The unrestricted Skyrme-tensor time-dependent Hartree-Fock and its application to the nuclear response from spherical to triaxial nuclei

The nuclear time-dependent Hartree-Fock model formulated in the three-dimensional space,based on the full Skyrme energy density functional and complemented with the tensor force,is presented for the first time. Full self-consistency is achieved by the model. The application to the isovector giant dipole resonance is discussed in the linear limit, ranging from spherical nuclei (16O, 120Sn) to systems displaying axial or triaxial deformation (24Mg, 28Si, 178Os, 190W, 238U). Particular attention is paid to the spin-dependent terms from the central sector of the functional, recently included together with the tensor. They turn out to be capable of producing a qualitative change on the strength distribution in this channel. The effect on the deformation properties is also discussed. The quantitative effects on the linear response are small and, overall, the giant dipole energy remains unaffected. Calculations are compared to predictions from the (quasi)-particle random phase approximation and experimental data where available, finding good agreement

Are data collected to support farm management suitable for monitoring soil indicators at the national scale?

Monitoring of topsoil properties (referred to as indicators) at the national scale has been limited in general to government-funded representative surveys. We consider a cost-effective complementary source of soil information for monitoring agricultural soil across England and Wales (E&W): soil measurements paid for by farmers that we refer to as farmers' data (FD). A potential problem in using FD for soil monitoring is any unattributable sources of bias, such as the sample design. Farmers may choose to focus their measurements (purposively) where they perceive a particular problem. Such a source of bias is avoided in the random sampling adopted by statistically designed surveys, such as the Countryside Survey (CS2007) and LUCAS (Land Use/Cover Area frame statistical Survey). We used measurements from 143 000 FD soil samples from a single laboratory to estimate national mean values and confidence intervals of five topsoil indicators (pH, available P (Olsen), K, Mg and organic matter (OM)) across three combinations of nation (England or Wales) and land use (arable and horticulture (A&H) or improved grassland (IG)). We computed mean estimates for FD over two time periods (2004–9 and 2010–2105) and assessed the significance of any change. We compared these estimates with those from representative national surveys to establish whether there was evidence for bias and whether it could be explained. Mean estimates of topsoil pH for the FD and the LUCAS survey (same analytical method) were consistent for both A&H and IG. Although FD estimates of mean Olsen P (OP) concentrations were similar to previous surveys, we show it is likely that the larger mean OP concentrations observed in the LUCAS survey compared with FD for arable topsoil in England are partly due to an attributable source of analytical bias. For such quantifiable sources of bias, it might be possible to adjust estimated mean values from FD. However, FD might also include sources of unattributable bias, such as the effect of purposive sampling. It is important that contemporaneous data from surveys with statistically unbiased designs are available so that we can assess whether unattributable sources exert a significant effect over estimates of mean values computed from FD. Highlights Assessment of farmers' data (FD) to provide a potentially cost-effective way to monitor topsoil indicators. Few studies have compared national-scale estimates of topsoil indicators with survey data from statistically unbiased designs and FD. Bias between mean estimates from national surveys and FD could be accounted for. The denser sampling of FD enables mapping of national survey data with greater accuracy

