Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

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

Miller, Aubrey L.

2005-07-01

This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFBmore » riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.« less

Advances of two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process.

PubMed

Chaohe, Yang; Xiaobo, Chen; Jinhong, Zhang; Chunyi, Li; Honghong, Shan

Two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process proposed by State Key Laboratory of Heavy oil Processing, China University of Petroleum, can remarkably enhance the propylene yield and minimize the dry gas and coke yields, and obtain high-quality light oils (gasoline and diesel). It has been commercialized since 2006. Up to now, three TMP commercial units have been put into production and other four commercial units are under design and construction. The commercial data showed that taking paraffinic based Daqing (China) atmospheric residue as the feedstock, the propylene yield reached 20.31 wt%, the liquid products yield (the total yield of liquefied petroleum gas, gasoline, and diesel) was 82.66 wt%, and the total yield of dry gas and coke was 14.28 wt%. Moreover, the research octane number of gasoline could be up to 96.

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2011 CFR

2011-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2013 CFR

2013-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2012 CFR

2012-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

X-ray Fluorescence Tomography of Aged Fluid-Catalytic-Cracking Catalyst Particles Reveals Insight into Metal Deposition Processes.

PubMed

Kalirai, Sam; Boesenberg, Ulrike; Falkenberg, Gerald; Meirer, Florian; Weckhuysen, Bert M

2015-11-01

Microprobe X-ray fluorescence tomography was used to investigate metal poison deposition in individual, intact and industrially deactivated fluid catalytic cracking (FCC) particles at two differing catalytic life-stages. 3 D multi-element imaging, at submicron resolution was achieved by using a large-array Maia fluorescence detector. Our results show that Fe, Ni and Ca have significant concentration at the exterior of the FCC catalyst particle and are highly co-localized. As concentrations increase as a function of catalytic life-stage, the deposition profiles of Fe, Ni, and Ca do not change significantly. V has been shown to penetrate deeper into the particle with increasing catalytic age. Although it has been previously suggested that V is responsible for damaging the zeolite components of FCC particles, no spatial correlation was found for V and La, which was used as a marker for the embedded zeolite domains. This suggests that although V is known to be detrimental to zeolites in FCC particles, a preferential interaction does not exist between the two.

Fluid catalytic cracking: recent developments on the grand old lady of zeolite catalysis.

PubMed

Vogt, E T C; Weckhuysen, B M

2015-10-21

Fluid catalytic cracking (FCC) is one of the major conversion technologies in the oil refinery industry. FCC currently produces the majority of the world's gasoline, as well as an important fraction of propylene for the polymer industry. In this critical review, we give an overview of the latest trends in this field of research. These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels. After providing some general background of the FCC process, including a short history as well as details on the process, reactor design, chemical reactions involved and catalyst material, we will discuss several trends in FCC catalysis research by focusing on ways to improve the zeolite structure stability, propylene selectivity and the overall catalyst accessibility by (a) the addition of rare earth elements and phosphorus, (b) constructing hierarchical pores systems and (c) the introduction of new zeolite structures. In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level. These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials.

Fluid catalytic cracking: recent developments on the grand old lady of zeolite catalysis

PubMed Central

2015-01-01

Fluid catalytic cracking (FCC) is one of the major conversion technologies in the oil refinery industry. FCC currently produces the majority of the world's gasoline, as well as an important fraction of propylene for the polymer industry. In this critical review, we give an overview of the latest trends in this field of research. These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels. After providing some general background of the FCC process, including a short history as well as details on the process, reactor design, chemical reactions involved and catalyst material, we will discuss several trends in FCC catalysis research by focusing on ways to improve the zeolite structure stability, propylene selectivity and the overall catalyst accessibility by (a) the addition of rare earth elements and phosphorus, (b) constructing hierarchical pores systems and (c) the introduction of new zeolite structures. In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level. These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials. PMID:26382875

A Survey of Corrosion and Conditions of Corrosion Protection Systems in Civil Works Structures of the U.S. Army Corps of Engineers

DTIC Science & Technology

2014-09-01

corrosion: coatings and cathodic protection (CP). Coatings consist of paints, epoxies, enamels , metalizing, and other coatings. CP is a chem- ical means...environmental factors such as water quality and resistivity. One of the major problems associated with lock gates is structural cracking in the...One of the problems described by Mr. Davis is fatigue crack growth resulting from the poor welding usually associated with stress risers and

Finite element analysis of the influence of elastic anisotropy on stress intensification at stress corrosion cracking initiation sites in fcc alloys

NASA Astrophysics Data System (ADS)

Meric de Bellefon, G.; van Duysen, J. C.

2018-05-01

A recent finite-element method (FEM)-based study from the present authors quantified the effect of elastic anisotropy of grains on stress intensification at potential intergranular stress corrosion cracking (IGSCC) initiation sites in austenitic stainless steels. In particular, it showed that the auxetic behavior of grains (negative Poisson's ratio) in some directions plays a very important role in IGSCC initiation, since it can induce local stress intensification factors of about 1.6. A similar effect is expected for other fcc alloys such as Ni-based alloys. The present article confirms those results and paves the way to the definition of an IGSCC susceptibility index by identifying grain configurations that are the most favorable for crack initiation. The index will rely on the probability to get those configurations on surface of specimens.

Fracture mechanics correlation of boron/aluminum coupons containing stress risers

NASA Technical Reports Server (NTRS)

Adsit, N. R.; Waszczak, J. P.

1975-01-01

The mechanical behavior of boron/aluminum near stress risers has been studied and reported. This effort was directed toward defining the tensile behavior of both unidirectional and (0/ plus or minus 45) boron/aluminum using linear elastic fracture mechanics (LEFM). The material used was 5.6-mil boron in 6061 aluminum, consolidated using conventional diffusion bonding techniques. Mechanical properties are reported for both unidirectional and (0/ plus or minus 45) boron/aluminum, which serve as control data for the fracture mechanics predictions. Three different flawed specimen types were studied. In each case the series of specimens remained geometrically similar to eliminate variations in finite size correction factors. The fracture data from these tests were reduced using two techniques. They both used conventional LEFM methods, but the existence of a characteristic flaw was assumed in one case and not the other. Both the data and the physical behavior of the specimens support the characteristic flaw hypothesis. Cracks were observed growing slowly in the (0/ plus or minus 45) laminates, until a critical crack length was reached at which time catastrophic failure occurred.

High-resolution single-molecule fluorescence imaging of zeolite aggregates within real-life fluid catalytic cracking particles.

PubMed

Ristanović, Zoran; Kerssens, Marleen M; Kubarev, Alexey V; Hendriks, Frank C; Dedecker, Peter; Hofkens, Johan; Roeffaers, Maarten B J; Weckhuysen, Bert M

2015-02-02

Fluid catalytic cracking (FCC) is a major process in oil refineries to produce gasoline and base chemicals from crude oil fractions. The spatial distribution and acidity of zeolite aggregates embedded within the 50-150 μm-sized FCC spheres heavily influence their catalytic performance. Single-molecule fluorescence-based imaging methods, namely nanometer accuracy by stochastic chemical reactions (NASCA) and super-resolution optical fluctuation imaging (SOFI) were used to study the catalytic activity of sub-micrometer zeolite ZSM-5 domains within real-life FCC catalyst particles. The formation of fluorescent product molecules taking place at Brønsted acid sites was monitored with single turnover sensitivity and high spatiotemporal resolution, providing detailed insight in dispersion and catalytic activity of zeolite ZSM-5 aggregates. The results point towards substantial differences in turnover frequencies between the zeolite aggregates, revealing significant intraparticle heterogeneities in Brønsted reactivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

FInal Report - Investment Casting Shell Cracking

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

Von Richards

2003-12-01

This project made a significant contribution to the understanding of the investment casting shell cracking problem. The effects of wax properties on the occurrence of shell cracking were demonstrated and can be measured. The properties measured include coefficient of thermal expansion, heating rate and crystallinity of the structure. The important features of production molds and materials properties have been indicated by case study analysis and fractography of low strength test bars. It was found that stress risers in shell cavity design were important and that typical critical flaws were either oversize particles or large pores just behind the prime coat.more » It was also found that the true effect of fugitive polymer fibers was not permeability increase, but rather a toughening mechanism due to crack deflection.« less

New theory for crack-tip twinning in fcc metals

NASA Astrophysics Data System (ADS)

Andric, Predrag; Curtin, W. A.

2018-04-01

Dislocation emission from a crack tip is a necessary mechanism for crack tip blunting and toughening. In fcc metals under Mode I loading, a first partial dislocation is emitted, followed either by a trailing partial dislocation ("ductile" behaviour) or a twinning partial dislocation ("quasi-brittle"). The twinning tendency is usually estimated using the Tadmor and Hai extension of the Rice theory. Extensive molecular statics simulations reveal that the predictions of the critical stress intensity factor for crack tip twinning are always systematically lower (20-35%) than observed. Analyses of the energy change during nucleation reveal that twin partial emission is not accompanied by creation of a surface step while emission of the trailing partial creates a step. The absence of the step during twinning motivates a modified model for twinning nucleation that accounts for the fact that nucleation does not occur directly at the crack tip. Predictions of the modified theory are in excellent agreement with all simulations that show twinning. Emission of the trailing partial dislocation, including the step creation, is predicted using a model recently introduced to accurately predict the first partial emission and shows why twinning is preferred. A second mode of twinning is found wherein the crack first advances by cleavage and then emits the twinning partial at the new crack tip; this mode dominates for emission beyond the first twinning partial. These new theories resolve all the discrepancies between the Tadmor twinning analysis and simulations, and have various implications for fracture behaviour and transitions.

Fracture Toughness and Fatigue Crack Growth Behavior of As-Cast High-Entropy Alloys

NASA Astrophysics Data System (ADS)

Seifi, Mohsen; Li, Dongyue; Yong, Zhang; Liaw, Peter K.; Lewandowski, John J.

2015-08-01

The fracture toughness and fatigue crack growth behavior of two as-vacuum arc cast high-entropy alloys (HEAs) (Al0.2CrFeNiTi0.2 and AlCrFeNi2Cu) were determined. A microstructure examination of both HEA alloys revealed a two-phase structure consisting of body-centered cubic (bcc) and face-centered cubic (fcc) phases. The notched and fatigue precracked toughness values were in the range of those reported in the literature for two-phase alloys but significantly less than recent reports on a single phase fcc-HEA that was deformation processed. Fatigue crack growth experiments revealed high fatigue thresholds that decreased significantly with an increase in load ratio, while Paris law slopes exhibited metallic-like behavior at low R with significant increases at high R. Fracture surface examinations revealed combinations of brittle and ductile/dimpled regions at overload, with some evidence of fatigue striations in the Paris law regime.

Life and death of a single catalytic cracking particle

PubMed Central

Meirer, Florian; Kalirai, Sam; Morris, Darius; Soparawalla, Santosh; Liu, Yijin; Mesu, Gerbrand; Andrews, Joy C.; Weckhuysen, Bert M.

2015-01-01

Fluid catalytic cracking (FCC) particles account for 40 to 45% of worldwide gasoline production. The hierarchical complex particle pore structure allows access of long-chain feedstock molecules into active catalyst domains where they are cracked into smaller, more valuable hydrocarbon products (for example, gasoline). In this process, metal deposition and intrusion is a major cause for irreversible catalyst deactivation and shifts in product distribution. We used x-ray nanotomography of industrial FCC particles at differing degrees of deactivation to quantify changes in single-particle macroporosity and pore connectivity, correlated to iron and nickel deposition. Our study reveals that these metals are incorporated almost exclusively in near-surface regions, severely limiting macropore accessibility as metal concentrations increase. Because macropore channels are “highways” of the pore network, blocking them prevents feedstock molecules from reaching the catalytically active domains. Consequently, metal deposition reduces conversion with time on stream because the internal pore volume, although itself unobstructed, becomes largely inaccessible. PMID:26601160

Effect of Steam Deactivation Severity of ZSM-5 Additives on LPG Olefins Production in the FCC Process.

PubMed

Gusev, Andrey A; Psarras, Antonios C; Triantafyllidis, Konstantinos S; Lappas, Angelos A; Diddams, Paul A

2017-10-21

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and additives are subject to deactivation. Zeolites (e.g., Rare Earth USY in the base catalyst and ZSM-5 in Olefins boosting additives) are prone to dealumination and partial structural collapse, thereby losing activity, micropore surface area, and undergoing changes in selectivity. Fresh catalyst and additives are added at appropriate respective levels to the FCC unit on a daily basis to maintain overall targeted steady-state (equilibrated) activity and selectivity. To mimic this process under accelerated laboratory conditions, a commercial P/ZSM-5 additive was hydrothermally equilibrated via a steaming process at two temperatures: 788 °C and 815 °C to simulate moderate and more severe equilibration industrial conditions, respectively. n -Dodecane was used as probe molecule and feed for micro-activity cracking testing at 560 °C to determine the activity and product selectivity of fresh and equilibrated P-doped ZSM-5 additives. The fresh/calcined P/ZSM-5 additive was very active in C 12 cracking while steaming limited its activity, i.e., at catalyst-to-feed (C/F) ratio of 1, about 70% and 30% conversion was obtained with the fresh and steamed additives, respectively. A greater activity drop was observed upon increasing the hydrothermal deactivation severity due to gradual decrease of total acidity and microporosity of the additives. However, this change in severity did not result in any selectivity changes for the LPG (liquefied petroleum gas) olefins as the nature (Brønsted-to-Lewis ratio) of the acid/active sites was not significantly altered upon steaming. Steam deactivation of ZSM-5 had also no significant effect on aromatics formation which was enhanced at higher conversion levels. Coke remained low with both fresh and steam-deactivated P/ZSM-5 additives.

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

Kuehler, C.W.

This paper reports on the need for specialty fluid catalytic cracking (FCC) additives which is likely to increase, given the refining environment and the arrival of reformulated gasoline prompted by the most recent national environmental laws. C.W. Kuehler of Chevron Research and Technology Co., U.S.A. covered the participants in the field and the state of FCC additive technology this past June at Akzo Chemie's catalysts symposium in Scheveningen, The Netherlands. Other authors of the paper presented were A.S. Krishna, C.R. Hsieh, A.R.English, and T.A. Pecoraro, all with Chevron. The FCC process has undergone numerous changes in its 50-year history, Kuehlermore » pointed out. It shows the impressive continual growth of the process. One important aspect of additives is their ability to alter and control the nature of the FCC catalyst, thereby controlling the reactions carried out in the reactor and regenerator.« less

Nitrogen Chemistry and Coke Transformation of FCC Coked Catalyst during the Regeneration Process

NASA Astrophysics Data System (ADS)

Shi, Junjun; Guan, Jianyu; Guo, Dawei; Zhang, Jiushun; France, Liam John; Wang, Lefu; Li, Xuehui

2016-06-01

Regeneration of the coked catalyst is an important process of fluid catalytic cracking (FCC) in petroleum refining, however, this process will emit environmentally harmful gases such as nitrogen and carbon oxides. Transformation of N and C containing compounds in industrial FCC coke under thermal decomposition was investigated via TPD and TPO to examine the evolved gaseous species and TGA, NMR and XPS to analyse the residual coke fraction. Two distinct regions of gas evolution are observed during TPD for the first time, and they arise from decomposition of aliphatic carbons and aromatic carbons. Three types of N species, pyrrolic N, pyridinic N and quaternary N are identified in the FCC coke, the former one is unstable and tends to be decomposed into pyridinic and quaternary N. Mechanisms of NO, CO and CO2 evolution during TPD are proposed and lattice oxygen is suggested to be an important oxygen resource. Regeneration process indicates that coke-C tends to preferentially oxidise compared with coke-N. Hence, new technology for promoting nitrogen-containing compounds conversion will benefit the in-situ reduction of NO by CO during FCC regeneration.

Edge cracks in nickel and aluminium single crystals: A molecular dynamics study

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

Chandra, Sagar, E-mail: sagarc@barc.gov.in; Chavan, V. M.; Patel, R. J.

A molecular dynamics study of edge cracks in Ni and Al single crystals under mode-I loading conditions is presented. Simulations are performed using embedded-atom method potentials for Ni and Al at a temperature of 0.5 K. The results reveal that Ni and Al show different fracture mechanisms. Overall failure behavior of Ni is brittle, while fracture in Al proceeds through void nucleation and coalescence with a zig-zag pattern of crack growth. The qualitative nature of results is discussed in the context of vacancy-formation energies and surface energies of the two FCC metals.

Development Of Simulation Model For Fluid Catalytic Cracking

NASA Astrophysics Data System (ADS)

Ghosh, Sobhan

2010-10-01

Fluid Catalytic Cracking (FCC) is the most widely used secondary conversion process in the refining industry, for producing gasoline, olefins, and middle distillate from heavier petroleum fractions. There are more than 500 units in the world with a total processing capacity of about 17 to 20% of the crude capacity. FCC catalyst is the highest consumed catalyst in the process industry. On one hand, FCC is quite flexible with respect to it's ability to process wide variety of crudes with a flexible product yield pattern, and on the other hand, the interdependence of the major operating parameters makes the process extremely complex. An operating unit is self balancing and some fluctuations in the independent parameters are automatically adjusted by changing the temperatures and flow rates at different sections. However, a good simulation model is very useful to the refiner to get the best out of the process, in terms of selection of the best catalyst, to cope up with the day to day changing of the feed quality and the demands of different products from FCC unit. In addition, a good model is of great help in designing the process units and peripherals. A simple empirical model is often adequate to monitor the day to day operations, but they are not of any use in handling the other problems such as, catalyst selection or, design / modification of the plant. For this, a kinetic based rigorous model is required. Considering the complexity of the process, large number of chemical species undergoing "n" number of parallel and consecutive reactions, it is virtually impossible to develop a simulation model based on the kinetic parameters. The most common approach is to settle for a semi empirical model. We shall take up the key issues for developing a FCC model and the contribution of such models in the optimum operation of the plant.

Carbon flow analysis and Carbon emission reduction of FCC in Chinese oil refineries

NASA Astrophysics Data System (ADS)

Jia, Fengrui; Wei, Na; Ma, Danzhu; Liu, Guangxin; Wu, Ming; Yue, Qiang

2017-08-01

The major problem of the energy production in oil refineries is the high emission of CO2 in China. The fluid catalytic cracking unit (FCC) is the key source of carbon emission in the oil refineries. According to the statistical data, the carbon emission of FCC unit accounts for more than 31% for the typical oil refineries. The carbon flow of FCC in the typical Chinese oil refineries were evaluated and analysed, which aimed at the solution of CO2 emission reduction. The method of substances flow analysis (SFA) and the mathematical programming were used to evaluate the carbon metabolism and optimize the carbon emission. The results indicated that the combustion emission of the reaction-regeneration subsystem (RRS) was the major source of FCC. The quantity of CO2 emission of RSS was more than 90%. The combustion efficiency and the amount of residual oil affected the carbon emission of RRS most according to the optimized analysis of carbon emission reduction. Moreover, the fractionation subsystem (TFS) had the highest environmental efficiency and the absorption-stabilization subsystem (ASS) had the highest resource efficiency (approximately to 1) of carbon.

Nitrogen Chemistry and Coke Transformation of FCC Coked Catalyst during the Regeneration Process

PubMed Central

Shi, Junjun; Guan, Jianyu; Guo, Dawei; Zhang, Jiushun; France, Liam John; Wang, Lefu; Li, Xuehui

2016-01-01

Regeneration of the coked catalyst is an important process of fluid catalytic cracking (FCC) in petroleum refining, however, this process will emit environmentally harmful gases such as nitrogen and carbon oxides. Transformation of N and C containing compounds in industrial FCC coke under thermal decomposition was investigated via TPD and TPO to examine the evolved gaseous species and TGA, NMR and XPS to analyse the residual coke fraction. Two distinct regions of gas evolution are observed during TPD for the first time, and they arise from decomposition of aliphatic carbons and aromatic carbons. Three types of N species, pyrrolic N, pyridinic N and quaternary N are identified in the FCC coke, the former one is unstable and tends to be decomposed into pyridinic and quaternary N. Mechanisms of NO, CO and CO2 evolution during TPD are proposed and lattice oxygen is suggested to be an important oxygen resource. Regeneration process indicates that coke-C tends to preferentially oxidise compared with coke-N. Hence, new technology for promoting nitrogen-containing compounds conversion will benefit the in-situ reduction of NO by CO during FCC regeneration. PMID:27270486

The application of an atomistic J-integral to a ductile crack.

PubMed

Zimmerman, Jonathan A; Jones, Reese E

2013-04-17

In this work we apply a Lagrangian kernel-based estimator of continuum fields to atomic data to estimate the J-integral for the emission dislocations from a crack tip. Face-centered cubic (fcc) gold and body-centered cubic (bcc) iron modeled with embedded atom method (EAM) potentials are used as example systems. The results of a single crack with a K-loading compare well to an analytical solution from anisotropic linear elastic fracture mechanics. We also discovered that in the post-emission of dislocations from the crack tip there is a loop size-dependent contribution to the J-integral. For a system with a finite width crack loaded in simple tension, the finite size effects for the systems that were feasible to compute prevented precise agreement with theory. However, our results indicate that there is a trend towards convergence.

Forecasting the zeolite-containing catalyst activity in catalytic cracking technology taking into account the feedstock composition

NASA Astrophysics Data System (ADS)

Ivashkina, Elena; Nazarova, Galina; Shafran, Tatyana; Stebeneva, Valeriya

2017-08-01

The effect of the feedstock composition and the process conditions on the current catalyst activity in catalytic cracking technology using a mathematical model is performed in this research. The mathematical model takes into account the catalyst deactivation by coke for primary and secondary cracking reactions. The investigation results have shown that the feedstock has significant effect on the yield and the content of coke on the catalyst. Thus, the relative catalyst activity is significantly reduced by 7.5-10.7 %. With increasing the catalytic cracking temperature due to the catalyst flow temperature rising, the coke content and the yield per feedstock increase and the catalyst activity decreases by 5.3-7.7%. Rising the process temperature together with the catalyst circulation ratio contributes to increase of the coke yield per feedstock in the catalytic cracking and decrease of the coke content on the catalyst. It is connected with the catalyst flow rising to the riser and the contact time decreasing in the reaction zone. Also, the catalyst activity decreases in the range of 3.8-5.5% relatively to the regenerated catalyst activity (83 %).

National Program for Inspection of Non-Federal Dams. Oliverian Dam (NH-00268) (NHWRB 02306), Connecticut River Basin, Benton, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1979-05-01

Condition of protective coating ; _. inside and out Corrosion ; Damaged parts_; Loose___ Other . .- Concrete : Cracking_/ I Spallingo_; Other...spillways have uncontrolled inlets. The principal - spillway consists of a drop inlet concrete riser which discharges to a 48-inch diameter reinforced... concrete conduit which passes through the dam (see Photos 3 and 5). The concrete conduit discharges to a plunge pool at the pipe outlet. (See Photos 8 and 9

Multiple use of waste catalysts with and without regeneration for waste polymer cracking.

PubMed

Salmiaton, A; Garforth, A A

2011-06-01

Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidized bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C(2)-C(7)) remained fairly constant. For the first time, these results indicate that "waste" FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Attrition Resistant Fischer-Tropsch Catalysts Based on FCC Supports

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

Adeyiga, Adeyinka

2010-02-05

Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditionsmore » as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%).« less

A mesostructured Y zeolite as a superior FCC catalyst--lab to refinery.

PubMed

García-Martínez, Javier; Li, Kunhao; Krishnaiah, Gautham

2012-12-18

A mesostructured Y zeolite was prepared by a surfactant-templated process at the commercial scale and tested in a refinery, showing superior hydrothermal stability and catalytic cracking selectivity, which demonstrates, for the first time, the promising future of mesoporous zeolites in large scale industrial applications.

Nanoscale Chemical Imaging of an Individual Catalyst Particle with Soft X-ray Ptychography

DOE PAGES

Wise, Anna M.; Weker, Johanna Nelson; Kalirai, Sam; ...

2016-02-26

Understanding Fe deposition in fluid catalytic cracking (FCC) catalysis is critical for the mitigation of catalyst degradation. We employ soft X-ray ptychography to determine at the nanoscale the distribution and chemical state of Fe in an aged FCC catalyst particle. We also show that both particle swelling due to colloidal Fe deposition and Fe penetration into the matrix as a result of precracking of large organic molecules occur. Furthermore, the application of ptychography allowed us to provide direct visual evidence for these two distinct Fe-based deactivation mechanisms, which have so far been proposed only on the basis of indirect evidence.

Corrosion of stainless steels in the riser during co-processing of bio-oils in a fluid catalytic cracking pilot plant

DOE PAGES

Brady, M. P.; Keiser, J. R.; Leonard, D. N.; ...

2017-01-31

Co-processing of bio-oils with conventional petroleum-based feedstocks is an attractive initial option to make use of renewable biomass as a fuel source while leveraging existing refinery infrastructures. But, bio-oils and their processing intermediates have high concentrations of organic oxygenates, which, among their other negative qualities, can result in increased corrosion issues. A range of stainless steel alloys (409, 410, 304L, 316L, 317L, and 201) was exposed at the base of the riser in a fluid catalytic cracking pilot plant while co-processing vacuum gas oil with pine-derived pyrolysis bio-oils that had been catalytically hydrodeoxygenated to ~ 2 to 28% oxygen. Wemore » studied the processing using a catalyst temperature of 704 °C, a reaction exit temperature of 520 °C, and total co-processing run times of 57–75 h. External oxide scaling 5–30 μm thick and internal attack 1–5 μm deep were observed in these short-duration exposures. The greatest extent of internal attack was observed for co-processing with the least stabilized bio-oil, and more so for types 409, 410, 304L, 316L, 317L stainless steel than for type 201. Finally, the internal attack involved porous Cr-rich oxide formation, associated with local Ni-metal enrichment and S-rich nanoparticles, primarily containing Cr or Mn. Implications for alloy selection and corrosion are discussed.« less

Corrosion of stainless steels in the riser during co-processing of bio-oils in a fluid catalytic cracking pilot plant

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

Brady, M. P.; Keiser, J. R.; Leonard, D. N.

Co-processing of bio-oils with conventional petroleum-based feedstocks is an attractive initial option to make use of renewable biomass as a fuel source while leveraging existing refinery infrastructures. But, bio-oils and their processing intermediates have high concentrations of organic oxygenates, which, among their other negative qualities, can result in increased corrosion issues. A range of stainless steel alloys (409, 410, 304L, 316L, 317L, and 201) was exposed at the base of the riser in a fluid catalytic cracking pilot plant while co-processing vacuum gas oil with pine-derived pyrolysis bio-oils that had been catalytically hydrodeoxygenated to ~ 2 to 28% oxygen. Wemore » studied the processing using a catalyst temperature of 704 °C, a reaction exit temperature of 520 °C, and total co-processing run times of 57–75 h. External oxide scaling 5–30 μm thick and internal attack 1–5 μm deep were observed in these short-duration exposures. The greatest extent of internal attack was observed for co-processing with the least stabilized bio-oil, and more so for types 409, 410, 304L, 316L, 317L stainless steel than for type 201. Finally, the internal attack involved porous Cr-rich oxide formation, associated with local Ni-metal enrichment and S-rich nanoparticles, primarily containing Cr or Mn. Implications for alloy selection and corrosion are discussed.« less

Demonstrating the Effect of Interphase Mass Transfer in a Transparent Fluidized Bed Reactor

ERIC Educational Resources Information Center

Saayman, Jean; Nicol, Willie

2011-01-01

A demonstration experiment is described that employs the ozone decomposition reaction at ambient conditions on Fe2O3 impregnated Fluidized Catalytic Cracking (FCC) catalyst. Using a two-dimensional see-through column the importance of interphase mass transfer is clearly illustrated by the significant difference in ozone conversion between the…

SRB frustrum 'smiley' cracking phenomenon study

NASA Technical Reports Server (NTRS)

Cruse, Thomas A.

1993-01-01

The thermal protection system installed on the SRB frustrums incurs the formation of debonds between the MSA-2 TPS material and the substrate. The debonds can lead to surface penetrating cracks, called 'smileys' near sealed fasteners and other surface discontinuities. The study concluded that the 'smileys' were caused as the result of stress risers caused by excess fastener sealant (PR-1422) and weakly bonded surfaces. Once the debond occurs, 'smileys' form when the debond area is sufficiently large. The loading for the debond and 'smiley' formation is seen to be depressurization at the vacuum conditions near the end of powered boost. The porous nature of the MSA-2 material covered by a vapor barrier paint provides internal pressure loading of the MSA-2 material. Recommendations for eliminating the problem include elimination of excess PR-1422 sealant and improved attention to bonding surface preparation.

The Microstructural Evolution of Fatigue Cracks in FCC Metals

NASA Astrophysics Data System (ADS)

Gross, David William

The microstructural evolution during fatigue crack propagation was investigated in a variety of planar and wavy slip FCC metals. The planar materials included Haynes 230, Nitronic 40, and 316 stainless steel, and the wavy materials included pure nickel and pure copper. Three different sets of experiments were performed to fully characterize the microstructural evolution. The first, performed on Haynes 230, mapped the strain field ahead a crack tip using digital image correlation and electron backscatter diffraction techniques. Focused ion beam (FIB) lift-out techniques were then utilized to extract transmission electron microscopy (TEM) samples at specific distances from the crack tip. TEM investigations compared the measured strain to the microstructure. Overall, the strain measured via DIC and EBSD was only weakly correlated to the density of planar slip bands in the microstructure. The second set of experiments concerned the dislocation structure around crack tips. This set of experiments was performed on all the materials. The microstructure at arrested fatigue cracks on the free surface was compared to the microstructure found beneath striations on the fracture surfaces by utilizing FIB micromachining to create site-specific TEM samples. The evolved microstructure depended on the slip type. Strong agreement was found between the crack tip microstructure at the free surface and the fracture surface. In the planar materials, the microstructure in the plastic zone consisted of bands of dislocations or deformation twins, before transitioning to a refined sub-grain microstructure near the crack flank. The sub-grain structure extended 300-500 nm away from the crack flank in all the planar slip materials studied. In contrast, the bulk structure in the wavy slip material consisted of dislocation cells and did not transition to a different microstructure as the crack tip was approached. The strain in wavy slip was highest near the crack tip, as the misorientations between the dislocation cells increased and the cell size decreased as the crack flank was approached. The final set of experiments involved reloading the arrested crack tips in monotonic tension. This was performed on both the Haynes 230 and 316 stainless steel. This technique exposed the fracture surface and location of the arrested crack tip away from the free surface, allowing for a sample to be extracted via FIB micromachining and TEM evaluation of the microstructure. This permitted the crack tip microstructure to be investigated without exposing the microstructure to crack closure or free surface effects. These experiments confirmed what was inferred from the earlier experiments, namely that the banded structure was a product of the crack tip plastic zone and the refined structure was a product of the strain associated with crack advance. Overall the microstructural complexity presented in this work was much higher than would be predicted by current models of fatigue crack propagation. It is recommended that future models attempt to simulate interactions between the dislocations emitted during fatigue crack growth and the pre-existing microstructure to more accurately simulate the processes occurring at the crack tip during crack growth.

Investigation of Three-Dimensional Stress Fields and Slip Systems for FCC Single Crystal Superalloy Notched Specimens

NASA Technical Reports Server (NTRS)

Arakere, Nagaraj K.; Magnan, Shannon; Ebrahimi, Fereshteh; Ferroro, Luis

2004-01-01

Metals and their alloys, except for a few intermetallics, are inherently ductile, i.e. plastic deformation precedes fracture in these materials. Therefore, resistance to fracture is directly related to the development of the plastic zone at the crack tip. Recent studies indicate that the fracture toughness of single crystals depends on the crystallographic orientation of the notch as well as the loading direction. In general, the dependence of crack propagation resistance on crystallographic orientation arises from the anisotropy of (i) elastic constants, (ii) plastic deformation (or slip), and (iii) the weakest fracture planes (e.g. cleavage planes). Because of the triaxial stress state at the notch tips, many slip systems that otherwise would not be activated during uniaxial testing, become operational. The plastic zone formation in single crystals has been tackled theoretically by Rice and his co-workers and only limited experimental work has been conducted in this area. The study of the stresses and strains in the vicinity of a FCC single crystal notch tip is of relatively recent origin. We present experimental and numerical investigation of 3D stress fields and evolution of slip sector boundaries near notches in FCC single crystal tension test specimens, and demonstrate that a 3D linear elastic finite element model that includes the effect of material anisotropy is shown to predict active slip planes and sectors accurately. The slip sector boundaries are shown to have complex curved shapes with several slip systems active simultaneously near the notch. Results are presented for surface and mid-plane of the specimens. The results demonstrate that accounting for 3D elastic anisotropy is very important for accurate prediction of slip activation near FCC single crystal notches loaded in tension. Results from the study will help establish guidelines for fatigue damage near single crystal notches.

Dynamics of Nanoscale Grain-Boundary Decohesion in Aluminum by Molecular-Dynamics Simulation

NASA Technical Reports Server (NTRS)

Yamakov, V.; Saether, E.; Phillips, D. R.; Glaessegen, E. H.

2007-01-01

The dynamics and energetics of intergranular crack growth along a flat grain boundary in aluminum is studied by a molecular-dynamics simulation model for crack propagation under steady-state conditions. Using the ability of the molecular-dynamics simulation to identify atoms involved in different atomistic mechanisms, it was possible to identify the energy contribution of different processes taking place during crack growth. The energy contributions were divided as: elastic energy, defined as the potential energy of the atoms in fcc crystallographic state; and plastically stored energy, the energy of stacking faults and twin boundaries; grain-boundary and surface energy. In addition, monitoring the amount of heat exchange with the molecular-dynamics thermostat gives the energy dissipated as heat in the system. The energetic analysis indicates that the majority of energy in a fast growing crack is dissipated as heat. This dissipation increases linearly at low speed, and faster than linear at speeds approaching 1/3 the Rayleigh wave speed when the crack tip becomes dynamically unstable producing periodic dislocation bursts until the crack is blunted.

Bioleaching of rare earth elements from waste phosphors and cracking catalysts

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

Reed, David W.; Fujita, Yoshiko; Daubaras, Dayna L.

Four microbial cultures were evaluated for organic acid production and their potential utility for leaching of rare earth elements (REE) from retorted phosphor powder (RPP) and spent fluidized cracking catalyst (FCC). Three of the cultures (2 bacterial, 1 fungal) were isolated from environmental and industrial materials known to contain rare earth elements. The other was the well-known and industrially important bacterium Gluconobacter oxydans. Gluconic acid was the predominant identified organic acid produced by all of the cultures; citric and acetic acid were among the other acids detected. There was also maximum REE leaching by cell free culture supernatants obtained withmore » Gluconobacter and the FCC; 49% of total REE was recovered, with preferential recovery of lanthanum over cerium. The phosphor powder was more difficult to leach; only ~2 % total REE was leached from RPP with Gluconobacter. Tests with the RPP indicated that the extent of REE solubilization was similar whether whole cell cultures or cell-free supernatants were used. However, Gluconobacter cell-free culture supernatants with 10-15 mM gluconic acid outperformed abiotically prepared leaching solutions with 30 mM gluconic acid concentrations. Abiotic tests showed that increasing gluconic acid concentrations increased leaching efficiency; for example, total REE leaching from FCC increased from 24 to 36 to 45% when gluconic acid was increased from 10 to 30 to 90 mM. Our research shows that utilizing microorganisms that produce gluconic acid can result in effective leaching of REE from waste materials, and optimizing gluconic acid production will improve recovery.« less

Bioleaching of rare earth elements from waste phosphors and cracking catalysts

DOE PAGES

Reed, David W.; Fujita, Yoshiko; Daubaras, Dayna L.; ...

2016-08-22

Four microbial cultures were evaluated for organic acid production and their potential utility for leaching of rare earth elements (REE) from retorted phosphor powder (RPP) and spent fluidized cracking catalyst (FCC). Three of the cultures (2 bacterial, 1 fungal) were isolated from environmental and industrial materials known to contain rare earth elements. The other was the well-known and industrially important bacterium Gluconobacter oxydans. Gluconic acid was the predominant identified organic acid produced by all of the cultures; citric and acetic acid were among the other acids detected. There was also maximum REE leaching by cell free culture supernatants obtained withmore » Gluconobacter and the FCC; 49% of total REE was recovered, with preferential recovery of lanthanum over cerium. The phosphor powder was more difficult to leach; only ~2 % total REE was leached from RPP with Gluconobacter. Tests with the RPP indicated that the extent of REE solubilization was similar whether whole cell cultures or cell-free supernatants were used. However, Gluconobacter cell-free culture supernatants with 10-15 mM gluconic acid outperformed abiotically prepared leaching solutions with 30 mM gluconic acid concentrations. Abiotic tests showed that increasing gluconic acid concentrations increased leaching efficiency; for example, total REE leaching from FCC increased from 24 to 36 to 45% when gluconic acid was increased from 10 to 30 to 90 mM. Our research shows that utilizing microorganisms that produce gluconic acid can result in effective leaching of REE from waste materials, and optimizing gluconic acid production will improve recovery.« less

Space Shuttle Orbiter Atlantis Liquid Oxygen Prevalve Detent Roller Cracking Investigation

NASA Technical Reports Server (NTRS)

Holleman, Elizabeth; Eddleman, David; Richard, James; Jacobs, Rebecca

2008-01-01

During routine inspections of the Space Shuttle's Main Propulsion System (MPS) Liquid Oxygen (LO2) pre-valve, the mechanism provided to maintain the valve in the open position was found cracked. The mechanism is a Vespel roller held against the valve visor by a stack of Belleville springs. The roller has been found cracked 3 times. All three instances were in the same valve in the same location. There are 6 pre-valves on each orbiter, and only one has exhibited this problem. Every-flight inspections were instituted and the rollers were found to be cracked after only one flight. Engineers at Marshall Space Flight Center, Johnson Space Center and Kennedy Space Center worked together to determine a solution. There were several possible contributors to the failure: a mis-aligned visor, an out of specification edge with a sharp radius, an out of specification tolerance stack up of a Belleville spring stack that caused un-predicted loads on the Vespel SP-21 roller, and a dimple machined into the side of the roller to indicate LO2 compatibility that created a stress riser. The detent assembly was removed and replaced with parts that were on the low-side of the tolerance stack up to eliminate the potential for high loads on the detent roller. After one flight, the roller was inspected and showed fewer signs of wear and no cracks.

Space Shuttle Orbiter Atlantis Liquid Oxygen Pre-Valve Detent Roller Cracking Investigation

NASA Technical Reports Server (NTRS)

Holleman, Elizabeth; Eddleman, David; Jacobs, Rebecca; Richard, James

2008-01-01

During routine inspections of the Space Shuttle s Main Propulsion System Liquid Oxygen (LO2) pre-valve, the mechanism provided to maintain the valve in the open position was found cracked. The mechanism is a Vespel roller held against the valve visor by a stack of Belleville springs. The roller has been found cracked 3 times. All three instances were in the same valve in the same location. There are 6 pre-valves on each orbiter, and only one has exhibited this problem. Every-flight inspections were instituted and the rollers were found to be cracked after only one flight. Engineers at Marshall Space Flight Center, Johnson Space Center, and Kennedy Space Center worked together to determine a solution. There were several possible contributors to the failure: a misaligned visor, an out-of-specification edge with a sharp radius, an out-of-specification tolerance stack up of a Belleville spring stack that caused un-predicted loads on the Vespel SP-21 roller, and a dimple machined into the side of the roller to indicate LO2 compatibility that created a stress riser. The detent assembly was removed and replaced with parts that were on the low side of the tolerance stack up to eliminate the potential for high loads on the detent roller. After one flight, the roller was inspected and showed fewer signs of wear and no cracks.

Analysis of fcc metals fracture behaviour: Fracture behaviour of fcc metals: brittle/ductile behaviour criteria : with ab-initio, embedded atom and pseudopotential parameterization for Au, Ir and Al. analysis for Au, Ir and Al.

NASA Astrophysics Data System (ADS)

Gornostyrev, Yu. N.; Katsnelson, M. I.; Mryasov, Oleg N.; Freeman, A. J.; Trefilov, M. V.

1998-03-01

Theoretical analysis of the fracture behaviour of fcc Au, Ir and Al have been performed within various brittle/ductile criteria (BDC) with ab-initio, embedded atom (EAM), and pseudopotential parameterizations. We systematically examined several important aspects of the fracture behaviour: (i) dislocation structure, (ii) energetics of the cleavage decohesion and (iii) character of the interatomic interactions. Unit dislocation structures were analyzed within a two dimensional generalization of the Peierls-Nabarro model with restoring forces determined from ab-initio total energy calculations and found to be split with well defined highly mobile partials for all considered metals. We find from ab-initio and pseudopotential that in contrast with most of fcc metals, cleavage decohesion curve for Al appreciably differs from UBER relation. Finally, using ab-initio, EAM and pseudopotential parameterizations, we demonstrate that (i) Au (as a typical example of a ductile metal) is well described within existing BDC's, (ii) anomalous cleavage-like crack propagation of Ir is driven predominantly by it's high elastic modulus and (iii) Al is not described within BDC due to it's long-range interatomic interactions (and hence requires adjustments of the brittle/ductile criteria).

30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... pipeline risers, and riser tensioning systems (each platform must be designed to accommodate all the loads imposed by all risers and riser does not have tensioning systems);(ii) Turrets and turret-and-hull... Platform Verification Program: (i) Drilling, production, and pipeline risers, and riser tensioning systems...

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

Honghong Shan; Jianfang Zhang; Guohe Que

The physical-chemical properties and catalytic cracking behaviors of Gudao VR and Gudao VRDS VR were studied. The properties are structural parameters show that the C/H, Mw, R{sub A}, f{sub A} values and nitrogen, sulfur, nickel, resin contents of the Gudao VRDS VR are obviously lower than those of Gudao VR, and that the content of saturates of Gudao VRDS VR are considerably higher than that of Gudao VR. The catalytic cracking experiments of Gudao VRDS VR in laboratory scale show that VRDS VR has good cracking behaviour. The research and industry scale results indicate that the VRDS process using Gudaomore » VR as feedstock is a kind of high efficiency hydrotreating process, and that VRDS-FCC complex technology can realize the deep processing of the crude, increase the light oil yields and enhance the economical profit of the enterprise.« less

A numerical study of crack tip constraint in ductile single crystals

NASA Astrophysics Data System (ADS)

Patil, Swapnil D.; Narasimhan, R.; Mishra, R. K.

In this work, the effect of crack tip constraint on near-tip stress and deformation fields in a ductile FCC single crystal is studied under mode I, plane strain conditions. To this end, modified boundary layer simulations within crystal plasticity framework are performed, neglecting elastic anisotropy. The first and second terms of the isotropic elastic crack tip field, which are governed by the stress intensity factor K and T-stress, are prescribed as remote boundary conditions and solutions pertaining to different levels of T-stress are generated. It is found that the near-tip deformation field, especially, the development of kink or slip shear bands, is sensitive to the constraint level. The stress distribution and the size and shape of the plastic zone near the crack tip are also strongly influenced by the level of T-stress, with progressive loss of crack tip constraint occurring as T-stress becomes more negative. A family of near-tip fields is obtained which are characterized by two terms (such as K and T or J and a constraint parameter Q) as in isotropic plastic solids.

Gum formation tendencies of olefinic structures in gasoline and synergistic effect of sulphur compounds

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

Nagpal, J.M.; Joshi, G.C.; Aswal, D.S.

1995-04-01

The high octane gasoline pool contains varying amounts of cracked naphthas as an important ingredient in formulating high octane lead free gasoline. The cracked naphthas are largely from Fluidized Catalytic Cracking (FCC) units and to lesser extend from thermal cracking units. While the role of olefinic unsaturation in gum formation during storage of gasoline has been extensively studied, there is little published work on contribution of individual olefin types in storage stability and gum formation tendency of gasoline containing these compound types. In the present work we report our results on storage stability and gum formation tendency of different olefinmore » types present in cracked naphthas through model compound matrix. It is found that cyclic olefins and cyclic diolefins are the most prolific gum formers. We have also studied the role of sulfur compounds present in the gasolines on gum formation tendency of olefins. While thiols enhance gum formation from all olefinic types, sulfides and disulfides interact depending on the structure of olefins. These can have either an accelerating, or inhibiting effect on gum formation.« less

The effect of fatigue cracks on fastener flexibility, load distribution, and fatigue crack growth

NASA Astrophysics Data System (ADS)

Whitman, Zachary Layne

Fatigue cracks typically occur at stress risers such as geometry changes and holes. This type of failure has serious safety and economic repercussions affecting structures such as aircraft. The need to prevent catastrophic failure due to fatigue cracks and other discontinuities has led to durability and damage tolerant methodologies influencing the design of aircraft structures. Holes in a plate or sheet filled with a fastener are common fatigue critical locations in aircraft structure requiring damage tolerance analysis (DTA). Often, the fastener is transferring load which leads to a loading condition involving both far-field stresses such as tension and bending, and localized bearing at the hole. The difference between the bearing stress and the tensile field at the hole is known as load transfer. The ratio of load transfer as well as the magnitude of the stresses plays a significant part in how quickly a crack will progress to failure. Unfortunately, the determination of load transfer in a complex joint is far from trivial. Many methods exist in the open literature regarding the analysis of splices, doublers and attachment joints to determine individual fastener loads. These methods work well for static analyses but greater refinement is needed for crack growth analysis. The first fastener in a splice or joint is typically the most critical but different fastener flexibility equations will all give different results. The constraint of the fastener head and shop end, along with the type of fastener, affects the stiffness or flexibility of the fastener. This in turn will determine the load that the fastener will transfer within a given fastener pattern. However, current methods do not account for the change in flexibility at a fastener as the crack develops. It is put forth that a crack does indeed reduce the stiffness of a fastener by changing its constraint, thus lessening the load transfer. A crack growth analysis utilizing reduced load transfer will result in a slower growing crack versus an analysis that ignores the effect.

30 CFR 250.524 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2011 CFR

2011-07-01

.../casing, tubing/riser, casing/casing, riser/casing, or riser/riser communication; (d) Any well that has... initial startup operations described in § 250.521; (e) Any hybrid well with casing or riser pressure...

Statistics of velocity fluctuations of Geldart A particles in a circulating fluidized bed riser

DOE PAGES

Vaidheeswaran, Avinash; Shaffer, Franklin; Gopalan, Balaji

2017-11-21

Here, the statistics of fluctuating velocity components are studied in the riser of a closed-loop circulating fluidized bed with fluid catalytic cracking catalyst particles. Our analysis shows distinct similarities as well as deviations compared to existing theories and bench-scale experiments. The study confirms anisotropic and non-Maxwellian distribution of fluctuating velocity components. The velocity distribution functions (VDFs) corresponding to transverse fluctuations exhibit symmetry, and follow a stretched-exponential behavior up to three standard deviations. The form of the transverse VDF is largely determined by interparticle interactions. The tails become more overpopulated with an increase in particle loading. The observed deviations from themore » Gaussian distribution are represented using the leading order term in the Sonine expansion, which is commonly used to approximate the VDFs in kinetic theory for granular flows. The vertical fluctuating VDFs are asymmetric and the skewness shifts as the wall is approached. In comparison to transverse fluctuations, the vertical VDF is determined by the local hydrodynamics. This is an observation of particle velocity fluctuations in a large-scale system and their quantitative comparison with the Maxwell-Boltzmann statistics.« less

30 CFR 250.905 - How do I get approval for the installation, modification, or repair of my platform?

Code of Federal Regulations, 2013 CFR

2013-07-01

... foundations; drilling, production, and pipeline risers and riser tensioning systems; turrets and turret-and... component design; pile foundations; drilling, production, and pipeline risers and riser tensioning systems... Loads imposed by jacket; decks; production components; drilling, production, and pipeline risers, and...

30 CFR 250.905 - How do I get approval for the installation, modification, or repair of my platform?

Code of Federal Regulations, 2014 CFR

2014-07-01

... foundations; drilling, production, and pipeline risers and riser tensioning systems; turrets and turret-and... component design; pile foundations; drilling, production, and pipeline risers and riser tensioning systems... Loads imposed by jacket; decks; production components; drilling, production, and pipeline risers, and...

Core disruptive accident margin seal

DOEpatents

Garin, John; Belsick, James C.

1978-01-01

An apparatus for sealing the annulus defined between a substantially cylindrical rotatable first riser assembly and plug combination disposed in a substantially cylindrical second riser assembly and plug combination of a nuclear reactor system. The apparatus comprises a flexible member disposed between the first and second riser components and attached to a metal member which is attached to an actuating mechanism. When the actuating mechanism is not actuated, the flexible member does not contact the riser components thus allowing the free rotation of the riser components. When desired, the actuating mechanism causes the flexible member to contact the first and second riser components in a manner to block the annulus defined between the riser components, thereby sealing the annulus between the riser components.

Vortex-induced vibration of two parallel risers: Experimental test and numerical simulation

NASA Astrophysics Data System (ADS)

Huang, Weiping; Zhou, Yang; Chen, Haiming

2016-04-01

The vortex-induced vibration of two identical rigidly mounted risers in a parallel arrangement was studied using Ansys- CFX and model tests. The vortex shedding and force were recorded to determine the effect of spacing on the two-degree-of-freedom oscillation of the risers. CFX was used to study the single riser and two parallel risers in 2-8 D spacing considering the coupling effect. Because of the limited width of water channel, only three different riser spacings, 2 D, 3 D, and 4 D, were tested to validate the characteristics of the two parallel risers by comparing to the numerical simulation. The results indicate that the lift force changes significantly with the increase in spacing, and in the case of 3 D spacing, the lift force of the two parallel risers reaches the maximum. The vortex shedding of the risers in 3 D spacing shows that a variable velocity field with the same frequency as the vortex shedding is generated in the overlapped area, thus equalizing the period of drag force to that of lift force. It can be concluded that the interaction between the two parallel risers is significant when the risers are brought to a small distance between them because the trajectory of riser changes from oval to curve 8 as the spacing is increased. The phase difference of lift force between the two risers is also different as the spacing changes.

30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., production, and pipeline risers, and riser tensioning systems (each platform must be designed to accommodate all the loads imposed by all risers and riser does not have tensioning systems);(ii) Turrets and... are subject to the Platform Verification Program: (i) Drilling, production, and pipeline risers, and...

30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., production, and pipeline risers, and riser tensioning systems (each platform must be designed to accommodate all the loads imposed by all risers and riser does not have tensioning systems);(ii) Turrets and... are subject to the Platform Verification Program: (i) Drilling, production, and pipeline risers, and...

30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., production, and pipeline risers, and riser tensioning systems (each platform must be designed to accommodate all the loads imposed by all risers and riser does not have tensioning systems);(ii) Turrets and... are subject to the Platform Verification Program: (i) Drilling, production, and pipeline risers, and...

