Preferential flow paths in the crust, as caused by the presence of the Luchlompolo fault in the drilled section of the Kola Superdeep Borehole (SG-3) and the dip angle of the rock structural elements (layering, schistosity, banding), are favourable for migration of deep fluids to the Earth’s surface. An investigation of the structure, anisotropy and permeability of rocks under PT-conditions in the SG-3 section, in addition to the occurrence of He-isotopes, reveals that the high-permeability zones of the exposed crustal segment are related to two important structural elements of the section: in the upper zone - to the Luchlompolo fault, in the lower one to the contact between the Proterozoic and Archaean complexes. The obtained results on the rock samples from SG-3 indicate a rough correlation between permeability and elastic anisotropy of various rock samples. Simulating increased PT-conditions, corresponding to the relevant depths of 6-8 km document the overlapping temperature and pressure effect, i.e. resulting in a sharp decrease of rock permeability., Felix F. Gorbatsevich, Serafim V. Ikorsky and Andrey V. Zharikov., and Obsahuje bibliografii
Let $\mathbb {Z}_n{\rm [i]}$ be the ring of Gaussian integers modulo $n$. We construct for $\mathbb {Z}_n{\rm [i]}$ a cubic mapping graph $\Gamma (n)$ whose vertex set is all the elements of\/ $\mathbb {Z}_n{\rm [i]}$ and for which there is a directed edge from $a \in \mathbb {Z}_n{\rm [i]}$ to $b \in \mathbb {Z}_n{\rm [i]}$ if $ b = a^3$. This article investigates in detail the structure of $\Gamma (n)$. We give suffcient and necessary conditions for the existence of cycles with length $t$. The number of $t$-cycles in $\Gamma _1(n)$ is obtained and we also examine when a vertex lies on a $t$-cycle of $\Gamma _2(n)$, where $\Gamma _1(n)$ is induced by all the units of $\mathbb {Z}_n{\rm [i]}$ while $\Gamma _2(n)$ is induced by all the zero-divisors of $\mathbb {Z}_n{\rm [i]}$. In addition, formulas on the heights of components and vertices in $\Gamma (n)$ are presented.
This paper discusses the comparison of the flow field downstream of two different swirl generators. Both swirl generators are used to imitate the flow at the exit of the hydraulic turbine runner and study spatio-temporal behaviour of the swirling flow in the draft tube (i.e. outlet diffuser part of the hydraulic turbine), which undergoes breakdown into vortex rope. Unsteady CFD computations are carried out for identical Reynolds number. Resulting velocity and vorticity profiles are correlated with the structure of the vortex rope. Difference in excited pressure pulsations is illustrated on amplitude-frequency spectra of static wall pressure. and Obsahuje seznam literatury
This paper recalls some properties of a cyclic semigroup and examines cyclic subsemigroups in a finite ordered semigroup. We prove that a partially ordered cyclic semigroup has a spiral structure which leads to a separation of three classes of such semigroups. The cardinality of the order relation is also estimated. Some results concern semigroups with a lattice order.
Scanning electron microscopy of the cystidicolid nematode Ascarophis mexicana Moravec, Salgado-Maldonado et Vivas-Rodríguez, 1995 enabled the first detailed study of its cephalic structure. In contrast to most Ascarophis species, its pseudolabia are highly reduced and sublabia are unlobed and weakly developed. Similascarophis is considered a synonym of Ascarophis, to which two its species are transferred as A. maulensis (Muñoz, González et George-Nascimento, 2004) comb. n. and A. chilensis (Muñoz, González et George-Nascimento, 2004) comb. n.
Scanning electron microscopy (SEM) examination of a paratype specimen (gravid female) of the philometrid nematode Paraphilometroides nemipteri Moravec et Shaharom-Harrison, 1989, the type species of Paraphilometroides Moravec et Shaharom-Harrison, 1989, made it possible to recognise the true structure of the cephalic end and the shape of cuticular ornamentations on the body. In contrast to other philometrid genera, the cephalic end is angular in lateral view and rounded in dorsoventral view; large external cephalic papillae are fused together to form a marked dorsal and a ventral ala, each bent into a curve; six minute internal papillae, including a pair of previously not reported lateral papillae, were found; amphids were indistinct. Cuticular ornamentations (inflations) were found to be transversely elongated. These features, especially the unique cephalic structure, clearly distinguish Paraphilometroides from other philometrids and confirm the validity of this genus.
In this paper, we determine all the normal forms of Hermitian matrices over finite group rings $R=F_{q^2}G$, where $q=p^{\alpha }$, $G$ is a commutative $p$-group with order $p^{\beta }$. Furthermore, using the normal forms of Hermitian matrices, we study the structure of unitary group over $R$ through investigating its BN-pair and order. As an application, we construct a Cartesian authentication code and compute its size parameters.
Biological membrane mimetics, such as liposomes, lipid bilayers and model membranes, are used in a broad range of scientific and technological applications due to the unique physical properties of these amphiphilic aggregates. They serve as platforms for studying soft matter physics of membranes and membrane dynamics, interactions of bilayers with drugs, and effects of various additives of environmental changes. State-of-the-art research takes advantage of the combination of the brilliance of X-ray scattering sources with peculiar properties of neutrons and the power of computer simulations. The advances in chemistry, and in particular the possibility of deuteration, enables improved experimental spatial resolution and the ability to pi-point labels within membranes. It is only a matter of time for many biological functions, which occur at the membrane interface, to be matched with the structural properties of these membranes., Článok referuje o zákonitostiach stavby lipidových membrán a ich interakciách s biologicky aktívnymi molekulami. Vplyv iónov nachádzajúcich sa v prirodzenom prostredí bunkovej membrány, anestetický efekt alkánov a účinok cholesterolu a melatonínu pri zabudovaní do membrány je diskutovaný najmä z pohľadu zmeny štruktúry lipidovej matrice membrány. Štruktúrne výsledky sú získané pomocou experimentálnych prístupov, pričom dôraz sa kladie na pokrok dosiahnutý v metódach využívajúcich moderné zdroje röntgenového žiarenia a neutrónov., Norbert Kučerka., and Obsahuje bibliografii