Massive parallel 3D PIC simulation of negative ion extraction

NASA Astrophysics Data System (ADS)

Revel, Adrien; Mochalskyy, Serhiy; Montellano, Ivar Mauricio; Wünderlich, Dirk; Fantz, Ursel; Minea, Tiberiu

2017-09-01

The 3D PIC-MCC code ONIX is dedicated to modeling Negative hydrogen/deuterium Ion (NI) extraction and co-extraction of electrons from radio-frequency driven, low pressure plasma sources. It provides valuable insight on the complex phenomena involved in the extraction process. In previous calculations, a mesh size larger than the Debye length was used, implying numerical electron heating. Important steps have been achieved in terms of computation performance and parallelization efficiency allowing successful massive parallel calculations (4096 cores), imperative to resolve the Debye length. In addition, the numerical algorithms have been improved in terms of grid treatment, i.e., the electric field near the complex geometry boundaries (plasma grid) is calculated more accurately. The revised model preserves the full 3D treatment, but can take advantage of a highly refined mesh. ONIX was used to investigate the role of the mesh size, the re-injection scheme for lost particles (extracted or wall absorbed), and the electron thermalization process on the calculated extracted current and plasma characteristics. It is demonstrated that all numerical schemes give the same NI current distribution for extracted ions. Concerning the electrons, the pair-injection technique is found well-adapted to simulate the sheath in front of the plasma grid.

Economic Analysis of an Integrated Annatto Seeds-Sugarcane Biorefinery Using Supercritical CO2 Extraction as a First Step

PubMed Central

Albarelli, Juliana Q.; Santos, Diego T.; Cocero, María José; Meireles, M. Angela A.

2016-01-01

Recently, supercritical fluid extraction (SFE) has been indicated to be utilized as part of a biorefinery, rather than as a stand-alone technology, since besides extracting added value compounds selectively it has been shown to have a positive effect on the downstream processing of biomass. To this extent, this work evaluates economically the encouraging experimental results regarding the use of SFE during annatto seeds valorization. Additionally, other features were discussed such as the benefits of enhancing the bioactive compounds concentration through physical processes and of integrating the proposed annatto seeds biorefinery to a hypothetical sugarcane biorefinery, which produces its essential inputs, e.g., CO2, ethanol, heat and electricity. For this, first, different configurations were modeled and simulated using the commercial simulator Aspen Plus® to determine the mass and energy balances. Next, each configuration was economically assessed using MATLAB. SFE proved to be decisive to the economic feasibility of the proposed annatto seeds-sugarcane biorefinery concept. SFE pretreatment associated with sequential fine particles separation process enabled higher bixin-rich extract production using low-pressure solvent extraction method employing ethanol, meanwhile tocotrienols-rich extract is obtained as a first product. Nevertheless, the economic evaluation showed that increasing tocotrienols-rich extract production has a more pronounced positive impact on the economic viability of the concept. PMID:28773616

Processing of Lunar Soil Simulant for Space Exploration Applications

NASA Technical Reports Server (NTRS)

Sen, Subhayu; Ray, Chandra S.; Reddy, Ramana

2005-01-01

NASA's long-term vision for space exploration includes developing human habitats and conducting scientific investigations on planetary bodies, especially on Moon and Mars. To reduce the level of up-mass processing and utilization of planetary in-situ resources is recognized as an important element of this vision. Within this scope and context, we have undertaken a general effort aimed primarily at extracting and refining metals, developing glass, glass-ceramic, or traditional ceramic type materials using lunar soil simulants. In this paper we will present preliminary results on our effort on carbothermal reduction of oxides for elemental extraction and zone refining for obtaining high purity metals. In additions we will demonstrate the possibility of developing glasses from lunar soil simulant for fixing nuclear waste from potential nuclear power generators on planetary bodies. Compositional analysis, x-ray diffraction patterns and differential thermal analysis of processed samples will be presented.

CPU and GPU-based Numerical Simulations of Combustion Processes

DTIC Science & Technology

2012-04-27

Distribution unlimited UCLA MAE Research and Technology Review April 27, 2012 Magnetohydrodynamic Augmentation of the Pulse Detonation Rocket Engines...Pulse Detonation Rocket-Induced MHD Ejector (PDRIME) – Energy extract from exhaust flow by MHD generator – Seeded air stream acceleration by MHD...accelerator for thrust enhancement and control • Alternative concept: Magnetic piston – During PDE blowdown process, MHD extracts energy and

Sample Results From The Extraction, Scrub, And Strip Test For The Blended NGS Solvent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washington, A. L. II; Peters, T. B.

This report summarizes the results of the extraction, scrub, and strip testing for the September 2013 sampling of the Next Generation Solvent (NGS) Blended solvent from the Modular Caustic Side-Solvent Extraction Unit (MCU) Solvent Hold Tank. MCU is in the process of transitioning from the BOBCalixC6 solvent to the NGS Blend solvent. As part of that transition, MCU has intentionally created a blended solvent to be processed using the Salt Batch program. This sample represents the first sample received from that blended solvent. There were two ESS tests performed where NGS blended solvent performance was assessed using either the Tankmore » 21 material utilized in the Salt Batch 7 analyses or a simulant waste material used in the V-5/V-10 contactor testing. This report tabulates the temperature corrected cesium distribution, or D Cs values, step recovery percentage, and actual temperatures recorded during the experiment. This report also identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. The calculated extraction D Cs values using the Tank 21H material and simulant are 59.4 and 53.8, respectively. The DCs values for two scrub and three strip processes for the Tank 21 material are 4.58, 2.91, 0.00184, 0.0252, and 0.00575, respectively. The D-values for two scrub and three strip processes for the simulant are 3.47, 2.18, 0.00468, 0.00057, and 0.00572, respectively. These values are similar to previous measurements of Salt Batch 7 feed with lab-prepared blended solvent. These numbers are considered compatible to allow simulant testing to be completed in place of actual waste due to the limited availability of feed material.« less

Automated Extraction of Flow Features

NASA Technical Reports Server (NTRS)

Dorney, Suzanne (Technical Monitor); Haimes, Robert

2005-01-01

Computational Fluid Dynamics (CFD) simulations are routinely performed as part of the design process of most fluid handling devices. In order to efficiently and effectively use the results of a CFD simulation, visualization tools are often used. These tools are used in all stages of the CFD simulation including pre-processing, interim-processing, and post-processing, to interpret the results. Each of these stages requires visualization tools that allow one to examine the geometry of the device, as well as the partial or final results of the simulation. An engineer will typically generate a series of contour and vector plots to better understand the physics of how the fluid is interacting with the physical device. Of particular interest are detecting features such as shocks, re-circulation zones, and vortices (which will highlight areas of stress and loss). As the demand for CFD analyses continues to increase the need for automated feature extraction capabilities has become vital. In the past, feature extraction and identification were interesting concepts, but not required in understanding the physics of a steady flow field. This is because the results of the more traditional tools like; isc-surface, cuts and streamlines, were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of a great deal of interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one "snapshot" of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments). Methods must be developed to abstract the feature of interest and display it in a manner that physically makes sense.

Automated Extraction of Flow Features

NASA Technical Reports Server (NTRS)

Dorney, Suzanne (Technical Monitor); Haimes, Robert

2004-01-01

Computational Fluid Dynamics (CFD) simulations are routinely performed as part of the design process of most fluid handling devices. In order to efficiently and effectively use the results of a CFD simulation, visualization tools are often used. These tools are used in all stages of the CFD simulation including pre-processing, interim-processing, and post-processing, to interpret the results. Each of these stages requires visualization tools that allow one to examine the geometry of the device, as well as the partial or final results of the simulation. An engineer will typically generate a series of contour and vector plots to better understand the physics of how the fluid is interacting with the physical device. Of particular interest are detecting features such as shocks, recirculation zones, and vortices (which will highlight areas of stress and loss). As the demand for CFD analyses continues to increase the need for automated feature extraction capabilities has become vital. In the past, feature extraction and identification were interesting concepts, but not required in understanding the physics of a steady flow field. This is because the results of the more traditional tools like; iso-surface, cuts and streamlines, were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of a great deal of interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one "snapshot" of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for (co-processing environments). Methods must be developed to abstract the feature of interest and display it in a manner that physically makes sense.

Reactive extraction at liquid-liquid systems

NASA Astrophysics Data System (ADS)

Wieszczycka, Karolina

2018-01-01

The chapter summarizes the state of knowledge about a metal transport in two-phase system. The first part of this review focuses on the distribution law and main factors determination in classical solvent extraction (solubility and polarity of the solute, as well as inter- and intramolecules interaction. Next part of the chapter is devoted to the reactive solvent extraction and the molecular modeling requiring knowledge on type of extractants, complexation mechanisms, metals ions speciation and oxidation during complexes forming, and other parameters that enable to understand the extraction process. Also the kinetic data that is needed for proper modeling, simulation and design of processes needed for critical separations are discussed. Extraction at liquid-solid system using solvent impregnated resins is partially identical as in the case of the corresponding solvent extraction, therefore this subject was also presented in all aspects of separation process (equilibrium, mechanism, kinetics).

Thermo-mechanical simulation of liquid-supported stretch blow molding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmer, J.; Stommel, M.

2015-05-22

Stretch blow molding is the well-established plastics forming method to produce Polyehtylene therephtalate (PET) bottles. An injection molded preform is heated up above the PET glass transition temperature (Tg∼85°C) and subsequently inflated by pressurized air into a closed cavity. In the follow-up filling process, the resulting bottle is filled with the final product. A recently developed modification of the process combines the blowing and filling stages by directly using the final liquid product to inflate the preform. In a previously published paper, a mechanical simulation and successful evaluation of this liquid-driven stretch blow molding process was presented. In this way,more » a realistic process parameter dependent simulation of the preform deformation throughout the forming process was enabled, whereas the preform temperature evolution during forming was neglected. However, the formability of the preform is highly reduced when the temperature sinks below Tg during forming. Experimental investigations show temperature-induced failure cases due to the fast heat transfer between hot preform and cold liquid. Therefore, in this paper, a process dependent simulation of the temperature evolution during processing to avoid preform failure is presented. For this purpose, the previously developed mechanical model is used to extract the time dependent thickness evolution. This information serves as input for the heat transfer simulation. The required material parameters are calibrated from preform cooling experiments recorded with an infrared-camera. Furthermore, the high deformation ratios during processing lead to strain induced crystallization. This exothermal reaction is included into the simulation by extracting data from preform measurements at different stages of deformation via Differential Scanning Calorimetry (DSC). Finally, the thermal simulation model is evaluated by free forming experiments, recorded by a high-speed infrared camera.« less

Aluminothermic Reduction-Molten Salt Electrolysis Using Inert Anode for Oxygen and Al-Base Alloy Extraction from Lunar Soil Simulant

NASA Astrophysics Data System (ADS)

Xie, Kaiyu; Shi, Zhongning; Xu, Junli; Hu, Xianwei; Gao, Bingliang; Wang, Zhaowen

2017-10-01

Aluminothermic reduction-electrolysis using an inert anode process is proposed to extract oxygen and metals from Minnesota Lunar Simulant-1 (MLS-1). Effective aluminothermic reduction between dissolved MLS-1 and dissolved metal aluminum was achieved in cryolite salt media. The product phases obtained by aluminothermic reduction at 980°C for 4 h were Al, Si, and Al5FeSi, while the chemical components were 79.71 mass% aluminum, 12.03 mass% silicon, 5.91 mass% iron, and 2.35 mass% titanium. The cryolite salt containing Al2O3 was subsequently electrolyzed with Fe0.58-Ni0.42 inert anode at 960°C for 4 h. Oxygen was evolved at the anode with an anodic current efficiency of 78.28%. The results demonstrate that this two-step process is remarkably feasible for the extraterrestrial extraction of oxygen and metals. This process will help expand the existing in situ resource utilization methods.

Modelling dental implant extraction by pullout and torque procedures.

PubMed

Rittel, D; Dorogoy, A; Shemtov-Yona, K

2017-07-01

Dental implants extraction, achieved either by applying torque or pullout force, is used to estimate the bone-implant interfacial strength. A detailed description of the mechanical and physical aspects of the extraction process in the literature is still missing. This paper presents 3D nonlinear dynamic finite element simulations of a commercial implant extraction process from the mandible bone. Emphasis is put on the typical load-displacement and torque-angle relationships for various types of cortical and trabecular bone strengths. The simulations also study of the influence of the osseointegration level on those relationships. This is done by simulating implant extraction right after insertion when interfacial frictional contact exists between the implant and bone, and long after insertion, assuming that the implant is fully bonded to the bone. The model does not include a separate representation and model of the interfacial layer for which available data is limited. The obtained relationships show that the higher the strength of the trabecular bone the higher the peak extraction force, while for application of torque, it is the cortical bone which might dictate the peak torque value. Information on the relative strength contrast of the cortical and trabecular components, as well as the progressive nature of the damage evolution, can be revealed from the obtained relations. It is shown that full osseointegration might multiply the peak and average load values by a factor 3-12 although the calculated work of extraction varies only by a factor of 1.5. From a quantitative point of view, it is suggested that, as an alternative to reporting peak load or torque values, an average value derived from the extraction work be used to better characterize the bone-implant interfacial strength. Copyright © 2017 Elsevier Ltd. All rights reserved.

Alkaline-side extraction of technetium from tank waste using crown ethers and other extractants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonnesen, P.V.; Moyer, B.A.; Presley, D.J.

The chemical development of a new crown-ether-based solvent-extraction process for the separation of (Tc) from alkaline tank-waste supernate is ready for counter-current testing. The process addresses a priority need in the proposed cleanup of Hanford and other tank wastes. This need has arisen from concerns due to the volatility of Tc during vitrification, as well as {sup 99}Tc`s long half-life and environmental mobility. The new process offers several key advantages that direct treatability--no adjustment of the waste composition is needed; economical stripping with water; high efficiency--few stages needed; non-RCRA chemicals--no generation of hazardous or mixed wastes; co-extraction of {sup 90}Sr;more » and optional concentration on a resin. A key concept advanced in this work entails the use of tandem techniques: solvent extraction offers high selectivity, while a subsequent column sorption process on the aqueous stripping solution serves to greatly concentrate the Tc. Optionally, the stripping solution can be evaporated to a small volume. Batch tests of the solvent-extraction and stripping components of the process have been conducted on actual melton Valley Storage Tank (MVST) waste as well as simulants of MVST and Hanford waste. The tandem process was demonstrated on MVST waste simulants using the three solvents that were selected the final candidates for the process. The solvents are 0.04 M bis-4,4{prime}(5{prime})[(tert-butyl)cyclohexano]-18-crown-6 (abbreviated di-t-BuCH18C6) in a 1:1 vol/vol blend of tributyl phosphate and Isopar{reg_sign} M (an isoparaffinic kerosene); 0.02 M di-t-BuCH18C6 in 2:1 vol/vol TBP/Isopar M and pure TBP. The process is now ready for counter-current testing on actual Hanford tank supernates.« less

Process-Structure Linkages Using a Data Science Approach: Application to Simulated Additive Manufacturing Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popova, Evdokia; Rodgers, Theron M.; Gong, Xinyi

A novel data science workflow is developed and demonstrated to extract process-structure linkages (i.e., reduced-order model) for microstructure evolution problems when the final microstructure depends on (simulation or experimental) processing parameters. Our workflow consists of four main steps: data pre-processing, microstructure quantification, dimensionality reduction, and extraction/validation of process-structure linkages. These methods that can be employed within each step vary based on the type and amount of available data. In this paper, this data-driven workflow is applied to a set of synthetic additive manufacturing microstructures obtained using the Potts-kinetic Monte Carlo (kMC) approach. Additive manufacturing techniques inherently produce complex microstructures thatmore » can vary significantly with processing conditions. Using the developed workflow, a low-dimensional data-driven model was established to correlate process parameters with the predicted final microstructure. In addition, the modular workflows developed and presented in this work facilitate easy dissemination and curation by the broader community.« less

Process-Structure Linkages Using a Data Science Approach: Application to Simulated Additive Manufacturing Data

DOE PAGES

Popova, Evdokia; Rodgers, Theron M.; Gong, Xinyi; ...

2017-03-13

A novel data science workflow is developed and demonstrated to extract process-structure linkages (i.e., reduced-order model) for microstructure evolution problems when the final microstructure depends on (simulation or experimental) processing parameters. Our workflow consists of four main steps: data pre-processing, microstructure quantification, dimensionality reduction, and extraction/validation of process-structure linkages. These methods that can be employed within each step vary based on the type and amount of available data. In this paper, this data-driven workflow is applied to a set of synthetic additive manufacturing microstructures obtained using the Potts-kinetic Monte Carlo (kMC) approach. Additive manufacturing techniques inherently produce complex microstructures thatmore » can vary significantly with processing conditions. Using the developed workflow, a low-dimensional data-driven model was established to correlate process parameters with the predicted final microstructure. In addition, the modular workflows developed and presented in this work facilitate easy dissemination and curation by the broader community.« less

Two-structured solid particle model for predicting and analyzing supercritical extraction performance.

PubMed

Samadi, Sara; Vaziri, Behrooz Mahmoodzadeh

2017-07-14

Solid extraction process, using the supercritical fluid, is a modern science and technology, which has come in vogue regarding its considerable advantages. In the present article, a new and comprehensive model is presented for predicting the performance and separation yield of the supercritical extraction process. The base of process modeling is partial differential mass balances. In the proposed model, the solid particles are considered twofold: (a) particles with intact structure, (b) particles with destructed structure. A distinct mass transfer coefficient has been used for extraction of each part of solid particles to express different extraction regimes and to evaluate the process accurately (internal mass transfer coefficient was used for the intact-structure particles and external mass transfer coefficient was employed for the destructed-structure particles). In order to evaluate and validate the proposed model, the obtained results from simulations were compared with two series of available experimental data for extraction of chamomile extract with supercritical carbon dioxide, which had an excellent agreement. This is indicative of high potentiality of the model in predicting the extraction process, precisely. In the following, the effect of major parameters on supercritical extraction process, like pressure, temperature, supercritical fluid flow rate, and the size of solid particles was evaluated. The model can be used as a superb starting point for scientific and experimental applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of wavelet transformation and adaptive neighborhood based modified backpropagation (ANMBP) for classification of brain cancer

NASA Astrophysics Data System (ADS)

Werdiningsih, Indah; Zaman, Badrus; Nuqoba, Barry

2017-08-01

This paper presents classification of brain cancer using wavelet transformation and Adaptive Neighborhood Based Modified Backpropagation (ANMBP). Three stages of the processes, namely features extraction, features reduction, and classification process. Wavelet transformation is used for feature extraction and ANMBP is used for classification process. The result of features extraction is feature vectors. Features reduction used 100 energy values per feature and 10 energy values per feature. Classifications of brain cancer are normal, alzheimer, glioma, and carcinoma. Based on simulation results, 10 energy values per feature can be used to classify brain cancer correctly. The correct classification rate of proposed system is 95 %. This research demonstrated that wavelet transformation can be used for features extraction and ANMBP can be used for classification of brain cancer.

Production of neutron-rich nuclei approaching r-process by gamma-induced fission of 238U at ELI-NP

NASA Astrophysics Data System (ADS)

Mei, Bo; Balabanski, Dimiter; Constantin, Paul; Anh Le, Tuan; Viet Cuong, Phan

2018-05-01

The investigation of neutron-rich exotic nuclei is crucial not only for nuclear physics but also for nuclear astrophysics. Experimentally, only few neutron-rich nuclei near the stability have been studied, however, most neutron-rich nuclei have not been measured due to their small production cross sections as well as short half-lives. At ELI-NP, gamma beams with high intensities will open new opportunities to investigate very neutron-rich fragments produced by photofission of 238U targets in a gas cell. Based on some simulations, a novel gas cell has been designed to produce, stop and extract 238U photofission fragments. The extraction time and efficiency of photofission fragments have been optimized by using SIMION simulations. According to these simulations, a high extraction efficiency and a short extraction time can be achieved for 238U photofission fragments in the gas cell, which will allow one to measure very neutron-rich fragments with short half-lives by using the IGISOL facility proposed at ELI-NP.

Detection of Nanosilver Agents in Antibacterial Textiles

NASA Astrophysics Data System (ADS)

Xu, Chengtao; Zhao, Jie; Wu, Jianjian; Nie, Jinmei; Cui, Chengmin; Xie, Weibin; Zhang, Yan

2018-01-01

The analytical techniques are needed to detect the nanosilver in textiles in direct contact with skin. In this paper, in order to discuss the extraction of nanosilver on the surface of textiles by human skin, we demonstrate the capability of constant temperature oscillation extraction method followed by Inductively Coupled Plasma Spectroscopy (ICP). The sweat and deionized water were selected as extraction solvent simulating the contact process of human skin with textiles. The SEM and TEM analysis shows the existence of nanosilver in the fabric and aqueous extract. ICP analysis shows accurately when analysing silver amounts in the range of 0.05∼1.2 mg/L with r2 values of 0.9997. The percent recoveries of all fabrics were all lower than 44 %.The results shows that the developed method of simulating of human sweat extraction was not very effective. So the nanosilver might not be transferred to human body effectively from the fabric.

Kinetics of ultrasound-assisted extraction of antioxidant polyphenols from food by-products: Extraction and energy consumption optimization.

PubMed

Pradal, Delphine; Vauchel, Peggy; Decossin, Stéphane; Dhulster, Pascal; Dimitrov, Krasimir

2016-09-01

Ultrasound-assisted extraction (UAE) of antioxidant polyphenols from chicory grounds was studied in order to propose a suitable valorization of this food industry by-product. The main parameters influencing the extraction process were identified. A new mathematical model for multi-criteria optimization of UAE was proposed. This kinetic model permitted the following and the prediction of the yield of extracted polyphenols, the antioxidant activity of the obtained extracts and the energy consumption during the extraction process in wide ranges of temperature (20-60°C), ethanol content in the solvent (0-60% (vol.) in ethanol-water mixtures) and ultrasound power (0-100W). After experimental validation of the model, several simulations at different technological restrictions were performed to illustrate the potentiality of the model to find the optimal conditions for obtaining a given yield within minimal process duration or with minimal energy consumption. The advantage of ultrasound assistance was clearly demonstrated both for the reduction of extraction duration and for the reduction of energy consumption. Copyright © 2016 Elsevier B.V. All rights reserved.

Cavity Optical Pulse Extraction: ultra-short pulse generation as seeded Hawking radiation.

PubMed

Eilenberger, Falk; Kabakova, Irina V; de Sterke, C Martijn; Eggleton, Benjamin J; Pertsch, Thomas

2013-01-01

We show that light trapped in an optical cavity can be extracted from that cavity in an ultrashort burst by means of a trigger pulse. We find a simple analytic description of this process and show that while the extracted pulse inherits its pulse length from that of the trigger pulse, its wavelength can be completely different. Cavity Optical Pulse Extraction is thus well suited for the development of ultrashort laser sources in new wavelength ranges. We discuss similarities between this process and the generation of Hawking radiation at the optical analogue of an event horizon with extremely high Hawking temperature. Our analytic predictions are confirmed by thorough numerical simulations.

Cavity Optical Pulse Extraction: ultra-short pulse generation as seeded Hawking radiation

PubMed Central

Eilenberger, Falk; Kabakova, Irina V.; de Sterke, C. Martijn; Eggleton, Benjamin J.; Pertsch, Thomas

2013-01-01

We show that light trapped in an optical cavity can be extracted from that cavity in an ultrashort burst by means of a trigger pulse. We find a simple analytic description of this process and show that while the extracted pulse inherits its pulse length from that of the trigger pulse, its wavelength can be completely different. Cavity Optical Pulse Extraction is thus well suited for the development of ultrashort laser sources in new wavelength ranges. We discuss similarities between this process and the generation of Hawking radiation at the optical analogue of an event horizon with extremely high Hawking temperature. Our analytic predictions are confirmed by thorough numerical simulations. PMID:24060831

Experimental Measurements of Heat Transfer through a Lunar Regolith Simulant in a Vibro-Fluidized Reactor Oven

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Berger, Gordon M.; Sacksteder, Kurt R.; Paz, Aaron

2012-01-01

Extraction of mission consumable resources such as water and oxygen from the planetary environment provides valuable reduction in launch-mass and potentially extends the mission duration. Processing of lunar regolith for resource extraction necessarily involves heating and chemical reaction of solid material with processing gases. Vibrofluidization is known to produce effective mixing and control of flow within granular media. In this study we present experimental results for vibrofluidized heat transfer in lunar regolith simulants (JSC-1 and JSC-1A) heated up to 900 C. The results show that the simulant bed height has a significant influence on the vibration induced flow field and heat transfer rates. A taller bed height leads to a two-cell circulation pattern whereas a single-cell circulation was observed for a shorter height. Lessons learned from these test results should provide insight into efficient design of future robotic missions involving In-Situ Resource Utilization.

Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previousmore » ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.« less

Influence of olive leaf processing on the bioaccessibility of bioactive polyphenols.

PubMed

Ahmad-Qasem, Margarita H; Cánovas, Jaime; Barrajón-Catalán, Enrique; Carreres, José E; Micol, Vicente; García-Pérez, José V

2014-07-02

Olive leaves are rich in bioactive compounds, which are beneficial for humans. The objective of this work was to assess the influence of processing conditions (drying and extraction) of olive leaves on the extract's bioaccessibility. Thus, extracts obtained from dried olive leaves (hot air drying at 70 and 120 °C or freeze-drying) by means of conventional or ultrasound-assisted extraction were subjected to in vitro digestion. Antioxidant capacity, total phenolic content, and HPLC-DAD/MS/MS analysis were carried out during digestion. The dehydration treatment used for the olive leaves did not have a meaningful influence on bioaccessibility. The digestion process significantly (p<0.05) affected the composition of the extracts. Oleuropein and verbascoside were quite resistant to gastric digestion but were largely degraded in the intestinal phase. Nevertheless, luteolin-7-O-glucoside was the most stable polyphenol during the in vitro simulation (43% bioaccessibility). Therefore, this compound may be taken into consideration in further studies that focus on the bioactivity of olive leaf extracts.

User's guide to the SEPHIS computer code for calculating the Thorex solvent extraction system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, S.B.; Rainey, R.H.

1979-05-01

The SEPHIS computer program was developed to simulate the countercurrent solvent extraction process. The code has now been adapted to model the Acid Thorex flow sheet. This report represents a practical user's guide to SEPHIS - Thorex containing a program description, user information, program listing, and sample input and output.

Geothermal reservoir simulation of hot sedimentary aquifer system using FEFLOW®

NASA Astrophysics Data System (ADS)

Nur Hidayat, Hardi; Gala Permana, Maximillian

2017-12-01

The study presents the simulation of hot sedimentary aquifer for geothermal utilization. Hot sedimentary aquifer (HSA) is a conduction-dominated hydrothermal play type utilizing deep aquifer, which is heated by near normal heat flow. One of the examples of HSA is Bavarian Molasse Basin in South Germany. This system typically uses doublet wells: an injection and production well. The simulation was run for 3650 days of simulation time. The technical feasibility and performance are analysed in regards to the extracted energy from this concept. Several parameters are compared to determine the model performance. Parameters such as reservoir characteristics, temperature information and well information are defined. Several assumptions are also defined to simplify the simulation process. The main results of the simulation are heat period budget or total extracted heat energy, and heat rate budget or heat production rate. Qualitative approaches for sensitivity analysis are conducted by using five parameters in which assigned lower and higher value scenarios.

In vitro antioxidant, antimicrobial and anti-proliferative activities of purple potato extracts (Solanum tuberosum cv Vitelotte noire) following simulated gastro-intestinal digestion.

PubMed

Ombra, Maria Neve; Fratianni, Florinda; Granese, Tiziana; Cardinale, Federica; Cozzolino, Autilia; Nazzaro, Filomena

2015-01-01

Analyses of antioxidant and in vitro antimicrobial and anti-proliferative activities of anthocyanin-rich extracts from purple potatoes, Solanum tuberosum L. cv Vitelotte noire (Solanaceae), were performed by simulating both a domestic cooking process and human digestion. Extracts of crude and cooked purple potato did not exhibit antimicrobial activity against the tester strains: Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. The behaviour changed after the simulated gastrointestinal transit, when an inhibition halo was observed against all tester strains used, ranging from 0.53 cm against B. cereus to 0.82 cm against E. coli. In addition antioxidant activity exhibited, before and after the simulated gastrointestinal digestion (5.96 mg/mL ± 0.92; 28 mg/mL ± 0 .13, respectively) and the persistence of anti-proliferative activity against the colon cancer cells Caco-2, SW48 and MCF7, MDA-MB-231 breast cancer cells, after the simulated digestion, (EC50 = 0.21; 1.13 μg/mL), suggest that vitelotte consumption might bring tangible benefits for human health.

Application of computational fluid dynamics for the simulation of cryogenic molecular sieve bed absorber of hydrogen isotopes recovery system for Indian LLCB-TBM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gayathri Devi, V.; Sircar, A.; Sarkar, B.

One of the most challenging tasks in the design of the fuel cycle system lies in the effective design of Tritium Extraction System (TES) which involves proper extraction and purification of tritium in the fuel cycle of the fusion reactor. Indian Lead Lithium cooled Ceramic Breeder Test Blanket Module (LLCB-TBM) would extract hydrogen isotopes through Cryogenic Molecular Sieve Bed (CMSB) adsorber system. A prototype Hydrogen Isotopes Recovery System (HIRS) is being developed to validate the concepts for tritium extraction by adsorption mass transfer mechanism. In this study, a design model has been developed and analyzed to simulate the adsorption massmore » transfer kinetics in a fixed bed adsorption column. The simulation leads primarily to effective design of HIRS, which is a state-of-the-art technology. The paper describes the process simulation approach and the results of Computational Fluid Dynamics (CFD) analysis. The effects of different operating conditions are studied to investigate their influence on the hydrogen isotopes adsorption capacity. The results of the present simulation study would be used to understand the best optimized transport phenomenon before realizing the TES as a system for LLCB-TBM. (authors)« less

Parallel processing of real-time dynamic systems simulation on OSCAR (Optimally SCheduled Advanced multiprocessoR)

NASA Technical Reports Server (NTRS)

Kasahara, Hironori; Honda, Hiroki; Narita, Seinosuke

1989-01-01

Parallel processing of real-time dynamic systems simulation on a multiprocessor system named OSCAR is presented. In the simulation of dynamic systems, generally, the same calculation are repeated every time step. However, we cannot apply to Do-all or the Do-across techniques for parallel processing of the simulation since there exist data dependencies from the end of an iteration to the beginning of the next iteration and furthermore data-input and data-output are required every sampling time period. Therefore, parallelism inside the calculation required for a single time step, or a large basic block which consists of arithmetic assignment statements, must be used. In the proposed method, near fine grain tasks, each of which consists of one or more floating point operations, are generated to extract the parallelism from the calculation and assigned to processors by using optimal static scheduling at compile time in order to reduce large run time overhead caused by the use of near fine grain tasks. The practicality of the scheme is demonstrated on OSCAR (Optimally SCheduled Advanced multiprocessoR) which has been developed to extract advantageous features of static scheduling algorithms to the maximum extent.

Simulation of target interpretation based on infrared image features and psychology principle

NASA Astrophysics Data System (ADS)

Lin, Wei; Chen, Yu-hua; Gao, Hong-sheng; Wang, Zhan-feng; Wang, Ji-jun; Su, Rong-hua; Huang, Yan-ping

2009-07-01

It's an important and complicated process in target interpretation that target features extraction and identification, which effect psychosensorial quantity of interpretation person to target infrared image directly, and decide target viability finally. Using statistical decision theory and psychology principle, designing four psychophysical experiment, the interpretation model of the infrared target is established. The model can get target detection probability by calculating four features similarity degree between target region and background region, which were plotted out on the infrared image. With the verification of a great deal target interpretation in practice, the model can simulate target interpretation and detection process effectively, get the result of target interpretation impersonality, which can provide technique support for target extraction, identification and decision-making.

Study on fermentation kinetics and extraction process of rhamnolipid production by papermaking wastewater

NASA Astrophysics Data System (ADS)

Yu, Keer

2018-01-01

Paper mill wastewater (PMW) is the outlet water generated during pulp and papermaking process in the paper industry. Fermentation by wastewater can lower the cost of production as well as alleviate the pressure of wastewater treatment. Rhamnolipids find broad placations as natural surfactants. This paper studied the rhamnolipids fermentation by employing Pseudomonas aeruginosa isolated by the laboratory, and determined to use wastewater which filtered by medium speed filter paper and strain Z2, the culture conditions were optimized, based on the flask shaking fermentation. On the basis of 5L tank fermentation, batch fermentation was carried out, the yield of fermentation reached 7.067g/L and the fermentation kinetics model of cell growth, product formation and substrate consumption was established by using origin software, and the fermentation process could be simulated well. And studied on the extraction process of rhamnolipids, through fermentation dynamic equation analysis can predict the in fill material yield can be further improved. Research on the extraction process of rhamnolipid simplifies the operation of extraction, and lays the foundation for the industrial extraction.

Parallel Visualization Co-Processing of Overnight CFD Propulsion Applications

NASA Technical Reports Server (NTRS)

Edwards, David E.; Haimes, Robert

1999-01-01

An interactive visualization system pV3 is being developed for the investigation of advanced computational methodologies employing visualization and parallel processing for the extraction of information contained in large-scale transient engineering simulations. Visual techniques for extracting information from the data in terms of cutting planes, iso-surfaces, particle tracing and vector fields are included in this system. This paper discusses improvements to the pV3 system developed under NASA's Affordable High Performance Computing project.

Parameter extraction using global particle swarm optimization approach and the influence of polymer processing temperature on the solar cell parameters

NASA Astrophysics Data System (ADS)

Kumar, S.; Singh, A.; Dhar, A.

2017-08-01

The accurate estimation of the photovoltaic parameters is fundamental to gain an insight of the physical processes occurring inside a photovoltaic device and thereby to optimize its design, fabrication processes, and quality. A simulative approach of accurately determining the device parameters is crucial for cell array and module simulation when applied in practical on-field applications. In this work, we have developed a global particle swarm optimization (GPSO) approach to estimate the different solar cell parameters viz., ideality factor (η), short circuit current (Isc), open circuit voltage (Voc), shunt resistant (Rsh), and series resistance (Rs) with wide a search range of over ±100 % for each model parameter. After validating the accurateness and global search power of the proposed approach with synthetic and noisy data, we applied the technique to the extract the PV parameters of ZnO/PCDTBT based hybrid solar cells (HSCs) prepared under different annealing conditions. Further, we examine the variation of extracted model parameters to unveil the physical processes occurring when different annealing temperatures are employed during the device fabrication and establish the role of improved charge transport in polymer films from independent FET measurements. The evolution of surface morphology, optical absorption, and chemical compositional behaviour of PCDTBT co-polymer films as a function of processing temperature has also been captured in the study and correlated with the findings from the PV parameters extracted using GPSO approach.

Image processing strategies based on saliency segmentation for object recognition under simulated prosthetic vision.

PubMed

Li, Heng; Su, Xiaofan; Wang, Jing; Kan, Han; Han, Tingting; Zeng, Yajie; Chai, Xinyu

2018-01-01

Current retinal prostheses can only generate low-resolution visual percepts constituted of limited phosphenes which are elicited by an electrode array and with uncontrollable color and restricted grayscale. Under this visual perception, prosthetic recipients can just complete some simple visual tasks, but more complex tasks like face identification/object recognition are extremely difficult. Therefore, it is necessary to investigate and apply image processing strategies for optimizing the visual perception of the recipients. This study focuses on recognition of the object of interest employing simulated prosthetic vision. We used a saliency segmentation method based on a biologically plausible graph-based visual saliency model and a grabCut-based self-adaptive-iterative optimization framework to automatically extract foreground objects. Based on this, two image processing strategies, Addition of Separate Pixelization and Background Pixel Shrink, were further utilized to enhance the extracted foreground objects. i) The results showed by verification of psychophysical experiments that under simulated prosthetic vision, both strategies had marked advantages over Direct Pixelization in terms of recognition accuracy and efficiency. ii) We also found that recognition performance under two strategies was tied to the segmentation results and was affected positively by the paired-interrelated objects in the scene. The use of the saliency segmentation method and image processing strategies can automatically extract and enhance foreground objects, and significantly improve object recognition performance towards recipients implanted a high-density implant. Copyright © 2017 Elsevier B.V. All rights reserved.

Membrane Permeability of Fatty Acyl Compounds Studied via Molecular Simulation

DOE PAGES

Vermaas, Josh V.; Beckham, Gregg T.; Crowley, Michael F.

2017-10-17

Interest in fatty acid-derived products as fuel and chemical precursors has grown substantially. Microbes can be genetically engineered to produce fatty acid-derived products that are able to cross host membranes and can be extracted into an applied organic overlay. This process is thought to be passive, with a rate dependent on the chemistry of the crossing compound. The relationship between the chemical composition and the energetics and kinetics of product accumulation within the overlay is not well understood. Through biased and unbiased molecular simulation, we compute the membrane permeability coefficients from production to extraction for different fatty acyl products, includingmore » fatty acids, fatty alcohols, fatty aldehydes, alkanes, and alkenes. These simulations identify specific interactions that accelerate the transit of aldehydes across the membrane bilayer relative to other oxidized products, specifically the lack of hydrogen bonds to the surrounding membrane environment. However, since extraction from the outer membrane leaflet into the organic phase is found to be rate limiting for the entire process, we find that fatty alcohols and fatty aldehydes would both manifest similar fluxes into a dodecane overlay under equivalent conditions, outpacing the accumulation of acids or alkanes into the organic phase. Since aldehydes are known to be highly reactive as well as toxic in high quantities, the findings suggest that indeed fatty alcohols are the optimal long-tail fatty acyl product for extraction.« less

Membrane Permeability of Fatty Acyl Compounds Studied via Molecular Simulation.

PubMed

Vermaas, Josh V; Beckham, Gregg T; Crowley, Michael F

2017-12-21

Interest in fatty acid-derived products as fuel and chemical precursors has grown substantially. Microbes can be genetically engineered to produce fatty acid-derived products that are able to cross host membranes and can be extracted into an applied organic overlay. This process is thought to be passive, with a rate dependent on the chemistry of the crossing compound. The relationship between the chemical composition and the energetics and kinetics of product accumulation within the overlay is not well understood. Through biased and unbiased molecular simulation, we compute the membrane permeability coefficients from production to extraction for different fatty acyl products, including fatty acids, fatty alcohols, fatty aldehydes, alkanes, and alkenes. These simulations identify specific interactions that accelerate the transit of aldehydes across the membrane bilayer relative to other oxidized products, specifically the lack of hydrogen bonds to the surrounding membrane environment. However, since extraction from the outer membrane leaflet into the organic phase is found to be rate limiting for the entire process, we find that fatty alcohols and fatty aldehydes would both manifest similar fluxes into a dodecane overlay under equivalent conditions, outpacing the accumulation of acids or alkanes into the organic phase. Since aldehydes are known to be highly reactive as well as toxic in high quantities, the findings suggest that indeed fatty alcohols are the optimal long-tail fatty acyl product for extraction.

Membrane Permeability of Fatty Acyl Compounds Studied via Molecular Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vermaas, Josh V.; Beckham, Gregg T.; Crowley, Michael F.

Interest in fatty acid-derived products as fuel and chemical precursors has grown substantially. Microbes can be genetically engineered to produce fatty acid-derived products that are able to cross host membranes and can be extracted into an applied organic overlay. This process is thought to be passive, with a rate dependent on the chemistry of the crossing compound. The relationship between the chemical composition and the energetics and kinetics of product accumulation within the overlay is not well understood. Through biased and unbiased molecular simulation, we compute the membrane permeability coefficients from production to extraction for different fatty acyl products, includingmore » fatty acids, fatty alcohols, fatty aldehydes, alkanes, and alkenes. These simulations identify specific interactions that accelerate the transit of aldehydes across the membrane bilayer relative to other oxidized products, specifically the lack of hydrogen bonds to the surrounding membrane environment. However, since extraction from the outer membrane leaflet into the organic phase is found to be rate limiting for the entire process, we find that fatty alcohols and fatty aldehydes would both manifest similar fluxes into a dodecane overlay under equivalent conditions, outpacing the accumulation of acids or alkanes into the organic phase. Since aldehydes are known to be highly reactive as well as toxic in high quantities, the findings suggest that indeed fatty alcohols are the optimal long-tail fatty acyl product for extraction.« less

Numerical simulation of stress distribution in Inconel 718 components realized by metal injection molding during supercritical debinding

NASA Astrophysics Data System (ADS)

Agne, Aboubakry; Barrière, Thierry

2018-05-01

Metal injection molding (MIM) is a process combining advantages of thermoplastic injection molding and powder metallurgy process in order to manufacture components with complex and near net-shape geometries. The debinding of a green component can be performed in two steps, first by using solvent debinding in order to extract the organic part of the binder and then by thermal degradation of the rest of the binder. A shorter and innovative method for extracting an organic binder involves the use of supercritical fluid instead of a regular solvent. The debinding via a supercritical fluid was recently investigated to extract organic binders contained in components obtained by Metal Injection Molding. It consists to put the component in an enclosure subjected to high pressure and temperature. The supercritical fluid has various properties depending on these two conditions, e.g., density and viscosity. The high-pressure combined with the high temperature during the process affect the component structure. Three mechanisms contributing to the deformation of the component can been differentiated: thermal expansion, binder extraction and supercritical fluid effect on the outer surfaces of the component. If one supposes that, the deformation due to binder extraction is negligible, thermal expansion and the fluid effect are probably the main mechanisms that can produce several stress. A finite-element model, which couples fluid-structures interaction and structural mechanics, has been developed and performed on the Comsol Multiphysics® finite-element software platform allowed to estimate the stress distribution during the supercritical debinding of MIM component composed of Inconel 718 powders, polypropylene, polyethylene glycol and stearic acid as binder. The proposed numerical simulations allow the estimation of the stress distribution with respect to the processing parameters for MIM components during the supercritical debinding process using a stationary solver.

Profiling of poorly stratified smoky atmospheres with scanning lidar

Treesearch

Vladimir Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

2012-01-01

The multiangle data processing technique is considered based on using the signal measured in zenith (or close to zenith) as a core source for extracting the information about the vertical atmospheric aerosol loading. The multiangle signals are used as the auxiliary data to extract the vertical transmittance profile from the zenith signal. Simulated and experimental...

SPECTROSCOPIC ONLINE MONITORING FOR PROCESS CONTROL AND SAFEGUARDING OF RADIOCHEMICAL STREAMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Samuel A.; Levitskaia, Tatiana G.

2013-09-29

There is a renewed interest worldwide to promote the use of nuclear power and close the nuclear fuel cycle. The long term successful use of nuclear power is critically dependent upon adequate and safe processing and disposition of the used nuclear fuel. Liquid-liquid extraction is a separation technique commonly employed for the processing of the dissolved used nuclear fuel. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices. This paper summarizes application of the absorption and vibrational spectroscopicmore » techniques supplemented by physicochemical measurements for radiochemical process monitoring. In this context, our team experimentally assessed the potential of Raman and spectrophotometric techniques for online real-time monitoring of the U(VI)/nitrate ion/nitric acid and Pu(IV)/Np(V)/Nd(III), respectively, in solutions relevant to spent fuel reprocessing. These techniques demonstrate robust performance in the repetitive batch measurements of each analyte in a wide concentration range using simulant and commercial dissolved spent fuel solutions. Spectroscopic measurements served as training sets for the multivariate data analysis to obtain partial least squares predictive models, which were validated using on-line centrifugal contactor extraction tests. Satisfactory prediction of the analytes concentrations in these preliminary experiments warrants further development of the spectroscopy-based methods for radiochemical process control and safeguarding. Additionally, the ability to identify material intentionally diverted from a liquid-liquid extraction contactor system was successfully tested using on-line process monitoring as a means to detect the amount of material diverted. A chemical diversion and detection from a liquid-liquid extraction scheme was demonstrated using a centrifugal contactor system operating with the simulant PUREX extraction system of Nd(NO3)3/nitric acid aqueous phase and TBP/n-dodecane organic phase. During a continuous extraction experiment, a portion of the feed from a counter-current extraction system was diverted while the spectroscopic on-line process monitoring system was simultaneously measuring the feed, raffinate and organic products streams. The amount observed to be diverted by on-line spectroscopic process monitoring was in excellent agreement with values based from the known mass of sample directly taken (diverted) from system feed solution.« less

[Comparison of two algorithms for development of design space-overlapping method and probability-based method].

PubMed

Shao, Jing-Yuan; Qu, Hai-Bin; Gong, Xing-Chu

2018-05-01

In this work, two algorithms (overlapping method and the probability-based method) for design space calculation were compared by using the data collected from extraction process of Codonopsis Radix as an example. In the probability-based method, experimental error was simulated to calculate the probability of reaching the standard. The effects of several parameters on the calculated design space were studied, including simulation number, step length, and the acceptable probability threshold. For the extraction process of Codonopsis Radix, 10 000 times of simulation and 0.02 for the calculation step length can lead to a satisfactory design space. In general, the overlapping method is easy to understand, and can be realized by several kinds of commercial software without coding programs, but the reliability of the process evaluation indexes when operating in the design space is not indicated. Probability-based method is complex in calculation, but can provide the reliability to ensure that the process indexes can reach the standard within the acceptable probability threshold. In addition, there is no probability mutation in the edge of design space by probability-based method. Therefore, probability-based method is recommended for design space calculation. Copyright© by the Chinese Pharmaceutical Association.

Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, C.; et al.

We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge withmore » the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed.« less

The Roles of Beneficiation in Lunar Work

NASA Technical Reports Server (NTRS)

Rickman, Doug L.

2010-01-01

Natural feedstocks used for any process are intrinsically variable. They may also contain deleterious components or low concentrations of desired fractions. For these three reasons it is standard industrial practice to beneficiate feedstocks. This is true across all industries which trans-form raw materials into standardized units. On the Moon there are three natural resources: vacuum, radiation and regolith. To utilize in situ resources on the Moon it is reasonable to presume some beneficiation of the regolith (ground rock) resource will be desirable if not essential. As on Earth, this will require fundamental understanding of the physics and chemistry of the relevant processes, which are exceeding complex in detail. Further, simulants are essential test articles for evaluation of components and systems planned for lunar deployment. Simulants are of course made from geologic feedstocks. Therefore, there is variation, deleterious components and incorrect concentrations of desired fractions in the feedstocks used for simulants. Thus, simulant production can benefit from beneficiation of the input feedstocks. Beneficiation of geologic feedstocks is the subject of extractive metallurgy. Clearly, NASA has two discrete interests pertaining to the science and technology of extractive metallurgy.

Feasibility of Surfactant-Free Supported Emulsion Liquid Membrane Extraction

NASA Technical Reports Server (NTRS)

Hu, Shih-Yao B.; Li, Jin; Wiencek, John M.

2001-01-01

Supported emulsion liquid membrane (SELM) is an effective means to conduct liquid-liquid extraction. SELM extraction is particularly attractive for separation tasks in the microgravity environment where density difference between the solvent and the internal phase of the emulsion is inconsequential and a stable dispersion can be maintained without surfactant. In this research, dispersed two-phase flow in SELM extraction is modeled using the Lagrangian method. The results show that SELM extraction process in the microgravity environment can be simulated on earth by matching the density of the solvent and the stripping phase. Feasibility of surfactant-free SELM (SFSELM) extraction is assessed by studying the coalescence behavior of the internal phase in the absence of the surfactant. Although the contacting area between the solvent and the internal phase in SFSELM extraction is significantly less than the area provided by regular emulsion due to drop coalescence, it is comparable to the area provided by a typical hollow-fiber membrane. Thus, the stripping process is highly unlikely to become the rate-limiting step in SFSELM extraction. SFSELM remains an effective way to achieve simultaneous extraction and stripping and is able to eliminate the equilibrium limitation in the typical solvent extraction processes. The SFSELM design is similar to the supported liquid membrane design in some aspects.

Mars Aqueous Processing System

NASA Technical Reports Server (NTRS)

Berggren, Mark; Wilson, Cherie; Carrera, Stacy; Rose, Heather; Muscatello, Anthony; Kilgore, James; Zubrin, Robert

2012-01-01

The goal of the Mars Aqueous Processing System (MAPS) is to establish a flexible process that generates multiple products that are useful for human habitation. Selectively extracting useful components into an aqueous solution, and then sequentially recovering individual constituents, can obtain a suite of refined or semi-refined products. Similarities in the bulk composition (although not necessarily of the mineralogy) of Martian and Lunar soils potentially make MAPS widely applicable. Similar process steps can be conducted on both Mars and Lunar soils while tailoring the reaction extents and recoveries to the specifics of each location. The MAPS closed-loop process selectively extracts, and then recovers, constituents from soils using acids and bases. The emphasis on Mars involves the production of useful materials such as iron, silica, alumina, magnesia, and concrete with recovery of oxygen as a byproduct. On the Moon, similar chemistry is applied with emphasis on oxygen production. This innovation has been demonstrated to produce high-grade materials, such as metallic iron, aluminum oxide, magnesium oxide, and calcium oxide, from lunar and Martian soil simulants. Most of the target products exhibited purities of 80 to 90 percent or more, allowing direct use for many potential applications. Up to one-fourth of the feed soil mass was converted to metal, metal oxide, and oxygen products. The soil residue contained elevated silica content, allowing for potential additional refining and extraction for recovery of materials needed for photovoltaic, semiconductor, and glass applications. A high-grade iron oxide concentrate derived from lunar soil simulant was used to produce a metallic iron component using a novel, combined hydrogen reduction/metal sintering technique. The part was subsequently machined and found to be structurally sound. The behavior of the lunar-simulant-derived iron product was very similar to that produced using the same methods on a Michigan iron ore concentrate, which demonstrates that lunar-derived material can be used in a manner similar to conventional terrestrial iron. Metallic iron was also produced from the Mars soil simulant. The aluminum and magnesium oxide products produced by MAPS from lunar and Mars soil simulants exhibited excellent thermal stability, and were shown to be capable of use for refractory oxide structural materials, or insulation at temperatures far in excess of what could be achieved using unrefined soils. These materials exhibited the refractory characteristics needed to support iron casting and forming operations, as well as other thermal processing needs. Extraction residue samples contained up to 79 percent silica. Such samples were successfully fused into a glass that exhibited high light transmittance.

Complementary experimental-simulational study of surfactant micellar phase in the extraction process of metallic ions: Effects of temperature and salt concentration

NASA Astrophysics Data System (ADS)

Soto-Ángeles, Alan Gustavo; Rodríguez-Hidalgo, María del Rosario; Soto-Figueroa, César; Vicente, Luis

2018-02-01

The thermoresponsive micellar phase behaviour that exhibits the Triton-X-100 micelles by temperature effect and addition of salt in the extraction process of metallic ions was explored from mesoscopic and experimental points. In the theoretical study, we analyse the formation of Triton-X-100 micelles, load and stabilization of dithizone molecules and metallic ions extraction inside the micellar core at room temperature; finally, a thermal analysis is presented. In the experimental study, the spectrophotometric outcomes confirm the solubility of the copper-dithizone complex in the micellar core, as well as the extraction of metallic ions of aqueous environment via a cloud-point at 332.2 K. The micellar solutions with salt present a low absorbance value compared with the micellar solutions without salt. The decrease in the absorbance value is attributed to a change in the size of hydrophobic region of colloidal micelles. All transitory stages of extraction process are discussed and analysed in this document.

Optimization of enzymatic extraction of pectin from Opuntia ficus indica cladodes after mucilage removal.

PubMed

Bayar, Nadia; Friji, Marwa; Kammoun, Radhouane

2018-02-15

In this study, pectin was isolated from Opuntia ficus indica (OFI) cladodes after removing mucilage using the xylanase and cellulase. The process variables were optimized by the Box Behnken design with three factors at three levels. The optimal extraction condition obtained was: liquid to solid (LS), cellulase to xylanase and enzymes to matter ratios of 22ml/g, 2:1U/U and 4U/g, respectively. The simulated extraction yield of 17.91% was validated by the experimental result (16.67±0.30). The enzyme-extracted pectin from OFI cladodes (EAEPC) was low methylated, with a high uronic acid content, a water and oil holding capacity of 5.42g/g and 1.23g/g, respectively, a good foam and emulsion stability and important DPPH radical scavenging activity. Both the OFI cladodes and enzymatic process present promising alternatives to traditional sources and extraction processes of pectin, respectively. EAEPC thus represents a promising additive in food industries. Copyright © 2017. Published by Elsevier Ltd.

Comparative study of beam losses and heat loads reduction methods in MITICA beam source

NASA Astrophysics Data System (ADS)

Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

2014-02-01

In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

Analysis of the production process of optically pure D-lactic acid from raw glycerol using engineered Escherichia coli strains.

PubMed

Posada, John A; Cardona, Carlos A; Gonzalez, Ramon

2012-02-01

Glycerol has become an ideal feedstock for producing fuels and chemicals. Here, five technological schemes for optically pure D: -lactic acid production from raw glycerol were designed, simulated, and economically assessed based on five fermentative scenarios using engineered Escherichia coli strains. Fermentative scenarios considered different qualities of glycerol (pure, 98 wt.%, and crude, 85 wt.%) with concentrations ranging from 20 to 60 g/l in the fermentation media, and two fermentation stages were also analyzed. Raw glycerol (60 wt.%) was considered as the feedstock feeding the production process in all cases; then a purification process of raw glycerol up to the required quality was required. Simulation processes were carried out using Aspen Plus, while economic assessments were performed using Aspen Icarus Process Evaluator. D: -Lactic acid recovery and purification processes were based on reactive extraction with tri-n-octylamine using dichloromethane as active extractant agent. The use of raw glycerol represents only between 2.4% and 7.8% of the total production costs. Also, the total production costs obtained of D: -lactic acid in all cases were lower than its sale price indicating that these processes are potentially profitable. Thus, the best configuration process requires the use of crude glycerol diluted at 40 g/l with total glycerol consumption and with D: -lactic acid recovering by reactive extraction. The lowest obtained total production cost was 1.015 US$/kg with a sale price/production cost ratio of 1.53.

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

DOE PAGES

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

2015-09-02

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Optimization of the Ethanol Recycling Reflux Extraction Process for Saponins Using a Design Space Approach

PubMed Central

Gong, Xingchu; Zhang, Ying; Pan, Jianyang; Qu, Haibin

2014-01-01

A solvent recycling reflux extraction process for Panax notoginseng was optimized using a design space approach to improve the batch-to-batch consistency of the extract. Saponin yields, total saponin purity, and pigment yield were defined as the process critical quality attributes (CQAs). Ethanol content, extraction time, and the ratio of the recycling ethanol flow rate and initial solvent volume in the extraction tank (RES) were identified as the critical process parameters (CPPs) via quantitative risk assessment. Box-Behnken design experiments were performed. Quadratic models between CPPs and process CQAs were developed, with determination coefficients higher than 0.88. As the ethanol concentration decreases, saponin yields first increase and then decrease. A longer extraction time leads to higher yields of the ginsenosides Rb1 and Rd. The total saponin purity increases as the ethanol concentration increases. The pigment yield increases as the ethanol concentration decreases or extraction time increases. The design space was calculated using a Monte-Carlo simulation method with an acceptable probability of 0.90. Normal operation ranges to attain process CQA criteria with a probability of more than 0.914 are recommended as follows: ethanol content of 79–82%, extraction time of 6.1–7.1 h, and RES of 0.039–0.040 min−1. Most of the results of the verification experiments agreed well with the predictions. The verification experiment results showed that the selection of proper operating ethanol content, extraction time, and RES within the design space can ensure that the CQA criteria are met. PMID:25470598

Using the HARV simulation aerodynamic model to determine forebody strake aerodynamic coefficients from flight data

NASA Technical Reports Server (NTRS)

Messina, Michael D.

1995-01-01

The method described in this report is intended to present an overview of a process developed to extract the forebody aerodynamic increments from flight tests. The process to determine the aerodynamic increments (rolling pitching, and yawing moments, Cl, Cm, Cn, respectively) for the forebody strake controllers added to the F/A - 18 High Alpha Research Vehicle (HARV) aircraft was developed to validate the forebody strake aerodynamic model used in simulation.

NASA Space Engineering Research Center for Utilization of Local Planetary Resources

NASA Technical Reports Server (NTRS)

Ramohalli, Kumar; Lewis, John S.

1989-01-01

Progress toward the goal of exploiting extraterrestrial resources for space missions is documented. Some areas of research included are as follows: Propellant and propulsion optimization; Automation of propellant processing with quantitative simulation; Ore reduction through chlorination and free radical production; Characterization of lunar ilmenite and its simulants; Carbothermal reduction of ilmenite with special reference to microgravity chemical reactor design; Gaseous carbonyl extraction and purification of ferrous metals; Overall energy management; and Information management for space processing.

Antioxidant effects of gastrointestinal digested purple carrot extract on the human cells of colonic mucosa.

PubMed

Olejnik, Anna; Rychlik, Joanna; Kidoń, Marcin; Czapski, Janusz; Kowalska, Katarzyna; Juzwa, Wojciech; Olkowicz, Mariola; Dembczyński, Radosław; Moyer, Mary Pat

2016-01-01

Purple carrot (PC) is a potential dietary constituent, which represents a valuable source of antioxidants and can modulate the reactive oxygen species (ROS) level in the gastrointestinal tract. Antioxidant capacity of a PC extract subjected to digestion process simulated in the artificial alimentary tract, including the stomach, small intestine and colon, was analyzed in normal human cells of colon mucosa. Results indicated that the extract obtained upon passage through the gastrointestinal tract, which could come into contact with the colonic cells in situ, was less potent than the extract, which was not subjected to digestion process. Digested PC extract exhibited intracellular ROS-inhibitory capacity, with 1mg/mL showing the ROS clearance of 18.4%. A 20.7% reduction in oxidative DNA damage due to colon mucosa cells' treatment with digested PC extract was observed. These findings indicate that PC extract is capable of colonic cells' protection against the adverse effects of oxidative stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

Plasma Processing of Lunar Regolith Simulant for Diverse Applications

NASA Technical Reports Server (NTRS)

Schofield, Elizabeth C.; Sen, Subhayu; O'Dell, J. Scott

2008-01-01

Versatile manufacturing technologies for extracting resources from the moon are needed to support future space missions. Of particular interest is the production of gases and metals from lunar resources for life support, propulsion, and in-space fabrication. Deposits made from lunar regolith could yield highly emissive coatings and near-net shaped parts for replacement or repair of critical components. Equally important is development of high fidelity lunar simulants for ground based validation of potential lunar surface operations. Described herein is an innovative plasma processing technique for insitu production of gases, metals, coatings, and deposits from lunar regolith, and synthesis of high fidelity lunar simulant from NASA issued lunar simulant JSC-1. Initial plasma reduction trials of JSC-1 lunar simulant have indicated production of metallic iron and magnesium. Evolution of carbon monoxide has been detected subsequent to reduction of the simulant using the plasma process. Plasma processing of the simulant has also resulted in glassy phases resembling the volcanic glass and agglutinates found in lunar regolith. Complete and partial glassy phase deposits have been obtained by varying the plasma process variables. Experimental techniques, product characterization, and process gas analysis will be discussed.

Radar image enhancement and simulation as an aid to interpretation and training

NASA Technical Reports Server (NTRS)

Frost, V. S.; Stiles, J. A.; Holtzman, J. C.; Dellwig, L. F.; Held, D. N.

1980-01-01

Greatly increased activity in the field of radar image applications in the coming years demands that techniques of radar image analysis, enhancement, and simulation be developed now. Since the statistical nature of radar imagery differs from that of photographic imagery, one finds that the required digital image processing algorithms (e.g., for improved viewing and feature extraction) differ from those currently existing. This paper addresses these problems and discusses work at the Remote Sensing Laboratory in image simulation and processing, especially for systems comparable to the formerly operational SEASAT synthetic aperture radar.

Chatter detection in milling process based on VMD and energy entropy

NASA Astrophysics Data System (ADS)

Liu, Changfu; Zhu, Lida; Ni, Chenbing

2018-05-01

This paper presents a novel approach to detect the milling chatter based on Variational Mode Decomposition (VMD) and energy entropy. VMD has already been employed in feature extraction from non-stationary signals. The parameters like number of modes (K) and the quadratic penalty (α) need to be selected empirically when raw signal is decomposed by VMD. Aimed at solving the problem how to select K and α, the automatic selection method of VMD's based on kurtosis is proposed in this paper. When chatter occurs in the milling process, energy will be absorbed to chatter frequency bands. To detect the chatter frequency bands automatically, the chatter detection method based on energy entropy is presented. The vibration signal containing chatter frequency is simulated and three groups of experiments which represent three cutting conditions are conducted. To verify the effectiveness of method presented by this paper, chatter feather extraction has been successfully employed on simulation signals and experimental signals. The simulation and experimental results show that the proposed method can effectively detect the chatter.

Sensitivity analysis of coupled processes and parameters on the performance of enhanced geothermal systems.

PubMed

Pandey, S N; Vishal, Vikram

2017-12-06

3-D modeling of coupled thermo-hydro-mechanical (THM) processes in enhanced geothermal systems using the control volume finite element code was done. In a first, a comparative analysis on the effects of coupled processes, operational parameters and reservoir parameters on heat extraction was conducted. We found that significant temperature drop and fluid overpressure occurred inside the reservoirs/fracture that affected the transport behavior of the fracture. The spatio-temporal variations of fracture aperture greatly impacted the thermal drawdown and consequently the net energy output. The results showed that maximum aperture evolution occurred near the injection zone instead of the production zone. Opening of the fracture reduced the injection pressure required to circulate a fixed mass of water. The thermal breakthrough and heat extraction strongly depend on the injection mass flow rate, well distances, reservoir permeability and geothermal gradients. High permeability caused higher water loss, leading to reduced heat extraction. From the results of TH vs THM process simulations, we conclude that appropriate coupling is vital and can impact the estimates of net heat extraction. This study can help in identifying the critical operational parameters, and process optimization for enhanced energy extraction from a geothermal system.

Wakefield Simulation of CLIC PETS Structure Using Parallel 3D Finite Element Time-Domain Solver T3P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, A.; Kabel, A.; Lee, L.

In recent years, SLAC's Advanced Computations Department (ACD) has developed the parallel 3D Finite Element electromagnetic time-domain code T3P. Higher-order Finite Element methods on conformal unstructured meshes and massively parallel processing allow unprecedented simulation accuracy for wakefield computations and simulations of transient effects in realistic accelerator structures. Applications include simulation of wakefield damping in the Compact Linear Collider (CLIC) power extraction and transfer structure (PETS).

Ionization Electron Signal Processing in Single Phase LArTPCs II. Data/Simulation Comparison and Performance in MicroBooNE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, C.; et al.

The single-phase liquid argon time projection chamber (LArTPC) provides a large amount of detailed information in the form of fine-grained drifted ionization charge from particle traces. To fully utilize this information, the deposited charge must be accurately extracted from the raw digitized waveforms via a robust signal processing chain. Enabled by the ultra-low noise levels associated with cryogenic electronics in the MicroBooNE detector, the precise extraction of ionization charge from the induction wire planes in a single-phase LArTPC is qualitatively demonstrated on MicroBooNE data with event display images, and quantitatively demonstrated via waveform-level and track-level metrics. Improved performance of inductionmore » plane calorimetry is demonstrated through the agreement of extracted ionization charge measurements across different wire planes for various event topologies. In addition to the comprehensive waveform-level comparison of data and simulation, a calibration of the cryogenic electronics response is presented and solutions to various MicroBooNE-specific TPC issues are discussed. This work presents an important improvement in LArTPC signal processing, the foundation of reconstruction and therefore physics analyses in MicroBooNE.« less

The behaviour of tributyl phosphate in an organic diluent

NASA Astrophysics Data System (ADS)

Leay, Laura; Tucker, Kate; Del Regno, Annalaura; Schroeder, Sven L. M.; Sharrad, Clint A.; Masters, Andrew J.

2014-09-01

Tributyl phosphate (TBP) is used as a complexing agent in the Plutonium Uranium Extraction (PUREX) liquid-liquid phase extraction process for recovering uranium and plutonium from spent nuclear reactor fuel. Here, we address the molecular and microstructure of the organic phases involved in the extraction process, using molecular dynamics to show that when TBP is mixed with a paraffinic diluent, the TBP self-assembles into a bi-continuous phase. The underlying self-association of TBP is driven by intermolecular interaction between its polar groups, resulting in butyl moieties radiating out into the organic solvent. Simulation predicts a TBP diffusion constant that is anomalously low compared to what might normally be expected for its size; experimental nuclear magnetic resonance (NMR) studies also indicate an extremely low diffusion constant, consistent with a molecular aggregation model. Simulation of TBP at an oil/water interface shows the formation of a bilayer system at low TBP concentrations. At higher concentrations, a bulk bi-continuous structure is observed linking to this surface bilayer. We suggest that this structure may be intimately connected with the surprisingly rapid kinetics of the interfacial mass transport of uranium and plutonium from the aqueous to the organic phase in the PUREX process.

Quantitative image processing in fluid mechanics

NASA Technical Reports Server (NTRS)

Hesselink, Lambertus; Helman, James; Ning, Paul

1992-01-01

The current status of digital image processing in fluid flow research is reviewed. In particular, attention is given to a comprehensive approach to the extraction of quantitative data from multivariate databases and examples of recent developments. The discussion covers numerical simulations and experiments, data processing, generation and dissemination of knowledge, traditional image processing, hybrid processing, fluid flow vector field topology, and isosurface analysis using Marching Cubes.

Modelling and simulation of a moving interface problem: freeze drying of black tea extract

NASA Astrophysics Data System (ADS)

Aydin, Ebubekir Sıddık; Yucel, Ozgun; Sadikoglu, Hasan

2017-06-01

The moving interface separates the material that is subjected to the freeze drying process as dried and frozen. Therefore, the accurate modeling the moving interface reduces the process time and energy consumption by improving the heat and mass transfer predictions during the process. To describe the dynamic behavior of the drying stages of the freeze-drying, a case study of brewed black tea extract in storage trays including moving interface was modeled that the heat and mass transfer equations were solved using orthogonal collocation method based on Jacobian polynomial approximation. Transport parameters and physical properties describing the freeze drying of black tea extract were evaluated by fitting the experimental data using Levenberg-Marquardt algorithm. Experimental results showed good agreement with the theoretical predictions.

Noisy text categorization.

PubMed

Vinciarelli, Alessandro

2005-12-01

This work presents categorization experiments performed over noisy texts. By noisy, we mean any text obtained through an extraction process (affected by errors) from media other than digital texts (e.g., transcriptions of speech recordings extracted with a recognition system). The performance of a categorization system over the clean and noisy (Word Error Rate between approximately 10 and approximately 50 percent) versions of the same documents is compared. The noisy texts are obtained through handwriting recognition and simulation of optical character recognition. The results show that the performance loss is acceptable for Recall values up to 60-70 percent depending on the noise sources. New measures of the extraction process performance, allowing a better explanation of the categorization results, are proposed.

Image Processing

NASA Technical Reports Server (NTRS)

1987-01-01

A new spinoff product was derived from Geospectra Corporation's expertise in processing LANDSAT data in a software package. Called ATOM (for Automatic Topographic Mapping), it's capable of digitally extracting elevation information from stereo photos taken by spaceborne cameras. ATOM offers a new dimension of realism in applications involving terrain simulations, producing extremely precise maps of an area's elevations at a lower cost than traditional methods. ATOM has a number of applications involving defense training simulations and offers utility in architecture, urban planning, forestry, petroleum and mineral exploration.

Teaching Process Simulation in Eleven Easy Lessons Using Excel and Its Tools

NASA Astrophysics Data System (ADS)

Morris, Arthur E.

The primary market driver for improving process technology is innovation, which requires a skilled and educated workforce. However, many Materials Science and Engineering departments have eliminated extractive metallurgy and chemical thermodynamics from their curricula, yet these topics contain the necessary fundamentals for process innovation. As a result, most MS&E students are ill-prepared for careers in processing. The dearth of process-oriented MS&E curricula has prompted some Universities to develop a "shared" effort to offer distance education between multiple institutions [1]. A target audience for a shared process simulation course would not only benefit students, but also be a basis for an on-line course for practicing engineers faced with new or changing career choices. To fill the gap, the basics of a process simulation course was developed in an abbreviated form as series of eleven articles and Excel workbooks published in Industrial Heating magazine between July 2012 and July 2013.

