Study on Wave Dissipation of the Structure Combined by Baffle and Submerged Breakwater

This paper proposes a structure combined by baffle and submerged breakwater （abbreviated to SCBSB in the following texts）. Such a combined structure is conducive to the water exchange in the harbor, and has strong capability on wave dissipation. Our paper focuses on the discussion of two typical structures, i.e., the submerged baffle and rectangular breakwater combined with the upper baffle respectively, which are named as SCBSB 1 and SCBSB2 for short. The eigenfunction method corrected by experimental results is used to investigate the wave dissipation characteristics. It shows that the calculated results agree well with the experimental data and the minimum value of the wave transmission coefficient can be obtained when the distance between the front and rear structures is from 1/4 to 1/2 of the incident wave length.

Experimental Study of Effect of Air Duct Structures on Heat Dissipation of Heating-Only Fan Coil

Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet type.Under natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of HFC.The results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.

Characteristics of viscous debris flow in a drainage channel with an energy dissipation structure

A new type of drainage channel with an energy dissipation structure has been proposed based on previous engineering experiences and practical requirements for hazard mitigation in earthquakeaffected areas.Experimental studies were performed to determine the characteristics of viscous debris flow in a drainage channel of this type with a slope of 15%.The velocity and depth of the viscous debris flow were measured,processed,and subsequently used to characterize the viscous debris flow in the drainage channel.Observations of this experiment showed that the surface of the viscous debris flow in a smooth drainage channel was smoother than that of a similar debris flow passing through the energy dissipation section in a channel of the new type studied here.However,the flow patterns in the two types of channels were similar at other points.These experimental results show that the depth of the viscous debris flow downstream of the energy dissipation structure increased gradually with the length of the energy dissipation structure.In addition,in the smooth channel,the viscous debris-flow velocity downstream of the energy dissipation structure decreased gradually with the length of the energy dissipation structure.Furthermore,theviscous debris-flow depth and velocity were slightly affected by variations in the width of the energy dissipation structure when the channel slope was 15%.Finally,the energy dissipation ratio increased gradually as the length and width of the energy dissipation structure increased;the maximum energy dissipation ratio observed was 62.9%(where B = 0.6m and L/w = 6.0).

The effects of managerial ability on firm performance and the mediating role of capital structure:evidence from Taiwan

This study utilizes mediation analysis and bootstrapping to analyze the mediating effect of capital structure on the association between managerial ability and firm performance.The dataset consists of 6384 firm-year observations from the Taiwan Residents electronics industry during 2005–2018.Our results indicate that(1)low(high)levels of debt are likely observed in firms with CEOs with high(low)ability,(2)managerial ability positively affects firm performance,and(3)capital structure mediates the positive relationship between managerial ability and firm performance.Overall,the findings may have limited generalizability due to the specific sample characteristics and provide convincing support for the importance of capital structure as a mediator in the managerial ability-firm performance nexus.Specifically,this study highlights the need for examining the effect of managerial ability on firm performance through a mediator.

Influence of topography on the fine structures of stratospheric gravity waves:An analysis using COSMIC-2 temperature data

We derive the potential energy of gravity waves(GWs)in the upper troposphere and stratosphere at 45°S-45°N from December 2019 to November 2022 by using temperature profiles retrieved from the Constellation Observing System for Meteorology,Ionosphere,and Climate-2(COSMIC-2)satellite.Owing to the dense sampling of COSMIC-2,in addition to the strong peaks of gravity wave potential energy(GWPE)above the Andes and Tibetan Plateau,we found weak peaks above the Rocky,Atlas,Caucasus,and Tianshan Mountains.The land-sea contrast is responsible for the longitudinal variations of the GWPE in the lower and upper stratosphere.At 40°N/S,the peaks were mainly above the topographic regions during the winter.At 20°N/S,the peaks were a slight distance away from the topographic regions and might be the combined effect of nontopographic GWs and mountain waves.Near the Equator,the peaks were mainly above the regions with the lowest sea level altitude and may have resulted from convection.Our results indicate that even above the local regions with lower sea level altitudes compared with the Andes and Tibetan Plateau,the GWPE also exhibits fine structures in geographic distributions.We found that dissipation layers above the tropopause jet provide the body force to generate secondary waves in the upper stratosphere,especially during the winter months of each hemisphere and at latitudes of greater than 20°N/S.

