Rotating effects on the scalar field in the cosmic string spacetime, in the spacetime with space-like dislocation and in the spacetime with a spiral dislocation

In the interface between general relativity and relativistic quantum mechanics, we analyse rotating effects on the scalar field subject to a hard-wall confining potential. We consider three different scenarios of general relativity given by the cosmic string spacetime, the spacetime with space-like dislocation and the spacetime with a spiral dislocation. Then, by searching for a discrete spectrum of energy, we analyse analogues effects of the Aharonov-Bohm effect for bound states and the Sagnac effect.Comment: 12 pages, no figure. To be published in The European Physical Journal

Coulomb-type interaction under Lorentz symmetry breaking effects

Based on models of confinement of quarks, we analyse a relativistic scalar particle subject to a scalar potential proportional to the inverse of the radial distance and under the effects of the violation of the Lorentz symmetry. We show that the effects of the Lorentz symmetry breaking can induced a harmonic-type potential. Then, we solve the Klein-Gordon equation analytically and discuss the influence of the background of the violation of the Lorentz symmetry on the relativistic energy levels.Comment: 10 pages, no figur

Accelerated particle beams in a 3D simulation of the quiet Sun

Observational and theoretical evidence suggest that beams of accelerated particles are produced in flaring events of all sizes in the solar atmosphere, from X-class flares to nanoflares. Current models of these types of particles in flaring loops assume an isolated 1D atmosphere. A more realistic environment for modelling accelerated particles can be provided by 3D radiative magnetohydrodynamics codes. Here, we present a simple model for particle acceleration and propagation in the context of a 3D simulation of the quiet solar atmosphere, spanning from the convection zone to the corona. We then examine the additional transport of energy introduced by the particle beams. The locations of particle acceleration associated with magnetic reconnection were identified by detecting changes in magnetic topology. At each location, the parameters of the accelerated particle distribution were estimated from local conditions. The particle distributions were then propagated along the magnetic field, and the energy deposition due to Coulomb collisions with the ambient plasma was computed. We find that particle beams originate in extended acceleration regions that are distributed across the corona. Upon reaching the transition region, they converge and produce strands of intense heating that penetrate the chromosphere. Within these strands, beam heating consistently dominates conductive heating below the bottom of the transition region. This indicates that particle beams qualitatively alter the energy transport even outside of active regions.Comment: Accepted for publication in A&

Weed Control by Means of Chemicals

Weed control by means of chemicals has become an important factor in our struggle to eradicate weeds. There are few weed problems which chemicals cannot at least aid. However, in many cases, their use is limited by their cost. It has generally been held that chemicals are too expensive for large infestations of weeds. In northwest Iowa where there are thousands of acres of European bindweed (Convolvulus arvensis L.) chemicals of the present day cannot be recommended on account of the cost. To control this noxious weed it has been necessary to resort to cultivation and competitive cropping, processes which take several years, and have for their objective a reduction in the amount of food reserves in the subterranean parts, to the point where there is not sufficient food material to regenerate new shoots

Leafy Spurge, Euphorbia Esula L.

Leafy spurge (Euphorbia Esula L.) has become a serious menace to agriculture in northwest Iowa and in the adjoining states, Minnesota, North and South Dakota. It was collected at Mount Pleasant (Henry County) in 1899 and at Ames (Story County) in 1907. This weed seems to develop most vigorously in northwestern Iowa, where large patches occur on many farms. In order to determine the most effective means of exterminating this weed pest, it was necessary to learn more about its life history, growth, habits and structure in areas where it was well established. An attempt has been made in this publication to place leafy spurge in its correct place taxonomically and to discuss the flowering, fruiting habits, pollination, seed studies, seed dispersal, root system, leaf, stem and root structures

Soil Moisture Relationship of the European Bindweed (Convolvulus Arvensis L.)

The European bindweed (Convohrulus arucnsis L.) has an extensive root system. A large number of feeding roots are located in the upper two feet but the main tap root often extends to a depth of twenty feet. Soil samples taken at one and two foot depths in 1933, 1934 and 1935, at Hawarden, Iowa, from corn ground, heavily infested with bindweed, and free from bindweed, showed very little difference in soil moisture content. As the soil moisture content was often below the wilting coefficient, it was found that the bindweed developed readily while the corn grew very little. European bindweed is able to complete successfully with corn because of its deeply penetrating root system

Control and eradication of European Bindweed

The European bindweed (Convolvulus arvensis L.), known also as Creeping Jennie and field bindweed, probably is present in every county in Iowa, although it is more prevalent in the northwestern part of the state. It is not uncommon to find tracts of 100 acres or more. Where a small grain field is heavily infested, the grain becomes lodged so that it is extremely difficult to cut with a grain binder, and the bundles do not dry readily. At times throughout the years 1930-1941, bindweed caused a complete failure of corn (fig. 1), grain and garden crops on certain tracts. In the states where European bindweed is most troublesome today, the weed was not serious up to the beginning of the twentieth century. This bulletin reports information obtained during the past 10 years from the experimental work on eradication of European bindweed at Hawarden and Cherokee, Iowa. The recommendations submitted are particularly applicable to Iowa