The Researches on Damage Detection Method for Truss Structures

NASA Astrophysics Data System (ADS)

Wang, Meng Hong; Cao, Xiao Nan

2018-06-01

This paper presents an effective method to detect damage in truss structures. Numerical simulation and experimental analysis were carried out on a damaged truss structure under instantaneous excitation. The ideal excitation point and appropriate hammering method were determined to extract time domain signals under two working conditions. The frequency response function and principal component analysis were used for data processing, and the angle between the frequency response function vectors was selected as a damage index to ascertain the location of a damaged bar in the truss structure. In the numerical simulation, the time domain signal of all nodes was extracted to determine the location of the damaged bar. In the experimental analysis, the time domain signal of a portion of the nodes was extracted on the basis of an optimal sensor placement method based on the node strain energy coefficient. The results of the numerical simulation and experimental analysis showed that the damage detection method based on the frequency response function and principal component analysis could locate the damaged bar accurately.

Interactive Exploration and Analysis of Large-Scale Simulations Using Topology-Based Data Segmentation.

PubMed

Bremer, Peer-Timo; Weber, Gunther; Tierny, Julien; Pascucci, Valerio; Day, Marcus S; Bell, John B

2011-09-01

Large-scale simulations are increasingly being used to study complex scientific and engineering phenomena. As a result, advanced visualization and data analysis are also becoming an integral part of the scientific process. Often, a key step in extracting insight from these large simulations involves the definition, extraction, and evaluation of features in the space and time coordinates of the solution. However, in many applications, these features involve a range of parameters and decisions that will affect the quality and direction of the analysis. Examples include particular level sets of a specific scalar field, or local inequalities between derived quantities. A critical step in the analysis is to understand how these arbitrary parameters/decisions impact the statistical properties of the features, since such a characterization will help to evaluate the conclusions of the analysis as a whole. We present a new topological framework that in a single-pass extracts and encodes entire families of possible features definitions as well as their statistical properties. For each time step we construct a hierarchical merge tree a highly compact, yet flexible feature representation. While this data structure is more than two orders of magnitude smaller than the raw simulation data it allows us to extract a set of features for any given parameter selection in a postprocessing step. Furthermore, we augment the trees with additional attributes making it possible to gather a large number of useful global, local, as well as conditional statistic that would otherwise be extremely difficult to compile. We also use this representation to create tracking graphs that describe the temporal evolution of the features over time. Our system provides a linked-view interface to explore the time-evolution of the graph interactively alongside the segmentation, thus making it possible to perform extensive data analysis in a very efficient manner. We demonstrate our framework by extracting and analyzing burning cells from a large-scale turbulent combustion simulation. In particular, we show how the statistical analysis enabled by our techniques provides new insight into the combustion process.

Two-step simulation of velocity and passive scalar mixing at high Schmidt number in turbulent jets

NASA Astrophysics Data System (ADS)

Rah, K. Jeff; Blanquart, Guillaume

2016-11-01

Simulation of passive scalar in the high Schmidt number turbulent mixing process requires higher computational cost than that of velocity fields, because the scalar is associated with smaller length scales than velocity. Thus, full simulation of both velocity and passive scalar with high Sc for a practical configuration is difficult to perform. In this work, a new approach to simulate velocity and passive scalar mixing at high Sc is suggested to reduce the computational cost. First, the velocity fields are resolved by Large Eddy Simulation (LES). Then, by extracting the velocity information from LES, the scalar inside a moving fluid blob is simulated by Direct Numerical Simulation (DNS). This two-step simulation method is applied to a turbulent jet and provides a new way to examine a scalar mixing process in a practical application with smaller computational cost. NSF, Samsung Scholarship.

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D( Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D( Cs) measured 12.5, exceeding the required value of 8. This value is consistent with resultsmore » from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D( Cs) results.« less

Investigation of different ethylenediamine-N,N'-disuccinic acid-enhanced washing configurations for remediation of a Cu-contaminated soil: process kinetics and efficiency comparison between single-stage and multi-stage configurations.

PubMed

Ferraro, Alberto; Fabbricino, Massimiliano; van Hullebusch, Eric D; Esposito, Giovanni

2017-09-01

A comparison of Cu extraction yields for three different ethylenediamine-N,N'-disuccinic acid (EDDS)-enhanced washing configurations was performed on a Cu-contaminated soil. Batch experiments were used to simulate a single-stage continuous stirred tank reactor (CSTR) and a multi-stage (side feeding and counter-current) reactor. Single-stage CSTR conditions were simulated for various EDDS:(Cu + Cd + Pb + Co + Ni + Zn) molar ratio (EDDS:M ratio) (from 1 to 30) and liquid to soil (L/S) ratio (from 15 to 45). The highest Cu extraction yield (≃56%) was achieved with EDDS:M = 30. In contrast, a Cu extraction yield decrease was observed with increasing L/S ratio with highest extracted Cu achievement (≃48%) for L/S = 15. Side feeding configuration was tested in four experimental conditions through different fractionation mode of EDDS dose and treatment time at each washing step. Results from the four tests showed all enhanced Cu extraction (maximum values from ≃43 to ≃51%) achieved at lower treatment time and lower EDDS:M molar ratio compared to CSTR configuration with L/S = 25 and EDDS:M = 10. The counter-current washing was carried out through two washing flows achieving a process performance enhancement with 27% increase of extracted Cu compared to single-stage CSTR configuration. Higher Cu extraction percentage (36.8%) was observed in the first washing phase than in the second one (24.7%).

Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

PubMed

Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

2015-07-17

The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%). Copyright © 2015 Elsevier B.V. All rights reserved.

DEMONSTRATION OF THE NEXT-GENERATION CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITH 2-CM CENTRIFUGAL CONTRACTORS USING TANK 49H WASTE AND WASTE SIMULANT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, R.; Peters, T.; Crowder, M.

2011-09-27

Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet using MaxCalix for the decontamination of high level waste (HLW). The demonstration was completed using a 12-stage, 2-cm centrifugal contactor apparatus at the Savannah River National Laboratory (SRNL). This represents the first CSSX process demonstration of the MaxCalix solvent system with Savannah River Site (SRS) HLW. Two tests lasting 24 and 27 hours processed non-radioactive simulated Tank 49H waste and actual Tank 49H HLW, respectively. Conclusions from this work include the following. The CSSX process is capable of reducing {sup 137}Cs in high level radioactivemore » waste by a factor of more than 40,000 using five extraction, two scrub, and five strip stages. Tests demonstrated extraction and strip section stage efficiencies of greater than 93% for the Tank 49H waste test and greater than 88% for the simulant waste test. During a test with HLW, researchers processed 39 liters of Tank 49H solution and the waste raffinate had an average decontamination factor (DF) of 6.78E+04, with a maximum of 1.08E+05. A simulant waste solution ({approx}34.5 liters) with an initial Cs concentration of 83.1 mg/L was processed and had an average DF greater than 5.9E+03, with a maximum DF of greater than 6.6E+03. The difference may be attributable to differences in contactor stage efficiencies. Test results showed the solvent can be stripped of cesium and recycled for {approx}25 solvent turnovers without the occurrence of any measurable solvent degradation or negative effects from minor components. Based on the performance of the 12-stage 2-cm apparatus with the Tank 49H HLW, the projected DF for MCU with seven extraction, two scrub, and seven strip stages operating at a nominal efficiency of 90% is {approx}388,000. At 95% stage efficiency, the DF in MCU would be {approx}3.2 million. Carryover of organic solvent in aqueous streams (and aqueous in organic streams) was less than 0.1% when processing Tank 49H HLW. The entrained solvent concentration measured in the decontaminated salt solution (DSS) was as much as {approx}140 mg/L, although that value may be overstated by as much as 50% due to modifier solubility in the DSS. The entrained solvent concentration was measured in the strip effluent (SE) and the results are pending. A steady-state concentration factor (CF) of 15.9 was achieved with Tank 49H HLW. Cesium distribution ratios [D(Cs)] were measured with non-radioactive Tank 49H waste simulant and actual Tank 49H waste. Below is a comparison of D(Cs) values of ESS and 2-cm tests. Batch Extraction-Strip-Scrub (ESS) tests yielded D(Cs) values for extraction of {approx}81-88 for tests with Tank 49H waste and waste simulant. The results from the 2-cm contactor tests were in agreement with values of 58-92 for the Tank 49H HLW test and 54-83 for the simulant waste test. These values are consistent with the reference D(Cs) for extraction of {approx}60. In tests with Tank 49H waste and waste simulant, batch ESS tests measured D(Cs) values for the two scrub stages as {approx}3.5-5.0 for the first scrub stage and {approx}1.0-3.0 for the second scrub stage. In the Tank 49H test, the D(Cs) values for the 2-cm test were far from the ESS values. A D(Cs) value of 161 was measured for the first scrub stage and 10.8 for the second scrub stage. The data suggest that the scrub stage is not operating as effectively as intended. For the simulant test, a D(Cs) value of 1.9 was measured for the first scrub stage; the sample from the second scrub stage was compromised. Measurements of the pH of all stage samples for the Tank 49H test showed that the pH for extraction and scrub stages was 14 and the pH for the strip stages was {approx}7. It is expected that the pH of the second scrub stage would be {approx}12-13. Batch ESS tests measured D(Cs) values for the strip stages to be {approx}0.002-0.010. A high value in Strip No.3 of a test with simulant solution has been attributed to issues associated with the limits of detection for the analytical method. In the 2-cm contactor tests, the first four strip stages of the Tank 49H waste test and all five strip stages in the simulant waste test had higher values than the ESS tests. Only the fifth strip stage D(Cs) value of the Tank 49H waste test matched that of the ESS tests. It is speculated that the less-than-optimal performance of the strip section is caused by inefficiencies in the scrub section. Because strip is sensitive to pH, the elevated pH value in the second scrub stage may be the cause of strip performance. In spite of the D(Cs) values obtained in the scrub and strip sections, testing showed that the solvent system is robust. Average DFs for the process far exceeded targets even though the scrub and strip stages did not function optimally. Correction of the issue in the scrub and strip stages is expected to yield even higher waste DFs.« less

Three-dimensional Models of Hydrothermal Circulation through a Seamount Network in Fast-spreading Crust

NASA Astrophysics Data System (ADS)

Fisher, A. T.; Lauer, R. M.; Winslow, D. M.

2015-12-01

There is a region of 20-24 M.y. old seafloor on the eastern flank of the East Pacific Rise, offshore of Costa Rica, where the advective heat loss from the crust is 60-85% of lithospheric. Much of this advective flux occurs through basement outcrops that penetrate regionally thick sediments, but rates and patterns of hydrothermal circulation in this area are poorly understood. We have run a series of numerical simulations of coupled fluid-heat transport to assess how crustal aquifer and outcrop properties and the distance(s) between outcrops control ridge-flank hydrothermal flows in this setting. Extracting a large fraction of lithospheric heat through this process requires crustal aquifer permeability on the order of 10-10 to 10-9 m2, values considerably higher than seen on other ridge flanks (where advective heat extraction is less efficient). In simulations using two crustal outcrops having a different size, vigorous discharge of outcrop-to-outcrop flow is favored through the smaller and/or less permeable outcrop. In addition, simulations with a larger grid (40 km square versus 20 km square) result in higher fluid flow rates, apparently because there is more heat to be mined by flow between the outcrops. For simulations matching regional heat extraction observations, the outcrop-to-outcrop flow rates from the smaller outcrops are 1,000-3,000 kg/s (for the smaller grids) and 2,000-10,000 kg/s (for larger grids), values consistent with predictions made on the basis of a regional heat flux budget. In many simulations, local convection in and out of individual, large outcrops also removes a significant fraction of lithospheric heat. Additional simulations were conducted with three or four outcrops per simulation grid, to further explore relationships between the geometry, properties, and advective heat extraction.

Numerical simulation of temperature distribution in cylindrical ilmenite (FeTiO3) due to microwave heating

NASA Astrophysics Data System (ADS)

Hidayat, Mas Irfan P.; Fellicia, Dian Mughni; Rafandi, Ferdiansyah Iqbal

2018-04-01

Microwave assisted heating has been extensively used in materials processing particularly in extraction of TiO2 from Ilmenite (FeTiO3) minerals. Nevertheless, this method could generate non-uniform temperature distribution during the heating process. The observation of this phenomena in cylindrical ilmenite has been conducted by numerical simulation using finite element method according to the Poynthing's theorem. Four different cylinders with variation on its height were simulated in ANSYS 17 with input microwave power of 5.5 Kw. The results indicated that height of heated object could vigorously influence the uniformity of temperature inside the body.

Extracting black-hole rotational energy: The generalized Penrose process

NASA Astrophysics Data System (ADS)

Lasota, J.-P.; Gourgoulhon, E.; Abramowicz, M.; Tchekhovskoy, A.; Narayan, R.

2014-01-01

In the case involving particles, the necessary and sufficient condition for the Penrose process to extract energy from a rotating black hole is absorption of particles with negative energies and angular momenta. No torque at the black-hole horizon occurs. In this article we consider the case of arbitrary fields or matter described by an unspecified, general energy-momentum tensor Tμν and show that the necessary and sufficient condition for extraction of a black hole's rotational energy is analogous to that in the mechanical Penrose process: absorption of negative energy and negative angular momentum. We also show that a necessary condition for the Penrose process to occur is for the Noether current (the conserved energy-momentum density vector) to be spacelike or past directed (timelike or null) on some part of the horizon. In the particle case, our general criterion for the occurrence of a Penrose process reproduces the standard result. In the case of relativistic jet-producing "magnetically arrested disks," we show that the negative energy and angular-momentum absorption condition is obeyed when the Blandford-Znajek mechanism is at work, and hence the high energy extraction efficiency up to ˜300% found in recent numerical simulations of such accretion flows results from tapping the black hole's rotational energy through the Penrose process. We show how black-hole rotational energy extraction works in this case by describing the Penrose process in terms of the Noether current.

Techno-economic analysis of extraction-based separation systems for acetone, butanol, and ethanol recovery and purification.

PubMed

Grisales Díaz, Víctor Hugo; Olivar Tost, Gerard

2017-01-01

Dual extraction, high-temperature extraction, mixture extraction, and oleyl alcohol extraction have been proposed in the literature for acetone, butanol, and ethanol (ABE) production. However, energy and economic evaluation under similar assumptions of extraction-based separation systems are necessary. Hence, the new process proposed in this work, direct steam distillation (DSD), for regeneration of high-boiling extractants was compared with several extraction-based separation systems. The evaluation was performed under similar assumptions through simulation in Aspen Plus V7.3 ® software. Two end distillation systems (number of non-ideal stages between 70 and 80) were studied. Heat integration and vacuum operation of some units were proposed reducing the energy requirements. Energy requirement of hybrid processes, substrate concentration of 200 g/l, was between 6.4 and 8.3 MJ-fuel/kg-ABE. The minimum energy requirements of extraction-based separation systems, feeding a water concentration in the substrate equivalent to extractant selectivity, and ideal assumptions were between 2.6 and 3.5 MJ-fuel/kg-ABE, respectively. The efficiencies of recovery systems for baseline case and ideal evaluation were 0.53-0.57 and 0.81-0.84, respectively. The main advantages of DSD were the operation of the regeneration column at atmospheric pressure, the utilization of low-pressure steam, and the low energy requirements of preheating. The in situ recovery processes, DSD, and mixture extraction with conventional regeneration were the approaches with the lowest energy requirements and total annualized costs.

Method of Moments Applied to the Analysis of Precision Spectra from the Neutron Time-of- flight Diagnostics at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Hatarik, Robert; Caggiano, J. A.; Callahan, D.; Casey, D.; Clark, D.; Doeppner, T.; Eckart, M.; Field, J.; Frenje, J.; Gatu Johnson, M.; Grim, G.; Hartouni, E.; Hurricane, O.; Kilkenny, J.; Knauer, J.; Ma, T.; Mannion, O.; Munro, D.; Sayre, D.; Spears, B.

2015-11-01

The method of moments was introduced by Pearson as a process for estimating the population distributions from which a set of ``random variables'' are measured. These moments are compared with a parameterization of the distributions, or of the same quantities generated by simulations of the process. Most diagnostics processes extract scalar parameters depending on the moments of spectra derived from analytic solutions to the fusion rate, necessarily based on simplifying assumptions of the confined plasma. The precision of the TOF spectra, and the nature of the implosions at the NIF require the inclusion of factors beyond the traditional analysis and require the addition of higher order moments to describe the data. This talk will present a diagnostic process for extracting the moments of the neutron energy spectrum for a comparison with theoretical considerations as well as simulations of the implosions. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

Simulation of the GEM detector for BM@N experiment

NASA Astrophysics Data System (ADS)

Baranov, Dmitriy; Rogachevsky, Oleg

2017-03-01

The Gas Electron Multiplier (GEM) detector is one of the basic parts of the BM@N experiment included in the NICA project. The simulation model that takes into account features of signal generation process in an ionization GEM chamber is presented in this article. Proper parameters for the simulation were extracted from data retrieved with the help of Garfield++ (a toolkit for the detailed simulation of particle detectors). Due to this, we are able to generate clusters in layers of the micro-strip readout that correspond to clusters retrieved from a real physics experiment.

Effects of composting process on the dissipation of extractable sulfonamides in swine manure.

PubMed

Liu, Bei; Li, Yanxia; Zhang, Xuelian; Feng, Chenghong; Gao, Min; Shen, Qiu

2015-01-01

Effects of composting on the fate of sulfonamides (SAs) in the manure-straw mixture were explored through a simulation of aerobic composting process. Additionally, factors of temperature and coexistence of heavy metal Cu that might influence the removal efficiency were particularly investigated. As shown in the results, the extractable SAs dissipated rapidly during the composting process. The coexistence of Cu in the composting process might have delayed the decline of SAs, but the drugs could still be completely removed by the end of the composting. In contrast to the thermophilic aerobic composting, extractable SAs in air-temperature-placed mixture dissipated much slower and 1.12-1.56mg/kg could be detected after 35days of incubation. The results confirmed that temperature could influence the dissipation of SAs, which was identified as a more important factor than Cu-coexistence. Hence, thermophilic aerobic composting is an effective process to eliminate VAs before manure land application. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnetic Nanofluid Rare Earth Element Extraction Process Report, Techno Economic Analysis, and Results for Geothermal Fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pete McGrail

This GDR submission is an interim technical report and raw data files from the first year of testing on functionalized nanoparticles for rare earth element extraction from geothermal fluids. The report contains Rare Earth Element uptake results (percent removal, mg Rare Earth Element/gram of sorbent, distribution coefficient) for the elements of Neodymium, Europium, Yttrium, Dysprosium, and Cesium. A detailed techno economic analysis is also presented in the report for a scaled up geothermal rare earth element extraction process. All rare earth element uptake testing was done on simulated geothermal brines with one rare earth element in each brine. The raremore » earth element uptake testing was conducted at room temperature.« less

Use of laboratory simulated pyrolysis in tracing the history of sedimentary organic matter

NASA Technical Reports Server (NTRS)

Kaplan, I. R.; Tannenbaum, E.; Huizinga, B. E.

1986-01-01

Results from laboratory simulated pyrolyses experiments show that in addition to depth of burial, preservation of kerogen, and hence any morphologic structure in it, is also dependent on the mineral matrix with which it is associated. In the presence of clay minerals, and especially under dry conditions, extractable lipids released during kerogen decomposition are more rapidly destroyed than in the presence of calcite or chert matrices. The result is production of gas, polar bitumen and pyrobitumen and destruction of biomarkers. During such an early reorganization of the kerogen, the biomarker constituents can be destroyed, or unrecognizably altered. The above process of organic residues maturation appears to be inhibited in the presence of water and is significantly reduced where kerogen is hosted in limestones, dolomites or cherts. These minerals have been characteristically found to be the most reliable in yielding morphological fossils and small quantities of extractable bitumen in Archean and Proterozoic rocks. To understand the validity of chemical and morphological fossils, in the early geologic record, it will be necessary to understand the process of kerogen in sedimentary rocks. To test the role of various minerals on the preservation process, kerogen extracted from a variety of rocks has been heated together with montmorillonite, illite and calcite. The kinetics of the process has been monitored and the products quantitatively identified.

Mathematical modeling of phase change electrodes and application to a novel titanium extraction process

NASA Astrophysics Data System (ADS)

Kar, Pritish

Titanium and its alloys have excellent engineering properties but their applications are limited because they are expensive and a good percentage of this cost results from the extraction process. The national agencies of many countries around the world have invested a lot of resources to develop a more cost-effective titanium extraction process. A result of one such research efforts is the Fray-Farthing-Chen (FFC) process in which pellets of titanium dioxide are made the cathode in an electrochemical cell with a graphite anode and an electrolyte of molten CaCl2 at 900°C. After electro-deoxidation, the pellets are reduced to titanium with oxygen in solid solution. From this short description, this one step process provides distinct advantages over the current process of extracting titanium known as the Kroll process that takes several days to complete. For investigation of the FFC process theoretically, a coupled electrochemical and diffusion based model was set-up to simulate the linear sweep voltammograms that was developed by collaborators working on lab-scale experiments on the FCC process. Using this model, a parameter called "deltadc" (that is the product of diffusion coefficients of oxygen in the phases, Ti3O5 and Ti2O3 and the stoichiometric range of these phases) was determined. The results suggest a reaction of first-order in the concentration of oxygen in the solid phase. For modeling the reaction of an individual sintered pellet of TiO 2 as it undergoes electro-deoxidation in a molten salt bath of CaCl 2, a similarity of this process with the operation of a lithium ion battery was exploited. Using the model, a number of parameters of physical importance, namely thickness of the sintered pellets, porosity of the pellets and the radius of the particles making up the pellets and the optimum values for the these parameters were proposed based on the simulation data. It is also shown that if the reduction is started with a pellet of partially reduced titanium dioxide (such as by reducing with hydrogen), one can avoid titanate formation. The work described in this dissertation will hopefully help in the development of a more cost-effective titanium extraction process.

Research on simulated infrared image utility evaluation using deep representation

NASA Astrophysics Data System (ADS)

Zhang, Ruiheng; Mu, Chengpo; Yang, Yu; Xu, Lixin

2018-01-01

Infrared (IR) image simulation is an important data source for various target recognition systems. However, whether simulated IR images could be used as training data for classifiers depends on the features of fidelity and authenticity of simulated IR images. For evaluation of IR image features, a deep-representation-based algorithm is proposed. Being different from conventional methods, which usually adopt a priori knowledge or manually designed feature, the proposed method can extract essential features and quantitatively evaluate the utility of simulated IR images. First, for data preparation, we employ our IR image simulation system to generate large amounts of IR images. Then, we present the evaluation model of simulated IR image, for which an end-to-end IR feature extraction and target detection model based on deep convolutional neural network is designed. At last, the experiments illustrate that our proposed method outperforms other verification algorithms in evaluating simulated IR images. Cross-validation, variable proportion mixed data validation, and simulation process contrast experiments are carried out to evaluate the utility and objectivity of the images generated by our simulation system. The optimum mixing ratio between simulated and real data is 0.2≤γ≤0.3, which is an effective data augmentation method for real IR images.

A Novel Optical/digital Processing System for Pattern Recognition

NASA Technical Reports Server (NTRS)

Boone, Bradley G.; Shukla, Oodaye B.

1993-01-01

This paper describes two processing algorithms that can be implemented optically: the Radon transform and angular correlation. These two algorithms can be combined in one optical processor to extract all the basic geometric and amplitude features from objects embedded in video imagery. We show that the internal amplitude structure of objects is recovered by the Radon transform, which is a well-known result, but, in addition, we show simulation results that calculate angular correlation, a simple but unique algorithm that extracts object boundaries from suitably threshold images from which length, width, area, aspect ratio, and orientation can be derived. In addition to circumventing scale and rotation distortions, these simulations indicate that the features derived from the angular correlation algorithm are relatively insensitive to tracking shifts and image noise. Some optical architecture concepts, including one based on micro-optical lenslet arrays, have been developed to implement these algorithms. Simulation test and evaluation using simple synthetic object data will be described, including results of a study that uses object boundaries (derivable from angular correlation) to classify simple objects using a neural network.

Simulation of Thermal Neutron Transport Processes Directly from the Evaluated Nuclear Data Files

NASA Astrophysics Data System (ADS)

Androsenko, P. A.; Malkov, M. R.

The main idea of the method proposed in this paper is to directly extract thetrequired information for Monte-Carlo calculations from nuclear data files. The met od being developed allows to directly utilize the data obtained from libraries and seehs to be the most accurate technique. Direct simulation of neutron scattering in themmal energy range using file 7 ENDF-6 format in terms of code system BRAND has beer achieved. Simulation algorithms have been verified using the criterion x2

Investigation of flavonoid influence on peroxidation processes intensity in the blood

NASA Astrophysics Data System (ADS)

Navolokin, N. A.; Mudrak, D. A.; Plastun, I. L.; Bucharskaya, A. B.; Agandeeva, K. E.; Ivlichev, A. V.; Tychina, S. A.; Afanasyeva, G. A.; Polukonova, N. V.; Maslyakova, G. N.

2017-03-01

Influence of flavonoids on the intensity of peroxidation processes in the blood is investigated by numerical modeling and by experiment in vivo. As an example we consider the effects of flavonoid-containing extract of Helichrysum arenarium L. with antitumor activity on serum of rats with transplanted liver cancer PC-1. It was found that the content of malondialdehyde, lipid hydroperoxides and average mass molecules were decreased in animals with transplanted liver cancer after intramuscular and oral administration of Helichrysum arenarium L extract in a dose of 1000 mg/mL. The extract reduces the intensity of lipid peroxidation processes in animals. The compound formation possibility of flavonoids and products of lipid peroxidation is investigated by numerical simulations. Using the density functional theory method of molecular modeling, we analyze hydrogen bonds formation and their influence on IR - spectra and structure of molecular complex which is formed due to interaction between flavonoids and products of lipid peroxidation processes on example of naringine and malondialdehyde. We have found that naringine can form a steady molecular complex with malondialdehyde by hydrogen bonds formation. Thus, the application of Helichrysum arenarium L. extract for suppression processes of lipid peroxidation and activation of enzymatic and non-enzymatic antioxidant systems is promising.

Impact extractive fracture of jointed steel plates of a bolted joint

NASA Astrophysics Data System (ADS)

Daimaruya, M.; Fujiki, H.; Ambarita, H.

2012-08-01

This study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a bolted joint used in a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behavior and fracture of jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a bolted joint used in cars is complicated, for simplifying the problem it might be classified into the shear fracture and the extractive fracture of jointed steel plates. Attention is given to the extractive fracture of jointed steel plates in this study. The extractive behavior and fracture of three kinds of steel plates used for cars are examined in experiments and numerical simulations. The impact extraction test of steel plates jointed by a bolt is performed using the one-bar method, together with the static test. In order to understand the mechanism of extractive fracture process of jointed steel plates, numerical simulations by a FEM code LS-DYNA are also carried out. The obtained results suggest that a stress-based fracture criterion may be developed for the impact extractive fracture of jointed steel plates of a bolted joint used in a car body.

Full Simulation for the Qweak Experiment at 1.16 and 0.877 GeV and their Impact on Extracting the PV Asymmetry in the N → Δ Transition.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuhait, Hend

The Qweak project is seeking to find new physics beyond the Standard Model. It is aimed to measure the weak charge of the proton, which has never been measured, at 4% precision at low momentum transfer. The experiment is performed by scattering electrons from protons and exploiting parity violation in the weak interaction at low four-momentum transfer. In this experiment, two measurements were considered: which are elastic and inelastic. The elastic is to measure the proton's weak charge. In addition, the inelastic asymmetry measurement, which will extract the low energy constant d. That measurement works in the neutral current sectormore » of the weak interaction. Qweak measures the asymmetry in the N → Δ; transition. Because the elastic radiative tail gives a dominant contribution to the uncertainty to the N → Δ; asymmetries, this thesis will discuss the radiative correction. In addition, this thesis will describe in details the extensive simulations preformed to determine the impact of all simulated background processes on extracting the PV N → Δ; asymmetries. In the process of verifying the validity of these background fractions, we determined the best value of a quantity measured during the Qweak experiment: the beam normal single spin asymmetry, Bn, in the N → Δ; transition.« less

A data-driven dynamics simulation framework for railway vehicles

NASA Astrophysics Data System (ADS)

Nie, Yinyu; Tang, Zhao; Liu, Fengjia; Chang, Jian; Zhang, Jianjun

2018-03-01

The finite element (FE) method is essential for simulating vehicle dynamics with fine details, especially for train crash simulations. However, factors such as the complexity of meshes and the distortion involved in a large deformation would undermine its calculation efficiency. An alternative method, the multi-body (MB) dynamics simulation provides satisfying time efficiency but limited accuracy when highly nonlinear dynamic process is involved. To maintain the advantages of both methods, this paper proposes a data-driven simulation framework for dynamics simulation of railway vehicles. This framework uses machine learning techniques to extract nonlinear features from training data generated by FE simulations so that specific mesh structures can be formulated by a surrogate element (or surrogate elements) to replace the original mechanical elements, and the dynamics simulation can be implemented by co-simulation with the surrogate element(s) embedded into a MB model. This framework consists of a series of techniques including data collection, feature extraction, training data sampling, surrogate element building, and model evaluation and selection. To verify the feasibility of this framework, we present two case studies, a vertical dynamics simulation and a longitudinal dynamics simulation, based on co-simulation with MATLAB/Simulink and Simpack, and a further comparison with a popular data-driven model (the Kriging model) is provided. The simulation result shows that using the legendre polynomial regression model in building surrogate elements can largely cut down the simulation time without sacrifice in accuracy.

Description of jambolan (Syzygium cumini (L.)) anthocyanin extraction kinetics at different stirring frequencies of the medium using diffusion models

NASA Astrophysics Data System (ADS)

da Silva, Wilton Pereira; Nunes, Jarderlany Sousa; Gomes, Josivanda Palmeira; de Araújo, Auryclennedy Calou; e Silva, Cleide M. D. P. S.

2018-05-01

Anthocyanin extraction kinetics was described for jambolan fruits. The spherical granules obtained were dried at 40 °C and the average radius of the sphere equivalent to the granules was determined. Solid-solvent ratio was fixed at 1:20 and temperature at 35 °C. A mixture of ethyl alcohol and hydrochloric acid (85:15) was used as solvent. Experiments were conducted with the following stirring frequencies: 0, 50, 100 and 150 rpm. Two diffusion models were used to describe the extraction process. The first one used an analytical solution, with boundary condition of the first kind. The second one used a numerical solution, with boundary condition of the third kind. The second model was the most adequate, and its results were used to determine empirical equations relating the process parameters with the stirring frequency, allowing to simulate new extraction kinetics.

Direct Simulation of Magnetic Resonance Relaxation Rates and Line Shapes from Molecular Trajectories

PubMed Central

Rangel, David P.; Baveye, Philippe C.; Robinson, Bruce H.

2012-01-01

We simulate spin relaxation processes, which may be measured by either continuous wave or pulsed magnetic resonance techniques, using trajectory-based simulation methodologies. The spin–lattice relaxation rates are extracted numerically from the relaxation simulations. The rates obtained from the numerical fitting of the relaxation curves are compared to those obtained by direct simulation from the relaxation Bloch–Wangsness–Abragam– Redfield theory (BWART). We have restricted our study to anisotropic rigid-body rotational processes, and to the chemical shift anisotropy (CSA) and a single spin–spin dipolar (END) coupling mechanisms. Examples using electron paramagnetic resonance (EPR) nitroxide and nuclear magnetic resonance (NMR) deuterium quadrupolar systems are provided. The objective is to compare those rates obtained by numerical simulations with the rates obtained by BWART. There is excellent agreement between the simulated and BWART rates for a Hamiltonian describing a single spin (an electron) interacting with the bath through the chemical shift anisotropy (CSA) mechanism undergoing anisotropic rotational diffusion. In contrast, when the Hamiltonian contains both the chemical shift anisotropy (CSA) and the spin–spin dipolar (END) mechanisms, the decay rate of a single exponential fit of the simulated spin–lattice relaxation rate is up to a factor of 0.2 smaller than that predicted by BWART. When the relaxation curves are fit to a double exponential, the slow and fast rates extracted from the decay curves bound the BWART prediction. An extended BWART theory, in the literature, includes the need for multiple relaxation rates and indicates that the multiexponential decay is due to the combined effects of direct and cross-relaxation mechanisms. PMID:22540276

Random bits, true and unbiased, from atmospheric turbulence

PubMed Central

Marangon, Davide G.; Vallone, Giuseppe; Villoresi, Paolo

2014-01-01

Random numbers represent a fundamental ingredient for secure communications and numerical simulation as well as to games and in general to Information Science. Physical processes with intrinsic unpredictability may be exploited to generate genuine random numbers. The optical propagation in strong atmospheric turbulence is here taken to this purpose, by observing a laser beam after a 143 km free-space path. In addition, we developed an algorithm to extract the randomness of the beam images at the receiver without post-processing. The numbers passed very selective randomness tests for qualification as genuine random numbers. The extracting algorithm can be easily generalized to random images generated by different physical processes. PMID:24976499

On Fast Post-Processing of Global Positioning System Simulator Truth Data and Receiver Measurements and Solutions Data

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Day, John H. (Technical Monitor)

2000-01-01

Post-processing of data, related to a GPS receiver test in a GPS simulator and test facility, is an important step towards qualifying a receiver for space flight. Although the GPS simulator provides all the parameters needed to analyze a simulation, as well as excellent analysis tools on the simulator workstation, post-processing is not a GPS simulator or receiver function alone, and it must be planned as a separate pre-flight test program requirement. A GPS simulator is a critical resource, and it is desirable to move off the pertinent test data from the simulator as soon as a test is completed. The receiver and simulator databases are used to extract the test data files for postprocessing. These files are then usually moved from the simulator and receiver systems to a personal computer (PC) platform, where post-processing is done typically using PC-based commercial software languages and tools. Because of commercial software systems generality their functions are notoriously slow and more than often are the bottleneck even for short duration simulator-based tests. There is a need to do post-processing faster and within an hour after test completion, including all required operations on the simulator and receiver to prepare and move off the post-processing files. This is especially significant in order to use the previous test feedback for the next simulation setup or to run near back-to-back simulation scenarios. Solving the post-processing timing problem is critical for a pre-flight test program success. Towards this goal an approach was developed that allows to speed-up post-processing by an order of a magnitude. It is based on improving the post-processing bottleneck function algorithm using a priory information that is specific to a GPS simulation application and using only the necessary volume of truth data. The presented postprocessing scheme was used in support of a few successful space flight missions carrying GPS receivers.

Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.

2009-01-01

Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles.

40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product... micrograms PCBs per liter of extract to obtain the equivalent measurement from a 100 gram sample. ...

40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product... micrograms PCBs per liter of extract to obtain the equivalent measurement from a 100 gram sample. ...

40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product... micrograms PCBs per liter of extract to obtain the equivalent measurement from a 100 gram sample. ...

40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product... micrograms PCBs per liter of extract to obtain the equivalent measurement from a 100 gram sample. ...

40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product... micrograms PCBs per liter of extract to obtain the equivalent measurement from a 100 gram sample. ...

Diode laser soldering using a lead-free filler material for electronic packaging structures

NASA Astrophysics Data System (ADS)

Chaminade, C.; Fogarassy, E.; Boisselier, D.

2006-04-01

As of today, several lead-free soldering pastes have been qualified for currently used soldering process. Regarding the new potential of laser-assisted soldering processes, the behaviour of the SnAgCu soldering paste requires, however, new investigations. In the first part of this study, the specific temperature profile of a laser soldering process is investigated using a high power diode laser (HPDL). These experimental results are compared to a thermal simulation developed for this specific application. The second part of this work deals with the diffusion of the tin-based filler material through the nickel barrier using the information extracted from the temperature simulations.

Modelling mass transfer during venting/soil vapour extraction: Non-aqueous phase liquid/gas mass transfer coefficient estimation

NASA Astrophysics Data System (ADS)

Esrael, D.; Kacem, M.; Benadda, B.

2017-07-01

We investigate how the simulation of the venting/soil vapour extraction (SVE) process is affected by the mass transfer coefficient, using a model comprising five partial differential equations describing gas flow and mass conservation of phases and including an expression accounting for soil saturation conditions. In doing so, we test five previously reported quations for estimating the non-aqueous phase liquid (NAPL)/gas initial mass transfer coefficient and evaluate an expression that uses a reference NAPL saturation. Four venting/SVE experiments utilizing a sand column are performed with dry and non-saturated sand at low and high flow rates, and the obtained experimental results are subsequently simulated, revealing that hydrodynamic dispersion cannot be neglected in the estimation of the mass transfer coefficient, particularly in the case of low velocities. Among the tested models, only the analytical solution of a convection-dispersion equation and the equation proposed herein are suitable for correctly modelling the experimental results, with the developed model representing the best choice for correctly simulating the experimental results and the tailing part of the extracted gas concentration curve.

Microwave Extraction of Lunar Water for Rocket Fuel

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Donahue, Benjamin; Kaukler, William

2008-01-01

Nearly 50% of the lunar surface is oxygen, present as oxides in silicate rocks and soil. Methods for reduction of these oxides could liberate the oxygen. Remote sensing has provided evidence of significant quantities of hydrogen possibly indicating hundreds of millions of metric tons, MT, of water at the lunar poles. If the presence of lunar water is verified, water is likely to be the first in situ resource exploited for human exploration and for LOX-H2 rocket fuel. In-Situ lunar resources offer unique advantages for space operations. Each unit of product produced on the lunar surface represents 6 units that need not to be launched into LEO. Previous studies have indicated the economic advantage of LOX for space tugs from LEO to GEO. Use of lunar derived LOX in a reusable lunar lander would greatly reduce the LEO mass required for a given payload to the moon. And Lunar LOX transported to L2 has unique advantages for a Mars mission. Several methods exist for extraction of oxygen from the soil. But, extraction of lunar water has several significant advantages. Microwave heating of lunar permafrost has additional important advantages for water extraction. Microwaves penetrate and heat from within not just at the surface and excavation is not required. Proof of concept experiments using a moon in a bottle concept have demonstrated that microwave processing of cryogenic lunar permafrost simulant in a vacuum rapidly and efficiently extracts water by sublimation. A prototype lunar water extraction rover was built and tested for heating of simulant. Microwave power was very efficiently delivered into a simulated lunar soil. Microwave dielectric properties (complex electric permittivity and magnetic permeability) of lunar regolith simulant, JSC-1A, were measured down to cryogenic temperatures and above room temperature. The microwave penetration has been correlated with the measured dielectric properties. Since the microwave penetration depth is a function of temperature and frequency, an extraction system can be designed for water removal from different depths.

A novel approach for extracting viscoelastic parameters of living cells through combination of inverse finite element simulation and Atomic Force Microscopy.

PubMed

Wei, Fanan; Yang, Haitao; Liu, Lianqing; Li, Guangyong

2017-03-01

Dynamic mechanical behaviour of living cells has been described by viscoelasticity. However, quantitation of the viscoelastic parameters for living cells is far from sophisticated. In this paper, combining inverse finite element (FE) simulation with Atomic Force Microscope characterization, we attempt to develop a new method to evaluate and acquire trustworthy viscoelastic index of living cells. First, influence of the experiment parameters on stress relaxation process is assessed using FE simulation. As suggested by the simulations, cell height has negligible impact on shape of the force-time curve, i.e. the characteristic relaxation time; and the effect originates from substrate can be totally eliminated when stiff substrate (Young's modulus larger than 3 GPa) is used. Then, so as to develop an effective optimization strategy for the inverse FE simulation, the parameters sensitivity evaluation is performed for Young's modulus, Poisson's ratio, and characteristic relaxation time. With the experiment data obtained through typical stress relaxation measurement, viscoelastic parameters are extracted through the inverse FE simulation by comparing the simulation results and experimental measurements. Finally, reliability of the acquired mechanical parameters is verified with different load experiments performed on the same cell.

Micro-Raman Technology to Interrogate Two-Phase Extraction on a Microfluidic Device.

PubMed

Nelson, Gilbert L; Asmussen, Susan E; Lines, Amanda M; Casella, Amanda J; Bottenus, Danny R; Clark, Sue B; Bryan, Samuel A

2018-05-21

Microfluidic devices provide ideal environments to study solvent extraction. When droplets form and generate plug flow down the microfluidic channel, the device acts as a microreactor in which the kinetics of chemical reactions and interfacial transfer can be examined. Here, we present a methodology that combines chemometric analysis with online micro-Raman spectroscopy to monitor biphasic extractions within a microfluidic device. Among the many benefits of microreactors is the ability to maintain small sample volumes, which is especially important when studying solvent extraction in harsh environments, such as in separations related to the nuclear fuel cycle. In solvent extraction, the efficiency of the process depends on complex formation and rates of transfer in biphasic systems. Thus, it is important to understand the kinetic parameters in an extraction system to maintain a high efficiency and effectivity of the process. This monitoring provided concentration measurements in both organic and aqueous plugs as they were pumped through the microfluidic channel. The biphasic system studied was comprised of HNO 3 as the aqueous phase and 30% (v/v) tributyl phosphate in n-dodecane comprised the organic phase, which simulated the plutonium uranium reduction extraction (PUREX) process. Using pre-equilibrated solutions (post extraction), the validity of the technique and methodology is illustrated. Following this validation, solutions that were not equilibrated were examined and the kinetics of interfacial mass transfer within the biphasic system were established. Kinetic results of extraction were compared to kinetics already determined on a macro scale to prove the efficacy of the technique.

A numerical study of EGS heat extraction process based on a thermal non-equilibrium model for heat transfer in subsurface porous heat reservoir

NASA Astrophysics Data System (ADS)

Chen, Jiliang; Jiang, Fangming

2016-02-01

With a previously developed numerical model, we perform a detailed study of the heat extraction process in enhanced or engineered geothermal system (EGS). This model takes the EGS subsurface heat reservoir as an equivalent porous medium while it considers local thermal non-equilibrium between the rock matrix and the fluid flowing in the fractured rock mass. The application of local thermal non-equilibrium model highlights the temperature-difference heat exchange process occurring in EGS reservoirs, enabling a better understanding of the involved heat extraction process. The simulation results unravel the mechanism of preferential flow or short-circuit flow forming in homogeneously fractured reservoirs of different permeability values. EGS performance, e.g. production temperature and lifetime, is found to be tightly related to the flow pattern in the reservoir. Thermal compensation from rocks surrounding the reservoir contributes little heat to the heat transmission fluid if the operation time of an EGS is shorter than 15 years. We find as well the local thermal equilibrium model generally overestimates EGS performance and for an EGS with better heat exchange conditions in the heat reservoir, the heat extraction process acts more like the local thermal equilibrium process.

Resist Parameter Extraction from Line-and-Space Patterns of Chemically Amplified Resist for Extreme Ultraviolet Lithography

NASA Astrophysics Data System (ADS)

Kozawa, Takahiro; Oizumi, Hiroaki; Itani, Toshiro; Tagawa, Seiichi

2010-11-01

The development of extreme ultraviolet (EUV) lithography has progressed owing to worldwide effort. As the development status of EUV lithography approaches the requirements for the high-volume production of semiconductor devices with a minimum line width of 22 nm, the extraction of resist parameters becomes increasingly important from the viewpoints of the accurate evaluation of resist materials for resist screening and the accurate process simulation for process and mask designs. In this study, we demonstrated that resist parameters (namely, quencher concentration, acid diffusion constant, proportionality constant of line edge roughness, and dissolution point) can be extracted from the scanning electron microscopy (SEM) images of patterned resists without the knowledge on the details of resist contents using two types of latest EUV resist.

Simulation Tools for Forest Health Analysis: An Application in the Red River Watershed, Idaho

Treesearch

Andrew J. McMahan; Eric L. Smith

2006-01-01

Software tools for landscape analyses--including FVS model extensions, and a number of FVS-related pre- and post-processing “tools”--are presented, using an analysis in the Red River Watershed, Nez Perce National Forest as an example. We present (1) a discussion of pre-simulation data analysis; (2) the Physiographic Information Extraction System (PIES), a tool that can...

Quantifying hydrogen-deuterium exchange of meteoritic dicarboxylic acids during aqueous extraction

NASA Astrophysics Data System (ADS)

Fuller, M.; Huang, Y.

2003-03-01

Hydrogen isotope ratios of organic compounds in carbonaceous chondrites provide critical information about their origins and evolutionary history. However, because many of these compounds are obtained by aqueous extraction, the degree of hydrogen-deuterium (H/D) exchange that occurs during the process needs to be quantitatively evaluated. This study uses compound- specific hydrogen isotopic analysis to quantify the H/D exchange during aqueous extraction. Three common meteoritic dicarboxylic acids (succinic, glutaric, and 2-methyl glutaric acids) were refluxed under conditions simulating the extraction process. Changes in D values of the dicarboxylic acids were measured following the reflux experiments. A pseudo-first order rate law was used to model the H/D exchange rates which were then used to calculate the isotope exchange resulting from aqueous extraction. The degree of H/D exchange varies as a result of differences in molecular structure, the alkalinity of the extraction solution and presence/absence of meteorite powder. However, our model indicates that succinic, glutaric, and 2-methyl glutaric acids with a D of 1800 would experience isotope changes of 38, 10, and 6, respectively during the extraction process. Therefore, the overall change in D values of the dicarboxylic acids during the aqueous extraction process is negligible. We also demonstrate that H/D exchange occurs on the chiral -carbon in 2-methyl glutaric acid. The results suggest that the racemic mixture of 2-methyl glutaric acid in the Tagish Lake meteorite could result from post-synthesis aqueous alteration. The approach employed in this study can also be used to quantify H/D exchange for other important meteoritic compounds such as amino acids.

Membrane-assisted extraction of monoterpenes: from in silico solvent screening towards biotechnological process application

PubMed Central

2018-01-01

This work focuses on the process development of membrane-assisted solvent extraction of hydrophobic compounds such as monoterpenes. Beginning with the choice of suitable solvents, quantum chemical calculations with the simulation tool COSMO-RS were carried out to predict the partition coefficient (logP) of (S)-(+)-carvone and terpinen-4-ol in various solvent–water systems and validated afterwards with experimental data. COSMO-RS results show good prediction accuracy for non-polar solvents such as n-hexane, ethyl acetate and n-heptane even in the presence of salts and glycerol in an aqueous medium. Based on the high logP value, n-heptane was chosen for the extraction of (S)-(+)-carvone in a lab-scale hollow-fibre membrane contactor. Two operation modes are investigated where experimental and theoretical mass transfer values, based on their related partition coefficients, were compared. In addition, the process is evaluated in terms of extraction efficiency and overall product recovery, and its biotechnological application potential is discussed. Our work demonstrates that the combination of in silico prediction by COSMO-RS with membrane-assisted extraction is a promising approach for the recovery of hydrophobic compounds from aqueous solutions. PMID:29765654

Deep liquid-chromatographic purification of uranium extract from technetium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volk, V.; Dvoeglazov, K; Podrezova, L.

The recycling of uranium in the nuclear fuel cycle requires the removal of a number of radioactive and stable impurities like {sup 99}Tc from spent fuels. In order to improve the grade of uranium extract purification from technetium the method of liquid chromatography and the apparatus for its performance have been developed. Process of technetium extraction and concentrating in aqueous solution containing reducing agent has been studied on simulated solutions (U-Tc-HNO{sub 3}-30% TBP-isoparM). The dynamic tests of the method have been carried out on the laboratory unit. Solution of diformyl-hydrazine in nitric acid was used as a stationary phase. Silicamore » gel with specific surface of 186 m{sup 2}/g was used as a carrier of the stationary phase. It is shown that the volume of purified extract increases as the solution temperature increases, concentration of reducing agent increases and extract flow rate decreases. It is established that the technetium content in uranium by this method could achieve a value below 0.3 ppm. Some variants of overload and composition of the stationary phase containing the extracted technetium have been offered and tested. It is defined that the method provides reduction of processing medium-active wastes by more than 10 times during finish refining process. (authors)« less

Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.

Rigorous assessment of patterning solution of metal layer in 7 nm technology node

NASA Astrophysics Data System (ADS)

Gao, Weimin; Ciofi, Ivan; Saad, Yves; Matagne, Philippe; Bachmann, Michael; Gillijns, Werner; Lucas, Kevin; Demmerle, Wolfgang; Schmoeller, Thomas

2016-01-01

In a 7 nm node (N7), the logic design requires a critical poly pitch of 42 to 45 nm and a metal 1 (M1) pitch of 28 to 32 nm. Such high-pattern density pushes the 193 immersion lithography solution toward its limit and also brings extremely complex patterning scenarios. The N7 M1 layer may require a self-aligned quadruple patterning (SAQP) with a triple litho-etch (LE3) block process. Therefore, the whole patterning process flow requires multiple exposure+etch+deposition processes and each step introduces a particular impact on the pattern profiles and the topography. In this study, we have successfully integrated a simulation tool that enables emulation of the whole patterning flow with realistic process-dependent three-dimensional (3-D) profile and topology. We use this tool to study the patterning process variations of the N7 M1 layer including the overlay control, the critical dimension uniformity budget, and the lithographic process window (PW). The resulting 3-D pattern structure can be used to optimize the process flow, verify design rules, extract parasitics, and most importantly, simulate the electric field, and identify hot spots for dielectric reliability. As an example application, the maximum electric field at M1 tip-to-tip, which is one of the most critical patterning locations, has been simulated and extracted. The approach helps to investigate the impact of process variations on dielectric reliability. We have also assessed the alternative M1 patterning flow with a single exposure block using extreme ultraviolet lithography (EUVL) and analyzed its advantages compared to the LE3 block approach.

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry.

PubMed

McCloy, J S; Sundaram, S K; Matyas, J; Woskov, P P

2011-05-01

Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system, describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. These results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.

Molecular dynamics: deciphering the data.

PubMed

Dauber-Osguthorpe, P; Maunder, C M; Osguthorpe, D J

1996-06-01

The dynamic behaviour of molecules is important in determining their activity. Molecular dynamics (MD) simulations give a detailed description of motion, from small fluctuations to conformational transitions, and can include solvent effects. However, extracting useful information about conformational motion from a trajectory is not trivial. We have used digital signal-processing techniques to characterise the motion in MD simulations, including: calculating the frequency distribution, applying filtering functions, and extraction of vectors defining the characteristic motion for each frequency in an MD simulation. We describe here some typical results obtained for peptides and proteins. The nature of the low-frequency modes of motion, as obtained from MD and normal mode (NM) analysis, of Ace-(Ala)31-Nma and of a proline mutant is discussed. Low-frequency modes extracted from the MD trajectories of Rop protein and phospholipase A2 reveal characteristic motions of secondary structure elements, as well as concerned motions that are of significance to the protein's biological activity. MD simulations are also used frequently as a tool for conformational searches and for investigating protein folding/unfolding. We have developed a novel method that uses time-domain filtering to channel energy into conformational motion and thus enhance conformational transitions. The selectively enhanced molecular dynamics method is tested on the small molecule hexane.

Molecular dynamics: Deciphering the data

NASA Astrophysics Data System (ADS)

Dauber-Osguthorpe, Pnina; Maunder, Colette M.; Osguthorpe, David J.

1996-06-01

The dynamic behaviour of molecules is important in determining their activity. Molecular dynamics (MD) simulations give a detailed description of motion, from small fluctuations to conformational transitions, and can include solvent effects. However, extracting useful information about conformational motion from a trajectory is not trivial. We have used digital signal-processing techniques to characterise the motion in MD simulations, including: calculating the frequency distribution, applying filtering functions, and extraction of vectors defining the characteristic motion for each frequency in an MD simulation. We describe here some typical results obtained for peptides and proteins. The nature of the low-frequency modes of motion, as obtained from MD and normal mode (NM) analysis, of Ace-(Ala)31-Nma and of a proline mutant is discussed. Low-frequency modes extracted from the MD trajectories of Rop protein and phospholipase A2 reveal characteristic motions of secondary structure elements, as well as concerted motions that are of significance to the protein's biological activity. MD simulations are also used frequently as a tool for conformational searches and for investigating protein folding/unfolding. We have developed a novel method that uses time-domain filtering to channel energy into conformational motion and thus enhance conformational transitions. The selectively enhanced molecular dynamics method is tested on the small molecule hexane.

Microwave Extraction of Water from Lunar Regolith Simulant

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William

2007-01-01

Nearly a decade ago the DOD Clementine lunar orbital mission obtained data indicating that the permanently shaded regions at the lunar poles may have permanently frozen water in the lunar soil. Currently NASA's Robotic Lunar Exploration Program, RLEP-2, is planned to land at the lunar pole to determine if water is present. The detection and extraction of water from the permanently frozen permafrost is an important goal for NASA. Extraction of water from lunar permafrost has a high priority in the In-Situ Resource Utilization, ISRU, community for human life support and as a fuel. The use of microwave processing would permit the extraction of water without the need to dig, drill, or excavate the lunar surface. Microwave heating of regolith is potentially faster and more efficient than any other heating methods due to the very low thermal conductivity of the lunar regolith. Also, microwaves can penetrate into the soil permitting water removal from deep below the lunar surface. A cryogenic vacuum test facility was developed for evaluating the use of microwave heating and water extraction from a lunar regolith permafrost simulant. Water is obtained in a cryogenic cold trap even with soil conditions below 0 C. The results of microwave extraction of water experiments will be presented.

Modeling of an integrated fermentation/membrane extraction process for the production of 2-phenylethanol and 2-phenylethylacetate.

PubMed

Adler, Philipp; Hugen, Thorsten; Wiewiora, Marzena; Kunz, Benno

2011-03-07

An unstructured model for an integrated fermentation/membrane extraction process for the production of the aroma compounds 2-phenylethanol and 2-phenylethylacetate by Kluyveromyces marxianus CBS 600 was developed. The extent to which this model, based only on data from the conventional fermentation and separation processes, provided an estimation of the integrated process was evaluated. The effect of product inhibition on specific growth rate and on biomass yield by both aroma compounds was approximated by multivariate regression. Simulations of the respective submodels for fermentation and the separation process matched well with experimental results. With respect to the in situ product removal (ISPR) process, the effect of reduced product inhibition due to product removal on specific growth rate and biomass yield was predicted adequately by the model simulations. Overall product yields were increased considerably in this process (4.0 g/L 2-PE+2-PEA vs. 1.4 g/L in conventional fermentation) and were even higher than predicted by the model. To describe the effect of product concentration on product formation itself, the model was extended using results from the conventional and the ISPR process, thus agreement between model and experimental data improved notably. Therefore, this model can be a useful tool for the development and optimization of an efficient integrated bioprocess. Copyright © 2010 Elsevier Inc. All rights reserved.

Modeling of In-stream Tidal Energy Development and its Potential Effects in Tacoma Narrows, Washington, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.

Understanding and providing proactive information on the potential for tidal energy projects to cause changes to the physical system and to key water quality constituents in tidal waters is a necessary and cost-effective means to avoid costly regulatory involvement and late stage surprises in the permitting process. This paper presents a modeling study for evaluating the tidal energy extraction and its potential impacts on the marine environment in a real world site - Tacoma Narrows of Puget Sound, Washington State, USA. An unstructured-grid coastal ocean model, fitted with a module that simulates tidal energy devices, was applied to simulate themore » tidal energy extracted by different turbine array configurations and the potential effects of the extraction at local and system-wide scales in Tacoma Narrows and South Puget Sound. Model results demonstrated the advantage of an unstructured-grid model for simulating the far-field effects of tidal energy extraction in a large model domain, as well as assessing the near-field effect using a fine grid resolution near the tidal turbines. The outcome shows that a realistic near-term deployment scenario extracts a very small fraction of the total tidal energy in the system and that system wide environmental effects are not likely; however, near-field effects on the flow field and bed shear stress in the area of tidal turbine farm are more likely. Model results also indicate that from a practical standpoint, hydrodynamic or water quality effects are not likely to be the limiting factor for development of large commercial-scale tidal farms. Results indicate that very high numbers of turbines are required to significantly alter the tidal system; limitations on marine space or other environmental concerns are likely to be reached before reaching these deployment levels. These findings show that important information obtained from numerical modeling can be used to inform regulatory and policy processes for tidal energy development.« less

Simulation of Subsurface Multiphase Contaminant Extraction Using a Bioslurping Well Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matos de Souza, Michelle; Oostrom, Mart; White, Mark D.

2016-07-12

Subsurface simulation of multiphase extraction from wells is notoriously difficult. Explicit representation of well geometry requires small grid resolution, potentially leading to large computational demands. To reduce the problem dimensionality, multiphase extraction is mostly modeled using vertically-averaged approaches. In this paper, a multiphase well model approach is presented as an alternative to simplify the application. The well model, a multiphase extension of the classic Peaceman model, has been implemented in the STOMP simulator. The numerical solution approach accounts for local conditions and gradients in the exchange of fluids between the well and the aquifer. Advantages of this well model implementationmore » include the option to simulate the effects of well characteristics and operation. Simulations were conducted investigating the effects of extraction location, applied vacuum pressure, and a number of hydraulic properties. The obtained results were all consistent and logical. A major outcome of the test simulations is that, in contrast with common recommendations to extract from either the gas-NAPL or the NAPL-aqueous phase interface, the optimum extraction location should be in between these two levels. The new model implementation was also used to simulate extraction at a field site in Brazil. The simulation shows a good match with the field data, suggesting that the new STOMP well module may correctly represent oil removal. The field simulations depend on the quality of the site conceptual model, including the porous media and contaminant properties and the boundary and extraction conditions adopted. The new module may potentially be used to design field applications and analyze extraction data.« less

Analysis of a reactive extraction process for biodiesel production using a lipase immobilized on magnetic nanostructures.

PubMed

Dussan, K J; Cardona, C A; Giraldo, O H; Gutiérrez, L F; Pérez, V H

2010-12-01

Magnetic nanoparticles were prepared by coprecipitating Fe(2+) and Fe(3+) ions in a sodium hydroxide solution and used as support for lipase. The lipase-coated particles were applied in a reactive extraction process that allowed separation of the products formed during transesterification. Kinetics data for triolein and ethanol consumption during biodiesel (ethyl oleate) synthesis together with a thermodynamic phase equilibrium model (liquid-liquid) were used for simulation of batch and continuous processes. The analysis demonstrated the possibility of applying this biocatalytic system in the reactive zone using external magnetic fields. This approach implies new advantages in efficient location and use of lipases in column reactors for producing biodiesel. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

A manifold learning approach to data-driven computational materials and processes

NASA Astrophysics Data System (ADS)

Ibañez, Ruben; Abisset-Chavanne, Emmanuelle; Aguado, Jose Vicente; Gonzalez, David; Cueto, Elias; Duval, Jean Louis; Chinesta, Francisco

2017-10-01

Standard simulation in classical mechanics is based on the use of two very different types of equations. The first one, of axiomatic character, is related to balance laws (momentum, mass, energy, …), whereas the second one consists of models that scientists have extracted from collected, natural or synthetic data. In this work we propose a new method, able to directly link data to computers in order to perform numerical simulations. These simulations will employ universal laws while minimizing the need of explicit, often phenomenological, models. They are based on manifold learning methodologies.

Improved system integration for integrated gasification combined cycle (IGCC) systems.

PubMed

Frey, H Christopher; Zhu, Yunhua

2006-03-01

Integrated gasification combined cycle (IGCC) systems are a promising technology for power generation. They include an air separation unit (ASU), a gasification system, and a gas turbine combined cycle power block, and feature competitive efficiency and lower emissions compared to conventional power generation technology. IGCC systems are not yet in widespread commercial use and opportunities remain to improve system feasibility via improved process integration. A process simulation model was developed for IGCC systems with alternative types of ASU and gas turbine integration. The model is applied to evaluate integration schemes involving nitrogen injection, air extraction, and combinations of both, as well as different ASU pressure levels. The optimal nitrogen injection only case in combination with an elevated pressure ASU had the highest efficiency and power output and approximately the lowest emissions per unit output of all cases considered, and thus is a recommended design option. The optimal combination of air extraction coupled with nitrogen injection had slightly worse efficiency, power output, and emissions than the optimal nitrogen injection only case. Air extraction alone typically produced lower efficiency, lower power output, and higher emissions than all other cases. The recommended nitrogen injection only case is estimated to provide annualized cost savings compared to a nonintegrated design. Process simulation modeling is shown to be a useful tool for evaluation and screening of technology options.

Scalable isosurface visualization of massive datasets on commodity off-the-shelf clusters

PubMed Central

Bajaj, Chandrajit

2009-01-01

Tomographic imaging and computer simulations are increasingly yielding massive datasets. Interactive and exploratory visualizations have rapidly become indispensable tools to study large volumetric imaging and simulation data. Our scalable isosurface visualization framework on commodity off-the-shelf clusters is an end-to-end parallel and progressive platform, from initial data access to the final display. Interactive browsing of extracted isosurfaces is made possible by using parallel isosurface extraction, and rendering in conjunction with a new specialized piece of image compositing hardware called Metabuffer. In this paper, we focus on the back end scalability by introducing a fully parallel and out-of-core isosurface extraction algorithm. It achieves scalability by using both parallel and out-of-core processing and parallel disks. It statically partitions the volume data to parallel disks with a balanced workload spectrum, and builds I/O-optimal external interval trees to minimize the number of I/O operations of loading large data from disk. We also describe an isosurface compression scheme that is efficient for progress extraction, transmission and storage of isosurfaces. PMID:19756231

The effect of an isoflavonid-rich liquorice extract on fermentation, methanogenesis and the microbiome in the rumen simulation technique.

PubMed

Ramos-Morales, E; Rossi, G; Cattin, M; Jones, E; Braganca, R; Newbold, C J

2018-03-01

Due to the antimicrobial activity of flavonoids, it has been suggested that they may provide a possible alternative to antibiotics to stimulate productivity and reduce the environmental load of ruminant agriculture. We hypothesised that an extract of liquorice, rich in prenylated isoflavonoids and particularly glabridin, might potentially improve the efficiency of nitrogen utilisation and reduce methane production in the rumen. When added to a long-term rumen simulating fermentor (RUSITEC), liquorice extract at 1 g L-1 decreased ammonia production (-51%; P < 0.001) without affecting the overall fermentation process. When added at 2 g L-1, decreases in not only ammonia production (-77%; P < 0.001), but also methane (-27%; P = 0.039) and total VFA production (-15%; P = 0.003) were observed. These effects in fermentation were probably related to a decrease in protozoa numbers, a less diverse bacteria population as well as changes in the structure of both the bacterial and archaeal communities. The inclusion of an isoflavonoid-rich extract from liquorice in the diet may potentially improve the efficiency of the feed utilisation by ruminants.

Using Microwaves to Heat Lunar Soil

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.

2011-01-01

This slide presentation reviews the use of microwaves to heat lunar soil in order to obtain water. There appears to be large amounts of water in the lunar poles, in Martian areas in lower latitudes and some of the Moons of Jupiter. The presence of water in the south lunar polar region was demonstrated by the Lunar CRater Observation and Sensing Satellite (LCROSS) mission. Microwaves can be used to extract water from lunar soil without excavation. Using microwaves on a lunar soil simulant at least 95% of the water from the regolith permafrost simulant was extracted (2 minutes). The process is modeled using COMSOL Multiphysics Finite Element analysis microwave physics module and demonstrated usingan experiment of an microwave apparatus on a rover.

Kinematic analysis and simulation of a substation inspection robot guided by magnetic sensor

NASA Astrophysics Data System (ADS)

Xiao, Peng; Luan, Yiqing; Wang, Haipeng; Li, Li; Li, Jianxiang

2017-01-01

In order to improve the performance of the magnetic navigation system used by substation inspection robot, the kinematic characteristics is analyzed based on a simplified magnetic guiding system model, and then the simulation process is executed to verify the reasonability of the whole analysis procedure. Finally, some suggestions are extracted out, which will be helpful to guide the design of the inspection robot system in the future.

Formalizing Knowledge in Multi-Scale Agent-Based Simulations

PubMed Central

Somogyi, Endre; Sluka, James P.; Glazier, James A.

2017-01-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused. PMID:29338063

Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

PubMed

Somogyi, Endre; Sluka, James P; Glazier, James A

2016-10-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

Vaccinium meridionale Swartz Supercritical CO₂ Extraction: Effect of Process Conditions and Scaling Up.

PubMed

López-Padilla, Alexis; Ruiz-Rodriguez, Alejandro; Restrepo Flórez, Claudia Estela; Rivero Barrios, Diana Marsela; Reglero, Guillermo; Fornari, Tiziana

2016-06-25

Vaccinium meridionale Swartz (Mortiño or Colombian blueberry) is one of the Vaccinium species abundantly found across the Colombian mountains, which are characterized by high contents of polyphenolic compounds (anthocyanins and flavonoids). The supercritical fluid extraction (SFE) of Vaccinium species has mainly focused on the study of V. myrtillus L. (blueberry). In this work, the SFE of Mortiño fruit from Colombia was studied in a small-scale extraction cell (273 cm³) and different extraction pressures (20 and 30 MPa) and temperatures (313 and 343 K) were investigated. Then, process scaling-up to a larger extraction cell (1350 cm³) was analyzed using well-known semi-empirical engineering approaches. The Broken and Intact Cell (BIC) model was adjusted to represent the kinetic behavior of the low-scale extraction and to simulate the large-scale conditions. Extraction yields obtained were in the range 0.1%-3.2%. Most of the Mortiño solutes are readily accessible and, thus, 92% of the extractable material was recovered in around 30 min. The constant CO₂ residence time criterion produced excellent results regarding the small-scale kinetic curve according to the BIC model, and this conclusion was experimentally validated in large-scale kinetic experiments.

Vaccinium meridionale Swartz Supercritical CO2 Extraction: Effect of Process Conditions and Scaling Up

PubMed Central

López-Padilla, Alexis; Ruiz-Rodriguez, Alejandro; Restrepo Flórez, Claudia Estela; Rivero Barrios, Diana Marsela; Reglero, Guillermo; Fornari, Tiziana

2016-01-01

Vaccinium meridionale Swartz (Mortiño or Colombian blueberry) is one of the Vaccinium species abundantly found across the Colombian mountains, which are characterized by high contents of polyphenolic compounds (anthocyanins and flavonoids). The supercritical fluid extraction (SFE) of Vaccinium species has mainly focused on the study of V. myrtillus L. (blueberry). In this work, the SFE of Mortiño fruit from Colombia was studied in a small-scale extraction cell (273 cm3) and different extraction pressures (20 and 30 MPa) and temperatures (313 and 343 K) were investigated. Then, process scaling-up to a larger extraction cell (1350 cm3) was analyzed using well-known semi-empirical engineering approaches. The Broken and Intact Cell (BIC) model was adjusted to represent the kinetic behavior of the low-scale extraction and to simulate the large-scale conditions. Extraction yields obtained were in the range 0.1%–3.2%. Most of the Mortiño solutes are readily accessible and, thus, 92% of the extractable material was recovered in around 30 min. The constant CO2 residence time criterion produced excellent results regarding the small-scale kinetic curve according to the BIC model, and this conclusion was experimentally validated in large-scale kinetic experiments. PMID:28773640

Rigging Test Bed Development for Validation of Multi-Stage Decelerator Extractions

NASA Technical Reports Server (NTRS)

Kenig, Sivan J.; Gallon, John C.; Adams, Douglas S.; Rivellini, Tommaso P.

2013-01-01

The Low Density Supersonic Decelerator project is developing new decelerator systems for Mars entry which would include testing with a Supersonic Flight Dynamics Test Vehicle. One of the decelerator systems being developed is a large supersonic ringsail parachute. Due to the configuration of the vehicle it is not possible to deploy the parachute with a mortar which would be the preferred method for a spacecraft in a supersonic flow. Alternatively, a multi-stage extraction process using a ballute as a pilot is being developed for the test vehicle. The Rigging Test Bed is a test venue being constructed to perform verification and validation of this extraction process. The test bed consists of a long pneumatic piston device capable of providing a constant force simulating the ballute drag force during the extraction events. The extraction tests will take place both inside a high-bay for frequent tests of individual extraction stages and outdoors using a mobile hydraulic crane for complete deployment tests from initial pack pull out to canopy extraction. These tests will measure line tensions and use photogrammetry to track motion of the elements involved. The resulting data will be used to verify packing and rigging as well, as validate models and identify potential failure modes in order to finalize the design of the extraction system.

Development of a Post-Processing Algorithm for Accurate Human Skull Profile Extraction via Ultrasonic Phased Arrays

NASA Astrophysics Data System (ADS)

Al-Ansary, Mariam Luay Y.

