Electric and Magnetic fields due to Dirac particles in FRW spacetime

Some solutions of the Maxwell equations with Dirac particles for the source in FRW spacetime are discussed. The Green's function of the equation for the radial component of the Maxwell fields, F_{r\eta} and F_{\theta\phi} is solved. Green's function is found to reduce to that of Minkowskian spacetime in the appropriate limit. Also, the Lienard-Wiechert type solution is derived. Also, the solutions with the Dirac particle current is also presented. It is found that the F_{r\eta} is composed of even angular momentum states while the odd states constitue F_{\theta\phi} .Comment: 8 pages including 2 figure

Effect of biochar and plastic mulch on growth, yield, and yield attributing characteristics of spring maize (Zea mays L.)

Spring maize is an important crop to meet the growing demand for maize. Moisture stress is an important yield limiting factor during the dry spring period. Biochar and plastic mulch help in soil moisture conservation and might contribute to the growth and yield of maize. A field experiment was conducted to evaluate the effects of biochar application and plastic mulch on growth, yield, and yield attributing characteristics of spring maize (Zea mays L.) in a sandy loam soil at Rampur, Chitwan, Nepal in 2018. The experiment was laid out in a split-plot design (SPD) with three replications. The Main plots were allocated to the mulching (mulching, and no mulching) while the Subplot was to the biochar rates of 0 t/ha, 5 t/ha, 15 t/ha, and 25 t/ha. There were twenty-four plots of each plot size 4.8 × 1.5 m2. The grounded biochar passed through a 1 mm sieve and was applied in the well-prepared plots two weeks before seed sowing. The maize seeds were sown at 60 cm row to row and 25 cm plant to plant distance. There were no significant effects due to both factors on maize seed emergence, plant height, number of leaves per plant, leaf area index, root length, dry matter content, stover yield, and yield attributes. But the yield was significantly influenced by their interactions. Significantly highest grain yield (2.58 t/ha) was obtained from 25 t/ha with plastic mulch followed by plastic mulch with 15 t/ha biochar (2.06 t/ha) and the least was recorded from control plots (1.19 t/ha). From the result, it can be concluded that the application of a higher biochar rate of 25 t/ha with plastic mulch contributes to a higher yield of spring maize

Using online learning modules to fight against antibiotic resistance in Australia

© 2013 Jorge Reyna, Santosh Khanal and Tessa Morgan. NPS MedicineWise and the Australian Commission on Safety and Quality in Health Care (ACSQHC) have launched a series of online learning modules designed to help combat antibiotic resistance in hospitals. The aim of the modules is to fill a previously unmet need for an online teaching resource on a common curriculum for hospitals and universities. The modules address specific areas where antibiotic use in hospitals needs improvement. Problem Based Learning has been used as pedagogical approach for the modules. Clinical scenarios are presented with a logical progression of tasks including clinical assessment and diagnosis, investigations, interpretation of results, and antibiotic selection. Expert advice and feedback has been incorporated at each step, helping to improve learning outcomes. Learners can access the modules at their own pace and revisit them upon completion. We report, for the first time, participants’ perceptions of the antimicrobial modules as learning resource, usability issues, and possible areas of improvement

Evidence for a Far-Traveled Thrust Sheet in the Greater Himalayan Thrust System, and an Alternative Model to Building the Himalaya

The Galchhi shear zone underlies the Kathmandu klippe in central Nepal and has emerged as a key structure for discriminating competing models for the formation of the Himalayan orogenic wedge. New chronologic data from the Galchhi area suggest a new structural and orogenic interpretation. Zircons from quartzites and an orthogneiss restrict protolith deposition to between 467+7/ – 10 Ma and ~570 Ma, with metamorphic zircon growth at 23-29 Ma. Comparable data from the Greater Himalayan Sequence (GHS) at the intra-GHS Langtang thrust, north of Galchhi, similarly restrict GHS deposition to between 475+7/ – 3 and ~660 Ma. Undeformed pegmatites near Galchhi constrain movement of the Galchhi shear zone to ≥22.5 ± 2.3 Ma, long before slip of the Main Central Thrust in the region (≤17 Ma). Shear sense indicators in the Galchhi area indicate both top-to-the-south and top-to-the-north shears. The old age of movement, Neoproterozoic youngest detrital zircons, occurrence of top-to-the-south shear sense indicators, and intrusive Paleozoic granites, all suggest that the Galchhi shear zone is an intra-GHS top-to-the-south thrust, rather than either a thrust involving Lesser Himalayan rocks, or a top-to-the-north shear zone that juxtaposed Tethyan and GHS rocks during coeval movement of the Main Central Thrust. The GHS in Nepal was not emplaced as a single body of rock but consists of at least two ductile “thrust sheets,” present in both the hinterland at Langtang and toward the foreland at Galchhi. GHS thrust sheets sequentially underplated during southward propagation of the thrust belt

