Seismic Fragility And Post-Earthquake Reparability of Concrete Frame With Low-Bond High-Strength Rebar Reinforced Concrete Column

To further study the global seismic behaviour and post-earthquake reparability of RC building frames with the proposed self-centring columns with low-bond high-strength reinforcements (LBHSRs), incremental dynamic analysis (IDA) of five-floor and ten-floor frame archetypes under excitation by twenty ground motions (GMs) was performed. First, the pushover results indicated that the use of LBHSR could substantially improve the yield and ultimate lateral drift of both the archetypes, although the archetype had a smaller longitudinal reinforcement ratio (LR) of the LBHSR and similar seismic resistance. The dynamic response results indicated that the archetype with LBHSRs exhibited a smaller residual story lateral drift although the effectiveness of the use of LBHSR to reduce seismic response was not apparent for the archetype subjected to a low-intensity earthquake. The seismic fragility results showed that LBHSR was more effective for preventing seismic collapse than for attaining the immediate occupancy (IO), life safety (LS), and collapse prevention (CP) limit states. Furthermore, the higher the LR, the lower was the likelihood of seismic collapse. The fragility curves of the residual story lateral drifts indicate that the use of LBHSR can significantly mitigate the residual deformation in the DS1, DS2, and DS3 damage states. Moreover, the effectiveness increases with the increase in the LR and earthquake intensity. Comparisons of residual story lateral drifts between the predicted results and IDA results indicated that the present calculation models are not suitable for predicting residual deformation. The model needs to be studied further.

Shape isomerism and magicity in Ni isotopes

A systematic study of shapes in Ni [Formula: see text] isotopes has been made in the Relativistic–Hartree–Bogoliubov (RHB) formalism with two types of density-dependent NN interactions which are based on the range of meson-exchange. The constraint calculations assuming the axial and triaxial-symmetry predict the shape isomerism in the case of [Formula: see text] isotopes. Significant jumps at [Formula: see text] in the binding energy per nucleon (BE/A) and in the [Formula: see text] correspond to the neutron shell closure, and [Formula: see text] as doubly magic nuclei. The present calculation supports the recently reported calculations using the non-relativistic Hartree–Fock (HF) Skyrme SIII [1] interaction predicting the importance of tensor parameter in order to reproduce the experimental findings of the proton level crossing at [Formula: see text]. The results obtained are in agreement with experiment and with other theoretical studies.

Physical Modal for Acoustic Resonance Based on the Circular Cavity Structure in the Compressor

On the basis of the rectangular cavity plate model, the Parker resonance phenomenon is investigated by using the present calculation method, which verifies the effectiveness of the numerical calculation method adopted in the paper. Acoustic resonance occurs in the multistage compressor. The acoustic resonance frequency will be locked in a specific range which presents no variation in the rotating speed. The propagation status of the sound source of the acoustic resonance frequency should be from back to forward with a helical shape. The research method of the characteristics and mechanism of the acoustic resonance is proposed based on the annular cavity structure with the numerical simulation. The calculation models of the flow field and the sound field are established. The criterion of the sound resonating with the cavity and the characteristic condition when acoustic resonance occurred in the annular cavity structure is confirmed. The theoretical model of the acoustic resonance which is developed in the paper will be useful for the the three-dimensional model investigation into the acoustic resonance in the compressor, which can provide the better exhibition of the coupling relationship between the acoustic mode in the cavity and the vibration mode of the structure when the acoustic resonance occurs.

Individual separation of surface, bulk and Begrenzungs effect components in the surface electron energy spectra

We present the first theoretical recipe for the clear and individual separation of surface, bulk and Begrenzungs effect components in surface electron energy spectra. The procedure ends up with the spectral contributions originated from surface and bulk-Begrenzungs excitations by using a simple method for dealing with the mixed scatterings. As an example, the model is applied to the reflection electron energy loss spectroscopy spectrum of Si. The electron spectroscopy techniques can directly use the present calculation schema to identify the origin of the electron signals from a sample. Our model provides the possibility for the detailed and accurate quantitative analysis of REELS spectra.

Rise of the DIS structure function FL at small x caused by double-logarithmic corrections

We present calculation of FL in the double-logarithmic approximation (DLA) and demonstrate that the synergic effect of the factor 1/x from the $$ {\alpha}_s^2 $$ α s 2 -order and the steep x-dependence of the totally resummed double logarithmic contributions of higher orders ensures the power-like rise of FL at small x and arbitrary Q2.

A Variational Technique for Thermodynamics of Liquid K(1-x)Rbx Alloys

Liquid K_(1-x) Rb_x binary alloys with various thermodynamical proportions of participating elements are investigated. The properties of thermodynamic interest are included in the study. The internal energy (Fint), Helmholtz free enrgy (FH) and the entropy (S) have been calculated in a concentration range from X=0.0 to X=1.0 increasing in a step of 0.1 in the present work. Apart from the internal energy (Fint), various contributions to this energy are also calculated and separately depicted in the present article. A variational approach has been adopted for the present calculation. A single potential with a set of two parameters is used for the calculation of all properties of the alloys. Static Hartree local field function (H) is used to consider screening effect. Various local field correction functions are used to take into account the exchange and correlation effect. Comparison with experimental data at some concentration shows the good agreement with the presently obtained data. With the help of current results, the applied model potential found very suitable with individual parameters for thermodynamical study. As the present results provide the data even where minimum availability of the experimental findings, it can serve as a data base for the future calculation which deals with thermodynamics of the liquid alloys. Present results allow one to get proportion based tuned properties of the K_(1-x) Rb_x for different requirements.