Ultrasound Imaging has been favored by clinicians for its safety, affordability, accessibility, and speed compared to other imaging modalities. However, the trade-offs to these benefits are a relatively lower image quality and interpretability, which can be addressed by, for example, post-processing methods. One particularly difficult imaging case is associated with the presence of a barrier, such as a human skull, with significantly different acoustical properties than the brain tissue as the target medium. Some methods were proposed in the literature to account for this structure if the skull's geometry is known. Measuring the skull's geometry is therefore an important task that requires attention. In this work, a new edge detection method for accurate human skull profile extraction via post-processing of ultrasonic A-Scans is introduced. This method, referred to as the Selective Echo Extraction algorithm, SEE, processes each A-Scan separately and determines the outermost and innermost boundaries of the skull by means of adaptive filtering. The method can also be used to determine the average attenuation coefficient of the skull. When applied to simulated B-Mode images of the skull profile, promising results were obtained. The profiles obtained from the proposed process in simulations were found to be within 0.15lambda +/- 0.11lambda or 0.09 +/- 0.07mm from the actual profiles. Experiments were also performed to test SEE on skull mimicking phantoms with major acoustical properties similar to those of the actual human skull. With experimental data, the profiles obtained with the proposed process were within 0.32lambda +/- 0.25lambda or 0.19 +/- 0.15mm from the actual profile.

Engineering aspects of rate-related processes in food manufacturing.

PubMed

Adachi, Shuji

2015-01-01

Many rate-related phenomena occur in food manufacturing processes. This review addresses four of them, all of which are topics that the author has studied in order to design food manufacturing processes that are favorable from the standpoint of food engineering. They include chromatographic separation through continuous separation with a simulated moving adsorber, lipid oxidation kinetics in emulsions and microencapsulated systems, kinetic analysis and extraction in subcritical water, and water migration in pasta.

Enhancement of temporal periodicity cues in cochlear implants: Effects on prosodic perception and vowel identification

NASA Astrophysics Data System (ADS)

Green, Tim; Faulkner, Andrew; Rosen, Stuart; Macherey, Olivier

2005-07-01

Standard continuous interleaved sampling processing, and a modified processing strategy designed to enhance temporal cues to voice pitch, were compared on tests of intonation perception, and vowel perception, both in implant users and in acoustic simulations. In standard processing, 400 Hz low-pass envelopes modulated either pulse trains (implant users) or noise carriers (simulations). In the modified strategy, slow-rate envelope modulations, which convey dynamic spectral variation crucial for speech understanding, were extracted by low-pass filtering (32 Hz). In addition, during voiced speech, higher-rate temporal modulation in each channel was provided by 100% amplitude-modulation by a sawtooth-like wave form whose periodicity followed the fundamental frequency (F0) of the input. Channel levels were determined by the product of the lower- and higher-rate modulation components. Both in acoustic simulations and in implant users, the ability to use intonation information to identify sentences as question or statement was significantly better with modified processing. However, while there was no difference in vowel recognition in the acoustic simulation, implant users performed worse with modified processing both in vowel recognition and in formant frequency discrimination. It appears that, while enhancing pitch perception, modified processing harmed the transmission of spectral information.

Static analysis techniques for semiautomatic synthesis of message passing software skeletons

DOE PAGES

Sottile, Matthew; Dagit, Jason; Zhang, Deli; ...

2015-06-29

The design of high-performance computing architectures demands performance analysis of large-scale parallel applications to derive various parameters concerning hardware design and software development. The process of performance analysis and benchmarking an application can be done in several ways with varying degrees of fidelity. One of the most cost-effective ways is to do a coarse-grained study of large-scale parallel applications through the use of program skeletons. The concept of a “program skeleton” that we discuss in this article is an abstracted program that is derived from a larger program where source code that is determined to be irrelevant is removed formore » the purposes of the skeleton. In this work, we develop a semiautomatic approach for extracting program skeletons based on compiler program analysis. Finally, we demonstrate correctness of our skeleton extraction process by comparing details from communication traces, as well as show the performance speedup of using skeletons by running simulations in the SST/macro simulator.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zalupski, Peter R.; Klaehn, John R.; Peterman, Dean R.

The feasibility of simultaneous separation of uranium, neptunium, plutonium, americium, and curium from a simulated dissolved used fuel simulant adjusted to 1.0 M nitric acid is investigated using a mixture of the soft donor bis(bis-3,5-trifluoromethyl)phenyl) dithiophosphinic acid (“0”) and the hard donor synergist trioctylphosphine oxide (TOPO) dissolved in toluene. The results reported in this work are compared to our recent demonstration of a complete actinide recovery from a simulated dissolved fuel solution using a synergistic combination of bis(o-trifluoromethylphenyl)dithiophosphinic acid (“1”) and TOPO dissolved in either toluene or trifluoromethylphenyl sulfone. While the extraction efficiency of americium was enhanced for the liquid-liquidmore » system containing “0”, enabling to accomplish a trivalent An/Ln separation at 1.0 M HNO3, the extraction of neptunium was drastically diminished, relative to “1”. The partitioning behavior of curium was also negatively impacted, introducing an effective opportunity for americium/curium separation. Radiometric and spectrophotometric studies demonstrate that the complete actinide recovery using the solvent based upon “0” and TOPO is not feasible. Additionally, the importance of radiolytic degradation processes is discussed through the comparisons of extraction properties of liquid-liquid systems based on both soft donor reagents.« less

3D Simulation Modeling of the Tooth Wear Process.

PubMed

Dai, Ning; Hu, Jian; Liu, Hao

2015-01-01

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

3D Simulation Modeling of the Tooth Wear Process

PubMed Central

Dai, Ning; Hu, Jian; Liu, Hao

2015-01-01

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942

Correlation of reaction sites during the chlorine extraction by hydrogen atom from Cl /Si(100)-2×1

NASA Astrophysics Data System (ADS)

Hsieh, Ming-Feng; Chung, Jen-Yang; Lin, Deng-Sung; Tsay, Shiow-Fon

2007-07-01

The Cl abstraction by gas-phase H atoms from a Cl-terminated Si(100) surface was investigated by scanning tunneling microscopy (STM), high-resolution core level photoemission spectroscopy, and computer simulation. The core level measurements indicate that some additional reactions occur besides the removal of Cl. The STM images show that the Cl-extracted sites disperse randomly in the initial phase of the reaction, but form small clusters as more Cl is removed, indicating a correlation between Cl-extracted sites. These results suggest that the hot-atom process may occur during the atom-adatom collision.

Fundamental Chemical Kinetic And Thermodynamic Data For Purex Process Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, R.J.; Fox, O.D.; Sarsfield, M.J.

2007-07-01

To support either the continued operations of current reprocessing plants or the development of future fuel processing using hydrometallurgical processes, such as Advanced Purex or UREX type flowsheets, the accurate simulation of Purex solvent extraction is required. In recent years we have developed advanced process modeling capabilities that utilize modern software platforms such as Aspen Custom Modeler and can be run in steady state and dynamic simulations. However, such advanced models of the Purex process require a wide range of fundamental data including all relevant basic chemical kinetic and thermodynamic data for the major species present in the process. Thismore » paper will summarize some of these recent process chemistry studies that underpin our simulation, design and testing of Purex solvent extraction flowsheets. Whilst much kinetic data for actinide redox reactions in nitric acid exists in the literature, the data on reactions in the diluted TBP solvent phase is much rarer. This inhibits the accurate modelization of the Purex process particularly when species show a significant extractability in to the solvent phase or when cycling between solvent and aqueous phases occurs, for example in the reductive stripping of Pu(IV) by ferrous sulfamate in the Magnox reprocessing plant. To support current oxide reprocessing, we have investigated a range of solvent phase reactions: - U(IV)+HNO{sub 3}; - U(IV)+HNO{sub 2}; - U(IV)+HNO{sub 3} (Pu catalysis); - U(IV)+HNO{sub 3} (Tc catalysis); - U(IV)+ Np(VI); - U(IV)+Np(V); - Np(IV)+HNO{sub 3}; - Np(V)+Np(V); Rate equations have been determined for all these reactions and kinetic rate constants and activation energies are now available. Specific features of these reactions in the TBP phase include the roles of water and hydrolyzed intermediates in the reaction mechanisms. In reactions involving Np(V), cation-cation complex formation, which is much more favourable in TBP than in HNO{sub 3}, also occurs and complicates the redox chemistry. Whilst some features of the redox chemistry in TBP appear similar to the corresponding reactions in aqueous HNO{sub 3}, there are notable differences in rates, the forms of the rate equations and mechanisms. Secondly, to underpin the development of advanced single cycle flowsheets using the complexant aceto-hydroxamic acid, we have also characterised in some detail its redox chemistry and solvent extraction behaviour with both Np and Pu ions. We find that simple hydroxamic acids are remarkably rapid reducing agents for Np(VI). They also reduce Pu(VI) and cause a much slower reduction of Pu(IV) through a complex mechanism involving acid hydrolysis of the ligand. AHA is a strong hydrophilic and selective complexant for the tetravalent actinide ions as evidenced by stability constant and solvent extraction data for An(IV), M(III) and U(VI) ions. This has allowed the successful design of U/Pu+Np separation flowsheets suitable for advanced fuel cycles. (authors)« less

Extraction of volatiles and metals from extraterrestrial ores

NASA Technical Reports Server (NTRS)

Lewis, John S.

1989-01-01

Extraterrestrial materials, processes, and products were identified which are associated with the production of propellants in space, including the most complete possible conversion of the feedstocks for propellant production into useful products with the minimum feasible expenditure of energy. Laboratory research was identified and begun on several processes that promise very large increases in the mass of useful products at the cost of only modest increases in energy consumption. Processes for manufacturing propellants then become processes for making propellants plus metals and refractories. It is the overall yield of useful materials per unit expended energy that matters, not simply the yield of propellants. Three tasks have been undertaken to date: (1) Literature search and compilation of a dBase 3 data base on space materials processing; (2) Gaseous carbonyl extraction and purification of ferrous metals; and (3) Characterization of lunar ilmenite and its simulants.

Informing Hospital Change Processes through Visualization and Simulation: A Case Study at a Children's Emergency Clinic.

PubMed

Persson, Johanna; Dalholm, Elisabeth Hornyánszky; Johansson, Gerd

2014-01-01

To demonstrate the use of visualization and simulation tools in order to involve stakeholders and inform the process in hospital change processes, illustrated by an empirical study from a children's emergency clinic. Reorganization and redevelopment of a hospital is a complex activity that involves many stakeholders and demands. Visualization and simulation tools have proven useful for involving practitioners and eliciting relevant knowledge. More knowledge is desired about how these tools can be implemented in practice for hospital planning processes. A participatory planning process including practitioners and researchers was executed over a 3-year period to evaluate a combination of visualization and simulation tools to involve stakeholders in the planning process and to elicit knowledge about needs and requirements. The initial clinic proposal from the architect was discarded as a result of the empirical study. Much general knowledge about the needs of the organization was extracted by means of the adopted tools. Some of the tools proved to be more accessible than others for the practitioners participating in the study. The combination of tools added value to the process by presenting information in alternative ways and eliciting questions from different angles. Visualization and simulation tools inform a planning process (or other types of change processes) by providing the means to see beyond present demands and current work structures. Long-term involvement in combination with accessible tools is central for creating a participatory setting where the practitioners' knowledge guides the process. © 2014 Vendome Group, LLC.

Conductivity Evolution of Fracture Proppant in Partial Monolayers and Multilayers

NASA Astrophysics Data System (ADS)

Fan, M.; Han, Y.; McClure, J. E.; Chen, C.

2017-12-01

Proppant is a granular material, typically sand, coated sand, or man-made ceramic materials, which is widely used in hydraulic fracturing to keep the induced fractures open. Optimization of proppant placement in a hydraulic fracture, as well as its role on the fracture's conductivity, is vital for effective and economical production of petroleum hydrocarbons. In this research, a numerical modeling approach, combining Discrete Element Method (DEM) with lattice Boltzmann (LB) method, was adopted to advance the understanding of fracture conductivity as function of proppant concentration under various effective stresses. DEM was used to simulate effective stress increase and the resultant proppant particle compaction and rearrangement during the process of reservoir depletion due to hydrocarbon extraction. DEM-simulated pore structure was extracted and imported into the LB simulator as boundary conditions to calculate the time-dependent permeability of the proppant pack. We first validated the DEM-LB coupling workflow; the simulated proppant pack permeabilities as functions of effective stress were in good agreement with laboratory measurements. Next, several proppant packs were generated with various proppant concentrations, ranging from partial-monolayer to multilayer structures. Proppant concentration is defined as proppant mass per unit fracture face area. Fracture conductivity as function of proppant concentration was measured in LB simulations. It was found that a partial-monolayer proppant pack with large-diameter particles was optimal in maintaining sufficient conductivity while lowering production costs. Three proppant packs with the same average diameter but different diameter distributions were generated. Specifically, we used the coefficient of variation (COV) of diameter, defined as the ratio of standard deviation of diameter to mean diameter, to characterize the heterogeneity in particle size. We obtained proppant pack porosity, permeability, and fracture width reduction as functions of effective stress. Under the same effective stress, a proppant pack with a smaller diameter COV had higher porosity and permeability and smaller fracture width reduction, which are all favorable for maintaining the fracture conductivity during the process of hydrocarbon extraction.

Simulation of ground-water flow and areas contributing recharge to extraction wells at the Drake Chemical Superfund Site, City of Lock Haven and Castanea Township, Clinton County, Pennsylvania

USGS Publications Warehouse

Schreffler, Curtis L.

2006-01-01

Extensive remediation of the Drake Chemical Superfund Site has been ongoing since 1983. Contaminated soils were excavated and incinerated on site between 1996 and 1999. After 1999, remedial efforts focused on contaminated ground water. A ground-water remediation system was started in November 2000. The source area of the contaminated ground water was assumed to be the zone 1 area on the Drake Chemical site. The remedial system was designed to capture ground water migrating from zone 1. Also, the remediation system was designed to pump and treat the water in an anoxic environment and re-infiltrate the treated water underground through an infiltration gallery that is hydrologically downgradient of the extraction wells. A numerical ground-water flow model of the surrounding region was constructed to simulate the areas contributing recharge to remedial extraction wells installed on the Drake Chemical site. The three-dimensional numerical flow model was calibrated using the parameter-estimation process in MODFLOW-2000. The model included three layers that represented three poorly sorted alluvial sediment units that were characterized from geologic well and boring logs. Steady-state ground-water flow was simulated to estimate the areas contributing recharge to three extraction wells for three different pumping scenarios--all wells pumping at 2 gallons per minute, at approximately 5 gallons per minute, and at 8 gallons per minute. Simulation results showed the contributing areas to the three extraction wells encompassed 92 percent of zone 1 at a pumping rate of approximately 5 gallons per minute. The contributing areas did not include a very small area in the southwestern part of zone 1 when the three extraction wells were pumped at approximately 5 gallons per minute. Pumping from a fourth extraction well in that area was discontinued early in the operation of the remediation system because the ground water in that area met performance standards. The areas contributing recharge to the three extraction wells did encompass zone 1 at a pumping rate of 8 gallons per minute. At pumping rates of 2 gallons per minute, the contributing areas for the three extraction wells did not encompass zone 1.

[Studying on purification technology of Resina Draconis phenol extracts based on design space method].

PubMed

Zhang, Jian; Zhang, Xin; Bi, Yu-An; Xu, Gui-Hong; Huang, Wen-Zhe; Wang, Zhen-Zhong; Xiao, Wei

2017-09-01

The "design space" method was used to optimize the purification process of Resina Draconis phenol extracts by using the concept of "quality derived from design" (QbD). The content and transfer rate of laurin B and 7,4'-dihydroxyflavone and yield of extract were selected as the critical quality attributes (CQA). Plackett-Burman design showed that the critical process parameters (CPP) were concentration of alkali, the amount of alkali and the temperature of alkali dissolution. Then the Box-Behnken design was used to establish the mathematical model between CQA and CPP. The variance analysis results showed that the P values of the five models were less than 0.05 and the mismatch values were all greater than 0.05, indicating that the model could well describe the relationship between CQA and CPP. Finally, the control limits of the above 5 indicators (content and transfer rate of laurine B and 7,4'-dihydroxyflavone, as well as the extract yield) were set, and then the probability-based design space was calculated by Monte Carlo simulation and verified. The results of the design space validation showed that the optimized purification method can ensure the stability of the Resina Draconis phenol extracts refining process, which would help to improve the quality uniformity between batches of phenol extracts and provide data support for production automation control. Copyright© by the Chinese Pharmaceutical Association.

Computational Simulation of Thermal and Spattering Phenomena and Microstructure in Selective Laser Melting of Inconel 625

NASA Astrophysics Data System (ADS)

Özel, Tuğrul; Arısoy, Yiğit M.; Criales, Luis E.

Computational modelling of Laser Powder Bed Fusion (L-PBF) processes such as Selective laser Melting (SLM) can reveal information that is hard to obtain or unobtainable by in-situ experimental measurements. A 3D thermal field that is not visible by the thermal camera can be obtained by solving the 3D heat transfer problem. Furthermore, microstructural modelling can be used to predict the quality and mechanical properties of the product. In this paper, a nonlinear 3D Finite Element Method based computational code is developed to simulate the SLM process with different process parameters such as laser power and scan velocity. The code is further improved by utilizing an in-situ thermal camera recording to predict spattering which is in turn included as a stochastic heat loss. Then, thermal gradients extracted from the simulations applied to predict growth directions in the resulting microstructure.

Large-Scale Membrane- and Lignin-Modified Adsorbent-Assisted Extraction and Preconcentration of Triazine Analogs and Aflatoxins

PubMed Central

Hu, Shun-Wei; Chen, Shushi

2017-01-01

The large-scale simultaneous extraction and concentration of aqueous solutions of triazine analogs, and aflatoxins, through a hydrocarbon-based membrane (e.g., polyethylene, polyethylene/polypropylene copolymer) under ambient temperature and atmospheric pressure is reported. The subsequent adsorption of analyte in the extraction chamber over the lignin-modified silica gel facilitates the process by reducing the operating time. The maximum adsorption capacity values for triazine analogs and aflatoxins are mainly adsorption mechanism-dependent and were calculated to be 0.432 and 0.297 mg/10 mg, respectively. The permeation, and therefore the percentage of analyte extracted, ranges from 1% to almost 100%, and varies among the solvents examined. It is considered to be vapor pressure- and chemical polarity-dependent, and is thus highly affected by the nature and thickness of the membrane, the discrepancy in the solubility values of the analyte between the two liquid phases, and the amount of adsorbent used in the process. A dependence on the size of the analyte was observed in the adsorption capacity measurement, but not in the extraction process. The theoretical interaction simulation and FTIR data show that the planar aflatoxin molecule releases much more energy when facing toward the membrane molecule when approaching it, and the mechanism leading to the adsorption. PMID:28398252

Forensic print extraction using 3D technology and its processing

NASA Astrophysics Data System (ADS)

Rajeev, Srijith; Shreyas, Kamath K. M.; Panetta, Karen; Agaian, Sos S.

2017-05-01

Biometric evidence plays a crucial role in criminal scene analysis. Forensic prints can be extracted from any solid surface such as firearms, doorknobs, carpets and mugs. Prints such as fingerprints, palm prints, footprints and lip-prints can be classified into patent, latent, and three-dimensional plastic prints. Traditionally, law enforcement officers capture these forensic traits using an electronic device or extract them manually, and save the data electronically using special scanners. The reliability and accuracy of the method depends on the ability of the officer or the electronic device to extract and analyze the data. Furthermore, the 2-D acquisition and processing system is laborious and cumbersome. This can lead to the increase in false positive and true negative rates in print matching. In this paper, a method and system to extract forensic prints from any surface, irrespective of its shape, is presented. First, a suitable 3-D camera is used to capture images of the forensic print, and then the 3-D image is processed and unwrapped to obtain 2-D equivalent biometric prints. Computer simulations demonstrate the effectiveness of using 3-D technology for biometric matching of fingerprints, palm prints, and lip-prints. This system can be further extended to other biometric and non-biometric modalities.

Large-Scale Membrane- and Lignin-Modified Adsorbent-Assisted Extraction and Preconcentration of Triazine Analogs and Aflatoxins.

PubMed

Hu, Shun-Wei; Chen, Shushi

2017-04-11

The large-scale simultaneous extraction and concentration of aqueous solutions of triazine analogs, and aflatoxins, through a hydrocarbon-based membrane (e.g., polyethylene, polyethylene/polypropylene copolymer) under ambient temperature and atmospheric pressure is reported. The subsequent adsorption of analyte in the extraction chamber over the lignin-modified silica gel facilitates the process by reducing the operating time. The maximum adsorption capacity values for triazine analogs and aflatoxins are mainly adsorption mechanism-dependent and were calculated to be 0.432 and 0.297 mg/10 mg, respectively. The permeation, and therefore the percentage of analyte extracted, ranges from 1% to almost 100%, and varies among the solvents examined. It is considered to be vapor pressure- and chemical polarity-dependent, and is thus highly affected by the nature and thickness of the membrane, the discrepancy in the solubility values of the analyte between the two liquid phases, and the amount of adsorbent used in the process. A dependence on the size of the analyte was observed in the adsorption capacity measurement, but not in the extraction process. The theoretical interaction simulation and FTIR data show that the planar aflatoxin molecule releases much more energy when facing toward the membrane molecule when approaching it, and the mechanism leading to the adsorption.

Extraction of Water from Martian Regolith Simulant via Open Reactor Concept

NASA Technical Reports Server (NTRS)

Trunek, Andrew J.; Linne, Diane L.; Kleinhenz, Julie E.; Bauman, Steven W.

2018-01-01

To demonstrate proof of concept water extraction from simulated Martian regolith, an open reactor design is presented along with experimental results. The open reactor concept avoids sealing surfaces and complex moving parts. In an abrasive environment like the Martian surface, those reactor elements would be difficult to maintain and present a high probability of failure. A general lunar geotechnical simulant was modified by adding borax decahydrate (Na2B4O7·10H2O) (BDH) to mimic the 3 percent water content of hydrated salts in near surface soils on Mars. A rotating bucket wheel excavated the regolith from a source bin and deposited the material onto an inclined copper tray, which was fitted with heaters and a simple vibration system. The combination of vibration, tilt angle and heat was used to separate and expose as much regolith surface area as possible to liberate the water contained in the hydrated minerals, thereby increasing the efficiency of the system. The experiment was conducted in a vacuum system capable of maintaining a Martian like atmosphere. Evolved water vapor was directed to a condensing system using the ambient atmosphere as a sweep gas. The water vapor was condensed and measured. Processed simulant was captured in a collection bin and weighed in real time. The efficiency of the system was determined by comparing pre- and post-processing soil mass along with the volume of water captured.

A combined model of heat and mass transfer for the in situ extraction of volatile water from lunar regolith

NASA Astrophysics Data System (ADS)

Reiss, P.

2018-05-01

Chemical analysis of lunar soil samples often involves thermal processing to extract their volatile constituents, such as loosely adsorbed water. For the characterization of volatiles and their bonding mechanisms it is important to determine their desorption temperature. However, due to the low thermal diffusivity of lunar regolith, it might be difficult to reach a uniform heat distribution in a sample that is larger than only a few particles. Furthermore, the mass transport through such a sample is restricted, which might lead to a significant delay between actual desorption and measurable outgassing of volatiles from the sample. The entire volatiles extraction process depends on the dynamically changing heat and mass transfer within the sample, and is influenced by physical parameters such as porosity, tortuosity, gas density, temperature and pressure. To correctly interpret measurements of the extracted volatiles, it is important to understand the interaction between heat transfer, sorption, and gas transfer through the sample. The present paper discusses the molecular kinetics and mechanisms that are involved in the thermal extraction process and presents a combined parametrical computation model to simulate this process. The influence of water content on the gas diffusivity and thermal diffusivity is discussed and the issue of possible resorption of desorbed molecules within the sample is addressed. Based on the multi-physical computation model, a case study for the ProSPA instrument for in situ analysis of lunar volatiles is presented, which predicts relevant dynamic process parameters, such as gas pressure and process duration.

Modeling In-stream Tidal Energy Extraction and Its Potential Environmental Impacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

In recent years, there has been growing interest in harnessing in-stream tidal energy in response to concerns of increasing energy demand and to mitigate climate change impacts. While many studies have been conducted to assess and map tidal energy resources, efforts for quantifying the associated potential environmental impacts have been limited. This paper presents the development of a tidal turbine module within a three-dimensional unstructured-grid coastal ocean model and its application for assessing the potential environmental impacts associated with tidal energy extraction. The model is used to investigate in-stream tidal energy extraction and associated impacts on estuarine hydrodynamic and biologicalmore » processes in a tidally dominant estuary. A series of numerical experiments with varying numbers and configurations of turbines installed in an idealized estuary were carried out to assess the changes in the hydrodynamics and biological processes due to tidal energy extraction. Model results indicated that a large number of turbines are required to extract the maximum tidal energy and cause significant reduction of the volume flux. Preliminary model results also indicate that extraction of tidal energy increases vertical mixing and decreases flushing rate in a stratified estuary. The tidal turbine model was applied to simulate tidal energy extraction in Puget Sound, a large fjord-like estuary in the Pacific Northwest coast.« less

Medical image diagnoses by artificial neural networks with image correlation, wavelet transform, simulated annealing

NASA Astrophysics Data System (ADS)

Szu, Harold H.

1993-09-01

Classical artificial neural networks (ANN) and neurocomputing are reviewed for implementing a real time medical image diagnosis. An algorithm known as the self-reference matched filter that emulates the spatio-temporal integration ability of the human visual system might be utilized for multi-frame processing of medical imaging data. A Cauchy machine, implementing a fast simulated annealing schedule, can determine the degree of abnormality by the degree of orthogonality between the patient imagery and the class of features of healthy persons. An automatic inspection process based on multiple modality image sequences is simulated by incorporating the following new developments: (1) 1-D space-filling Peano curves to preserve the 2-D neighborhood pixels' relationship; (2) fast simulated Cauchy annealing for the global optimization of self-feature extraction; and (3) a mini-max energy function for the intra-inter cluster-segregation respectively useful for top-down ANN designs.

Feature ranking and rank aggregation for automatic sleep stage classification: a comparative study.

PubMed

Najdi, Shirin; Gharbali, Ali Abdollahi; Fonseca, José Manuel

2017-08-18

Nowadays, sleep quality is one of the most important measures of healthy life, especially considering the huge number of sleep-related disorders. Identifying sleep stages using polysomnographic (PSG) signals is the traditional way of assessing sleep quality. However, the manual process of sleep stage classification is time-consuming, subjective and costly. Therefore, in order to improve the accuracy and efficiency of the sleep stage classification, researchers have been trying to develop automatic classification algorithms. Automatic sleep stage classification mainly consists of three steps: pre-processing, feature extraction and classification. Since classification accuracy is deeply affected by the extracted features, a poor feature vector will adversely affect the classifier and eventually lead to low classification accuracy. Therefore, special attention should be given to the feature extraction and selection process. In this paper the performance of seven feature selection methods, as well as two feature rank aggregation methods, were compared. Pz-Oz EEG, horizontal EOG and submental chin EMG recordings of 22 healthy males and females were used. A comprehensive feature set including 49 features was extracted from these recordings. The extracted features are among the most common and effective features used in sleep stage classification from temporal, spectral, entropy-based and nonlinear categories. The feature selection methods were evaluated and compared using three criteria: classification accuracy, stability, and similarity. Simulation results show that MRMR-MID achieves the highest classification performance while Fisher method provides the most stable ranking. In our simulations, the performance of the aggregation methods was in the average level, although they are known to generate more stable results and better accuracy. The Borda and RRA rank aggregation methods could not outperform significantly the conventional feature ranking methods. Among conventional methods, some of them slightly performed better than others, although the choice of a suitable technique is dependent on the computational complexity and accuracy requirements of the user.

Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William; Hepburn, Frank

2009-01-01

This disk contains 2 videos that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The 1st video shows the results of the COMSOL models. The second video shows brief views of the lunar surface.

Using Microwaves for Extracting Water from the Moon

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William; Hepburn, Frank

2009-01-01

This disk contains a video that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The video shows the partial results of the COMSOL modeling.

JSC Mars-1 Martian Soil Simulant: Melting Experiments and Electron Microprobe Studies

NASA Technical Reports Server (NTRS)

Carpenter, P.; Sebille, L.; Boles, W.; Chadwell, M.; Schwarz, L.

2003-01-01

JSC Mars-1 has been developed as a Martian regolith simulant, and is the <1 mm size fraction of a palagonitic tephra (a glassy volcanic ash altered at low temperatures) from Pu'u Nene cinder cone on the Island of Hawaii. The Mars-1 simulant forms the basis for numerous terrestrial studies which aim to evaluate the suitability of Martian soil for materials processing. Martian soil may be sintered to form building materials for construction, and also melted or reacted to extract metals for various uses, as well as oxygen for life support.

Features Extraction of Flotation Froth Images and BP Neural Network Soft-Sensor Model of Concentrate Grade Optimized by Shuffled Cuckoo Searching Algorithm

PubMed Central

Wang, Jie-sheng; Han, Shuang; Shen, Na-na; Li, Shu-xia

2014-01-01

For meeting the forecasting target of key technology indicators in the flotation process, a BP neural network soft-sensor model based on features extraction of flotation froth images and optimized by shuffled cuckoo search algorithm is proposed. Based on the digital image processing technique, the color features in HSI color space, the visual features based on the gray level cooccurrence matrix, and the shape characteristics based on the geometric theory of flotation froth images are extracted, respectively, as the input variables of the proposed soft-sensor model. Then the isometric mapping method is used to reduce the input dimension, the network size, and learning time of BP neural network. Finally, a shuffled cuckoo search algorithm is adopted to optimize the BP neural network soft-sensor model. Simulation results show that the model has better generalization results and prediction accuracy. PMID:25133210

Interoperability format translation and transformation between IFC architectural design file and simulation file formats

DOEpatents

Chao, Tian-Jy; Kim, Younghun

2015-02-03

Automatically translating a building architecture file format (Industry Foundation Class) to a simulation file, in one aspect, may extract data and metadata used by a target simulation tool from a building architecture file. Interoperability data objects may be created and the extracted data is stored in the interoperability data objects. A model translation procedure may be prepared to identify a mapping from a Model View Definition to a translation and transformation function. The extracted data may be transformed using the data stored in the interoperability data objects, an input Model View Definition template, and the translation and transformation function to convert the extracted data to correct geometric values needed for a target simulation file format used by the target simulation tool. The simulation file in the target simulation file format may be generated.

Simultaneous measurement of temperature and emissivity of lunar regolith simulant using dual-channel millimeter-wave radiometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, J. S.; Sundaram, S. K.; Matyas, J.

Millimeter wave (MMW) radiometry can be used for simultaneous measurement of emissivity and temperature of materials under extreme environments (high temperature, pressure, and corrosive environments). The state-of-the-art dual channel MMW passive radiometer with active interferometric capabilities at 137 GHz described here allows for radiometric measurements of sample temperature and emissivity up to at least 1600 °C with simultaneous measurement of sample surface dynamics. These capabilities have been used to demonstrate dynamic measurement of melting of powders of simulated lunar regolith and static measurement of emissivity of solid samples. The paper presents the theoretical background and basis for the dual-receiver system,more » describes the hardware in detail, and demonstrates the data analysis. Post-experiment analysis of emissivity versus temperature allows further extraction from the radiometric data of millimeter wave viewing beam coupling factors, which provide corroboratory evidence to the interferometric data of the process dynamics observed. Finally, these results show the promise of the MMW system for extracting quantitative and qualitative process parameters for industrial processes and access to real-time dynamics of materials behavior in extreme environments.« less

Automated Knowledge Discovery from Simulators

NASA Technical Reports Server (NTRS)

Burl, Michael C.; DeCoste, D.; Enke, B. L.; Mazzoni, D.; Merline, W. J.; Scharenbroich, L.

2006-01-01

In this paper, we explore one aspect of knowledge discovery from simulators, the landscape characterization problem, where the aim is to identify regions in the input/ parameter/model space that lead to a particular output behavior. Large-scale numerical simulators are in widespread use by scientists and engineers across a range of government agencies, academia, and industry; in many cases, simulators provide the only means to examine processes that are infeasible or impossible to study otherwise. However, the cost of simulation studies can be quite high, both in terms of the time and computational resources required to conduct the trials and the manpower needed to sift through the resulting output. Thus, there is strong motivation to develop automated methods that enable more efficient knowledge extraction.

A graph-Laplacian-based feature extraction algorithm for neural spike sorting.

PubMed

Ghanbari, Yasser; Spence, Larry; Papamichalis, Panos

2009-01-01

Analysis of extracellular neural spike recordings is highly dependent upon the accuracy of neural waveform classification, commonly referred to as spike sorting. Feature extraction is an important stage of this process because it can limit the quality of clustering which is performed in the feature space. This paper proposes a new feature extraction method (which we call Graph Laplacian Features, GLF) based on minimizing the graph Laplacian and maximizing the weighted variance. The algorithm is compared with Principal Components Analysis (PCA, the most commonly-used feature extraction method) using simulated neural data. The results show that the proposed algorithm produces more compact and well-separated clusters compared to PCA. As an added benefit, tentative cluster centers are output which can be used to initialize a subsequent clustering stage.

Extraction of manganese from electrolytic manganese residue by bioleaching.

PubMed

Xin, Baoping; Chen, Bing; Duan, Ning; Zhou, Changbo

2011-01-01

Extraction of manganese from electrolytic manganese residues using bioleaching was investigated in this paper. The maximum extraction efficiency of Mn was 93% by sulfur-oxidizing bacteria at 4.0 g/l sulfur after bioleaching of 9days, while the maximum extraction efficiency of Mn was 81% by pyrite-leaching bacteria at 4.0 g/l pyrite. The series bioleaching first by sulfur-oxidizing bacteria and followed by pyrite-leaching bacteria evidently promoted the extraction of manganese, witnessing the maximum extraction efficiency of 98.1%. In the case of sulfur-oxidizing bacteria, the strong dissolution of bio-generated sulfuric acid resulted in extraction of soluble Mn2+, while both the Fe2+ catalyzed reduction of Mn4+ and weak acidic dissolution of Mn2+ accounted for the extraction of manganese with pyrite-leaching bacteria. The chemical simulation of bioleaching process further confirmed that the acid dissolution of Mn2+ and Fe2+ catalyzed reduction of Mn4+ were the bioleaching mechanisms involved for Mn extraction from electrolytic manganese residues. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evaluation of hydrolysis-esterification biodiesel production from wet microalgae.

PubMed

Song, Chunfeng; Liu, Qingling; Ji, Na; Deng, Shuai; Zhao, Jun; Li, Shuhong; Kitamura, Yutaka

2016-08-01

Wet microalgae hydrolysis-esterification route has the advantage to avoid the energy-intensive units (e.g. drying and lipid extraction) in the biodiesel production process. In this study, techno-economic evaluation of hydrolysis-esterification biodiesel production process was carried out and compared with conventional (usually including drying, lipid extraction, esterification and transesterification) biodiesel production process. Energy and material balance of the conventional and hydrolysis-esterification processes was evaluated by Aspen Plus. The simulation results indicated that drying (2.36MJ/L biodiesel) and triolein transesterification (1.89MJ/L biodiesel) are the dominant energy-intensive stages in the conventional route (5.42MJ/L biodiesel). By contrast, the total energy consumption of hydrolysis-esterification route can be reduced to 1.81MJ/L biodiesel, and approximately 3.61MJ can be saved to produce per liter biodiesel. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Effective Method to Detect Volatile Intermediates Generated in the Bioconversion of Coal to Methane by Gas Chromatography-Mass Spectrometry after In-Situ Extraction Using Headspace Solid-Phase Micro-Extraction under Strict Anaerobic Conditions.

PubMed

Liu, Jianmin; Wang, Baoyu; Tai, Chao; Wu, Li; Zhao, Han; Guan, Jiadong; Chen, Linyong

2016-01-01

Bioconversion of coal to methane has gained increased attention in recent decades because of its economic and environmental advantages. However, the mechanism of this process is difficult to study in depth, partly because of difficulties associated with the analysis of intermediates generated in coal bioconversion. In this investigation, we report on an effective method to analyze volatile intermediates generated in the bioconversion of coal under strict anaerobic conditions. We conduct in-situ extraction of intermediates using headspace solid-phase micro-extraction followed by detection by gas chromatography-mass spectrometry. Bioconversion simulation equipment was modified and combined with a solid-phase micro-extraction device. In-situ extraction could be achieved by using the combined units, to avoid a breakdown in anaerobic conditions and to maintain the experiment continuity. More than 30 intermediates were identified qualitatively in the conversion process, and the variation in trends of some typical intermediates has been discussed. Volatile organic acids (C2-C7) were chosen for a quantitative study of the intermediates because of their importance during coal bioconversion to methane. Fiber coating, extraction time, and solution acidity were optimized in the solid-phase micro-extraction procedure. The pressure was enhanced during the bioconversion process to investigate the influence of headspace pressure on analyte extraction. The detection limits of the method ranged from 0.0006 to 0.02 mmol/L for the volatile organic acids and the relative standard deviations were between 4.6% and 11.5%. The volatile organic acids (C2-C7) generated in the bioconversion process were 0.01-1.15 mmol/L with a recovery range from 80% to 105%. The developed method is useful for further in-depth research on the bioconversion of coal to methane.

An Effective Method to Detect Volatile Intermediates Generated in the Bioconversion of Coal to Methane by Gas Chromatography-Mass Spectrometry after In-Situ Extraction Using Headspace Solid-Phase Micro-Extraction under Strict Anaerobic Conditions

PubMed Central

Liu, Jianmin; Wang, Baoyu; Tai, Chao; Wu, Li; Zhao, Han; Guan, Jiadong; Chen, Linyong

2016-01-01

Bioconversion of coal to methane has gained increased attention in recent decades because of its economic and environmental advantages. However, the mechanism of this process is difficult to study in depth, partly because of difficulties associated with the analysis of intermediates generated in coal bioconversion. In this investigation, we report on an effective method to analyze volatile intermediates generated in the bioconversion of coal under strict anaerobic conditions. We conduct in-situ extraction of intermediates using headspace solid-phase micro-extraction followed by detection by gas chromatography-mass spectrometry. Bioconversion simulation equipment was modified and combined with a solid-phase micro-extraction device. In-situ extraction could be achieved by using the combined units, to avoid a breakdown in anaerobic conditions and to maintain the experiment continuity. More than 30 intermediates were identified qualitatively in the conversion process, and the variation in trends of some typical intermediates has been discussed. Volatile organic acids (C2–C7) were chosen for a quantitative study of the intermediates because of their importance during coal bioconversion to methane. Fiber coating, extraction time, and solution acidity were optimized in the solid-phase micro-extraction procedure. The pressure was enhanced during the bioconversion process to investigate the influence of headspace pressure on analyte extraction. The detection limits of the method ranged from 0.0006 to 0.02 mmol/L for the volatile organic acids and the relative standard deviations were between 4.6% and 11.5%. The volatile organic acids (C2–C7) generated in the bioconversion process were 0.01–1.15 mmol/L with a recovery range from 80% to 105%. The developed method is useful for further in-depth research on the bioconversion of coal to methane. PMID:27695055

Interoperability format translation and transformation between IFC architectural design file and simulation file formats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Tian-Jy; Kim, Younghun

Automatically translating a building architecture file format (Industry Foundation Class) to a simulation file, in one aspect, may extract data and metadata used by a target simulation tool from a building architecture file. Interoperability data objects may be created and the extracted data is stored in the interoperability data objects. A model translation procedure may be prepared to identify a mapping from a Model View Definition to a translation and transformation function. The extracted data may be transformed using the data stored in the interoperability data objects, an input Model View Definition template, and the translation and transformation function tomore » convert the extracted data to correct geometric values needed for a target simulation file format used by the target simulation tool. The simulation file in the target simulation file format may be generated.« less

Accurate electrical prediction of memory array through SEM-based edge-contour extraction using SPICE simulation

NASA Astrophysics Data System (ADS)

Shauly, Eitan; Rotstein, Israel; Peltinov, Ram; Latinski, Sergei; Adan, Ofer; Levi, Shimon; Menadeva, Ovadya

2009-03-01

The continues transistors scaling efforts, for smaller devices, similar (or larger) drive current/um and faster devices, increase the challenge to predict and to control the transistor off-state current. Typically, electrical simulators like SPICE, are using the design intent (as-drawn GDS data). At more sophisticated cases, the simulators are fed with the pattern after lithography and etch process simulations. As the importance of electrical simulation accuracy is increasing and leakage is becoming more dominant, there is a need to feed these simulators, with more accurate information extracted from physical on-silicon transistors. Our methodology to predict changes in device performances due to systematic lithography and etch effects was used in this paper. In general, the methodology consists on using the OPCCmaxTM for systematic Edge-Contour-Extraction (ECE) from transistors, taking along the manufacturing and includes any image distortions like line-end shortening, corner rounding and line-edge roughness. These measurements are used for SPICE modeling. Possible application of this new metrology is to provide a-head of time, physical and electrical statistical data improving time to market. In this work, we applied our methodology to analyze a small and large array's of 2.14um2 6T-SRAM, manufactured using Tower Standard Logic for General Purposes Platform. 4 out of the 6 transistors used "U-Shape AA", known to have higher variability. The predicted electrical performances of the transistors drive current and leakage current, in terms of nominal values and variability are presented. We also used the methodology to analyze an entire SRAM Block array. Study of an isolation leakage and variability are presented.

Sharp Interface Tracking in Rotating Microflows of Solvent Extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glimm, James; Almeida, Valmor de; Jiao, Xiangmin

2013-01-08

The objective of this project is to develop a specialized sharp interface tracking simulation capability for predicting interaction of micron-sized drops and bubbles in rotating flows relevant to optimized design of contactor devices used in solvent extraction processes of spent nuclear fuel reprocessing. The primary outcomes of this project include the capability to resolve drops and bubbles micro-hydrodynamics in solvent extraction contactors, determining from first principles continuum fluid mechanics how micro-drops and bubbles interact with each other and the surrounding shearing fluid for realistic flows. In the near term, this effort will play a central role in providing parameters andmore » insight into the flow dynamics of models that average over coarser scales, say at the millimeter unit length. In the longer term, it will prove to be the platform to conduct full-device, detailed simulations as parallel computing power reaches the exaflop level. The team will develop an accurate simulation tool for flows containing interacting droplets and bubbles with sharp interfaces under conditions that mimic those found in realistic contactor operations. The main objective is to create an off-line simulation capability to model drop and bubble interactions in a domain representative of the averaged length scale. The technical approach is to combine robust interface tracking software, subgrid modeling, validation quality experiments, powerful computational hardware, and a team with simulation modeling, physical modeling and technology integration experience. Simulations will then fully resolve the microflow of drops and bubbles at the microsecond time scale. This approach is computationally intensive but very accurate in treating important coupled physical phenomena in the vicinity of interfaces. The method makes it possible to resolve spatial scales smaller than the typical distance between bubbles and to model some non-equilibrium thermodynamic features such as finite critical tension in cavitating liquids« less

The distinguishing signature of Magnetic Penrose Process

NASA Astrophysics Data System (ADS)

Dadhich, Naresh; Tursunov, Arman; Ahmedov, Bobomurat; Stuchlík, Zdeněk

2018-04-01

In this Letter, we wish to point out that the distinguishing feature of Magnetic Penrose process (MPP) is its super high efficiency exceeding 100% (which was established in mid 1980s for discrete particle accretion) of extraction of rotational energy of a rotating black hole electromagnetically for a magnetic field of milli Gauss order. Another similar process, which is also driven by electromagnetic field, is Blandford-Znajek mechanism (BZ), which could be envisaged as high magnetic field limit MPP as it requires threshold magnetic field of order 104G. Recent simulation studies of fully relativistic magnetohydrodynamic flows have borne out super high efficiency signature of the process for high magnetic field regime; viz BZ. We would like to make a clear prediction that similar simulation studies of MHD flows for low magnetic field regime, where BZ would be inoperative, would also have super efficiency.

Numerical analysis of electronegative plasma in the extraction region of negative hydrogen ion sources

NASA Astrophysics Data System (ADS)

Kuppel, S.; Matsushita, D.; Hatayama, A.; Bacal, M.

2011-01-01

This numerical study focuses on the physical mechanisms involved in the extraction of volume-produced H- ions from a steady state laboratory negative hydrogen ion source with one opening in the plasma electrode (PE) on which a dc-bias voltage is applied. A weak magnetic field is applied in the source plasma transversely to the extracted beam. The goal is to highlight the combined effects of the weak magnetic field and the PE bias voltage (upon the extraction process of H- ions and electrons). To do so, we focus on the behavior of electrons and volume-produced negative ions within a two-dimensional model using the particle-in-cell method. No collision processes are taken into account, except for electron diffusion across the magnetic field using a simple random-walk model at each time step of the simulation. The results show first that applying the magnetic field (without PE bias) enhances H- ion extraction, while it drastically decreases the extracted electron current. Secondly, the extracted H- ion current has a maximum when the PE bias is equal to the plasma potential, while the extracted electron current is significantly reduced by applying the PE bias. The underlying mechanism leading to the above results is the gradual opening by the PE bias of the equipotential lines towards the parts of the extraction region facing the PE. The shape of these lines is due originally to the electron trapping by the magnetic field.

Classification and recognition of texture collagen obtaining by multiphoton microscope with neural network analysis

NASA Astrophysics Data System (ADS)

Wu, Shulian; Peng, Yuanyuan; Hu, Liangjun; Zhang, Xiaoman; Li, Hui

2016-01-01

Second harmonic generation microscopy (SHGM) was used to monitor the process of chronological aging skin in vivo. The collagen structures of mice model with different ages were obtained using SHGM. Then, texture feature with contrast, correlation and entropy were extracted and analysed using the grey level co-occurrence matrix. At last, the neural network tool of Matlab was applied to train the texture of collagen in different statues during the aging process. And the simulation of mice collagen texture was carried out. The results indicated that the classification accuracy reach 85%. Results demonstrated that the proposed approach effectively detected the target object in the collagen texture image during the chronological aging process and the analysis tool based on neural network applied the skin of classification and feature extraction method is feasible.

Parameter extraction with neural networks

NASA Astrophysics Data System (ADS)

Cazzanti, Luca; Khan, Mumit; Cerrina, Franco

1998-06-01

In semiconductor processing, the modeling of the process is becoming more and more important. While the ultimate goal is that of developing a set of tools for designing a complete process (Technology CAD), it is also necessary to have modules to simulate the various technologies and, in particular, to optimize specific steps. This need is particularly acute in lithography, where the continuous decrease in CD forces the technologies to operate near their limits. In the development of a 'model' for a physical process, we face several levels of challenges. First, it is necessary to develop a 'physical model,' i.e. a rational description of the process itself on the basis of know physical laws. Second, we need an 'algorithmic model' to represent in a virtual environment the behavior of the 'physical model.' After a 'complete' model has been developed and verified, it becomes possible to do performance analysis. In many cases the input parameters are poorly known or not accessible directly to experiment. It would be extremely useful to obtain the values of these 'hidden' parameters from experimental results by comparing model to data. This is particularly severe, because the complexity and costs associated with semiconductor processing make a simple 'trial-and-error' approach infeasible and cost- inefficient. Even when computer models of the process already exists, obtaining data through simulations may be time consuming. Neural networks (NN) are powerful computational tools to predict the behavior of a system from an existing data set. They are able to adaptively 'learn' input/output mappings and to act as universal function approximators. In this paper we use artificial neural networks to build a mapping from the input parameters of the process to output parameters which are indicative of the performance of the process. Once the NN has been 'trained,' it is also possible to observe the process 'in reverse,' and to extract the values of the inputs which yield outputs with desired characteristics. Using this method, we can extract optimum values for the parameters and determine the process latitude very quickly.

Removal and recovery of acetic acid and two furans during sugar purification of simulated phenols-free biomass hydrolysates.

PubMed

Lee, Sang Cheol

2017-12-01

A cost-effective five-step sugar purification process involving simultaneous removal and recovery of fermentation inhibitors from biomass hydrolysates was first proposed here. Only the three separation steps (PB, PC and PD) in the process were investigated here. Furfural was selectively removed up to 98.4% from a simulated five-component hydrolysate in a cross-current three-stage extraction system with n-hexane. Most of acetic acid in a simulated four-component hydrolysate was selectively removed by emulsion liquid membrane, and it could be concentrated in the stripping solution up to 4.5 times its initial concentration in the feed solution. 5-Hydroxymethylfurfural was selectively removed from a simulated three-component hydrolysate in batch and continuous fixed-bed column adsorption systems with L-493 adsorbent. Also, 5-hydroxymethylfurfural could be concentrated to about 9 times its feed concentration in the continuous adsorption system through a fixed-bed column desorption experiment with aqueous ethanol solution. These results have shown that the proposed purification process was valid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quark fragmentation functions in NJL-jet model

NASA Astrophysics Data System (ADS)

Bentz, Wolfgang; Matevosyan, Hrayr; Thomas, Anthony

2014-09-01

We report on our studies of quark fragmentation functions in the Nambu-Jona-Lasinio (NJL) - jet model. The results of Monte-Carlo simulations for the fragmentation functions to mesons and nucleons, as well as to pion and kaon pairs (dihadron fragmentation functions) are presented. The important role of intermediate vector meson resonances for those semi-inclusive deep inelastic production processes is emphasized. Our studies are very relevant for the extraction of transverse momentum dependent quark distribution functions from measured scattering cross sections. We report on our studies of quark fragmentation functions in the Nambu-Jona-Lasinio (NJL) - jet model. The results of Monte-Carlo simulations for the fragmentation functions to mesons and nucleons, as well as to pion and kaon pairs (dihadron fragmentation functions) are presented. The important role of intermediate vector meson resonances for those semi-inclusive deep inelastic production processes is emphasized. Our studies are very relevant for the extraction of transverse momentum dependent quark distribution functions from measured scattering cross sections. Supported by Grant in Aid for Scientific Research, Japanese Ministry of Education, Culture, Sports, Science and Technology, Project No. 20168769.

Copper extraction from ammoniacal medium in a pulsed sieve-plate column with LIX 84-I.

PubMed

Gameiro, M Lurdes F; Machado, Remígio M; Ismael, M Rosinda C; Reis, M Teresa A; Carvalho, Jorge M R

2010-11-15

This article reports on a study of copper removal from ammoniacal aqueous solution (1.0 kg m(-3) Cu, pH 9.5) by liquid-liquid extraction using a pulsed sieve-plate column. The extractant tested was the hydroxyoxime LIX 84-I (2-hydroxy-5-nonylacetophenone oxime) in the aliphatic diluent Shellsol D-70. The results of the pilot plant experiments demonstrated the feasibility of operating the extraction process in this type of column, with efficiencies of copper removal in the range of 90.5-99.5%. Several effects on the column performance were examined, namely the aqueous and organic flow rates and the pulse velocity. The axial dispersion model was applied to simulate the concentration profiles, which reasonably predicted the experimental data. The overall mass transfer coefficient was evaluated from the experimental data and was found to be between 9×10(-6) and 1.2×10(-5) m s(-1). These data were compared with the ones obtained from the resistances in series model, which indicated that the resistance due to chemical reaction was 84-91% of the overall resistance to mass transfer. The extraction using a hollow fiber contactor was also carried out to compare the membrane process performance with the one of conventional process. Copyright © 2010 Elsevier B.V. All rights reserved.

Design of Snook in Depillaring Panel Using Continuous Miner

NASA Astrophysics Data System (ADS)

Chawla, Shailendra; Jaiswal, Ashok; Shrivastva, B. K.

2018-04-01

Different patterns of extraction of pillars during depillaring operation with continuous miner are adopted depending upon the geo-mining condition. Various sizes of snook are left during final extraction of coal in mechanized depillaring operation. The size of the snook plays a significant role in providing safe mining condition. Stability of the snook left during final extraction with continuous miner was analyzed using numerical modelling. A case study has been chosen for the simulation of the depillaring process with three scenarios of varying width of snook, i.e., 3.5, 4.5, and 5.5 m. The mine panel consists of 4 × 8 array of pillars having the width of 41 m center to center. Double split and fender method of mining is used with the straight line of extraction. Field investigation shows that the failure of immediate roof occurs after extraction of two or three fenders (i.e., about 40 m). The thickness of immediate roof was 2 m. A numerical model of a depillaring panel was simulated with three different sizes of snook, i.e., 3.5, 4.5, and 5.5 m in the study. An immediate roof of 2 m thickness was considered in the model. An interface has been introduced in between immediate and main roof. The immediate roof behaves as a cantilever during depillaring. It is concluded from the simulation of different size of snooks that snook width of 5.5 m shows reasonable residual strength to hold the immediate roof. Higher tensile stress was developed at the top of the immediate roof above the edge of the snook which leads the possible roof failure towards the goaf side. Vertical stress profile and yield profile in the panel at different stages of mechanized depillaring have also been plotted.

Optimizing the recovery of copper from electroplating rinse bath solution by hollow fiber membrane.

PubMed

Oskay, Kürşad Oğuz; Kul, Mehmet

2015-01-01

This study aimed to recover and remove copper from industrial model wastewater solution by non-dispersive solvent extraction (NDSX). Two mathematical models were developed to simulate the performance of an integrated extraction-stripping process, based on the use of hollow fiber contactors using the response surface method. The models allow one to predict the time dependent efficiencies of the two phases involved in individual extraction or stripping processes. The optimal recovery efficiency parameters were determined as 227 g/L of H2SO4 concentration, 1.22 feed/strip ratio, 450 mL/min flow rate (115.9 cm/min. flow velocity) and 15 volume % LIX 84-I concentration in 270 min by central composite design (CCD). At these optimum conditions, the experimental value of recovery efficiency was 95.88%, which was in close agreement with the 97.75% efficiency value predicted by the model. At the end of the process, almost all the copper in the model wastewater solution was removed and recovered as CuSO4.5H2O salt, which can be reused in the copper electroplating industry.

Optical Analysis of Power Distribution in Top-Emitting Organic Light Emitting Diodes Integrated with Nanolens Array Using Finite Difference Time Domain.

PubMed

Han, Kyung-Hoon; Park, Young-Sam; Cho, Doo-Hee; Han, Yoonjay; Lee, Jonghee; Yu, Byounggon; Cho, Nam Sung; Lee, Jeong-Ik; Kim, Jang-Joo

2018-06-06

Recently, we have addressed that a formation mechanism of a nanolens array (NLA) fabricated by using a maskless vacuum deposition is explained as the increase in surface tension of organic molecules induced by their crystallization. Here, as another research using finite difference time domain simulations, not electric field intensities but transmitted energies of electromagnetic waves inside and outside top-emitting blue organic light-emitting diodes (TOLEDs), without and with NLAs, are obtained, to easily grasp the effect of NLA formation on the light extraction of TOLEDs. Interestingly, the calculations show that NLA acts as an efficient light extraction structure. With NLA, larger transmitted energies in the direction from emitting layer to air are observed, indicating that NLAs send more light to air otherwise trapped in the devices by reducing the losses by waveguide and absorption. This is more significant for higher refractive index of NLA. Simulation and measurement results are consistent. A successful increase in both light extraction efficiency and color stability of blue TOLEDs, rarely reported before, is accomplished by introducing the highly process-compatible NLA technology using the one-step dry process. Blue TOLEDs integrated with a N, N'-di(1-naphthyl)- N, N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine NLA with a refractive index of 1.8 show a 1.55-times-higher light extraction efficiency, compared to those without it. In addition, viewing angle characteristics are enhanced and image blurring is reduced, indicating that the manufacturer-adaptable technology satisfies the requirements of highly efficient and color-stable top-emission displays.

FPGA based hardware optimized implementation of signal processing system for LFM pulsed radar

NASA Astrophysics Data System (ADS)

Azim, Noor ul; Jun, Wang

2016-11-01

Signal processing is one of the main parts of any radar system. Different signal processing algorithms are used to extract information about different parameters like range, speed, direction etc, of a target in the field of radar communication. This paper presents LFM (Linear Frequency Modulation) pulsed radar signal processing algorithms which are used to improve target detection, range resolution and to estimate the speed of a target. Firstly, these algorithms are simulated in MATLAB to verify the concept and theory. After the conceptual verification in MATLAB, the simulation is converted into implementation on hardware using Xilinx FPGA. Chosen FPGA is Xilinx Virtex-6 (XC6LVX75T). For hardware implementation pipeline optimization is adopted and also other factors are considered for resources optimization in the process of implementation. Focusing algorithms in this work for improving target detection, range resolution and speed estimation are hardware optimized fast convolution processing based pulse compression and pulse Doppler processing.

Automated Design Tools for Integrated Mixed-Signal Microsystems (NeoCAD)

DTIC Science & Technology

2005-02-01

method, Model Order Reduction (MOR) tools, system-level, mixed-signal circuit synthesis and optimization tools, and parsitic extraction tools. A unique...Mission Area: Command and Control mixed signal circuit simulation parasitic extraction time-domain simulation IC design flow model order reduction... Extraction 1.2 Overall Program Milestones CHAPTER 2 FAST TIME DOMAIN MIXED-SIGNAL CIRCUIT SIMULATION 2.1 HAARSPICE Algorithms 2.1.1 Mathematical Background

Microfluidic droplet-based liquid-liquid extraction.

PubMed

Mary, Pascaline; Studer, Vincent; Tabeling, Patrick

2008-04-15

We study microfluidic systems in which mass exchanges take place between moving water droplets, formed on-chip, and an external phase (octanol). Here, no chemical reaction takes place, and the mass exchanges are driven by a contrast in chemical potential between the dispersed and continuous phases. We analyze the case where the microfluidic droplets, occupying the entire width of the channel, extract a solute-fluorescein-from the external phase (extraction) and the opposite case, where droplets reject a solute-rhodamine-into the external phase (purification). Four flow configurations are investigated, based on straight or zigzag microchannels. Additionally to the experimental work, we performed two-dimensional numerical simulations. In the experiments, we analyze the influence of different parameters on the process (channel dimensions, fluid viscosities, flow rates, drop size, droplet spacing, ...). Several regimes are singled out. In agreement with the mass transfer theory of Young et al. (Young, W.; Pumir, A.; Pomeau, Y. Phys. Fluids A 1989, 1, 462), we find that, after a short transient, the amount of matter transferred across the droplet interface grows as the square root of time and the time it takes for the transfer process to be completed decreases as Pe-2/3, where Pe is the Peclet number based on droplet velocity and radius. The numerical simulation is found in excellent consistency with the experiment. In practice, the transfer time ranges between a fraction and a few seconds, which is much faster than conventional systems.

Electronic simulation of the supported liquid membrane in electromembrane extraction systems: Improvement of the extraction by precise periodical reversing of the field polarity.

PubMed

Moazami, Hamid Reza; Nojavan, Saeed; Zahedi, Pegah; Davarani, Saied Saeed Hosseiny

2014-09-02

In order to understand the limitations of electromebrane extraction procedure better, a simple equivalent circuit has been proposed for a supported liquid membrane consisting of a resistor and a low leakage capacitor in series. To verify the equivalent circuit, it was subjected to a simulated periodical polarity changing potential and the resulting time variation of the current was compared with that of a real electromembrane extraction system. The results showed a good agreement between the simulated current patterns and those of the real ones. In order to investigate the impact of various limiting factors, the corresponding values of the equivalent circuit were estimated for a real electromembrane extraction system and were attributed to the physical parameters of the extraction system. A dual charge transfer mechanism was proposed for electromembrane extraction by combining general migration equation and fundamental aspects derived from the simulation. Dual mechanism comprises a current dependent contribution of analyte in total current and could support the possibility of an improvement in performance of an electromembrane extraction by application of an asymmetric polarity changing potential. The optimization of frequency and duty cycle of the asymmetric polarity exchanging potential resulted in a higher recovery (2.17 times greater) in comparison with the conventional electromebrane extraction. The simulation also provided more quantitative approaches toward the investigation of the mechanism of extraction and contribution of different limiting factors in electromembrane extraction. Results showed that the buildup of the double layer is the main limiting factor and the Joule heating has lesser impact on the performance of an electromebrane extraction system. Copyright © 2014 Elsevier B.V. All rights reserved.

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

2008-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

2010-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.

Computational and experimental analysis of the flow in an annular centrifugal contactor

NASA Astrophysics Data System (ADS)

Wardle, Kent E.

The annular centrifugal contactor has been developed for solvent extraction processes for recycling used nuclear fuel. The compact size and high efficiency of these contactors have made them the choice for advanced reprocessing schemes and a key equipment for a proposed future advanced fuel cycle facility. While a sufficient base of experience exists to facilitate successful operation of current contactor technology, a more complete understanding of the fluid flow within the contactor would enable further advancements in design and operation of future units and greater confidence for use of such contactors in a variety of other solvent extraction applications. This research effort has coupled computational fluid dynamics modeling with a variety of experimental measurements and observations to provide a valid detailed analysis of the flow within the centrifugal contactor. CFD modeling of the free surface flow in the annular mixing zone using the Volume of Fluid (VOF) volume tracking method combined with Large Eddy Simulation (LES) of turbulence was found to have very good agreement with the experimental measurements and observations. A detailed study of the flow and mixing for different housing vane geometries was performed and it was found that the four straight mixing vane geometry had greater mixing for the flow rate simulated and more predictable operation over a range of low to moderate flow rates. The separation zone was also modeled providing a useful description of the flow in this region and identifying critical design features. It is anticipated that this work will form a foundation for additional efforts at improving the design and operation of centrifugal contactors and provide a framework for progress towards simulation of solvent extraction processes.

Automobile shredded residue valorisation by hydrometallurgical metal recovery.

PubMed

Granata, Giuseppe; Moscardini, Emanuela; Furlani, Giuliana; Pagnanelli, Francesca; Toro, Luigi

2011-01-15

The aim of this work was developing a hydrometallurgical process to recover metals from automobile shredded residue (or car fluff). Automobile shredded residue (ASR) was characterised by particle size distribution, total metal content and metal speciation in order to guide the choice of target metals and the operating conditions of leaching. Characterisation results showed that Fe is the most abundant metal in the waste, while Zn was the second abundant metal in the fraction with diameter lower than 500 μm. Sequential extractions denoted that Zn was easily extractable by weak acid attack, while Fe and Al required a strong acid attack to be removed. In order to recover zinc from <500 μm fraction leaching tests were operated using acetic acid, sulphuric acid and sodium hydroxide at different concentrations. Sulphuric acid determined the highest zinc extraction yield, while acetic acid determined the highest zinc extractive selectivity. Sodium hydroxide promoted an intermediate situation between sulphuric and acetic acid. Zn recovery by electro winning using acetic leach liquor determined 95% of Zn electro deposition yield in 1h, while using sulphuric leach liquor 40% yield in 1h and 50% yield in 2h were obtained. Simulation results showed that the sulphuric leaching process was more attractive than acetic leaching process. Copyright © 2010 Elsevier B.V. All rights reserved.

Laboratory simulation studies of steady-state and potential catalytic effects in the ROPE{trademark} process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guffey, F.D.; Holper, P.A.

The Western Research Institute is currently developing a process for the recovery of distillable liquid products from alternate fossil fuel sources such as tar sand and oil shale. The processing concept is based on recycling a fraction of the produced oil back into the reactor with the raw resource. This concept is termed the recycle oil pyrolysis and extraction (ROPE{sup TM}) process. The conversion of the alternate resource to a liquid fuel is performed in two stages. The first recovery stage is performed at moderate temperatures (325--420{degrees}C [617--788{degrees}F]) in the presence of product oil recycle. The second stage is performedmore » at higher temperatures (450--540{degrees}C [842--1004{degrees}F]) in the absence of product oil. The experiments reported here were performed Asphalt Ridge tar sand in the all-glass laboratory simulation reactor to simulate (1) the recycling of SAE 50 weight oil in the recycle oil pyrolysis zone and (2) to evaluate the potential catalytic effects of the sand matrix.« less

Laboratory simulation studies of steady-state and potential catalytic effects in the ROPE trademark process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guffey, F.D.; Holper, P.A.

The Western Research Institute is currently developing a process for the recovery of distillable liquid products from alternate fossil fuel sources such as tar sand and oil shale. The processing concept is based on recycling a fraction of the produced oil back into the reactor with the raw resource. This concept is termed the recycle oil pyrolysis and extraction (ROPE{sup TM}) process. The conversion of the alternate resource to a liquid fuel is performed in two stages. The first recovery stage is performed at moderate temperatures (325--420{degrees}C (617--788{degrees}F)) in the presence of product oil recycle. The second stage is performedmore » at higher temperatures (450--540{degrees}C (842--1004{degrees}F)) in the absence of product oil. The experiments reported here were performed Asphalt Ridge tar sand in the all-glass laboratory simulation reactor to simulate (1) the recycling of SAE 50 weight oil in the recycle oil pyrolysis zone and (2) to evaluate the potential catalytic effects of the sand matrix.« less

Laboratory-scale integrated ARP filter test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poirier, M.; Burket, P.

2016-03-01

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. There is a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. This task attempted to simulate the entire ARP process, including multiple batches (5), washing, chemical cleaning, andmore » blending the feed with heels and recycle streams. The objective of the tests was to determine whether one of these processes is causing excessive fouling of the crossflow or secondary filter. The authors conducted the tests with feed solutions containing 6.6 M sodium Salt Batch 6 simulant supernate with no MST.« less

The distinguishing signature of magnetic Penrose process

NASA Astrophysics Data System (ADS)

Dadhich, Naresh; Tursunov, Arman; Ahmedov, Bobomurat; Stuchlík, Zdeněk

2018-07-01

In this Letter, we wish to point out that the distinguishing feature of magnetic Penrose process (MPP) is its super high-efficiency exceeding 100 per cent (which was established in mid 1980s for discrete particle accretion) of extraction of rotational energy of a rotating black hole electromagnetically for a magnetic field of milli Gauss order. Another similar process, which is also driven by the electromagnetic field, is Blandford-Znajek mechanism (BZ) that could be envisaged as high magnetic field limit MPP as it requires threshold magnetic field of order 104 G. Recent simulation studies of fully relativistic magnetohydrodynamic (MHD) flows have borne out super high-efficiency signature of the process for high magnetic field regime; viz BZ. We would like to make a clear prediction that similar simulation studies of MHD flows for low magnetic field regime, where BZ would be inoperative, would also have superefficiency.

Pneumatic Regolith Transfer Systems for In-Situ Resource Utilization

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Townsend, Ivan I., III; Mantovani, James G.

2010-01-01

One aspect of In-Situ Resource Utilization (lSRU) in a lunar environment is to extract oxygen and other elements from the minerals that make up the lunar regolith. Typical ISRU oxygen production processes include but are not limited to hydrogen reduction, carbothermal and molten oxide electrolysis. All of these processes require the transfer of regolith from a supply hopper into a reactor for chemical reaction processing, and the subsequent extraction of the reacted regolith from the reactor. This paper will discuss recent activities in the NASA ISRU project involved with developing pneumatic conveying methods to achieve lunar regolith simulant transfer under I-g and 1/6-g gravitational environments. Examples will be given of hardware that has been developed and tested by NASA on reduced gravity flights. Lessons learned and details of pneumatic regolith transfer systems will be examined as well as the relative performance in a 1/6th G environment

3D Simulation of Multiple Simultaneous Hydraulic Fractures with Different Initial Lengths in Rock

NASA Astrophysics Data System (ADS)

Tang, X.; Rayudu, N. M.; Singh, G.

2017-12-01

Hydraulic fracturing is widely used technique for extracting shale gas. During this process, fractures with various initial lengths are induced in rock mass with hydraulic pressure. Understanding the mechanism of propagation and interaction between these induced hydraulic cracks is critical for optimizing the fracking process. In this work, numerical results are presented for investigating the effect of in-situ parameters and fluid properties on growth and interaction of multi simultaneous hydraulic fractures. A fully coupled 3D fracture simulator, TOUGH- GFEM is used for simulating the effect of different vital parameters, including in-situ stress, initial fracture length, fracture spacing, fluid viscosity and flow rate on induced hydraulic fractures growth. This TOUGH-GFEM simulator is based on 3D finite volume method (FVM) and partition of unity element method (PUM). Displacement correlation method (DCM) is used for calculating multi - mode (Mode I, II, III) stress intensity factors. Maximum principal stress criteria is used for crack propagation. Key words: hydraulic fracturing, TOUGH, partition of unity element method , displacement correlation method, 3D fracturing simulator

Pore Fluid Extraction by Reactive Solitary Waves in 3-D

NASA Astrophysics Data System (ADS)

Omlin, Samuel; Malvoisin, Benjamin; Podladchikov, Yury Y.

2017-09-01

In the lower crust, viscous compaction is known to produce solitary porosity and fluid pressure waves. Metamorphic (de)volatilization reactions can also induce porosity changes in response to the propagating fluid pressure anomalies. Here we present results from high-resolution simulations using Graphic Processing Unit parallel processing with a model that includes both viscous (de)compaction and reaction-induced porosity changes. Reactive porosity waves propagate in a manner similar to viscous porosity waves, but through a different mechanism involving fluid release and trap in the solid by reaction. These waves self-generate from red noise or an ellipsoidal porosity anomaly with the same characteristic size and abandon their source region to propagate at constant velocity. Two waves traveling at different velocities pass through each other in a soliton-like fashion. Reactive porosity waves thus provide an additional mechanism for fluid extraction at shallow depths with implications for ore formation, diagenesis, metamorphic veins formation, and fluid extraction from subduction zones.

