An Oil-Hydraulic Workbench for Advanced Dynamic Testing

2006 ◽  
Author(s):  
Enrico Ravina
Keyword(s):  
Dynamic Testing ◽  
Mechanical Equipment ◽  
Structural Elements ◽  
Virtual Instrumentation ◽  
Shock Absorbers ◽  
Mechanical Field ◽  
Potential Applications ◽  
Static And Dynamic Tests ◽  
Mechanical Devices ◽  
And Control

The paper refers on a polyvalent oil-hydraulic testbench, designed and realized in order to develop a wide and diversified range of static and dynamic tests on mechanical components and structural elements. The testbench is an experimental mechatronic unit, integrating mechanical equipment, electronic devices and elaboration and control systems, aided by virtual instrumentation. In order to describe the main features and potentialities of the proposed testbench, the paper refers on tests of specific mechanical devices (shock absorbers) and of samples of structural elements (glued junctions). The possible and potential applications of the proposed workbench are very wide and oriented to validation, experimental identification, advanced testing and diagnostics in mechanical field.

scholarly journals Self-rotating 3D chiral mechanical metamaterials

2021 ◽  
Vol 477 (2251) ◽  
pp. 20200825
Author(s):  
K. K. Dudek ◽  
A. Drzewiński ◽  
M. Kadic
Keyword(s):  
Rotational Motion ◽  
Attitude Control ◽  
Structural Unit ◽  
Three Dimensional ◽  
Point Of View ◽  
Complex Structures ◽  
Structural Elements ◽  
Mechanical Metamaterials ◽  
Potential Applications ◽  
And Control

In this work, we demonstrate that three-dimensional chiral mechanical metamaterials are able to self-twist and control their global rotation. We also discuss the possibility of adjusting the extent of the global rotation manifested by the system in a programmable manner. In addition, we show that the effect of the global rotation can be observed both for small systems composed of a single structural unit as well as more complex structures incorporating several structural elements connected to each other. Finally, it is discussed that the results presented in this work are very promising from the point of view of potential applications such as satellites or telescopes in space, where appropriately designed mechanical metamaterials could be used for the attitude control as well as other systems where the control of the rotational motion is required.

Short Review and opinion: New matter properties and applications based on Hybrids Graphene based Metamaterials

2020 ◽  
Vol 04 ◽  
Author(s):  
A. Guillermo Bracamonte
Keyword(s):  
Short Review ◽  
New Materials ◽  
Design And Synthesis ◽  
Chemical Structures ◽  
Current State ◽  
Potential Applications ◽  
Fundamental Research ◽  
Miniaturized Instrumentation ◽  
And Control ◽  
Conductive Properties

: Graphene as Organic material showed special attention due to their electronic and conductive properties. Moreover, its highly conjugated chemical structures and relative easy modification permitted varied design and control of targeted properties and applications. In addition, this Nanomaterial accompanied with pseudo Electromagnetic fields permitted photonics, electronics and Quantum interactions with their surrounding that generated new materials properties. In this context, this short Review, intends to discuss many of these studies related with new materials based on graphene for light and electronic interactions, conductions, and new modes of non-classical light generation. It should be highlighted that these new materials and metamaterials are currently in progress. For this reason it was showed and discussed some representative examples from Fundamental Research with Potential Applications as well as for their incorporations to real Advanced devices and miniaturized instrumentation. In this way, it was proposed this Special issue entitled “Design and synthesis of Hybrids Graphene based Metamaterials”, in order to open and share the knowledge of the Current State of the Art in this Multidisciplinary field.

Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah
Keyword(s):  
High Efficiency ◽  
Combustion Engine ◽  
Renewable Energy Sources ◽  
Stirling Engine ◽  
Energy Sources ◽  
Heat Engines ◽  
Stirling Engines ◽  
Parabolic Dish ◽  
Mechanical Devices ◽  
And Control

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

scholarly journals Foaming of rhamnolipids fermentation: impact factors and fermentation strategies

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhijin Gong ◽  
Ge Yang ◽  
Chengchuan Che ◽  
Jinfeng Liu ◽  
Meiru Si ◽  
...  
Keyword(s):  
Production Process ◽  
Large Scale ◽  
Commercial Production ◽  
Impact Factors ◽  
Scale Production ◽  
Large Scale Production ◽  
Foaming Behavior ◽  
Production Strategies ◽  
Potential Applications ◽  
And Control

