Towards Precise Simulation of Optical Elastography Technique

A parallel combination of oil cycle and fossil fuel boiler is utilized in the integrated solar power plant (ISPP) to achieve better efficiency and reduce cost of electricity generation. There are two cycles, oil and steam, in an ISPP. To enhance performance and achieve control optimization more precise simulation for power plant dynamics are needed. In this paper, a dynamic simulation of an ISPP was developed using the HYSYS software. To enhance efficiency and reduce damage to turbine due to flow rate variations of produced steam by oil cycle, the prime control requirement is to maintain the inlet steam temperature and flow rate of the turbine at a constant value. In this paper, to control the complete oil cycle, two fuzzy controllers are proposed: continuous controller and a switching controller. In steam cycle three controllers are proposed for boiler and reboiler heat exchanger. These controllers are used to maintain constant the inlet steam temperature and flow rate to turbine. Simulation results of the integrated solar power plant and the control systems show that the applied control systems can manage the oil and steam cycles in different situations.

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Spatial Simulation of Precipitation Resources in Chongqing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.4261 ◽

2012 ◽

Vol 518-523 ◽

pp. 4261-4265

Author(s):

Xiao Song Lin ◽

Sha Sha Yu ◽

Hai Yan Wang

Keyword(s):

Spatial Distribution ◽

Spatial Interpolation ◽

Regional Difference ◽

Interpolation Method ◽

Annual Precipitation ◽

Regression Equations ◽

Spatial Simulation ◽

Simulation Data ◽

Spatial Interpolation Method ◽

Precise Simulation

Years’ precipitation data of Chongqing from 101 metrological stations has been adopted in the paper and the regression equations between annual precipitation and altitude, longitude, and height have been obtained by the use of SPSS, then elaborate simulation of Chongqing’s precipitation resources based on regression analysis was completed through the 1km×1km grid system and fitted equation. Elaborated simulation of precipitation resources was realized by best spatial interpolation method with the support of GIS; then the results of two different simulation methods were coupled in the form of linear combination to obtain the coupling simulation of spatial distribution of Chongqing’s precipitation resources, finally the precipitation resources were summed up and distributed according to different administration areas at county level and thus obtain precise simulation data of precipitation resources in each county of Chongqing. The results showed that there is a remarkable regional difference in the spatial distribution of precipitation resources of Chongqing, and it decreases from the southeast to the northwest in general, with the annual precipitation higher than 1270mm in southeast and lower than 1080mm in northwest.

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Modeling and Extraction of Parameters Based on Physical Effects in Bipolar Transistors

Active and Passive Electronic Components ◽

10.1155/2011/895247 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8

Author(s):

Agnes Nagy ◽

Alicia Polanco ◽

Manuel Alvarez

Keyword(s):

Integrated Circuits ◽

Extraction Method ◽

Bipolar Transistors ◽

Electronic Systems ◽

Emission Coefficient ◽

Physical Explanation ◽

Simulation Procedure ◽

Physical Effects ◽

Precise Simulation ◽

Theoretical Results

The rising complexity of electronic systems, the reduction of components size, and the increment of working frequencies demand every time more accurate and stable integrated circuits, which require more precise simulation programs during the design process. PSPICE, widely used to simulate the general behavior of integrated circuits, does not consider many of the physical effects that can be found in real devices. Compact models, HICUM and MEXTRAM, have been developed over recent decades, in order to eliminate this deficiency. This paper presents some of the physical aspects that have not been studied so far, such as the expression of base-emitter voltage, including the emitter emission coefficient effect (n), physical explanation and simulation procedure, as well as a new extraction method for the diffusion potentialVDE(T), based on the forward biased base-emitter capacitance, showing excellent agreement between experimental and theoretical results.

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COMPARISON OF FRACTIONAL NOISE DISTRIBUTIONS FOR GENERATING HETEROGENEOUS PERMEABILITY FIELDS IN OIL RESERVOIR SIMULATIONS: A CASE STUDY

Fractals ◽

10.1142/s0218348x18500664 ◽

2018 ◽

Vol 26 (04) ◽

pp. 1850066

Author(s):

MARYAM GHORBANI ◽

MOHAMMAD REZA KHORSAND MOVAGHAR

Keyword(s):

Hurst Exponent ◽

Reservoir Rock ◽

Rock Properties ◽

Heterogeneous Reservoirs ◽

Regionalized Variables ◽

Geostatistical Models ◽

Permeability Distribution ◽

Simulation Results ◽

Core Permeability ◽

Precise Simulation

Prediction of reservoir rock properties, especially permeability distribution is needed for precise simulation of heterogeneous reservoirs. Interwell permeability fields have recently been considered for dynamic simulation using geostatistical models and fractal geometries. The geostatistical models employ experimentally observed variograms to characterize the spatial variability of regionalized variables such as permeability. Fractal models can be useful in assessing the spatial correlation of a property because their variogram can be characterized with a single parameter called the Hurst exponent. In this study, based on core permeability data of each well, Hurst exponent (using [Formula: see text] analysis) is assigned locally to each well by means of stream lines and as averaged value for interwell spaces. Then, permeability distributions are created using Fractional Brownian Motion (FBM) and Fractional Gaussian Noise (FGN) models by implementing fast Fourier transform (FFT). Through comparison between simulation results of these models, as well as real grid simulation results, the averaged distribution was shown to give better results over a locally assigned fractal distribution. Furthermore, predictions of field pressure using the FGN model were shown to function better than the FBM model for vertical wells.

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Camera-based optical palpation

Scientific Reports ◽

10.1038/s41598-020-72603-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Rowan W. Sanderson ◽

Qi Fang ◽

Andrea Curatolo ◽

Wayne Adams ◽

Devina D. Lakhiani ◽

...

Keyword(s):

Spatial Resolution ◽

Digital Camera ◽

Base Material ◽

Cost Effective ◽

Digital Photograph ◽

Imaging Tool ◽

Measured Strain ◽

Dense Distribution ◽

Optical Elastography ◽

The Relationship

Abstract Optical elastography is undergoing extensive development as an imaging tool to map mechanical contrast in tissue. Here, we present a new platform for optical elastography by generating sub-millimetre-scale mechanical contrast from a simple digital camera. This cost-effective, compact and easy-to-implement approach opens the possibility to greatly expand applications of optical elastography both within and beyond the field of medical imaging. Camera-based optical palpation (CBOP) utilises a digital camera to acquire photographs that quantify the light intensity transmitted through a silicone layer comprising a dense distribution of micro-pores (diameter, 30–100 µm). As the transmission of light through the micro-pores increases with compression, we deduce strain in the layer directly from intensity in the digital photograph. By pre-characterising the relationship between stress and strain of the layer, the measured strain map can be converted to an optical palpogram, a map of stress that visualises mechanical contrast in the sample. We demonstrate a spatial resolution as high as 290 µm in CBOP, comparable to that achieved using an optical coherence tomography-based implementation of optical palpation. In this paper, we describe the fabrication of the micro-porous layer and present experimental results from structured phantoms containing stiff inclusions as small as 0.5 × 0.5 × 1 mm. In each case, we demonstrate high contrast between the inclusion and the base material and validate both the contrast and spatial resolution achieved using finite element modelling. By performing CBOP on freshly excised human breast tissue, we demonstrate the capability to delineate tumour from surrounding benign tissue.

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