An Evolutionary Analysis of World Energy Consumption and World Population

The evolution of large-scale systems is described by a model based on the assumption of hyperbolic growth and saturation processes. It is shown that this Hyper-Logistic Evolution Model (HLEM) successfully describes the development of world population and global primary energy consumption over the past century; the model is also used to provide projections of world population and primary energy consumption up to the year 2100

Qualitative Analysis of Nonlinear Systems by the Lotka-Volterra Approach

In this paper, the authors summarize recent results obtained by applying the Lotka-Volterra approach to problems in nonlinear systems analysis. This approach was developed at the Mathematics and Cybernetics Division of the GDR Academy of Sciences (Berlin); various applications have been investigated in collaboration with the System and Decision Sciences Program at IIASA. This paper should also be seen as a contribution to the debate on future directions of research at IIASA, in particular possible research into the evolution of macrosystems

Contribution of Round Potato Production to Household Income in Mbeya and Makete Districts, Tanzania

In Tanzania, agriculture remains the largest sector of the economy, and hence its performance has substantial impacts on income and poverty.  Round potatoes are grown in all continents under various climatic conditions. Smallholder farmers in Mbeya Rural and Makete Districts in Tanzania recognise the potential of round potatoes as a crop contributing significantly to household income and food security. The purpose of this study was to determine the contribution of potato production to household income in Mbeya and Makete Districts in the southern highlands of Tanzania. The specific objectives of the research were to: (1) analyse round potato production and other crops grown in the study area, (2) assess household income from round potato and from other sources in the study area and (3) determine the impact of round potato production on household income. A cross-sectional research involving 233 potato farmers was conducted in March 2012 through structured interviews using a questionnaire, focus group discussions and key informant interviews. The dependent variable, household income, was regressed on eight independent variables to find the impact of each of them on the dependent variable. The results showed that there was high positive significant impact of income from round potato per adjusted adult equivalent unit (AAEU) on household income (p < 0.001). It is concluded that round potatoes are more profitable than other major crops grown in the study area. Moreover, if given due attention and care, round potatoes can contribute greatly to household income. It is recommended that the government should support farmers in terms of availability of inputs, training on improved agricultural technologies and support for research on round potatoes so that they can help increase household income. Keywords: Round potato, household income, Southern Highlands, Tanzani

Impact of Round Potato Production on Household Food Security in the Southern Highlands of Tanzania

Smallholder farmers in Mbeya Rural and Makete Districts recognise food insecurity as a problem affecting them. They also recognise the potential of round potato as a crop contributing to household food security. However, the extent to which the crop contributes to food security had not been quantified. The purpose of this study was to determine the contribution of potato production to household food security in Mbeya and Makete Districts in the Southern Highlands of Tanzania. The specific objectives of the paper are to: (1) analyse round potato production and other crops grown in the study area, (2) assess food security in terms of dietary energy consumed (DEC) and (3) determine the impact of round potato production on food security. Multistage sampling was used to select 233 potato farmers. The research was a cross-sectional one and was conducted mainly through structured interviews using a questionnaire, which was supplemented with focus group discussions and key informant interviews. The dependent variable, food security in terms of dietary energy consumed per adult equivalent per day, was regressed on seven independent variables to find the impact of each of them on the dependent variable. The variables were household size, age of household head, DEC from potato, income from potato, income from other crops, years of schooling of household head and income from non-agricultural activities. The results showed that there were positive significant impacts of DEC from potato, household size and income from non-agricultural activities on food security. It is recommended that the government should support farmers in terms of availability of inputs, training on improved technologies and support research on round potato. Keywords: Round potato, Food security, Southern Highlands, Tanzani

Dynamic Problems of Evolution

Evolution and growth of natural and man-made processes have impressed human beings from the very beginning. What is evolution? Is it the passage from an initial to a higher stage? What does "higher" mean in a world of many objectives? Is "higher" bound to the existence of monotonous indicators like entropy, or is it "gambling" within a predetermined combinatoric multifold of possibilities? Questions of this kind arise from the phenomena in our environment, from the spring-off of new species, but also from processes in our man-made technological world. How is the transition of basic innovation to technology and use of the corresponding products by society, what forecast can be made from increasing CO2, in the atmosphere on the impact on climate, from features of seismologic waves on future events etc. That means there is a strong connection between evolution processes and the emphasis of systems analysis as a help for strategic actions. This paper deals with general considerations about possible growth mechanisms as a base for creating valid growth models. But the main goal is to show how the parameters in growth models can be estimated using on one hand a fuzzy approach together with vector optimization and on the other hand a Bayesian approach. It can be seen that both approaches are useful and applicable and we get informations from one approach which the other one cannot give us. We studied already the growth of cracks in materials, processes well described in [10]. Preliminary results are contained in [13]. Research will be continued to identify the superposition of driving forces and of coupled systems in which oscillations can arise because of time delays between their driving-force pulses

Propagating modes of non-Abelian tensor gauge field of second rank

In the recently proposed extension of the YM theory, non-Abelian tensor gauge field of the second rank is represented by a general tensor whose symmetric part describes the propagation of charged gauge boson of helicity two and its antisymmetric part - the helicity zero charged gauge boson. On the non-interacting level these polarizations are similar to the polarizations of the graviton and of the Abelian antisymmetric B field, but the interaction of these gauge bosons carrying non-commutative internal charges cannot be directly identified with the interaction of gravitons or B field. Our intention here is to illustrate this result from different perspectives which would include Bianchi identity for the corresponding field strength tensor and the analysis of the second-order partial differential equation which describes in this theory the propagation of non-Abelian tensor gauge field of the second rank.Comment: 22 pages, Latex fil

Large Anomalous Hall and Nernst Effects in High Curie-Temperature Iron-Based Heusler Compounds

Abstract The interplay between topology and magnetism has recently sparked the frontier studies of magnetic topological materials that exhibit intriguing anomalous Hall and Nernst effects owning to the large intrinsic Berry curvature (BC). To better understand the anomalous quantum transport properties of these materials and their implications for future applications such as electronic and thermoelectric devices, it is crucial to discover more novel material platforms for performing anomalous transverse transport studies. Here, it is experimentally demonstrated that low-cost Fe-based Heusler compounds exhibit large anomalous Hall and Nernst effects. An anomalous Hall conductivity of 250?750 S cm?1 and Nernst thermopower of above 2 µV K?1 are observed near room temperature. The positive effect of anti-site disorder on the anomalous Hall transport is revealed. Considering the very high Curie temperature (nearly 1000 K), larger Nernst thermopowers at high temperatures are expected owing to the existing magnetic order and the intrinsic BC. This work provides a background for developing low-cost Fe-based Heusler compounds as a new material platform for anomalous transport studies and applications, in particular, near and above room temperature