AbstractRhamnolipids have recently attracted considerable attentions because of their excellent biosurfactant performance and potential applications in agriculture, environment, biomedicine, etc., but severe foaming causes the high cost of production, restraining their commercial production and applications. To reduce or eliminate the foaming, numerous explorations have been focused on foaming factors and fermentation strategies, but a systematic summary and discussion are still lacking. Additionally, although these studies have not broken through the bottleneck of foaming, they are conducive to understanding the foaming mechanism and developing more effective rhamnolipids production strategies. Therefore, this review focuses on the effects of fermentation components and control conditions on foaming behavior and fermentation strategies responded to the severe foaming in rhamnolipids fermentation and systematically summarizes 6 impact factors and 9 fermentation strategies. Furthermore, the potentialities of 9 fermentation strategies for large-scale production are discussed and some further strategies are suggested. We hope this review can further facilitate the understanding of foaming factors and fermentation strategies as well as conducive to developing the more effective large-scale production strategies to accelerate the commercial production process of rhamnolipids.

Some problems of assessing the dynamic crack resistance of structural steels

2021 ◽  
Vol 18 (3) ◽  
pp. 428-435
Author(s):  
Vladimir I. SMIRNOV ◽  
◽  
Tatiana A. KNOPOVA ◽  
Sergey S. MAYER ◽  
◽  
...  
Keyword(s):  
Crack Resistance ◽  
High Speed ◽  
Dynamic Testing ◽  
Practical Importance ◽  
Dynamic Strength ◽  
Structural Steels ◽  
Dynamic Crack ◽  
Unstable Fracture ◽  
Structural Elements ◽  
Limiting State

Objective: Solving the problem of determining the conditions for the onset and development of unstable fracture, which is extremely important for the development of methods for calculating the limiting states of structural elements, improving the dynamic testing schemes of materials and classifying steels according to their ability to resist fracture. Methods: Analytical methods for assessing the limiting state of structural elements are used. Results: A brief overview of the available test methods for structural steels for dynamic strength and crack resistance is given. The experience accumulated by domestic and foreign practices in testing steels for strength and crack resistance under high-speed loading is analyzed. The disadvantages of the existing methods for assessing the indicators of dynamic strength and resistance to brittle fracture are indicated. Practical importance: It is shown that along with the traditional methods for assessing strength based on safety factors, it is necessary to develop and apply new methods for assessing the limiting state of structural elements, including by the criteria of crack resistance

The concept of development of the Contract System of the Ministry of Internal Affairs of Russia as a tool for effective use of budget funds and ensuring competition in the state procurement market

2021 ◽  
pp. 76-87
Author(s):  
A. A. Tsviliy-Buklanova
Keyword(s):  
Public Procurement ◽  
The State ◽  
Regulatory Framework ◽  
Structural Elements ◽  
Departmental Level ◽  
Internal Affairs ◽  
Effective Use ◽  
And Control

The article is devoted to the relevance of the development and adoption of the Concept for the development of the Contract System of the Ministry of Internal Affairs of Russia in order to increase the efficiency of using budget funds and eliminate corruption risks in the implementation of public procurement. The regulatory framework of federal and departmental level was considered, attention was paid to practical aspects of procurement of goods, works and services for the needs of internal affairs bodies, issues of regulation and control are reflected. Structural elements of the Concept, ways to improve the Contract System of the Ministry of Internal Affairs of Russia are proposed.

FFG7 Class Frigate and DD963 Class Destroyer Marine Gas Turbine Propulsion Systems Maintenance and Operational Training Facility

1985 ◽  
Vol 22 (01) ◽  
pp. 1-27
Author(s):  
Ralph J. Della Rocca ◽  
John D. Stehn
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Mechanical Equipment ◽  
Propulsion Systems ◽  
Electrical Systems ◽  
Training Facility ◽  
Hands On ◽  
Systems Maintenance ◽  
And Control ◽  
Major Emphasis

