scholarly journals Experimental Studies and Numerical Analyses on the Properties of a New Type Segment for Gas Pipeline Shield Tunnel.

1996 ◽  
pp. 43-56 ◽  
Author(s):  
Mitsutoshi Hayashi ◽  
Masayuki Saitoh ◽  
Atsushi Koizumi
Keyword(s):  
Experimental Studies ◽  
Gas Pipeline ◽  
Numerical Analyses ◽  
Shield Tunnel ◽  
New Type

scholarly journals Acousto-Optic Cells with Phased-Array Transducers and Their Application in Systems of Optical Information Processing

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 451
Author(s):  
Vladimir Balakshy ◽  
Maxim Kupreychik ◽  
Sergey Mantsevich ◽  
Vladimir Molchanov
Keyword(s):  
Phased Array ◽  
Power Conversion ◽  
Experimental Studies ◽  
Acoustic Power ◽  
Acoustic Mode ◽  
Bragg Angle ◽  
Excitation Band ◽  
Acousto Optic Interaction ◽  
Array Transducer ◽  
New Type

This paper presents the results of theoretical and experimental studies of anisotropic acousto-optic interaction in a spatially periodical acoustic field created by a phased-array transducer with antiphase excitation of adjacent sections. In this case, contrary to the nonsectioned transducer, light diffraction is absent when the optical beam falls on the phased-array cell at the Bragg angle. However, the diffraction takes place at some other angles (called “optimal” here), which are situated on the opposite sides to the Bragg angle. Our calculations show that the diffraction efficiency can reach 100% at these optimal angles in spite of a noticeable acousto-optic phase mismatch. This kind of acousto-optic interaction possesses a number of interesting regularities which can be useful for designing acousto-optic devices of a new type. Our experiments were performed with a paratellurite (TeO2) cell in which a shear acoustic mode was excited at a 9∘ angle to the crystal plane (001). The piezoelectric transducer had to nine antiphase sections. The efficiency of electric to acoustic power conversion was 99% at the maximum frequency response, and the ultrasound excitation band extended from 70 to 160 MHz. The experiments have confirmed basic results of the theoretical analysis.

scholarly journals Falling weight impact test of a new-type flexible rock-shed

2018 ◽  
Vol 38 (2) ◽  
pp. 242-252
Author(s):  
Jianrong Yang ◽  
Zhiyu Zhang
Keyword(s):  
Experimental Studies ◽  
Steel Tube ◽  
Time Interval ◽  
Explicit Finite Element ◽  
Numerical Studies ◽  
Structural Details ◽  
Tensile Forces ◽  
New Type ◽  
Falling Weight ◽  
The Impact

A new concept of a flexible rock-shed is presented for protection of the railway from falling rocks. The flexible rock-shed is made of flexible nets connected by specific spring spacer bars to an array of reinforced concrete portable frames which are linked by a longitudinal steel tube truss. To evaluate the performance of the flexible rock-shed, experimental and numerical studies are carried out in the present study. Impact tests are conducted on a full-scale partial model of the prototype structure when it is subjected to a falling block of 340 kg. The impact time interval, maximum deflection of the flexible net, tensile forces in the supporting ropes, and axial strains of spring spacer bars are recorded. To further examine the dynamic behavior of the flexible rock-shed, numerical simulations are also carried out by using the explicit finite element code ANSYS/LS-DYNA. It is found that the numerical results coincide well with the experimental data and both the numerical and experimental studies reveal that the structure can withstand impact energy of 50 kJ with all the materials working in the elastic range. The structural details are improved and the basis for the design and construction of similar structures in the future is provided.<br>

scholarly journals Experimental research of two stroke aircraft diesel engine

2019 ◽  
Vol 179 (4) ◽  
pp. 75-79
Author(s):  
Łukasz GRABOWSKI ◽  
Paweł KARPIŃSKI ◽  
Grzegorz BARAŃSKI
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Experimental Studies ◽  
Injection System ◽  
Temperature Control System ◽  
Maximum Pressure ◽  
System Control ◽  
Fuel Injection System ◽  
Measurement Systems ◽  
New Type

This paper presents the results of experimental studies of the opposed-piston diesel engine. This engine was designed during one of the stages of the research on a new-type drive unit for gyrocopter applications. In order to conduct research, a special test stand as well as control and measurement systems were developed. As part of the work on the engine, the fuel injection system, engine temperature control system and measurement systems were designed. In addition, a computer program has been developed for the fuel injection system control (injectors, valves fuel pressure regulators). The paper presents the results of the preliminary tests for a single value of engine speed (1500 rpm) and three values of load defined by torque. The measured value of the indicated pressure made it possible to calculate the maximum pressure. The results obtained from the bench tests were analyzed.

