Modeling of thermal processes in the contact zones of fuel elements

In this work, using two specific examples, a general approach to the mathematical modeling of thermal processes in the contact zones of fuel elements in the development and optimization of various technological processes, systems and devices is considered. In the first example, a mathematical model of heat transfer in the contact zone (metal-hybrid thermal interface) between the heat-generating element and the heat-dissipating radiator is considered. In the second case, the thermal process in the processing of materials with a bonded diamond tool in the contact zone "diamond grain – binder – processed material" is considered and analyzed. The general approach to modeling thermal processes in the contact zones of various fuel elements makes it possible to optimize the parameters of technological processing modes and the correct operating conditions for products and systems

Revising Postsocialism

This article reflects on the current explanatory value of concepts such as postsocialism and Eastern Europe by exploring how they are represented in contemporary art projects in Estonia. Through an overview of recent exhibitions in which I collaborated with local artists and curators, the research considers generational differences in relation to cultural discourses of the postsocialist experience. Methodologically, artists and curators were not simply my informants in the field, but makers of analytical knowledge themselves in their practice. Exhibitions were also approached as contact zones, whereby new cultural forms are simultaneously reflected and constructed. Critically, this inquiry gathers new ways of representing and conceptualising cultural changes in Estonia and novel perspectives of interpreting the relations to the Soviet past. The focus is put on art practice because of its capacity of bringing together global and local frames of reference simultaneously. The research also draws attention to the inbetweenness of the first post-Soviet generation (those born near the time of the breakup of the USSR); they are revising established cultural forms as well as historical representations through mixing practices, and therefore updating traditional ideas of identity and attachment to places.

Transplanting Coral Fragments in Close Contact Enhances Their Survival and Growth on Seawalls

Accelerated urbanisation has replaced many natural shorelines with coastal defences, resulting in the loss of natural habitats. However, structures such as seawalls can support some biotic assemblages, albeit of lower species richness. Ecological engineering techniques such as coral transplantation can enhance biodiversity on these artificial structures, but its success is circumscribed by high costs. Little is known about the fusion of discrete coral colonies that could potentially improve coral transplantation success on seawalls, particularly for the slow-growing massive species that are generally well-adapted to living on seawalls. Here, we investigated the feasibility and cost-effectiveness of transplanting Platygyra sinensis on seawalls by comparing the survivability and growth of fragments transplanted adjoining with those transplanted further apart. Fragments (approximately 3 cm diameter; n = 24) derived from three individuals were randomly grouped into two treatments, transplanted at 0.5 cm and 5 cm apart. Fragments in the former treatment came into contact with each other after three months. We observed that in all cases, the contact zones were characterised by a border of raised skeletal ridges without tissue necrosis, often termed nonfusion (=histoincompatible fusion). The adjoining transplants showed better survival (75 vs. 43%) and grew at a rate that was significantly higher than fragments transplanted 5 cm apart (3.7 ± 1.6 vs. 0.6 ± 1.1 cm2 month−1). Our projections demonstrated the possibility of reducing transplantation cost (USD cm−2) by 48.3% through nonfusion. These findings present nonfusion as a possible strategy to increase the overall cost-effectiveness of transplanting slow-growing massive species on seawalls.

Lay Expertise, Botanical Science, and Botanic Gardens as “Contact Zones”

Botanic gardens came into existence in the late 1500s to document, study, and preserve plants originating from all over the world. The scientific field of botany was a direct outcome of these developments. From the 1600s onward, botanic gardens also paid key roles in acclimatizing plants across distinct ecosystems and respective climate zones. This often entailed the appropriation of Indigenous systems of plant expertise that were then used without recognition within the parameters of scientific botanical expertise. As such, botanic gardens operated as contact zones of unequal power dynamics between European and Indigenous knowledge systems. Botanic gardens were intimately embroiled with the global expansion of European colonialism and processes of empire building. They helped facilitate the establishment of cash-crop systems around the world, which effectively amounted to the extractive systems of plant wealth accumulation that characterize the modern European colonial enterprise. In the mid-20th century, botanic gardens began to take on leading roles in the conservation of plant biodiversity while also attending to issues of social equity and sustainable development. Relationships between lay expertise and scientific knowledge acquired renewed significance in this context, as did discussions of the knowledge politics that these interactions entailed. As a consequence of these transformations, former colonial exchanges within the botanical garden world between Indigenous knowledge practices and their appropriation by science came under scrutiny in the final decades of the 20th century. Efforts to decolonize botanic gardens and their knowledge practices emerged in the second decade of the 20th century.

