Equation-Solving DRESOR Method for Radiative Transfer in an Absorbing–Emitting and Isotropically Scattering Slab With Diffuse Boundaries

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Wang Guihua ◽  
Zhou Huaichun ◽  
Cheng Qiang ◽  
Wang Zhichao
Keyword(s):  
Boundary Surface ◽  
Computation Time ◽  
Incident Radiation ◽  
Dimensional System ◽  
Equation Solving ◽  
The Monte Carlo Method ◽  
Order Of Magnitude ◽  
Reflecting Boundaries ◽  
Overall Performance ◽  
Set Up

The distribution of ratios of energy scattered by the medium or reflected by the boundary surface (DRESOR) method can provide radiative intensity with high directional resolution, but also suffers the common drawbacks of the Monte Carlo method (MCM), i.e., it is time-consuming and produces unavoidable statistical errors. In order to overcome the drawbacks of the MCM, the so-called equation-solving DRESOR (ES-DRESOR) method, an equation-solving method to calculate the DRESOR values differently from the MCM used before, was proposed previously. In this method, a unit blackbody emission is supposed within a small zone around a specified point, while there is no emission elsewhere in a plane-parallel, emitting, absorbing, and isotropically scattering medium with transparent boundaries. The set of equations for the DRESOR values based on two expressions for the incident radiation was set up and solved successfully. In this paper, the ES-DRESOR method is extended to a one-dimensional system with diffusely reflecting boundaries. The principle and formulas are given. Several examples with different parameters are taken to examine the performance of the proposed method. The results showed that all the DRESOR values obtained using the ES-DRESOR method agree well with those got using MCM. The average relative error for the intensity obtained by the ES-DRESOR method is 9.446 × 10−6, lower by over 1 order of magnitude than the 2.638 × 10−4 obtained by the MCM under the same conditions. More importantly, the CPU time for computing the DRESOR values, which ranges from several hundred seconds to several thousand seconds using the MCM, is reduced to 0.167 s using the ES-DRESOR method. The computation time is shortened by about 3 orders of magnitude. The overall performance of the ES-DRESOR method is excellent.

Equation Solving DRESOR Method for Radiative Transfer in Three-Dimensional Isotropically Scattering Media

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Zhifeng Huang ◽  
Huaichun Zhou ◽  
Guihua Wang ◽  
Pei-feng Hsu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Computation Time ◽  
Discrete Ordinates ◽  
Distinct Advantage ◽  
Reverse Monte Carlo ◽  
Scattering Media ◽  
Equation Solving ◽  
Radiative Intensity ◽  
The Monte Carlo Method

Distributions of ratios of energy scattered or reflected (DRESOR) method is a very efficient tool used to calculate radiative intensity with high directional resolution, which is very useful for inverse analysis. The method is based on the Monte Carlo (MC) method and it can solve radiative problems of great complexity. Unfortunately, it suffers from the drawbacks of the Monte Carlo method, which are large computation time and unavoidable statistical errors. In this work, an equation solving method is applied to calculate DRESOR values instead of using the Monte Carlo sampling in the DRESOR method. The equation solving method obtains very accurate results in much shorter computation time than when using the Monte Carlo method. Radiative intensity with high directional resolution calculated by these two kinds of DRESOR method is compared with that of the reverse Monte Carlo (RMC) method. The equation solving DRESOR (ES-DRESOR) method has better accuracy and much better time efficiency than the Monte Carlo based DRESOR (original DRESOR) method. The ES-DRESOR method shows a distinct advantage for calculating radiative intensity with high directional resolution compared with the reverse Monte Carlo method and the discrete ordinates method (DOM). Heat flux comparisons are also given and the ES-DRESOR method shows very good accuracy.

scholarly journals Doublel-robot coordination workspace Analysis based on Matlab

2018 ◽  
Vol 232 ◽  
pp. 03057
Author(s):  
Wei Wang ◽  
Yong Xu
Keyword(s):  
Boundary Surface ◽  
Value Theory ◽  
Working Space ◽  
The Monte Carlo Method ◽  
Workspace Analysis ◽  
Solution Equation ◽  
Space Boundary ◽  
Robot Cooperation ◽  
Limit Position ◽  
Cooperation System

