Search results for "OTU"

Computational modelling of boron nitride nanostructures based on density-functional tight-binding

2014

Boorinitridin (BN) nanorakenteet ovat sekä rakenteellisesti että lujuusominaisuuksiensa puolesta hyvin samankaltaisia vastaavien hiilirakenteiden kanssa. Suurimpana erona on BN:n sähköinen eristävyys kun taas hiilirakenteet ovat johteita tai puolijohteita. BN onkin hyvin lupaava nanomateriaali ja sille on odotettavissa sovelluksia muun muassa muiden nanorakenteiden suojaajana ja komposiittimateriaalien nanokudosaineena. BN:n nanorakenteiden ominaisuuksia tutkitaan laskennallisesti yleensä joko tiheysfunktionaaliteorialla (DFT) tai tiukan sidoksen (TB) malleilla. Ensin mainittu on tarkka mutta laskennallisesti vaativa, kun taas jälkimmäinen on laskennallisesti kevyt mutta epätarkka. Tässä ty…

4,4-Di-fluoro-2,3;5,6-bis-(tetra-methylene)-4-bora-3a,4a-di-aza-s-indacene (LD540).

2014

The title compound, C18H21BF2N2, is a lipophilic dye based on a BODIPY fluorophore backbone, which was developed for microscopic imaging of lipid droplets; the molecule has a planar BODIPY core [dihedral angle between the pyrrole rings = 2.3 (3)°] and two tetramethylene substituents at the 2,3- and 5,6-positions in a half-chair conformation. One of the tetramethylene substituents is disordered over two two sets of sites with site occupancies of 0.5. In the crystal, pairs of C—H...F interactions link the molecules into inversion dimers. Neighbouring dimers are linked by further C—H...F interactions, forming an infinite array. C—H...π and π–π [centroid–centroid distance = 4.360 (3) Å] interac…

Polyelectrolyte properties of filamentous biopolymers and their consequences in biological fluids.

2014

Anionic polyelectrolyte filaments are common in biological cells. DNA, RNA, the cytoskeletal filaments F-actin, microtubules, and intermediate filaments, and polysaccharides such as hyaluronan that form the pericellular matrix all have large net negative charge densities distributed over their surfaces. Several filamentous viruses with diameters and stiffnesses similar to those of cytoskeletal polymers also have similar negative charge densities. Extracellular protein filaments such collagen, fibrin and elastin, in contrast, have notably smaller charge densities and do not behave as highly charged polyelectrolytes in solution. This review summarizes data that demonstrate generic counterion-…

Why is there truth? Foucault in the age of post-truth politics

2019

Contemporary debates about post‐truth politics have raised the question of the complicity of Michel Foucault’s thought in the apparent decline of the authority of truth in Western democracies. In this article we probe this question in the analysis of Foucault’s theory of true discourses developed in his 1980‐1981 lecture course ‘Subjectivity and Truth’. In this course Foucault argues for non‐necessary and supplementary character of truths in relation to the reality of which they speak. This argument leads him to abandon the familiar approaches to truth as reflecting, concealing or rationalizing reality and look for the effects of truth in the processes of subjectivation. We explore the affi…

Solid-State Synthesis of “Bamboo-Like” and Straight Carbon Nanotubes by Thermolysis of Hexa-peri-hexabenzocoronene–Cobalt Complexes

2006

Does risk of predation by mammalian predators affect the spacing behaviour of rodents? Two large-scale experiments.

2000

Predator-prey interactions between small mammals and their avian and mammalian predators have attracted much attention. However, large-scale field experiments examining small-mammal antipredatory responses under the risk of predation by mammals are rare. As recently pointed out, the scale of experiments may cause misleading results in studies of decision-making under predation risk. We studied the effect of small mustelid predators on the spacing behaviour of the gray-tailed vole (Microtus canicaudus) and the bank vole (Clethrionomys glareolus) in two separate field enclosure experiments. The experiments were conducted during the breeding season in North America and northern Europe, where s…

Phenotypic Flexibility in the Social Organization of Clethrionomys

1990

I review the flexibility of social organization and spacing behavior in Clethrionomys. This review is based on a 6-year comparative study and several experimental studies on cyclic populations of the bank vole, C. glareolus, in Central Finland. The social organization of Clethrionomys populations shows great flexibility during both the breeding and nonbreeding season, and is dependent on habitat patchiness, food availability, Predation, kinship, philopatry, and familiarity between individuals. The first three factors are most important in destabilizing a population, whereas the last three stabilize a population without exhausting its resources. Female territoriality can weaken in a producti…

A Comparative Study of Phenotypic Changes in Microtus Social Organization

1990

Monogamy, polygyny, and promiscuity have been found in populations of M. oeconomus and M. agrestis in different environmental situations in northern Finland. Thus the mating systems seem to be more variable both between and within species in Microtus than in Clethrionomys. Spacing behavior in Microtus caused a temporary decline in population density in mid-summer, but in Clethrionomys a decline occurred only in the beginning of the breeding season. Habitat quality affected spacing behavior in similar ways in Microtus and Clethrionomys but did not affect differences in breeding limitation. Despite the differences in population regulation, both Clethrionomys and Microtus populations cycle syn…

Electrostatic Anchoring of Mn4 Single-Molecule Magnets onto Chemically Modified Multiwalled Carbon Nanotubes

2012

Two different routes that enable the electrostatic grafting of cationic single-molecule magnets (SMMs) onto the surface of chemically modified anionic multi-walled carbon nanotubes (MWNTs) are described. The chemical nature and physical properties of the resulting hybrids are discussed on the basis of a complete battery of experimental techniques. The data show that the chemical nature of the SMM unit remains intact, while its magnetic response is significantly affected by the grafting process, which is likely due to surface effects.

A Comprehensive Survey on Cooperative Relaying and Jamming Strategies for Physical Layer Security

2019

Physical layer security (PLS) has been extensively explored as an alternative to conventional cryptographic schemes for securing wireless links. Many studies have shown that the cooperation between the legitimate nodes of a network can significantly enhance their secret communications performance, relative to the noncooperative case. Motivated by the importance of this class of PLS systems, this paper provides a comprehensive survey of the recent works on cooperative relaying and jamming techniques for securing wireless transmissions against eavesdropping nodes, which attempt to intercept the transmissions. First, it provides a in-depth overview of various secure relaying strategies and sch…