Cross sections of proton-induced reactions on 152Gd, 155Gd and 159Tb with emphasis on the production of selected Tb radionuclides

Cross sections are presented for various Dy, Tb and Gd radionuclides produced in the proton bombardment of 159Tb as well as for the reactions 152Gd(p,4n)149Tb and 155Gd(p,4n)152Tb up to 66 MeV. The experimental excitation functions are compared with theoretical predictions by means of the geometrydependent hybrid (GDH) model as implemented in the code ALICE/ASH, as well as with values from the TENDL-2012 library and previous literature experimental data, where available. Physical yields have been derived for the production of some of the medically important radioterbiums, namely 149Tb (radionuclide therapy), 152Tb (PET) and 155Tb (SPECT). The indirect production of high-purity 155Tb via the decay of its precursor 155Dy is reported. The possibility of a large-scale production facility based on a commercial 70 MeV cyclotron is also discussed

Contracting arrangements in agribusiness procurement practices in South Africa

Contracting arrangements in agribusiness procurement practices in South AfricaProcurement, contracting, agro-processing,

Opening the black box of intra-household decision-making: Theory and non-parametric empirical tests of general collective consumption models.

We non-parametrically test a general collective consumption model with public consumption and externalities inside the household. We further propose a novel approach to model special cases of the general collective model. These special cases include alternative restrictions on the `sharing rule' that applies to each household, and which defines the distribution of the household budget over the household members. A limiting case is the unitary model. Our application uses data from the Russia Longitudinal Monitoring Survey (RLMS); the panel structure of this data set allows non-parametric testing of the behavioral models without relying on preference homogeneity assumptions across similar individuals. This application includes test results but also a power analysis for different specifications of the collective consumption model. Our main findings are that the most general collective model, together with a large class of special but still fairly general cases, cannot be rejected by the data, while other, restricted, versions of the general model, including the unitary alternative, are rejected. Since these tests are entirely non-parametric, this provides strong evidence in favor of models focusing on intra-household decision-making.Consumption; Decision making; Model; Models; Tests; Theory;

Scanning and visualization of Roman Adriatic townscapes

Since 2000 a team from Ghent University has achieved intensive non-invasive intra-site prospections on four abandoned Roman towns in central Adriatic Italy (Marche Region): the coastal colony of Potentia and the inland municipia of Ricina, Trea and Septempeda. These urban surveys include total coverage geophysical prospections (such as GPR, geomagnetic and earth resistance approaches), low altitude aerial photography (including NIR photography with drone and helikite), geomorphological augerings, surface artifact collection, and micro-topographical field measurements. A GIS-based integration of all survey data, maps and re-studied legacy data has procured a formidable database for the computer-aided digital 3D mapping and interpretation of these complex ancient sites. The methodological acquisitions and archaeological results not only contribute to the understanding of Roman urbanization in this part of Italy, but also support and innovate the use of integrated approaches to geospatial mapping and analysis of ancient urban environments. Based on earlier experiences with 3D visualizations of the abandoned Roman town of Ammaia in Lusitania, as part of the EC funded Project ‘Radiography of the Past’ (http://www2.radiopast.eu/), the project in Adriatic Italy moves now towards presenting the new data in digital formats that allow specialists from archaeology and cultural heritage management, as well as the wider public to immerse into the visual world of Roman Late Republican and Imperial townscapes of a whole valley and its coastal environment

Chain-wide learning for inclusive agrifood market development : a guide to multi-stakeholder processes for linking small-scale producers to modern markets

This guide provides a set of concepts and analytical tools for finding ways to better link small-scale producers to the modern markets associated with today’s largescale supermarket retail and wholesale operations. It is has been developed through iterative testing with partners in several organisations and countries. The guide is a product of the Regoverning Markets Programme, a multi-agency programme to generate strategic information and anticipatory policy advice on small-scale producers in these fast changing markets

Geometry and the onset of rigidity in a disordered network

Disordered spring networks that are undercoordinated may abruptly rigidify when sufficient strain is applied. Since the deformation in response to applied strain does not change the generic quantifiers of network architecture - the number of nodes and the number of bonds between them - this rigidity transition must have a geometric origin. Naive, degree-of-freedom based mechanical analyses such as the Maxwell-Calladine count or the pebble game algorithm overlook such geometric rigidity transitions and offer no means of predicting or characterizing them. We apply tools that were developed for the topological analysis of zero modes and states of self-stress on regular lattices to two-dimensional random spring networks, and demonstrate that the onset of rigidity, at a finite simple shear strain $\gamma^\star$, coincides with the appearance of a single state of self stress, accompanied by a single floppy mode. The process conserves the topologically invariant difference between the number of zero modes and the number of states of self stress, but imparts a finite shear modulus to the spring network. Beyond the critical shear, we confirm previously reported critical scaling of the modulus. In the sub-critical regime, a singular value decomposition of the network's compatibility matrix foreshadows the onset of rigidity by way of a continuously vanishing singular value corresponding to nascent state of self stress.Comment: 6 pages, 6 figue