Aiming at the requirements of dual robot collaborative operation, a dual robot cooperation system model is established in SolidWorks2012 software to study the dual robot cooperation space. The D-H parameters are established, and the kinematics positive solution equation is obtained. The dual robot cooperative kinematics model is given. Based on the Monte Carlo method, the workspace of the dual robot is solved. The extreme value theory method is used to analyze and calculate, so as to extract the precise boundary contour of the common area of the dual robot workspace, and the collaborative space boundary surface and limit position of the dual robot are determined. The optimal coordinated working space of the dual robot end effector is obtained, which lays a theoretical foundation for the coordinated trajectory planning of the dual robot.

scholarly journals The Response to Stratospheric Forcing and Its Dependence on the State of the Troposphere

2009 ◽  
Vol 66 (7) ◽  
pp. 2107-2115 ◽  
Author(s):  
Cegeon J. Chan ◽  
R. Alan Plumb
Keyword(s):  
Time Scale ◽  
Equilibrium Temperature ◽  
Intrinsic Variability ◽  
Winter Solstice ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Order Of Magnitude ◽  
Leading Mode ◽  
Set Up ◽  
Hemisphere Winter

Abstract In simple GCMs, the time scale associated with the persistence of one particular phase of the model’s leading mode of variability can often be unrealistically large. In a particularly extreme example, the time scale in the Polvani–Kushner model is about an order of magnitude larger than the observed atmosphere. From the fluctuation–dissipation theorem, one implication of these simple models is that responses are exaggerated, since such setups are overly sensitive to any external forcing. Although the model’s equilibrium temperature is set up to represent perpetual Southern Hemisphere winter solstice, it is found that the tropospheric eddy-driven jet has a preference for two distinct regions: the subtropics and midlatitudes. Because of this bimodality, the jet persists in one region for thousands of days before “switching” to another. As a result, the time scale associated with the intrinsic variability is unrealistic. In this paper, the authors systematically vary the model’s tropospheric equilibrium temperature profile, one configuration being identical to that of Polvani and Kushner. Modest changes to the tropospheric state to either side of the parameter space removed the bimodality in the zonal-mean zonal jet’s spatial distribution and significantly reduced the time scale associated with the model’s internal mode. Consequently, the tropospheric response to the same stratospheric forcing is significantly weaker than in the Polvani and Kushner case.

scholarly journals Weekly water-loss from Spherical Water-loss Integrators on a Clearing and below Secondary Growth in Central Amazonia ()

1972 ◽  
Vol 2 (1) ◽  
pp. 33-36 ◽  
Author(s):  
W. L. F. Brinkmann
Keyword(s):  
Solar Radiation ◽  
Water Loss ◽  
Standing Crop ◽  
Secondary Growth ◽  
Tropical Agriculture ◽  
Air Humidity ◽  
Central Amazonia ◽  
Order Of Magnitude ◽  
Set Up ◽  
The Impact

Abstract: Spherical ceramic bulbs were set up as weekly water-loss integrators on a clearing and below a 2 year-old Cecropia-commumty at Km 18 of the Manaus-Itacoatiara Road. The instruments worked well in distinguishing the particular responses of individual sites to the impact of atmospheric agents as solar radiation, air temperature, air humidity and wind. Water-loss was primarily dependent on the order of magnitude of the weekly total of solar radiation and the presence or lack of a standing crop. Already a scarce secondary growth will reduce the weekly amount of water lost to the atmosphere considerably. Shelter-wood, however, considering the crop specific demands if introduced to tropical agriculture would provide favourable conditions as far as the impact of atmospheric controls on the tropical environment are concerned.

scholarly journals Mapping gaseous amines, ammonia, and their particulate counterparts in marine atmospheres of China’s marginal seas: Part 1 – Differentiating marine emission from continental transport

2021 ◽  
Author(s):  
Dihui Chen ◽  
Yanjie Shen ◽  
Juntao Wang ◽  
Yang Gao ◽  
Huiwang Gao ◽  
...  
Keyword(s):  
Significant Negative Correlation ◽  
The Yellow Sea ◽  
Sea Spray ◽  
Marine Atmosphere ◽  
Coastal Site ◽  
Marginal Seas ◽  
Range Transport ◽  
Order Of Magnitude ◽  
Using Data ◽  
Set Up