The need for a gas turbine training facility became apparent with the introduction into the U.S. Navy fleet of the first ships of the FFG7 Frigate and DD963 Destroyer Classes with gas turbine propulsion plants. This facility, constructed at the Great Lakes Naval Training Center, provides "hands-on" training for maintenance and operation of marine gas turbines and associated propulsion plant components and controls and their piping and electrical systems. The Navy intends to train at this facility approximately 1000 personnel per year in the use of their latest and newest propulsion plants. The design of the facility reproduces as closely as possible the existing machinery and control spaces of the two different classes of ships and integrates them into a single main building with the school and the mechanical equipment wings. This paper presents an overview of the need for well-trained, qualified naval personnel to man the expanding fleet of marine gas turbine propulsion systems, existing training facilities and the various stages in the development of the FFG7/DD963 Gas Turbine Maintenance and Operational Training Facility. In regard to the facility, the paper discusses the planning and managing of the project; development of the designs for the building and propulsion plants; construction of the building facilities and FFG7 plant; the fabrication, transportation and erection of the FFG7 within the building; and the testing and operation of the FFG7 plant since light-off. Major emphasis is given to the FFG7 plant since the DD963 plant is being reconsidered in conjunction with the CG47 upgrading and is awaiting a decision to proceed.

Metallic Foams Obtained from Nickel Based Superalloy Hollow Spheres

2011 ◽  
Vol 672 ◽  
pp. 141-144 ◽  
Author(s):  
Ioan Vida-Simiti ◽  
Nicolaie Jumate ◽  
Emil Bruj ◽  
Niculina Sechel ◽  
György Thalmaier ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Catalyst Support ◽  
Hollow Spheres ◽  
High Porosity ◽  
Structural Elements ◽  
Metallic Foams ◽  
Hollow Particles ◽  
Nickel Based Superalloy ◽  
Shock Absorbers ◽  
Thermal Barriers

In this work, hollow spherical nickel based superalloy powders obtained by liquid phase atomization were used. The obtained powder was divided into six size particle ranges between 200 µm and 630 µm using a shatter box. Samples from all six ranges were obtained by spreading the powder into the sintering die and consolidating them by sintering at 900°C and 1000°C for 30 minutes in vacuum (10-4 Torr). The metallic foams obtained by sintering hollow particles presents high porosity, and can be used as thermal barriers, catalyst support, shock absorbers or lightweight structural elements.

scholarly journals In Situ Monitoring of Growth of Vertically Stacked h-BN/Graphene Heterostructures on Ni Substrates and Their Interface Interaction

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 328-336
Author(s):  
Wei Wei ◽  
Guanhua Zhang ◽  
Jiaqi Pan ◽  
Yi Cui ◽  
Qiang Fu
Keyword(s):  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
In Situ Monitoring ◽  
High Coverage ◽  
Interface Interaction ◽  
Domain Boundaries ◽  
Potential Applications ◽  
Surface Microscopy ◽  
Mechanical Devices

Vertically stacked hexagonal boron nitride (h-BN)/graphene heterostructures present potential applications in electronic, photonic, and mechanical devices, and their interface interaction is one of the critical factors that affect the performances. In this work, the vertical h-BN/graphene heterostructures with high coverage are synthesized by chemical vapor deposition (CVD) of h-BN on Ni substrates followed by segregation growth of graphene at the h-BN/Ni interfaces, which are monitored by in situ surface microscopy and surface spectroscopy. We find that h-BN overlayers can be decoupled from Ni substrates by the graphene interlayers. Furthermore, the h-BN domain boundaries exhibit a confinement effect on the graphene interlayer growth and the lower graphene domains are limited within the upper h-BN domains. This work provides new insights into the formation mechanism and interface interaction of the vertical heterostructures.

Modeling, Control, and Validation of Electrohydrostatic Shock Absorbers

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Renato Galluzzi ◽  
Andrea Tonoli ◽  
Nicola Amati
Keyword(s):  
Dynamic Performance ◽  
Working Environment ◽  
Modeling And Control ◽  
Active Devices ◽  
Shock Absorbers ◽  
Damping Control ◽  
Variable Damping ◽  
And Control ◽  
Damping Systems

The implementation of variable damping systems to increase the adaptability of mechanical structures to their working environment has been gaining increasing scientific interest, and numerous attempts have been devoted to address vibration control by means of active and semi-active devices. Although research results seem promising in some cases, the proposed solutions are often not able to fulfill requirements in terms of compactness and simplicity on one hand, and dynamic performance on the other. In this context, the present paper discusses the modeling and control of an electrohydrostatic actuation (EHA) system for its implementation as a damping device. A model of the device is proposed and analyzed for design purposes. Subsequently, a damping control strategy is presented. Finally, a case study introduces and validates an EHA prototype for helicopter rotor blade lead–lag damping.

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