ТЕХНОЛОГИЯ И ПРИМЕНЕНИЕ ЭЛЕКТРОХИМИЧЕСКИХ ПРЕОБРАЗОВАТЕЛЕЙ

2020 ◽  
Vol 96 (3s) ◽  
pp. 450-455
Author(s):  
В.Г. Криштоп ◽  
Д.А. Жевненко ◽  
П.В. Дудкин ◽  
Е.С. Горнев ◽  
В.Г. Попов ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Engineering Applications ◽  
Electrochemical Systems ◽  
Seismic Sensors ◽  
Microelectronic Technology ◽  
Wide Range ◽  
Electrochemical Transducers ◽  
Element Base ◽  
New Devices

Электрохимические системы очень перспективны для разработки новой элементной базы для микроэлектроники и для использования в широком спектре инженерных задач. Мы разработали новую микроэлектронную технологию для изготовления электрохимических преобразователей (ЭХП) и новые приборы на основе новых электрохимических микроэлектронных чипов. Планарные электрохимические преобразователи могут использоваться в акселерометрах, сейсмических датчиках, датчиках вращения, гидрофонах и датчиках давления. Electrochemical systems are very promising for the development of a new element base for microelectronics, and for use in a wide range of engineering applications. We have developed a new microelectronic technology for manufacturing electrochemical transducers (ECP) and new devices based on new electrochemical microelectronic chips. Planar electrochemical transducers are used in accelerometers, seismic sensors, rotation sensors, hydrophones and pressure sensors.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

A Theoretical Insight into the Curing Mechanism of Phthalonitrile Resins Promoted by Aromatic Amines

2021 ◽  
Author(s):  
Zuowei Chen ◽  
Liquan Wang ◽  
Jiaping Lin ◽  
Lei Du
Keyword(s):  
High Temperature ◽  
Aromatic Amines ◽  
Academic Research ◽  
Engineering Applications ◽  
Wide Range ◽  
Curing Mechanism ◽  
Theoretical Insight ◽  
Insight Into

High-temperature phthalonitrile resins have a wide range of applications, and understanding their curing mechanism is of great importance for academic research and engineering applications. However, the actual curing mechanism is...

GT36 Turbine Aero-Thermal Development and Validation

2017 ◽  
Author(s):  
S. Naik ◽  
J. Krueckels ◽  
M. Henze ◽  
W. Hofmann ◽  
M. Schnieder
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Pressure Sensors ◽  
Thermal Design ◽  
Local Pressure ◽  
Cooling Systems ◽  
Wide Range ◽  
Turbine Vanes ◽  
Thermal Development ◽  
Development And Validation

This paper describes the aero-thermal development and validation of the GT36 heavy duty gas turbine. The turbine which has evolved from the existing and proven GT26 design, consists of an optimised annulus flow path, higher lift aerofoil profiles, optimised aerodynamic matching between the turbine stages and new and improved cooling systems of the turbine vanes and blades. A major design feature of the turbine has been to control and reduce the aerodynamic losses, associated with the aerofoil profiles, trailing edges, blade tips, endwalls and coolant ejection. The advantages of these design changes to the overall gas turbine efficiency have been verified via extensive experimental testing in high-speed cascade test rigs and via the utilisation of high fidelity multi-row computational fluid dynamics design systems. The thermal design and cooling systems of the turbine vanes, blades have also been improved and optimised. For the first stage vane and blade aerofoils and platforms, multi-row film cooling with new and optimised diffuser cooling holes have been implemented and validated in high speed linear cascades. Additionally, the internal cooling design features of all the blades and vanes were also improved and optimised, which allowed for more homogenous metal temperatures distributions on the aerofoils. The verification and validation of the internal thermal designs of all the turbine components has been confirmed via extensive testing in dedicated Perspex models, where measurements were conducted for local pressure losses, overall flow distributions and local heat transfer coefficients. The turbine is currently being tested and undergoing validation in the GT36 Test Power Plant in Birr, Switzerland. The gas turbine is heavily instrumented with a wide range of validation instrumentation including thermocouples, pressure sensors, strain gauges and five-hole probes. In addition to performance mapping and operational validation, a dedicated thermal paint validation test will also be performed.