Response Spectrum Analysis of 7-story Assembled Frame Structure with Energy Dissipation System

Viscoelastic damper is an effective passive damping device,which can reduce the seismic response of the structure by increasing the damping and dissipating the vibration energy of structures.It has a wide application prospect in actual structural vibration control because of simple device and economical material.In view of the poor seismic behaviors of assembled frame structure connections,various energy dissipation devices are proposed to improve the seismic performance.The finite element numerical analysis method is adopted to analyze relevant energy dissipation structural parameters.The response spectrum of a 7-story assembled frame structure combined the ordinary steel support,ordinary viscoelastic damper,and viscoelastic damper with displacement amplification device is analyzed.The analysis results show that the mechanical behavior of assembled frame structure with ordinary steel supports are not significantly different from those without energy dissipation devices.The assembled frame structure with viscoelastic damper has better seismic performance and energy dissipation,especially for the viscoelastic damper with displacement amplification devices.The maximum value of inter-story displacement angle decreases by 32.24%;the maximum floor displacement decreases by 31.91%,and the base shear decreases by 13.62%compared with the assembled frame structures without energy dissipation devices.The results show that the seismic fortification ability of the structure is significantly improved,and the overall structure is more uniformly stressed.The damping structure with viscoelastic damper mainly reduces the dynamic response of the structure by increasing the damping coefficient,rather than by changing the natural vibration period of the structure.This paper provides an effective theoretical basis and reference for improving the energy dissipation system and the seismic performance of assembled frame structures.

Discussion of Dissipation Structure in a Directionally Solidified Alloy

The dissipation theory was introduced into the solidification area to describe the inherent laws of solidification from a new viewpoint. Discussion demonstrates that the solid / liquid interface in a directionally solidified alloy belongs to a kind of dissipation structure

Damping characteristics of friction damped braced frame and its effectiveness in the mega-sub controlled structure system

Based on energy dissipation and structural control principle, a new structural configuration, called the megasub controlled structure （MSCS） with friction damped braces （FDBs）, is first presented. Meanwhile, to calculate the damping coefficient in the slipping state a new analytical method is proposed. The damping characteristics of one-storey friction damped braced frame （FDBF） are investigated, and the influence of the structural parameters on the energy dissipation and the practical engineering design are discussed. The nonlinear dynamic equations and the analytical model of the MSCS with FDBs are established. Three building structures with different structural configurations, which were designed with reference to the conventional mega-sub structures such as used in Tokyo City Hall, are comparatively investigated. The results illustrate that the structure presented in the paper has excellent dynamic properties and satisfactory control effectiveness.

Hydraulic Design Method of Wave Dissipating Structure with Partially Perforated Front Wall

Based on the matching conditions of different fluid regions, the eigenfunction expansion method is used to develop a theoretical formula for wave reflection in front of the perforated structure with a partially slit front wall. The accuracy of the solution is verified by comparing the numerical results with experimental data. In addition, a new hydraulic design method is developed by derivation of the theoretical formula with respect to the porosity of the slit wall, and the results of this design method is drafted for harbour engineers to use.

Experimental study of friction dissipators for seismic protection of building structures

This paper presents the results from unidirectional shaking table tests of two reduced scale steel models of a building frame, with one and two floors, respectively. These frames incorporate friction dissipators at every floor. The inputs are sine-dwells and artificial and registered earthquakes. This study is part of a larger research project aiming to assess the seismic efficiency of friction dissipators by means of an integrated numerical and experimental approach. Inside this framework, the main objectives of these experiments are to： （i） collect a wide range of results to calibrate a numerical model derived within the project, （ii） clarify some of the most controversial issues about friction dissipators （including behavior for inputs containing pulses, capacity to reduce resonance peaks, introduction of high frequencies in the response, and self- generated eccentricities）, （iii） better understand their dynamic behavior, （iv） provide insight on the feasibility and reliability of using simple friction dissipators for seismic protection of building structures and （v） characterize the hysteretic behavior of these devices. Most of these objectives are satisfactorily reached and relevant conclusions are stated.