HELIOGate, a Portal for the Heliophysics Community

NASA Astrophysics Data System (ADS)

Pierantoni; Gabriele; Carley, Eoin

2014-10-01

Heliophysics is the branch of physics that investigates the interactions between the Sun and the other bodies of the solar system. Heliophysicists rely on data collected from numerous sources scattered across the Solar System. The data collected from these sources is processed to extract metadata and the metadata extracted in this fashion is then used to build indexes of features and events called catalogues. Heliophysicists also develop conceptual and mathematical models of the phenomena and the environment of the Solar System. More specifically, they investigate the physical characteristics of the phenomena and they simulate how they propagate throughout the Solar System with mathematical and physical abstractions called propagation models. HELIOGate aims at addressing the need to combine and orchestrate existing web services in a flexible and easily configurable fashion to tackle different scientific questions. HELIOGate also offers a tool capable of connecting to size! able computation and storage infrastructures to execute data processing codes that are needed to calibrate raw data and to extract metadata.

Modeling of membrane processes for air revitalization and water recovery

NASA Technical Reports Server (NTRS)

Lange, Kevin E.; Foerg, Sandra L.; Dall-Bauman, Liese A.

1992-01-01

Gas-separation and reverse-osmosis membrane models are being developed in conjunction with membrane testing at NASA JSC. The completed gas-separation membrane model extracts effective component permeabilities from multicomponent test data, and predicts the effects of flow configuration, operating conditions, and membrane dimensions on module performance. Variable feed- and permeate-side pressures are considered. The model has been applied to test data for hollow-fiber membrane modules with simulated cabin-air feeds. Results are presented for a membrane designed for air drying applications. Extracted permeabilities are used to predict the effect of operating conditions on water enrichment in the permeate. A first-order reverse-osmosis model has been applied to test data for spiral wound membrane modules with a simulated hygiene water feed. The model estimates an effective local component rejection coefficient under pseudosteady-state conditions. Results are used to define requirements for a detailed reverse-osmosis model.

Automated Fluid Feature Extraction from Transient Simulations

NASA Technical Reports Server (NTRS)

Haimes, Robert

2000-01-01

In the past, feature extraction and identification were interesting concepts, but not required in understanding the physics of a steady flow field. This is because the results of the more traditional tools like iso-surfaces, cuts and streamlines, were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of a great deal of interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one 'snap-shot' of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments like pV3). And methods must be developed to abstract the feature and display it in a manner that physically makes sense.

Photonuclear production of yttrium-88 - A high energy gamma emitter for hydrocarbon extraction applications.

PubMed

Dale, Daniel S; Starovoitova, Valeriia N; Forest, Tony A; Oliphant, Emily

2018-05-05

The use of fracing has risen over the past decade and revolutionized energy production in the US. However, there is still an impetus for further optimization of the extraction of oil and natural gas from vast shale reservoirs. In this work, we discuss photonuclear production of yttrium-88 as a promising radiotracer for fracing operations. Single neutron knock-out from natural monoisotopic yttrium-89 is an inexpensive process resulting in high activity of 88 Y with minimal impurities. MCNPX simulations were performed to estimate the 88 Y yield. Irradiations of natural yttrium using a 32 MeV electron linac equipped with a tungsten bremsstrahlung converter were done to benchmark the simulations. Activities of 88 Y, 87g Y, and 87m Y were measured and found to be in good agreement with the predictions. Copyright © 2018 Elsevier Ltd. All rights reserved.

In situ Orbit Extraction from Live, High Precision Collisionless Simulations of Systems Formed by Cold Collapse

NASA Astrophysics Data System (ADS)

Noriega-Mendoza, H.; Aguilar, L. A.

2018-04-01

We performed high precision, N-body simulations of the cold collapse of initially spherical, collisionless systems using the GYRFALCON code of Dehnen (2000). The collapses produce very prolate spheroidal configurations. After the collapse, the systems are simulated for 85 and 170 half-mass radius dynamical timescales, during which energy conservation is better than 0.005%. We use this period to extract individual particle orbits directly from the simulations. We then use the TAXON code of Carpintero and Aguilar (1998) to classify 1 to 1.5% of the extracted orbits from our final, relaxed configurations: less than 15% are chaotic orbits, 30% are box orbits and 60% are tube orbits (long and short axis). Our goal has been to prove that direct orbit extraction is feasible, and that there is no need to "freeze" the final N-body system configuration to extract a time-independent potential.

Modeling of negative ion transport in a plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riz, David; Departement de Recherches sur la Fusion Controelee CE Cadarache, 13108 St Paul lez Durance; Pamela, Jerome

1998-08-20

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The ion trajectory is calculated by numerically solving the 3-D motion equation, while the atomic processes of destruction, of elastic collision H{sup -}/H{sup +} and of charge exchange H{sup -}/H{sup 0} are handled at each time step by a Monte-Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have allowed to explain, either quantitatively or qualitatively, severalmore » phenomena observed in negative ion sources, such as the isotopic H{sup -}/D{sup -} effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm{sup -3}), negative ions can reach the extraction region provided if they are produced at a distance lower than 2 cm from the plasma grid in the case of 'volume production' (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.« less

Modeling of negative ion transport in a plasma source (invited)

NASA Astrophysics Data System (ADS)

Riz, David; Paméla, Jérôme

1998-02-01

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The H-/D- trajectory is calculated by numerically solving the 3D motion equation, while the atomic processes of destruction, of elastic collision with H+/D+ and of charge exchange with H0/D0 are handled at each time step by a Monte Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have been allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that, in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided they are produced at a distance lower than 2 cm from the plasma grid in the case of volume production (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

Modeling of negative ion transport in a plasma source

NASA Astrophysics Data System (ADS)

Riz, David; Paméla, Jérôme

1998-08-01

A code called NIETZSCHE has been developed to simulate the negative ion transport in a plasma source, from their birth place to the extraction holes. The ion trajectory is calculated by numerically solving the 3-D motion equation, while the atomic processes of destruction, of elastic collision H-/H+ and of charge exchange H-/H0 are handled at each time step by a Monte-Carlo procedure. This code can be used to calculate the extraction probability of a negative ion produced at any location inside the source. Calculations performed with NIETZSCHE have allowed to explain, either quantitatively or qualitatively, several phenomena observed in negative ion sources, such as the isotopic H-/D- effect, and the influence of the plasma grid bias or of the magnetic filter on the negative ion extraction. The code has also shown that in the type of sources contemplated for ITER, which operate at large arc power densities (>1 W cm-3), negative ions can reach the extraction region provided if they are produced at a distance lower than 2 cm from the plasma grid in the case of «volume production» (dissociative attachment processes), or if they are produced at the plasma grid surface, in the vicinity of the extraction holes.

Techno-Economic Analysis of Magnesium Extraction from Seawater via a Catalyzed Organo-Metathetical Process

NASA Astrophysics Data System (ADS)

Liu, Jian; Bearden, Mark D.; Fernandez, Carlos A.; Fifield, Leonard S.; Nune, Satish K.; Motkuri, Radha K.; Koech, Philip K.; McGrail, B. Pete

2018-03-01

Magnesium (Mg) has many useful applications especially in the form of various Mg alloys that can decrease weight while increasing strength compared with common steels. To increase the affordability and minimize environment consequence, a novel catalyzed organo-metathetical (COMET) process was proposed to extract Mg from seawater aiming to achieve a significant reduction in total energy and production cost compared with the melting salt electrolysis method currently adapted by US Mg LLC. A process flow sheet for a reference COMET process was set up using Aspen Plus. The energy consumption, production cost, and CO2 emissions were estimated using the Aspen economic analyzer. Our results showed that it is possible to produce Mg from seawater with a production cost of 2.0/kg-Mg while consuming about 35.6 kWh/kg-Mg and releasing 7.7 kg CO2/kg-Mg. Under the simulated conditions, the reference COMET process maintains a comparable CO2 emission rate, saves about 40% in production cost, and saves about 15% in energy consumption compared with a simplified US Mg process.

Optimal control of nutrition restricted dynamics model of Microalgae biomass growth model

NASA Astrophysics Data System (ADS)

Ratianingsih, R.; Azim; Nacong, N.; Resnawati; Mardlijah; Widodo, B.

2017-12-01

The biomass of the microalgae is very potential to be proposed as an alternative renewable energy resources because it could be extracted into lipid. Afterward, the lipid could be processed to get the biodiesel or bioethanol. The extraction of the biomass on lipid synthesis process is very important to be studied because the process just gives some amount of lipid. A mathematical model of restricted microalgae biomass growth just gives 1/3 proportion of lipid with respect to the biomass in the synthesis process. An optimal control is designed to raise the ratio between the number of lipid formation and the microalgae biomass to be used in synthesis process. The minimum/ Pontryagin maximum principle is used to get the optimal lipid production. The simulation shows that the optimal lipid formation could be reach by simultaneously controlling the carbon dioxide, in the respiration and photosynthesis the process, and intake nutrition rates of liquid waste and urea substrate. The production of controlled microalgae lipid could be increase 6.5 times comparing to the uncontrolled one.

Statistical process control using optimized neural networks: a case study.

PubMed

Addeh, Jalil; Ebrahimzadeh, Ata; Azarbad, Milad; Ranaee, Vahid

2014-09-01

The most common statistical process control (SPC) tools employed for monitoring process changes are control charts. A control chart demonstrates that the process has altered by generating an out-of-control signal. This study investigates the design of an accurate system for the control chart patterns (CCPs) recognition in two aspects. First, an efficient system is introduced that includes two main modules: feature extraction module and classifier module. In the feature extraction module, a proper set of shape features and statistical feature are proposed as the efficient characteristics of the patterns. In the classifier module, several neural networks, such as multilayer perceptron, probabilistic neural network and radial basis function are investigated. Based on an experimental study, the best classifier is chosen in order to recognize the CCPs. Second, a hybrid heuristic recognition system is introduced based on cuckoo optimization algorithm (COA) algorithm to improve the generalization performance of the classifier. The simulation results show that the proposed algorithm has high recognition accuracy. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Process simulation of modified dry grind ethanol plant with recycle of pretreated and enzymatically hydrolyzed distillers' grains.

PubMed

Kim, Youngmi; Mosier, Nathan; Ladisch, Michael R

2008-08-01

Distillers' grains (DG), a co-product of a dry grind ethanol process, is an excellent source of supplemental proteins in livestock feed. Studies have shown that, due to its high polymeric sugar contents and ease of hydrolysis, the distillers' grains have potential as an additional source of fermentable sugars for ethanol fermentation. The benefit of processing the distillers' grains to extract fermentable sugars lies in an increased ethanol yield without significant modification in the current dry grind technology. Three different potential configurations of process alternatives in which pretreated and hydrolyzed distillers' grains are recycled for an enhanced overall ethanol yield are proposed and discussed in this paper based on the liquid hot water (LHW) pretreatment of distillers' grains. Possible limitations of each proposed process are also discussed. This paper presents a compositional analysis of distillers' grains, as well as a simulation of the modified dry grind processes with recycle of distillers' grains. Simulated material balances for the modified dry grind processes are established based on the base case assumptions. These balances are compared to the conventional dry grind process in terms of ethanol yield, compositions of its co-products, and accumulation of fermentation inhibitors. Results show that 14% higher ethanol yield is achievable by processing and hydrolyzing the distillers' grains for additional fermentable sugars, as compared to the conventional dry grind process. Accumulation of fermentation by-products and inhibitory components in the proposed process is predicted to be 2-5 times higher than in the conventional dry grind process. The impact of fermentation inhibitors is reviewed and discussed. The final eDDGS (enhanced dried distillers' grains) from the modified processes has 30-40% greater protein content per mass than DDGS, and its potential as a value-added process is also analyzed. While the case studies used to illustrate the process simulation are based on LHW pretreated DG, the process simulation itself provides a framework for evaluation of the impact of other pretreatments.

Generalized Likelihood Uncertainty Estimation (GLUE) methodology for optimization of extraction in natural products.

PubMed

Maulidiani; Rudiyanto; Abas, Faridah; Ismail, Intan Safinar; Lajis, Nordin H

2018-06-01

Optimization process is an important aspect in the natural product extractions. Herein, an alternative approach is proposed for the optimization in extraction, namely, the Generalized Likelihood Uncertainty Estimation (GLUE). The approach combines the Latin hypercube sampling, the feasible range of independent variables, the Monte Carlo simulation, and the threshold criteria of response variables. The GLUE method is tested in three different techniques including the ultrasound, the microwave, and the supercritical CO 2 assisted extractions utilizing the data from previously published reports. The study found that this method can: provide more information on the combined effects of the independent variables on the response variables in the dotty plots; deal with unlimited number of independent and response variables; consider combined multiple threshold criteria, which is subjective depending on the target of the investigation for response variables; and provide a range of values with their distribution for the optimization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Lunar Resource Utilization: Development of a Reactor for Volatile Extraction from Regolith

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie E.; Sacksteder, Kurt R.; Nayagam, Vedha

2007-01-01

The extraction and processing of planetary resources into useful products, known as In- Situ Resource Utilization (ISRU), will have a profound impact on the future of planetary exploration. One such effort is the RESOLVE (Regolith and Environment Science, Oxygen and Lunar Volatiles Extraction) Project, which aims to extract and quantify these resources. As part of the first Engineering Breadboard Unit, the Regolith Volatiles Characterization (RVC) reactor was designed and built at the NASA Glenn Research Center. By heating and agitating the lunar regolith, loosely bound volatiles, such as hydrogen and water, are released and stored in the reactor for later analysis and collection. Intended for operation on a robotic rover, the reactor features a lightweight, compact design, easy loading and unloading of the regolith, and uniform heating of the regolith by means of vibrofluidization. The reactor performance was demonstrated using regolith simulant, JSC1, with favorable results.

From Particles and Point Clouds to Voxel Models: High Resolution Modeling of Dynamic Landscapes in Open Source GIS

NASA Astrophysics Data System (ADS)

Mitasova, H.; Hardin, E. J.; Kratochvilova, A.; Landa, M.

2012-12-01

Multitemporal data acquired by modern mapping technologies provide unique insights into processes driving land surface dynamics. These high resolution data also offer an opportunity to improve the theoretical foundations and accuracy of process-based simulations of evolving landforms. We discuss development of new generation of visualization and analytics tools for GRASS GIS designed for 3D multitemporal data from repeated lidar surveys and from landscape process simulations. We focus on data and simulation methods that are based on point sampling of continuous fields and lead to representation of evolving surfaces as series of raster map layers or voxel models. For multitemporal lidar data we present workflows that combine open source point cloud processing tools with GRASS GIS and custom python scripts to model and analyze dynamics of coastal topography (Figure 1) and we outline development of coastal analysis toolbox. The simulations focus on particle sampling method for solving continuity equations and its application for geospatial modeling of landscape processes. In addition to water and sediment transport models, already implemented in GIS, the new capabilities under development combine OpenFOAM for wind shear stress simulation with a new module for aeolian sand transport and dune evolution simulations. Comparison of observed dynamics with the results of simulations is supported by a new, integrated 2D and 3D visualization interface that provides highly interactive and intuitive access to the redesigned and enhanced visualization tools. Several case studies will be used to illustrate the presented methods and tools and demonstrate the power of workflows built with FOSS and highlight their interoperability.Figure 1. Isosurfaces representing evolution of shoreline and a z=4.5m contour between the years 1997-2011at Cape Hatteras, NC extracted from a voxel model derived from series of lidar-based DEMs.

Mechanistic study of lead desorption during the leaching process of ion-absorbed rare earths: pH effect and the column experiment

NASA Astrophysics Data System (ADS)

Xue, Q.; Tang, J., Sr.; Chen, H.

2017-12-01

High concentrations of ammonium sulfate, often used in the in-situ mining process, can result in a decrease of pH in the environment and dissolution of rare earth metals. Ammonium sulfate can also cause desorption of toxic heavy metals, leading to environmental and human health implications. In this study, the desorption behavior and fraction changes of lead in the ion-absorbed rare earth ore were studied using batch desorption experiments and column leaching tests. Results from batch desorption experiments showed that the desorption process of lead included fast and slow stages, and followed an Elovich model well. The desorption rate and the proportion of lead content in the solution to the total lead in the soil were observed to increase with a decrease in the initial pH of the ammonium sulfate solution. The lead in soil included an acid extractable fraction, reducible fraction, oxidizable fraction, and a residual fraction, with the predominant fractions being the reducible and acid extractable fractions. 96% of the extractable fraction in soil were desorbed into solution at pH=3.0, and the content of the reducible fraction was observed to initially increase (when pH>4.0) and then decrease (when pH<4.0) with a decrease in pH. Column leaching tests indicated that the content of lead in the different fractions of soil followed the trend of reducible fraction > oxidizable fraction > acid extractable fraction > residual fraction after the simulating leaching mining process. The change in pH was also found to have a larger influence on the acid extractable and reducible fractions than the other two fractions. The proportion of the extractable fraction being leached was ca. 86%, and the reducible fraction was enriched along the migration direction of the leaching liquid. These results suggest that certain lead fractions may desorb again and contaminate the environment via acid rain, which provides significant information for environmental assessment and remediation after mining process.

Complete recovery of actinides from UREX-like raffinates using a combination of hard and soft donor ligands. II. soft donor structure variation

DOE PAGES

Zalupski, Peter R.; Klaehn, John R.; Peterman, Dean R.

2015-07-30

The feasibility of simultaneous separation of uranium, neptunium, plutonium, americium, and curium from a simulated dissolved used fuel simulant adjusted to 1.0 M nitric acid is investigated using a mixture of the soft donor bis(bis-3,5-trifluoromethyl)phenyl) dithiophosphinic acid (“0”) and the hard donor synergist trioctylphosphine oxide (TOPO) dissolved in toluene. The results reported in this work are compared to our recent demonstration of a complete actinide recovery from a simulated dissolved fuel solution using a synergistic combination of bis(o-trifluoromethylphenyl)dithiophosphinic acid (“1”) and TOPO dissolved in either toluene or trifluoromethylphenyl sulfone. While the extraction efficiency of americium was enhanced for the liquid-liquidmore » system containing “0”, enabling to accomplish a trivalent An/Ln separation at 1.0 M HNO3, the extraction of neptunium was drastically diminished, relative to “1”. The partitioning behavior of curium was also negatively impacted, introducing an effective opportunity for americium/curium separation. Radiometric and spectrophotometric studies demonstrate that the complete actinide recovery using the solvent based upon “0” and TOPO is not feasible. Additionally, the importance of radiolytic degradation processes is discussed through the comparisons of extraction properties of liquid-liquid systems based on both soft donor reagents.« less

Automation for System Safety Analysis

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Fleming, Land; Throop, David; Thronesbery, Carroll; Flores, Joshua; Bennett, Ted; Wennberg, Paul

2009-01-01

This presentation describes work to integrate a set of tools to support early model-based analysis of failures and hazards due to system-software interactions. The tools perform and assist analysts in the following tasks: 1) extract model parts from text for architecture and safety/hazard models; 2) combine the parts with library information to develop the models for visualization and analysis; 3) perform graph analysis and simulation to identify and evaluate possible paths from hazard sources to vulnerable entities and functions, in nominal and anomalous system-software configurations and scenarios; and 4) identify resulting candidate scenarios for software integration testing. There has been significant technical progress in model extraction from Orion program text sources, architecture model derivation (components and connections) and documentation of extraction sources. Models have been derived from Internal Interface Requirements Documents (IIRDs) and FMEA documents. Linguistic text processing is used to extract model parts and relationships, and the Aerospace Ontology also aids automated model development from the extracted information. Visualizations of these models assist analysts in requirements overview and in checking consistency and completeness.

A direct method of extracting surface recombination velocity from an electron beam induced current line scan

NASA Astrophysics Data System (ADS)

Ong, Vincent K. S.

1998-04-01

The extraction of diffusion length and surface recombination velocity in a semiconductor with the use of an electron beam induced current line scan has traditionally been done by fitting the line scan into complicated theoretical equations. It was recently shown that a much simpler equation is sufficient for the extraction of diffusion length. The linearization coefficient is the only variable that is needed to be adjusted in the curve fitting process. However, complicated equations are still necessary for the extraction of surface recombination velocity. It is shown in this article that it is indeed possible to extract surface recombination velocity with a simple equation, using only one variable, the linearization coefficient. An intuitive feel for the reason behind the method was discussed. The accuracy of the method was verified with the use of three-dimensional computer simulation, and was found to be even slightly better than that of the best existing method.

Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction, Global Yield, Extraction Kinetics, Chemical Composition and Cost of Manufacturing

PubMed Central

Sicaire, Anne-Gaëlle; Vian, Maryline; Fine, Frédéric; Joffre, Florent; Carré, Patrick; Tostain, Sylvain; Chemat, Farid

2015-01-01

The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil) and non-food (bio fuel) applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS) simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols). Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF) as alternative solvent compared to hexane as petroleum solvent. PMID:25884332

Liquid-liquid extraction of Cd(II) from pure and Ni/Cd acidic chloride media using Cyanex 921: a selective treatment of hazardous leachate of spent Ni-Cd batteries.

PubMed

Choi, Seon-Young; Nguyen, Viet Tu; Lee, Jae-Chun; Kang, Ho; Pandey, B D

2014-08-15

The present paper is focused on solvent extraction of hazardous Cd(II) from acidic chloride media by Cyanex 921, a new extractant mixed with 10% (v/v) TBP in xylene. The optimum conditions for extraction and stripping of Cd(II) were investigated with an aqueous feed of 0.1 mol/L Cd(II) in 2.0 mol/L HCl. McCabe-Thiele diagram was in good agreement with the simulation studies, showing the quantitative extraction (99.9%) of Cd(II) within two counter-current stages utilizing 0.30 mol/L Cyanex 921 at O/A ratio of 3/2 in 10 min. Stoichiometry of the complexes extracted was determined and confirmed by numerical treatment and graphical method, revealing the formation of HCdCl3 · 2L and HCdCl3 · 4L for Cyanex 921(L) concentration in the range 0.03-0.1 mol/L and 0.1-1.0 mol/L, respectively. The thermodynamic parameters for the extraction of cadmium were also determined. The stripping efficiency of cadmium from the loaded organic with 0.10 mol/L HCl was 99.6% in a three-stage counter-current process at an O/A ratio of 2/3. Cyanex 921 was successfully applied for the separation of Cd(II) from Ni(II) in the simulated leach liquor of spent Ni-Cd batteries. The study demonstrates the applicability of the present hydrometallurgical approach for the treatment of hazardous waste, the spent Ni-Cd batteries. Copyright © 2014 Elsevier B.V. All rights reserved.

Batch process fault detection and identification based on discriminant global preserving kernel slow feature analysis.

PubMed

Zhang, Hanyuan; Tian, Xuemin; Deng, Xiaogang; Cao, Yuping

2018-05-16

As an attractive nonlinear dynamic data analysis tool, global preserving kernel slow feature analysis (GKSFA) has achieved great success in extracting the high nonlinearity and inherently time-varying dynamics of batch process. However, GKSFA is an unsupervised feature extraction method and lacks the ability to utilize batch process class label information, which may not offer the most effective means for dealing with batch process monitoring. To overcome this problem, we propose a novel batch process monitoring method based on the modified GKSFA, referred to as discriminant global preserving kernel slow feature analysis (DGKSFA), by closely integrating discriminant analysis and GKSFA. The proposed DGKSFA method can extract discriminant feature of batch process as well as preserve global and local geometrical structure information of observed data. For the purpose of fault detection, a monitoring statistic is constructed based on the distance between the optimal kernel feature vectors of test data and normal data. To tackle the challenging issue of nonlinear fault variable identification, a new nonlinear contribution plot method is also developed to help identifying the fault variable after a fault is detected, which is derived from the idea of variable pseudo-sample trajectory projection in DGKSFA nonlinear biplot. Simulation results conducted on a numerical nonlinear dynamic system and the benchmark fed-batch penicillin fermentation process demonstrate that the proposed process monitoring and fault diagnosis approach can effectively detect fault and distinguish fault variables from normal variables. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Image Processing Strategies Based on a Visual Saliency Model for Object Recognition Under Simulated Prosthetic Vision.

PubMed

Wang, Jing; Li, Heng; Fu, Weizhen; Chen, Yao; Li, Liming; Lyu, Qing; Han, Tingting; Chai, Xinyu

2016-01-01

Retinal prostheses have the potential to restore partial vision. Object recognition in scenes of daily life is one of the essential tasks for implant wearers. Still limited by the low-resolution visual percepts provided by retinal prostheses, it is important to investigate and apply image processing methods to convey more useful visual information to the wearers. We proposed two image processing strategies based on Itti's visual saliency map, region of interest (ROI) extraction, and image segmentation. Itti's saliency model generated a saliency map from the original image, in which salient regions were grouped into ROI by the fuzzy c-means clustering. Then Grabcut generated a proto-object from the ROI labeled image which was recombined with background and enhanced in two ways--8-4 separated pixelization (8-4 SP) and background edge extraction (BEE). Results showed that both 8-4 SP and BEE had significantly higher recognition accuracy in comparison with direct pixelization (DP). Each saliency-based image processing strategy was subject to the performance of image segmentation. Under good and perfect segmentation conditions, BEE and 8-4 SP obtained noticeably higher recognition accuracy than DP, and under bad segmentation condition, only BEE boosted the performance. The application of saliency-based image processing strategies was verified to be beneficial to object recognition in daily scenes under simulated prosthetic vision. They are hoped to help the development of the image processing module for future retinal prostheses, and thus provide more benefit for the patients. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Molecular simulations of self-assembly processes of amphiphiles in dilute solutions: the challenge for quantitative modelling

NASA Astrophysics Data System (ADS)

Jusufi, Arben

2013-11-01

We report on two recent developments in molecular simulations of self-assembly processes of amphiphilic solutions. We focus on the determination of micelle formation of ionic surfactants which exhibit the archetype of self-assembling compounds in solution. The first approach is centred on the challenge in predicting micellisation properties through explicit solvent molecular dynamics simulations. Even with a coarse-grained (CG) approach and the use of highly optimised software packages run on graphics processing unit hardware, it remains in many cases computationally infeasible to directly extract the critical micelle concentration (cmc). However, combined with a recently presented theoretical mean-field model this task becomes resolved. An alternative approach to study self-assembly is through implicit solvent modelling of the surfactants. Here we review some latest results and present new ones regarding capabilities of such a modelling approach in determining the cmc, and the aggregate structures in the dilute regime, that is currently not accessible through explicit solvent simulations, neither through atomistic nor through CG approaches. A special focus is put on surfactant concentration effects and surfactant correlations quantified by scattering intensities that are compared to recently published small-angle X-ray scattering data.

A real time ECG signal processing application for arrhythmia detection on portable devices

NASA Astrophysics Data System (ADS)

Georganis, A.; Doulgeraki, N.; Asvestas, P.

2017-11-01

Arrhythmia describes the disorders of normal heart rate, which, depending on the case, can even be fatal for a patient with severe history of heart disease. The purpose of this work is to develop an application for heart signal visualization, processing and analysis in Android portable devices e.g. Mobile phones, tablets, etc. The application is able to retrieve the signal initially from a file and at a later stage this signal is processed and analysed within the device so that it can be classified according to the features of the arrhythmia. In the processing and analysing stage, different algorithms are included among them the Moving Average and Pan Tompkins algorithm as well as the use of wavelets, in order to extract features and characteristics. At the final stage, testing is performed by simulating our application in real-time records, using the TCP network protocol for communicating the mobile with a simulated signal source. The classification of ECG beat to be processed is performed by neural networks.

3D numerical simulations of negative hydrogen ion extraction using realistic plasma parameters, geometry of the extraction aperture and full 3D magnetic field map

NASA Astrophysics Data System (ADS)

Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Franzen, P.; Fantz, U.; Minea, T.

2014-02-01

Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.

Automated Fluid Feature Extraction from Transient Simulations

NASA Technical Reports Server (NTRS)

Haimes, Robert; Lovely, David

1999-01-01

In the past, feature extraction and identification were interesting concepts, but not required to understand the underlying physics of a steady flow field. This is because the results of the more traditional tools like iso-surfaces, cuts and streamlines were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of much interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one "snap-shot" of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments like pV3). And methods must be developed to abstract the feature and display it in a manner that physically makes sense. The following is a list of the important physical phenomena found in transient (and steady-state) fluid flow: (1) Shocks, (2) Vortex cores, (3) Regions of recirculation, (4) Boundary layers, (5) Wakes. Three papers and an initial specification for the (The Fluid eXtraction tool kit) FX Programmer's guide were included. The papers, submitted to the AIAA Computational Fluid Dynamics Conference, are entitled : (1) Using Residence Time for the Extraction of Recirculation Regions, (2) Shock Detection from Computational Fluid Dynamics results and (3) On the Velocity Gradient Tensor and Fluid Feature Extraction.

Migration studies of 3-chloro-1,2-propanediol (3-MCPD) in polyethylene extrusion-coated paperboard food packaging.

PubMed

Pace, Gregory V; Hartman, Thomas G

2010-06-01

The manufacturing process of paperboard food packaging can produce small quantities of 3-chloro-1,2-propanediol (3-MCPD or 3-monochloropropane-1,2-diol) when wet-strength resins containing epichlorohydrin are used. 3-MCPD is from the same family as 1,3-dichloro-2-propanol (1,3-DCP), which is known to cause cancer in animals. 3-MCPD has been found in acid hydrolyzed vegetable protein, Asian sauces and paperboard for food contact. In this investigation, we conducted extraction studies to measure 3-MCPD migration into food simulant solvents from the food contact side of polyethylene extrusion-coated paperboard beverage cartons and aqueous extractions of cut pieces from the entire paperboard. We demonstrate that 3-MCPD confirmed present at concentrations up to 9.9 mg kg(-1) within the paperboard matrix does not migrate through the polyethylene-coated food contact surface. The aqueous extraction of the entire paperboard and food contact side extractions with aqueous/acidic food simulants were performed using US Food and Drug Administration (FDA) and European Commission (EU) migration testing protocols. We also show that no significant amount of 3-MCPD migrates through the unskived edges on the inside seam of the paperboard structure. The methodology for the aqueous and migration cell extractions using GC-MS analyses was validated with a limit of quantification (LOQ) of 0.009 mg kg(-1) and a limit of detection (LOD) of 0.005 mg kg(-1).

The 2010 Field Demonstration of the Solar Carbothermal Reduction of Regolith to Produce Oxygen

NASA Technical Reports Server (NTRS)

Muscatello, Anthony; Gustafson, Robert (Bob)

2010-01-01

This slide presentation reviews a demonstration of the use of solar carbothermal reduction processing of regolith to produce oxygen and silicon from silica. A contractor developed the Carbothermal Regolith Reduction Module to demonstrate the extraction of oxygen from lunar regolith simulant using concentrated solar energy at a site that has similar terrain to the moon and Mars.

Measuring uncertainty by extracting fuzzy rules using rough sets and extracting fuzzy rules under uncertainty and measuring definability using rough sets

NASA Technical Reports Server (NTRS)

Worm, Jeffrey A.; Culas, Donald E.

1991-01-01

Computers are not designed to handle terms where uncertainty is present. To deal with uncertainty, techniques other than classical logic must be developed. This paper examines the concepts of statistical analysis, the Dempster-Shafer theory, rough set theory, and fuzzy set theory to solve this problem. The fundamentals of these theories are combined to provide the possible optimal solution. By incorporating principles from these theories, a decision-making process may be simulated by extracting two sets of fuzzy rules: certain rules and possible rules. From these rules a corresponding measure of how much we believe these rules is constructed. From this, the idea of how much a fuzzy diagnosis is definable in terms of its fuzzy attributes is studied.

Permeability and permeability anisotropy in Crab Orchard sandstone: Experimental insights into spatio-temporal effects

NASA Astrophysics Data System (ADS)

Gehne, Stephan; Benson, Philip M.

2017-08-01

Permeability in tight crustal rocks is primarily controlled by the connected porosity, shape and orientation of microcracks, the preferred orientation of cross-bedding, and sedimentary features such as layering. This leads to a significant permeability anisotropy. Less well studied, however, are the effects of time and stress recovery on the evolution of the permeability hysteresis which is becoming increasingly important in areas ranging from fluid migration in ore-forming processes to enhanced resource extraction. Here, we report new data simulating spatio-temporal permeability changes induced using effective pressure, simulating burial depth, on a tight sandstone (Crab Orchard). We find an initially (measured at 5 MPa) anisotropy of 2.5% in P-wave velocity and 180% in permeability anisotropy is significantly affected by the direction of the effective pressure change and cyclicity; anisotropy values decrease to 1% and 10% respectively after 3 cycles to 90 MPa and back. Furthermore, we measure a steadily increasing recovery time (10-20 min) for flow parallel to cross-bedding, and a far slower recovery time (20-50 min) for flow normal to cross-bedding. These data are interpreted via strain anisotropy and accommodation models, similar to the "seasoning" process often used in dynamic reservoir extraction.

Charge relaxation and dynamics in organic semiconductors

NASA Astrophysics Data System (ADS)

Kwok, H. L.

2006-08-01

Charge relaxation in dispersive materials is often described in terms of the stretched exponential function (Kohlrausch law). The process can be explained using a "hopping" model which in principle, also applies to charge transport such as current conduction. This work analyzed reported transient photoconductivity data on functionalized pentacene single crystals using a geometric hopping model developed by B. Sturman et al and extracted values (or range of values) on the materials parameters relevant to charge relaxation as well as charge transport. Using the correlated disorder model (CDM), we estimated values of the carrier mobility for the pentacene samples. From these results, we observed the following: i) the transport site density appeared to be of the same order of magnitude as the carrier density; ii) it was possible to extract lower bound values on the materials parameters linked to the transport process; and iii) by matching the simulated charge decay to the transient photoconductivity data, we were able to refine estimates on the materials parameters. The data also allowed us to simulate the stretched exponential decay. Our observations suggested that the stretching index and the carrier mobility were related. Physically, such interdependence would allow one to demarcate between localized molecular interactions and distant coulomb interactions.

Optimization of dynamic-microwave assisted enzymatic hydrolysis extraction of total ginsenosides from stems and leaves of panax ginseng by response surface methodology.

PubMed

Wang, Xiao-Yan; Ren, Hui

2018-03-21

Ginseng stems and leaves (GSAL) are abundant in ginsenosides compounds. For efficient utilization of GSAL and the enhancement of total ginsenosides (TG) compound yields in GSAL, TG from GSAL were extracted, using dynamic-microwave assisted extraction coupled with enzymatic hydrolysis (DMAE-EH) method. The extraction process has been simulated and its main influencing factors such as ethanol concentration, microwave temperature, microwave time and pump flow rate have been optimized by response surface methodology coupled with a Box-Behnken design(BBD). The experimental results indicated that optimal extraction conditions of TG from GSAL were as follows: ethanol concentration of 75%, microwave temperature of 60°C, microwave time of 20 min and pump flow rate of 38 r/min. After experimental verification, the experimental yields of TG was 60.62 ± 0.85 mg g -1 , which were well agreement with the predicted by the model. In general, the present results demonstrated that DMAE-EH method was successfully used to extract total ginsenosides in GSAL.

Information Extraction for System-Software Safety Analysis: Calendar Year 2008 Year-End Report

NASA Technical Reports Server (NTRS)

Malin, Jane T.

2009-01-01

This annual report describes work to integrate a set of tools to support early model-based analysis of failures and hazards due to system-software interactions. The tools perform and assist analysts in the following tasks: 1) extract model parts from text for architecture and safety/hazard models; 2) combine the parts with library information to develop the models for visualization and analysis; 3) perform graph analysis and simulation to identify and evaluate possible paths from hazard sources to vulnerable entities and functions, in nominal and anomalous system-software configurations and scenarios; and 4) identify resulting candidate scenarios for software integration testing. There has been significant technical progress in model extraction from Orion program text sources, architecture model derivation (components and connections) and documentation of extraction sources. Models have been derived from Internal Interface Requirements Documents (IIRDs) and FMEA documents. Linguistic text processing is used to extract model parts and relationships, and the Aerospace Ontology also aids automated model development from the extracted information. Visualizations of these models assist analysts in requirements overview and in checking consistency and completeness.

Comparative of signal processing techniques for micro-Doppler signature extraction with automotive radar systems

NASA Astrophysics Data System (ADS)

Rodriguez-Hervas, Berta; Maile, Michael; Flores, Benjamin C.

2014-05-01

In recent years, the automotive industry has experienced an evolution toward more powerful driver assistance systems that provide enhanced vehicle safety. These systems typically operate in the optical and microwave regions of the electromagnetic spectrum and have demonstrated high efficiency in collision and risk avoidance. Microwave radar systems are particularly relevant due to their operational robustness under adverse weather or illumination conditions. Our objective is to study different signal processing techniques suitable for extraction of accurate micro-Doppler signatures of slow moving objects in dense urban environments. Selection of the appropriate signal processing technique is crucial for the extraction of accurate micro-Doppler signatures that will lead to better results in a radar classifier system. For this purpose, we perform simulations of typical radar detection responses in common driving situations and conduct the analysis with several signal processing algorithms, including short time Fourier Transform, continuous wavelet or Kernel based analysis methods. We take into account factors such as the relative movement between the host vehicle and the target, and the non-stationary nature of the target's movement. A comparison of results reveals that short time Fourier Transform would be the best approach for detection and tracking purposes, while the continuous wavelet would be the best suited for classification purposes.

Radiolytic Treatment of the Next-Generation Caustic-Side Solvent Extraction (NGS) Solvent and its Effect on the NGS Process

DOE PAGES

Roach, Benjamin D.; Williams, Neil J.; Duncan, Nathan C.; ...

2014-12-01

We show in this work that the solvent used in the Next Generation Caustic-Side Solvent Extraction (NGS) process can withstand a radiation dose well in excess of the dose it would receive in multiple years of treating legacy salt waste at the US Department of Energy Savannah River Site. The solvent was subjected to a maximum of 50 kGy of gamma radiation while in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS-15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). Bench-top testing ofmore » irradiated solvent confirmed that irradiation has inconsequential impact on the extraction, scrubbing, and stripping performance of the solvent up to 13 times the estimated 0.73 kGy/y annual absorbed dose. Lastly, stripping performance is the most sensitive step to radiation, deteriorating more due to buildup of p-sec-butylphenol (SBP) and possibly other proton-ionizable products than to degradation of the guanidine suppressor, as shown by chemical analyses.« less

Radiolytic Treatment of the Next-Generation Caustic-Side Solvent Extraction (NGS) Solvent and its Effect on the NGS Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roach, Benjamin D.; Williams, Neil J.; Duncan, Nathan C.

We show in this work that the solvent used in the Next Generation Caustic-Side Solvent Extraction (NGS) process can withstand a radiation dose well in excess of the dose it would receive in multiple years of treating legacy salt waste at the US Department of Energy Savannah River Site. The solvent was subjected to a maximum of 50 kGy of gamma radiation while in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS-15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). Bench-top testing ofmore » irradiated solvent confirmed that irradiation has inconsequential impact on the extraction, scrubbing, and stripping performance of the solvent up to 13 times the estimated 0.73 kGy/y annual absorbed dose. Lastly, stripping performance is the most sensitive step to radiation, deteriorating more due to buildup of p-sec-butylphenol (SBP) and possibly other proton-ionizable products than to degradation of the guanidine suppressor, as shown by chemical analyses.« less

Simulation and study of small numbers of random events

NASA Technical Reports Server (NTRS)

Shelton, R. D.

1986-01-01

Random events were simulated by computer and subjected to various statistical methods to extract important parameters. Various forms of curve fitting were explored, such as least squares, least distance from a line, maximum likelihood. Problems considered were dead time, exponential decay, and spectrum extraction from cosmic ray data using binned data and data from individual events. Computer programs, mostly of an iterative nature, were developed to do these simulations and extractions and are partially listed as appendices. The mathematical basis for the compuer programs is given.

Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Curreri, Peter A.

2009-01-01

This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and MSFC, and Ohio State University and MIT. Progress in measuring cell efficiency for oxygen production, development of non reacting electrodes, and cell feeding and withdrawal will be discussed.

Applications of acoustic-gravity waves numerical modeling to tsunami signals observed by gravimetry satellites in very low orbit

NASA Astrophysics Data System (ADS)

Brissaud, Q.; Garcia, R.; Sladen, A.; Martin, R.; Komatitsch, D.

2016-12-01

Acoustic and gravity waves propagating in planetary atmospheres have been studied intensively as markers of specific phenomena (tectonic events, explosions) or as contributors to atmosphere dynamics. To get a better understanding of the physics behind these dynamic processes, both acoustic and gravity waves propagation should be modeled in an attenuating and windy 3D atmosphere from the ground all the way to the upper thermosphere. Thus, in order to provide an efficient numerical tool at the regional or global scale we introduce a high-order finite-difference time domain (FDTD) approach that relies on the linearized compressible Navier-Stokes equations with spatially non constant physical parameters (density, viscosities and speed of sound) and background velocities (wind). We present applications of these simulations to the propagation of gravity waves generated by tsunamis for realistic cases for which atmospheric models are extracted from empirical models including variations with altitude of atmospheric parameters, and tsunami forcing at the ocean surface is extracted from shallow water simulations. We describe the specific difficulties induced by the size of the simulation, the boundary conditions and the spherical geometry and compare the simulation outputs to data gathered by gravimetric satellites crossing gravity waves generated by tsunamis.

Simultaneous Sensor and Process Fault Diagnostics for Propellant Feed System

NASA Technical Reports Server (NTRS)

Cao, J.; Kwan, C.; Figueroa, F.; Xu, R.

2006-01-01

The main objective of this research is to extract fault features from sensor faults and process faults by using advanced fault detection and isolation (FDI) algorithms. A tank system that has some common characteristics to a NASA testbed at Stennis Space Center was used to verify our proposed algorithms. First, a generic tank system was modeled. Second, a mathematical model suitable for FDI has been derived for the tank system. Third, a new and general FDI procedure has been designed to distinguish process faults and sensor faults. Extensive simulations clearly demonstrated the advantages of the new design.

Quantifying Dimer and Trimer Formation by Tri- n -butyl Phosphates in n -Dodecane: Molecular Dynamics Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vo, Quynh N.; Dang, Liem X.; Nilsson, Mikael

2016-07-21

Tri-n-butyl phosphate (TBP), a representative of neutral organophosphorous ligands, is an important extractant used in solvent extraction process for the recovery of uranium and plutonium from spent nuclear fuel. Microscopic pictures of TBP isomerism and its behavior in n-dodecane diluent were investigated utilizing MD simulations with previously optimized force field parameters for TBP and n-dodecane. Potential Mean Force (PMF) calculations on a single TBP molecule show seven probable TBP isomers. Radial Distribution Functions (RDF) of TBP suggests the existence of TBP trimers at high TBP concentrations in addition to dimers. 2D PMF calculations were performed to determine the angle andmore » distance criteria for TBP trimers. The dimerization and trimerization constants of TBP in n-dodecane were obtained and match our own experimental values using FTIR technique. The new insights into the conformational behaviors of TBP molecule as a monomer and as part of an aggregate could greatly aid the understanding of the complexation between TBP and metal ions in solvent extraction system. The U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences funded the work performed by LXD.« less

High-grade glioma diffusive modeling using statistical tissue information and diffusion tensors extracted from atlases.

PubMed

Roniotis, Alexandros; Manikis, Georgios C; Sakkalis, Vangelis; Zervakis, Michalis E; Karatzanis, Ioannis; Marias, Kostas

2012-03-01

Glioma, especially glioblastoma, is a leading cause of brain cancer fatality involving highly invasive and neoplastic growth. Diffusive models of glioma growth use variations of the diffusion-reaction equation in order to simulate the invasive patterns of glioma cells by approximating the spatiotemporal change of glioma cell concentration. The most advanced diffusive models take into consideration the heterogeneous velocity of glioma in gray and white matter, by using two different discrete diffusion coefficients in these areas. Moreover, by using diffusion tensor imaging (DTI), they simulate the anisotropic migration of glioma cells, which is facilitated along white fibers, assuming diffusion tensors with different diffusion coefficients along each candidate direction of growth. Our study extends this concept by fully exploiting the proportions of white and gray matter extracted by normal brain atlases, rather than discretizing diffusion coefficients. Moreover, the proportions of white and gray matter, as well as the diffusion tensors, are extracted by the respective atlases; thus, no DTI processing is needed. Finally, we applied this novel glioma growth model on real data and the results indicate that prognostication rates can be improved. © 2012 IEEE

Artificial retina model for the retinally blind based on wavelet transform

NASA Astrophysics Data System (ADS)

Zeng, Yan-an; Song, Xin-qiang; Jiang, Fa-gang; Chang, Da-ding

2007-01-01

Artificial retina is aimed for the stimulation of remained retinal neurons in the patients with degenerated photoreceptors. Microelectrode arrays have been developed for this as a part of stimulator. Design such microelectrode arrays first requires a suitable mathematical method for human retinal information processing. In this paper, a flexible and adjustable human visual information extracting model is presented, which is based on the wavelet transform. With the flexible of wavelet transform to image information processing and the consistent to human visual information extracting, wavelet transform theory is applied to the artificial retina model for the retinally blind. The response of the model to synthetic image is shown. The simulated experiment demonstrates that the model behaves in a manner qualitatively similar to biological retinas and thus may serve as a basis for the development of an artificial retina.

A novel quantum steganography scheme for color images

NASA Astrophysics Data System (ADS)

Li, Panchi; Liu, Xiande

In quantum image steganography, embedding capacity and security are two important issues. This paper presents a novel quantum steganography scheme using color images as cover images. First, the secret information is divided into 3-bit segments, and then each 3-bit segment is embedded into the LSB of one color pixel in the cover image according to its own value and using Gray code mapping rules. Extraction is the inverse of embedding. We designed the quantum circuits that implement the embedding and extracting process. The simulation results on a classical computer show that the proposed scheme outperforms several other existing schemes in terms of embedding capacity and security.

Classification of electronically generated phantom targets by an Atlantic bottlenose dolphin (Tursiops truncatus).

PubMed

Aubauer, R; Au, W W; Nachtigall, P E; Pawloski, D A; DeLong, C M

2000-05-01

Animal behavior experiments require not only stimulus control of the animal's behavior, but also precise control of the stimulus itself. In discrimination experiments with real target presentation, the complex interdependence between the physical dimensions and the backscattering process of an object make it difficult to extract and control relevant echo parameters separately. In other phantom-echo experiments, the echoes were relatively simple and could only simulate certain properties of targets. The echo-simulation method utilized in this paper can be used to transform any animal echolocation sound into phantom echoes of high fidelity and complexity. The developed phantom-echo system is implemented on a digital signal-processing board and gives an experimenter fully programmable control over the echo-generating process and the echo structure itself. In this experiment, the capability of a dolphin to discriminate between acoustically simulated phantom replicas of targets and their real equivalents was tested. Phantom replicas were presented in a probe technique during a materials discrimination experiment. The animal accepted the phantom echoes and classified them in the same manner as it classified real targets.

Linking Chaotic Advection with Subsurface Biogeochemical Processes

NASA Astrophysics Data System (ADS)

Mays, D. C.; Freedman, V. L.; White, S. K.; Fang, Y.; Neupauer, R.

2017-12-01

This work investigates the extent to which groundwater flow kinematics drive subsurface biogeochemical processes. In terms of groundwater flow kinematics, we consider chaotic advection, whose essential ingredient is stretching and folding of plumes. Chaotic advection is appealing within the context of groundwater remediation because it has been shown to optimize plume spreading in the laminar flows characteristic of aquifers. In terms of subsurface biogeochemical processes, we consider an existing model for microbially-mediated reduction of relatively mobile uranium(VI) to relatively immobile uranium(IV) following injection of acetate into a floodplain aquifer beneath a former uranium mill in Rifle, Colorado. This model has been implemented in the reactive transport code eSTOMP, the massively parallel version of STOMP (Subsurface Transport Over Multiple Phases). This presentation will report preliminary numerical simulations in which the hydraulic boundary conditions in the eSTOMP model are manipulated to simulate chaotic advection resulting from engineered injection and extraction of water through a manifold of wells surrounding the plume of injected acetate. This approach provides an avenue to simulate the impact of chaotic advection within the existing framework of the eSTOMP code.

Including Delbrück scattering in GEANT4

NASA Astrophysics Data System (ADS)

Omer, Mohamed; Hajima, Ryoichi

2017-08-01

Elastic scattering of γ-rays is a significant interaction among γ-ray interactions with matter. Therefore, the planning of experiments involving measurements of γ-rays using Monte Carlo simulations usually includes elastic scattering. However, current simulation tools do not provide a complete picture of elastic scattering. The majority of these tools assume Rayleigh scattering is the primary contributor to elastic scattering and neglect other elastic scattering processes, such as nuclear Thomson and Delbrück scattering. Here, we develop a tabulation-based method to simulate elastic scattering in one of the most common open-source Monte Carlo simulation toolkits, GEANT4. We collectively include three processes, Rayleigh scattering, nuclear Thomson scattering, and Delbrück scattering. Our simulation more appropriately uses differential cross sections based on the second-order scattering matrix instead of current data, which are based on the form factor approximation. Moreover, the superposition of these processes is carefully taken into account emphasizing the complex nature of the scattering amplitudes. The simulation covers an energy range of 0.01 MeV ≤ E ≤ 3 MeV and all elements with atomic numbers of 1 ≤ Z ≤ 99. In addition, we validated our simulation by comparing the differential cross sections measured in earlier experiments with those extracted from the simulations. We find that the simulations are in good agreement with the experimental measurements. Differences between the experiments and the simulations are 21% for uranium, 24% for lead, 3% for tantalum, and 8% for cerium at 2.754 MeV. Coulomb corrections to the Delbrück amplitudes may account for the relatively large differences that appear at higher Z values.

Development of a helicon ion source: Simulations and preliminary experiments.

PubMed

Afsharmanesh, M; Habibi, M

2018-03-01

In the present context, the extraction system of a helicon ion source has been simulated and constructed. Results of the ion source commissioning at up to 20 kV are presented as well as simulations of an ion beam extraction system. Argon current of more than 200 μA at up to 20 kV is extracted and is characterized with a Faraday cup and beam profile monitoring grid. By changing different ion source parameters such as RF power, extraction voltage, and working pressure, an ion beam with current distribution exhibiting a central core has been detected. Jump transition of ion beam current emerges at the RF power near to 700 W, which reveals that the helicon mode excitation has reached this power. Furthermore, measuring the emission line intensity of Ar ii at 434.8 nm is the other way we have used for demonstrating the mode transition from inductively coupled plasma to helicon. Due to asymmetrical longitudinal power absorption of a half-helix helicon antenna, it is used for the ion source development. The modeling of the plasma part of the ion source has been carried out using a code, HELIC. Simulations are carried out by taking into account a Gaussian radial plasma density profile and for plasma densities in range of 10 18 -10 19 m -3 . Power absorption spectrum and the excited helicon mode number are obtained. Longitudinal RF power absorption for two different antenna positions is compared. Our results indicate that positioning the antenna near to the plasma electrode is desirable for the ion beam extraction. The simulation of the extraction system was performed with the ion optical code IBSimu, making it the first helicon ion source extraction designed with the code. Ion beam emittance and Twiss parameters of the ellipse emittance are calculated at different iterations and mesh sizes, and the best values of the mesh size and iteration number have been obtained for the calculations. The simulated ion beam extraction system has been evaluated using optimized parameters such as the gap distance between electrodes, electrodes aperture, and extraction voltage. The gap distance, ground electrode aperture, and extraction voltage have been changed between 3 and 9 mm, 2-6.5 mm, and 10-35 kV in the simulations, respectively.

Development of a helicon ion source: Simulations and preliminary experiments

NASA Astrophysics Data System (ADS)

Afsharmanesh, M.; Habibi, M.

2018-03-01

In the present context, the extraction system of a helicon ion source has been simulated and constructed. Results of the ion source commissioning at up to 20 kV are presented as well as simulations of an ion beam extraction system. Argon current of more than 200 μA at up to 20 kV is extracted and is characterized with a Faraday cup and beam profile monitoring grid. By changing different ion source parameters such as RF power, extraction voltage, and working pressure, an ion beam with current distribution exhibiting a central core has been detected. Jump transition of ion beam current emerges at the RF power near to 700 W, which reveals that the helicon mode excitation has reached this power. Furthermore, measuring the emission line intensity of Ar ii at 434.8 nm is the other way we have used for demonstrating the mode transition from inductively coupled plasma to helicon. Due to asymmetrical longitudinal power absorption of a half-helix helicon antenna, it is used for the ion source development. The modeling of the plasma part of the ion source has been carried out using a code, HELIC. Simulations are carried out by taking into account a Gaussian radial plasma density profile and for plasma densities in range of 1018-1019 m-3. Power absorption spectrum and the excited helicon mode number are obtained. Longitudinal RF power absorption for two different antenna positions is compared. Our results indicate that positioning the antenna near to the plasma electrode is desirable for the ion beam extraction. The simulation of the extraction system was performed with the ion optical code IBSimu, making it the first helicon ion source extraction designed with the code. Ion beam emittance and Twiss parameters of the ellipse emittance are calculated at different iterations and mesh sizes, and the best values of the mesh size and iteration number have been obtained for the calculations. The simulated ion beam extraction system has been evaluated using optimized parameters such as the gap distance between electrodes, electrodes aperture, and extraction voltage. The gap distance, ground electrode aperture, and extraction voltage have been changed between 3 and 9 mm, 2-6.5 mm, and 10-35 kV in the simulations, respectively.

Multiscale Modeling of Damage Processes in fcc Aluminum: From Atoms to Grains

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Saether, E.; Yamakov, V.

2008-01-01

Molecular dynamics (MD) methods are opening new opportunities for simulating the fundamental processes of material behavior at the atomistic level. However, current analysis is limited to small domains and increasing the size of the MD domain quickly presents intractable computational demands. A preferred approach to surmount this computational limitation has been to combine continuum mechanics-based modeling procedures, such as the finite element method (FEM), with MD analyses thereby reducing the region of atomic scale refinement. Such multiscale modeling strategies can be divided into two broad classifications: concurrent multiscale methods that directly incorporate an atomistic domain within a continuum domain and sequential multiscale methods that extract an averaged response from the atomistic simulation for later use as a constitutive model in a continuum analysis.

Experimental Demonstration of the Molten Oxide Electrolysis Method for Oxygen and Iron Production from Simulated Lunar Materials

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

2006-01-01

This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT).

Vadose Zone Fate and Transport Simulation of Chemicals Associated with Coal Seam Gas Extraction

NASA Astrophysics Data System (ADS)

Simunek, J.; Mallants, D.; Jacques, D.; Van Genuchten, M.

2017-12-01

The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this presentation is to provide an overview of the HYDRUS models and their add-on modules, and to demonstrate applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the vadose zone. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated) provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the coupled HYDRUS-PHREEQC module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in the vadose zone leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration is complexation of naturally present trace metals with inorganic ligands such as (bi)carbonate that enter the soil upon infiltration with alkaline produced water.

Feature extraction algorithm for space targets based on fractal theory

NASA Astrophysics Data System (ADS)

Tian, Balin; Yuan, Jianping; Yue, Xiaokui; Ning, Xin

2007-11-01

In order to offer a potential for extending the life of satellites and reducing the launch and operating costs, satellite servicing including conducting repairs, upgrading and refueling spacecraft on-orbit become much more frequently. Future space operations can be more economically and reliably executed using machine vision systems, which can meet real time and tracking reliability requirements for image tracking of space surveillance system. Machine vision was applied to the research of relative pose for spacecrafts, the feature extraction algorithm was the basis of relative pose. In this paper fractal geometry based edge extraction algorithm which can be used in determining and tracking the relative pose of an observed satellite during proximity operations in machine vision system was presented. The method gets the gray-level image distributed by fractal dimension used the Differential Box-Counting (DBC) approach of the fractal theory to restrain the noise. After this, we detect the consecutive edge using Mathematical Morphology. The validity of the proposed method is examined by processing and analyzing images of space targets. The edge extraction method not only extracts the outline of the target, but also keeps the inner details. Meanwhile, edge extraction is only processed in moving area to reduce computation greatly. Simulation results compared edge detection using the method which presented by us with other detection methods. The results indicate that the presented algorithm is a valid method to solve the problems of relative pose for spacecrafts.

A GPU-based large-scale Monte Carlo simulation method for systems with long-range interactions

NASA Astrophysics Data System (ADS)

Liang, Yihao; Xing, Xiangjun; Li, Yaohang

2017-06-01

In this work we present an efficient implementation of Canonical Monte Carlo simulation for Coulomb many body systems on graphics processing units (GPU). Our method takes advantage of the GPU Single Instruction, Multiple Data (SIMD) architectures, and adopts the sequential updating scheme of Metropolis algorithm. It makes no approximation in the computation of energy, and reaches a remarkable 440-fold speedup, compared with the serial implementation on CPU. We further use this method to simulate primitive model electrolytes, and measure very precisely all ion-ion pair correlation functions at high concentrations. From these data, we extract the renormalized Debye length, renormalized valences of constituent ions, and renormalized dielectric constants. These results demonstrate unequivocally physics beyond the classical Poisson-Boltzmann theory.

Numerical simulation of ion charge breeding in electron beam ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, L., E-mail: zhao@far-tech.com; Kim, Jin-Soo

2014-02-15

The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results ofmore » radial profiles and velocity space distributions of the trapped ions are presented.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Cheng, Liang; Chuah, Mooi Choo

In the generation, transmission, and distribution sectors of the smart grid, intelligence of field devices is realized by programmable logic controllers (PLCs). Many smart-grid subsystems are essentially cyber-physical energy systems (CPES): For instance, the power system process (i.e., the physical part) within a substation is monitored and controlled by a SCADA network with hosts running miscellaneous applications (i.e., the cyber part). To study the interactions between the cyber and physical components of a CPES, several co-simulation platforms have been proposed. However, the network simulators/emulators of these platforms do not include a detailed traffic model that takes into account the impactsmore » of the execution model of PLCs on traffic characteristics. As a result, network traces generated by co-simulation only reveal the impacts of the physical process on the contents of the traffic generated by SCADA hosts, whereas the distinction between PLCs and computing nodes (e.g., a hardened computer running a process visualization application) has been overlooked. To generate realistic network traces using co-simulation for the design and evaluation of applications relying on accurate traffic profiles, it is necessary to establish a traffic model for PLCs. In this work, we propose a parameterized model for PLCs that can be incorporated into existing co-simulation platforms. We focus on the DNP3 subsystem of slave PLCs, which automates the processing of packets from the DNP3 master. To validate our approach, we extract model parameters from both the configuration and network traces of real PLCs. Simulated network traces are generated and compared against those from PLCs. Our evaluation shows that our proposed model captures the essential traffic characteristics of DNP3 slave PLCs, which can be used to extend existing co-simulation platforms and gain further insights into the behaviors of CPES.« less

Space colonization.

PubMed

Parrish, Clyde F

2003-12-01

A series of workshops were sponsored by the Physical Science Division of NASA's Office of Biological and Physical Research to address operational gravity-compliant in-situ resource utilization and life support techologies. Workshop participants explored a Mars simulation study on Devon Island, Canada; the processing of carbon dioxide in regenerative life support systems; space tourism; rocket technology; plant growth research for closed ecological systems; and propellant extraction of planetary regoliths.

[An Extraction and Recognition Method of the Distributed Optical Fiber Vibration Signal Based on EMD-AWPP and HOSA-SVM Algorithm].

PubMed

Zhang, Yanjun; Liu, Wen-zhe; Fu, Xing-hu; Bi, Wei-hong

2016-02-01

Given that the traditional signal processing methods can not effectively distinguish the different vibration intrusion signal, a feature extraction and recognition method of the vibration information is proposed based on EMD-AWPP and HOSA-SVM, using for high precision signal recognition of distributed fiber optic intrusion detection system. When dealing with different types of vibration, the method firstly utilizes the adaptive wavelet processing algorithm based on empirical mode decomposition effect to reduce the abnormal value influence of sensing signal and improve the accuracy of signal feature extraction. Not only the low frequency part of the signal is decomposed, but also the high frequency part the details of the signal disposed better by time-frequency localization process. Secondly, it uses the bispectrum and bicoherence spectrum to accurately extract the feature vector which contains different types of intrusion vibration. Finally, based on the BPNN reference model, the recognition parameters of SVM after the implementation of the particle swarm optimization can distinguish signals of different intrusion vibration, which endows the identification model stronger adaptive and self-learning ability. It overcomes the shortcomings, such as easy to fall into local optimum. The simulation experiment results showed that this new method can effectively extract the feature vector of sensing information, eliminate the influence of random noise and reduce the effects of outliers for different types of invasion source. The predicted category identifies with the output category and the accurate rate of vibration identification can reach above 95%. So it is better than BPNN recognition algorithm and improves the accuracy of the information analysis effectively.

Force and Stress along Simulated Dissociation Pathways of Cucurbituril-Guest Systems.

PubMed

Velez-Vega, Camilo; Gilson, Michael K

2012-03-13

The field of host-guest chemistry provides computationally tractable yet informative model systems for biomolecular recognition. We applied molecular dynamics simulations to study the forces and mechanical stresses associated with forced dissociation of aqueous cucurbituril-guest complexes with high binding affinities. First, the unbinding transitions were modeled with constant velocity pulling (steered dynamics) and a soft spring constant, to model atomic force microscopy (AFM) experiments. The computed length-force profiles yield rupture forces in good agreement with available measurements. We also used steered dynamics with high spring constants to generate paths characterized by a tight control over the specified pulling distance; these paths were then equilibrated via umbrella sampling simulations and used to compute time-averaged mechanical stresses along the dissociation pathways. The stress calculations proved to be informative regarding the key interactions determining the length-force profiles and rupture forces. In particular, the unbinding transition of one complex is found to be a stepwise process, which is initially dominated by electrostatic interactions between the guest's ammoniums and the host's carbonyl groups, and subsequently limited by the extraction of the guest's bulky bicyclooctane moiety; the latter step requires some bond stretching at the cucurbituril's extraction portal. Conversely, the dissociation of a second complex with a more slender guest is mainly driven by successive electrostatic interactions between the different guest's ammoniums and the host's carbonyl groups. The calculations also provide information on the origins of thermodynamic irreversibilities in these forced dissociation processes.

Lunar Metal Oxide Electrolysis with Oxygen and Photovoltaic Array Production Applications

NASA Technical Reports Server (NTRS)

Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

2006-01-01

This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT). The production of oxygen and reduced iron were observed. Electrolysis was also performed on the supporting electrolyte with JSC-1 Lunar Simulant. The cell current for the supporting electrolyte alone is negligible while the current for the electrolyte with JSC-1 shows significant current and a peak at about -0.6 V indicating reductive reaction in the simulant.

An accurate behavioral model for single-photon avalanche diode statistical performance simulation

NASA Astrophysics Data System (ADS)

Xu, Yue; Zhao, Tingchen; Li, Ding

2018-01-01

An accurate behavioral model is presented to simulate important statistical performance of single-photon avalanche diodes (SPADs), such as dark count and after-pulsing noise. The derived simulation model takes into account all important generation mechanisms of the two kinds of noise. For the first time, thermal agitation, trap-assisted tunneling and band-to-band tunneling mechanisms are simultaneously incorporated in the simulation model to evaluate dark count behavior of SPADs fabricated in deep sub-micron CMOS technology. Meanwhile, a complete carrier trapping and de-trapping process is considered in afterpulsing model and a simple analytical expression is derived to estimate after-pulsing probability. In particular, the key model parameters of avalanche triggering probability and electric field dependence of excess bias voltage are extracted from Geiger-mode TCAD simulation and this behavioral simulation model doesn't include any empirical parameters. The developed SPAD model is implemented in Verilog-A behavioral hardware description language and successfully operated on commercial Cadence Spectre simulator, showing good universality and compatibility. The model simulation results are in a good accordance with the test data, validating high simulation accuracy.

A Nth-order linear algorithm for extracting diffuse correlation spectroscopy blood flow indices in heterogeneous tissues.

PubMed

Shang, Yu; Yu, Guoqiang

2014-09-29

Conventional semi-infinite analytical solutions of correlation diffusion equation may lead to errors when calculating blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements in tissues with irregular geometries. Very recently, we created an algorithm integrating a N th-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in homogenous tissues with arbitrary geometries for extraction of BFI (i.e., αD B ). The purpose of this study is to extend the capability of the N th-order linear algorithm for extracting BFI in heterogeneous tissues with arbitrary geometries. The previous linear algorithm was modified to extract BFIs in different types of tissues simultaneously through utilizing DCS data at multiple source-detector separations. We compared the proposed linear algorithm with the semi-infinite homogenous solution in a computer model of adult head with heterogeneous tissue layers of scalp, skull, cerebrospinal fluid, and brain. To test the capability of the linear algorithm for extracting relative changes of cerebral blood flow (rCBF) in deep brain, we assigned ten levels of αD B in the brain layer with a step decrement of 10% while maintaining αD B values constant in other layers. Simulation results demonstrate the accuracy (errors < 3%) of high-order ( N  ≥ 5) linear algorithm in extracting BFIs in different tissue layers and rCBF in deep brain. By contrast, the semi-infinite homogenous solution resulted in substantial errors in rCBF (34.5% ≤ errors ≤ 60.2%) and BFIs in different layers. The N th-order linear model simplifies data analysis, thus allowing for online data processing and displaying. Future study will test this linear algorithm in heterogeneous tissues with different levels of blood flow variations and noises.

A microscopic lane changing process model for multilane traffic

NASA Astrophysics Data System (ADS)

Lv, Wei; Song, Wei-guo; Liu, Xiao-dong; Ma, Jian

2013-03-01

In previous simulations lane-changing behavior is usually assumed as an instantaneous action. However, in real traffic, lane changing is a continuing process which can seriously affect the following cars. In this paper, a microscopic lane-changing process (LCP) model is clearly described. A new idea of simplifying the lane-changing process to the car-following framework is presented by controlling fictitious cars. To verify the model, the results of flow, lane-changing frequency, and single-car velocity are extracted from experimental observations and are compared with corresponding simulation. It is found that the LCP model agrees well with actual traffic flow and lane-changing behaviors may induce a 12%-18% reduction of traffic flow. The results also reflect that most of the drivers on the two roads in a city are conservative but not aggressive to change lanes. Investigation of lane-changing frequency shows that the largest lane-changing frequency occurs at a medium density range from 15 vehs km lane to 35 vehs km lane. It also implies that the lane-changing process might strengthen velocity variation at medium density and weaken velocity variation at high density. It is hoped that the idea of this study may be helpful to promote the modeling and simulation study of traffic flow.

Highly Efficient Flexible Quantum Dot Solar Cells with Improved Electron Extraction Using MgZnO Nanocrystals.

PubMed

Zhang, Xiaoliang; Santra, Pralay Kanti; Tian, Lei; Johansson, Malin B; Rensmo, Håkan; Johansson, Erik M J

2017-08-22

Colloidal quantum dot (CQD) solar cells have high potential for realizing an efficient and lightweight energy supply for flexible or wearable electronic devices. To achieve highly efficient and flexible CQD solar cells, the electron transport layer (ETL), extracting electrons from the CQD solid layer, needs to be processed at a low-temperature and should also suppress interfacial recombination. Herein, a highly stable MgZnO nanocrystal (MZO-NC) layer is reported for efficient flexible PbS CQD solar cells. Solar cells fabricated with MZO-NC ETL give a high power conversion efficiency (PCE) of 10.4% and 9.4%, on glass and flexible plastic substrates, respectively. The reported flexible CQD solar cell has the record efficiency to date of flexible CQD solar cells. Detailed theoretical simulations and extensive characterizations reveal that the MZO-NCs significantly enhance charge extraction from CQD solids and diminish the charge accumulation at the ETL/CQD interface, suppressing charge interfacial recombination. These important results suggest that the low-temperature processed MZO-NCs are very promising for use in efficient flexible solar cells or other flexible optoelectronic devices.

Modeling ECM fiber formation: structure information extracted by analysis of 2D and 3D image sets

NASA Astrophysics Data System (ADS)

Wu, Jun; Voytik-Harbin, Sherry L.; Filmer, David L.; Hoffman, Christoph M.; Yuan, Bo; Chiang, Ching-Shoei; Sturgis, Jennis; Robinson, Joseph P.