On the elasticity of centres and the possibility of multiple roofs: revisiting some of Ulrich Ammon’s views on language variation and pluricentricity

Against the background of a concise overview of Ulrich Ammon’s oeuvre this article first of all provides a constructive-critical account of some of the key concepts and questions that guided his macrosociolinguistic work on pluricentric languages and variation in German. In what follows, an attempt is made to further develop some of Ammon’s thoughts through emphasising the elasticity of the concept of pluricentricity and arguing for a creative use of the concept of “roofing” when describing the intricate interplay of standard and nonstandard varieties especially in language contact zones.

Hidden diversity within the Nemastoma bidentatum Roewer, 1914 complex (Opiliones: Nemastomatidae) Part I: Morphological evidence

Nemastoma bidentatum Roewer, 1914 is a complex of closely related litter-dwelling harvestmen, characterized by a penis glans with two pairs of lateral lancet-like spines, and a femur IV with a saw-like series of pointed tubercles. Here we a) revise the hitherto known taxa within the N. bidentatum complex, and b) analyze in detail the relations among the taxa in Slovenia. The study revealed that the N. bidentatum complex consists of four species: N. bidentatum Roewer, 1914 s. str., N. relictum Gruber & Martens, 1968 stat. nov., N. pluridentatum (Hadži, 1973) stat. nov. and N. kozari Novak, Kozel, Podlesnik & Raspotnig sp. nov. Moreover, N. bidentatum s. str. consists of six subspecies: N. bidentatum bidentatum Roewer, 1914, N. bidentatum sparsum Gruber & Martens, 1968, N. bidentatum gruberi Novak, Slana Novak, Kozel & Raspotnig ssp. nov., N. bidentatum martensi Novak, Slana Novak & Raspotnig ssp. nov., N. bidentatum schmidti Novak, Raspotnig & Slana Novak ssp. nov. and N. bidentatum sneznikensis Novak, Komposch, Slana Novak & Raspotnig ssp. nov. In Slovenia, the six subspecies of N. bidentatum form a parapatric complex around N. bidentatum schmidti. Hybrids occur in the contact zones between adjacent subspecies, but they are missing between distant subspecies. The taxonomic distinction of lineages / subspecies is congruent with their distribution patterns. With six of the nine taxa present, Slovenia is considered the center of the N. bidentatum complex speciation. At the time being, this complex is the most diversified harvestman group on a subspecific and young-species level and provides important details on speciation processes in Opiliones.

The distribution and biogeography of slow worms (Anguis, Squamata) across the Western Palearctic, with an emphasis on secondary contact zones

The slow-worm lizards (Anguis) comprise five species occurring throughout most of the Western Palearctic. Although these species are relatively uniform morphologically – with the exception of A. cephallonica, which exhibits a quite unique morphology – they are genetically deeply divergent. Here, we provide detailed distribution maps for each species and discuss their biogeography and conservation based on updated genetic data and a robust distribution database. We pay particular attention to the so called ‘grey zone’, which typically represents secondary contact zones and in some cases confirmed or presumed hybrid zones. Four of the five species live in parapatry, while only two species, A. cephallonica and A. graeca from the southern Balkans occur in partial sympatry. Further research should focus on the eco-evolutionary interactions between species in contact, including their hybridization rates, to reveal deeper details of the slow-worm evolutionary and natural history.

New Data about the Distribution of Three Phylogenetic Lineages of Arctic Charr Salvelinus alpinus (Salmonidae) in their Contact Zones in the North of East Siberia

In order to study the distribution of phylogenetic mtDNA lineages of Arctic charr Salvelinus alpinus in their contact zones in the north of East Siberia we analyzed nucleotide sequences of mtDNA control region of charr from 10 Arctic populations in the area from the Yenisei to the Lena. At the Putorana plateau, haplotypes of Atlantic and Siberian subgroups of Eurasian group were recorded, in the Khatanga River basin, haplotypes of Atlantic subgroup, in the Lena River delta, haplotypes of Siberian subgroup and of Bering group were observed. Some Siberian haplotypes found at the Putorana and in the Lena delta, have been earlier registered in other regions of East Siberia. New findings, along with published materials allow to specify the ranges of these three phylogenetic lineages and the margins of their contact zones; they also evidence wide sympatry of Atlantic and Siberian haplotypes in Taimyr water bodies and support close relationship of charr of Siberian subgroup from all main areas of their distribution.