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Robot Pheromone Communication Using Vortex Ring Transmission

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Journal of Bionic Engineering 2009年第2期6卷 153-160页

作者： R.Andrew Russell Intelligent Robotics Research centre Monash University

Unpredictable air movements have proved to be a problem in previous studies investigating robot communication by means of airborne pheromone chemicals. The project described in this paper investigates the use of air vortex rings as a means of carrying pheromone chemicals between transmitting and receiving robots. Sensitivity to chemicals including pheromones released by conspecifics is essential for many aspects of an insect's life. They assist in finding food, locating a mate, avoiding danger and help coordinate the activities of social insects. In the future, autonomous robots will be challenged by many situations similar to those that face insects and other simple creatures. Chemical communication may prove useful for these robots as well. This paper describes the equipment developed for generating and detecting vortex rings. Results of experiments involving location and tracking of a sequence of pheromone vortex rings are also presented.

关键词： chemical communication vortex transmission crickets biomimetic robots

Wavy properties and analytical modeling of free-surface flows in the development of the multi-domain method

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Journal of Hydrodynamics 2016年第6期28卷 971-976页

作者： Xiaobo CHEN Hui LIANG Deepwater Technology Research centre Bureau Veritas

The wavy （oscillatory both in space and in time） properties of free-surface flows due to presence of floating bodies are analyzed within the framework of the potential-flow theory by assuming that the fluid is perfect and flow irrotational. A so-called new multi-domain method has been developed based on the fluid domain division by an analytical control surface surrounding bodies and the application of different methods adapted in the external and internal domains. In the analytical domain external to the control surface, the fundamental solution satisfying the linear boundary condition on the free surface associated with a point singularity （often called Green fimction and referred here as point solution） is applied to capture all wavy features of free-surface flows extending horizontally to infinity. Unlike classical studies in which the control surface is discretized, the unknown velocity potential and its normal derivatives are expressed by expansions of orthogonal elementary functions. The velocity potential associa- ted with each elementary distribution （elementary solutions） on the control surface can be obtained by performing multi-fold inte- grals in an analytical way. In the domain internal to the control surface containing the bodies, we could apply different methods like the Rankine source method based on the boundary integral equations for which the elementary solutions obtained in the external domain playing the role of Dirichlet-to-Neumarm operator close the problem.

关键词： analytical modeling multi-domain method point solution (PS) elementary solution (ES) body solution (BS)

Electrochemical behavior of cerium(Ⅳ) in a RTIL and its mixture with ethanol

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Journal of Rare Earths 2014年第7期32卷 641-647页

作者： Arijit Sengupta M.S.Murali P.K.Mohapatra Radiochemistry Division Bhabha Atomic Research Centre

A systematic study was carried out to explore the electrochemical behavior of Ce in room temperature ionic liquid（CnmimBr, where n=6, 8, 10） and mixture of C6 mimBr and ethanol by cyclic voltammetry. With increase in the number of carbon atoms on the alkyl substituent on methyl imidazolium cation, the electrochemical window of the ionic liquids was found to extend towards more negative potential value, as a result there was a possibility of reduction of Ce to lower oxidation states. The diffusion coefficient and activation energy for the diffusion were calculated in all the ionic liquids and one of their mixtures with ethanol. With increase in n value, the diffusion coefficient of Ce decreased due to increase in viscosity of the medium while the activation energy for the diffusion followed a reverse trend for C6 mimBr, C8 mimBr and C10 mimBr, respectively. The observations indicated that the nature of species of Ce might be different in room temperature ionic liquids（RTILs） from that present in their mixtures with ethanol.