2002-05-01

Recent evidence supports the notion that biological functions of extracellular matrix (ECM) are highly correlated to its structure. Understanding this fibrous structure is very crucial in tissue engineering to develop the next generation of biomaterials for restoration of tissues and organs. In this paper, we integrate confocal microscopy imaging and image-processing techniques to analyze the structural properties of ECM. We describe a 2D fiber middle-line tracing algorithm and apply it via Euclidean distance maps (EDM) to extract accurate fibrous structure information, such as fiber diameter, length, orientation, and density, from single slices. Based on a 2D tracing algorithm, we extend our analysis to 3D tracing via Euclidean distance maps to extract 3D fibrous structure information. We use computer simulation to construct the 3D fibrous structure which is subsequently used to test our tracing algorithms. After further image processing, these models are then applied to a variety of ECM constructions from which results of 2D and 3D traces are statistically analyzed.

The Filament Sensor for Near Real-Time Detection of Cytoskeletal Fiber Structures

PubMed Central

Eltzner, Benjamin; Wollnik, Carina; Gottschlich, Carsten; Huckemann, Stephan; Rehfeldt, Florian

2015-01-01

A reliable extraction of filament data from microscopic images is of high interest in the analysis of acto-myosin structures as early morphological markers in mechanically guided differentiation of human mesenchymal stem cells and the understanding of the underlying fiber arrangement processes. In this paper, we propose the filament sensor (FS), a fast and robust processing sequence which detects and records location, orientation, length, and width for each single filament of an image, and thus allows for the above described analysis. The extraction of these features has previously not been possible with existing methods. We evaluate the performance of the proposed FS in terms of accuracy and speed in comparison to three existing methods with respect to their limited output. Further, we provide a benchmark dataset of real cell images along with filaments manually marked by a human expert as well as simulated benchmark images. The FS clearly outperforms existing methods in terms of computational runtime and filament extraction accuracy. The implementation of the FS and the benchmark database are available as open source. PMID:25996921

Process integration possibilities for biodiesel production from palm oil using ethanol obtained from lignocellulosic residues of oil palm industry.

PubMed

Gutiérrez, Luis F; Sánchez, Oscar J; Cardona, Carlos A

2009-02-01

In this paper, integration possibilities for production of biodiesel and bioethanol using a single source of biomass as a feedstock (oil palm) were explored through process simulation. The oil extracted from Fresh Fruit Bunches was considered as the feedstock for biodiesel production. An extractive reaction process is proposed for transesterification reaction using in situ produced ethanol, which is obtained from two types of lignocellulosic residues of palm industry (Empty Fruit Bunches and Palm Press Fiber). Several ways of integration were analyzed. The integration of material flows between ethanol and biodiesel production lines allowed a reduction in unit energy costs down to 3.4%, whereas the material and energy integration leaded to 39.8% decrease of those costs. The proposed integrated configuration is an important option when the technology for ethanol production from biomass reaches such a degree of maturity that its production costs be comparable with those of grain or cane ethanol.

Simulation and optimization of continuous extractive fermentation with recycle system

NASA Astrophysics Data System (ADS)

Widjaja, Tri; Altway, Ali; Rofiqah, Umi; Airlangga, Bramantyo

2017-05-01

Extractive fermentation is continuous fermentation method which is believed to be able to substitute conventional fermentation method (batch). The recovery system and ethanol refinery will be easier. Continuous process of fermentation will make the productivity increase although the unconverted sugar in continuous fermentation is still in high concentration. In order to make this process more efficient, the recycle process was used. Increasing recycle flow will enhance the probability of sugar to be re-fermented. However, this will make ethanol enter fermentation column. As a result, the accumulated ethanol will inhibit the growth of microorganism. This research aims to find optimum conditions of solvent to broth ratio (S:B) and recycle flow to fresh feed ratio in order to produce the best yield and productivity. This study employed optimization by Hooke Jeeves method using Matlab 7.8 software. The result indicated that optimum condition occured in S: B=2.615 and R: F=1.495 with yield = 50.2439 %.

Experiments on Plume Spreading by Engineered Injection and Extraction

NASA Astrophysics Data System (ADS)

Mays, D. C.; Jones, M.; Tigera, R. G.; Neupauer, R.

2014-12-01

The notion that groundwater remediation is transport-limited emphasizes the coupling between physical (i.e., hydrodynamic), geochemical, and microbiological processes in the subsurface. Here we leverage this coupling to promote groundwater remediation using the approach of engineered injection and extraction. In this approach, inspired by the literature on chaotic advection, uncontaminated groundwater is injected and extracted through a manifold of wells surrounding the contaminated plume. The potential of this approach lies in its ability to actively manipulate the velocity field near the contaminated plume, generating plume spreading above and beyond that resulting from aquifer heterogeneity. Plume spreading, in turn, promotes mixing and reaction by chemical and biological processes. Simulations have predicted that engineered injection and extraction generates (1) chaotic advection whose characteristics depend on aquifer heterogeneity, and (2) faster rates and increased extent of groundwater remediation. This presentation focuses on a complimentary effort to experimentally demonstrate these predictions experimentally. In preparation for future work using refractive index matched (RIM) porous media, the experiments reported here use a Hele-Shaw apparatus containing silicone oil. Engineered injection and extraction is used to manipulate the geometry of an initially circular plume of black pigment, and photographs record the plume geometry after each step of injection of extraction. Image analysis, using complimentary Eulerian and Lagrangian approaches, reveals the thickness and variability of the dispersion zone surrounding the deformed plume of black pigment. The size, shape, and evolution of this dispersion zone provides insight into the interplay between engineered injection and extraction, which generates plume structure, and dispersion (here Taylor dispersion), which destroys plume structure. These experiments lay the groundwork for application of engineered injection and extraction at field sites where improvements to the rate, extent, and cost of remediation are hoped.

Kinetic modeling of ultrasound-assisted extraction of phenolic compounds from grape marc: influence of acoustic energy density and temperature.

PubMed

Tao, Yang; Zhang, Zhihang; Sun, Da-Wen

2014-07-01

The effects of acoustic energy density (6.8-47.4 W/L) and temperature (20-50 °C) on the extraction yields of total phenolics and tartaric esters during ultrasound-assisted extraction from grape marc were investigated in this study. The ultrasound treatment was performed in a 25-kHz ultrasound bath system and the 50% aqueous ethanol was used as the solvent. The initial extraction rate and final extraction yield increased with the increase of acoustic energy density and temperature. The two site kinetic model was used to simulate the kinetics of extraction process and the diffusion model based on the Fick's second law was employed to determine the effective diffusion coefficient of phenolics in grape marc. Both models gave satisfactory quality of data fit. The diffusion process was divided into one fast stage and one slow stage and the diffusion coefficients in both stages were calculated. Within the current experimental range, the diffusion coefficients of total phenolics and tartaric esters for both diffusion stages increased with acoustic energy density. Meanwhile, the rise of temperature also resulted in the increase of diffusion coefficients of phenolics except the diffusion coefficient of total phenolics in the fast stage, the value of which being the highest at 40 °C. Moreover, an empirical equation was suggested to correlate the effective diffusion coefficient of phenolics in grape marc with acoustic energy density and temperature. In addition, the performance comparison of ultrasound-assisted extraction and convention methods demonstrates that ultrasound is an effective and promising technology to extract bioactive substances from grape marc. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of simulated angiographic procedures. Part 2: extracting efficiency data from audio and video recordings.

PubMed

Duncan, James R; Kline, Benjamin; Glaiberman, Craig B

2007-04-01

To create and test methods of extracting efficiency data from recordings of simulated renal stent procedures. Task analysis was performed and used to design a standardized testing protocol. Five experienced angiographers then performed 16 renal stent simulations using the Simbionix AngioMentor angiographic simulator. Audio and video recordings of these simulations were captured from multiple vantage points. The recordings were synchronized and compiled. A series of efficiency metrics (procedure time, contrast volume, and tool use) were then extracted from the recordings. The intraobserver and interobserver variability of these individual metrics was also assessed. The metrics were converted to costs and aggregated to determine the fixed and variable costs of a procedure segment or the entire procedure. Task analysis and pilot testing led to a standardized testing protocol suitable for performance assessment. Task analysis also identified seven checkpoints that divided the renal stent simulations into six segments. Efficiency metrics for these different segments were extracted from the recordings and showed excellent intra- and interobserver correlations. Analysis of the individual and aggregated efficiency metrics demonstrated large differences between segments as well as between different angiographers. These differences persisted when efficiency was expressed as either total or variable costs. Task analysis facilitated both protocol development and data analysis. Efficiency metrics were readily extracted from recordings of simulated procedures. Aggregating the metrics and dividing the procedure into segments revealed potential insights that could be easily overlooked because the simulator currently does not attempt to aggregate the metrics and only provides data derived from the entire procedure. The data indicate that analysis of simulated angiographic procedures will be a powerful method of assessing performance in interventional radiology.

A new methodology for determination of macroscopic transport parameters in drying porous media

NASA Astrophysics Data System (ADS)

Attari Moghaddam, A.; Kharaghani, A.; Tsotsas, E.; Prat, M.

2015-12-01

Two main approaches have been used to model the drying process: The first approach considers the partially saturated porous medium as a continuum and partial differential equations are used to describe the mass, momentum and energy balances of the fluid phases. The continuum-scale models (CM) obtained by this approach involve constitutive laws which require effective material properties, such as the diffusivity, permeability, and thermal conductivity which are often determined by experiments. The second approach considers the material at the pore scale, where the void space is represented by a network of pores (PN). Micro- or nanofluidics models used in each pore give rise to a large system of ordinary differential equations with degrees of freedom at each node of the pore network. In this work, the moisture transport coefficient (D), the pseudo desorption isotherm inside the network and at the evaporative surface are estimated from the post-processing of the three-dimensional pore network drying simulations for fifteen realizations of the pore space geometry from a given probability distribution. A slice sampling method is used in order to extract these parameters from PN simulations. The moisture transport coefficient obtained in this way is shown in Fig. 1a. The minimum of average D values demonstrates the transition between liquid dominated moisture transport region and vapor dominated moisture transport region; a similar behavior has been observed in previous experimental findings. A function is fitted to the average D values and then is fed into the non-linear moisture diffusion equation. The saturation profiles obtained from PN and CM simulations are shown in Fig. 1b. Figure 1: (a) extracted moisture transport coefficient during drying for fifteen realizations of the pore network, (b) average moisture profiles during drying obtained from PN and CM simulations.

Accurate phase extraction algorithm based on Gram–Schmidt orthonormalization and least square ellipse fitting method

NASA Astrophysics Data System (ADS)

Lei, Hebing; Yao, Yong; Liu, Haopeng; Tian, Yiting; Yang, Yanfu; Gu, Yinglong

2018-06-01

An accurate algorithm by combing Gram-Schmidt orthonormalization and least square ellipse fitting technology is proposed, which could be used for phase extraction from two or three interferograms. The DC term of background intensity is suppressed by subtraction operation on three interferograms or by high-pass filter on two interferograms. Performing Gram-Schmidt orthonormalization on pre-processing interferograms, the phase shift error is corrected and a general ellipse form is derived. Then the background intensity error and the corrected error could be compensated by least square ellipse fitting method. Finally, the phase could be extracted rapidly. The algorithm could cope with the two or three interferograms with environmental disturbance, low fringe number or small phase shifts. The accuracy and effectiveness of the proposed algorithm are verified by both of the numerical simulations and experiments.

Hybrid Feature Extraction-based Approach for Facial Parts Representation and Recognition

NASA Astrophysics Data System (ADS)

Rouabhia, C.; Tebbikh, H.

2008-06-01

Face recognition is a specialized image processing which has attracted a considerable attention in computer vision. In this article, we develop a new facial recognition system from video sequences images dedicated to person identification whose face is partly occulted. This system is based on a hybrid image feature extraction technique called ACPDL2D (Rouabhia et al. 2007), it combines two-dimensional principal component analysis and two-dimensional linear discriminant analysis with neural network. We performed the feature extraction task on the eyes and the nose images separately then a Multi-Layers Perceptron classifier is used. Compared to the whole face, the results of simulation are in favor of the facial parts in terms of memory capacity and recognition (99.41% for the eyes part, 98.16% for the nose part and 97.25 % for the whole face).

Hardware Verification of Laser Noise Cancellation and Gravitational Wave Extraction using Time-Delay Interferometry

NASA Astrophysics Data System (ADS)

Mitryk, Shawn; Mueller, Guido

The Laser Interferometer Space Antenna (LISA) is a space-based modified Michelson interfer-ometer designed to measure gravitational radiation in the frequency range from 30 uHz to 1 Hz. The interferometer measurement system (IMS) utilizes one-way laser phase measurements to cancel the laser phase noise, reconstruct the proof-mass motion, and extract the gravitational wave (GW) induced laser phase modulations in post-processing using a technique called time-delay interferometry (TDI). Unfortunately, there exist few hard-ware verification experiments of the IMS. The University of Florida LISA Interferometry Simulator (UFLIS) is designed to perform hardware-in-the-loop simulations of the LISA interferometry system, modeling the characteris-tics of the LISA mission as accurately as possible. This depends, first, on replicating the laser pre-stabilization by locking the laser phase to an ultra-stable Zerodur cavity length reference using the PDH locking method. Phase measurements of LISA-like photodetector beat-notes are taken using the UF-phasemeter (PM) which can measure the laser BN frequency to within an accuracy of 0.22 uHz. The inter-space craft (SC) laser links including the time-delay due to the 5 Gm light travel time along the LISA arms, the laser Doppler shifts due to differential SC motion, and the GW induced laser phase modulations are simulated electronically using the electronic phase delay (EPD) unit. The EPD unit replicates the laser field propagation between SC by measuring a photodetector beat-note frequency with the UF-phasemeter and storing the information in memory. After the requested delay time, the frequency information is added to a Doppler offset and a GW-like frequency modulation. The signal is then regenerated with the inter-SC laser phase affects applied. Utilizing these components, I will present the first complete TDI simulations performed using the UFLIS. The LISA model is presented along-side the simulation, comparing the generation and measurement of LISA-like signals. Phasemeter measurements are used in post-processing and combined in the linear combinations defined by TDI, thus, canceling the laser phase and phase-lock loop noise to extract the applied GW modulation buried under the noise. Nine order of magnitude common mode laser noise cancellation is achieved at a frequency of 1 mHz and the GW signal is clearly visible after the laser and PLL noise cancellation.

Integrating Data Sources for Process Sustainability ...

EPA Pesticide Factsheets

To perform a chemical process sustainability assessment requires significant data about chemicals, process design specifications, and operating conditions. The required information includes the identity of the chemicals used, the quantities of the chemicals within the context of the sustainability assessment, physical properties of these chemicals, equipment inventory, as well as health, environmental, and safety properties of the chemicals. Much of this data are currently available to the process engineer either from the process design in the chemical process simulation software or online through chemical property and environmental, health, and safety databases. Examples of these databases include the U.S. Environmental Protection Agency’s (USEPA’s) Aggregated Computational Toxicology Resource (ACToR), National Institute for Occupational Safety and Health’s (NIOSH’s) Hazardous Substance Database (HSDB), and National Institute of Standards and Technology’s (NIST’s) Chemistry Webbook. This presentation will provide methods and procedures for extracting chemical identity and flow information from process design tools (such as chemical process simulators) and chemical property information from the online databases. The presentation will also demonstrate acquisition and compilation of the data for use in the EPA’s GREENSCOPE process sustainability analysis tool. This presentation discusses acquisition of data for use in rapid LCI development.

Novel Fluorinated Tensioactive Extractant Combined with Flotation for Decontamination of Extractant Residual during Solvent Extraction

NASA Astrophysics Data System (ADS)

Wu, Xue; Chang, Zhidong; Liu, Yao; Choe, Chol Ryong

2017-12-01

Solvent-extraction is widely used in chemical industry. Due to the amphiphilic character, a large amount of extractant remains in water phase, which causes not only loss of reagent, but also secondary contamination in water phase. Novel fluorinated extractants with ultra-low solubility in water were regarded as effective choice to reduce extractant loss in aqueous phase. However, trace amount of extractant still remained in water. Based on the high tensioactive aptitude of fluorinated solvent, flotation was applied to separate fluorinated extractant remaining in raffinate. According to the data of surface tension measurement, the surface tension of solution was obviously decreased with the addition of fluorinated extractant tris(2,2,3,3,4,4,5,5-octafluoropentyl) phosphate (FTAP). After flotation, the FTAP dissolved in water can be removed as much as 70%, which proved the feasibility of this key idea. The effects of operation time, gas velocity, pH and salinity of bulk solution on flotation performance were discussed. The optimum operating parameters were determined as gas velocity of 12ml/min, operating time of 15min, pH of 8.7, and NaCl volume concentration of 1.5%, respectively. Moreover, adsorption process of FTAP on bubble surface was simulated by ANSYS VOF model using SIMPLE algorithm. The dynamic mechanism of flotation was also theoretically investigated, which can be considered as supplement to the experimental results.

Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar

NASA Technical Reports Server (NTRS)

Gaier, James R.; Siamidis, John; Larkin, Elizabeth M.G.

2008-01-01

A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10-8 Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust stimulant processing capabilities: heating and cooling while stirring in order to degas and remove absorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions, and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples

Tracking Blade Tip Vortices for Numerical Flow Simulations of Hovering Rotorcraft

NASA Technical Reports Server (NTRS)

Kao, David L.

2016-01-01

Blade tip vortices generated by a helicopter rotor blade are a major source of rotor noise and airframe vibration. This occurs when a vortex passes closely by, and interacts with, a rotor blade. The accurate prediction of Blade Vortex Interaction (BVI) continues to be a challenge for Computational Fluid Dynamics (CFD). Though considerable research has been devoted to BVI noise reduction and experimental techniques for measuring the blade tip vortices in a wind tunnel, there are only a handful of post-processing tools available for extracting vortex core lines from CFD simulation data. In order to calculate the vortex core radius, most of these tools require the user to manually select a vortex core to perform the calculation. Furthermore, none of them provide the capability to track the growth of a vortex core, which is a measure of how quickly the vortex diffuses over time. This paper introduces an automated approach for tracking the core growth of a blade tip vortex from CFD simulations of rotorcraft in hover. The proposed approach offers an effective method for the quantification and visualization of blade tip vortices in helicopter rotor wakes. Keywords: vortex core, feature extraction, CFD, numerical flow visualization

Hotspot detection using image pattern recognition based on higher-order local auto-correlation

NASA Astrophysics Data System (ADS)

Maeda, Shimon; Matsunawa, Tetsuaki; Ogawa, Ryuji; Ichikawa, Hirotaka; Takahata, Kazuhiro; Miyairi, Masahiro; Kotani, Toshiya; Nojima, Shigeki; Tanaka, Satoshi; Nakagawa, Kei; Saito, Tamaki; Mimotogi, Shoji; Inoue, Soichi; Nosato, Hirokazu; Sakanashi, Hidenori; Kobayashi, Takumi; Murakawa, Masahiro; Higuchi, Tetsuya; Takahashi, Eiichi; Otsu, Nobuyuki

2011-04-01

Below 40nm design node, systematic variation due to lithography must be taken into consideration during the early stage of design. So far, litho-aware design using lithography simulation models has been widely applied to assure that designs are printed on silicon without any error. However, the lithography simulation approach is very time consuming, and under time-to-market pressure, repetitive redesign by this approach may result in the missing of the market window. This paper proposes a fast hotspot detection support method by flexible and intelligent vision system image pattern recognition based on Higher-Order Local Autocorrelation. Our method learns the geometrical properties of the given design data without any defects as normal patterns, and automatically detects the design patterns with hotspots from the test data as abnormal patterns. The Higher-Order Local Autocorrelation method can extract features from the graphic image of design pattern, and computational cost of the extraction is constant regardless of the number of design pattern polygons. This approach can reduce turnaround time (TAT) dramatically only on 1CPU, compared with the conventional simulation-based approach, and by distributed processing, this has proven to deliver linear scalability with each additional CPU.

Modifier mass transfer kinetic effect in the performance of solvent gradient simulated moving bed (SG-SMB) process

NASA Astrophysics Data System (ADS)

Câmara, L. D. T.

2015-09-01

The solvent-gradient simulated moving bed process (SG-SMB) is the new tendency in the performance improvement if compared to the traditional isocratic solvent conditions. In such SG-SMB separation process the modulation of the solvent strength leads to significant increase in the purities and productivity followed by reduction in the solvent consumption. A stepwise modelling approach was utilized in the representation of the interconnected chromatographic columns of the system combined with lumped mass transfer models between the solid and liquid phase. The influence of the solvent modifier was considered applying the Abel model which takes into account the effect of modifier volume fraction over the partition coefficient. The modelling and simulations were carried out and compared to the experimental SG-SMB separation of the amino acids phenylalanine and tryptophan. A lumped mass transfer kinetic model was applied for both the modifier (ethanol) as well as the solutes. The simulation results showed that such simple and global mass transfer models are enough to represent all the mass transfer effect between the solid adsorbent and the liquid phase. The separation performance can be improved reducing the interaction or the mass transfer kinetic effect between the solid adsorbent phase and the modifier. The simulations showed great agreement fitting the experimental data of the amino acids concentrations both at the extract as well as at the raffinate.

Engineered Materials for Cesium and Strontium Storage Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sean M. McDeavitt

2010-04-14

Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation andmore » decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at Purdue University and is detailed in Appendix A. Steam reforming proved to be too rigorous for efficient The second stage of this project was carried out at Texas A&M University and is Detailed in Appendix B. In this stage, a gentler ceramic synthesis process using Cs and Sr loaded kaolinite and bentonite clays was developed in collaboration with Dr. M. Kaminski at Argonne National Laboratory.« less

Free-product plume distribution and recovery modeling prediction in a diesel-contaminated volcanic aquifer

NASA Astrophysics Data System (ADS)

Hernández-Espriú, Antonio; Martínez-Santos, Pedro; Sánchez-León, Emilio; Marín, Luis E.

Light non-aqueous phase liquids (LNAPL) represent one of the most serious problems in aquifers contaminated with petroleum hydrocarbons liquids. To design an appropriate remediation strategy it is essential to understand the behavior of the plume. The aim of this paper is threefold: (1) to characterize the fluid distribution of an LNAPL plume detected in a volcanic low-conductivity aquifer (∼0.4 m/day from slug tests interpretation), (2) to simulate the recovery processes of the free-product contamination and (3) to evaluate the primary recovery efficiency of the following alternatives: skimming, dual-phase extraction, Bioslurping and multi-phase extraction wells. The API/Charbeneau analytical model was used to investigate the recovery feasibility based on the geological properties and hydrogeological conditions with a multi-phase (water, air, LNAPL) transport approach in the vadose zone. The modeling performed in this research, in terms of LNAPL distribution in the subsurface, show that oil saturation is 7% in the air-oil interface, with a maximum value of 70% in the capillary fringe. Equilibrium between water and LNAPL phases is reached at a depth of 1.80 m from the air-oil interface. On the other hand, the LNAPL recovery model results suggest a remarkable enhancement of the free-product recovery when simultaneous extra-phase extraction was simulated from wells, in addition to the LNAPL lens. Recovery efficiencies were 27%, 65%, 66% and 67% for skimming, dual-phase extraction, Bioslurping and multi-phase extraction, respectively. During a 3-year simulation, skimmer wells and multi-phase extraction showed the lowest and highest LNAPL recovery rates, with expected values from 207 to 163 and 2305 to 707 l-LNAPL/day, respectively. At a field level we are proposing a well distribution arrangement that alternates pairs of dual-phase well-Bioslurping well. This not only improves the recovery of the free-product plume, but also pumps the dissolve plume and enhances in situ biodegradation in the vadose zone. Thus, aquifer and soil remediation can be achieved at a shorter time. Rough calculations suggest that LNAPL can be recovered at an approximate cost of 6-10/l.

The modification at CSNS ion source

NASA Astrophysics Data System (ADS)

Liu, S.; Ouyang, H.; Huang, T.; Xiao, Y.; Cao, X.; Lv, Y.; Xue, K.; Chen, W.

2017-08-01

The commissioning of CSNS front end has been finished. Above 15 mA beam intensity is obtained at the end of RFQ. For CSNS ion source, it is a type of penning surface plasma ion source, similar to ISIS ion source. To improve the operation stability and reduce spark rate, some modifications have been performed, including Penning field, extraction optics and post acceleration. PBGUNS is applied to optimize beam extraction. The co-extraction electrons are considered at PBGUNS simulation and various extracted structure are simulated aiming to make the beam through the extracted electrode without loss. The stability of ion source is improved further.

[Optimization of lime milk precipitation process of Lonicera Japonica aqueous extract based on quality by design concept].

PubMed

Shen, Jin-Jing; Gong, Xing-Chu; Pan, Jian-Yang; Qu, Hai-Bin

2017-03-01

Design space approach was applied in this study to optimize the lime milk precipitation process of Lonicera Japonica (Jinyinhua) aqueous extract. The evaluation indices for this process were total organic acid purity and amounts of 6 organic acids obtained from per unit mass of medicinal materials. Four critical process parameters (CPPs) including drop speed of lime milk, pH value after adding lime milk, settling time and settling temperature were identified by using the weighted standardized partial regression coefficient method. Quantitative models between process evaluation indices and CPPs were established by a stepwise regression analysis. A design space was calculated by a Monte-Carlo simulation method, and then verified. The verification test results showed that the operation within the design space can guarantee the stability of the lime milk precipitation process. The recommended normal operation space is as follows： drop speed of lime milk of 1.00-1.25 mL•min⁻¹, pH value of 11.5-11.7, settling time of 1.0-1.2 h, and settling temperature of 10-20 ℃.. Copyright© by the Chinese Pharmaceutical Association.

The Future Impact of Wind on BPA Power System Ancillary Services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makarov, Yuri V.; Lu, Shuai; McManus, Bart

Wind power is growing in a very fast pace as an alternative generating resource. As the ratio of wind power over total system capacity increases, the impact of wind on various system aspects becomes significant. This paper presents a methodology to study the future impact of wind on BPA power system ancillary services including load following and regulation. Existing approaches for similar analysis include dispatch model simulation and standard deviation evaluation. The methodology proposed in this paper uses historical data and stochastic processes to simulate the load balancing processes in BPA power system. Then capacity, ramp rate and ramp durationmore » characteristics are extracted from the simulation results, and load following and regulation requirements are calculated accordingly. It mimics the actual power system operations therefore the results can be more realistic yet the approach is convenient to perform. Further, the ramp rate and ramp duration data obtained from the analysis can be used to evaluate generator response or maneuverability and energy requirement, respectively, additional to the capacity requirement.« less

Spatial-temporal-covariance-based modeling, analysis, and simulation of aero-optics wavefront aberrations.

PubMed

Vogel, Curtis R; Tyler, Glenn A; Wittich, Donald J

2014-07-01

We introduce a framework for modeling, analysis, and simulation of aero-optics wavefront aberrations that is based on spatial-temporal covariance matrices extracted from wavefront sensor measurements. Within this framework, we present a quasi-homogeneous structure function to analyze nonhomogeneous, mildly anisotropic spatial random processes, and we use this structure function to show that phase aberrations arising in aero-optics are, for an important range of operating parameters, locally Kolmogorov. This strongly suggests that the d5/3 power law for adaptive optics (AO) deformable mirror fitting error, where d denotes actuator separation, holds for certain important aero-optics scenarios. This framework also allows us to compute bounds on AO servo lag error and predictive control error. In addition, it provides us with the means to accurately simulate AO systems for the mitigation of aero-effects, and it may provide insight into underlying physical processes associated with turbulent flow. The techniques introduced here are demonstrated using data obtained from the Airborne Aero-Optics Laboratory.

Study on the extrusion of nickel-based spark plug electrodes by numerical simulation

NASA Astrophysics Data System (ADS)

Saby, Q.; Courbon, C.; Salvatore, F.; Fabre, D.; Romeyer, F.

2018-05-01

Interest in metal forming simulation has grown rapidly during the last decades and is now well established even in industry. It provides a flexible and relatively cheap method to perform sensitivity analyses, getting a better insight into the forming process and use it as an optimisation tool. As far as wear is concerned, numerical simulation can be seen as a relevant approach to assess the thermomechanical loadings applied to the active die surface and therefore predict their wear behaviour. In this study, a Finite-Element (FE) based model has been developed in order to investigate the cold forming process of a nickel-based sparkplug electrode. A fully thermo-mechanically coupled implicit formulation has been used in order to model the forward extrusion step with a special emphasis on the contact conditions at the workpiece-die interface. Contact pressure, relative sliding velocity and temperature profiles have been extracted versus time and qualitatively compared to the wear phenomena observed on the worn production dies.

Towards a Video Passive Content Fingerprinting Method for Partial-Copy Detection Robust against Non-Simulated Attacks

PubMed Central

2016-01-01

Passive content fingerprinting is widely used for video content identification and monitoring. However, many challenges remain unsolved especially for partial-copies detection. The main challenge is to find the right balance between the computational cost of fingerprint extraction and fingerprint dimension, without compromising detection performance against various attacks (robustness). Fast video detection performance is desirable in several modern applications, for instance, in those where video detection involves the use of large video databases or in applications requiring real-time video detection of partial copies, a process whose difficulty increases when videos suffer severe transformations. In this context, conventional fingerprinting methods are not fully suitable to cope with the attacks and transformations mentioned before, either because the robustness of these methods is not enough or because their execution time is very high, where the time bottleneck is commonly found in the fingerprint extraction and matching operations. Motivated by these issues, in this work we propose a content fingerprinting method based on the extraction of a set of independent binary global and local fingerprints. Although these features are robust against common video transformations, their combination is more discriminant against severe video transformations such as signal processing attacks, geometric transformations and temporal and spatial desynchronization. Additionally, we use an efficient multilevel filtering system accelerating the processes of fingerprint extraction and matching. This multilevel filtering system helps to rapidly identify potential similar video copies upon which the fingerprint process is carried out only, thus saving computational time. We tested with datasets of real copied videos, and the results show how our method outperforms state-of-the-art methods regarding detection scores. Furthermore, the granularity of our method makes it suitable for partial-copy detection; that is, by processing only short segments of 1 second length. PMID:27861492

A systematic review of validated sinus surgery simulators.

PubMed

Stew, B; Kao, S S-T; Dharmawardana, N; Ooi, E H

2018-06-01

Simulation provides a safe and effective opportunity to develop surgical skills. A variety of endoscopic sinus surgery (ESS) simulators has been described in the literature. Validation of these simulators allows for effective utilisation in training. To conduct a systematic review of the published literature to analyse the evidence for validated ESS simulation. Pubmed, Embase, Cochrane and Cinahl were searched from inception of the databases to 11 January 2017. Twelve thousand five hundred and sixteen articles were retrieved of which 10 112 were screened following the removal of duplicates. Thirty-eight full-text articles were reviewed after meeting search criteria. Evidence of face, content, construct, discriminant and predictive validity was extracted. Twenty articles were included in the analysis describing 12 ESS simulators. Eleven of these simulators had undergone validation: 3 virtual reality, 7 physical bench models and 1 cadaveric simulator. Seven of the simulators were shown to have face validity, 7 had construct validity and 1 had predictive validity. None of the simulators demonstrated discriminate validity. This systematic review demonstrates that a number of ESS simulators have been comprehensively validated. Many of the validation processes, however, lack standardisation in outcome reporting, thus limiting a meta-analysis comparison between simulators. © 2017 John Wiley & Sons Ltd.

Ajustement statistique des simulations climatiques : l'exemple des précipitations saisonnières de l'Amérique tropicaleStatistical adjustment of simulated climate: example of seasonal rainfall of tropical America.

NASA Astrophysics Data System (ADS)

Moron, Vincent; Navarra, Antonio

2000-05-01

This study presents the skill of the seasonal rainfall of tropical America from an ensemble of three 34-year general circulation model (ECHAM 4) simulations forced with observed sea surface temperature between 1961 and 1994. The skill gives a first idea of the amount of potential predictability if the sea surface temperatures are perfectly known some time in advance. We use statistical post-processing based on the leading modes (extracted from Singular Value Decomposition of the covariance matrix between observed and simulated rainfall fields) to improve the raw skill obtained by simple comparison between observations and simulations. It is shown that 36-55 % of the observed seasonal variability is explained by the simulations on a regional basis. Skill is greatest for Brazilian Nordeste (March-May), but also for northern South America or the Caribbean basin in June-September or northern Amazonia in September-November for example.

Model-based design of a pilot-scale simulated moving bed for purification of citric acid from fermentation broth.

PubMed

Wu, Jinglan; Peng, Qijun; Arlt, Wolfgang; Minceva, Mirjana

2009-12-11

One of the conventional processes used for the recovery of citric acid from its fermentation broth is environmentally harmful and cost intensive. In this work an innovative benign process, which comprises simulated moving bed (SMB) technology and use of a tailor-made tertiary poly(4-vinylpyridine) (PVP) resin as a stationary phase is proposed. This paper focuses on a model-based design of the operation conditions for an existing pilot-scale SMB plant. The SMB unit is modeled on the basis of experimentally determined hydrodynamics, thermodynamics and mass transfer characteristics in a single chromatographic column. Three mathematical models are applied and validated for the prediction of the experimentally attained breakthrough and elution profiles of citric acid and the main impurity component (glucose). The transport dispersive model was selected for the SMB simulation and design studies, since it gives a satisfactory prediction of the elution profiles within acceptable computational time. The equivalent true moving bed (TMB) and SMB models give a good prediction of the experimentally attained SMB separation performances, obtained with a real clarified and concentrated fermentation broth as a feed mixture. The SMB separation requirements are set to at least 99.8% citric acid purity and 90% citric acid recovery in the extract stream. The complete regeneration in sections 1 and 4 is unnecessary. Therefore the net flow rates in all four SMB sections have been considered in the unit design. The influences of the operating conditions (the flow rate in each section, switching time and unit configuration) on the SMB performances were investigated systematically. The resulting SMB design provides 99.8% citric acid purity and 97.2% citric acid recovery in the extract. In addition the citric acid concentration in the extract is a half of its concentration in the pretreated fermentation broth (feed).

Speciation and bioaccessibility of mercury in adobe bricks and dirt floors in Huancavelica, Peru.

PubMed

Hagan, Nicole; Robins, Nicholas; Gonzales, Ruben Dario Espinoza; Hsu-Kim, Heileen

2015-04-01

Huancavelica, Peru, a historic cinnabar refining site, is one of the most mercury (Hg)-contaminated urban areas in the world. Exposure is amplified because residents build their adobe brick homes from contaminated soil. The objectives of this study were to compare two Hg-leaching procedures, and their application as risk-assessment screening tools in Hg-contaminated adobe brick homes in Huancavelica. The purpose was to evaluate potential health implications, particularly for children, after ingestion of Hg-contaminated particles. Hg was measured in adobe brick and dirt floor samples from 60 households by total Hg extraction, simulated gastric fluid (GF) extraction, and sequential selective extraction (SSE), which provides more detailed data but is resource-intensive. Most of the Hg present in samples was relatively insoluble, although in some households soluble Hg species were present at concentrations that may be of concern after ingestion. A strong correlation was identified between results from simulated GF extraction of adobe bricks and dirt floors and the more soluble fractions of Hg from SSE. Simulated GF extraction data were combined with ingestion and body mass characteristics for small children to compare potential risk of ingestion of Hg-contaminated soil with current health standards. Simulated GF extraction can be used as a risk assessment screening tool for effective allocation of time and resources to households that have measurable concentrations of bioaccessible Hg. Combining simulated GF extraction data with health standards enables intervention strategies targeted at households with the greatest potential health threat from ingestion of Hg-contaminated particles.

Study of negative ion transport phenomena in a plasma source

NASA Astrophysics Data System (ADS)

Riz, D.; Paméla, J.

1996-07-01

NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H-/H+) and charge exchanges (H-/H0). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NI produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter.

Mechanistic study of lead desorption during the leaching process of ion-absorbed rare earths: pH effect and the column experiment.

PubMed

Tang, Jie; Xue, Qiang; Chen, Honghan; Li, Wenting

2017-05-01

High concentrations of ammonium sulfate, often used in the in situ mining process, can result in a decrease of pH in the environment and dissolution of rare earth metals. Ammonium sulfate can also cause desorption of toxic heavy metals, leading to environmental and human health implications. In this study, the desorption behavior and fraction changes of lead in the ion-absorbed rare earth ore were studied using batch desorption experiments and column leaching tests. Results from batch desorption experiments showed that the desorption process of lead included fast and slow stages and followed an Elovich model well. The desorption rate and the proportion of lead content in the solution to the total lead in the soil were observed to increase with a decrease in the initial pH of the ammonium sulfate solution. The lead in soil included an acid-extractable fraction, reducible fraction, oxidizable fraction, and a residual fraction, with the predominant fractions being the reducible and acid-extractable fractions. Ninety-six percent of the extractable fraction in soil was desorbed into solution at pH = 3.0, and the content of the reducible fraction was observed to initially increase (when pH >4.0) and then decrease (when pH <4.0) with a decrease in pH. Column leaching tests indicated that the content of lead in the different fractions of soil followed the trend of reducible fraction > oxidizable fraction > acid-extractable fraction > residual fraction after the simulating leaching mining process. The change in pH was also found to have a larger influence on the acid-extractable and reducible fractions than the other two fractions. The proportion of the extractable fraction being leached was ca. 86%, and the reducible fraction was enriched along the migration direction of the leaching liquid. These results suggest that certain lead fractions may desorb again and contaminate the environment via acid rain, which provides significant information for environmental assessment and remediation after mining process. Graphical abstract ᅟ.

Determination of the bioaccessible fraction of metals in urban aerosol using simulated lung fluids

NASA Astrophysics Data System (ADS)

Coufalík, Pavel; Mikuška, Pavel; Matoušek, Tomáš; Večeřa, Zbyněk

2016-09-01

Determination of the bioaccessible fraction of metals in atmospheric aerosol is a significant issue with respect to air pollution in the urban environment. The aim of this work was to compare of metal bioaccessibility determined according to the extraction yields of six simulated lung fluids. Aerosol samples of the PM1 fraction were collected in Brno, Czech Republic. The total contents of Cd, Ce, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn in the samples were determined and their enrichment factors were calculated. The bioaccessible proportions of elements were determined by means of extraction in Gamble's solution, Gamble's solution with dipalmitoyl phosphatidyl choline (DPPC), artificial lysosomal fluid, saline, water, and in a newly proposed solution based on DPPC, referred to as "Simulated Alveoli Fluid" (SAF). The chemical composition and surface tension of the simulated lung fluids were the main parameters influencing extraction yields. Gamble's solutions and the newly designed solution of SAF exhibited the lowest extraction efficiency, and also had the lowest surface tensions. The bioaccessibility of particulate metals should be assessed by synthetic lung fluids with a low surface tension, which simulate better the behavior and composition of native lung surfactant. The bioaccessibility of metals in aerosol assessed by means of the extraction in water or artificial lysosomal fluid can be overestimated.

The role of vegetation on gully erosion stabilization at a severely degraded landscape: A case study from Calhoun Experimental Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Bastola, S.; Dialynas, Y. G.; Bras, R. L.; Noto, L. V.; Istanbulluoglu, E.

2018-05-01

Gully erosion was evidence of land degradation in the southern Piedmont, site of the Calhoun Critical Zone Observatory (CCZO), during the cotton farming era. Understanding of the underlying gully erosion processes is essential to develop gully erosion models that could be useful in assessing the effectiveness of remedial and soil erosion control measures such as gully backfilling, revegetation, and terracing. Development and validation of process-based gully erosion models is difficult because observations of the formation and progression of gullies are limited. In this study, analytic formulations of the two dominant gullying processes, namely, plunge pool erosion and slab failure, are utilized to simulate the gullying processes in the 4-km2 Holcombe's Branch watershed. In order to calibrate parameters of the gully erosion model, gully features (e.g., depth and area) extracted from a high-resolution LiDAR map are used. After the calibration, the gully model is able to delineate the spatial extent of gullies whose statistics are in close agreement with the gullies extracted from the LiDAR DEM. Several simulations with the calibrated model are explored to evaluate the effectiveness of various gully remedial measures, such as backfilling and revegetation. The results show that in the short-term, the reshaping of the topographical surface by backfilling and compacting gullies is effective in slowing down the growth of gullies (e.g., backfilling decreased the spatial extent of gullies by 21-46% and decreased the average depth of gullies by up to 9%). Revegetation, however, is a more effective approach to stabilizing gullies that would otherwise expand if no gully remedial measures are implemented. Analyses of our simulations show that the gully stabilization effect of revegetation varies over a wide range, i.e., leading to 23-69% reduction of the spatial extent of gullies and up to 45% reduction in the depth of gullies, depending on the selection of plant species and management practices.

Monitoring, analyzing and simulating of spatial-temporal changes of landscape pattern over mining area

NASA Astrophysics Data System (ADS)

Liu, Pei; Han, Ruimei; Wang, Shuangting

2014-11-01

According to the merits of remotely sensed data in depicting regional land cover and Land changes, multi- objective information processing is employed to remote sensing images to analyze and simulate land cover in mining areas. In this paper, multi-temporal remotely sensed data were selected to monitor the pattern, distri- bution and trend of LUCC and predict its impacts on ecological environment and human settlement in mining area. The monitor, analysis and simulation of LUCC in this coal mining areas are divided into five steps. The are information integration of optical and SAR data, LULC types extraction with SVM classifier, LULC trends simulation with CA Markov model, landscape temporal changes monitoring and analysis with confusion matrixes and landscape indices. The results demonstrate that the improved data fusion algorithm could make full use of information extracted from optical and SAR data; SVM classifier has an efficient and stable ability to obtain land cover maps, which could provide a good basis for both land cover change analysis and trend simulation; CA Markov model is able to predict LULC trends with good performance, and it is an effective way to integrate remotely sensed data with spatial-temporal model for analysis of land use / cover change and corresponding environmental impacts in mining area. Confusion matrixes are combined with landscape indices to evaluation and analysis show that, there was a sustained downward trend in agricultural land and bare land, but a continues growth trend tendency in water body, forest and other lands, and building area showing a wave like change, first increased and then decreased; mining landscape has undergone a from small to large and large to small process of fragmentation, agricultural land is the strongest influenced landscape type in this area, and human activities are the primary cause, so the problem should be pay more attentions by government and other organizations.

Modelling and extraction technique for micro-doppler signature of aircraft rotor blades

NASA Astrophysics Data System (ADS)

Praveen, N.; Valarmathi, J.

2017-11-01

The process of detecting and distinguishing between different aircrafts has been a major point of interest in Defence applications. Micro-Doppler effect is one such phenomenon unique for aircrafts with different rotor dynamics and design. In this paper, we focus on deducing a mathematical model for micro-Doppler signature, of aircraft rotor blades assumed to be rotating in a plane perpendicular to the flying direction, induced on the incident radar signal. Also, we use the Wigner-Ville Distribution (WVD) to extract this signature from the radar return. This mathematical model is compared with the simulation results obtained from MATLAB, to validate the results and show the accurateness of the developed model.

Artificial Intelligence-Based Models for the Optimal and Sustainable Use of Groundwater in Coastal Aquifers

NASA Astrophysics Data System (ADS)

Sreekanth, J.; Datta, Bithin

2011-07-01

Overexploitation of the coastal aquifers results in saltwater intrusion. Once saltwater intrusion occurs, it involves huge cost and long-term remediation measures to remediate these contaminated aquifers. Hence, it is important to have strategies for the sustainable use of coastal aquifers. This study develops a methodology for the optimal management of saltwater intrusion prone aquifers. A linked simulation-optimization-based management strategy is developed. The methodology uses genetic-programming-based models for simulating the aquifer processes, which is then linked to a multi-objective genetic algorithm to obtain optimal management strategies in terms of groundwater extraction from potential well locations in the aquifer.

Wakefield Computations for the CLIC PETS using the Parallel Finite Element Time-Domain Code T3P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, A; Kabel, A.; Lee, L.

In recent years, SLAC's Advanced Computations Department (ACD) has developed the high-performance parallel 3D electromagnetic time-domain code, T3P, for simulations of wakefields and transients in complex accelerator structures. T3P is based on advanced higher-order Finite Element methods on unstructured grids with quadratic surface approximation. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with unprecedented accuracy, aiding the design of the next generation of accelerator facilities. Applications to the Compact Linear Collider (CLIC) Power Extraction and Transfer Structure (PETS) are presented.

Mars Colony in situ resource utilization: An integrated architecture and economics model

NASA Astrophysics Data System (ADS)

Shishko, Robert; Fradet, René; Do, Sydney; Saydam, Serkan; Tapia-Cortez, Carlos; Dempster, Andrew G.; Coulton, Jeff

2017-09-01

This paper reports on our effort to develop an ensemble of specialized models to explore the commercial potential of mining water/ice on Mars in support of a Mars Colony. This ensemble starts with a formal systems architecting framework to describe a Mars Colony and capture its artifacts' parameters and technical attributes. The resulting database is then linked to a variety of ;downstream; analytic models. In particular, we integrated an extraction process (i.e., ;mining;) model, a simulation of the colony's environmental control and life support infrastructure known as HabNet, and a risk-based economics model. The mining model focuses on the technologies associated with in situ resource extraction, processing, storage and handling, and delivery. This model computes the production rate as a function of the systems' technical parameters and the local Mars environment. HabNet simulates the fundamental sustainability relationships associated with establishing and maintaining the colony's population. The economics model brings together market information, investment and operating costs, along with measures of market uncertainty and Monte Carlo techniques, with the objective of determining the profitability of commercial water/ice in situ mining operations. All told, over 50 market and technical parameters can be varied in order to address ;what-if; questions, including colony location.

An approach to optimize the batch mixing process for improving the quality consistency of the products made from traditional Chinese medicines*

PubMed Central

Yan, Bin-jun; Qu, Hai-bin

2013-01-01

The efficacy of traditional Chinese medicine (TCM) is based on the combined effects of its constituents. Variation in chemical composition between batches of TCM has always been the deterring factor in achieving consistency in efficacy. The batch mixing process can significantly reduce the batch-to-batch quality variation in TCM extracts by mixing them in a well-designed proportion. However, reducing the quality variation without sacrificing too much of the production efficiency is one of the challenges. Accordingly, an innovative and practical batch mixing method aimed at providing acceptable efficiency for industrial production of TCM products is proposed in this work, which uses a minimum number of batches of extracts to meet the content limits. The important factors affecting the utilization ratio of the extracts (URE) were studied by simulations. The results have shown that URE was affected by the correlation between the contents of constituents, and URE decreased with the increase in the number of targets and the relative standard deviations of the contents. URE could be increased by increasing the number of storage tanks. The results have provided a reference for designing the batch mixing process. The proposed method has possible application value in reducing the quality variation in TCM and providing acceptable production efficiency simultaneously. PMID:24190450

An approach to optimize the batch mixing process for improving the quality consistency of the products made from traditional Chinese medicines.

PubMed

Yan, Bin-jun; Qu, Hai-bin

2013-11-01

The efficacy of traditional Chinese medicine (TCM) is based on the combined effects of its constituents. Variation in chemical composition between batches of TCM has always been the deterring factor in achieving consistency in efficacy. The batch mixing process can significantly reduce the batch-to-batch quality variation in TCM extracts by mixing them in a well-designed proportion. However, reducing the quality variation without sacrificing too much of the production efficiency is one of the challenges. Accordingly, an innovative and practical batch mixing method aimed at providing acceptable efficiency for industrial production of TCM products is proposed in this work, which uses a minimum number of batches of extracts to meet the content limits. The important factors affecting the utilization ratio of the extracts (URE) were studied by simulations. The results have shown that URE was affected by the correlation between the contents of constituents, and URE decreased with the increase in the number of targets and the relative standard deviations of the contents. URE could be increased by increasing the number of storage tanks. The results have provided a reference for designing the batch mixing process. The proposed method has possible application value in reducing the quality variation in TCM and providing acceptable production efficiency simultaneously.

Impact of urbanization on flood of Shigu creek in Dongguan city

NASA Astrophysics Data System (ADS)

Pan, Luying; Chen, Yangbo; Zhang, Tao

2018-06-01

Shigu creek is a highly urbanized small watershed in Dongguan City. Due to rapid urbanization, quick flood response has been observed, which posted great threat to the flood security of Dongguan City. To evaluate the impact of urbanization on the flood changes of Shigu creek is very important for the flood mitigation of Shigu creek, which will provide insight for flood planners and managers for if to build a larger flood mitigation system. In this paper, the Land cover/use changes of Shigu creek from 1987-2015 induced by urbanization was first extracted from a local database, then, the Liuxihe model, a physically based distributed hydrological model, is employed to simulate the flood processes impacted by urbanization. Precipitation of 3 storms was used for flood processes simulation. The results show that the runoff coefficient and peak flow have increased sharply.

Semantic World Modelling and Data Management in a 4d Forest Simulation and Information System

NASA Astrophysics Data System (ADS)

Roßmann, J.; Hoppen, M.; Bücken, A.

2013-08-01

Various types of 3D simulation applications benefit from realistic forest models. They range from flight simulators for entertainment to harvester simulators for training and tree growth simulations for research and planning. Our 4D forest simulation and information system integrates the necessary methods for data extraction, modelling and management. Using modern methods of semantic world modelling, tree data can efficiently be extracted from remote sensing data. The derived forest models contain position, height, crown volume, type and diameter of each tree. This data is modelled using GML-based data models to assure compatibility and exchangeability. A flexible approach for database synchronization is used to manage the data and provide caching, persistence, a central communication hub for change distribution, and a versioning mechanism. Combining various simulation techniques and data versioning, the 4D forest simulation and information system can provide applications with "both directions" of the fourth dimension. Our paper outlines the current state, new developments, and integration of tree extraction, data modelling, and data management. It also shows several applications realized with the system.

Analytical solutions for a soil vapor extraction model that incorporates gas phase dispersion and molecular diffusion

NASA Astrophysics Data System (ADS)

Huang, Junqi; Goltz, Mark N.

2017-06-01

To greatly simplify their solution, the equations describing radial advective/dispersive transport to an extraction well in a porous medium typically neglect molecular diffusion. While this simplification is appropriate to simulate transport in the saturated zone, it can result in significant errors when modeling gas phase transport in the vadose zone, as might be applied when simulating a soil vapor extraction (SVE) system to remediate vadose zone contamination. A new analytical solution for the equations describing radial gas phase transport of a sorbing contaminant to an extraction well is presented. The equations model advection, dispersion (including both mechanical dispersion and molecular diffusion), and rate-limited mass transfer of dissolved, separate phase, and sorbed contaminants into the gas phase. The model equations are analytically solved by using the Laplace transform with respect to time. The solutions are represented by confluent hypergeometric functions in the Laplace domain. The Laplace domain solutions are then evaluated using a numerical Laplace inversion algorithm. The solutions can be used to simulate the spatial distribution and the temporal evolution of contaminant concentrations during operation of a soil vapor extraction well. Results of model simulations show that the effect of gas phase molecular diffusion upon concentrations at the extraction well is relatively small, although the effect upon the distribution of concentrations in space is significant. This study provides a tool that can be useful in designing SVE remediation strategies, as well as verifying numerical models used to simulate SVE system performance.

Simulation for learning and teaching procedural skills: the state of the science.

PubMed

Nestel, Debra; Groom, Jeffrey; Eikeland-Husebø, Sissel; O'Donnell, John M

2011-08-01

Simulation is increasingly used to support learning of procedural skills. Our panel was tasked with summarizing the "best evidence." We addressed the following question: To what extent does simulation support learning and teaching in procedural skills? We conducted a literature search from 2000 to 2010 using Medline, CINAHL, ERIC, and PSYCHINFO databases. Inclusion criteria were established and then data extracted from abstracts according to several categories. Although secondary sources of literature were sourced from key informants and participants at the "Research Consensus Summit: State of the Science," they were not included in the data extraction process but were used to inform discussion. Eighty-one of 1,575 abstracts met inclusion criteria. The uses of simulation for learning and teaching procedural skills were diverse. The most commonly reported simulator type was manikins (n = 17), followed by simulated patients (n = 14), anatomic simulators (eg, part-task) (n = 12), and others. For research design, most abstracts (n = 52) were at Level IV of the National Health and Medical Research Council classification (ie, case series, posttest, or pretest/posttest, with no control group, narrative reviews, and editorials). The most frequent Best Evidence Medical Education ranking was for conclusions probable (n = 37). Using the modified Kirkpatrick scale for impact of educational intervention, the most frequent classification was for modification of knowledge and/or skills (Level 2b) (n = 52). Abstracts assessed skills (n = 47), knowledge (n = 32), and attitude (n = 15) with the majority demonstrating improvements after simulation-based interventions. Studies focused on immediate gains and skills assessments were usually conducted in simulation. The current state of the science finds that simulation usually leads to improved knowledge and skills. Learners and instructors express high levels of satisfaction with the method. While most studies focus on short-term gains attained in the simulation setting, a small number support the transfer of simulation learning to clinical practice. Further study is needed to optimize the alignment of learner, instructor, simulator, setting, and simulation for learning and teaching procedural skills. Instructional design and educational theory, contextualization, transferability, accessibility, and scalability must all be considered in simulation-based education programs. More consistently, robust research designs are required to strengthen the evidence.

Investigation of a Plasma Edge Cathode Under High Current Density Electron Extraction

DTIC Science & Technology

1991-12-05

simu- lation using the MAGIC code confirmed the expected features of the scheme. SLTMMARY .. . . . . . . . . . .. . . . . . . . . . . 1 I...description. An electron temperature of 1 eV was mea- sured in the extraction region without extraction turned on. The plasma from the plasma gun was...jet is reduced if the time between shots is reduced to below I min. The numerical simulation with MAGIC gave confirming results. The simulated current

About Distributed Simulation-based Optimization of Forming Processes using a Grid Architecture

NASA Astrophysics Data System (ADS)

Grauer, Manfred; Barth, Thomas

2004-06-01

Permanently increasing complexity of products and their manufacturing processes combined with a shorter "time-to-market" leads to more and more use of simulation and optimization software systems for product design. Finding a "good" design of a product implies the solution of computationally expensive optimization problems based on the results of simulation. Due to the computational load caused by the solution of these problems, the requirements on the Information&Telecommunication (IT) infrastructure of an enterprise or research facility are shifting from stand-alone resources towards the integration of software and hardware resources in a distributed environment for high-performance computing. Resources can either comprise software systems, hardware systems, or communication networks. An appropriate IT-infrastructure must provide the means to integrate all these resources and enable their use even across a network to cope with requirements from geographically distributed scenarios, e.g. in computational engineering and/or collaborative engineering. Integrating expert's knowledge into the optimization process is inevitable in order to reduce the complexity caused by the number of design variables and the high dimensionality of the design space. Hence, utilization of knowledge-based systems must be supported by providing data management facilities as a basis for knowledge extraction from product data. In this paper, the focus is put on a distributed problem solving environment (PSE) capable of providing access to a variety of necessary resources and services. A distributed approach integrating simulation and optimization on a network of workstations and cluster systems is presented. For geometry generation the CAD-system CATIA is used which is coupled with the FEM-simulation system INDEED for simulation of sheet-metal forming processes and the problem solving environment OpTiX for distributed optimization.

Active illuminated space object imaging and tracking simulation

NASA Astrophysics Data System (ADS)

Yue, Yufang; Xie, Xiaogang; Luo, Wen; Zhang, Feizhou; An, Jianzhu

2016-10-01

Optical earth imaging simulation of a space target in orbit and it's extraction in laser illumination condition were discussed. Based on the orbit and corresponding attitude of a satellite, its 3D imaging rendering was built. General simulation platform was researched, which was adaptive to variable 3D satellite models and relative position relationships between satellite and earth detector system. Unified parallel projection technology was proposed in this paper. Furthermore, we denoted that random optical distribution in laser-illuminated condition was a challenge for object discrimination. Great randomicity of laser active illuminating speckles was the primary factor. The conjunction effects of multi-frame accumulation process and some tracking methods such as Meanshift tracking, contour poid, and filter deconvolution were simulated. Comparison of results illustrates that the union of multi-frame accumulation and contour poid was recommendable for laser active illuminated images, which had capacities of high tracking precise and stability for multiple object attitudes.

Multi-Scale Modeling of Liquid Phase Sintering Affected by Gravity: Preliminary Analysis

NASA Technical Reports Server (NTRS)

Olevsky, Eugene; German, Randall M.

2012-01-01

A multi-scale simulation concept taking into account impact of gravity on liquid phase sintering is described. The gravity influence can be included at both the micro- and macro-scales. At the micro-scale, the diffusion mass-transport is directionally modified in the framework of kinetic Monte-Carlo simulations to include the impact of gravity. The micro-scale simulations can provide the values of the constitutive parameters for macroscopic sintering simulations. At the macro-scale, we are attempting to embed a continuum model of sintering into a finite-element framework that includes the gravity forces and substrate friction. If successful, the finite elements analysis will enable predictions relevant to space-based processing, including size and shape and property predictions. Model experiments are underway to support the models via extraction of viscosity moduli versus composition, particle size, heating rate, temperature and time.

State of the art in electromagnetic modeling for the Compact Linear Collider

DOE Office of Scientific and Technical Information (OSTI.GOV)

Candel, Arno; Kabel, Andreas; Lee, Lie-Quan

SLAC's Advanced Computations Department (ACD) has developed the parallel 3D electromagnetic time-domain code T3P for simulations of wakefields and transients in complex accelerator structures. T3P is based on state-of-the-art Finite Element methods on unstructured grids and features unconditional stability, quadratic surface approximation and up to 6th-order vector basis functions for unprecedented simulation accuracy. Optimized for large-scale parallel processing on leadership supercomputing facilities, T3P allows simulations of realistic 3D structures with fast turn-around times, aiding the design of the next generation of accelerator facilities. Applications include simulations of the proposed two-beam accelerator structures for the Compact Linear Collider (CLIC) - wakefieldmore » damping in the Power Extraction and Transfer Structure (PETS) and power transfer to the main beam accelerating structures are investigated.« less

Enhanced centrifuge-based approach to powder characterization

NASA Astrophysics Data System (ADS)

Thomas, Myles Calvin

Many types of manufacturing processes involve powders and are affected by powder behavior. It is highly desirable to implement tools that allow the behavior of bulk powder to be predicted based on the behavior of only small quantities of powder. Such descriptions can enable engineers to significantly improve the performance of powder processing and formulation steps. In this work, an enhancement of the centrifuge technique is proposed as a means of powder characterization. This enhanced method uses specially designed substrates with hemispherical indentations within the centrifuge. The method was tested using simulations of the momentum balance at the substrate surface. Initial simulations were performed with an ideal powder containing smooth, spherical particles distributed on substrates designed with indentations. The van der Waals adhesion between the powder, whose size distribution was based on an experimentally-determined distribution from a commercial silica powder, and the indentations was calculated and compared to the removal force created in the centrifuge. This provided a way to relate the powder size distribution to the rotational speed required for particle removal for various indentation sizes. Due to the distinct form of the data from these simulations, the cumulative size distribution of the powder and the Hamaker constant for the system were be extracted. After establishing adhesion force characterization for an ideal powder, the same proof-of-concept procedure was followed for a more realistic system with a simulated rough powder modeled as spheres with sinusoidal protrusions and intrusions around the surface. From these simulations, it was discovered that an equivalent powder of smooth spherical particles could be used to describe the adhesion behavior of the rough spherical powder by establishing a size-dependent 'effective' Hamaker constant distribution. This development made it possible to describe the surface roughness effects of the entire powder through one adjustable parameter that was linked to the size distribution. It is important to note that when the engineered substrates (hemispherical indentations) were applied, it was possible to extract both powder size distribution and effective Hamaker constant information from the simulated centrifuge adhesion experiments. Experimental validation of the simulated technique was performed with a silica powder dispersed onto a stainless steel substrate with no engineered surface features. Though the proof-of-concept work was accomplished for indented substrates, non-ideal, relatively flat (non-indented) substrates were used experimentally to demonstrate that the technique can be extended to this case. The experimental data was then used within the newly developed simulation procedure to show its application to real systems. In the absence of engineered features on the substrates, it was necessary to specify the size distribution of the powder as an input to the simulator. With this information, it was possible to extract an effective Hamaker constant distribution and when the effective Hamaker constant distribution was applied in conjunction with the size distribution, the observed adhesion force distribution was described precisely. An equation was developed that related the normalized effective Hamaker constants (normalized by the particle diameter) to the particle diameter was formulated from the effective Hamaker constant distribution. It was shown, by application of the equation, that the adhesion behavior of an ideal (smooth, spherical) powder with an experimentally-validated, effective Hamaker constant distribution could be used to effectively represent that of a realistic powder. Thus, the roughness effects and size variations of a real powder are captured in this one distributed parameter (effective Hamaker constant distribution) which provides a substantial improvement to the existing technique. This can lead to better optimization of powder processing by enhancing powder behavior models.

Spectroscopic methods of process monitoring for safeguards of used nuclear fuel separations

NASA Astrophysics Data System (ADS)

Warburton, Jamie Lee

To support the demonstration of a more proliferation-resistant nuclear fuel processing plant, techniques and instrumentation to allow the real-time, online determination of special nuclear material concentrations in-process must be developed. An ideal materials accountability technique for proliferation resistance should provide nondestructive, realtime, on-line information of metal and ligand concentrations in separations streams without perturbing the process. UV-Visible spectroscopy can be adapted for this precise purpose in solvent extraction-based separations. The primary goal of this project is to understand fundamental URanium EXtraction (UREX) and Plutonium-URanium EXtraction (PUREX) reprocessing chemistry and corresponding UV-Visible spectroscopy for application in process monitoring for safeguards. By evaluating the impact of process conditions, such as acid concentration, metal concentration and flow rate, on the sensitivity of the UV-Visible detection system, the process-monitoring concept is developed from an advanced application of fundamental spectroscopy. Systematic benchtop-scale studies investigated the system relevant to UREX or PUREX type reprocessing systems, encompassing 0.01-1.26 M U and 0.01-8 M HNO3. A laboratory-scale TRansUranic Extraction (TRUEX) demonstration was performed and used both to analyze for potential online monitoring opportunities in the TRUEX process, and to provide the foundation for building and demonstrating a laboratory-scale UREX demonstration. The secondary goal of the project is to simulate a diversion scenario in UREX and successfully detect changes in metal concentration and solution chemistry in a counter current contactor system with a UV-Visible spectroscopic process monitor. UREX uses the same basic solvent extraction flowsheet as PUREX, but has a lower acid concentration throughout and adds acetohydroxamic acid (AHA) as a complexant/reductant to the feed solution to prevent the extraction of Pu. By examining UV-Visible spectra gathered in real time, the objective is to detect the conversion from the UREX process, which does not separate Pu, to the PUREX process, which yields a purified Pu product. The change in process chemistry can be detected in the feed solution, aqueous product or in the raffinate stream by identifying the acid concentration, metal distribution and the presence or absence of AHA. A fiber optic dip probe for UV-Visible spectroscopy was integrated into a bank of three counter-current centrifugal contactors to demonstrate the online process monitoring concept. Nd, Fe and Zr were added to the uranyl nitrate system to explore spectroscopic interferences and identify additional species as candidates for online monitoring. This milestone is a demonstration of the potential of this technique, which lies in the ability to simultaneously and directly monitor the chemical process conditions in a reprocessing plant, providing inspectors with another tool to detect nuclear material diversion attempts. Lastly, dry processing of used nuclear fuel is often used as a head-end step before solvent extraction-based separations such as UREX or TRUEX. A non-aqueous process, used fuel treatment by dry processing generally includes chopping of used fuel rods followed by repeated oxidation-reduction cycles and physical separation of the used fuel from the cladding. Thus, dry processing techniques are investigated and opportunities for online monitoring are proposed for continuation of this work in future studies.

Extraction of diffuse correlation spectroscopy flow index by integration of Nth-order linear model with Monte Carlo simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, Yu; Lin, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu

2014-05-12

Conventional semi-infinite solution for extracting blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements may cause errors in estimation of BFI (αD{sub B}) in tissues with small volume and large curvature. We proposed an algorithm integrating Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in tissue for the extraction of αD{sub B}. The volume and geometry of the measured tissue were incorporated in the Monte Carlo simulation, which overcome the semi-infinite restrictions. The algorithm was tested using computer simulations on four tissue models with varied volumes/geometries and applied on an in vivo strokemore » model of mouse. Computer simulations shows that the high-order (N ≥ 5) linear algorithm was more accurate in extracting αD{sub B} (errors < ±2%) from the noise-free DCS data than the semi-infinite solution (errors: −5.3% to −18.0%) for different tissue models. Although adding random noises to DCS data resulted in αD{sub B} variations, the mean values of errors in extracting αD{sub B} were similar to those reconstructed from the noise-free DCS data. In addition, the errors in extracting the relative changes of αD{sub B} using both linear algorithm and semi-infinite solution were fairly small (errors < ±2.0%) and did not rely on the tissue volume/geometry. The experimental results from the in vivo stroke mice agreed with those in simulations, demonstrating the robustness of the linear algorithm. DCS with the high-order linear algorithm shows the potential for the inter-subject comparison and longitudinal monitoring of absolute BFI in a variety of tissues/organs with different volumes/geometries.« less

The effect of arsenic chemical form and mixing regime on arsenic mass transfer from soil to magnetite.

PubMed

Yang, Kyung; Kim, Byung-Chul; Nam, Kyoungphile; Choi, Yongju

2017-03-01

This study investigated the effect of chemical forms of arsenic (As) and soil-magnetite mixing regimes on As mass transfer in magnetite-amended soil. Two soil samples with different component ratios of As chemical forms were prepared. In the absence of magnetite, the amount of desorbable As was strongly dependent on the fraction of easily extractable As in soil. Contact of the soils with magnetite in a slurry phase significantly reduced soil As concentration for both soils. Changes in As concentrations in soil, magnetite, and water by the slurry phase contact were simulated using an As mass transfer model. The model parameters were determined independently for each process of As soil desorption and magnetite sorption. The experimentally measured As mass transfer from soil to magnetite was significantly greater than the simulation result. By sequential extraction, it was observed that the soil As concentration was significantly reduced not only for easily extractable As, but also for relatively strongly bound forms of As. Enclosing the magnetite in a dialysis bag substantially limited the As mass transfer from soil to magnetite. These results suggest that improving the mixture between Fe oxides and soils can facilitate the effectiveness of As stabilization using Fe oxides.

Quantification of groundwater extraction-induced subsidence in the Mekong delta, Vietnam: 3D process-based numerical modeling

NASA Astrophysics Data System (ADS)

Minderhoud, Philip S. J.; Erkens, Gilles; Pham, Hung V.; Bui, Vuong T.; Kooi, Henk; Erban, Laura; Stouthamer, Esther

2017-04-01

The demand for groundwater in the Vietnamese Mekong delta has steadily risen over the past decades. As a result, hydraulic heads in the aquifers dropped on average 0.3-0.7 m/yr-1, potentially causing aquifer-system compaction. At present, the delta is experiencing subsidence rates up to several centimeters per year that outpace global sea level rise by an order of magnitude. However, the exact contribution of groundwater extraction to total subsidence in the delta has not been assessed yet. The objective of our study is to quantify the impact of 25 years of groundwater extraction on subsidence. We built a 3D numerical hydrogeological model comprising the multi-aquifer system of the entire Vietnamese Mekong delta. Groundwater dynamics in the aquifers was simulated over the past quarter-century based on the known extraction history and measured time series of hydraulic head. Subsequently, we calculated corresponding aquifer system compaction using a coupled land subsidence module, which includes a direct, elastic component and a secular, viscous component (i.e. creep). The hydrogeological model is able to reproduce the measured drawdowns in the multi-aquifer system of the past 25 years. Corresponding subsidence rates resulting from aquifer system compaction show a gradual increase over the past two decades to significant annual rates up to several centimeters. Groundwater extraction seems to be a dominant driver of subsidence in the delta, but does not explain the total measured subsidence. This process-based modeling approach can be used to quantify groundwater extraction-induced subsidence for coastal areas and at delta-scale worldwide.

Caffeine Extraction from Raw and Roasted Coffee Beans.