30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

Code of Federal Regulations, 2014 CFR

2014-07-01

..., production, and pipeline risers, and riser tensioning systems (each platform must be designed to accommodate all the loads imposed by all risers and riser does not have tensioning systems);(ii) Turrets and... are subject to the Platform Verification Program: (i) Drilling, production, and pipeline risers, and...

Dynamic analysis of a circulating fluidized bed riser

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

Panday, Rupen; Shadle, Lawrence J.; Guenther, Chris

2012-01-01

A linear state model is proposed to analyze dynamic behavior of a circulating fluidized bed riser. Different operating regimes were attained with high density polyethylene beads at low and high system inventories. The riser was operated between the classical choking velocity and the upper transport velocity demarcating fast fluidized and transport regimes. At a given riser superficial gas velocity, the aerations fed at the standpipe were modulated resulting in a sinusoidal solids circulation rate that goes into the riser via L-valve. The state model was derived based on the mass balance equation in the riser. It treats the average solidsmore » fraction across the entire riser as a state variable. The total riser pressure drop was modeled using Newton’s second law of motion. The momentum balance equation involves contribution from the weight of solids and the wall friction caused by the solids to the riser pressure drop. The weight of solids utilizes the state variable and hence, the riser inventory could be easily calculated. The modeling problem boils down to estimating two parameters including solids friction coefficient and time constant of the riser. It has been shown that the wall friction force acts in the upward direction in fast fluidized regime which indicates that the solids were moving downwards on the average with respect to the riser wall. In transport regimes, the friction acts in the opposite direction. This behavior was quantified based on a sign of Fanning friction factor in the momentum balance equation. The time constant of the riser appears to be much higher in fast fluidized regime than in transport conditions.« less

Engineering report for simulated riser installation

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

Brevick, C.H., Westinghouse Hanford

1996-05-09

The simulated riser installation field tests demonstrated that new access ports (risers) can be installed safely, quickly, and economically in the concrete domes of existing underground single- shell waste storage tanks by utilizing proven rotary drilling equipment and vacuum excavation techniques. The new riser installation will seal against water intrusion, provide as table riser anchored to the tank dome, and be installed in accordance with ALARA principles. The information contained in the report will apply to actual riser installation activity in the future.

30 CFR 250.524 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2012 CFR

2012-07-01

... psig during a casing diagnostic test; (c) Any well that has demonstrated tubing/casing, tubing/riser, casing/casing, riser/casing, or riser/riser communication; (d) Any well that has sustained casing... operations described in § 250.521; (e) Any hybrid well with casing or riser pressure exceeding 100 psig; or...

30 CFR 250.525 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2013 CFR

2013-07-01

... psig during a casing diagnostic test; (c) Any well that has demonstrated tubing/casing, tubing/riser, casing/casing, riser/casing, or riser/riser communication; (d) Any well that has sustained casing... operations described in § 250.521; (e) Any hybrid well with casing or riser pressure exceeding 100 psig; or...

30 CFR 250.525 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2014 CFR

2014-07-01

... psig during a casing diagnostic test; (c) Any well that has demonstrated tubing/casing, tubing/riser, casing/casing, riser/casing, or riser/riser communication; (d) Any well that has sustained casing... operations described in § 250.521; (e) Any hybrid well with casing or riser pressure exceeding 100 psig; or...

NASA CPAS Drogue Textile Riser Feasibility Study

NASA Technical Reports Server (NTRS)

Hennings, Elsa J.; Petersen, Michael L.; Anderson, Brian; Johnson, Brian

2015-01-01

Steel cable was chosen for the lower end of the drogue and main parachute risers on NASA's Orion Multi Purpose Crew Vehicle Parachute Assembly System (CPAS) to protect the risers from extreme temperatures and abrasion should they contact the crew module during deployment, as was done for Apollo. Due to the weight and deployment complexity inherent in steel, there was significant interest in the possibility of substituting textile for steel for the drogue and main parachute risers. However, textile risers could be damaged when subjected to high temperature and abrasion. Investigations were consequently performed by a subset of the authors to determine whether sacrificial, non-load-bearing textile riser covers could be developed to mitigate the thermal and abrasion concerns. Multiple material combinations were tested, resulting in a cover design capable of protecting the riser against severe riser/crew module contact interactions. A feasibility study was then conducted to evaluate the performance of the textile drogue riser cover in relevant abrasive environments. This paper describes the testing performed and documents the results of this feasibility study.

Effects of Dynamic Impact Loading on Microstructure of FCC (TWIP) Steel

DTIC Science & Technology

2014-08-01

experimental development and fundamental studies into weld metal solidification cracking in steels and stainless steels . He has also undertaken...bands (ABS) may appear when the steel is subjected to high strain rate deformation. They concluded the following: 1. For TWIP steel deformed under...mm) was selected as a trial material in this case. The Explosive Bulge Test (EBT) was performed on the TWIP steel using charge weight (PE4 high

Nonlinear quasi-static analysis of ultra-deep-water top-tension riser

NASA Astrophysics Data System (ADS)

Gao, Guanghai; Qiu, Xingqi; Wang, Ke; Liu, Jianjun

2017-09-01

In order to analyse the ultra-deep-water top-tension riser deformation in drilling conditions, a nonlinear quasi-static analysis model and equation are established. The riser in this model is regarded as a simply supported beam located in the vertical plane and is subjected to non-uniform axial and lateral forces. The model and the equation are solved by the finite element method. The effects of riser outside diameter, top tension ratio, sea surface current velocity, drag force coefficient, floating system drift distance and water depth on the riser lateral displacement are discussed. Results show that the riser lateral displacement increase with the increase in the sea surface current velocity, drag force coefficient and water depth, whereas decrease with the increase in the riser outside diameter, top tension ratio. The top tension ratio has an important influence on the riser deformation and it should be set reasonably under different circumstances. The drift of the floating system has a complicated influence on the riser deformation and it should avoid a large drift distance in the proceedings of drilling and production.

Physical simulation of the response of the Enserch Garden Banks 388 FPF/free standing rigid riser to wind, waves, and current

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

Edwards, R.Y.; Johnson, T.L.; Johnson, R.P.

1995-12-31

This paper describes large scale hydrodynamic model tests of the Enserch Exploration Garden Banks 388 Floating Production Facility (FPF). This unique facility consists of a semi-submersible connected to a template on the sea floor 2,096 feet below the surface through a buoyant, free standing ``rigid`` riser. The top of the riser and its manifold are located well below the surface to minimize the forces exerted on the riser by waves. Numerous flexible conductors connect the semi-submersible to the manifold on the top of the riser. The emphasis of the model test program was to confirm the estimates of: The structuralmore » response of the buoyant, rigid production riser and an adjacent drilling riser; The relative displacements between the semisubmersible and the production riser; The relative displacements between the production riser and drilling riser; and The forces which must be endured by the tensioners and flexible hoses which join the semi-submersible to the production riser. The paper describes the planning and preparation of the model components, the unique aspects of the simulation of the environments and the structural properties of the models, the execution of the experiments and the handling of the large number of measurements necessary to characterize the response of the multi-component system. Finally, the data analysis tools which were employed to provide an understanding of the responses of the system are discussed. 22 figs., 1 tab.« less

Core disruptive accident margin seal

DOEpatents

Garin, John

1978-01-01

An apparatus for sealing the annulus defined between a substantially cylindrical rotatable first riser assembly and plug combination disposed in a substantially cylindrical second riser assembly and plug combination of a nuclear reactor system. The apparatus comprises a flexible metal member having a first side attached to one of the riser components and a second side extending toward the other riser component and an actuating mechanism attached to the flexible metal member while extending to an accessible location. When the actuating mechanism is not activated, the flexible metal member does not contact the other riser component thus allowing the free rotation of the riser assembly and plug combination. When desired, the actuating mechanism causes the second side of the flexible metal member to contact the other riser component thereby sealing the annulus between the components.

A CFD study of gas-solid jet in a CFB riser flow

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

Li, Tingwen; Guenther, Chris

2012-03-01

Three-dimensional high-resolution numerical simulations of a gas–solid jet in a high-density riser flow were conducted. The impact of gas–solid injection on the riser flow hydrodynamics was investigated with respect to voidage, tracer mass fractions, and solids velocity distribution. The behaviors of a gas–solid jet in the riser crossflow were studied through the unsteady numerical simulations. Substantial separation of the jetting gas and solids in the riser crossflow was observed. Mixing of the injected gas and solids with the riser flow was investigated and backmixing of gas and solids was evaluated. In the current numerical study, both the overall hydrodynamics ofmore » riser flow and the characteristics of gas–solid jet were reasonably predicted compared with the experimental measurements made at NETL.« less

Flow Regime Study in a High Density Circulating Fluidized Bed Riser with an Abrupt Exit

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

Mei, J.S.; Shadle, L.J.; Yue, P.C.

2007-01-01

Flow regime study was conducted in a 0.3 m diameter, 15.5 m height circulating fluidized bed (CFB) riser with an abrupt exit at the National Energy Technology Laboratory of the U.S. Department of Energy. Local particle velocities were measured at various radial positions and riser heights using an optical fiber probe. On-line measurement of solid circulating rate was continuously recorded by the Spiral. Glass beads of mean diameter 61 μm and particle density of 2,500 kg/m3 were used as bed material. The CFB riser was operated at various superficial gas velocities ranging from 3 to 7.6 m/s and solid massmore » flux from 20 to 550 kg/m2-s. At a constant riser gas velocity, transition from fast fluidization to dense suspension upflow (DSU) regime started at the bottom of the riser with increasing solid flux. Except at comparatively low riser gas velocity and solid flux, the apparent solid holdup at the top exit region was higher than the middle section of the riser. The solid fraction at this top region could be much higher than 7% under high riser gas velocity and solid mass flux. The local particle velocity showed downward flow near the wall at the top of the riser due to its abrupt exit. This abrupt geometry reflected the solids and, therefore, caused solid particles traveling downward along the wall. However, at location below, but near, the top of the riser the local particle velocities were observed flowing upward at the wall. Therefore, DSU was identified in the upper region of the riser with an abrupt exit while the fully developed region, lower in the riser, was still exhibiting core-annular flow structure. Our data were compared with the flow regime boundaries proposed by Kim et al. [1] for distinguishing the dilute pneumatic transport, fast fluidization, and DSU.« less

Mapping Metals Incorporation of a Whole Single Catalyst Particle Using Element Specific X-ray Nanotomography

DOE PAGES

Meirer, Florian; Morris, Darius T.; Kalirai, Sam; ...

2015-01-02

Full-field transmission X-ray microscopy has been used to determine the 3D structure of a whole individual fluid catalytic cracking (FCC) particle at high spatial resolution and in a fast, noninvasive manner, maintaining the full integrity of the particle. Using X-ray absorption mosaic imaging to combine multiple fields of view, computed tomography was performed to visualize the macropore structure of the catalyst and its availability for mass transport. We mapped the relative spatial distributions of Ni and Fe using multiple-energy tomography at the respective X-ray absorption K-edges and correlated these distributions with porosity and permeability of an equilibrated catalyst (E-cat) particle.more » Both metals were found to accumulate in outer layers of the particle, effectively decreasing porosity by clogging of pores and eventually restricting access into the FCC particle.« less

Microwave-assisted Extraction of Rare Earth Elements from Petroleum Refining Catalysts and Ambient Fine Aerosols Prior to Inductively Coupled Plasma - Mass Spectrometry

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.; Kulkarni, Pranav; Chellam, Shankar

2006-01-01

In the absence of a certified reference material, a robust microwave-assisted acid digestion procedure followed by inductively coupled plasma - mass spectrometry (ICP-MS) was developed to quantify rare earth elements (REEs) in fluidized-bed catalytic cracking (FCC) catalysts and atmospheric fine particulate matter (PM2.5). High temperature (200 C), high pressure (200 psig), acid digestion (HNO3, HF, and H3BO3) with 20 minute dwell time effectively solubilized REEs from six fresh catalysts, a spent catalyst, and PM2.5. This method was also employed to measure 27 non-REEs including Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Zr, Mo, Cd, Cs, Ba, Pb, and U. Complete extraction of several REEs (Y, La, Ce, Pr, Nd, Tb, Dy, and Er) required HF indicating that they were closely associated with the aluminosilicate structure of the zeolite FCC catalysts. Internal standardization using 115In quantitatively corrected non-spectral interferences in the catalyst digestate matrix. Inter-laboratory comparison using ICP-optical emission spectroscopy (ICP-OES) and instrumental neutron activation analysis (INAA) demonstrated the applicability of the newly developed analytical method for accurate analysis of REEs in FCC catalysts. The method developed for FCC catalysts was also successfully implemented to measure trace to ultra-trace concentrations of La, Ce, Pr, Nd, Sm, Gd, Eu, and Dy in ambient PM2.5 in an industrial area of Houston, TX.

Assessment of primary healthcare professionals' management of hypertensive patients with riser pattern.

PubMed

Sagarra-Tió, María; Félez-Carrobé, Estel; Baiget, Montserrat; Félez, Jordi

2015-02-01

Ambulatory blood pressure monitoring (ABPM) was implemented in our primary care setting four years ago. Since then, 450 ABPMs have been performed and 69 riser subjects identified. The riser pattern is an independent risk factor for both incidence of cardiovascular events and their associated mortality. The purpose of this study was to assess the amount of control of essential hypertension (EH) among riser patients and to evaluate how our health professionals manage therapeutic changes in riser individuals. This retrospective study involved 34,289 inhabitants served in a centre in the Barcelona metropolitan area. EH individuals (450) were recruited and ABPM was performed following guidelines of the MAPAPRES (www.cardiorisc.com/MP/index_MP.asp). Good control of blood pressure was observed in 46% of dipper and non-dipper subjects but only 35% of riser subjects had blood pressures within good control ranges. The measured cardiovascular risk was either high or very high in 35% of riser individuals. Changes in medication were introduced in riser patients with both good and poor blood pressure control. A second follow-up ABPM was done in only 27% of the riser individuals. In these subjects, therapeutic changes successfully modified ABPM patterns in 87% of cases. Therapeutic changes in riser patients were introduced when these subjects were poorly controlled and these changes were highly effective. Additional ABPM to confirm the effectiveness of therapeutic changes was only performed in some individuals. Thus, for management of riser patients, more specific training of health professionals is needed. © The European Society of Cardiology 2013.

System for estimating fatigue damage

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

LeMonds, Jeffrey; Guzzo, Judith Ann; Liu, Shaopeng

In one aspect, a system for estimating fatigue damage in a riser string is provided. The system includes a plurality of accelerometers which can be deployed along a riser string and a communications link to transmit accelerometer data from the plurality of accelerometers to one or more data processors in real time. With data from a limited number of accelerometers located at sensor locations, the system estimates an optimized current profile along the entire length of the riser including riser locations where no accelerometer is present. The optimized current profile is then used to estimate damage rates to individual risermore » components and to update a total accumulated damage to individual riser components. The number of sensor locations is small relative to the length of a deepwater riser string, and a riser string several miles long can be reliably monitored along its entire length by fewer than twenty sensor locations.« less

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... line pipe and risers; pressure-regulating devices (including back-pressure regulators); sensing devices... § 250.198), if applicable. (ii) If you propose to use one or more pipeline risers for a tension leg... riser, with calculations, and the fatigue point at which you would replace the riser; (B) The results of...

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

Sterndorff, M.J.; O`Brien, P.

ROLF (Retrievable Offshore Loading Facility) has been proposed as an alternative offshore oil export tanker loading system for the North Sea. The system consists of a flexible riser ascending from the seabed in a lazy wave configuration to the bow of a dynamically positioned tanker. In order to supplant and support the numerical analyses performed to design the system, an extensive model test program was carried out in a 3D offshore basin at scale 1:50. A model riser with properties equivalent to the properties of the oil filled prototype riser installed in seawater was tested in several combinations of wavesmore » and current. During the tests the forces at the bow of the tanker and at the pipeline end manifold were measured together with the motions of the tanker and the riser. The riser motions were measured by means of a video based 3D motion monitoring system. Of special importance was accurate determination of the minimum bending radius for the riser. This was derived based on the measured riser motions. The results of the model tests were compared to numerical analyses by an MCS proprietary riser analysis program.« less

Riser Difference Uncertainty Methodology Based on Tank AY-101 Wall Thickness Measurements with Application to Tank AN-107

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

Weier, Dennis R.; Anderson, Kevin K.; Berman, Herbert S.

2005-03-10

The DST Integrity Plan (RPP-7574, 2003, Double-Shell Tank Integrity Program Plan, Rev. 1A, CH2M HILL Hanford Group, Inc., Richland, Washington.) requires the ultrasonic wall thickness measurement of two vertical scans of the tank primary wall while using a single riser location. The resulting measurements are then used in extreme value methodology to predict the minimum wall thickness expected for the entire tank. The representativeness of using a single riser in this manner to draw conclusions about the entire circumference of a tank has been questioned. The only data available with which to address the representativeness question comes from Tank AY-101more » since only for that tank have multiple risers been used for such inspection. The purpose of this report is to (1) further characterize AY-101 riser differences (relative to prior work); (2) propose a methodology for incorporating a ''riser difference'' uncertainty for subsequent tanks for which only a single riser is used, and (3) specifically apply the methodology to measurements made from a single riser in Tank AN-107.« less

Guided-waves technique for inspecting the health of wall-covered building risers

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Chen, J. M.; Wan, X.

2015-03-01

The inspection technique uses guided ultrasonic waves (GW) has been proven effective in detecting pipes' defects. However, as of today, the technique has not attracted much market attention because of insufficient field tests and lack of traceable records with proven results in commercial applications. In this paper, it presents the results obtained by using GW to inspect the defects occurred in real gas risers that are commonly installed in tall buildings. The purpose of having risers is to deliver gas from any building external piping system to each household unit of the building. The risers extend from the external wall of the building, penetrate thorough the concrete wall, into the kitchen or bathroom of each household unit. Similar to in-service pipes, risers are prone to corrosion due to water leaks into the concrete wall. However, the corrosion occurs in the section of riser, which is covered by the concrete wall, is difficult to be inspected by conventional techniques. Hence, GW technique was employed. The effectiveness of GW technique was tested by laboratory and on-site experiments using real risers gathered from tall buildings. The experimental results show that GW can partially penetrate thorough the riser's section that is covered by wall. The integrity of the wall-covered section of a riser can be determined by the reflected wave signals generated by the corroded area that may exit inside the wall-covered section. Based on the reflected wave signal, one can determine the health of the wall-covered riser.

Mechanisms of fracture of ring samples made of FCC metals on loading with magnetic-pulse method

NASA Astrophysics Data System (ADS)

Morozov, Viktor; Kats, Victor; Savenkov, Georgiy; Lukin, Anton

2018-05-01

Results of study of deformation and fracture of ring-shaped samples made of thin strips of cuprum, aluminum and steel in wide range of loading velocity are presented. Three developed by us schemes of magnetic-pulse method are used for the samples loading. The method of samples fracture with the high electrical resistance (e.g. steel) is proposed. Crack velocity at the sample fracture is estimated. Fracture surfaces are inspected. Mechanisms of dynamic fracture of the sample arere discussed.

Riser pattern is a predictor of kidney mortality among patients with chronic kidney disease.

PubMed

Nakai, Kentaro; Fujii, Hideki; Watanabe, Kentaro; Watanabe, Shuhei; Awata, Rie; Kono, Keiji; Yonekura, Yuriko; Goto, Shunsuke; Nishi, Shinichi

Hypertension is a crucial risk factor for cardiovascular death and loss of residual kidney function. Absence of the nocturnal decline in blood pressure (BP) predicts cardiovascular events and poor prognosis. However, characteristics of hypertension in moderate-to-severe chronic kidney disease (CKD) have not been fully evaluated. We aimed to assess the circadian variation of BP and kidney survival in CKD patients. Patients who were examined by 24-h ambulatory BP monitoring (ABPM) and estimated glomerular filtration rate (eGFR), <45 ml/min/1.73 m(2), were enrolled in the study. The impacts of BP circadian rhythm and brain natriuretic peptide (BNP) on kidney survival were evaluated. A total of 124 patients were enrolled. The average age was 64 ± 14 years, 57% were male, and 43% had diabetes. Forty-five percent of patients had a non-dipper pattern, 35% had a riser pattern, 19% had a dipper pattern, and 1% had an extreme-dipper pattern. The prevalence of diabetes and plasma BNP levels was higher and eGFR was lower in the riser-pattern group than in the non-riser-pattern group. Kidney survival rates were significantly worse in the riser-pattern group than in the non-riser-pattern group (p < 0.05). Moreover, among riser and non-riser pattern groups divided by BNP levels, the riser group with higher BNP level showed the worst kidney survival (p < 0.05). The riser pattern is frequently associated with several conditions at higher risk for kidney survival. Patients with a rising pattern and higher BNP levels have a worse kidney prognosis.

Acoustic and Perceptual Measures of SATB Choir Performances on Two Types of Portable Choral Riser Units in Three Singer-Spacing Conditions

ERIC Educational Resources Information Center

Daugherty, James F.; Manternach, Jeremy N.; Brunkan, Melissa C.

2013-01-01

Under controlled conditions, we assessed acoustically (long-term average spectra) and perceptually (singer survey, listener survey) six performances of an soprano, alto, tenor, and bass (SATB) choir ("N" = 27) as it sang the same musical excerpt on two portable riser units (standard riser step height, taller riser step height) with…

Schools of Authentic and Inclusive Learning. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

ERIC Educational Resources Information Center

Hanley-Maxwell, Cheryl; Phelps, L. Allen; Braden, Jeff; Warren, Valli

This brief provides an overview of the foundation and framework for the Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities. RISER focuses on secondary schools engaged in reform efforts that include students with disabilities and seeks to identify restructuring practices that benefit all students. RISERs goal is to…

Composite risers for deep-water offshore technology: Problems and prospects. 1. Metal-composite riser

NASA Astrophysics Data System (ADS)

Beyle, A. I.; Gustafson, C. G.; Kulakov, V. L.; Tarnopol'skii, Yu. M.

1997-09-01

Prospects for the application of advanced composites in the offshore technology of oil production are considered. The use of composites in vertical pipelines-risers seems to be the most efficient. The operating loads are studied and the attendant problems are formulated. A comparative analysis of the characteristics of metal, composite, and metal-composite deep-water risers is presented. A technique is developed for designing multilayered risers, taking into account the action of internal and external pressures, gravity, and the axial tensile force created by tensioners, as well as the residual technological stresses due to the difference in coefficients of thermal expansion, physical-chemical shrinkage, and force winding. Numerical estimations are given for a two-layered riser with an inner metal layer of steel, titanium, or aluminum alloys and a composite layer of glass- or carbon-fiber plastics formed by circumferential winding. It is shown that the technological stresses substantially affect the characteristics of the riser.

Jet penetration into a riser operated in dense suspension upflow: experimental and model comparisons

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

Shadle, L.J.; Ludlow, C.J.; Spenik, J.L.

2008-05-13

Solids tracers were used to characterize the penetration of a gas-solids jet directed toward the center of the 0.3-m diameter, circulating fluidized bed (CFB) riser. The penetration was measured by tracking phosphorescent particles illuminated immediately prior to injection into the riser. Photosensors and piezoelectric detectors were traversed across the radius of the riser at various axial positions to detect the phosphorescent jet material and particles traveling in the radial direction. Local particle velocities were measured at various radial positions, riser heights, and azimuthal angles using an optical fiber probe. Four (4) variables were tested including the jet velocity, solids feedmore » rate into the jet, the riser velocity, and overall CFB circulation rate over 8 distinct test cases with the central, or base case, repeated each time the test series was conducted. In addition to the experimental measurements made, the entire riser with a side feed jet of solids was simulated using the Eulerian-Eulerian computer model MFIX.« less

Vortex-induced vibration (VIV) effects of a drilling riser due to vessel motion

NASA Astrophysics Data System (ADS)

Joseph, R. S.; Wang, J.; Ong, M. C.; Jakobsen, J. B.

2017-12-01

A marine riser undergoes oscillatory motion in water due to the vessel motions, known as global dynamic response. This to-and-fro motion of the riser will generate an equivalent flow that can cause Vortex-Induced Vibrations (VIVs), even in the absence of the ocean current. In the present work, full-scale measurement data of a drilling riser operating in the Gulf of Mexico are analysed. The VIV occurrences for the riser are identified from the data and the possible excitation sources are discussed. The oscillatory flow due to vessel motion is compared with the ocean current and its possibility to excite VIV is analysed. The full-scale data analysis provides an insight into the vessel motion-induced VIV of marine risers in the actual field environment.

Effect of vanadium contamination on the framework and micropore structure of ultra stable Y-zeolite.

PubMed

Etim, U J; Xu, B; Ullah, Rooh; Yan, Z

2016-02-01

Y-zeolites are the main component of fluid catalytic cracking (FCC) catalyst for conversion of crude petroleum to products of high demand including transportation fuel. We investigated effects of vanadium which is present as one of the impurities in FCC feedstock on the framework and micropore structure of ultra-stable (US) Y-zeolite. The zeolite samples were prepared and characterized using standard techniques including: (1) X-ray diffraction, (2) N2 adsorption employing non local density functional theory method, NLDFT, (3) Transmittance and Pyridine FTIR, (4) Transmittance electron microscopy (TEM), and (5) (27)Al and (29)Si MAS-NMR. Results revealed that in the presence of steam, vanadium caused excessive evolution of non inter-crystalline mesopores and structural damage. The evolved mesopore size averaged about 25.0nm at 0.5wt.% vanadium loading, far larger than mesopore size in zeolitic materials with improved hydrothermal stability and performance for FCC catalyst. A mechanism of mesopore formation based on accelerated dealumination has been proposed and discussed. Vanadium immobilization experiments conducted to mitigate vanadium migration into the framework clearly showed vanadium is mobile at reaction conditions. From the results, interaction of vanadium with the passivator limits and decreases mobility and activity of vanadium into inner cavities of the zeolite capable of causing huge structure breakdown and acid sites destruction. This study therefore deepens insight into the causes of alteration in activity and selectivity of vanadium contaminated catalyst and hints on a possible mechanism of passivation in vanadium passivated FCC catalyst. Copyright © 2015 Elsevier Inc. All rights reserved.

OTEC riser cable system, Phase II: conceptual design

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

Not Available

1980-10-01

Studies are summarized of conceptual designs of riser cable systems for OTEC pilot plants of both the spar and plantship configurations located at sites off the southeast coast of Puerto Rico. The studies utilize a baseline pilot plant riser cable, the design of which has been developed and reported on in other reports. Baseline riser cable systems for OTEC pilot plants are identified, system hardware consistent with these designs are conceptualized, and comparisons of the various system concepts are provided. It is concluded that there are three riser cable systems feasible for a spar pilot plant platform at the Puntamore » Yeguas site, and two riser cable systems feasible at the plantship pilot plant at the Punta Tuna site. Recommendations for further investigations in the areas of materials, hardware design and pre-installation site surveys are also addressed.« less

Garden Banks 388 deepwater production riser structural and environmental monitoring system

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

Thrall, D.E.; Pokladnik, R.L.

1995-12-01

A deepwater production riser, to be installed in 1995 in Garden Banks 388 in the Gulf of Mexico, has been instrumented with bonded resistance strain gages so that the remaining operational fatigue life can be quantified. The riser supports flowlines from subsea oil and gas wells to a floating combination drilling/production vessel, and thus is fixed at its lower end and free to move at its upper terminus. The distribution of bending stresses throughout the riser, which is attached to a template at 2,096 foot depth and extends to within 150 feet of the surface, reaches a maximum at themore » bottom. The riser is instrumented with strain gages, inclinometers, and accelerometers at five locations along its length so that tension, bending, orientation, and motion of the riser can be monitored at these locations, including the bottom joint. Correlation of the riser response data with the excitation or environmental data, including wave motion, current velocities, wind velocities, and vessel mooring tensions and positions is enhanced by acquiring and archiving all data on a single common system having multiple redundant elements for reliability. This paper describes the production riser structural and environmental monitoring system used on the Garden Banks 388 project.« less

46 CFR 151.50-5 - Cargoes having toxic properties.

Code of Federal Regulations, 2012 CFR

2012-10-01

... vent riser shall extend at least 12 feet above the highest level accessible to personnel. The vent riser may be collapsible for ease of stowage when not in use. Vapor return lines or vent risers for...

30 CFR 250.917 - What are the CVA's primary duties during the fabrication phase?

Code of Federal Regulations, 2011 CFR

2011-07-01

... overall structure, including any turrets, turret-and-hull interfaces, any mooring line and chain and riser... must also consider: (i) Drilling, production, and pipeline risers, and riser tensioning systems (at...

46 CFR 151.50-5 - Cargoes having toxic properties.

Code of Federal Regulations, 2010 CFR

2010-10-01

... vent riser shall extend at least 12 feet above the highest level accessible to personnel. The vent riser may be collapsible for ease of stowage when not in use. Vapor return lines or vent risers for...

30 CFR 250.917 - What are the CVA's primary duties during the fabrication phase?

Code of Federal Regulations, 2012 CFR

2012-07-01

... turrets, turret-and-hull interfaces, any mooring line and chain and riser tensioning line segments; and...) Drilling, production, and pipeline risers, and riser tensioning systems (at least for the initial...

46 CFR 151.50-5 - Cargoes having toxic properties.

Code of Federal Regulations, 2011 CFR

2011-10-01

... vent riser shall extend at least 12 feet above the highest level accessible to personnel. The vent riser may be collapsible for ease of stowage when not in use. Vapor return lines or vent risers for...

46 CFR 151.50-5 - Cargoes having toxic properties.

Code of Federal Regulations, 2013 CFR

2013-10-01

... vent riser shall extend at least 12 feet above the highest level accessible to personnel. The vent riser may be collapsible for ease of stowage when not in use. Vapor return lines or vent risers for...

30 CFR 250.917 - What are the CVA's primary duties during the fabrication phase?

Code of Federal Regulations, 2014 CFR

2014-07-01

... turrets, turret-and-hull interfaces, any mooring line and chain and riser tensioning line segments; and...) Drilling, production, and pipeline risers, and riser tensioning systems (at least for the initial...

46 CFR 151.50-5 - Cargoes having toxic properties.

Code of Federal Regulations, 2014 CFR

2014-10-01

... vent riser shall extend at least 12 feet above the highest level accessible to personnel. The vent riser may be collapsible for ease of stowage when not in use. Vapor return lines or vent risers for...

30 CFR 250.917 - What are the CVA's primary duties during the fabrication phase?

Code of Federal Regulations, 2013 CFR

2013-07-01

... turrets, turret-and-hull interfaces, any mooring line and chain and riser tensioning line segments; and...) Drilling, production, and pipeline risers, and riser tensioning systems (at least for the initial...

A biomechanical evaluation of staircase riser heights and tread depths during stair-climbing.

PubMed

Mital, A; Fard, H F; Khaledi, H

1987-08-01

Several different staircase riser heights and tread depths were investigated in order to determine riser height and tread depth that minimized moments acting at the ankle, knee, and hipjoints while walking upstairs. The results indicated that joint moments were minimized when the riser height was 102 mm. For the tread depth, least moments were obtained when the depth was 305 mm. Copyright © 1987. Published by Elsevier Ltd.

MICROBIALLY MEDIATED LEACHING OF RARE EARTH ELEMENTS FROM RECYCLABLE MATERIALS

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

Reed, D. W.; Fujita, Y.; Daubaras, D. L.

2016-09-01

Bioleaching offers a potential approach for recovery of rare earth elements (REE) from recyclable materials, such as fluorescent lamp phosphors or degraded industrial catalysts. Microorganisms were enriched from REE-containing ores and recyclable materials with the goal of identifying strains capable of extracting REE from solid materials. Over 100 heterotrophic microorganisms were isolated and screened for their ability to produce organic acids capable of leaching REE. The ten most promising isolates were most closely related to Pseudomonas, Acinetobacter and Talaromyces. Of the acids produced, gluconic acid appeared to be the most effective at leaching REE (yttrium, lanthanum, cerium, europium, and terbium)more » from retorted phosphor powders (RPP), fluidized cracking catalyst (FCC), and europium-doped yttrium oxide (YOEu). We found that an Acinetobacter isolates, BH1, was the most capable strain and able to leach 33% of the total REE content from the FCC material. These results support the continuing evaluation of gluconic acid-producing microbes for large-scale REE recovery from recyclable materials.« less

Assessment of the Pozzolanic Activity of a Spent Catalyst by Conductivity Measurement of Aqueous Suspensions with Calcium Hydroxide

PubMed Central

Velázquez, Sergio; Monzó, José M.; Borrachero, María V.; Payá, Jordi

2014-01-01

The pozzolanic activity of the spent catalyst produced by fluid catalytic cracking (FCC) has been studied by various methods in recent years. However, no quick and easy method has been reported for this activity based on the associated studies. In this work, the pozzolanic activity of a spent catalyst was investigated by measuring its electrical conductivity in aqueous suspensions of pozzolan/calcium hydroxide. The behavior of the FCC catalyst residue was compared to that of reactive and inert materials of similar chemical compositions. Further, the influence of temperature on the suspension was studied, and also, a new method was proposed in which the pozzolan/calcium hydroxide ratio was varied (with the initial presence of solid Ca(OH)2 in the system). It was concluded that the method is effective, fast and simple for evaluating the high reactivity of the catalyst. Therefore, this method is an alternative for the evaluation of the reactivity of pozzolanic materials. PMID:28788583

Microstructure and mechanical properties of Ni and Fe-base boride-dispersion-strengthened microcrystalline alloys

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

Wade, C.S.; Park, H.G.; Hoagland, R.G.

This paper considers the relation between microstructure and mechanical properties of two Ni-base and two Fe-base Boride-Dispersion-Strengthened Microcrystalline (BDSM) alloys. In these very fine grained materials the borides were primarily Cr, Mo, and MoFe in a fcc matrix in three of the alloys, and a bcc in one of the Fe-base alloys. Strength data and resistance to stress corrosion cracking are reported and, in the latter case, extraordinary resistance to SCC in NaCl, Na{sub 2}S{sub 2}O{sub 3} and boiling MgCl{sub 2} environments was observed in every case. The fcc BDSM alloys also demonstrated excellent thermal stability in terms of strengthmore » and fracture roughness up to 1000 C. The bcc alloy suffered severe loss of toughness. The fracture mode involved ductile rupture in all alloys and they display a reasonably linear correlation between K{sub Ic} and the square root of particle spacing.« less

Riser Blood Pressure Pattern Is Associated With Mild Cognitive Impairment in Heart Failure Patients.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Nishimura, Yoshioki; Hoshide, Satoshi; Kario, Kazuomi

2016-02-01

The riser pattern, an abnormal blood pressure (BP) rhythm in which sleep BP exceeds awake BP, is a predictor of future stroke events. Although the riser pattern is caused by autonomic dysfunction, its significance in heart failure (HF) patients is not established. HF patients often suffered from cognitive impairment (CI), but the relationship between riser pattern and CI is not clearly understood. We tested the hypothesis that the riser pattern is associated with mild CI, a form of brain damage that could develop to dementia. We performed Mini-Mental State Examination (MMSE), ambulatory BP monitoring (ABPM), echocardiography, and blood tests in 444 HF patients just before leaving hospitals. Mild CI, a measure of cognitive function, was defined as the score <26. The mean age of the patients was 68±13 years; 61.5% were male; 22.5% were riser pattern. The MMSE score was significantly lower in the Riser group than in the Non-dipper and Dipper group (23±4 vs. 25±5, 26±4, respectively, P < 0.01). In multivariable logistic regression analysis, a riser pattern was significantly associated with mild CI (odds ratio 2.38, 95% confidence intervals 1.29-4.42, P < 0.01) after adjusting for significant covariates. The riser pattern was associated with mild CI in HF patients. An abnormal circadian BP rhythm in HF patients is clinically significant as a potential indicator of subclinical brain damage. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effect of riser end geometry on gas-solid hydrodynamics in a CFB riser operating in the core annular and dilute homogeneous flow regimes

DOE PAGES

Breault, Ronald W.; Monazam, Esmail R.; Shadle, Lawrence J.; ...

2017-02-12

Riser hydrodynamics are a function of the flow rates of gas and solids as well as the exit geometry, particularly when operated above the upper transport velocity. This work compares the exit voidage for multiple geometries and two different solids: Geldart group A glass beads and Geldart group B coke. Geometries were changed by modifying the volume of an abrupt T-shaped exit above the lateral riser exit. This was accomplished by positioning a plunger at various heights above the exit from zero to 0.38 m. A dimensionless expression used to predict smooth exit voidage was modified to account for themore » effect of the depth of the blind-T. The new correlation contains the solids-gas load ratio, solids-to-gas density ratio, bed-to-particle diameter ratio, gas Reynolds Number, as well as a term for the exit geometry. This study also found that there was a minimum riser roof height above the blind-T exit beyond which the riser exit voidage was not affected by the exit geometry. A correlation for this minimum riser roof height has also been developed in this study. This study covered riser superficial gas velocities of 4.35 to 7.7 m/s and solids circulation rates of 1.3 to 11.5 kg/s.« less

Vector form Intrinsic Finite Element Method for the Two-Dimensional Analysis of Marine Risers with Large Deformations

NASA Astrophysics Data System (ADS)

Li, Xiaomin; Guo, Xueli; Guo, Haiyan

2018-06-01

Robust numerical models that describe the complex behaviors of risers are needed because these constitute dynamically sensitive systems. This paper presents a simple and efficient algorithm for the nonlinear static and dynamic analyses of marine risers. The proposed approach uses the vector form intrinsic finite element (VFIFE) method, which is based on vector mechanics theory and numerical calculation. In this method, the risers are described by a set of particles directly governed by Newton's second law and are connected by weightless elements that can only resist internal forces. The method does not require the integration of the stiffness matrix, nor does it need iterations to solve the governing equations. Due to these advantages, the method can easily increase or decrease the element and change the boundary conditions, thus representing an innovative concept of solving nonlinear behaviors, such as large deformation and large displacement. To prove the feasibility of the VFIFE method in the analysis of the risers, rigid and flexible risers belonging to two different categories of marine risers, which usually have differences in modeling and solving methods, are employed in the present study. In the analysis, the plane beam element is adopted in the simulation of interaction forces between the particles and the axial force, shear force, and bending moment are also considered. The results are compared with the conventional finite element method (FEM) and those reported in the related literature. The findings revealed that both the rigid and flexible risers could be modeled in a similar unified analysis model and that the VFIFE method is feasible for solving problems related to the complex behaviors of marine risers.

Successful performance of a refinery with Eureka unit

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

Hirotani, Y.; Takeuchi, T.; Miyabuchi, Y.

1981-03-01

Since starting in February, 1976, 3,400,000 Kl of vacuum residue (13,000,000 Kl of crude oil equivalent) has been successfully processed in the Eureka unit of Fuji Oil refinery complex and more than 2,500,000 Kl of cracked oil and 1,000,000 tons of pitch have been produced. The operation rate has been 94 to 98% except for the annual shutdown period for inspection. The cracked oil is easily desulfurized to make naphta, diesel oil and a large amount of gas oil (low sulfur fuel oil, 0.1 wt % sulfur). As for the desulfurization of cracked oil, the increase in H/sub 2/ consumptionmore » and the decline of catalyst life are observed. However, the operation conditions do not differ much from those for straight run fractions. Processing both hydrotreated and untreated cracked heavy oil (CHO) with FCC unit has proved to be possible. In case of untreated CHO, however, it causes a slight increase in make up catalyst and coke yield. It is demonstrated that heavy crude oils, such as Bachaquero, can effectively be processed in this system. No additional pollution problems have occurred by introducing an Eureka unit to the refinery, although it is located in the district where the most stringent environmental regulations are urged.« less

Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG.

PubMed

Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

2015-11-24

To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the "HYSY-981" ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results.

Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG

PubMed Central

Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

2015-01-01

To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the “HYSY-981” ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results. PMID:26610517

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

29 CFR 1926.1052 - Stairways.

Code of Federal Regulations, 2011 CFR

2011-07-01

...° from horizontal. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Variations in riser height or... having four or more risers or rising more than 30 inches (76 cm), whichever is less, shall be equipped...

30 CFR 250.1007 - What to include in applications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and risers; pressure-regulating devices (including back-pressure regulators); sensing devices with.... (ii) If you propose to use one or more pipeline risers for a tension leg platform or other floating platform, your application must include: (A) The design fatigue life of the riser, with calculations, and...

29 CFR 1926.1052 - Stairways.

Code of Federal Regulations, 2012 CFR

2012-07-01

...° from horizontal. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Variations in riser height or... having four or more risers or rising more than 30 inches (76 cm), whichever is less, shall be equipped...

29 CFR 1926.1052 - Stairways.

Code of Federal Regulations, 2010 CFR

2010-07-01

...° from horizontal. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Variations in riser height or... having four or more risers or rising more than 30 inches (76 cm), whichever is less, shall be equipped...

29 CFR 1926.1052 - Stairways.

Code of Federal Regulations, 2013 CFR

2013-07-01

...° from horizontal. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Variations in riser height or... having four or more risers or rising more than 30 inches (76 cm), whichever is less, shall be equipped...

29 CFR 1926.1052 - Stairways.

Code of Federal Regulations, 2014 CFR

2014-07-01

...° from horizontal. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Variations in riser height or... having four or more risers or rising more than 30 inches (76 cm), whichever is less, shall be equipped...

Investigation of the motion processes of wastewater in sewerage of high-rise buildings

NASA Astrophysics Data System (ADS)

Pomogaeva, Valentina; Metechko, Lyudmila; Prokofiev, Dmitry; Narezhnaya, Tamara

2018-03-01

When designing, constructing and operating sewage pipelines in high-rise buildings, issues of failure-free operation of a network arise. Investigation of the processes of wastewater moving allows identifying problem areas during operation, assessing the possibility of obstructions and breakdowns of plumbing traps on the gravity drainage sections of the pipeline. The article performs the schemes of the water outflow from the floor sewer into the riser, including the places where the riser is bent, of air delivery to the working riser under the change of the direction of drain movement with the dropout line set-up, with the installation of an automatic anti-vacuum valve, with the installation of the ventilation pipeline. Investigations of the process of sewage waste flow in a sewage riser were carried out, in order to select the appropriate structure. The authors consider structure features of some sections of sewerage in high-rise buildings. The exhaustion value in the riser is determined from the rarefactions that occur below the compressed cross-section of the riser and the loss of the air flow pressure coming from the atmosphere into the riser during the deflooding of the liquid. Preventing the formation of obstructions and breakdowns of plumbing traps is an integral part of sewage networks.

COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS

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

Ibrahim, Essam A

2013-01-09

Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations tomore » study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.« less

Study of hot cracking potential in a 6-ton steel ingot casting

NASA Astrophysics Data System (ADS)

Yang, Jing'an; Liu, Baicheng; Shen, Houfa

2018-04-01

A new hot cracking potential (HCP) criterion, for the appearance of hot tearing in steel ingot castings, is proposed. The maximum value of the first principal stress, divided by the dynamic yield strength in the brittle temperature range (BTR), was used to identify the HCP. Experiments were carried out on a 6-ton P91 steel ingot in which severe hot tearing was detected in the upper centerline. Another ingot, with a better heat preservation riser, and without hot tearing, was used for comparison. Samples were obtained from the area of the ingot body with hot tearing, and their morphologies were inspected by a X-ray high energy industrial computed tomography. The carbon and sulfur distributions around the hot tearing were characterized by an infrared spectrometry carbon and sulfur analyzer. High temperature mechanical properties were obtained by a Gleeble thermal simulation machine, under different strain rates. Then, thermo-mechanical simulations using an elasto-viscoplastic finite-element model were conducted to analyze the stress and strain evolution during ingot solidification. The results showed that the hot tearing area, which was rich in both carbon and sulfur, was under excessive tensile stress in the BTR, bearing the highest HCP.

46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

Code of Federal Regulations, 2012 CFR

2012-10-01

... landings of all stairways shall be composed of steel, and risers must be of approved incombustible material... of riser of stairs in different flights of stairs in a stairway or stairtower must be minimized. In... riser shall not have a variance exceeding 5 millimeters (0.19685 inches). (h) In a stairway or...

30 CFR 250.516 - Blowout preventer system tests, inspections, and maintenance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... inspection, whichever is longer. (2) You must visually inspect your BOP system and marine riser at least once.... The District Manager may approve alternate methods and frequencies to inspect a marine riser. (h) BOP... drills, and inspections of the BOP system, system components, and marine riser in the driller's report...

46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

Code of Federal Regulations, 2011 CFR

2011-10-01

... landings of all stairways shall be composed of steel, and risers must be of approved incombustible material... of riser of stairs in different flights of stairs in a stairway or stairtower must be minimized. In... riser shall not have a variance exceeding 5 millimeters (0.19685 inches). (h) In a stairway or...

30 CFR 250.517 - Blowout preventer system tests, inspections, and maintenance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... on a daily basis. You must visually inspect your subsea BOP system and marine riser at least once... equipment. The BSEE District Manager may approve alternate methods and frequencies to inspect a marine riser..., actuations, crew drills, and inspections of the BOP system, system components, and marine riser in the...

30 CFR 250.517 - Blowout preventer system tests, inspections, and maintenance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... on a daily basis. You must visually inspect your subsea BOP system and marine riser at least once... equipment. The BSEE District Manager may approve alternate methods and frequencies to inspect a marine riser..., actuations, crew drills, and inspections of the BOP system, system components, and marine riser in the...

46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

Code of Federal Regulations, 2013 CFR

2013-10-01

... landings of all stairways shall be composed of steel, and risers must be of approved incombustible material... of riser of stairs in different flights of stairs in a stairway or stairtower must be minimized. In... riser shall not have a variance exceeding 5 millimeters (0.19685 inches). (h) In a stairway or...

46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

Code of Federal Regulations, 2014 CFR

2014-10-01

... landings of all stairways shall be composed of steel, and risers must be of approved incombustible material... of riser of stairs in different flights of stairs in a stairway or stairtower must be minimized. In... riser shall not have a variance exceeding 5 millimeters (0.19685 inches). (h) In a stairway or...

Flow Regime Study in a Circulating Fluidized Bed Riser with an Abrupt Exit: [1] High Density Suspension

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

Mei, J.S.; Lee, G.T.; Seachman, S.M.

2008-05-13

Flow regime study was conducted in a 0.3 m diameter, 15.5 m tall circulating fluidized bed (CFB) riser with an abrupt exit at the National Energy Technology Laboratory of the U. S. Department of Energy. A statistical designed test series was conducted including four (4) operating set points and a duplicated center point (therefore a total of 6 operating set points). Glass beads of mean diameter 200 μm and particle density of 2,430 kg/m3 were used as bed material. The CFB riser was operated at various superficial gas velocities ranging from 5.6 to 7.6 m/s and solid mass flux frommore » a low of 86 to a high of 303 kg/m2-s. Results of the apparent solids fraction profile as well as the radial particle velocity profile were analyzed in order to identify the presence of Dense Suspension Upflow (DSU) conditions. DSU regime was found to exist at the bottom of the riser, while the middle section of the riser was still exhibiting core-annular flow structure. Due to the abrupt geometry of the exit, the DSU regime was also found at the top of the riser. In addition the effects of the azimuthal angle, riser gas velocity, and mass solids flux on the particle velocity were investigated and are discussed in this paper.« less

30 CFR 250.1002 - Design requirements for DOI pipelines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of 0.72 for the submerged component and 0.60 for the riser component. E = Longitudinal joint factor... incorporated by reference in 30 CFR 250.198. (5) You must design pipeline risers for tension leg platforms and other floating platforms according to the design standards of API RP 2RD, Design of Risers for Floating...

30 CFR 250.1002 - Design requirements for DOI pipelines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of 0.72 for the submerged component and 0.60 for the riser component. E = Longitudinal joint factor... incorporated by reference in 30 CFR 250.198. (5) You must design pipeline risers for tension leg platforms and other floating platforms according to the design standards of API RP 2RD, Design of Risers for Floating...

46 CFR 72.05-20 - Stairways, ladders, and elevators.

Code of Federal Regulations, 2012 CFR

2012-10-01

... landings of all Types 1, 2, and 3 stairways shall be of solid steel construction. Risers shall be of... width of the stairs, the depth of the tread, or the height of the risers in any flight. Where variation in height of riser or depth of tread in different flights is necessary, such variations shall be...

29 CFR 1917.120 - Fixed stairways.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be positioned within the range of 30 degrees to 50 degrees to the horizontal with uniform riser.... Riser height shall be from 6 to 7.5 inches (15.24 to 19.05 cm), stair width a minimum of 22 inches (55... stairs having four or more risers shall have stair railings or handrails complying with § 1917.112(c)(1...

30 CFR 250.1002 - Design requirements for DOI pipelines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... of 0.72 for the submerged component and 0.60 for the riser component. E = Longitudinal joint factor... incorporated by reference in 30 CFR 250.198. (5) You must design pipeline risers for tension leg platforms and other floating platforms according to the design standards of API RP 2RD, Design of Risers for Floating...

46 CFR 72.05-20 - Stairways, ladders, and elevators.

Code of Federal Regulations, 2014 CFR

2014-10-01

... landings of all Types 1, 2, and 3 stairways shall be of solid steel construction. Risers shall be of... width of the stairs, the depth of the tread, or the height of the risers in any flight. Where variation in height of riser or depth of tread in different flights is necessary, such variations shall be...

29 CFR 1917.120 - Fixed stairways.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be positioned within the range of 30 degrees to 50 degrees to the horizontal with uniform riser.... Riser height shall be from 6 to 7.5 inches (15.24 to 19.05 cm), stair width a minimum of 22 inches (55... stairs having four or more risers shall have stair railings or handrails complying with § 1917.112(c)(1...

46 CFR 72.05-20 - Stairways, ladders, and elevators.

Code of Federal Regulations, 2013 CFR

2013-10-01

... landings of all Types 1, 2, and 3 stairways shall be of solid steel construction. Risers shall be of... width of the stairs, the depth of the tread, or the height of the risers in any flight. Where variation in height of riser or depth of tread in different flights is necessary, such variations shall be...

29 CFR 1917.120 - Fixed stairways.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be positioned within the range of 30 degrees to 50 degrees to the horizontal with uniform riser.... Riser height shall be from 6 to 7.5 inches (15.24 to 19.05 cm), stair width a minimum of 22 inches (55... stairs having four or more risers shall have stair railings or handrails complying with § 1917.112(c)(1...

29 CFR 1917.120 - Fixed stairways.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be positioned within the range of 30 degrees to 50 degrees to the horizontal with uniform riser.... Riser height shall be from 6 to 7.5 inches (15.24 to 19.05 cm), stair width a minimum of 22 inches (55... stairs having four or more risers shall have stair railings or handrails complying with § 1917.112(c)(1...

