Diferencijalna metoda ocijenivanja karakteristika tla prema rezultatima ispitivanja pilota

Piles testing for determination of their bearing capacity performs by applying a load with measurement of the value of settlement on its head. By standard pile test, it is impossible to determine the value of shear resistance along the shaft of a pile and a compression below its toe. The new test procedure allows to determine the values of these characteristics. Tests were performed using equipment for standard pile tests. The essence of the developed method is to use the elastic properties of the soil and pile material to estimate characteristics of soil resistance. For this purpose, instead of the stepwise-increasing method was applied cyclically increasing load. Each stage represents an independent cycle, consisting of the load application, holding it up to the stabilization of strains and unloading stage.Ispitivanja nosivosti pilota provodi se tako da se na glavu pilota aplicira opterećenje te se tijekom tog opterećenja mjeri slijeganje njegove glave. Prema rezultatima standardnih ispitivanja nije moguće odrediti vrijednost smicanja uzduž podzemnog djela oplošja pilota a niti kompresiju ispod vrha. Nova, predložena u ovom radu, metoda ispitivanja omogućuje određivanje tih traženih karakteristika. Ispitivanja se provode uz pomoć standardne opreme koja se koristi za ispitivanje pilota. Suština razrađene metode je u korištenju elastičnih svojstava tla i materijala pilota za određivanje parametara čvrstoće tla. Sukladno tome, umjesto stupnjevito rastućeg opterećenja primjenjuje se ciklički rastuće opterećenje. Svaki stupanj je zapravo samostalni ciklus koji se sastoji od nanošenja opterećenja, njegovog zadržavanja do trenutka stabilizacije slijeganja te rasterećenja

Productivity and resistance to stress factors of winter wheat varieties bred by ARC “Donskoy”

The purpose of the research is to evaluate modern varieties of winter soft wheat bred by the Federal State Budgetary Scientific Institution Agrarian Research Center “Donskoy” (ARC “Donskoy”) in terms of yield, elements of its structure and resistance to bio and abiotic stress factors. On average, over the years of the study (2019–2021), the yield of winter soft wheat varieties bred by the Federal State Budgetary Scientific Institution ARC “Donskoy” for the predecessor maize for grain changed from 6.33 t/ha for the Don 107 standard to 7.23 t/ha for the new varieties Flagman. Reliable yield increases in all years of the study were formed by the following varieties: Volny Don (+0.61 t/ha; +0.70 t/ha; +0.39 t/ha), Region 161 (+0.67 t/ha; +0.41 t/ha; +0.41 t/ha) and Flagman (+0.57 t/ha, +0.99 t/ha; +1.14 t/ha). An analysis of the correlation relationships between the yield of winter soft wheat varieties with elements of its structure showed that productivity in the conditions of 2019–2021 the following indicators had the maximum influence: productive bushiness (r=0.27±0.15), weight of 1000 grains (r=0.32±0.14) and density of productive stems (r=0.45±0.10). High frost resistance was noted in such varieties as Zhavoronok (74.4%), Region 161 (84.2%) and Aksai (70.5%). According to the results of the correlation analysis of yield with resistance to bio and abiotic environmental factors, no significant relationships were found. This indicates the possibility of combining high productivity and resistance to the studied stress factors in one genotype

Iskustvo projektiranja i izgradnje stambene zgrade u stješnjenim gradskim uvjetima

In the article the experience of mastering a difficult geological and relief related site area is presented. The drop markers led to the necessity of constructing a semi-underground three-level parking. The protection of foundation pit from existent building and transport communications is accepted as a sheet pile wall from double-row borings piles, incorporated by grillage. Sheet pile wall is integrated into the structural scheme of the building. The appropriate calculations of the basic parameters and the overall stability of building are executed. Routine tests of borings piles wall and prismatic piles of main pile field have confirmed the validity and effectiveness of the design decision.U članku je predstavljeno iskustvo geološki i reljefno zahtjevnog gradilišta. Zbog nepovoljnih visinskih razlika izvodio se polu-podzemni parking na 3 nivoa. Osiguranje građevinske jame izvedeno je uz pomoć dva reda bušenih pilota povezanih naglavnom konstrukcijom i žmurja. Potporna konstrukcija integrirana je u opću konstrukciju stambene zgrade. Provedeni su odgovarajući proračuni osnovnih parametara i opće stabilnosti građevine. Kontrolna ispitivanja bušenih pilota potporne konstrukcije i pilota temeljne konstrukcije potvrdili su ispravnost i efektivnost odabranog projektnog rješenja

