Ecosystems as climate controllers – biotic feedbacks (a review)

There is good evidence that higher global temperature will promote a rise of green house gas levels, implying a positive feedback which will increase the effect of the anthropogenic emissions on global temperatures. Here we present a review about the results which deal with the possible feedbacks between ecosystems and the climate system. There are a lot of types of feedback which are classified. Some circulation models are compared to each other regarding their role in interactive carbon cycle

The effect of the reproductivity's velocity on the biodiversity of a theoretical ecosystem

Climate change has a great impact on the build and the work of natural ecosystems. Disappearance of some population or growth of the number in some species can be already caused by little change in temperature. A Theoretical Ecosystem Growth Model was investigated in order to examine the effects of various climate patterns on the ecological equilibrium. This paper examines the diversity of a theoretical ecosystem on the grounds of changing in temperature-climate patterns. Simulations were made from the simplest case to the more complex exercise to explain harder questions. Daily temperature values were calculated according to various functions. The effect of existing climate patterns (historical or future daily temperatures) was analysed where temperature values were from various climatic zones. In this paper it is examined what kind of environmental conditions result larger diversity related to the velocity of reproduction

Effects of Temperature–Climate Patterns on the Production of Some Competitive Species on Grounds of Modelling

Climate change has serious effects on the setting up and the operation of natural ecosystems. Small increase in temperature could cause rise in the amount of some species or potential disappearance of others. During our researches, the dispersion of the species and biomass production of a theoretical ecosystem were examined on the effect of the temperature–climate change. The answers of the ecosystems which are given to the climate change could be described by means of global climate modelling and dynamic vegetation models. The examination of the operation of the ecosystems is only possible in huge centres on supercomputers because of the number and the complexity of the calculation. The number of the calculation could be decreased to the level of a PC by considering the temperature and the reproduction during modelling a theoretical ecosystem, and several important theoretical questions could be answered

Comparative Assessment of Climate Change Scenarios Based on Aquatic Food Web Modeling

In the years 2004 and 2005, we collected samples of phytoplankton, zooplankton, and macroinvertebrates in an artificial small pond in Budapest (Hungary). We set up a simulation model predicting the abundances of the cyclopoids, Eudiaptomus zachariasi, and Ischnura pumilio by considering only temperature and the abundance of population of the previous day. Phytoplankton abundance was simulated by considering not only temperature but the abundances of the three mentioned groups. When we ran the model with the data series of internationally accepted climate change scenarios, the different outcomes were discussed. Comparative assessment of the alternative climate change scenarios was also carried out with statistical methods

Laboratory X-ray tomography for metal additive manufacturing: Round robin test

This paper reports on the results of a round robin test conducted by ten X-ray micro computed tomography (micro-CT) laboratories with the same three selected titanium alloy (Ti6Al4V) laser powder bed fusion (L-PBF) test parts. These parts were a 10-mm cube, a 60-mm long and 40-mm high complex-shaped bracket, and a 15-mm diameter rod. Previously developed protocols for micro-CT analysis of these parts were provided to all participants, including suggested scanning parameters and image analysis steps. No further information on the samples were provided, and they were selected from a variety of parts from a previous different type of round robin study where various L-PBF laboratories provided identical parts for micro-CT analysis at one laboratory. In this new micro-CT round robin test which involves various micro-CT laboratories, parts from the previous work were selected such that each part had a different characteristic flaw type, and all laboratories involved in the study analyzed the same set of parts. The 10-mm cube contained subsurface pores just under its top surface (relative to build direction), and all participants could positively identify this. The complex bracket had contour pores around its outer vertical sides, and was warped with two arms deflected towards one another. Both of these features were positively identified by all participants. The 15-mm diameter rod had a layered stop/start flaw, which was also positively identified by all participants. Differences were found among participants for quantitative evaluations, ranging from no quantitative measurement made, to under and overestimation of the values in all analyses attempted. This round robin provides the opportunity to highlight typical causes of errors in micro-CT scanning and image analysis as applied to additively manufactured parts. Some workflow variations, sources of error and ways to increase the reproducibility of such analysis workflows are discussed. The ultimate aim of this work is to advance the efficient use of micro-CT facilities for process optimization and quality inspections for additively manufactured products. The results provide confidence in the use of laboratory micro-CT but also indicate the need for further development of standards, protocols and image analysis workflows for quantitative assessment, especially for direct and quantitative comparisons between different laboratories.status: Published onlin