30 CFR 250.516 - Blowout preventer system tests, inspections, and maintenance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... marine riser at least once each day if weather and sea conditions permit. You may use television cameras... inspect a marine riser. (h) BOP maintenance. You must maintain your BOP system to ensure that the... components, and marine riser in the driller's report. In addition, you must: (1) Record BOP test pressures on...

Catalytic cracking of model compounds of bio-oil over HZSM-5 and the catalyst deactivation.

PubMed

Chen, Guanyi; Zhang, Ruixue; Ma, Wenchao; Liu, Bin; Li, Xiangping; Yan, Beibei; Cheng, Zhanjun; Wang, Tiejun

2018-08-01

The catalytic cracking upgrading reactions over HZSM-5 of different model compounds of bio-oil have been studied with a self-designed fluid catalytic cracking (FCC) equipment. Typical bio-oil model compounds, such as acetic acid, guaiacol, n-heptane, acetol and ethyl acetate, were chosen to study the products distribution, reaction pathway and deactivation of catalysts. The results showed: C 6 -C 8 aromatic hydrocarbons, C 2 -C 4 olefins, C 1 -C 5 alkanes, CO and CO 2 were the main products, and the selectivity of olefins was: ethylene>propylene>butylene. Catalyst characterization methods, such as FI-IR, TG-TPO and Raman, were used to study the deactivation mechanism of catalysts. According to the catalyst characterization results, a catalyst deactivation mechanism was proposed as follows: Firstly, the precursor which consisted of a large number of long chain saturated aliphatic hydrocarbons and a small amount CC of aromatics formed on the catalyst surface. Then the active sites of catalysts had been covered, the coke type changed from thermal coke to catalytic coke and gradually blocked the channels of the molecular sieve, which accelerated the deactivation of catalyst. Copyright © 2018 Elsevier B.V. All rights reserved.

29 CFR 1910.23 - Guarding floor and wall openings and holes.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Stairway railings and guards. (1) Every flight of stairs having four or more risers shall be equipped with... than 30 inches from upper surface of top rail to surface of tread in line with face of riser at forward... face of riser or to surface of ramp. (iii) The size of handrails shall be: When of hardwood, at least 2...

29 CFR 1910.23 - Guarding floor and wall openings and holes.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Stairway railings and guards. (1) Every flight of stairs having four or more risers shall be equipped with... than 30 inches from upper surface of top rail to surface of tread in line with face of riser at forward... face of riser or to surface of ramp. (iii) The size of handrails shall be: When of hardwood, at least 2...

29 CFR 1910.23 - Guarding floor and wall openings and holes.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Stairway railings and guards. (1) Every flight of stairs having four or more risers shall be equipped with... than 30 inches from upper surface of top rail to surface of tread in line with face of riser at forward... face of riser or to surface of ramp. (iii) The size of handrails shall be: When of hardwood, at least 2...

29 CFR 1910.23 - Guarding floor and wall openings and holes.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Stairway railings and guards. (1) Every flight of stairs having four or more risers shall be equipped with... than 30 inches from upper surface of top rail to surface of tread in line with face of riser at forward... face of riser or to surface of ramp. (iii) The size of handrails shall be: When of hardwood, at least 2...

Moving from Science to Service: Transposing and Sustaining the Early Risers Prevention Program in a Community Service System

ERIC Educational Resources Information Center

Bloomquist, Michael L.; August, Gerald J.; Horowitz, Jason L.; Lee, Susanne S.; Jensen, Cheryl

2008-01-01

This paper summarizes an effort to transpose and sustain the evidence-based Early Risers "Skills for Success" conduct problems prevention program in a real world community service system. The Early Risers program had previously been implemented by a local agency within the context of research-based operations. In the current initiative,…

Damage localization of marine risers using time series of vibration signals

NASA Astrophysics Data System (ADS)

Liu, Hao; Yang, Hezhen; Liu, Fushun

2014-10-01

Based on dynamic response signals a damage detection algorithm is developed for marine risers. Damage detection methods based on numerous modal properties have encountered issues in the researches in offshore oil community. For example, significant increase in structure mass due to marine plant/animal growth and changes in modal properties by equipment noise are not the result of damage for riser structures. In an attempt to eliminate the need to determine modal parameters, a data-based method is developed. The implementation of the method requires that vibration data are first standardized to remove the influence of different loading conditions and the autoregressive moving average (ARMA) model is used to fit vibration response signals. In addition, a damage feature factor is introduced based on the autoregressive (AR) parameters. After that, the Euclidean distance between ARMA models is subtracted as a damage indicator for damage detection and localization and a top tensioned riser simulation model with different damage scenarios is analyzed using the proposed method with dynamic acceleration responses of a marine riser as sensor data. Finally, the influence of measured noise is analyzed. According to the damage localization results, the proposed method provides accurate damage locations of risers and is robust to overcome noise effect.

Experimental and computational investigations on severe slugging in a catenary riser

NASA Astrophysics Data System (ADS)

Duan, Jin-long; Chen, Ke; You, Yun-xiang; Gao, Song

2017-12-01

Severe slugging can occur in a pipeline-riser system at relatively low liquid and gas flow rates during gas-oil transportation, possibly causing unexpected damage to the production facilities. Experiments with air and water are conducted in a horizontal and downward inclined pipeline followed by a catenary riser in order to investigate the mechanism and characteristics of severe slugging. A theoretical model is introduced to compare with the experiments. The results show that the formation mechanism of severe slugging in a catenary riser is different from that in a vertical riser due to the riser geometry and five flow patterns are obtained and analyzed. A gas-liquid mixture slug stage is observed at the beginning of one cycle of severe slugging, which is seldom noticed in previous studies. Based on both experiments and computations, the time period and variation of pressure amplitude of severe slugging are found closely related to the superficial gas velocity, implying that the gas velocity significantly influences the flow patterns in our experiments. Moreover, good agreements between the experimental data and the numerical results are shown in the stability curve and flow regime map, which can be a possible reference for design in an offshore oil-production system.

The relationship between a blunted morning surge and a reversed nocturnal blood pressure dipping or "riser" pattern.

PubMed

Fujiwara, Takeshi; Tomitani, Naoko; Sato, Keiko; Okura, Ayako; Suzuki, Noriyuki; Kario, Kazuomi

2017-11-01

The authors sought to determine the association between the blunted morning blood pressure (BP) surge and nocturnal BP dipping of the "riser" pattern in 501 patients with hypertension enrolled in the ACHIEVE-ONE (Ambulatory Blood Pressure Control and Home Blood Pressure [Morning and Evening] Lowering by the N-Channel Blocker Cilnidipine) trial. The patients' sleep-trough morning BP surge and prewaking surge were calculated and then classified according to their nocturnal systolic BP reduction pattern as extreme dippers, dippers, nondippers, and risers. The prevalence of the riser pattern was significantly higher in both the lowest sleep-trough morning BP surge decile and the prewaking surge decile (blunted surge group) compared with the remaining deciles (56.0% vs 10.4% [P<.0001] and 59.2% vs 10.2% [P<.0001], respectively). The riser pattern was a significant determinant of both blunted sleep-trough morning BP surge (odds ratio, 73.3; P<.0001) and blunted prewaking surge (odds ratio, 14.8; P<.0001). The high prevalence of the riser pattern in patients with blunted morning BP surges may account for the cardiovascular risk previously reported in such patients. ©2017 Wiley Periodicals, Inc.

Riser Feeding Evaluation Method for Metal Castings Using Numerical Analysis

NASA Astrophysics Data System (ADS)

Ahmad, Nadiah

One of the design aspects that continues to create a challenge for casting designers is the optimum design of casting feeders (risers). As liquid metal solidifies, the metal shrinks and forms cavities inside the casting. In order to avoid shrinkage cavities, risers are added to the casting shape to supply additional molten metal when shrinkage occurs during solidification. The shrinkage cavities in the casting are compensated by controlling the cooling rate to promote directional solidification. This control can be achieved by designing the casting such that the cooling begins at the sections that are farthest away from the risers and ends at the risers. Therefore, the risers will solidify last and feed the casting with the molten metal. As a result, the shrinkage cavities formed during solidification are in the risers which are later removed from the casting. Since casting designers have to usually go through iterative processes of validating the casting designs which are very costly due to expensive simulation processes or manual trials and errors on actual casting processes, this study investigates more efficient methods that will help casting designers utilize their casting experiences systematically to develop good initial casting designs. The objective is to reduce the casting design method iterations; therefore, reducing the cost involved in that design processes. The aim of this research aims at finding a method that can help casting designers design effective risers used in sand casting process of aluminum-silicon alloys by utilizing the analysis of solidification simulation. The analysis focuses on studying the significance of pressure distribution of the liquid metal at the early stage of casting solidification, when heat transfer and convective fluid flow are taken into account in the solidification simulation. The mathematical model of casting solidification was solved using the finite volume method (FVM). This study focuses to improve our understanding of the feeding behavior in aluminum-silicon alloys and the effective feeding by considering the pressure gradient distribution of the molten metal at casting dendrite coherency point. For this study, we will identify the relationship between feeding efficiency, shrinkage behavior and how the change in riser size affects the pressure gradient in the casting. This understanding will be used to help in the design of effective risers.

Microstructural and mechanical characteristics of Ni–Cr thin films

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

Petley, Vijay; Sathishkumar, S.; Thulasi Raman, K.H.

2015-06-15

Highlights: • Ni–Cr thin films of varied composition deposited by DC magnetron co-sputtering. • Thin film with Ni–Cr: 80–20 at% composition exhibits most distinct behavior. • The films were tensile tested and exhibited no cracking till the substrate yielding. - Abstract: Ni–Cr alloy thin films have been deposited using magnetron co-sputtering technique at room temperature. Crystal structure was evaluated using GIXRD. Ni–Cr solid solution upto 40 at% of Cr exhibited fcc solid solution of Cr in Ni and beyond that it exhibited bcc solid solution of Ni in Cr. X-ray diffraction analysis shows formation of (1 1 1) fiber texturemore » in fcc and (2 2 0) fiber texture in bcc Ni–Cr thin films. Electron microscopy in both in-plane and transverse direction of the film surface revealed the presence of columnar microstructure for films having Cr upto 40 at%. Mechanical properties of the films are evaluated using nanoindentation. The modulus values increased with increase of Cr at% till the film is fcc. With further increase in Cr at% the modulus values decreased. Ni–Cr film with 20 at% Ni exhibits reduction in modulus and is correlated to the poor crystallization of the film as reflected in XRD analysis. The Ni–Cr thin film with 80 at% Ni and 20 at% Cr exhibited the most distinct columnar structure with highest electrical resistivity, indentation hardness and elastic modulus.« less

Development of a numerical procedure for mixed mode K-solutions and fatigue crack growth in FCC single crystal superalloys

NASA Astrophysics Data System (ADS)

Ranjan, Srikant

2005-11-01

Fatigue-induced failures in aircraft gas turbine and rocket engine turbopump blades and vanes are a pervasive problem. Turbine blades and vanes represent perhaps the most demanding structural applications due to the combination of high operating temperature, corrosive environment, high monotonic and cyclic stresses, long expected component lifetimes and the enormous consequence of structural failure. Single crystal nickel-base superalloy turbine blades are being utilized in rocket engine turbopumps and jet engines because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. These materials have orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. Computation of stress intensity factors (SIFs) and the ability to model fatigue crack growth rate at single crystal cracks subject to mixed-mode loading conditions are important parts of developing a mechanistically based life prediction for these complex alloys. A general numerical procedure has been developed to calculate SIFs for a crack in a general anisotropic linear elastic material subject to mixed-mode loading conditions, using three-dimensional finite element analysis (FEA). The procedure does not require an a priori assumption of plane stress or plane strain conditions. The SIFs KI, KII, and KIII are shown to be a complex function of the coupled 3D crack tip displacement field. A comprehensive study of variation of SIFs as a function of crystallographic orientation, crack length, and mode-mixity ratios is presented, based on the 3D elastic orthotropic finite element modeling of tensile and Brazilian Disc (BD) specimens in specific crystal orientations. Variation of SIF through the thickness of the specimens is also analyzed. The resolved shear stress intensity coefficient or effective SIF, Krss, can be computed as a function of crack tip SIFs and the resolved shear stress on primary slip planes. The maximum value of Krss and DeltaKrss was found to determine the crack growth direction and the fatigue crack growth rate respectively. The fatigue crack driving force parameter, DeltaK rss, forms an important multiaxial fatigue damage parameter that can be used to predict life in superalloy components.

Refining fault slip rates using multiple displaced terrace risers-An example from the Honey Lake fault, NE California, USA

NASA Astrophysics Data System (ADS)

Gold, Ryan D.; Briggs, Richard W.; Crone, Anthony J.; DuRoss, Christopher B.

2017-11-01

Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference observed globally) produce large uncertainties in the slip-rate estimate. In this investigation, we explore how the full range of displacements and bounding ages from multiple faulted terrace risers can be combined to yield a more accurate fault slip rate. We use 0.25-m cell size digital terrain models derived from airborne lidar data to analyze three sites where terrace risers are offset right-laterally by the Honey Lake fault in NE California, USA. We use ages for locally extensive subhorizontal surfaces to bracket the time of riser formation: an upper surface is the bed of abandoned Lake Lahontan having an age of 15.8 ± 0.6 ka and a lower surface is a fluvial terrace abandoned at 4.7 ± 0.1 ka. We estimate lateral offsets of the risers ranging between 6.6 and 28.3 m (median values), a greater than fourfold difference in values. The amount of offset corresponds to the riser's position relative to modern stream meanders: the smallest offset is in a meander cutbank position, whereas the larger offsets are in straight channel or meander point-bar positions. Taken in isolation, the individual terrace-riser offsets yield slip rates ranging from 0.3 to 7.1 mm/a. However, when the offset values are collectively assessed in a probabilistic framework, we find that a uniform (linear) slip rate of 1.6 mm/a (1.4-1.9 mm/a at 95% confidence) can satisfy the data, within their respective uncertainties. This investigation demonstrates that integrating observations of multiple offset elements (crest, midpoint, and base) from numerous faulted and dated terrace risers at closely spaced sites can refine slip-rate estimates on strike-slip faults.

Attrition of fluid cracking catalyst in fluidized beds

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

Boerefijn, R.; Ghadiri, M.

1996-12-31

Particle attrition in fluid catalytic cracking units causes loss of catalyst, which could amount to a few tonnes per day! The dependence of attrition on the process conditions and catalyst properties is therefore of great industrial interest, but it is however not well established at present. The process of attrition in the jetting area of fluidised beds is addressed and the attrition test method of Forsythe & Hertwig is analysed in this paper. This method is used commonly to assess the attrition propensity of FCC powder, whereby the attrition rate in a single jet at very high orifice velocity (300more » m s{sup -1}) is measured. There has been some concern on the relevance of this method to attrition in FCC units. Therefore, a previously-developed model of attrition in the jetting region is employed in an attempt to establish a solid basis of interpretation of the Forsythe & Hertwig test and its application as an industrial standard test. The model consists of two parts. The first part predicts the solids flow patterns in the jet region, simulating numerically the Forsythe & Hertwig test. The second part models the breakage of single particles upon impact. Combining these two models, thus linking single particle mechanical properties to macroscopic flow phenomena, results in the modelling of the attrition rate of particles entrained into a single high speed jet. High speed video recordings are made of a single jet in a two-dimensional fluidised bed, at up to 40500 frames per second, in order to quantify some of the model parameters. Digital analysis of the video images yields values for particle velocities and entrainment rates in the jet, which can be compared to model predictions. 15 refs., 8 figs.« less

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

Not Available

Kongsberg Engineering a.s. has developed an oil loading system for the Central North Sea, in 492-ft waters, which is not permanent, is safer, economical and withstands the environmental forces in the area. The ''Subload'' system is based on loading directly from a seafloor terminal to two 78,000 dwt dynamically positioned shuttle tankers. Upon arrival at the field, a shuttle tanker fitted with an SPM loading yoke and a riser reel deploys a 16-in. flexible riser attached to a lower riser package fitted with thrusters. Controlled by signals from a special high-accuracy underwater maneuver the lower riser end into docking positionmore » with the seafloor terminal. The terminal is located at the end of a two-km, 28-in. pipe line from the production platform. Presentation of the system, the company said that the diverless hookup procedure between the intrument-controlled riser connection and the subsea wellhead requires 45 minutes. The shuttle tanker loading could be completed twice a day in seven and a half hours per operation.« less

Guidelines for riser splash zone design and repair

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

NONE

1995-02-01

The many years of offshore oil and gas development has established the subsea pipeline as a reliable and cost effective means of transportation for produced hydrocarbons. The requirement for subsea pipeline systems will continue to move into deeper water and more remote locations with the future development of oil and gas exploration. The integrity of subsea pipeline and riser systems, throughout their operating lifetime, is an important area for operators to consider in maximizing reliability and serviceability for economic, contractual and environmental reasons. Adequate design and installation are the basis for ensuring the integrity of any subsea pipeline and risermore » systems. In the event of system damage, from any source, quick and accurate repair and reinstatement of the pipeline system is essential. This report has been developed to provide guidelines for riser and splash zone design, to perform a detailed overview of existing riser repair techniques and products, and to prepare comprehensive guidelines identifying the capabilities and limits of riser reinstatement systems.« less

A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

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

Loebner, Keith T. K., E-mail: kloebner@stanford.edu; Underwood, Thomas C.; Cappelli, Mark A.

2015-06-15

A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenummore » pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.« less

Two cases of malignant hypertension with reversible diffuse leukoencephalopathy exhibiting a reversible nocturnal blood pressure "riser" pattern.

PubMed

Eguchi, Kazuo; Kasahara, Kentaro; Nagashima, Akinori; Mor, Tadashi; Nii, Takanobu; Ibaraki, Kazuo; Kario, Kazuomi; Shimada, Kazuyuki

2002-05-01

We report two cases of malignant hypertension with reversible diffuse leukoencephalopathy demonstrating a nocturnal blood pressure (BP) rising pattern ("riser" pattern). Case 1 was a 54-year-old man diagnosed with malignant hypertension who presented with diffuse leukoencephalopathy and nocturnal BP rise during the acute phase. These abnormal findings diminished after treatment of hypertension. Case 2 was a 50-year-old woman diagnosed with malignant hypertension in association with leukoencephalopathy, heart failure and acute renal failure. She also presented with a "riser" pattern during the acute phase. In contrast to case 1, the leukoencephalopathy and "riser" pattern in case 2 were not improved even after 1 month of treatment. Following intensive antihypertensive treatment, renal failure was improved in case 1, but renal failure was not improved after 1 month in case 2. In conclusion, a possible explanation of this phenomenon is that a causative volume overload due to renal dysfunction produced the temporal leukoencephalopathy-like brain edema and "riser" pattern in these cases.

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

Breault, Ronald W.; Monazam, Esmail R.; Shadle, Lawrence J.

Riser hydrodynamics are a function of the flow rates of gas and solids as well as the exit geometry, particularly when operated above the upper transport velocity. This work compares the exit voidage for multiple geometries and two different solids: Geldart group A glass beads and Geldart group B coke. Geometries were changed by modifying the volume of an abrupt T-shaped exit above the lateral riser exit. This was accomplished by positioning a plunger at various heights above the exit from zero to 0.38 m. A dimensionless expression used to predict smooth exit voidage was modified to account for themore » effect of the depth of the blind-T. The new correlation contains the solids-gas load ratio, solids-to-gas density ratio, bed-to-particle diameter ratio, gas Reynolds Number, as well as a term for the exit geometry. This study also found that there was a minimum riser roof height above the blind-T exit beyond which the riser exit voidage was not affected by the exit geometry. A correlation for this minimum riser roof height has also been developed in this study. This study covered riser superficial gas velocities of 4.35 to 7.7 m/s and solids circulation rates of 1.3 to 11.5 kg/s.« less

New theory for Mode I crack-tip dislocation emission

NASA Astrophysics Data System (ADS)

Andric, Predrag; Curtin, W. A.

2017-09-01

A material is intrinsically ductile under Mode I loading when the critical stress intensity KIe for dislocation emission is lower than the critical stress intensity KIc for cleavage. KIe is usually evaluated using the approximate Rice theory, which predicts a dependence on the elastic constants and the unstable stacking fault energy γusf for slip along the plane of dislocation emission. Here, atomistic simulations across a wide range of fcc metals show that KIe is systematically larger (10-30%) than predicted. However, the critical (crack tip) shear displacement is up to 40% smaller than predicted. The discrepancy arises because Mode I emission is accompanied by the formation of a surface step that is not considered in the Rice theory. A new theory for Mode I emission is presented based on the ideas that (i) the stress resisting step formation at the crack tip creates "lattice trapping" against dislocation emission such that (ii) emission is due to a mechanical instability at the crack tip. The new theory is formulated using a Peierls-type model, naturally includes the energy to form the step, and reduces to the Rice theory (no trapping) when the step energy is small. The new theory predicts a higher KIe at a smaller critical shear displacement, rationalizing deviations of simulations from the Rice theory. Specific predictions of KIe for the simulated materials, usually requiring use of the measured critical crack tip shear displacement due to complex material non-linearity, show very good agreement with simulations. An analytic model involving only γusf, the surface energy γs, and anisotropic elastic constants is shown to be quite accurate, serves as a replacement for the analytical Rice theory, and is used to understand differences between Rice theory and simulation in recent literature. The new theory highlights the role of surface steps created by dislocation emission in Mode I, which has implications not only for intrinsic ductility but also for crack tip twinning and fracture due to chemical interactions at the crack tip.

Off-axis silicon carbide substrates

DOEpatents

Edgar, James; Dudley, Michael; Kuball, Martin; Zhang, Yi; Wang, Guan; Chen, Hui; Zhang, Yu

2014-09-02

A method of epitaxial growth of a material on a crystalline substrate includes selecting a substrate having a crystal plane that includes a plurality of terraces with step risers that join adjacent terraces. Each terrace of the plurality or terraces presents a lattice constant that substantially matches a lattice constant of the material, and each step riser presents a step height and offset that is consistent with portions of the material nucleating on adjacent terraces being in substantial crystalline match at the step riser. The method also includes preparing a substrate by exposing the crystal plane; and epitaxially growing the material on the substrate such that the portions of the material nucleating on adjacent terraces merge into a single crystal lattice without defects at the step risers.

CFD Modeling of a CFB Riser Using Improved Inlet Boundary Conditions

NASA Astrophysics Data System (ADS)

Peng, B. T.; Zhang, C.; Zhu, J. X.; Qi, X. B.

2010-03-01

A computational fluid dynamics (CFD) model based on Eulerian-Eulerian approach coupled with granular kinetics theory was adopted to investigate the hydrodynamics and flow structures in a circulating fluidized bed (CFB) riser column. A new approach to specify the inlet boundary conditions was proposed in this study to simulate gas-solids flow in CFB risers more accurately. Simulation results were compared with the experimental data, and good agreement between the numerical results and experimental data was observed under different operating conditions, which indicates the effectiveness and accuracy of the CFD model with the proposed inlet boundary conditions. The results also illustrate a clear core annulus structure in the CFB riser under all operating conditions both experimentally and numerically.

Apparatus for hot-gas desulfurization of fuel gases

DOEpatents

Bissett, Larry A.

1992-01-01

An apparatus for removing sulfur values from a hot fuel gas stream in a fdized bed contactor containing particulate sorbent material by employing a riser tube regeneration arrangement. Sulfur-laden sorbent is continuously removed from the fluidized bed through a stand pipe to the riser tube and is rapidly regenerated in the riser tube during transport of the sorbent therethrough by employing an oxygen-containing sorbent regenerating gas stream. The riser tube extends from a location below the fluidized bed to an elevation above the fluidized bed where a gas-solid separating mechanism is utilized to separate the regenerated particulate sorbent from the regeneration gases and reaction gases so that the regenerated sorbent can be returned to the fluidized bed for reuse.

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

Dayton, David C; Kataria, Atish; Gupta, Rabhubir

The objective of the project is to develop and demonstrate a novel fluidized-bed process module called a Therminator to simultaneously destroy and/or remove tar, NH3 and H2S from raw syngas produced by a fluidized-bed biomass gasifier. The raw syngas contains as much as 10 g/m3 of tar, 4,000 ppmv of NH3 and 100 ppmv of H2S. The goal of the Therminator module would be to use promising regenerable catalysts developed for removing tar, ammonia, and H2S down to low levels (around 10 ppm). Tars are cracked to a non-condensable gas and coke that would deposit on the acid catalyst. Wemore » will deposit coke, much like a fluid catalytic cracker (FCC) in a petroleum refinery. The deposited coke fouls the catalyst, much like FCC, but the coke would be burned off in the regenerator and the regenerated catalyst would be returned to the cracker. The rapid circulation between the cracker and regenerator would ensure the availability of the required amount of regenerated catalyst to accomplish our goal. Also, by removing sulfur down to less than 10 ppmv, NH3 decomposition would also be possible in the cracker at 600-700°C. In the cracker, tar decomposes and lays down coke on the acid sites of the catalyst, NH3 is decomposed using a small amount of metal (e.g., nickel or iron) catalyst incorporated into the catalyst matrix, and H2S is removed by a small amount of a metal oxide (e.g. zinc oxide or zinc titanate) by the H2S-metal oxide reaction to form metal sulfide. After a tolerable decline in activity for these reactions, the catalyst particles (and additives) are transported to the regenerator where they are exposed to air to remove the coke and to regenerate the metal sulfide back to metal oxide. Sulfate formation is avoided by running the regeneration with slightly sub-stoichiometric quantity of oxygen. Following regeneration, the catalyst is transported back to the cracker and the cycling continues. Analogous to an FCC reactor system, rapid cycling will allow the use of very active cracking catalysts that lose activity due to coking within the order of several seconds.« less

A study on the influence of microstructure on small fatigue cracks

NASA Astrophysics Data System (ADS)

Castelluccio, Gustavo M.

In spite of its significance in industrial applications, the prediction of the influence of microstructure on the early stages of crack formation and growth in engineering alloys remains underdeveloped. The formation and early growth of fatigue cracks in the high cycle fatigue regime lasts for much of the fatigue life, and it is strongly influenced by microstructural features such as grain size, twins and morphological and crystallographic texture. However, most fatigue models do not predict the in uence of the microstructure on early stages of crack formation, or they employ parameters that should be calibrated with experimental data from specimens with microstructures of interest. These post facto strategies are adequate to characterize materials, but they are not fully appropriate to aid in the design of fatigue-resistant engineering alloys. This thesis considers finite element computational models that explicitly render the microstructure of selected FCC metallic systems and introduces a fatigue methodology that estimates transgranular and intergranular fatigue growth for microstructurally small cracks. The driving forces for both failure modes are assessed by means of fatigue indicators, which are used along with life correlations to estimate the fatigue life. Furthermore, cracks with meandering paths are modeled by considering crack growth on a grain-by-grain basis with a damage model embedded analytically to account for stress and strain redistribution as the cracks extend. The methodology is implemented using a crystal plasticity constitutive model calibrated for studying the effect of microstructure on early fatigue life of a powder processed Ni-base RR1000 superalloy at elevated temperature under high cycle fatigue conditions. This alloy is employed for aircraft turbine engine disks, which undergo a thermomechanical production process to produce a controlled bimodal grain size distribution. The prediction of the fatigue life for this complex microstructure presents particular challenges that are discussed and addressed. The conclusions of this work describe the mechanistic of microstructural small crack. In particular, the fatigue crack growth driving force has been characterized as it evolves within grains and crosses to other grains. Furthermore, the computational models serve as a tool to assess the effects of microstructural features on early stages of fatigue crack formation and growth, such as distributions of grain size and twins.

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

Gianetto, A.; Farag, H.I.; Blasetti, A.P.

Changes of the relative importance of intradiffusion on USY zeolite crystals were studied as a way of affecting selectivity of catalytic cracking reactions. Zeolite crystals were synthesized (Si/Al = 2.4), activated and stabilized using ion exchange and steam calcination to obtain USSY (Ultra Stable Submicron Y) zeolites. After the activation the zeolites were pelletized (45--60 [mu]m particles). USSYs were tested in a novel Riser Simulator. Results obtained show that total aromatics (BTX), benzene, C[sub 4] olefins, and coke were significantly affected with the change of zeolite crystal sizes. Gasolines produced with USSY zeolites contain less aromatics and particularly lower benzenemore » levels. Experimental results were analyzed with a model including several lumps: unconverted gas oil, gasoline, light gases, and coke. This model also accounts for catalyst deactivation as a function of coke on catalyst. Various kinetic parameters were determined with their corresponding spans for the 95% level of confidence.« less

[Soft-ridged bench terrace design in hilly loess region].

PubMed

Cao, Shixiong; Chen, Li; Gao, Wangsheng

2005-08-01

Reconfiguration of hillside field into terrace is regarded as one of the key techniques for water and soil conservation in mountainous regions. On slopes exceeding 30 degrees, the traditional techniques of terracing are difficult to apply as risers (i.e., backslopes), and if not reinforced, are so abrupt and easy to collapse under gravity alone, thus damaging the terrace. To improve the reconfiguration of hillside field into terrace, holistic techniques of soft-ridged bench terrace engineering, including revegetation, with trees and planting grasses on riser slopes, were tested between 1997 and 2001 in Xiabiangou watershed of Yan' an, Shaanxi Province. A "working with Nature" engineering approach, riser slopes of 45 degrees, similar to the pre-existing slope of 35 degrees, was employed to radically reduce gravity-erosion. Based on the concepts of biodiversity and the principles of landscape ecology, terrace benches, bunds, and risers were planted with trees, shrubs, forage grasses, and crops, serving to generate a diverse array of plants, a semi-forested area, and to stabilize terrace bunds. Soft-ridged bench terrace made it possible to significantly reduce hazards arising from gravity erosion, and reduce the costs of individual bench construction and maintenance by 24.9% and 55.5% of the costs under traditional techniques, respectively. Such a construction allowed an enrichment and concentration of nutrients in the soils of terrace bunds, providing an ideal environment for a range of plants to grow and develop. The terrace riser could be planted with drought-resistant plants ranging from forage grasses to trees, and this riser vegetation would turn the exposed bunds and risers existing under traditional techniques into plant-covered belts, great green ribbons decorating farmland and contributing to the enhancement of the landscape biology.

Short Sleep Duration is an Independent Predictor of Cardiovascular Events in Japanese Hypertensive Patients

PubMed Central

Eguchi, Kazuo; Pickering, Thomas G.; Schwartz, Joseph E.; Hoshide, Satoshi; Ishikawa, Joji; Ishikawa, Shizukiyo; Shimada, Kazuyuki; Kario, Kazuomi

2013-01-01

Context It is not known whether short duration of sleep is a predictor of future cardiovascular events in hypertensive patients. Objective To test the hypothesis that short duration of sleep is independently associated with incident cardiovascular diseases (CVD). Design, Setting, and Participants We performed ambulatory BP monitoring (ABPM) in 1255 subjects with hypertension (mean age: 70.4±9.9 years) and they were followed for an average of 50±23 months. Short sleep duration was defined as <7.5 hrs (20th percentile). Multivariable Cox hazard models predicting CVD events were used to estimate the adjusted hazard ratio (HR) and 95% CI for short sleep duration. A riser pattern was defined when average nighttime SBP exceeded daytime SBP. Main Outcome Measures The end point was cardiovascular events: stroke, fatal or non-fatal myocardial infarction (MI), and sudden cardiac death. Results In multivariable analyses, short duration of sleep (<7.5 hrs) was associated with incident CVD (HR=1.68; 1.06–2.66, P=.03). A synergistic interaction was observed between short sleep duration and the riser pattern (P=.089). When subjects were categorized on the basis of their sleep time and riser/non-riser patterns, the shorter sleep+riser group had a substantially and significantly higher incidence of CVD than the predominant normal sleep+non-riser group (HR=4.43;2.09–9.39, P<0.001), independent of covariates. Conclusions Short duration of sleep is associated with incident CVD risk, and the combination of riser pattern and short duration of sleep that is most strongly predictive of future CVD, independent of ambulatory BP levels. Physicians should inquire about sleep duration in the risk assessment of hypertensive patients. PMID:19001199

Upper Ocean Measurements of Water Masses and Circulation in the Japan Sea

DTIC Science & Technology

2003-09-30

Japan Sea via Tsugaru Strait into the N. Pacific and through Soya Strait into the Okhotsk Sea. On float entered the Okhotsk Sea through Soya Strait and...Riser (2003) Connections between the Japan Sea and Okhotsk Sea through Soya Strait. Submitted to Journal of Geophysical Research. Riser, S., M...PUBLICATIONS Danchenkov, M. and S. Riser (2003) Connections between the Japan Sea and Okhotsk Sea through Soya Strait. Submitted to Journal of Geophysical

Numerical Simulation of the Vortex-Induced Vibration of A Curved Flexible Riser in Shear Flow

NASA Astrophysics Data System (ADS)

Zhu, Hong-jun; Lin, Peng-zhi

2018-06-01

A series of fully three-dimensional (3D) numerical simulations of flow past a free-to-oscillate curved flexible riser in shear flow were conducted at Reynolds number of 185-1015. The numerical results obtained by the two-way fluid-structure interaction (FSI) simulations are in good agreement with the experimental results reported in the earlier study. It is further found that the frequency transition is out of phase not only in the inline (IL) and crossflow (CF) directions but also along the span direction. The mode competition leads to the non-zero nodes of the rootmean- square (RMS) amplitude and the relatively chaotic trajectories. The fluid-structure interaction is to some extent reflected by the transverse velocity of the ambient fluid, which reaches the maximum value when the riser reaches the equilibrium position. Moreover, the local maximum transverse velocities occur at the peak CF amplitudes, and the values are relatively large when the vibration is in the resonance regions. The 3D vortex columns are shed nearly parallel to the axis of the curved flexible riser. As the local Reynolds number increases from 0 at the bottom of the riser to the maximum value at the top, the wake undergoes a transition from a two-dimensional structure to a 3D one. More irregular small-scale vortices appeared at the wake region of the riser, undergoing large amplitude responses.

Riser Pattern: Another Determinant of Heart Failure With Preserved Ejection Fraction.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Hoshide, Satoshi; Kario, Kazuomi

2016-10-01

Paradoxical increase in blood pressure (BP) during sleep, exceeding those of awake BP, is called the "riser" BP pattern, and known as an abnormal circadian BP rhythm, has been reported to be associated with adverse cardiovascular prognoses. However, the significance of ambulatory BP in heart failure patients with preserved ejection fraction (HFpEF) has never been reported. Here, we tested our hypothesis that abnormal circadian BP rhythm is associated with HFpEF. The authors enrolled 508 patients with hospitalized HF (age 68±13 years; 315 men, 193 women). There were 232 cases of HFpEF and 276 cases of heart failure with reduced ejection fraction (HFrEF). The riser BP pattern was significantly more frequent in the HFpEF (28.9%) group compared with the HFrEF group (19.9%). In a multivariable logistic regression analysis, the riser BP pattern was associated with HFpEF (odds ratio, 1.73; 95% confidence interval, 1.02-2.91; P=.041) independent of the other covariates. In conclusion, the riser BP pattern was associated with HFpEF. ©2016 Wiley Periodicals, Inc.

30 CFR 291.101 - What definitions apply to this part?

Code of Federal Regulations, 2011 CFR

2011-07-01

... horizontal component or riser. Examples include anodes, valves, flanges, fittings, umbilicals, subsea... as a separate entity). Pipeline is the piping, risers, accessories and appurtenances installed for...

Effects of water-control structures on hydrologic and water-quality characteristics in selected agricultural drainage canals in eastern North Carolina

USGS Publications Warehouse

Treece, M.W.; Jaynes, M.L.

1994-01-01

November of water into and out of tidally affected canals in eastern North Carolina was documented before and after the installation of water-control structures. Water levels in five of the canals downstream from the water-control structures were controlled primarily by water-level fluctuations in estuarine receiving waters. Water-control structures also altered upstream water levels in all canals. Water levels were lowered upstream from tide gates, but increased upstream from flashboard risers. Both types of water-control structures attenuated the release of runoff following rainfall events, but in slightly different ways. Tide gates appeared to reduce peak discharge rates associated with rainfall, and flashboard risers lengthened the duration of runoff release. Tide gates had no apparent effect on pH, dissolved oxygen, suspended-sediment, or total phosphorus concentrations downstream from the structures. Specific conductance measured from composite samples collected with automatic samples increased downstream of tide gates after installation. Median concentrations of nitrite plus nitrate nitrogen were near the minimum detection level throughout the study; however, the number of observations of concentrations exceeding 0.1 milligram per liter dropped significantly after tide gates were installed. Following tide-gate installation, instantaneous loadings of nitrite plus nitrate nitrogen were significantly reduced at one test site, but this reduction was not observed at the other test site. Loadings of other nutrient species and suspended sediment did not change at the tide-gate test sites after tide-gate installation. Specific conductance was lower in the Beaufort County canals than in the Hyde County canals. Although there was a slight increase in median values at the flashboard-riser sites, the mean and maximum values declined substantially downstream from the risers following installation. This decline of specific conductance in the canals occurred despite a large increase of specific conductance in the tidal creek. Flashboard risers had no significant effect on concentrations of dissolved oxygen, suspended sediment, total ammonia plus organic nitrogen, or phosphorus. Maximum concentrations of ammonia nitrogen were smaller at both test sites after riser installation. In addition, concentrations of nitrite plus nitrate nitrogen exceeding 1.0 milligram per liter rarely occurred at the flashboard-riser test sites following installation of the risers. Median loadings of nitrite plus nitrate nitrogen and total nitrogen decreased at one riser test site following flashboard-riser installation. Tide gates and flashboard risers were associated with reductions in concentrations and export of nitrite plus nitrate nitrogen; however, these changes should be interpreted cautiously because reductions were not observed consistently at every site. The hydrology and baseline water-quality characteristics of the two study areas differ, making comparisons of the effectiveness of the two types of water-control structures difficult to interpret. The effects of water-control structures on the hydrology of the drainage canals are more meaningful than the changes in water quality. Tide gates and flashboard risers altered the hydrologic characteristics of the drainage canals and created an environment favorable for nutrient loss or transformation. Both structures retained agricultural drainage upstream, which increased potential storage for infiltration and reduced the potential for surface runoff, sediment, and nutrient transport, and higher peak outflow rates.

Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

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

Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu

2005-06-04

Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemicalmore » industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at various planes. Together, these two techniques can provide the needed local solids flow dynamic information for the same setup under identical operating conditions, and the data obtained can be used as a benchmark for development, and refinement of the appropriate riser models. For the above reasons these two techniques were implemented in this study on a fully developed section of the riser. To derive the global mixing information in the riser, accurate solids RTD is needed and was obtained by monitoring the entry and exit of a single radioactive tracer. Other global parameters such as Cycle Time Distribution (CTD), overall solids holdup in the riser, solids recycle percentage at the bottom section of the riser were evaluated from different solids travel time distributions. Besides, to measure accurately and in-situ the overall solids mass flux, a novel method was applied.« less

30 CFR 291.101 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... component or riser. Examples include anodes, valves, flanges, fittings, umbilicals, subsea manifolds...). Pipeline is the piping, risers, accessories and appurtenances installed for transportation of oil and gas...

30 CFR 291.101 - What definitions apply to this part?

Code of Federal Regulations, 2013 CFR

2013-07-01

... component or riser. Examples include anodes, valves, flanges, fittings, umbilicals, subsea manifolds...). Pipeline is the piping, risers, accessories and appurtenances installed for transportation of oil and gas...

30 CFR 291.101 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... component or riser. Examples include anodes, valves, flanges, fittings, umbilicals, subsea manifolds...). Pipeline is the piping, risers, accessories and appurtenances installed for transportation of oil and gas...

Flexural behavior of the fibrous cementitious composites (FCC) containing hybrid fibres

NASA Astrophysics Data System (ADS)

Ramli, Mahyuddin; Ban, Cheah Chee; Samsudin, Muhamad Fadli

2018-02-01

In this study, the flexural behavior of the fibrous cementitious composites containing hybrid fibers was investigated. Waste materials or by product materials such as pulverized fuel ash (PFA) and ground granulated blast-furnace slag (GGBS) was used as supplementary cement replacement. In addition, barchip and kenaf fiber will be used as additional materials for enhance the flexural behavior of cementitious composites. A seven mix design of fibrous cementitious composites containing hybrid fiber mortar were fabricated with PFA-GGBS as cement replacement at 50% with hybridization of barchip and kenaf fiber between 0.5% and 2.0% by total volume weight. The FCC with hybrid fibers mortar will be fabricated by using 50 × 50 × 50 mm, 40 × 40 × 160 mm and 350 × 125 × 30 mm steel mold for assessment of mechanical performances and flexural behavior characteristics. The flexural behavior and mechanical performance of the PFA-GGBS with hybrid fiber mortar block was assessed in terms of load deflection response, stress-strain response, crack development, compressive and flexural strength after water curing for 28 days. Moreover, the specimen HBK 1 and HBK 2 was observed equivalent or better in mechanical performance and flexural behavior as compared to control mortar.

CHIMNEY FOR BOILING WATER REACTOR

DOEpatents

Petrick, M.

1961-08-01

A boiling-water reactor is described which has vertical fuel-containing channels for forming steam from water. Risers above the channels increase the head of water radially outward, whereby water is moved upward through the channels with greater force. The risers are concentric and the radial width of the space between them is somewhat small. There is a relatively low rate of flow of water up through the radially outer fuel-containing channels, with which the space between the risers is in communication. (AE C)

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, Anstein

1994-01-01

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat.

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, A.

1994-08-16

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat. 3 figs.

Orion Parachute Riser Cutter Development

NASA Technical Reports Server (NTRS)

Oguz, Sirri; Salazar, Frank

2011-01-01

This paper presents the tests and analytical approach used on the development of a steel riser cutter for the CEV Parachute Assembly System (CPAS) used on the Orion crew module. Figure 1 shows the riser cutter and the steel riser bundle which consists of six individual cables. Due to the highly compressed schedule, initial unavailability of the riser material and the Orion Forward Bay mechanical constraints, JSC primarily relied on a combination of internal ballistics analysis and LS-DYNA simulation for this project. Various one dimensional internal ballistics codes that use standard equation of state and conservation of energy have commonly used in the development of CAD devices for initial first order estimates and as an enhancement to the test program. While these codes are very accurate for propellant performance prediction, they usually lack a fully defined kinematic model for dynamic predictions. A simple piston device can easily and accurately be modeled using an equation of motion. However, the accuracy of analytical models is greatly reduced on more complicated devices with complex external loads, nonlinear trajectories or unique unlocking features. A 3D finite element model of CAD device with all critical features included can vastly improve the analytical ballistic predictions when it is used as a supplement to the ballistic code. During this project, LS-DYNA structural 3D model was used to predict the riser resisting load that was needed for the ballistic code. A Lagrangian model with eroding elements shown in Figure 2 was used for the blade, steel riser and the anvil. The riser material failure strain was fine tuned by matching the dent depth on the anvil with the actual test data. LS-DYNA model was also utilized to optimize the blade tip design for the most efficient cut. In parallel, the propellant type and the amount were determined by using CADPROG internal ballistics code. Initial test results showed a good match with LS-DYNA and CADPROG simulations. Final paper will present a detailed roadmap from initial ballistic modeling and LS-DYNA simulation to the performance testing. Blade shape optimization study will also be presented.

Numerical simulations of vortex-induced vibrations of a flexible riser with different aspect ratiosin uniform and shear currents

NASA Astrophysics Data System (ADS)

Duanmu, Yu; Zou, Lu; Wan, De-cheng

2017-12-01

This paper aimed at describing numerical simulations of vortex-induced vibrations (VIVs) of a long flexible riser with different length-to-diameter ratio (aspect ratio) in uniform and shear currents. Three aspect ratios were simulated: L/D = 500, 750 and 1 000. The simulation was carried out by the in-house computational fluid dynamics (CFD) solver viv-FOAM-SJTU developed by the authors, which was coupled with the strip method and developed on the OpenFOAM platform. Moreover, the radial basis function (RBF) dynamic grid technique is applied to the viv-FOAM-SJTU solver to simulate the VIV in both in-line (IL) and cross-flow (CF) directions of flexible riser with high aspect ratio. The validation of the benchmark case has been completed. With the same parameters, the aspect ratio shows a significant influence on VIV of a long flexible riser. The increase of aspect ratio exerted a strong effect on the IL equilibrium position of the riser while producing little effect on the curvature of riser. With the aspect ratio rose from 500 to 1 000, the maximum IL mean displacement increased from 3 times the diameter to 8 times the diameter. On the other hand, the vibration mode of the riser would increase with the increase of aspect ratio. When the aspect ratio was 500, the CF vibration was shown as a standing wave with a 3rd order single mode. When the aspect ratio was 1 000, the modal weights of the 5th and 6th modes are high, serving as the dominant modes. The effect of the flow profile on the oscillating mode becomes more and more apparent when the aspect ratio is high, and the dominant mode of riser in shear flow is usually higher than that in uniform flow. When the aspect ratio was 750, the CF oscillations in both uniform flow and shear flow showed multi-mode vibration of the 4th and 5th mode. While, the dominant mode in uniform flow is the 4th order, and the dominant mode in shear flow is the 5th order.

Refining fault slip rates using multiple displaced terrace risers—An example from the Honey Lake fault, NE California, USA

USGS Publications Warehouse

Gold, Ryan D.; Briggs, Richard; Crone, Anthony J.; Duross, Christopher

2017-01-01

Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference observed globally) produce large uncertainties in the slip-rate estimate. In this investigation, we explore how the full range of displacements and bounding ages from multiple faulted terrace risers can be combined to yield a more accurate fault slip rate. We use 0.25-m cell size digital terrain models derived from airborne lidar data to analyze three sites where terrace risers are offset right-laterally by the Honey Lake fault in NE California, USA. We use ages for locally extensive subhorizontal surfaces to bracket the time of riser formation: an upper surface is the bed of abandoned Lake Lahontan having an age of 15.8 ± 0.6 ka and a lower surface is a fluvial terrace abandoned at 4.7 ± 0.1 ka. We estimate lateral offsets of the risers ranging between 6.6 and 28.3 m (median values), a greater than fourfold difference in values. The amount of offset corresponds to the riser's position relative to modern stream meanders: the smallest offset is in a meander cutbank position, whereas the larger offsets are in straight channel or meander point-bar positions. Taken in isolation, the individual terrace-riser offsets yield slip rates ranging from 0.3 to 7.1 mm/a. However, when the offset values are collectively assessed in a probabilistic framework, we find that a uniform (linear) slip rate of 1.6 mm/a (1.4–1.9 mm/a at 95% confidence) can satisfy the data, within their respective uncertainties. This investigation demonstrates that integrating observations of multiple offset elements (crest, midpoint, and base) from numerous faulted and dated terrace risers at closely spaced sites can refine slip-rate estimates on strike-slip faults.

Summary of JIP

DOT National Transportation Integrated Search

2008-04-01

The SCRIM (Steel Catenary Riser Integrity Management) Joint Industry Project was an industry-sponsored initiative, managed and delivered by MCS, to develop industry guidelines for the integrity management of offshore risers. The original scope of the...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2010 CFR

2010-07-01

... assemblies, umbilicals, manifolds, termination skids, production and pipeline risers, platforms, templates... on the OCS. Facilities include production and pipeline risers, templates, pilings, and any other...

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

Taylor, W.M.; Tison, M.; Bahoumina, A.

The tieback of eleven 10 3/4-in., high-pressure risers in Elf Congo`s offshore N`Kossa field used a cold-forge tieback system to create a metal seal. The time-saving tieback method allows for placing the risers in residual tension. The installation work was completed in the fall of 1995. Average time to complete the 10 3/4-in. casing tiebacks, including test and nipple-up and nipple-down times, averaged 52 hr/well. Tiebacks for all three casing strings averaged 90 hr for all surface and subsea operations including BOP test and nipple-up/nipple-down time. Metal sealing of the primary casing annulus has been made practical because the offshoremore » industry has gone toward compact-wellheads and hanging of the completion on a mandrel. Hanging the completion on a mandrel, however, has it own set of considerations. Exact riser length may be difficult to predict before running because the riser must first be locked into the mudline casing hanger and then landed out on the support shoulder in the surface head. Also, a general desire is that riser tieback strings should be in tension after installation. This is not always easy with a passive or dumb hanger and fixed should configuration. Threaded, adjustable mandrel hanger systems exist but can require very close casing string space-out to achieve the desired residual riser tension. The paper describes the objectives, forged sleeves, running sequence, cold forging, and the prototype test.« less

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2013 CFR

2013-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

30 CFR 250.1012 - Required payments for pipeline right-of-way holders.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., pipeline risers, and other facilities and devices associated with the accessory. (2) Your accessory site is... rental includes the areal extent of anchor chains, pipeline risers, and other facilities and devices...

30 CFR 250.1003 - Installation, testing, and repair requirements for DOI pipelines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... obstructions. (4) Pipeline risers installed after April 1, 1988, shall be protected from physical damage that could result from contact with floating vessels. Riser protection on pipelines installed on or before...

30 CFR 250.1003 - Installation, testing, and repair requirements for DOI pipelines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... obstructions. (4) Pipeline risers installed after April 1, 1988, shall be protected from physical damage that could result from contact with floating vessels. Riser protection on pipelines installed on or before...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2014 CFR

2014-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

30 CFR 250.1012 - Required payments for pipeline right-of-way holders.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., pipeline risers, and other facilities and devices associated with the accessory. (2) Your accessory site is... rental includes the areal extent of anchor chains, pipeline risers, and other facilities and devices...

30 CFR 250.1003 - Installation, testing, and repair requirements for DOI pipelines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... obstructions. (4) Pipeline risers installed after April 1, 1988, shall be protected from physical damage that could result from contact with floating vessels. Riser protection on pipelines installed on or before...

30 CFR 250.1012 - Required payments for pipeline right-of-way holders.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., pipeline risers, and other facilities and devices associated with the accessory. (2) Your accessory site is... rental includes the areal extent of anchor chains, pipeline risers, and other facilities and devices...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2012 CFR

2012-07-01

... trees, jumper assemblies, umbilicals, manifolds, termination skids, production and pipeline risers... attached to the seabed on the OCS. Facilities include production and pipeline risers, templates, pilings...

30 CFR 250.1700 - What do the terms “decommissioning”, “obstructions”, and “facility” mean?

Code of Federal Regulations, 2011 CFR

2011-07-01

... pipeline risers, platforms, templates, pilings, pipelines, pipeline valves, and power cables. (c) Facility... risers, templates, pilings, and any other facility or equipment that constitutes an obstruction such as...

An efficient structural finite element for inextensible flexible risers

NASA Astrophysics Data System (ADS)

Papathanasiou, T. K.; Markolefas, S.; Khazaeinejad, P.; Bahai, H.