Evaluation on Ecological Environment of City Based on Entropy and Dissipative Structure Theory—In Case of Dangyang in Hubei Province

Evaluation on ecological environment system is to describe and assess the quality of ecological environment, and accurately reflect the ecological environmental quality and pollution situation. In this paper, after reviewing the domestic and foreign relative researches, from the theory perspective of the dissipative structure of complex system, we analyzed the city ecological system dissipative structure characteristic, and discussed the process forming dissipative structure, then we constructed the city ecosystem entropy parameter table and entropy evaluated model. The total entropy dynamic, scientifically reflects the city ecology system level and developing trend, so in fact it provides the theory basis and method to improve the overall quality of ecological environment, finally we took Dangyang as a case study, and got the same conclusion with the actual situation.

Improving Concrete Containment Structures Associated with Fixed-Cone Valves

Fixed-Cone valves are often used to dissipate energy and regulate flow at the low level outlet works of dams. Fixed-Cone valves, also known as Howell-Bunger valves, create an expanding conical jet allowing the energy of the water to dissipate over a large area. However, in many applications constructing the large stilling basin necessary for these valves is either not possible or not feasible. In order to reduce the relative size of the stilling basin, hoods or concrete containment structures have been used in conjunction with Fixed-Cone valves. This paper discusses the use of baffles in concrete containment structures in order to dissipate energy in a considerably confined space. It was determined that using baffles, in place of a deflector ring and end sill (Used in traditional containment structures.), significantly improves the function of containment structures by reducing downstream flow velocities and improving flow patterns and stability. This information will be useful to engineers allowing them to minimize scour and erosion associated with concrete containment structures.

DYNAMIC RESPONSE AND ENERGY DISSIPATION ANALYSIS OF THE WALL WITH HORIZONTAL SHORT KEYWAYS AND LOWRISE SHEARWALL

A new type of ductile lowrise shearwall with many short horizontalkeyways is proposed in this paper in order to improve the earthquake resistant behav-ior of ordinary lowrise shearwall.The behavior of this wall is studied through low-frequency cyclic loading test.Based on the test results,the paper puts forward thedifferent restoring force models for different lowrise shearwalls,and a program fortheir nonlinear dynamic analysis is worked out.Thr(?)h directly inputting earth-quake waves,the paper analyses the dynamic response and energy dissipation of 3types of lowrise shearwalls.The calculation results dem(?)strate that the newly de-vised ductile shearwall has good earthquake resistant behavior.

EXPERIMENTAL STUDY OF MEASUREMENT FOR DISSIPATION RATE SCALING EXPONENT IN HEATED WALL TURBULENCE

Experimental investigations have been devoted to the study of scaling law of coarse-grained dissipation rate structure function for velocity and temperature fluctuation of non-isotropic and inhomogeneous turbulent flows at moderate Reynolds number. Much attention has been paid to the case of turbulent boundary layer, which is typically the non-istropic and inhomogeneous trubulence because of the dynamically important existence of organized coherent structure burst process in the near wall region . Longitudinal velocity and temperature have been measured at different vertical positions in turbulent boundary layer over a heated and unheated flat plate in a wind tunnel using hot wire anemometer. The influence of non-isotropy and inhomogeneity and heating the wall on the scaling law of the dissipation rate structure function is studied because of the existence of organized coherent structure burst process in the near wall region . The scaling law of coarse-grained dissipation rate structure function is foun

Nonequilibrium Thermodynamic and Dissipative Structure Mechanism of Fluidized Beds

Fluidized beds are nonlinear dynamic systems that exchange mass and energy with outside. They are governed not only byfluid dynamics, but by thermodynamics, especially the second law of thermodynamics as well. According to Prigogine's dissipative structure theory, the following have been concluded: (l) a fixed bed is on thermodynamic blanch, and bubbling, turbulent and fast beds areon the dissipatve structure branches. (2) Entropy in fluidized beds is divided into tWo parts: entropy production and entropy flux. The latter increases with gas velocity and decreases with pressure of the systems. That means the entropy of a system may reduce and the systemwith higher gas velocity behaves as dissipative structure characteristics. (3) For a giVen velocity, a fluidized bed operates stably on thewhole, but it is unstable to local gas-solid phases. The unstable phases are described by fluid dynamic equations, While the minimum ofsystem energy function assures whole stability of the system. (4) A transition criterion of a bubbling bed is derived from Prigogine's stability theory.