PubMed

Chiang, Donyau; Lin, Chih-Yang; Hu, Chen-Ti; Lee, Sanboh

2018-04-01

Coffee is a stimulant, psychoactive, popular daily beverage, and its caffeine affects human physiological health and behavior. These important issues prompted us to study caffeine extraction from both the raw and roasted coffee beans of 3 types at different temperatures. A hemispheric model is developed to simulate the extraction process of the caffeine from the coffee beans of hemisphere is proposed. The experimental data are in good agreement with the predicted model. The effective diffusivities of caffeine in both the raw and roasted beans increase with temperature in all 3 types. An incubation period, decreasing with increasing temperature, is observed in all samples studied. Caffeine extraction in roasted beans is more rapid than that for the raw beans and the time difference is significant at low temperatures. In both the raw and roasted samples, caffeine diffusion in the raw beans and the incubation behavior are thermally activated processes. Single activation energies are obtained for diffusion within the extraction temperature range for all beans tested with the exception of one type of the coffee beans, Mandheling, which exhibits 2 activation energies in raw samples. The surface energies of the epidermis of the raw beans and roasted beans obtained from the contact angle measurements are used to interpret the difference of incubation periods. This study has a potential application to the decaffeinated coffee industry.Caffeine affects human physiological health and behavior so that caffeine extraction from coffee beans of different types at different temperatures is important for product refining and customers. © 2018 Institute of Food Technologists®.

Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells

PubMed Central

Melianas, Armantas; Etzold, Fabian; Savenije, Tom J.; Laquai, Frédéric; Inganäs, Olle; Kemerink, Martijn

2015-01-01

In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium. PMID:26537357

On the accuracy and precision of numerical waveforms: effect of waveform extraction methodology

NASA Astrophysics Data System (ADS)

Chu, Tony; Fong, Heather; Kumar, Prayush; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilagyi, Bela

2016-08-01

We present a new set of 95 numerical relativity simulations of non-precessing binary black holes (BBHs). The simulations sample comprehensively both black-hole spins up to spin magnitude of 0.9, and cover mass ratios 1-3. The simulations cover on average 24 inspiral orbits, plus merger and ringdown, with low initial orbital eccentricities e\\lt {10}-4. A subset of the simulations extends the coverage of non-spinning BBHs up to mass ratio q = 10. Gravitational waveforms at asymptotic infinity are computed with two independent techniques: extrapolation and Cauchy characteristic extraction. An error analysis based on noise-weighted inner products is performed. We find that numerical truncation error, error due to gravitational wave extraction, and errors due to the Fourier transformation of signals with finite length of the numerical waveforms are of similar magnitude, with gravitational wave extraction errors dominating at noise-weighted mismatches of ˜ 3× {10}-4. This set of waveforms will serve to validate and improve aligned-spin waveform models for gravitational wave science.

Crystallization-assisted nano-lens array fabrication for highly efficient and color stable organic light emitting diodes.

PubMed

Park, Young-Sam; Han, Kyung-Hoon; Kim, Jehan; Cho, Doo-Hee; Lee, Jonghee; Han, Yoonjay; Lim, Jong Tae; Cho, Nam Sung; Yu, Byounggon; Lee, Jeong-Ik; Kim, Jang-Joo

2017-01-07

To date, all deposition equipment has been developed to produce planar films. Thus lens arrays with a lens diameter of <1 mm have been manufactured by combining deposition with other technologies, such as masks, surface treatment, molding etc. Furthermore, a nano-lens array (NLA) with a sufficiently small lens diameter (<1 μm) is necessary to avoid image quality degradation in high resolution displays. In this study, an organic NLA made using a conventional deposition technique - without combining with other techniques - is reported. Very interestingly, grazing-incidence small-angle X-ray scattering (GI-SAXS) experiments indicate that the NLA is formed by the crystallization of organic molecules and the resulting increase in surface tension. The lens diameter can be tuned for use with any kind of light by controlling the process parameters. As an example of their potential applications, we use NLAs as a light extraction film for organic light emitting diodes (OLEDs). The NLA is integrated by directly depositing it on the top electrode of a collection of OLEDs. This is a dry process, meaning that it is fully compatible with the current OLED production process. Devices with NLAs exhibited a light extraction efficiency 1.5 times higher than devices without, which corresponds well with simulation results. The simulations show that this high efficiency is due to the reduction of the guided modes by scattering at the NLA. The NLAs also reduce image blurring, indicating that they increase color stability.

Analysis of roll-stamped light guide plate fabricated with laser-ablated stamper

NASA Astrophysics Data System (ADS)

Na, Hyunjun; Hong, Seokkwan; Kim, Jongsun; Hwang, Jeongho; Joo, Byungyun; Yoon, Kyunghwan; Kang, Jeongjin

2017-12-01

LGP (light guide plate) is one of the major components of LCD (liquid crystal display), and it makes surface illumination for LCD backlit. LGP is a transparent plastic plate usually produced by injection molding process. On the back of LGP there are micron size patterns for extraction of light. Recently a roll-stamping process has achieved the high mass productivity of thinner LGPs. In order to fabricate optical patterns on LGPs, a fabricating tool called as a stamper is used. Micro patterns on metallic stampers are made by several micro machining processes such as chemical etching, LIGA-reflow, and laser ablation. In this study, a roll-stamping process by using a laser ablated metallic stamper was dealt with in consideration of the compatibility with the roll-stamping process. LGP fabricating tests were performed using a roll-stamping process with four different roll pressures. Pattern shapes on the stamper fabricated by laser ablation and transcription ratios of the roll-stamping process were analyzed, and LGP luminance was evaluated. Based on the evaluation, optical simulation model for LGP was made and simulation accuracy was evaluated. Simulation results showed good agreements with optical performance of LGPs in the brightness and uniformity. It was also shown that the roll-stamped LGP has the possibility of better optical performance than the conventional injection molded LGP. It was also shown that the roll-stamped LGP with the laser ablated stamper is potential to have better optical performance than the conventional injection molded LGP.

Extended morphological processing: a practical method for automatic spot detection of biological markers from microscopic images.

PubMed

Kimori, Yoshitaka; Baba, Norio; Morone, Nobuhiro

2010-07-08

A reliable extraction technique for resolving multiple spots in light or electron microscopic images is essential in investigations of the spatial distribution and dynamics of specific proteins inside cells and tissues. Currently, automatic spot extraction and characterization in complex microscopic images poses many challenges to conventional image processing methods. A new method to extract closely located, small target spots from biological images is proposed. This method starts with a simple but practical operation based on the extended morphological top-hat transformation to subtract an uneven background. The core of our novel approach is the following: first, the original image is rotated in an arbitrary direction and each rotated image is opened with a single straight line-segment structuring element. Second, the opened images are unified and then subtracted from the original image. To evaluate these procedures, model images of simulated spots with closely located targets were created and the efficacy of our method was compared to that of conventional morphological filtering methods. The results showed the better performance of our method. The spots of real microscope images can be quantified to confirm that the method is applicable in a given practice. Our method achieved effective spot extraction under various image conditions, including aggregated target spots, poor signal-to-noise ratio, and large variations in the background intensity. Furthermore, it has no restrictions with respect to the shape of the extracted spots. The features of our method allow its broad application in biological and biomedical image information analysis.

A data-driven multiplicative fault diagnosis approach for automation processes.

PubMed

Hao, Haiyang; Zhang, Kai; Ding, Steven X; Chen, Zhiwen; Lei, Yaguo

2014-09-01

This paper presents a new data-driven method for diagnosing multiplicative key performance degradation in automation processes. Different from the well-established additive fault diagnosis approaches, the proposed method aims at identifying those low-level components which increase the variability of process variables and cause performance degradation. Based on process data, features of multiplicative fault are extracted. To identify the root cause, the impact of fault on each process variable is evaluated in the sense of contribution to performance degradation. Then, a numerical example is used to illustrate the functionalities of the method and Monte-Carlo simulation is performed to demonstrate the effectiveness from the statistical viewpoint. Finally, to show the practical applicability, a case study on the Tennessee Eastman process is presented. Copyright © 2013. Published by Elsevier Ltd.

Multiphase flow predictions from carbonate pore space images using extracted network models

NASA Astrophysics Data System (ADS)

Al-Kharusi, Anwar S.; Blunt, Martin J.

2008-06-01

A methodology to extract networks from pore space images is used to make predictions of multiphase transport properties for subsurface carbonate samples. The extraction of the network model is based on the computation of the location and sizes of pores and throats to create a topological representation of the void space of three-dimensional (3-D) rock images, using the concept of maximal balls. In this work, we follow a multistaged workflow. We start with a 2-D thin-section image; convert it statistically into a 3-D representation of the pore space; extract a network model from this image; and finally, simulate primary drainage, waterflooding, and secondary drainage flow processes using a pore-scale simulator. We test this workflow for a reservoir carbonate rock. The network-predicted absolute permeability is similar to the core plug measured value and the value computed on the 3-D void space image using the lattice Boltzmann method. The predicted capillary pressure during primary drainage agrees well with a mercury-air experiment on a core sample, indicating that we have an adequate representation of the rock's pore structure. We adjust the contact angles in the network to match the measured waterflood and secondary drainage capillary pressures. We infer a significant degree of contact angle hysteresis. We then predict relative permeabilities for primary drainage, waterflooding, and secondary drainage that agree well with laboratory measured values. This approach can be used to predict multiphase transport properties when wettability and pore structure vary in a reservoir, where experimental data is scant or missing. There are shortfalls to this approach, however. We compare results from three networks, one of which was derived from a section of the rock containing vugs. Our method fails to predict properties reliably when an unrepresentative image is processed to construct the 3-D network model. This occurs when the image volume is not sufficient to represent the geological variations observed in a core plug sample.

Interactive visualization to advance earthquake simulation

USGS Publications Warehouse

Kellogg, L.H.; Bawden, G.W.; Bernardin, T.; Billen, M.; Cowgill, E.; Hamann, B.; Jadamec, M.; Kreylos, O.; Staadt, O.; Sumner, D.

2008-01-01

The geological sciences are challenged to manage and interpret increasing volumes of data as observations and simulations increase in size and complexity. For example, simulations of earthquake-related processes typically generate complex, time-varying data sets in two or more dimensions. To facilitate interpretation and analysis of these data sets, evaluate the underlying models, and to drive future calculations, we have developed methods of interactive visualization with a special focus on using immersive virtual reality (VR) environments to interact with models of Earth's surface and interior. Virtual mapping tools allow virtual "field studies" in inaccessible regions. Interactive tools allow us to manipulate shapes in order to construct models of geological features for geodynamic models, while feature extraction tools support quantitative measurement of structures that emerge from numerical simulation or field observations, thereby enabling us to improve our interpretation of the dynamical processes that drive earthquakes. VR has traditionally been used primarily as a presentation tool, albeit with active navigation through data. Reaping the full intellectual benefits of immersive VR as a tool for scientific analysis requires building on the method's strengths, that is, using both 3D perception and interaction with observed or simulated data. This approach also takes advantage of the specialized skills of geological scientists who are trained to interpret, the often limited, geological and geophysical data available from field observations. ?? Birkhaueser 2008.

Thermodynamics of coupled protein adsorption and stability using hybrid Monte Carlo simulations.

PubMed

Zhong, Ellen D; Shirts, Michael R

2014-05-06

A better understanding of changes in protein stability upon adsorption can improve the design of protein separation processes. In this study, we examine the coupling of the folding and the adsorption of a model protein, the B1 domain of streptococcal protein G, as a function of surface attraction using a hybrid Monte Carlo (HMC) approach with temperature replica exchange and umbrella sampling. In our HMC implementation, we are able to use a molecular dynamics (MD) time step that is an order of magnitude larger than in a traditional MD simulation protocol and observe a factor of 2 enhancement in the folding and unfolding rate. To demonstrate the convergence of our systems, we measure the travel of our order parameter the fraction of native contacts between folded and unfolded states throughout the length of our simulations. Thermodynamic quantities are extracted with minimum statistical variance using multistate reweighting between simulations at different temperatures and harmonic distance restraints from the surface. The resultant free energies, enthalpies, and entropies of the coupled unfolding and absorption processes are in qualitative agreement with previous experimental and computational observations, including entropic stabilization of the adsorbed, folded state relative to the bulk on surfaces with low attraction.

Preliminary investigation of groundwater flow and trichloroethene transport in the Surficial Aquifer System, Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota

USGS Publications Warehouse

King, Jeffrey N.; Davis, J. Hal

2016-05-16

The August 20, 2001, groundwater flow model simulator and the 2001 trichloroethene transport simulator were applied to a groundwater extraction and treatment system that existed in 2011. Furnished trichloroethene source areas and concentrations in the 2001 simulator were replaced with different, furnished, hypothetical source areas and concentrations. Forcing in 2001 was replaced with forcing in 2011. No trichloroethene concentrations greater than 3 µg/L were simulated as discharging to the Mississippi River during applications of the 2001 simulator to the 2011 groundwater extraction and treatment system. These applications were not intended to represent historical conditions. Differences between furnished and actual trichloroethene sources may explain differences between measurements and simulation results for the 2001 trichloroethene transport simulator. Causes of differences between furnished and actual trichloroethene sources may cause differences between hypothetical application results and the performance of the actual U.S. Department of the Navy groundwater extraction and treatment system at the Naval Industrial Reserve Ordnance Plant. Other limitations may also cause differences between application results and performance.

Engineering workstation: Sensor modeling

NASA Technical Reports Server (NTRS)

Pavel, M; Sweet, B.

1993-01-01

The purpose of the engineering workstation is to provide an environment for rapid prototyping and evaluation of fusion and image processing algorithms. Ideally, the algorithms are designed to optimize the extraction of information that is useful to a pilot for all phases of flight operations. Successful design of effective fusion algorithms depends on the ability to characterize both the information available from the sensors and the information useful to a pilot. The workstation is comprised of subsystems for simulation of sensor-generated images, image processing, image enhancement, and fusion algorithms. As such, the workstation can be used to implement and evaluate both short-term solutions and long-term solutions. The short-term solutions are being developed to enhance a pilot's situational awareness by providing information in addition to his direct vision. The long term solutions are aimed at the development of complete synthetic vision systems. One of the important functions of the engineering workstation is to simulate the images that would be generated by the sensors. The simulation system is designed to use the graphics modeling and rendering capabilities of various workstations manufactured by Silicon Graphics Inc. The workstation simulates various aspects of the sensor-generated images arising from phenomenology of the sensors. In addition, the workstation can be used to simulate a variety of impairments due to mechanical limitations of the sensor placement and due to the motion of the airplane. Although the simulation is currently not performed in real-time, sequences of individual frames can be processed, stored, and recorded in a video format. In that way, it is possible to examine the appearance of different dynamic sensor-generated and fused images.

Combined endeavor of Neutrosophic Set and Chan-Vese model to extract accurate liver image from CT scan.

PubMed

Siri, Sangeeta K; Latte, Mrityunjaya V

2017-11-01

Many different diseases can occur in the liver, including infections such as hepatitis, cirrhosis, cancer and over effect of medication or toxins. The foremost stage for computer-aided diagnosis of liver is the identification of liver region. Liver segmentation algorithms extract liver image from scan images which helps in virtual surgery simulation, speedup the diagnosis, accurate investigation and surgery planning. The existing liver segmentation algorithms try to extort exact liver image from abdominal Computed Tomography (CT) scan images. It is an open problem because of ambiguous boundaries, large variation in intensity distribution, variability of liver geometry from patient to patient and presence of noise. A novel approach is proposed to meet challenges in extracting the exact liver image from abdominal CT scan images. The proposed approach consists of three phases: (1) Pre-processing (2) CT scan image transformation to Neutrosophic Set (NS) and (3) Post-processing. In pre-processing, the noise is removed by median filter. The "new structure" is designed to transform a CT scan image into neutrosophic domain which is expressed using three membership subset: True subset (T), False subset (F) and Indeterminacy subset (I). This transform approximately extracts the liver image structure. In post processing phase, morphological operation is performed on indeterminacy subset (I) and apply Chan-Vese (C-V) model with detection of initial contour within liver without user intervention. This resulted in liver boundary identification with high accuracy. Experiments show that, the proposed method is effective, robust and comparable with existing algorithm for liver segmentation of CT scan images. Copyright © 2017 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu

Conventional semi-infinite analytical solutions of correlation diffusion equation may lead to errors when calculating blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements in tissues with irregular geometries. Very recently, we created an algorithm integrating a Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in homogenous tissues with arbitrary geometries for extraction of BFI (i.e., αD{sub B}). The purpose of this study is to extend the capability of the Nth-order linear algorithm for extracting BFI in heterogeneous tissues with arbitrary geometries. The previous linear algorithm was modified to extract BFIs in different typesmore » of tissues simultaneously through utilizing DCS data at multiple source-detector separations. We compared the proposed linear algorithm with the semi-infinite homogenous solution in a computer model of adult head with heterogeneous tissue layers of scalp, skull, cerebrospinal fluid, and brain. To test the capability of the linear algorithm for extracting relative changes of cerebral blood flow (rCBF) in deep brain, we assigned ten levels of αD{sub B} in the brain layer with a step decrement of 10% while maintaining αD{sub B} values constant in other layers. Simulation results demonstrate the accuracy (errors < 3%) of high-order (N ≥ 5) linear algorithm in extracting BFIs in different tissue layers and rCBF in deep brain. By contrast, the semi-infinite homogenous solution resulted in substantial errors in rCBF (34.5% ≤ errors ≤ 60.2%) and BFIs in different layers. The Nth-order linear model simplifies data analysis, thus allowing for online data processing and displaying. Future study will test this linear algorithm in heterogeneous tissues with different levels of blood flow variations and noises.« less

Metals and Oxygen Mining from Meteorites, Asteroids and Planets using Reusable Ionic Liquids

NASA Technical Reports Server (NTRS)

Karr, Laurel J.; Paley, Mark S.; Marone, Matthew J.; Kaukler, William F.; Curreri, Peter A.

2012-01-01

In order for humans to explore beyond Low Earth Orbit both safely and economically, it will be essential to learn how to make use of in situ materials and energy in an environment much different than on earth. Precursor robotic missions will be necessary to determine what resources will be available and to demonstrate the capabilities for their use. To that end, we have recently been studying acidic Ionic Liquid (IL) systems for use in a low temperature (< 200 C) process to solubilize regolith, and to extract, as water, the oxygen available in metal oxides. Using this method, we have solubilized lunar regolith simulant (JSC-1A), as well as extraterrestrial materials in the form of meteorites, and have extracted up to 80% of the available oxygen. Moreover, by using a hydrogen gas electrode, we have shown that the IL can be regenerated at the anode and metals (e.g. iron) can be plated onto the cathode. These results indicate that IL processing is an excellent candidate for extracting oxygen in situ, for life support and propulsion, and for extracting metals to be used as feedstock in fabrication processes. We have obtained small amounts of meteorite materials believed by meteoriticists to have originated from our moon, Mars, and the asteroid Vesta, and were able to solubilize those using acidic IL systems. From the Vesta meteorite, we were able to extract about 60% of the available oxygen as water. As far as is known, this is the first time that extraterrestrial/earth hybrid water has been obtained. NMR analysis provided proof that the liquid retrieved is indeed water. We have also been able to electro-plate nickel and iron contained in meteorite material. By varying voltage they can be plated separately (electro-winning), and we plan to soon have sufficient quantities to form usable parts utilizing the additive manufacturing process.

Simulated Leaching (Migration) Study for a Model Container-Closure System Applicable to Parenteral and Ophthalmic Drug Products.

PubMed

Jenke, Dennis; Egert, Thomas; Hendricker, Alan; Castner, James; Feinberg, Tom; Houston, Christopher; Hunt, Desmond G; Lynch, Michael; Nicholas, Kumudini; Norwood, Daniel L; Paskiet, Diane; Ruberto, Michael; Smith, Edward J; Holcomb, Frank; Markovic, Ingrid

2017-01-01

A simulating leaching (migration) study was performed on a model container-closure system relevant to parenteral and ophthalmic drug products. This container-closure system consisted of a linear low-density polyethylene bottle (primary container), a polypropylene cap and an elastomeric cap liner (closure), an adhesive label (labeling), and a foil overpouch (secondary container). The bottles were filled with simulating solvents (aqueous salt/acid mixture at pH 2.5, aqueous buffer at pH 9.5, and 1/1 v/v isopropanol/water), a label was affixed to the filled and capped bottles, the filled bottles were placed into the foil overpouch, and the filled and pouched units were stored either upright or inverted for up to 6 months at 40 °C. After storage, the leaching solutions were tested for leached substances using multiple complementary analytical techniques to address volatile, semi-volatile, and non-volatile organic and inorganic extractables as potential leachables.The leaching data generated supported several conclusions, including that (1) the extractables (leachables) profile revealed by a simulating leaching study can qualitatively be correlated with compositional information for materials of construction, (2) the chemical nature of both the extracting medium and the individual extractables (leachables) can markedly affect the resulting profile, and (3) while direct contact between a drug product and a system's material of construction may exacerbate the leaching of substances from that material by the drug product, direct contact is not a prerequisite for migration and leaching to occur. LAY ABSTRACT: The migration of container-related extractables from a model pharmaceutical container-closure system and into simulated drug product solutions was studied, focusing on circumstances relevant to parenteral and ophthalmic drug products. The model system was constructed specifically to address the migration of extractables from labels applied to the outside of the primary container. The study demonstrated that (1) the extractables that do migrate can be correlated to the composition of the materials used to construct the container-closure systems, (2) the extent of migration is affected by the chemical nature of the simulating solutions and the extractables themselves, and (3) even though labels may not be in direct contact with a contained solution, label-related extractables can accumulate as leachables in those solutions. © PDA, Inc. 2017.

Ozone photochemistry in an oil and natural gas extraction region during winter: simulations of a snow-free season in the Uintah Basin, Utah

NASA Astrophysics Data System (ADS)

Edwards, P. M.; Young, C. J.; Aikin, K.; deGouw, J. A.; Dubé, W. P.; Geiger, F.; Gilman, J. B.; Helmig, D.; Holloway, J. S.; Kercher, J.; Lerner, B.; Martin, R.; McLaren, R.; Parrish, D. D.; Peischl, J.; Roberts, J. M.; Ryerson, T. B.; Thornton, J.; Warneke, C.; Williams, E. J.; Brown, S. S.

2013-03-01

The Uintah Basin in northeastern Utah, a region of intense oil and gas extraction, experienced ozone (O3) concentrations above levels harmful to human health for multiple days during the winters of 2009-2010 and 2010-2011. These wintertime O3 pollution episodes occur during cold, stable periods when the ground is snowcovered, and have been linked to emissions from the oil and gas extraction process. The Uintah Basin Winter Ozone Study (UBWOS) was a field intensive in early 2012, whose goal was to address current uncertainties in the chemical and physical processes that drive wintertime O3 production in regions of oil and gas development. Although elevated O3 concentrations were not observed during the winter of 2011-2012, the comprehensive set of observations tests of our understanding of O3 photochemistry in this unusual emissions environment. A box model, constrained to the observations and using the explicit Master Chemical Mechanism (MCM) V3.2 chemistry scheme, has been used to investigate the sensitivities of O3 production during UBWOS 2012. Simulations identify the O3 production photochemistry to be highly radical limited. Production of OH from O3 photolysis (through reaction of O(1D) with water vapor) contributed only 170 pptv day-1, 8% of the total primary radical source on average. Other radical sources, including the photolysis of formaldehyde (HCHO, 52%), nitrous acid (HONO, 26%), and nitryl chloride (ClNO2, 13%) were larger. O3 production was also found to be highly sensitive to aromatic volatile organic compound (VOC) concentrations, due to radical amplification reactions in the oxidation scheme of these species. Radical production was shown to be small in comparison to the emissions of nitrogen oxides (NOx), such that NOx acted as the primary radical sink. Consequently, the system was highly VOC sensitive, despite the much larger mixing ratio of total non-methane hydrocarbons (230 ppbv (2080 ppbC), 6 week average) relative to NOx (5.6 ppbv average). However, the importance of radical sources which are themselves derived from NOx emissions and chemistry, such as ClNO2 and HONO, make the response of the system to changes in NOx emissions uncertain. These box model simulations provide useful insight into the chemistry controlling winter O3 production in regions of oil and gas extraction.

Neurophysiological mechanisms involved in language learning in adults

PubMed Central

Rodríguez-Fornells, Antoni; Cunillera, Toni; Mestres-Missé, Anna; de Diego-Balaguer, Ruth

2009-01-01

Little is known about the brain mechanisms involved in word learning during infancy and in second language acquisition and about the way these new words become stable representations that sustain language processing. In several studies we have adopted the human simulation perspective, studying the effects of brain-lesions and combining different neuroimaging techniques such as event-related potentials and functional magnetic resonance imaging in order to examine the language learning (LL) process. In the present article, we review this evidence focusing on how different brain signatures relate to (i) the extraction of words from speech, (ii) the discovery of their embedded grammatical structure, and (iii) how meaning derived from verbal contexts can inform us about the cognitive mechanisms underlying the learning process. We compile these findings and frame them into an integrative neurophysiological model that tries to delineate the major neural networks that might be involved in the initial stages of LL. Finally, we propose that LL simulations can help us to understand natural language processing and how the recovery from language disorders in infants and adults can be accomplished. PMID:19933142

Processing of glass-ceramics from lunar resources

NASA Technical Reports Server (NTRS)

Fabes, B. D.; Poisl, W. H.

1991-01-01

The goal is to fabricate useful ceramic materials from the by-products of lunar oxygen production processes. Specifically, the crystal nucleation and growth kinetics of ilmenite-extracted lunar regolith were studied in order to produce glass-ceramics with optimal mechanical, thermal, and abrasion resistant properties. In the initial year of the program, construction and calibration of a high temperature viscometer, used for determining the viscosity of simulated lunar glasses was finished. A series of lunar simulants were also prepared, and the viscosity of each was determined over a range of temperatures. It was found that an increase in the concentration of Fe2O3 decreases the viscosity of the glass. While this may be helpful in processing the glass, Fe2O3 concentrations greater than approximately 10 wt percent resulted in uncontrolled crystallization during viscosity measurements. Impurities (such as Na2O, MnO, and K2O) in the regolith appeared to decrease the viscosity of the parent glass. These effects, as well as those of TiO2 and SiO2 on the processability of the glass, however, remain to be quantified.

a Probability-Based Statistical Method to Extract Water Body of TM Images with Missing Information

NASA Astrophysics Data System (ADS)

Lian, Shizhong; Chen, Jiangping; Luo, Minghai

2016-06-01

Water information cannot be accurately extracted using TM images because true information is lost in some images because of blocking clouds and missing data stripes, thereby water information cannot be accurately extracted. Water is continuously distributed in natural conditions; thus, this paper proposed a new method of water body extraction based on probability statistics to improve the accuracy of water information extraction of TM images with missing information. Different disturbing information of clouds and missing data stripes are simulated. Water information is extracted using global histogram matching, local histogram matching, and the probability-based statistical method in the simulated images. Experiments show that smaller Areal Error and higher Boundary Recall can be obtained using this method compared with the conventional methods.

An adaptive unsaturated bistable stochastic resonance method and its application in mechanical fault diagnosis

NASA Astrophysics Data System (ADS)

Qiao, Zijian; Lei, Yaguo; Lin, Jing; Jia, Feng

2017-02-01

In mechanical fault diagnosis, most traditional methods for signal processing attempt to suppress or cancel noise imbedded in vibration signals for extracting weak fault characteristics, whereas stochastic resonance (SR), as a potential tool for signal processing, is able to utilize the noise to enhance fault characteristics. The classical bistable SR (CBSR), as one of the most widely used SR methods, however, has the disadvantage of inherent output saturation. The output saturation not only reduces the output signal-to-noise ratio (SNR) but also limits the enhancement capability for fault characteristics. To overcome this shortcoming, a novel method is proposed to extract the fault characteristics, where a piecewise bistable potential model is established. Simulated signals are used to illustrate the effectiveness of the proposed method, and the results show that the method is able to extract weak fault characteristics and has good enhancement performance and anti-noise capability. Finally, the method is applied to fault diagnosis of bearings and planetary gearboxes, respectively. The diagnosis results demonstrate that the proposed method can obtain larger output SNR, higher spectrum peaks at fault characteristic frequencies and therefore larger recognizable degree than the CBSR method.

Telerobotic Surgery: An Intelligent Systems Approach to Mitigate the Adverse Effects of Communication Delay. Chapter 4

NASA Technical Reports Server (NTRS)

Cardullo, Frank M.; Lewis, Harold W., III; Panfilov, Peter B.

2007-01-01

An extremely innovative approach has been presented, which is to have the surgeon operate through a simulator running in real-time enhanced with an intelligent controller component to enhance the safety and efficiency of a remotely conducted operation. The use of a simulator enables the surgeon to operate in a virtual environment free from the impediments of telecommunication delay. The simulator functions as a predictor and periodically the simulator state is corrected with truth data. Three major research areas must be explored in order to ensure achieving the objectives. They are: simulator as predictor, image processing, and intelligent control. Each is equally necessary for success of the project and each of these involves a significant intelligent component in it. These are diverse, interdisciplinary areas of investigation, thereby requiring a highly coordinated effort by all the members of our team, to ensure an integrated system. The following is a brief discussion of those areas. Simulator as a predictor: The delays encountered in remote robotic surgery will be greater than any encountered in human-machine systems analysis, with the possible exception of remote operations in space. Therefore, novel compensation techniques will be developed. Included will be the development of the real-time simulator, which is at the heart of our approach. The simulator will present real-time, stereoscopic images and artificial haptic stimuli to the surgeon. Image processing: Because of the delay and the possibility of insufficient bandwidth a high level of novel image processing is necessary. This image processing will include several innovative aspects, including image interpretation, video to graphical conversion, texture extraction, geometric processing, image compression and image generation at the surgeon station. Intelligent control: Since the approach we propose is in a sense predictor based, albeit a very sophisticated predictor, a controller, which not only optimizes end effector trajectory but also avoids error, is essential. We propose to investigate two different approaches to the controller design. One approach employs an optimal controller based on modern control theory; the other one involves soft computing techniques, i.e. fuzzy logic, neural networks, genetic algorithms and hybrids of these.

Unsupervised Detection of Planetary Craters by a Marked Point Process

NASA Technical Reports Server (NTRS)

Troglio, G.; Benediktsson, J. A.; Le Moigne, J.; Moser, G.; Serpico, S. B.

2011-01-01

With the launch of several planetary missions in the last decade, a large amount of planetary images is being acquired. Preferably, automatic and robust processing techniques need to be used for data analysis because of the huge amount of the acquired data. Here, the aim is to achieve a robust and general methodology for crater detection. A novel technique based on a marked point process is proposed. First, the contours in the image are extracted. The object boundaries are modeled as a configuration of an unknown number of random ellipses, i.e., the contour image is considered as a realization of a marked point process. Then, an energy function is defined, containing both an a priori energy and a likelihood term. The global minimum of this function is estimated by using reversible jump Monte-Carlo Markov chain dynamics and a simulated annealing scheme. The main idea behind marked point processes is to model objects within a stochastic framework: Marked point processes represent a very promising current approach in the stochastic image modeling and provide a powerful and methodologically rigorous framework to efficiently map and detect objects and structures in an image with an excellent robustness to noise. The proposed method for crater detection has several feasible applications. One such application area is image registration by matching the extracted features.

Singular Spectrum Analysis for Astronomical Time Series: Constructing a Parsimonious Hypothesis Test

NASA Astrophysics Data System (ADS)

Greco, G.; Kondrashov, D.; Kobayashi, S.; Ghil, M.; Branchesi, M.; Guidorzi, C.; Stratta, G.; Ciszak, M.; Marino, F.; Ortolan, A.

We present a data-adaptive spectral method - Monte Carlo Singular Spectrum Analysis (MC-SSA) - and its modification to tackle astrophysical problems. Through numerical simulations we show the ability of the MC-SSA in dealing with 1/f β power-law noise affected by photon counting statistics. Such noise process is simulated by a first-order autoregressive, AR(1) process corrupted by intrinsic Poisson noise. In doing so, we statistically estimate a basic stochastic variation of the source and the corresponding fluctuations due to the quantum nature of light. In addition, MC-SSA test retains its effectiveness even when a significant percentage of the signal falls below a certain level of detection, e.g., caused by the instrument sensitivity. The parsimonious approach presented here may be broadly applied, from the search for extrasolar planets to the extraction of low-intensity coherent phenomena probably hidden in high energy transients.

Python Open source Waveform ExtractoR (POWER): an open source, Python package to monitor and post-process numerical relativity simulations

NASA Astrophysics Data System (ADS)

Johnson, Daniel; Huerta, E. A.; Haas, Roland

2018-01-01

Numerical simulations of Einstein’s field equations provide unique insights into the physics of compact objects moving at relativistic speeds, and which are driven by strong gravitational interactions. Numerical relativity has played a key role to firmly establish gravitational wave astrophysics as a new field of research, and it is now paving the way to establish whether gravitational wave radiation emitted from compact binary mergers is accompanied by electromagnetic and astro-particle counterparts. As numerical relativity continues to blend in with routine gravitational wave data analyses to validate the discovery of gravitational wave events, it is essential to develop open source tools to streamline these studies. Motivated by our own experience as users and developers of the open source, community software, the Einstein Toolkit, we present an open source, Python package that is ideally suited to monitor and post-process the data products of numerical relativity simulations, and compute the gravitational wave strain at future null infinity in high performance environments. We showcase the application of this new package to post-process a large numerical relativity catalog and extract higher-order waveform modes from numerical relativity simulations of eccentric binary black hole mergers and neutron star mergers. This new software fills a critical void in the arsenal of tools provided by the Einstein Toolkit consortium to the numerical relativity community.

Modeling of rotating disc contactor (RDC) column

NASA Astrophysics Data System (ADS)

Ismail, Wan Nurul Aiffah; Zakaria, Siti Aisyah; Noor, Nor Fashihah Mohd; Sulong, Ibrahim; Arshad, Khairil Anuar

2014-12-01

Liquid-liquid extraction is one of the most important separation processes. Different kinds of liquid-liquid extractor such as Rotating Disc Contactor (RDC) Column being used in industries. The study of liquid-liquid extraction in an RDC column has become a very important subject to be discussed not just among chemical engineers but mathematician as well. In this research, the modeling of small diameter RDC column using the chemical system involving cumene/isobutryric asid/water are analyzed by the method of Artificial Neural Network (ANN). In the previous research, we begin the process of analyzed the data using methods of design of the experiments (DOE) to identify which factor and their interaction factor are significant and to determine the percentage of contribution of the variance for each factor. From the result obtained, we continue the research by discussed the development and validation of an artificial neural network model in estimating the concentration of continuous and concentration of dispersed outlet for an RDC column. It is expected that an efficient and reliable model will be formed to predict RDC column performance as an alternative to speed up the simulation process.

Correlation of heat transfer coefficient in quenching process using ABAQUS

NASA Astrophysics Data System (ADS)

Davare, Sandeep Kedarnath; Balachandran, G.; Singh, R. K. P.

2018-04-01

During the heat treatment by quenching in a liquid medium the convective heat transfer coefficient plays a crucial role in the extraction of heat. The heat extraction ultimately influences the cooling rate and hence the hardness and mechanical properties. A Finite Element analysis of quenching a simple flat copper sample with different orientation of sample and with different quenchant temperatures were carried out to check and verify the results obtained from the experiments. The heat transfer coefficient (HTC) was calculated from temperature history in a simple flat copper disc sample experimentally. This HTC data was further used as input to simulation software and the cooling curves were back calculated. The results obtained from software and using experimentation shows nearly consistent values.

Terrain-driven unstructured mesh development through semi-automatic vertical feature extraction

NASA Astrophysics Data System (ADS)

Bilskie, Matthew V.; Coggin, David; Hagen, Scott C.; Medeiros, Stephen C.

2015-12-01

A semi-automated vertical feature terrain extraction algorithm is described and applied to a two-dimensional, depth-integrated, shallow water equation inundation model. The extracted features describe what are commonly sub-mesh scale elevation details (ridge and valleys), which may be ignored in standard practice because adequate mesh resolution cannot be afforded. The extraction algorithm is semi-automated, requires minimal human intervention, and is reproducible. A lidar-derived digital elevation model (DEM) of coastal Mississippi and Alabama serves as the source data for the vertical feature extraction. Unstructured mesh nodes and element edges are aligned to the vertical features and an interpolation algorithm aimed at minimizing topographic elevation error assigns elevations to mesh nodes via the DEM. The end result is a mesh that accurately represents the bare earth surface as derived from lidar with element resolution in the floodplain ranging from 15 m to 200 m. To examine the influence of the inclusion of vertical features on overland flooding, two additional meshes were developed, one without crest elevations of the features and another with vertical features withheld. All three meshes were incorporated into a SWAN+ADCIRC model simulation of Hurricane Katrina. Each of the three models resulted in similar validation statistics when compared to observed time-series water levels at gages and post-storm collected high water marks. Simulated water level peaks yielded an R2 of 0.97 and upper and lower 95% confidence interval of ∼ ± 0.60 m. From the validation at the gages and HWM locations, it was not clear which of the three model experiments performed best in terms of accuracy. Examination of inundation extent among the three model results were compared to debris lines derived from NOAA post-event aerial imagery, and the mesh including vertical features showed higher accuracy. The comparison of model results to debris lines demonstrates that additional validation techniques are necessary for state-of-the-art flood inundation models. In addition, the semi-automated, unstructured mesh generation process presented herein increases the overall accuracy of simulated storm surge across the floodplain without reliance on hand digitization or sacrificing computational cost.

Simulation of Helium-3 Extraction from Lunar Ilmenite

NASA Technical Reports Server (NTRS)

Kuhlman, K. R.; Kulcinski, G. L.; Schmitt, H. H.

2004-01-01

Knowledge of the trapping mechanisms and diffusion characteristics of solar-wind implanted isotopes in the minerals of the lunar regolith will enable the optimization of the processes to extract solar wind gases from regolith particles. Extraction parameters include the temperature and duration of extraction, particle size, and gas yield. Diffusion data will increase the efficiency and profitability of future mining ventures. This data will also assist in optimizing the evaluations of various potential mining sites based on remote sensing data. For instance, if magnesian ilmenite (Mg,Fel.,Ti03) is found to retain He better than stoichiometric ilmenite (FeTi03), remote sensing data for Mg could be considered in addition to Ti and maturity data. The context of the currently discussed work is the mining of helium-3 for potential use as a fuel for fusion energy generation. However, the potential resources deposited by the solar wind include hydrogen (and derived water), helium-4, nitrogen and carbon. Implantation experiments such as those performed for helium isotopes in ilmenite are important for the optimized extraction of these additional resources. These experiments can easily be reproduced for most elements or isotopes of interest.

Simultaneous Separation of Manganese, Cobalt, and Nickel by the Organic-Aqueous-Aqueous Three-Phase Solvent Extraction

NASA Astrophysics Data System (ADS)

Shirayama, Sakae; Uda, Tetsuya

2016-04-01

This research outlines an organic-aqueous-aqueous three-phase solvent extraction method and proposes its use in a new metal separation process for the recycling of manganese (Mn), cobalt (Co), and nickel (Ni) from used lithium ion batteries (LIBs). The three-phase system was formed by mixing xylene organic solution, 50 pct polyethylene glycol (PEG) aqueous solution, and 1 mol L-1 sodium sulfate (Na2SO4) aqueous solution. The xylene organic solution contained 2-ethylhexylphosphonic acid (D2EHPA) as an extractant for Mn ion, and the Na2SO4 aqueous solution contained 1 mol L-1 potassium thiocyanate (KSCN) as an extractant for Co ion. Concentrations of the metal ions were varied by dissolving metal sulfates in the Na2SO4 aqueous solution. As a result of the experiments, Mn, Co, and Ni ions were distributed in the xylene organic phase, PEG-rich aqueous phase, and Na2SO4-rich aqueous phase, respectively. The separation was effective when the pH value was around 4. Numerical simulation was also conducted in order to predict the distribution of metal ions after the multi-stage counter-current extractions.

Manufacture of Lunar Regolith Simulants

NASA Technical Reports Server (NTRS)

Rickman, D. L.; Wilson, S. A.; Stoeser, D. B.; Weinstein, M. A.; Edmunson, J. E.

2013-01-01

The manufacture of lunar regolith simulants can use many technologies unfamiliar to the aerospace industry. Many of these technologies are extensively used in the mining industry. Rock crushing, grinding, process control as a function of particle size, as well as other essential concepts are explained here. Notes are provided on special considerations necessary, given the unusual nature of the desired final product. For example, wet grinding, which is an industry norm, can alter the behavior of simulant materials. As the geologic materials used for simulants can contain minerals such as quartz and pyrite, guidance is provided regarding concepts, risks, measurement, and handling. Extractive metallurgy can be used to produce high-grade components for subsequent manufacture, reducing the compromises inherent in using just rock. Several of the components needed in simulants such as glasses, agglutinates, and breccias are simply not available or not reasonably matched by existing terrestrial resources. Therefore, techniques to produce these in useful quantities were developed and used. Included in this list is the synthesis of specific minerals. The manufacture of two simulants, NU-LHT-1M and NU-LHT-2M, is covered in detail.

Characterization and modeling of radiation effects NASA/MSFC semiconductor devices

NASA Technical Reports Server (NTRS)

Kerns, D. V., Jr.; Cook, K. B., Jr.

1978-01-01

A literature review of the near-Earth trapped radiation of the Van Allen Belts, the radiation within the solar system resulting from the solar wind, and the cosmic radiation levels of deep space showed that a reasonable simulation of space radiation, particularly the Earth orbital environment, could be simulated in the laboratory by proton bombardment. A 3 MeV proton accelerator was used to irradiate CMOS integrated circuits fabricated from three different processes. The drain current and output voltage for three inverters was recorded as the input voltage was swept from zero to ten volts after each successive irradiation. Device parameters were extracted. Possible damage mechanisms are discussed and recommendations for improved radiation hardness are suggested.

Modeling DNP3 Traffic Characteristics of Field Devices in SCADA Systems of the Smart Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Cheng, Liang; Chuah, Mooi Choo

In the generation, transmission, and distribution sectors of the smart grid, intelligence of field devices is realized by programmable logic controllers (PLCs). Many smart-grid subsystems are essentially cyber-physical energy systems (CPES): For instance, the power system process (i.e., the physical part) within a substation is monitored and controlled by a SCADA network with hosts running miscellaneous applications (i.e., the cyber part). To study the interactions between the cyber and physical components of a CPES, several co-simulation platforms have been proposed. However, the network simulators/emulators of these platforms do not include a detailed traffic model that takes into account the impactsmore » of the execution model of PLCs on traffic characteristics. As a result, network traces generated by co-simulation only reveal the impacts of the physical process on the contents of the traffic generated by SCADA hosts, whereas the distinction between PLCs and computing nodes (e.g., a hardened computer running a process visualization application) has been overlooked. To generate realistic network traces using co-simulation for the design and evaluation of applications relying on accurate traffic profiles, it is necessary to establish a traffic model for PLCs. In this work, we propose a parameterized model for PLCs that can be incorporated into existing co-simulation platforms. We focus on the DNP3 subsystem of slave PLCs, which automates the processing of packets from the DNP3 master. To validate our approach, we extract model parameters from both the configuration and network traces of real PLCs. Simulated network traces are generated and compared against those from PLCs. Our evaluation shows that our proposed model captures the essential traffic characteristics of DNP3 slave PLCs, which can be used to extend existing co-simulation platforms and gain further insights into the behaviors of CPES.« less

Device and circuit analysis of a sub 20 nm double gate MOSFET with gate stack using a look-up-table-based approach

NASA Astrophysics Data System (ADS)

Chakraborty, S.; Dasgupta, A.; Das, R.; Kar, M.; Kundu, A.; Sarkar, C. K.

2017-12-01

In this paper, we explore the possibility of mapping devices designed in TCAD environment to its modeled version developed in cadence virtuoso environment using a look-up table (LUT) approach. Circuit simulation of newly designed devices in TCAD environment is a very slow and tedious process involving complex scripting. Hence, the LUT based modeling approach has been proposed as a faster and easier alternative in cadence environment. The LUTs are prepared by extracting data from the device characteristics obtained from device simulation in TCAD. A comparative study is shown between the TCAD simulation and the LUT-based alternative to showcase the accuracy of modeled devices. Finally the look-up table approach is used to evaluate the performance of circuits implemented using 14 nm nMOSFET.

An adaptive singular spectrum analysis method for extracting brain rhythms of electroencephalography

PubMed Central

Hu, Hai; Guo, Shengxin; Liu, Ran

2017-01-01

Artifacts removal and rhythms extraction from electroencephalography (EEG) signals are important for portable and wearable EEG recording devices. Incorporating a novel grouping rule, we proposed an adaptive singular spectrum analysis (SSA) method for artifacts removal and rhythms extraction. Based on the EEG signal amplitude, the grouping rule determines adaptively the first one or two SSA reconstructed components as artifacts and removes them. The remaining reconstructed components are then grouped based on their peak frequencies in the Fourier transform to extract the desired rhythms. The grouping rule thus enables SSA to be adaptive to EEG signals containing different levels of artifacts and rhythms. The simulated EEG data based on the Markov Process Amplitude (MPA) EEG model and the experimental EEG data in the eyes-open and eyes-closed states were used to verify the adaptive SSA method. Results showed a better performance in artifacts removal and rhythms extraction, compared with the wavelet decomposition (WDec) and another two recently reported SSA methods. Features of the extracted alpha rhythms using adaptive SSA were calculated to distinguish between the eyes-open and eyes-closed states. Results showed a higher accuracy (95.8%) than those of the WDec method (79.2%) and the infinite impulse response (IIR) filtering method (83.3%). PMID:28674650

The Future Impact of Wind on BPA Power System Load Following and Regulation Requirements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makarov, Yuri V.; Lu, Shuai; McManus, Bart

Wind power is growing in a very fast pace as an alternative generating resource. As the ratio of wind power over total system capacity increases, the impact of wind on various system aspects becomes significant. This paper presents a methodology to study the future impact of wind on BPA power system load following and regulation requirements. Existing methodologies for similar analysis include dispatch model simulation and standard deviation evaluation on load and wind data. The methodology proposed in this paper uses historical data and stochastic processes to simulate the load balancing processes in the BPA power system. It mimics themore » actual power system operations therefore the results are close to reality yet the study based on this methodology is convenient to perform. The capacity, ramp rate and ramp duration characteristics are extracted from the simulation results. System load following and regulation capacity requirements are calculated accordingly. The ramp rate and ramp duration data obtained from the analysis can be used to evaluate generator response or maneuverability requirement and regulating units’ energy requirement, respectively.« less

Semantic Information Processing of Physical Simulation Based on Scientific Concept Vocabulary Model

NASA Astrophysics Data System (ADS)

Kino, Chiaki; Suzuki, Yoshio; Takemiya, Hiroshi

Scientific Concept Vocabulary (SCV) has been developed to actualize Cognitive methodology based Data Analysis System: CDAS which supports researchers to analyze large scale data efficiently and comprehensively. SCV is an information model for processing semantic information for physics and engineering. In the model of SCV, all semantic information is related to substantial data and algorisms. Consequently, SCV enables a data analysis system to recognize the meaning of execution results output from a numerical simulation. This method has allowed a data analysis system to extract important information from a scientific view point. Previous research has shown that SCV is able to describe simple scientific indices and scientific perceptions. However, it is difficult to describe complex scientific perceptions by currently-proposed SCV. In this paper, a new data structure for SCV has been proposed in order to describe scientific perceptions in more detail. Additionally, the prototype of the new model has been constructed and applied to actual data of numerical simulation. The result means that the new SCV is able to describe more complex scientific perceptions.

A case study on Simulation and Design optimization to improve Productivity in cooling tower manufacturing industry

NASA Astrophysics Data System (ADS)

Pranav Nithin, R.; Gopikrishnan, S.; Sumesh, A.

2018-02-01

Cooling towers are the heat transfer devices commonly found in industries which are used to extract the high temperature from the coolants and make it reusable in various plants. Basically, the cooling towers has Fills made of PVC sheets stacked together to increase the surface area exposure of the cooling liquid flowing through it. This paper focuses on the study in such a manufacturing plant where fills are being manufactured. The productivity using the current manufacturing method was only 6 to 8 fills per day, where the ideal capacity was of 14 fills per day. In this plant manual labor was employed in the manufacturing process. A change in the process modification designed and implemented will help the industry to increase the productivity to 14. In this paper, initially the simulation study was done using ARENA the simulation package and later the new design was done using CAD Package and validated using Ansys Mechanical APDL. It’s found that, by the implementation of the safe design the productivity can be increased to 196 Units.

Liquid-liquid extraction of uranyl by TBP: the TBP and ions models and related interfacial features revisited by MD and PMF simulations.

PubMed

Benay, G; Wipff, G

2014-03-20

We report a molecular dynamics (MD) study of biphasic systems involved in the liquid-liquid extraction of uranyl nitrate by tri-n-butylphosphate (TBP) to hexane, from "pH neutral" or acidic (3 M nitric acid) aqueous solutions, to assess the model dependence of the surface activity and partitioning of TBP alone, of its UO2(NO3)2(TBP)2 complex, and of UO2(NO3)2 or UO2(2+) uncomplexed. For this purpose, we first compare several electrostatic representations of TBP with regards to its polarity and conformational properties, its interactions with H2O, HNO3, and UO2(NO3)2 species, its relative free energies of solvation in water or oil environments, the properties of the pure TBP liquid and of the pure-TBP/water interface. The free energies of transfer of TBP, UO2(NO3)2, UO2(2+), and the UO2(NO3)2(TBP)2 complex across the water/oil interface are then investigated by potential of mean force (PMF) calculations, comparing different TBP models and two charge models of uranyl nitrate. Describing uranyl and nitrate ions with integer charges (+2 and -1, respectively) is shown to exaggerate the hydrophilicity and surface activity of the UO2(NO3)2(TBP)2 complex. With more appropriate ESP charges, mimicking charge transfer and polarization effects in the UO2(NO3)2 moiety or in the whole complex, the latter is no more surface active. This feature is confirmed by MD, PMF, and mixing-demixing simulations with or without polarization. Furthermore, with ESP charges, pulling the UO2(NO3)2 species to the TBP phase affords the formation of UO2(NO3)2(TBP)2 at the interface, followed by its energetically favorable extraction. The neutral complexes should therefore not accumulate at the interface during the extraction process, but diffuse to the oil phase. A similar feature is found for an UO2(NO3)2(Amide)2 neutral complex with fatty amide extracting ligands, calling for further simulations and experimental studies (e.g., time evolution of the nonlinear spectroscopic signature and of surface tension) on the interfacial landscape upon ion extraction.

Independent component analysis for the extraction of reliable protein signal profiles from MALDI-TOF mass spectra.

PubMed

Mantini, Dante; Petrucci, Francesca; Del Boccio, Piero; Pieragostino, Damiana; Di Nicola, Marta; Lugaresi, Alessandra; Federici, Giorgio; Sacchetta, Paolo; Di Ilio, Carmine; Urbani, Andrea

2008-01-01

Independent component analysis (ICA) is a signal processing technique that can be utilized to recover independent signals from a set of their linear mixtures. We propose ICA for the analysis of signals obtained from large proteomics investigations such as clinical multi-subject studies based on MALDI-TOF MS profiling. The method is validated on simulated and experimental data for demonstrating its capability of correctly extracting protein profiles from MALDI-TOF mass spectra. The comparison on peak detection with an open-source and two commercial methods shows its superior reliability in reducing the false discovery rate of protein peak masses. Moreover, the integration of ICA and statistical tests for detecting the differences in peak intensities between experimental groups allows to identify protein peaks that could be indicators of a diseased state. This data-driven approach demonstrates to be a promising tool for biomarker-discovery studies based on MALDI-TOF MS technology. The MATLAB implementation of the method described in the article and both simulated and experimental data are freely available at http://www.unich.it/proteomica/bioinf/.

Automated Fluid Feature Extraction from Transient Simulations

NASA Technical Reports Server (NTRS)

Haimes, Robert

1998-01-01

In the past, feature extraction and identification were interesting concepts, but not required to understand the underlying physics of a steady flow field. This is because the results of the more traditional tools like iso-surfaces, cuts and streamlines were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of much interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one 'snap-shot' of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments like pV3). And methods must be developed to abstract the feature and display it in a manner that physically makes sense. The following is a list of the important physical phenomena found in transient (and steady-state) fluid flow: Shocks; Vortex ores; Regions of Recirculation; Boundary Layers; Wakes.

Evolving the capacity to understand actions, intentions, and goals.

PubMed

Hauser, Marc; Wood, Justin

2010-01-01

We synthesize the contrasting predictions of motor simulation and teleological theories of action comprehension and present evidence from a series of studies showing that monkeys and apes-like humans-extract the meaning of an event by (a) going beyond the surface appearance of actions, attributing goals and intentions to the agent; (b) using details about the environment to infer when an action is rational or irrational; (c) making predictions about an agent's goal and the most probable action to obtain the goal, within the constraints of the situation; (d) predicting the most probable outcome of actions even when they are physiologically incapable of producing the actions; and (e) combining information about means and outcomes to make decisions about social interactions, some with moral relevance. These studies reveal the limitations of motor simulation theories, especially those that rely on the notion of direct matching and mirror neuron activation. They provide support, however, for a teleological theory, rooted in an inferential process that extracts information about action means, potential goals, and the environmental constraints that limit rational action.

Shale Fracture Analysis using the Combined Finite-Discrete Element Method

NASA Astrophysics Data System (ADS)

Carey, J. W.; Lei, Z.; Rougier, E.; Knight, E. E.; Viswanathan, H.

2014-12-01

Hydraulic fracturing (hydrofrac) is a successful method used to extract oil and gas from highly carbonate rocks like shale. However, challenges exist for industry experts estimate that for a single $10 million dollar lateral wellbore fracking operation, only 10% of the hydrocarbons contained in the rock are extracted. To better understand how to improve hydrofrac recovery efficiencies and to lower its costs, LANL recently funded the Laboratory Directed Research and Development (LDRD) project: "Discovery Science of Hydraulic Fracturing: Innovative Working Fluids and Their Interactions with Rocks, Fractures, and Hydrocarbons". Under the support of this project, the LDRD modeling team is working with the experimental team to understand fracture initiation and propagation in shale rocks. LANL's hybrid hydro-mechanical (HM) tool, the Hybrid Optimization Software Suite (HOSS), is being used to simulate the complex fracture and fragment processes under a variety of different boundary conditions. HOSS is based on the combined finite-discrete element method (FDEM) and has been proven to be a superior computational tool for multi-fracturing problems. In this work, the comparison of HOSS simulation results to triaxial core flooding experiments will be presented.

A weighted information criterion for multiple minor components and its adaptive extraction algorithms.

PubMed

Gao, Yingbin; Kong, Xiangyu; Zhang, Huihui; Hou, Li'an

2017-05-01

Minor component (MC) plays an important role in signal processing and data analysis, so it is a valuable work to develop MC extraction algorithms. Based on the concepts of weighted subspace and optimum theory, a weighted information criterion is proposed for searching the optimum solution of a linear neural network. This information criterion exhibits a unique global minimum attained if and only if the state matrix is composed of the desired MCs of an autocorrelation matrix of an input signal. By using gradient ascent method and recursive least square (RLS) method, two algorithms are developed for multiple MCs extraction. The global convergences of the proposed algorithms are also analyzed by the Lyapunov method. The proposed algorithms can extract the multiple MCs in parallel and has advantage in dealing with high dimension matrices. Since the weighted matrix does not require an accurate value, it facilitates the system design of the proposed algorithms for practical applications. The speed and computation advantages of the proposed algorithms are verified through simulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Uncertainty analysis of wavelet-based feature extraction for isotope identification on NaI gamma-ray spectra

DOE PAGES

Stinnett, Jacob; Sullivan, Clair J.; Xiong, Hao

2017-03-02

Low-resolution isotope identifiers are widely deployed for nuclear security purposes, but these detectors currently demonstrate problems in making correct identifications in many typical usage scenarios. While there are many hardware alternatives and improvements that can be made, performance on existing low resolution isotope identifiers should be able to be improved by developing new identification algorithms. We have developed a wavelet-based peak extraction algorithm and an implementation of a Bayesian classifier for automated peak-based identification. The peak extraction algorithm has been extended to compute uncertainties in the peak area calculations. To build empirical joint probability distributions of the peak areas andmore » uncertainties, a large set of spectra were simulated in MCNP6 and processed with the wavelet-based feature extraction algorithm. Kernel density estimation was then used to create a new component of the likelihood function in the Bayesian classifier. Furthermore, identification performance is demonstrated on a variety of real low-resolution spectra, including Category I quantities of special nuclear material.« less

Study of negative ion transport phenomena in a plasma source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riz, D.; Pamela, J.

1996-07-01

NIETZSCHE (Negative Ions Extraction and Transport ZSimulation Code for HydrogEn species) is a negative ion (NI) transport code developed at Cadarache. This code calculates NI trajectories using a 3D Monte-Carlo technique, taking into account the main destruction processes, as well as elastic collisions (H{sup {minus}}/H{sup +}) and charge exchanges (H{sup {minus}}/H{sup 0}). It determines the extraction probability of a NI created at a given position. According to the simulations, we have seen that in the case of volume production, only NI produced close to the plasma grid (PG) can be extracted. Concerning the surface production, we have studied how NImore » produced on the PG and accelerated by the plasma sheath backward into the source could be extracted. We demonstrate that elastic collisions and charge exchanges play an important role, which in some conditions dominates the magnetic filter effect, which acts as a magnetic mirror. NI transport in various conditions will be discussed: volume/surface production, high/low plasmas density, tent filter/transverse filter. {copyright} {ital 1996 American Institute of Physics.}« less

Comprehensive capacitance-voltage analysis including quantum effects for high-k interfaces on germanium and other alternative channel materials

NASA Astrophysics Data System (ADS)

Anwar, Sarkar R. M.

High mobility alternative channel materials to silicon are critical to the continued scaling of metal oxide semiconductor (MOS) devices. However, before they can be incorporated into advanced devices, some major issues need to be solved. The high mobility materials suffer from lower allowable thermal budgets compared to Si (before desorption and defect formation becomes an issue) and the absence of a good quality native oxide has further increased the interest in the use of high-k dielectrics. However, the high interface state density and high electric fields at these semiconductor/high-k interfaces can significantly impact the capacitance-voltage (C-V) profile, and current C-V modeling software cannot account for these effects. This in turn affects the parameters extracted from the C-V data of the high mobility semiconductor/high-k interface, which are crucial to fully understand the interface properties and expedite process development. To address this issue, we developed a model which takes into account quantum corrections which can be applied to a number of these alternative channel materials including SixGe1-x, Ge, InGaAs, and GaAs. The C-V simulation using this QM correction model is orders of magnitude faster compared to a full band Schrodinger-Poisson solver. The simulated C-V is directly benchmarked to a self consistent Schrodinger-Poisson solution for each bulk semiconductor material, and from the benchmarking process the QM correction parameters are extracted. The full program, C-V Alternative Channel Extraction (CV ACE), incorporates a quantum mechanical correction model, along with the interface state density model, and can extract device parameters such as equivalent oxide thickness (EOT), doping density and flat band voltage (Vfb) as well as the interface state density profile using multiple measurements performed at different frequencies and temperatures, simultaneously. The program was used to analyze experimentally measured C-V profiles and the extracted device parameters show excellent agreement with the known device structure and previously published results. CV ACE has been applied in the development of a process flow for germanium interface passivation in Ge based MOS devices using a GeOx interlayer. A post atomic layer deposition (ALD) plasma oxidation (PPO) process was developed using radio frequency (RF) plasma in a plasma enhanced chemical vapor deposition (PECVD) chamber and demonstrated significant surface passivation. Various gases were investigated and 1% O2/Ar was found to reduce the growth rate and provide excellent control over the degradation of EOT. A 100 W plasma with 1% O2/Ar was found to provide the best combination of EOT and low Dit and is concluded to be the optimum process for PPO of germanium surfaces. CV ACE and PPO were also utilized to investigate other process development challenges. A study of the impact of low temperature anneals on Ge-based MOS devices was found to result in a degradation of the electrical thickness and a change in fixed charge, indicating that the process window is very narrow and at much lower temperatures than for Si.

Ocean Carbon States: Data Mining in Observations and Numerical Simulations Results

NASA Astrophysics Data System (ADS)

Latto, R.; Romanou, A.

2017-12-01

Advanced data mining techniques are rapidly becoming widely used in Climate and Earth Sciences with the purpose of extracting new meaningful information from increasingly larger and more complex datasets. This is particularly important in studies of the global carbon cycle, where any lack of understanding of its combined physical and biogeochemical drivers is detrimental to our ability to accurately describe, understand, and predict CO2 concentrations and their changes in the major carbon reservoirs. The analysis presented here evaluates the use of cluster analysis as a means of identifying and comparing spatial and temporal patterns extracted from observational and model datasets. As the observational data is organized into various regimes, which we will call "ocean carbon states", we gain insight into the physical and/or biogeochemical processes controlling the ocean carbon cycle as well as how well these processes are simulated by a state-of-the-art climate model. We find that cluster analysis effectively produces realistic, dynamic regimes that can be associated with specific processes at different temporal scales for both observations and the model. In addition, we show how these regimes can be used to illustrate and characterize the model biases in the model air-sea flux of CO2. These biases are attributed to biases in salinity, sea surface temperature, wind speed, and nitrate, which are then used to identify the physical processes that are inaccurately reproduced by the model. In this presentation, we provide a proof-of-concept application using simple datasets, and we expand to more complex ones, using several physical and biogeochemical variable pairs, thus providing considerable insight into the mechanisms and phases of the ocean carbon cycle over different temporal and spatial scales.

Automatical and accurate segmentation of cerebral tissues in fMRI dataset with combination of image processing and deep learning

NASA Astrophysics Data System (ADS)

Kong, Zhenglun; Luo, Junyi; Xu, Shengpu; Li, Ting

2018-02-01

Image segmentation plays an important role in medical science. One application is multimodality imaging, especially the fusion of structural imaging with functional imaging, which includes CT, MRI and new types of imaging technology such as optical imaging to obtain functional images. The fusion process require precisely extracted structural information, in order to register the image to it. Here we used image enhancement, morphometry methods to extract the accurate contours of different tissues such as skull, cerebrospinal fluid (CSF), grey matter (GM) and white matter (WM) on 5 fMRI head image datasets. Then we utilized convolutional neural network to realize automatic segmentation of images in deep learning way. Such approach greatly reduced the processing time compared to manual and semi-automatic segmentation and is of great importance in improving speed and accuracy as more and more samples being learned. The contours of the borders of different tissues on all images were accurately extracted and 3D visualized. This can be used in low-level light therapy and optical simulation software such as MCVM. We obtained a precise three-dimensional distribution of brain, which offered doctors and researchers quantitative volume data and detailed morphological characterization for personal precise medicine of Cerebral atrophy/expansion. We hope this technique can bring convenience to visualization medical and personalized medicine.

Virtual reality lead extraction as a method for training new physicians: a pilot study.

PubMed

Maytin, Melanie; Daily, Thomas P; Carillo, Roger G

2015-03-01

It is estimated that the demand for transvenous lead extraction (TLE) has reached an annual extraction rate of nearly 24,000 patients worldwide. Despite technologic advances, TLE still has the potential for significant morbidity and mortality. Complication rates with TLE directly parallel operator experience. However, obtaining adequate training during and postfellowship can be difficult. Given the potential for catastrophic complications and the steep learning curve (up to 300 cases) associated with this procedure, we sought to validate a virtual reality (VR) lead extraction simulator as an innovative training and evaluation tool for physicians new to TLE. We randomized eight electrophysiology fellows to VR simulator versus conventional training. We compared procedural skill competency between the groups using simulator competency, tactile measurements, markers of proficiency and attitudes, and cognitive abilities battery. Practical skills and simulator complications differed significantly between the VR simulator and conventional training groups. The VR simulator group executed patient preparation and procedure performance better than the conventional group (P < 0.01). All four fellows randomized to conventional training experienced a simulator complication (two superior vena cava [SVC] tears, three right ventricle [RV] avulsions) versus one fellow in the VR simulator group (one SVC tear) (P = 0.02). Tactile measurements revealed a trend toward excess pushing versus pulling forces among the conventionally trained group. The time for lead removal was also significantly higher in the conventional training group (12.46 minutes vs 5.54 minutes, P = 0.02). There was no significant difference in baseline or posttraining cognitive ability. We contend that the implementation of alternative training tools such as a VR simulation model will improve physician training and allow for an innovative pathway to assess the achievement of competency. ©2014 Wiley Periodicals, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, K. A.; Schoefer, V.; Tomizawa, M.

The new accelerator complex at J-PARC will operate with both high energy and very high intensity proton beams. With a design slow extraction efficiency of greater than 99% this facility will still be depositing significant beam power onto accelerator components [2]. To achieve even higher efficiencies requires some new ideas. The design of the extraction system and the accelerator lattice structure leaves little room for improvement using conventional techniques. In this report we will present one method for improving the slow extraction efficiency at J-PARC by adding duodecapoles or octupoles to the slow extraction system. We will review the theorymore » of resonant extraction, describe simulation methods, and present the results of detailed simulations. From our investigations we find that we can improve extraction efficiency and thereby reduce the level of residual activation in the accelerator components and surrounding shielding.« less

Hardware-in-the-Loop Power Extraction Using Different Real-Time Platforms (PREPRINT)

DTIC Science & Technology

2008-07-01

engine controller ( FADEC ). Incorporating various transient subsystem level models into a complex modeling tool can be a challenging process when each...used can also be modified or replaced as appropriate. In its current configuration, the generic turbine engine model’s FADEC runs primarily on a...simulation in real-time, two platforms were tested: dSPACE and National Instruments’ (NI) LabVIEW Real-Time. For both dSPACE and NI, the engine and FADEC

Modelling space-based integral-field spectrographs and their application to Type Ia supernova cosmology

NASA Astrophysics Data System (ADS)

Shukla, Hemant; Bonissent, Alain

2017-04-01

We present the parameterized simulation of an integral-field unit (IFU) slicer spectrograph and its applications in spectroscopic studies, namely, for probing dark energy with type Ia supernovae. The simulation suite is called the fast-slicer IFU simulator (FISim). The data flow of FISim realistically models the optics of the IFU along with the propagation effects, including cosmological, zodiacal, instrumentation and detector effects. FISim simulates the spectrum extraction by computing the error matrix on the extracted spectrum. The applications for Type Ia supernova spectroscopy are used to establish the efficacy of the simulator in exploring the wider parametric space, in order to optimize the science and mission requirements. The input spectral models utilize the observables such as the optical depth and velocity of the Si II absorption feature in the supernova spectrum as the measured parameters for various studies. Using FISim, we introduce a mechanism for preserving the complete state of a system, called the partial p/partial f matrix, which allows for compression, reconstruction and spectrum extraction, we introduce a novel and efficient method for spectrum extraction, called super-optimal spectrum extraction, and we conduct various studies such as the optimal point spread function, optimal resolution, parameter estimation, etc. We demonstrate that for space-based telescopes, the optimal resolution lies in the region near R ˜ 117 for read noise of 1 e- and 7 e- using a 400 km s-1 error threshold on the Si II velocity.

Ballistic missile precession frequency extraction by spectrogram's texture

NASA Astrophysics Data System (ADS)

Wu, Longlong; Xu, Shiyou; Li, Gang; Chen, Zengping

2013-10-01

In order to extract precession frequency, an crucial parameter in ballistic target recognition, which reflected the kinematical characteristics as well as structural and mass distribution features, we developed a dynamic RCS signal model for a conical ballistic missile warhead, with a log-norm multiplicative noise, substituting the familiar additive noise, derived formulas of micro-Doppler induced by precession motion, and analyzed time-varying micro-Doppler features utilizing time-frequency transforms, extracted precession frequency by measuring the spectrogram's texture, verified them by computer simulation studies. Simulation demonstrates the excellent performance of the method proposed in extracting the precession frequency, especially in the case of low SNR.

The technique of entropy optimization in motor current signature analysis and its application in the fault diagnosis of gear transmission

NASA Astrophysics Data System (ADS)

Chen, Xiaoguang; Liang, Lin; Liu, Fei; Xu, Guanghua; Luo, Ailing; Zhang, Sicong

2012-05-01

Nowadays, Motor Current Signature Analysis (MCSA) is widely used in the fault diagnosis and condition monitoring of machine tools. However, although the current signal has lower SNR (Signal Noise Ratio), it is difficult to identify the feature frequencies of machine tools from complex current spectrum that the feature frequencies are often dense and overlapping by traditional signal processing method such as FFT transformation. With the study in the Motor Current Signature Analysis (MCSA), it is found that the entropy is of importance for frequency identification, which is associated with the probability distribution of any random variable. Therefore, it plays an important role in the signal processing. In order to solve the problem that the feature frequencies are difficult to be identified, an entropy optimization technique based on motor current signal is presented in this paper for extracting the typical feature frequencies of machine tools which can effectively suppress the disturbances. Some simulated current signals were made by MATLAB, and a current signal was obtained from a complex gearbox of an iron works made in Luxembourg. In diagnosis the MCSA is combined with entropy optimization. Both simulated and experimental results show that this technique is efficient, accurate and reliable enough to extract the feature frequencies of current signal, which provides a new strategy for the fault diagnosis and the condition monitoring of machine tools.