2017-12-01

A core part of all numerical models used for flexible riser analysis is the structural component representing the main body of the riser as a slender beam. Loads acting on this structural element are self-weight, buoyant and hydrodynamic forces, internal pressure and others. A structural finite element for an inextensible riser with a point-wise enforcement of the inextensibility constrain is presented. In particular, the inextensibility constraint is applied only at the nodes of the meshed arc length parameter. Among the virtues of the proposed approach is the flexibility in the application of boundary conditions and the easy incorporation of dissipative forces. Several attributes of the proposed finite element scheme are analysed and computation times for the solution of some simplified examples are discussed. Future developments aim at the appropriate implementation of material and geometric parameters for the beam model, i.e. flexural and torsional rigidity.

Triggered emissions close to the proton gyrofrequency seen by Cluster

NASA Astrophysics Data System (ADS)

Grison, Benjamin; Pickett, Jolene; Omura, Yoshiharu; Santolik, Ondrej; Decreau, Pierrette; Masson, Arnaud; Engebretson, Mark; Cornilleau-Wehrlin, Nicole; Robert, Patrick; Dandouras, Iannis

Electromagnetic ion cyclotron (EMIC) triggered emissions have been recently observed onboard the Cluster spacecraft close to the plasmapause in the equatorial region of the magnetosphere. These waves appear as "risers": electromagnetic structures that have a positive frequency drift with time, i.e., the EMIC analogue of rising frequency whistler mode triggered emissions and chorus waves. In our first results concerning the emission process based on a single event, these risers have the following properties: they propagate away from the direction of the magnetic equator, they have elliptical left-handed polarization corresponding to the transverse Alfven mode, and frequency drifts of about 30 mHz/s. These risers are not common in the Cluster data set. Nevertheless a few other events were found with similar properties. Another interesting preliminary result is the existence of risers with a polarization opposite that of the EMIC triggered emissions and which correspond to the fast magnetosonic mode.

Bench and Riser Soil Water Content on Semiarid Hillslopes with Terracettes

NASA Astrophysics Data System (ADS)

Heinse, R.; Corrao, M.; Eitel, J.; Link, T. E.

2015-12-01

Microtopographic features known as terracettes are found throughout many semiarid rangelands. These path-like features roughly perpendicular to the slope are frequently traversed by grazing animals on steep hillslopes. The soil properties and hydrologic function, however, are virtually unknown. This research aimed to identify differences in soil properties between terracette bench and riser features, and their influence on soil water content for two terracetted sites and two non-terracetted control sites (grazed and ungrazed) in Eastern Washington State. Measurements of volumetric water content (θ_v), bulk density, soil texture, saturated hydraulic conductivity, pH, and ECa_a were collected along with compaction, vegetative cover and cattle density throughout the 2013 and 2014 field seasons. Results show small but significant volumetric water content differences between terracette benches and risers in the upper 10 cm with benches exhibiting higher mean θ_v than risers throughout the year. Soil bulk density on benches (1600 kg m-3^{-3}) was significantly higher than that of risers (1300 kg m-3^{-3}) with no differences in soil texture. The saturated hydraulic conductivity on benches was roughly half of that for risers. No significant soil differences were noted below 20 cm depth. Terracetted sites showed greater field-averaged θ_v compared to non-terracetted sites suggesting a positive trend with animal stocking rates. Higher water content on terracette benches is attributed to shifts in pore size distribution with compaction, and a reduction in root-water uptake due to plant-root impedance. This increased soil water does not however increase forage production as it is not accessible to plants.

IODP Expedition 338: NanTroSEIZE Stage 3: NanTroSEIZE plate boundary deep riser 2

NASA Astrophysics Data System (ADS)

Moore, G. F.; Kanagawa, K.; Strasser, M.; Dugan, B.; Maeda, L.; Toczko, S.

2014-01-01

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is designed to investigate fault mechanics and seismogenesis along a subduction megathrust, with objectives that include characterizing fault slip, strain accumulation, fault and wall rock composition, fault architecture, and state variables throughout an active plate boundary system. Integrated Ocean Drilling Program (IODP) Expedition 338 was planned to extend and case riser Hole C0002F from 856 to 3600 meters below the seafloor (m b.s.f.). Riser operations extended the hole to 2005.5 m b.s.f., collecting logging-while-drilling (LWD) and measurement-while-drilling, mud gas, and cuttings data. Results reveal two lithologic units within the inner wedge of the accretionary prism that are separated by a prominent fault zone at ~ 1640 m b.s.f. Due to damage to the riser during unfavorable winds and strong currents, riser operations were suspended, and Hole C0002F left for re-entry during future riser drilling operations. Contingency riserless operations included coring at the forearc basin site (C0002) and at two slope basin sites (C0021 and C0022), and LWD at one input site (C0012) and at three slope basin sites (C0018, C0021 and C0022). Cores and logs from these sites comprehensively characterize the alteration stage of the oceanic basement input to the subduction zone, the early stage of Kumano Basin evolution, gas hydrates in the forearc basin, and recent activity of the shallow megasplay fault zone system and associated submarine landslides.

78 FR 44119 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

...: 3060-0874. Title: FCC Form 2000 A through H, FCC Form RDA, FCC Form 475-B, FCC Form 1088 A through H...: FCC Form 2000 A through H, FCC Form RDA, FCC Form 475- B, FCC Form 1088 A through H, and FCC Form 501...

Shallow Water Propagation

DTIC Science & Technology

2014-09-30

improvements in single-scattering treatments at stair-step risers in approximations for range dependence; non-uniform depth gridding to treat thin layers...turns out for such problems that preserving accuracy requires conceptually splitting a stair- riser interface into two interfaces separated by a very

Holocene slip rate for the central Altyn Tagh Fault: Preliminary results from the Tuzidun site based on 14C and 10Be dating of a displaced fluvial terrace riser.

NASA Astrophysics Data System (ADS)

Gold, R. D.; Cowgill, E. S.; Arrowsmith, R.; Muretta, M.; Gosse, J.; Chen, X.; Wang, X.

2007-12-01

The active, left-slip Altyn Tagh Fault (ATF) defines the northern boundary of the Tibetan Plateau and is among the world's longest intracontinental strike-slip faults. Despite a decade of concentrated work, the Holocene slip rate for the central ATF is still disputed, with millennial slip rates derived from faulted landforms ranging from 9 to 27 mm/yr. To address this factor-of-three difference, we are investigating a new slip-rate site near Tuzidun (37.73N, 86.72E) along the Cherchen He reach of the fault. The new site is situated where a south-flowing, ephemeral stream channel crosses the N70E-striking, active trace of the ATF. This channel is flanked by a set of inset fluvial terraces along its eastern bank. North of the ATF, these terraces include both a younger/lower T1 tread and an older/higher T2 terrace, which are vertically separated by an intervening T2/T1 riser. South of the fault, the stream is inset into an alluvial fan, F1. The F1 fan is separated from the higher, T2 fluvial terrace tread to the east, by the T2/F1 riser. Our neotectonic mapping and survey data indicate that the T2/F1 riser on the south/downstream side of the ATF and the T2/T1 riser on the north/upstream side have been displaced from one another by left slip along the ATF. The present separation between these riser segments is ~56 m, though lateral erosion of the riser may have diminished the true offset. To account for this possibility, we have developed three end-member reconstructions that yield offsets ranging from 56 to105 m. Ongoing geochronologic and geomorphic analyses are designed further limit the range of possible displacements. Preliminary age analyses from the Tuzidun site include 22 new radiocarbon dates from buried organic materials and 7 analyses of 10Be concentration in quartz extracted from amalgamated samples of terrace conglomerates. The 14C analyses are from samples collected from within the T2 tread on both sides of the ATF and from loess deposits that cap the downstream T2/F1 riser face. The 10Be analyses are from samples collected in two depth profiles, north and south of the ATF, dug into the T2 deposit at the crest of the displaced riser. The calibrated 14C dates and 10Be surface-exposure ages are compatible, and indicate that the surfaces at the crest and toe of the riser were abandoned at ~6 ka and ~4.4 ka, respectively. To bracket the millennial slip rate at this site, we consider three end-member reconstructions. The first is an upper-terrace reconstruction, in which the riser started recording displacement as soon as the upper-terrace, T2, was abandoned, providing a minimum constraint on the slip rate of ~9 mm/yr since ~6 ka. An intermediate interpretation is a lower-terrace reconstruction, in which the riser accumulated no displacement until the lower surface, F1, was abandoned, yielding a slip rate of ~13 mm/yr since ~4.4 ka. The final reconstruction is one in which erosion of the upstream T2 surface, prior to T1/F1 deposition, diminished the present-day observed offset. In this case, up to 105 m of displacement has occurred since abandonment of the T2 surface, which permits a slip rate as high as ~18 mm/yr since ~6 ka. The new slip rate of 9-18 mm/yr for the Tuzidun site is consistent with our preliminary results from three additional slip-rate sites along the central ATF, and taken together, provides an upper limit of 18 mm/yr for the Holocene slip rate along this reach of the fault.

30 CFR 250.530 - When does my casing pressure request approval become invalid?

Code of Federal Regulations, 2012 CFR

2012-07-01

... request approval become invalid? A casing pressure request becomes invalid when: (a) The casing or riser... different casing or riser on the same well requires a casing pressure request; or (e) A well has more than...

30 CFR 250.530 - When does my casing pressure request approval become invalid?

Code of Federal Regulations, 2010 CFR

2010-07-01

... become invalid? A casing pressure request becomes invalid when: (a) The casing or riser pressure... casing or riser on the same well requires a casing pressure request; or (e) A well has more than one...

30 CFR 250.1708 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... inspect your BOP system and marine riser at least once every 3 days if weather and sea conditions permit... alternate methods and frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP...

30 CFR 250.531 - When does my casing pressure request approval become invalid?

Code of Federal Regulations, 2014 CFR

2014-07-01

... request approval become invalid? A casing pressure request becomes invalid when: (a) The casing or riser... different casing or riser on the same well requires a casing pressure request; or (e) A well has more than...

30 CFR 250.617 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... your BOP system and marine riser at least once each day if weather and sea conditions permit. You may... and frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP system to...

30 CFR 250.618 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... marine riser at least once every 3 days if weather and sea conditions permit. You may use television... frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP system to ensure that...

30 CFR 250.617 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... BOP system and marine riser at least once each day if weather and sea conditions permit. You may use... frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP system to ensure that...

30 CFR 250.530 - When does my casing pressure request approval become invalid?

Code of Federal Regulations, 2011 CFR

2011-07-01

... casing or riser pressure increases by 200 psig over the approved casing pressure request pressure; (b... stimulated; (d) A different casing or riser on the same well requires a casing pressure request; or (e) A...

30 CFR 250.618 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... marine riser at least once every 3 days if weather and sea conditions permit. You may use television... frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP system to ensure that...

30 CFR 250.1708 - What are my BOP inspection and maintenance requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... inspect your BOP system and marine riser at least once every 3 days if weather and sea conditions permit... alternate methods and frequencies to inspect a marine riser. (b) BOP maintenance. You must maintain your BOP...

30 CFR 250.531 - When does my casing pressure request approval become invalid?

Code of Federal Regulations, 2013 CFR

2013-07-01

... request approval become invalid? A casing pressure request becomes invalid when: (a) The casing or riser... different casing or riser on the same well requires a casing pressure request; or (e) A well has more than...

Parametric study on the behavior of an innovative subsurface tension leg platform in ultra-deep water

NASA Astrophysics Data System (ADS)

Zhen, Xing-wei; Huang, Yi

2017-10-01

This study focuses on a new technology of Subsurface Tension Leg Platform (STLP), which utilizes the shallowwater rated well completion equipment and technology for the development of large oil and gas fields in ultra-deep water (UDW). Thus, the STLP concept offers attractive advantages over conventional field development concepts. STLP is basically a pre-installed Subsurface Sea-star Platform (SSP), which supports rigid risers and shallow-water rated well completion equipment. The paper details the results of the parametric study on the behavior of STLP at a water depth of 3000 m. At first, a general description of the STLP configuration and working principle is introduced. Then, the numerical models for the global analysis of the STLP in waves and current are presented. After that, extensive parametric studies are carried out with regarding to SSP/tethers system analysis, global dynamic analysis and riser interference analysis. Critical points are addressed on the mooring pattern and riser arrangement under the influence of ocean current, to ensure that the requirements on SSP stability and riser interference are well satisfied. Finally, conclusions and discussions are made. The results indicate that STLP is a competitive well and riser solution in up to 3000 m water depth for offshore petroleum production.

Experimental Research on the Dense CFB's Riser and the Simulation Based on the EMMS Model

NASA Astrophysics Data System (ADS)

Wang, X. Y.; Wang, S. D.; Fan, B. G.; Liao, L. L.; Jiang, F.; Xu, X.; Wu, X. Z.; Xiao, Y. H.

2010-03-01

The flow structure in the CFB (circulating fluidized bed) riser has been investigated. Experimental studies were performed in a cold square section unit with 270 mm×270 mm×10 m. Since the drag force model based on homogeneous two-phase flow such as the Gidaspow drag model could not depict the heterogeneous structures of the gas-solid flow, the structure-dependent energy-minimization multi-scale (EMMS) model based on the heterogenerity was applied in the paper and a revised drag force model based on the EMMS model was proposed. A 2D two-fluid model was used to simulate a bench-scale square cross-section riser of a cold CFB. The typical core-annulus structure and the back-mixing near the wall of the riser were observed and the assembly and fragmentation processes of clusters were captured. By comparing with the Gidaspow drag model, the results obtained by the revised drag model based on EMMS shows better consistency with the experimental data. The model can also depict the difference from the two exit configurations. This study once again proves the key role of drag force in CFD (Computational Fluid Dynamics) simulation and also shows the availability of the revised drag model to describe the gas-solid flow in CFB risers.

Overview of Emic Triggered Chorus Emissions in Cluster Data

NASA Astrophysics Data System (ADS)

Grison, B.; Pickett, J. S.; Omura, Y.; Santolik, O.; Engebretson, M. J.; Dandouras, I. S.; Masson, A.; Decreau, P. M.; Adrian, M. L.; Cornilleau Wehrlin, N.

2010-12-01

Electromagnetic ion cyclotron (EMIC) triggered emissions have been recently observed onboard the Cluster spacecraft close to the plasmapause in the equatorial region of the magnetosphere (Pickett et al., 2010). The nonlinear mechanism of the wave amplification is the same as for the well known whistler-mode chorus emissions (Omura et al., 2010). The EMIC triggered emissions appear as risers: electromagnetic structures that have a positive frequency drift with time. They can thus be considered as the EMIC analogue of rising frequency whistler-mode chorus emissions. In addition, they propagate away from the magnetic equator. These EMIC risers are not common in Cluster data. We present an overview of the properties of all the identified cases. Risers can be sorted out in two groups: in the first one the starting frequency of EMIC emissions is close to one half of the local proton gyrofrequency and the risers have a clear left-hand polarization. In the second group the risers have an opposite polarization with a starting frequency close to one half of the He+ gyrofrequency. Most of the cases have been detected close to 22 MLT (magnetic local time). This dependence will be investigated to determine if it is linked to the orbit effects or if there is a physical cause.

Promoting stair climbing: stair-riser banners are better than posters... sometimes.

PubMed

Olander, Ellinor K; Eves, Frank F; Puig-Ribera, Anna

2008-04-01

Stair-riser banners are twice as effective as posters in encouraging stair climbing in shopping centres. This study tested the effectiveness of stair-riser banners in an English train station in 2006-2007. The train station had a 39-step staircase and an adjacent escalator. Baseline observations (3.5 weeks) were followed by 10.5 weeks of a banner intervention supplemented with 3 weeks of a poster intervention. Both poster and banner featured the message 'Stair climbing burns more calories per minute than jogging. Take the stairs'. Ascending escalator and stair users (N=36,239) were coded for gender. Analyses, controlling for effects of gender and pedestrian traffic volume, revealed no significant change in stair climbing between baseline (40.6%) and the banner intervention (40.9%; p=0.98). Addition of the poster increased stair climbing (44.3%; OR=1.36, 95% CIs 1.16-1.60, p<0.001), with the effect reduced at higher pedestrian traffic volumes. While stair-riser banners had no effect, the poster intervention increased stair climbing. The high pedestrian volumes as the wave of disembarking passengers seek to leave the station would have obscured the visibility of the banner for many commuters. Thus stair-riser banners appear unsuitable point-of-choice prompts in stations where pedestrian traffic volume is high.

RELIABLE RADIOGRAPHIC INSPECTION OF FLEXIBLE RISERS FOR THE OIL INDUSTRY

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

Almeida, Romulo M.; Rebello, Joao Marcos A.; Vaz, Murilo A.

2010-02-22

Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segmentmore » protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.« less

Reliable Radiographic Inspection of Flexible Risers for the Oil Industry

NASA Astrophysics Data System (ADS)

Almeida, Rômulo M.; Rebello, Joao Marcos A.; Vaz, Murilo A.

2010-02-01

Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.

78 FR 29369 - Information Collections Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

... Control Number: 3060-0874. Title: FCC Form 2000 A through H, FCC Form RDA, FCC Form 475-B, FCC Form 1088 A... Form 2000 A through H, FCC Form RDA, FCC Form 475- B, FCC Form 1088 A through H, and FCC Form 501. Type...

75 FR 13540 - Notice of Public Information Collections Being Submitted to the Office of Management and Budget...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-22

... INFORMATION: OMB Control Number: 3060-0874. Title: FCC Form 2000 A through F, FCC Form 475-B, FCC Form 1088 A...): FCC Form 2000 A through F, FCC Form 475-B, FCC Form 1088 A through H, and FCC Form 501. Type of Review... indecent programming. The FCC Form 475-B will remain unchanged. The FCC Form 1088 Consumer Complaint Form...

78 FR 18591 - Information Collection Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

... Number: 3060-0874. Title: FCC Form 2000 A through G, FCC Form 475-B, FCC Form 1088 A through H, and FCC... through G, FCC Form 475-B, FCC Form 1088 A through H, and FCC Form 501. Type of Review: Extension of a..., and/or indecent programming. The FCC Form 475-B will remain unchanged. The FCC Form 1088 Consumer...

30 CFR 550.160 - When will BOEM grant me a right-of-use and easement, and what requirements must I meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... rental includes the areal extent of anchor chains, pipeline risers, and other equipment associated with..., pipeline risers, and other equipment associated with the platform, artificial island, or installation or...

30 CFR 550.160 - When will BOEM grant me a right-of-use and easement, and what requirements must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... rental includes the areal extent of anchor chains, pipeline risers, and other equipment associated with..., pipeline risers, and other equipment associated with the platform, artificial island, or installation or...

75 FR 17708 - Kinder Morgan Louisiana Pipeline LLC; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... authorization to construct and operate a new tap, including ball valve and riser and approximately 15 feet of 8..., riser, 15-feet of 8-inch diameter piping and such other appurtenant facilities as deemed necessary to...

30 CFR 550.160 - When will BOEM grant me a right-of-use and easement, and what requirements must I meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... rental includes the areal extent of anchor chains, pipeline risers, and other equipment associated with..., pipeline risers, and other equipment associated with the platform, artificial island, or installation or...

Association between abnormal nocturnal blood pressure profile and dementia in Parkinson's disease.

PubMed

Tanaka, Ryota; Shimo, Yasushi; Yamashiro, Kazuo; Ogawa, Takashi; Nishioka, Kenya; Oyama, Genko; Umemura, Atsushi; Hattori, Nobutaka

2018-01-01

Circadian blood pressure alterations are frequently observed in Parkinson's disease, but the association between these changes and dementia in the condition remains unclear. Here, we assess the relationship between abnormal nocturnal blood pressure profiles and dementia in Parkinson's disease. We enrolled 137 patients with Parkinson's disease, who underwent 24 h ambulatory blood pressure monitoring, following cognitive and clinical assessment. Twenty-seven patients (19.7%) were diagnosed with dementia in this cohort. We observed significant associations of dementia with age, male gender, Hoehn-Yahr (H-Y) stage, diabetes mellitus, history of stroke, presence of cerebrovascular lesions on MRI, and orthostatic hypotension. Univariate logistic regression analysis showed that among the patterns of nocturnal blood pressure profiles, the riser pattern was significantly associated with dementia (OR 11.6, 95%CI: 2.14-215.0, P < 0.01), and this trend was observed after adjusting for all confounding factors except orthostatic hypotension (OR 19.2, 95%CI: 1.12-1960.3, P = 0.04). However, coexistence of a riser pattern and orthostatic hypotension was related to a higher prevalence of dementia (45.2%) than was a riser pattern alone (9.5%). Furthermore, coexistence of a riser pattern and orthostatic hypotension was significantly more associated with dementia than was a riser pattern alone, even after adjusting for confounders (OR 1625.1, 95%CI: 21.9-1343909.5, P < 0.01). Our results suggest a relationship between a riser pattern coexisting with orthostatic hypotension and dementia in Parkinson's disease. Further prospective studies are warranted to investigate whether abnormal nocturnal blood pressure profiles predict dementia in Parkinson's disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Commercialization of the Chevron FCC vanadium trap

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

Kennedy, J.V.; Kuehler, C.W.; Krishna, A.S.

1995-09-01

Vanadium, present to varying degrees in FCC feed, deposits on the catalyst virtually quantitatively in the cracking process. In resid operations, vanadium levels on catalyst can reach 10,000 ppm at typical catalyst make-up rates. Once on the catalyst, vanadium destroys the zeolite and restricts access to active sites. This reduces catalyst activity. A vanadium trap is a material that when introduced into the catalyst inventory selectively reacts with migrating vanadium, thus protecting the zeolite and other active components of the catalyst. The trap may be incorporated into the catalyst, or introduced as a separate particle. Only a limited amount ofmore » trap can be incorporated into the catalyst without limiting the amount of zeolite that can be included. Gulf began development of a vanadium trap during the early 1980`s. The work produced a variety of promising materials whose use as vanadium traps was subsequently patented. The work ultimately led to a formulation with a phase very active for trapping vanadium while still quite sulfur tolerant. Based on these results, an extensive pilot plant evaluation was undertaken by Chevron after the Chevron-Gulf merger to better simulate commercial operation. The paper describes pilot plant tests as well as 3 commercial tests of this vanadium trap.« less

Early Risers. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

"Early Risers" is a multi-year prevention program for elementary school children demonstrating early aggressive and disruptive behavior. The intervention model includes two child-focused components and two parent/family components. The Child Skills component is designed to teach skills that enhance children's emotional and behavioral…

Computational Fluid Dynamics–Discrete Element Method (CFD-DEM) Study of Mass-Transfer Mechanisms in Riser Flow

PubMed Central

2017-01-01

We report a computational fluid dynamics–discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system behavior in detail. The most important factors are found to be directly related to particle cluster formation. Low air-to-solids flux ratios lead to more heterogeneous systems, where the cluster formation is more pronounced and mass transfer more influenced. Falling clusters can be partially circumvented by the gas phase, which therefore does not fully interact with the cluster particles, leading to poor gas–solid contact efficiencies. Cluster gas–solid contact efficiencies are quantified at several gas superficial velocities, reaction rates, and dilution factors in order to gain more insight regarding the influence of clustering phenomena on the performance of riser reactors. PMID:28553011

Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) Study of Mass-Transfer Mechanisms in Riser Flow.

PubMed

Carlos Varas, Álvaro E; Peters, E A J F; Kuipers, J A M

2017-05-17

We report a computational fluid dynamics-discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system behavior in detail. The most important factors are found to be directly related to particle cluster formation. Low air-to-solids flux ratios lead to more heterogeneous systems, where the cluster formation is more pronounced and mass transfer more influenced. Falling clusters can be partially circumvented by the gas phase, which therefore does not fully interact with the cluster particles, leading to poor gas-solid contact efficiencies. Cluster gas-solid contact efficiencies are quantified at several gas superficial velocities, reaction rates, and dilution factors in order to gain more insight regarding the influence of clustering phenomena on the performance of riser reactors.

78 FR 5177 - Information Collection Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-24

...-0874. Title: FCC Form 2000 A through G, FCC Form 475-B, FCC Form 1088 A through H, and FCC Form 501... 475-B, FCC Form 1088 A through H, and FCC Form 501. Type of Review: Extension of a currently approved.../or indecent programming. The FCC Form 475-B will remain unchanged. The FCC Form 1088 Consumer...

Core disruptive accident margin seal

DOEpatents

Golden, Martin P.

1979-01-01

Apparatus for sealing the annulus defined within a substantially cylindrical rotatable riser assembly and plug combination of a nuclear reactor closure head. The apparatus comprises an inflatable sealing mechanism disposed in one portion of the riser assembly near the annulus such that upon inflation the sealing mechanism is radially actuated against the other portion of the riser assembly thereby sealing the annulus. The apparatus further comprises a connecting mechanism which places one end of the sealing mechanism in fluid communication with the reactor cover gas so that overpressurization of the reactor cover gas will increase the radial actuation of the sealing mechanism thus enhancing sealing of the annulus.

Performance of thermal sprayed aluminium coatings in the splash zone and for riser service

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

Fischer, K.P.; Rosbrook, T.; Thomason, W.H.

1994-12-31

Historically, the coatings used in the splash zone have been either heavy duty coal tar epoxy or a glassflake epoxy. In 1982 Conoco justified a minimum 20 year service life for a sealed thermal sprayed aluminium (TSA) coating for the Hutton TLP risers and tethers. In 1984 the Hutton TLP was installed with 200 microns thickness TSA as the corrosion protection coating and without adding a corrosion allowance. After eight years service the TSA coating on the production risers and tethers is still in good condition. It was noted that the splash zone area was indistinguishable from the remainder ofmore » the inspected components. However, there was a noticeable difference between the production risers and the tethers. The tethers having a vinyl sealer showed a blistered surface while the risers with a silicone sealer did not show any blistering. No corrosion has been observed underneath any of the blisters. The importance of adequate sealers in connection with blistering has been documented by testing. The excellent long term performance of TSA coating in the splash zone has been further documented by the results of field studies published in the last few years. These experiences indicate that TSA coatings properly applied and with the use of specific sealer systems may provide a service life in excess of 30 years with no required maintenance.« less

Crystal accumulation in the Hanford Waste Treatment Plant high level waste melter. Preliminary settling and resuspension testing

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

Fox, K. M.; Fowley, M. D.; Miller, D. H.

2016-05-01

The full-scale, room-temperature Hanford Tank Waste Treatment and Immobilization Plant (WTP) High-Level Waste (HLW) melter riser test system was successfully operated with silicone oil and magnetite particles at a loading of 0.1 vol %. Design and construction of the system and instrumentation, and the selection and preparation of simulant materials, are briefly reviewed. Three experiments were completed. A prototypic pour rate was maintained, based on the volumetric flow rate. Settling and accumulation of magnetite particles were observed at the bottom of the riser and along the bottom of the throat after each experiment. The height of the accumulated layer atmore » the bottom of the riser, after the first pouring experiment, approximated the expected level given the solids loading of 0.1 vol %. More detailed observations of particle resuspension and settling were made during and after the third pouring experiment. The accumulated layer of particles at the bottom of the riser appeared to be unaffected after a pouring cycle of approximately 15 minutes at the prototypic flow rate. The accumulated layer of particles along the bottom of the throat was somewhat reduced after the same pouring cycle. Review of the time-lapse recording showed that some of the settling particles flow from the riser into the throat. This may result in a thicker than expected settled layer in the throat.« less

Refiners have several options for reducing gasoline benzene

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

Goelzer, A.R.; Hernandez-Robinson, A.; Ram, S.

1993-09-13

Although the linkage between gasoline benzene content and evaporative, running, and tailpipe emission is not yet defined, the U.S. 1990 Clean Air Act Amendments mandate a benzene content of less than 1.0 vol% in reformulated gasolines. Likewise, the California Air Resources Board plans to restrict benzene to less than about 0.8 vol %. Mobil Research and Development Corp. and Badger Co. Inc. have developed several alternatives for reducing benzene levels in gasoline. Where benzene extraction is viable and maximum catalytic reformer hydrogen is needed, the companies' cumene and ethylbenzene processes are desirable. Mobil's benzene reduction process can be an alternativemore » to benzene hydrosaturation. All of these processes utilize low-value offgas from the fluid catalytic cracking (FCC) unit.« less

30 CFR 250.916 - What are the CVA's primary duties during the design phase?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Stress analyses; (vi) Material designations; (vii) Soil and foundation conditions; (viii) Safety factors... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and... pipeline risers, and riser tensioning systems; (ii) Turrets and turret-and-hull interfaces; (iii...

Subsurface Stress Fields in FCC Single Crystal Anisotropic Contacts

NASA Technical Reports Server (NTRS)

Arakere, Nagaraj K.; Knudsen, Erik; Swanson, Gregory R.; Duke, Gregory; Ham-Battista, Gilda

2004-01-01

Single crystal superalloy turbine blades used in high pressure turbomachinery are subject to conditions of high temperature, triaxial steady and alternating stresses, fretting stresses in the blade attachment and damper contact locations, and exposure to high-pressure hydrogen. The blades are also subjected to extreme variations in temperature during start-up and shutdown transients. The most prevalent high cycle fatigue (HCF) failure modes observed in these blades during operation include crystallographic crack initiation/propagation on octahedral planes, and non-crystallographic initiation with crystallographic growth. Numerous cases of crack initiation and crack propagation at the blade leading edge tip, blade attachment regions, and damper contact locations have been documented. Understanding crack initiation/propagation under mixed-mode loading conditions is critical for establishing a systematic procedure for evaluating HCF life of single crystal turbine blades. This paper presents analytical and numerical techniques for evaluating two and three dimensional subsurface stress fields in anisotropic contacts. The subsurface stress results are required for evaluating contact fatigue life at damper contacts and dovetail attachment regions in single crystal nickel-base superalloy turbine blades. An analytical procedure is presented for evaluating the subsurface stresses in the elastic half-space, based on the adaptation of a stress function method outlined by Lekhnitskii. Numerical results are presented for cylindrical and spherical anisotropic contacts, using finite element analysis (FEA). Effects of crystal orientation on stress response and fatigue life are examined. Obtaining accurate subsurface stress results for anisotropic single crystal contact problems require extremely refined three-dimensional (3-D) finite element grids, especially in the edge of contact region. Obtaining resolved shear stresses (RSS) on the principal slip planes also involves considerable post-processing work. For these reasons it is very advantageous to develop analytical solution schemes for subsurface stresses, whenever possible.

Laboratory Production of Biofuels and Biochemicals from a Rapeseed Oil through Catalytic Cracking Conversion.

PubMed

Ng, Siauw H; Shi, Yu; Heshka, Nicole E; Zhang, Yi; Little, Edward

2016-09-02

The work is based on a reported study which investigates the processability of canola oil (bio-feed) in the presence of bitumen-derived heavy gas oil (HGO) for production of transportation fuels through a fluid catalytic cracking (FCC) route. Cracking experiments are performed with a fully automated reaction unit at a fixed weight hourly space velocity (WHSV) of 8 hr(-1), 490-530 °C, and catalyst/oil ratios of 4-12 g/g. When a feed is in contact with catalyst in the fluid-bed reactor, cracking takes place generating gaseous, liquid, and solid products. The vapor produced is condensed and collected in a liquid receiver at -15 °C. The non-condensable effluent is first directed to a vessel and is sent, after homogenization, to an on-line gas chromatograph (GC) for refinery gas analysis. The coke deposited on the catalyst is determined in situ by burning the spent catalyst in air at high temperatures. Levels of CO2 are measured quantitatively via an infrared (IR) cell, and are converted to coke yield. Liquid samples in the receivers are analyzed by GC for simulated distillation to determine the amounts in different boiling ranges, i.e., IBP-221 °C (gasoline), 221-343 °C (light cycle oil), and 343 °C+ (heavy cycle oil). Cracking of a feed containing canola oil generates water, which appears at the bottom of a liquid receiver and on its inner wall. Recovery of water on the wall is achieved through washing with methanol followed by Karl Fischer titration for water content. Basic results reported include conversion (the portion of the feed converted to gas and liquid product with a boiling point below 221 °C, coke, and water, if present) and yields of dry gas (H2-C2's, CO, and CO2), liquefied petroleum gas (C3-C4), gasoline, light cycle oil, heavy cycle oil, coke, and water, if present.

OTEC riser cable model and prototype testing

NASA Astrophysics Data System (ADS)

Kurt, J. P.; Schultz, J. A.; Roblee, L. H. S.

1981-12-01

Two different OTEC riser cables have been developed to span the distance between a floating OTEC power plant and the ocean floor. The major design concerns for a riser cable in the dynamic OTEC environment are fatigue, corrosion, and electrical/mechanical aging of the cable components. The basic properties of the cable materials were studied through tests on model cables and on samples of cable materials. Full-scale prototype cables were manufactured and were tested to measure their electrical and mechanical properties and performance. The full-scale testing was culminated by the electrical/mechanical fatigue test, which exposes full-scale cables to simultaneous tension, bending and electrical loads, all in a natural seawater environment.

76 FR 57989 - Privacy Act System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-19

... one new, consolidated system of records, FCC/PSHSB-1, ``FCC Emergency and Continuity Contacts System (ECCS).'' FCC/PSHSB-1, ``FCC Emergency and Continuity Contacts System (ECCS)'' will incorporate the..., FCC/EB-4, ``Crisis Management Contacts,'' and FCC/OMD-11, ``Continuity of Operations Plan (COOP...

30 CFR 250.527 - What must I include in my casing pressure request?

Code of Federal Regulations, 2011 CFR

2011-07-01

... casing/riser calculated MAWOPs; (h) All casing/riser pre-bleed down pressures; (i) Shut-in tubing... test (oil, gas, basic sediment, and water); (l) Well status (shut-in, temporarily abandoned, producing, injecting, or gas lift); (m) Well type (dry tree, hybrid, or subsea); (n) Date of diagnostic test; (o) Well...

The Early Risers Preventive Intervention: Testing for Six-year Outcomes and Mediational Processes

ERIC Educational Resources Information Center

Bernat, Debra H.; August, Gerald J.; Hektner, Joel M.; Bloomquist, Michael L.

2007-01-01

We examined effects of the Early Risers "Skills for Success" early-age-targeted prevention program on serious conduct problems following 5 years of continuous intervention and one year of follow-up. We also examined if intervention effects on proximally-targeted variables found after 3 years mediated intervention effects on conduct…

Tibial plateau fracture following gracilis-semitendinosus anterior cruciate ligament reconstruction: The tibial tunnel stress-riser.

PubMed

Sundaram, R O; Cohen, D; Barton-Hanson, N

2006-06-01

Tibial plateau fractures following anterior cruciate ligament (ACL) reconstruction are extremely rare. This is the first reported case of a tibial plateau fracture following four-strand gracilis-semitendinosus autograft ACL reconstruction. The tibial tunnel alone may behave as a stress riser which can significantly reduce bone strength.

Multiphase flow modeling and simulation of explosive volcanic eruptions

NASA Astrophysics Data System (ADS)

Neri, Augusto

Recent worldwide volcanic activity, such as eruptions at Mt. St. Helens, Washington, in 1980, Mt. Pinatubo, Philippines, in 1991, as well as the ongoing eruption at Montserrat, West Indies, highlighted again the complex nature of explosive volcanic eruptions as well as the tremendous risk associated to them. In the year 2000, about 500 million people are expected to live under the shadow of an active volcano. The understanding of pyroclastic dispersion processes produced by explosive eruptions is, therefore, of primary interest, not only from the scientific point of view, but also for the huge worldwide risk associated with them. The thesis deals with an interdisciplinary research aimed at the modeling and simulation of explosive volcanic eruptions by using multiphase thermo-fluid-dynamic models. The first part of the work was dedicated to the understanding and validation of recently developed kinetic theory of two-phase flow. The hydrodynamics of fluid catalytic cracking particles in the IIT riser were simulated and compared with lab experiments. Simulation results confirm the validity of the kinetic theory approach. Transport of solids in the riser is due to dense clusters. On a time-average basis the bottom of the riser and the walls are dense, in agreement with IIT experimental data. The low frequency of oscillation (about 0.2 Hz) is also in agreement with data. The second part of the work was devoted to the development of transient two-dimensional multiphase and multicomponent flow models of pyroclastic dispersion processes. In particular, the dynamics of ground-hugging high-speed and high-temperature pyroclastic flows generated by the collapse of volcanic columns or by impulsive discrete explosions, was investigated. The model accounts for the mechanical and thermal non-equilibrium between a multicomponent gas phase and N different solid phases representative of pyroclastic particles of different sizes. Pyroclastic dispersion dynamics describes the formation of the initial vertical jet, the column collapse, and the building of the pyroclastic fountain, followed by the generation of radially spreading pyroclastic flows. The development of thermal convective instabilities in the flow lead to the formation of co-ignimbritic or phoenix clouds. Simulation results strongly highlight the importance of the multiphase flow formulation of the mixture. Large particles tend to segregate and sediment along the ground, whereas fine particles tend to form ascending buoyant plumes. Mixtures rich in fine grained particles produce larger runout of the flow and larger ascending plumes than mixtures rich in coarse particles. Simulation results appear to be qualitatively in agreement with field observations, but require to be fully validated by the simulation of well-known test cases.

Computation of turbulence and dispersion of cork in the NETL riser

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

Jiradilok, Veeraya; Gidaspow, Dimitri; Breault, R.W.

The knowledge of dispersion coefficients is essential for reliable design of gasifiers. However, a literature review had shown that dispersion coefficients in fluidized beds differ by more than five orders of magnitude. This study presents a comparison of the computed axial solids dispersion coefficients for cork particles to the NETL riser cork data. The turbulence properties, the Reynolds stresses, the granular temperature spectra and the radial and axial gas and solids dispersion coefficients are computed. The standard kinetic theory model described in Gidaspow’s 1994 book, Multiphase Flow and Fluidization, Academic Press and the IIT and Fluent codes were used tomore » compute the measured axial solids volume fraction profiles for flow of cork particles in the NETL riser. The Johnson–Jackson boundary conditions were used. Standard drag correlations were used. This study shows that the computed solids volume fractions for the low flux flow are within the experimental error of those measured, using a two-dimensional model. At higher solids fluxes the simulated solids volume fractions are close to the experimental measurements, but deviate significantly at the top of the riser. This disagreement is due to use of simplified geometry in the two-dimensional simulation. There is a good agreement between the experiment and the three-dimensional simulation for a high flux condition. This study concludes that the axial and radial gas and solids dispersion coefficients in risers operating in the turbulent flow regime can be computed using a multiphase computational fluid dynamics model.« less

Application of SP test to Evaluate Embrittlement of Dual Phase Stainless Steel Caused by Sigma Phase and Neutron Irradiation

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

Lee, J.S.; Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011; Kim, I.S.

2004-07-01

The degradation of mechanical properties in dual phase 309L stainless steel RPV clad caused by the presence of s-phase as well as neutron irradiation was investigated using a small punch (SP) test. Two kinds of overlay-weld clad were fabricated on SA508 cl.3 pressure vessel steel plates with ER309L welding consumable strip by differing in heat input rates. The microstructure of the clad was composed of a main part of fcc austenite, a few percent of bcc d- ferrite and brittle bct s-phase. Area fraction of s-phase was ranging approximately 2 {approx} 8 percent depending on welding conditions. The JMTR wasmore » utilized for neutron irradiation and SP specimens were irradiated up to 1.02 x 10{sup 19} n/cm{sup 2} (E>1 MeV) at 563 K. After irradiation the SP ductile-to-brittle transition behavior moved to higher temperatures, however, it was more strongly affected by the amount of brittle s-phase rather than the irradiation at current doses. The cracking appearances in the SP specimens gradually changed from circumferential to radial cracking as the test temperature became low, content of {sigma}-phase increased and the specimens were irradiated. Those results were accounted for in terms of the inconsistency of fracture stress between the phases as well as the effects of stress-strain portioning combined with the changes of governing stress components for crack initiation. (authors)« less

FRAUD/SABOTAGE Killing Nuclear-Reactors!!! ``Super"alloys GENERIC ENDEMIC Wigner's-Disease IN-stability!!!

NASA Astrophysics Data System (ADS)

Asphahani, Aziz; Siegel, Sidney; Siegel, Edward

2010-03-01

Siegel [[J.Mag.Mag.Mtls.7,312(78); PSS(a)11,45(72); Semis.& Insuls.5(79)] (at: ORNL, ANS, Westin``KL"ouse, PSEG, IAEA, ABB) warning of old/new nuclear-reactors/spent-fuel-casks/refineries/ jet/missile/rocket-engines austenitic/FCC Ni/Fe-based (so MIS- called)``super"alloys(182/82;Hastelloy-X; 600;304/304L-SSs; 690 !!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's- diseas(WD)[J.Appl.Phys.17,857(46)]; Ostwald-ripening; spinodal- decomposition; overageing-embrittlement; thermomechanical- INstability: Mayo[Google: ``If Leaks Could Kill"; at flickr.com search on ``Giant-Magnotoresistance"; find: [Siegel<<<``Fert"(88) 2007-Nobel/Wolf/Japan-prizes]necessitating NRC inspections on 40+25=65 Westin``KL"ouse PWRs(12/06)]; Lai[Met.Trans.AIME,9A,827 (78)]-Sabol-Stickler[PSS(70)]; Ashpahani[Intl.Conf. H in Metals (77)]; Russell[Prog. Mtls.Sci.(83)]; Pollard[last UCS rept. (9/95)]; Lofaro[BNL/DOE/NRC Repts.]; Pringle[Nuclear-Power:From Physics to Politics(79)]; Hoffman[animatedsoftware.com],...what DOE/NRC MISlabels as ``butt-welds" ``stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embrit- tlement caused brittle-fracture cracking from early/ongoing AEC/DOE-n``u''tional-la``v''atories sabotage!!!

FRAUD/SABOTAGE Killing Nuclear-Reactors Need Modeling!!!: "Super"alloys GENERIC ENDEMIC Wigner's-Disease/.../IN-stability: Ethics? SHMETHICS!!!

NASA Astrophysics Data System (ADS)

Asphahani, Aziz; Siegel, Sidney; Siegel, Edward

2010-03-01

Carbides solid-state chemistry domination of old/new nuclear- reactors/spent-fuel-casks/refineries/jet/missile/rocket-engines in austenitic/FCC Ni/Fe-based(so miscalled)``super"alloys(182/82; Hastelloy-X,600,304/304L-SSs,...,690!!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's-diseas(WD)[J.Appl.Phys.17,857 (1946)]/Ostwald-ripening/spinodal-decomposition/overageing- embrittlement/thermal-leading-to-mechanical(TLTM)-INstability: Mayo[Google:``If Leaks Could Kill"; at flickr.com search on ``Giant-Magnotoresistance"; find: Siegel[J.Mag.Mag.Mtls.7,312 (1978)]<<<``Fert"-"Gruenberg"(1988/89)2007-physics Nobel/Wolf/ Japan-prizes]necessitating NRC-inspections of 40+25 = 65 Westin- ``KLouse PWRs(12/2006)]-Lai[Met.Trans.AIME,9A,827(1978)]-Sabol- Stickler[Phys.Stat.Sol.(1970)]-Ashpahani[Intl.Conf. H in Metals, Paris(1977]-Russell[Prog.Mtls.Sci.(1983)]-Pollard[last UCS rept. (9/1995)]-Lofaro[BNL/DOE/NRC Repts.]-Pringle[Nuclear-Power:From Physics to Politics(1979)]-Hoffman[animatedsoftware.com], what DOE/NRC MISlabels as ``butt-welds" ``stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embritt- lement caused brittle-fracture cracking from early/ongoing AEC/ DOE-n"u"tional-la"v"atories sabotage!!!

FRAUD/SABOTAGE Killing Nuclear-Reactors Need Modeling!!!: ``Super'' alloys GENERIC ENDEMIC Wigner's-Disease/.../IN-stability: Ethics? SHMETHICS!!!

NASA Astrophysics Data System (ADS)

O'Grady, Joseph; Bument, Arlden; Siegel, Edward

2011-03-01

Carbides solid-state chemistry domination of old/new nuclear-reactors/spent-fuel-casks/refineries/jet/missile/rocket-engines is austenitic/FCC Ni/Fe-based (so miscalled)"super"alloys(182/82;Hastelloy-X,600,304/304L-SSs,...690!!!) GENERIC ENDEMIC EXTANT detrimental(synonyms): Wigner's-disease(WD) [J.Appl.Phys.17,857 (46)]/Ostwald-ripening/spinodal-decomposition/overageing-embrittlement/thermal-leading-to-mechanical(TLTM)-INstability: Mayo[Google: fLeaksCouldKill > ; - Siegel [ J . Mag . Mag . Mtls . 7 , 312 (78) = atflickr . comsearchonGiant - Magnotoresistance [Fert" [PRL(1988)]-"Gruenberg"[PRL(1989)] 2007-Nobel]necessitating NRC inspections on 40+25=65 Westin"KL"ouse PWRs(12/2006)]-Lai [Met.Trans.AIME, 9A,827(78)]-Sabol-Stickler[Phys.Stat.Sol.(70)]-Ashpahani[ Intl.Conf. Hydrogen in Metals, Paris(1977]-Russell [Prog.Mtls.Sci.(1983)]-Pollard [last UCS rept.(9/1995)]-Lofaro [BNL/DOE/NRC Repts.]-Pringle [ Nuclear-Power:From Physics to Politics(1979)]-Hoffman [animatedsoftware.com], what DOE/NRC MISlabels as "butt-welds" "stress-corrosion cracking" endpoint's ROOT-CAUSE ULTIMATE-ORIGIN is WD overageing-embrittlement caused brittle-fracture cracking from early/ongoing AEC/DOE-n"u"tional-la"v"atories sabotage!!!

Development of Millimeter-Wave Velocimetry and Acoustic Time-of-Flight Tomography for Measurements in Densely Loaded Gas-Solid Riser Flow

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

Fort, James A.; Pfund, David M.; Sheen, David M.

2007-04-01

The MFDRC was formed in 1998 to advance the state-of-the-art in simulating multiphase turbulent flows by developing advanced computational models for gas-solid flows that are experimentally validated over a wide range of industrially relevant conditions. The goal was to transfer the resulting validated models to interested US commercial CFD software vendors, who would then propagate the models as part of new code versions to their customers in the US chemical industry. Since the lack of detailed data sets at industrially relevant conditions is the major roadblock to developing and validating multiphase turbulence models, a significant component of the work involvedmore » flow measurements on an industrial-scale riser contributed by Westinghouse, which was subsequently installed at SNL. Model comparisons were performed against these datasets by LANL. A parallel Office of Industrial Technology (OIT) project within the consortium made similar comparisons between riser measurements and models at NETL. Measured flow quantities of interest included volume fraction, velocity, and velocity-fluctuation profiles for both gas and solid phases at various locations in the riser. Some additional techniques were required for these measurements beyond what was currently available. PNNL’s role on the project was to work with the SNL experimental team to develop and test two new measurement techniques, acoustic tomography and millimeter-wave velocimetry. Acoustic tomography is a promising technique for gas-solid flow measurements in risers and PNNL has substantial related experience in this area. PNNL is also active in developing millimeter wave imaging techniques, and this technology presents an additional approach to make desired measurements. PNNL supported the advanced diagnostics development part of this project by evaluating these techniques and then by adapting and developing the selected technology to bulk gas-solids flows and by implementing them for testing in the SNL riser testbed.« less

A novel circulating loop bioreactor with cells immobilized in loofa ( Luffa cylindrica) sponge for the bioconversion of raw cassava starch to ethanol.

PubMed

Roble, N D; Ogbonna, J C; Tanaka, H

2003-02-01

A circulating loop bioreactor (CLB) with cells immobilized in loofa sponge was constructed for simultaneous aerobic and anaerobic processes. The CLB consists of an aerated riser and a non-aerated downcomer column connected at the top and bottom by cylindrical pipes. Ethanol production from raw cassava starch was investigated in the CLB. Aspergillus awamori IAM 2389 and Saccharomyces cerevisiae IR2 immobilized on loofa sponge were placed, respectively, in the aerated riser column and non-aerated downcomer column. Both alpha-amylase and glucoamylase activities increased as the aeration rate was increased. Ethanol yield and productivity increased with an increase in the aeration rate up to 0.5 vvm, but decreased at higher aeration rates. The CLB was operated at an aeration rate of 0.5 vvm for more than 600 h, resulting in an average ethanol productivity and yield from raw cassava starch of 0.5 g-ethanol l(-1) x h(-1) and 0.45 g ethanol/g starch, respectively. In order to increase ethanol productivity, it was necessary to increase the dissolved oxygen (DO) concentration in the riser column and decrease the DO concentration in the downcomer column. However, increasing the aeration rate resulted in increases in the DO concentration in both the riser and the downcomer columns. At high aeration rate, there was no significant difference in the DO concentration in the riser and downcomer columns. The aeration rate was therefore uncoupled from the liquid circulation by attaching a time-controlled valve in the upper connecting pipe. By optimizing the time and frequency of valve opening, and operation at high aeration rate, it was possible to maintain a very high DO concentration in the riser column and a low DO concentration in the downcomer column. Under these conditions, ethanol productivity increased by more than 100%, to 1.17 g l(-1) x h(-1).

Plant Functional Traits on Green Risers and Brown Treads of Periglacial Patterned Ground at Glacier National Park, Montana

NASA Astrophysics Data System (ADS)

Apple, M. E.; Ricketts, M. K.

2016-12-01

On the stair-stepped solifluction terraces of the periglacial patterned ground at Glacier National Park, Montana, the clearly visible striped pattern of green alternating with brown is formed by contrasts in the percent cover of plants with different functional traits. The sloping green risers dominated by the mat-forming dwarf shrubs, Dryas octopetela (Mountain Dryad) and Salix arctica (Arctic Willow) alternate with the relatively flat, sparsely covered brown rocky treads which are inhabitated by herbaceous, and often taprooted plants. Eleven species were restricted to the brown treads, including the rare arctic-alpine species Papaver pygmaeum (Pygmy Poppy), Aqiulegia jonesii (Jones' Columbine), Draba macounii, and Erigeron lanatus. Of these, the first three arise from taproots or branched rootcrowns. They are restricted to the brown rocky treads while E. lanatus arises from a caudex and grows on the treads and risers. The relative abundance of rare plants was significantly higher on the brown treads and no rare species were restricted to the green risers. The community weighted trait means were significantly higher for Raunkiaer cryptophytes and hemicryptophytes, graminoid, herbaceous and rosetted forms, and stolons, Underground traits varied significantly as well, since taproots, caudices, and other substantial roots had higher incidences on the brown treads than on the green risers. The brown, rocky treads are relatively flat with low percent plant cover and likely a water-stressed environment, hence the substantial investment in underground structures. In contrast, the sloped green risers are essentially covered by the mat-forming dwarf shrubs, D. octopetela and S. arctica, which augment their woody roots with the anchorage of adventitious roots and which provide shade and water retention for other plants, including seedlings of Abies lasiocarpa (Subalpine fir) and Pinus albicaulus (Whitebark Pine). Water from summer thunderstorms and seasonal melting supplies the periglacial patterned ground, which is by definition close to Glacier National Park's vanishing snowfields and glaciers, so their loss will likely influence water availability for these alpine plants.