Electrodynamics in Friedmann-Robertson-Walker Universe: Maxwell and Dirac fields in Newman-Penrose formalism

Maxwell and Dirac fields in Friedmann-Robertson-Walker spacetime is investigated using the Newman-Penrose method. The variables are all separable, with the angular dependence given by the spin-weighted spherical harmonics. All the radial parts reduce to the barrier penetration problem, with mostly repulsive potentials representing the centrifugal energies. Both the helicity states of the photon field see the same potential, but that of the Dirac field see different ones; one component even sees attractive potential in the open universe. The massless fields have the usual exponential time dependencies; that of the massive Dirac field is coupled to the evolution of the cosmic scale factor $a$. The case of the radiation filled flat universe is solved in terms of the Whittaker function. A formal series solution, valid in any FRW universe, is also presented. The energy density of the Maxwell field is explicitly shown to scale as $a^{-4}$. The co-moving particle number density of the massless Dirac field is found to be conserved, but that of the massive one is not. Particles flow out of certain regions, and into others, creating regions that are depleted of certain linear and angular momenta states, and others with excess. Such current of charged particles would constitute an electric current that could generate a cosmic magnetic field. In contrast, the energy density of these massive particles still scales as $a^{-4}$.Comment: 18 pages including 9 figure

Diversity of butterflies with respect to altitudinal rise at various pockets of the Langtang National Park, central Nepal

The Langtang National Park which covers an area of 1760 sq.km was studied extensively for the occurrence and status of butterflies within the altitudinal ranges of 1500 m at Syaprubensi to 4300 m around Langtang glacier area. Addition to altitudes, the decline in floral diversity with temperature reduction in higher elevation basically controlled the species richness of butterflies specifically above 3000 m elevations. Habitat preference for diverse species of these colorful and agile insects is poorly represented above that elevation. This study conducted at different periods in 2010 and 2011 covering both the spring and summer seasons came up with a list of different status categories of 126 species. A rich diversity was noted at 1500 m (Syaprubensi) to 2900 m at Deurali on the way to the glacier (4300 m). Parnassius hardwickei and Parnassius epaphus epaphus which were seen with good population in previous studies at Dhimsa (3200 m) are at declining stage as a consequence of habitat loss and human interferences

Projecting Nepal's Demographic Future- How to deal with spatial and demographic heterogeneity

This Working Paper outlines the efforts of the cooperation between researchers at IIASA’s World Population Program and the Ministry of Health and Population, Nepal to conduct small-area population projections on Village Development Committee and Municipality levels for Nepal from 2011 to 2031. In order to fulfil this aim it was necessary to compile, harmonize and estimate small-area population data based on the latest census and survey data. Due to the lack of comprehensive fine-grained data on the demographic determinants fertility, mortality, and migration we estimate those with different methodological approaches like the Child-Women-Ratio or mortality corrections. In recent time, internal and international migration has become the most common of the three demographic components; therefore, most efforts went into estimating the rates of migration flows to and from several directions. The creation of this small-area fertility, mortality and migration data by age and sex enables us to apply the well-known cohort component method in a multi-state framework (each district as a state) and to create reasonable scenarios on the prospective population development for Nepal on regional and local level. This will help national, regional and local actors and policymakers to set appropriate measures to steer and adapt to the future characteristics of the Nepalese society on all administrative levels

The dissimilar chemical composition of the planet-hosting stars of the XO-2 binary system

Using high-quality spectra of the twin stars in the XO-2 binary system, we have detected significant differences in the chemical composition of their photospheres. The differences correlate strongly with the elements' dust condensation temperature. In XO-2N, volatiles are enhanced by about 0.015 dex and refractories are overabundant by up to 0.090 dex. On average, our error bar in relative abundance is 0.012 dex. We present an early metal-depletion scenario in which the formation of the gas giant planets known to exist around these stars is responsible for a 0.015 dex offset in the abundances of all elements while 20 M_Earth of non-detected rocky objects that formed around XO-2S explain the additional refractory-element difference. An alternative explanation involves the late accretion of at least 20 M_Earth of planet-like material by XO-2N, allegedly as a result of the migration of the hot Jupiter detected around that star. Dust cleansing by a nearby hot star as well as age or Galactic birthplace effects can be ruled out as valid explanations for this phenomenon.Comment: ApJ, in press. Complete linelist (Table 3) available in the "Other formats -> Source" downloa