The production of artificial farm manures

These experiments on the production of artificial farm manure show that a good grade of well-decomposed manure may be made by composting straw or corn stalks with certain chemicals, provided a sufficient supply of water is added to keep the compost heap moist. The addition of a proper amount of water is essential for the best decomposition of the materials and for the production of the best grade of manure. Decomposition was found to proceed somewhat faster in the laboratory than in the open, probably because of the more even temperature. The addition of small amounts of soluble nitrogen hastened the decomposition process in the open and also under controlled conditions in the laboratory or greenhouse, but was more effective when applied to composts in the open. The results obtained in the greenhouse indicate that too much aeration may be very undesirable in the making of artificial manures, decreasing the decomposition processes and causing a considerable loss in nitrogen. A certain degree of aeration, however, is very beneficial in the decomposition of various composts. A proper relationship between the amount of water and the aeration must be established and maintained to secure the best results. Inoculation of composts with fresh manure, soil, or cultures of molds may speed up the decomposition process. The results of the experiments carried out along this line, however, as reported here, indicate that with an even temperature, optimum moisture conditions and the best aeration, decomposition of composts prepared with various chemical reagents will proceed quite rapidly, and good artificial farm manures may be produced without any inoculation. It seems very desirable that some reagent supplying soluble nitrogen be employed in preparing composts from straw, corn stalks or other similar materials, in order to hasten the decomposition processes, and permit of the earlier production of a well-decomposed manure. Such a reagent will also increase the fertilizing value of the manure produced because of the nitrogen added. Artificial farm manure may be produced by composting straw and such materials without the addition of any reagents, but the process proceeds much slower and the manure formed is of less value when applied to the soil. These experiments show that a satisfactory artificial farm manure cannot be produced under average Iowa conditions without the addition of water. The average rainfall in Iowa will not provide sufficient moisture for optimum decomposition in the composts, nor for the production of a good grade of manure. For the production of artificial farm manures from oats straw, the addition of 800 to 1,000 gallons of water per ton of straw is probably the best, giving most nearly optimum conditions of moisture, air and temperature in the compost. The method suggested in Missouri for composting by the use of a mechanical mixer attached to the thresher proved satisfactory, saving much time and labor in the preparation of the composts. The method involves little expense and is easily followed. When artificial farm manures are to be made on a large scale, it would certainly be desirable to follow the Missouri method. The tests with various chemicals indicate that any of the reagents used may be employed to advantage in preparing artificial manures. The maintenance of proper moisture and air conditions in the composts is apparently more important than minor variations in the reagents used, provided, of course, that they contain a satisfactory source of soluble nitrogen. In general the experiments which have been carried out in the open indicate that the production of artificial farm manure from straw or corn stalks is feasible on Iowa farms, provided the farmer is willing to spend the necessary amount of time and effort in preparing the composts. The expense involved need not be large, but, obviously, it will vary considerably according to the particular farm conditions and the equipment available. The cost of production must be kept at a minimum or the manure produced will not give profitable results. The practice of making artificial farm manure cannot be recommended for general farm use, but where conditions are favorable and the facilities are available at little cost, artificial farm manure may be produced which will be equal in value to farm manure and will serve to supplement the inadequate supply of that important fertilizing material

Soil Survey of Iowa, Report No. 1—Bremer County Soils

What soils need to make them highly productive and to keep them so, and how their needs may be supplied are problems which are met constantly on the farm to-day. To enable every Iowa farmer to solve these problems for his local conditions, a complete survey and study of the soils of the state has been undertaken, the results of which will be published in a series of county reports

Media outlets and their moguls: why concentrated individual or family ownership is bad for editorial independence

This article investigates the levels of owner influence in 211 different print and broadcast outlets in 32 different European media markets. Drawing on the literature from industrial organisation, it sets out reasons why we should expect greater levels of influence where ownership of individual outlets is concentrated; where it is concentrated in the hands of individuals or families; and where ownership groups own multiple outlets in the same media market. Conversely, we should expect lower levels of influence where ownership is dispersed between transnational companies. The articles uses original data on the ownership structures of these outlets, and combines it with reliable expert judgments as to the level of owner influence in each of the outlets. These hypotheses are tested and confirmed in a multilevel regression model of owner influence. The findings are relevant for policy on ownership limits in the media, and for the debate over transnational versus local control of media

An Upper Bound on the Higgs Boson Mass from a Positivity Condition on the Mass Matrix

We impose the condition that the eigenvalues of the mass matrix in the shifted Lagrangian density be positive at \phi=\phi_{0}, the vacuum expectation value of the scalar field. Using the one-loop effective potential of the standard model, this condition leads to an upper bound on the Higgs boson mass m_{H}: m_{H}<230GeV, for a top quark mass of 175GeV.Comment: LaTex, 5 page

Dependence of Variational Perturbation Expansions on Strong-Coupling Behavior. Inapplicability of delta-Expansion to Field Theory

We show that in applications of variational theory to quantum field theory it is essential to account for the correct Wegner exponent omega governing the approach to the strong-coupling, or scaling limit. Otherwise the procedure either does not converge at all or to the wrong limit. This invalidates all papers applying the so-called delta-expansion to quantum field theory.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper (including all PS fonts) at http://www.physik.fu-berlin.de/~kleinert/34