Cyclic stress effect on stress corrosion cracking of duplex stainless steel in chloride and caustic solutions

NASA Astrophysics Data System (ADS)

Yang, Di

Duplex stainless steel (DSS) is a dual-phase material with approximately equal volume amount of austenite and ferrite. It has both great mechanical properties (good ductility and high tensile/fatigue strength) and excellent corrosion resistance due to the mixture of the two phases. Cyclic loadings with high stress level and low frequency are experienced by many structures. However, the existing study on corrosion fatigue (CF) study of various metallic materials has mainly concentrated on relatively high frequency range. No systematic study has been done to understand the ultra-low frequency (˜10-5 Hz) cyclic loading effect on stress corrosion cracking (SCC) of DSSs. In this study, the ultra-low frequency cyclic loading effect on SCC of DSS 2205 was studied in acidified sodium chloride and caustic white liquor (WL) solutions. The research work focused on the environmental effect on SCC of DSS 2205, the cyclic stress effect on strain accumulation behavior of DSS 2205, and the combined environmental and cyclic stress effect on the stress corrosion crack initiation of DSS 2205 in the above environments. Potentiodynamic polarization tests were performed to investigate the electrochemical behavior of DSS 2205 in acidic NaCl solution. Series of slow strain rate tests (SSRTs) at different applied potential values were conducted to reveal the optimum applied potential value for SCC to happen. Room temperature static and cyclic creep tests were performed in air to illustrate the strain accumulation effect of cyclic stresses. Test results showed that cyclic loading could enhance strain accumulation in DSS 2205 compared to static loading. Moreover, the strain accumulation behavior of DSS 2205 was found to be controlled by the two phases of DSS 2205 with different crystal structures. The B.C.C. ferrite phase enhanced strain accumulation due to extensive cross-slips of the dislocations, whereas the F.C.C. austenite phase resisted strain accumulation due to cyclic strain hardening. Cyclic SSRTs were performed under the conditions that SCC occurs in sodium chloride and WL solutions. Test results show that cyclic stress facilitated crack initiations in DSS 2205. Stress corrosion cracks initiated from the intermetallic precipitates in acidic chloride environment, and the cracks initiated from austenite phase in WL environment. Cold-working has been found to retard the crack initiations induced by cyclic stresses.

Human Strength Capabilities for the Operation of Parachute Ripcords and Riser Releases

DTIC Science & Technology

1983-10-01

Parachutes Human Strength Ripcords Isometric Force Riser Releases Anthropometry 0 24 SITRACT (Con i, e on reveres. id. If neceay and Identify by block numb... Anthropometry . . . .. .. ... .. 41 DISCUSSIONS . . . . . . . . . . . . . 43 Other Studies . . . . . . . . . 44 CONCLUSIONS AND RECOMMENDATIONS...tendency to produce greater forces. Anthropometry . Results of the anthropometric measurements are given in Table 11, listing the means, standard

Secondary School Reform, Inclusion, and Authentic Assessment. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

ERIC Educational Resources Information Center

Braden, Jeffery P.; Schroeder, Jennifer L.; Buckley, Jacquelyn A.

The Research Institute on Secondary Education Reform for Youth with Disabilities (RISER) has identified Schools of Authentic and Inclusive Learning (SAIL) to explore whether and how secondary students with disabilities are included in secondary education reform. In this brief, the literature describing the intersection of reform, inclusion, and…

47 CFR 73.4091 - Direct broadcast satellites.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Report and Order, General Docket 80-603, FCC 82-285, adopted June 23, 1982. 90 FCC 2d 676; 47 FR 31555, July 21, 1982. (b) See Memorandum Opinion and Order, FCC 82-427, adopted September 23, 1982. 91 FCC 2d. (c) See Memorandum Opinion and Order, FCC 82-498, adopted November 4, 1982. 91 FCC 2d. [48 FR 9012...

47 CFR 73.4280 - Character evaluation of broadcast applicants.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Docket 78-108, FCC 85-648, adopted December 10, 1985. 102 FCC 2d 1179; 51 FR 3049, January 23, 1986. (b) See Policy Statement and Order, FCC 90-195, adopted May 10, 1990. 5 FCC Rcd 3252, 55 FR 23082, June 6, 1990. (c) See Memorandum Opinion and Order, FCC 91-146, adopted May 1, 1991. 6 FCC Rcd 3448, 56 FR...

Abnormal Circadian Blood Pressure Profile as a Prognostic Marker in Patients with Nonischemic Dilated Cardiomyopathy.

PubMed

Sawamura, Akinori; Okumura, Takahiro; Takeshita, Kyosuke; Watanabe, Naoki; Kano, Naoaki; Mori, Hiroaki; Fukaya, Kenji; Morimoto, Ryota; Hirashiki, Akihiro; Bando, Yasuko Kureishi; Murohara, Toyoaki

An abnormal circadian blood pressure (BP) profile is considered a risk factor for cardiovascular disease. However, its significance in heart failure patients with nonischemic etiology is unknown. Herein, we investigated the prognostic value of a circadian BP profile in patients with nonischemic dilated cardiomyopathy (NIDCM). We enrolled 114 NIDCM patients (76 males, mean age 53.1 years). The percent nighttime BP fall (%NBPF) was defined using ambulatory BP monitoring as a percent decrease in mean systolic BP in nighttime from daytime. All patients were divided into three groups: dipper (%NBPF ≥10), non-dipper (0 ≤ %NBPF < 10), and riser (%NBPF <0). Riser patients had the highest serum creatinine levels (dipper, 0.78 ± 0.20 mg/dl; non-dipper, 0.85 ± 0.21 mg/dl; riser, 0.99 ± 0.23 mg/dl; p = 0.006). In survival analysis, riser patients had the highest cumulative cardiac-related deaths (log-rank, p = 0.001), which was an independent predictor of cardiac-related deaths (hazard ratio, 12.6; 95% confidence interval, 1.76-253; p = 0.01). Multivariate analysis revealed that the norepinephrine level at 24-hour collected urine (24 h U-NE) and the serum creatinine level were independent determinants of %NBPF (adjusted R2 = 0.20; 24 h U-NE, p = 0.0001; serum creatinine, p = 0.04). The riser profile was associated with poor prognosis of NIDCM, which may reflect impaired sympathetic nervous system activity. Evaluating the circadian BP profile may be useful for risk stratification in NIDCM patients. © 2016 S. Karger AG, Basel.

75 FR 26091 - Safety Zone; Riser for DEEPWATER HORIZON at Mississippi Canyon 252 Outer Continental Shelf MODU...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... establishing a safety zone around the riser for the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU... Mexico in response to the sinking of the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), which.... 147.T08-849 to read as follows: Sec. 147.T08-849 DEEPWATER HORIZON Mobile Offshore Drilling Unit...

Parent Participation within Community Center or In-Home Outreach Delivery Models of the Early Risers Conduct Problems Prevention Program

ERIC Educational Resources Information Center

Bloomquist, Michael L; August, Gerald J.; Lee, Susanne S.; Piehler, Timothy F.; Jensen, Marcia

2012-01-01

A variety of predictors of parent participation in prevention programming have been identified in past research, but few studies have investigated how those predictors may vary by implementation context. Patterns of parent participation were examined in the Early Risers Conduct Problems Prevention Program using two family-focused service delivery…

Riser Pattern Is a Novel Predictor of Adverse Events in Heart Failure Patients With Preserved Ejection Fraction.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Hoshide, Satoshi; Kario, Kazuomi

2017-01-25

The cardiovascular prognosis of heart failure with preserved ejection fraction (HFpEF) has been shown to be similar to that of heart failure with reduced ejection fraction (HFrEF). It is unknown which factors predict cardiovascular outcome in HFpEF. We tested the hypothesis that the abnormal pattern of circadian blood pressure (BP) rhythm known as the riser BP pattern is associated with adverse outcomes in HFpEF.Methods and Results:We performed a prospective, observational cohort study of hospitalized HF patients who underwent ambulatory BP monitoring (ABPM). Five hundred and sixteen hospitalized HF patients (age, 69±13 years; male, n=321 [62%]; female, n=195 [38%]) were followed up for a median 20.9 months. The composite outcome consisting of all-cause mortality and cardiovascular events was observed in 220 patients. On Kaplan-Meier analysis, the riser BP pattern subgroup had a significantly higher incidence of the composite outcome than the other subgroups of HFpEF patients (HR, 3.01; 95% CI: 1.54-6.08, P<0.01), but not the HFrEF patients. The riser BP pattern was found to be a novel predictor of cardiovascular outcome in HFpEF patients.

Influence of cross-sectional ratio of down comer to riser on the efficiency of liquid circulation in loop air lift bubble column

NASA Astrophysics Data System (ADS)

Yamamoto, Tatsumi; Kawasaki, Hiroyuki; Mori, Hidetoshi

2017-11-01

Loop type bubble columns have good performance of liquid circulation and mass transfer by airlift effect, where the liquid circulation time is an important measurable characteristic parameter. This parameter is affected by the column construction, the aspect ratio of the column, the cross-sectional area ratio of down comer to riser (R), and the superficial gas velocity in the riser (UGR). In this work, the mean gas holdup and the liquid circulation time (TC) have been measured in four types of loop airlift type bubble column: concentric tube internal loop airlift type, rectangular internal loop airlift type, external loop airlift type, external loop airlift with separator. Air and tap water were used as gas and liquid phase, respectively. The results have demonstrated that the mean gas holdup in riser increases in proportion to UGR, and that it in downcomer changes according to the geometric parameters of each bubble column. TC has been found to conform to an empirical equation which depends on UGR and the length of draft tube or division plate in the region of 0.33 < R < 1.

47 CFR 1.1152 - Schedule of annual regulatory fees and filing locations for wireless radio services.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) (47 CFR, Part 90) (a) New, Renew/Mod (FCC 601 & 159) $40.00 FCC, P.O. Box 979097, St. Louis, MO 63197-9000. (b) New, Renew/Mod (Electronic Filing) (FCC 601 & 159) 40.00 FCC, P.O. Box 979097, St. Louis, MO 63197-9000. (c) Renewal Only (FCC 601 & 159) 40.00 FCC, P.O. Box 979097, St. Louis, MO 63197-9000. (d...

Status and availability of FCC hardware

NASA Technical Reports Server (NTRS)

Romriell, G. K.

1973-01-01

The source availability of FCC and/or FCC connectors was surveyed. The results for the following areas are presented: (1) cost of FCC versus standard round cable, (2) qualification status, (3) size of wire available in FCC, (4) availability of hermetic connectors for FCC, (5) conversion from flat cable to round cable and visa versa, (6) availability of shielded flat cable for RF usage, (7) termination techniques, and (8) repair techniques.

47 CFR 95.117 - Where to contact the FCC.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.117 Where to contact the FCC. Additional GMRS information...) FCC World Wide Web homepage: http://www.fcc.gov/wtb/prs. (c) In writing, to the FCC, Attention: GMRS...

Lights Will Guide You : Sample Preparation and Applications for Integrated Laser and Electron Microscopy

NASA Astrophysics Data System (ADS)

Karreman, M. A.

2013-03-01

Correlative microscopy is the combined use of two different forms of microscopy in the study of a specimen, allowing for the exploitation of the advantages of both imaging tools. The integrated Laser and Electron Microscope (iLEM), developed at Utrecht University, combines a fluorescence microscope (FM) and a transmission electron microscope (TEM) in a single set-up. The region of interest in the specimen is labeled or tagged with a fluorescent probe and can easily be identified within a large field of view with the FM. Next, this same area is retraced in the TEM and can be studied at high resolution. The iLEM demands samples that can be imaged with both FM and TEM. Biological specimen, typically composed of light elements, generate low image contrast in the TEM. Therefore, these samples are often ‘contrasted’ with heavy metal stains. FM, on the other hand, images fluorescent samples. Sample preparation for correlative microscopy, and iLEM in particular, is complicated by the fact that the heavy metals stains employed for TEM quench the fluorescent signal of the probe that is imaged with FM. The first part of this thesis outlines preparation procedures for biological material yielding specimen that can be imaged with the iLEM. Here, approaches for the contrasting of thin sections of cells and tissue are introduced that do not affect the fluorescence signal of the probe that marks the region of interest. Furthermore, two novel procedures, VIS2FIXH and VIS2FIX­FS are described that allow for the chemical fixation of thin sections of cryo-immobilized material. These procedures greatly expedite the sample preparation process, and open up novel possibilities for the immuno-labeling of difficult antigens, eg. proteins and lipids that are challenging to preserve. The second part of this thesis describes applications of iLEM in research in the field of life and material science. The iLEM was employed in the study of UVC induced apoptosis (programmed cell death) of human umbilical vein endothelial cells. A novel, RNA containing body was identified in the nuclei of cells going through the various stages of the apoptotic process. Furthermore, we demonstrated the potential of iLEM in the study of Facio Scapulo Humeral Dystrophy (FSHD), the third most common form of inherited muscular dystrophy. In this study, diseased cells are identified based on the immuno-labeling of proteins associated with FSHD pathology. In the field of heterogeneous catalysis, a structural and functional characterization of Fluid Catalytic Cracking (FCC) particles was performed with iLEM. FCC particles are employed in petrochemical industry, where they catalyze the breakdown of large molecules in crude oil fractions into functional products with lower molecular weight, like gasoline. The catalytic sites in the FCC particles were selectively stained with a fluorescent probe, and next their structure was investigated with TEM. The iLEM allowed for the identification and characterization of catalytically active areas in the FCC particles. Furthermore, a unique study of the deactivation processes taking place in an industrial FCC unit was performed by analyzing a sample derived from a FCC reactor

47 CFR 73.3617 - Information available on the Internet.

Code of Federal Regulations, 2013 CFR

2013-10-01

....fcc.gov/mb/; the Audio Division's address is http://www.fcc.gov/mmb/audio; the Video Division's address is http://www.fcc.gov/mb/video; the Policy Division's address is http://www.fcc.gov/mb/policy; the Engineering Division's address is http://www.fcc.gov/mb/engineering; and the Industry Analysis Division's...

47 CFR 73.3617 - Information available on the Internet.

Code of Federal Regulations, 2012 CFR

2012-10-01

....fcc.gov/mb/; the Audio Division's address is http://www.fcc.gov/mmb/audio; the Video Division's address is http://www.fcc.gov/mb/video; the Policy Division's address is http://www.fcc.gov/mb/policy; the Engineering Division's address is http://www.fcc.gov/mb/engineering; and the Industry Analysis Division's...

47 CFR 73.3617 - Information available on the Internet.

Code of Federal Regulations, 2014 CFR

2014-10-01

....fcc.gov/mb/; the Audio Division's address is http://www.fcc.gov/mmb/audio; the Video Division's address is http://www.fcc.gov/mb/video; the Policy Division's address is http://www.fcc.gov/mb/policy; the Engineering Division's address is http://www.fcc.gov/mb/engineering; and the Industry Analysis Division's...

Maintenance Effects of an Evidence-Based Prevention Innovation for Aggressive Children Living in Culturally Diverse Urban Neighborhoods: The Early Risers Effectiveness Study

ERIC Educational Resources Information Center

August, Gerald J.; Lee, Susanne S.; Bloomquist, Michael L.; Realmuto, George M.; Hektner, Joel M.

2004-01-01

The present study assessed the ability of the Early Risers' Skills for Success Program to maintain program effects 1 year post intervention. Participants were 327 kindergarten and first-grade children who screened positive for aggressive behavior and who were randomized to program and control conditions. Program children participated in 2…

The Relationship of an Ecological Model of Career Development to Authentic Learning. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

ERIC Educational Resources Information Center

Collet-Klingenberg, Lana L.; Hanley-Maxwell, Cheryl; Stuart, Shannon

This brief discusses how the Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities model, Schools of Authentic Inclusive Learning (SAIL), and career development constructs and processes intersect. The brief provides an overview of SAIL, of authentic and inclusive learning, and of career development theory, while…

Towards a census of high-redshift dusty galaxies with Herschel. A selection of "500 μm-risers"

NASA Astrophysics Data System (ADS)

Donevski, D.; Buat, V.; Boone, F.; Pappalardo, C.; Bethermin, M.; Schreiber, C.; Mazyed, F.; Alvarez-Marquez, J.; Duivenvoorden, S.

2018-06-01

Context. Over the last decade a large number of dusty star-forming galaxies has been discovered up to redshift z = 2 - 3 and recent studies have attempted to push the highly confused Herschel SPIRE surveys beyond that distance. To search for z ≥ 4 galaxies they often consider the sources with fluxes rising from 250 μm to 500 μm (so-called "500 μm-risers"). Herschel surveys offer a unique opportunity to efficiently select a large number of these rare objects, and thus gain insight into the prodigious star-forming activity that takes place in the very distant Universe. Aims: We aim to implement a novel method to obtain a statistical sample of 500 μm-risers and fully evaluate our selection inspecting different models of galaxy evolution. Methods: We consider one of the largest and deepest Herschel surveys, the Herschel Virgo Cluster Survey. We develop a novel selection algorithm which links the source extraction and spectral energy distribution fitting. To fully quantify selection biases we make end-to-end simulations including clustering and lensing. Results: We select 133 500 μm-risers over 55 deg2, imposing the criteria: S500 > S350 > S250, S250 > 13.2 mJy and S500 > 30 mJy. Differential number counts are in fairly good agreement with models, displaying a better match than other existing samples. The estimated fraction of strongly lensed sources is 24+6-5% based on models. Conclusions: We present the faintest sample of 500 μm-risers down to S250 = 13.2 mJy. We show that noise and strong lensing have an important impact on measured counts and redshift distribution of selected sources. We estimate the flux-corrected star formation rate density at 4 < z < 5 with the 500 μm-risers and find it to be close to the total value measured in far-infrared. This indicates that colour selection is not a limiting effect to search for the most massive, dusty z > 4 sources.

Obseration of flow regime transition in CFB riser using an LDV

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

Yue, Paul C.; Mei, Joseph S.; Shadle, Lawrence J.

2011-01-01

The solids flow in a circulating fluidized bed (CFB) riser is often described to have a core-annular structure. For a given superficial gas velocity, at the initial introduction of solids into a riser a flow structure of dilute upflow regime exists. Continuing to increase the solids flow in the riser transitions the flow structure to the core-annular flow regime. However, with further increase of solids flow a condition is reached, depending on the superficial gas velocity, where all the solids across the riser cross section flow upwards, even those at the wall. When the solids flux, solids fraction and gasmore » velocity are relatively high, such a condition is described as the dense phase suspense upflow (DSU) regime. In this paper we report our observations of these flow regime transitions by using a laser Doppler velocimeter (LDV) to monitor the upward and downward particle flow velocities at and near the riser wall of the National Energy Technology Laboratory’s 30.4 centimeters diameter CFB cold flow model. The particles were high density polyethylene (PPE) spheres with a Sauter mean diameter of 861 micron and a density of 800 kg/m3. Three superficial gas velocities of 6.55 m/s, 10.67 m/s and 13.72 m/s were used in this study. For the case of superficial gas velocity 6.55 m/s, the experimental data show that the transition from dilute upflow to core-annular flow occurred when the solids flux was about 7 kg/m{sup 2}-s and the transition from core-annular flow to dense suspension upflow was about 147 kg/m{sup 2}-s. As the superficial gas velocity was increased to 10.67 m/s the corresponding flow regime transitions were at 34 kg/m{sup 2}-s and 205 kg/m{sup 2}-s, respectively. For the case of superficial gas velocity of 13.72 m/s the data showed no distinct transition of flow regimes. The particles were all upflow for the range of solids fluxes from 10 kg/m{sup 2}-s to 286 kg/m{sup 2}-s.« less

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

Vaidheeswaran, Avinash; Shaffer, Franklin; Gopalan, Balaji

Here, the statistics of fluctuating velocity components are studied in the riser of a closed-loop circulating fluidized bed with fluid catalytic cracking catalyst particles. Our analysis shows distinct similarities as well as deviations compared to existing theories and bench-scale experiments. The study confirms anisotropic and non-Maxwellian distribution of fluctuating velocity components. The velocity distribution functions (VDFs) corresponding to transverse fluctuations exhibit symmetry, and follow a stretched-exponential behavior up to three standard deviations. The form of the transverse VDF is largely determined by interparticle interactions. The tails become more overpopulated with an increase in particle loading. The observed deviations from themore » Gaussian distribution are represented using the leading order term in the Sonine expansion, which is commonly used to approximate the VDFs in kinetic theory for granular flows. The vertical fluctuating VDFs are asymmetric and the skewness shifts as the wall is approached. In comparison to transverse fluctuations, the vertical VDF is determined by the local hydrodynamics. This is an observation of particle velocity fluctuations in a large-scale system and their quantitative comparison with the Maxwell-Boltzmann statistics.« less

47 CFR 0.441 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... information and general inquiries may be submitted by: (1) Internet at http://www.fcc.gov/cgb/fccinfo or http://www.fcc.gov/foia. (2) Telephone at 1-888-CALL-FCC (1-888-225-5322). (3) TDD/TDY at 1-888-TELL-FCC (1... in resolving any concerns related to a Freedom of Information Act request. See http://www.fcc.gov...

47 CFR 0.441 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... information and general inquiries may be submitted by: (1) Internet at http://www.fcc.gov/cgb/fccinfo or http://www.fcc.gov/foia. (2) Telephone at 1-888-CALL-FCC (1-888-225-5322). (3) TDD/TDY at 1-888-TELL-FCC (1... in resolving any concerns related to a Freedom of Information Act request. See http://www.fcc.gov...

47 CFR 0.441 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... information and general inquiries may be submitted by: (1) Internet at http://www.fcc.gov/cgb/fccinfo or http://www.fcc.gov/foia. (2) Telephone at 1-888-CALL-FCC (1-888-225-5322). (3) TDD/TDY at 1-888-TELL-FCC (1... in resolving any concerns related to a Freedom of Information Act request. See http://www.fcc.gov...

[Study of shear rate in modified airlift nitrifying bioreactor].

PubMed

Jin, Ren-cun; Zheng, Ping

2006-06-01

The characteristics of shear rate in an airlift nitrifying bioreactor and its influencing factors were studied. The results showed that the shear rate was different in different sections of the bioreactor. With inlet gas flowrate at 430 approximately 2700 L x h(-1), the overall shear rate was (0.702 approximately 3.13) x 10(5) s(-1), shear rate in riser was (1.07 approximately 31.3) x 10(5) s(-1) and in gas-liquid separator was (1.12 approximately 25.0) x 10(5) s(-1), respectively. It indicates that the highest shear rates prevailed in the riser part of bioreactor. The operational variables and the bioreactor configurations exerted a significant influence on the shear level of the bioreactor. When inlet gas flowrate was raised from 1300 to 2700 L x h(-1), shear rate in riser and separator ascended first and then descended subsequently. The diameter of draft tube (d) was negatively correlated with shear rate. When the draft tube with diameter of 5.5 cm was installed, the shear rates in riser, separator and overall shear rate were 85.5%, 82.3% and 80.6%, respectively less as compared with that with diameter of 4.0 cm. The number of static mixers (N) was positively correlated with the shear rate. When d was set at 4.0 cm, with N of 10 and 39, the shear rates in riser were 6.14 and 7.97 times higher respectively, than that of conventional bioreactor. The ratio of maximum local shear rate to overall shear rate was 3.68 approximately 7.66, and the homogeneity of the shear field in airlift bioreactors could be improved if d and N were set at 5.5 cm and 10 approximately 13, respectively.

Analysis of the acceleration region in a circulating fluidized bed riser operating above fast fluidization velocities

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

Monazam, E.R.; Shadle, L.J.

2008-11-05

In commercial circulating fluidized bed (CFB) processes the acceleration zone greatly contributes to solids mixing, gas and solids dispersion, and particle residence times. A new analysis was developed to describe the relative gas-solids concentration in the acceleration region of a transport system with air as the fluidizing agent for Geldart-type B particles. A theoretical expression was derived from a drag relationship and momentum and continuity equations to describe the evolution of the gas-solids profile along the axial direction. The acceleration zone was characterized using nondimensional analysis of the continuum equations (balances of masses and momenta) that described multiphase flows. Inmore » addition to acceleration length, the boundary condition for the solids fraction at the bottom of the riser and the fully developed regions were measured using an industrial scale CFB of 0.3 m diameter and 15 m tall. The operating factors affecting the flow development in the acceleration region were determined for three materials of various sizes and densities in core annular and dilute regimes of the riser. Performance data were taken from statistically designed experiments over a wide range of Fr (0.5-39), Re (8-600), Ar (29-3600), load ratio (0.2-28), riser to particle diameter ratio (375-5000), and gas to solids density ratio (138-1381). In this one-dimensional system of equations, velocities and solid fractions were assumed to be constant over any cross section. The model and engineering correlations were compared with literature expressions to assess their validity and range of applicability. These expressions can be used as tools for simulation and design of a CFB riser and can also be easily coupled to a kinetics model for process simulation.« less

Short sleep duration as an independent predictor of cardiovascular events in Japanese patients with hypertension.

PubMed

Eguchi, Kazuo; Pickering, Thomas G; Schwartz, Joseph E; Hoshide, Satoshi; Ishikawa, Joji; Ishikawa, Shizukiyo; Shimada, Kazuyuki; Kario, Kazuomi

2008-11-10

It is not known whether short duration of sleep is a predictor of future cardiovascular events in patients with hypertension. To test the hypothesis that short duration of sleep is independently associated with incident cardiovascular diseases (CVD), we performed ambulatory blood pressure (BP) monitoring in 1255 subjects with hypertension (mean [SD] age, 70.4 [9.9] years) and followed them for a mean period of 50 (23) months. Short sleep duration was defined as less than 7.5 hours (20th percentile). Multivariable Cox hazard models predicting CVD events were used to estimate the adjusted hazard ratio and 95% confidence interval (CI) for short sleep duration. A riser pattern was defined when mean nighttime systolic BP exceeded daytime systolic BP. The end point was a cardiovascular event: stroke, fatal or nonfatal myocardial infarction (MI), and sudden cardiac death. In multivariable analyses, short duration of sleep (<7.5 hours) was associated with incident CVD (hazard ratio [HR], 1.68; 95% CI, 1.06-2.66; P = .03). A synergistic interaction was observed between short sleep duration and the riser pattern (P = .09). When subjects were classified according to their sleep time and a riser vs nonriser pattern, the group with shorter sleep duration plus the riser pattern had a substantially and significantly higher incidence of CVD than the group with predominant normal sleep duration plus the nonriser pattern (HR, 4.43; 95% CI, 2.09-9.39; P < .001), independent of covariates. Short duration of sleep is associated with incident CVD risk and the combination of the riser pattern and short duration of sleep that is most strongly predictive of future CVD, independent of ambulatory BP levels. Physicians should inquire about sleep duration in the risk assessment of patients with hypertension.

Proximal tibial fracture following anterior cruciate ligament reconstruction surgery: a biomechanical analysis of the tibial tunnel as a stress riser.

PubMed

Aldebeyan, Wassim; Liddell, Antony; Steffen, Thomas; Beckman, Lorne; Martineau, Paul A

2017-08-01

This is the first biomechanical study to examine the potential stress riser effect of the tibial tunnel or tunnels after ACL reconstruction surgery. In keeping with literature, the primary hypothesis tested in this study was that the tibial tunnel acts as a stress riser for fracture propagation. Secondary hypotheses were that the stress riser effect increases with the size of the tunnel (8 vs. 10 mm), the orientation of the tunnel [standard (STT) vs. modified transtibial (MTT)], and with the number of tunnels (1 vs. 2). Tibial tunnels simulating both single bundle hamstring graft (8 mm) and bone-patellar tendon-bone graft (10 mm) either STT or MTT position, as well as tunnels simulating double bundle (DB) ACL reconstruction (7, 6 mm), were drilled in fourth-generation saw bones. These five experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure on a Materials Testing System to simulate tibial plateau fracture. There were no statistically significant differences in peak load to failure between any of the groups, including the control group. The fracture occurred through the tibial tunnel in 100 % of the MTT tunnels (8 and 10 mm) and 80 % of the DB tunnels specimens; however, the fractures never (0 %) occurred through the tibial tunnel of the standard tunnels (8 or 10 mm) (P = 0.032). In the biomechanical model, the tibial tunnel does not appear to be a stress riser for fracture propagation, despite suggestions to the contrary in the literature. Use of a standard, more vertical tunnel decreases the risk of ACL graft compromise in the event of a fracture. This may help to inform surgical decision making on ACL reconstruction technique.

78 FR 66357 - Proposed Changes to FCC Form 499-A, FCC Form 499-Q, and Accompanying Instructions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-05

... 499-A, FCC Form 499-Q, and Accompanying Instructions AGENCY: Federal Communications Commission. ACTION..., FCC Form 499-Q (Form 499-Q) and accompanying instructions (Form 499-Q Instructions) to be used in 2014... Worksheet, FCC Form 499-Q (Form 499-Q) and accompanying instructions (Form 499-Q Instructions) to be used in...

Medical Student Self-Efficacy with Family-Centered Care during Bedside Rounds

PubMed Central

Young, Henry N.; Schumacher, Jayna B.; Moreno, Megan A.; Brown, Roger L.; Sigrest, Ted D.; McIntosh, Gwen K.; Schumacher, Daniel J.; Kelly, Michelle M.; Cox, Elizabeth D.

2012-01-01

Purpose Factors that support self-efficacy must be understood in order to foster family-centered care (FCC) during rounds. Based on social cognitive theory, this study examined (1) how 3 supportive experiences (observing role models, having mastery experiences, and receiving feedback) influence self-efficacy with FCC during rounds and (2) whether the influence of these supportive experiences was mediated by self-efficacy with 3 key FCC tasks (relationship building, exchanging information, and decision making). Method Researchers surveyed 184 students during pediatric clerkship rotations during the 2008–2011 academic years. Surveys assessed supportive experiences and students’ self-efficacy with FCC during rounds and with key FCC tasks. Measurement models were constructed via exploratory and confirmatory factor analyses. Composite indicator structural equation (CISE) models evaluated whether supportive experiences influenced self-efficacy with FCC during rounds and whether self-efficacy with key FCC tasks mediated any such influences. Results Researchers obtained surveys from 172 eligible students who were 76% (130) White and 53% (91) female. Observing role models and having mastery experiences supported self-efficacy with FCC during rounds (each p<0.01), while receiving feedback did not. Self-efficacy with two specific FCC tasks, relationship building and decision making (each p < 0.05), mediated the effects of these two supportive experiences on self-efficacy with FCC during rounds. Conclusions Observing role models and having mastery experiences foster students’ self-efficacy with FCC during rounds, operating through self-efficacy with key FCC tasks. Results suggest the importance of helping students gain self-efficacy in key FCC tasks before the rounds experience and helping educators implement supportive experiences during rounds. PMID:22534602

Characteristics of air-water upward intermittent flows with surfactant additive in a pipeline-riser system

NASA Astrophysics Data System (ADS)

Gao, Meng-chen; Xu, Jing-yu

2018-04-01

The effect of the surfactant additive on the upward intermittent flows in a pipeline-riser system is studied experimentally, in a 3 m long horizontal pipe connected to a Perspex pipe of 2.0 m long and 25 mm in diameter, inclined to the horizontal plane by 7°, followed by the vertical PVC riser of 3.5 m high and 25 mm in diameter, operating at the atmospheric end pressure. Based on the analysis of the pressure signal and the visual observation of the riser, it is shown that the additive of surfactant to the carrying liquid makes bubbles smaller in size but much larger in number in the upward intermittent flows. In addition, the additive of surfactant to a two-phase flow does not have a significant impact on the in-situ gas fraction, the pressure drop and the frequency of the liquid slug, but it reduces significantly the velocity of the liquid slug. When the superficial liquid velocity is set, an exponential relationship between the dimensionless velocity of the liquid slug and the Webber number can be obtained. These results might be used for estimating the characteristic parameters of the upward intermittent flow based upon the input operating conditions.

Investigation of gas-solids flow in a circulating fluidized bed using 3D electrical capacitance tomography

NASA Astrophysics Data System (ADS)

Mao, Mingxu; Ye, Jiamin; Wang, Haigang; Yang, Wuqiang

2016-09-01

The hydrodynamics of gas-solids flow in the bottom of a circulating fluidized bed (CFB) are complicated. Three-dimensional (3D) electrical capacitance tomography (ECT) has been used to investigate the hydrodynamics in risers of different shapes. Four different ECT sensors with 12 electrodes each are designed according to the dimension of risers, including two circular ECT sensors, a square ECT sensor and a rectangular ECT sensor. The electrodes are evenly arranged in three planes to obtain capacitance in different heights and to reconstruct the 3D images by linear back projection (LBP) algorithm. Experiments were carried out on the four risers using sands as the solids material. The capacitance and differential pressure are measured under the gas superficial velocity from 0.6 m s-1 to 3.0 m s-1 with a step of 0.2 m s-1. The flow regime is investigated according to the solids concentration and differential pressure. The dynamic property of bubbling flows is analyzed theoretically and the performance of the 3D ECT sensors is evaluated. The experimental results show that 3D ECT can be used in the CFB with different risers to predict the hydrodynamics of gas-solids bubbling flows.

78 FR 1860 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... request for comments. SUMMARY: The Federal Communications Commission (FCC), as part of its continuing... than 25 employees. The FCC may not conduct or sponsor a collection of information unless it displays a....gov ; and to Cathy Williams, FCC, via email [email protected]fcc.gov and to [email protected]fcc.gov . Include in the...

Microstructural studies of hydrogen damage in metastable stainless steels. Ph.D. Thesis

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

Chen, S.

1994-12-31

The primary objective of this dissertation is to determine the role of microstructure in hydrogen-induced damage in austenitic stainless steels. Specific attention was focused on the interactions between hydrogen and the austenitic grain, twin boundaries and the matrix, and the associated phase transformations. An experimental program of research was conducted to determine the phase transformation and cracking path in hydrogen charged stainless steels. Normal-purity AISI 304 (Fe18CrYNi) and high-purity 305 (Fe18Cr12Ni) solution-annealet stainless steels were examined. The steels were cathodically charged with hydrogen at 1, 10 and 100 mA/sq cm at room temperature for 5 min. to 32 hours, inmore » an 1N H2SO4 solution with 0.25 g/l of NaAsO2 added as a hydrogen recombination poison. Resultant changes in microstructure and hydrogen damage due to charging and subsequent room temperature aging were studied by x-ray diffraction, optical microscope (in the Nomarski mode), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A new phase in 305 stainless steel was observed, and was identified as an epsilon(*) (hcp) hydride due to hydrogen charging. Two new phases in 304 stainless steel were found as gamma(*) (fcc) and epsilon(*) hydrides from hydrogen charging. The hydride formation mechanisms during charging were: (1) gamma yields gamma(*) hydride and (2) gamma yields epsilon yields epsilon(*) hydride. These hydrides are unstable and decomposed during room temperature aging in air. The decomposition mechanisms were: (1) epsilon(*) hydride (hcp) yields expanded epsilon (hcp) phase yields a (bcc) phase; (2) gamma(*) hydride yields gamma phase. The grain and twin boundary cracks were the results of charging and identified as the preferred cracking sites. Transgranular crack initiation and growth accompanied the decomposition of hydrides and were controlled by hydrogen outgassing during room temperature aging.« less

47 CFR 95.219 - (R/C Rule 19) How do I answer correspondence from the FCC?

Code of Federal Regulations, 2010 CFR

2010-10-01

... You Need to Know § 95.219 (R/C Rule 19) How do I answer correspondence from the FCC? (a) If it appears to the FCC that you have violated the Communications Act or FCC rules, the FCC may send you a... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 19) How do I answer correspondence...

Life after High School: Which Postschool Outcomes Matter for Students with and without Disabilities in Restructured High Schools? Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

ERIC Educational Resources Information Center

Mooney, Marianne; Phelps, L. Allen

The Research Institute on Secondary Education Reform for Youth with Disabilities (RISER) has been studying three significantly restructured high schools that have included students with disabilities and their parents in the design and/or implementation of school reform efforts. Each of these schools has operated for 3-12 years with its new,…

Promoting stair use: single versus multiple stair-riser messages.

PubMed

Webb, Oliver J; Eves, Frank F

2005-09-01

Message banners attached to stair risers produced a significant increase in pedestrian stair use, exceeding effects previously reported for conventional posters. Multiple instances of the same message banner, however, were as effective as banners featuring different messages. Therefore, greater visibility, rather than message variety, appears to account for the superiority of the banner format. Our findings indicate the feasibility of simple stair-use promotion campaigns based around the repetition of a single message.

Hydrodynamic optimization of membrane bioreactor by horizontal geometry modification using computational fluid dynamics.

PubMed

Yan, Xiaoxu; Wu, Qing; Sun, Jianyu; Liang, Peng; Zhang, Xiaoyuan; Xiao, Kang; Huang, Xia

2016-01-01

Geometry property would affect the hydrodynamics of membrane bioreactor (MBR), which was directly related to membrane fouling rate. The simulation of a bench-scale MBR by computational fluid dynamics (CFD) showed that the shear stress on membrane surface could be elevated by 74% if the membrane was sandwiched between two baffles (baffled MBR), compared with that without baffles (unbaffled MBR). The effects of horizontal geometry characteristics of a bench-scale membrane tank were discussed (riser length index Lr, downcomer length index Ld, tank width index Wt). Simulation results indicated that the average cross flow of the riser was negatively correlated to the ratio of riser and downcomer cross-sectional area. A relatively small tank width would also be preferable in promoting shear stress on membrane surface. The optimized MBR had a shear elevation of 21.3-91.4% compared with unbaffled MBR under same aeration intensity. Copyright © 2015 Elsevier Ltd. All rights reserved.

47 CFR 73.4060 - Citizens agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., Docket 20495, FCC 75-1359, adopted December 10, 1975. 57 F.C.C. 2d 42; 40 F.R. 49730, December 30, 1975. (b) See Memorandum Opinion and Order, FCC 78-875, adopted December 21, 1978. 70 F.C.C. 2d 1672. [44...

Estimating the Size and Timing of Maximum Amplitude for Cycle 23 from Its Early Cycle Behavior

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.; Reichmann, Edwin J.

1998-01-01

On the basis of the lowest observed smoothed monthly mean sunspot number, cycle 23 appears to have conventionally begun in May 1996, in conjunction with the first appearance of a new cycle, high-latitude spot-group. Such behavior, however, is considered rather unusual, since, previously (based upon the data- available cycles 12-22), the first appearance of a new cycle, high-latitude spot- group has always preceded conventional onset by at least 3 months. Furthermore, accepting May 1996 as the official start for cycle 23 poses a dilemma regarding its projected size and timing of maximum amplitude. Specifically, from the max-min and amplitude-period relationships we infer that cycle 23 should be above average in size and a fast riser, with maximum amplitude occurring before May 2000 (being in agreement with projections for cycle 23 based on precursor information), yet from its initial languid rate of rise (during the first 6 months of the cycle) we infer that it should be below average in size and a slow riser, with maximum amplitude occurring after May 2000. The dilemma vanishes, however, when we use a slightly later-occurring onset. For example, using August 1996, a date associated with a local secondary minimum prior to the rapid rise that began shortly thereafter (in early 1997), we infer that cycle 23's rate of rise is above that for the mean of cycles 1-22, the mean of cycles 10-22 (the modern era cycles), the mean of the modern era'fast risers,' and the largest of the modern era 'slow risers' (i.e., cycle 20), thereby, suggesting that cycle 23 will be both fast-rising and above average in size, peaking before August 2000. Additionally, presuming cycle 23 to be a well- behaved fast-rising cycle (regardless of whichever onset date is used), we also infer that its maximum amplitude likely will measure about 144.0 q+/- 28.8 (from the general behavior found for the bulk of modern era fast risers; i.e., 5 of 7 have had their maximum amplitude to lie within 20% of the mean curve for modern era fast risers). It is apparent, then, that sunspot number growth during 1998 will prove crucial for correctly establishing the size and shape of cycle 23.

47 CFR 73.1670 - Auxiliary transmitters.

Code of Federal Regulations, 2010 CFR

2010-10-01

... broadcast station may, without further authority from the FCC, install and use with the main antenna system... or auxiliary antenna. (6) For testing, upon the request of representatives of the FCC. (b... auxiliary antenna must be obtained by filing an application for a construction permit on FCC form 301 (FCC...

47 CFR 18.211 - Multiple listing of equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... same or essentially the same equipment will be marketed under more than one FCC Identifier, equipment authorization must be requested on an FCC Form 731 for each FCC Identifier. (b) If equipment authorization for additional FCC Identifiers is requested in the initial application, a statement shall be included describing...

75 FR 77781 - Amendment of the Commission's Rules Governing Hearing Aid-Compatible Mobile Handsets...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-14

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 20 [FCC 10-145; WT Docket No. 07-250] Amendment [email protected]fcc.gov . SUPPLEMENTARY INFORMATION: The Federal Communications Commission (FCC) has received...). Form No.: FCC Form 655--electronic only. Estimated Annual Burden: 925 respondents; 925 responses; 12...

78 FR 69415 - Proposed Changes to FCC Form 499-A, FCC Form 499-Q, and Accompanying Instructions.

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-19

... FEDERAL COMMUNICATIONS COMMISSION [WC Docket No. 06-122; DA 13-2090] Proposed Changes to FCC Form 499-A, FCC Form 499-Q, and Accompanying Instructions. AGENCY: Federal Communications Commission. ACTION: Notice; correction. SUMMARY: The Federal Communications Commission published a document in the...

The FCC in Fiscal 1971.

ERIC Educational Resources Information Center

Federal Communications Commission, Washington, DC.

Fiscal 1971 saw major actions by the Federal Communications Commission (FCC) in all areas of its jurisdiction. In broadcasting, the FCC proposed new renewal rules and policies and issued a number of significant rulings on Fairness Doctrine matters. A policy statement outlining FCC cable television plans was submitted to the Congress. In the common…

78 FR 63196 - Privacy Act System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Technology Center (ITC) staff and contractors, who maintain the FCC's computer network. Other FCC employees... and Offices (B/ Os); 2. Electronic data, records, and files that are stored in the FCC's computer.... Access to the FACA electronic records, files, and data, which are housed in the FCC's computer network...

Helical wire stress analysis of unbonded flexible riser under irregular response

NASA Astrophysics Data System (ADS)

Wang, Kunpeng; Ji, Chunyan

2017-06-01

A helical wire is a critical component of an unbonded flexible riser prone to fatigue failure. The helical wire has been the focus of much research work in recent years because of the complex multilayer construction of the flexible riser. The present study establishes an analytical model for the axisymmetric and bending analyses of an unbonded flexible riser. The interlayer contact under axisymmetric loads in this model is modeled by setting radial dummy springs between adjacent layers. The contact pressure is constant during the bending response and applied to determine the slipping friction force per unit helical wire. The model tracks the axial stress around the angular position at each time step to calculate the axial force gradient, then compares the axial force gradient with the slipping friction force to judge the helical wire slipping region, which would be applied to determine the bending stiffness for the next time step. The proposed model is verified against the experimental data in the literature. The bending moment-curvature relationship under irregular response is also qualitatively discussed. The stress at the critical point of the helical wire is investigated based on the model by considering the local flexure. The results indicate that the present model can well simulate the bending stiffness variation during irregular response, which has significant effect on the stress of helical wire.

Packaged FBG sensors for real-time stress monitoring on deep-water riser

NASA Astrophysics Data System (ADS)

Xu, Jian; Yang, Dexing; Jiang, Yajun; Wang, Meirong; Zhai, Huailun; Bai, Yang

2014-11-01

The safety of under-water risers in drilling platform is of great significance. A packaged fiber Bragg grating (FBG) sensor for real-time stress monitoring is designed for the applications on oil drilling risers under 3000 meters deep water. A copper tube which is the main component of the sensor has a small hole along its axes and a groove at its each end. The bare FBG is passed through the small hole and fixed to its ends by epoxy resin. Then the copper tube is packaged by filling the groove with structural adhesive. In order to avoid that the outer water-pressure is applied on the epoxy resin through the structural adhesive, a gap between the two types of glues is left. The relationships between the stress of the riser and the tension, pressure, temperature of the single sensor are discussed, respectively. The measured tension sensitivity is 136.75 pm/KN while the minimum R-square value is 0.99997. The experimental results also show that there is a good linear response between water-pressure and the Bragg wavelength from 0 to 30MPa, and the sensor can even survive under the pressure more than 30MPa. In addition, the Bragg wavelength shifts linearly with the increasing temperature from 0 to 40°C. So, the pressure and temperature can be easily compensated if another sensor without tension is used.

Drilling Fluid Contamination during Riser Drilling Quantified by Chemical and Molecular Tracers

NASA Astrophysics Data System (ADS)

Inagaki, F.; Lever, M. A.; Morono, Y.; Hoshino, T.

2012-12-01

Stringent contamination controls are essential to any type of microbiological investigation, and are particularly challenging in ocean drilling, where samples are retrieved from hundreds of meters below the seafloor. In summer 2012, Integrated Ocean Drilling Expedition 337 aboard the Japanese vessel Chikyu pioneered the use of chemical tracers in riser drilling while exploring the microbial ecosystem of coalbeds 2 km below the seafloor off Shimokita, Japan. Contamination tests involving a perfluorocarbon tracer that had been successfully used during past riserless drilling expeditions were complemented by DNA-based contamination tests. In the latter, likely microbial contaminants were targeted via quantitative polymerase chain reaction assays using newly designed, group-specific primers. Target groups included potential indicators of (a) drilling mud viscosifiers (Xanthomonas, Halomonas), (b) anthropogenic wastewater (Bifidobacterium, Blautia, Methanobrevibacter), and (c) surface seawater (SAR 11, Marine Group I Archaea). These target groups were selected based on past evidence suggesting viscosifiers, wastewater, and seawater as the main sources of microbial contamination in cores retrieved by ocean drilling. Analyses of chemical and molecular tracers are in good agreement, and indicate microorganisms associated with mud viscosifiers as the main contaminants during riser drilling. These same molecular analyses are then extended to subseafloor samples obtained during riserless drilling operations. General strategies to further reduce the risk of microbial contamination during riser and riserless drilling operations are discussed.

Development and Testing of a Mobile Platform for Tank Remediation

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

Nance, T.A.

2001-01-16

The Department of Energy (DOE) is committed to removing millions of gallons of high level radioactive waste from waste storage tanks at the Savannah River Site (SRS). SRS was the first site in the DOE complex to have emptied and closed high level waste tanks. Tank closure at the Site is now progressing to tanks containing waste composed of liquid and large deposits of solids, including a tank that has a potential ''heel''. A heel is a hardened mass of solid waste material spread across the tank bottom. Tank closure requires breaking up this heel and moving the material tomore » the intake of a pumping system for transfer from the tank. In the past, overhead spray systems have been used with some success at moving waste. But the limited number of risers restricts the coverage area of the overhead spray system. Therefore, a floor- level spray system will be used to separate manageable size chunks of the material from the heel. The chunks will be guided into the pump's intake to be remove from the tank. The floor-level spray system movement will be accomplished by using a mobile platform, a crawler, which provides transport to nearly every point on the tank floor. Transport of the spray system will allow the system to ''corral'' the waste away from the tank walls and control the movement of the material across the tank floor. Because the available access riser is small, and a wide crawler platform is required to support the spray system, the crawler's frame must fold to enter the tank. After entry into the tank, the crawler unfolds on the tank floor using the crawler drive tracks to expand the frame and position the mobile platform under the entry riser. The spray system will then be lowered separately through the entry riser and mated onto the crawler on the tank floor. The crawler and spray system are tethered and controlled remotely by personnel at the control station. Motorized cable reels will also be remotely controlled to pay out, retrieve, and manage the tethers as the mobile platform moves the spray system across the tank floor. Both the crawler and spray systems are designed to be retrievable. Development of the tank cleaning system was evaluated using a performance test program. The tests evaluated the spray system dynamics, the crawler's fit through the riser, the crawler landing in mocked up tank with simulant, the crawler's traction, and the crawler and spray system mating. Initial testing verified the crawler platform was compatible with the dynamics produced by the spray system. The riser fit test confirmed that a dedicated riser is required for deployment of the crawler and the spray system. The crawler traction test defined the capabilities of the crawler at different levels of simulant. Deployment testing through a mockup riser verified the basic system processes. Finally, testing of the complete system in a full-scale mockup with sludge simulant was performed to evaluate the tank cleaning ability of the crawler. This paper describes th e tank conditions, the tank closure process, the development of the crawler and spray system, and the testing program and results used to evaluate the mobile platform and spray system.« less

47 CFR 73.3617 - Information available on the Internet.

Code of Federal Regulations, 2010 CFR

2010-10-01

... include copies of public notices and texts of recent decisions. The Media Bureau's address is http://www.fcc.gov/mb/; the Audio Division's address is http://www.fcc.gov/mmb/audio; the Video Division's address is http://www.fcc.gov/mb/video; the Policy Division's address is http://www.fcc.gov/mb/policy; the...

47 CFR 0.409 - Commission policy on private printing of FCC forms.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Commission policy on private printing of FCC... ORGANIZATION General Information General § 0.409 Commission policy on private printing of FCC forms. The Commission has established a policy regarding the printing of blank FCC forms by private companies if they...

77 FR 74010 - Proposed Changes to FCC Form 499-A, FCC Form 499-Q, and Accompanying Instructions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-12

... 499-A, FCC Form 499-Q, and Accompanying Instructions AGENCY: Federal Communications Commission. ACTION... revenues, and the quarterly Telecommunications Reporting Worksheet, FCC Form 499-Q (Form 499-Q) and accompanying instructions (Form 499-Q Instructions) to be used in 2013 to report projected collected revenues...

Faulted terrace risers place new constraints on the late Quaternary slip rate for the central Altyn Tagh fault, northwest Tibet

USGS Publications Warehouse

Gold, R.D.; Cowgill, E.; Arrowsmith, J.R.; Chen, X.; Sharp, W.D.; Cooper, K.M.; Wang, X.-F.