scholarly journals Reconfigurable and Tunable Metamaterials: A Review of the Theory and Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Jeremiah P. Turpin ◽  
Jeremy A. Bossard ◽  
Kenneth L. Morgan ◽  
Douglas H. Werner ◽  
Pingjuan L. Werner
Keyword(s):  
Electromagnetic Properties ◽  
Electromagnetic Spectrum ◽  
Environmental Stimuli ◽  
Wide Range ◽  
Active Circuit ◽  
Circuit Elements ◽  
Tunable Metamaterial ◽  
New Devices ◽  
The Way

Metamaterials are being applied to the development and construction of many new devices throughout the electromagnetic spectrum. Limitations posed by the metamaterial operational bandwidth and losses can be effectively mitigated through the incorporation of tunable elements into the metamaterial devices. There are a wide range of approaches that have been advanced in the literature for adding reconfiguration to metamaterial devices all the way from the RF through the optical regimes, but some techniques are useful only for certain wavelength bands. A range of tuning techniques span from active circuit elements introduced into the resonant conductive metamaterial geometries to constituent materials that change electromagnetic properties under specific environmental stimuli. This paper presents a survey of the development of reconfigurable and tunable metamaterial technology as well as of the applications where such capabilities are valuable.

A New Approach to Maximize the Potential of Reciprocating Engines Operating on Bio-Fuel Energy

2011 ◽  
Author(s):  
Henry Lam ◽  
Mark Richter ◽  
Geoff Ashton
Keyword(s):  
Combustion Engine ◽  
Pressure Ratio ◽  
Waste Water Treatment ◽  
Pressure Sensors ◽  
Bulk Temperature ◽  
Lean Burn ◽  
Fuel Gas ◽  
Heating Value ◽  
Combustion Performance ◽  
Wide Range

Since the Industrial Revolution one of the oldest and “greenest” bio-fuel energy sources has been the byproduct of sewage and landfill. These biogases also known as Land Fill Gas or Digester Gas can be used as a fuel in an internal combustion engine, the clear choice for their efficiency in heat recovery and utility as a prime mover. The problem with bio-fuels is their unpredictable and varying fuel heating values which creates a challenge for maintaining air fuel ratio (AFR). If AFR is not controlled this can lead to engine instability and an increase in NOx, CO and THC emissions. With today’s ever increasing scrutiny of combustion pollutants this could spell the end of these types of fuels in combustion engines. AETC has embraced this challenge to provide a system that addresses the seasonal fuel gas quality, Low Heating Value (LHV) fluctuation to operate engines at best achievable emissions. This case study focuses on two Caterpillar 3516 Generator Engines rated 1000VA, at 1200 rpm, lean burn gas and turbocharged, running on renewable energy source supplementing power to a waste water treatment facility in California. The engines operate on wide range of fuel mixture including landfill, digester gas and air blended natural gas over a heating value range from 350–650 BTU. The fuel gas LHV constantly varies depending on fuel availability controlled by pressure switches within the individual fuel headers. Determining fuel heating values by using a gas calorimeter is not a viable option due to its high cost and poor reliability when operating in the environment of unfiltered Digester and landfill gas. AETC installed their Advanced Monitoring System (AMS) to utilize the engine as a calorimeter and to determine the fuels LHV. As part of the AMS functionality, the system acquired all the existing AFRC parameters such as kilo-Watt, RPM, Fuel Flow, Air Manifold Pressure and Temperature to determine the combustion performance. This simple approach offers surprisingly good performance while tying together basic thermodynamics, combustion performance and emissions. The system can also be used to parametrically determine engine emissions, based on the calculated combustion pressure without installing pressure sensors. The AMS monitors and determines emissions based on Trapped Equivalence Ratio, Effective Bulk Temperature or Pressure Ratio on single or multiple fuels providing a green/red light as an indicator of in/out of compliance accurately meeting today’s most stringent regulatory conditions.

