, Authorship pattern, Citation pattern, Geographical distribution

Analysis of activity concentrations due to natural radionuclides in the fish of Kainji Lake

A study was conducted for natural radioactivity of some fish samples from Kainji Lake, situated between latitudes 9~' 50' - 10~' 57' North and longitudes 4~'25'-4~'45' East, New Bussa, Niger state, Nigeria, using gamma spectroscopy method with Nal(TI) detector. Radioactivity a phenomenon that leads to production of radiations, and radiation is known to trigger or induce cancer. The fish are analyzed to estimate the radioactivity (activity) concentrations due to natural radionuclides (Radium 222(226Ra), Thorium 232(232Th) and Potassium 40 (40K). The obtained result shows that the activity concentration for (226Ra), in all the fish samples collected ranges from 16.06 ~c 0.44 Bqkg-1 to 67.39 ~c 12.34 Bqkg-1 with an average value of 37.22 ~c 4.31 Bqkg-1. That of 232Th, ranges from 42.66 ~c 0.81 Bqkg-1 to 200.6 ~c 10.66 Bqkg-1 and the average value stands at 94.82 ~c 3.82 Bqkg-1. The activity concentration for 40K, ranges between 243.3 ~c 1.56 Bqkg-1 to 384.98 ~c 11.97 Bqkg-1 and the average is 618.2 ~c 26.81 Bqkg-1. This indicated that average daily intake due to natural activity from the fish is valued at 0.999 Bq/day, 2.545Bq/day and 10.31 Bq/day for 226Ra, 232Th and 40K respectively. This shows a promising result, since the activity concentration values for most of the fish are within the acceptable limits. However location Upstream02 (9~'51'.285~AN, 4~'35'.533~AE) and Upstream07 (9~'51'.285~AN, 4~'35'.533~AE) fish, became outliers with significant values of 1 13.10~kSvy-1 and 121.68~kSvy-1 effective dose. This could be attributed to variation in geological formations in the lake as well as the feeding habits of these fish. The work shows that consumers of fish from Kainji Lake have no risk of radioactivity ingestion, even though no amount of radiation is assumed to be totally safe

New cosmological solutions and stability analysis in full extended thermodynamics

The Einstein's field equations of FRW universes filled with a dissipative fluid described by full theory of causal transport equations are analyzed. New exact solutions are found using a non-local transformations on the nonlinear differential equation for the Hubble factor. The stability of the de Sitter and asymptotically friedmannian solutions are analyzed using Lyapunov function method.Comment: 13 pages, LaTeX 2.09. To be published in International Journal of Modern Physics

Generalized power expansions in cosmology

It is given an algorithm to obtain generalized power asymptotic expansions of the solutions of the Einstein equations arising for several homogeneous cosmological models. This allows to investigate their behavior near the initial singularity or for large times. An implementation of this algorithm in the CAS system Maple V Release 4 is described and detailed calculations for three equations are shown.Comment: 22 pages, LaTeX, elsart.sty. To be published in Computer Physics Communications Thematic Issue "Computer Algebra in Physics Research