Design and application of star map simulation system for star sensors

NASA Astrophysics Data System (ADS)

Wu, Feng; Shen, Weimin; Zhu, Xifang; Chen, Yuheng; Xu, Qinquan

2013-12-01

Modern star sensors are powerful to measure attitude automatically which assure a perfect performance of spacecrafts. They achieve very accurate attitudes by applying algorithms to process star maps obtained by the star camera mounted on them. Therefore, star maps play an important role in designing star cameras and developing procession algorithms. Furthermore, star maps supply significant supports to exam the performance of star sensors completely before their launch. However, it is not always convenient to supply abundant star maps by taking pictures of the sky. Thus, star map simulation with the aid of computer attracts a lot of interests by virtue of its low price and good convenience. A method to simulate star maps by programming and extending the function of the optical design program ZEMAX is proposed. The star map simulation system is established. Firstly, based on analyzing the working procedures of star sensors to measure attitudes and the basic method to design optical system by ZEMAX, the principle of simulating star sensor imaging is given out in detail. The theory about adding false stars and noises, and outputting maps is discussed and the corresponding approaches are proposed. Then, by external programming, the star map simulation program is designed and produced. Its user interference and operation are introduced. Applications of star map simulation method in evaluating optical system, star image extraction algorithm and star identification algorithm, and calibrating system errors are presented completely. It was proved that the proposed simulation method provides magnificent supports to the study on star sensors, and improves the performance of star sensors efficiently.

Numerical modelling of lithospheric flexure in front of subduction zones in Japan and its role to initiate melt extraction from the LVZ.

NASA Astrophysics Data System (ADS)

Bessat, A.; Pilet, S.; Duretz, T.; Schmalholz, S. M.

2017-12-01

Petit-spot volcanoes were found fifteen years ago by Japanese researchers at the top of the subducting plate in Japan (Hirano 2006). This discovery is of great significance as it highlights the importance of tectonic processes for the initiation of intraplate volcanism. The location of these small lava flows is unusual and seems to be related to the plate flexure, which may facilitate the extraction of low degree melts from the base of the lithosphere, a hypothesis previously suggested to explain changes in electric and seismic properties at 70-90 km depth, i.e. within the low velocity zone (LVS) (Sifré 2014). A critical question is related to the process associated with the extraction of this low degree melts from the LVZ. First models suggested that extension associated to plate bending allows large cracks to propagate across the lithosphere and could promote the extraction of low degree melts at the base of the lithosphere (Hirano 2006 & Yamamoto 2014). However, the study of petit-spot mantle xenoliths from Japan (Pilet 2016) has demonstrated that low degree melts are not directly extracted to the surface but percolate, interact and metasomatize the oceanic lithosphere. In order to understand the melt extraction process in the region of plate bending, we performed 2D thermo-mechanical simulations of Japanese-type subduction. The numerical model considers viscoelastoplastic deformation. This allows the quantification of state of the stress, strain rates, and viscosities which will control the percolation of melt initially stocked at the base of the lithosphere. Initial results show that plate flexure changes the distribution of the deformation mechanism in the flexure zone, between 40 km to 80 km depth. A change of the dominant deformation mechanism from diffusion creep to dislocation creep and from there to Peierls creep was observed about 200 to 300 km from the trench. These changes are linked to the augmentation of the stresses in the flexure zone. At the base of the lithosphere diffusion creep is observed as a thin layer (20 km), which becomes smaller (10 km) as the subduction progresses in favour of the dislocation creep. Further work will be necessary to prove whether the associated stress distributions is compatible with the development of porosity waves, a critical process to extract melts in low porosity media.

Simulation of ground-water flow and solute transport in the Glen Canyon aquifer, East-Central Utah

USGS Publications Warehouse

Freethey, Geoffrey W.; Stolp, Bernard J.

2010-01-01

The extraction of methane from coal beds in the Ferron coal trend in central Utah started in the mid-1980s. Beginning in 1994, water from the extraction process was pressure injected into the Glen Canyon aquifer. The lateral extent of the aquifer that could be affected by injection is about 7,600 square miles. To address regional-scale effects of injection over a decadal time frame, a conceptual model of ground-water movement and transport of dissolved solids was formulated. A numerical model that incorporates aquifer concepts was then constructed and used to simulate injection.The Glen Canyon aquifer within the study area is conceptualized in two parts—an active area of ground-water flow and solute transport that exists between recharge areas in the San Rafael Swell and Desert, Waterpocket Fold, and Henry Mountains and discharge locations along the Muddy, Dirty Devil, San Rafael, and Green Rivers. An area of little or negligible ground-water flow exists north of Price, Utah, and beneath the Wasatch Plateau. Pressurized injection of coal-bed methane production water occurs in this area where dissolved-solids concentrations can be more than 100,000 milligrams per liter. Injection has the potential to increase hydrologic interaction with the active flow area, where dissolved-solids concentrations are generally less than 3,000 milligrams per liter.Pressurized injection of coal-bed methane production water in 1994 initiated a net addition of flow and mass of solutes into the Glen Canyon aquifer. To better understand the regional scale hydrologic interaction between the two areas of the Glen Canyon aquifer, pressurized injection was numerically simulated. Data constraints precluded development of a fully calibrated simulation; instead, an uncalibrated model was constructed that is a plausible representation of the conceptual flow and solute-transport processes. The amount of injected water over the 36-year simulation period is about 25,000 acre-feet. As a result, simulated water levels in the injection areas increased by 50 feet and dissolved-solids concentrations increased by 100 milligrams per liter or more. These increases are accrued into aquifer storage and do not extend to the rivers during the 36-year simulation period. The amount of change in simulated discharge and solute load to the rivers is less than the resolution accuracy of the numerical simulation and is interpreted as no significant change over the considered time period.

Complete wetting of graphene by biological lipids

NASA Astrophysics Data System (ADS)

Luan, Binquan; Huynh, Tien; Zhou, Ruhong

2016-03-01

Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a graphene sheet.Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a graphene sheet. Electronic supplementary information (ESI) available: The movie showing the simulation trajectory for the extraction of lipids from the membrane. See DOI: 10.1039/C6NR00202A

Development of new antioxidant active packaging films based on ethylene vinyl alcohol copolymer (EVOH) and green tea extract.

PubMed

Lopez de Dicastillo, Carol; Nerin, Cristina; Alfaro, Pilar; Catala, Ramon; Gavara, Rafael; Hernandez-Munoz, Pilar

2011-07-27

Ethylene vinyl alcohol copolymer (EVOH) films containing green tea extract were successfully produced by extrusion. The films were brown and translucent, and the addition of the extract increased the water and oxygen barrier at low relative humidity but increased the water sensitivity, the glass transition temperature, and the crystallinity of the films and improved their thermal resistance. An analysis by HPLC revealed that the antioxidant components of the extract suffered partial degradation during extrusion, reducing the content of catechin gallates and increasing the concentration of free gallic acid. Exposure of the films to various food simulants showed that the liquid simulants increased their capacity to reduce DPPH(•) and ABTS(•+) radicals. The release of green tea extract components into the simulant monitored by HPLC showed that all compounds present in the green tea extract were partially released, although the extent and kinetics of release were dependent on the type of food. In aqueous food simulants, gallic acid was the main antioxidant component released with partition coefficient values ca. 200. In 95% ethanol (fatty food simulant) the K value for gallic acid decreased to 8 and there was a substantial contribution of catechins (K in the 1000 range) to a greatly increased antioxidant efficiency. Kinetically, gallic acid was released more quickly than catechins, owing to its faster diffusivity in the polymer matrix as a consequence of its smaller molecular size, although the most relevant effect is the plasticization of the matrix by alcohol, increasing the diffusion coefficient >10-fold. Therefore, the materials here developed with the combination of antioxidant substances that constitute the green tea extract could be used in the design of antioxidant active packaging for all type of foods, from aqueous to fatty products, the compounds responsible for the protection being those with the higher compatibility with the packaged product.

Soybean protein-based microparticles for oral delivery of probiotics with improved stability during storage and gut resistance.

PubMed

González-Ferrero, C; Irache, J M; González-Navarro, C J

2018-01-15

The present work describes the encapsulation of probiotics using a by-product as wall material and a process feasible to be scaled-up: coacervation of soybean protein concentrate (SPC) by using calcium salts and spray-drying. SPC was extracted from soybean flour, produced during the processing of soybean milk, by alkaline extraction following isoelectric precipitation. Two probiotic strains were selected for encapsulation (Lactobacillus plantarum CECT 220 and Lactobacillus casei CECT 475) in order to evaluate the ability of SPC to encapsulate and protect bacteria from stress conditions. The viability of these encapsulated strains under in vitro gastrointestinal conditions and shelf-life during storage were compared with the most common forms commercialized nowadays. Results show that SPC is a feasible material for the development of probiotic microparticles with adequate physicochemical properties and enhanced significantly both probiotic viability and tolerance against simulated gastrointestinal fluids when compared to current available commercial forms. Copyright © 2017 Elsevier Ltd. All rights reserved.

MorphoGraphX: A platform for quantifying morphogenesis in 4D.

PubMed

Barbier de Reuille, Pierre; Routier-Kierzkowska, Anne-Lise; Kierzkowski, Daniel; Bassel, George W; Schüpbach, Thierry; Tauriello, Gerardo; Bajpai, Namrata; Strauss, Sören; Weber, Alain; Kiss, Annamaria; Burian, Agata; Hofhuis, Hugo; Sapala, Aleksandra; Lipowczan, Marcin; Heimlicher, Maria B; Robinson, Sarah; Bayer, Emmanuelle M; Basler, Konrad; Koumoutsakos, Petros; Roeder, Adrienne H K; Aegerter-Wilmsen, Tinri; Nakayama, Naomi; Tsiantis, Miltos; Hay, Angela; Kwiatkowska, Dorota; Xenarios, Ioannis; Kuhlemeier, Cris; Smith, Richard S

2015-05-06

Morphogenesis emerges from complex multiscale interactions between genetic and mechanical processes. To understand these processes, the evolution of cell shape, proliferation and gene expression must be quantified. This quantification is usually performed either in full 3D, which is computationally expensive and technically challenging, or on 2D planar projections, which introduces geometrical artifacts on highly curved organs. Here we present MorphoGraphX ( www.MorphoGraphX.org), a software that bridges this gap by working directly with curved surface images extracted from 3D data. In addition to traditional 3D image analysis, we have developed algorithms to operate on curved surfaces, such as cell segmentation, lineage tracking and fluorescence signal quantification. The software's modular design makes it easy to include existing libraries, or to implement new algorithms. Cell geometries extracted with MorphoGraphX can be exported and used as templates for simulation models, providing a powerful platform to investigate the interactions between shape, genes and growth.

Refraction-based X-ray Computed Tomography for Biomedical Purpose Using Dark Field Imaging Method

NASA Astrophysics Data System (ADS)

Sunaguchi, Naoki; Yuasa, Tetsuya; Huo, Qingkai; Ichihara, Shu; Ando, Masami

We have proposed a tomographic x-ray imaging system using DFI (dark field imaging) optics along with a data-processing method to extract information on refraction from the measured intensities, and a reconstruction algorithm to reconstruct a refractive-index field from the projections generated from the extracted refraction information. The DFI imaging system consists of a tandem optical system of Bragg- and Laue-case crystals, a positioning device system for a sample, and two CCD (charge coupled device) cameras. Then, we developed a software code to simulate the data-acquisition, data-processing, and reconstruction methods to investigate the feasibility of the proposed methods. Finally, in order to demonstrate its efficacy, we imaged a sample with DCIS (ductal carcinoma in situ) excised from a breast cancer patient using a system constructed at the vertical wiggler beamline BL-14C in KEK-PF. Its CT images depicted a variety of fine histological structures, such as milk ducts, duct walls, secretions, adipose and fibrous tissue. They correlate well with histological sections.

Process monitoring using automatic physical measurement based on electrical and physical variability analysis

NASA Astrophysics Data System (ADS)

Shauly, Eitan N.; Levi, Shimon; Schwarzband, Ishai; Adan, Ofer; Latinsky, Sergey

2015-04-01

A fully automated silicon-based methodology for systematic analysis of electrical features is shown. The system was developed for process monitoring and electrical variability reduction. A mapping step was created by dedicated structures such as static-random-access-memory (SRAM) array or standard cell library, or by using a simple design rule checking run-set. The resulting database was then used as an input for choosing locations for critical dimension scanning electron microscope images and for specific layout parameter extraction then was input to SPICE compact modeling simulation. Based on the experimental data, we identified two items that must be checked and monitored using the method described here: transistor's sensitivity to the distance between the poly end cap and edge of active area (AA) due to AA rounding, and SRAM leakage due to a too close N-well to P-well. Based on this example, for process monitoring and variability analyses, we extensively used this method to analyze transistor gates having different shapes. In addition, analysis for a large area of high density standard cell library was done. Another set of monitoring focused on a high density SRAM array is also presented. These examples provided information on the poly and AA layers, using transistor parameters such as leakage current and drive current. We successfully define "robust" and "less-robust" transistor configurations included in the library and identified unsymmetrical transistors in the SRAM bit-cells. These data were compared to data extracted from the same devices at the end of the line. Another set of analyses was done to samples after Cu M1 etch. Process monitoring information on M1 enclosed contact was extracted based on contact resistance as a feedback. Guidelines for the optimal M1 space for different layout configurations were also extracted. All these data showed the successful in-field implementation of our methodology as a useful process monitoring method.

Techno-Economic Analysis of Magnesium Extraction from Seawater via a Catalyzed Organo-Metathetical Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jian; Bearden, Mark D.; Fernandez, Carlos A.

Magnesium (Mg) has many useful applications especially in various Mg alloys which can decrease weight while increasing strength. To increase the affordability and minimize environment consequence, a novel catalyzed organo-metathetical (COMET) process was proposed to extract Mg from seawater aiming to achieve significant reduction in total energy and production cost comparing with the melting salt electrolysis method currently adopted by US Mg LLC. A process flowsheet for a reference COMET process was set-up using Aspen Plus which included five key steps, anhydrous MgCl2 production, transmetallation, dibutyl Mg decomposition, n-BuLi regeneration, and LiCL electrolysis. The energy and production cost and CO2more » emission were estimated based on the Aspen modeling using Aspen economic analyzer. Our results showed that it is possible to produce Mg from seawater with a production cost of $2.0/kg-Mg while consuming about 35.3 kWh/kg-Mg and releasing 7.0 kg CO2/kg-Mg. A simplified US Mg manufacturing process was also generated using Aspen and the cost and emission results were estimated for comparison purpose. Under our simulation conditions, the reference COMET process maintain a comparable CO2 emission rate and can save about 40% in production cost and save about 15% energy compared to the simplified US Mg process.« less

Experimental benchmark of the NINJA code for application to the Linac4 H- ion source plasma

NASA Astrophysics Data System (ADS)

Briefi, S.; Mattei, S.; Rauner, D.; Lettry, J.; Tran, M. Q.; Fantz, U.

2017-10-01

For a dedicated performance optimization of negative hydrogen ion sources applied at particle accelerators, a detailed assessment of the plasma processes is required. Due to the compact design of these sources, diagnostic access is typically limited to optical emission spectroscopy yielding only line-of-sight integrated results. In order to allow for a spatially resolved investigation, the electromagnetic particle-in-cell Monte Carlo collision code NINJA has been developed for the Linac4 ion source at CERN. This code considers the RF field generated by the ICP coil as well as the external static magnetic fields and calculates self-consistently the resulting discharge properties. NINJA is benchmarked at the diagnostically well accessible lab experiment CHARLIE (Concept studies for Helicon Assisted RF Low pressure Ion sourcEs) at varying RF power and gas pressure. A good general agreement is observed between experiment and simulation although the simulated electron density trends for varying pressure and power as well as the absolute electron temperature values deviate slightly from the measured ones. This can be explained by the assumption of strong inductive coupling in NINJA, whereas the CHARLIE discharges show the characteristics of loosely coupled plasmas. For the Linac4 plasma, this assumption is valid. Accordingly, both the absolute values of the accessible plasma parameters and their trends for varying RF power agree well in measurement and simulation. At varying RF power, the H- current extracted from the Linac4 source peaks at 40 kW. For volume operation, this is perfectly reflected by assessing the processes in front of the extraction aperture based on the simulation results where the highest H- density is obtained for the same power level. In surface operation, the production of negative hydrogen ions at the converter surface can only be considered by specialized beam formation codes, which require plasma parameters as input. It has been demonstrated that this input can be provided reliably by the NINJA code.

Design and Simulation of Material-Integrated Distributed Sensor Processing with a Code-Based Agent Platform and Mobile Multi-Agent Systems

PubMed Central

Bosse, Stefan

2015-01-01

Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques. PMID:25690550

Design and simulation of material-integrated distributed sensor processing with a code-based agent platform and mobile multi-agent systems.

PubMed

Bosse, Stefan

2015-02-16

Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

Ozone photochemistry in an oil and natural gas extraction region during winter: simulations of a snow-free season in the Uintah Basin, Utah

NASA Astrophysics Data System (ADS)

Edwards, P. M.; Young, C. J.; Aikin, K.; deGouw, J.; Dubé, W. P.; Geiger, F.; Gilman, J.; Helmig, D.; Holloway, J. S.; Kercher, J.; Lerner, B.; Martin, R.; McLaren, R.; Parrish, D. D.; Peischl, J.; Roberts, J. M.; Ryerson, T. B.; Thornton, J.; Warneke, C.; Williams, E. J.; Brown, S. S.

2013-09-01

The Uintah Basin in northeastern Utah, a region of intense oil and gas extraction, experienced ozone (O3) concentrations above levels harmful to human health for multiple days during the winters of 2009-2010 and 2010-2011. These wintertime O3 pollution episodes occur during cold, stable periods when the ground is snow-covered, and have been linked to emissions from the oil and gas extraction process. The Uintah Basin Winter Ozone Study (UBWOS) was a field intensive in early 2012, whose goal was to address current uncertainties in the chemical and physical processes that drive wintertime O3 production in regions of oil and gas development. Although elevated O3 concentrations were not observed during the winter of 2011-2012, the comprehensive set of observations tests our understanding of O3 photochemistry in this unusual emissions environment. A box model, constrained to the observations and using the near-explicit Master Chemical Mechanism (MCM) v3.2 chemistry scheme, has been used to investigate the sensitivities of O3 production during UBWOS 2012. Simulations identify the O3 production photochemistry to be highly radical limited (with a radical production rate significantly smaller than the NOx emission rate). Production of OH from O3 photolysis (through reaction of O(1D) with water vapor) contributed only 170 pptv day-1, 8% of the total primary radical source on average (primary radicals being those produced from non-radical precursors). Other radical sources, including the photolysis of formaldehyde (HCHO, 52%), nitrous acid (HONO, 26%), and nitryl chloride (ClNO2, 13%) were larger. O3 production was also found to be highly sensitive to aromatic volatile organic compound (VOC) concentrations, due to radical amplification reactions in the oxidation scheme of these species. Radical production was shown to be small in comparison to the emissions of nitrogen oxides (NOx), such that NOx acted as the primary radical sink. Consequently, the system was highly VOC sensitive, despite the much larger mixing ratio of total non-methane hydrocarbons (230 ppbv (2080 ppbC), 6 week average) relative to NOx (5.6 ppbv average). However, the importance of radical sources which are themselves derived from NOx emissions and chemistry, such as ClNO2 and HONO, make the response of the system to changes in NOx emissions uncertain. Model simulations attempting to reproduce conditions expected during snow-covered cold-pool conditions show a significant increase in O3 production, although calculated concentrations do not achieve the highest seen during the 2010-2011 O3 pollution events in the Uintah Basin. These box model simulations provide useful insight into the chemistry controlling winter O3 production in regions of oil and gas extraction.

Unsupervised Pathological Area Extraction using 3D T2 and FLAIR MR Images

NASA Astrophysics Data System (ADS)

Dvořák, Pavel; Bartušek, Karel; Smékal, Zdeněk

2014-12-01

This work discusses fully automated extraction of brain tumor and edema in 3D MR volumes. The goal of this work is the extraction of the whole pathological area using such an algorithm that does not require a human intervention. For the good visibility of these kinds of tissues both T2-weighted and FLAIR images were used. The proposed method was tested on 80 MR volumes of publicly available BRATS database, which contains high and low grade gliomas, both real and simulated. The performance was evaluated by the Dice coefficient, where the results were differentiated between high and low grade and real and simulated gliomas. The method reached promising results for all of the combinations of images: real high grade (0.73 ± 0.20), real low grade (0.81 ± 0.06), simulated high grade (0.81 ± 0.14), and simulated low grade (0.81 ± 0.04).

A Semi-Analytical Extraction Method for Interface and Bulk Density of States in Metal Oxide Thin-Film Transistors

PubMed Central

Chen, Weifeng; Wu, Weijing; Zhou, Lei; Xu, Miao; Wang, Lei; Peng, Junbiao

2018-01-01

A semi-analytical extraction method of interface and bulk density of states (DOS) is proposed by using the low-frequency capacitance–voltage characteristics and current–voltage characteristics of indium zinc oxide thin-film transistors (IZO TFTs). In this work, an exponential potential distribution along the depth direction of the active layer is assumed and confirmed by numerical solution of Poisson’s equation followed by device simulation. The interface DOS is obtained as a superposition of constant deep states and exponential tail states. Moreover, it is shown that the bulk DOS may be represented by the superposition of exponential deep states and exponential tail states. The extracted values of bulk DOS and interface DOS are further verified by comparing the measured transfer and output characteristics of IZO TFTs with the simulation results by a 2D device simulator ATLAS (Silvaco). As a result, the proposed extraction method may be useful for diagnosing and characterising metal oxide TFTs since it is fast to extract interface and bulk density of states (DOS) simultaneously. PMID:29534492

Integration of Genetic Algorithms and Fuzzy Logic for Urban Growth Modeling

NASA Astrophysics Data System (ADS)

Foroutan, E.; Delavar, M. R.; Araabi, B. N.

2012-07-01

Urban growth phenomenon as a spatio-temporal continuous process is subject to spatial uncertainty. This inherent uncertainty cannot be fully addressed by the conventional methods based on the Boolean algebra. Fuzzy logic can be employed to overcome this limitation. Fuzzy logic preserves the continuity of dynamic urban growth spatially by choosing fuzzy membership functions, fuzzy rules and the fuzzification-defuzzification process. Fuzzy membership functions and fuzzy rule sets as the heart of fuzzy logic are rather subjective and dependent on the expert. However, due to lack of a definite method for determining the membership function parameters, certain optimization is needed to tune the parameters and improve the performance of the model. This paper integrates genetic algorithms and fuzzy logic as a genetic fuzzy system (GFS) for modeling dynamic urban growth. The proposed approach is applied for modeling urban growth in Tehran Metropolitan Area in Iran. Historical land use/cover data of Tehran Metropolitan Area extracted from the 1988 and 1999 Landsat ETM+ images are employed in order to simulate the urban growth. The extracted land use classes of the year 1988 include urban areas, street, vegetation areas, slope and elevation used as urban growth physical driving forces. Relative Operating Characteristic (ROC) curve as an fitness function has been used to evaluate the performance of the GFS algorithm. The optimum membership function parameter is applied for generating a suitability map for the urban growth. Comparing the suitability map and real land use map of 1999 gives the threshold value for the best suitability map which can simulate the land use map of 1999. The simulation outcomes in terms of kappa of 89.13% and overall map accuracy of 95.58% demonstrated the efficiency and reliability of the proposed model.

3D-information fusion from very high resolution satellite sensors

NASA Astrophysics Data System (ADS)

Krauss, T.; d'Angelo, P.; Kuschk, G.; Tian, J.; Partovi, T.

2015-04-01

In this paper we show the pre-processing and potential for environmental applications of very high resolution (VHR) satellite stereo imagery like these from WorldView-2 or Pl'eiades with ground sampling distances (GSD) of half a metre to a metre. To process such data first a dense digital surface model (DSM) has to be generated. Afterwards from this a digital terrain model (DTM) representing the ground and a so called normalized digital elevation model (nDEM) representing off-ground objects are derived. Combining these elevation based data with a spectral classification allows detection and extraction of objects from the satellite scenes. Beside the object extraction also the DSM and DTM can directly be used for simulation and monitoring of environmental issues. Examples are the simulation of floodings, building-volume and people estimation, simulation of noise from roads, wave-propagation for cellphones, wind and light for estimating renewable energy sources, 3D change detection, earthquake preparedness and crisis relief, urban development and sprawl of informal settlements and much more. Also outside of urban areas volume information brings literally a new dimension to earth oberservation tasks like the volume estimations of forests and illegal logging, volume of (illegal) open pit mining activities, estimation of flooding or tsunami risks, dike planning, etc. In this paper we present the preprocessing from the original level-1 satellite data to digital surface models (DSMs), corresponding VHR ortho images and derived digital terrain models (DTMs). From these components we present how a monitoring and decision fusion based 3D change detection can be realized by using different acquisitions. The results are analyzed and assessed to derive quality parameters for the presented method. Finally the usability of 3D information fusion from VHR satellite imagery is discussed and evaluated.

Mechatronics technology in predictive maintenance method

NASA Astrophysics Data System (ADS)

Majid, Nurul Afiqah A.; Muthalif, Asan G. A.

2017-11-01

This paper presents recent mechatronics technology that can help to implement predictive maintenance by combining intelligent and predictive maintenance instrument. Vibration Fault Simulation System (VFSS) is an example of mechatronics system. The focus of this study is the prediction on the use of critical machines to detect vibration. Vibration measurement is often used as the key indicator of the state of the machine. This paper shows the choice of the appropriate strategy in the vibration of diagnostic process of the mechanical system, especially rotating machines, in recognition of the failure during the working process. In this paper, the vibration signature analysis is implemented to detect faults in rotary machining that includes imbalance, mechanical looseness, bent shaft, misalignment, missing blade bearing fault, balancing mass and critical speed. In order to perform vibration signature analysis for rotating machinery faults, studies have been made on how mechatronics technology is used as predictive maintenance methods. Vibration Faults Simulation Rig (VFSR) is designed to simulate and understand faults signatures. These techniques are based on the processing of vibrational data in frequency-domain. The LabVIEW-based spectrum analyzer software is developed to acquire and extract frequency contents of faults signals. This system is successfully tested based on the unique vibration fault signatures that always occur in a rotating machinery.

Interactive Visualization to Advance Earthquake Simulation

NASA Astrophysics Data System (ADS)

Kellogg, Louise H.; Bawden, Gerald W.; Bernardin, Tony; Billen, Magali; Cowgill, Eric; Hamann, Bernd; Jadamec, Margarete; Kreylos, Oliver; Staadt, Oliver; Sumner, Dawn

2008-04-01

The geological sciences are challenged to manage and interpret increasing volumes of data as observations and simulations increase in size and complexity. For example, simulations of earthquake-related processes typically generate complex, time-varying data sets in two or more dimensions. To facilitate interpretation and analysis of these data sets, evaluate the underlying models, and to drive future calculations, we have developed methods of interactive visualization with a special focus on using immersive virtual reality (VR) environments to interact with models of Earth’s surface and interior. Virtual mapping tools allow virtual “field studies” in inaccessible regions. Interactive tools allow us to manipulate shapes in order to construct models of geological features for geodynamic models, while feature extraction tools support quantitative measurement of structures that emerge from numerical simulation or field observations, thereby enabling us to improve our interpretation of the dynamical processes that drive earthquakes. VR has traditionally been used primarily as a presentation tool, albeit with active navigation through data. Reaping the full intellectual benefits of immersive VR as a tool for scientific analysis requires building on the method’s strengths, that is, using both 3D perception and interaction with observed or simulated data. This approach also takes advantage of the specialized skills of geological scientists who are trained to interpret, the often limited, geological and geophysical data available from field observations.

Subthreshold SPICE Model Optimization

NASA Astrophysics Data System (ADS)

Lum, Gregory; Au, Henry; Neff, Joseph; Bozeman, Eric; Kamin, Nick; Shimabukuro, Randy

2011-04-01

The first step in integrated circuit design is the simulation of said design in software to verify proper functionally and design requirements. Properties of the process are provided by fabrication foundries in the form of SPICE models. These SPICE models contain the electrical data and physical properties of the basic circuit elements. A limitation of these models is that the data collected by the foundry only accurately model the saturation region. This is fine for most users, but when operating devices in the subthreshold region they are inadequate for accurate simulation results. This is why optimizing the current SPICE models to characterize the subthreshold region is so important. In order to accurately simulate this region of operation, MOSFETs of varying widths and lengths are fabricated and the electrical test data is collected. From the data collected the parameters of the model files are optimized through parameter extraction rather than curve fitting. With the completed optimized models the circuit designer is able to simulate circuit designs for the sub threshold region accurately.

Potential-based dynamical reweighting for Markov state models of protein dynamics.

PubMed

Weber, Jeffrey K; Pande, Vijay S

2015-06-09

As simulators attempt to replicate the dynamics of large cellular components in silico, problems related to sampling slow, glassy degrees of freedom in molecular systems will be amplified manyfold. It is tempting to augment simulation techniques with external biases to overcome such barriers with ease; biased simulations, however, offer little utility unless equilibrium properties of interest (both kinetic and thermodynamic) can be recovered from the data generated. In this Article, we present a general scheme that harnesses the power of Markov state models (MSMs) to extract equilibrium kinetic properties from molecular dynamics trajectories collected on biased potential energy surfaces. We first validate our reweighting protocol on a simple two-well potential, and we proceed to test our method on potential-biased simulations of the Trp-cage miniprotein. In both cases, we find that equilibrium populations, time scales, and dynamical processes are reliably reproduced as compared to gold standard, unbiased data sets. We go on to discuss the limitations of our dynamical reweighting approach, and we suggest auspicious target systems for further application.

DOE Office of Scientific and Technical Information (OSTI.GOV)

TESP combines existing domain simulators in the electric power grid, with new transactive agents, growth models and evaluation scripts. The existing domain simulators include GridLAB-D for the distribution grid and single-family residential buildings, MATPOWER for transmission and bulk generation, and EnergyPlus for large buildings. More are planned for subsequent versions of TESP. The new elements are: TEAgents - simulate market participants and transactive systems for market clearing. Some of this functionality was extracted from GridLAB-D and implemented in Python for customization by PNNL and others; Growth Model - a means for simulating system changes over a multiyear period, including bothmore » normal load growth and specific investment decisions. Customizable in Python code; and Evaluation Script - a means of evaluating different transactive systems through customizable post-processing in Python code. TESP provides a method for other researchers and vendors to design transactive systems, and test them in a virtual environment. It allows customization of the key components by modifying Python code.« less

Characterization of autoregressive processes using entropic quantifiers

NASA Astrophysics Data System (ADS)

Traversaro, Francisco; Redelico, Francisco O.

2018-01-01

The aim of the contribution is to introduce a novel information plane, the causal-amplitude informational plane. As previous works seems to indicate, Bandt and Pompe methodology for estimating entropy does not allow to distinguish between probability distributions which could be fundamental for simulation or for probability analysis purposes. Once a time series is identified as stochastic by the causal complexity-entropy informational plane, the novel causal-amplitude gives a deeper understanding of the time series, quantifying both, the autocorrelation strength and the probability distribution of the data extracted from the generating processes. Two examples are presented, one from climate change model and the other from financial markets.

The 2010 Field Demonstration of the Solar Carbothermal Reduction of Regolith to Produce Oxygen

NASA Technical Reports Server (NTRS)

Gustafson, R. J.; White, B. C.; Fidler, M. J.; Muscatello, Anthony C.

2010-01-01

The Moon and other space exploration destinations are comprised of a variety of oxygen-bearing minerals, providing a virtually unlimited quantity of raw material which can be processed to produce oxygen. One attractive method to extract oxygen from the regolith is the carbothermal reduction process, which is not sensitive to variations in the mineral composition of the regolith. It also creates other valuable resources within the processed regolith, such as iron and silicon metals. Using funding from NASA, ORBITEC recently built and tested the Carbothermal Regolith Reduction Module to process lunar regolith simulants using concentrated solar energy. This paper summarizes the experimental test results obtained during a demonstration of the system at a lunar analog test site on the Mauna Kea volcano on Hawaii in February 2010.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sang Beom; Dsilva, Carmeline J.; Debenedetti, Pablo G., E-mail: pdebene@princeton.edu

Understanding the mechanisms by which proteins fold from disordered amino-acid chains to spatially ordered structures remains an area of active inquiry. Molecular simulations can provide atomistic details of the folding dynamics which complement experimental findings. Conventional order parameters, such as root-mean-square deviation and radius of gyration, provide structural information but fail to capture the underlying dynamics of the protein folding process. It is therefore advantageous to adopt a method that can systematically analyze simulation data to extract relevant structural as well as dynamical information. The nonlinear dimensionality reduction technique known as diffusion maps automatically embeds the high-dimensional folding trajectories inmore » a lower-dimensional space from which one can more easily visualize folding pathways, assuming the data lie approximately on a lower-dimensional manifold. The eigenvectors that parametrize the low-dimensional space, furthermore, are determined systematically, rather than chosen heuristically, as is done with phenomenological order parameters. We demonstrate that diffusion maps can effectively characterize the folding process of a Trp-cage miniprotein. By embedding molecular dynamics simulation trajectories of Trp-cage folding in diffusion maps space, we identify two folding pathways and intermediate structures that are consistent with the previous studies, demonstrating that this technique can be employed as an effective way of analyzing and constructing protein folding pathways from molecular simulations.« less

GIS-based analysis and modelling with empirical and remotely-sensed data on coastline advance and retreat

NASA Astrophysics Data System (ADS)

Ahmad, Sajid Rashid

With the understanding that far more research remains to be done on the development and use of innovative and functional geospatial techniques and procedures to investigate coastline changes this thesis focussed on the integration of remote sensing, geographical information systems (GIS) and modelling techniques to provide meaningful insights on the spatial and temporal dynamics of coastline changes. One of the unique strengths of this research was the parameterization of the GIS with long-term empirical and remote sensing data. Annual empirical data from 1941--2007 were analyzed by the GIS, and then modelled with statistical techniques. Data were also extracted from Landsat TM and ETM+ images. The band ratio method was used to extract the coastlines. Topographic maps were also used to extract digital map data. All data incorporated into ArcGIS 9.2 were analyzed with various modules, including Spatial Analyst, 3D Analyst, and Triangulated Irregular Networks. The Digital Shoreline Analysis System was used to analyze and predict rates of coastline change. GIS results showed the spatial locations along the coast that will either advance or retreat over time. The linear regression results highlighted temporal changes which are likely to occur along the coastline. Box-Jenkins modelling procedures were utilized to determine statistical models which best described the time series (1941--2007) of coastline change data. After several iterations and goodness-of-fit tests, second-order spatial cyclic autoregressive models, first-order autoregressive models and autoregressive moving average models were identified as being appropriate for describing the deterministic and random processes operating in Guyana's coastal system. The models highlighted not only cyclical patterns in advance and retreat of the coastline, but also the existence of short and long-term memory processes. Long-term memory processes could be associated with mudshoal propagation and stabilization while short-term memory processes were indicative of transitory hydrodynamic and other processes. An innovative framework for a spatio-temporal information-based system (STIBS) was developed. STIBS incorporated diverse datasets within a GIS, dynamic computer-based simulation models, and a spatial information query and graphical subsystem. Tests of the STIBS proved that it could be used to simulate and visualize temporal variability in shifting morphological states of the coastline.

Machine processing of remotely sensed data - quantifying global process: Models, sensor systems, and analytical methods; Proceedings of the Eleventh International Symposium, Purdue University, West Lafayette, IN, June 25-27, 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mengel, S.K.; Morrison, D.B.

1985-01-01

Consideration is given to global biogeochemical issues, image processing, remote sensing of tropical environments, global processes, geology, landcover hydrology, and ecosystems modeling. Topics discussed include multisensor remote sensing strategies, geographic information systems, radars, and agricultural remote sensing. Papers are presented on fast feature extraction; a computational approach for adjusting TM imagery terrain distortions; the segmentation of a textured image by a maximum likelihood classifier; analysis of MSS Landsat data; sun angle and background effects on spectral response of simulated forest canopies; an integrated approach for vegetation/landcover mapping with digital Landsat images; geological and geomorphological studies using an image processing technique;more » and wavelength intensity indices in relation to tree conditions and leaf-nutrient content.« less

igun - A program for the simulation of positive ion extraction including magnetic fields

NASA Astrophysics Data System (ADS)

Becker, R.; Herrmannsfeldt, W. B.

1992-04-01

igun is a program for the simulation of positive ion extraction from plasmas. It is based on the well known program egun for the calculation of electron and ion trajectories in electron guns and lenses. The mathematical treatment of the plasma sheath is based on a simple analytical model, which provides a numerically stable calculation of the sheath potentials. In contrast to other ion extraction programs, igun is able to determine the extracted ion current in succeeding cycles of iteration by itself. However, it is also possible to set values of current, plasma density, or ion current density. Either axisymmetric or rectangular coordinates can be used, including axisymmetric or transverse magnetic fields.

Extractive fermentation of xylanase from Aspergillus tamarii URM 4634 in a bioreactor.

PubMed

da Silva, Anna Carolina; Soares de França Queiroz, Alana Emília; Evaristo dos Santos Nascimento, Talita Camila; Rodrigues, Cristine; Gomes, José Erick Galindo; Souza-Motta, Cristina Maria; Porto de Souza Vandenberghe, Luciana; Valente de Medeiros, Erika; Moreira, Keila Aparecida; Herculano, Polyanna Nunes

2014-08-01

Of the many reported applications for xylanase, its use as a food supplement has played an important role for monogastric animals, because it can improve the utilisation of nutrients. The aim of this work was to produce xylanase by extractive fermentation in an aqueous two-phase system using Aspergillus tamarii URM 4634, increasing the scale of production in a bioreactor, partially characterising the xylanase and evaluating its influence on monogastric digestion in vitro. Through extractive fermentation in a bioreactor, xylanase was obtained with an activity of 331.4 U mL(-1) and 72% yield. The xylanase was stable under variable pH and temperature conditions, and it was optimally active at pH 3.6 and 90 °C. Xylanase activity potentiated the simulation of complete monogastric digestion by 6%, and only Mg2+ inhibited its activity. This process provides a system for efficient xylanase production by A. tamarii URM 4634 that has great potential for industrial use.

Direct Extraction of Tumor Response Based on Ensemble Empirical Mode Decomposition for Image Reconstruction of Early Breast Cancer Detection by UWB.

PubMed

Li, Qinwei; Xiao, Xia; Wang, Liang; Song, Hang; Kono, Hayato; Liu, Peifang; Lu, Hong; Kikkawa, Takamaro

2015-10-01

A direct extraction method of tumor response based on ensemble empirical mode decomposition (EEMD) is proposed for early breast cancer detection by ultra-wide band (UWB) microwave imaging. With this approach, the image reconstruction for the tumor detection can be realized with only extracted signals from as-detected waveforms. The calibration process executed in the previous research for obtaining reference waveforms which stand for signals detected from the tumor-free model is not required. The correctness of the method is testified by successfully detecting a 4 mm tumor located inside the glandular region in one breast model and by the model located at the interface between the gland and the fat, respectively. The reliability of the method is checked by distinguishing a tumor buried in the glandular tissue whose dielectric constant is 35. The feasibility of the method is confirmed by showing the correct tumor information in both simulation results and experimental results for the realistic 3-D printed breast phantom.

Extraction of Water from Polar Lunar Permafrost with Microwaves - Dielectric Property Measurements

NASA Technical Reports Server (NTRS)

Ethridge, Edwin C.; Kaukler, William

2009-01-01

Remote sensing indicates the presence of hydrogen rich regions associated with the lunar poles. The logical hypothesis is that there is cryogenically trapped water ice located in craters at the lunar poles. Some of the craters have been in permanent darkness for a billion years. The presence of water at the poles as well as other scientific advantages of a polar base, have influenced NASA plans for the lunar outpost. The lunar outpost has water and oxygen requirements on the order of 1 ton per year scaling up to as much as 10 tons per year. Microwave heating of the frozen permafrost has unique advantages for water extraction. Proof of principle experiments have successfully demonstrated that microwaves will couple to the cryogenic soil in a vacuum and the sublimed water vapor can be successfully captured on a cold trap. The dielectric properties of lunar soil will determine the hardware requirements for extraction processes. Microwave frequency dielectric property measurements of lunar soil simulant have been measured.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinnett, Jacob; Sullivan, Clair J.; Xiong, Hao

Low-resolution isotope identifiers are widely deployed for nuclear security purposes, but these detectors currently demonstrate problems in making correct identifications in many typical usage scenarios. While there are many hardware alternatives and improvements that can be made, performance on existing low resolution isotope identifiers should be able to be improved by developing new identification algorithms. We have developed a wavelet-based peak extraction algorithm and an implementation of a Bayesian classifier for automated peak-based identification. The peak extraction algorithm has been extended to compute uncertainties in the peak area calculations. To build empirical joint probability distributions of the peak areas andmore » uncertainties, a large set of spectra were simulated in MCNP6 and processed with the wavelet-based feature extraction algorithm. Kernel density estimation was then used to create a new component of the likelihood function in the Bayesian classifier. Furthermore, identification performance is demonstrated on a variety of real low-resolution spectra, including Category I quantities of special nuclear material.« less

A new method for the prediction of chatter stability lobes based on dynamic cutting force simulation model and support vector machine

NASA Astrophysics Data System (ADS)

Peng, Chong; Wang, Lun; Liao, T. Warren

2015-10-01

Currently, chatter has become the critical factor in hindering machining quality and productivity in machining processes. To avoid cutting chatter, a new method based on dynamic cutting force simulation model and support vector machine (SVM) is presented for the prediction of chatter stability lobes. The cutting force is selected as the monitoring signal, and the wavelet energy entropy theory is used to extract the feature vectors. A support vector machine is constructed using the MATLAB LIBSVM toolbox for pattern classification based on the feature vectors derived from the experimental cutting data. Then combining with the dynamic cutting force simulation model, the stability lobes diagram (SLD) can be estimated. Finally, the predicted results are compared with existing methods such as zero-order analytical (ZOA) and semi-discretization (SD) method as well as actual cutting experimental results to confirm the validity of this new method.

Modeling and numerical simulations of growth and morphologies of three dimensional aggregated silver films

NASA Astrophysics Data System (ADS)

Davis, L. J.; Boggess, M.; Kodpuak, E.; Deutsch, M.

2012-11-01

We report on a model for the deposition of three dimensional, aggregated nanocrystalline silver films, and an efficient numerical simulation method developed for visualizing such structures. We compare our results to a model system comprising chemically deposited silver films with morphologies ranging from dilute, uniform distributions of nanoparticles to highly porous aggregated networks. Disordered silver films grown in solution on silica substrates are characterized using digital image analysis of high resolution scanning electron micrographs. While the latter technique provides little volume information, plane-projected (two dimensional) island structure and surface coverage may be reliably determined. Three parameters governing film growth are evaluated using these data and used as inputs for the deposition model, greatly reducing computing requirements while still providing direct access to the complete (bulk) structure of the films throughout the growth process. We also show how valuable three dimensional characteristics of the deposited materials can be extracted using the simulated structures.

Petascale Kinetic Simulations in Space Sciences: New Simulations and Data Discovery Techniques and Physics Results

NASA Astrophysics Data System (ADS)

Karimabadi, Homa

2012-03-01

Recent advances in simulation technology and hardware are enabling breakthrough science where many longstanding problems can now be addressed for the first time. In this talk, we focus on kinetic simulations of the Earth's magnetosphere and magnetic reconnection process which is the key mechanism that breaks the protective shield of the Earth's dipole field, allowing the solar wind to enter the Earth's magnetosphere. This leads to the so-called space weather where storms on the Sun can affect space-borne and ground-based technological systems on Earth. The talk will consist of three parts: (a) overview of a new multi-scale simulation technique where each computational grid is updated based on its own unique timestep, (b) Presentation of a new approach to data analysis that we refer to as Physics Mining which entails combining data mining and computer vision algorithms with scientific visualization to extract physics from the resulting massive data sets. (c) Presentation of several recent discoveries in studies of space plasmas including the role of vortex formation and resulting turbulence in magnetized plasmas.

Simulation of Martian surface conditions and dust transport

NASA Astrophysics Data System (ADS)

Nørnberg, P.; Merrison, J. P.; Finster, K.; Folkmann, F.; Gunnlaugsson, H. P.; Hansen, A.; Jensen, J.; Kinch, K.; Lomstein, B. Aa.; Mugford, R.

2002-11-01

The suspended atmospheric dust which is also found deposited over most of the Martian globe plays an important (possibly vital) role in shaping the surface environment. It affects the weather (solar flux), water transport and possibly also the electrical properties at the surface. The simulation facilities at Aarhus provide excellent tools for studying the properties of this Martian environment. Much can be learned from such simulations, supporting and often inspiring new investigations of the planet. Electrical charging of a Mars analogue dust is being studied within a wind tunnel simulation aerosol. Here electric fields are used to extract dust from suspension. Although preliminary the results indicate that a large fraction of the dust is charged to a high degree, sufficient to dominate adhesion/cohesion processes. A Mars analogue dust layer has been shown to be an excellent trap for moisture, causing increased humidity in the soil below. This allows the possibility for liquid water to be stable close to the surface (less than 10 cm). This is being investigated in an environment simulator where heat and moisture transport can be studied through layers of Mars analogue dust.

Fetal ECG extraction from abdominal signals: a review on suppression of fundamental power line interference component and its harmonics.

PubMed

Ţarălungă, Dragoş-Daniel; Ungureanu, Georgeta-Mihaela; Gussi, Ilinca; Strungaru, Rodica; Wolf, Werner

2014-01-01

Interference of power line (PLI) (fundamental frequency and its harmonics) is usually present in biopotential measurements. Despite all countermeasures, the PLI still corrupts physiological signals, for example, electromyograms (EMG), electroencephalograms (EEG), and electrocardiograms (ECG). When analyzing the fetal ECG (fECG) recorded on the maternal abdomen, the PLI represents a particular strong noise component, being sometimes 10 times greater than the fECG signal, and thus impairing the extraction of any useful information regarding the fetal health state. Many signal processing methods for cancelling the PLI from biopotentials are available in the literature. In this review study, six different principles are analyzed and discussed, and their performance is evaluated on simulated data (three different scenarios), based on five quantitative performance indices.

Fetal ECG Extraction from Abdominal Signals: A Review on Suppression of Fundamental Power Line Interference Component and Its Harmonics

PubMed Central

Ţarălungă, Dragoş-Daniel; Ungureanu, Georgeta-Mihaela; Gussi, Ilinca; Strungaru, Rodica; Wolf, Werner

2014-01-01

Interference of power line (PLI) (fundamental frequency and its harmonics) is usually present in biopotential measurements. Despite all countermeasures, the PLI still corrupts physiological signals, for example, electromyograms (EMG), electroencephalograms (EEG), and electrocardiograms (ECG). When analyzing the fetal ECG (fECG) recorded on the maternal abdomen, the PLI represents a particular strong noise component, being sometimes 10 times greater than the fECG signal, and thus impairing the extraction of any useful information regarding the fetal health state. Many signal processing methods for cancelling the PLI from biopotentials are available in the literature. In this review study, six different principles are analyzed and discussed, and their performance is evaluated on simulated data (three different scenarios), based on five quantitative performance indices. PMID:24660020

The role of vegetation on gully stabilization at a severely degraded landscape: a case study from Calhoun experimental critical zone observatory

NASA Astrophysics Data System (ADS)

Dialynas, Y. G.; Bastola, S.; Bras, R. L.; Noto, L. V.; Istanbulluoglu, E.

2016-12-01

Gully erosion was the primary driver of land degradation in Southern Piedmont, site of the Calhoun Critical Zone Observatory (CCZO), during the cotton farming era. Understanding of underlying erosion processes is essential to develop a model useful in assessing the effectiveness of gully stabilization and soil erosion control. Development of process-based gully erosion models is difficult because observations of the formation and progression of gullies are limited. In this study, analytic formulations of the two dominant gullying processes, namely, plunge pool erosion and slab failure, are utilized to simulate the gullying processes in the 4 km2 Holcombe's Branch watershed. Gully features (e.g., depth and area) automatically extracted from high-resolution LiDAR DEM are used to calibrate parameters of the gully model. The statistics of the spatial extent of simulated gullies are in close agreement with the gullies obtained from the LiDAR map. Simulations initialized with contemporary topography suggest that few gully complexes have the potential to progress further. Several simulations are used to evaluate the effectiveness of various gully treatment measures, such as backfilling of gullies and revegetation, by initializing the model with the historical topographical surface. Simulation results show that in the short-term, the reshaping of the topographical surface by backfilling and compacting gullies is effective in slowing down the growth of gullies (e.g., backfilling decreased the spatial extent of gullies by 20-38% and decreased the average depth by 0.005-8%). Revegetation, however, is a more effective approach to stabilizing gullies which would, otherwise, expand if left barren. Moreover simulations suggest that the gully stabilization effect of revegetation can lead to a 23-70% reduction of gully area and 1.3-45% reduction in the depth of gullies, depending on forest type and management practices.

Sensor Analytics: Radioactive gas Concentration Estimation and Error Propagation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Dale N.; Fagan, Deborah K.; Suarez, Reynold

2007-04-15

This paper develops the mathematical statistics of a radioactive gas quantity measurement and associated error propagation. The probabilistic development is a different approach to deriving attenuation equations and offers easy extensions to more complex gas analysis components through simulation. The mathematical development assumes a sequential process of three components; I) the collection of an environmental sample, II) component gas extraction from the sample through the application of gas separation chemistry, and III) the estimation of radioactivity of component gases.

Multisite EPR oximetry from multiple quadrature harmonics.

PubMed

Ahmad, R; Som, S; Johnson, D H; Zweier, J L; Kuppusamy, P; Potter, L C

2012-01-01

Multisite continuous wave (CW) electron paramagnetic resonance (EPR) oximetry using multiple quadrature field modulation harmonics is presented. First, a recently developed digital receiver is used to extract multiple harmonics of field modulated projection data. Second, a forward model is presented that relates the projection data to unknown parameters, including linewidth at each site. Third, a maximum likelihood estimator of unknown parameters is reported using an iterative algorithm capable of jointly processing multiple quadrature harmonics. The data modeling and processing are applicable for parametric lineshapes under nonsaturating conditions. Joint processing of multiple harmonics leads to 2-3-fold acceleration of EPR data acquisition. For demonstration in two spatial dimensions, both simulations and phantom studies on an L-band system are reported. Copyright © 2011 Elsevier Inc. All rights reserved.

THERMO-HYDRO-MECHANICAL MODELING OF WORKING FLUID INJECTION AND THERMAL ENERGY EXTRACTION IN EGS FRACTURES AND ROCK MATRIX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert Podgorney; Chuan Lu; Hai Huang

2012-01-01

Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing), to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid-heat system and our ability to reliably predict how reservoirs behave under stimulation and production. Reliable performance predictions ofmore » EGS reservoirs require accurate and robust modeling for strongly coupled thermal-hydrological-mechanical (THM) processes. Conventionally, these types of problems have been solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulators with a solid mechanics simulator via input files. An alternative approach is to solve the system of nonlinear partial differential equations that govern multiphase fluid flow, heat transport, and rock mechanics simultaneously, using a fully coupled, fully implicit solution procedure, in which all solution variables (pressure, enthalpy, and rock displacement fields) are solved simultaneously. This paper describes numerical simulations used to investigate the poro- and thermal- elastic effects of working fluid injection and thermal energy extraction on the properties of the fractures and rock matrix of a hypothetical EGS reservoir, using a novel simulation software FALCON (Podgorney et al., 2011), a finite element based simulator solving fully coupled multiphase fluid flow, heat transport, rock deformation, and fracturing using a global implicit approach. Investigations are also conducted on how these poro- and thermal-elastic effects are related to fracture permeability evolution.« less

Inferring the photometric and size evolution of galaxies from image simulations. I. Method

NASA Astrophysics Data System (ADS)

Carassou, Sébastien; de Lapparent, Valérie; Bertin, Emmanuel; Le Borgne, Damien

2017-09-01

Context. Current constraints on models of galaxy evolution rely on morphometric catalogs extracted from multi-band photometric surveys. However, these catalogs are altered by selection effects that are difficult to model, that correlate in non trivial ways, and that can lead to contradictory predictions if not taken into account carefully. Aims: To address this issue, we have developed a new approach combining parametric Bayesian indirect likelihood (pBIL) techniques and empirical modeling with realistic image simulations that reproduce a large fraction of these selection effects. This allows us to perform a direct comparison between observed and simulated images and to infer robust constraints on model parameters. Methods: We use a semi-empirical forward model to generate a distribution of mock galaxies from a set of physical parameters. These galaxies are passed through an image simulator reproducing the instrumental characteristics of any survey and are then extracted in the same way as the observed data. The discrepancy between the simulated and observed data is quantified, and minimized with a custom sampling process based on adaptive Markov chain Monte Carlo methods. Results: Using synthetic data matching most of the properties of a Canada-France-Hawaii Telescope Legacy Survey Deep field, we demonstrate the robustness and internal consistency of our approach by inferring the parameters governing the size and luminosity functions and their evolutions for different realistic populations of galaxies. We also compare the results of our approach with those obtained from the classical spectral energy distribution fitting and photometric redshift approach. Conclusions: Our pipeline infers efficiently the luminosity and size distribution and evolution parameters with a very limited number of observables (three photometric bands). When compared to SED fitting based on the same set of observables, our method yields results that are more accurate and free from systematic biases.

Hydration of Caffeine at High Temperature by Neutron Scattering and Simulation Studies.

PubMed

Tavagnacco, L; Brady, J W; Bruni, F; Callear, S; Ricci, M A; Saboungi, M L; Cesàro, A

2015-10-22

The solvation of caffeine in water is examined with neutron diffraction experiments at 353 K. The experimental data, obtained by taking advantage of isotopic H/D substitution in water, were analyzed by empirical potential structure refinement (EPSR) in order to extract partial structure factors and site-site radial distribution functions. In parallel, molecular dynamics (MD) simulations were carried out to interpret the data and gain insight into the intermolecular interactions in the solutions and the solvation process. The results obtained with the two approaches evidence differences in the individual radial distribution functions, although both confirm the presence of caffeine stacks at this temperature. The two approaches point to different accessibility of water to the caffeine sites due to different stacking configurations.

Efficient in-situ visualization of unsteady flows in climate simulation

NASA Astrophysics Data System (ADS)

Vetter, Michael; Olbrich, Stephan

2017-04-01

The simulation of climate data tends to produce very large data sets, which hardly can be processed in classical post-processing visualization applications. Typically, the visualization pipeline consisting of the processes data generation, visualization mapping and rendering is distributed into two parts over the network or separated via file transfer. Within most traditional post-processing scenarios the simulation is done on a supercomputer whereas the data analysis and visualization is done on a graphics workstation. That way temporary data sets with huge volume have to be transferred over the network, which leads to bandwidth bottlenecks and volume limitations. The solution to this issue is the avoidance of temporary storage, or at least significant reduction of data complexity. Within the Climate Visualization Lab - as part of the Cluster of Excellence "Integrated Climate System Analysis and Prediction" (CliSAP) at the University of Hamburg, in cooperation with the German Climate Computing Center (DKRZ) - we develop and integrate an in-situ approach. Our software framework DSVR is based on the separation of the process chain between the mapping and the rendering processes. It couples the mapping process directly to the simulation by calling methods of a parallelized data extraction library, which create a time-based sequence of geometric 3D scenes. This sequence is stored on a special streaming server with an interactive post-filtering option and then played-out asynchronously in a separate 3D viewer application. Since the rendering is part of this viewer application, the scenes can be navigated interactively. In contrast to other in-situ approaches where 2D images are created as part of the simulation or synchronous co-visualization takes place, our method supports interaction in 3D space and in time, as well as fixed frame rates. To integrate in-situ processing based on our DSVR framework and methods in the ICON climate model, we are continuously evolving the data structures and mapping algorithms of the framework to support the ICON model's native grid structures, since DSVR originally was designed for rectilinear grids only. We now have implemented a new output module to ICON to take advantage of the DSVR visualization. The visualization can be configured as most output modules by using a specific namelist and is exemplarily integrated within the non-hydrostatic atmospheric model time loop. With the integration of a DSVR based in-situ pathline extraction within ICON, a further milestone is reached. The pathline algorithm as well as the grid data structures have been optimized for the domain decomposition used for the parallelization of ICON based on MPI and OpenMP. The software implementation and evaluation is done on the supercomputers at DKRZ. In principle, the data complexity is reduced from O(n3) to O(m), where n is the grid resolution and m the number of supporting point of all pathlines. The stability and scalability evaluation is done using Atmospheric Model Intercomparison Project (AMIP) runs. We will give a short introduction in our software framework, as well as a short overview on the implementation and usage of DSVR within ICON. Furthermore, we will present visualization and evaluation results of sample applications.

Extraction and Separation Modeling of Orion Test Vehicles with ADAMS Simulation

NASA Technical Reports Server (NTRS)

Fraire, Usbaldo, Jr.; Anderson, Keith; Cuthbert, Peter A.

2013-01-01

The Capsule Parachute Assembly System (CPAS) project has increased efforts to demonstrate the performance of fully integrated parachute systems at both higher dynamic pressures and in the presence of wake fields using a Parachute Compartment Drop Test Vehicle (PCDTV) and a Parachute Test Vehicle (PTV), respectively. Modeling the extraction and separation events has proven challenging and an understanding of the physics is required to reduce the risk of separation malfunctions. The need for extraction and separation modeling is critical to a successful CPAS test campaign. Current PTV-alone simulations, such as Decelerator System Simulation (DSS), require accurate initial conditions (ICs) drawn from a separation model. Automatic Dynamic Analysis of Mechanical Systems (ADAMS), a Commercial off the Shelf (COTS) tool, was employed to provide insight into the multi-body six degree of freedom (DOF) interaction between parachute test hardware and external and internal forces. Components of the model include a composite extraction parachute, primary vehicle (PTV or PCDTV), platform cradle, a release mechanism, aircraft ramp, and a programmer parachute with attach points. Independent aerodynamic forces were applied to the mated test vehicle/platform cradle and the separated test vehicle and platform cradle. The aero coefficients were determined from real time lookup tables which were functions of both angle of attack ( ) and sideslip ( ). The atmospheric properties were also determined from a real time lookup table characteristic of the Yuma Proving Grounds (YPG) atmosphere relative to the planned test month. Representative geometries were constructed in ADAMS with measured mass properties generated for each independent vehicle. Derived smart separation parameters were included in ADAMS as sensors with defined pitch and pitch rate criteria used to refine inputs to analogous avionics systems for optimal separation conditions. Key design variables were dispersed in a Monte Carlo analysis to provide the maximum expected range of the state variables at programmer deployment to be used as ICs in DSS. Extensive comparisons were made with Decelerator System Simulation Application (DSSA) to validate the mated portion of the ADAMS extraction trajectory. Results of the comparisons improved the fidelity of ADAMS with a ramp pitch profile update from DSSA. Post-test reconstructions resulted in improvements to extraction parachute drag area knock-down factors, extraction line modeling, and the inclusion of ball-to-socket attachments used as a release mechanism on the PTV. Modeling of two Extraction parachutes was based on United States Air Force (USAF) tow test data and integrated into ADAMS for nominal and Monte Carlo trajectory assessments. Video overlay of ADAMS animations and actual C-12 chase plane test videos supported analysis and observation efforts of extraction and separation events. The COTS ADAMS simulation has been integrated with NASA based simulations to provide complete end to end trajectories with a focus on the extraction, separation, and programmer deployment sequence. The flexibility of modifying ADAMS inputs has proven useful for sensitivity studies and extraction/separation modeling efforts. 1

A New Efficient Hybrid Intelligent Model for Biodegradation Process of DMP with Fuzzy Wavelet Neural Networks

NASA Astrophysics Data System (ADS)

Huang, Mingzhi; Zhang, Tao; Ruan, Jujun; Chen, Xiaohong

2017-01-01

A new efficient hybrid intelligent approach based on fuzzy wavelet neural network (FWNN) was proposed for effectively modeling and simulating biodegradation process of Dimethyl phthalate (DMP) in an anaerobic/anoxic/oxic (AAO) wastewater treatment process. With the self learning and memory abilities of neural networks (NN), handling uncertainty capacity of fuzzy logic (FL), analyzing local details superiority of wavelet transform (WT) and global search of genetic algorithm (GA), the proposed hybrid intelligent model can extract the dynamic behavior and complex interrelationships from various water quality variables. For finding the optimal values for parameters of the proposed FWNN, a hybrid learning algorithm integrating an improved genetic optimization and gradient descent algorithm is employed. The results show, compared with NN model (optimized by GA) and kinetic model, the proposed FWNN model have the quicker convergence speed, the higher prediction performance, and smaller RMSE (0.080), MSE (0.0064), MAPE (1.8158) and higher R2 (0.9851) values. which illustrates FWNN model simulates effluent DMP more accurately than the mechanism model.

A New Efficient Hybrid Intelligent Model for Biodegradation Process of DMP with Fuzzy Wavelet Neural Networks

PubMed Central

Huang, Mingzhi; Zhang, Tao; Ruan, Jujun; Chen, Xiaohong

2017-01-01

A new efficient hybrid intelligent approach based on fuzzy wavelet neural network (FWNN) was proposed for effectively modeling and simulating biodegradation process of Dimethyl phthalate (DMP) in an anaerobic/anoxic/oxic (AAO) wastewater treatment process. With the self learning and memory abilities of neural networks (NN), handling uncertainty capacity of fuzzy logic (FL), analyzing local details superiority of wavelet transform (WT) and global search of genetic algorithm (GA), the proposed hybrid intelligent model can extract the dynamic behavior and complex interrelationships from various water quality variables. For finding the optimal values for parameters of the proposed FWNN, a hybrid learning algorithm integrating an improved genetic optimization and gradient descent algorithm is employed. The results show, compared with NN model (optimized by GA) and kinetic model, the proposed FWNN model have the quicker convergence speed, the higher prediction performance, and smaller RMSE (0.080), MSE (0.0064), MAPE (1.8158) and higher R2 (0.9851) values. which illustrates FWNN model simulates effluent DMP more accurately than the mechanism model. PMID:28120889

Three-Dimensional Geometric Modeling of Membrane-bound Organelles in Ventricular Myocytes: Bridging the Gap between Microscopic Imaging and Mathematical Simulation

PubMed Central

Yu, Zeyun; Holst, Michael J.; Hayashi, Takeharu; Bajaj, Chandrajit L.; Ellisman, Mark H.; McCammon, J. Andrew; Hoshijima, Masahiko

2009-01-01

A general framework of image-based geometric processing is presented to bridge the gap between three-dimensional (3D) imaging that provides structural details of a biological system and mathematical simulation where high-quality surface or volumetric meshes are required. A 3D density map is processed in the order of image pre-processing (contrast enhancement and anisotropic filtering), feature extraction (boundary segmentation and skeletonization), and high-quality and realistic surface (triangular) and volumetric (tetrahedral) mesh generation. While the tool-chain described is applicable to general types of 3D imaging data, the performance is demonstrated specifically on membrane-bound organelles in ventricular myocytes that are imaged and reconstructed with electron microscopic (EM) tomography and two-photon microscopy (T-PM). Of particular interest in this study are two types of membrane-bound Ca2+-handling organelles, namely, transverse tubules (T-tubules) and junctional sarcoplasmic reticulum (jSR), both of which play an important role in regulating the excitation-contraction (E-C) coupling through dynamic Ca2+ mobilization in cardiomyocytes. PMID:18835449

Three-dimensional geometric modeling of membrane-bound organelles in ventricular myocytes: bridging the gap between microscopic imaging and mathematical simulation.

PubMed

Yu, Zeyun; Holst, Michael J; Hayashi, Takeharu; Bajaj, Chandrajit L; Ellisman, Mark H; McCammon, J Andrew; Hoshijima, Masahiko

2008-12-01

A general framework of image-based geometric processing is presented to bridge the gap between three-dimensional (3D) imaging that provides structural details of a biological system and mathematical simulation where high-quality surface or volumetric meshes are required. A 3D density map is processed in the order of image pre-processing (contrast enhancement and anisotropic filtering), feature extraction (boundary segmentation and skeletonization), and high-quality and realistic surface (triangular) and volumetric (tetrahedral) mesh generation. While the tool-chain described is applicable to general types of 3D imaging data, the performance is demonstrated specifically on membrane-bound organelles in ventricular myocytes that are imaged and reconstructed with electron microscopic (EM) tomography and two-photon microscopy (T-PM). Of particular interest in this study are two types of membrane-bound Ca(2+)-handling organelles, namely, transverse tubules (T-tubules) and junctional sarcoplasmic reticulum (jSR), both of which play an important role in regulating the excitation-contraction (E-C) coupling through dynamic Ca(2+) mobilization in cardiomyocytes.

Development of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) Process for Cesium Removal from High-Level Tank Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moyer, Bruce A; Bonnesen, Peter V; Delmau, Laetitia Helene

2011-01-01

This paper describes the chemical performance of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) process in its current state of development for removal of cesium from the alkaline high-level tank wastes at the Savannah River Site (SRS) in the US Department of Energy (USDOE) complex. Overall, motivation for seeking a major enhancement in performance for the currently deployed CSSX process stems from needs for accelerating the cleanup schedule and reducing the cost of salt-waste disposition. The primary target of the NG-CSSX development campaign in the past year has been to formulate a solvent system and to design a corresponding flowsheet thatmore » boosts the performance of the SRS Modular CSSX Unit (MCU) from a current minimum decontamination factor of 12 to 40,000. The chemical approach entails use of a more soluble calixarene-crown ether, called MaxCalix, allowing the attainment of much higher cesium distribution ratios (DCs) on extraction. Concurrently decreasing the Cs-7SB modifier concentration is anticipated to promote better hydraulics. A new stripping chemistry has been devised using a vitrification-friendly aqueous boric acid strip solution and a guanidine suppressor in the solvent, resulting in sharply decreased DCs on stripping. Results are reported herein on solvent phase behavior and batch Cs distribution for waste simulants and real waste together with a preliminary flowsheet applicable for implementation in the MCU. The new solvent will enable MCU to process a much wider range of salt feeds and thereby extend its service lifetime beyond its design life of three years. Other potential benefits of NG-CSSX include increased throughput of the SRS Salt Waste Processing Facility (SWPF), currently under construction, and an alternative modular near-tank application at Hanford.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, Ruth; Mamrosh, Darryl; Salih, Hafiz H.

Brine extraction is a promising strategy for the management of increased reservoir pressure, resulting from carbon dioxide (CO 2) injection in deep saline reservoirs. The extracted brines usually have high concentrations of total dissolved solids (TDS) and various contaminants, and require proper disposal or treatment. In this article, first by conducting a critical review, we evaluate the applicability, limits, and advantages or challenges of various commercially available and emerging desalination technologies that can potentially be employed to treat the highly saline brine (with TDS values >70.000 ppm) and those that are applicable to a ~200,000 ppm TDS brine extracted frommore » the Mt. Simon Sandstone, a potential CO 2 storage site in Illinois, USA. Based on the side-by-side comparison of technologies, evaporators are selected as the most suitable existing technology for treating Mt. Simon brine. Process simulations are then conducted for a conceptual design for desalination of 454 m 3/h (2000 gpm) pretreated brine for near-zero liquid discharge by multi-effect evaporators. In conclusion, the thermal energy demand is estimated at 246kWh perm 3 of recoveredwater, ofwhich 212kWh/m 3 is required for multiple-effect evaporation and the remainder for salt drying. The process also requires additional electrical power of ~2 kWh/m 3.« less

Numerical framework for the modeling of electrokinetic flows

NASA Astrophysics Data System (ADS)

Deshpande, Manish; Ghaddar, Chahid; Gilbert, John R.; St. John, Pamela M.; Woudenberg, Timothy M.; Connell, Charles R.; Molho, Joshua; Herr, Amy; Mungal, Godfrey; Kenny, Thomas W.