The Effects of Additive Manufacturing and Electric Poling Techniques on PVdF Thin Films: Towards 3D Printed Functional Materials

2020 ◽  
Author(s):  
Jinsheng Fan ◽  
David Gonzalez ◽  
Jose Garcia ◽  
Brittany Newell ◽  
Robert A. Nawrocki
Keyword(s):  
Thin Films ◽  
Smart Materials ◽  
Vinylidene Fluoride ◽  
Pressure Sensors ◽  
Functional Materials ◽  
Piezoelectric Constant ◽  
Β Phase ◽  
Calibration Curves ◽  
Wide Range ◽  
3D Printed

Abstract Mechanical flexibility, faster processing, lower fabrication cost and biocompatibility enable poly (vinylidene fluoride) (PVdF) to have a wide range of applications. This work investigated the use of a piezoelectric polymeric material, PVdF, in combination with 3D printing, to explore new strategies for the fabrication of smart materials with embedded functions, namely sensing. The motivation behind this research was to design and fabricate PVdF thin films that will be used to build pressure sensors with applications in active intelligent structures. In this work, 3D printed PVdF thin films with thickness values in the range of 250 to 350 μm were poled under high direct current electrical fields, which were varied from 0.4 to 12 MV/m and temperatures from 80 to 140 °C. Copper electrodes were applied, forming a standard capacitor layered structure, to facilitate poling and to collect piezoelectric output voltage. The poling process enabled the piezoelectric crystalline phase transition of printed PVdF films to transfer from the non-active a α-phase to the piezoelectric active β-phase and rearranged the dipole alignments of the β-phase. The efficiency of poling was evaluated through the piezoelectric constant calculated from measured calibration curves. These calibration curves demonstrated the PVdF sensing device have a positive linear correlation between mechanical input and voltage output. We found that a peak value in piezoelectric constant correlated with poling voltages and temperatures. The highest piezoelectric constant achieved through contact poling was 32.29 pC/N poled at 750 V and 120 °C, and temperature was deemed the most important factors to influence piezoelectric constant. We believe that the present work demonstrates a path towards fully 3D printed smart, functional materials.

scholarly journals Locally Controlled Sensing Properties of Stretchable Pressure Sensors Enabled by Micro-Patterned Piezoresistive Device Architecture

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6588
Author(s):  
Jun Ho Lee ◽  
Jae Sang Heo ◽  
Keon Woo Lee ◽  
Jae Cheol Shin ◽  
Jeong-Wan Jo ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Silver Nanowires ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Fast Response ◽  
Large Area ◽  
Site Specific ◽  
Sensing Properties ◽  
Sensing Range ◽  
Wide Range

For wearable health monitoring systems and soft robotics, stretchable/flexible pressure sensors have continuously drawn attention owing to a wide range of potential applications such as the detection of human physiological and activity signals, and electronic skin (e-skin). Here, we demonstrated a highly stretchable pressure sensor using silver nanowires (AgNWs) and photo-patternable polyurethane acrylate (PUA). In particular, the characteristics of the pressure sensors could be moderately controlled through a micro-patterned hole structure in the PUA spacer and size-designs of the patterned hole area. With the structural-tuning strategies, adequate control of the site-specific sensitivity in the range of 47~83 kPa−1 and in the sensing range from 0.1 to 20 kPa was achieved. Moreover, stacked AgNW/PUA/AgNW (APA) structural designed pressure sensors with mixed hole sizes of 10/200 µm and spacer thickness of 800 µm exhibited high sensitivity (~171.5 kPa−1) in the pressure sensing range of 0~20 kPa, fast response (100~110 ms), and high stretchability (40%). From the results, we envision that the effective structural-tuning strategy capable of controlling the sensing properties of the APA pressure sensor would be employed in a large-area stretchable pressure sensor system, which needs site-specific sensing properties, providing monolithic implementation by simply arranging appropriate micro-patterned hole architectures.

When the Hydrophone Works as an Accelerometer

2020 ◽  
Vol 92 (1) ◽  
pp. 365-377
Author(s):  
Giovanni Iannaccone ◽  
Giuseppe Pucciarelli ◽  
Sergio Guardato ◽  
Gian Paolo Donnarumma ◽  
Giovanni Macedonio ◽  
...  
Keyword(s):  
Shallow Water ◽  
Water Pressure ◽  
Vertical Component ◽  
Forced Oscillations ◽  
Campi Flegrei ◽  
Frequency Range ◽  
Ground Acceleration ◽  
Seismic Sensors ◽  
Wide Range ◽  
Amplitude Spectra