Abstract. To study sea-derived gaseous amines, ammonia, and primary particulate aminium ions in the marine atmospheres of China's marginal seas, an onboard URG-9000D Ambient Ion Monitor-Ion chromatography (AIM-IC, Thermo Fisher) was set up on the front deck of the R/V Dongfanghong 3 to semi-continuously measure the spatiotemporal variations in the concentrations of atmospheric trimethylamine (TMAgas), dimethylamine (DMAgas), and ammonia (NH3gas) along with their particulate matter (PM2.5) counterparts. In this study, we differentiated marine emissions of the gas species originating from continental transport using data obtained from December 9 to 22, 2019 during the cruise over the Yellow and Bohai Seas, facilitated by additional measurements collected at a coastal site near the Yellow Sea during summer 2019. The data obtained during the cruise and the coastal site demonstrated that the observed TMAgas and protonated trimethylamine (TMAH+) in PM2.5 over the Yellow and Bohai Seas overwhelmingly originated from marine sources. During the cruise, there was no significant correlation (P > 0.05) between the simultaneously measured TMAH+ and TMAgas concentrations. Additionally, the concentrations of TMAH+ in the marine atmosphere varied around 0.28 ± 0.18 μg m−3 (average  ±  standard deviation), with several episodic hourly average values exceeding 1 μg m−3, which were approximately one order of magnitude larger than those of TMAgas (approximately 0.031 ± 0.009 μg m−3). Moreover, there was a significant negative correlation (P < 0.01) between the concentrations of TMAH+ and NH4+ in PM2.5 during the cruise. Therefore, the observed TMAH+ in PM2.5 was overwhelmingly derived from primary sea-spray aerosols. Using the TMAgas and TMAH+ in PM2.5 as tracers for sea-derived basic gases and sea-spray particulate aminium ions, the values of non-sea-derived DMAgas and NH3gas, as well as non-sea-spray particulate DMAH+ in PM2.5, were estimated, and the estimated average values of each species contributed to 16 %, 34 %, and 65 % of the observed average concentrations, respectively. Uncertainties remained in the estimations as TMAH+ may decompose into smaller molecules in seawater to varying extents. The non-sea-derived gases and non-sea-spray particulate DMAH+ likely originated from long-range transport from the upwind continents, according to the recorded offshore winds and increased concentrations of SO42− and NH4+ in PM2.5. The lack of a detectable increase in the particulate DMAH+, NH4+, and SO42− concentrations in several SO2 plumes did not support the secondary formation of particulate DMAH+ in the marine atmosphere.

scholarly journals Enhancement the stability of power system using optimal location of FACTS devices

2020 ◽  
Vol 18 (2) ◽  
pp. 648
Author(s):  
Ali Najim Abdullah ◽  
Ahmed Majeed Ghadhban ◽  
Hayder Salim Hameed ◽  
Husham Idan Hussein
Keyword(s):  
Power Network ◽  
Performance Factors ◽  
Facts Devices ◽  
Clearing Time ◽  
Thyristor Controlled Series Capacitor ◽  
Overall Performance ◽  
Set Up ◽  
The Stability ◽  
And Control ◽  
Better Than

<p><span>This paper proposes a steady-state of the Static Var Compensator (SVC) &amp; Thyristor Controlled Series Capacitor (TCSC) set up for enhancing the damping overall performance and growing the integral clearing time (CCT) of a power network. The indispensable clearing time is carried out through increasing the time fault interval until the gadget loses stability. Increasing the CCT can be contribute to reliability of the safety gadget, decrease the protection machine ranking and cost. In order to attain most enhancement of machine stability via optimizing location, sizing and control modes of SVC and TCSC. Models and methodology for putting and designing shunt FACT’s units SVC (injected reactive strength Q) and series FACT’s devices TCSC (chose capacitive region) are examined in a 6-bus system. Performance factors are described to show validation of SVC and TCSC on extraordinary conditions. It is proven that the SVC is better than TCSC. </span></p>

scholarly journals Method for fast determination of the angle of ionizing radiation incidence from data measured by a Timepix3 detector

2021 ◽  
Vol 10 (1) ◽  
pp. 63-70
Author(s):  
Felix Lehner ◽  
Jürgen Roth ◽  
Oliver Hupe ◽  
Marc Kassubeck ◽  
Benedikt Bergmann ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Incidence Angle ◽  
Computation Time ◽  
Incident Radiation ◽  
Angle Of Incidence ◽  
Time Behavior ◽  
Calculation Algorithm ◽  
3D Geometry ◽  
Photon Event ◽  
Radiation Incidence

Abstract. This paper presents a method of how to determine spatial angles of ionizing radiation incidence quickly, using a Timepix3 detector. This work focuses on the dosimetric applications where detectors and measured quantities show significant angle dependencies. A determined angle of incidence can be used to correct for the angle dependence of a planar Timepix3 detector. Up until now, only passive dosemeters have been able to provide a correct dose and preserve the corresponding incidence angle of the radiation. Unfortunately, passive dosemeters cannot provide this information in “real” time. In our special setup we were able to retrieve the spatial angles with a runtime of less than 600 ms. Employing the new Timepix3 detector enables the use of effective data analysis where the direction of incident radiation is computed from a simple photon event map. In order to obtain this angle, we combine the information extracted from the map with known 3D geometry surrounding the detector. Moreover, we analyze the computation time behavior, conditions and optimizations of the developed spatial angle calculation algorithm.