2011-01-01

The active, left-lateral Altyn Tagh fault defines the northwestern margin of the Tibetan Plateau in western China. To clarify late Quaternary temporal and spatial variations in slip rate along the central portion of this fault system (85??-90??E), we have more than doubled the number of dated offset markers along the central Altyn Tagh fault. In particular, we determined offset-age relations for seven left-laterally faulted terrace risers at three sites (Kelutelage, Yukuang, and Keke Qiapu) spanning a 140-km-long fault reach by integrating surficial geologic mapping, topographic surveys (total station and tripod-light detection and ranging [T-LiDAR]), and geochronology (radiocarbon dating of organic samples, 230Th/U dating of pedogenic carbonate coatings on buried clasts, and terrestrial cosmogenic radionuclide exposure age dating applied to quartz-rich gravels). At Kelutelage, which is the westernmost site (37.72??N, 86.67??E), two faulted terrace risers are offset 58 ?? 3 m and 48 ?? 4 m, and formed at 6.2-6.1 ka and 5.9-3.7 ka, respectively. At the Yukuang site (38.00??N, 87.87??E), four faulted terrace risers are offset 92 ?? 12 m, 68 ?? 6 m, 55 ?? 13 m, and 59 ?? 9 m and formed at 24.2-9.5 ka, 6.4-5.0 ka, 5.1-3.9 ka, and 24.2-6.4 ka, respectively. At the easternmost site, Keke Qiapu (38.08??N, 88.12??E), a faulted terrace riser is offset 33 ?? 6 m and has an age of 17.1-2.2 ka. The displacement-age relationships derived from these markers can be satisfied by an approximately uniform slip rate of 8-12 mm/yr. However, additional analysis is required to test how much temporal variability in slip rate is permitted by this data set. ?? 2011 Geological Society of America.

Tolerability and camouflaging effect of corrective makeup for acne: results of a clinical study of a novel face compact cream

PubMed Central

Monfrecola, Giuseppe; Cacciapuoti, Sara; Capasso, Claudia; Delfino, Mario; Fabbrocini, Gabriella

2016-01-01

Background A novel face compact cream (FCC) containing a new patented formulation was recently developed to provide acne patients with cosmetic camouflage for their lesions and to have beneficial effects on the multifactorial components of the disease. This pilot investigation aimed to evaluate the real-life tolerability, potential for comedogenicity and covering effect provided by this FCC. Methods This single-center study evaluated the FCC applied once daily for 28 days in 20 females with facial acne. Tolerability was assessed by rating skin reactions on a scale from 1 =absent to 4 =evident. Comedogenicity potential was evaluated by determining the number of facial acne lesions before and after use of the FCC. The covering effect was rated in ten patients 30 minutes after application on a scale from 1 =none to 5 =excellent. Patients rated their opinions on the FCC on day 28 using a questionnaire. Results Assessment of tolerability on days 0, 14, and 28 showed that skin reactions, including erythema, edema, dryness, desquamation, tight feeling, itching, and burning, were absent in all patients. The FCC was noncomedogenic and provided a significant 15.8% reduction in facial acne lesions after 28 days (P<0.001). The FCC provided a good covering effect 30 minutes after application in 80% of patients. All patients (100%) were satisfied with the FCC, with 90% agreeing that the FCC was effective and 80% stating that the FCC improved their skin. Conclusion The FCC was positively perceived, well tolerated, noncomedogenic, and provided an effective covering of acne in this small group of female patients with 1 month of follow-up. PMID:27785082

Tolerability and camouflaging effect of corrective makeup for acne: results of a clinical study of a novel face compact cream.

PubMed

Monfrecola, Giuseppe; Cacciapuoti, Sara; Capasso, Claudia; Delfino, Mario; Fabbrocini, Gabriella

2016-01-01

A novel face compact cream (FCC) containing a new patented formulation was recently developed to provide acne patients with cosmetic camouflage for their lesions and to have beneficial effects on the multifactorial components of the disease. This pilot investigation aimed to evaluate the real-life tolerability, potential for comedogenicity and covering effect provided by this FCC. This single-center study evaluated the FCC applied once daily for 28 days in 20 females with facial acne. Tolerability was assessed by rating skin reactions on a scale from 1 =absent to 4 =evident. Comedogenicity potential was evaluated by determining the number of facial acne lesions before and after use of the FCC. The covering effect was rated in ten patients 30 minutes after application on a scale from 1 =none to 5 =excellent. Patients rated their opinions on the FCC on day 28 using a questionnaire. Assessment of tolerability on days 0, 14, and 28 showed that skin reactions, including erythema, edema, dryness, desquamation, tight feeling, itching, and burning, were absent in all patients. The FCC was noncomedogenic and provided a significant 15.8% reduction in facial acne lesions after 28 days ( P <0.001). The FCC provided a good covering effect 30 minutes after application in 80% of patients. All patients (100%) were satisfied with the FCC, with 90% agreeing that the FCC was effective and 80% stating that the FCC improved their skin. The FCC was positively perceived, well tolerated, noncomedogenic, and provided an effective covering of acne in this small group of female patients with 1 month of follow-up.

Atomistic Simulation of Interstitial Dislocation Loop Evolution under Applied Stresses in BCC Iron

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

Long, Xue Hao; Wang, Dong; Setyawan, Wahyu

Evolution of an interstitial 1/2⟨111⟩ dislocation loop under tensile, shear, and torsion stresses is studied with molecular statics method. Under a tensile stress, the dependence of ultimate tensile strength on size of loop is calculated. The formation of small shear loops around the initial prismatic loop is confirmed as an intermediate state to form the final dislocation network. Under a shear stress, the rotation of a loop is observed not only by a change of the habit plane but also through a transformation between a shear and a prismatic loop. Under torsion, a perfect BCC crystal may undergo a BCCmore » to FCC or BCC to HCP transformation. The present work indicates that a 1/2⟨111⟩ loop can delay these transformations, resulting in the formation of micro-crack on the surface.« less

The elastic properties and stability of fcc-Fe and fcc-FeNi alloys at inner-core conditions

NASA Astrophysics Data System (ADS)

Martorell, Benjamí; Brodholt, John; Wood, Ian G.; Vočadlo, Lidunka

2015-07-01

The agreement between shear wave velocities for the Earth's inner core observed from seismology with those derived from mineral physics is considerably worse than for any other region of the Earth. Furthermore, there is still debate as to the phase of iron present in the inner core, particularly when alloying with nickel and light elements is taken into account. To investigate the extent to which the mismatch between seismology and mineral physics is a function of either crystal structure and/or the amount of nickel present, we have used ab initio molecular dynamics simulations to calculate the elastic constants and seismic velocities (Vp and Vs) of face centred cubic (fcc) iron at Earth's inner core pressures (360 GPa) and at temperatures up to ˜7000 K. We find that Vp for fcc iron (fcc-Fe) is very similar to that for hexagonal close packed (hcp) iron at all temperatures. In contrast, Vs for fcc-Fe is significantly higher than in hcp-Fe, with the difference increasing with increasing temperature; the difference between Vs for the core (from seismology) and Vs for fcc-Fe exceeds 40 per cent. These results are consistent with previous work at lower temperatures. We have also investigated the effect of 6.5 and 13 atm% Ni in fcc-Fe. We find that Ni only slightly reduces Vp and Vs (e.g. by 2 per cent in Vs for 13 atm% Ni at 5500 K), and cannot account for the difference between the velocities observed in the core and those of pure fcc-Fe. We also tried to examine pre-melting behaviour in fcc-Fe, as reported in hcp-Fe by extending the study to very high temperatures (at which superheating may occur). However, we find that fcc-Fe spontaneously transforms to other hcp-like structures before melting; two hcp-like structures were found, both of hexagonal symmetry, which may most easily be regarded as being derived from an hcp crystal with stacking faults. That the structure did not transform to a true hcp phase is likely as a consequence of the limited size of the simulation box (108 atoms). At 360 GPa, in pure fcc-Fe, we find that the transition from fcc to the hcp-like structure occurs at 7000 K, whereas in the Ni bearing system, the transition occurs at higher temperature (7250 K). This reinforces previous work showing that fcc-Fe might transform to hcp-Fe just before melting, and that Ni tends to stabilize the fcc structure with respect to hcp.

Tank 241-Z-361 Sludge Retrieval and Treatment Alternatives

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

HAMPTON, B.K.

2000-05-24

The Plutonium Finishing Plant (PFP) Tank 241-Z-361 (Z-361) contains legacy sludge resulting from waste discharges from past missions at PFP. A sketch of the tank is shown in Figure 1. In this view various risers and penetrations are shown along with the sludge level depicted by the horizontal line halfway up the tank, and the ground level depicted by the horizontal line above the tank. The HEPA filter installed for breathing is also shown on one of the risers.

Method and apparatus for production of subsea hydrocarbon formations

DOEpatents

Blandford, Joseph W.

1994-01-01

A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and export riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

Method and apparatus for production of subsea hydrocarbon formations

DOEpatents

Blandford, Joseph W.

1992-01-01

A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and expert riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

Fleet Mooring Underwater Inspection Report La Maddalena, Italy.

DTIC Science & Technology

1981-12-01

Peg Top mooring buoys at the bow at the NATO Naval Facility, St. Stefano , Sardinia, Italy. The ship using the mooring is moored at the stern to the...LAT: NSO LA MADDALENA NORTH RISER/MED MOOR LON:SANTO STEFANO ,ISardinia, Italy ii DATE DIVERS U 1WATER DEPTH SUPERVISOR INITIALS 5. INSPECTION 18-25 Sep...0) 0 蟙 W. .-. MOORING INSPECTION REPORT Page 3 of 3 1. FACILITY 2. MOORING NO. 13. TYPE/CLASSMOORING 4. LAT.RISER/MD MOOR SANTO STEFANO , NSO LA

76 FR 29749 - Information Collections Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-23

.... SUMMARY: The Federal Communications Commission (FCC), as part of its continuing effort to reduce paperwork... concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of information... soon as possible. ADDRESSES: Direct all PRA comments to Cathy Williams, FCC, via e-mail [email protected]fcc.gov...

47 CFR 73.5002 - Application and certification procedures; return of mutually exclusive applications not subject...

Code of Federal Regulations, 2012 CFR

2012-10-01

... broadcast service auctions, or to apply for a noncommercial educational station, as described in 47 U.S.C... engineering data contained in the appropriate FCC form (FCC Form 301, FCC Form 346, or FCC Form 349... permitted to resolve their mutual exclusivities by making amendments to their engineering submissions...

The subsea deployment and installation of flexible pipe catenaries for the Enserch Garden Banks 388 Freestanding Production Riser

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

Herman, R.J.

1997-07-01

This narrative addresses the development of the subsea flexible pipe catenary handling tools and procedures as used in the Gulf of Mexico on the Enserch Garden Banks 388 Freestanding Production Riser. The philosophy that was invoked for the development of the tools and procedures was targeted on long term utilization and field maintenance capability with minimum vessel relocation requirements and minimum production interruptions. The initial emphasis for the required tools and procedures was to develop worker safe, environmentally friendly and cost effective equipment. These tools are for the deployment and installation of 3-inch Production and Annulus flexible pipe catenaries frommore » the Enserch Garden Banks 388 Floating Production Vessel to the system`s Freestanding Production Riser. The Pull In Jib system is common to the handling of all the catenaries. The Pull In Jib system has been designed to support the greater loads of the 8-inch and 12-inch export line catenaries.« less

Energy absorption device for shock loading

NASA Astrophysics Data System (ADS)

Howard, C. D.; Lagrange, Donald E.; Beatty, David A.; Littman, David C.

1995-02-01

A shock energy absorbing device provides shock protection for the riser line employed to attach an aerodynamic deceleration device to a primary body during deployment of the system into an airstream. During deployment, for example, by dropping an unopened parachute and attached load or by rocket delivery of the unopened parachute and attached load, the parachute is made to open at a desired altitude whereupon very large shock tension forces are generated which are applied to the line. In order to protect the line from failing under these forces and to reduce the requirement for a bulky, heavy line, a shock absorber is provided in the form of a block having one or more breakable web portions formed therein and through which the riser line is threaded. Upon deployment of the system into an airstream, the shock tension forces operate to fracture some or all of the breakable web portions thereby dissipating the shock energy generated during deployment and protecting the riser line from failure.

MP-Pic simulation of CFB riser with EMMS-based drag model

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

Li, F.; Song, F.; Benyahia, S.

2012-01-01

MP-PIC (multi-phase particle in cell) method combined with the EMMS (energy minimization multi- scale) drag force model was implemented with the open source program MFIX to simulate the gas–solid flows in CFB (circulatingfluidizedbed) risers. Calculated solid flux by the EMMS drag agrees well with the experimental value; while the traditional homogeneous drag over-predicts this value. EMMS drag force model can also predict the macro-and meso-scale structures. Quantitative comparison of the results by the EMMS drag force model and the experimental measurements show high accuracy of the model. The effects of the number of particles per parcel and wall conditions onmore » the simulation results have also been investigated in the paper. This work proved that MP-PIC combined with the EMMS drag model can successfully simulate the fluidized flows in CFB risers and it serves as a candidate to realize real-time simulation of industrial processes in the future.« less

Robust output feedback stabilization for a flexible marine riser system.

PubMed

Zhao, Zhijia; Liu, Yu; Guo, Fang

2017-12-06

The aim of this paper is to develop a boundary control for the vibration reduction of a flexible marine riser system in the presence of parametric uncertainties and system states obtained inaccurately. To this end, an adaptive output feedback boundary control is proposed to suppress the riser's vibration fusing with observer-based backstepping, high-gain observers and robust adaptive control theory. In addition, the parameter adaptive laws are designed to compensate for the system parametric uncertainties, and the disturbance observer is introduced to mitigate the effects of external environmental disturbance. The uniformly bounded stability of the closed-loop system is achieved through rigorous Lyapunov analysis without any discretisation or simplification of the dynamics in the time and space, and the state observer error is ensured to exponentially converge to zero as time grows to infinity. In the end, the simulation and comparison studies are carried out to illustrate the performance of the proposed control under the proper choice of the design parameters. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Transient Characterization of Type B Particles in a Transport Riser

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

Shadle, L.J.; Monazam, E.R.; Mei, J.S.

2007-01-01

Simple and rapid dynamic tests were used to evaluate fluid dynamic behavior of granular materials in the transport regime. Particles with densities ranging from 189 to 2,500 kg/m3 and Sauter mean size from 61 to 812 μm were tested in a 0.305 m diameter, 15.5 m height circulating fluidized bed (CFB) riser. The transient tests involved the abrupt stoppage of solids flow for each granular material over a wide range gas flow rates. The riser emptying time was linearly related to the Froude number in each of three different operating regimes. The flow structure along the height of the risermore » followed a distinct pattern as tracked through incremental pressures. These results are discussed to better understand the transformations that take place when operating over various regimes. During the transients the particle size distribution was measured. The effects of pressure, particle size, and density on test performance are also presented.« less

Nuclear reactor pressure vessel support system

DOEpatents

Sepelak, George R.

1978-01-01

A support system for nuclear reactor pressure vessels which can withstand all possible combinations of stresses caused by a postulated core disrupting accident during reactor operation. The nuclear reactor pressure vessel is provided with a flange around the upper periphery thereof, and the flange includes an annular vertical extension formed integral therewith. A support ring is positioned atop of the support ledge and the flange vertical extension, and is bolted to both members. The plug riser is secured to the flange vertical extension and to the top of a radially outwardly extension of the rotatable plug. This system eliminates one joint through which fluids contained in the vessel could escape by making the fluid flow path through the joint between the flange and the support ring follow the same path through which fluid could escape through the plug risers. In this manner, the sealing means to prohibit the escape of contained fluids through the plug risers can also prohibit the escape of contained fluid through the securing joint.

Statistical analysis on the signals monitoring multiphase flow patterns in pipeline-riser system

NASA Astrophysics Data System (ADS)

Ye, Jing; Guo, Liejin

2013-07-01

The signals monitoring petroleum transmission pipeline in offshore oil industry usually contain abundant information about the multiphase flow on flow assurance which includes the avoidance of most undesirable flow pattern. Therefore, extracting reliable features form these signals to analyze is an alternative way to examine the potential risks to oil platform. This paper is focused on characterizing multiphase flow patterns in pipeline-riser system that is often appeared in offshore oil industry and finding an objective criterion to describe the transition of flow patterns. Statistical analysis on pressure signal at the riser top is proposed, instead of normal prediction method based on inlet and outlet flow conditions which could not be easily determined during most situations. Besides, machine learning method (least square supported vector machine) is also performed to classify automatically the different flow patterns. The experiment results from a small-scale loop show that the proposed method is effective for analyzing the multiphase flow pattern.

Family-centred care delivery: comparing models of primary care service delivery in Ontario.

PubMed

Mayo-Bruinsma, Liesha; Hogg, William; Taljaard, Monica; Dahrouge, Simone

2013-11-01

To determine whether models of primary care service delivery differ in their provision of family-centred care (FCC) and to identify practice characteristics associated with FCC. Cross-sectional study. Primary care practices in Ontario (ie, 35 salaried community health centres, 35 fee-for-service practices, 32 capitation-based health service organizations, and 35 blended remuneration family health networks) that belong to 4 models of primary care service delivery. A total of 137 practices, 363 providers, and 5144 patients. Measures of FCC in patient and provider surveys were based on the Primary Care Assessment Tool. Statistical analyses were conducted using linear mixed regression models and generalized estimating equations. Patient-reported FCC scores were high and did not vary significantly by primary care model. Larger panel size in a practice was associated with lower odds of patients reporting FCC. Provider-reported FCC scores were significantly higher in community health centres than in family health networks (P = .035). A larger number of nurse practitioners and clinical services on-site were both associated with higher FCC scores, while scores decreased as the number of family physicians in a practice increased and if practices were more rural. Based on provider and patient reports, primary care reform strategies that encourage larger practices and more patients per family physician might compromise the provision of FCC, while strategies that encourage multidisciplinary practices and a range of services might increase FCC.

Family-Centered Care in Neonatal Intensive Care Units: Combining Intensive Care and Family Support.

PubMed

Araki, Shunsuke; Saito, Tomoko; Ichikawa, Saori; Saito, Kaori; Takada, Tsuzumi; Noguchi, Satoko; Yamada, Miki; Nakagawa, Fumi

Advances in treatment in neonatal intensive care units (NICU) for preterm and sick newborns have improved the mortality rate of patients, but admission to the NICU may disrupt parent-infant interaction, with adverse consequences for infants and their families because of physical, psychological, and emotional separation. The concept of family centered care (FCC), in which family members are part of the care team and infants are close to the family, is important and has become popular in NICU. In 2013, we created a team called "Kodomo-Kazoku Mannaka" to promote FCC in Japan, and visited the NICU at Uppsala University Hospital in Sweden, which is internationally famous for FCC. Since this fruitful visit, we have been promoting FCC in Japan by exhibitions and presentations of the FCC ideas at academic conferences and using internet services. A questionnaire survey conducted in 2015 revealed that the importance and the benefits of FCC in NICU are recognized, although there are some barriers to FCC in each facility. It is hard to change facilities and social systems right away, but it is easier and more important to change people's minds. Our role is to spread the concept of FCC and to help each facility find its own way to adopt it. We will continue to make efforts encourage to promote FCC in Japan.

76 FR 38175 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

... request for comments. SUMMARY: The Federal Communications Commission (FCC), as part of its continuing... small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of...-mail [email protected] ; and to Cathy Williams, FCC, via e-mail [email protected]fcc.gov and to Cathy...

76 FR 45565 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

... request for comments. SUMMARY: The Federal Communications Commission (FCC), as part of its continuing... small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of... via e-mail [email protected] ; and to Cathy Williams, FCC, via e-mail [email protected]fcc.gov and to...

47 CFR 73.4107 - FM broadcast assignments, increasing availability of.

Code of Federal Regulations, 2012 CFR

2012-10-01

... broadcast assignments, increasing availability of. (a) See, First Report and Order MM Docket 84-231, FCC 84... and Order, MM Docket 84-231, FCC 85-124, adopted March 14, 1985. 101 FCC 2d 630; 50 FR 15558, April 19, 1985. (c) See, Memorandum Opinion and Order, MM Docket 84-231, FCC 86-76, adopted February 10, 1986. 51...

47 CFR 73.4107 - FM broadcast assignments, increasing availability of.

Code of Federal Regulations, 2013 CFR

2013-10-01

... broadcast assignments, increasing availability of. (a) See, First Report and Order MM Docket 84-231, FCC 84... and Order, MM Docket 84-231, FCC 85-124, adopted March 14, 1985. 101 FCC 2d 630; 50 FR 15558, April 19, 1985. (c) See, Memorandum Opinion and Order, MM Docket 84-231, FCC 86-76, adopted February 10, 1986. 51...

47 CFR 73.4107 - FM broadcast assignments, increasing availability of.

Code of Federal Regulations, 2011 CFR

2011-10-01

... broadcast assignments, increasing availability of. (a) See, First Report and Order MM Docket 84-231, FCC 84... and Order, MM Docket 84-231, FCC 85-124, adopted March 14, 1985. 101 FCC 2d 630; 50 FR 15558, April 19, 1985. (c) See, Memorandum Opinion and Order, MM Docket 84-231, FCC 86-76, adopted February 10, 1986. 51...

47 CFR 73.4107 - FM broadcast assignments, increasing availability of.

Code of Federal Regulations, 2014 CFR

2014-10-01

... broadcast assignments, increasing availability of. (a) See, First Report and Order MM Docket 84-231, FCC 84... and Order, MM Docket 84-231, FCC 85-124, adopted March 14, 1985. 101 FCC 2d 630; 50 FR 15558, April 19, 1985. (c) See, Memorandum Opinion and Order, MM Docket 84-231, FCC 86-76, adopted February 10, 1986. 51...

Reassessment of Atomic Mobilities in fcc Cu-Ag-Sn System Aiming at Establishment of an Atomic Mobility Database in Sn-Ag-Cu-In-Sb-Bi-Pb Solder Alloys

NASA Astrophysics Data System (ADS)

Xu, Huixia; Zhang, Lijun; Cheng, Kaiming; Chen, Weimin; Du, Yong

2017-04-01

To establish an accurate atomic mobility database in solder alloys, a reassessment of atomic mobilities in the fcc (face centered cubic) Cu-Ag-Sn system was performed as reported in the present work. The work entailed initial preparation of three fcc Cu-Sn diffusion couples, which were used to determine the composition-dependent interdiffusivities at 873 K, 923 K, and 973 K, to validate the literature data and provide new experimental data at low temperatures. Then, atomic mobilities in three boundary binaries, fcc Cu-Sn, fcc Ag-Sn, and fcc Cu-Ag, were updated based on the data for various experimental diffusivities obtained from the literature and the present work, together with the available thermodynamic database for solder alloys. Finally, based on the large number of interdiffusivities recently measured from the present authors, atomic mobilities in the fcc Cu-Ag-Sn ternary system were carefully evaluated. A comprehensive comparison between various calculated/model-predicted diffusion properties and the experimental data was used to validate the reliability of the obtained atomic mobilities in ternary fcc Cu-Ag-Sn alloys.

Fuel cycle cost uncertainty from nuclear fuel cycle comparison

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

Li, J.; McNelis, D.; Yim, M.S.

2013-07-01

This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for themore » discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC.« less

Quasi-Dual-Packed-Kerneled Au49 (2,4-DMBT)27 Nanoclusters and the Influence of Kernel Packing on the Electrochemical Gap.

PubMed

Liao, Lingwen; Zhuang, Shengli; Wang, Pu; Xu, Yanan; Yan, Nan; Dong, Hongwei; Wang, Chengming; Zhao, Yan; Xia, Nan; Li, Jin; Deng, Haiteng; Pei, Yong; Tian, Shi-Kai; Wu, Zhikun

2017-10-02

Although face-centered cubic (fcc), body-centered cubic (bcc), hexagonal close-packed (hcp), and other structured gold nanoclusters have been reported, it was unclear whether gold nanoclusters with mix-packed (fcc and non-fcc) kernels exist, and the correlation between kernel packing and the properties of gold nanoclusters is unknown. A Au 49 (2,4-DMBT) 27 nanocluster with a shell electron count of 22 has now been been synthesized and structurally resolved by single-crystal X-ray crystallography, which revealed that Au 49 (2,4-DMBT) 27 contains a unique Au 34 kernel consisting of one quasi-fcc-structured Au 21 and one non-fcc-structured Au 13 unit (where 2,4-DMBTH=2,4-dimethylbenzenethiol). Further experiments revealed that the kernel packing greatly influences the electrochemical gap (EG) and the fcc structure has a larger EG than the investigated non-fcc structure. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A computational and theoretical analysis of falling frequency VLF emissions

NASA Astrophysics Data System (ADS)

Nunn, David; Omura, Yoshiharu

2012-08-01

Recently much progress has been made in the simulation and theoretical understanding of rising frequency triggered emissions and rising chorus. Both PIC and Vlasov VHS codes produce risers in the region downstream from the equator toward which the VLF waves are traveling. The VHS code only produces fallers or downward hooks with difficulty due to the coherent nature of wave particle interaction across the equator. With the VHS code we now confine the interaction region to be the region upstream from the equator, where inhomogeneity factor S is positive. This suppresses correlated wave particle interaction effects across the equator and the tendency of the code to trigger risers, and permits the formation of a proper falling tone generation region. The VHS code now easily and reproducibly triggers falling tones. The evolution of resonant particle current JE in space and time shows a generation point at -5224 km and the wavefield undergoes amplification of some 25 dB in traversing the nonlinear generation region. The current component parallel to wave magnetic field (JB) is positive, whereas it is negative for risers. The resonant particle trap shows an enhanced distribution function or `hill', whereas risers have a `hole'. According to recent theory (Omura et al., 2008, 2009) sweeping frequency is due primarily to the advective term. The nonlinear frequency shift term is now negative (˜-12 Hz) and the sweep rate of -800 Hz/s is approximately nonlinear frequency shift divided by TN, the transition time, of the order of a trapping time.

University students' notebook computer use: lessons learned using e-diaries to report musculoskeletal discomfort.

PubMed

Jacobs, K; Foley, G; Punnett, L; Hall, V; Gore, R; Brownson, E; Ansong, E; Markowitz, J; McKinnon, M; Steinberg, S; Ing, A; Wuest, Ellen; Dibiccari, Leah

2011-02-01

The objective of this pilot study was to identify if notebook accessories (ergonomic chair, desktop monitor and notebook riser) combined with a wireless keyboard, mouse and participatory ergonomics training would have the greatest impact on reducing self-reported upper extremity musculoskeletal discomfort in university students. In addition to pre-post computing and health surveys, the Ecological Momentary Assessment was used to capture change in discomfort over time using a personal digital assistant (PDA) as the e-diary. The PDA was programmed with a survey containing 45 questions. Four groups of university students were randomised to either intervention (three external computer accessories) or to control. Participants reported less discomfort with the ergonomic chair and notebook riser based on the pre-post survey data and the e-diary/PDA ANOVA analysis. However, the PDA data, adjusted for the effect of hours per day of computer use, showed no benefit of the chair and limited benefit from the riser. Statement of Relevance:University students' use of notebook computers has increased. This study found evidence of a positive effect of an adjustable chair or notebook riser when combined with ergonomic training on reducing discomfort. Daily notebook computer use of 4 h was confirmed as a risk factor. Without some form of ergonomic intervention, these students are likely to enter the workforce with poor computing habits, which places them on the road to future injuries as technology continues to play a dominant role in their lives.

Properties of hot-rolled sheets from ferritic steel with increased strength

NASA Astrophysics Data System (ADS)

Perlovich, Yu.; Isaenkova, M.; Dobrokhotov, P.; Stolbov, S.; Bannykh, O.; Bannykh, I.; Antsyferova, M.

2017-10-01

Sheets from ferritic steel 3 mm thick with increased strength after thermal hardening were studied by use of various X-ray methods and mechanical testing. Rolling of steel was carried out at 1100°C with rather great reductions per pass, so that plastic deformation of metal spread by the significant distance from the surface. The texture of sheet proved to have two sharply different layers: the inner layer of ˜40% thick with the usual rolling texture of BCC metals and the external layer with the rolling texture of FCC metals. At that, within the intermediate layer the texture is weakened. Texture formation within the external layer is conditioned by the process of dynamical deformation ageing: interstitial impurities from atmosphere block dislocations, prevent from their slip and at increased temperatures promote their collective climb. As a result, the direction of lattice rotation as well as the final rolling texture change. Due to texture layering, by impact testing of the sheet the plane of crack propagation must be changed when this crack reaches the inner layer, and then an additional energy for its further movement is required. Thermal hardening of the sheet retains the type of rolling texture, though results in some its scattering, but at the same time the breaking point of steel grows twice owing to formation of intermetallic particles.

47 CFR 73.4107 - FM broadcast assignments, increasing availability of.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-640, adopted December 19, 1984. 100 FCC 2d 1332; 50 FR 3514, January 25, 1994. (b) See, Second Report and Order, MM Docket 84-231, FCC 85-124, adopted March 14, 1985. 101 FCC 2d 630; 50 FR 15558, April 19, 1985. (c) See, Memorandum Opinion and Order, MM Docket 84-231, FCC 86-76, adopted February 10, 1986. 51...

75 FR 38523 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of... advise the FCC contact listed below as soon as possible. ADDRESSES: Direct all PRA comments to Nicholas A....eop.gov and to the Federal Communications Commission via email to [email protected]fcc.gov and [email protected]fcc...

76 FR 24878 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-03

... information collection burden for small business concerns with fewer than 25 employees. The FCC may not... allowed by this notice, you should advise the FCC contact listed below as soon as possible. ADDRESSES...-mail to [email protected]fcc.gov and [email protected]fcc.gov . To view a copy of this information collection request...

47 CFR 95.422 - (CB Rule 22) How do I answer correspondence from the FCC?

Code of Federal Regulations, 2010 CFR

2010-10-01

... You Need to Know § 95.422 (CB Rule 22) How do I answer correspondence from the FCC? (a) If it appears to the FCC that you have violated the Communications Act or these rules, the FCC may send you a... 47 Telecommunication 5 2010-10-01 2010-10-01 false (CB Rule 22) How do I answer correspondence...

Towards future circular colliders

NASA Astrophysics Data System (ADS)

Benedikt, Michael; Zimmermann, Frank

2016-09-01

The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program will extend through the second half of the 2030's. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ˜100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCCee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

Accurate Monte Carlo simulations on FCC and HCP Lennard-Jones solids at very low temperatures and high reduced densities up to 1.30

NASA Astrophysics Data System (ADS)

Adidharma, Hertanto; Tan, Sugata P.

2016-07-01

Canonical Monte Carlo simulations on face-centered cubic (FCC) and hexagonal closed packed (HCP) Lennard-Jones (LJ) solids are conducted at very low temperatures (0.10 ≤ T∗ ≤ 1.20) and high densities (0.96 ≤ ρ∗ ≤ 1.30). A simple and robust method is introduced to determine whether or not the cutoff distance used in the simulation is large enough to provide accurate thermodynamic properties, which enables us to distinguish the properties of FCC from that of HCP LJ solids with confidence, despite their close similarities. Free-energy expressions derived from the simulation results are also proposed, not only to describe the properties of those individual structures but also the FCC-liquid, FCC-vapor, and FCC-HCP solid phase equilibria.

Family-centred care delivery

PubMed Central

Mayo-Bruinsma, Liesha; Hogg, William; Taljaard, Monica; Dahrouge, Simone

2013-01-01

Abstract Objective To determine whether models of primary care service delivery differ in their provision of family-centred care (FCC) and to identify practice characteristics associated with FCC. Design Cross-sectional study. Setting Primary care practices in Ontario (ie, 35 salaried community health centres, 35 fee-for-service practices, 32 capitation-based health service organizations, and 35 blended remuneration family health networks) that belong to 4 models of primary care service delivery. Participants A total of 137 practices, 363 providers, and 5144 patients. Main outcome measures Measures of FCC in patient and provider surveys were based on the Primary Care Assessment Tool. Statistical analyses were conducted using linear mixed regression models and generalized estimating equations. Results Patient-reported FCC scores were high and did not vary significantly by primary care model. Larger panel size in a practice was associated with lower odds of patients reporting FCC. Provider-reported FCC scores were significantly higher in community health centres than in family health networks (P = .035). A larger number of nurse practitioners and clinical services on-site were both associated with higher FCC scores, while scores decreased as the number of family physicians in a practice increased and if practices were more rural. Conclusion Based on provider and patient reports, primary care reform strategies that encourage larger practices and more patients per family physician might compromise the provision of FCC, while strategies that encourage multidisciplinary practices and a range of services might increase FCC. PMID:24235195

US domestic and international regulatory issues

NASA Technical Reports Server (NTRS)

Levin, Lon C.; Nash, Dennis C.

1993-01-01

The U.S. domestic and international regulatory and policy milestones since 1982, when NASA filed its petition with the Federal Communications Commission (FCC) to establish the U.S. domestic Mobile Satellite Service (MSS), are described. In 1985, the FCC proposed to establish MSS services and allocate spectrum for such service. In 1986, the FCC allocated L-band spectrum for MSS. In 1987, at the Mobile World Administrative Radio Conference (MOB WARC-87), despite U.S., Canadian, and Mexican efforts, the WARC did not adopt a multi-service, generic MSS allocation. In 1989, the FCC licensed the first MSS system. After two decisions by the U.S. Court of Appeals, the FCC's licensing actions remain intact. The FCC also has permitted Comsat to provide international aeronautical and land MSS via the Inmarsat system. Inmarsat, however, may not serve the domestic U.S. market. In 1991, the FCC accepted applications for MSS systems, most of which were non-geostationary proposals, for operation in the Radiodetermination Satellite Service (RDSS) bands, and the VHF and UHF bands. In 1992, the FCC proposed rules for non-geostationary MSS systems and applied a negotiated rulemaking procedure to each. Also in 1992, the U.S. position for flexibility in existing MSS bands and for additional worldwide MSS allocations was adopted in large part at the 1992 World Administrative Radio Conference (WARC-92).

Drawing on wisdom from the past: an elder abuse intervention with tribal communities.

PubMed

Holkup, Patricia A; Salois, Emily Matt; Tripp-Reimer, Toni; Weinert, Clarann

2007-04-01

The Family Care Conference (FCC) is an elder-focused, family-centered, community-based intervention for the prevention and mitigation of elder abuse. It is based on a family conference intervention developed by the Maori people of New Zealand, who determined that Western European ways of working with child welfare issues were undermining such family values as the definition and meaning of family, the importance of spirituality, the use of ritual, and the value of non-interference. The FCC provides the opportunity for family members to come together to discuss and develop a plan for the well-being of their elders. Using a community-based participatory research approach, investigators piloted and implemented the FCC in one northwestern Native American community. The delivery of the FCC intervention has grown from having been introduced and facilitated by the researchers, to training community members to facilitate the family meetings, to becoming incorporated into a Tribal agency, which will oversee the implementation of the FCC. To date, families have accepted and appreciated the FCC intervention. The constructive approach of the FCC process helps to bring focus to families' concerns and aligns their efforts toward positive action. The strength-based FCC provides a culturally anchored and individualized means of identifying frail Native American elders' needs and finding solutions from family and available community resources.

Mobile satellite regulation in the United States

NASA Technical Reports Server (NTRS)

Levin, Lon C.; Sonnenfeldt, Walter H.

1990-01-01

During the last decade, the U.S. FCC has developed the regulatory structure for the provision of mobile services via satellite. In May 1989, the FCC awarded American Mobile Satellite Corporation (AMSC) a license to provide the full range of domestic mobile satellite services in the U.S. At that time, the FCC reaffirmed the U.S. mobile satellite industry structure and spectrum allocations that had been adopted previously. Also in May 1989, the FCC authorized the Communications Satellite Corporation (COMSAT), the U.S. Signatory to Inmarsat, to provide international aeronautical satellite service via the Inmarsat system. Earlier in 1989, the FCC permitted the use of Ku-band satellites to provide messaging and tracking services. In the mid-1980's, the FCC established the Radiodetermination Satellite Service and awarded licenses. Among the mobile satellite matters currently facing the FCC are whether additional spectrum should be allocated for domestic 'generic' mobile satellite services, the regulatory structure for the provision of mobile satellite service on an interim basis before AMSC launches its dedicated satellites, and whether to authorize a low earth orbit satellite system to provide mobile data service.

Extending residential care through telephone counseling: Initial results from the Betty Ford Center Focused Continuing Care protocol

PubMed Central

Cacciola, John S.; Camilleri, Amy C.; Carise, Deni; Rikoon, Samuel H.; McKay, James R.; McLellan, A. Thomas; Wilson, Cheryl; Schwarzlose, John T.

2009-01-01

There is increasing evidence that a chronic care model may be effective when treating substance use disorders. In 1996, the Betty Ford Center (BFC) began implementing a telephone-based continuing care intervention now called Focused Continuing Care (FCC) to assist and support patients in their transition from residential treatment to longer-term recovery in the “real world”. This article reports on patient utilization and outcomes of FCC. FCC staff placed clinically directed telephone calls to patients (N=4094) throughout the first year after discharge. During each call, a short survey was administered to gauge patient recovery and guide the session. Patients completed an average of 5.5 (40%) of 14 scheduled calls, 58% completed 5 or more calls, and 85% were participating in FCC two months post-discharge or later. There was preliminary evidence that greater participation in FCC yielded more positive outcomes and that early post-discharge behaviors predict subsequent outcomes. FCC appears to be a feasible therapeutic option. Efforts to revise FCC to enhance its clinical and administrative value are described. PMID:18539402

Presentation to DOT Workshop

DOT National Transportation Integrated Search

2015-03-12

LightSquared Comments on Testing Program. The FCC has Exclusive Jurisdiction to Regulate Spectrum Emissions. The Established Process is for Agencies to Ask the FCC to Conduct Such Studies. The Only Purpose of Any Such Study is to Inform FCC Regulator...

Modeling right-lateral offset of a Late Pleistocene terrace riser along the Polaris fault using ground based LiDAR imagery

NASA Astrophysics Data System (ADS)

Howle, J. F.; Bawden, G. W.; Hunter, L. E.; Rose, R. S.

2009-12-01

High resolution (centimeter level) three-dimensional point-cloud imagery of offset glacial outwash deposits were collected by using ground based tripod LiDAR (T-LiDAR) to characterize the cumulative fault slip across the recently identified Polaris fault (Hunter et al., 2009) near Truckee, California. The type-section site for the Polaris fault is located 6.5 km east of Truckee where progressive right-lateral displacement of middle to late Pleistocene deposits is evident. Glacial outwash deposits, aggraded during the Tioga glaciation, form a flat lying ‘fill’ terrace on both the north and south sides of the modern Truckee River. During the Tioga deglaciation melt water incised into the terrace producing fluvial scarps or terrace risers (Birkeland, 1964). Subsequently, the terrace risers on both banks have been right-laterally offset by the Polaris fault. By using T-LiDAR on an elevated tripod (4.25 m high), we collected 3D high-resolution (thousands of points per square meter; ± 4 mm) point-cloud imagery of the offset terrace risers. Vegetation was removed from the data using commercial software, and large protruding boulders were manually deleted to generate a bare-earth point-cloud dataset with an average data density of over 240 points per square meter. From the bare-earth point cloud we mathematically reconstructed a pristine terrace/scarp morphology on both sides of the fault, defined coupled sets of piercing points, and extracted a corresponding displacement vector. First, the Polaris fault was approximated as a vertical plane that bisects the offset terrace risers, as well as bisecting linear swales and tectonic depressions in the outwash terrace. Then, piercing points to the vertical fault plane were constructed from the geometry of the geomorphic elements on either side of the fault. On each side of the fault, the best-fit modeled outwash plane is projected laterally and the best-fit modeled terrace riser projected upward to a virtual intersection in space, creating a vector. These constructed vectors were projected to intersection with the fault plane, defining statistically significant piercing points. The distance between the coupled set of piercing points, within the plane of the fault, is the cumulative displacement vector. To assess the variability of the modeled geomorphic surfaces, including surface roughness and nonlinearity, we generated a suite of displacement models by systematically incorporating larger areas of the model domain symmetrically about the fault. Preliminary results of 10 models yield an average cumulative displacement of 5.6 m (1 Std Dev = 0.31 m). As previously described, Tioga deglaciation melt water incised into the outwash terrace leaving terrace risers that were subsequently offset by the Polaris fault. Therefore, the age of the Tioga outwash terrace represents a maximum limiting age of the tectonic displacement. Using regional age constraints of 15 to 13 kya for the Tioga outwash terrace (Benson et al., 1990; Clark and Gillespie, 1997; James et al., 2002) and the above model results, we estimate a preliminary minimum fault slip rate of 0.40 ± 0.05 mm/yr for the Polaris type-section site.

Supercubes, Supersquares, and Superrods of Face-Centered Cubes (FCC): Atomic and Electronic Requirements of [Mm(SR)l(PR'3)8]q Nanoclusters (M = Coinage Metals) and Their Implications with Respect to Nucleation and Growth of FCC Metals.

PubMed

Teo, Boon K; Yang, Huayan; Yan, Juanzhu; Zheng, Nanfeng

2017-10-02

Understanding the nucleation and growth pathways of nanocrystallites allows precise control of the size and shape of functional crystalline nanomaterials of importance in nanoscience and nanotechnology. This paper provides a detailed analysis of the stereochemical and electronic requirements of three series of nanoclusters based on face-centered cubes (fcc) as the basic building blocks, namely, 1-, 2-, and 3-D assemblages of fcc to form superrods (n), supersquares (n 2 ), and supercubes (n 3 ). The generating functions for calculating the numbers (and arrangements) of surface and interior metal atoms, as well as the number and dispositions of the ligands, for these particular sequences of fcc metal clusters of the general formula [M m (SR) l (PR' 3 ) 8 ] q (where M = coinage metals; SR = thiolates (or group XI ligands), and PR' 3 = phosphines) are presented. An electron-counting scheme based on the jelliumatic shell nodel, a variant of the jellium model, predicts the electron requirements and hence the chemical compositions that are critical in the design and synthesis of the next generation of giant nanoclusters in the nanorealm. The ligand binding specificities, which are keys to effective surface ligand control of the size and shape of these nanoclusters, are defined. Finally, a connection is made with regard to the growth of fcc metals, n 3 , from fcc supercubes (n < 10) to fcc nanocrystallites/particles (10 < n < 10 2 ) and to fcc bulk phase (n > 10 2 ).

New roles of LWD and wireline logging in scientific ocean drilling

NASA Astrophysics Data System (ADS)

Sanada, Y.; Kido, Y. N.; Moe, K.; Aoike, K.

2014-12-01

D/V Chikyu implemented by CDEX/JAMSTEC joined IODP from 2007. Various LWD (Logging While Drilling) and wireline logging have been carried out in many expeditions and for various purposes. Significant features of logging in Chikyu expeditions are many use of LWD than wireline logging, and riser dirlling. riser selected specific tools for each scientific target, and 3) carried out various borehole experiments. LWD has been more popular than wireline logging in Chikyu expeditions, because its advantages match theirs science targets. The advantages are followings. 1) LWD has more opportunities for measurement in unstable borehole, such as in the series of Nankai trough drilling expeditions. 2) LWD realtime data allows us to make realtime interpretation and operational decision. Realtime interpretation was required to set obsevartory at the properposition. 3) LWD before coring allows us to make a strategy of spot coring.We can design coring intervals for our interest and core length to improve core recovery.Riser drilling brings us merits for logging. One is hole stability (good hole condition) and the other is the use of large diameter tools. Controled drilling mud in riser drilling system prevent mud invasion to formation and mitigates collapse of borehole wall. They reduce the risk of tool stack and improve data quality. Large diameter of riser pipe enhances variation of tool seizes. A couple of new tools were used for new measurement and improvement of the data quality. For example, SonicScanner (trademark of Schulumberger) successfully measured compressional and share velocity in very low velocities at the soft sediment, where it has been difficult to measure them with conventional DSI tool (Exp319). The stress and pore pressure in the borehole were measured with the wireline logging tool, (Schlumberger MDT). The single probe tool enable to measure temporal formation fluid pressure. The double packer tool enable to fracture test by sealing and pumping in the borehole. These in-situ measurement and stress experiment data are very important to understand physical properties and mechanism of fault zone (Exp319).Those new technologies and tools also expand the envelope of scientific ocean drilling.

Experimental Plan for Crystal Accumulation Studies in the WTP Melter Riser

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

Miller, D.; Fowley, M.

2015-04-28

This experimental plan defines crystal settling experiments to be in support of the U.S. Department of Energy – Office of River Protection crystal tolerant glass program. The road map for development of crystal-tolerant high level waste glasses recommends that fluid dynamic modeling be used to better understand the accumulation of crystals in the melter riser and mechanisms of removal. A full-scale version of the Hanford Waste Treatment and Immobilization Plant (WTP) melter riser constructed with transparent material will be used to provide data in support of model development. The system will also provide a platform to demonstrate mitigation or recoverymore » strategies in off-normal events where crystal accumulation impedes melter operation. Test conditions and material properties will be chosen to provide results over a variety of parameters, which can be used to guide validation experiments with the Research Scale Melter at the Pacific Northwest National Laboratory, and that will ultimately lead to the development of a process control strategy for the full scale WTP melter. The experiments described in this plan are divided into two phases. Bench scale tests will be used in Phase 1 (using the appropriate solid and fluid simulants to represent molten glass and spinel crystals) to verify the detection methods and analytical measurements prior to their use in a larger scale system. In Phase 2, a full scale, room temperature mockup of the WTP melter riser will be fabricated. The mockup will provide dynamic measurements of flow conditions, including resistance to pouring, as well as allow visual observation of crystal accumulation behavior.« less

Geographic, Racial/Ethnic, and Sociodemographic Disparities in Parent-Reported Receipt of Family-Centered Care among US Children

PubMed Central

Azuine, Romuladus E.; Singh, Gopal K.; Ghandour, Reem M.; Kogan, Michael D.

2015-01-01

This study examined geographic, racial/ethnic, and sociodemographic disparities in parental reporting of receipt of family-centered care (FCC) and its components among US children aged 0–17 years. We used the 2011-2012 National Survey of Children's Health to estimate the prevalence and odds of not receiving FCC by covariates. Based on parent report, 33.4% of US children did not receive FCC. Children in Arizona, Mississippi, Nevada, California, New Jersey, Virginia, Florida, and New York had at least 1.51 times higher adjusted odds of not receiving FCC than children in Vermont. Non-Hispanic Black and Hispanic children had 2.11 and 1.58 times higher odds, respectively, of not receiving FCC than non-Hispanic White children. Children from non-English-speaking households had 2.23 and 2.35 times higher adjusted odds of not receiving FCC overall and their doctors not spending enough time in their care than children from English-speaking households, respectively. Children from low-education and low-income households had a higher likelihood of not receiving FCC. The clustering of children who did not receive FCC and its components in several Southern and Western US states, as well as children from poor, uninsured, and publicly insured and of minority background, is a cause for concern in the face of federal policies to reduce health care disparities. PMID:26793395

Geographic, Racial/Ethnic, and Sociodemographic Disparities in Parent-Reported Receipt of Family-Centered Care among US Children.

PubMed

Azuine, Romuladus E; Singh, Gopal K; Ghandour, Reem M; Kogan, Michael D

2015-01-01

This study examined geographic, racial/ethnic, and sociodemographic disparities in parental reporting of receipt of family-centered care (FCC) and its components among US children aged 0-17 years. We used the 2011-2012 National Survey of Children's Health to estimate the prevalence and odds of not receiving FCC by covariates. Based on parent report, 33.4% of US children did not receive FCC. Children in Arizona, Mississippi, Nevada, California, New Jersey, Virginia, Florida, and New York had at least 1.51 times higher adjusted odds of not receiving FCC than children in Vermont. Non-Hispanic Black and Hispanic children had 2.11 and 1.58 times higher odds, respectively, of not receiving FCC than non-Hispanic White children. Children from non-English-speaking households had 2.23 and 2.35 times higher adjusted odds of not receiving FCC overall and their doctors not spending enough time in their care than children from English-speaking households, respectively. Children from low-education and low-income households had a higher likelihood of not receiving FCC. The clustering of children who did not receive FCC and its components in several Southern and Western US states, as well as children from poor, uninsured, and publicly insured and of minority background, is a cause for concern in the face of federal policies to reduce health care disparities.

47 CFR 95.428 - (CB Rule 28) How do I contact the FCC?

Code of Federal Regulations, 2010 CFR

2010-10-01

... SERVICES PERSONAL RADIO SERVICES Citizens Band (CB) Radio Service Other Things You Need to Know § 95.428... Wide Web homepage: http://www.fcc.gov. (c) In writing, to FCC, Attention: CB, 1270 Fairfield Road...

The FCC: A Research Tool.

ERIC Educational Resources Information Center

Wilson, Paul

The numerous forms filed with the Federal Communications Commission (FCC) provide information about a variety of topics. Basic licensing information that is available concerns engineering, ownership, and equal employment opportunity. The FCC's broadcast bureau collects information about programing, the ascertainment of community needs, public…

Stochastic dynamic analysis of marine risers considering Gaussian system uncertainties

NASA Astrophysics Data System (ADS)

Ni, Pinghe; Li, Jun; Hao, Hong; Xia, Yong

2018-03-01

This paper performs the stochastic dynamic response analysis of marine risers with material uncertainties, i.e. in the mass density and elastic modulus, by using Stochastic Finite Element Method (SFEM) and model reduction technique. These uncertainties are assumed having Gaussian distributions. The random mass density and elastic modulus are represented by using the Karhunen-Loève (KL) expansion. The Polynomial Chaos (PC) expansion is adopted to represent the vibration response because the covariance of the output is unknown. Model reduction based on the Iterated Improved Reduced System (IIRS) technique is applied to eliminate the PC coefficients of the slave degrees of freedom to reduce the dimension of the stochastic system. Monte Carlo Simulation (MCS) is conducted to obtain the reference response statistics. Two numerical examples are studied in this paper. The response statistics from the proposed approach are compared with those from MCS. It is noted that the computational time is significantly reduced while the accuracy is kept. The results demonstrate the efficiency of the proposed approach for stochastic dynamic response analysis of marine risers.

Apparatus and methods for regeneration of precipitating solvent

DOEpatents

Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang; Bonsu, Alexander

2015-08-25

A regenerator that can handle rich loaded chemical solvent containing precipitated absorption reaction products is disclosed. The invention is particularly suitable for separating CO.sub.2 from large gas streams that are typical of power plant processes. The internally circulating liquid stream in the regenerator (ICLS regenerator) rapidly heats-up the in-coming rich solvent stream in a downcomer standpipe as well as decreases the overall concentration of CO.sub.2 in the mixed stream. Both these actions lead to dissolution of precipitates. Any remaining precipitate further dissolves as heat is transferred to the mixed solution with an inverted bayonet tube heat exchanger in the riser portion of the regenerator. The evolving CO.sub.2 bubbles in the riser portion of the regenerator lead to substantial gas hold-up and the large density difference between the solutions in the downcomer standpipe and riser portions promotes internal circulation of the liquid stream in the regenerator. As minor amounts of solvent components present in the exit gas stream are condensed and returned back to the regenerator, pure CO.sub.2 gas stream exits the disclosed regenerator and condenser system.