Abstract We show the equivalence of earthquake-induced ground acceleration and water-pressure waveforms for the case of collocated hydrophones and seafloor seismometers installed in shallow water. In particular, the comparison of the waveforms and amplitude spectra of the acceleration and water-pressure signals confirms the existence of a frequency range of “forced oscillations” in which the water-pressure variations are proportional to the vertical component of the ground acceleration. We demonstrate the equivalence of the acceleration and water-pressure signals for a set of local earthquakes (epicenter distance of a few tens of kilometers) and regional earthquakes with a wide range of magnitude (2.7<Mw<6.8), recorded by seismometers and hydrophones operating in shallow water (depth less than 80 m) in the Campi Flegrei caldera (southern Italy). We describe the “forced oscillations” theory, and we demonstrate the signals equivalence in the frequency range 0.1–10 Hz, thus extending the frequency range of application of the hydrophones as accelerometers. The high correlation between the ground acceleration, derived from the ground velocity, and hydrophone pressure signals in the mentioned frequency range enables the use of the hydrophone waveforms for standard seismological studies (i.e., earthquake source). The calibration of hydrophones by comparison with collocated accelerometers, or seismometers, is also enabled in a range of frequencies that is very difficult to reproduce in a laboratory. The results of our work also open the possibility of hydrophones being more extensively used in place of accelerometers in marine environments where accurate installation of seismic sensors is difficult or unaffordable.

scholarly journals Advancement of Nanobiomaterials to Deliver Natural Compounds for Tissue Engineering Applications

2020 ◽  
Vol 21 (18) ◽  
pp. 6752
Author(s):  
Sathish Sundar Dhilip Kumar ◽  
Heidi Abrahamse
Keyword(s):  
Tissue Engineering ◽  
Engineering Application ◽  
Natural Compounds ◽  
Treatment Modalities ◽  
Tissue Engineering Application ◽  
Engineering Applications ◽  
Synthetic Drugs ◽  
Medicinal Compounds ◽  
Wide Range ◽  
Clinical Benefits

Recent advancement in nanotechnology has provided a wide range of benefits in the biological sciences, especially in the field of tissue engineering and wound healing. Nanotechnology provides an easy process for designing nanocarrier-based biomaterials for the purpose and specific needs of tissue engineering applications. Naturally available medicinal compounds have unique clinical benefits, which can be incorporated into nanobiomaterials and enhance their applications in tissue engineering. The choice of using natural compounds in tissue engineering improves treatment modalities and can deal with side effects associated with synthetic drugs. In this review article, we focus on advances in the use of nanobiomaterials to deliver naturally available medicinal compounds for tissue engineering application, including the types of biomaterials, the potential role of nanocarriers, and the various effects of naturally available medicinal compounds incorporated scaffolds in tissue engineering.

Temperature Compensation in MEMS Capacitive Pressure Sensors for Harsh Environment Applications

2018 ◽  
Author(s):  
Rahul Jitendrab Suthar ◽  
Mohammad Shavezipur
Keyword(s):  
Ambient Temperature ◽  
Pressure Range ◽  
Metal Layer ◽  
Pressure Sensors ◽  
Thin Metal Film ◽  
Temperature Drift ◽  
Crystal Silicon ◽  
Temperature Changes ◽  
Simulation And Optimization ◽  
Wide Range

A novel design for MEMS capacitive pressure sensors is presented that can effectively eliminate the temperature drift in sensor for high temperature applications. The design uses a bilayer membrane made of a thin metal film deposited on the top of membrane to balance the deformation the membrane experiences when the ambient temperature changes. The thermal expansion mismatch of the metal layer and the membrane results in out-of-plane bending if the temperature changes. This deformation can compensate the deformation in the membrane due to the temperature change. By optimizing the dimensions of the top metal layer (shape and thickness), it is possible to minimize the change in the device capacitance due to temperature rise. A coupled-field multiphysics solver in ANSYS® APDL is used for design, simulation and optimization of the sensor’s structure and to solve the governing equations of the coupled electrostatic and structural physics. The membrane material is silicon carbide (SiC), the top metal layer is nickel (Ni) and the substrate is a single-crystal silicon wafer. The thickness and dimensions of top metal layer is optimized using FEM simulations. The results display a very stable capacitance value for a large pressure range and over a wide range of ambient temperature (0–600°C), demonstrating the proposed design can effectively eliminate the temperature effect. Different pressure values ranging from 0.0 to 20 bars have been examined in the simulations and for most of the pressure range, a highly stable capacitance value is observed with less than 0.5% error over 600 °C temperature range.

Sign in / Sign up

Export Citation Format

Share Document