Experimental Study of Air Distribution Characteristics in Room of Stratum Ventilation under Two Kinds of Air Change Times

2013 ◽  
Vol 409-410 ◽  
pp. 668-672
Author(s):  
Yong Mei Xu ◽  
Jian Tang ◽  
Jun Han ◽  
Chu Qin Lin
Keyword(s):  
Experimental Study ◽  
Thermal Comfort ◽  
Experimental Studies ◽  
Air Distribution ◽  
Distribution Characteristics ◽  
Breathing Zone ◽  
Wind Speeds ◽  
Pollutant Concentrations ◽  
New Type ◽  
Better Than

Aimed at a new type of ventilation - stratum ventilation, air distributions at a breathing-zone in a model office were measured under kinds of air changes, the measure parameters in the experimental studies included temperatures, wind speeds and pollutant concentrations, based on which the thermal comfort at a breathing-zone were studied. Experimental results show that, the temperature, pollutant concentration and wind speeds in a breathing-zone under 5 times air changes are better than those under 6 times air changes. The calculating results of PMV and PPD indicate that the thermal comfort at a breathing-zone under 5 times air changes is better. The experimental study is instructive for the development of the ventilation.

Study on the Dynamic Active Confocal Probe Based on Time Difference for Surface Measurement

2006 ◽  
Vol 532-533 ◽  
pp. 89-92
Author(s):  
Hong Wei Zhang ◽  
Guo Xiong Zhang ◽  
Yu Ming Fan ◽  
Jia Qin ◽  
Zhi Li ◽  
...  
Keyword(s):  
Tuning Fork ◽  
Experimental Studies ◽  
Processing System ◽  
Electric Circuit ◽  
Time Difference ◽  
System Structure ◽  
Quality Monitoring ◽  
Surface Measurement ◽  
Signal Processing System ◽  
New Type

With the development of modern industry, the consciousness of quality monitoring increases rapidly. The requirements to the dimensional control and profile monitoring of the products including the mechanical, optical and electric ones become higher and higher. New, non-contact and convenient instruments are needed to enable people to evaluate their products. A new type of dynamic active confocal probe is developed in this paper. The key point of this new method is that the displacement measurement of the vibrating lens located on the tuning fork is converted to time difference measurement, which is much simpler and assures higher accuracy in measurement. System structure and improvement, electric circuit and signal processing system are discussed. Experimental studies of the probe performance and analyses of the experimental results are presented.

Theoretical and Experimental Study of the Dynamics of the Tripod-Ball Sliding Joint With Clearance

2001 ◽  
Author(s):  
Jia Xiaohong ◽  
Ji Linhong ◽  
Jin Dewen ◽  
Zhang Jichuan
Keyword(s):  
Mathematical Model ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Active System ◽  
New Concepts ◽  
Sliding Joint ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model ◽  
Kane Method

Abstract Clearance is inevitable in the kinematic joints of mechanisms. In this paper the dynamic behavior of a crank-slider mechanism with clearance in its tripod-ball sliding joint is investigated theoretically and experimentally. The mathematical model of this new-type joint is established, and the new concepts of basal system and active system are put forward. Based on the mode-change criterion established in this paper, the consistent equations of motion in full-scale are derived by using Kane method. The experimental rig was set up to measure the effects of the clearance on the dynamic response. Corresponding experimental studies verify the theoretical results satisfactorily. In addition, due to the nonlinear elements in the improved mathematical model of the joint with clearance, the chaotic responses are found in numerical simulation.

scholarly journals Evolutionary dynamics drives role specialization in a community of players

2020 ◽  
Vol 17 (168) ◽  
pp. 20200174 ◽  
Author(s):  
Danyang Jia ◽  
Xinyu Wang ◽  
Zhao Song ◽  
Ivan Romić ◽  
Xuelong Li ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Experimental Studies ◽  
Current Standard ◽  
Complex Processes ◽  
Spatial Games ◽  
Powerful Means ◽  
New Type ◽  
Standard Models ◽  
Natural Fact ◽  
Role Specialization

The progression of game theory from classical to evolutionary and spatial games provided a powerful means to study cooperation, and enabled a better understanding of general cooperation-promoting mechanisms. However, current standard models assume that at any given point players must choose either cooperation or defection, meaning that regardless of the spatial structure in which they exist, they cannot differentiate between their neighbours and adjust their behaviour accordingly. This is at odds with interactions among organisms in nature who are well capable of behaving differently towards different members of their communities. We account for this natural fact by introducing a new type of player—dubbed link players—who can adjust their behaviour to each individual neighbour. This is in contrast to more common node players whose behaviour affects all neighbours in the same way. We proceed to study cooperation in pure and mixed populations, showing that cooperation peaks at moderately low densities of link players. In such conditions, players naturally specialize in different roles. Node players tend to be either cooperators or defectors, while link players form social insulation between cooperative and defecting clusters by acting both as cooperators and defectors. Such fairly complex processes emerging from a simple model reflect some of the complexities observed in experimental studies on social behaviour in microbes and pave a way for the development of richer game models.