Effect of particle size distribution on the hydrodynamics of dense CFB risers

NASA Astrophysics Data System (ADS)

Bakshi, Akhilesh; Khanna, Samir; Venuturumilli, Raj; Altantzis, Christos; Ghoniem, Ahmed

2015-11-01

Circulating Fluidized Beds (CFB) are favorable in the energy and chemical industries, due to their high efficiency. While accurate hydrodynamic modeling is essential for optimizing performance, most CFB riser simulations are performed assuming equally-sized solid particles, owing to limited computational resources. Even though this approach yields reasonable predictions, it neglects commonly observed experimental findings suggesting the strong effect of particle size distribution (psd) on the hydrodynamics and chemical conversion. Thus, this study is focused on the inclusion of discrete particle sizes to represent the psd and its effect on fluidization via 2D numerical simulations. The particle sizes and corresponding mass fluxes are obtained using experimental data in dense CFB riser while the modeling framework is described in Bakshi et al 2015. Simulations are conducted at two scales: (a) fine grid to resolve heterogeneous structures and (b) coarse grid using EMMS sub-grid modifications. Using suitable metrics which capture bed dynamics, this study provides insights into segregation and mixing of particles as well as highlights need for improved sub-grid models.

CFD Modelling of Particle Mixtures in a 2D CFB

NASA Astrophysics Data System (ADS)

Seppälä, M.; Kallio, S.

The capability of Fluent 6.2.16 to simulate particle mixtures in a laboratory scale 2D circulating fluidized bed (CFB) unit has been tested. In the simulations, the solids were described as one or two particle phases. The loading ratio of small to large particles, particle diameters and the gas inflow velocity were varied. The 40 cm wide and 3 m high 2D CFB was modeled using a grid with 31080 cells. The outflow of particles at the top of the CFB was monitored and emanated particles were fed back to the riser through a return duct. The paper presents the segregation patterns of the particle phases obtained from the simulations. When the fraction of large particles was 50% or larger, large particles segregated, as expected, to the wall regions and to the bottom part of the riser. However, when the fraction of large particles was 10%, an excess of large particles was found in the upper half of the riser. The explanation for this unexpected phenomenon was found in the distribution of the large particles between the slow clusters and the faster moving lean suspension.

Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation

DOE PAGES

Foust, Thomas D.; Ziegler, Jack L.; Pannala, Sreekanth; ...

2017-02-28

Here in this computational study, we model the mixing of biomass pyrolysis vapor with solid catalyst in circulating riser reactors with a focus on the determination of solid catalyst residence time distributions (RTDs). A comprehensive set of 2D and 3D simulations were conducted for a pilot-scale riser using the Eulerian-Eulerian two-fluid modeling framework with and without sub-grid-scale models for the gas-solids interaction. A validation test case was also simulated and compared to experiments, showing agreement in the pressure gradient and RTD mean and spread. For simulation cases, it was found that for accurate RTD prediction, the Johnson and Jackson partialmore » slip solids boundary condition was required for all models and a sub-grid model is useful so that ultra high resolutions grids that are very computationally intensive are not required. Finally, we discovered a 2/3 scaling relation for the RTD mean and spread when comparing resolved 2D simulations to validated unresolved 3D sub-grid-scale model simulations.« less

Closed-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1997-01-01

ABSTRACT Closed-loop HIRF experiments were performed on a fault tolerant flight control computer (FCC) at the NASA Langley Research Center. The FCC used in the experiments was a quad-redundant flight control computer executing B737 Autoland control laws. The FCC was placed in one of the mode-stirred reverberation chambers in the HIRF Laboratory and interfaced to a computer simulation of the B737 flight dynamics, engines, sensors, actuators, and atmosphere in the Closed-Loop Systems Laboratory. Disturbances to the aircraft associated with wind gusts and turbulence were simulated during tests. Electrical isolation between the FCC under test and the simulation computer was achieved via a fiber optic interface for the analog and discrete signals. Closed-loop operation of the FCC enabled flight dynamics and atmospheric disturbances affecting the aircraft to be represented during tests. Upset was induced in the FCC as a result of exposure to HIRF, and the effect of upset on the simulated flight of the aircraft was observed and recorded. This paper presents a description of these closed- loop HIRF experiments, upset data obtained from the FCC during these experiments, and closed-loop effects on the simulated flight of the aircraft.

47 CFR 95.225 - (R/C Rule 25) How do I contact the FCC?

Code of Federal Regulations, 2010 CFR

2010-10-01

... SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service Other Things You Need to Know § 95.225... Wide Web homepage: http://www.fcc.gov. (c) In writing, to FCC, Attention: R/C, 1270 Fairfield Road...

Parents' and professionals' perceptions of family-centered care for children with autism spectrum disorder across service sectors.

PubMed

Hodgetts, Sandra; Nicholas, David; Zwaigenbaum, Lonnie; McConnell, David

2013-11-01

Family-centered care (FCC) has been linked with improved parent and child outcomes, yet its implementation can be challenging due to family, professional, organizational and systemic factors and policies. This study aims to increase knowledge and understanding of how families with children with autism spectrum disorder (ASD) experience FCC in Alberta, Canada. 152 parents with a child with ASD completed the Measure of Processes of Care, separately for each utilized service sector, and 146 professionals working with persons with ASD completed the Measure of Processes of Care - Service Providers. Additionally, in-depth interviews were conducted with a sub-sample of 19 parents, purposefully sampled for diversity in child and family characteristics. Data were collected in 2011. Descriptive and inferential statistics were used to analyze quantitative data. Interview transcripts were analyzed using grounded theory constant comparison methods, yielding a data generated theoretical model depicting families' experiences with FCC over time and across service sectors. There were no statistically significant differences in FCC scores across service sectors, but statistically significant differences in FCC scores between parents' and professionals' were found. Qualitative data revealed positive experiences and perceptions of receiving FCC from professionals "on the ground" across sectors, but negative experiences and perceptions of FCC at the systems level (i.e., administration, funders). These broad experiences emerged as a core theme "System of Exclusion", which integrated the key themes: (1) "The Fight", (2) "Roles and Restrictions of Care", and (3) "Therapeutic Rapport". Professionals and service providers can use findings to ensure that services reflect current conceptualizations of FCC, and decision and policy makers can use findings to recognize systemic barriers to implementing FCC and inform policy change. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Adidharma, Hertanto, E-mail: adidharm@uwyo.edu; Tan, Sugata P.

Canonical Monte Carlo simulations on face-centered cubic (FCC) and hexagonal closed packed (HCP) Lennard-Jones (LJ) solids are conducted at very low temperatures (0.10 ≤ T{sup ∗} ≤ 1.20) and high densities (0.96 ≤ ρ{sup ∗} ≤ 1.30). A simple and robust method is introduced to determine whether or not the cutoff distance used in the simulation is large enough to provide accurate thermodynamic properties, which enables us to distinguish the properties of FCC from that of HCP LJ solids with confidence, despite their close similarities. Free-energy expressions derived from the simulation results are also proposed, not only to describe themore » properties of those individual structures but also the FCC-liquid, FCC-vapor, and FCC-HCP solid phase equilibria.« less

Installation Restoration Program. Phase II. Confirmation/Quantification Stage 2 for Griffiss Air Force Base, New York.

DTIC Science & Technology

1985-02-20

Surface Cemennt/entonte Grout Rat 20/1 6" Diameter Bore "Ole 8 Foit B.G.S. Bentorito 4" Diameter POes" Schedle 409 Fee S.O.S.PVC Riser Pipe with...Casing with Locking Cap GRiser Pipe StickupGround Surface 2.2Fe Cement/BSentonite Grout Ratio 20/1 8" Diameter Bore Hole cv Ile- 3 Feet B.G.S...Ground Surface 4’. Ground Surface .0~ Cemtert/Bentonlte Grout Rat 20/1 8" Diamneter Bore Hole__ 4" Diameter Pl O Schedule 404 PVC Riser Pipe FetBGS

Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

NASA Technical Reports Server (NTRS)

Fox, G. L.

1984-01-01

Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

Pilot Test of Hot Gas Decontamination of Explosives-Contaminated Equipment at Hawthorne Army Ammunition Plant (HWAAP), Hawthorne, Nevada. Appendices. Revision

DTIC Science & Technology

1990-06-01

was used to spike the following items of equipment: 0 powder boxes o steam-heated risers o steam-heated discharge valves o steel pipe o aluminum pipe...expose it to the internal surfaces. For pipe ( aluminum and steel), one end of the pipe section was covered with parafilm wax. Spike solution was added...spike the following items of equipment: "o powder box "o steam-heated riser "o steam-heated discharge valve "O steel pipe "o aluminum pipe Prior to

47 CFR 1.8001 - FCC Registration Number (FRN).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false FCC Registration Number (FRN). 1.8001 Section 1.8001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE FCC... unique identifying number that is assigned to entities doing business with the Commission. (b) The FRN is...

47 CFR 73.4185 - Political broadcasting and telecasting, the law of.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: Political Primer 1984,” 100 FCC 2d 1476 (1984). (b) See Report and Order, MM Docket 91-168, FCC 91-403, adopted December 12, 1991. 7 FCC Rcd 678; 57 FR 189, January 3, 1992; Memorandum Opinion and Order, MM...

47 CFR 73.4185 - Political broadcasting and telecasting, the law of.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: Political Primer 1984,” 100 FCC 2d 1476 (1984). (b) See Report and Order, MM Docket 91-168, FCC 91-403, adopted December 12, 1991. 7 FCC Rcd 678; 57 FR 189, January 3, 1992; Memorandum Opinion and Order, MM...

Stacking fault density and bond orientational order of fcc ruthenium nanoparticles

NASA Astrophysics Data System (ADS)

Seo, Okkyun; Sakata, Osami; Kim, Jae Myung; Hiroi, Satoshi; Song, Chulho; Kumara, Loku Singgappulige Rosantha; Ohara, Koji; Dekura, Shun; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi

2017-12-01

We investigated crystal structure deviations of catalytic nanoparticles (NPs) using synchrotron powder X-ray diffraction. The samples were fcc ruthenium (Ru) NPs with diameters of 2.4, 3.5, 3.9, and 5.4 nm. We analyzed average crystal structures by applying the line profile method to a stacking fault model and local crystal structures using bond orientational order (BOO) parameters. The reflection peaks shifted depending on rules that apply to each stacking fault. We evaluated the quantitative stacking faults densities for fcc Ru NPs, and the stacking fault per number of layers was 2-4, which is quite large. Our analysis shows that the fcc Ru 2.4 nm-diameter NPs have a considerably high stacking fault density. The B factor tends to increase with the increasing stacking fault density. A structural parameter that we define from the BOO parameters exhibits a significant difference from the ideal value of the fcc structure. This indicates that the fcc Ru NPs are highly disordered.

In situ TEM observation of FCC Ti formation at elevated temperatures

DOE PAGES

Yu, Qian; Kacher, Josh; Gammer, Christoph; ...

2017-07-04

Pure Ti traditionally exhibits the hexagonal closed packed (HCP) crystallographic structure under ambient conditions and the body centered cubic (BCC) structure at elevated temperatures. In addition to these typical structures for Ti alloys, the presence of a face centered cubic (FCC) phase associated with thin films, interfaces, or high levels of plastic deformation has occasionally been reported. Here in this paper we show that small FCC precipitates form in freestanding thin foils during in situ transmission electron microscope (TEM) heating and we discuss the potential origins of the FCC phase in light of the in situ observations. This FCC phasemore » was found to be stable upon cooling and under ambient conditions, which allowed us to explore its mechanical properties and stability via nanomechanical in situ TEM testing. It was found that FCC platelets within the HCP matrix phase were stable under mechanical deformation and exhibited similar mechanical deformation behavior as the parent HCP phase.« less

In situ TEM observation of FCC Ti formation at elevated temperatures

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

Yu, Qian; Kacher, Josh; Gammer, Christoph

Pure Ti traditionally exhibits the hexagonal closed packed (HCP) crystallographic structure under ambient conditions and the body centered cubic (BCC) structure at elevated temperatures. In addition to these typical structures for Ti alloys, the presence of a face centered cubic (FCC) phase associated with thin films, interfaces, or high levels of plastic deformation has occasionally been reported. Here in this paper we show that small FCC precipitates form in freestanding thin foils during in situ transmission electron microscope (TEM) heating and we discuss the potential origins of the FCC phase in light of the in situ observations. This FCC phasemore » was found to be stable upon cooling and under ambient conditions, which allowed us to explore its mechanical properties and stability via nanomechanical in situ TEM testing. It was found that FCC platelets within the HCP matrix phase were stable under mechanical deformation and exhibited similar mechanical deformation behavior as the parent HCP phase.« less

Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K

NASA Astrophysics Data System (ADS)

Dorogokupets, P. I.; Dymshits, A. M.; Litasov, K. D.; Sokolova, T. S.

2017-03-01

The equations of state for solid (with bcc, fcc, and hcp structures) and liquid phases of Fe were defined via simultaneous optimization of the heat capacity, bulk moduli, thermal expansion, and volume at room and higher temperatures. The calculated triple points at the phase diagram have the following parameters: bcc-fcc-hcp is located at 7.3 GPa and 820 K, bcc-fcc-liquid at 5.2 GPa and 1998 K, and fcc-hcp-liquid at 106.5 GPa and 3787 K. At conditions near the fcc-hcp-liquid triple point, the Clapeyron slope of the fcc-liquid curve is dT/dP = 12.8 K/GPa while the slope of the hcp-liquid curve is higher (dT/dP = 13.7 K/GPa). Therefore, the hcp-liquid curve overlaps the metastable fcc-liquid curve at pressures of about 160 GPa. At high-pressure conditions, the metastable bcc-hcp curve is located inside the fcc-Fe or liquid stability field. The density, adiabatic bulk modulus and P-wave velocity of liquid Fe calculated up to 328.9 GPa at adiabatic temperature conditions started from 5882 K (outer/inner core boundary) were compared to the PREM seismological model. We determined the density deficit of hcp-Fe at the inner core boundary (T = 5882 K and P = 328.9 GPa) to be 4.4%.

Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K.

PubMed

Dorogokupets, P I; Dymshits, A M; Litasov, K D; Sokolova, T S

2017-03-06

The equations of state for solid (with bcc, fcc, and hcp structures) and liquid phases of Fe were defined via simultaneous optimization of the heat capacity, bulk moduli, thermal expansion, and volume at room and higher temperatures. The calculated triple points at the phase diagram have the following parameters: bcc-fcc-hcp is located at 7.3 GPa and 820 K, bcc-fcc-liquid at 5.2 GPa and 1998 K, and fcc-hcp-liquid at 106.5 GPa and 3787 K. At conditions near the fcc-hcp-liquid triple point, the Clapeyron slope of the fcc-liquid curve is dT/dP = 12.8 K/GPa while the slope of the hcp-liquid curve is higher (dT/dP = 13.7 K/GPa). Therefore, the hcp-liquid curve overlaps the metastable fcc-liquid curve at pressures of about 160 GPa. At high-pressure conditions, the metastable bcc-hcp curve is located inside the fcc-Fe or liquid stability field. The density, adiabatic bulk modulus and P-wave velocity of liquid Fe calculated up to 328.9 GPa at adiabatic temperature conditions started from 5882 K (outer/inner core boundary) were compared to the PREM seismological model. We determined the density deficit of hcp-Fe at the inner core boundary (T = 5882 K and P = 328.9 GPa) to be 4.4%.

75 FR 56533 - Privacy Act System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... add one new system of records, FCC/OMD-23, ``Cadapult Space Management System (CSMS).'' The FCC's Space Management Center (SMC) in the Office of Managing Director (OMD) will use the CSMS information... and contractors following the FCC/National Treasury Union (NTEU) space assignment policy. In the event...

76 FR 69738 - Revised 2011 Annual Telecommunications Reporting Worksheet (FCC Form 499-A) and Accompanying...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... Telecommunications Reporting Worksheet (FCC Form 499-A) and Accompanying Instructions AGENCY: Federal Communications... Telecommunications Reporting Worksheet (FCC Form 499-A) and accompanying instructions that have been approved by the... INFORMATION CONTACT: Ernesto Beckford, Wireline Competition Bureau, Telecommunications Access Policy Division...

Insights into PM10 sources in Houston, Texas: Role of petroleum refineries in enriching lanthanoid metals during episodic emission events

NASA Astrophysics Data System (ADS)

Bozlaker, Ayşe; Buzcu-Güven, Birnur; Fraser, Matthew P.; Chellam, Shankararaman

2013-04-01

Petroleum refineries may emit large quantities of pollutants during non-routine operations that include start-ups and shutdowns, planned maintenance, and unplanned equipment failures. The Texas Commission on Environmental Quality (TCEQ) tracks such events by requiring industries to self-report estimates of these emissions because they often have a detrimental impact on local air quality and potentially, public health. An inventory of non-routine episodic emission events is available via TCEQ's website. However, there is on-going concern that such episodic emissions are sometimes under-reported or even not cataloged. Herein, we present concentrations of 42 main group, transition, and lanthanoid elements in 114 time-resolved (3 or 6 h) samples collected over a 1-month period. We also develop strategies to identify aerosol sources using elemental tracers and compare source apportionment (performed by positive matrix factorization) based on ambient measurements to inventoried non-routine emission events. Through interpretation of key marker elements, five sources impacting concentrations of metals in PM10 were identified and calculated to contribute 73% of the measured PM10 mass. On average, primary emissions from fluidized-bed catalytic cracking (FCC) units negligibly contributed to apportioned PM10 mass. However, 35 samples were identified as impacted by transient PM10 emissions from FCC units because of elevated levels of lanthanoid metals and their ratios. Only 31 of these 35 samples coincided with self-reported non-routine emission events. Further, roughly half of the emission event self-reports detailed only emissions of gaseous pollutants. Based on this, we posit that not all PM10 emission events are reported and even self-reported emission events are incomplete - those that only catalog gaseous pollutants may also include unreported PM emissions.

78 FR 49126 - Modernizing the FCC Form 477 Data Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 0, 1, and 43 [WC Docket No. 11-10; FCC 13-87] Modernizing the FCC Form 477 Data Program AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: The Report and Order revises the Federal Communications Commission's Form 477 collection to...

77 FR 36177 - National Environmental Policy Act Compliance for Proposed Tower Registrations; Effects of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

...: Application for Antenna Structure Registration, FCC Form 854. Form Number: FCC Form 854. Respondents... Commission's rules. Needs and Uses: The purpose of FCC Form 854 is to register antenna structures (radio... make changes to existing registered antenna structures or pending applications for registration; and to...

76 FR 20976 - Wireline Competition Bureau Releases 2011 Annual Telecommunications Reporting Worksheet (FCC Form...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... Releases 2011 Annual Telecommunications Reporting Worksheet (FCC Form 499-A) and Accompanying Instructions... Competition Bureau released the revised annual Telecommunications Reporting Worksheet (FCC Form 499-A) and... telecommunications activities) into Appendix B. (5) Noting that email addresses are generally required so that the...

75 FR 23763 - Notice of Public Information Collections Approved by the Office of Management and Budget (OMB)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... Construct or Make Changes in an FM Translator or FM Booster Station, FCC Form 349. Form No.: FCC Form 349... Commission actions. FCC Form 349 is used to apply for authority to construct a new FM translator or FM...

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

Tracy, Cameron L.; Park, Sulgiye; Rittman, Dylan R.

High pressure x-ray diffraction measurements reveal that the face-centered cubic (fcc) high-entropy alloy CrMnFeCoNi transforms martensitically to a hexagonal close-packed (hcp) phase at ~14 GPa. We attribute this to suppression of the local magnetic moments, destabilizing the fcc phase. Similar to fcc-to-hcp transformations in Al and the noble gases, this transformation is sluggish, occurring over a range of >40 GPa. But, the behavior of CrMnFeCoNi is unique in that the hcp phase is retained following decompression to ambient pressure, yielding metastable fcc-hcp mixtures.

Flat conductor cable for electrical packaging

NASA Technical Reports Server (NTRS)

Angele, W.

1972-01-01

Flat conductor cable (FCC) is relatively new, highly promising means for electrical packaging and system integration. FCC offers numerous desirable traits (weight, volume and cost savings, flexibility, high reliability, predictable and repeatable electrical characteristics) which make it extremely attractive as a packaging medium. FCC, today, finds wide application in everything from integration of lunar equipment to the packaging of electronics in nuclear submarines. Described are cable construction and means of termination, applicable specifications and standards, and total FCC systems. A list of additional sources of data is also included for more intensive study.

A novel "wastes-treat-wastes" technology: role and potential of spent fluid catalytic cracking catalyst assisted ozonation of petrochemical wastewater.

PubMed

Chen, Chunmao; Yu, Ji; Yoza, Brandon A; Li, Qing X; Wang, Gang

2015-04-01

Catalytic ozonation is a promising wastewater treatment technology. However, the high cost of the catalyst hinders its application. A novel "wastes-treat-wastes" technology was developed to reuse spent fluid catalytic cracking catalysts (sFCCc) for the ozonation of petrochemical wastewater in this study. Multivalent vanadium (V(4+) and V(5+)), iron (Fe(2+) and Fe(3+)) and nickel (Ni(2+)) oxides that are distributed on the surface of sFCCc and poisoned FCC catalysts are the catalytic components for ozonation. The sFCCc assisted catalytic ozonation (sFCCc-O) of nitrobenzene indicated that the sFCCc significantly promoted hydroxyl radical mediated oxidation. The degradation rate constant of nitrobenzene in sFCCc-O (0.0794 min(-1) at 298 K) was approximately doubled in comparison with that in single ozonation (0.0362 min(-1) at 298 K). The sFCCc-O of petrochemical wastewater increased chemical oxygen demand removal efficiency by three-fold relative to single ozonation. The number of oxygen-containing (Ox) polar contaminants in the effluent (253) from sFCCc-O treatment decreased to about 70% of the initial wastewater (353). The increased oxygen/carbon atomic ratio and decreased number of Ox polar contaminants indicated a high degree of degradation. The present study showed the role and potential of sFCCc for catalytic ozonation of petrochemical wastewater, particularly in an advantage of the cost-effectiveness through "wastes-treat-wastes". Copyright © 2015 Elsevier Ltd. All rights reserved.

The simulation and experimental validation on gas-solid two phase flow in the riser of a dense fluidized bed

NASA Astrophysics Data System (ADS)

Wang, Xue-Yao; Jiang, Fan; Xu, Xiang; Wang, Sheng-Dian; Fan, Bao-Guo; Xiao, Yun-Han

2009-06-01

Gas-solid flow in dense CFB (circulating fluidized bed)) riser under the operating condition, superficial gas 15.5 m/s and solid flux 140 kg/m2s using Geldart B particles (sand) was investigated by experiments and CFD (computational fluid dynamics) simulation. The overall and local flow characteristics are determined using the axial pressure profiles and solid concentration profiles. The cold experimental results indicate that the axial solid concentration distribution contains a dilute region towards the up-middle zone and a dense region near the bottom and the top exit zones. The typical core-annulus structure and the back-mixing phenomenon near the wall of the riser can be observed. In addition, owing to the key role of the drag force of gas-solid phase, a revised drag force coefficient, based on the EMMS (energy-minimization multi-scale) model which can depict the heterogeneous character of gas-solid two phase flow, was proposed and coupled into the CFD control equations. In order to find an appropriate drag force model for the simulation of dense CFB riser, not only the revised drag force model but some other kinds of drag force model were used in the CFD. The flow structure, solid concentration, clusters phenomenon, fluctuation of two phases and axial pressure drop were analyzed. By comparing the experiment with the simulation, the results predicted by the EMMS drag model showed a better agreement with the experimental axial average pressure drop and apparent solid volume fraction, which proves that the revised drag force based on the EMMS model is an appropriate model for the dense CFB simulation.

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

Liu, Jiyuan; Zhang, Zicheng, E-mail: zhangzicheng2004@126.com; Manabe, Ken-ichi

Transformation-induced plasticity aided seamless steel tube comprising of ferrite, bainite, and metastable austenite was processed through forging, piercing, cold-drawing, and two-stage heat treatment. T-shape hydroforming is a classic forming method for experimental research and practical production. The current work studied austenite-to-martensite transformation and microcrack initiation and propagation of the tube during T-shape hydroforming using electron backscattering diffraction, scanning electron microscopy, and transmission electron microscopy. The strain distribution in the bcc-phase and fcc-phase was studied by evaluating changes in the average local misorientation. Compared to the compressive stress, metastable austenite with similar strain surrounding or inside the grains transformed easier undermore » tensile loading conditions. The inclusions were responsible for microcrack initiation. The propagation of the cracks is hindered by martensite/austenite constituent due to transformation induced plasticity effect. The volume fraction of untransformed retained austenite decreased with increase in strain implying transformation-induced plasticity effect. - Highlights: • Hydroformed tubes processed via TRIP concept • EBSD provided estimate of micro local strain. • Retained austenite hinders propagation of microcracks.« less

A comparative investigation of SO2 oxidative transfer over CuO with a CeO2 surface

NASA Astrophysics Data System (ADS)

Liu, Yifeng; Shen, Benxian; Pi, Zhipeng; Chen, Hua; Zhao, Jigang

2017-04-01

To further improve the catalytic desulfurization function of the Mg-Al spinel sulfur transfer agent in a fluid catalytic cracking (FCC) unit, the reaction paths of SO2 oxidation by O2 over the metal oxide surface of CuO (111) and CeO2 (111) were investigated. In reference to the fact that SO2 reacting with O2 over CuO was a Mars-van Krevelen cycle, a similar reaction law for SO2 oxidation over CeO2 was also verified by characterization methods (e.g., IR, XPS). Meanwhile, the molecular simulation results indicated that the rate-control step of SO2 oxidation over CeO2 (111) and CuO (111) was a SO3 desorption step. The lower energy barrier in the rate-control step corresponded to better catalytic performance; hence, it could explain the reason that CeO2 had a better sulfur oxidization transfer performance than CuO.

Computer simulation of surface and film processes

NASA Technical Reports Server (NTRS)

Tiller, W. A.; Halicioglu, M. T.

1984-01-01

All the investigations which were performed employed in one way or another a computer simulation technique based on atomistic level considerations. In general, three types of simulation methods were used for modeling systems with discrete particles that interact via well defined potential functions: molecular dynamics (a general method for solving the classical equations of motion of a model system); Monte Carlo (the use of Markov chain ensemble averaging technique to model equilibrium properties of a system); and molecular statics (provides properties of a system at T = 0 K). The effects of three-body forces on the vibrational frequencies of triatomic cluster were investigated. The multilayer relaxation phenomena for low index planes of an fcc crystal was analyzed also as a function of the three-body interactions. Various surface properties for Si and SiC system were calculated. Results obtained from static simulation calculations for slip formation were presented. The more elaborate molecular dynamics calculations on the propagation of cracks in two-dimensional systems were outlined.

On Campus Web-Monitoring Rules, Colleges and the FCC Have a Bad Connection

ERIC Educational Resources Information Center

Hartle, Terry W.

2006-01-01

A regulation issued by the US Federal Communications Commission (FCC) requires facilities-based Internet services providers who operate their own equipment, including colleges, to make their Internet systems compliant with a statute known as the Communications Assistance for Law Enforcement Act (Calea) by April 2007. However, the FCC does not…

77 FR 3266 - Information Collection Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

... business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of... advise the FCC contact listed below as soon as possible. ADDRESSES: Submit your PRA comments to Judith B.Herman, Federal Communications Commission, via the Internet at [email protected]fcc.gov . To submit your...

77 FR 43536 - Wireless E911 Phase II Location Accuracy Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-25

... Docket No. 07-114; FCC 11-107] Wireless E911 Phase II Location Accuracy Requirements AGENCY: Federal...- 2413, or email: [email protected]fcc.gov . SUPPLEMENTARY INFORMATION: This document announces that, on... Commission's Order, FCC 11-107, published at 76 FR 59916, September 28, 2011. The OMB Control Number is 3060...

77 FR 65320 - Empowering Consumers To Prevent and Detect Billing for Unauthorized Charges (“Cramming...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-26

.... 98-170; FCC 12-42] Empowering Consumers To Prevent and Detect Billing for Unauthorized Charges..., [email protected]fcc.gov or (202) 418-2887, of the Consumer and Governmental Affairs Bureau. SUPPLEMENTARY... information collection requirements contained in the Commission's Report and Order, FCC 12-42, published at 77...

Termination of flat conductor cable to NASA/MSFC plugs

NASA Technical Reports Server (NTRS)

Angele, W.

1972-01-01

Data, supplemented with artwork, are presented on the major steps involved with terminating flat conductor cable (FCC) to MSFC's FCC plugs. Cable and shield preparation steps include material cutting, insulation stripping, and plating of exposed conductors. Methods and equipment required to terminate FCC to each of four MSFC plugs are described.

47 CFR 73.642 - Subscription TV service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... available to the FCC upon request. (d) The use of the visual vertical blanking interval or an aural... programming may be used only upon specific FCC authorization. Letter requests to use either the video blanking intervals or aural subcarriers during periods of non-subscription programming are to be sent to the FCC in...

47 CFR 73.642 - Subscription TV service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... available to the FCC upon request. (d) The use of the visual vertical blanking interval or an aural... programming may be used only upon specific FCC authorization. Letter requests to use either the video blanking intervals or aural subcarriers during periods of non-subscription programming are to be sent to the FCC in...

Symmetry-guaranteed nodal-line semimetals in an fcc lattice

NASA Astrophysics Data System (ADS)

Kawakami, Takuto; Hu, Xiao

2017-12-01

We demonstrate theoretically that nodal-line semimetals (NLSs) can be realized in an fcc lattice with orbitals belonging to the same irreducible representation, such as {px,py,pz} or {dx y,dy z,dz x} orbitals on every lattice site. The three orbitals are divided into two subgroups in terms of the parity with respect to the mirror reflections on high-symmetry planes of the fcc lattice, which, with rotation symmetry, endows symmetry-guaranteed NL passing through W points in the Brillouin zone. Depending on the parameters, there also appears an accidental NL around the Γ point. We notice that the symmetry-guaranteed NL addressed in the present work can be found in band structures of elemental solids taking the fcc structure, such as Cu, Ag, Au, In, Ga, etc., as well as opal, which is an fcc photonic crystal of SiO2 spheres. Furthermore, we clarify that the fcc lattice of Si spheres exhibits a NL in a frequency band where no other photonic band exists, which provides a unique platform to realize topological NLSs under intensive search, and can be explored for achieving slow light.

Face-centred cubic to body-centred cubic phase transformation under [1 0 0] tensile loading

NASA Astrophysics Data System (ADS)

Xie, Hongxian; Yu, Jiayun; Yu, Tao; Yin, Fuxing

2018-06-01

Molecular dynamics simulation was used to verify a speculation of the existence of a certain face-centred cubic (FCC) to body-centred cubic (BCC) phase transformation pathway. Four FCC metals, Ni, Cu, Au and Ag, were stretched along the [1 0 0] direction at various strain rates and temperatures. Under high strain rate and low temperature, and beyond the elastic limit, the bifurcation of the FCC phase occurred with sudden contraction along one lateral direction and expansion along the other lateral direction. When the lattice constant along the expansion direction converged with that of the stretched direction, the FCC phase transformed into an unstressed BCC phase. By reducing the strain rate or increasing the temperature, dislocation or 'momentum-induced melting' mechanisms began to control the plastic deformation of the FCC metals, respectively.

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

Fischer, F.J.

As the petroleum industry has moved into deeper and deeper water for the recovery of oil and gas, weight-sensitive floating platforms have replaced stationary, bottom-founded structures. The cost penalty for weight or vertical tension supported by floaters such as tension leg platforms (TLPs) is in the range of $10--20/kg. Hence, there is considerable incentive to reduce the weight of equipment or structural members on these platforms and downward forces exerted on these platforms by production and export risers, and mooring lines. Thus, there are numerous opportunities for utilizing light-weight, high-strength composites. The offshore petroleum industry has acknowledged the desirable performancemore » characteristics of composites for some time but only recently has there been some optimism that composites could be cost-effective. For most, if not all perceived applications, advanced composites are not considered to be technically enabling for current water depths of interest, i.e., 600--1,200m. However, in a very real sense, they may be economically enabling. In particular, they may allow marginal prospects to be developed or may expedite field development subject to capital constraints. The paper discusses composite production risers, break-even costs and savings, and riser tensioners.« less

Study of cluster behavior in the riser of CFB by the DSMC method

NASA Astrophysics Data System (ADS)

Liu, H. P.; Liu, D. Y.; Liu, H.

2010-03-01

The flow behaviors of clusters in the riser of a two-dimensional (2D) circulating fluidized bed was numerically studied based on the Euler-Lagrangian approach. Gas turbulence was modeled by means of Large Eddy Simulation (LES). Particle collision was modeled by means of the direct simulation Monte Carlo (DSMC) method. Clusters' hydrodynamic characteristics are obtained using a cluster identification method proposed by sharrma et al. (2000). The descending clusters near the wall region and the up- and down-flowing clusters in the core were studied separately due to their different flow behaviors. The effects of superficial gas velocity on the cluster behavior were analyzed. Simulated results showed that near wall clusters flow downward and the descent velocity is about -45 cm/s. The occurrence frequency of the up-flowing cluster is higher than that of down-flowing cluster in the core of riser. With the increase of superficial gas velocity, the solid concentration and occurrence frequency of clusters decrease, while the cluster axial velocity increase. Simulated results were in agreement with experimental data. The stochastic method used in present paper is feasible for predicting the cluster flow behavior in CFBs.

IMPACT OF PARTICLE AGGLOMERATION ON ACCUMULATION RATES IN THE GLASS DISCHARGE RISER OF HLW MELTER

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

Matyas, Josef; Jansik, Danielle P.; Owen, Antionette T.

2013-08-05

The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with X-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, andmore » on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185±155 µm, and produced >3 mm thick layer after 120 h at 850 °C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.« less

Impact Of Particle Agglomeration On Accumulation Rates In The Glass Discharge Riser Of HLW Melter

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

Kruger, A. A.; Rodriguez, C. A.; Matyas, J.

2012-11-12

The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with x-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, andmore » on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185+-155 {mu}m, and produced >3 mm thick layer after 120 h at 850 deg C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.« less

Reconstruction of Twist Torque in Main Parachute Risers

NASA Technical Reports Server (NTRS)

Day, Joshua D.

2015-01-01

The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

Peri-anterior cruciate ligament reconstruction femur fracture: a biomechanical analysis of the femoral tunnel as a stress riser.

PubMed

Han, Yung; Sardar, Zeeshan; McGrail, Scott; Steffen, Thomas; Martineau, Paul A

2011-12-01

Sixteen case reports of distal femur fractures as post-operative complications after anterior cruciate ligament (ACL) reconstruction have been described in the literature. The femoral tunnel has been suggested as a potential stress riser for fracture formation. Additionally, double bundle ACL reconstructions may compound this risk. This is the first biomechanical study to examine the significance of a stress riser effect of the femoral tunnel(s) after ACL reconstruction. The hypotheses tested in this study are that the femoral tunnel acts as a stress riser for fracture and that this effect increases with the size of the tunnel (8 mm vs. 10 mm) and with the number of tunnels (1 vs. 2). Femoral tunnels simulating single bundle (SB) hamstring graft (8 mm), bone-patellar tendon-bone graft (10 mm), and double bundle (DB) ACL reconstruction (7, 6 mm) were drilled in fourth-generation saw bones. These three experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure. All fractures occurred through the tunnels in the DB group, whereas fractures did not consistently occur through the tunnels in the SB groups. The mean fracture load was 6,145N ± 471N in the native group, 5,691N ± 198N in the 8 mm SB group, 5,702N ± 282N in the 10 mm SB group, and 4,744N ± 418N in the DB group. The mean fracture load for the DB group was significantly lower when compared to the native, 8 mm SB, and 10 mm SB groups independently (P value = 0.0016, 0.0060, and 0.0038, respectively). The mean fracture loads for neither SB groups were not significantly different from the native group. An anatomically placed femoral tunnel in single bundle ACL reconstruction in our experimental model was not a significant stress riser to fracture, whereas the two femoral tunnels in double bundle ACL reconstruction significantly decreased load to failure. The results support the sparsity of reported peri-ACL reconstruction femur fractures in single femoral tunnel techniques. However, the increased fracture risk in double bundle ACL reconstruction may be a cause for concern and impact patient selection.

Attrition resistant catalysts and sorbents based on heavy metal poisoned FCC catalysts

DOEpatents

Gangwal, S.; Jothimurugesan, K.

1999-07-27

A heavy metal poisoned, spent FCC catalyst is treated by chemically impregnating the poisoned catalyst with a new catalytic metal or metal salt to provide an attrition resistant catalyst or sorbent for a different catalytic or absorption process, such as catalysts for Fischer-Tropsh Synthesis, and sorbents for removal of sulfur gases from fuel gases and flue-gases. The heavy metal contaminated FCC catalyst is directly used as a support for preparing catalysts having new catalytic properties and sorbents having new sorbent properties, without removing or passivating the heavy metals on the spent FCC catalyst as an intermediate step.

Attrition resistant catalysts and sorbents based on heavy metal poisoned FCC catalysts

DOEpatents

Gangwal, Santosh; Jothimurugesan, Kandaswamy

1999-01-01

A heavy metal poisoned, spent FCC catalyst is treated by chemically impregnating the poisoned catalyst with a new catalytic metal or metal salt to provide an attrition resistant catalyst or sorbent for a different catalytic or absorption processes, such as catalysts for Fischer-Tropsh Synthesis, and sorbents for removal of sulfur gasses from fuel gases and flue-gases. The heavy metal contaminated FCC catalyst is directly used as a support for preparing catalysts having new catalytic properties and sorbents having new sorbent properties, without removing or "passivating" the heavy metals on the spent FCC catalyst as an intermediate step.

Critical temperature of the Ising ferromagnet on the fcc, hcp, and dhcp lattices

NASA Astrophysics Data System (ADS)

Yu, Unjong

2015-02-01

By an extensive Monte-Carlo calculation together with the finite-size-scaling and the multiple histogram method, the critical coupling constant (Kc = J /kBTc) of the Ising ferromagnet on the fcc, hcp, and double hcp (dhcp) lattices were obtained with unprecedented precision: Kcfcc= 0.1020707(2) , Kchcp= 0.1020702(1) , and Kcdhcp= 0.1020706(2) . The critical temperature Tc of the hcp lattice is found to be higher than those of the fcc and the dhcp lattice. The dhcp lattice seems to have higher Tc than the fcc lattice, but the difference is within error bars.

Comparison of the magnetic properties of metastable hexagonal close-packed Ni nanoparticles with those of the stable face-centered cubic Ni nanoparticles.

PubMed

Jeon, Yoon Tae; Moon, Je Yong; Lee, Gang Ho; Park, Jeunghee; Chang, Yongmin

2006-01-26

We report the first magnetic study of pure and metastable hexagonal close-packed (hcp) Ni nanoparticles (sample 1). We also produced stable face-centered cubic (fcc) Ni nanoparticles, as mixtures with the hcp Ni nanoparticles (samples 2 and 3). We compared the magnetic properties of the hcp Ni nanoparticles with those of the fcc Ni nanoparticles by observing the evolution of magnetic properties from those of the hcp Ni nanoparticles to those of the fcc Ni nanoparticles as the number of fcc Ni nanoparticles increased from sample 1 to sample 3. The blocking temperature (T(B)) of the hcp Ni nanoparticles is approximately 12 K for particle diameters ranging between 8.5 and 18 nm, whereas those of the fcc Ni nanoparticles are 250 and 270 K for average particle diameters of 18 and 26 nm, respectively. The hcp Ni nanoparticles seem to be antiferromagnetic for T < T(B) and paramagnetic for T > T(B). This is very different from the fcc Ni nanoparticles, which are ferromagnetic for T < T(B) and superparamagnetic for T > T(B). This unusual magnetic state of the metastable hcp Ni nanoparticles is likely related to their increased bond distance (2.665 angstroms), compared to that (2.499 angstroms) of the stable fcc Ni nanoparticles.

Family-centered care in pediatric critical care transport.

PubMed

Joyce, Crystal N; Libertin, Rachel; Bigham, Michael T

2015-01-01

Family-centered care (FCC) in medicine highlights mutually beneficial partnerships among providers, patients, and families. In the field of specialty pediatric critical care transport (SPCCT), FCC includes family presence during transport. We sought to describe family presence and family/staff perspectives of FCC in transport. This institutional review board-approved study established family presence rates among 5 SPCCT teams. At the top-performing family presence team, parents of transported children were interviewed. A staff survey measured perspectives on FCC using SurveyMonkey (Palo Alto, CA). Statistical tests including chi-square and Fisher exact tests for comparative data were applied using SPSSv17.0 software (SPSS Inc, Chicago, IL). The cohort-wide range of family presence was 23% to 66%. Parents were 4 times more likely to accompany their child if transported by ground versus air (ground: 26 [59%] vs. air: 6 [26%]). Sex, race, travel distance from referral hospital, and child's age did not influence the rate of family accompaniment. Most staff (76%) received education on FCC. This study informs how transport factors and parent/staff perceptions influence parental presence on transport at a single center. Opportunities to optimize transport FCC include defining protocols for ground and air transport, establishing a more welcoming attitude toward parents, and designing an FCC educational module specific for transport staff. Copyright © 2015 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Giants That Occasionally Roar: Broadcast Regulatory Policy in the United States.

ERIC Educational Resources Information Center

Busby, Linda J.

In this document, broadcast regulatory issues since 1940 are outlined and discussed in relation to social forces. The 1940s saw open warfare between the Federal Communications Commission (FCC) and broadcasters, as a result of the FCC expanding its powers. In 1946, the FCC issued its "Public Service Responsibility of Broadcast Licensees,"…

78 FR 72889 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-04

... burden for small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a... FCC Form 525. Type of Review: Revision of a currently approved collection. Respondents: Business or... Rulemaking, 26 FCC Rcd 17663 (2011) (USF/ICC Transformation Order); see also Connect America Fund et al., WC...

47 CFR 73.3540 - Application for voluntary assignment or transfer of control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Application for voluntary assignment or transfer of control. (a) Prior consent of the FCC must be obtained for a voluntary assignment or transfer of control. (b) Application should be filed with the FCC at least... “Assignment of license” or FCC Form 316 “Short form” (See paragraph (f) of this section). (d) Application for...

47 CFR 73.3540 - Application for voluntary assignment or transfer of control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Application for voluntary assignment or transfer of control. (a) Prior consent of the FCC must be obtained for a voluntary assignment or transfer of control. (b) Application should be filed with the FCC at least... “Assignment of license” or FCC Form 316 “Short form” (See paragraph (f) of this section). (d) Application for...

47 CFR 73.3540 - Application for voluntary assignment or transfer of control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Application for voluntary assignment or transfer of control. (a) Prior consent of the FCC must be obtained for a voluntary assignment or transfer of control. (b) Application should be filed with the FCC at least... “Assignment of license” or FCC Form 316 “Short form” (See paragraph (f) of this section). (d) Application for...

47 CFR 73.3540 - Application for voluntary assignment or transfer of control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Application for voluntary assignment or transfer of control. (a) Prior consent of the FCC must be obtained for a voluntary assignment or transfer of control. (b) Application should be filed with the FCC at least... “Assignment of license” or FCC Form 316 “Short form” (See paragraph (f) of this section). (d) Application for...

75 FR 15352 - Universal Service Support for Low-Income Consumers; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-29

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 54 [WC Docket No. 05-195; WC Docket No. 03-109; FCC... Access Policy Division at (202) 418-7400 (voice), (202) 418- 0484 (TTY), or e-mail at [email protected]fcc.gov . SUPPLEMENTARY INFORMATION: Background In a Report and Order (FCC 07-150), the Commission adopted...

77 FR 58990 - Information Collection Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-25

.... SUMMARY: The Federal Communications Commission (FCC), as part of its continuing effort to reduce paperwork... than 25 employees. The FCC may not conduct or sponsor a collection of information unless it displays a.... ADDRESSES: Direct all PRA comments to the Federal Communications Commission via email to [email protected]fcc.gov and...

76 FR 76623 - Connect America Fund; Developing a Unified Intercarrier Compensation Regime

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-08

...-109; GN Docket No. 09-51, CC Docket Nos. 01-92, 96-45, WT Docket No. 10-208, FCC 11-161] Connect... Policy Division, Wireline Competition Bureau, at (202) 418-1520, or email: [email protected]fcc.gov... relating to the access stimulation rules contained in the Commission's Order, FCC 11-161, published at 76...

75 FR 34738 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-18

... employees. The FCC may not conduct or sponsor a collection of information unless it displays a currently... to do so within the period of time allowed by this notice, you should advise the FCC contact listed... the Federal Communications Commission via email to [email protected]fcc.gov . FOR FURTHER INFORMATION CONTACT...

47 CFR 95.421 - (CB Rule 21) What are the penalties for violating these rules?

Code of Federal Regulations, 2010 CFR

2010-10-01

... FCC finds that you have willfully or repeatedly violated the Communications Act or the FCC Rules, you...) of the Communications Act.) (b) If the FCC finds that you have violated any section of the... section 312(b) of the Communications Act.) (c) If a Federal court finds that you have willfully and...

47 CFR 3.53 - FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s). 3.53 Section 3.53 Telecommunication FEDERAL COMMUNICATIONS... telecommunications service to U.S. registered vessel(s). An accounting authority must inform the FCC immediately...

47 CFR 3.53 - FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s). 3.53 Section 3.53 Telecommunication FEDERAL COMMUNICATIONS... telecommunications service to U.S. registered vessel(s). An accounting authority must inform the FCC immediately...

47 CFR 3.53 - FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s). 3.53 Section 3.53 Telecommunication FEDERAL COMMUNICATIONS... telecommunications service to U.S. registered vessel(s). An accounting authority must inform the FCC immediately...

47 CFR 3.53 - FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s). 3.53 Section 3.53 Telecommunication FEDERAL COMMUNICATIONS... telecommunications service to U.S. registered vessel(s). An accounting authority must inform the FCC immediately...

47 CFR 3.53 - FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 false FCC notification of refusal to provide telecommunications service to U.S. registered vessel(s). 3.53 Section 3.53 Telecommunication FEDERAL COMMUNICATIONS... telecommunications service to U.S. registered vessel(s). An accounting authority must inform the FCC immediately...

76 FR 12308 - Modernizing the FCC Form 477 Data Program; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-07

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 1, 20, and 43 [WCB: WC Docket Nos. 07-38, 09-190, 10-132, 11-10; FCC 11-14] Modernizing the FCC Form 477 Data Program; Correction AGENCY: Federal..., Deputy Manager. [FR Doc. 2011-5095 Filed 3-4-11; 8:45 am] BILLING CODE 6712-01-P ...

78 FR 44121 - FCC Extends Reply Comment Dates for Indecency Cases Policy

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

... FEDERAL COMMUNICATIONS COMMISSION [GN Docket No. 13-86; DA 13-1560] FCC Extends Reply Comment... number of this Notice, GN Docket No. 13-86, on the front page. The Public Notice, DA 13-1560, released... documents from BCPI, please provide the appropriate FCC document number DA 13-1560. The Public Notice is...

Effect of the fcc-hcp martensitic transition on the equation of state of solid krypton up to 140 GPa

NASA Astrophysics Data System (ADS)

Rosa, A. D.; Garbarino, G.; Briggs, R.; Svitlyk, V.; Morard, G.; Bouhifd, M. A.; Jacobs, J.; Irifune, T.; Mathon, O.; Pascarelli, S.

2018-03-01

Solid krypton (Kr) undergoes a pressure-induced martensitic phase transition from a face-centered cubic (fcc) to a hexagonal close-packed (hcp) structure. These two phases coexist in a very wide pressure domain inducing important modifications of the bulk properties of the resulting mixed phase system. Here, we report a detailed in situ x-ray diffraction and absorption study of the influence of the fcc-hcp phase transition on the compression behavior of solid krypton in an extended pressure domain up to 140 GPa. The onset of the hcp-fcc transformation was observed in this study at around 2.7 GPa and the coexistence of these two phases up to 140 GPa, the maximum investigated pressure. The appearance of the hcp phase is also evidenced by the pressure-induced broadening and splitting of the first peak in the XANES spectra. We demonstrate that the transition is driven by a continuous nucleation and intergrowth of nanometric hcp stacking faults that evolve in the fcc phase. These hcp stacking faults are unaffected by high-temperature annealing, suggesting that plastic deformation is not at their origin. The apparent small Gibbs free-energy differences between the two structures that decrease upon compression may explain the nucleation of hcp stacking faults and the large coexistence domain of fcc and hcp krypton. We observe a clear anomaly in the equation of state of the fcc solid at ˜20 GPa when the proportion of the hcp form reaches ˜20 % . We demonstrate that this anomaly is related to the difference in stiffness between the fcc and hcp phases and propose two distinct equation of states for the low and high-pressure regimes.

Role of distortion in the hcp vs fcc competition in rare-gas solids

NASA Astrophysics Data System (ADS)

Krainyukova, N. V.

2011-05-01

As a prototype of an initial or intermediate structure between hcp and fcc lattices we consider a distorted bcc crystal. We calculate the temperature and pressure dependences of the lattice parameters for the heavier rare gas solids Ar, Kr, Xe in a quasiharmonic approximation with Aziz potentials, and confirm earlier predictions that the hcp structure predominates over fcc in the bulk within wide ranges of P and T. The situation is different for confined clusters with up to 105 atoms, where, owing to the specific surface energetics and terminations, structures with five-fold symmetry made up of fcc fragments are dominant. As a next step we consider the free relaxation of differently distorted bcc clusters, and show that two types (monoclinic and orthorhombic) of initial distortion are a driving force for the final hcp vs fcc configurations. Possible energy relationships between the initial and final structures are obtained and analyzed.

Family centered care within an infant-toddler unit.

PubMed

Neal, Annmarie; Frost, Michelle; Kuhn, Janna; Green, Angela; Gance-Cleveland, Bonnie; Kersten, Rebecca

2007-01-01

Family centered care (FCC) is an essential component of pediatric nursing. A unit-based FCC Committee was charged with evaluating care on an inpatient infant-toddler unit. The committee adapted the Institute of Family Centered Care survey tools and used them to evaluate parent and staff perceptions of FCC care provided on the unit. The survey tools covered the following areas: environment, nursing care, education, communication, and respect and equality. A convenience sample of 38 parents and 75 staff completed surveys. Families provided significantly more positive responses than the staff did, indicating overall satisfaction with the care received. However, they did identify concerns about educational issues and pain assessment. In contrast, the staff reported more negative perceptions regarding the delivery of FCC, and their primary concern was the unit environment. The FCC Committee used the findings from the survey to first educate the staff and then implement changes to improve the environment and the care delivered.