关键词： cerium cyclic voltammetry diffusion coefficient activation energy ethanol Cn mimBr (n=6, 8, 10) rare earths

Analyzing hydro abrasive erosion in Kaplan turbine:A case study from India

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Journal of Hydrodynamics 2016年第5期28卷 863-872页

作者： Anant Kr.RAI Arun KUMAR Alternate Hydro Energy centre IIT Roorkee

Sediment flow through hydro turbine causes erosion of hydraulic components resulting in drop of turbine efficiency, parti- cularly in hydropower plants of the Himalayan region. The measurement of erosion and monitoring of sediment flow in turbine are major concerns in erosion study. Attempts have been made to study erosion mainly in Pelton and Francis turbines. In this study, a simple and effective method has been presented to measure erosion in a Kaplan turbine of a run-of-river scheme Chilla hydropower plant in foothills of Himalaya. Recent techniques were used to measure sediment parameters like concentration, size, shape and mineral content. A standard erosion model is applied to estimate the erosion in Kaplan turbine blade, runner chamber and draft tube cone. A calibration factor has been proposed to apply the erosion model for site specific conditions. It has been found that the outer trailing edges of the turbine blade and upper rtmner chamber are most erosion prone zones. Sediment analysis revealed that effective operation can reduce erosion in turbine components. The estimated erosion values from model are found to be consistent with measu- red values. Finally, suggestions for design improvements and effective operation of erosion affected hydropower plants are given.

关键词： turbine sediment erosion measurement IEC 62364 hydropower

Determination of the effective density and fractal dimension of PM emissions from an aircraft auxiliary power unit

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Journal of Environmental Sciences 2018年第12期30卷 11-18页

作者： Emamode A.Ubogu James Cronly Bhupendra Khandelwal Swapneel Roy Low Carbon Combustion centre University of Sheffield

Gas turbine particulate matter（PM） emissions contribute to air quality degradation and are dangerous to both human health and the environment. Currently, PM mass concentrations determined from gravimetric measurements are the default parameter for gas turbine emissions compliance with PM regulations. The measurement of particle size however, is of significant interest due to its specific effects on health and climate science. The mass concentration can be determined from the number-size distribution measurement but requires the experimental evaluation of effective density of a number of particles to establish the powerlaw relationship. In this study, the effective density of PM emissions from an aircraft Auxiliary Power Unit（APU） with petroleum diesel, conventional aviation fuel（Jet A-1） and a multicomponent surrogate fuel（Banner NP 1014） as combusting fuels have been *** experimental configuration consisting of a Differential Mobility Analyzer, a Centrifugal Particle Mass Analyzer and a Condensation Particle Counter（DMA-CPMA-CPC） was deployed for this purpose. Overall, a decrease in the effective density（220–1900 km-3） with an increase in the particle size was observed and found to depend on the engine operating condition and the type of fuel undergoing combustion. There was a change in the trend of the effective densities between the PM emissions generated from the fuels burnt and the engine operating conditions with increasing particle size.

关键词： Particulate emissions Partiulate size-density analysis Fuel variability

A Wind Tunnel Experimental Study on the Wake Characteristics of a Horizontal Axis Wind Turbine

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Journal of Thermal Science 2025年第1期 145-158页

作者： GUO Xingduo LI Yinran LI Rennian MA Yulong WEI Kui College of Energy and Power Engineering Lanzhou University of Technology Key Laboratory of Fluid Machinery and Systems Gansu Provincial Technology centre for Wind Turbines

The characteristics of wind turbine wakes are influenced by multiple factors,including the atmospheric boundary layer(ABL) wind and wind turbine operating conditions(e.g.,tip speed ratio and yaw angle).In this study,two types of ABL winds with different velocity gradients and turbulence intensities are generated in a wind tunnel through configurations of spires,baffles,and various numbers of roughness elements.A wind turbine with a rotor diameter of 0.8 m and a hub height of 0.6 m is tested under varying tip speed ratios,yaw angles,and ABL wind *** results indicate that the streamwise velocity deficit in the near-wake region becomes more pronounced with an increase in the tip speed ratio,while the far-wake velocity deficit remains largely unaffected by changes in the tip speed *** the yaw angle increases,the wake deflection becomes more prominent and the wake narrows;the offset of the wake center at various downstream positions grows linearly,reaching a maximum value of approximately half the rotor ***,the turbulence level and influence range in the wake region are reduced when the turbine is *** ABL wind conditions,high turbulence intensity in the incoming flow accelerates wake recovery,and the Reynolds stress at different lateral positions tends to become consistent with increasing longitudinal ***,turbulence has a significant impact on the meandering characteristics of the wind turbine wake,with greater fluctuations in the wake center observed under higher turbulence ***,this study provides insights that could inform the optimal operation of wind farms.

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Role of boron in TiAl alloy development: a review

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Rare Metals 2016年第1期35卷 1-14页

作者： Dawei Hu Interdisciplinary Research centre in Materials University of Birmingham

Boron was found to be a unique grain refiner in cast TiAl alloys in the beginning of 1990 s and has become an element in most of the TiAl alloys developed to *** the past 25 or so years,efforts to understand the role of boron in solidification,solid-phase transformation,thermal and thermomechanical processing and mechanical properties of TiAl alloys and the relevant mechanisms never *** a result,abundant knowledge on boron in TiAl alloys has been accumulated but scattered in various research papers and conference *** review summarises the progress in understanding boron and its impacts on the TiAl alloy systems.

关键词： Titanium aluminide TiAl Ti3Al Boron Grain refinement

Optimal rejection of bounded perturbations in linear leader-following consensus protocol: invariant ellipsoid method

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Science China(Information Sciences) 2024年第8期67卷 24-34页

作者： Siyuan WANG Andrey POLYAKOV Min LI Gang ZHENG Driss BOUTAT INSA centre Val de Loire INRIA

The objective of the invariant ellipsoid method is to minimize the smallest invariant and attractive set of a linear control system operating under the influence of bounded external disturbances. This study extends the application of this method to address the leader-following consensus problem. Initially, a linear control protocol is designed for the multi-agent system in the absence of disturbances. Subsequently, in the presence of bounded disturbances, by employing a similar linear control protocol, a necessary and sufficient condition is introduced to derive the optimal control parameters for the multi-agent system such that the state of followers converges to and remains in a minimal invariant ellipsoid around the state of the leader.

关键词： multi-agent system leader-following consensus invariant ellipsoid disturbance

Comparison of Cardiac Output Measurement by Noninvasive Method with Electrical Cardiometry and Invasive Method with Thermodilution Technique in Patients Undergoing Coronary Artery Bypass Grafting

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World Journal of Cardiovascular Surgery 2014年第7期4卷 123-130页

作者： Randhir Singh Rajput Sambhunath Das Sandeep Chauhan A. K. Bisoi Sumit Vasdev Department of Cardiothoracic and Vascular anaesthesia CN Centre VII Floor All India Institute of Medical Science New Delhi India

Objective: This study was conducted to compare the cardiac output by using Electrical Cardiometry (EC), a noninvasive method of continuous cardiac output monitoring during cardiac surgery with pulmonary artery catheter (PAC) derived cardiac output. Design: Prospective observational clinical study. Setting: Cardiac surgery operating room of a tertiary care cardiac center. Participants: Twenty five patients undergoing coronary artery bypass surgery with cardiopulmonary bypass. Measurements and Main Results: A total of 150 double data of cardiac output were compared with Thermodilution Cardiac Output (TDCO) and Thoracic Electrical Bioimpedance (TEBCO). The TDCO value ranges from 1.8-6.9 litre·min-1 with a mean of 4.39 ± 1.16 litre·min-1 and TEBCO ranges from 1.8-7.1 litre·min-1 with a mean of 4.21 ± 1.16 litre·min-1. The averaged Bland-Altman analysis for TDCO and TEBCO revealed that a mean bias was 0.18 and limit of agreement was -1.25 - 0.89 litre·min-1 and the percentage error (PE) ranged from 22%-32%. The precision for the TDCO was measured to be ±16.2% and the precision for TEBCO was ±19.6%. Receiver Operating Characteristic (ROC) curve analysis between TDCO and TEBCO with a cutoff of 15% shows a sensitivity of 84% and specificity of 63 and area under ROC curve of 0.80. Mountain plot between TDCO and TEBCO shows that a median percentile is 0.25 and value of 97.5 percentile is 1.525. Conclusions: The present study indicates that the electric cardiometry device yields numerically comparable results to cardiac outputs derived from the PAC during the cardiac surgery. Therefore, electrical cardiometry can be used to evaluate haemodynamic variables with clinically acceptable accuracy, when invasive methods are to be avoided or not available.

关键词： Electric Cardiometry Thermodilution Pulmonary Artery Catheter Non Invasive Cardiac Output Thoracic Electrical Bioimpedance