北方高纬度地区生态系统动态、生物多样性管理及社会政策

由于受到众多因素大规模作用的影响,高纬度地区生态系统的变化异常活跃.这些地区的生态系统非常脆弱,各种全球变化过程都在影响着可更新林木资源持续生产和当地社会赖以生存的动植物资源丰度.本文对于北半球高纬度地区生态系统的一些新认识及其(所包含的)意义进行了讨论,并对提高生态系统的恢复力所采取的必要管理措施进行了探讨.认为在生态系统面临各种变化和干扰时系统管理的焦点应该从系统的恢复转移到系统功能的维系上来.生物多样性的作用是确保生态系统在经历干扰和重组时能够进行重组和发展,这一作用应该在系统管理与相关的方针政策中得到重视.强调应重新考虑现在的生态保护区的概念以发展一些动态的管理方法,使生态系统在面临环境变化时能够进行可持续的管理.而高纬度地区一些土著人习惯性的生态保护区的特点与那些对保护区进行动态保护的观点往往是一致的.针对高纬度地区动态景观中的生物多样性管理我们提出了新的发展方向,并从非传统的观点方面为其提供了经验例证.这些非传统的观点与看法可能会有助于提高生物多样性可持续管理和生态系统功能发挥的潜力.     

Assessment of the maximum possible liquid superheat during flashing leak flow

During the discharge of flashing liquids through leaks due to abrupt depressurization a transient thermodynamic non-equilibrium in the form of a boiling delay in the superheated liquid flow can occur. As a consequence the actual mass flow quality is smaller than calculated under the assumption of an immediate adjustment of the thermodynamic equilibrium between the phases. For the prediction of the leak mass flow for a given pressure difference the magnitude of this self-adjusting mass flow quality is needed.

Most of the models cited in the literature include only the equilibrium mass quality as limiting quantity and ignore further effects as that of the depressurization velocity or the mean nucleus distance. For the assessment of the maximum possible liquid superheat during flashing only the conduction heat transfer from a stagnant liquid to the bubble surface is used to describe the bubble growth.

The sub-model for the bubble growth due to expansion and mass transfer necessary for the global prediction of the transient thermodynamic non-equilibrium in flashing liquids was validated using bubble radii measured by Hooper et al. [Bubble growth and pressure relationship in the flashing of superheated water. Technical publication 6904, Mechanical Engineering Department, University of Toronto, 1969] for the case of a sudden depressurization of initially saturated water. On this basis the calculated time-dependent temperature field, the actual mass quality, the mean liquid temperature and, in comparison to the corresponding values based on the assumption of immediate thermodynamic equilibrium, the maximum possible liquid superheat are predicted.     

UV-C as an efficient means to combat biofilm formation in show caves: evidence from the La Glacière Cave (France) and laboratory experiments

Environmental Science and Pollution Research - Ultra-violet C (UV-C) treatment is commonly used in sterilization processes in industry, laboratories, and hospitals, showing its efficacy against...     

UV-C as a means to combat biofilm proliferation on prehistoric paintings: evidence from laboratory experiments

A laboratory investigation of UV-C effects was conducted over a 62-h period: a much higher dose than in classic UV-C treatment was applied to five pigments and two painting binders used by prehistoric humans. Colorimetric parameters were compared to a control to see if UV-C can change pigment and binder color. Infrared spectroscopy, scanning electron microscopy, inductively coupled plasma and X-ray crystallography were also carried out to confirm colorimetric measurement. In order to understand how microorganism may physically deteriorate paintings, limestone blocks were painted and monitored until their complete colonization by algae, cyanobacteria, fungi and/or mosses. The results show that UV-C has no effect on mineral compounds. Conversely, it is noteworthy that binder color changed under both UV-C light conditions as well as in visible light. Concerning painted blocks, a fast proliferation has been observed with deterioration of the paintings. These results show the high importance of treating biofilm as soon as possible. Moreover, these findings may be a promising avenue inducing cave managers to use friendly UV-C light to treat contaminated cave paintings and also in the prevention of biodeterioration by lampenflora.     

Long-term land-cover/use change in a traditional farming landscape in Romania inferred from pollen data,historical maps and satellite images

Regional Environmental Change - Traditional farming landscapes in the temperate zone that have persisted for millennia can be exceptionally species-rich and are therefore key conservation targets....     

Reduction of Baltic Sea Nutrient Inputs and Allocation of Abatement Costs Within the Baltic Sea Catchment

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion €.