To thermally upgrade exterior masonry walls, interior insulation is often the only possible retrofitting technique, especially when dealing with historic buildings. Unfortunately, it is also the riskiest post-insulation technique, as frost damage, interstitial condensation, and other damage patterns might be induced. To diminish those risks, nowadays so-called capillary active interior insulation systems are often promoted. These systems aim a minimal reduction of the inward drying potential, while interstitial condensation is buffered.
Currently, several capillary active systems are on sale. These different types have, however, widely varying properties. In this article, a closer look at the hygrothermal properties and the working principle of a number of “capillary active” interior insulation systems is made. The spread in capillary absorption coefficients and the vapor diffusion resistances of the different systems is discussed and their influence is illustrated. Based on all this, a more nuanced view on capillary active insulation systems is pursued.
The mounds at Witz Naab and Killer Bee are the only known remaining aboveground evidence of a once-thriving salt industry in Punta Ycacos Lagoon, a large saltwater system in Paynes Creek National Park, Belize. Over one hundred ancient Maya salt works dated to the Classic period (a.d. 300–900) have been submerged by sea-level rise in the lagoon. We have hypothesized that mounds were once numerous features on the landscape prior to a sea-level rise that occurred in the area during the Terminal Classic period. Lacking at these underwater sites are earthen mounds formed by discarded soil from the leaching process in which the salinity of seawater was enriched by leaching brine through salty soil. Enriching the salinity of seawater by leaching or by solar evaporation is virtually universal in ethnographic case studies. Data from the excavations are evaluated to interpret the ancient activities that produced the earthen mounds, scales of production, and how the coastal Maya of southern Belize participated in the larger Classic Maya economy. 相似文献
Invasive vegetation species can lead to major changes in the geomorphology of coastal systems. Within temperate estuaries in the southern hemisphere, especially Australia and New Zealand, the cordgrass Spartina spp. has become established. These species are highly invasive, and their prolific growth leads to the development of supratidal environments in formerly intertidal and subtidal environments. Here, we quantified the impact of Spartina invasion on the geomorphology and sequestration capacity of carbon in the sediments of Anderson Inlet, Victoria, Australia. Spartina was first introduced to the area in the 1930s to aid in land reclamation and control coastal erosion associated with coastal development. We found that Spartina now dominates the intertidal areas of the Inlet and promotes accretion (18 mm/year) causing the formation of over 108 ha of supratidal islands over the past 100 years. These newly formed islands are calculated to potentially contain over 5.5 million tonnes of CO2 equivalent carbon. Future management of the inlet and other Spartina‐dominated environments within Australian presents a dilemma for resource managers; on the one hand, Spartina is highly invasive and can outcompete native tidal marshes, thereby warranting its eradication, but on the other hand it is likely more resilient to rising sea levels and has the potential for carbon sequestration. Whether or not the potential advantages outweigh the significant habitat change that is anticipated, any management strategies will likely require additional research into costs and benefits of all ecosystem services provided by Spartina including in relation to nutrient cycling, shoreline stabilisation, and biodiversity as well as in response to the longevity of carbon found within the sediments. 相似文献
Historians’ interest in the history of human migrations is not limited to recent years. Migrations had already figured as explanatory factors in connection with cultural and historical change in the work of classical and ancient studies scholars of the late nineteenth and early twentieth centuries. In the writings of these scholars, migrations acted as historical landmarks or epochal thresholds and played a key role in the construction of geo-historical areas. This model has been called “migrationism” and cannot be explained simply on the basis of the history of individual disciplines, but must be seen in its complex interaction with scientific and historical contexts. However, “migrationism” does not relate to fixed political and scientific positions or movements. For this reason, it cannot be explained adequately by using a historically or ideologically based approach. Relying on narratological approaches, this article examines migration narratives that historians of this period used to explain the rise and fall of ancient civilizations. Referring to contemporary historiographical representations of the ancient Near East, it distinguishes three main narratives that are still common today: narratives of foundation, narratives of destruction, and narratives of mixtures. In this sense, analyzing older migration narratives helps us to sharpen the critical view on the genealogy of our own views on the history—and present—of human migrations. 相似文献