ANALYSIS OF DISSIPATIVE STRUCTURE IN MATERIAL COMMINUTION

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Estimation of Turbulent Kinetic Energy Dissipation Rate in the Bottom Boundary Layer of the Pearl River Estuary

A structure function approach is applied to estimate the turbulent kinetic energy （TKE） dissipation rate in the bottom boundary layer of the Pearl River Estuary （PRE）. Simultaneous measurements with an acoustic Doppler velocimeter （ADV） supplied independent data for the verification of the structure function method. The results show that, 1） the structure function approach is reliable and successfully applied method to estimate the TKE dissipation rate. The observed dissipation rates range between 8.3 ×10^-4 W/kg and 4.9× 10^-6 W/kg in YM01 and between 3.4×10^-4 W/kg and 4.8×10^-7 W/kg in YM03, respectively, while exhibiting a strong quarter-diurnal variation. 2） The balance between the shear production and viscous dissipation is better achieved in the straight river. This first-order balance is significantly broken in the estuary by non-shear production/dissipation due to wave-induced fluctuations.

What are the challenges facing cancer therapy base on the dissipative structure theory

Cancer therapy is facing challenges.Since current theory could not have a breakthrough,we ought to find a new way to conquer cancer by exploring the emerging theory in cancer therapy.The complexity science,emerging in the 1980s,is the new stage of the system science development.It raises a series of transformation from humanities to natural science.Dissipative structure theory as a major science of complexity science,when applied to medical field,probable provide opportunity and inspiration referring to treatment.Dissipative structure theory,in brief,claims that a dissipative structure transform chaos to relatively stable non-equilibrium state through non-equilibrium phase transition.From the microscopic order,cancer composed by tumor cells is a dissipative structure,whose external environment is the human body.From the macroscopic order,the human body is a dissipative structure,whose external environment is the natural and social environment.The reason for tumor occurrence and progression is relatively non-equilibrium disrupted and negative entropy is not enough to correct high positive entropy.Survival with the tumor is to enhance negative entropy to resist highly positive entropy and then build a new relative non-equilibrium state.Innovative angle from the theory may enlighten us make the better use of dissipative structure theory in clinical cancer therapy.

The Characteristics of Turbulence Structure and Transfer over the Middle Area of the Tibetan Plateau

In this paper, turbulent data obtained from the Damxung site during the Secondary Tibetan Plateau Science Experiment (TIPEX) in 1998 are used to study the characteristics of the turbulent spectra, turbulence transport, and the dissipation rates of turbulent kinetic energy, temperature variance, and humidity variance in the middle area of the Tibetan Plateau. The turbulent spectra of wind velocity, potential temperature, and humidity satisfy the-2/3 power law in the high frequency range. Horizontal transportation of heat and water vapor is negligible compared with vertical transportation under strong unstable conditions, and as the stability parameter z/L increases (where z is the observational height, and L is the Monin Obukhov length), horizontal transportation becomes dominant under near-neutral, neutral, and stable conditions. The non-dimensional temperature and humidity variances are 20% less than the temperature and humidity gradient variances. These deficits appear to increase as the absolute stability parameter increases. Moreover, the effects of turbulence transportation and pressure variance exist throughout the entire stability region.

Rapid Prediction of Structural Responses of Double-Bottom Structures in Shoal Grounding Scenario

This study presents a simplified analytical model for predicting the structural responses of double-bottom ships in a shoal grounding scenario. This solution is based on a series of analytical models developed from elastic-plastic mechanism theories for different structural components, including bottom girders, floors, bottom plating, and attached stiffeners. We verify this simplified analytical model by numerical simulation, and establish finite element models for a typical tanker hold and a rigid indenter representing seabed obstacles. Employing the LS-DYNA finite element solver, we conduct numerical simulations for shoal-grounding cases with a wide range of slope angles and indentation depths. In comparison with numerical simulations, we verify the proposed simplified analytical model with respect to the total energy dissipation and the horizontal grounding resistance. We also investigate the interaction effect of deformation patterns between bottom structure components. Our results show that the total energy dissipation and resistances predicted by the analytical model agree well with those from numerical simulations.