Balancing Green ICT Business Development with Corporate Social Responsibility (CSR)

2011 ◽  
pp. 607-620
Author(s):  
Marco Garito
Keyword(s):  
Decision Making ◽  
Co2 Emission ◽  
Industrial Revolution ◽  
Positive Impact ◽  
Business Decision ◽  
Personal Level ◽  
Overall Performance ◽  
Green Ict ◽  
Set Up ◽  
Corporate Social

The debate over green ICT has been triggered by media during the climate change summit in Kyoto in 2007. This was when the industry tried to build up a clean and non-polluting image. While the Copenhagen summit on the environment failed to produce a conclusive decision, it is now clear that its carbon footprint is a remarkable factor in all business decision making. Governments around the world have set up defined programs and targets that companies have to reach. ICT is aimed at achieving reduction in the 2% of CO2 emission levels. The advantage of the positive impact of Green ICT initiatives would be seen in the clear results in management‘s decision making. However, the adoption of green ICT programs gives the opportunity to fully rethink over current business process and develop new solutions. The benefit of environmental friendly companies can also affect the overall performance and deliver measurable results in terms of customer‘s preference, brand value, ROI, not to count the needed change of behaviour at individual and personal level (such as waste disposal). The chapter wants to outline those topics and properly address the issues behind what the author considers as equivalent to the next industrial revolution.

scholarly journals Carbaryl Photochemical Degradation on Soil Model Surfaces

Soil Systems ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 17 ◽  
Author(s):  
Marie Siampiringue ◽  
Rajae Chahboune ◽  
Pascal Wong-Wah-Chung ◽  
Mohamed Sarakha
Keyword(s):  
Liquid Chromatography ◽  
Light Exposure ◽  
Degradation Mechanism ◽  
Parent Compound ◽  
Toxicity Tests ◽  
Photochemical Degradation ◽  
First Order Kinetics ◽  
A Value ◽  
Order Of Magnitude ◽  
Set Up

The phototransformation of carbaryl was investigated upon solar light exposure on three surfaces, silica, kaolin and sand, as soil models. By excitation with a Suntest set up at the surface of the three solid supports, the degradation of carbaryl followed first-order kinetics with a rate constant of 0.10 h−1. By using the Kubelka Munk model, the quantum yield disappearance at the surface of kaolin was evaluated to 2.4 × 10−3. Such a value is roughly one order of magnitude higher than that obtained in aqueous solutions. The results indicated that the particle size and the specific surface area of the various models have significant effects. The photo-oxidative properties as well as the byproduct elucidation by liquid chromatography combined with diode arrays (LC-DAD) and liquid chromatography coupled mass spectrometry (LC-MS) analyses allowed us to propose the degradation mechanism pathways. The main products were 1-naphtol and 2-hydroxy-1,4-naphthoquinone, which arise from a photo-oxidation process together with products from photo-Fries, photo-ejection and methyl carbamate hydrolysis. The toxicity tests clearly showed a significant decrease of the toxicity in the early stages of the irradiation. This clearly shows that the generated products are less toxic than the parent compound.

scholarly journals An Efficient Implementation of the Finite-volume Method For the Solution of Radiation Transport in Circuit Breakers

2017 ◽  
Vol 4 (2) ◽  
pp. 177-181
Author(s):  
A. Mazaheri ◽  
J. Y. Trépanier ◽  
R. Camarero ◽  
P. Robin-Jouan
Keyword(s):  
Finite Volume ◽  
Radiation Transport ◽  
Computation Time ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Circuit Breakers ◽  
Explicit Approach ◽  
Order Of Magnitude ◽  
Implicit Approach ◽  
Volume Method

In this paper, we propose to revisit the method to solve the radiation transport equation in circuit breakers to reduce the computation time. It is based on an explicit approach using a space marching algorithm. The method can further be accelerated using a Cartesian grid and using the axisymmetric assumption. Comparisons performed in terms of accuracy and efficiency between the P1 model, the implicit finite-volume discrete ordinate method and the space-marching finite-volume discrete ordinate method show that the explicit approach is more that an order of magnitude faster than the implicit approach, for the same accuracy.

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