Master equation theory applied to the redistribution of polarized radiation in the weak radiation field limit

Context. This paper presents a numerical application of a self-consistent theory of partial redistribution in nonlocal thermodynamical equilibrium conditions, developed in previous papers of the series. Aims. The code was described in IV of this series. However, in that previous paper, the numerical results were unrealistic. The present paper presents an approximation able to restore the reliability of the outgoing polarization profiles. Methods. The convergence of the results is also proved. It is demonstrated that the step increment decreases like 1/Nα, with α > 1. Results. Thanks to these additions, the results series behaves like a Riemann series, which is absolutely convergent. However, convergence is not fully reached in line wings within the allocated computing time. Development of efficient acceleration methods would be desirable for future work. Conclusions. Agreement between the computed and observed linear polarization profiles remains qualitative only. The discrepancy is assigned to the plane parallel atmosphere model, which is insufficient to describe the chromosphere, where these lines are formed. As all the integrals are numerical in the code, it could probably be adapted to more realistic and higher dimensional model atmospheres. However, this is time consuming for lines with a hyperfine structure, as in the Na I D lines. The net linear polarization observed in Na I D1 with the Zürich Imaging Polarimeter ZIMPOL mounted on the McMath-Pierce telescope at Kitt Peak is not confirmed by the present calculations and could be an artefact of instrumental polarization. The presence of instrumental polarization could be confirmed by the higher linear polarization degree observed by this instrument in the Na I D2 line center with respect to the present calculation result where the magnetic field is not accounted for. At this precise point, the Hanle effect acts as a depolarizing effect in the second solar spectrum. The observed linear polarization excess is found to be of the same order of magnitude in both line centers, namely 0.1%, which is also comparable to the instrumental polarization compensation level of this experiment.

Full-heavy tetraquarks in constituent quark models

The full-heavy tetraquarks $$bb{\bar{b}}{\bar{b}}$$ b b b ¯ b ¯ and $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ are systematically investigated within the chiral quark model and the quark delocalization color screening model. Two structures, meson–meson and diquark–antidiquark, are considered. For the full-beauty $$bb{\bar{b}}{\bar{b}}$$ b b b ¯ b ¯ systems, there is no any bound state or resonance state in two structures in the chiral quark model, while the wide resonances with masses around $$19.1-19.4$$ 19.1 - 19.4 GeV and the quantum numbers $$J^{P}=0^{+}$$ J P = 0 + , $$1^{+}$$ 1 + , and $$2^{+}$$ 2 + are possible in the quark delocalization color screening model. For the full-charm $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ systems, the results are qualitative consistent in two quark models. No bound state can be found in the meson–meson configuration, while in the diquark–antidiquark configuration there may exist the resonance states, with masses range between 6.2 to 7.4 GeV, and the quantum numbers $$J^{P}=0^{+}$$ J P = 0 + , $$1^{+}$$ 1 + , and $$2^{+}$$ 2 + . And the separation between the diquark and the antidiquark indicates that these states may be the compact resonance states. The reported state X(6900) is possible to be explained as a compact resonance state with $$IJ^{P}=00^{+}$$ I J P = 00 + in present calculation. All these full-charm resonance states are worth searching in the experiments further.

Determination of stress state based on well logging data and laboratory measurements – a CBM well in the southeastern part of the Upper Silesian Coal Basin (Poland)

The main objective of this study is to present calculation methods of horizontal stress profiles, taking into account the stress boundaries model, poro-elastic horizontal strain model and the effective stress ratio approach, using calibration with wellbore failure. The mechanical earth model (MEM) parameters from log measurements and well testing data were estimated for a well located in the southeastern part of the Upper Silesian Coal Basin. Log-derived horizontal stresses of the well are commonly treated as the final product of geomechanical modelling in oil and gas practices. A less popular method for estimating horizontal stresses is based on Kirsch equations juxtaposed with compressional and tensile failure observed on a micro-imager or six-arm caliper. Using this approach, horizontal stresses are determined based on the fact that when hoop stresses exceed the formation's tensile strength, tensile fractures are created, and when those stresses exceed the compressive strength of the formation, breakouts can be identified. The advantage of this method is that it can be run without in situ stress measurements. The presented workflow is recommended every time there is an image log and dipole sonic measurement in the available dataset, both being necessary to observe the failure zones and MEM.

A Simplified Model for Predicting Natural Draft Wet Cooling Tower Performance of Large Steam Power Plants

Flexible plant operation and rapid load changes become major issues for steam turbine operation. In thermal power plants, the steam turbine performance is closely related to the condenser, and an accurate prediction of coolant temperature as function of changing weather conditions is necessary in order to optimize power plant fleet operation. In this contribution, a one-dimensional model for simulating the performance of large natural draft wet cooling towers is presented. The evaporation zone model rests on the evaporative cooling theory developed by Merkel and Poppe. The off-design behavior of the cooling tower, that is relevant to part load performance, is modeled by an empirical power-law approach. A user-friendly method is presented in order to identify required model parameters by means of already available power plant data. The simulation tool can be employed easily for existing power plants for which the original cooling tower design and construction data lost their validity. The outcome of the present calculation method is successfully compared with field data from representative cooling towers at Middle-European sites.