Thrust and slip line analysis on a swamp shoe

This paper attempts to develop an analytical method which can evaluate the thrust and the slip line exerted by continuos swamp shoes. In this analysis, all the slip lines in the ground and the adhesion between a swamp shoe and the ground are considered. An equation was found through the analysis and calculated values of the thrust and the slip line are examined through experiments with a swamp shoe.     

Structure of Exotic Three-Body Systems

The classification of large halos formed by two identical particles and a core is systematically addressed according to interparticle distances. The root-mean-square distances between the constituents are described by universal scaling functions obtained from a renormalized zero-range model. Applications for halo nuclei, ¹¹Li and ¹⁴Be, and for atomic ⁴He₃ are briefly discussed. The generalization to four-body systems is proposed.     

A Novel Aspect of Photodynamic Action: Induction of Recurrent Spikes in Cytosolic Calcium Concentration

Effects of photodynamic action of gadolinium porphyrin-like macrocycle B (PLMGdB) on cytosolic Ca²⁺ concentration, [Ca²⁺]_c, was investigated in isolated rat pancreatic acini. The PLMGdB alone or light alone (2 min) had no effect on [Ca²⁺]_c. Cell-bound PLMGdB upon brief (0.5–2.0 min) light activation triggered recurrent spikes in [Ca²⁺]_c. At lower PLMGdB concentration (100 nM) the spikes continued during the whole period of monitoring [Ca²⁺]_c. At a higher concentration of 500 nM, the spikes continued for the first 40 min, followed by a gradual increase in basal [Ca²⁺]_c upon which smaller spikes were superimposed. At 1, the spikes continued for the first 20 min, after that spiking gradually degenerated into a plateau phase. In many aspects, photodynamically triggered spikes resembled spikes generated by physiological concentrations of cholecystokinin. The spikes triggered by photodynamic action were likely to be the result of the ignition of a physiological “chain reaction”, because functional inositol-1,4,5-trisphosphate (IP₃) receptors were required for spiking to occur. Two-aminoe-thoxydiphenylborate, an inhibitory modulator of IP₃-triggered Ca²⁺ release from intracellular stores, effectively inhibited photodynamically generated spikes. Therefore photodynamic action appears to be able to permanently transfix a physiological process, leading to long-lasting pharmacological or therapeutic effects.     

Electron paramagnetic resonance spectroscopy in studies of the chemical states of manganese in particulate substances in river waters and of the reduction of manganese by tannery effluents

The chemical states of manganese(II) species in particulate substances in river water, with and without the influence of tannery effluents, were investigated by the use of electron paramagnetic resonance (e.p.r.) spectroscopy. In the e.p.r. spectra of the particulate substances in river water, the six-line signal characteristic of Mn(II) was distinctly observed. The relative intensity of the Mn(II) signal was found to be higher in the lower reaches of a river, and especially below tannery effluent inflows, suggesting that manganese in river water is reduced by natural and artificially added organic compounds. It is shown that the reduction of manganese in river sediments and manganese dioxide by tannery effluents can afford an insoluble Mn(II) species at pH 11 and a soluble Mn(II) species at pH 7.     

Theory of irreversible processes in nonequilibrium quantum systems. II. Cluster expansions with contraction for homogenous systems

On the basis of a method developed in a previous paper, a systematic rule for obtaining a symmetrized collision superoperator of the Van Hove generalized master equation including an arbitrary number of particles is given. In the formalism, the quantum statistical effect is taken into account through the use of contractions (internal and external contractions) on the basis of the cluster expansion. As an application of this general rule, a symmetrized collision superoperator including the effect of three-particle collisions is obtained.     