1998-09-01

This paper presents a numerical framework for design-based analyses of electrokinetic flow in interconnects. Electrokinetic effects, which can be broadly divided into electrophoresis and electroosmosis, are of importance in providing a transport mechanism in microfluidic devices for both pumping and separation. Models for the electrokinetic effects can be derived and coupled to the fluid dynamic equations through appropriate source terms. In the design of practical microdevices, however, accurate coupling of the electrokinetic effects requires the knowledge of several material and physical parameters, such as the diffusivity and the mobility of the solute in the solvent. Additionally wall-based effects such as chemical binding sites might exist that affect the flow patterns. In this paper, we address some of these issues by describing a synergistic numerical/experimental process to extract the parameters required. Experiments were conducted to provide the numerical simulations with a mechanism to extract these parameters based on quantitative comparisons with each other. These parameters were then applied in predicting further experiments to validate the process. As part of this research, we have created NetFlow, a tool for micro-fluid analyses. The tool can be validated and applied in existing technologies by first creating test structures to extract representations of the physical phenomena in the device, and then applying them in the design analyses to predict correct behavior.

Tracking Simulation of Third-Integer Resonant Extraction for Fermilab's Mu2e Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Chong Shik; Amundson, James; Michelotti, Leo

2015-02-13

The Mu2e experiment at Fermilab requires acceleration and transport of intense proton beams in order to deliver stable, uniform particle spills to the production target. To meet the experimental requirement, particles will be extracted slowly from the Delivery Ring to the external beamline. Using Synergia2, we have performed multi-particle tracking simulations of third-integer resonant extraction in the Delivery Ring, including space charge effects, physical beamline elements, and apertures. A piecewise linear ramp profile of tune quadrupoles was used to maintain a constant averaged spill rate throughout extraction. To study and minimize beam losses, we implemented and introduced a number ofmore » features, beamline element apertures, and septum plane alignments. Additionally, the RF Knockout (RFKO) technique, which excites particles transversely, is employed for spill regulation. Combined with a feedback system, it assists in fine-tuning spill uniformity. Simulation studies were carried out to optimize the RFKO feedback scheme, which will be helpful in designing the final spill regulation system.« less

Prediction of the Vickers Microhardness and Ultimate Tensile Strength of AA5754 H111 Friction Stir Welding Butt Joints Using Artificial Neural Network.

PubMed

De Filippis, Luigi Alberto Ciro; Serio, Livia Maria; Facchini, Francesco; Mummolo, Giovanni; Ludovico, Antonio Domenico

2016-11-10

A simulation model was developed for the monitoring, controlling and optimization of the Friction Stir Welding (FSW) process. This approach, using the FSW technique, allows identifying the correlation between the process parameters (input variable) and the mechanical properties (output responses) of the welded AA5754 H111 aluminum plates. The optimization of technological parameters is a basic requirement for increasing the seam quality, since it promotes a stable and defect-free process. Both the tool rotation and the travel speed, the position of the samples extracted from the weld bead and the thermal data, detected with thermographic techniques for on-line control of the joints, were varied to build the experimental plans. The quality of joints was evaluated through destructive and non-destructive tests (visual tests, macro graphic analysis, tensile tests, indentation Vickers hardness tests and t thermographic controls). The simulation model was based on the adoption of the Artificial Neural Networks (ANNs) characterized by back-propagation learning algorithm with different types of architecture, which were able to predict with good reliability the FSW process parameters for the welding of the AA5754 H111 aluminum plates in Butt-Joint configuration.

A Subsystem Test Bed for Chinese Spectral Radioheliograph

NASA Astrophysics Data System (ADS)

Zhao, An; Yan, Yihua; Wang, Wei

2014-11-01

The Chinese Spectral Radioheliograph is a solar dedicated radio interferometric array that will produce high spatial resolution, high temporal resolution, and high spectral resolution images of the Sun simultaneously in decimetre and centimetre wave range. Digital processing of intermediate frequency signal is an important part in a radio telescope. This paper describes a flexible and high-speed digital down conversion system for the CSRH by applying complex mixing, parallel filtering, and extracting algorithms to process IF signal at the time of being designed and incorporates canonic-signed digit coding and bit-plane method to improve program efficiency. The DDC system is intended to be a subsystem test bed for simulation and testing for CSRH. Software algorithms for simulation and hardware language algorithms based on FPGA are written which use less hardware resources and at the same time achieve high performances such as processing high-speed data flow (1 GHz) with 10 MHz spectral resolution. An experiment with the test bed is illustrated by using geostationary satellite data observed on March 20, 2014. Due to the easy alterability of the algorithms on FPGA, the data can be recomputed with different digital signal processing algorithms for selecting optimum algorithm.

Noise tolerant illumination optimization applied to display devices

NASA Astrophysics Data System (ADS)

Cassarly, William J.; Irving, Bruce

2005-02-01

Display devices have historically been designed through an iterative process using numerous hardware prototypes. This process is effective but the number of iterations is limited by the time and cost to make the prototypes. In recent years, virtual prototyping using illumination software modeling tools has replaced many of the hardware prototypes. Typically, the designer specifies the design parameters, builds the software model, predicts the performance using a Monte Carlo simulation, and uses the performance results to repeat this process until an acceptable design is obtained. What is highly desired, and now possible, is to use illumination optimization to automate the design process. Illumination optimization provides the ability to explore a wider range of design options while also providing improved performance. Since Monte Carlo simulations are often used to calculate the system performance but those predictions have statistical uncertainty, the use of noise tolerant optimization algorithms is important. The use of noise tolerant illumination optimization is demonstrated by considering display device designs that extract light using 2D paint patterns as well as 3D textured surfaces. A hybrid optimization approach that combines a mesh feedback optimization with a classical optimizer is demonstrated. Displays with LED sources and cold cathode fluorescent lamps are considered.

Objects Classification by Learning-Based Visual Saliency Model and Convolutional Neural Network.

PubMed

Li, Na; Zhao, Xinbo; Yang, Yongjia; Zou, Xiaochun

2016-01-01

Humans can easily classify different kinds of objects whereas it is quite difficult for computers. As a hot and difficult problem, objects classification has been receiving extensive interests with broad prospects. Inspired by neuroscience, deep learning concept is proposed. Convolutional neural network (CNN) as one of the methods of deep learning can be used to solve classification problem. But most of deep learning methods, including CNN, all ignore the human visual information processing mechanism when a person is classifying objects. Therefore, in this paper, inspiring the completed processing that humans classify different kinds of objects, we bring forth a new classification method which combines visual attention model and CNN. Firstly, we use the visual attention model to simulate the processing of human visual selection mechanism. Secondly, we use CNN to simulate the processing of how humans select features and extract the local features of those selected areas. Finally, not only does our classification method depend on those local features, but also it adds the human semantic features to classify objects. Our classification method has apparently advantages in biology. Experimental results demonstrated that our method made the efficiency of classification improve significantly.

Reactive transport modeling of subsurface arsenic removal systems in rural Bangladesh.

PubMed

Rahman, M M; Bakker, M; Patty, C H L; Hassan, Z; Röling, W F M; Ahmed, K M; van Breukelen, B M

2015-12-15

Subsurface Arsenic Removal (SAR) is a technique for in-situ removal of arsenic from groundwater. Extracted groundwater is aerated and re-injected into an anoxic aquifer, where the oxygen in the injected water reacts with ferrous iron in the aquifer to form hydrous ferric oxide (HFO). Subsequent extraction of groundwater contains temporarily lower As concentrations, because As sorbs onto the HFO. Injection, storage, and extraction together is called a cycle. A reactive transport model (RTM) was developed in PHREEQC to determine the hydrogeochemical processes responsible for As (im)mobilization during experimental SAR operation performed in Bangladesh. Oxidation of Fe(II) and As(III) were modeled using kinetic-rate expressions. Cation exchange, precipitation of HFO, and surface complexation, were modeled as equilibrium processes. A best set of surface complexation reactions and corresponding equilibrium constants was adopted from previous studies to simulate all 20 cycles of a SAR experiment. The model gives a reasonable match with observed concentrations of different elements in the extracted water (e.g., the r(2) value of As was 0.59 or higher). As concentrations in the extracted water are governed by four major processes. First, As concentration decreases in response to the elevated pH of injection water and likewise increases when native neutral pH groundwater flows in. Second, the sorption capacity for As increases due to the gradual buildup of HFO. Third, As sorption is enhanced by preferential removal of As(V). Fourth, competitive sorption of Si limits the capacity of freshly precipitated HFO for As sorption. Transferability of the developed reactive transport model was demonstrated through successful application of the model, without further calibration, to two additional SAR sites in Bangladesh. This gives confidence that the model could be useful to assess potential SAR performance at locations in Bangladesh based on local hydrogeochemical conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

PubMed

Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

2016-03-01

Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%. © 2016 Wiley Periodicals, Inc.

Solid-phase extraction and purification of membrane proteins using a UV-modified PMMA microfluidic bioaffinity μSPE device.

PubMed

Battle, Katrina N; Jackson, Joshua M; Witek, Małgorzata A; Hupert, Mateusz L; Hunsucker, Sally A; Armistead, Paul M; Soper, Steven A

2014-03-21

We present a novel microfluidic solid-phase extraction (μSPE) device for the affinity enrichment of biotinylated membrane proteins from whole cell lysates. The device offers features that address challenges currently associated with the extraction and purification of membrane proteins from whole cell lysates, including the ability to release the enriched membrane protein fraction from the extraction surface so that they are available for downstream processing. The extraction bed was fabricated in PMMA using hot embossing and was comprised of 3600 micropillars. Activation of the PMMA micropillars by UV/O3 treatment permitted generation of surface-confined carboxylic acid groups and the covalent attachment of NeutrAvidin onto the μSPE device surfaces, which was used to affinity select biotinylated MCF-7 membrane proteins directly from whole cell lysates. The inclusion of a disulfide linker within the biotin moiety permitted release of the isolated membrane proteins via DTT incubation. Very low levels (∼20 fmol) of membrane proteins could be isolated and recovered with ∼89% efficiency with a bed capacity of 1.7 pmol. Western blotting indicated no traces of cytosolic proteins in the membrane protein fraction as compared to significant contamination using a commercial detergent-based method. We highlight future avenues for enhanced extraction efficiency and increased dynamic range of the μSPE device using computational simulations of different micropillar geometries to guide future device designs.

Student and educator experiences of maternal-child simulation-based learning: a systematic review of qualitative evidence.

PubMed

MacKinnon, Karen; Marcellus, Lenora; Rivers, Julie; Gordon, Carol; Ryan, Maureen; Butcher, Diane

2017-11-01

Although maternal-child care is a pillar of primary health care, there is a global shortage of maternal-child health care providers. Nurse educators experience difficulties providing undergraduate students with maternal-child learning experiences for a number of reasons. Simulation has the potential to complement learning in clinical and classroom settings. Although systematic reviews of simulation are available, no systematic reviews of qualitative evidence related to maternal-child simulation-based learning (SBL) for undergraduate nursing students and/or educators have been located. The aim of this systematic review was to identify the appropriateness and meaningfulness of maternal-child simulation-based learning for undergraduate nursing students and nursing educators in educational settings to inform curriculum decision-making. The review questions are: INCLUSION CRITERIA TYPES OF PARTICIPANTS: Pre-registration or pre-licensure or undergraduate nursing or health professional students and educators. Experiences of simulation in an educational setting with a focus relevant to maternal child nursing. Qualitative research and educational evaluation using qualitative methods. North America, Europe, Australia and New Zealand. A three-step search strategy identified published studies in the English language from 2000 until April 2016. Identified studies that met the inclusion criteria were retrieved and critically appraised using the Joanna Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI) by at least two independent reviewers. Overall the methodological quality of the included studies was low. Qualitative findings were extracted by two independent reviewers using JBI-QARI data extraction tools. Findings were aggregated and categorized on the basis of similarity in meaning. Categories were subjected to a meta-synthesis to produce a single comprehensive set of synthesized findings. Twenty-two articles from 19 studies were included in the review. A total of 112 findings were extracted from the included articles. Findings were grouped into 15 categories created on the basis of similarity of meaning. Meta-synthesis of these categories generated three synthesized findings.Synthesized finding 1 Students experienced simulated learning experiences (SLE) as preparation that enhanced their confidence in practice. When simulation was being used for evaluation purposes many students experienced anxiety about the SLE.Synthesized finding 2 Pedagogical practices thought to be appropriate and meaningful included: realistic, relevant and engaging scenarios, a safe non-threatening learning environment, supportive guidance throughout the process, and integration with curriculum.Synthesized finding 3 Barriers and enablers to incorporating SLEs into maternal child education were identified including adequate resources, technological support and faculty development. Students and educators recognized that some things, such as relationship building, could not be simulated. Students felt that simulation prepared them for practice through building their self-confidence related to frequently and infrequently seen maternal-child scenarios. Specific pedagogical elements support the meaningfulness of the simulation for student learning. The presence or absence of resources impacts the capacity of educators to integrate simulation activities throughout curricula.

Validation of the SEPHIS Program for the Modeling of the HM Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyser, E.A.

The SEPHIS computer program is currently being used to evaluate the effect of all process variables on the criticality safety of the HM 1st Uranium Cycle process in H Canyon. The objective of its use has three main purposes. (1) To provide a better technical basis for those process variables that do not have any realistic effect on the criticality safety of the process. (2) To qualitatively study those conditions that have been previously recognized to affect the nuclear safety of the process or additional conditions that modeling has indicated may pose a criticality safety issue. (3) To judge themore » adequacy of existing or future neutron monitors locations in the detection of the initial stages of reflux for specific scenarios.Although SEPHIS generally over-predicts the distribution of uranium to the organic phase, it is a capable simulation tool as long as the user recognizes its biases and takes special care when using the program for scenarios where the prediction bias is non-conservative. The temperature coefficient used by SEPHIS is poor at predicting effect of temperature on uranium extraction for the 7.5 percent TBP used in the HM process. Therefore, SEPHIS should not be used to study temperature related scenarios. However, within normal operating temperatures when other process variables are being studied, it may be used. Care must be is given to understanding the prediction bias and its effect on any conclusion for the particular scenario that is under consideration. Uranium extraction with aluminum nitrate is over-predicted worse than for nitric acid systems. However, the extraction section of the 1A bank has sufficient excess capability that these errors, while relatively large, still allow SEPHIS to be used to develop reasonable qualitative assessments for reflux scenarios. However, high losses to the 1AW stream cannot be modeled by SEPHIS.« less

Testing a one-dimensional prescription of dynamical shear mixing with a two-dimensional hydrodynamic simulation

NASA Astrophysics Data System (ADS)

Edelmann, P. V. F.; Röpke, F. K.; Hirschi, R.; Georgy, C.; Jones, S.

2017-07-01

Context. The treatment of mixing processes is still one of the major uncertainties in 1D stellar evolution models. This is mostly due to the need to parametrize and approximate aspects of hydrodynamics in hydrostatic codes. In particular, the effect of hydrodynamic instabilities in rotating stars, for example, dynamical shear instability, evades consistent description. Aims: We intend to study the accuracy of the diffusion approximation to dynamical shear in hydrostatic stellar evolution models by comparing 1D models to a first-principle hydrodynamics simulation starting from the same initial conditions. Methods: We chose an initial model calculated with the stellar evolution code GENEC that is just at the onset of a dynamical shear instability but does not show any other instabilities (e.g., convection). This was mapped to the hydrodynamics code SLH to perform a 2D simulation in the equatorial plane. We compare the resulting profiles in the two codes and compute an effective diffusion coefficient for the hydro simulation. Results: Shear instabilities develop in the 2D simulation in the regions predicted by linear theory to become unstable in the 1D stellar evolution model. Angular velocity and chemical composition is redistributed in the unstable region, thereby creating new unstable regions. After a period of time, the system settles in a symmetric, steady state, which is Richardson stable everywhere in the 2D simulation, whereas the instability remains for longer in the 1D model due to the limitations of the current implementation in the 1D code. A spatially resolved diffusion coefficient is extracted by comparing the initial and final profiles of mean atomic mass. Conclusions: The presented simulation gives a first insight on hydrodynamics of shear instabilities in a real stellar environment and even allows us to directly extract an effective diffusion coefficient. We see evidence for a critical Richardson number of 0.25 as regions above this threshold remain stable for the course of the simulation. The movie of the simulation is available at http://www.aanda.org

Improved model reduction and tuning of fractional-order PI(λ)D(μ) controllers for analytical rule extraction with genetic programming.

PubMed

Das, Saptarshi; Pan, Indranil; Das, Shantanu; Gupta, Amitava

2012-03-01

Genetic algorithm (GA) has been used in this study for a new approach of suboptimal model reduction in the Nyquist plane and optimal time domain tuning of proportional-integral-derivative (PID) and fractional-order (FO) PI(λ)D(μ) controllers. Simulation studies show that the new Nyquist-based model reduction technique outperforms the conventional H(2)-norm-based reduced parameter modeling technique. With the tuned controller parameters and reduced-order model parameter dataset, optimum tuning rules have been developed with a test-bench of higher-order processes via genetic programming (GP). The GP performs a symbolic regression on the reduced process parameters to evolve a tuning rule which provides the best analytical expression to map the data. The tuning rules are developed for a minimum time domain integral performance index described by a weighted sum of error index and controller effort. From the reported Pareto optimal front of the GP-based optimal rule extraction technique, a trade-off can be made between the complexity of the tuning formulae and the control performance. The efficacy of the single-gene and multi-gene GP-based tuning rules has been compared with the original GA-based control performance for the PID and PI(λ)D(μ) controllers, handling four different classes of representative higher-order processes. These rules are very useful for process control engineers, as they inherit the power of the GA-based tuning methodology, but can be easily calculated without the requirement for running the computationally intensive GA every time. Three-dimensional plots of the required variation in PID/fractional-order PID (FOPID) controller parameters with reduced process parameters have been shown as a guideline for the operator. Parametric robustness of the reported GP-based tuning rules has also been shown with credible simulation examples. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

RCWA and FDTD modeling of light emission from internally structured OLEDs.

PubMed

Callens, Michiel Koen; Marsman, Herman; Penninck, Lieven; Peeters, Patrick; de Groot, Harry; ter Meulen, Jan Matthijs; Neyts, Kristiaan

2014-05-05

We report on the fabrication and simulation of a green OLED with an Internal Light Extraction (ILE) layer. The optical behavior of these devices is simulated using both Rigorous Coupled Wave Analysis (RCWA) and Finite Difference Time-Domain (FDTD) methods. Results obtained using these two different techniques show excellent agreement and predict the experimental results with good precision. By verifying the validity of both simulation methods on the internal light extraction structure we pave the way to optimization of ILE layers using either of these methods.

Bayesian modelling of uncertainties of Monte Carlo radiative-transfer simulations

NASA Astrophysics Data System (ADS)

Beaujean, Frederik; Eggers, Hans C.; Kerzendorf, Wolfgang E.

2018-07-01

One of the big challenges in astrophysics is the comparison of complex simulations to observations. As many codes do not directly generate observables (e.g. hydrodynamic simulations), the last step in the modelling process is often a radiative-transfer treatment. For this step, the community relies increasingly on Monte Carlo radiative transfer due to the ease of implementation and scalability with computing power. We consider simulations in which the number of photon packets is Poisson distributed, while the weight assigned to a single photon packet follows any distribution of choice. We show how to estimate the statistical uncertainty of the sum of weights in each bin from the output of a single radiative-transfer simulation. Our Bayesian approach produces a posterior distribution that is valid for any number of packets in a bin, even zero packets, and is easy to implement in practice. Our analytic results for large number of packets show that we generalize existing methods that are valid only in limiting cases. The statistical problem considered here appears in identical form in a wide range of Monte Carlo simulations including particle physics and importance sampling. It is particularly powerful in extracting information when the available data are sparse or quantities are small.

Model-independent determination of the triple Higgs coupling at e + e – colliders

DOE PAGES

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; ...

2018-03-20

Here, the observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e +e –→Zhh. We showmore » that, by combining the measurement of this process with other measurements available at a 500 GeV e +e – collider, it is possible to quote model-independent limits on the effective field theory parameter c 6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e +e – data.« less

Local Time-Dependent Charging in a Perovskite Solar Cell.

PubMed

Bergmann, Victor W; Guo, Yunlong; Tanaka, Hideyuki; Hermes, Ilka M; Li, Dan; Klasen, Alexander; Bretschneider, Simon A; Nakamura, Eiichi; Berger, Rüdiger; Weber, Stefan A L

2016-08-03

Efficient charge extraction within solar cells explicitly depends on the optimization of the internal interfaces. Potential barriers, unbalanced charge extraction, and interfacial trap states can prevent cells from reaching high power conversion efficiencies. In the case of perovskite solar cells, slow processes happening on time scales of seconds cause hysteresis in the current-voltage characteristics. In this work, we localized and investigated these slow processes using frequency-modulation Kelvin probe force microscopy (FM-KPFM) on cross sections of planar methylammonium lead iodide (MAPI) perovskite solar cells. FM-KPFM can map the charge density distribution and its dynamics at internal interfaces. Upon illumination, space charge layers formed at the interfaces of the selective contacts with the MAPI layer within several seconds. We observed distinct differences in the charging dynamics at the interfaces of MAPI with adjacent layers. Our results indicate that more than one process is involved in hysteresis. This finding is in agreement with recent simulation studies claiming that a combination of ion migration and interfacial trap states causes the hysteresis in perovskite solar cells. Such differences in the charging rates at different interfaces cannot be separated by conventional device measurements.

Texture generation for use in synthetic infrared scenes

NASA Astrophysics Data System (ADS)

Ota, Clem Z.; Rollins, John M.; Bleiweiss, Max P.

1996-06-01

In the process of creating synthetic scenes for use in simulations/visualizations, texture is used as a surrogate to 'high' spatial definition. For example, if one were to measure the location of every blade of grass and all of the characteristics of each blade of grass in a lawn, then in the process of composing a scene of the lawn, it would be expected that the result would appear 'real;' however, because this process is excruciatingly laborious, various techniques have been devised to place the required details in the scene through the use of texturing. Experience gained during the recent Smart Weapons Operability Enhancement Joint Test and Evaluation (SWOE JT&E) has shown the need for higher fidelity texturing algorithms and a better parameterization of those that are in use. In this study, four aspects of the problem have been analyzed: texture extraction, texture insertion, texture metrics, and texture creation algorithms. The results of extracting real texture from an image, measuring it with a variety of metrics, and generating similar texture with three different algorithms is presented. These same metrics can be used to define clutter and to make comparisons between 'real' and synthetic (or artificial) scenes in an objective manner.

Model-independent determination of the triple Higgs coupling at e + e – colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon

Here, the observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e +e –→Zhh. We showmore » that, by combining the measurement of this process with other measurements available at a 500 GeV e +e – collider, it is possible to quote model-independent limits on the effective field theory parameter c 6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e +e – data.« less

Design and implementation of the tree-based fuzzy logic controller.

PubMed

Liu, B D; Huang, C Y

1997-01-01

In this paper, a tree-based approach is proposed to design the fuzzy logic controller. Based on the proposed methodology, the fuzzy logic controller has the following merits: the fuzzy control rule can be extracted automatically from the input-output data of the system and the extraction process can be done in one-pass; owing to the fuzzy tree inference structure, the search spaces of the fuzzy inference process are largely reduced; the operation of the inference process can be simplified as a one-dimensional matrix operation because of the fuzzy tree approach; and the controller has regular and modular properties, so it is easy to be implemented by hardware. Furthermore, the proposed fuzzy tree approach has been applied to design the color reproduction system for verifying the proposed methodology. The color reproduction system is mainly used to obtain a color image through the printer that is identical to the original one. In addition to the software simulation, an FPGA is used to implement the prototype hardware system for real-time application. Experimental results show that the effect of color correction is quite good and that the prototype hardware system can operate correctly under the condition of 30 MHz clock rate.

Model-independent determination of the triple Higgs coupling at e+e- colliders

NASA Astrophysics Data System (ADS)

Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; Peskin, Michael E.; Tian, Junping

2018-03-01

The observation of Higgs pair production at high-energy colliders can give evidence for the presence of a triple Higgs coupling. However, the actual determination of the value of this coupling is more difficult. In the context of general models for new physics, double Higgs production processes can receive contributions from many possible beyond-Standard-Model effects. This dependence must be understood if one is to make a definite statement about the deviation of the Higgs field potential from the Standard Model. In this paper, we study the extraction of the triple Higgs coupling from the process e+e-→Z h h . We show that, by combining the measurement of this process with other measurements available at a 500 GeV e+e- collider, it is possible to quote model-independent limits on the effective field theory parameter c6 that parametrizes modifications of the Higgs potential. We present precise error estimates based on the anticipated International Linear Collider physics program, studied with full simulation. Our analysis also gives new insight into the model-independent extraction of the Higgs boson coupling constants and total width from e+e- data.

Oxygen Extraction from Regolith Using Ionic Liquids

NASA Technical Reports Server (NTRS)

Barrios, Elizabeth A.; Curreri, Peter A.; Karr, Laurel J.

2011-01-01

An important concern with long-duration manned space travel is the need to furnish enough materials to the vehicle, as well as the crew, for the duration of the mission. By extracting oxygen from the oxides present in regolith, propellant and life support could be supplied to the vehicle and the crew while in space, thereby limiting the amount of supplies needed prior to lift-off. Using a class of compounds known as ionic liquids, we have been able to lower the electrolysis operating temperature from 1600 C (molten oxide electrolysis) to less than 200 C, making this process much more feasible in terms of energy consumption and materials handling. To make this process ready for deployment into space, we have investigated what steps of the process would be affected by the low-gravity environment in space. In the lab, the solubilization of lunar regolith simulant in ionic liquid produces water vapor that is normally distilled out of solution and subsequently electrolyzed for oxygen production. This distillation is not possible in space, so we have tested a method known as pervaporation and have suggested a way this technique could be incorporated into a reactor design.

Separation of time scales in one-dimensional directed nucleation-growth processes

NASA Astrophysics Data System (ADS)

Pierobon, Paolo; Miné-Hattab, Judith; Cappello, Giovanni; Viovy, Jean-Louis; Lagomarsino, Marco Cosentino

2010-12-01

Proteins involved in homologous recombination such as RecA and hRad51 polymerize on single- and double-stranded DNA according to a nucleation-growth kinetics, which can be monitored by single-molecule in vitro assays. The basic models currently used to extract biochemical rates rely on ensemble averages and are typically based on an underlying process of bidirectional polymerization, in contrast with the often observed anisotropic polymerization of similar proteins. For these reasons, if one considers single-molecule experiments, the available models are useful to understand observations only in some regimes. In particular, recent experiments have highlighted a steplike polymerization kinetics. The classical model of one-dimensional nucleation growth, the Kolmogorov-Avrami-Mehl-Johnson (KAMJ) model, predicts the correct polymerization kinetics only in some regimes and fails to predict the steplike behavior. This work illustrates by simulations and analytical arguments the limitation of applicability of the KAMJ description and proposes a minimal model for the statistics of the steps based on the so-called stick-breaking stochastic process. We argue that this insight might be useful to extract information on the time and length scales involved in the polymerization kinetics.

An artificial intelligence based improved classification of two-phase flow patterns with feature extracted from acquired images.

PubMed

Shanthi, C; Pappa, N

2017-05-01

Flow pattern recognition is necessary to select design equations for finding operating details of the process and to perform computational simulations. Visual image processing can be used to automate the interpretation of patterns in two-phase flow. In this paper, an attempt has been made to improve the classification accuracy of the flow pattern of gas/ liquid two- phase flow using fuzzy logic and Support Vector Machine (SVM) with Principal Component Analysis (PCA). The videos of six different types of flow patterns namely, annular flow, bubble flow, churn flow, plug flow, slug flow and stratified flow are recorded for a period and converted to 2D images for processing. The textural and shape features extracted using image processing are applied as inputs to various classification schemes namely fuzzy logic, SVM and SVM with PCA in order to identify the type of flow pattern. The results obtained are compared and it is observed that SVM with features reduced using PCA gives the better classification accuracy and computationally less intensive than other two existing schemes. This study results cover industrial application needs including oil and gas and any other gas-liquid two-phase flows. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Parameter Extraction Method for the Electrical Model of a Silicon Photomultiplier

NASA Astrophysics Data System (ADS)

Licciulli, Francesco; Marzocca, Cristoforo

2016-10-01

The availability of an effective electrical model, able to accurately reproduce the signals generated by a Silicon Photo-Multiplier coupled to the front-end electronics, is mandatory when the performance of a detection system based on this kind of detector has to be evaluated by means of reliable simulations. We propose a complete extraction procedure able to provide the whole set of the parameters involved in a well-known model of the detector, which includes the substrate ohmic resistance. The technique allows achieving very good quality of the fit between simulation results provided by the model and experimental data, thanks to accurate discrimination between the quenching and substrate resistances, which results in a realistic set of extracted parameters. The extraction procedure has been applied to a commercial device considering a wide range of different conditions in terms of input resistance of the front-end electronics and interconnection parasitics. In all the considered situations, very good correspondence has been found between simulations and measurements, especially for what concerns the leading edge of the current pulses generated by the detector, which strongly affects the timing performance of the detection system, thus confirming the effectiveness of the model and the associated parameter extraction technique.

Opto-electronic characterization of third-generation solar cells.

PubMed

Neukom, Martin; Züfle, Simon; Jenatsch, Sandra; Ruhstaller, Beat

2018-01-01

We present an overview of opto-electronic characterization techniques for solar cells including light-induced charge extraction by linearly increasing voltage, impedance spectroscopy, transient photovoltage, charge extraction and more. Guidelines for the interpretation of experimental results are derived based on charge drift-diffusion simulations of solar cells with common performance limitations. It is investigated how nonidealities like charge injection barriers, traps and low mobilities among others manifest themselves in each of the studied cell characterization techniques. Moreover, comprehensive parameter extraction for an organic bulk-heterojunction solar cell comprising PCDTBT:PC 70 BM is demonstrated. The simulations reproduce measured results of 9 different experimental techniques. Parameter correlation is minimized due to the combination of various techniques. Thereby a route to comprehensive and accurate parameter extraction is identified.

Selective aqueous extraction of organics coupled with trapping by membrane separation

DOEpatents

van Eikeren, Paul; Brose, Daniel J.; Ray, Roderick J.

1991-01-01

An improvement to processes for the selective extractation of organic solutes from organic solvents by water-based extractants is disclosed, the improvement comprising coupling various membrane separation processes with the organic extraction process, the membrane separation process being utilized to continuously recycle the water-based extractant and at the same time selectively remove or concentrate organic solute from the water-based extractant.

Lamb wave detection of limpet mines on ship hulls.

PubMed

Bingham, Jill; Hinders, Mark; Friedman, Adam

2009-12-01

This paper describes the use of ultrasonic guided waves for identifying the mass loading due to underwater limpet mines on ship hulls. The Dynamic Wavelet Fingerprint Technique (DFWT) is used to render the guided wave mode information in two-dimensional binary images because the waveform features of interest are too subtle to identify in time domain. The use of wavelets allows both time and scale features from the original signals to be retained, and image processing can be used to automatically extract features that correspond to the arrival times of the guided wave modes. For further understanding of how the guided wave modes propagate through the real structures, a parallel processing, 3D elastic wave simulation is developed using the finite integration technique (EFIT). This full field, technique models situations that are too complex for analytical solutions, such as built up 3D structures. The simulations have produced informative visualizations of the guided wave modes in the structures as well as mimicking directly the output from sensors placed in the simulation space for direct comparison to experiments. Results from both drydock and in-water experiments with dummy mines are also shown.

Damage Detection in Composite Structures with Wavenumber Array Data Processing

NASA Technical Reports Server (NTRS)

Tian, Zhenhua; Leckey, Cara; Yu, Lingyu

2013-01-01

Guided ultrasonic waves (GUW) have the potential to be an efficient and cost-effective method for rapid damage detection and quantification of large structures. Attractive features include sensitivity to a variety of damage types and the capability of traveling relatively long distances. They have proven to be an efficient approach for crack detection and localization in isotropic materials. However, techniques must be pushed beyond isotropic materials in order to be valid for composite aircraft components. This paper presents our study on GUW propagation and interaction with delamination damage in composite structures using wavenumber array data processing, together with advanced wave propagation simulations. Parallel elastodynamic finite integration technique (EFIT) is used for the example simulations. Multi-dimensional Fourier transform is used to convert time-space wavefield data into frequency-wavenumber domain. Wave propagation in the wavenumber-frequency domain shows clear distinction among the guided wave modes that are present. This allows for extracting a guided wave mode through filtering and reconstruction techniques. Presence of delamination causes spectral change accordingly. Results from 3D CFRP guided wave simulations with delamination damage in flat-plate specimens are used for wave interaction with structural defect study.

Atom based grain extraction and measurement of geometric properties

NASA Astrophysics Data System (ADS)

Martine La Boissonière, Gabriel; Choksi, Rustum

2018-04-01

We introduce an accurate, self-contained and automatic atom based numerical algorithm to characterize grain distributions in two dimensional Phase Field Crystal (PFC) simulations. We compare the method with hand segmented and known test grain distributions to show that the algorithm is able to extract grains and measure their area, perimeter and other geometric properties with high accuracy. Four input parameters must be set by the user and their influence on the results is described. The method is currently tuned to extract data from PFC simulations in the hexagonal lattice regime but the framework may be extended to more general problems.

Fetal Electrocardiogram Extraction and Analysis Using Adaptive Noise Cancellation and Wavelet Transformation Techniques.

PubMed

Sutha, P; Jayanthi, V E

2017-12-08

Birth defect-related demise is mainly due to congenital heart defects. In the earlier stage of pregnancy, fetus problem can be identified by finding information about the fetus to avoid stillbirths. The gold standard used to monitor the health status of the fetus is by Cardiotachography(CTG), cannot be used for long durations and continuous monitoring. There is a need for continuous and long duration monitoring of fetal ECG signals to study the progressive health status of the fetus using portable devices. The non-invasive method of electrocardiogram recording is one of the best method used to diagnose fetal cardiac problem rather than the invasive methods.The monitoring of the fECG requires development of a miniaturized hardware and a efficient signal processing algorithms to extract the fECG embedded in the mother ECG. The paper discusses a prototype hardware developed to monitor and record the raw mother ECG signal containing the fECG and a signal processing algorithm to extract the fetal Electro Cardiogram signal. We have proposed two methods of signal processing, first is based on the Least Mean Square (LMS) Adaptive Noise Cancellation technique and the other method is based on the Wavelet Transformation technique. A prototype hardware was designed and developed to acquire the raw ECG signal containing the mother and fetal ECG and the signal processing techniques were used to eliminate the noises and extract the fetal ECG and the fetal Heart Rate Variability was studied. Both the methods were evaluated with the signal acquired from a fetal ECG simulator, from the Physionet database and that acquired from the subject. Both the methods are evaluated by finding heart rate and its variability, amplitude spectrum and mean value of extracted fetal ECG. Also the accuracy, sensitivity and positive predictive value are also determined for fetal QRS detection technique. In this paper adaptive filtering technique uses Sign-sign LMS algorithm and wavelet techniques with Daubechies wavelet, employed along with de noising techniques for the extraction of fetal Electrocardiogram.Both the methods are having good sensitivity and accuracy. In adaptive method the sensitivity is 96.83, accuracy 89.87, wavelet sensitivity is 95.97 and accuracy is 88.5. Additionally, time domain parameters from the plot of heart rate variability of mother and fetus are analyzed.

Gauge invariant spectral Cauchy characteristic extraction

NASA Astrophysics Data System (ADS)

Handmer, Casey J.; Szilágyi, Béla; Winicour, Jeffrey

2015-12-01

We present gauge invariant spectral Cauchy characteristic extraction. We compare gravitational waveforms extracted from a head-on black hole merger simulated in two different gauges by two different codes. We show rapid convergence, demonstrating both gauge invariance of the extraction algorithm and consistency between the legacy Pitt null code and the much faster spectral Einstein code (SpEC).

Numerical simulations of heat transfer through fractured rock for an enhanced geothermal system development in Seokmodo, Korea

NASA Astrophysics Data System (ADS)

Shin, Jiyoun; Kim, Kyung-Ho; Hyun, Yunjung; Lee, Kang-Keun

2010-05-01

Estimating the expected capacity and efficiency of energy is a crucial issue in the construction of geothermal plant. It is the lasting temperature of extracted geothermal water that determines the effectiveness of enhanced geothermal systems (EGS), so the heat transfer processes in geothermal reservoirs under site-specific geologic conditions should be understood first. The construction of the first geothermal plant in Korea is under planning in Seokmodo, where a few flowing artesian wells showing relatively high water temperature of around 70°C were discovered lately. The site of interest is a part of the island region, consisting of the reclaimed land surrounded by the sea and small mountains. Geothermal gradient measures approximately 45°C/km and the geothermal water is as saline as seawater. Geologic structure in this region is characterized by the fractured granite. In this study, thermo-hydrological (TH) numerical simulations for the temperature evolution in a fractured geothermal reservoir under the supposed injection-extraction operating conditions were carried out using TOUGH2. Multiple porosity model which is useful to calculate the transient interporosity flow in TH coupled heat transfer problem was used in simulations. Several fracture planes which had been investigated in the field were assigned to have highly permeable properties in order to avoid the averaging approximation and describe the dominant flow through the fractures. This heterogeneous model showed the rise of relatively hot geothermal water in the densely fractured region. The temperature of the extracted geothermal water also increased slowly for 50 years due to the rising flow through the fractures. The most sensitive factor which affects the underground thermal distribution and temperature of geothermal water was permeability of the medium. Change in permeabilities of rock and fracture within the range of 1 order might cause such an extreme change in the temperature of geothermal water that the measurement of the permeability should be performed through a very careful process in order to guarantee a reliable simulation. As the fracture spacing became narrower, overall thermal distribution appeared to be similar to that from EPM model. This suggests that EPM model, which is easy to design and takes less time, can be replaced for the densely fractured medium. Change in fracture aperture within the range of that of actual rocks did not cause a remarkable difference in temperature distribution, which means that measuring accuracy of the actual aperture value in rocks is relatively less important. This demonstrates that the distribution and the structure of fracture system make a great contribution to the whole simulation for fluid and heat flow mechanisms in geologic medium, and thus require an intensive geologic investigation for the fractures including strike and dip information, permeability and connecting relation. In addition, the simulation results show that the heterogeneous model can include the description for the significant fracture flow and it can be a practical tool for a site-specific simulation for EGS sites. This preliminary simulation was useful to estimate the scale of the geothermal reservoir and the energy potential in Seokmodo and it can be further expanded to a long-term simulation to predict the evolution of the geothermal reservoir under the potential EGS operations. Acknowledgement: This study was financially supported by KIGAM, KETEP and BK21.

Low-cost, disposable microfluidics device for blood plasma extraction using continuously alternating paramagnetic and diamagnetic capture modes

PubMed Central

Kim, Pilkee; Ong, Eng Hui; Yoon, Yong-Jin; Ng, Sum Huan Gary; Puttachat, Khuntontong

2016-01-01

Blood plasma contains biomarkers and substances that indicate the physiological state of an organism, and it can be used to diagnose various diseases or body condition. To improve the accuracy of diagnostic test, it is required to obtain the high purity of blood plasma. This paper presents a low-cost, disposable microfluidics device for blood plasma extraction using magnetophoretic behaviors of blood cells. This device uses alternating magnetophoretic capture modes to trap and separate paramagnetic and diamagnetic cells away from blood plasma. The device system is composed of two parts, a disposable microfluidics chip and a non-disposable (reusable) magnetic field source. Such modularized device helps the structure of the disposable part dramatically simplified, which is beneficial for low-cost mass production. A series of numerical simulation and parametric study have been performed to describe the mechanism of blood cell separation in the microchannel, and the results are discussed. Furthermore, experimental feasibility test has been carried out in order to demonstrate the blood plasma extraction process of the proposed device. In this experiment, pure blood plasma has been successfully extracted with yield of 21.933% from 75 μl 1:10 dilution of deoxygenated blood. PMID:27042252

LISA Framework for Enhancing Gravitational Wave Signal Extraction Techniques

NASA Technical Reports Server (NTRS)

Thompson, David E.; Thirumalainambi, Rajkumar

2006-01-01

This paper describes the development of a Framework for benchmarking and comparing signal-extraction and noise-interference-removal methods that are applicable to interferometric Gravitational Wave detector systems. The primary use is towards comparing signal and noise extraction techniques at LISA frequencies from multiple (possibly confused) ,gravitational wave sources. The Framework includes extensive hybrid learning/classification algorithms, as well as post-processing regularization methods, and is based on a unique plug-and-play (component) architecture. Published methods for signal extraction and interference removal at LISA Frequencies are being encoded, as well as multiple source noise models, so that the stiffness of GW Sensitivity Space can be explored under each combination of methods. Furthermore, synthetic datasets and source models can be created and imported into the Framework, and specific degraded numerical experiments can be run to test the flexibility of the analysis methods. The Framework also supports use of full current LISA Testbeds, Synthetic data systems, and Simulators already in existence through plug-ins and wrappers, thus preserving those legacy codes and systems in tact. Because of the component-based architecture, all selected procedures can be registered or de-registered at run-time, and are completely reusable, reconfigurable, and modular.

Prediction of SOFC Performance with or without Experiments: A Study on Minimum Requirements for Experimental Data

DOE PAGES

Yang, Tao; Sezer, Hayri; Celik, Ismail B.; ...

2015-06-02

In the present paper, a physics-based procedure combining experiments and multi-physics numerical simulations is developed for overall analysis of SOFCs operational diagnostics and performance predictions. In this procedure, essential information for the fuel cell is extracted first by utilizing empirical polarization analysis in conjunction with experiments and refined by multi-physics numerical simulations via simultaneous analysis and calibration of polarization curve and impedance behavior. The performance at different utilization cases and operating currents is also predicted to confirm the accuracy of the proposed model. It is demonstrated that, with the present electrochemical model, three air/fuel flow conditions are needed to producemore » a set of complete data for better understanding of the processes occurring within SOFCs. After calibration against button cell experiments, the methodology can be used to assess performance of planar cell without further calibration. The proposed methodology would accelerate the calibration process and improve the efficiency of design and diagnostics.« less

Emulsion droplet interactions: a front-tracking treatment

NASA Astrophysics Data System (ADS)

Mason, Lachlan; Juric, Damir; Chergui, Jalel; Shin, Seungwon; Craster, Richard V.; Matar, Omar K.

2017-11-01

Emulsion coalescence influences a multitude of industrial applications including solvent extraction, oil recovery and the manufacture of fast-moving consumer goods. Droplet interaction models are vital for the design and scale-up of processing systems, however predictive modelling at the droplet-scale remains a research challenge. This study simulates industrially relevant moderate-inertia collisions for which a high degree of droplet deformation occurs. A hybrid front-tracking/level-set approach is used to automatically account for interface merging without the need for `bookkeeping' of interface connectivity. The model is implemented in Code BLUE using a parallel multi-grid solver, allowing both film and droplet-scale dynamics to be resolved efficiently. Droplet interaction simulations are validated using experimental sequences from the literature in the presence and absence of background turbulence. The framework is readily extensible for modelling the influence of surfactants and non-Newtonian fluids on droplet interaction processes. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM), PETRONAS.

Computational Analysis of the Combustion Processes in an Axisymmetric, RBCC Flowpath

NASA Technical Reports Server (NTRS)

Steffen, Christopher J., Jr.; Yungster, Shaye

2001-01-01

Computational fluid dynamic simulations have been used to study the combustion processes within an axisymmetric, RBCC flowpath. Two distinct operating modes have been analyzed to date, including the independent ramjet stream (IRS) cycle and the supersonic combustion ramjet (scramJet) cycle. The IRS cycle investigation examined the influence of fuel-air ratio, fuel distribution, and rocket chamber pressure upon the combustion physics and thermal choke characteristics. Results indicate that adjustment of the amount and radial distribution of fuel can control the thermal choke point. The secondary massflow rate was very sensitive to the fuel-air ratio and the rocket chamber pressure. The scramjet investigation examined the influence of fuel-air ratio and fuel injection schedule upon combustion performance estimates. An analysis of the mesh-dependence of these calculations was presented. Jet penetration data was extracted from the three-dimensional simulations and compared favorably with experimental correlations of similar flows. Results indicate that combustion efficiency was very sensitive to the fuel schedule.

Dual RBFNNs-Based Model-Free Adaptive Control With Aspen HYSYS Simulation.

PubMed

Zhu, Yuanming; Hou, Zhongsheng; Qian, Feng; Du, Wenli

2017-03-01

In this brief, we propose a new data-driven model-free adaptive control (MFAC) method with dual radial basis function neural networks (RBFNNs) for a class of discrete-time nonlinear systems. The main novelty lies in that it provides a systematic design method for controller structure by the direct usage of I/O data, rather than using the first-principle model or offline identified plant model. The controller structure is determined by equivalent-dynamic-linearization representation of the ideal nonlinear controller, and the controller parameters are tuned by the pseudogradient information extracted from the I/O data of the plant, which can deal with the unknown nonlinear system. The stability of the closed-loop control system and the stability of the training process for RBFNNs are guaranteed by rigorous theoretical analysis. Meanwhile, the effectiveness and the applicability of the proposed method are further demonstrated by the numerical example and Aspen HYSYS simulation of distillation column in crude styrene produce process.

Development of Numerical Tools for the Investigation of Plasma Detachment from Magnetic Nozzles

NASA Technical Reports Server (NTRS)

Sankaran, Kamesh; Polzin, Kurt A.

2007-01-01

A multidimensional numerical simulation framework aimed at investigating the process of plasma detachment from a magnetic nozzle is introduced. An existing numerical code based on a magnetohydrodynamic formulation of the plasma flow equations that accounts for various dispersive and dissipative processes in plasmas was significantly enhanced to allow for the modeling of axisymmetric domains containing three.dimensiunai momentum and magnetic flux vectors. A separate magnetostatic solver was used to simulate the applied magnetic field topologies found in various nozzle experiments. Numerical results from a magnetic diffusion test problem in which all three components of the magnetic field were present exhibit excellent quantitative agreement with the analytical solution, and the lack of numerical instabilities due to fluctuations in the value of del(raised dot)B indicate that the conservative MHD framework with dissipative effects is well-suited for multi-dimensional analysis of magnetic nozzles. Further studies will focus on modeling literature experiments both for the purpose of code validation and to extract physical insight regarding the mechanisms driving detachment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Yanmei; Li, Xinli; Bai, Yan

The measurement of multiphase flow parameters is of great importance in a wide range of industries. In the measurement of multiphase, the signals from the sensors are extremely weak and often buried in strong background noise. It is thus desirable to develop effective signal processing techniques that can detect the weak signal from the sensor outputs. In this paper, two methods, i.e., lock-in-amplifier (LIA) and improved Duffing chaotic oscillator are compared to detect and process the weak signal. For sinusoidal signal buried in noise, the correlation detection with sinusoidal reference signal is simulated by using LIA. The improved Duffing chaoticmore » oscillator method, which based on the Wigner transformation, can restore the signal waveform and detect the frequency. Two methods are combined to detect and extract the weak signal. Simulation results show the effectiveness and accuracy of the proposed improved method. The comparative analysis shows that the improved Duffing chaotic oscillator method can restrain noise strongly since it is sensitive to initial conditions.« less

System identification methods for aircraft flight control development and validation

NASA Technical Reports Server (NTRS)

Tischler, Mark B.

1995-01-01

System-identification methods compose a mathematical model, or series of models, from measurements of inputs and outputs of dynamic systems. The extracted models allow the characterization of the response of the overall aircraft or component subsystem behavior, such as actuators and on-board signal processing algorithms. This paper discusses the use of frequency-domain system-identification methods for the development and integration of aircraft flight-control systems. The extraction and analysis of models of varying complexity from nonparametric frequency-responses to transfer-functions and high-order state-space representations is illustrated using the Comprehensive Identification from FrEquency Responses (CIFER) system-identification facility. Results are presented for test data of numerous flight and simulation programs at the Ames Research Center including rotorcraft, fixed-wing aircraft, advanced short takeoff and vertical landing (ASTOVL), vertical/short takeoff and landing (V/STOL), tiltrotor aircraft, and rotor experiments in the wind tunnel. Excellent system characterization and dynamic response prediction is achieved for this wide class of systems. Examples illustrate the role of system-identification technology in providing an integrated flow of dynamic response data around the entire life-cycle of aircraft development from initial specifications, through simulation and bench testing, and into flight-test optimization.

Real-time Adaptive EEG Source Separation using Online Recursive Independent Component Analysis

PubMed Central

Hsu, Sheng-Hsiou; Mullen, Tim; Jung, Tzyy-Ping; Cauwenberghs, Gert

2016-01-01

Independent Component Analysis (ICA) has been widely applied to electroencephalographic (EEG) biosignal processing and brain-computer interfaces. The practical use of ICA, however, is limited by its computational complexity, data requirements for convergence, and assumption of data stationarity, especially for high-density data. Here we study and validate an optimized online recursive ICA algorithm (ORICA) with online recursive least squares (RLS) whitening for blind source separation of high-density EEG data, which offers instantaneous incremental convergence upon presentation of new data. Empirical results of this study demonstrate the algorithm's: (a) suitability for accurate and efficient source identification in high-density (64-channel) realistically-simulated EEG data; (b) capability to detect and adapt to non-stationarity in 64-ch simulated EEG data; and (c) utility for rapidly extracting principal brain and artifact sources in real 61-channel EEG data recorded by a dry and wearable EEG system in a cognitive experiment. ORICA was implemented as functions in BCILAB and EEGLAB and was integrated in an open-source Real-time EEG Source-mapping Toolbox (REST), supporting applications in ICA-based online artifact rejection, feature extraction for real-time biosignal monitoring in clinical environments, and adaptable classifications in brain-computer interfaces. PMID:26685257

Dynamic fiber Bragg gratings based health monitoring system of composite aerospace structures

NASA Astrophysics Data System (ADS)

Panopoulou, A.; Loutas, T.; Roulias, D.; Fransen, S.; Kostopoulos, V.

2011-09-01

The main purpose of the current work is to develop a new system for structural health monitoring of composite aerospace structures based on real-time dynamic measurements, in order to identify the structural state condition. Long-gauge Fibre Bragg Grating (FBG) optical sensors were used for monitoring the dynamic response of the composite structure. The algorithm that was developed for structural damage detection utilizes the collected dynamic response data, analyzes them in various ways and through an artificial neural network identifies the damage state and its location. Damage was simulated by slightly varying locally the mass of the structure (by adding a known mass) at different zones of the structure. Lumped masses in different locations upon the structure alter the eigen-frequencies in a way similar to actual damage. The structural dynamic behaviour has been numerically simulated and experimentally verified by means of modal testing on two different composite aerospace structures. Advanced digital signal processing techniques, e.g. the wavelet transform (WT), were used for the analysis of the dynamic response for feature extraction. WT's capability of separating the different frequency components in the time domain without loosing frequency information makes it a versatile tool for demanding signal processing applications. The use of WT is also suggested by the no-stationary nature of dynamic response signals and the opportunity of evaluating the temporal evolution of their frequency contents. Feature extraction is the first step of the procedure. The extracted features are effective indices of damage size and location. The classification step comprises of a feed-forward back propagation network, whose output determines the simulated damage location. Finally, dedicated training and validation activities were carried out by means of numerical simulations and experimental procedures. Experimental validation was performed initially on a flat stiffened panel, representing a section of a typical aeronautical structure, manufactured and tested in the lab and, as a second step, on a scaled up space oriented structure, which is a composite honeycomb plate, used as a deployment base for antenna arrays. An integrated FBG sensor network, based on the advantage of multiplexing, was mounted on both structures and different excitation positions and boundary conditions were used. The analysis of operational dynamic responses was employed to identify both the damage and its position. The system that was designed and tested initially on the thin composite panel, was successfully validated on the larger honeycomb structure. Numerical simulation of both structures was used as a support tool at all the steps of the work providing among others the location of the optical sensors used. The proposed work will be the base for the whole system qualification and validation on an antenna reflector in future work.

Extraction of membrane structure in eyeball from MR volumes

NASA Astrophysics Data System (ADS)

Oda, Masahiro; Kin, Taichi; Mori, Kensaku

2017-03-01

This paper presents an accurate extraction method of spherical shaped membrane structures in the eyeball from MR volumes. In ophthalmic surgery, operation field is limited to a small region. Patient specific surgical simulation is useful to reduce complications. Understanding of tissue structure in the eyeball of a patient is required to achieve patient specific surgical simulations. Previous extraction methods of tissue structure in the eyeball use optical coherence tomography (OCT) images. Although OCT images have high resolution, imaging regions are limited to very small. Global structure extraction of the eyeball is difficult from OCT images. We propose an extraction method of spherical shaped membrane structures including the sclerotic coat, choroid, and retina. This method is applied to a T2 weighted MR volume of the head region. MR volume can capture tissue structure of whole eyeball. Because we use MR volumes, out method extracts whole membrane structures in the eyeball. We roughly extract membrane structures by applying a sheet structure enhancement filter. The rough extraction result includes parts of the membrane structures. Then, we apply the Hough transform to extract a sphere structure from the voxels set of the rough extraction result. The Hough transform finds a sphere structure from the rough extraction result. An experimental result using a T2 weighted MR volume of the head region showed that the proposed method can extract spherical shaped membrane structures accurately.

Effectiveness of the Multilayered Caries Model and Visuo-tactile Virtual Reality Simulator for Minimally Invasive Caries Removal: A Randomized Controlled Trial.

PubMed

Dwisaptarini, A P; Suebnukarn, S; Rhienmora, P; Haddawy, P; Koontongkaew, S

This work presents the multilayered caries model with a visuo-tactile virtual reality simulator and a randomized controlled trial protocol to determine the effectiveness of the simulator in training for minimally invasive caries removal. A three-dimensional, multilayered caries model was reconstructed from 10 micro-computed tomography (CT) images of deeply carious extracted human teeth before and after caries removal. The full grey scale 0-255 yielded a median grey scale value of 0-9, 10-18, 19-25, 26-52, and 53-80 regarding dental pulp, infected carious dentin, affected carious dentin, normal dentin, and normal enamel, respectively. The simulator was connected to two haptic devices for a handpiece and mouth mirror. The visuo-tactile feedback during the operation varied depending on the grey scale. Sixth-year dental students underwent a pretraining assessment of caries removal on extracted teeth. The students were then randomly assigned to train on either the simulator (n=16) or conventional extracted teeth (n=16) for 3 days, after which the assessment was repeated. The posttraining performance of caries removal improved compared with pretraining in both groups (Wilcoxon, p<0.05). The equivalence test for proportional differences (two 1-sided t-tests) with a 0.2 margin confirmed that the participants in both groups had identical posttraining performance scores (95% CI=0.92, 1; p=0.00). In conclusion, training on the micro-CT multilayered caries model with the visuo-tactile virtual reality simulator and conventional extracted tooth had equivalent effects on improving performance of minimally invasive caries removal.

Microfluidics: an enabling screening technology for enhanced oil recovery (EOR).

PubMed

Lifton, Victor A

2016-05-21

Oil production is a critical industrial process that affects the entire world population and any improvements in its efficiency while reducing its environmental impact are of utmost societal importance. The paper reviews recent applications of microfluidics and microtechnology to study processes of oil extraction and recovery. It shows that microfluidic devices can be useful tools in investigation and visualization of such processes used in the oil & gas industry as fluid propagation, flooding, fracturing, emulsification and many others. Critical macro-scale processes that define oil extraction and recovery are controlled by the micro-scale processes based on wetting, adhesion, surface tension, colloids and other concepts of microfluidics. A growing number of research efforts demonstrates that microfluidics is becoming, albeit slowly, an accepted methodology in this area. We propose several areas of development where implementation of microfluidics may bring about deeper understanding and hence better control over the processes of oil recovery based on fluid propagation, droplet generation, wettability control. Studies of processes such as hydraulic fracturing, sand particle propagation in porous networks, high throughput screening of chemicals (for example, emulsifiers and surfactants) in microfluidic devices that simulate oil reservoirs are proposed to improve our understanding of these complicated physico-chemical systems. We also discuss why methods of additive manufacturing (3D printing) should be evaluated for quick prototyping and modification of the three-dimensional structures replicating natural oil-bearing rock formations for studies accessible to a wider audience of researchers.

The numerical simulation on swelling factor and extraction rate of a tight crude oil and SC-CO2 system

NASA Astrophysics Data System (ADS)

Zou, Hongjun; Gong, Houjian; Li, Yajun; Dong, Mingzhe

2018-03-01

A method was established to study swelling and extraction between CO2 and crude oil, and the influences of pressure, temperature and molecular weight were investigated. Firstly, laboratory analysis was conducted to determine the pseudo-component and other parameters of the crude oil. Then swelling and extraction of the crude oil and SC-CO2 system were calculated by computer simulation. The results show that the pressure and temperature have little influence on the swelling and extraction between CO2 and crude oil when the mole fraction of CO2 is lower. A higher pressure and temperature is more beneficial to the interaction of CO2 and crude oil, while the swelling and extraction will not be obvious when the system is miscible. And the smaller the molecular weight of the oil is, the larger the maximum value of the swelling factor of CO2 and crude oil changes. The study of swelling and extraction plays an important role in the oilfield stimulation.

Formulation of microspheres containing Crataegus monogyna Jacq. extract with free radical scavenging activity.

PubMed

Lucconi, Giulia; Chlapanidas, Theodora; Martino, Emanuela; Gaggeri, Raffaella; Perteghella, Sara; Rossi, Daniela; Faragò, Silvio; Vigo, Daniele; Faustini, Massimo; Collina, Simona; Torre, Maria Luisa

2014-02-01

Extracts of Crataegus monogyna Jacq. (hawthorn) show an interesting free radical scavenging (FRS) effect, related to their flavonoids content. Unfortunately, their oral administration is affected by their low bioavailability. The aim of this work is to obtain a multiparticulate drug delivery system for hawthorn extracts for oral administration. The extracts from flowering tops (FL) or fruits (FR) of hawthorn were obtained with maceration, using ethanol as an extraction solvent, and their antioxidant activity was evaluated. FL extract showed the highest FRS activity (EC50 3.72 ± 1.21 µg/ml), so it was selected to prepare microparticulate systems by a spray-drying technique, which were characterized by granulometric analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy, confocal fluorescence microscopy and hyperoside content. Antioxidant activity was evaluated before and after gastrointestinal transit in vitro simulation. Results indicate that the microparticulate systems maintained the antioxidant activity of hawthorn also after gastrointestinal transit in vitro simulation, exhibiting properties suitable for oral administration.

Lunar Regolith Simulant Feed System for a Hydrogen Reduction Reactor System

NASA Technical Reports Server (NTRS)

Mueller, R. P.; Townsend, Ivan I., III

2009-01-01

One of the goals of In-Situ Resource Utilization (ISRU) on the moon is to produce oxygen from the lunar regolith which is present in the form of Ilmenite (FeTi03) and other compounds. A reliable and attainable method of extracting some of the oxygen from the lunar regolith is to use the hydrogen reduction process in a hot reactor to create water vapor which is then condensed and electrolyzed to obtain oxygen for use as a consumable. One challenge for a production system is to reliably acquire the regolith with an excavator hauler mobility platform and then introduce it into the reactor inlet tube which is raised from the surface and above the reactor itself. After the reaction, the hot regolith (-1000 C) must be expelled from the reactor for disposal by the excavator hauler mobility system. In addition, the reactor regolith inlet and outlet tubes must be sealed by valves during the reaction in order to allow collection of the water vapor by the chemical processing sub-system. These valves must be able to handle abrasive regolith passing through them as well as the heat conduction from the hot reactor. In 2008, NASA has designed and field tested a hydrogen reduction system called ROxygen in order to demonstrate the feasibility of extracting oxygen from lunar regolith. The field test was performed with volcanic ash known as Tephra on Mauna Kea volcano on the Big Island of Hawai'i. The tephra has similar properties to lunar regolith, so that it is regarded as a good simulant for the hydrogen reduction process. This paper will discuss the design, fabrication, operation, test results and lessons learned with the ROxygen regolith feed system as tested on Mauna Kea in November 2008.

Practicing DSAM in aberrant domain: use of multi-disciplinary techniques

NASA Astrophysics Data System (ADS)

Das, S.; Samanta, S.; Bhattacharjee, R.; Raut, R.; Ghugre, S. S.; Sinha, A. K.; Garg, U.; Chakrabarti, R.; Mukhopadhyay, S.; Madhavan, N.; Muralithar, S.; Singh, R. P.; Sethi, J.; Saha, S.; Palit, R.

2016-10-01

Measurement of level lifetime of nuclear states is of relevance in nuclear structure research as it provides us with an unique probe into the underlying microscopic structure of these states. Of the several experimental techniques for lifetime measurements, the Doppler Shift Attenuation Method (DSAM) is the one adopted for measuring lifetimes typically in the range of few tens of fs to few ps. The technique is based on the analysis of the observed Doppler affected gamma rays emitted by the recoils in flight. The crucial component in the related analysis is the simulation of the stopping process, of the residues of interest, in the target and the backing media. This requires calculation of the corresponding stopping powers and the same has been identified as one of the principal uncertainties in the extracted lifetime in DSAM. Traditionally the method is pursued with a thin target, for production of nuclei of interest, on a thick elemental backing wherein stopping process is perceived to occur. The present work in light of it's objectives uses a setup which is in sharp variance with the conventional scenario, such as the use of a thick molecular target, which contributes both to the production of the residues as well as their subsequent slowing down. This demanded extensive developments in the analysis procedure particularly in the domain of simulating the stopping process with due incorporation of the nuances of nuclear reaction kinematics besides subjecting the molecular medium to a detailed structural characterization, routinely carried out in the domain of material science. These developments have been used to extract the level lifetimes of nuclei at the interface of the sd & pf shells such as 26Mg, 29Si, and 32P.

Camera calibration based on the back projection process

NASA Astrophysics Data System (ADS)

Gu, Feifei; Zhao, Hong; Ma, Yueyang; Bu, Penghui

2015-12-01

Camera calibration plays a crucial role in 3D measurement tasks of machine vision. In typical calibration processes, camera parameters are iteratively optimized in the forward imaging process (FIP). However, the results can only guarantee the minimum of 2D projection errors on the image plane, but not the minimum of 3D reconstruction errors. In this paper, we propose a universal method for camera calibration, which uses the back projection process (BPP). In our method, a forward projection model is used to obtain initial intrinsic and extrinsic parameters with a popular planar checkerboard pattern. Then, the extracted image points are projected back into 3D space and compared with the ideal point coordinates. Finally, the estimation of the camera parameters is refined by a non-linear function minimization process. The proposed method can obtain a more accurate calibration result, which is more physically useful. Simulation and practical data are given to demonstrate the accuracy of the proposed method.

A first approach to the distortion analysis of nonlinear analog circuits utilizing X-parameters

NASA Astrophysics Data System (ADS)

Weber, H.; Widemann, C.; Mathis, W.

2013-07-01

In this contribution a first approach to the distortion analysis of nonlinear 2-port-networks with X-parameters1 is presented. The X-parameters introduced by Verspecht and Root (2006) offer the possibility to describe nonlinear microwave 2-port-networks under large signal conditions. On the basis of X-parameter measurements with a nonlinear network analyzer (NVNA) behavioral models can be extracted for the networks. These models can be used to consider the nonlinear behavior during the design process of microwave circuits. The idea of the present work is to extract the behavioral models in order to describe the influence of interfering signals on the output behavior of the nonlinear circuits. Hereby, a simulator is used instead of a NVNA to extract the X-parameters. Assuming that the interfering signals are relatively small compared to the nominal input signal, the output signal can be described as a superposition of the effects of each input signal. In order to determine the functional correlation between the scattering variables, a polynomial dependency is assumed. The required datasets for the approximation of the describing functions are simulated by a directional coupler model in Cadence Design Framework. The polynomial coefficients are obtained by a least-square method. The resulting describing functions can be used to predict the system's behavior under certain conditions as well as the effects of the interfering signal on the output signal. 1 X-parameter is a registered trademark of Agilent Technologies, Inc.

An RF-only ion-funnel for extraction from high-pressure gases

DOE PAGES

Brunner, T.; Fudenberg, D.; Varentsov, V.; ...

2015-01-27

An RF ion-funnel technique has been developed to extract ions from a high-pressure (10 bar) noble-gas environment into a vacuum (10 -6 mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting 136Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to simulations. This demonstration of extraction of ions, with mass comparable to that of the gas generating the high-pressure, has applications to Ba tagging from a Xe-gasmore » time-projection chamber for double-beta decay, as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m > 40 u) carrier gas.« less

Development of tea extracts and chitosan composite films for active packaging materials.

PubMed

Peng, Yong; Wu, Yan; Li, Yunfei

2013-08-01

The effects of 0.5%, 1% and 2% green tea extracts (GTE) and black tea extracts (BTE) on the physical, structural and antioxidant properties of chitosan films were investigated. Results showed that the addition of tea extracts significantly decreased water vapour permeability and increased the antioxidant ability of films. The DPPH radical scavenging ability of GTE films was stronger than that of BTE films in all food simulants (0%, 20%, 75% and 95% ethanol). The equilibration time in different food simulants decreased with the increased ethanol concentration. DSC and FTIR spectra analysis indicated that there was strong interaction in film matrix, which could be reflected by the physical and mechanical properties of composite films. This study revealed that an active chitosan film could be obtained by incorporation of tea extracts, which may provide new formulation options for developing an antioxidant active packaging. Copyright © 2013 Elsevier B.V. All rights reserved.

Amine–Oxide Hybrid Materials for CO 2 Capture from Ambient Air

DOE PAGES

Didas, Stephanie A.; Choi, Sunho; Chaikittisilp, Watcharop; ...

2015-09-10

Oxide supports functionalized with amine moieties have been used for decades as catalysts and chromatographic media. Owing to the recognized impact of atmospheric CO 2 on global climate change, the study of the use of amine-oxide hybrid materials as CO 2 sorbents has exploded in the past decade. While the majority of the work has concerned separation of CO 2 from dilute mixtures such as flue gas from coal-fired power plants, it has been recognized by us and others that such supported amine materials are also perhaps uniquely suited to extract CO 2 from ultradilute gas mixtures, such as ambientmore » air. As unique, low temperature chemisorbents, they can operate under ambient conditions, spontaneously extracting CO 2 from ambient air, while being regenerated under mild conditions using heat or the combination of heat and vacuum. This Account describes the evolution of our activities on the design of amine-functionalized silica materials for catalysis to the design, characterization, and utilization of these materials in CO 2 separations. New materials developed in our laboratory, such as hyperbranched aminosilica materials, and previously known amine-oxide hybrid compositions, have been extensively studied for CO 2 extraction from simulated ambient air (400 ppm of CO 2). The role of amine type and structure (molecular, polymeric), support type and structure, the stability of the various compositions under simulated operating conditions, and the nature of the adsorbed CO 2 have been investigated in detail. The requirements for an effective, practical air capture process have been outlined and the ability of amine-oxide hybrid materials to meet these needs has been discussed. Ultimately, the practicality of such a “direct air capture” process is predicated not only on the physicochemical properties of the sorbent, but also how the sorbent operates in a practical process that offers a scalable gas-solid contacting strategy. In conclusion, the utility of low pressure drop monolith contactors is suggested to offer a practical mode of amine sorbent/air contacting for direct air capture.« less

Amine–Oxide Hybrid Materials for CO 2 Capture from Ambient Air

DOE PAGES

Didas, Stephanie A.; Choi, Sunho; Chaikittisilp, Watcharop; ...

2015-09-10

CONSPECTUS: Oxide supports functionalized with amine moieties have been used for decades as catalysts and chromatographic media. Owing to the recognized impact of atmospheric CO2 on global climate change, the study of the use of amine-oxide hybrid materials as CO2 sorbents has exploded in the past decade. While the majority of the work has concerned separation of CO2 from dilute mixtures such as flue gas from coal-fired power plants, it has been recognized by us and others that such supported amine materials are also perhaps uniquely suited to extract CO2 from ultradilute gas mixtures, such as ambient air. As unique,more » low temperature chemisorbents, they can operate under ambient conditions, spontaneously extracting CO2 from ambient air, while being regenerated under mild conditions using heat or the combination of heat and vacuum. This Account describes the evolution of our activities on the design of amine-functionalized silica materials for catalysis to the design, characterization, and utilization of these materials in CO2 separations. New materials developed in our laboratory, such as hyperbranched aminosilica materials, and previously known amine-oxide hybrid compositions, have been extensively studied for CO2 extraction from simulated ambient air (400 ppm of CO2). The role of amine type and structure (molecular, polymeric), support type and structure, the stability of the various compositions under simulated operating conditions, and the nature of the adsorbed CO2 have been investigated in detail. The requirements for an effective, practical air capture process have been outlined and the ability of amine−oxide hybrid materials to meet these needs has been discussed. Ultimately, the practicality of such a “direct air capture” process is predicated not only on the physicochemical properties of the sorbent, but also how the sorbent operates in a practical process that offers a scalable gas−solid contacting strategy. In this regard, the utility of low pressure drop monolith contactors is suggested to offer a practical mode of amine sorbent/air contacting for direct air capture.« less