A method to include machine manufacturing energy in energy balance analysis

Manufacturing and also maintenance and repair energy demand is hard to find, there are only few research data available and this data seems no to be very reliable. Manufacturing energy damand can be calculated by estimating the mean tractor usage and calculating the manufacturing energy per consumed fuel liter. In this way it is easy to estimate the manufacturing energy, because it can be calculated with the liter/ha figures. Fuel consumption for different works in the form of liter/ha can easily be found in literature

Mapping the three-body system - decay time and reversibility

In this paper we carry out a quantitative analysis of the three-body systems and map them as a function of decaying time and intial conguration, look at this problem as an example of a simple deterministic system, and ask to what extent the orbits are really predictable. We have investigated the behavior of about 200 000 general Newtonian three body systems using the simplest initial conditions. Within our resolution these cover all the possible states where the objects are initially at rest and have no angular momentum. We have determined the decay time-scales of the triple systems and show that the distribution of this parameter is fractal in appearance. Some areas that appear stable on large scales exhibit very narrow strips of instability and the overall pattern, dominated by resonances, reminds us of a traditional Maasai warrior shield. Also an attempt is made to recover the original starting conguration of the three bodies by backward integration. We find there are instances where the evolution to the future and to the past lead to different orbits, in spite of time symmetric initial conditions. This implies that even in simple deterministic systems there exists an Arrow of Time.Comment: 8 pages, 9 figures. Accepted for publication in MNRAS. Includes low-resolution figures. High-resolution figures are available as PNG

Collisional dynamics around binary black holes in galactic centers

We follow the sinking of two massive black holes in a spherical stellar system where the black holes become bound under the influence of dynamical friction. Once bound, the binary hardens by three-body encounters with surrounding stars. We find that the binary wanders inside the core, providing an enhanced supply of reaction partners for the hardening. The binary evolves into a highly eccentric orbit leading to coalescence well beyond a Hubble time. These are the first results from a hybrid ``self consistent field'' (SCF) and direct Aarseth N-body integrator (NBODY6), which combines the advantages of the direct force calculation with the efficiency of the field method. The code is designed for use on parallel architectures and is therefore applicable to collisional N-body integrations with extraordinarily large particle numbers (> 10^5). This creates the possibility of simulating the dynamics of both globular clusters with realistic collisional relaxation and stellar systems surrounding supermassive black holes in galactic nuclei.Comment: 38 pages, 13 figures, submitted to ApJ, accepted, revised text and added figure

Long-Term Evolution of Massive Black Hole Binaries. II. Binary Evolution in Low-Density Galaxies

We use direct-summation N-body integrations to follow the evolution of binary black holes at the centers of galaxy models with large, constant-density cores. Particle numbers as large as 400K are considered. The results are compared with the predictions of loss-cone theory, under the assumption that the supply of stars to the binary is limited by the rate at which they can be scattered into the binary's influence sphere by gravitational encounters. The agreement between theory and simulation is quite good; in particular, we are able to quantitatively explain the observed dependence of binary hardening rate on N. We do not verify the recent claim of Chatterjee, Hernquist & Loeb (2003) that the hardening rate of the binary stabilizes when N exceeds a particular value, or that Brownian wandering of the binary has a significant effect on its evolution. When scaled to real galaxies, our results suggest that massive black hole binaries in gas-poor nuclei would be unlikely to reach gravitational-wave coalescence in a Hubble time.Comment: 13 pages, 8 figure

Baltic Ecological Recycling Agriculture and Society (BERAS project) - a case of Juva milk system

The aim of the study was to determine the potential, impact and prerequisites of localization and enhanced recycling in a rural food system, illustrated by the case of Juva milk. An interdisciplinary scenario based on the increase of local, organic milk to 50 % of milk comsumption was created and the sustainability was compared, on the basis of the statistics and data collected from the actors, with the present milk system

Unleashing Potato’s Potential in Sudan. A Scoping Mission Report

CIP, in partnership with Orgamed Farms Ltd and Stokman Rozen Kenya conducted a scoping exercise to assess private interest in seed production, and the potato sector and partners in general. This scoping report maps partners relevant to potato development and provides an agro-ecological and socio-economic assessment of potential areas for developing potato sector considering differing profiles of value chains: rural, food security focused, urban, commercially driven. The scoping exercise shows great potential to uplift the potato sector to transform the various value chains, and ultimately contribute to development goals to improve livelihoods of Sudanese. Limited access to costly seed is the principal bottle to potato sector development, with the majority of certified seed being imported and sold at 1.37 to 1.87 USD/kg, whereas commercial seed in East African countries ranges from 0.5 to 0.6 USD/kg. As a result, market prices for potato for consumption are high, having been observed as much as 2.20 USD/kg in rural markets, prohibitive for rural households to afford as a food security crop. High production costs affecting supply prevent potato from reaching its potential to provide income and economic development from household to regional levels, and contribute to food security at the national level. At the same time, urbanization, change of dietary habits and removal of wheat import subsidizes continue to drive demand of potato in Sudan. The scoping report will advise pathways to support potato to reach its potential through creating opportunities for diverse partners, including national and regional institutions, private sector, national NGOs, farmer organizations and microfinance institutions