Specifičnosti procesa deformacije tla podloge pokusnih temeljnih ploča

The basic principles of methods for determination of interconnection of the structural strength, the coefficients of lateral pressure and lateral extension according the results of research in the field. The increase of the structural strength of the artificial massive in time shown, its influence on the depth of the deformation zone revealed, the correlation of the settlements by compaction and lateral extension, as well as on the lateral extension coefficient. The methods for determining the coefficients of lateral expansion and lateral pressure developed and tested. The assumption of a linear decrease of the relative settlements оn the depth on the basis of which the total value of settlement, in the first approximation, divided into two parts ‒ due to compaction (decrease of porosity) and lateral extension (reshape) accepted.U radu su predstavljeni osnovni principi metodologije određivanja povezanosti strukturne čvrstoće, koeficijenata bočnog tlaka i poprečnog širenja prema rezultatima terenskih istraživanja. Pokazano povećanje strukturne čvrstoće umjetnih naslaga u vremenu, otkriven njen utjecaj na dubinu zone deformacije, odnos slijeganja izazvanih sabijanjem i poprečnim širenjem, te također utjecaj na koeficijent poprečnog širenja. Razrađeni su i ispitane metodologije određivanja koeficijenta bočnog širenja i bočnog tlaka. Prihvaćena je pretpostavka o linearnom smanjenju relativnih slijeganja po dubini, na temelju koje ukupna veličina slijeganja, u prvoj iteraciji, podijeljena u dva djela – uslijed sabijanja (smanjenja obujma pora) i bočnog širenja (promjene oblika)

Structure and Magnetic Fields in the Precessing Jet System SS 433 II. Intrinsic Brightness of the Jets

Deep Very Large Array imaging of the binary X-ray source SS 433, sometimes classified as a microquasar, has been used to study the intrinsic brightness distribution and evolution of its radio jets. The intrinsic brightness of the jets as a function of age at emission of the jet material tau is recovered by removal of the Doppler boosting and projection effects. We find that intrinsically the two jets are remarkably similar when compared for equal tau, and that they are best described by Doppler boosting of the form D^{2+alpha}, as expected for continuous jets. The intrinsic brightnesses of the jets as functions of age behave in complex ways. In the age range 60 < tau < 150 days, the jet decays are best represented by exponential functions of tau, but linear or power law functions are not statistically excluded. This is followed by a region out to tau ~ 250 days during which the intrinsic brightness is essentially constant. At later times the jet decay can be fit roughly as exponential or power law functions of tau.Comment: 30 Pages, 11 Figures, Submitted to Ap

Species identification based on a semi-diagnostic marker : Evaluation of a simple conchological test for distinguishing blue mussels Mytilus edulis L. and M. trossulus Gould