Understanding nurses' and parents' perceptions of family-centred care.

PubMed

Stuart, Megan; Melling, Sally

2014-09-01

To explore and compare differences between parents' and nurses' perceptions of family-centred care (FCC) for children's acute short-stay admissions. Mixed-method questionnaires were designed to compare care task delegation between nurse and parent participants in the study. Parents and nurses had similar perceptions of task allocation in FCC. Parents generally were prepared to undertake basic care tasks only, rather than help with nursing interventions. Nurses had a comprehensive understanding of FCC. Most parents were not able to define FCC but carried it out naturally. In the UK, nurses and parents have similar expectations of FCC. It is unusual for parents to be given information or opportunities to engage in the care of the child beyond everyday tasks. The investigation highlighted the importance of negotiating with family members on each separate admission because, although most parents would be comfortable undertaking care tasks, each family and each situation is different.

Radiation detector device for rejecting and excluding incomplete charge collection events

DOEpatents

Bolotnikov, Aleksey E.; De Geronimo, Gianluigi; Vernon, Emerson; Yang, Ge; Camarda, Giuseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B.

2016-05-10

A radiation detector device is provided that is capable of distinguishing between full charge collection (FCC) events and incomplete charge collection (ICC) events based upon a correlation value comparison algorithm that compares correlation values calculated for individually sensed radiation detection events with a calibrated FCC event correlation function. The calibrated FCC event correlation function serves as a reference curve utilized by a correlation value comparison algorithm to determine whether a sensed radiation detection event fits the profile of the FCC event correlation function within the noise tolerances of the radiation detector device. If the radiation detection event is determined to be an ICC event, then the spectrum for the ICC event is rejected and excluded from inclusion in the radiation detector device spectral analyses. The radiation detector device also can calculate a performance factor to determine the efficacy of distinguishing between FCC and ICC events.

CHARACTERIZATION OF DEFECTS IN ALLOY 152, 52 AND 52M WELDS

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

Bruemmer, Stephen M.; Toloczko, Mychailo B.; Olszta, Matthew J.

2009-08-27

Defect distributions have been documented by optical metallography, scanning electron microscopy and electron backscatter diffraction in alloy 152 and 52 mockups welds, alloy 52 and 52M overlay mockups and an alloy 52M inlay. Primary defects were small cracks at grain boundaries except for more extensive cracking in the dilution zone of an alloy 52 overlay on 304SS. Detailed characterizations of the dilution zone cracks were performed by analytical transmission electron microscopy identifying grain boundary titanium-nitride precipitation associated with the intergranular separations. I. INTRODUCTION Weldments continue to be a primary location of stress-corrosion cracking (SCC) in light-water reactor systems. While problemsmore » related to heat-affected-zone (HAZ) sensitization and intergranular (IG) SCC of austenitic stainless alloys in boiling-water reactors (BWRs) have been significantly reduced, SCC has now been observed in HAZs of non-sensitized materials and in dissimilar metal welds where Ni-base alloy weld metals are used. IGSCC in weld metals has been observed in both BWRs and pressurized water reactors (PWRs) with recent examples for PWR pressure vessel penetrations producing the most concern. This has led to the replacement of alloy 600/182/82 welds with higher Cr, more corrosion-resistant replacement materials (alloy 690/152/52/52M). Complicating this issue has been a known susceptibility to cracking during welding [1-7] of these weld metals. There is a critical need for an improved understanding of the weld metal metallurgy and defect formation in Ni-base alloy welds to effectively assess long-term performance. A series of macroscopic to microscopic examinations were performed on available mockup welds made with alloy 52 or alloy 152 plus selected overlay and inlay mockups. The intent was to expand our understanding of weld metal structures in simulated LWR service components with a focus on as-welded defects. Microstructural features, defect distributions, defect characteristics and weld residual strains were examined by optical metallography, scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Industry-supplied mock-up welds were characterized including alloy 52 and 152 weldments, alloy 52M overlay and inlay welds, and an alloy 52 overlay. II. WELDMENTS II.A. Alloy 52 and 152 Weld Mockups The alloy 52 and 152 weld mockups were fabricated by MHI for the Kewaunee reactor and were obtained from the EPRI NDE Center. The mockups were U-groove welds joining two plates of 304SS as shown in Figure 1. Alloy 152 butter (heat 307380) was placed on the U-groove surface for both mockups by shielded metal arc welding (SMAW). For the alloy 152 weld mockup, the alloy 152 fill (heat 307380) was also applied using SMAW while for the alloy 52 weld mockup, the alloy 52 fill (heat NX2686JK) was applied using gas tungsten arc welding (GTAW). Welding parameters for the fill materials were substantially different with the alloy 152 SMAW having a deposition speed of 4-25 cm/min with a current of 95-145 A and the alloy 52 GTAW having a deposition speed of 4-10 cm/min with a current of 150-300 A. One prominent feature in these mockup welds is the presence of a crack starting at the 304SS butt joint at the bottom of the U-groove and extending up into the weld. It appears that the 304SS plate on either side of the butt joint acted as an anchor for the weld resulting in a stress rise across the slit that drove crack formation and extension up into the fill weld. As will be shown in the next section, the extent of the cracking around this stress riser was much greater in the MHI 52 weld mockup.« less

47 CFR 95.219 - (R/C Rule 19) How do I answer correspondence from the FCC?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false (R/C Rule 19) How do I answer correspondence from the FCC? 95.219 Section 95.219 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... You Need to Know § 95.219 (R/C Rule 19) How do I answer correspondence from the FCC? (a) If it appears...

47 CFR 95.422 - (CB Rule 22) How do I answer correspondence from the FCC?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false (CB Rule 22) How do I answer correspondence from the FCC? 95.422 Section 95.422 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... You Need to Know § 95.422 (CB Rule 22) How do I answer correspondence from the FCC? (a) If it appears...

76 FR 41253 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

... small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of... should advise the FCC contact listed below as soon as possible. ADDRESSES: Direct all PRA comments [email protected] and to the Federal Communications Commission via e-mail to [email protected]fcc.gov and Paul...

75 FR 60457 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-30

... burden for small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a... allowed by this notice, you should advise the FCC contact listed below as soon as possible. ADDRESSES... via email to [email protected]fcc.gov . FOR FURTHER INFORMATION CONTACT: Judith B. Herman, Office of Managing...

Parent Perspectives on Rehabilitation Services for Their Children with Disabilities: A Mixed Methods Approach

ERIC Educational Resources Information Center

Schreiber, Joseph; Benger, Jennifer; Salls, Joyce; Marchetti, Gregory; Reed, Lindsey

2011-01-01

Health care providers have adopted a family-centered care (FCC) approach. Parent satisfaction is an indicator of the effectiveness of FCC. The purpose of this project was to describe parent perceptions of the extent to which FCC behaviors occurred in an outpatient pediatric rehabilitation facility. The Measure of Processes of Care (MPOC)-20, a…

75 FR 48334 - Notice of Public Information Collection(s) Being Submitted for Review and Approval to the Office...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... small business concerns with fewer than 25 employees. The FCC may not conduct or sponsor a collection of... should advise the FCC contact listed below as soon as possible. ADDRESSES: Direct all PRA comments to... [email protected] and to the Federal Communications Commission via email to [email protected]fcc.gov . To...

47 CFR 95.218 - (R/C Rule 18) What are the penalties for violating these rules?

Code of Federal Regulations, 2010 CFR

2010-10-01

... FCC finds that you have willfully or repeatedly violated the Communications Act or the FCC Rules, you...) of the Communications Act.) (b) If the FCC finds that you have violated any section of the... section 312(b) of the Communications Act.) (c) If a federal court finds that you have willfully and...

Flight simulation for flight control computer S/N 0104-1 (ASTP)

NASA Technical Reports Server (NTRS)

1975-01-01

Flight control computer (FCC) 0104-I has been designated the prime unit for the SA-210 launch vehicle. The results of the final flight simulation for FCC S/N 0104-I are documented. These results verify satisfactory implementation of the design release and proper interfacing of the FCC with flight-type control sensor elements and simulated thrust vector control system.

78 FR 6102 - Information Collection(s) Being Reviewed by the Federal Communications Commission, Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-29

... Forbearance Order), pet. for recon pending, pet.for review pending, NASUCA v. FCC, Case No. 08-1226 (D.C. Cir... Proposed Rulemaking, 23 FCC Rcd 13747 (2008) (Verizon/Qwest Cost Assignment Forbearance Order), pet. for recon. pending, pet. for review pending, NASCUA v. FCC, Case No. 08-1353 (D.C. Cir. Filed Nov. 4, 2008...

High pressure synthesis of a hexagonal close-packed phase of the high-entropy alloy CrMnFeCoNi

DOE PAGES

Tracy, Cameron L.; Park, Sulgiye; Rittman, Dylan R.; ...

2017-05-25

High pressure x-ray diffraction measurements reveal that the face-centered cubic (fcc) high-entropy alloy CrMnFeCoNi transforms martensitically to a hexagonal close-packed (hcp) phase at ~14 GPa. We attribute this to suppression of the local magnetic moments, destabilizing the fcc phase. Similar to fcc-to-hcp transformations in Al and the noble gases, this transformation is sluggish, occurring over a range of >40 GPa. But, the behavior of CrMnFeCoNi is unique in that the hcp phase is retained following decompression to ambient pressure, yielding metastable fcc-hcp mixtures.

Individual differences in forced-choice recognition memory: partitioning contributions of recollection and familiarity.

PubMed

Migo, Ellen M; Quamme, Joel R; Holmes, Selina; Bendell, Andrew; Norman, Kenneth A; Mayes, Andrew R; Montaldi, Daniela

2014-01-01

In forced-choice recognition memory, two different testing formats are possible under conditions of high target-foil similarity: Each target can be presented alongside foils similar to itself (forced-choice corresponding; FCC), or alongside foils similar to other targets (forced-choice noncorresponding; FCNC). Recent behavioural and neuropsychological studies suggest that FCC performance can be supported by familiarity whereas FCNC performance is supported primarily by recollection. In this paper, we corroborate this finding from an individual differences perspective. A group of older adults were given a test of FCC and FCNC recognition for object pictures, as well as standardized tests of recall, recognition, and IQ. Recall measures were found to predict FCNC, but not FCC performance, consistent with a critical role for recollection in FCNC only. After the common influence of recall was removed, standardized tests of recognition predicted FCC, but not FCNC performance. This is consistent with a contribution of only familiarity in FCC. Simulations show that a two-process model, where familiarity and recollection make separate contributions to recognition, is 10 times more likely to give these results than a single-process model. This evidence highlights the importance of recognition memory test design when examining the involvement of recollection and familiarity.

Energy barrier of bcc-fcc phase transition via the Bain path in Yukawa system

NASA Astrophysics Data System (ADS)

Kiyokawa, Shuji

2018-05-01

In the Yukawa system with the dimensionless screening parameter κ>1.5 , when bcc-fcc transition occurs via Bain path, we show that spontaneous transitions do not occur even if the system temperature reaches the transition point of bcc-fcc because it is necessary to increase once the free energy in the process of transition from bcc to fcc through Bain deformation. Here, we refer the temporary increment of the free energy during Bain deformation as Bain barrier. Since there are the Bain barriers at the transitions between bcc and fcc phases, these phases may coexist as metastable state in the wide region (not a coexistence line) of κ and the coupling constant Γ. We study the excess energy of the system and the free energy difference between bcc and fcc phases by the Monte Carlo method, where the simulation box is divided into a large number of elements with small volume and a particle in the box is restricted be placed in one of these elements. By this method, we can tabulate the values of the interparticle potential and can calculate the internal energy fast and precisely.

Use of negotiated rulemaking in developing technical rules for low-Earth orbit mobile satellite systems

NASA Technical Reports Server (NTRS)

Taylor, Leslie A.

1993-01-01

Technical innovations have converged with the exploding market demand for mobile telecommunications to create the impetus for low-earth orbit (LEO) communications satellite systems. The so-called 'Little LEO's' propose use of VHF and UHF spectrum to provide position - location and data messaging services. The so-called 'Big LEO's' propose to utilize the RDSS bands to provide voice and data services. In the United States, several applications were filed with the U.S. Federal Communications Commission (FCC) to construct and operate these mobile satellite systems. To enable the prompt introduction of such new technology services, the FCC is using innovative approaches to process the applications. Traditionally, when the FCC is faced with 'mutually exclusive' applications, e.g. a grant of one would preclude a grant of the others, it uses selection mechanisms such as comparative hearings or lotteries. In the case of the LEO systems, the FCC has sought to avoid these time-consuming approaches by using negotiated rulemakings. The FCC's objective is to enable the multiple applicants and other interested parties to agree on technical and service rules which will enable the grant of all qualified applications. With regard to the VHF/UHF systems, the Advisory Committee submitted a consensus report to the FCC. The process for the systems operating in the bands above 1 GHz involved more parties and more issues but still provided the FCC useful technical information to guide the adoption of rules for the new mobile satellite service.

Use of negotiated rulemaking in developing technical rules for low-Earth orbit mobile satellite systems

NASA Astrophysics Data System (ADS)

Taylor, Leslie A.

Technical innovations have converged with the exploding market demand for mobile telecommunications to create the impetus for low-earth orbit (LEO) communications satellite systems. The so-called 'Little LEO's' propose use of VHF and UHF spectrum to provide position - location and data messaging services. The so-called 'Big LEO's' propose to utilize the RDSS bands to provide voice and data services. In the United States, several applications were filed with the U.S. Federal Communications Commission (FCC) to construct and operate these mobile satellite systems. To enable the prompt introduction of such new technology services, the FCC is using innovative approaches to process the applications. Traditionally, when the FCC is faced with 'mutually exclusive' applications, e.g. a grant of one would preclude a grant of the others, it uses selection mechanisms such as comparative hearings or lotteries. In the case of the LEO systems, the FCC has sought to avoid these time-consuming approaches by using negotiated rulemakings. The FCC's objective is to enable the multiple applicants and other interested parties to agree on technical and service rules which will enable the grant of all qualified applications. With regard to the VHF/UHF systems, the Advisory Committee submitted a consensus report to the FCC. The process for the systems operating in the bands above 1 GHz involved more parties and more issues but still provided the FCC useful technical information to guide the adoption of rules for the new mobile satellite service.

Status of the Future Circular Collider Study

NASA Astrophysics Data System (ADS)

Benedikt, Michael

2016-03-01

Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

Structural analysis of color video camera installation on tank 241AW101 (2 Volumes)

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

Strehlow, J.P.

1994-08-24

A video camera is planned to be installed on the radioactive storage tank 241AW101 at the DOE` s Hanford Site in Richland, Washington. The camera will occupy the 20 inch port of the Multiport Flange riser which is to be installed on riser 5B of the 241AW101 (3,5,10). The objective of the project reported herein was to perform a seismic analysis and evaluation of the structural components of the camera for a postulated Design Basis Earthquake (DBE) per the reference Structural Design Specification (SDS) document (6). The detail of supporting engineering calculations is documented in URS/Blume Calculation No. 66481-01-CA-03 (1).

Gray Infrastructure Tool | EPA Center for Exposure ...

EPA Pesticide Factsheets

2016-03-07

Natural channel with flood plain panel added Default depth increment of 0.5 is used for Natural Channel with FP Units option added – SI or US units. Default option is US units Conversion options added wherever necessary Additional options added to FTABLE such as clear FTABLE Significant digits for FTABLE calculations is changed to 4 Previously a default Cd value is used for calculations (under-drain and riser) but now a user defined value is used Default values of Cd for riser orifice and under-drain textboxes is changed to 0.6 Previously a default increment value of 0.1 is used for all the channel panels but now user can specify the increment

Tibial plateau fracture after anterior cruciate ligament reconstruction: Role of the interference screw resorption in the stress riser effect.

PubMed

Thaunat, Mathieu; Nourissat, Geoffroy; Gaudin, Pascal; Beaufils, Philippe

2006-06-01

We report a case of tibial plateau fracture after previous anterior cruciate ligament (ACL) reconstruction using patellar tendon autograft and bioabsorbable screws 4 years previously. The fracture occurred through the tibial tunnel. The interference screw had undergone complete resorption and the tunnel widening had increased. The resorption of the interference screw did not simultaneously promote and foster the growth of surrounding bone tissue. Therefore, the area of reactive tissue left by the screw resorption in an enlarged bone tunnel may lead to vulnerability of the tibial plateau. Stress risers would occur following ACL reconstruction if either resorption is not complete or bony integration is not complete.

Bed inventory overturn in a circulating fluid bed riser with pant-leg structure

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

Jinjing Li; Wei Wang; Hairui Yang

2009-05-15

The special phenomenon, nominated as bed inventory overturn, in circulating fluid bed (CFB) riser with pant-leg structure was studied with model calculation and experimental work. A compounded pressure drop mathematic model was developed and validated with the experimental data in a cold experimental test rig. The model calculation results agree well with the measured data. In addition, the intensity of bed inventory overturn is directly proportional to the fluidizing velocity and is inversely proportional to the branch point height. The results in the present study provide significant information for the design and operation of a CFB boiler with pant-leg structure.more » 15 refs., 10 figs., 1 tab.« less

Green Infrastructure Tool | EPA Center for Exposure ...

EPA Pesticide Factsheets

2016-03-07

Units option added – SI or US units. Default option is US units Additional options added to FTABLE such as clear FTABLE Significant digits for FTABLE calculations is changed to 5 Previously a default Cd value was used for calculations (under-drain and riser) but now a user-defined value option is given Conversion options added wherever necessary Default values of suction head and hydraulic conductivity are changed based on units selected in infiltration panel Default values of Cd for riser orifice and under-drain textboxes is changed to 0.6. Previously a default increment value of 0.1 is used for all the channel panels but now user can specify the increment

Parachute dynamics and stability analysis. [using nonlinear differential equations of motion

NASA Technical Reports Server (NTRS)

Ibrahim, S. K.; Engdahl, R. A.

1974-01-01

The nonlinear differential equations of motion for a general parachute-riser-payload system are developed. The resulting math model is then applied for analyzing the descent dynamics and stability characteristics of both the drogue stabilization phase and the main descent phase of the space shuttle solid rocket booster (SRB) recovery system. The formulation of the problem is characterized by a minimum number of simplifying assumptions and full application of state-of-the-art parachute technology. The parachute suspension lines and the parachute risers can be modeled as elastic elements, and the whole system may be subjected to specified wind and gust profiles in order to assess their effects on the stability of the recovery system.

The annealing temperature dependences of microstructures and magnetic properties in electro-chemical deposited CoNiFe thin films

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

Suharyadi, Edi, E-mail: esuharyadi@ugm.ac.id; Riyanto, Agus; Abraha, Kamsul

2016-04-19

CoNiFe thin films with various compositions had been successfully fabricated using electro-chemical deposition method. The crystal structure of Co{sub 65}Ni{sub 15}Fe{sub 20}, Co{sub 62}Ni{sub 15}Fe{sub 23}, and Co{sub 55}Ni{sub 15}Fe{sub 30} thin films was fcc, bcc-fcc mix, and bcc, respectively. The difference crystal structure results the difference in magnetic properties. The saturation magnetic flux density (Bs) of Co{sub 65}Ni{sub 15}Fe{sub 20}, Co{sub 62}Ni{sub 15}Fe{sub 23}, and Co{sub 55}Ni{sub 15}Fe{sub 30} thin films was 1.89 T, 1.93 T, and 2.05 T, respectively. An optimal annealing temperature was determined for controlling the microstructure and magnetic properties of CoNiFe thin films. Depending onmore » annealing temperature, the ratio of bcc and fcc structure varied without changing the film composition. By annealing at temperature of T ≥ 350°C, the intensity ratio of X-ray diffraction peaks for bcc(110) to fcc(111) increased. The increase of phase ratio of bcc(110) to fcc(111) caused the increase of Bs, from 1.89 T to 1.95 T. Coercivity (Hc) also increased after annealing, from 2.6 Oe to 18.6 Oe for fcc phase thin films, from 2.0 Oe to 12.0 Oe for fcc-bcc mix phase thin films, and 7.8 Oe to 8 Oe for bcc phase thin films. The changing crystal structures during annealing process indicated that the thermal treatment at high temperature cause the changing crystallinity and atomic displacement. The TEM bright-field images with corresponding selected-area electron diffraction (SAED) patterns showed that there are strongly effects of thermal annealing on the size of fcc and bcc phase crystalline grain as described by size of individual spot and discontinuous rings. The size of crystalline grains increased by thermal annealing. The evolution of bcc and fcc structures of CoNiFe during annealing is though to be responsible for the change of magnetic properties.« less

Single crystal plastic behavior of a single-phase, face-center-cubic-structured, equiatomic FeNiCrCo alloy

DOE PAGES

Wu, Zhenggang; Gao, Y. F.; Bei, Hongbin

2015-07-25

To understand the fundamental deformation mechanisms of compositionally complex alloys, single crystals of a multi-component equiatomic FeNiCoCr alloy with face-centered cubic (FCC) structure were grown for mechanical studies. Similarly to typical FCC pure metals, slip trace analyses indicate that dislocation slips take place on (1 1 1) planes along [11¯0] directions. The critical resolved shear stress (CRSS) obeys the Schmid law at both 77 and 293 K, and tension–compression asymmetry is not observed. Although this material slips in a normal FCC manner both at 293 and 77 K, compared to typical FCC metals the CRSS’s strong temperature dependence is abnormal.

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

Lv, Q.; Kraus, A.; Hu, R.

CFD analysis has been focused on important component-level phenomena using STARCCM+ to supplement the system analysis of integral system behavior. A notable area of interest was the cavity region. This area is of particular interest for CFD analysis due to the multi-dimensional flow and complex heat transfer (thermal radiation heat transfer and natural convection), which are not simulated directly by RELAP5. CFD simulations allow for the estimation of the boundary heat flux distribution along the riser tubes, which is needed in the RELAP5 simulations. The CFD results can also provide additional data to help establish what level of modeling detailmore » is necessary in RELAP5. It was found that the flow profiles in the cavity region are simpler for the water-based concept than for the air-cooled concept. The local heat flux noticeably increases axially, and is higher in the fins than in the riser tubes. These results were utilized in RELAP5 simulations as boundary conditions, to provide better temperature predictions in the system level analyses. It was also determined that temperatures were higher in the fins than the riser tubes, but within design limits for thermal stresses. Higher temperature predictions were identified in the edge fins, in part due to additional thermal radiation from the side cavity walls.« less

Fracture during intravenous bisphosphonate treatment in a child with osteogenesis imperfecta: an argument for a more frequent, low-dose treatment regimen.

PubMed

Biggin, Andrew; Briody, Julie N; Ormshaw, Elizabeth; Wong, Karen K Y; Bennetts, Bruce H; Munns, Craig F

2014-01-01

Intravenous bisphosphonate therapy is the mainstay of medical treatment in osteogenesis imperfecta (OI) and has been shown to increase bone mass, decrease bone pain, improve mobility, and reduce the incidence of fractures. Sclerotic metaphyseal lines parallel to the growth plate are seen on long bone radiographs following cyclical intravenous therapy. These areas create stress risers within the bone that may act as foci for subsequent fractures as exemplified in this clinical case. An 8-year-old girl with OI sustained a distal radial fracture following 3 years of treatment with 6-monthly intravenous zoledronate. Her diagnosis, response to treatment, and subsequent fracture at a sclerotic metaphyseal line is described. Peripheral quantitative computer tomography was used to characterise the presence of multiple stress risers at the distal forearm. Trabecular bone mineral density fluctuated from 34 to 126% compared to neighbouring 2-mm regions. There remain many unanswered questions about optimal bisphosphonate treatment regimens in children with OI. The formation of stress risers following intravenous bisphosphonate treatment raises the hypothesis that a more frequent and low-dose bisphosphonate regimen would provide more uniform dosing of bone in the growing child and reduce the likelihood of fractures compared to current treatment practices.

Freely chosen cadence during a covert manipulation of ambient temperature.

PubMed

Hartley, Geoffrey L; Cheung, Stephen S

2013-01-01

The present study investigated relationships between changes in power output (PO) to torque (TOR) or freely chosen cadence (FCC) during thermal loading. Twenty participants cycled at a constant rating of perceived exertion while ambient temperature (Ta) was covertly manipulated at 20-min intervals of 20 °C, 35 °C, and 20 °C. The magnitude responses of PO, FCC and TOR were analyzed using repeated-measures ANOVA, while the temporal correlations were analyzed using Auto-Regressive Integrated Moving Averages (ARIMA). Increases in Ta caused significant thermal strain (p < .01), and subsequently, a decrease in PO and TOR magnitude (p < .01), whereas FCC remained unchanged (p = .51). ARIMA indicates that changes in PO were highly correlated to TOR (stationary r2 = .954, p = .04), while FCC was moderately correlated (stationary r2 = .717, p = .01) to PO. In conclusion, changes in PO are caused by a modulation in TOR, whereas FCC remains unchanged and therefore, unaffected by thermal stressors.

Family support and family-centered care in the neonatal intensive care unit: origins, advances, impact.

PubMed

Gooding, Judith S; Cooper, Liza G; Blaine, Arianna I; Franck, Linda S; Howse, Jennifer L; Berns, Scott D

2011-02-01

Family-centered care (FCC) has been increasingly emphasized as an important and necessary element of neonatal intensive care. FCC is conceptualized as a philosophy with a set of guiding principles, as well as a cohort of programs, services, and practices that many hospitals have embraced. Several factors drive the pressing need for family-centered care and support of families of infants in NICUs, including the increase in the number of infants in NICUs; growth in diversity of the population and their concurrent needs; identification of parental and familial stress and lack of parenting confidence; and gaps in support for families, as identified by parents and NICU staff. We explore the origins of and advances in FCC in the NICU and identify various delivery methods and aspects of FCC and family support in the NICU. We examine the research and available evidence supporting FCC in the NICU and offer recommendations for increased dissemination and for future study. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of pressure on the superconducting {ital T}{sub {ital c}} of lanthanum

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

Tissen, V.G.; Ponyatovskii, E.G.; Nefedova, M.V.

1996-04-01

The effect of pressure on the superconducting transition temperature {ital T}{sub {ital c}} of La was studied up to 50 GPa. {ital T}{sub {ital c}}({ital P}) shows a rather complicated variation with a discontinuous increase in {ital T}{sub {ital c}} at about 2.2 GPa due to the first-order phase transition from dhcp to fcc structure. At about 5.4 GPa a sharp peak is observed due to the soft-mode phase transition from fcc to the distorted fcc structure and two broad maxima are found within the stability region of the distorted fcc structure around 12 and 39 GPa. Some differences betweenmore » these and previous low-pressure data for metastable fcc La are noticed. The results are discussed in connection with pressure-induced structural phase transitions found in earlier x-ray-diffraction experiments and band-structure calculations giving evidences for van Hove singularities in the density of states. {copyright} {ital 1996 The American Physical Society.}« less

Electronic properties of carbon in the fcc phase.

NASA Astrophysics Data System (ADS)

Cab, Cesar; Canto, Gabriel

2005-03-01

The observation of a new carbon phase in nanoparticles obtained from Mexican crude oil having the face-centered-cubic structure (fcc) has been reported. However, more recently has been suggested that hydrogen is present in the samples forming CH with the zincblende structure. The structural and electronic properties of C(fcc) and CH(zincblende) are unknown. In the present work we have studied the electronic structure of C(fcc) and CH(zincblende) by means of first-principles total-energy calculations. The results were obtained with the pseudopotentials LCAO method (SIESTA code) and the Generalized Gradient Approximation (GGA) for the exchange-correlation potential. We have analyzed the band structure, the local density of states (LDOS), and orbital population. We find that in contrast to graphite and diamond, both fcc carbon and CH with the zincblende structure exhibit metallic behavior. This research was supported by Consejo Nacional de Ciencia y Tecnolog'ia (Conacyt-M'exico) under Grants No. 43830-F, No. 44831-F, and No. 43828-Y.

The relative energy of fcc and hcp foams

NASA Astrophysics Data System (ADS)

Whyte, D.; Weaire, D.; Drenckhan, W.; Hutzler, S.

2015-06-01

The energies of face-centred cubic (fcc) and hexagonal close-packed (hcp) monodisperse foams, associated with their total surface area, are equal in the wet and dry limits, in the usual model. We prove that for all intermediate values of liquid fraction, hcp has lower energy. Energy considerations are thus not sufficient to explain the observed preference for crystallization into fcc over hcp in experiments using monodisperse bubbles.

Ultra Wideband (UWB) Synchronous Impulse Reconstruction (SIRE) Radar Upgrade Assessment Field Experiment

DTIC Science & Technology

2011-04-01

Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields ’, OET Bulletin 65, August 1997. 2. DA Pamphlet...wide range of frequencies, there is no single value for the Maximum Permissible Exposure (MPE). As recommended, the FCC MPE, reference 1, to...power accumulated in a 6-min period. The FCC defines general population/uncontrolled exposures as situations in which the general public may be

Individual differences in forced-choice recognition memory: Partitioning contributions of recollection and familiarity

PubMed Central

Migo, Ellen M.; Quamme, Joel R.; Holmes, Selina; Bendell, Andrew; Norman, Kenneth A.; Mayes, Andrew R.; Montaldi, Daniela

2014-01-01

In forced-choice recognition memory, two different testing formats are possible under conditions of high target-foil similarity: each target can be presented alongside foils similar to itself (forced-choice corresponding; FCC), or alongside foils similar to other targets (forced-choice non-corresponding; FCNC).Recent behavioural and neuropsychological studies suggest that FCC performance can be supported by familiarity whereas FCNC performance is supported primarily by recollection. In this paper, we corroborate this finding from an individual differences perspective. A group of older adults were given a test of FCC and FCNC recognition for object pictures, as well as standardised tests of recall, recognition and IQ. Recall measures were found to predict FCNC, but not FCC performance, consistent with a critical role for recollection in FCNC only. After the common influence of recall was removed, standardised tests of recognition predicted FCC, but not FCNC performance. This is consistent with a contribution of only familiarity in FCC. Simulations show that a two process model, where familiarity and recollection make separate contributions to recognition, is ten times more likely to give these results than a single-process model. This evidence highlights the importance of recognition memory test design when examining the involvement of recollection and familiarity. PMID:24796268

Evaluation of Kapton pyrolysis, arc tracking, and flashover on SiO(x)-coated polyimide insulated samples of flat flexible current carriers for Space Station Freedom

NASA Technical Reports Server (NTRS)

Stueber, Thomas J.; Mundson, Chris

1993-01-01

Kapton polyimide wiring insulation was found to be vulnerable to pyrolization, arc tracking, and flashover when momentary short-circuit arcs have occurred on aircraft power systems. Short-circuit arcs between wire pairs can pyrolize the polyimide resulting in a conductive char between conductors that may sustain the arc (arc tracking). Furthermore, the arc tracking may spread (flashover) to other wire pairs within a wire bundle. Polyimide Kapton will also be used as the insulating material for the flexible current carrier (FCC) of Space Station Freedom (SSF). The FCC, with conductors in a planar type geometric layout as opposed to bundles, is known to sustain arc tracking at proposed SSF power levels. Tests were conducted in a vacuum bell jar that was designed to conduct polyimide pyrolysis, arc tracking, and flashover studies on samples of SSF's FCC. Test results will be reported concerning the minimal power level needed to sustain arc tracking and the FCC susceptibility to flashover. Results of the FCC arc tracking tests indicate that only 22 volt amps were necessary to sustain arc tracking (proposed SSF power level is 400 watts). FCC flashover studies indicate that the flashover event is highly unlikely.

Beam Induced Hydrodynamic Tunneling in the Future Circular Collider Components

NASA Astrophysics Data System (ADS)

Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

2016-08-01

A future circular collider (FCC) has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80-100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t) at a typical speed of 850 km /h . Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC beam with a solid copper target using an energy-deposition code (fluka) and a 2D hydrodynamic code (big2) iteratively. These simulations show that, although the penetration length of a single FCC proton and its shower in solid copper is about 1.5 m, the full FCC beam will penetrate up to about 350 m into the target because of the "hydrodynamic tunneling." These simulations also show that a significant part of the target is converted into high-energy-density matter. We also discuss this interesting aspect of this study.

Association of family-centered care with improved anticipatory guidance delivery and reduced unmet needs in child health care.

PubMed

Kuo, Dennis Z; Frick, Kevin D; Minkovitz, Cynthia S

2011-11-01

Little is known about the association of family-centered care (FCC) with the quality of pediatric primary care. The objectives were to assess (1) associations between family-centered care (FCC), receipt of anticipatory guidance, and unmet need for health care; and (2) whether these associations vary for children with special health care needs (CSHCN). The study, a secondary data analysis of the 2004 Medical Expenditure Panel Survey, used a nationally representative sample of family members of children 0-17 years. We measured receipt of FCC in the last 12 months with a composite score average>3.5 on a 4 point Likert scale from 4 Consumer Assessment of Healthcare Providers and Systems questions. Outcome measures were six anticipatory guidance and six unmet health care service needs items. FCC was reported by 69.6% of family members. One-fifth (22.1%) were CSHCN. Thirty percent of parents reported≥4 of 6 anticipatory guidance topics discussed and 32.5% reported≥1 unmet need. FCC was positively associated with anticipatory guidance for all children (OR=1.45; 95% CI 1.19, 1.76), but no relation was found for CSHCN in stratified analyses (OR=1.01; 95% CI .75, 1.37). FCC was associated with reduced unmet needs (OR=.38; 95% CI .31, .46), with consistent findings for both non-CSHCN and CSHCN subgroups. Family-centered care is associated with greater receipt of anticipatory guidance and reduced unmet needs. The association between FCC and anticipatory guidance did not persist for CSHCN, suggesting the need for enhanced understanding of appropriate anticipatory guidance for this population.

B-type natriuretic peptide is a determinant of the nocturnal increase in blood pressure independently of arterial hypertrophy and hypoxia.

PubMed

Tabara, Yasuharu; Igase, Michiya; Miki, Tetsuro; Ohyagi, Yasumasa; Matsuda, Fumihiko; Kohara, Katsuhiko

2016-12-01

Loss of the nocturnal blood pressure (BP) drop is a risk factor for cardiovascular outcomes. However, clinical parameters that predispose to changes in nocturnal BP are currently uncertain. Given the possible involvement of salt sensitivity in nocturnal BP levels, we investigated a hypothesized association between plasma B-type natriuretic peptide (BNP) levels - a marker of body fluid retention - and nocturnal BP in a general population. Study participants were 1020 general individuals. Participants were divided into four groups (riser, nondipper, dipper, and extreme dipper) by their percentage changes in nocturnal SBP measured using an ambulatory BP monitor. Plasma BNP levels were positively associated with circadian BP change (β = 0.162, P < 0.001) independently of carotid hypertrophy (β = 0.133, P < 0.001), and awake heart rate (β = -0.102, P = 0.001) and SBP (β = -0.246, P < 0.001). Risers showed 1.6 times higher BNP levels than dippers, whereas oxygen desaturation during sleep was frequently observed in nondippers. Results of multinomial logistic regression analysis indicated that BNP level was a significant determinant for the riser pattern [odds ratio (OR) 1.27 (BNP 10 pg/ml), P < 0.001], whereas oxygen desaturation was specifically associated with the nondipping pattern (OR 1.04, P = 0.001). When participants were subdivided by BNP level, risers were more frequent in the high BNP subgroup (19.5%) than in the low BNP subgroup (6.7%) (OR 3.39, P < 0.001). A slight increase in plasma BNP level was independently associated with rising nocturnal BP. Our results may help to understand the pathophysiology of circadian BP variation, and be a clue to identify individuals who require careful BP monitoring.

Recent scientific and operational achievements of D/V Chikyu

NASA Astrophysics Data System (ADS)

Taira, Asahiko; Toczko, Sean; Eguchi, Nobu; Kuramoto, Shin'ichi; Kubo, Yusuke; Azuma, Wataru

2014-12-01

The D/V Chikyu, a scientific drilling vessel, is equipped with industry-standard riser capabilities. Riser drilling technology enables remarkable drilling and downhole logging capabilities and provides unprecedented hole-stability, enabling the shipboard team to retrieve high-quality wire-line logging data as well as well-preserved core samples. The 11 March 2011 Tohoku Oki mega-earthquake and tsunami cost over 18,000 casualties in NE Japan. Chikyu, docked in the Port of Hachinohe, was damaged by the tsunami. By April 2012, the ship was back in operation; drilling the toe of the Japan Trench fault zone where topographic surveys suggested there was up to 50 m eastward motion, the largest earthquake rupture ever recorded. During Integrated Ocean Drilling Program (IODP) Expeditions 343 and 343 T, Chikyu drilled 850 m below sea floor (mbsf) in 6,900+ m water depth and recovered core samples of a highly brecciated shear zone composed of pelagic claystone. A subseafloor observatory looking for temperature signatures caused by the fault friction during the earthquake, was installed and later successfully recovered. The recovered temperature loggers recorded data from which the level of friction during the mega-earthquake slip could be determined. Following Exp. 343, Chikyu began IODP Exp. 337, a riser drilling expedition into the Shimokita coal beds off Hachinohe, to study the deep subsurface biosphere in sedimentary units including Paleogene-Neogene coal beds. New records in scientific ocean drilling were achieved in deepest penetration (drilling reached 2,466 mbsf) and sample recovery. Currently Chikyu is conducting deep riser drilling at the Nankai Trough in the final stage of the NanTroSEIZE campaign. During the years 2011 to 2013, including drilling in the Okinawa Hydrothermal System, Chikyu's operational and scientific achievements have demonstrated that the ship's capabilities are vital for opening new frontiers in earth and biological sciences.

Evaluation of take-home exposure and risk associated with the handling of clothing contaminated with chrysotile asbestos.

PubMed

Sahmel, J; Barlow, C A; Simmons, B; Gaffney, S H; Avens, H J; Madl, A K; Henshaw, J; Lee, R J; Van Orden, D; Sanchez, M; Zock, M; Paustenbach, D J

2014-08-01

The potential for para-occupational (or take-home) exposures from contaminated clothing has been recognized for the past 60 years. To better characterize the take-home asbestos exposure pathway, a study was performed to measure the relationship between airborne chrysotile concentrations in the workplace, the contamination of work clothing, and take-home exposures and risks. The study included air sampling during two activities: (1) contamination of work clothing by airborne chrysotile (i.e., loading the clothing), and (2) handling and shaking out of the clothes. The clothes were contaminated at three different target airborne chrysotile concentrations (0-0.1 fibers per cubic centimeter [f/cc], 1-2 f/cc, and 2-4 f/cc; two events each for 31-43 minutes; six events total). Arithmetic mean concentrations for the three target loading levels were 0.01 f/cc, 1.65 f/cc, and 2.84 f/cc (National Institute of Occupational Health and Safety [NIOSH] 7402). Following the loading events, six matched 30-minute clothes-handling and shake-out events were conducted, each including 15 minutes of active handling (15-minute means; 0.014-0.097 f/cc) and 15 additional minutes of no handling (30-minute means; 0.006-0.063 f/cc). Percentages of personal clothes-handling TWAs relative to clothes-loading TWAs were calculated for event pairs to characterize exposure potential during daily versus weekly clothes-handling activity. Airborne concentrations for the clothes handler were 0.2-1.4% (eight-hour TWA or daily ratio) and 0.03-0.27% (40-hour TWA or weekly ratio) of loading TWAs. Cumulative chrysotile doses for clothes handling at airborne concentrations tested were estimated to be consistent with lifetime cumulative chrysotile doses associated with ambient air exposure (range for take-home or ambient doses: 0.00044-0.105 f/cc year). © 2014 Society for Risk Analysis.

Rethinking family-centred care for the child and family in hospital.

PubMed

Tallon, Mary M; Kendall, Garth E; Snider, Paul D

2015-05-01

This paper presents and discusses an alternative model of family-centred care (FCC) that focuses on optimising the health and developmental outcomes of children through the provision of appropriate support to the child's family. The relevance, meaning and effectiveness of FCC have been challenged recently. Studies show that parents in hospital often feel unsupported, judged by hospital staff and uncertain about what care they should give to their child. With no convincing evidence relating FCC to improved child health outcomes, it has been suggested that FCC should be replaced with a new improved model to guide the care of children in hospital. This integrative review discusses theory and evidence-based literature that supports the practice of an alternative model of FCC that is focused on the health and developmental outcomes of children who are seriously ill, rather than the organisational requirements of children's hospitals. Theories and research findings in a wide range of disciplines including epidemiology, psychology, sociology, anthropology and neuroscience were accessed for this discussion. Nursing literature regarding partnership building, communication and FCC was also accessed. This paper discusses the benefits of applying a bioecological model of human development, the family and community resource framework, the concepts of allostatic load and biological embedding, empowerment theory, and the nurse-family partnership model to FCC. While there is no direct evidence showing that the implementation of this alternative model of FCC in the hospital setting improves the health and developmental outcomes of children who are seriously ill, there is a great deal of evidence from community nursing practice that suggests it is very likely to do so. Application of these theoretical concepts to practice has the potential to underpin a theory of nursing that is relevant for all nurses irrespective of the age of those they care for and the settings within which they work. © 2015 John Wiley & Sons Ltd.

Controlling factors of turf-banked solifluction lobe evolution in the Turtmann glacier forefield (Switzerland)

NASA Astrophysics Data System (ADS)

Draebing, Daniel; Eichel, Jana

2016-04-01

Soil structure and moisture, thermal conditions and vegetation control solifluction movement, however, the spatial distribution of controlling factors and resultant spatial variability of movement are poorly understood. We use a (1) geomorphological and vegetation mapping of solifluction lobe properties, (2) temperature loggers to quantify thermal conditions, (3) 2D Electrical Resistivity Tomography (ERT), Puerkhauer drilling and TDR measurements to evaluate material properties as well as (4) 3D Time-Lapse ERT to quantify spatial variability of material properties. Our results are used to (5) evaluate the influence of potential controlling factors on solifluction movement. Investigations took place on three turf-banked lobes (TBL) located at proximal and distal slopes of Little Ice Age and 1920s lateral moraines in the Turtmann glacier forefield, Swiss Alps. (1) Vegetation is spatially differentiated at TBLs. The treads are mostly covered by the ecosystem engineer Dryas octopetala, while other dwarf shrubs, shrubs and pioneer species were found at the high lobe risers (0.8-1.8 m). In contrast, less vegetated ridge-like features at the upper part of the treads are colonized by frost-tolerant species. Large blocks are located at the lobe fronts, probably impeding the lobe movement. (2) Temperature loggers show a lack of ground cooling due to snow isolation at the vegetated lower tread between 2014 and 2015. Thus, significant ground cooling in winter is reduced to the wind-exposed upper parts (ridges). (3) TBL material consists of sandy silt, thus, lobe material is much finer than subjacent moraine till and indicates former colluviation. As a consequence, 2D ERT demonstrates low-resistant areas until depths equal to riser height, thus, the finer TBL body is higher saturated than the coarser surrounding parent slope and more susceptible to gelifluction. On the contrary, risers show high resistivities indicating dry conditions which are supported by TDR results. Furthermore, ERT demonstrates the absence of permafrost in all measured TBLs. (4) Time-Lapse 3D ERT shows low-resistant areas at the rim of lobes in contrast to the high-resistant treads. In addition, resistivity increases with TBL depth. Thus, resistivity values indicate higher saturated conditions along the lobe axis with decreasing saturated conditions at the rim. (5) High-saturated conditions favour gelifluction movement while low-freezing activity and dense vegetation cover result in a lack of ice lenses and absence of permafrost and, thus, impermeable layers. Therefore, the highly permeable material favours drainage and seepage without development of critical pore water pressures. The D. octopetala mat on the tread increases near-surface shear strength, which decreases near-surface movement. In addition, later successional shrubs species colonizing the risers indicate limited frontal movement. As a consequence, our results suggest that solifluction movement is limited to the low- vegetation cover, highly saturated parts of the lobe affected by winter ground cooling. However, the large riser height reflects high past solifluction activity. Location of the lobes at the foot of slopes and large riser height indicate that TBLs are close to their final cycle of development. Due to the moraine age, the length of the cycle can be assumed to be maximum 100 years.

Coexistence of a metastable double hcp phase in bcc-fcc structure transition of Te under high pressure

NASA Astrophysics Data System (ADS)

Akahama, Yuichi; Okawa, Naoki; Sugimoto, Toshiyuki; Fujihisa, Hiroshi; Hirao, Naoshisa; Ohishi, Yasuo

2018-02-01

The structural phase transitions of tellurium (Te) are investigated at pressures of up to 330 GPa at 298 K using an X-ray powder diffraction technique. In the experiments, it was found that the high-pressure bcc phase (Te-V) transitioned to the fcc phase (Te-VI) at 99 GPa, although a double hcp phase (dhcp) coexisted with the fcc phase. As the pressure was increased and decreased, the dhcp phase vanished at 255 and 100 GPa, respectively. These results suggest that the dhcp phase is metastable at 298 K and the structure of the highest-pressure phase of Te is fcc. The present results provide important information regarding the high-pressure behavior of group-16 elements.

Advancing family-centred care in child and adolescent mental health: a critical review of the literature.

PubMed

MacKean, Gail; Spragins, Wendy; L'Heureux, Laura; Popp, Janice; Wilkes, Chris; Lipton, Harold

2012-01-01

Family-centred care (FCC) is a key factor in increasing health and related system responsiveness to the needs of children and families; unfortunately, it is an unfamiliar service model in children's mental health. This critical review of the literature addresses three key questions: What are the concepts, characteristics and principles of FCC in the context of delivering mental health services to children? What are the enablers, barriers and demonstrated benefits to using a family-centred approach to care in children's mental health? And how can we facilitate moving an FCC model forward in children's mental health? A range of databases was searched for the years 2000–2011, for children ages zero to 18 years. Articles were selected for inclusion if a family-centred approach to care was articulated and the context was the intervention and treatment side of the mental healthcare system. This literature review uncovered a multiplicity of terms and concepts, all closely related to FCC. Two of the most frequently used terms in children's mental health are family centred and family focused, which have important differences, particularly in regard to how the family is viewed. Initial benefits to FCC include improved child and family management skills and function, an increased stability of living situation, improved cost-effectiveness, increased consumer and family satisfaction and improved child and family health and well-being. Significant challenges exist in evaluating FCC because of varying interpretations of its core concepts and applications. Nonetheless, a shared understanding of FCC in a children's mental health context seems possible, and examples can be found of best practices, enablers and strategies, including opportunities for innovative policy change to overcome barriers.

Effects of Co doping on the metamagnetic states of the ferromagnetic fcc Fe-Co alloy.

PubMed

Ortiz-Chi, Filiberto; Aguayo, Aarón; de Coss, Romeo

2013-01-16

The evolution of the metamagnetic states in the ferromagnetic face centered cubic (fcc) Fe(1-x)Co(x) alloy as a function of Co concentration has been studied by means of first-principles calculations. The ground state properties were obtained using the full-potential linear augmented plane wave method and the generalized gradient approximation for the exchange-correlation functional. The alloying was modeled using the virtual crystal approximation and the magnetic states were obtained from the calculations of the total energy as a function of the spin moment, using the fixed spin moment method. For ferromagnetic fcc Fe, the binding-energy curve shows metamagnetic behavior, with two minima corresponding to a small-volume, low-spin (LS) state and a large-volume, high-spin (HS) state, which are separated by a small energy (E(LS) ≲ E(HS)). The evolution of the magnetic moment, the exchange integral (J), and the binding-energy curve is analyzed in the whole range of Co concentrations (x). The magnetic moment corresponding to the HS state decreases monotonically from 2.6 μ(B)/atom in fcc Fe to 1.7 μ(B)/atom in fcc Co. In contrast, the exchange integral for the HS state shows a maximum at around x = 0.45. The thermal dependence of the lattice parameter is evaluated with a method based on statistical mechanics using the binding-energy curve as an effective potential. It is observed that the behavior of the lattice parameter with temperature is tuned by Co doping, from negative thermal expansion in fcc Fe to positive thermal expansion in fcc Co, through the modification of the energetics of the metamagnetic states.

Bcc and Fcc transition metals and alloys: a central role for the Jahn-Teller effect in explaining their ideal and distorted structures.

PubMed

Lee, Stephen; Hoffmann, Roald

2002-05-01

Transition metal elements, alloys, and intermetallic compounds often adopt the body centered cubic (bcc) and face centered cubic (fcc) structures. By comparing quantitative density functional with qualitative tight-binding calculations, we analyze the electronic factors which make the bcc and fcc structures energetically favorable. To do so, we develop a tight-binding function, DeltaE(star), a function that measures the energetic effects of transferring electrons within wave vector stars. This function allows one to connect distortions in solids to the Jahn-Teller effect in molecules and to provide an orbital perspective on structure determining deformations in alloys. We illustrate its use by considering first a two-dimensional square net. We then turn to three-dimensional fcc and bcc structures, and distortions of these. Using DeltaE(star), we rationalize the differences in energy of these structures. We are able to deduce which orbitals are responsible for instabilities in seven to nine valence electron per atom (e(-)/a) bcc systems and five and six e(-)/a fcc structures. Finally we demonstrate that these results account for the bcc and fcc type structures found in both the elements and binary intermetallic compounds of group 4 through 9 transition metal atoms. The outline of a theory of metal structure deformations based on loss of point group operation rather than translational symmetry is presented.

A new false color composite technique for dust enhancement and point source determination in Middle East

NASA Astrophysics Data System (ADS)

Karimi, Khadijeh; Taheri Shahraiyni, Hamid; Habibi Nokhandan, Majid; Hafezi Moghaddas, Naser; Sanaeifar, Melika

2011-11-01

The dust storm happens in the Middle East with very high frequency. According to the dust storm effects, it is vital to study on the dust storms in the Middle East. The first step toward the study on dust storm is the enhancement of dust storms and determination of the point sources. In this paper, a new false color composite (FCC) map for the dust storm enhancement and point sources determination in the Middle East has been developed. The 28 Terra-MODIS images in 2008 and 2009 were utilized in this study. We tried to replace the Red, Green and Blue bands in RGB maps with the bands or maps that enhance the dust storms. Hence, famous indices for dust storm detection (NDDI, D and BTD) were generated using the different bands of MODIS images. These indices with some bands of MODIS were utilized for FCC map generation with different combinations. Among the different combinations, four better FCC maps were selected and these four FCC are compared using visual interpretation. The results of visual interpretations showed that the best FCC map for enhancement of dust storm in the middle east is an especial combination of the three indices (Red: D, Green: BTD and Blue: NDDI). Therefore, we utilized of this new FCC method for the enhancement of dust storms and determination of point sources in Middle East.