Constraints on two-neutron separation energy in the Borromean C nucleus

The recently extracted matter radius of carbon isotope ²²C allows us to estimate the mean-square distance of a halo neutron with respect to the center-of-mass of this nucleus. By considering this information, we suggest an energy region for an experimental investigation of the unbound ²¹C virtual state. Our analysis, in a renormalized zero-ranged three-body model, also indicates that the two-neutron separation energy in ²²C is expected to be found below ∼0.4 MeV$\sim 0.4\text{MeV}$, where the ²²C is approximated by a Borromean configuration with a pointlike ²⁰C and two s-wave halo neutrons. A virtual-state energy of ²¹C close to zero, would make the ²²C, within Borromean nuclei configurations, the most promising candidate to present an excited bound Efimov state or a continuum three-body resonance.     

Borromean three-body heteroatomic resonances

We present an approach to analyze recent experimental evidences of Efimov resonant states in mixtures of ultracold gases, by considering two-species three-body atomic systems bound in a Borromean configuration, where all the two-body interactions are unbound. For such Borromean three-body systems, it is shown that a continuum three-body s-wave resonance emerges from an Efimov state as a scattering length or a three-body scale is moved. The energy and width of the resonant state are determined from a scaling function with arguments given by dimension-less energy ratios relating the two-body virtual state subsystem energies with the shallowest three-body bound state. The peculiar behavior of such resonances is that their peaks are expected to move to lower values of the scattering length, with increasing width, as one raises the temperature. For Borromean systems, two resonant peaks are expected in ultralow-temperature regimes, which will disappear at higher energies. It is shown how a Borromean-Efimov excited bound state turns out to a resonant state by tuning the virtual two-body subsystem energies or scattering lengths, with all energies written in units of the next deeper shallowest Efimov state energy. The resonance position and width for the decay into the continuum are obtained as universal scaling functions (limit cycle) of the dimensionless ratios of the two and three-body scales, which are calculated numerically within a zero-range renormalized three-body model.     

Trimer–Tetramer Interwoven States in the Scaling Limit

We report here some results we have obtained on the scale dependence of tetramer energies at the unitary limit, considering the number of tetramer energy levels appearing between the ground and the excited Efimov trimers. Our numerical investigation is done by solving a renormalized set of Faddeev–Yakubovsky equations for identical bosons with zero-range interaction, requiring a four-body scale, which in principle can be independent of the trimer properties. The ratio between the three- and four-body scales is introduced by considering the two lower trimer states and corresponding associated tetramers. We conclude that at least three tetramers are possible to exist between two Efimov states by varying the relation between such scales, and considering the relation between three-body Efimov states in the unitary limit. The results for the trimer–tetramer interwoven states are shown through a correlation between tetramers attached to consecutive Efimov trimer states.     

Dynamics characterization of modified Gross–Pitaevskii equation

The dynamics of dissipative and coherent N$N$-body systems, such as a Bose–Einstein condensate, which can be described by an extended Gross–Pitaevskii formalism, is investigated. In order to analyze chaotic and unstable regimes, two approaches are considered: a metric one, based on calculations of Lyapunov exponents, and an algorithmic one, based on the Lempel–Ziv criterion. The consistency of both approaches is established, with the Lempel–Ziv algorithmic found as an efficient complementary approach to the metric one for the fast characterization of dynamical behaviors obtained from finite sequences.     

A sufficient condition for a graph to be weakly k-linked

For a pair (s, t) of vertices of a graph G, let λ_G(s, t) denote the maximal number of edge-disjoint paths between s and t. Let (s₁, t₁), (s₂, t₂), (s₃, t₃) be pairs of vertices of G and k > 2. It is shown that if λ_G(s_i, t_i) ≥ 2k + 1 for each i = 1, 2, 3, then there exist 2k + 1 edge-disjoint paths such that one joins s₁ and t₁, another joins s₂ and t₂ and the others join s₃ and t₃. As a corollary, every (2k + 1)-edge-connected graph is weakly (k + 2)-linked for k ≥ 2, where a graph is weakly k-linked if for any k vertex pairs (s_i, t_i), 1 ≤ i ≤ k, there exist k edge-disjoint paths P₁, P₂,…, P_k such that P_i joins s_i and t_i for i = 1, 2,…, k.