Cryptic and hybridizing species may lack diagnostic taxonomic characters leaving researchers with semi-diagnostic ones. Identification based on such characters is probabilistic, the probability of correct identification depending on the species composition in a mixed population. Here we test the possibilities of applying a semi-diagnostic conchological character for distinguishing two cryptic species of blue mussels, Mytilus edulis and M. trossulus. These ecologically, stratigraphically and economically important molluscs co-occur and hybridize in many areas of the North Atlantic and the neighboring Arctic. Any cues for distinguishing them in sympatry without genotyping would save much research effort. Recently these species have been shown to statistically differ in the White Sea, where a simple character of the shell was used to distinguish two mussel morphotypes. In this paper, we analyzed the associations between morphotypes and species-specific genotypes based on an abundant material from the waters of the Kola Peninsula (White Sea, Barents Sea) and a more limited material from Norway, the Baltic Sea, Scotland and the Gulf of Maine. The performance of the "morphotype test" for species identification was formally evaluated using approaches from evidence-based medicine. Interspecific differences in the morphotype frequencies were ubiquitous and unidirectional, but their scale varied geographically (from 75% in the White Sea to 15% in the Baltic Sea). In addition, salinity-related variation of this character within M. edulis was revealed in the Arctic Barents Sea. For every studied region, we established relationships between the proportions of the morphotypes in the populations as well as between the proportions of the morphotypes in samples and the probabilities of mussels of different morphotypes being M. trossulus and M. edulis. We provide recommendations for the application of the morphotype test to mussels from unstudied contact zones and note that they may apply equally well to other taxa identified by semi-diagnostic traits.Peer reviewe

Balancing torques in membrane-mediated interactions: Exact results and numerical illustrations

Torques on interfaces can be described by a divergence-free tensor which is fully encoded in the geometry. This tensor consists of two terms, one originating in the couple of the stress, the other capturing an intrinsic contribution due to curvature. In analogy to the description of forces in terms of a stress tensor, the torque on a particle can be expressed as a line integral along any contour surrounding the particle. Interactions between particles mediated by a fluid membrane are studied within this framework. In particular, torque balance places a strong constraint on the shape of the membrane. Symmetric two-particle configurations admit simple analytical expressions which are valid in the fully nonlinear regime; in particular, the problem may be solved exactly in the case of two membrane-bound parallel cylinders. This apparently simple system provides some flavor of the remarkably subtle nonlinear behavior associated with membrane-mediated interactions.Comment: 16 pages, 10 figures, REVTeX4 style. The Gaussian curvature term was included in the membrane Hamiltonian; section II.B was rephrased to smoothen the flow of presentatio

Interface mediated interactions between particles -- a geometrical approach

Particles bound to an interface interact because they deform its shape. The stresses that result are fully encoded in the geometry and described by a divergence-free surface stress tensor. This stress tensor can be used to express the force on a particle as a line integral along any conveniently chosen closed contour that surrounds the particle. The resulting expression is exact (i.e., free of any "smallness" assumptions) and independent of the chosen surface parametrization. Additional surface degrees of freedom, such as vector fields describing lipid tilt, are readily included in this formalism. As an illustration, we derive the exact force for several important surface Hamiltonians in various symmetric two-particle configurations in terms of the midplane geometry; its sign is evident in certain interesting limits. Specializing to the linear regime, where the shape can be analytically determined, these general expressions yield force-distance relations, several of which have originally been derived by using an energy based approach.Comment: 18 pages, 7 figures, REVTeX4 style; final version, as appeared in Phys. Rev. E. Compared to v2 several minor mistakes, as well as one important minus sign in Eqn. (18a) have been cured. Compared to v1, this version is significantly extended: Lipid tilt degrees of freedom for membranes are included in the stress framework, more technical details are given, estimates for the magnitude of forces are mad

The puzzle of HD 104994 (WR 46)

Intense coordinated spectroscopic and photometric monitoring of the suspected Wolf-Rayet binary WR 46 in 1999 reveals clear periodic variations, P = 0.329 ± 0.013 days, in the radial velocities of the emission lines of highest ionization potential, O VI and N V, found deepest in the Wolf-Rayet wind and thus least likely to be perturbed by a companion. These are accompanied by coherent variability in the profiles of lines with lower ionization/excitation potential and in the continuum flux. Most probably originating from orbital motion of the Wolf-Rayet component of the binary, this periodic radial velocity signal disappears from time to time, thus creating a puzzle yet to be solved. We show that the entangled patterns of the line profile variability are mainly governed by transitions between high and low states of the system's continuum flux.Facultad de Ciencias Astronómicas y Geofísica