scholarly journals An Analysis of Excavation Support Safety Based on Experimental Studies

2015 ◽  
Vol 37 (3) ◽  
pp. 19-29 ◽  
Author(s):  
Karolina Gorska ◽  
Marek Wyjadłowski
Keyword(s):  
Experimental Studies ◽  
Stability Loss ◽  
Numerical Analyses ◽  
Structural Safety ◽  
3D Fem ◽  
Steady Growth ◽  
Excavation Support ◽  
Safety Estimation ◽  
Soldier Pile ◽  
Made In

Abstract The article presents the results of inclinometric measurements and numerical analyses of soldier-pile wall displacements. The excavation under investigation was made in cohesive soils. The measurements were conducted at points located at the edge of the cantilever excavation support system. The displacements of the excavation support observed over the period of three years demonstrated the pattern of steady growth over the first two months, followed by a gradual levelling out to a final plateau. The numerical analyses were conducted based on 3D FEM models. The numerical analysis of the problem comprise calculations of the global structural safety factor depending on the displacement of the chosen points in the lagging and conducted by means of the φ/c reduction procedure. The adopted graphical method of safety estimation is very conservative in the sense that it recognizes stability loss quite early, when one could further load the medium or weaken it by further strength reduction. The values of the Msf factor are relatively high. This is caused by the fact that the structure was designed for excavation twice as deep. Nevertheless, the structure is treated as a temporary one.

Influence of Different Outlet Diameters on Atomization Performance of Liquid Beset Gas Nozzles

2012 ◽  
Vol 550-553 ◽  
pp. 3184-3187
Author(s):  
Ding Ping Liu ◽  
Bing Jie Zhang
Keyword(s):  
High Speed ◽  
Power Plants ◽  
Thermal Power ◽  
Experimental Studies ◽  
Spray Nozzle ◽  
Particle Size Analyzer ◽  
Compressed Gas ◽  
New Type ◽  
Atomization Performance ◽  
Gas Nozzle

The wet FGD system with the characteristics of stable and mature, which had been widely used in the large thermal power plants. In this system, spray nozzle plays a key role, and the atomization performance of the spray nozzle affects the desulfurization reaction rate and efficiency directly. A new type spray nozzle, liquid beset gas nozzle was came up with in this article. It makes use of compressed gas in the internal pipeline to crush the liquid flowed out of the external pipeline into small particles. To optimize the nozzle's structure and develop its atomization performance, then considered outlet diameters of nozzle as one of the main influencing factors, sets three outlet diameters of nozzles: 4mm, 5mm and 6mm. This experiment with water for medium uses a laser particle size analyzer and a high speed camera for analysis to take atomization performance's tests of liquid beset gas nozzles under different outlet diameters and working conditions. The results of experimental studies were concluded. Firstly, when the outlet diameter is 5mm, the total spraying performance was the best. Because this outlet diameter can make the nozzle be in a balance between effective crush, fully mixing and jams preventing. Secondly, the new type nozzle had certain adaptability, when working pressures changed, and can be widely used in the wet FGD system.

scholarly journals Dynamic Shock Cushioning Characteristics and Vibration Transmissibility of X-PLY Corrugated Paperboard

2011 ◽  
Vol 18 (4) ◽  
pp. 525-535 ◽  
Author(s):  
Yanfeng Guo ◽  
Wencai Xu ◽  
Yungang Fu ◽  
Hongtao Wang
Keyword(s):  
Experimental Studies ◽  
Least Mean Square ◽  
Vibration Transmissibility ◽  
Characterization Of Properties ◽  
New Type ◽  
Vibration Tests ◽  
Vibration Damage ◽  
Protective Packaging ◽  
Frequency Curves

X-PLY corrugated paperboard is a new-type corrugated paperboard with three layers of orthotropic corrugated sandwiches structure, and may be employed to protect products from shock or vibration damage during distribution. This article deals with the characterization of properties of X-PLY corrugated paperboard relevant to its application for protective packaging in distribution, such as dynamic cushioning curves, vibration transmissibility and frequency curves. The main feature of article is the evaluation on the dynamic shock cushioning characteristics and vibration transmissibility of X-PLY corrugated paperboards by a series of experimental studies on the drop shock tester and vibration tester, the establishment of experimental formulas of dynamic cushioning curves, and the analysis of peak frequencies, vibration transmissibility and damping ratios. By using the fitting polynomial of curve and method of the least mean square, the experimental formulas and characteristic coefficients of dynamic cushioning curves have been obtained. From the vibration tests with slow sine sweep, the peak frequencies and vibration transmissibility are measured and used to estimate the damping ratios. These works provide basic data and curves relevant to its application for protective packaging in distribution.

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